U.S. patent number RE41,329 [Application Number 11/493,942] was granted by the patent office on 2010-05-11 for machining apparatus for workpiece and method therefor.
This patent grant is currently assigned to TDK Corporation. Invention is credited to Tetsuo Abe, Masaki Kouzu, Akio Ogawa, Masahiro Sasaki, Hiroshi Shindou, Masao Yamaguchi.
United States Patent |
RE41,329 |
Shindou , et al. |
May 11, 2010 |
Machining apparatus for workpiece and method therefor
Abstract
To provide an apparatus that may impart a complicated bend
deformation to an object to be machined such as a ceramic bar
elongated in one direction or the like, and may reduce the
non-uniformity in machining amount of the object to be machined
upon the machining work of the object to be machined, specifically
a correcting mechanism for deforming the object to be machined
together with a jig holding the object to be machined is provided
in a machining apparatus. The correcting mechanism includes a base,
a plurality of levers provided at first ends with pins, a shaft
fixed to the base for rotatably supporting the levers, and a
plurality of correcting drive means coupled to second ends of said
levers for pivoting the levers to the shaft to thereby pivoting the
pins. The jig includes a plurality of load receiving portions
arranged in a holding portion elongated on one direction for
holding the object to be machined whereby portions corresponding to
the load receiving portion in the holding portion are deformed
together with the object to be machined in accordance with pivoting
of each pin.
Inventors: |
Shindou; Hiroshi (Tokyo,
JP), Sasaki; Masahiro (Tokyo, JP), Ogawa;
Akio (Tokyo, JP), Abe; Tetsuo (Tokyo,
JP), Kouzu; Masaki (Tokyo, JP), Yamaguchi;
Masao (Tokyo, JP) |
Assignee: |
TDK Corporation (Tokyo,
JP)
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Family
ID: |
18566956 |
Appl.
No.: |
11/493,942 |
Filed: |
July 27, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
09789547 |
Feb 22, 2001 |
06767275 |
Jul 27, 2004 |
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Foreign Application Priority Data
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Feb 22, 2000 [JP] |
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2000-044145 |
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Current U.S.
Class: |
451/41; 451/55;
451/5; 451/387; 451/279; 451/276; 451/158 |
Current CPC
Class: |
B24B
49/16 (20130101); G11B 5/3173 (20130101); B24B
37/048 (20130101); G11B 5/3169 (20130101); G11B
5/3103 (20130101); G11B 5/3163 (20130101); G11B
5/3967 (20130101); G11B 5/3116 (20130101) |
Current International
Class: |
B24B
9/00 (20060101); B24B 7/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1239278 |
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Dec 1999 |
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CN |
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60-076011 |
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Apr 1985 |
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JP |
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2-095572 |
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Apr 1990 |
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JP |
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5-44085 |
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Jul 1993 |
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JP |
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7-112672 |
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Dec 1995 |
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JP |
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11-016124 |
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Jan 1999 |
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JP |
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2000-11315 |
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Jan 2000 |
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JP |
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2000-301448 |
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Oct 2000 |
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JP |
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2001-219359 |
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Aug 2001 |
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JP |
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Primary Examiner: Eley; Timothy V
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier
& Neustadt, L.L.P.
Claims
What is claimed is:
1. A method for machining an object elongated in one direction held
on a jig and depressed onto a machining surface formed in a
machining base that is rotationally driven through said jig, said
method comprising: measuring a machining amount at a plurality of
positions of the object to be machined when the object to be
machined is depressed against said machining surface; and rotating
a plurality of levers, each of which has a pin .Iadd.having a tip
end .Iaddend.at an end .[.thereof.]. .Iadd.of said levers.Iaddend.,
together with said pins by a plurality of correcting drive means on
the basis of the measured machining amount for imparting a
predetermined deformation to the object to be machined together
with said jig by the rotation of each of said pins, whose tip end
is received within said jig.
2. A method for machining an object elongated in one direction held
on a jig and depressed onto a machining surface formed in a
machining base that is rotationally driven through said jig, said
method comprising: measuring a machining amount at a plurality of
positions of the object to be machined when the object to be
machined is depressed against said machining surface; and driving a
plurality of shafts, disposed on the same axis with a plurality of
correcting drive means and having pins, on the basis of the
measured machining amount for imparting a predetermined deformation
to the object to be machined together with said jig by the drive
along the axes of said pins with tip ends received in said jig.
3. A method for machining an object elongated in one direction held
on a jig and depressed onto a machining surface formed in a
machining base that is rotationally driven through said jig, said
method comprising: measuring a machining amount at a plurality of
positions of the object to be machined when the object to be
machined is depressed against said machining surface; and linearly
driving a plurality of shafts having pins by a pair of correcting
drive means disposed on a plurality of straight lines on the basis
of the measured machining amount and imparting a predetermined
deformation onto the object to be machined and said jig by the
drive on the straight lines of said pins, wherein a tip end of each
of said pins is received in said jig.
4. A machining apparatus for machining an object elongated in one
direction, said apparatus comprising: a machining base with a
machining surface to be rotationally driven; a machining head
mounted frame disposed movably to said machining surface; and a
machining head supported by said machining head mounted frame,
wherein said machining head includes a jig for holding the object
to be machined, an up-and-down moving portion moving up and down
relative to the machining surface together with said jig, and a
correcting mechanism supported by said up-and-down moving portion,
said correcting mechanism includes a plurality of correcting drive
means and a plurality of driven portions each of which has a pin,
said jig includes a body portion fixed to said up-and-down moving
portion, a holding portion elongated in one direction and fixed to
said body portion for holding said object to be machined, and a
plurality of load receiving portions arranged in parallel in said
one direction on said holding portion, and said load receiving
portions receive said pins and are driven in accordance with a
movement of each driven portion whereby portions corresponding to
said load receiving portions in said holding portion are partially
deformed together with said object to be machined.
5. A machining apparatus for machining an object elongated in one
direction, said apparatus comprising: a machining base with a
machining surface to be rotationally driven; a machining head
mounted frame disposed movably to said machining surface; and a
machining head supported by said machining head mounted frame,
wherein said machining head includes a jig for holding the object
to be machined, an up-and-down moving portion moving up and down
relative to the machining surface together with said jig, and a
correcting mechanism supported by said up-and-down moving portion,
said correcting mechanism includes a base fixed to said up-and-down
moving portion, a plurality of levers having pins at ends thereof,
a shaft fixed to said base for rotatably supporting said levers,
and a plurality of correcting drive means coupled to other ends of
said levers for pivoting said levers with respect to said shaft to
thereby pivot said pins, said jig includes a body portion fixed to
said tip-and-down moving portion, a holding portion elongated in
one direction and fixed to said body portion for holding said
object to be machined, and a plurality of load receiving portions
arranged in parallel in said one direction on said holding portion,
and said load receiving portions receive said pins and are driven
in accordance with a pivotal movement of each pin whereby portions
corresponding to said load receiving portion in said holding
portion are deformed together with said object to be machined.
6. An apparatus according to claim 5, wherein tip ends of said pins
are substantially spherical.
7. An apparatus according to claim 5, wherein adjacent levers of
said plurality of levers have different lengths from each other,
and distances between said plurality of correcting drive means and
said shaft are different from each other in accordance with a
length of said levers.
8. An apparatus according to claim 5, wherein said shaft supports
said levers in a position in the vicinity of said pins.
9. An apparatus according to any one of claims 5 to 8, wherein said
correcting drive means are REC plungers.
10. A machining apparatus for machining an object elongated in one
direction, said apparatus comprising: a machining base with a
machining surface to be rotationally driven; a machining head
mounted frame disposed movably to said machining surface; and a
machining head supported by said machining head mounted frame,
wherein said machining head includes a jig for holding the object
to be machined, an up-and-down moving portion moving up and down
relative to the machining surface together with said jig, and a
correcting mechanism supported by said up-and-down moving portion,
said correcting mechanism includes a base fixed to said up-and-down
moving portion, a plurality of correcting drive means fixed to said
base at an end of each of said correcting drive means, a shaft
coupled coaxially with said correcting drive means, and pins
projecting from said shaft, said jig includes a body portion fixed
to said up-and-down moving portion, a holding portion elongated in
one direction and fixed to said body portion for holding said
object to be machined, and a plurality of load receiving portions
arranged in parallel in said one direction on said holding portion,
and said load receiving portions receive said pins and are driven
in accordance with a movement of each pin whereby portions
corresponding to said load receiving portion in said holding
portion are deformed together with said object to be machined.
11. A machining apparatus for machining an object, elongated in one
direction, to be machined, comprising: a machining base with a
machining surface to be rotationally driven, a machining head
mounted frame disposed movably to said machining surface, and a
machining head supported by said machining head mounted frame,
wherein said machining head includes a jig for holding the object
to be machined, an up-and-down moving portion moving up and down
relative to the machining surface together with said jig, and a
correcting mechanism supported by said up-and-down moving portion,
said correcting mechanism includes a base fixed to said up-and-down
moving portion, a plurality of frame members to said base, a
plurality of correcting drive means held on centerlines of said
frame members, and a plurality of shafts extending in parallel with
a drive direction of said correcting drive means, an end of each of
said shafts being coupled with each of said frame members and the
other end of each of said shafts being provided with a pin, said
jig includes a body portion fixed to said up-and-down moving
portion, a holding portion elongated in one direction and fixed to
said body portion for holding said object to be machined, and a
plurality of load receiving portions arranged in parallel in said
one direction on said holding portion, and said load receiving
portions receive said pins and are driven in accordance with a
pivotal movement of each pin whereby portions corresponding to said
load receiving portion in said holding portion are deformed
together with said object to be machined.
12. An apparatus according to claim 10 or 11, wherein tip ends of
said pins are substantially spherical.
13. An apparatus according to claim 11, wherein the adjacent shafts
each have different lengths from each other, and distances between
said correcting drive means and said pins are different from each
other in accordance with a length of said shaft.
14. An apparatus according to claim 11, wherein said shafts are
arranged coaxially with said correcting drive means.
15. An apparatus according to claim 10 or 11, wherein said
correcting drive means are piezoelectric element actuators.
16. A machining apparatus for machining an object elongated in one
direction, said apparatus comprising: a machining base with a
machining surface to be rotationally driven; a machining head
mounted frame disposed movably to said machining surface; and a
machining head supported by said machining head mounted frame,
wherein said machining head includes a jig for holding the object
to be machined, an up-and-down moving portion moving up and down
relative to the machining surface together with said jig, and a
correcting mechanism supported by said up-and-down moving portion,
said correcting mechanism includes a plurality of shafts, each of
which has a pin at one end thereof and a convex portion having two
sides, a pair of correcting drive members disposed on one line on
both sides of said convex portions and clamping said convex
portions, and a base fixed to said up-and-down moving portion with
recess portions receiving said pair of correcting drive members and
said convex portions, said pair of correcting drive members drive
said convex portion in a straight line to drive said shafts and
said pins in parallel with said straight line, said jig includes a
body portion fixed to said up-and-down moving portion, a holding
portion elongated in one direction and fixed to said body portion
for holding said object to be machined, and a plurality of load
receiving portions arranged in parallel in said one direction on
said holding portion, and said load receiving portions receive said
pins and are driven in accordance with the movement of each pin
whereby portions corresponding to said load receiving portion in
said holding portion are deformed together with said object to be
machined.
17. An apparatus according to claim 16, wherein tip ends of said
pins are substantially spherical.
18. An apparatus according to claim 16, wherein sizes of
projections of the convex portions adjacent to each other are
different from each other and an arrangement of said correcting
drive members each received in said recess portion and a size of
said recess portions are defined in accordance with the sizes of
said convex portions.
19. An apparatus according to claim 16 or 18, wherein said pressure
medium is pressurized air.
20. An apparatus according to claim 16 or 18, wherein said pair of
correcting drive members have a pair of pistons to be driven by
pressure medium, and said base has a pair of pressure medium
introduction ports in communication with a rear portion of each of
said pair of pistons.
21. An apparatus according to claim 20, wherein said pair of
adjacent pressure medium introduction ports are each arranged at
different distances from a predetermined surface of said base.
22. An apparatus according to claim 16 or 18, wherein one of said
pair of correcting drive members has a pressure-driven piston and
the other is formed of an elastic member, and said base has a
pressure port in communication with a rear portion of said
piston.
23. An apparatus according to claim 22, wherein said adjacent
pressure medium introduction ports are each arranged at different
distances from a predetermined surface of said base.
24. A machining apparatus for machining an object elongated in one
direction, said apparatus comprising: a machining base with a
machining surface to be rotationally driven; a machining head
mounted frame disposed movably to said machining surface; and a
machining head supported by said machining head mounted frame,
wherein said machining head includes a jig for holding the object
to be machined, wherein said jig includes an up-and-down moving
portion moving up and down relative to the machining surface
together with said jig, and a correcting mechanism supported by
said up-and-down moving portion, said correcting mechanism includes
a shaft, a plurality of levers composed of linear portions, each of
which is provided with a pin at an end thereof and rotatably
supported by said shaft at a portion thereof different from said
pin and driven portions coupled at end portions with said linear
portions having convex portions, each of said convex portions
having two sides, a pair of correcting drive members disposed in a
linear manner on both sides of said convex portions while clamping
the convex portions, and a base having recess portions for
receiving said pair of correcting drive members and said convex
portions and fixed to said up-and-down moving portion, said pair of
correcting drive members driven in the linear manner so as to drive
the convex portion clamped by said pair of correcting drive
members, whereby said levers and said pins are pivoted about said
shaft, said jig includes a body portion fixed to said up-and-down
moving portion, a holding portion elongated in one direction and
fixed to said body portion for holding said object to be machined,
and a plurality of load receiving portions arranged in parallel in
said one direction on said holding portion, and said load receiving
portions receive said pins and are driven in accordance with the
pivotal movement of each pin whereby portions corresponding to said
load receiving portion in said holding portion are deformed
together with said object to be machined.
25. An apparatus according to any one of claims 5, 10, 11, 16 and
24, wherein said jig has an electrode to be connected to an
electric element formed on the object to be machined, and said
correcting mechanism has a probe unit to be brought into contact
with said electrode.
26. An apparatus according to claim 25, wherein said machining head
has a balancing actuator, said jig has through holes in a central
portion thereof and at end portions with respect to a longitudinal
direction of said jig, said jig is supported by said correcting
mechanism by a fixing pin passing through said through hole in the
central portion, and said jig is depressed to a direction toward
said machining surface through said positioning pins at both end
portions by the balancing actuator.
27. An apparatus according to claim 25, wherein said machining head
is supported through an adjust ring supported by said machining
head mounted frame and in contact with said machining surface and
an angle of said machining head supported by said machining head
mounted frame facing said machining surface is defined by said
adjust ring.
28. An apparatus according to claim 25, wherein said machining head
is mounted rotatably to rails for mounting said machining head.
29. An apparatus according to claim 28, further comprising a
machining head swinging means, wherein said machining head swinging
means perform reciprocating rotational motion of said machining
head within a predetermined angular range.
30. An apparatus according to claim 25, wherein said object to be
machined is a ceramic rod provided with a plurality of magnetic
heads.
31. An apparatus according to claim 24, wherein tip ends of said
pins are spherical.
32. An apparatus according to claim 24, wherein sizes of
projections of the adjacent convex portions are different from each
other and the arrangement of said correcting drive members each
received in said recess portion and a size of said recess portions
are defined in accordance with the sizes of said convex
portions.
33. An apparatus according to claim 24 or 32, wherein one of said
pair of correcting drive members has a pressure-driven piston and
the other is formed of an elastic member, and said base has a
pressure port in communication with a rear portion of said
piston.
34. An apparatus according to claim 33, wherein said adjacent
pressure medium introduction ports are each arranged at different
distances from a predetermined surface of said base.
35. An apparatus according to claim 33, wherein tip end portions of
said pistons are substantially spherical.
36. An apparatus according to claim 24 or 32, wherein said pressure
medium is pressurized air.
37. An apparatus according to claim 24 or 32, wherein said pair of
correcting drive members have a pair of pistons to be driven by
pressure medium, and said base has a pair of pressure medium
introduction ports in communication with a rear portion of each of
said pair of pistons.
38. An apparatus according to claim 37, wherein said pair of
adjacent pressure medium introduction ports are each arranged at
different distances from a predetermined surface of said base.
39. An apparatus according to claim 37, wherein tip end portions of
said pistons are substantially spherical.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a polishing machining apparatus
and a machining method for machining a workpiece to be polished
where a plurality of magnetic heads are arranged, and more
particularly to an apparatus and a method for correcting a bend of
the workpiece during the machining work.
2. Related Background Art
A thin film magnetic head to be used in a magnetic disc apparatus
or the like is composed of parts obtained by machining a rod-shaped
ceramic (hereinafter referred to as a ceramic bar) where a number
of element parts made of a magnetic thin film or the like forming
induction type magnetic converting elements, magnetic resistors
(hereinafter referred to as MRs) elements or the like are formed in
a line on a surface. Conventionally, in a batch type manufacturing
process of parts for the thin film magnetic head, the ceramic bar
where the plurality of element portions are formed is polished, and
a process for machining a throat height or an MR height of each
element part to a suitable level is executed. In general, in the
magnetic disc apparatus, in order to stabilize the output
characteristics from the magnetic head, it is necessary to keep a
distance between the magnetic polar portions of the magnetic head
and a surface of a recording medium to an extremely narrow constant
distance. The value of the throat height or the like is used as an
important parameter for defining this distance.
In the following description, the throat height means a length
(height) of the tip end portion of the magnetic poles for
performing the recording/reproduction of magnetic signals in such a
head core part, i.e., the portion where the two magnetic poles face
each other at a fine gap. Also, the MR height means a length
(height) from the end portion of the MR element on the side facing
the medium to the opposite end portion thereof. In order to make it
possible to perform the suitable recording/reproduction of the
signals, the values of the throat height, the MR height and the
like must be selected suitably. In order to obtain the
predetermined values, high precision is needed for the polishing
work.
The ceramic bar is to be cut into respective element portions in a
process thereafter. Each of the element portions constitutes a part
of a magnetic head for the magnetic disc apparatus. In the case
where the magnetic head is used in the magnetic disc apparatus, the
ceramic portion becomes a slider that is to be lifted away from the
magnetic disc by the blow pressure caused by the rotation of the
disc. The element portion becomes a head core for performing the
recording and/or reproducing the magnetic signals of the disc.
However, in general, the above-described ceramic bar has a strain,
a bend or the like due to the stress caused by the formation of the
element portion or the cutting operation from the ceramic
substrate. It is therefore difficult to obtain the high machining
precision only by fixing the ceramic bar and effecting the
polishing work thereon. For this reason, a non-general polishing
apparatus for performing the polishing work of the magnetic head
with high precision in the form of the ceramic bar as disclosed in,
for example, U.S. Pat. No. 5,620,356 or the like has been proposed.
Also, the present assignee proposes some apparatus and some methods
(Japanese Patent Application No. 11-162799 or the like).
An actual polishing method for the above-described ceramic bar will
now be described.
First of all, the surface opposite the polishing surface of the
ceramic bar, is fixed with adhesives or the like to a jig, and the
surface to be polished of the ceramic bar is depressed through the
jig against the polishing surface of a polishing base to perform
the polishing work to the surface to be polished. The jig has a
beam structure. A load is applied to several, three to seven,
specific points on the jig from the outside of the jig to thereby
cause deformation in the jig as a whole. Furthermore, this beam
structure allows the portions fixed to the ceramic bar to be
subjected to the complicated deformation by the balance adjustment
of the above-described load, and the ceramic bar is bent
simultaneously with the fixed portions to thereby make it possible
to correct the bend or the like owned by the ceramic bar per
se.
In the polishing work, in a predetermined element portion on the
ceramic bar fixed to the jig, the values such as a throat height
are measured optically or electrically to thereby obtain the
difference between the measurement value and the target value,
i.e., the amount of polished portion needed upon the measurement.
The loads at the plurality of points are adjusted on the basis of
the necessary polishing amount in the predetermined element portion
obtained and the portion in the vicinity of the predetermined
element portion, and the ceramic bar is polished while being
deformed through the jig. These steps are repeated whereby the
values such as the throat height and the like of all the elements
formed in the ceramic bar fall within the predetermined range.
Opening portions into which pins or the like may be inserted are
formed in the beam portion of the jig. The loads to the jig in the
above-described process are given by transmitting the loads due to
an actuator such as a low friction cylinder to the pins inserted
into the opening portions of the jig through transmission parts.
The adjustment of the loads to the jig is performed by adjusting
the loads from this actuator, i.e., a drive amount of the actuator.
Incidentally, Japanese Patent Application No. 10-178949 filed by
the present applicant discloses a specific example of a jig for
causing an effective deformation or a load distribution to the
ceramic bar.
In a recording density in the current magnetic disc apparatus or
the like, it is possible to make the values such as a throat height
fall within an allowable range to some extent by a machining method
of the magnetic head using the above-described jig. However, the
high recording density is accelerated, and recently, the high
precision of the throat height or the miniaturization of the
elements are remarkable. It is difficult to make the values such as
the throat height fall within the allowable range over the full
length of the ceramic bar.
In the case where the allowable range of the values such as the
throat height is narrowed, there is an approach to cope with this
by, for example, increasing the application points of the loads
that cause the deformation in the jig. However, since this leads to
the increase of the number of the actuators that actually apply the
loads or the transmission portions (application points) of the
loads, if the actuators or the like used in the conventional
apparatus are needed, it is difficult to actually perform this
approach since the space for mounting the actuators or the like
would be increased remarkably in view of the structure of the
polishing apparatus. Also, in the case where the jig per se is
miniaturized in accordance with the miniaturization of the
elements, there would be a problem in that it is difficult to
arrange the necessary number of the actuators or the like for
applying the loads to the application points of necessary loads,
and the like.
Furthermore, in the conventional polishing method, since the affect
of the repulsive force from the polishing surface exists between
the application point of the load and the beam or between the
application points, it is impossible to sufficiently deform the
ceramic bar. Accordingly, also in some conventional cases,
depending upon the allowable range of the values such as a throat
height, the values of the portion that may not be deformed could
not fall within the allowable range. The approach to increase the
number of the application points of the load and the number of the
actuators for this problem has been attempted but there is a limit
in the allowable range due to the above described problem.
Also, the conventional apparatus has three to seven actuators for
deforming the jig in addition to the actuator for applying the main
pressure for depressing the ceramic bar against the polishing
surface and adjusting the load balance at both end portions in the
longitudinal direction of the ceramic bar. However, actually, in
order to bend the retainer portions to a necessary level, the three
to seven actuators have to have a large stroke due to the necessary
bend level and the actuators that always have the large stroke and
occupy the large space in the structure are necessary as in the
conventional case. Moreover, in order to make it possible to
provide the complicated bend, the opening portion of the jig into
which the pins cooperating with the actuators are inserted is
increased to provide the form that may imparts a moment in the
vertical direction, in the lateral direction and in the rotational
direction with respect to the opening portion. In addition, it is
necessary to effect the complicated drive control for each
actuator. Accordingly, the conventional apparatus is not suitable
for imparting the predetermined deformation amount to the very
restricted portions of the ceramic bar.
SUMMARY OF THE INVENTION
In view of the above, an object of the present invention is to
provide an apparatus that easily imparts a complicated bend
deformation or the like to an object to be machined (polished) such
as a ceramic bar by using an actuator having a small drive stroke
in comparison with a conventional apparatus to make it possible to
impart a depression force also to a specific portion whereby
decreasing non-uniformity of a machining (polishing) amount of the
object to be machined (polished) through the machining (polishing)
process of the object to be machined (polished).
In order to solve this and other objects, according to the present
invention, there is provided a machining apparatus for machining an
object, elongated in one direction, to be machined, comprising: a
machining base with a machining surface to be rotationally driven,
a machining head mounted frame disposed movably to the machining
surface, and a machining head supported by the machining head
mounted frame, characterized in that the machining head includes a
jig for holding the object to be machined, an up-and-down moving
portion moving up and down relative to the machining surface
together with the jig, and a correcting mechanism supported by the
up-and-down moving portion, the correcting mechanism includes a
base fixed to the up-and-down moving portion, a plurality of levers
each of which has a pin at one end, a shaft fixed to the base for
rotatably supporting the levers, and a plurality of correcting
drive means coupled to other ends of the levers for pivoting the
levers with respect to the shaft to thereby pivot the pins, the jig
includes a body portion fixed to the up-and-down moving portion, a
holding portion elongated in one direction and fixed to the body
portion for holding the object to be machined, and a plurality of
load receiving portions arranged in parallel in the one direction
on the holding portion, and the load receiving portions receive the
pins and are driven in accordance with the pivotal movement of each
pin whereby portions corresponding to the load receiving portion in
the holding portion are deformed together with the object to be
machined.
Also, according to the present invention, it is preferable that tip
ends of the pins are substantially spherical. It is preferable that
the adjacent levers each have different lengths from each other,
and distances between the plurality of correcting drive means and
the shaft are different from each other in accordance with a length
of the levers. Also, it is preferable that the shaft supports the
levers in a position in the vicinity of the pins and the correcting
drive means are REC plungers.
Furthermore, in order to attain the above-noted object, according
to the present invention, there is provided a machining apparatus
for machining an object, elongated in one direction, to be
machined, comprising: a machining base with a machining surface to
be rotationally driven, a machining head mounted frame disposed
movably to the machining surface, and a machining head supported by
the machining head mounted frame, characterized in that the
machining head includes a jig for holding the object to be
machined, an up-and-down moving portion moving up and down relative
to the machining surface together with the jig, and a correcting
mechanism supported by the up-and-down moving portion, the
correcting mechanism includes a base fixed to the up-and-down
moving portion, a plurality of correcting drive means each of which
is fixed at an end to the base, a shaft coupled coaxially with the
correcting drive means, and pins projecting from the shaft, the jig
includes a body portion fixed to the up-and-down moving portion, a
holding portion elongated in one direction and fixed to the body
portion for holding the object to be machined, and a plurality of
load receiving portions arranged in parallel to the one direction
on the holding portion, and the load receiving portions receive the
pins and are driven in accordance with the movement of each pin
whereby portions corresponding to the load receiving portion in the
holding portion are deformed together with the object to be
machined.
Furthermore, in order to attain the above-noted object, according
to the present invention, there is provided a machining apparatus
for machining an object, elongated in one direction, to be
machined, comprising: a machining base with a machining surface to
be rotationally driven, a machining head mounted frame disposed
movably to the machining surface, and a machining head supported by
the machining head mounted frame, characterized in that the
machining head includes a jig for holding the object to be
machined, an up-and-down moving portion moving up and down relative
to the machining surface together with the jig, and a correcting
mechanism supported by the up-and-down moving portion, the
correcting mechanism includes a base fixed to the up-and-down
moving portion, a plurality of substantially frame-like members
fixed to the base, a plurality of correcting drive means held on
centerlines of the substantially frame-like members, and a
plurality of shafts extending in parallel with a drive direction of
the correcting drive means, coupled at first ends with the
substantially frame-like members and provided at the other ends
with pins, the jig includes a body portion fixed to the up-and-down
moving portion, a holding portion elongated in one direction and
fixed to the body portion for holding the object to be machined,
and a plurality of load receiving portions arranged in parallel in
the one direction on the holding portion, and the load receiving
portions receive the pins and are driven in accordance with the
movement of each pin whereby portions corresponding to the load
receiving portion in the holding portion are deformed together with
the object to be machined.
Also, according to the present invention, it is preferable that tip
ends of the pins are substantially spherical and the adjacent
shafts each have different lengths from each other, and distances
between the correcting drive means and the pins are different from
each other in accordance with a length of the shafts. Also,
according to the present invention, it is preferable that the
shafts are arranged coaxially with the correcting drive means and
the correcting drive means are piezoelectric element actuators.
Furthermore, in order to attain the above-noted object, according
to the present invention, there is provided a machining apparatus
for machining an object, elongated in one direction, to be
machined, comprising: a machining base with a machining surface to
be rotationally driven, a machining head mounted frame disposed
movably to the machining surface, and a machining head supported by
the machining head mounted frame, characterized in that the
machining head includes a jig for holding the object to be
machined, an up-and-down moving portion moving up and down relative
to the machining surface together with the jig, and a correcting
mechanism supported by the up-and-down moving portion, the
correcting mechanism includes a plurality of shafts provided at
ends with pins and having convex portions different from the pins,
a pair of correcting drive members disposed on one line on both
sides of the convex portions and clamping the convex portions, and
a base fixed to the up-and-down moving portion with recess portions
receiving the pair of correcting drive member and the convex
portions, the pair of correcting drive members drive the convex
portion in a straight line to drive the shafts and the pins in
parallel with the straight line, the jig includes a body portion
fixed to the up-and-down moving portion, a holding portion
elongated in one direction and fixed to the body portion for
holding the object to be machined, and a plurality of load
receiving portions arranged in parallel in the one direction on the
holding portion, and the load receiving portions receive the pins
and are driven in accordance with the movement of each pin whereby
portions corresponding to the load receiving portion in the holding
portion are deformed together with the object to be machined.
Also, according to the present invention, it is preferable that tip
ends of the pins are substantially spherical and sizes of
projections of the adjacent convex portions are different from each
other and the arrangement of the correcting drive members each
received in the recess portion and a size of the recess portions
are defined in accordance with the sizes of the convex portions.
Also, according to the present invention, it is preferable that the
pair of correcting drive members have a pair of pistons to be
driven by pressure medium, and the base has a pair of pressure
medium introduction ports in communication with a rear portion of
each of the pair of pistons and the pair of adjacent pressure
medium introduction ports are each arranged at different distances
from a predetermined surface of the base.
Also, according to the present invention, it is preferable that one
of the pair of correcting drive members has a piston to be driven
by pressure medium, the other being formed of elastic member, and
the base has a pressure medium introduction port in communication
with a rear portion of the piston. Also, it is preferable that the
pair of adjacent pressure medium introduction ports are each
arranged at different distances from a predetermined surface of the
base. Also, it is preferable that the pressure medium is
pressurized air.
Furthermore, in order to attain the above-noted object, according
to the present invention, there is provided a machining apparatus
for machining an object, elongated in one direction, to be
machined, comprising: a machining base with a machining surface to
be rotationally driven, a machining head mounted frame disposed
movably to the machining surface, and a machining head supported by
the machining head mounted frame, characterized in that the
machining head includes a jig for holding the object to be
machined, an up-and-down moving portion moving up and down relative
to the machining surface together with the jig, and a correcting
mechanism supported by the up-and-down moving portion, the
correcting mechanism includes a shaft, a plurality of levers
composed of linear portions provided at ends with pins and
supported rotatably by the shaft at portions different from the
pins and driven portions coupled at end portions with the linear
portions having convex portions, a pair of correcting drive members
disposed in a linear manner on both sides of the convex portions
while clamping the convex portions, and a base having recess
portions for receiving the pair of correcting drive members and the
convex portions and fixed to the up-and-down moving portion, the
pair of correcting drive members drive in the linear manner to
thereby drive the convex portion clamped thereby, whereby the
levers and the pins are pivoted about the shaft, the jig includes a
body portion fixed to the up-and-down moving portion, a holding
portion elongated in one direction and fixed to the body portion
for holding the object to be machined, and a plurality of load
receiving portions arranged in parallel in the one direction on the
holding portion, and the load receiving portions receive the pins
and are driven in accordance with the pivotal movement of each pin
whereby portions corresponding to the load receiving portion in the
holding portion are deformed together with the object to be
machined.
Also, according to the present invention, it is preferable that tip
ends of the pins are spherical and it is preferable that sizes of
projections of the adjacent convex portions are different from each
other and the arrangement of the correcting drive members each
received in the recess portion and a size of the recess portion are
defined in accordance with the sizes of the convex portions. It is
also preferable that the pair of correcting drive members have a
pair of pistons to be driven by pressure medium, and the base has a
pair of pressure medium introduction ports in communication with a
rear portion of each of the pair of pistons. It is preferable that
the pair of adjacent pressure medium introduction ports are each
arranged at different distances from a predetermined surface of the
base.
Also, it is preferable that one of the pair of correcting drive
members has a piston to be driven by pressure medium, the other
being formed of elastic member and the base has a pressure medium
introduction port in communication with a rear portion of the
piston. Its preferable that the pair of adjacent pressure medium
introduction ports are each arranged at different distances from a
predetermined surface of the base. Also, it is preferable the
pressure medium is pressurized air and tip end portions of the
pistons are substantially spherical.
Furthermore, according to the present invention, it is preferable
that the jig has an electrode to be connected to an electric
element formed on the object to be machined, and the correcting
mechanism has a probe unit to be brought into contact with the
electrode. Also, according to the present invention, it is
preferable that the machining head has a balancing actuator, the
jig has through holes in a central portion and both end portions in
the longitudinal direction of the body portion, the jig is
supported by the correcting mechanism by a fixing pin passing
through the through hole in the central portion, and the jig is
depressed to a direction toward the machining surface through the
positioning pins at both end portions by the balancing
actuator.
Also, according to the present invention, it is preferable that the
machining head is supported through an adjust ring supported by the
machining head mounting frame and in contact with the machining
surface, and an angle of the machining head supported by the
machining head mounting frame facing the machining surface is
defined by the adjust ring. Also, it is preferable that the
machining head is mounted rotatably to rails for mounting the
machining head. Furthermore, it is preferable that the apparatus
according to the invention further comprises a machining head
swinging means, in which the machining head swinging means performs
reciprocating rotational motion of the machining head within a
predetermined angular range. It is more preferable that the object
to be machined is a rod-like ceramic provided with a plurality of
magnetic heads.
Furthermore, in order to attain the above-noted object, according
to the present invention, there is provided a method for machining
an object, to be machined, elongated in one direction by holding
the object to be machined to a jig, and depressing the object to be
machined to a machining surface formed in a machining base that is
rotationally driven, through the jig, comprising the steps of:
measuring a machining amount at a plurality of positions of the
object to be machined when the object to be machined is depressed
against the machining surface; and rotating a plurality of levers
having pins at ends, together with the pins by a plurality of
correcting drive means on the basis of the measured machining
amount for imparting a predetermined deformation to the object to
be machined together with the jig by the rotation of the pins with
tip ends received in the jig.
Furthermore, in order to attain the above-noted object, according
to the present invention, there is provided a method for machining
an object to be machined, elongated in one direction by holding the
object to be machined to a jig, and depressing the object to be
machined to a machining surface formed in a machining base that is
rotationally driven, through the jig, comprising the steps of:
measuring a machining amount of a plurality of positions of the
object to be machined when the object to be machined is depressed
against the machining surface; and driving a plurality of shafts,
disposed on the same axes with a plurality of correcting drive
means and having pins, on the basis of the measured machining
amount for imparting a predetermined deformation to the object to
be machined together with the jig by the drive along the axes of
the pins with tip ends received in the jig.
Furthermore, in order to attain the above-noted object, according
to the present invention, there is provided a method for machining
an object to be machined, elongated in one direction by holding the
object to be machined to a jig, and depressing the object to be
machined to a machining surface formed in a machining base that is
rotationally driven, through the jig, comprising the steps of:
measuring a machining amount at a plurality of positions of the
object to be machined when the object to be machined is depressed
against the machining surface; and driving a plurality of shafts
having pins linearly by a pair of correcting drive means disposed
on a plurality of straight lines on the basis of the measured
machining amount and imparting a predetermined deformation to the
object to be machined together with the jig by the drive on the
straight lines of the pins with tip ends received in the jig.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall frontal view showing a polishing apparatus of
a magnetic head in accordance with an embodiment of the present
invention.
FIG. 2 is an overall plan view showing the polishing apparatus of
the magnetic head in accordance with the embodiment of the present
invention.
FIG. 3 is frontal view showing a polishing head and the like in the
polishing apparatus of the magnetic head shown in FIG. 1.
FIG. 4 is a plan view showing the polishing head shown in FIG.
3.
FIG. 5 is a side elevational view showing the polishing head shown
in FIG. 3.
FIG. 6 is a side elevational cross-sectional view showing the
polishing head shown in FIG. 3.
FIG. 7 is a bottom view showing an adjust ring usable in the
polishing head according to the invention.
FIG. 8 is a plan view showing a correcting mechanism in accordance
with a first embodiment of the invention.
FIG. 9 is a frontal view of the correcting mechanism shown in FIG.
8.
FIG. 10 is a side elevational view of the correcting mechanism
shown in FIG. 8.
FIG. 11 is a schematic cross-sectional view taken along the line
11--11 of the correcting mechanism shown in FIG. 9.
FIG. 12 is a frontal view of a polished object mounting jig used in
the embodiment of the invention.
FIG. 13 is a block diagram in conjunction with a polishing amount
control in accordance with the embodiment of the invention.
FIG. 14 is a diagram showing detail of the measurement and a
multiplex substrate shown in FIG. 13.
FIG. 15 is a view showing a detail of a micro actuator driving
substrate shown in FIG. 13.
FIG. 16 is a side elevational cross-sectional view of a polishing
head according to a second embodiment of the invention.
FIG. 17 is a plan view of a correcting mechanism in accordance with
the second embodiment of the present invention.
FIG. 18 is a frontal view of the correcting mechanism shown in FIG.
17.
FIG. 19 is a schematic cross-sectional view taken along the line
19--19 of the correcting mechanism shown in FIG. 18.
FIG. 20 is a side elevational cross-sectional view of a polishing
head according to a third embodiment of the invention.
FIG. 21 is a plan view of a correcting mechanism in accordance with
the third embodiment of the present invention.
FIG. 22 is a frontal view of the correcting mechanism shown in FIG.
21.
FIG. 23 is a schematic cross-sectional view taken along the line
23--23 of the correcting mechanism shown in FIG. 22.
FIG. 24 is a view showing a rear surface of the correcting
mechanism where adjacent pressurized medium introduction ports are
arranged in a staggered manner in the third embodiment.
FIG. 25 is a schematic cross-sectional view taken along the line
25--25 in the correcting mechanism shown in FIG. 24.
FIG. 26 is a side elevational cross-sectional view of a polishing
head according to a fourth embodiment of the invention.
FIG. 27 is a plan view of a correcting mechanism in accordance with
the fourth embodiment of the present invention.
FIG. 28 is a frontal view of the correcting mechanism shown in FIG.
27.
FIG. 29 is a schematic cross-sectional view taken along the line
29--29 of the correcting mechanism shown in FIG. 28.
FIG. 30 is a view showing a rear surface of the correcting
mechanism where adjacent pressurized medium introduction ports are
arranged in a staggered manner in the fourth embodiment.
FIG. 31 is a schematic cross-sectional view taken along the line
31--31 in the correcting mechanism shown in FIG. 30.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
(First Embodiment)
A machining apparatus, i.e., a polishing apparatus of a magnetic
head in accordance with a first embodiment of the present invention
will now be described with reference to the accompanying drawings.
FIG. 1 is an overall frontal view showing the polishing apparatus
of the magnetic head in accordance with the embodiment of the
invention. FIG. 2 is a plan view. The overall structure of the
magnetic head polishing apparatus will now be described with
reference to FIGS. 1 and 2. The magnetic head polishing apparatus
is provided with a base 1. A polishing base 2 which is a machining
base is supported rotatably in a horizontal plane by the base 1.
Furthermore, the polishing base 2 is rotationally driven through a
belt 6 by a base drive motor 4 that is a rotary drive source
provided within the base 1.
Also, a pair of guide rails 8 that are away from each other in the
vertical direction are supported by the upper portion of the base 1
so as to extend in the horizontal direction. Furthermore, a lateral
movement slider 10 is guided to be slidable in the horizontal
direction by the pair of guide rails 8. A polishing head mounted
frame 12 that is a machining head mounted frame is mounted on the
lateral movement slider 10 to be movable in the vertical direction
(to be driven vertically for adjustment of the height level). The
drive of the lateral movement slider 10 may be executed by, for
example, threadedly engaging a ball screw nut on the slider 10 side
with a ball screw shaft in parallel with the guide rails 8 and
rotationally driving the ball screw shaft by a motor. Furthermore,
the slider 10 and the polishing head mounting frame 12 may take a
reciprocation linear motion.
As shown in FIG. 3, a rotary support portion 16 is rotatably
supported through an annular bearing portion 14 inside of the
polishing head mounting frame 12. A polishing head 20 that is the
machining head is mounted on the rotary support portion 16 through
a coupling member 18 that is a rigid member. The polishing head 20
has a bottom plate 22 and a vertical support plate 24 fixed and
implanted vertically in parallel with each other on the bottom
plate 22. As shown in FIGS. 2 and 3, a belt wheel (pulley) 28 is
fixed to the rotary support portion 16. A polishing head swinging
motor 32 for rotationally driving a belt wheel (pulley) 30 is
mounted outside of the polishing head mounting frame 12. A belt 34
is laid around the belt wheels 28 and 30. The motor 32, the belt
wheels 28 and 30 and the belt 34 function as a swing means for
performing reciprocating rotational motion (swing motion) to the
polishing head 20 within a predetermined angular range.
Incidentally, in this embodiment, a rigid member is used as the
coupling member 18 and may hold the polishing head 20 stably
substantially in the vertical direction to a polishing surface 2a.
However, in the case where it is difficult to ensure the polishing
head 20 in a stable posture to the polishing surface 2a in a
polishing step, it is possible to use an elastic member such as a
spring or a rubber as the coupling member and to further use an
adjust ring for the purpose of stabilizing the posture of the
head.
In this case, the adjust ring (wear pad) 26 is fixed to the bottom
surface of the bottom plate 22 of the polishing head 20 and is
disposed in contact with the polishing surface 2a that is the top
surface of the polishing base 2. FIG. 7 is a bottom view showing an
example of the adjust ring. As shown in FIG. 7, the adjust ring 26
is one obtained by, for example, embedding a number of cylindrical
dummies 38 made of wear-resistive ceramic in an aluminum made ring
body 36. The lower end faces of the cylindrical dummies 38 somewhat
project from the ring body 36. The number of the cylindrical
dummies 38 is selected in conformity with the weight balance of the
polishing head 20 to be laid on the adjust ring 26. In the case of
the adjust ring 26 shown in FIG. 7, since an arcuate portion 40 out
of the arcuate portions 40 and 42 of the adjust ring 26 in contact
with the polishing base 2 is subjected to more load of the
polishing head 20, the number of the cylindrical dummies 38 is
increased therefor.
As shown in FIGS. 3 to 6, a slantable shaft 44 in parallel with a
lower surface of the polishing base 2 is provided between the
portions of the vertical support plate 24 of the polishing head 20.
A slantable portion 46 slantable to the polishing head 20 is
pivoted about the slantable shaft 44.
As shown in FIGS. 5 and 6, a lower portion of a motor mounting seat
portion 48 is mounted rotatably at a pivot shaft 50 in the vertical
support plate 24 of the polishing head 20. A slanting motor 52 is
fixed to an upper portion of the motor mounting seat portion 48. A
ball screw shaft 54 is coupled to a rotary drive shaft of the motor
52. A ball screw nut 56 is engaged with this ball screw shaft 54.
One end of an arm 58 that is connected at the other end to the
slantable portion 46 is coupled at a pivot shaft 60 to the ball
screw nut 56. The mechanism from the pivot shaft 50 to the pivot
shaft 60 constitutes a slantable portion driving means for slanting
the slantable portion 46 at a predetermined angle from the vertical
plane to the polishing surface 2a of the polishing base 2.
An up-and-down moving portion 64 is mounted to be movable up and
down to the slantable portion 46 through a slide bearing (cross
roller guide) 62 in the slantable portion 46. It should be noted
that, since the movement of the up-and-down moving portion 64 is
performed together with the slantable portion 46, the slantable
portion 46 and the up-and-down moving portion 64 are always kept in
a parallel condition. A back plate 68 is pivoted at a pivot shaft
66 perpendicular to the slantable shaft 44 and in parallel with the
lower surface of the polishing base 2.
As shown in FIGS. 3 and 5, balancing actuators 70A and 70B are
mounted through a bracket 72 on an upper portion of the slantable
portion 46. These balancing actuators 70A and 70B are used for
lifting upwardly right and left sides of a pivot shaft (a central
portion in the longitudinal direction) of the back plate 68
(application of drawing pressure) and for controlling the load
applied to the back plate 68.
The balancing actuators 70A and 70B shown in this embodiment are
electromagnetic REC plungers and are composed of frames 74A and
74B, coils 76A and 76B mounted inside the frames 74a and 74B to
form the stationary portions, magnets 78A and 78B mounted on
central portions of the actuators 70A and 70B to form movable
portions and rods 80A and 80B mounted integrally with the centers
of the magnets 78A and 78B. Up-and-down moving members 82A and 82B
each having an L-shaped cross section are connected to be movable
up and down along slide bearing 84A and 84B mounted on the frames
74A and 74B at the lower ends of the rods 80A and 80B. The lower
end sides of the up-and-down moving members 82A and 82B and the
right side and left side of the back plate 68 are coupled with each
other through coupling links 88A and 88B. Here it should be noted
that the moving direction of the magnets 78A and 78B and a
direction in which a force is applied to the back plate 68 are
parallel with each other.
In the actual polishing work, the adjustment of the main depressing
load to the polishing surface 2a of an object 92 to be polished is
performed by the balancing actuators 70A and 70B. Simultaneously,
the adjustment of the rough balance of the depressing load in the
longitudinal direction of the object 92 to be polished is
performed. In this embodiment, more specifically, a force for
drawing the object 92 to be polished mainly upwardly (drawing
force) is applied to the actuators 70A and 70B in response to the
change in magnitude of the polishing amount and the portion to be
polished in the longitudinal direction of the object 92 to be
polished. However, it is possible to partially apply the depressing
force (force in the direction the object 92 to be polished is
depressed against the polishing surface) in response to the
necessary polishing amount of each portion.
A correcting mechanism 100 for actually correcting the bend or the
like of the object 92 to be polished through a jig 94 upon the
polishing work is fixed to the back plate 68 and the correcting
mechanism 100 per se is driven by the balancing actuators 70A and
70B. Hereafter, the correcting mechanism 100 will be described in
detail.
FIGS. 8, 9 and 10 are a plan view, a frontal view and a side
elevational view of the correcting mechanism 100 in accordance with
this embodiment, respectively. A base 101 is fixed substantially in
parallel with the back plate 68 by means of screws or the like so
that the correcting mechanism 100 per se is fixed to the back plate
68. A bracket 103 is fixed through a holder 102 at an upper portion
of the base 101. Both side surfaces of the bracket 103 are arranged
substantially in parallel with the back plate 68. Plates 104 and
105 are fixed in parallel on both side surfaces of the bracket 103.
The bracket 103 is clamped between these two plates so that a
correcting actuator 106 composed of a plurality of correcting drive
means is held in a predetermined position.
FIG. 11 is a side elevational view showing the structure of the
drive portion of the correcting mechanism 100. As shown in FIG. 11,
each correcting actuator 106, at the driving portion thereof, is
connected to one end of a lever 113 extending substantially
perpendicular to the drive direction through a joint 118 and a pin
117. Furthermore, the lever 113 is rotatably supported through a
bearing 112 by a shaft 111 fixed to the base 101 and is rotated
about the shaft 111 by the drive of the correcting actuator 106.
The lever 113 is provided with a pin 113a at the other end of the
coupling portion with the driving portion so as to be rotated about
the shaft 111.
In the embodiment, the shaft 111 is provided in the vicinity of the
pin 113a for supporting the lever 113 whereby the drive force
obtained from the correcting actuator 106 is amplified due to the
lever principle and the fine control to the pin 113a may be
performed. The tip end of the pin 113a is machined in a spherical
shape and is driven in a direction that is substantially
perpendicular to the driving direction of the actuator
(substantially in the vertical direction of the polishing surface
2a) by the drive of the correcting actuator 106.
Incidentally, since the interval of the adjacent pins 113a is
smaller than the size (diameter in this case) of the correcting
actuators 106 used in this embodiment, it is impossible to simply
arrange the correcting actuators 106 in parallel with each other.
Therefore, as shown in FIG. 11, the length of the lever 113 is
changed in each case so that the correcting actuators 106 are
arranged in a staggered manner to provide the retainer space for
the correcting actuators 106. In this case, the drive amounts of
the tip ends of the pins 113a are different from each other due to
the difference in length of the levers 113. However, according to
this embodiment, the respective drive strokes of the correcting
actuators 106 are limited to a predetermined range, and
simultaneously therewith, the count numbers for measuring the
actual drive amounts of the pins 113a are made different from each
other to thereby keep constant the drive amounts of the tip
ends.
As shown in FIGS. 6 or 9, a pair of positioning pins 107a and a
fixing pin 107 projecting in a direction opposite the back plate 68
are fixed in parallel with each other at both end portions and the
central portion in the longitudinal direction in the lower portion
of the base 101. A bracket 108 having probe units 109 and 110
composed of a plurality of resistor measuring terminals 128 or the
like is fixed by using the pair of positioning pins 107a. The jig
94 for holding the object 92 to be polished is held so as to clamp
the bracket 108 to the base 101 by using both the fixing pin 107
and the positioning pins 107a.
As shown in a frontal view of FIG. 12, for example, the jig 94 is
formed in an integral frame shape composed of a body portion 131
elongated in one direction, a holding portion 132 having
substantially the same length as that of the body portion 131
disposed in parallel with the body portion 131 and joint portions
133 and 134 for coupling the body portion 131 and the holding
portion 132 at both end portions in the longitudinal direction.
Holes 120a and 120 through which the positioning pins 107a and the
fixing pin 107 pass are provided in the body portion 131, and the
body portion 131 is fixed to the base 101. In the holding portion
132, a plurality of load receiving portions 145 are arranged in the
longitudinal direction on the portion of the inside of the frame
and holding portion 132 holds the object 92 to be polished on the
portion of the outside of the frame.
A load receiving hole 146 is formed in a central portion of each
load receiving portion 145. When the jig 94 is fixed to the base
101, a spherical portion at the tip end of the pin 113a is inserted
into the load receiving hole 146. In accordance with the drive of
the correcting actuator 106, the tip end portion of the pin 113a
depresses the peripheral portion of the load receiving hole 146 to
drive the load receiving portion 145 up and down. In accordance
with the movement of this load receiving portion 145, the holding
portion 132 is partially deformed and simultaneously, the portion
92 to be polished is locally deformed.
Incidentally, the tip end portion of the pin 113a is not moved up
and down in a linear manner but is moved up and down while
depicting an arcuate locus in accordance with the arcuate rotation
of the lever 113 about shaft 111. For this reason, in the
embodiment, the tip end portion is made spherical so that the tip
end portion may slide to the peripheral portion of the load
receiving hole 146 to enable the smooth slide of the load receiving
portion 145 with respect to the tip end portion.
In the object 92 to be polished to be fixed to the holding portion
body 132, element portions of a number of magnetic heads made of
magnetic thin film pattern are arranged in a single line on the
elongated rectangular ceramic bar (to be divided into elements for
sliders of the thin film magnetic head). The magnetic thin film
pattern of these element portions is arranged on one side
longitudinal surface of the ceramic bar. Accordingly, the bottom
surface of the ceramic bar is polished so that the throat height
and the MR height may be reduced in the element portion formed on
the above-described longitudinal side surface.
As described above, the strain, the distortion or the like is
present in the object 92 to be polished. When the object 92 is to
be polished, it is necessary to polish it after correcting the
strain or the like. In this embodiment, the amount of bend
deformation that is needed in each position in the longitudinal
direction of the object 92 to be polished is corrected by driving
up and down each load receiving portion 145 formed in the lateral
longitudinal jig 94 by the necessary amount.
Accordingly, upon the polishing work, it is necessary to seek the
necessary drive amount of the loading receiving portion 145, i.e.,
the amount of bend deformation of the object 92 to be polished. A
specific example for seeking the necessary amount of deformation
during polishing work and driving the correcting actuator 106 on
the basis of the sought value will now be described. In the
embodiment, additional electrodes are provided on the longitudinal
side surface of the ceramic bar in addition to the elements. The
additional electrodes reduce the size of the ceramic bar in
accordance with the polishing work of the ceramic bar and increase
the resistance value. In the embodiment of the invention, the
polishing work according to a so-called closed loop control in
which the change of the resistance value of the additional
electrodes is monitored and the polishing amount at the monitoring
time is sought to thereby seek the further necessary amount of
deformation on the basis of the obtained polishing amount is
performed to control the polishing amount in the object 92 to be
polished.
For this reason, the electrodes electrically connected to the
additional electrodes by wire bonding are formed in advance on a
surface, on the confronting side to the bracket 108, of the lateral
longitudinal jig 94. Measurement pins 128 biased by spring or the
like are implanted in the probe units 109 and 110 on the bracket
108. When the lateral longitudinal jig 94 is fixed to the base 101,
the above-described electrodes and the measurement pins 128 are
bought into contact with each other. Furthermore, the measurement
pins 128 are connected to the resistance value measurement means
(not shown), and the lateral longitudinal jig 94 is fixed to the
base 101 to thereby make it possible to measure the resistance
value of the additional electrodes.
The structure of the specific resistance value measurement means
and the control means of the actuator 106 will now be described.
FIG. 13 is a control block diagram for driving the correcting
actuator 106 on the basis of the resistance value of the measured
additional electrodes including the above-described measurement
means and control means. FIG. 14 is a detailed block diagram of a
measurement and multiplex substrate 220. FIG. 15 is a detailed
block diagram of the actuator drive substrate. Incidentally, in the
embodiment, since the resistance value is measured in accordance
with a four-terminal method, a plurality of measurement pins 128
are brought into contact with a single additional electrode
201.
The voltage obtained by the additional electrode 201 through the
measurement pins 128 with the measurement and multiplex substrate
220 is converted into resistance values on the basis of the
calculation used in a well known four-terminal measurement.
Furthermore, these values are converted and multiplexed as digital
data and inputted into an input/output terminal 211 of a
microcomputer 210. Furthermore, using the data inputted in the
computer 210, the polishing amount of the object 92 to be polished
is calculated to display the polishing amount to the operator.
The above-described signal processing from the measurement of the
resistance values to the output of the digital data will now be
described in detail with reference to FIG. 13. In the measurement
and multiplex substrate 220, the supply of current from a constant
current power source 221 to the plurality of measurement pins 128,
the measurement of voltage between the respective pins, and, in a
calculation portion 223, the numerical calculation on the basis of
the comparison of the value of a correcting resistance 222 with the
measurement value are continuously performed to obtain the
resistance value of the additional electrode. The obtained value is
converted into digital data by an A/D converter 224.
The necessary polishing amount of the portion where the measured
additional electrode on a surface 92a to be polished and the amount
of vicinity thereof is formed and sought. Subsequently, in order to
perform the polishing work with the necessary amount, the drive
amount needed for each load receiving portion 145 is sought as
drive amount data in the computer 210. The drive amount data is
inputted into an actuator drive substrate 230 through the input
terminal 211 from the computer 210.
The data is converted into a contact signal in the actuator drive
substrate 230. The drive current is outputted to each correcting
actuator 106 from a drive current output device 232 that has
received the control signal. In response to the output, each
correcting actuator 106 finely adjusts the amount of deformation
given to the object 92 to be polished by the drive of the load
receiving portion 145 of the lateral longitudinal jig 94 to thereby
finely adjust the load balance of the polishing amount of the
object 92 in each position in the longitudinal direction with
respect to the polishing surface 2a.
As described above, the correcting substrate 106 is controlled
through the closed loop so that the object may be polished while
monitoring the polishing amount to cope with the case where the
allowable range of the non-uniformity of the polishing amount
becomes narrower. Incidentally, it is possible to seek the
polishing amount from the resistance of the actual elements, for
example, the MR value without using the additional electrode.
The operation of the actual apparatus and the polishing method in
accordance with the embodiment of this invention will now be
described. First of all, in a position where the polishing head 20
shown in FIGS. 1 and 2 is out of the polishing base 2, the lateral
longitudinal jig 94 holding the object 92 to be polished where a
plurality of elements for the thin film magnetic heads are arranged
is fixed to the base 101 by using the fixing pin 107 and the
positioning pins 107a. At that time, the additional electrode and
electrodes provided on the side surface 94a of the lateral
longitudinal jig 94 have already been wire bonded and the
measurement pin 128 is brought into contact with the
above-described electrode.
All the tip end portion of the pin 113a of each lever 113 is
inserted into the load receiving hole 146 of the jig 94.
Thereafter, the slant angle of the back plate 68 with respect to
the polishing head 20 is set at zero in the initial stage (in the
case where the adjust ring is used, in a vertical position to the
bottom surface of the adjust ring 26, i.e., the vertical posture to
the polishing base 2).
Here, depending upon the structure of the object to be polished, in
the case where, for example, the elements and the like are built in
the arrangement on the object to be polished that needs a very
large polishing amount to obtain a predetermined throat height,
there are some cases where a rough polishing work is performed in
advance by another apparatus before the above-described mounting
work. In this embodiment, in this case, this rough polishing is not
performed under the condition that the object 92 to be polished is
held in the lateral longitudinal jig 94 but the rough polishing is
performed under the condition that the object 92 to be polished is
fixed to another jig (not shown). However, the rough polishing may
be performed by using the lateral longitudinal jig 94. After the
completion of the rough polishing, the object 92 to be polished is
removed away from the another jig and is again fixed to the lateral
longitudinal jig 94.
After the mounting work of the lateral longitudinal jig 94 and the
slant angle setting of the back plate 68, the polishing head
mounting frame 12 on which the polishing head 20 is mounted is
moved in a linear manner along the guide rails 8 and positioned
above the polishing base 2 that is rotationally driven.
Furthermore, in order to bring the object 92 to be polished into
contact with the polishing surface 2a on the top surface of the
polishing base 2, the polishing head mounting frame 12 is lowered.
When the adjust ring 26 is used, the polishing head mounting frame
12 is lowered so that a part of the lower surface of the plurality
of cylindrical dummies 38 embedded in the lower surface thereof is
brought into contact with the polishing surface 2a of the top
surface of the polishing base 2 and the part is kept in contact
therewith at a suitable pressure.
Furthermore, the balancing actuators 70A and 70B are driven so that
each parallel pressure force applied to the left side and the right
side of the back plate 68 is adjusted and the object 92 to be
polished is kept under the condition that object 92 to be polished
is depressed substantially in parallel and against to the polishing
surface 2a. In this embodiment, the main pressure is obtained from
the balancing actuators 70A and 70B. However, in this stage, the
pressure to such an extent that the back plate 68 is supported is
applied so as to keep the right and left balancing actuators 70A
and 70B under the condition that both end portions of the object 92
to be polished is in contact with the polishing surface 2a.
Incidentally, this adjustment may be performed by visual
observation or may be performed by using a contact sensor or the
like. Also, it is possible to roughly measure, in advance, the bend
of the object 92 to be polished and to adjust the balance of the
pressure by the balancing actuators 70A and 70B so as to correct
the bend in response to the measurement result.
Under this condition, the polishing of the object 92 to be polished
is executed. The measurement of the polishing amount in accordance
with the resistance value measurement of the additional electrode
is performed at each desired timing to obtain the necessary
polishing amount in each additional electrode formation position at
a desired interval in the polishing step. Each correcting actuator
106, i.e., the drive amount of the load receiving portion 145 is
controlled in response to the obtained necessary polishing amount
to make it possible to obtain the desired throat height or the
like. Incidentally, in the case where the bend of the object to be
polished is remarkable and simple like an arcuate shape and the
distribution of the necessary polishing amount is remarkable, it is
preferable to first perform the adjustment of the balance of the
deformation amount by the balancing actuators 70A and 70B and
thereafter to perform the drive amount adjustment of the correcting
actuators.
Incidentally, in the case where the adjust ring is used, since,
during the polishing step, the local wear is likely to occur if the
same place of the adjust ring 26 is in contact with the polishing
base 2, the rotary support portion 16 on which the polishing head
20 and the adjust ring 26 are mounted is reciprocatingly rotated
within a predetermined angular range by the polishing head swinging
motor 32, and the polishing head mounting frame 12 is
reciprocatingly moved in a linear manner in a predetermined range.
Accordingly, during the polishing step, the polishing head 20 and
the adjust ring 26 take the composite motion of the reciprocating
rotational motion and the reciprocating linear motion.
According to the above-described method, the bend of the ceramic
bar that is the object to be polished may be corrected in more
detail and may be polished so that the values of the throat height
or the like may fall within the allowable range over the full
length of the ceramic bar.
Incidentally, in this embodiment, the polishing head having the REC
plungers as the balancing actuators 70A and 70B is used. However,
the balancing actuators are not limited thereto or thereby, and it
is possible to use a variety of kinds of low frictional cylinder
such as an electromagnetic one. Also, in this embodiment, two
actuators are used to compensate for the insufficiency of the drive
stroke of the correcting actuators 106. However, in order to more
effectively compensate for the drive stroke of the correcting
actuators, it is possible to increase the number of the balancing
actuators. Also, in this case where the drive stroke of the
correcting actuator 106 per se is sufficiently large, it is
possible to dispense with the balancing actuators and to take the
structure that has only the single drawing or depressing
actuator.
Furthermore, in this embodiment, the REC plungers are used as the
correcting actuators. However, the application of the present
invention is not limited to this embodiment. It is possible to take
a structure that has a pneumatic or electromagnetic cylinder or the
like. Also, in this embodiment, the shaft 111 supports the levers
113 in the vicinity of the pins 113a. The application of the
invention is not limited to this embodiment. It is possible take a
variety of arrangements such as the arrangement where the shaft is
located, for example, in the vicinity of the correcting actuators
106 in view of the drive stroke and the drive load of the
correcting actuators 106 and the pins 113a. Also, the mounting
position of the correcting actuators 106 to the plates 104 and 105
and the length of the levers 113 are not limited to those shown in
this embodiment. It is preferable that these factors are selected
in accordance with the size of the actuators 106 and the interval
of the adjacent pins 113a.
Also, the control in accordance with the closed loop of the
embodiment is performed only by means of each correcting of micro
actuator. However, in some possible cases, the necessary polishing
amount obtained exceeds the drive range of the micro actuator, for
example. For these cases, in the case where the obtained necessary
polishing amount is greater than a predetermined value, the bend
correction of the object to be polished only by the balancing
actuators 70A and 70B at one end is performed and the operation
goes into the subroutine for reducing the necessary polishing
amount at first. It is possible to take the structure for
performing the micro actuator in accordance with the closed loop
thereafter.
Also, in this embodiment, the fixture of the object 92 to be
polished to the lateral longitudinal jig 94 or the transfer jig,
and the fixture of the transfer jig to the lateral longitudinal jig
94 are performed by thermoplastic adhesives. However, this
invention is not limited thereto. It is possible to adopt the
fixture with thermosetting or any other kind of adhesives, viscous
material made of resin or the like, electrostatic adhesion, vacuum
suction or the like.
Also, in the foregoing embodiment, only the polishing work has been
described. It is obvious for those skilled in the art to apply the
present invention not only to the polishing work but also the
grinding work or any other suitable work. Furthermore, the present
invention is not limited to the specific manners in the foregoing
embodiment but it is possible for those skilled artisan to
variously modify or change the invention within the scope of the
appended claims.
(Second Embodiment)
A polishing apparatus for a magnetic head in accordance with a
second embodiment of this invention will now be described with
reference to the accompanying drawings. Incidentally, since the
difference between the first embodiment and the second embodiment
is only the structure of the bend correcting mechanism 100 and the
bend correcting mechanism 200, the duplicated description as to the
portions except for the correcting mechanisms 100 and 200, the
control blocks for detecting the necessary polishing amount of the
object 92 to be polished or the like in the overall structure of
the apparatus will be omitted. The correcting mechanism 200 in
accordance with the second embodiment of this invention will now be
described in detail.
FIG. 16 is a side elevational view of the polishing head according
to this embodiment. FIGS. 17, 18 and 19 are a plan view, a frontal
view and a side elevational view of the correcting mechanism 200 in
accordance with this embodiment, respectively. The correcting
mechanism 200 in accordance with this embodiment is composed of a
base 150, a holder 151, an actuator holder 152 that is a frame-like
member, a correcting actuator 153 that is a correcting drive means,
a fixing pin 154, positioning pins 154a, a guide bracket 155,
shafts 156 and pins 157. The base 150 is fixed substantially in
parallel to the back plate 68 by fastening means such as screws.
With this means, the correcting mechanism 200 per se is fixed to
the back plate 68.
The holder 151 is fixed to the upper portion of the base 150. The
holder 151 holds a plurality of actuator blocks 152 substantially
in parallel to the back plate 68. Each actuator holder 152 has the
frame-like shape. The actuator holder 152 holds the correcting
actuator 153 so as to be drivable in the same direction as the
drive direction of the balancing actuators 70A and 70B. The
actuator holder 152 is made of material that may be flexed and is
driven to expand or contract in the drive direction of the
correcting actuator in response to the expansion or contraction of
the correcting actuator 152. The actuator holder 152 is fixed to
the holder 151 substantially immediately above the correcting
actuator 153, and holds one end of the shaft 156 extending in the
drive direction of the correcting actuator 153 substantially
immediately below the correcting actuator.
The fixing pin 154 for fixing the jig 94 holding the guide bracket
155 and the object 92 to be polished and the positioning pins 154a
for defining the fixture position are fixed to the lower portion of
the base 150. The above-described shaft 156 passes through each
guide hole 155a provided in the guide bracket 155. Thus, the
vertical drive of the shaft 156 in accordance with the correcting
actuator 153 is prevented from being displaced out of the drive
direction by the guide hole 155a. Each pin 157 extending in the
opposite direction to the base 150 is provided at the other end of
the shaft 156. In this embodiment, the tip end of the pin 157 is
machined into a spherical shape. The tip end is driven in a
direction substantially in parallel with the drive direction of the
actuator (substantially perpendicular to the polishing surface 2a)
by the drive of the correcting actuator 153.
As shown by dotted lines in FIG. 19, the jig 94 holding the object
92 to be polished positions so as to clamp the bracket 155 by the
base 150 and the jig 94 by using the positioning pins 154a and is
fixed and held by using the fixing pin 154. Incidentally, in this
embodiment, since it is impossible to obtain the sufficient number
of the contact points to the resistance measurement terminals 128
due to the work for the guide holes 155a or the like, the probe
units 109 and 110 made of a plurality of resistance measurement
terminals 128 or the like are not provided directly to the guide
bracket 155. For this reason, unlike the first embodiment, the
probe units 109 and 110 are discrete units from the guide brackets
155 that may be removed. The guide bracket 155 is fixed by using
the fixing pin 154 to the opposite surface to the facing surface of
the guide bracket 155 of the jig 94.
It is possible to use the jig 94 as exemplified in the first
embodiment except that the surface thereof where the electrodes
electrically connected to the additional electrode by wire bonding
is formed in advance, is the opposite surface to the facing surface
of the guide bracket 155. Namely, when the jig 94 is fixed to the
base 150, the spherical portion at the tip end of the pin 157 is
inserted into the load receiving hole 146. According to the drive
of the correcting actuator 153, the tip end portion of the pin 157
depresses the circumferential portion of the load receiving hole
146 to drive the loading receiving portion 145 up and down. The
movement of the load receiving portion 145 deforms partially the
holding portion 132 and simultaneously gives a local deformation
also to the object 92 to be polished.
Incidentally, since the interval between the tip end portions of
the adjacent pins 157 is large in comparison with the size of the
correcting actuator 153 used in this embodiment (in this case, the
cross-sectional area in the direction perpendicular to the
expansion/contraction drive direction), it is possible to arrange
simply the correcting actuators 153 in parallel with each other.
However, in the case where it is necessary to reduce the interval
between the pin tip end portions in comparison with the size of the
correcting actuators 153, it is possible to arrange the respective
correcting actuators 153 in a staggered manner and to provide a
holding space for each correcting actuator 153.
Also, in this embodiment, each actuator holder 152 has the
frame-like shape (frame). The correcting actuator 153 and the shaft
156 are arranged on a centerline thereof, and are held on the
centerline to the holder 151. However, the arrangement of the
present invention is not limited thereto. If the rigidity of the
correcting actuator may be compensated for, it is possible to take
a variety of shapes such as a U-shape, for example, for the shape
of the actuator holder. Furthermore, in the case where the rigidity
of the correcting actuator per se is high, it is possible to take a
structure for removing the actuator holder. Also, in the foregoing
embodiment, it is possible to displace the pins in view of the
moment to be applied to the tip end of each pin or the like.
Also, in the embodiment, a piezoelectric actuator is used as the
correcting actuator 153. However, the correcting actuator is not
limited thereto. Also with respect to the arrangement of the probe
units 109 and 110, it is possible to take the same arrangement as
that of the first embodiment in response to the number of the
contact points with the available resistance measurement terminal
128. Furthermore, the modifications or the like of each structure
described in conjunction with the mode of the first embodiment such
as the modification of the structure of the balancing actuators may
be applied to this embodiment in the same manner.
(Third Embodiment)
In the second embodiment, the tip end portion of each pin 157 is
moved up and down in a linear manner in response to the deformation
of the correcting actuator 153. For this reason, in the second
embodiment, the drive amount of the correcting actuator 153 is
small in comparison with the first embodiment, and, in addition,
the piezoelectric element is used as each actuator so that a large
deformation force may be given to the holder 152 with high
precision, advantageously. However, since the piezoelectric
elements that have a relatively small amount of deformation are
used, there is a fear that the deformation amount to be given would
be insufficient. Therefore, in accordance with the third
embodiment, air cylinders are used as the correcting actuators.
A polishing apparatus for a magnetic head in accordance with a
third embodiment of this invention will now be described with
reference to the accompanying drawings. Incidentally, since the
difference between the first embodiment and the third embodiment is
the structure of the bend correcting mechanism 100 and the bend
correcting mechanism 300, the duplicated description as to the
portions except for the correcting mechanism 300, the control
blocks for detecting the necessary polishing amount of the object
92 to be polished or the like in the overall structure of the
apparatus will be omitted. The correcting mechanism 300 in
accordance with the third embodiment of this invention will now be
described in detail.
FIG. 20 is a side elevational view of the polishing head according
to this embodiment. FIGS. 21, 22 and 23 are a plan view, a frontal
view and a cross-sectional view taken along the line 23--23 of FIG.
22, respectively. The correcting mechanism 300 in accordance with
this embodiment is composed of a base 301, cylinder syringes 302,
303, piston 304, 305, a guide bracket 306, a fixing pin 307,
positioning pins 307a and shaft 308.
The base 301 is fixed substantially in parallel to the back plate
68 to only the upper portion by means of screws or the like to
thereby fix the correcting mechanism 300 per se to the back plate
68. A recess portion 321 that is composed of a top surface 321a, a
bottom surface 321b and a vertical surface 321c is formed on the
surface opposite (hereinafter referred to as top surface) to the
back plate 68 side in the lower portion of the base 301. Also,
pressurized gas introduction ports 323, 324 that are pressure
medium introduction ports are provided on the surface on the back
plate side (hereinafter referred as rear side surface). The
pressurized gas introduced through the ports is introduced into the
recess portion 321 from the top surface 321a and the bottom surface
321b through gas passages 325 and 326 that are medium flow paths
formed in the interior of the base 301.
Namely, in this embodiment, the correcting drive member is
constituted by the pistons driven by the pressurized gas and the
cylinder syringes for receiving the pistons and the correcting
drive means is constituted by a pair of correcting drive
members.
A guide groove is provided in the drive direction (hereinafter
referred to as vertical direction) of the balancing actuators 70A
and 70B in the guide bracket 306. The surface side where guide
groove is formed is faced to the top surface side of the base 301
so that the shaft 308 is held slidable in the vertical direction in
the guide groove. The shaft 308 has a convex portion 308a received
in the recess portion 321 and a pin 308b projecting in a direction
different from the vertical direction in the lower portion in the
vertical direction. The recess portions 321 further receives the
pistons 304 and 305 in contact with the convex portion 308a at
upper surface and downward surface thereof in the vertical
direction and the cylinder syringes 302 and 303 for receiving the
pistons 304 and 305 slidably in the vertical direction,
respectively.
For instance, in the case where the pressurized gas is introduced
into the pressurized air introduction port 323, the pressurized air
that reaches the top surface 321a through the gas flow path 325
drives the piston 304 within the cylinder syringe 302 downwardly in
the vertical direction. The piston 305 is also in contact with the
convex portion 308a of the shaft 308. However, in this case, since
the force of the piston 304 for driving downwardly the convex
portion 308a is stronger, the shaft 308 and the pin 308b are driven
downwardly. Also, in the case where the shaft 308 and the pin 308b
are to be driven upwardly, it is sufficient to introduce the
pressurized gas into the pressurized gas introduction port 324. It
is possible to adjust the drive amount of the shaft 308 and the pin
308b by the adjustment of the pressure balance of the gas to be
introduced to the port 323 and the port 324.
As shown by dotted lines in FIG. 23, the jig 94 holding the object
92 to be polished positions so as to clamp guide bracket 306 by the
base 301 and the jig 94 by using the positioning pins 307a, and is
fixed and held by using the fixing pin 307. Incidentally, in this
embodiment, since it is impossible to obtain the sufficient number
of the contact points to the resistance measurement terminals 128
due to the work for the guide groove or the like, the probe units
109 and 110 made of a plurality of resistance measurement terminals
128 or the like are not provided directly to the guide bracket 306.
For this reason, unlike the first embodiment, the probe units 109
and 110 are discrete units from the guide bracket 306 that may be
removed. The guide bracket 306 is fixed by using the fixing pin 307
to the opposite surface of the facing surface to the guide bracket
306 of the jig 94.
It is possible to use the jig 94 as exemplified in the first
embodiment except that the surface thereof where the electrodes
electrically connected to the additional electrode by wire bonding
is formed in advance is the opposite surface to the facing surface,
of the guide bracket 307. Namely, when the jig 94 is fixed to the
base 301, the spherical portion at the tip end of the pin 308b is
inserted into the load receiving hole 146. According to the drive
of the pistons 304 and 305, the tip end of the pin 308b depresses
the circumferential portion of the load receiving hole 146 to drive
the loading receiving portion 145 up and down. The movement of the
load receiving portion 145 deforms locally the holding portion 132
and simultaneously gives a local deformation also to the object 92
to be polished.
Incidentally, since the interval between the tip end portions of
the adjacent pins 308b is large in comparison with the size of the
pistons 304 and 305 used in this embodiment (in this case, the
cross-sectional area in the direction perpendicular to the drive
direction) or the size of the pressurized air gas introduction
ports 323 and 324 (more exactly, an outer diameter of a connector
used when a tube for introduction of the pressurized air to each
port is connected), it is possible to arrange simply these
components in parallel with each other. However, in the case where
it is necessary to reduce the interval between the pin tip portions
in comparison with the size of these pistons or the ports, it is
possible to arrange the respective adjacent pistons, i.e., the
adjacent recess portions for receiving the pistons in astaggered
manner, to arrange the respective adjacent ports in the staggered
manner or to combine these components.
The example in which these components are combined is shown in
FIGS. 24 and 25. FIG. 24 is a view of the base 301 as viewed from
the rear side. FIG. 25 is a view corresponding to FIG. 23 of the
embodiment in which the ports are not arranged in a staggered
manner. As is apparent from FIG. 24, it is possible to increase the
number of the ports considerably in comparison with the case where
the ports 323 and 324 are arranged in parallel. Furthermore, as
shown in FIG. 25, not only is the arrangement of the ports 323 and
324 displaced but also the depths of the adjacent recess portions
321 are different to arrange the cylinder syringes and the pistons
not in parallel but in a staggered manner. With such an
arrangement, it is possible to reduce the interval between the
adjacent pins 308b not depending upon the size of the pistons and
the ports.
The arrangement of the ports and the pistons in this modification
is simply an example and the arrangement may be displaced more
complicatedly so as to make it possible to reduce the distance
between the adjacent pins more. Also, in this embodiment, the
pressurized gas is used as the drive source. It is however possible
to use the liquid such as hydraulic fluid. Also, in this
embodiment, the correcting drive means is constituted by a pair of
correcting drive members composed of the pistons the cylinder
syringes and the like. However, it is possible to compose one of
the correcting drive members of piston, cylinder syringe and the
like, and the other correcting drive member of elastic material
such as spring or rubber. Furthermore, the modifications or the
like of each structure described in conjunction with the mode of
the first embodiment such as the modification of the structure of
the balancing actuators may be applied to this embodiment in the
same manner.
(Fourth Embodiment)
A polishing apparatus for a magnetic head in accordance with a
fourth embodiment of this invention will now be described with
reference to the accompanying drawings. Incidentally, since the
difference between the third embodiment and the fourth embodiment
is the structure of the bend correcting mechanism 300 and the bend
correcting mechanism 400, the duplicated description as to the
portions except for the correcting mechanisms 400, the control
blocks for detecting the necessary polishing amount of the object
92 to be polished or the like in the overall structure of the
apparatus will be omitted. The correcting mechanism 400 in
accordance with the fourth embodiment of this invention will now be
described in detail.
FIG. 26 is a side elevational view of the polishing head according
to this embodiment. FIGS. 27, 28 and 29 are a plan view, a frontal
view and a cross-sectional view taken along the line 29--29 of FIG.
28, respectively of the correcting mechanism 400 in accordance with
this embodiment. The correcting mechanism 400 in accordance with
this embodiment is composed of a base 401, cylinder syringes 402,
403, pistons 404, 405, a guide bracket 406, a positioning (fixing)
pin 407, positioning pins 407a and levers 408.
The base 401 is fixed substantially in parallel to the back plate
68 to only the upper portion by means of screws to thereby fix the
correcting mechanism 400 per se the back plate 68. A recess portion
421 that is composed of a top surface 421a, a bottom surface 421b
and a vertical surface 421c is formed on the surface opposite
(hereinafter referred to as top surface) to the back plate 68 in
the lower portion of the base 401. Also, pressurized gas
introduction ports 423, 424 that are pressure medium introduction
ports are provided on the surface on the back plate side
(hereinafter referred as to as rear side surface). The pressurized
gas introduced through the ports is introduced into the top surface
421a and the bottom surface 421b through gas passages 425 and 426
that are medium flow paths formed in the interior of the base
401.
A guide groove is provided in the drive direction (hereinafter
referred to as vertical direction) of the balancing actuators 70A
and 70B in the guide bracket 406. The surface side where the guide
groove is formed is faced to the top surface side of the base 401
so that the lever 408 is held slidable in the vertical direction in
the guide groove. The lever 408 is composed of a linear shaped
portion which pivotally supports at one end about a shaft 420 which
is supported by the base 401 and provided at the other end with the
pin 408b, and a driven portion fixed at one end to this linear
shaped portion and provided at the other end with a convex portion
408a received in the recess portion 421 and received in the guide
groove except for the convex portion 408a. The recess portions 421
further receives the pistons 404 and 405 in contact with the convex
portion 408a up and down in the vertical direction of the convex
portion 408a, and the cylinder syringes 402 and 403 for receiving
the pistons 404 and 405 slidably in the vertical direction,
respectively.
For instance, in the case where the pressurized gas is introduced
into the pressurized air introduction port 423, the pressurized air
that reaches the top surface 421a through the gas flow path 425
drives the piston 404 within the cylinder syringe 402 upwardly in
the vertical direction. The piston 405 is also in contact with the
convex portion 408a of the lever 408. However, in this case, since
the force of the piston 404 for driving downwardly the convex
portion 408a is stronger, the convex portion 408a is driven
substantially downwardly. The convex portion 408 is driven
downwardly, to rotationally drive the lever 408 about the shaft
420, so that the pin 408b is moved substantially in the vertical
direction. Also, in the case where the lever 408 and the pin 408b
are to be driven substantially upwardly, it is sufficient to
introduce the pressurized gas into the pressurized gas introduction
port 424. It is possible to adjust the drive amount of the lever
408 and the pin 408b by the adjustment of the pressure balance of
the gas to be introduced to the port 423 and the port 424.
Incidentally, since the fixture of the jig 94 to the base 401, the
fixture of the probe units 109 and 110, the deformation of the jig
94 and the object 92 to be polished due to the insertion of the tip
end portion of the pin 408b into the load receiving hole 146 of the
jig 94 and the like are the same as those of the third embodiment,
the detailed explanation thereof will be omitted.
Incidentally, since the interval between the tip end portions of
the adjacent pins 408b is large in comparison with the size of the
pistons 404 and 405 used in this embodiment (in this case, the
cross-sectional area in the direction perpendicular to the drive
direction) or the size of the pressurized air gas introduction
ports 423 and 424, it is possible to simply arrange these
components in parallel with each other. However, in the case where
it is necessary to reduce the interval between the pin tip portions
in comparison with the size of these pistons or the ports, it is
possible to arrange the respective adjacent pistons, i.e., the
adjacent recess portions for receiving the pistons in a staggered
manner, to arrange the respective adjacent ports in the staggered
manner or to combine these components.
The example in which these components are combined is shown in
FIGS. 30 and 31. FIG. 30 is a view of the base 401 as viewed from
the rear side. FIG. 31 is a view corresponding to the embodiment of
FIG. 29 in which the ports are not arranged in a staggered manner.
As is apparent from FIG. 30, it is possible to increase the number
of the ports considerably in comparison with the case where the
ports are arranged in parallel. Furthermore, as shown in FIG. 31,
not only is the arrangement of the ports displaced but also the
depths of the adjacent recess portions 421 are different to arrange
the cylinder syringes and the pistons not in parallel but in a
staggered manner. With such an arrangement, it is possible to
reduce the interval between the adjacent pins 408b not depending
upon the size of the pistons and the ports.
The arrangement of the ports and pistons in this modification is
simply an example and the arrangement may be displaced more
complicatedly so as to make it possible to reduce the distance
between the adjacent pins more. Also, in this embodiment, the
pressurized gas is used as the drive source. It is however possible
to use the liquid such as hydraulic fluid. Furthermore, the
modifications or the like of each structure described in
conjunction with the mode of the first embodiment, such as the
modification of the structure of the balancing actuators, may be
applied to this embodiment in the same manner.
According to the machining apparatus and machining method according
to this invention, it is possible to impart the complicated
deformation or the like to the object to be machined such as a
ceramic bar, and to thus suppress the non-uniformity of the
machining amount of the object to be machined upon the machining
work of the object to be machined.
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