U.S. patent application number 11/698058 was filed with the patent office on 2008-03-27 for ultrasonic crimping apparatus, crimping member, ultrasonic crimping method and arm production method.
This patent application is currently assigned to FUJITSU LIMITED. Invention is credited to Naoki Ishikawa, Hidehiko Kira, Takayoshi Matsumura.
Application Number | 20080072643 11/698058 |
Document ID | / |
Family ID | 39223465 |
Filed Date | 2008-03-27 |
United States Patent
Application |
20080072643 |
Kind Code |
A1 |
Matsumura; Takayoshi ; et
al. |
March 27, 2008 |
Ultrasonic crimping apparatus, crimping member, ultrasonic crimping
method and arm production method
Abstract
The ultrasonic crimping apparatus of the invention includes: a
supporting section that supports a crimped object having a crimped
section with a through hole formed therein; a crimping member in a
bar shape that is smaller toward a front end thereof and larger
toward a rear end thereof; a driving section that causes the
crimping member to be inserted in the through hole, first from the
front end thereof; an ultrasonic application section that applies
ultrasonic wave to the crimping member, thereby causing radial
displacement of the crimping member; and a crimping control section
that causes the crimping member to be inserted into the through
hole of the crimped object, while causing application of ultrasonic
wave to the crimping member, thereby causing the crimped section of
the crimped object to be crimped.
Inventors: |
Matsumura; Takayoshi;
(Kawasaki, JP) ; Ishikawa; Naoki; (Kawasaki,
JP) ; Kira; Hidehiko; (Kawasaki, JP) |
Correspondence
Address: |
KRATZ, QUINTOS & HANSON, LLP
1420 K Street, N.W., Suite 400
WASHINGTON
DC
20005
US
|
Assignee: |
FUJITSU LIMITED
Kawasaki
JP
|
Family ID: |
39223465 |
Appl. No.: |
11/698058 |
Filed: |
January 26, 2007 |
Current U.S.
Class: |
72/56 ;
G9B/5.148 |
Current CPC
Class: |
B23P 11/005 20130101;
G11B 5/4806 20130101; B21D 26/00 20130101; B21D 39/00 20130101 |
Class at
Publication: |
72/56 |
International
Class: |
B21D 26/02 20060101
B21D026/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 21, 2006 |
JP |
2006-256199 |
Claims
1. An ultrasonic crimping apparatus comprising: a supporting
section that supports a crimped object having a crimped section
with a through hole formed in the crimped section; a crimping
member in a bar shape that is smaller toward a front end thereof
and larger toward a rear end thereof; a driving section that causes
the crimping member to be inserted in the through hole of the
crimped object supported by the supporting section, first from the
front end of the crimping member; an ultrasonic application section
that applies ultrasonic wave to the crimping member, thereby
causing radial displacement of the crimping member; and a crimping
control section that causes the crimping member to be inserted into
the through hole of the crimped object, while causing application
of ultrasonic wave to the crimping member, thereby causing the
crimped section of the crimped object to be crimped.
2. The ultrasonic crimping apparatus according to claim 1, wherein
the supporting section supports a crimped object having a plurality
of crimped sections with a plurality of through holes formed in the
crimped sections such that the through holes are aligned to enable
the crimping member to be inserted into the through holes
simultaneously, and the crimping control section causes the
crimping member to be inserted into the through holes, while
causing application of ultrasonic wave to the crimping member,
thereby causing the crimped sections to be crimped
simultaneously.
3. The ultrasonic crimping apparatus according to claim 2, wherein
the crimping member has a maximum thickness area that is uniform in
thickness over a predetermined length and that has a maximum
thickness to be inserted into the through holes, and the crimping
control section causes the driving section to make the crimping
member inserted into the through holes until the maximum thickness
area of the crimping member is inserted through the through
holes.
4. The ultrasonic crimping apparatus according to claim 1, wherein
the crimping member has a first section and a second section that
are formed alternatively in the crimping member in a longitudinal
direction, when ultrasonic wave is applied to the crimping member,
the first section having minimum radial displacement of the
crimping member, the second section having maximum radial
displacement of the crimping member and further having a uniform
thickness area where thickness of the crimping member is uniform
over a predetermined length.
5. A crimping member that crimps a crimped object having a crimped
section with a through hole formed in the crimping section, and
that is inserted through the through hole and thereby crimps the
crimped section, wherein: the crimping member is in a bar shape
that is smaller toward a front end thereof and larger toward a rear
end thereof; and the crimping member has an ultrasonic vibrator
that is disposed at the rear end of the crimping member and that
vibrates in response to application of a voltage of a frequency
equal to ultrasonic wave.
6. The crimping member according to claim 5, wherein the crimping
member has a maximum thickness area that is uniform in thickness
over a predetermined length and that has a maximum thickness to be
inserted into the through hole, the maximum thickness area being
formed at the rear end of the crimping member.
7. The crimping member according to claim 5, wherein the crimping
member has a first section and a second section that are
alternatively formed in the crimping member in the longitudinal
direction, when ultrasonic wave is applied to the crimping member,
the first section having minimum radial displacement of the
crimping section, the second section having maximum radial
displacement of the crimping section and further having a uniform
thickness area where thickness of the crimping member is uniform
over a predetermined length.
8. An ultrasonic crimping method comprising the steps of: preparing
a crimping member in a bar shape that is smaller toward a front end
thereof and larger toward a rear end thereof and is displaced
radially in response to application of ultrasonic wave; and
inserting the crimping member, first from the front end thereof,
into a though hole formed in a crimped section of a crimped object
while applying ultrasonic wave to the crimping member, thereby
crimping the crimped section of the crimped object.
9. The ultrasonic crimping method according to claim 8, wherein the
crimping member has a maximum thickness area that is uniform in
thickness over a predetermined length and that has a maximum
thickness to be inserted into the through hole, the maximum
thickness area being formed at the rear end, the crimped object has
a plurality of crimped sections with a plurality of through holes
formed in the crimped sections, the through holes are aligned so
that the crimping member can be inserted into the through holes
simultaneously, and the crimping member is inserted, first from the
front end thereof, into the through holes until the maximum
thickness area of the crimping member passes through the though
holes, thereby crimping the crimped sections simultaneously.
10. A method of producing an arm of a disk apparatus, the arm
including: a carriage whose front end is rotatably moved along and
above a surface of a disk in a radial direction of the disk; and a
suspension that extends from the front end of the carriage and
whose rear end is fixed to the front end of the carriage and whose
front end is provided with a head that accesses the disk, the head
being positioned so as to access the disk, the method comprising
the steps of: preparing a crimping member that is smaller toward a
front end thereof and larger toward a rear end thereof and is
displaced radially in response to application of ultrasonic wave;
aligning a first through hole formed in the front end of the
carriage with a second through hole formed in the rear end of the
suspension; and inserting the crimping member into the aligned
first and second through holes first from the front end of the
crimping member, while applying ultrasonic wave to the crimping
member, thereby crimping the suspension onto the carriage.
11. A crimped object comprising: a crimped section with a through
hole formed in the crimping section, wherein the crimped section is
crimped by inserting a crimping member into the though hole first
from a front end of the crimping member, while applying ultrasonic
wave to the crimping member, thereby crimping the crimping section,
the crimping member being in a bar shape that is smaller toward the
front end thereof and larger toward a rear end thereof and is
displaced radially in response to application of ultrasonic wave.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an ultrasonic crimping
apparatus that crimps a crimped object with a crimped section by
using ultrasonic wave, a crimping member, an ultrasonic crimping
method and an arm production method for producing an arm of a disk
apparatus.
[0003] 2. Description of the Related Art
[0004] Amid the advanced information-oriented society, the amount
of information is steadily increasing. In such circumstances,
development of a recording format and a recording apparatus of
super-high recording density is long awaited. Especially, a disk
apparatus in which information access is preformed by applying
light or a magnetic field onto a rotating disk is attracting
attention because of its information-rewritable capacity. Thus,
research and development for a larger-capacity and miniaturized
disk apparatus is vigorously conducted.
[0005] Typically, a disk apparatus has plural disks and plural
heads for performing information access to the respective disks in
order to improve recording capacity as well as speed up information
access. In such a disk apparatus, it is important to suppress
unevenness in access precision of the respective heads and thus to
make the floating quantity of the heads from the respective disks
uniform.
[0006] In a typical method of moving a head, a head is adhered onto
the front end of the respective suspensions that are each fixed to
a carriage, which is caused to rotate above and along a surface of
a disk, thereby moving the heads integrally. Japanese Patent
Laid-Open No. 2004-127491, for example, discloses the technique
that a suspension is fixed to a carriage by using an ultrasonic
horn with a bulb attached to its end.
[0007] FIG. 1 illustrates a carriage assembly and how to fix a
suspension to a carriage.
[0008] A carriage assembly 10 is composed of a carriage 11 that
rotates above and along a surface of a disk, and a suspension 12
with a head 13 adhered onto its end. Through holes 11a and 12a are
formed respectively in a front end of the carriage 11 and a rear
end of the suspension 12. Crimping of the through holes 11a and 12a
fixes the suspension 12 to the front end of the carriage 11.
Although FIG. 1 shows a single suspension, in fact, plural
suspensions are fixed to the carriage and the head 13 is adhered
onto each of the suspensions.
[0009] A crimping apparatus 20 that performs crimping to the
carriage assembly 10 is composed of an ultrasonic horn 22, a
vibrator 21 and a moving mechanism (not shown) for moving the
ultrasonic horn 22 toward the carriage assembly 10. The ultrasonic
horn 22 has a bulb 23 that is formed at its end and is larger than
the through holes 11a and 12a respectively of the carriage 11 and
suspension 12. The vibrator 21 applies ultrasonic wave to the
ultrasonic horn 22, thereby causing the ultrasonic horn 22 to
contract and expand in the longitudinal direction.
[0010] At first, the carriage 11 and the suspension 12 are held
such that the respective through holes 11a and 12a are aligned. The
bulb 23 of the ultrasonic horn 22 is then positioned to the aligned
through holes 11a and 12a. Subsequently, the vibrator 21 applies
ultrasonic wave to the ultrasonic horn 22, thereby causing the
ultrasonic horn 22 to contract and expand in the longitudinal
direction. Then, the ultrasonic horn 22 is moved toward the
carriage assembly 10 to insert the bulb 23 into the through holes
11a and 12a respectively of the carriage 11 and the suspension 12.
Consequently, the through holes 11a and 12a are crimped, thereby
fixing the suspension 12 to the carriage 11.
[0011] However, according to the technique disclosed in Japanese
Patent Laid-Open No. 2004-127491, as the bulb 23 is forcibly
inserted into the through holes 11a and 12a, the suspension 12 of a
thin plate is likely to be deformed. Accordingly, the suspension 12
may be fixed to the carriage 11 in the state of being bent with
respect to the carriage 11, leading to fluctuations in the floating
amount of the head 13 from the disk and resulting in degraded
precision of information access.
[0012] Such a problem is not limited to the case in which a
suspension with a head adhered thereon is fixed to a carriage, but
also generally applied to a crimping apparatus that crimps a
crimped object having a crimping section.
SUMMARY OF THE INVENTION
[0013] The present invention has been made in view of the above
circumstances, and provides an ultrasonic crimping apparatus, a
crimping member, an ultrasonic crimping method and an arm
production method that can securely crimp a crimped object while
suppressing deformation of the crimped object.
[0014] An ultrasonic crimping apparatus according to the invention
has:
[0015] a supporting section that supports a crimped object having a
crimped section with a through hole formed in the crimped
section;
[0016] a crimping member in a bar shape that is smaller toward a
front end thereof and larger toward a rear end thereof;
[0017] a driving section that causes the crimping member to be
inserted in the through hole of the crimped object supported by the
supporting section, first from the front end of the crimping
member;
[0018] an ultrasonic application section that applies ultrasonic
wave to the crimping member, thereby causing radial displacement of
the crimping member; and
[0019] a crimping control section that causes the crimping member
to be inserted into the through hole of the crimped object, while
causing application of ultrasonic wave to the crimping member,
thereby causing the crimped section of the crimped object to be
crimped.
[0020] According to the ultrasonic crimping apparatus of the
invention, the crimping member is inserted into the through hole of
the crimped object, first from the smaller front end than the rear
end, while being displaced radially. Accordingly, the through hole
of the object is gradually enlarged radially, which prevents
deformation of the crimped object.
[0021] In the ultrasonic crimping apparatus according to the
invention, the supporting section may support a crimped object
having a plurality of crimped sections with a plurality of through
holes formed in the crimped sections such that the through holes
are aligned to enable the crimping member to be inserted into the
through holes simultaneously, and
[0022] the crimping control section causes the crimping member to
be inserted into the through holes, while causing application of
ultrasonic wave to the crimping member, thereby causing the crimped
sections to be crimped simultaneously.
[0023] The above feature of the ultrasonic crimping apparatus
enables precise and efficient crimping of plural crimped
sections.
[0024] Additionally, the crimping member may have a maximum
thickness area that is uniform in thickness over a predetermined
length and that has a maximum thickness to be inserted into the
through holes, and
the crimping control section causes the driving section to make the
crimping member inserted into the through holes until the maximum
thickness area of the crimping member is inserted through the
through holes.
[0025] Crimping the plural crimped sections finally at the maximum
thickness area that has uniform maximum thickness suppresses
fluctuations in crimped state among the crimped sections.
[0026] Preferably, the crimping member has a first section and a
second section that are formed alternatively in the crimping member
in a longitudinal direction, when ultrasonic wave is applied to the
crimping member, the first section having minimum radial
displacement of the crimping member, the second section having
maximum radial displacement of the crimping member and further
having a uniform thickness area where thickness of the crimping
member is uniform over a predetermined length.
[0027] As the uniform thickness area is formed in the side section
of the maximum radial displacement, the crimped section is
efficiently crimped.
[0028] Additionally, a crimping member according to the invention
crimps a crimped object having a crimped section with a through
hole formed in the crimping section, and is inserted through the
through hole and thereby crimps the crimped section, wherein:
[0029] the crimping member is in a bar shape that is smaller toward
a front end thereof and larger toward a rear end thereof; and
the crimping member has an ultrasonic vibrator that is disposed at
the rear end of the crimping member and that vibrates in response
to application of a voltage of a frequency equal to ultrasonic
wave.
[0030] Gradual crimping of the crimped object prevents deformation
of the crimped object.
[0031] The crimping member according to the invention may have a
maximum thickness area that is uniform in thickness over a
predetermined length and that has a maximum thickness to be
inserted into the through hole, the maximum thickness area being
formed at the rear end of the crimping member.
[0032] As the maximum thickness area is formed at the rear end of
the crimping member, it is possible to evenly perform precise
crimping to the crimped object with the plural through holes.
[0033] Preferably, the crimping member has a first section and a
second section that are alternatively formed in the crimping member
in the longitudinal direction, when ultrasonic wave is applied to
the crimping member, the first section having minimum radial
displacement of the crimping section, the second section having
maximum radial displacement of the crimping section and further
having a uniform thickness area where thickness of the crimping
member is uniform over a predetermined length.
[0034] Provision of the uniform thickness area in the second
section enables efficient crimping of the crimped object.
[0035] An ultrasonic crimping method according to the invention has
the steps of:
[0036] preparing a crimping member in a bar shape that is smaller
toward a front end thereof and larger toward a rear end thereof and
is displaced radially in response to application of ultrasonic
wave; and
inserting the crimping member, first from the front end thereof,
into a though hole formed in a crimped section of a crimped object
while applying ultrasonic wave to the crimping member, thereby
crimping the crimped section of the crimped object.
[0037] The ultrasonic crimping method of the invention prevents
deformation of the crimped object, thereby performing precise
crimping of the crimped object.
[0038] Further, in the ultrasonic crimping method, the crimping
member may have a maximum thickness area that is uniform in
thickness over a predetermined length and that has a maximum
thickness to be inserted into the through hole, the maximum
thickness area being formed at the rear end, the crimped object has
a plurality of crimped sections with a plurality of through holes
formed in the crimped sections, the through holes are aligned so
that the crimping member can be inserted into the through holes
simultaneously, and the crimping member is inserted, first from the
front end thereof, into the through holes until the maximum
thickness area of the crimping member passes through the though
holes, thereby crimping the crimped sections simultaneously.
[0039] The above method enables precise crimping of the crimped
object even with plural through holes formed therein.
[0040] A method of producing an arm of a disk apparatus according
to the invention, the arm including: a carriage whose front end is
rotatably moved along and above a surface of a disk in a radial
direction of the disk; and a suspension that extends from the front
end of the carriage and whose rear end is fixed to the front end of
the carriage and whose front end is provided with a head that
accesses the disk, the head being positioned so as to access the
disk, the method including the steps of:
[0041] preparing a crimping member that is smaller toward a front
end thereof and larger toward a rear end thereof and is displaced
radially in response to application of ultrasonic wave;
[0042] aligning a first through hole formed in the front end of the
carriage with a second through hole formed in the rear end of the
suspension; and
inserting the crimping member into the aligned first and second
through holes first from the front end of the crimping member,
while applying ultrasonic wave to the crimping member, thereby
crimping the suspension onto the carriage.
[0043] In manufacturing a disk apparatus, it is required to fix a
suspension with a head formed at the front end thereof accurately
to the front end of the carriage. According to the arm production
method of the invention, it is possible to prevent deformation of
the suspension, thereby securely fixing the suspension to the
carriage. Therefore, a disk apparatus in which the arm production
method of the invention is applied can accurately access a
disk.
[0044] Incidentally, the arm production method described above is
of only the basic mode in order to avoid redundancy. However, the
arm production method is not limited to the above description, but
can be applied to various modes corresponding to the modes of the
ultrasonic crimping apparatus.
[0045] Additionally, a crimped object according to the invention
including:
[0046] a crimped section with a through hole formed in the crimping
section,
[0047] wherein the crimped section is crimped by inserting a
crimping member into the though hole first from a front end of the
crimping member, while applying ultrasonic wave to the crimping
member, thereby crimping the crimping section, the crimping member
being in a bar shape that is smaller toward the front end thereof
and larger toward a rear end thereof and is displaced radially in
response to application of ultrasonic wave.
[0048] As mentioned above, the present invention prevents
deformation of the crimped object and enables secure crimping of
the crimped object.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] FIG. 1 illustrates how to fix a suspension to a
carriage.
[0050] FIG. 2 shows a hard disk apparatus manufactured by applying
one embodiment of the present invention.
[0051] FIG. 3 is an exploded perspective view of a carriage and a
suspension.
[0052] FIG. 4 is a side view of the suspension and the
carriage.
[0053] FIG. 5 is a schematic diagram of an ultrasonic crimping
apparatus of the embodiment.
[0054] FIG. 6 is a graph showing amplitudes of an ultrasonic horn
of the embodiment.
[0055] FIG. 7 shows the analysis result of radial displacement in
the ultrasonic horn.
[0056] FIG. 8 illustrates a principle of crimping processing by
using the ultrasonic horn.
[0057] FIG. 9 is a schematic view illustrating a part of the front
end of an ultrasonic horn of a second embodiment.
[0058] FIG. 10 illustrates crimping processing using the ultrasonic
horn of the second embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0059] Embodiments of the present invention will be described below
with reference to the attached drawings.
[0060] FIG. 2 shows a hard disk apparatus 100 manufactured by
applying one embodiment of the present invention.
[0061] The hard disk apparatus 100 shown in FIG. 2 is used by being
connected to or incorporated in a host apparatus typified by a
personal computer.
[0062] A housing 101 of the hard disk apparatus 100 accommodates: a
magnetic disk 200 for recording information therein; a spindle
motor 110 for rotating the magnetic disk 200; a magnetic head 120
(see FIG. 4) for approaching and facing a surface of the magnetic
disk 200; a carriage assembly 130 that has the magnetic head 120
adhered onto the front end thereof and moves above and along the
surface of the magnetic disk 200 around an arm shaft 131 thereof; a
voice coil motor 140 for driving the carriage assembly 130; and a
control circuit 150 for controlling the operation of the hard disk
apparatus 100. The hard disk apparatus 100 serves for recording
information to and reading information from the magnetic disk 200
by using the magnetic field of the magnetic head 120.
[0063] The magnetic disk 200 has linear trucks formed on the
surface thereof which are divided into plural sectors along the
circumferential direction of the trucks. In the hard disk apparatus
100, a series of logic addresses are assigned to the respective
sectors.
[0064] The carriage assembly 130 further has a carriage 132 driven
by the voice coil motor 140 and a suspension 133 with the magnetic
head 120 adhered onto the front end thereof. The carriage 132 and
the suspension 133 are connected to each other at a joining section
134.
[0065] Incidentally, the hard disk apparatus 100 is mounted with
plural magnetic disks 200, front and back surfaces of which are
each accessed by the respective magnetic heads 120. In other words,
the hard disk apparatus 100 has the plural suspensions 133 which
each have the magnetic head 120 attached to the front end thereof
and assigned to each of the front and back surfaces of the magnetic
disks 200. The plural suspensions 133 are connected to the carriage
132, so that the plural magnetic heads 120 are moved
integrally.
[0066] In writing information to the magnetic disk 200, a host
apparatus (not shown) sends to the hard disk apparatus 100
information to be recorded in the magnetic disk 200 together with a
logic address for a writing position. The logic address is
converted by the control circuit 150 into a physical address
constituted by: a cylinder number representing which truck of the
plural trucks on the magnetic disk 200 is a target; a head number
representing which magnetic head of the plural magnetic heads is a
target; and a sector number representing which sector of the plural
sectors on the trucks is a target. The control circuit 150 also
drives the spindle motor 110 to rotate the magnetic disk 200 as
well as the voice coil motor 140 to move the carriage 132 to a
position above the truck represented by the cylinder number of the
physical address. The magnetic head 120 is moved, relative to the
rotating magnetic disk 200, to a position above the sector
represented by the sector number of the physical address, so that
the magnetic head 120 is positioned above the magnetic disk
200.
[0067] In addition to positioning of the magnetic head 120, the
control circuit 150 applies electric current carrying write
information to the magnetic head 120 represented by the head number
of the physical address.
[0068] The magnetic field in accordance with the electric current
is generated by a coil provided in the magnetic head 120. The
magnetic flux in accordance with the magnetic field is directed to
the magnetic disk 200, so that the magnetization of the direction
according to the write information can be formed on the magnetic
disk 200 and the write information is recorded in the magnetic disk
200.
[0069] In reading information recorded in the magnetic disk 200,
the host apparatus (not shown) sends to the hard disk apparatus 100
a logic address of a recording position where information is
recorded. Subsequently, the control circuit 150, as in writing
information, drives the spindle motor 110 to rotate the magnetic
disk 200 and the voice coil motor 140 to move the carriage 132, so
that the magnetic head 120 is positioned above the magnetic disk
200.
[0070] The reproduction signal in accordance with the magnetic
field generated by magnetization is produced and is converted into
digital data to be sent to the host apparatus via the control
circuit 150.
[0071] Based on the above mentioned mechanism, information access
is performed with respect to the magnetic disk 200.
[0072] It should be noted that a distance (i.e., the floating
quantity) between the respective magnetic disks 200 and the
respective magnetic heads 120 should be controlled so as to be
uniform for obtaining accurate access of the magnetic head 120 to
the magnetic disk 200. For this reason, the respective suspensions
133 are required to be fixed precisely to the carriage 132.
[0073] Hereafter, detailed explanation will be made on how to fix
the suspension 133 to the carriage 132.
[0074] FIG. 3 is an exploded perspective view of the carriage 132
and the suspension 133.
[0075] As shown in FIG. 3, the carriage 132 is constituted by: the
arm shaft 131; a trunk section 1321 extending from the arm shaft
131; and a stem section 1322 branching from the trunk section 1321.
The ends of the stem section each have a joining section 134B that
the suspension 133 is connected to and has a through hole 132a
formed therein.
[0076] Meanwhile, the suspension 133 has a joining section 134A
that is connected to the carriage 132 and has a through hole 133a
formed therein. A ridge 135 is formed around the circumference of
the through hole 133a.
[0077] In assembling the carriage 132 and the suspension 133, the
magnetic head 120 is first adhered onto the front end of the
respective suspensions 133, followed by insertion of the ridge 135
of the suspension 133 into the hole 132a of the carriage 132.
According to the example shown in FIG. 3, the six suspensions 133
are fixed to the carriage 132 in the following manner: the first
suspension is inserted so as to be disposed under the top level of
the stem section 1322; the second two suspensions are inserted such
that they sandwich the second level of the stem section 1322; the
third two suspensions are inserted such that they sandwich the
third level of the stem section 1322; and the last suspension is
inserted so as to be disposed on the bottom level of the stem
section 1322.
[0078] FIG. 4 is a side view of the suspension 133 and the carriage
132.
[0079] As shown in FIG. 4, the plural suspensions 133 are connected
to the carriage 132 such that the magnetic heads 120 face one
another. Further, the ridge 135 of the suspension 133 is formed
such that the circumference of the ridge 135 and the through hole
132a of the carriage match. FIG. 4 shows the state where the
suspension 133 is temporarily fixed to the carriage 132 by
positioning the through hole 133a on the through hole 132a.
[0080] Subsequently, the suspension 133 and the carriage 132 are
supported by an ultrasonic crimping apparatus 300 for crimping the
through holes 133a onto 132a.
[0081] FIG. 5 is a schematic diagram of the ultrasonic crimping
apparatus 500 of the embodiment.
[0082] The ultrasonic crimping apparatus 300 is constituted by: a
supporting section 310 for supporting the carriage 132; a motor 320
for driving and rotating a pole screw 330; the screw 330 rotated by
the motor 320; a transmission section 340 for changing rotation of
the screw 330 to linear movement and transmitting the linear
movement to an ultrasonic horn 350; the ultrasonic horn 350 to be
vibrated by application of ultrasonic wave; a vibrator 360 for
applying ultrasonic wave to the ultrasonic horn 350 in the
longitudinal direction; an oscillator 370 for oscillating the
vibrator 360; and a control section 380 for controlling a whole of
the ultrasonic crimping apparatus 300. The supporting section 310
corresponds to an example of the supporting section of the
invention, while the ultrasonic horn 350 corresponds to an example
of the crimping member of the invention. In addition, the vibrator
360 corresponds to an example of the ultrasonic application section
and the ultrasonic vibrator of the invention. Further, a
combination of the motor 320, the screw 330 and the transmission
section 340 corresponds to an example of the driving section of the
invention, while the control section 380 corresponds to the
crimping control section of the invention.
[0083] The ultrasonic horn 350 in a tapered bar shape, which is
larger toward its rear end and smaller toward its front end, is
attached so as to face the supporting section 310.
[0084] Now, explanation of FIG. 5 is temporarily stopped for
describing vibration of the ultrasonic horn 350.
[0085] FIG. 6 is a graph showing amplitudes of the ultrasonic horn
350.
[0086] The abscissa in the graph shown in FIG. 6 is associated with
a distance from the root of the ultrasonic horn 350, while the
ordinate is associated with an amplitude of the ultrasonic horn
350. The amplitude in vibration direction (in the longitudinal
direction of the ultrasonic horn 350) is plotted with white dots,
while the radial amplitude is plotted with black dots.
[0087] As the ultrasonic horn 350 is gradually tapered, application
of ultrasonic wave to the ultrasonic horn 350 in the longitudinal
direction causes the ultrasonic horn 350 to contract and extend in
vibration direction as well as displace in radial direction even
though the displacement amount is approximately as small as
one-tenth of the amount of the amplitude in the vibration
direction. Further, sections of minimum displacement and sections
of maximum displacement are formed alternatively in the ultrasonic
horn 350 in the longitudinal direction (see FIG. 7).
[0088] FIG. 7 shows an analysis result of radial displacement in
the ultrasonic horn 350.
[0089] Closely hatched portions indicate vibration with large
radial amplitude. The darker the hatched portion is, the larger the
radial amplitude is. In the longitudinal direction, there are
formed in the ultrasonic horn 350 three side portions P1, P2 and P3
of maximum displacement in radial direction.
[0090] FIG. 8 illustrates a principle of crimping processing by
using the ultrasonic horn 350.
[0091] As shown in FIG. 8A, insertion of the front end of the
ultrasonic horn 350 into a through hole H and application of the
ultrasonic wave to the ultrasonic horn 350 in the longitudinal
direction causes the front end of the ultrasonic horn 350 to
displace also in the radial direction, which pushes and enlarges
the through hole H.
[0092] Subsequently, the ultrasonic horn 350 is further moved into
the through hole H up to a position where the thickness of the
through hole H and that of the ultrasonic horn 350 match. Then, the
though hole H is further pushed and enlarged by radial displacement
of an approximately middle portion of the ultrasonic horn 350.
[0093] Then, the ultrasonic horn 350 is further inserted into the
though hole H up to the root portion thereof which is the largest
portion of the ultrasonic horn 350, where the through hole H is
further pushed and enlarged by radial displacement of the root
portion.
[0094] In this way, the ultrasonic horn 350 gradually pushes and
enlarges the though hole H in radial direction.
[0095] Now, description will continue referring back to FIG. 5.
[0096] In fixing the suspension 133 to the carriage 132, the
carriage 132 to which the suspension 133 is temporarily fixed is
first supported by the supporting section 310, and then the front
end of the ultrasonic horn 350 is positioned in a position where
the through holes 133a and 132a respectively of the suspension 133
and the carriage 132 face each other.
[0097] After positioning of the ultrasonic horn 350, the control
section 380 gives instruction to drive the motor 320 and the
oscillator 370.
[0098] Driving of the motor 320 and rotation of the screw 330
causes the ultrasonic horn 350 to be moved toward the suspension
133 and the carriage 132 by the transmission section 340, and then
the front end of the ultrasonic horn 350 to be inserted into the
though holes 132a and 133a.
[0099] Subsequently, the oscillator 370 oscillates the vibrator
360, which applies ultrasonic wave to the ultrasonic horn 350.
[0100] The application of ultrasonic wave to the ultrasonic horn
350 causes radial displacement of the front end of the ultrasonic
horn 350, which pushes and enlarges the through holes 132a and 133a
and causes the ridge 135 of the suspension 133 to be bent outward,
so that the suspension 133 is fixed onto the carriage 132.
[0101] Subsequently, the ultrasonic horn 350 is further inserted
into the through holes 132a and 133a up to a position where the
thickness of the ultrasonic horn 350 and that of the enlarged
through holes 132a, 133a match. Crimping is further secured by
radial displacement of an approximately middle portion of the
ultrasonic horn 350.
[0102] Further, the ultrasonic horn 350 is inserted into the
through holes 132a, 133a up to the largest root portion of the
ultrasonic horn 350, where fixing is strengthened by radial
displacement in the largest root portion.
[0103] As described above, according to the embodiment, the though
holes 132a and 133a respectively of the carriage 132 and the
suspension 133 are pushed and enlarged by radial displacement of
the ultrasonic horn 350, by gradually inserting the ultrasonic horn
350, from the smaller portion to the larger portion thereof, into
the through holes 132a and 133a according to the enlarged thickness
of the through holes 132a and 133a. Such gradual insertion of the
ultrasonic horn 350 prevents deformation of the suspension in a
thin plate, and thereby enables the uniform floating amount of the
plural magnetic heads 120 from the respective magnetic disks
200.
[0104] Up to this point the description of the first embodiment has
been given. Hereafter a description will be given of a second
embodiment of the invention. The second embodiment is similar to
the first embodiment except the shape of an ultrasonic horn. Thus,
to avoid redundancy, only characteristic points of the second
embodiment will be described below. In the following description,
components having the same functions as those of the
above-described components are denoted by the same reference
characters.
[0105] As shown in FIG. 7, in the ultrasonic horn 350 according to
the first embodiment, sections of minimum displacement is minimized
and sections of maximum displacement are formed alternatively in
the longitudinal direction. According to the second embodiment,
crimping processing is performed in the sections of maximized
displacement.
[0106] FIG. 9 is a schematic view illustrating a part of the front
end of an ultrasonic horn 400.
[0107] In the ultrasonic horn 400 according to the second
embodiment, uniform thickness areas 410, 420, and 430, whose
thickness are respectively uniform over a certain length, are
formed in the positions corresponding to P1, P2 and P3 side
portions according to the first embodiment shown in FIG. 7. The
uniform thickness areas 410, 420 and 430 correspond to an example
of the uniform thickness area of the invention.
[0108] FIG. 10 illustrates crimping processing using the ultrasonic
horn 400.
[0109] As shown in FIG. 10, the ultrasonic horn 400 is constituted
by: a tapered portion 401 which is smaller toward the front end and
larger toward the rear end; and a fixed thickness area 402 of the
fixed thickness. The tapered portion 401 further has the uniform
thickness areas 410, 420 and 430 formed therein.
[0110] As shown in FIG. 3, the ends of the stem section 1322 are
branched from the carriage 132, and the respective ends of the stem
section 1322 are mated with suspensions 133. Accordingly, the
carriage 132 fixed to the suspensions 133 is supported by the
supporting section 310 shown in FIG. 5, such that the plural
through holes 132a formed in the ends of the stem section 1322 are
aligned with the plural through holes 133a of the suspensions
133.
[0111] The plural through holes 132a, 133a of the carriage 132 and
suspensions 133 are crimped first in the tapered portion 401,
sequentially in the order of the uniform thickness areas 410,420
and 430. Lastly, in the fixed thickness area 402 at the root of the
ultrasonic horn 400, the plural through holes 132a of the carriage
132 and the plural through holes 133a of the suspensions 133 are
crimped simultaneously.
[0112] Provision of such uniform thickness areas 410, 420 and 430
in the ultrasonic horn 400 enables efficient and uniform crimping
of the plural through holes 133a and 132a of the suspensions 133
and the carriage 132. Additionally, simultaneous and final crimping
of the plural through holes 132a and 133a can suppress fluctuations
in crimped status.
[0113] It should be noted that the above description is not limited
to production of a carriage assembly (arm) of a magnetic disk
apparatus, but also employed, for example, to production of an arm
for a magneto-optical disk.
* * * * *