U.S. patent application number 09/735628 was filed with the patent office on 2001-06-21 for working fluid, working process using the working fluid, and method of production of the working fluid.
Invention is credited to Enomoto, Toshiyuki, Etoh, Kei, Tani, Yasuhiro.
Application Number | 20010004631 09/735628 |
Document ID | / |
Family ID | 18434261 |
Filed Date | 2001-06-21 |
United States Patent
Application |
20010004631 |
Kind Code |
A1 |
Enomoto, Toshiyuki ; et
al. |
June 21, 2001 |
Working fluid, working process using the working fluid, and method
of production of the working fluid
Abstract
A working fluid according to the invention is supplied to a
working point where a working of a workpiece is performed with the
working fluid. The working fluid contains a solvent and
microcapsules filled with liquid-state substances, the
microcapsules being dispersed in the solvent. A working process
according to the invention performs a working of a workpiece with
the working fluid, the working fluid containing the solvent and the
microcapsules filled with the liquid-state substances, the
microcapsules being dispersed in the solvent. In the working
process according to the invention, the working fluid is supplied
to a working point of the workpiece. The working of the workpiece
is performed at the working point with the working fluid supplied
to the working point. Further, in a method of production according
to the invention, microcapsules that are filled with liquid-state
substances are produced by performing a selected process, and the
microcapsules and a solvent are mixed so that the microcapsules are
dispersed in the solvent to form the working fluid.
Inventors: |
Enomoto, Toshiyuki; (Tokyo,
JP) ; Tani, Yasuhiro; (Tokyo, JP) ; Etoh,
Kei; (Tokyo, JP) |
Correspondence
Address: |
OBLON SPIVAK MCCLELLAND MAIER & NEUSTADT PC
FOURTH FLOOR
1755 JEFFERSON DAVIS HIGHWAY
ARLINGTON
VA
22202
US
|
Family ID: |
18434261 |
Appl. No.: |
09/735628 |
Filed: |
December 14, 2000 |
Current U.S.
Class: |
508/110 ; 451/36;
451/41; 51/293; 51/306 |
Current CPC
Class: |
B24B 37/04 20130101;
C10M 171/06 20130101 |
Class at
Publication: |
508/110 ; 51/306;
51/293; 451/41; 451/36 |
International
Class: |
C10M 101/00; B24B
001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 17, 1999 |
JP |
11-353942 |
Claims
What is claimed is:
1. A working fluid which is supplied to a working point where a
working of a workpiece is performed with the working fluid,
comprising: a solvent; and microcapsules filled with liquid-state
substances, said microcapsules being dispersed in the solvent.
2. The working fluid of claim 1, wherein said microcapsules have an
average particle size ranging from 0.1 .mu.m to 1000 .mu.m.
3. A working process which performs a working of a workpiece with a
working fluid, the working fluid containing a solvent and
microcapsules filled with liquid-state substances, the
microcapsules being dispersed in the solvent, comprising the steps
of: supplying the working fluid to a working point of the
workpiece; and performing a cutting process of the workpiece at the
working point while supplying the working fluid to the working
point.
4. A working process which performs a working of a workpiece with a
working fluid, the working fluid containing a solvent and
microcapsules filled with liquid-state substances, the
microcapsules being dispersed in the solvent, comprising the steps
of: supplying the working fluid to a working point of the
workpiece; and performing a grinding process of the workpiece at
the working point while supplying the working fluid to the working
point.
5. A working process which performs a working of a workpiece with a
working fluid, the working fluid containing a solvent and
microcapsules filled with liquid-state substances, the
microcapsules being dispersed in the solvent, comprising the steps
of: forming a mixture of the working fluid and abrasive particles;
supplying the mixture of the working fluid and the abrasive
particles to a working point of the workpiece; and performing a
polishing process of the workpiece at the working point while
supplying the mixture to the working point.
6. A working process which performs a working of a workpiece with a
working fluid, the working fluid containing a solvent and
microcapsules filled with liquid-state substances, the
microcapsules being dispersed in the solvent, comprising the steps
of: supplying the working fluid to a working point of the
workpiece; and performing a plastic deformation process of the
workpiece at the working point while supplying the working fluid to
the working point.
7. A method of production of a working fluid which is supplied to a
working point where a working of a workpiece is performed with the
working fluid, comprising the steps of: producing microcapsules
that are filled with liquid-state substances; and mixing the
microcapsules and a solvent so that the microcapsules are dispersed
in the solvent to form the working fluid, wherein, in said
producing step, a process, which is selected from the group
including at least a surface polymerization process, an "in situ"
polymerization process, a coacervation process, an immersion
hardening/coating process and an immersion drying process, is
performed to produce the microcapsules filled with the liquid-state
substances.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a working fluid which is
supplied to a working point where a working of a workpiece is
performed with the working fluid, a working process which performs
the working of a workpiece by using the working fluid supplied to
the working point, and a method of production which produces the
working fluid.
[0003] 2. Description of the Related Art
[0004] In conventional metalworking processes, working fluids
fulfill basically four major functions: lubrication, cooling,
cleaning or chemical effects, and chip removal. In the majority of
working fluids it is essential that a working fluid be supplied to
the working point.
[0005] In recent years, there is an increasing demand for
environmental protection in the field of metalworking as well. It
is desirable to reduce as much as possible the amount of the
working fluid needed to perform the metalworking of the workpiece.
The reduction of the working fluid amount to the desired level is
attributable to reduction of the cost of manufacture including the
processing of liquid waste. Developments of many working fluids are
directed to achieving environmental protection by using the working
fluid materials including harmless components that are not harmful
to the environment as well as the workers. See Japanese journal
"Machines And Tools", September 1997, pp.31-34, and Japanese
journal "Mechanical Technology", May 1999, pp.43-46.
[0006] As to the reduction of the working fluid amount to the
desired level, some improvements of the working fluids or the
working processes have been proposed. For example, some improved
working fluid is aimed at achieving excellent cooling effects on
the workpiece while supplying a small amount of the working fluid
to the working point.
[0007] Additionally, as disclosed in Japanese Patent Application
No.3-290958 and Japanese Laid-Open Patent Application No.5-329742,
a foam-state machining fluid that can reduce the amount of the
working fluid to such a desired level needed to perform the
machining of a workpiece is known. Even if a small amount of the
foam-state machining fluid is supplied to the working point where
the machining of the workpiece is performed, the foam-state
machining fluid can stay at the working point for a relatively long
time during the machining. It is possible to achieve good cooling
and lubrication effects on the workpiece even when a small amount
of the foam-state working fluid is supplied to the working
point.
[0008] However, in the case of the foam-state working fluid of the
above-mentioned documents, it is difficult that the foam-state
working fluid enters the working point of a workpiece the working
of which is performed under extremely high pressure. Hence, when
the working point is under extremely high pressure, the foam-state
working fluid is inappropriate for the working of the
workpiece.
[0009] Further, some working-fluid manufacturer has marketed an
emulsion-state working fluid which is aimed at reducing the working
fluid amount to the desired level. It is made certain that the
emulsion-state working fluid is more appropriate for the working of
the workpiece while reducing the working fluid amount to the
desired level, for at least the following reason.
[0010] Generally, oil-based fluids can provide better lubrication
effects on the workpiece than water-based fluids. The oil-based
working fluids are effective in providing good lubrication effects
on the workpiece. However, the oil-based working fluids have a
relatively high viscosity as compared with that of water-based
working fluids. When the working point is subjected to extremely
high pressure, it is difficult that the oil-based working fluids
enter the working point of the workpiece under extremely high
pressure because of the high viscosity thereof.
[0011] On the other hand, in the emulsion-state working fluid, the
oil is dispersed in water with the aid of a surface-active
substance, and the viscosity of the emulsion-state working fluid is
apparently decreased from the level of viscosity of the
non-emulsion-state working fluid. Because of the decreased
viscosity, the emulsion-state working fluid can easily enter the
working point of the workpiece. From this standpoint, the
emulsion-state working fluid appears to be appropriate for
performing the working of the workpiece under extremely high
pressure.
[0012] Further, even if a small amount of the emulsion-state
working fluid is supplied to the working point where the working of
the workpiece is performed, the emulsion-state working fluid can
stay at the working point for a relatively long time during the
working. The emulsion-state working fluid appears to be effective
in providing good cooling and lubrication effects on the workpiece
even when a small amount of the emulsion-state working fluid is
supplied to the working point.
[0013] However, the emulsion state of a conventional emulsion-state
working fluid is quickly collapsed due to the working pressure at
the working point or others after it is supplied to the working
point. Further, in the case of the metalworking of a metal
workpiece, the surface-active substance of the emulsion-state
working fluid reacts with the metal ions of the workpiece surface,
and the emulsion state of the working fluid is quickly collapsed or
deteriorated by the reaction. Because of the reaction of the
surface-active substance and the metal ions or the working
pressure, the time the emulsion state of the working fluid is held
is shortened, which will be detrimental to achieving good
lubrication and cooling of the workpiece.
[0014] Additionally, when the working fluid from the working point
is circulated in the working machine in order to reuse the working
fluid for the working of the workpiece, the emulsion state of the
working fluid is likely to be deteriorated during the circulation.
Further, when the oil-based working fluid is dispersed in
water-based (aqueous) solvent with the aid of the surface-active
agent, nitrogen-based or chlorine-based surface-active agents are
often used. However, in order to meet the demand for environmental
protection, it is desirable to reduce as much as possible the
amount of nitrogen or chlorine contained in the surface-active
agents, used to provide the emulsion-state working fluid.
SUMMARY OF THE INVENTION
[0015] An object of the present invention is to provide an improved
working fluid which can appropriately eliminate the collapsing of
the emulsion state due to the working pressure or the deterioration
of the emulsion state due to the circulation of the working fluid,
and is effective in providing good cooling and lubrication effects
on the workpiece even when a small amount of the working fluid is
supplied to the working point.
[0016] Another object of the present invention is to provide a
working process which performs the working of a workpiece by using
a working fluid, the working fluid appropriately eliminating the
collapsing of the emulsion state due to the working pressure or the
deterioration of the emulsion state due to the circulation of the
working fluid, and being effective in providing good cooling and
lubrication effects on the workpiece even when a small amount of
the working fluid is supplied to the working point.
[0017] Another object of the present invention is to provide a
method of production of a working fluid which can appropriately
eliminate the collapsing of the emulsion state due to the working
pressure or the deterioration of the emulsion state due to the
circulation of the working fluid, and is effective in providing
good cooling and lubrication effects on the workpiece even when a
small amount of the working fluid is supplied to the working
point.
[0018] According to one preferred embodiment of the invention, a
working fluid, which is supplied to a working point where a working
of a workpiece is performed with the working fluid, contains a
solvent, and microcapsules filled with liquid-state substances, the
microcapsules being dispersed in the solvent.
[0019] According to another preferred embodiment of the invention,
a working process performs a working of a workpiece with a working
fluid, the working fluid containing a solvent and microcapsules
filled with liquid-state substances, the microcapsules being
dispersed in the solvent, the working process including the steps
of: supplying the working fluid to a working point of the
workpiece; and performing a cutting process of the workpiece at the
working point while supplying the working fluid to the working
point.
[0020] According to another preferred embodiment of the invention,
a working process performs a working of a workpiece with a working
fluid, the working fluid containing a solvent and microcapsules
filled with liquid-state substances, the microcapsules being
dispersed in the solvent, the working process including the steps
of: supplying the working fluid to a working point of the
workpiece; and performing a grinding process of the workpiece at
the working point while supplying the working fluid to the working
point.
[0021] According to another preferred embodiment of the present
invention, a working process performs a working of a workpiece with
a working fluid, the working fluid containing a solvent and
microcapsules filled with liquid-state substances, the
microcapsules being dispersed in the solvent, the working process
including the steps of: forming a mixture of the working fluid and
abrasive particles; supplying the mixture of the working fluid and
the abrasive particles to a working point of the workpiece; and
performing a polishing process of the workpiece at the working
point while supplying the mixture to the working point.
[0022] According to another preferred embodiment of the invention,
a working process performs a working of a workpiece with a working
fluid, the working fluid containing a solvent and microcapsules
filled with liquid-state substances, the microcapsules being
dispersed in the solvent, the working process including the steps
of: supplying the working fluid to a working point of the
workpiece; and performing a plastic deformation process of the
workpiece at the working point while supplying the working fluid to
the working point.
[0023] According to another preferred embodiment of the invention,
a method of production of a working fluid which is supplied to a
working point where a working of a workpiece is performed with the
working fluid, the method of production including the steps of:
producing microcapsules that are filled with liquid-state
substances; and mixing the microcapsules and a solvent so that the
microcapsules are dispersed in the solvent to form the working
fluid, wherein, in the producing step, a process, which is selected
from the group including at least a surface polymerization process,
an "in situ" polymerization process, a coacervation process, an
immersion hardening/coating process and an immersion drying
process, is performed to produce the microcapsules filled with the
liquid-state substances.
[0024] In the above preferred embodiments of the invention, the
working fluid contains the solvent and the microcapsules filled
with the liquid-state substances, the microcapsules being dispersed
in the solvent. Hence, the working fluid and the working process of
the present invention are effective in providing good cooling and
lubrication effects on the workpiece even when a small amount of
the working fluid is supplied to the working point. The abrupt
collapsing of the emulsion state due to the working pressure or the
deterioration of the emulsion state due to the circulation of the
working fluid, as in the conventional emulsion-state working fluid,
can be appropriately eliminated.
[0025] Further, the method of production of the above preferred
embodiment can provide the working fluid that is effective in
providing good cooling and lubrication effects on the workpiece
even when a small amount of the working fluid is supplied to the
working point.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Other objects, features and advantages of the present
invention will be apparent from the following detailed description
when read in conjunction with the accompanying drawings in
which:
[0027] FIG. 1 is a diagram for explaining a cutting process in
which the working process of the invention is embodied.
[0028] FIG. 2 is a diagram of a working fluid application device
which is used to supply the working fluid of the invention to the
working point.
[0029] FIG. 3 is a diagram for explaining a plastic working process
in which the working process of the invention is embodied.
[0030] FIG. 4 is a diagram for explaining a grinding process in
which the working process of the invention is embodied.
[0031] FIG. 5 is a diagram for explaining a polishing process in
which the working process of the invention is embodied.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0032] A description will now be provided of preferred embodiments
of the present invention with reference to the accompanying
drawings.
[0033] The working fluid according to the present invention is
supplied to a working point where a working of a workpiece is
performed with the working fluid. The working fluid according to
the present invention contains a solvent and microcapsules filled
with liquid-state substances, the microcapsules being dispersed in
the solvent. The liquid-state substances in the microcapsules of
the working fluid provide lubrication, cooling and cleaning effects
on the workpiece when performing the working of the workpiece.
[0034] The working process according to the present invention is
provided to perform a working of a workpiece with the working fluid
being supplied to the working point. Further, the method of
production according to the present invention is provided to
produce the working fluid from source materials.
[0035] Next, a description will be provided of one preferred
embodiment of the method of production of the working fluid
according to the present invention.
[0036] The method of production of the present embodiment generally
includes a producing step and a mixing step. In the producing step,
microcapsules that are filled with liquid-state substances are
produced. The microcapsules have a predetermined average particle
size. In the mixing step, the microcapsules and a solvent are mixed
in a given ratio so that the microcapsules are dispersed in the
solvent to form the working fluid. The liquid-state substances in
the microcapsules of the working fluid may include not only normal
machining fluids (for example, lubricants) but also cleaning or
chemical-effect liquids (for example, etchants).
[0037] In the producing step of the above production method, any
suitable process, which is selected from the group including at
least a surface polymerization process, an "in situ" polymerization
process, a coacervation process, an immersion hardening/coating
process and an immersion drying process, is performed to produce
the microcapsules that are filled with the liquid-state substances
(lubricants or etchants).
[0038] When the surface polymerization process or the "in situ"
polymerization process is performed as the selected process, the
mixing step is performed by adjusting the mixing speed so as to
create the emulsion state in which the microcapsules are dispersed
in the solvent, and to allow the microcapsules to have an average
particle size ranging from 0.1 .mu.m to 1000 .mu.m.
[0039] As to the materials of the microcapsule walls, when the "in
situ" polymerization process is performed as the selected process,
an appropriate catalyst for the polymerization is supplied from the
outer layer of the microcapsule core substances so that the
microcapsule walls of a melamine resin or the like are formed
thereon.
[0040] After the producing step is performed in this way, the
microcapsules and the solvent are mixed in the given ratio in the
mixing step, so that the microcapsules are dispersed in the solvent
to form the working fluid. For example, the microcapsules are
dispersed in water by the mixing. The solvent that is mixed with
the microcapsules is preferably a water-based (aqueous) liquid.
Alternatively, an oil-based liquid may be used instead. Further,
when the necessity occurs, suitable surface-active agents or
abrasive particles may be added to the solvent that is mixed with
the microcapsules.
[0041] Next, a description will be provided of preferred
embodiments of the working process according to the present
invention. As described above, the working process according to the
present invention provided to perform the working of a workpiece
with the working fluid being supplied to the working point. The
working of the workpiece may include at least a cutting process, a
plastic working process, a grinding process, and a polishing
process.
[0042] FIG. 1 shows a cutting process in which the working process
of the invention is embodied. In the present embodiment, a cutting
tool, such as a milling cutter, is brought into contact with the
workpiece at the working point, and, during the cutting process,
the working fluid is continuously supplied to the working point at
a controlled flow rate by using a working fluid application device
having a nozzle.
[0043] As shown in FIG. 1, before a start of the cutting process, a
cutting tool (for example, a milling cutter) 13 is brought into
contact with a workpiece 14 at the working point. At a start of the
cutting process, the working fluid application device (not shown)
is controlled by a control unit (not shown), and a working fluid 12
in which the microcapsules filled with a machining fluid are
dispersed in the solvent, is sprayed from a nozzle 11 of the
working fluid application device onto the working point at a
controlled flow rate.
[0044] FIG. 2 shows a working fluid application device which is
used to supply the working fluid 12 to the working point in one
preferred embodiment of the working process of the invention.
[0045] In the working fluid application device of FIG. 2, the
working fluid 12 that is stored in a reservoir 19 is delivered to a
pressure tank 17 by controlling operation of a pump 18. A fluid
surface sensor 16 is provided on the pressure tank 17, and this
fluid surface sensor 16 outputs a signal, indicating the amount of
the working fluid 12 contained in the pressure tank 17, to the
control unit (not shown). The control unit detects the amount of
the working fluid 12 within the pressure tank 17 based on the
signal output by the fluid surface sensor 16. The control unit
controls the operation of the pump 18 in accordance with the
detected working fluid amount of the pressure tank 17, so that the
top surface of the working fluid 12 within the pressure tank 17 is
kept at a constant height.
[0046] Further, in the working fluid application device of FIG. 2,
an air supplying device 20 is provided to supply compressed air to
the pressure tank 17, the compressed air being at a given pressure.
The working fluid 12 from the pressure tank 17 is delivered to the
nozzle 11 via a flow control valve 15 with the aid of the
compressed air. The control unit controls operation of the flow
control valve 15, so that the flow of the working fluid delivered
from the pressure tank 17 to the nozzle 11 is appropriately
controlled by the control valve 15. Specifically, the control unit
sets the opening position of the flow control valve 15 to one of a
completely closed position, a completely open position, and a
reduced-opening position, so that the working fluid 12 is sprayed
from the nozzle 11 onto the working point at a controlled flow
rate. The control unit controls the operation of the flow control
valve 15 so that the spraying of the working fluid onto the working
point is matched with the timing of the placement of the cutting
tool 13 onto the workpiece 14.
[0047] In the above-described embodiment, the working fluid from
the working point is circulated in a working machine including a
milling machine of the milling cutter 13, in order to reuse the
working fluid for the working of the workpiece, which is not
illustrated in FIG. 1.
[0048] In the above-described embodiment, the working fluid 12 from
the pressure tank 17 is delivered through a single pipe to the
nozzle 11. However, the present invention is not limited to this
embodiment. Alternatively, a mixture of the working fluid 12 and
the compressed air may be delivered through a double pipe to the
nozzle 11, so that the fluid-air mixture is sprayed from the nozzle
11 onto the working point.
[0049] Further, in the above-described embodiment, the working
fluid 12 is sprayed from the nozzle 11 of the working fluid
application device onto the working point. However, the present
invention is not limited to this embodiment. Alternatively, a
cutting tool with an oil hole may be used instead, and the working
fluid 12 may be sprayed from the oil hole of the cutting tool to
the working point.
[0050] According to the working process of the present embodiment,
the working fluid 12 contains the solvent and the microcapsules
filled with the liquid-state substances (the machining fluid), the
microcapsules being dispersed in the solvent. Regardless of the
viscosity of the liquid-state substances, the microcapsules of the
working fluid 12 have a low viscosity. The working fluid 12 can
easily enter the working point and the emulsion state of the
microcapsules of the working fluid 12 is slowly collapsed by the
working pressure at the working point. Hence, the working process
of the present embodiment is effective in providing good cooling
and lubrication effects on the workpiece even when a small amount
of the working fluid 12 is supplied to the working point. The
abrupt collapsing of the emulsion state due to the working pressure
or the deterioration of the emulsion state due to the circulation
of the working fluid, as in the conventional emulsion-state working
fluid, can be appropriately eliminated.
[0051] FIG. 3 shows a plastic working process in which the working
process of the invention is embodied. In the present embodiment,
the plastic working process, such as bending or drawing, employs
the working fluid 12, including the microcapsules, that is already
applied to the workpiece surface (a single side or both sides of
the workpiece), rather than continuously supplying the working
fluid 12 to the working point at a controlled flow rate.
[0052] As shown in FIG. 3, before a start of the plastic working, a
given amount of the working fluid 12 is applied to a sheet-like
workpiece 14, and this workpiece 14 is held on a die 22. A holder
plate 23 is placed thereon to fix the workpiece 14 on the die 22.
At a start of the plastic working process, a punch 21 of a press
(not shown) is lowered so that the workpiece 14 is allowed to draw
into the die 22.
[0053] According to the working process of the present embodiment,
the surface of the workpiece 14 in contact with the punch 21 is
subjected to the friction force and the deformation force, and the
surface of the workpiece 14 in contact with the die 22 is subjected
to the friction force. The working fluid 12 contains the solvent
and the microcapsules filled with the liquid-state substances (the
machining fluid), the microcapsules being dispersed in the solvent.
Regardless of the viscosity of the liquid-state substances, the
microcapsules of the working fluid 12 have a low viscosity. The
given amount of the working fluid 12 is provided, in advance, to
the working point, and the emulsion state of the microcapsules of
the working fluid 12 is slowly collapsed by the working pressure at
the working point. Hence, the working process of the present
embodiment is effective in providing good cooling and lubrication
effects on the workpiece 14. The abrupt collapsing of the emulsion
state due to the working pressure at the working point, as in the
conventional emulsion-state working fluid, can be appropriately
eliminated.
[0054] FIG. 4 shows a grinding process in which the working process
of the invention is embodied. In the present embodiment, a grinding
wheel is brought into contact with the workpiece at the working
point, and, during the grinding process, the working fluid 12,
including the microcapsules (which are filled with a grinding
fluid), is continuously supplied to the working point at a
controlled flow rate from the nozzle 11 of the working fluid
application device of FIG. 2. An upper or lower surface or an
internal or external surface of the workpiece 14 is ground by the
grinding wheel.
[0055] As shown in FIG. 4, a rotating table 44 is rotated around
its central axis by a drive motor (not shown), and a disc-like
workpiece 14 is positioned and fixed on the rotating table 44. A
grinding wheel 41 is attached to an end of a spindle 42, and the
grinding wheel 41 is rotated around the spindle 42. The spindle 42
is supported by a supporting column 43. At a start of the grinding
process, the workpiece 14, which is rotated on the rotating table
44 in a direction indicated by the arrow, may be moved to come in
contact with the grinding wheel 41, which is rotated around the
spindle 42 in a direction indicated by the arrow. Otherwise, the
rotating grinding wheel 41 may be moved to bring the grinding wheel
42 into contact with the rotating workpiece 14. During the grinding
process, the rotating grinding wheel 41 may be delivered at a
constant speed in a longitudinal direction (indicated by the arrow
"Y" in FIG. 4). The rotating table 44 is provided on a movable
table 45, and the movable table 45 is provided so that it is
movable in both a lateral direction (indicated by the arrow "X" in
FIG. 4) and a vertical direction (indicated by the arrow "Z" in
FIG. 4). Further, during the grinding process, the working fluid 12
in which the microcapsules filled with the grinding fluid are
dispersed in the solvent is sprayed at a controlled flow rate from
the nozzle 11 of the working fluid application device of FIG. 2
onto the working point between the workpiece 14 and the grinding
wheel 41.
[0056] In the grinding process of FIG. 4, the grinding depth (in
the direction "Z") is adjusted, and one of the workpiece 14 and the
grinding wheel 41 is moved in the direction X or the direction Y to
the other. While the working fluid 12 is continuously supplied to
the working point, the workpiece 14 is rotated on the rotating
table 44 in the indicated direction and the grinding wheel 41 is
rotated around the spindle 42 in the indicated direction.
[0057] According to the grinding process of the present embodiment,
any of a side-cut grinding, a precision grinding or a spark-out
grinding may be carried out. Similar to the cutting process of FIG.
1, the working fluid 12 contains the solvent and the microcapsules
filled with the liquid-state substances (the grinding fluid), the
microcapsules being dispersed in the solvent. Regardless of the
viscosity of the liquid-state substances, the microcapsules of the
working fluid 12 have a low viscosity. Even when a small amount of
the working fluid 12 is supplied to the working point, the emulsion
state of the microcapsules of the working fluid 12 is slowly
collapsed by the working pressure at the working point. Hence, the
working process of the present embodiment is effective in providing
good cooling and lubrication effects on the workpiece 14. The
abrupt collapsing of the emulsion state due to the working pressure
at the working point or the deterioration of the emulsion state due
to the circulation of the working fluid, as in the conventional
emulsion-state working fluid, can be appropriately eliminated.
[0058] FIG. 5 shows a polishing process in which the working
process of the invention is embodied. In the present embodiment, an
abrasive tape is brought into contact with the workpiece at the
working point, and, during the polishing process, the working fluid
12, including the microcapsules (which are filled with a polishing
fluid), is continuously supplied to the working point at a
controlled flow rate from the nozzle 11 of the working fluid
application device of FIG. 2. An upper or lower surface (or an
internal or external surface) of the workpiece 14 is polished by
the abrasive tape.
[0059] As shown in FIG. 5, an abrasive tape 32 in which the
abrasive is bonded with an appropriate bonding agent into the tape
32, is brought into contact with the workpiece while the working
fluid 12 is continuously supplied to the working point between the
workpiece and the abrasive tape 32. A rotating table 31 is rotated
around its central axis by a drive motor (not shown), and a
disc-like workpiece 14 is positioned and fixed on the rotating
table 31. The abrasive tape 32 is rotated by a drive mechanism (not
shown) in a direction indicated by the arrow in FIG. 5. A pressure
roller 33, which is provided to be movable in a radial direction of
the disc-like workpiece 14, is depressed on the abrasive tape 32 so
that the abrasive tape 32 contacts the workpiece 14 under a given
pressure. During the polishing process, the working fluid 12 in
which the microcapsules filled with the polishing fluid are
dispersed in the solvent is sprayed at a controlled flow rate from
the nozzle 11 of the working fluid application device of FIG. 2
onto the working point between the workpiece 14 and the abrasive
tape 32. While the working fluid 12 is continuously supplied to the
working point, the workpiece 14 is rotated on the rotating table 31
in the indicated direction and the abrasive tape 32 is rotated in
the indicated direction. At the same time, the pressure roller 33
is moved at a constant rate in the radial direction of the
disc-like workpiece 14 so that the polishing of the workpiece 14 is
carried out.
[0060] In the above-described embodiment, only one nozzle 11 of the
working fluid application device is provided. The number of the
nozzles 11 that are provided in the polishing equipment may be
altered depending on the width dimension of the abrasive tape
32.
[0061] In the above-described embodiment, the abrasive tape 32 is
provided to polish the disc-like workpiece 14. Alternatively,
another polishing tool (for example, an abrasive cloth) may be used
according to the type of the workpiece.
[0062] According to the polishing process of the present
embodiment, the working fluid 12 contains the solvent and the
microcapsules filled with the liquid-state substances (the
polishing fluid), the microcapsules being dispersed in the solvent.
Regardless of the viscosity of the liquid-state substances, the
microcapsules of the working fluid 12 have a low viscosity. Even
when a small amount of the working fluid 12 is supplied to the
working point, the emulsion state of the microcapsules of the
working fluid 12 is slowly collapsed by the working pressure at the
working point. Hence, the working process of the present embodiment
is effective in providing good cooling and lubrication effects on
the workpiece 14. The abrupt collapsing of the emulsion state due
to the working pressure at the working point or the deterioration
of the emulsion state due to the circulation of the working fluid,
as in the conventional emulsion-state working fluid, can be
appropriately eliminated.
[0063] Next, a description will be provided of one preferred
embodiment of the working fluid of the invention.
[0064] In the present embodiment, by performing either the surface
polymerization process or the "in situ" polymerization process,
microcapsules that are filled with an oil-based cutting fluid are
produced. In the mixing step, the microcapsules and water are mixed
in a given ratio so that the microcapsules are dispersed in water
to form the working fluid. In the present embodiment, the working
fluid containing the microcapsules filled with the cutting fluid,
the microcapsules being dispersed in water, is produced for use in
the cutting process. The mixing speed is suitably adjusted so as to
create the emulsion state in which the microcapsules are dispersed
in water, and to allow the microcapsules to have an average
particle size ranging from 0.1 .mu.m to 1000 .mu.m.
[0065] As to the materials of the microcapsule walls, when the "in
situ" polymerization process is performed, an appropriate catalyst
for the polymerization is supplied from the outer layer of the
microcapsule core substances so that the microcapsule walls of a
melamine resin are formed thereon.
[0066] For the purpose of comparison, three types of fluid: water,
the cutting fluid (filled into the microcapsules), and the working
fluid of the above embodiment (containing the microcapsules) are
respectively supplied to the working point where a cutting process
of a stainless steel workpiece is performed. As a result, in the
case of water, even if a large amount of water is supplied, the
lubrication effects on the workpiece has been extremely low, and
the cutting of the workpiece cannot be achieved. In the cases of
the cutting fluid and the working fluid of the above embodiment,
the cutting of the workpiece has been normally performed.
[0067] Further, by reducing the flow rate of the working fluid
supplied to the working point, the cutting of the workpiece is
performed for the cases of the cutting fluid and the working fluid
of the above embodiment. As a result, in the case of the working
fluid of the above embodiment, even when the flow rate is reduced
to 0.5 ml/hour, the cutting of the workpiece has been normally
performed. However, in the case of the cutting fluid, when the flow
rate is reduced to 3 ml/hour, the cutting of the workpiece cannot
be performed.
[0068] Therefore, it is made certain that, according to the working
fluid of the above embodiment, it is possible to achieve good
cooling and lubrication effects on the workpiece even when a small
amount of the working fluid is supplied to the working point.
[0069] The present invention is not limited to the above-described
embodiments, and variations and modifications may be made without
departing from the scope of the present invention.
[0070] Further, the present invention is based on Japanese priority
application No.11-359342, filed on Dec. 17, 1999, the entire
contents of which are hereby incorporated by reference.
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