JP3630987B2 - Processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a processing apparatus, and more particularly, to a processing apparatus using EEM (Elastic Emission Machining).
[0002]
Here, the EEM means that powder particles having a property of being bonded to the workpiece by interaction are transported to the surface of the workpiece by water flow, and the powder particles and the surface atoms of the workpiece are bonded by interaction. At the same time, it refers to a technique for processing the surface of the workpiece in atomic order by removing the surface atoms of the workpiece by reducing the bonding force between the surface atoms of the workpiece and the atoms behind the workpiece.
[0003]
[Prior art]
2. Description of the Related Art Conventionally, a processing apparatus using EEM has a processing stage for holding a workpiece and a drive mechanism for moving the processing stage in a tank having an open top. The tank is filled with a processing liquid in which powder particles having a property of being bonded to a workpiece by interaction are dispersed in pure water. Then, a rotating shaft is inserted into the working fluid from above the tank, and an elastic body at the tip of the rotating shaft is disposed in the vicinity of the work surface of the work piece. The elastic body is rotated. As a result, the powder particles are transported to the surface of the work piece, and the powder particles and the surface atoms of the work piece are combined by interaction, and the bonding force between the surface atoms of the work piece and the atoms on the back side thereof. To remove surface atoms from the workpiece. As a result, it is possible to process the surface of the workpiece flatly with an atomic size order (accuracy of 5 mm or less according to measurement by Tari step or the like).
[0004]
[Problems to be solved by the invention]
However, in the processing apparatus using the conventional EEM, since the upper part of the tank is opened, there is a problem that oxygen in the atmosphere dissolves in the processing liquid and adversely affects the stability of the processing phenomenon. Further, since the processing stage and the drive mechanism are installed in the same tank, there is a problem that the processing liquid is contaminated by wear powder generated between the guide surface and the processing stage.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to provide a machining apparatus that can keep a machining fluid in a good state and can keep a machining phenomenon caused by EEM highly stable.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the processing apparatus according to claim 1 uses a processing liquid in which powder particles having a property of being bonded to a workpiece by interaction are dispersed in pure water, and the processing liquid flows. In a processing apparatus for processing a polished surface of the workpiece by flowing by a generating unit, the processing liquid is stored, and a sealed tank made of a nonmagnetic material at least part of a wall, and a processing liquid in the sealed tank The machining stage is immersed in, supported by a hydrostatic bearing, and holds the workpiece, and is provided outside the sealed tank and passes through a portion made of a nonmagnetic material on the wall of the sealed tank. And a driving unit that moves the processing stage by magnetic coupling with the working stage.
[0007]
In the processing apparatus according to claim 1, the workpiece is held in the sealed tank by a processing stage in a state where the sealed tank is filled with the processing liquid. In this state, the machining fluid flows toward the workpiece surface of the workpiece by the flow generation unit. The powder particles in the machining fluid and the surface atoms of the workpiece are bonded by interaction, and the bonding force between the surface atoms of the workpiece and the atoms on the back side is reduced to remove the surface atoms of the workpiece. It is. At this time, in the above processing apparatus, since the tank for storing the processing liquid is a sealed tank, oxygen in the atmosphere does not dissolve in the processing liquid.
[0008]
Further, the workpiece can be moved relative to the flow of the machining liquid because it is moved by the driving unit using magnetic coupling through the portion made of the nonmagnetic material on the wall of the sealed tank. Moreover, since the drive unit is outside the sealed tank and is not in the machining liquid, the machining liquid is not contaminated by the drive unit, and it is not necessary to seal the drive unit. Since the processing stage is supported by the hydrostatic bearing, no abrasion powder is generated between the guide surface and the processing stage.
[0009]
In this way, oxygen in the atmosphere does not dissolve in the machining fluid, and no abrasion powder is generated between the guide surface and the machining stage, so there is no need to seal the drive unit and the machining fluid is contaminated. It will not be done. That is, since the machining fluid is kept in a good state, the machining phenomenon by EEM can be kept highly stable.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The illustrated embodiment of the present invention will be described in detail below.
[0011]
FIG. 1 shows a configuration of a processing apparatus 1 according to an embodiment of the present invention. The processing apparatus 1 includes a sealed tank 3 for storing a processing liquid 2, a processing stage 6 for holding a workpiece 5, a driving stage 28 as a driving unit for moving the processing stage 6, and the driving stage 28. And a control unit 8 for controlling.
[0012]
The closed tank 3 is configured by attaching a processing tank 4 having a concave cross section having flanges 10a and 10b to an upper surface 9a of a support plate 9 via a seal (not shown) with an opening facing downward. The support plate 9 is stretched horizontally on the upper ends of support members 25 a and 25 b erected on the peripheral edge of the base plate 39.
[0013]
A column member 12 is erected on the upper surface 9 a of the support plate 9 in the closed tank 3 immediately inside the wall surface of the processing tank 4. The column member 12 includes support columns 12a and 12b arranged perpendicular to the upper surface 9a of the base, and a beam 12c extending horizontally over the upper ends of the support columns 12a and 12b. Then, the polishing unit 11 is attached via an attachment member 13 at substantially the center in the horizontal direction of the beam 12c.
[0014]
The polishing unit 11 includes a fixed plate 14 that is horizontally attached to the attachment member 13, a movable plate 15 that is horizontally provided below the fixed plate 14, and a movable plate 15 that is mounted on the fixed plate 14. And a coil spring 17 that pressurizes downward with 16 as a fulcrum. Below the movable plate 15, a motor 18, a holding member 19, a pure water static pressure rotary bearing 20, a polyurethane sphere 21 as an elastic body, a pure water static pressure rotary bearing 22, and a holding member 23 are arranged in this order with the movable plate 15. They are arranged in a row in parallel. The motor 18 and the pure water hydrostatic rotary bearings 20 and 22 are attached to the movable plate 15 via holding members 19 and 23. The output shaft of the motor 18 passes through the pure water hydrostatic rotary bearing 20, passes through the center of the polyurethane sphere 21, and the tip thereof is supported by the pure water hydrostatic rotary bearing 22. The polyurethane sphere 21 rotates integrally with the output shaft of the motor 18 and functions as a flow generation unit.
[0015]
In addition, a circular through hole 32 penetrating between the upper surface 9a and the lower surface 9b is formed in the central portion of the support plate 9 located directly below the processing tank 4. The nonmagnetic film 7 is provided on the same plane as the lower surface 9 b of the support plate 9 so as to close the through hole 32. On the upper surface 9 a of the support plate 9, a static pressure pocket 31 having a concave cross section surrounding the through hole 32 is provided. As shown in FIG. 2, the static pressure pockets 31 are arranged at four positions concentrically with the through hole 32 at an angular interval of 90 °. On the bottom surface of the static pressure pocket 31, a throttle hole 30 for blowing pure water at a substantially central position is provided. Then, pure water blows out from these throttle holes 30 to support the processing stage 6. The hydrostatic pocket 31 and the throttle hole 30 constitute a hydrostatic bearing.
[0016]
A magnetic coupling stage 26 is attached to the lower surface of the processing stage 6. As shown in FIG. 3A, the magnetic coupling stage 26 includes eight fan-shaped N magnets 41 and S magnets 42. These N magnets 41 and S magnets 42 are alternately arranged on the upper surface of the cylindrical member 40 made of a nonmagnetic material at an angular interval of 45 ° around the center thereof. The magnets 41 and 42 are embedded so that the upper surface of the columnar member 40 is flat.
[0017]
A substantially U-shaped suspension member 29 is provided on the wall of the closed tank 3, that is, the lower surface 9b of the support plate 9, and its flange 29a is disposed so that the bottom 29b of the suspension member 29 faces the nonmagnetic film 7. , 29c. A driving stage 28 as a driving unit is placed on the bottom 29 b of the suspension member 29. The drive stage 28 includes a magnetic coupling stage 27, a θ drive unit 28a that rotates the magnetic coupling stage 27 in a horizontal plane, and a magnetic coupling stage 27 and the θ drive unit 28a that are integrally translated in the X direction in a horizontal plane. An X drive unit 28b, a magnetic coupling stage 27, a θ drive unit 28a, and an X drive unit 28b are integrally provided in order from the top to move in parallel in the Y direction within a horizontal plane. The upper magnetic coupling stage 27 has a pattern in which the pole of the magnetic coupling stage 26 shown in FIG. 3A is inverted, and is magnetically coupled to the magnetic coupling stage 26 in the sealed tank 3 through the nonmagnetic film 7. ing. Therefore, the lower stage units 28a, 28b, and 28c move in the θ direction, the X direction, and the Y direction, respectively, so that the processing stage 6 moves horizontally in parallel on the upper surface 9a of the support plate 9 that serves as a guide surface. And can also be rotated.
[0018]
A control unit 8 provided outside the processing apparatus 1 controls the drive stage 28. The control unit 8 is constituted by a CPU (Central Processing Unit) and controls the overall operation of the processing apparatus 1 according to a control program stored in a ROM (Read Only Memory) (not shown).
[0019]
The control unit 8 also controls the density adjusting device 24. The concentration adjusting device 24 includes a filtration membrane inside, and retains moisture containing a high-molecular substance while passing through moisture containing low-molecular substances and ions in the taken processing liquid 2 by ultrafiltration. As a result, the machining liquid 2 having an increased powder particle concentration is returned to the sealed tank 3. Therefore, by controlling the flow rate of the working fluid 2 taken into the concentration adjusting device 24, the powder particle concentration in the working fluid 2 in the sealed tank 3 can be maintained constant.
[0020]
During operation, the hermetically sealed tank 3 is filled with a machining liquid in which powder particles having a property of being bonded to the workpiece 5 by interaction are uniformly dispersed. Pure water is supplied to the pure water hydrostatic rotary bearings 20 and 22 from a pure water pump (not shown) outside the processing apparatus 1. The pure water pump also supplies pure water to the pure water hydrostatic bearings 30 and 31. The concentration adjusting device 24 keeps the concentration of the working fluid 2 (the proportion of powder particles in pure water) constant.
[0021]
The processing stage 6 holds the workpiece 5 in a state where the processing liquid 2 is filled in the sealed tank 3. Then, the machining liquid 2 flows toward the workpiece surface of the workpiece 5 by the flow generated by the polyurethane sphere 21 rotated by the motor 18. The powder particles in the machining liquid 2 and the surface atoms of the workpiece 5 are bonded by interaction, and the bonding force between the surface atoms of the workpiece 5 and the atoms on the back side thereof is reduced, so that the workpiece 5 Remove surface atoms. At this time, in this processing apparatus 1, since the tank for storing the processing liquid 2 is the sealed tank 3, oxygen or the like in the atmosphere does not dissolve in the processing liquid 2.
[0022]
The control unit 8 controls and moves the drive stage 28. The drive stage 28 moves the processing stage 6 through the nonmagnetic film 7 provided on the lower surface 9 b of the support plate 9 and using magnetic coupling acting between the magnetic stages 26 and 27. As a result, the workpiece 5 held on the machining stage 6 is displaced relative to the flow of the machining liquid 2. Therefore, the polished surface of the workpiece 5 can be finished in a desired shape. At this time, since the driving unit for moving the processing stage 6 is provided outside the sealed tank 3, it is not necessary to seal the driving unit and the processing liquid 2 is not contaminated. Further, since the processing stage 6 is supported by pure water ejected from the throttle hole 30 in the bottom surface of the static pressure pocket 31, the processing stage 6 is worn between the lower surface of the processing stage 6 and the upper surface 9 a of the support plate 9. Does not produce powder.
[0023]
Thus, oxygen in the atmosphere is not dissolved in the machining liquid 2 and no abrasion powder is generated between the guide surface and the machining stage 6, so that the machining liquid 2 is kept in a good state. Therefore, in the processing apparatus 1 of the present invention, the processing phenomenon by EEM can be kept highly stable.
[0024]
The configuration of the magnetic coupling stage 26 is as shown in FIG. 3A. However, as shown in FIG. 3B, the upper surface of the magnetic coupling stage 26 'is partitioned into square cells. N magnets 51 and S magnets 52 may be alternately arranged in the formed grid.
[0025]
【The invention's effect】
As is clear from the above, in the processing apparatus of the first aspect of the invention, since the tank for storing the processing liquid is a sealed tank, oxygen in the atmosphere does not dissolve in the processing liquid.
[0026]
In the processing apparatus according to the first aspect of the present invention, since the driving unit for moving the processing stage is provided outside the sealed tank, it is not necessary to seal the driving unit and the processing liquid is not contaminated. .
[0027]
In the processing apparatus according to the first aspect of the present invention, since the processing stage is supported by the hydrostatic bearing, no wear powder is generated between the guide surface and the processing stage.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a processing apparatus according to an embodiment of the present invention.
FIG. 2 is a view of the bottom of the closed tank of the processing apparatus as viewed from above.
FIG. 3 is a diagram showing a configuration of a magnetic coupling stage provided in the processing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Processing apparatus 3 Sealed tank 5 Work piece 6 Processing stage 7 Nonmagnetic film 11 Polishing unit 26, 26 ', 27 Magnetic coupling stage 28 Drive stage

Claims (1)

Using a machining liquid in which powder particles having properties that bind to the workpiece by interaction are dispersed in pure water, the machining liquid is flowed by a flow generating unit to process the polished surface of the workpiece. In processing equipment,
While storing the processing fluid, at least a part of the wall is a sealed tank made of a non-magnetic material,
A processing stage that is immersed in the processing liquid in the sealed tank, supported by a hydrostatic bearing, and holds the workpiece;
A drive unit that is provided outside the hermetic tank and moves the machining stage through magnetic coupling with the machining stage through a portion made of a non-magnetic material on the wall of the hermetic tank; Processing equipment.

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