JPH0420725B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrolytic abrasive compound automatic polishing apparatus for mirror polishing the free-form surface of a member made of a metal material.

[Prior Art] Conventionally, electrolytic abrasive composite polishing has been carried out in which a passive film formed on the surface of a workpiece due to electrolysis is removed using abrasive grains, thereby mirror-polishing the surface of the workpiece. , targets planes, cylindrical surfaces, and other rotating surfaces, and does not consider application to arbitrary free-form surfaces. Therefore, this polishing apparatus cannot be applied to polishing free-form surfaces.

However, it is desired in various technical fields to be able to easily mirror-polish arbitrary free-form surfaces, such as molds and other metal parts with complex uneven surfaces, and weld bead parts of stainless steel plates. There is.

Mirror polishing of such free-form surfaces has traditionally been carried out by buffing or manual polishing using an appropriate polishing tool, but this not only requires skill but also creates a very poor working environment. There's a problem.

Furthermore, it is extremely effective to perform the mirror polishing of the free-form surface automatically by following the unevenness of the curved surface, but if this is to be achieved using general technology, it is necessary to measure the shape of the free-form surface in advance. Since the tool must be moved along the shape of the object while being scanned or measured, the automation equipment becomes extremely complex and expensive. Furthermore, the buffing is a polishing method that is extremely difficult to automate.

[Problems to be Solved by the Invention] The present invention uses electrolytic abrasive composite polishing to remove a passive film formed on the surface of a workpiece by electrolysis using abrasive grains, thereby mirror-polishing the surface of the workpiece. of,
It is an object of the present invention to provide an electrolytic abrasive composite automatic polishing device that can be applied to polishing free-form surfaces of metal members.

[Means for solving the problems] In order to achieve the above object, in the present invention,
A movable table in a two-dimensional automatic feeding device is configured to be movable relative to a workpiece within a two-dimensional plane,
This moving stage is provided with a guide in a direction perpendicular to the above plane, and the electrode tool rotated by a rotary drive machine is slidable along this guide, and the workpiece is moved by the electrode tool's own weight or spring. The electrode tool is attached to the guide with a pressing force applied to the object and the support angle adjustable.
A liquid-permeable viscoelastic abrasive body is attached to the surface of a disc-shaped conductive tool base, and the peripheral portion of this viscoelastic abrasive body can be deformed to follow the surface of the workpiece while holding abrasive grains. A supply pipe is provided to supply electrolyte to the peripheral portion of the viscoelastic polishing body, and a current for electrolysis is passed between the electrode tool and the workpiece. Technical measures have been taken to connect it to the power supply.

[Function] In the automatic polishing device having the above configuration, the workpiece is installed in the machine frame, and the rotation axis of the electrode tool is set on a plane that evens out the unevenness on the contact surface between the viscoelastic polishing body and the workpiece. and thereby bring the peripheral portion of the viscoelastic abrasive body into contact with the surface of the workpiece.

Then, while supplying the electrolyte to the electrode tool through the electrolyte supply pipe, a current is passed between the electrode tool and the workpiece, and the movable stage is moved two-dimensionally while rotating the electrode tool with a rotary drive machine. move it,
Performs processing of the workpiece.

At this time, even if the surface of the workpiece has some unevenness, the electrode tool deforms the peripheral portion of the viscoelastic polishing body to follow the shape of the workpiece surface and fits onto the surface. Can be mirror polished.

In addition, the electrode tool slides freely in the Z direction along the guide, and a pressing force is applied to the workpiece by the electrode tool's own weight or a spring, and the viscoelastic abrasive body exerts a pressing force against the workpiece. Since the viscoelastic polishing body deforms to follow the workpiece, the free-form surface of the workpiece can be polished simply by two-dimensionally feeding the electrode tool using the two-dimensional feeding device described above.

[Example] The electrolytic abrasive composite polishing apparatus of the present invention shown in FIGS. 1 and 2 includes a polishing head 1 equipped with an electrode tool 20.
0 is attached to a two-dimensional automatic feeder 53.

As shown in FIGS. 6 and 7, the polishing head 10 includes a pistol-shaped head body 11 and a rotary drive machine 12 consisting of a motor and a speed reduction device 13 provided on its output side. A rotary shaft 14 rotated by the head body 11 is led out from the head body 11, and the electrode tool 20 is attached to the tip thereof.

The electrode tool 20 is mainly composed of a substantially disk-shaped tool base 21 made of conductive copper or other material, and a viscoelastic polishing body 22 attached to the surface of the tool base 21. The above tool base 21
This is constructed by integrally joining a disc-shaped surface plate 24 attached to the tip of the rotating shaft 14 and a back plate 25 forming a liquid reservoir 26 around the back surface of the surface plate at the peripheral edge. , the surface plate 24
The back plate is provided with a recess 29 in its center into which the head of a screw 28 for attachment to the rotating shaft 14 is inserted, and a number of electrolyte outlet ports 30 are provided at positions slightly inward from the periphery. 25 has an electrolyte supply opening 31 formed at its center between it and the rotating shaft 14, and a power supply sliding contact 33 for supplying an electrolytic current (to be described later) is brought into contact around the opening 31. A sliding contact surface 32 is formed.

The viscoelastic polishing body 22 attached to the surface of the tool base 21 is made of a sponge-like member such as foamed polyurethane or other synthetic resin foam, or a viscoelastic body with liquid permeability such as nylon nonwoven fabric, It is designed to be attached to the surface of the conductive tool base, and when it is formed of a sponge-like member as shown in the figure, a recess 34 is formed inside it.
is formed and attached to the tool base 21, and a contact plate 35 is attached to the viscoelastic polishing body 22 and the center thereof.
They can be attached to the rotating shaft by fixing them together with the tool base 21 to the rotating shaft 14 with screws 28. In addition, when using the viscoelastic abrasive body 22 such as a nylon nonwoven fabric, its peripheral portion is adhered to the surface of the tool base 21 or fixed by appropriate means, and then the abutment plate 35 is brought into contact with the rotating shaft 14. It can be fixed with screws 28.

In addition, the viscoelastic polishing body 22 can have abrasive grains dispersed throughout its surface or inside, and in that case, a synthetic resin bond mixed with abrasive grains such as alumina is bonded to a nylon nonwoven fabric or the like. The abrasive grains can be held in an adhesive state, or the abrasive grains in a free state can be supported by the mesh of the nonwoven fabric without fixing the abrasive grains.

A large number of electrolyte outlet ports 30 opened in the surface plate 24 are provided slightly inward from the periphery of the tool base 21 to form an electrolyte reservoir 26 in the inner periphery of the tool base 21 of the electrode tool 20. However, the electrolytic solution is temporarily stored in this liquid reservoir 26 so that the electrolytic solution can be stably supplied from a large number of electrolytic solution outlets 30. Therefore, the electrode tool 20
While the electrode tool rotates, the electrolytic solution sequentially flows out from the electrolytic solution outlet 30, and the electrolytic solution causes contact between the viscoelastic abrasive body 22 and the workpiece around the electrode tool 20 due to the centrifugal force accompanying the rotation of the electrode tool. Supplied to the contact area.
Therefore, almost no equipment is required for pumping the electrolyte, and the electrode tool 20 has excellent ability to retain the electrolyte, so it can be used not only on horizontal free-form surfaces but also on horizontal free-form surfaces.
Even curved surfaces that are close to vertical can be polished by stably supplying electrolyte.

The electrolyte supply pipe 38 is for supplying electrolyte to the polishing portion around the electrode tool 20, and has a supply port 40 opened at one end of the head body 11, and also supplies the electrolyte to the polishing portion around the electrode tool 20. A delivery port 41 at the other end is opened in an electrolyte supply opening 31 around the rotating shaft 14 provided at the center of the back plate 25 of the tool base 21 . Instead of or in addition to holding abrasive grains in the viscoelastic polishing body 22,
It is also possible to mix abrasive grains into the electrolyte supplied through the electrolyte supply pipe 38.

The power supply terminal 43 at one end of the head body 11 is for supplying current for electrolysis to the electrode tool 20 through the power supply sliding contact 33 and the sliding contact surface 32 in contact with it. The tool 20 is configured as a negative pole so that they can be connected to a power source (not shown).

In addition, in the figure, 44 indicates a switch operator for rotating the rotary drive machine 12.

The two-dimensional automatic feeder 53 to which the polishing head 10 is attached is, as shown in FIGS. 1 and 2,
It is attached via a support plate 51 on the upper surface of the machine frame 50 to a machine frame 50 formed by joining angles arranged along each edge line of a rectangular parallelepiped.

This automatic feeding device 53 is connected to the polishing head 10.
The movable table 54 on which the base plate 55 is attached can be freely moved in the X and Y directions perpendicular to each other in a horizontal plane. A pair of X-direction guide rods 58, 58 are attached, and a feed screw 60 rotatably driven by a motor 59 attached to the base plate 55 is rotatably supported.
The feed screw 60 is screwed into an X-direction moving table 61 whose movement in the X-direction is guided by slidably inserting direction guide rods 58, 58 therethrough. Therefore, when the feed screw 60 is rotated by the rotation of the motor 59, the X direction moving table 61 moves between the guide rods 58, 5.
8 and transported in the X direction.

Furthermore, a pair of Y-direction guide rods 63, 63 are slidably inserted into the X-direction moving table 61 in a direction perpendicular to the X-direction guide rods 58, 58, and
A feed screw 64 is screwed in. These guide rods 6
3 and 63 are support members 6 at both ends of the moving table 54.
5.66, and the feed screw 64 is rotatably supported by both support members 65 and 66. One end of the feed screw 64 is connected to a motor 68 provided on the moving table 54. Therefore, by rotating the motor 68, the moving table 54 is moved in the Y direction relative to the X direction moving table 61.

Each motor 59 in the automatic feeder 53,
68 is connected to a controller (not shown),
Its drive is controlled. This controller controls the driving of the motors 59 and 68 so as to move the moving table 54 along a preset path, and utilizes a known controller used in various two-dimensional automatic feeding devices. be able to.

As shown in detail in FIGS. 3 to 5, a pair of guides 70 and 71 are installed on the movable table 54 so that the polishing head 10 can be slid in the Z direction perpendicular to the XY plane. It is placed vertically. The guides 70 and 71 are provided with guide elongated holes 72 and 73, respectively, in the longitudinal direction thereof.

On the other hand, the holder 74 of the polishing head 10 is
A pair of divided pieces 75 with supporting rods 77 and 78 protruding from them,
76 and divided support pieces 79 and 80 provided opposite to them.
and a connecting plate 81 that connects the divided pieces 75 and 76.
are integrated with bolts 82 and 83, and the polishing head 10 is fixed between them. Sliders 85 and 86 having square outer circumferential surfaces are rotatably fitted to the support rods 77 and 78 attached to the divided pieces 75 and 76, and the wing nut 8
7, 88, and these sliders 85, 86 are slidably inserted into the elongated holes 72, 73 of the guides 70, 71. An angle indicator plate 89 displaying the inclination angle is fixed to the slider 85, and an arrow plate 90 is fitted into the support rod 77 so that it can slide in the axial direction but cannot rotate.

Therefore, as shown in FIG.
If the rectangular sliders 85, 86 are fixed in that direction by tightening the butterfly nuts 87, 88 with the sliders 85, 86 tilted appropriately, the polishing head 10 can be moved so that the sliders 85, 86 are aligned with the guides 70, 71. long hole 7
2, 73, it slides freely in the Z direction while maintaining its angle, and its inclination angle is determined by the direction of the arrow board 90 with respect to the angle display on the angle indicator board 89. You can know it.

If the sliding resistance when the sliders 85 and 86 slide through the elongated holes 72 and 73 of the guides 70 and 71 becomes a problem, consideration should be given to reducing the sliding resistance of such two members. Various known linear slide mechanisms can be used.

In the automatic polishing apparatus having the above configuration, the workpiece 45 is installed in the machine frame 50, and the electrode tool 20 is placed inside the machine frame 50.
The rotating shaft 14 connects the viscoelastic polishing body 22 and the workpiece 45
The polishing head 10 is tilted so as to be tilted with respect to a plane that averages out the irregularities on the contact surface with the workpiece 45, and thereby, as explained with reference to FIG. surface. The inclination angle of the rotating shaft 14 at this time is
It is necessary to maintain the angle within the range of 5 to 60 degrees, and more preferably within the range of 10 to 45 degrees.

Then, the electrode tool 2 is supplied through the electrolyte supply pipe 38.
While supplying an aqueous solution such as NaNO ₃ or KHO ₃ to the electrode tool 20 and the workpiece 45, a current of several amperes is passed between the electrode tool 20 and the workpiece 45 at a voltage of several volts to 10-odd volts. While rotating the electrode tool 20, the moving table 54 is moved two-dimensionally to process the workpiece 45. The movement of the movable table 54 at this time is performed along an appropriate route set in advance in the controller for moving the movable table 54 according to the shape of the workpiece.

When the electrode tool 20 has a diameter of about 12 cm, the viscoelastic abrasive body 22 can be pressed against the surface of a workpiece having some unevenness at a rotation speed of several hundred rpm or less by the rotary drive machine 12. By deforming the peripheral portion to follow the surface shape of the workpiece and fitting it to the surface, the workpiece can be mirror-polished. In this case, the pressing pressure of the electrode tool 20 against the protrusions on the surface of the workpiece at the contact surface between the viscoelastic polishing body 22 and the workpiece 45 is naturally greater than the pressure against the recesses in the contact surface. The amount removed by abrasive grains or the like increases at the convex portion. However, since it is possible to achieve the same surface roughness for both relatively large concave portions and convex portions, efficient polishing can be performed when shape accuracy is not an issue.

The above electrolytic abrasive composite polishing is performed using an electrolytic solution such as NaNO ₃ or KNO ₃ at a very low current density, but in this case, a passive film tends to form on the surface of the workpiece. It is electrically inactivated and the electrolytic action is extremely reduced. However, on the surface of the workpiece, the abrasive grains act as microcutting edges, which increases the probability that minute protrusions will be mechanically polished. The tip of the part is selectively polished by abrasive grains, and the passive film is removed by grinding at the polished part, increasing electrical activation. Therefore, electrolytic action concentrates on this activated part, and this effect is suppressed. Through repetition, protrusions on the surface of the workpiece are selectively removed, the surface roughness is improved, and the surface is polished to a mirror finish.

During the above-mentioned automatic polishing, it is necessary that the inclination angle of the rotation axis of the electrode tool is always maintained within the above-mentioned appropriate angle range with respect to the contact surface between the workpiece and the viscoelastic polishing body. However, if this is not possible, it is sufficient to temporarily stop the polishing process, change the above-mentioned inclination angle, and then continue automatic polishing again.

If a device that can automatically change the inclination angle of the rotation axis of the electrode tool is added, automatic polishing can be continuously performed without interrupting processing even if the inclination of the contact surface changes.

While the polishing head 10 is two-dimensionally moved by the two-dimensional automatic feeder 53, the viscoelastic polishing body is pressed against the surface of the workpiece by the own weight of the polishing head 10. must be set appropriately. If the weight of the polishing device itself is insufficient to obtain the necessary pressing force, a spring may be provided between the movable table 54 and the polishing head 10. When polishing the surface of an object, it is necessary to form the above-mentioned automatic polishing device horizontally and to provide the above-mentioned spring in order to obtain the necessary pressing force of the viscoelastic polishing body.

The pressing pressure of the viscoelastic abrasive body against the surface of the workpiece is light, on the order of several tens of kPa, so the cutting depth of the abrasive grains is much smaller than with conventional hard grinding wheels, and it does not scratch the surface of the workpiece. Most of the frictional resistance during polishing is thought to occur between the viscoelastic polishing body and the workpiece. In this way, since the pressing pressure is light and the viscoelastic polishing body deforms to follow the workpiece, when polishing the free-form surface of the workpiece, the polishing head is moved by the two-dimensional feed device 53 described above. By simply moving the polishing head 10 two-dimensionally, the polishing head 10 can be automatically moved in the Z direction and operated to follow the workpiece.

In the above embodiment, the polishing head 10 is moved two-dimensionally by a two-dimensional feeder, but the workpiece 45 may also be moved two-dimensionally.

Such electrolytic abrasive composite polishing can be applied to polishing free-form surfaces of various metal products, and is particularly suitable for polishing the surfaces of stainless steel and the like.

[Effects of the Invention] As described above, according to the electrolytic abrasive composite automatic polishing device of the present invention, polishing can be performed while automatically moving the electrode tool along a free-form surface, and
By polishing only the peripheral portion of the viscoelastic polishing body in the electrode tool by bringing it into contact with the workpiece, it is possible to polish the minute portion of the viscoelastic polishing body by bringing it into stable contact with the workpiece.

Moreover, in the present invention, the electrode tool is slidable in the Z direction along a guide provided on the moving stage of the two-dimensional automatic feeder, and is configured to apply a pressing force to the workpiece using its own weight or a spring. ,
Furthermore, since a highly flexible viscoelastic polishing body that can be deformed to follow the surface of the workpiece is used, a two-dimensional automatic feeder can be effectively utilized.

That is, in general, in order to automatically perform mirror polishing of a free-form surface by following the irregularities of the curved surface, it is necessary to measure the shape of the free-form surface in advance, or to move the tool along the shape while measuring it. Therefore, the automation equipment becomes very complicated and expensive, but with the above configuration, the workpiece can be freely moved by simply feeding the electrode tool two-dimensionally using the two-dimensional automatic feeding device. This is possible by polishing the curved surface.

Furthermore, the polishing body that can be tilted at any angle not only allows the angle to be adjusted according to the unevenness of the surface to be polished, but also allows a small area around the polishing body to be brought into contact with the target surface at an appropriate inclination. This is effective for evenly polishing the surface to be polished.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view of the electrolytic abrasive composite automatic polishing device according to the present invention, Fig. 2 is a partially cutaway side view of the same, and Fig. 3 shows the mounting structure of the polishing head to the two-dimensional feeder. 4 is a front view of the main part thereof, FIG. 5 is a sectional view taken along the line A-A in FIG. 4, FIG. 6 is a sectional view of the main part of the polishing head, and FIG. FIG. 8 is a partially cutaway front view of the electrode tool, and is an enlarged sectional view of essential parts showing a mode of polishing by the polishing head. 12...Rotary drive machine, 20...Electrode tool, 21
... Tool base, 23 ... Viscoelastic abrasive body, 38 ...
Supply pipe, 53... Two-dimensional automatic feeding device, 54...
...Moving table, 70, 71...Guide.

Claims (1)

[Claims] 1. A movable table in a two-dimensional automatic feeder is configured to be movable relative to the workpiece within a two-dimensional plane, and a guide is provided on this movable table in a direction perpendicular to the plane, and the rotary drive machine Therefore, the rotating electrode tool is attached to the guide so that it can slide freely along the guide, a pressing force is applied to the workpiece by the electrode tool's own weight or a spring, and the support angle is adjustable. This electrode tool is constructed by attaching a fluid-permeable viscoelastic abrasive body to the surface of a disc-shaped conductive tool base, and using the peripheral portion of this viscoelastic abrasive body to hold abrasive grains and to clean the workpiece. A supply pipe is formed by forming a machined surface that can be deformed to follow the surface and supplies an electrolytic solution to the peripheral portion of the viscoelastic polishing body, and
An electrolytic abrasive composite automatic polishing device, characterized in that the electrode tool is connected to a power source that flows an electric current for electrolysis between the electrode tool and the workpiece.