JPH03196964A - Workpiece polishing method and device - Google Patents

Abstract

PURPOSE:To improve the extent of polishing speed and accuracy by reciprocating a fluidic abradant on a polished surface as rotating relatively with this surface. CONSTITUTION:A fluidic abradant 5 filled up in a pressure body 6 on one side passes through a polished surface of a workpiece 1 held in space between holders 4 by a pressurizing means 10, and then it flows into the pressure body 6 on the other. When preset pressurization is carried out by a control means 11, the fluidic abradant 5 shifted to the pressure body 6 on the other flows into the first pressure body by the pressurizing means 10. With a series of operations repeated, the fluidic abradant 5 reciprocates whereby abrasive operation on the polished surface is thus performed in succession. In addition, since the fluidic abradant 5 relatively rotates with the polished surface, at time of the abradant 5 flowing, a flowing direction of the abradant 5 will not come to a direction going along a vertical grinding line turned up on the polished surface 1 but come to a crossing direction. Consequently, the extent of polishing speed and accuracy is improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention involves applying a fluid abrasive material, which is a mixture of a viscoelastic material and abrasive grains, in contact with the polished surface of a workpiece under high pressure. The present invention relates to a polishing method and apparatus for polishing the surface to be polished by flowing fluid, and in particular to a method and apparatus for polishing a workpiece for polishing a hole in a mold die having grinding lines in the axial direction by wire electrical discharge machining or the like. It is related to the device.

[Conventional technology]

Conventionally, this type of polishing method and device was disclosed in Japanese Patent Application Laid-open No. 5
As described in No. 9-156661 and Japanese Unexamined Patent Publication No. 59-156662, a fluid abrasive is brought into pressure contact with the polished surface of the workpiece and reciprocated approximately linearly, thereby polishing the workpiece. A method and apparatus for applying frictional flow through a surface are known, and are schematically shown in FIG.

In the figure, the α cylinder is a workpiece, and pressurizing cylinders α are disposed facing each other at the upper and lower openings of the workpiece so as to sandwich the surface to be polished Q8a), which is the inner surface of the workpiece. . (a), (2) are pressurized pistons, (2), @ are ball screws, (2), @ are drive motors, (2) are control devices that control the drive motor (2), (2) are upper and lower This is a fluid abrasive material filled between the pressurized cylinder, α hole, and α hole.

According to the polishing process in the polishing apparatus having the above configuration, first, the drive motor (2) and (support) are driven by the control device (c) to pressurize the fluid abrasive material (2) by the piston (2) and the gradient. By applying pressure, the fluid abrasive material (2) has a polished surface Q8a)
It will be in a state where it is fully pressurized and in close contact with. In this way, with the abrasive material (2) held under pressure between the piston rods, the drive motors (a) and (a) are simultaneously driven to perform vertical and relative reciprocating motion to polish the surface to be polished Q8a). The plan was to do so.

Problem to be solved by invention C] By the way, the mold die, which is the workpiece, is generally formed by wire electric discharge machining, and in this case, the drilled hole has an axial direction. Many grinding lines appear.

When the surface to be polished Q8a) of the workpiece is polished by the conventional technique, the fluid abrasive material (2) flows only in the direction of pressure, that is, in the direction of movement of the piston, and the surface to be polished Q8a) is polished. It took a considerable amount of time to sufficiently grind the grinding streaks, and even after sufficient polishing, the surface became undulated, making it impossible to obtain good polishing accuracy.

The present invention has been made in view of the above problems, and its purpose is to shorten the polishing time and improve polishing accuracy in this type of polishing process (generally referred to as abrasive flow polishing process). It is an object of the present invention to provide a polishing method and apparatus.

[Means for solving/: solving problems]

In order to achieve the above object, the present invention makes the flowing direction of the fluid abrasive not just along the grinding streaks on the surface to be polished, but in a direction that intersects with the grinding streaks on the surface to be polished. The structure is such that the surface is polished.

That is, the present invention provides a polishing method in which a fluid abrasive material, which is a mixture of a viscoelastic substance and abrasive grains, is brought into pressure contact with the surface to be polished of a workpiece and is made to flow. ,
This polishing method is characterized by reciprocating while rotating relative to the surface to be polished, and furthermore, as an apparatus for carrying out the above method, a pressurizing body filled with a fluid abrasive and pressurized is attached to the workpiece. A pressurizing means for passing the fluid abrasive material through the surface to be polished of the workpiece, and a pressurizing means for moving the fluid abrasive material and the surface to be polished 2 of the workpiece relative to each other. This polishing device is equipped with a rotating means for rotating the polishing device.

[Effect]

The fluid abrasive filled in one pressurizing body passes through the polished surface of the workpiece held between the holders by the pressurizing means, and flows to the other pressurizing body.

Then, when a predetermined pressure is applied by the control means, the fluid abrasive material that has moved into the other pressurizing body is caused to flow into the first pressurizing body by the pressurizing means.

By repeating the above series of operations, the fluid abrasive moves back and forth, and the surface to be polished is continuously polished.

Furthermore, since the fluid abrasive rotates relative to the polished surface, when the fluid abrasive flows, the flow direction of the fluid abrasive appears on the polished surface of the workpiece. Since the direction is not along the vertical grinding lines but intersects them, the polishing speed and polishing accuracy are improved.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

[Example 1] As shown in Fig. 1, (1) is a workpiece, and holders (4) are installed in the upper and lower openings (3) of the workpiece so as to sandwich the surface (2) to be polished. Pressure cylinders (6) filled with a fluid abrasive material (5) are disposed facing each other to constitute a polishing apparatus A.

As shown in Figure 2, a hole (7) is bored in the center of the holders (4), (4), and a spiral groove (8) is formed on the circumferential surface of the hole (7). It has been subjected.

FIG. 3 shows an embodiment of a polishing machine for processing a workpiece using the polishing apparatus A of the present invention (9).

(9) is a hydraulic cylinder that operates the pressurizing piston 701.0, and is connected to a pressurizing pump (not shown).

αυ is a control device that controls the pressurizing force, pressurizing speed, etc. of the pressurizing bonder.

In addition, the upper pressurizing cylinder is fixed to the housing (2), and the space between both housings can be adjusted.
The housing υ is connected to a hydraulic cylinder α■.

Further, a pressure bonder serving as a pressure means is connected to a control device αυ so that the fluid abrasive material (5) can continuously reciprocate.

In the polishing machine with the above configuration, after the space between the upper and lower housings is expanded by the hydraulic cylinder (2) and the workpiece is placed on the lower holder, the upper housing (2) is moved by the hydraulic cylinder (2). The workpiece (1) is held by the upper and lower holding AC4), (4).

Then, the pressure bonder is driven by the control device α0 to move the pressure piston and pressurize the fluid abrasive material (5).

By applying pressure, the fluid abrasive material (5) comes into close contact with the surface to be polished (2) under sufficient pressure.

In this way, one hydraulic cylinder (
9) to start flowing the fluid abrasive material (5).

When the flow in one direction is finished, the pressure in the other hydraulic cylinder (9) is increased by the control device, and the flowable abrasive material (5) is
flow in the opposite direction.

As described above, the fluid abrasive material (5) is attached to the holder (4).
The spiral groove (8) provided in the shaft allows the shaft to perform relative reciprocating motion up and down while rotating.

Although a hydraulic pump is used as the pressurizing means, an air pump, a drive motor, etc. may also be used.

In addition, in the above embodiment, the spiral grooves (8) were formed in the holders (4), (4) as means for rotating the fluid abrasive material (5), but as shown in FIG. The same effect can be expected even if a spiral groove (8) is formed in a part of the pressure cylinders (6), (6). In this case, the workpiece (1) can also be directly held between the pressure cylinders (6) and (6) without using the holder (4).

[Embodiment 2] In FIG. 5, 04) is a protrusion provided on the piston head of the pressure pistons α and α.

As the pressurizing means, a spline shaft connecting the pressurizing pistons αS, αS and the hydraulic pump is provided, and as a rotating means, a pulley that meshes with the spline shaft is provided, which is connected to a drive motor, and the pressurizing pistons αS, αS, (
The mechanism is such that the US is rotated and relatively reciprocated.

With the above configuration, the fluid abrasive material (5) rotates and reciprocates to polish the polished surface (2) of the workpiece (1).

[Example 3] This example differs from the previous example in that the fluid abrasive (5)
Rather than applying heat rotation, the workpiece (1) is rotated so that the flow direction of the fluid abrasive (5) intersects with the grinding streaks appearing on the surface to be polished (2). The outline is shown in Figure 6.

In the figure, a holder α for holding the workpiece (1),
The α shaft is rotatably supported via a bearing Qη.

The holder αφ and the drive motor are inherited by a rotation transmission means such as a belt or a gear, and are rotated together with the gripped workpiece (1).

An elastic membrane can also be provided on the bearing α force to prevent the fluid abrasive material (5) from flowing out.

In addition, the pressing force of the fluid abrasive material (5) by the pressurizing piston QO, α according to the present invention is usually 30 to 50 kg/c-
It will be held in

The fluid abrasive material (5) in each of the above examples includes rubber,
A viscoelastic material such as synthetic resin mixed with abrasive grains is used.

The abrasive grains are TiC, TiN, and SiC.

SiN, diamond powder, and CBN ff are used as viscoelastic materials such as semisolid polyethylene resin, silicone resin,
Natural rubber etc. are used.

Further, although the spiral groove (8) provided in the holder has a width and a depth of 2 mm and a pitch of 4 m+n, the present invention is not limited to this.

In order to compare the functions of the present invention and the conventional polishing apparatus, the apparatus of Example 1 was used to polish a powder sintered mold die, which had been machined with holes by wire electric discharge machining, under the same conditions.

The workpiece for the above comparison has a substantially cylindrical machined hole with a machined hole diameter of 2nwn-1 and an axial length of 51TII11.
It is a semi-sintered die made of 0% Co alloy, and the machined holes are made by wire electrical discharge machining, and the circumferential surface roughness of the machined holes is 17s.
That's about it.

As a result of the above comparison, the device of Example 1 of the present invention has 0.3I
The polishing accuracy was 0.6I@ with the conventional device, and the polishing accuracy was significantly improved.

In addition, the weight of the workpiece is measured after polishing to determine the amount of polishing.
When the variation in the diameter of the machined hole was calculated, it was found that Example 1 of the present invention
Good results were also obtained in terms of polishing speed, with the polishing rate being 5I@ for the conventional device and 3.5 for the conventional device.

〔Effect of the invention〕

As described above, the present invention has a configuration in which the flowing direction of the fluid abrasive material intersects with the grinding streaks appearing on the surface to be polished, so that it has excellent effects such as significantly improving polishing speed and polishing accuracy. .

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a main part showing an embodiment of the polishing device for a workpiece according to the present invention, FIG. 2 is a perspective view showing an embodiment of a holder used in the polishing device of the present invention, and FIG. FIG. 4 is a partially cutaway perspective view showing an embodiment of the polishing machine to which the polishing device of the present invention is attached, and FIG. 4 shows a different embodiment of the polishing device of the present invention.
(A) is a sectional view of the main part, (B) is an explanatory view of the main part of (A), and FIG. FIG. 6 is a sectional view of a main part showing another embodiment of the present invention, and FIG. 7 is an explanatory view showing a conventional polishing apparatus. (1), α[Yes]...Workpiece (2)
, (18a) Surface to be polished (3)...
...Opening (4), αQ...1 holder (5), (241-...-Fluid abrasive material
(6), α cap (goods)...-pressure cylinder (7)...
......Hole (s)...Curve...Spiral groove (9), α■...Hydraulic cylinder αtun αpupil, (2)...Making Pressure piston αυ, (fl−=−
・Control device @・・River・・・Housing Q41・・・・・・・・・Protrusion
αη・Mountain/River...Bearing Cυ...
... Ball screw (a) Quadruple ...
- Drive motor Fig. 0 ○ Fig. 3 Fig. Fig. 3 (A) c mouth) Fig. Fig. 3

Claims (2)

[Claims] (1) A polishing method in which a fluid abrasive material made of a viscoelastic material mixed with abrasive grains is brought into pressure contact with the polished surface of the workpiece and made to flow. A method for polishing a workpiece characterized by reciprocating while rotating relative to the surface to be polished. (2) A pressurizing body that is filled with a fluid abrasive and pressurized is placed between the holders that grip the workpiece, and a pressurizing means that allows the fluid abrasive to pass through the polished surface of the workpiece. and,
An apparatus for polishing a workpiece, comprising a rotating means for relatively rotating the fluid abrasive material and the surface to be polished of the workpiece.