JP2004034258A - Polishing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polishing device 1 capable of polishing a finishing portion 41 with a small diameter without giving a force in the bending direction. <P>SOLUTION: An approximately cylindrical polishing portion 11 is filled with a polishing solution 30 and the finishing portion 41 is turned in the polishing solution 30 in the polishing portion 11 by a drive unit 20. The polishing solution 30 in the polishing portion 11 is circulated by a pump 60. Thereby, the outer peripheral surface of the finishing portion 41 is polished by a frictional force with the polishing solution 30 acting on the whole outer peripheral surface of the finishing portion 41. Therefore, the polishing device 1 which can polish the finishing portion 41 with the small diameter can be provided without applying a bending forth to the finishing portion 41 by pressing a lap plate unlike a conventional polishing device. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a polishing apparatus for polishing an outer peripheral portion of a cylindrical shaft, and is particularly suitable for polishing a shaft having a small diameter.
[0002]
[Prior art]
Conventionally, a polishing apparatus for polishing an outer peripheral portion of a cylindrical shaft, which is a material to be polished, has a polishing liquid containing an abrasive while holding and fixing one end side of the shaft to a main shaft of a driving means, and rotating the shaft around the center of the shaft as a rotation axis. The outer peripheral surface of the shaft is polished by contacting the wrap plate containing the above with the outer peripheral portion of the shaft and pressing it in the radial direction.
[0003]
[Problems to be solved by the invention]
However, in this method, in the case of a shaft having a small diameter, particularly a shaft having a diameter of 0.1 mm or less, the shaft has low rigidity, so that the shaft is bent or broken by the pressing force of the lap plate, so that polishing becomes difficult. There is a problem.
[0004]
The present invention has been made in view of such a problem, and an object of the present invention is to provide a polishing apparatus that can polish a shaft having a small diameter without giving a force in a bending direction to the shaft. .
[0005]
[Means for Solving the Problems]
The present invention employs the following technical means to achieve the above object.
[0006]
The polishing apparatus according to claim 1 of the present invention includes a driving unit that holds and rotates a substantially shaft-shaped workpiece, a polishing body provided with a substantially cylindrical hole-shaped polishing unit, and both ends in the axial direction of the polishing unit. , A polishing liquid containing polishing grains filled in the polishing section and the passage, and a polishing liquid in the polishing section and the passage are circulated to generate a polishing liquid flow in the polishing section in the axial direction of the polishing section. And a circulating unit for rotating a part of the material to be polished in the polishing liquid in the polishing unit by the driving unit. When the material to be polished is rotated in the polishing liquid in the polishing section, a frictional force is generated between the surface of the material to be polished and the polishing liquid due to a speed difference between the two. That is, a frictional force is generated between the polishing abrasive grains contained in the polishing liquid and the surface of the workpiece, and the surface of the workpiece is polished by the frictional force. This frictional force acts uniformly in the entire circumferential direction of the surface of the workpiece. Therefore, the force acting in the radial direction of the workpiece, that is, the force acting to bend the workpiece is substantially zero. Accordingly, it is possible to prevent a force in the bending direction from acting on the workpiece during polishing as in the conventional polishing apparatus, so that the polishing can be performed without applying a force in the bending direction to the workpiece. Equipment can be provided.
[0007]
In the polishing section, the polishing liquid is caused to flow in the axial direction of the polishing section. Thus, the abrasive grains in contact with the outer peripheral surface of the workpiece can be constantly replaced, and the outer peripheral surface of the workpiece can be uniformly polished. Furthermore, the temperature rise on the surface of the material to be polished can be suppressed and maintained at a constant temperature.
[0008]
The polishing apparatus according to a second aspect of the present invention is configured such that the driving means rotates the material to be polished and simultaneously reciprocates in the axial direction. Thus, the abrasive grains in contact with the outer peripheral surface of the workpiece can be constantly replaced, and the outer peripheral surface of the workpiece can be uniformly polished. Further, the temperature rise on the surface of the material to be polished can be suppressed and maintained at a constant temperature to make the polishing state uniform.
[0009]
A polishing apparatus according to a third aspect of the present invention includes a control unit that adjusts at least one of a rotation speed of a driving unit and a flow rate of a polishing liquid flow by a circulation unit. This makes it possible to optimally adjust the rotation speed and the polishing liquid flow rate of the workpiece according to the material or diameter of the workpiece.
[0010]
In this case, as in the polishing apparatus according to the fourth aspect of the present invention, if the apparatus is provided with control means for adjusting the axial reciprocating movement speed of the material to be polished by the driving means, the material or diameter of the material to be polished can be improved. , The axial reciprocating speed of the workpiece can be optimized.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a polishing apparatus according to an embodiment of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 shows an overall schematic diagram of a polishing apparatus 1 according to an embodiment of the present invention.
[0013]
The polishing apparatus 1 roughly includes a polishing body 10 provided with a polishing portion 11 having a substantially cylindrical hole shape, a driving unit 20 as driving means for holding and rotating a shaft 40 which is a shaft-like material to be polished, The polishing unit 30 is filled with the polishing liquid 30, and a part of the shaft 40 is polished by being rotated by the drive unit 40 while being immersed in the polishing liquid 30 in the polishing unit 11.
[0014]
The polishing main body 10 is formed of a metal material, and has a cylindrical hole-shaped polishing portion 11 as shown in FIG. In the polishing main body 10, communication passages 12 and 13, which are passages, are provided so as to communicate with both ends of the polishing section 11, respectively. Further, an external conduit 50 which is a passage is connected to the polishing main body 10, and is connected to both communication passages 12 and 13. That is, both end sides of the polishing section 11 communicate with each other via both communication passages 12 and 13 and the external conduit 50.
[0015]
The inner diameter of the polishing section 11 is set in accordance with the outer diameter of the finishing section 41 of the shaft 40 that is the material to be polished. That is, the gap formed between the inner peripheral wall surface of the polishing unit 11 and the outer peripheral surface of the finishing unit 41 is set to have a predetermined size.
[0016]
The inside of the polishing section 11, the communication passages 12, 13 and the external conduit 50 is filled with a polishing liquid 30 containing polishing abrasive grains (not shown). As the polishing liquid 30, for example, a liquid obtained by mixing an oil-soluble diamond slurry, which is a polishing abrasive, into a mixed liquid of glycerin stearate, polyethylene glycol, or the like is used.
[0017]
In the middle of the external conduit 50, a pump 60 as a circulation means is connected. By operating the pump 60, the polishing liquid 30 is circulated in the closed circuit of the polishing section 11, the two communication passages 12 and 13, and the external conduit 50, and the polishing liquid 11 is circulated in the polishing section 11 in the axial direction (in FIG. 1). A polishing liquid 30 flow (up and down direction) can be generated. In the polishing apparatus 1 according to one embodiment of the present invention, the above-mentioned polishing liquid 30 flows in the direction of the arrow in FIG. The pump 60 may be of any type as long as it is for pumping liquid. However, since the polishing liquid 30 is sucked and discharged, the pump 60 is made of a material and a structure having excellent wear resistance, for example, a diaphragm pump, an air ejector pump. It is more desirable to use such as.
[0018]
The drive unit 20, which is a drive unit for holding and rotating the shaft 40 as a material to be polished, includes an attachment 22 for detachably holding the shaft 40 at one end of a main shaft 21 rotated by, for example, an electric motor. At the time of polishing, the shaft 40 is held and fixed coaxially with the main shaft 21 by the attachment 22. The main shaft 21 of the drive unit 20 can reciprocate in the axial direction during rotation, that is, during the polishing operation. Further, the drive unit 20 is fixed to the polishing main body 10 directly or via another member (not shown) while maintaining a positional relationship where the main shaft 21 and the polishing portion 11 are coaxial.
[0019]
The control device 70 controls the operation states of the drive unit 20 and the pump 30. An operation panel 71 is connected to the control device 70. When the operator operates the operation panel 71, the control device 70 adjusts the rotation speed of the main shaft of the drive unit 20 and the discharge flow rate of the pump 30 according to the operation. Control to the level you did.
[0020]
Here, a polishing operation by the polishing apparatus 1 according to the embodiment of the present invention will be described.
[0021]
Here, in the polishing apparatus 1 according to the embodiment of the present invention, the shaft 40 is formed of carbide tool steel, and the outer diameter of the finished portion 41 is 0.17 mm. On the other hand, the inner diameter of the polishing section 11 of the polishing main body 10 is 0.29 mm. Therefore, a gap of 0.6 mm is formed between the outer peripheral surface of the finishing unit 41 and the inner peripheral surface of the polishing unit 11.
[0022]
Incidentally, the pressure of the polishing liquid 30 in the gap between the outer peripheral surface of the finishing unit 41 and the inner peripheral surface of the polishing unit 11 changes depending on the size of the above-mentioned gap. As the gap becomes smaller, the pressure of the polishing liquid 30 increases. The magnitude of the frictional force by the polishing liquid 30 acting on the outer peripheral surface of the finishing portion 41 is substantially proportional to the pressure of the polishing liquid 30. On the other hand, the polishing rate (polishing weight per unit time) increases as the frictional force increases. Therefore, the polishing rate can be freely set by changing the size of the gap between the outer peripheral surface of the finishing section 41 and the inner peripheral surface of the polishing section 11. However, in the polishing section 11, polishing abrasive grains that are in contact with the outer peripheral surface of the finishing section 41 are constantly replaced, and a minimum amount of polishing liquid necessary to suppress a temperature rise of the outer peripheral surface of the finishing section 41 and maintain a good polishing state. It is necessary to secure a gap for obtaining the flow rate.
[0023]
First, a shaft 40 as a material to be polished is held and fixed to the drive unit 20. At this time, the shaft 40 is attached to the attachment 22 with the drive unit 20 moved upward in FIG.
[0024]
Next, the drive unit 20 is moved downward in FIG. 1 so that the finishing portion 41, which is a portion of the shaft 40 requiring polishing, is completely accommodated in the polishing portion 11.
[0025]
Next, the polishing section 11 is filled with the polishing liquid 30, and then the operation panel 71 is operated to operate the pump 30 to circulate the polishing liquid 30.
[0026]
Next, the operation panel 71 is operated to drive the drive unit 20 to rotate the shaft 40. This starts the polishing process. Further, the operation panel 71 is operated as necessary to reciprocate the shaft 40 in the axial direction.
[0027]
Here, the rotation speed of the shaft 40 and the circulation flow rate of the polishing liquid 30 are determined based on the material of the shaft 40, the diameter of the finishing portion 41, the specifications of the polishing liquid 30, and the like.
[0028]
When the finishing part 41 is rotated in the polishing liquid 30 in the polishing part 11, since the radial velocity component of the finishing part 41 of the polishing liquid 30 is 0, the rotation between the outer peripheral surface of the finishing part 41 and the polishing liquid 30 is performed. Generates frictional force. That is, a frictional force is generated between the polishing abrasive grains contained in the polishing liquid 30 and the outer peripheral surface of the finishing unit 41, and the outer peripheral surface of the finishing unit 41 is polished by the frictional force. This frictional force acts uniformly on the entire outer circumferential surface of the finishing portion 41 in the circumferential direction. Therefore, the force acting in the radial direction of the finishing portion 41, that is, the force acting to bend the finishing portion 41 is substantially zero.
[0029]
The outer diameter of the finishing portion 41 in the polishing apparatus 1 according to one embodiment of the present invention is as thin as 0.17 mm. Therefore, in the case of using a method in which the lap plate is pressed against the outer peripheral surface of the finishing unit 41 as in a conventional polishing apparatus, there is a problem that the finishing unit 41 bends or breaks due to a radial force acting on the finishing unit 41. And polishing was difficult.
[0030]
On the other hand, according to the polishing apparatus 1 according to the embodiment of the present invention described above, since the finishing portion 41 is rotated in the polishing liquid 30, the magnitude of the force acting to bend the finishing portion 41 during polishing is provided. Is almost zero, and does not damage the finished portion 41 such as bending or breakage. Therefore, it is possible to realize a polishing apparatus capable of polishing the finished portion 41 having a small diameter without giving a force in the bending direction to the finished portion 41.
[0031]
In the polishing apparatus 1 according to the embodiment of the present invention, the polishing liquid 30 is caused to flow in the polishing unit 11 in the axial direction, and the finishing unit 41 is reciprocated in the axial direction by the drive unit 20. Exercise. Accordingly, the abrasive grains that come into contact with the outer peripheral surface of the finishing unit 41 can be constantly replaced, so that the polishing state (surface roughness) of the outer peripheral surface of the finishing unit 41 can be uniformly polished. Further, a rise in the temperature of the outer peripheral surface of the finished portion 41 can be suppressed.
[0032]
FIG. 2 shows a modification of the polishing apparatus 1 according to one embodiment of the present invention. In this modification, as shown in FIG. 2, a member 14 provided with a polishing unit 11 is detachably mounted on the polishing main body 10. The optimum value of the inner diameter of the polishing section 11 differs depending on the outer diameter and the material of the finishing section 41. Therefore, it is necessary to prepare a dedicated polishing body corresponding to the specification of the finishing unit 41. However, according to this modified example, by replacing the member 14 provided with the polishing unit 11, 41 can easily cope with the polishing process.
[0033]
In the polishing apparatus 1 according to the embodiment of the present invention described above, the material of the shaft 40 is made of cemented carbide tool steel. However, other materials, for example, a metal material other than cemented carbide tool steel or ceramics or the like is used. It may be a non-metallic material.
[Brief description of the drawings]
FIG. 1 is an overall schematic diagram of a polishing apparatus 1 according to an embodiment of the present invention.
FIG. 2 is a sectional view showing a modified example of the polishing apparatus 1 according to one embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Polishing apparatus 10 Polishing main body 11 Polishing part 12 Communication passage (path)
13 communication passage (passage)
14 member 20 drive unit (drive means)
21 Spindle (drive means)
22 Attachment (drive means)
30 polishing liquid 40 shaft (material to be polished)
41 Finishing part (material to be polished)
50 External pipeline (passage)
60 pump (circulation means)
70 Control device 71 Operation panel

Claims (4)

Driving means for holding and rotating the shaft-shaped workpiece,
A polishing body provided with a cylindrical hole-shaped polishing portion,
A passage communicating with both ends in the axial direction of the polishing unit,
A polishing liquid containing polishing abrasive grains filled in the polishing section and the pipeline,
Circulating means for circulating the polishing liquid in the polishing section and the pipeline to generate a polishing liquid flow in the polishing section in the axial direction of the polishing section,
A polishing apparatus, wherein a part of the material to be polished is rotated in the polishing liquid in the polishing section by the driving means. The polishing apparatus according to claim 1, wherein the driving unit reciprocates in the axial direction at the same time as rotating the workpiece. The polishing apparatus according to claim 1, further comprising a control unit configured to adjust at least one of a rotation speed of the driving unit and a flow rate of the polishing liquid by the circulation unit. 4. The polishing apparatus according to claim 2, further comprising control means for adjusting an axial reciprocating speed of the workpiece by the driving means.

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