JPS61257759A - Magnetic polishing method for upper/lower faces of work - Google Patents

Abstract

PURPOSE:To polish the upper/lower faces of work uniformly with high accuracy by arranging one magnetic pole facing through a gap against the flange type lower face of work and the other magnetic pole facing through a gap against the upper face of work while shifting in lateral direction of the upper face of work against the magnetic pole face. CONSTITUTION:Magnetic field is produced between the gaps 4, 5 then magnetic abrasive grains are thrown into said gaps thereafter a work 1 is rotated. Since the magnetic pole 7 is shifted by T in lateral direction of the upper face 1e of work against the magnetic pole 3, the flux density is maximized to concentrate the flux firmly against the upper/lower faces of work in the gap 45. Then the upper/lower faces of work are entirely covered with magnetic abrasive grains to prevent dispersion of magnetic abrasive grains upon rotation of work while to facilitate repeated adhesion and moving of magnetic abrasive grains against the surface of work along the field distribution thus to provide a new edge against the surface of work. Consequently, the upper/lower faces of relatively short work can be polished uniformly with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a method for magnetically polishing the upper and lower surfaces of a workpiece.

Conventional technology To finish the upper and lower surfaces of workpieces with complex shapes, such as inner hook parts of sewing machines, or workpieces with upper and lower surfaces that require polishing, conventional techniques include sand savers, elastic grindstones, and abrasive belts. , brushes, etc. were used, and manual polishing was the main method. Also British Patent Specification No. 1370356
In the No. 1, a pair of magnetic poles are placed on opposite sides of the outer cylindrical surface of the workpiece, and magnetic abrasive grains are held in an electromagnetic field applied to the gap between the magnetic poles and the workpiece surface, and the magnetic abrasive grains are attached to the workpiece. A method of magnetically polishing the circumferential cylindrical surface by simultaneously imparting rotation and vibration is disclosed.

Problems to be Solved by the Invention The conventional method of using tools such as sandpaper puffs to finish the top and bottom surfaces of the workpiece has problems on the tool side, such as the diameter of the puff that touches the surface of the part becoming smaller and the need to replace the puff frequently. The wear of the tool was severe, the tool had to be replaced frequently, the finishing process was many, the machining time was long, and the surface finish could not be said to be good over time. This invention was devised for the purpose of automating the surface finishing of the upper and lower surfaces of a workpiece by magnetic polishing instead of the conventional manual work. Also British Patent Specification No. 1370
In the magnetic polishing method disclosed in No. 356, both ends of a relatively long workpiece, such as a cylinder, are held rotatably, and the magnetic pole surface of the magnetic pole is formed into an arc concentric with the workpiece, and the outer periphery of the long workpiece is Although it is possible to magnetically polish cylindrical surfaces, it is relatively short! There is a problem in that it is difficult to magnetically polish the upper and lower surfaces of a workpiece.

Therefore, an object of the present invention is to provide a magnetic polishing method that can magnetically polish the upper and lower surfaces of a workpiece.

Means to Solve the Problem This invention uses a chuck to rotatably hold a relatively short workpiece having upper and lower surfaces to be polished with the upper and lower surfaces exposed to the outside, and to attach the workpiece to the flange-shaped lower surface of the workpiece. One magnetic pole having magnetic pole surfaces facing each other with a gap is arranged, the magnetic pole surface of the magnetic pole is provided with unevenness so as to concentrate magnetic flux, and the upper and lower surfaces are sandwiched between the magnetic pole surface of the one magnetic pole. , while shifting the position in the width direction of the upper surface of the workpiece on the diagonally opposite side, arrange the other magnetic pole having a magnetic pole face facing the upper surface with a gap in a part including the corner of the upper surface of the workpiece,
The magnetic pole surface of the magnetic pole is provided with unevenness to concentrate the magnetic flux, a direct current magnetic field is formed that configures one magnetic pole as an N pole and the other magnetic pole as an S pole, and magnetic abrasive grains are placed in the respective gaps. The feature is that the workpiece is placed in the machine and the workpiece is rotated to polish the upper and lower surfaces.

The details of this invention will be explained below based on the drawings.

1 to 5 show a first embodiment of this invention,
Workpiece 1 is an inner hook part of a sewing machine, and is shown in Fig. 4 (a).
and (as shown in →, the thread path 1b
The upper surface 1e has holes, but generally covers the entire surface, and the upper surface lθ and the lower surface 1a are all surfaces to be polished because the threads slide thereon.

In Fig. 1, reference numeral 2 denotes a chuck, which is connected to a rotating main shaft (not shown), and is connected to a rotating main shaft (not shown). There are slots in three places on the tip of 2a, and the workpiece 1
When the shaft 1f, which is integrally provided inside, is inserted into the hole of the inner cylinder 2a and the inner cylinder 2a is pressed against the tapered inner surface of the outer cylinder 2b with air, the shaft 1f is clamped by the inner cylinder 2a, and the chuck 2 By rotating the workpiece 1, the workpiece 1 is rotatably held while exposing the upper and lower surfaces 1a and 1θ to the outside. The inner cylinder 2a and the outer cylinder 2b of the chuck 2 are made of a non-magnetic material when the workpiece is a magnetic material, and are made of a magnetic material when the workpiece is a non-magnetic material. The illustrated chuck 2 is a clamping type like a drill chuck, but if the workpiece 1 is a cylindrical body without a shaft 1f, a slot is provided at the tip of the outer cylinder 2b instead of the inner cylinder 2a. , the inner cylinder 2a relative to the inner tapered part of the outer cylinder 2b
It may be of an open chuck type in which the tip of the outer cylinder 2b expands in diameter and is fastened to the inner wall of the cylindrical body by pressing. When the inner cylinder 2a and the outer cylinder 2b of the magnetic material of the chuck 2 are provided extending within the inner cavity of the workpiece 1 to near the inner wall of the upper surface 1e, when the workpiece 1 is made of a non-magnetic material, the magnetic field on the processing surface is reduced. Formation becomes more effective. When the workpiece is made of a non-magnetic material, the wall thickness of the workpiece needs to be thin enough for magnetic lines of force to pass through.

In FIG. 1, 1 is a workpiece, 2 is a chuck, 3 is one magnetic pole, and 7 is the other magnetic pole. One of the magnetic poles 3 is attached to a stretched surface 11 that protrudes from a part of the flange-like lower surface 1a of the workpiece 1.
It has magnetic pole faces 3a facing perpendicularly with a gap 4 in between, and the A-A cross section of the magnetic pole face 3a has an uneven shape as shown in Fig. 2, thereby forming a uniform magnetic field. magnetic flux can be concentrated on the machined surface. The other magnetic pole 7 is a side that diagonally faces the magnetic pole surface 3a of one magnetic pole 3 across the upper and lower surfaces of the workpiece, and is a portion including a corner of the upper surface 1e of the workpiece, and is 2ffll with respect to the upper surface le. It has magnetic pole faces 7a that face each other vertically with a gap 5 between them. In addition, the magnetic pole 7 extends perpendicularly from the magnetic pole surface 7a and faces each other with a gap 6 at the corner of the upper surface and the upper end of the body surface so that the magnetic flux can be well radiated to the corner of the upper surface of the workpiece. It has a magnetic pole face 7C. In addition, the other magnetic pole 7 is shifted from the magnetic pole surface of one magnetic pole 3 by an amount T in the width direction of the upper surface of the workpiece.
It is the sum of the distance T between the end faces of TU18a and the distance T2 between the center of the workpiece and the end face of the magnetic pole face 7a.
mST, is 10,52IIST2 is 7.5n. The BB cross section of the magnetic pole surface 7a and the C-C cross section of the magnetic pole surface 7C have an uneven shape as shown in FIG.

A magnetic pole surface 3a of one magnetic pole 3 and a magnetic pole surface 7a of the other magnetic pole 7
, 7c have almost the same magnetic pole area.

Figure 1 of the 3rd public tower (a device used to teach Kuzubo Dharma; 1 is the workpiece, 3 and 7 are magnetic poles, and 20 is a magnetic pole head that holds the magnetic poles 3 and 7, respectively. The magnetic pole head 20 can be finely adjusted on the support base 23 in the direction of the paper using the side surface 22, and the support base 23 is linked to the support bed 241: an air cylinder 26 fixed by a frame 25. The support base 2 is connected to the air cylinder 26 for operation.
3 moves back and forth on the support ped 24 together with the magnetic pole head 2o in the axial direction of the magnetic pole head 20. 27 is York,
28 is an electromagnetic coil, and the yoke 27 is fixed to the base 3o via a spacer 29 made of a non-magnetic material.

Effects In FIGS. 1♀ and 3, when electricity is applied to form a DC magnetic field through the yoke 27, the support bed 24, the support base 23, and the magnetic pole head 2°, configuring the magnetic pole 3 as the north pole and the magnetic pole 7 as the south pole, As shown in FIG. 5, a part of the lower surface 1a of the workpiece 1 corresponds to the N pole of the magnetic pole 3, and a part including the corner of the upper surface 1e of the workpiece 1 corresponds to the S pole of the magnetic pole 7. is configured as a north pole, a magnetic field is generated in gaps 4 and 5, and when magnetic abrasive grains are introduced into these gaps and the chuck 2 is rotated to rotate the workpiece 1, the magnetic pole surface 3a becomes as shown in FIG. Because the workpiece has an uneven shape, the magnetic flux concentrates on a part of the lower surface 1a of the workpiece, and the magnetic field holds the magnetic abrasive grains firmly against the rotation of the workpiece, and the magnetic abrasive grains held by the magnetic field The friction between the grains and the lower surface of the rotating workpiece uniformly polishes the lower surface 1a. In addition, due to the magnetic pole surfaces 7a, 7c having an uneven shape, magnetic flux is concentrated from the center of the upper surface 1e of the workpiece to the upper end of the workpiece through the corners, and the magnetic field φ causes the magnetic abrasive grains to rotate. On the other hand, the top surface of the workpiece e is polished uniformly by the friction between the magnetic abrasive grains held in the magnetic field and the top surface of the rotating workpiece.

Since the other magnetic pole 7 is shifted from the one magnetic pole 3 by T in the width direction of the upper surface 1e of the workpiece, the magnetic flux density is maximized and the magnetic flux is concentrated on the upper and lower surfaces of the workpiece in the gaps 4 and 5. To make the crucible stronger and prevent the magnetic abrasive grains from flying out when the workpiece rotates, the magnetic abrasive grains cover the entire upper and lower surfaces of the crucible, and a new cutting edge is applied to the workpiece surface. The magnetic abrasive grains are made to adhere to the workpiece surface along the magnetic field distribution and to easily reverse movement.

Thus, by this method, the upper and lower surfaces of a workpiece having a complicated shape, such as the inner hook part of a sewing machine, can be inspected at a circumferential speed of 10
0 m/1IilI, magnetic velocity density 8ooo to 1ooo Gauss, gap 1.5 to 2a @ closed, barrel finish and paper finish 180 nameplate base, 90
It was polished to a near mirror finish in seconds.

The workpiece used in this example is an inner hook part of a sewing machine.The lower surface 1a of the part is shaped like a flange as shown in FIG. As shown in , there are holes, but they cover almost the entire surface.When polishing the upper surface 1e of the workpiece 1, the circumferential speed of the upper surface of the workpiece 1
- It becomes almost equal to zero as it goes towards the top surface 1θ
It often happens that the abrasive grains become stagnant in the center of the grinder, and the center is not polished as well as the other surrounding areas. Therefore, it is possible to rotate the workpiece by making the axis of the workpiece eccentric to the rotational axis, thereby causing movement of the abrasive grains toward the center of the upper surface 1θ of the workpiece, and polishing the center sufficiently. can. Figure 6 shows the state of the eccentric movement of the workpiece. 1 is the workpiece, 2 is the chuck, 41 is the connecting shaft connected to the chuck 2, 42 is the rotating main shaft, and the connecting shaft 41 is connected to the connecting shaft 41. A bevel 43 is provided at the tip, and the bevel 43 is inserted into the groove 45 of the member 44 with a receiver provided on the rotating main shaft 42, and is aligned with the axis N of the workpiece relative to the rotational axis M of the rotating main shaft 42. After sliding the bezel 43 in the groove 45 of the member 44, the connecting shaft 41 is fixed by a nut 46.

As a result, the center of the upper surface 1e of the workpiece 1 rotates at a position offset by Δ, so the circumferential speed with respect to the center increases and movement of the abrasive grains occurs, thus polishing the center of the upper surface. is carried out without any problems. If the workpiece is an inner hook part of a sewing machine, Δ may be approximately 5 mm or more. In Fig. 1, gap 6 is also larger than gap 5 by 6 minutes. The device for causing such eccentric movement of the workpiece is not limited to the device shown in FIG. 6, and various other devices may be used.

FIG. 7 shows a second embodiment of the present invention, in which one magnetic pole 3 facing the lower surface 1a of the workpiece is provided with a magnetic pole face 3b facing the workpiece with a gap in a part of the body surface. This embodiment is similar to the embodiment shown in FIG. 1 except for this point, and the same members are given the same reference numerals. In Fig. 7, one magnetic pole 3
has a magnetic pole surface 3a facing perpendicularly to the pumping protrusion surface 11 of the lower surface 1a of the workpiece 1 with a gap 4 therebetween, and extends perpendicularly from the magnetic pole surface 3a to form a pumping protrusion on the irregular-shaped body surface of the workpiece 1. It has a magnetic pole surface 3b facing each other with a gap 4 in a part of the body surface including the shell surface 1g, and the D-D cross section of the magnetic pole surface 3b has an uneven shape as shown in FIG. . According to the method shown in FIG. 7, the upper and lower surfaces are completely polished, and the lower and upper ends of the irregularly shaped barrel surface are polished.

FIG. 8 shows a third embodiment of the present invention, in which the workpiece 1
SUS material (stainless steel) with the shape shown in the diagram
The lower surface 1a has a flange-like surface that requires polishing.
1. It is noted that the upper surface 1s in the form of a flange extending diagonally and the body surface IC connecting both surfaces correspond to the magnetic pole surfaces of the pair of magnetic poles corresponding to the surfaces 1, a, le, and lc to be polished. Except for this, this embodiment is similar to the embodiment shown in FIG. 1, and the same members are given the same reference numerals. In FIG. 8, the chuck 2 consists of an inner tube 2a and an outer tube 2b made of magnetic material inserted into the inner cavity of the workpiece 1. A slot is provided at the tip of the outer tube 2b, and the inner surface of the outer tube 2b is tapered. This is an open chuck in which the tip of the outer cylinder 2b expands in diameter and fastens to the inner wall of the workpiece by pressing the inner cylinder 2a against the workpiece.

One of the magnetic poles 3 has a magnetic pole surface 3a facing the lower surface 1a of the workpiece 1 perpendicularly with a gap 4 of 2fRtx, and extends from the magnetic pole surface 3a in a perpendicular direction to the trunk surface of the workpiece 1.
It has magnetic pole faces 3b facing each other with two gaps 4 at C, and the A-A cross section of the magnetic pole face 3a and the D-D cross section of the magnetic pole face 3b have uneven shapes as shown in FIG. ing. The other magnetic pole 7 is shifted by an amount T in the width direction of the upper surface 1e of the workpiece on the side that diagonally faces the magnetic pole surface of the one magnetic pole 3 across the upper and lower surfaces of the workpiece. It has a magnetic pole surface 7a extending from a portion including the corner of 1e to near the upper end of the flange portion and facing diagonally with a gap 5 of 2 nm with respect to the upper surface 1e.
The trunk surface of workpiece 1 extends horizontally by tl from 1cl:,2
It has magnetic pole faces 7C facing each other with a gap 5 of am in between, and the FF cross section of the magnetic pole face 7a and the G-G cross section of the magnetic pole face 7C have an uneven shape as shown in FIG. According to the method shown in FIG. 8, the flange-shaped lower surface 1a that requires polishing, the flange-shaped upper surface 1e extending obliquely, and the body surface IC connecting both surfaces are polished uniformly and accurately.

FIG. 9 shows a fourth embodiment of the present invention, in which the workpiece 1
is a cylindrical body with a flange made of magnetic material such as steel, and the flange part at the tip is polished, and the bottom surface 1 that requires polishing is
Upper surface 1 where a is a stepped flange surface and requires polishing
This is the same as the first embodiment shown in FIG. 1, except that e is a stepped disk surface and the magnetic pole surface of the other magnetic pole 7 corresponds to the stepped disk surface. The members are given the same reference numerals. In FIG. 9, the chuck 2 is the shaft portion 1 of the workpiece 1.
31 is a chuck part made of a non-magnetic material such as SUS material (stainless steel), and 60 is a chuck part made of a non-magnetic material such as 5O8 (stainless steel). and 60 are fixed together by screws 61. The chuck portion 60 has a tapered surface 64
The chuck body 62 is fitted into the tapered surface of the chuck body 62 made of a non-magnetic material. The chuck body 62 is fixed to a rotating main shaft (not shown) via a connecting member 63. 65 is a non-magnetic dust seal plate, and 66 and 67 are oil seals. The chuck part 60 is screwed onto the dropper 32, and by pulling the dropper 32, the workpiece 1 is fastened to the chuck part 31. In FIG. 9, the magnetic pole face 3a of the magnetic pole 3 is disposed perpendicularly facing the protruding face 11 of the stepped flange face 1a with a gap 4 therebetween. The other magnetic pole 7 is on the side that diagonally faces the magnetic pole surface 3a across the upper and lower surfaces 1a and le, and is shifted by an amount T in the width direction of the upper surface 1e of the workpiece 1 while moving the upper surface 1θ of the workpiece 1. It has a magnetic pole surface 7a which extends from a portion including the corner to approximately the center and faces perpendicularly to the upper surface 1e with a gap 5 therebetween, and the cross section of the magnetic pole surface 7a is as shown in FIG. It has an uneven shape. 9th
According to the method shown in the figure, the upper surface 1e and lower surface 1a of the workpiece 1 are polished uniformly and accurately, as in the first embodiment.

Effects of the Invention This invention enables magnetic polishing of the upper and lower surfaces of a relatively short workpiece without using any conventional tools such as a puff, and also aims to automate the surface polishing of the workpiece. be able to. In addition, in this invention, a pair of magnetic poles are arranged with their positions shifted in the width direction of the upper surface of the workpiece, thereby preventing the magnetic abrasive grains from flying outward when the workpiece rotates. The magnetic abrasive grains adhere to the workpiece surface and prevent movement.In contrast, a new cutting edge is created, so the surface to be polished is a comparison in which the top and bottom surfaces are the same. The entire surface of a target short workpiece can be polished uniformly and accurately.

In addition, in this invention, since the upper and lower surfaces of the workpiece are exposed to the outside and rotatably held by the chuck, there is a limit to securing a clearance between the upper and lower surfaces of the workpiece to the pumping surface. It is possible to use a magnetic pole whose magnetic pole surface is freely shaped according to the shape, and this makes it possible to uniformly and accurately polish the upper and lower surfaces of not only the inner hook part of a sewing machine but also complex-shaped workpieces that have upper and lower surfaces that need to be polished. can do.

[Brief explanation of drawings]

FIG. 1 is a partially sectional side view showing the method of the present invention;
Figure 2 shows lines A-A, B-B, C, -G in Figure 1, line D-D in Figure 7, line A-A, D-DF-F, and G-G in Figure 8. FIG. 9 is a cross-sectional view taken along the line Fi −, FIG. 3 is a schematic diagram showing an apparatus for carrying out the method shown in FIG. 1;
Fig. 4 (a) is a perspective view of the inner hook part of the sewing machine, which is a workpiece, seen from the outside, Fig. 4 (b) is a perspective view of the inner hook part of the sewing machine, seen from the inside, and Fig. 5 shows the operation of the present invention. Schematic diagram, Figure 6 is a partially cross-sectional schematic diagram showing the eccentric movement of the workpiece,
FIG. 7 is a side view showing a second embodiment of the present invention, FIG. 8 is a side view partially showing a third embodiment of the invention in cross section, and FIG. 9 is a side view partially showing a fourth embodiment of the invention. FIG. 3 is a side view shown in cross section. 1...Workpiece, 2...Chuck, 3.
...One magnetic pole, 7...Other magnetic pole, 3a.
...Pole surface of one magnetic pole, 7a, 7c...Pole surface of the other magnetic pole, 4.5...Gap.

Claims (1)

[Claims] 1. A relatively short workpiece having upper and lower surfaces to be polished is rotatably held by a chuck with the upper and lower surfaces exposed to the outside, and a gap is provided to the flange-shaped lower surface of the workpiece. One magnetic pole having magnetic pole surfaces facing each other is arranged, the magnetic pole surface of the magnetic pole is provided with unevenness to concentrate magnetic flux, and the upper and lower surfaces are diagonally opposed to the magnetic pole surface of the one magnetic pole. The other magnetic pole is shifted in the width direction of the upper surface of the workpiece on the side where the workpiece is to be processed, and the other magnetic pole has a magnetic pole face that faces the upper surface with a gap in a portion including the corner of the upper surface of the workpiece. The surface is provided with irregularities to concentrate magnetic flux, a DC magnetic field is formed in which one magnetic pole is the north pole and the other magnetic pole is the south pole, and magnetic abrasive grains are introduced into each of the gaps,
A method for magnetically polishing the upper and lower surfaces of a workpiece, which is characterized by rotating the workpiece and polishing the upper and lower surfaces. 2. The magnetic polishing method according to claim 1, wherein the workpiece is rotated with the axis of the workpiece eccentric to the rotation axis.