JP2002118025A - Cutting method using wire saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent magnet pieces containing no adjoining surface from becoming inaccurate in thickness due to the fact that a wire is fitted in the adjoining surfaces of adjacent magnet blocks and getting to run unstably, and resultantly adjacent wires becoming unstable in running also, in a method where a plurality of magnet blocks are arranged into a magnet train, composed of the magnet blocks whose adjacent surfaces are brought into contact with each other, and the magnet train is made to bear against a plurality of wires which run rectilinearly in parallel and cut out into a plurality of magnet pieces at the same time. SOLUTION: A method of cutting a magnet block with a wire saw is carried out with the steps which include a glass plate 11 being pasted on a processing jig 12, a plurality of magnet blocks are pasted on the undersurface of the glass plate 11 to make a magnet train 10, the adjoining surfaces of the magnet blocks are tilted, set arcuate or made rugged surfaces to be engaged with each other so as not to coincide with the direction in which a wire 3 runs rectilinearly, and the wire 3 is prevented from being fitted into the adjoining surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a sintered permanent magnet of the Nd--Fe--B type, and cuts and cuts a magnet block molded and sintered to a predetermined size. The present invention relates to a cutting method using a wire saw in which a plurality of magnet blocks are arranged and held, and a plurality of wires are divided and cut simultaneously.

[0002]

2. Description of the Related Art As information devices become smaller and thinner, the demand for permanent magnets having a small or thin shape is rapidly increasing. In particular, Nd-Fe, which can provide strong magnetization and has a relatively low cost, is available. -B type sintered permanent magnet is used as a head magnet for driving a hard disk. The magnet piece 1 shown in FIG. 8 is an intermediate product used as a head driving magnet, and the magnet piece 1 is subjected to surface treatment and plating. When magnetized, it becomes a head driving magnet. This magnet piece 1 is a magnet block 1 shown in FIG.
00 is cut into a predetermined thickness. The magnet block 100 is formed by press-molding and sintering powder after fine pulverization, and a glass jig is detachably attached to a workpiece attachment portion of a wire saw. One surface of the plate is adhered, a plurality of magnet blocks 100 are arranged and adhered to the other surface of the glass plate to form a magnet row 10, and a processing jig is attached to a workpiece mounting portion of a wire saw and cut. Of the same row of magnets 10
The magnet block 100 is cut, and FIG.
1 is a state in which the magnet block 100 is adhered, and the magnet blocks 100 which are shown when the magnet block 100 is viewed from the direction of the arrow A shown in FIG. The adjacent portion 101 is orthogonal to the longitudinal direction of the glass plate 11, the wire for cutting the magnet block 100 is also orthogonal to the longitudinal direction of the glass plate 11, and the wire for cutting the adjacent portion 101 in the wire saw is parallel. is there.

By the way, one magnet block 100 is cut into, for example, 10 to 30 magnet pieces 1.
The number of cuts will increase or decrease depending on the thickness of the magnets, and a plurality of wires cut the magnet block 100 of the magnet row 10 at the same time. As an example, there is a difference in the variation in the thickness with respect to the adjacent portion 101. For example, the thickness is measured by cutting the magnet array 10 into a total of 125 pieces except for both ends, and the sample is subjected to the population of the adjacent portion 101 under the same condition. When the variation is examined every time, the population of the first sample including the adjacent portion 101 is σ = 138 μm, the population of the second sample including only the sample adjacent to the first sample is σ = 12 μm, and the other third sample is Was σ = 5 μm,
First, the portion corresponding to the first sample is not suitable for the magnet piece 1 like the end of the magnet row 10, and the portion corresponding to the third sample has the smallest variation and is suitable for the magnet piece 1 without additional processing. It is a part corresponding to 2 samples and is not suitable for the magnet piece 1 unless additional processing is performed according to the required thickness accuracy. The additional processing requires additional steps and time, increases the cost, and prolongs the delivery time. Will occur.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the problems in the prior art as described above. Therefore, the problem to be solved by the present invention is to Third variation in the thickness of the corresponding part
An object of the present invention is to provide a cutting method using a wire saw with high cutting accuracy, which does not cause variation in thickness of a portion corresponding to the second sample.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, a plurality of magnet blocks are formed as a magnet row in which adjacent surfaces are in contact with each other, and the magnet row is formed. In a method of simultaneously cutting a plurality of magnet pieces while abutting on a plurality of wires running in a straight line in parallel, the mutually adjacent surfaces of the magnet block are not matched with the direction in which the wires run in a straight line. Cutting method using a wire saw.

According to a second aspect of the present invention, there is provided a cutting method using a wire saw according to the first aspect, wherein the mutually adjacent surfaces of the magnet block are inclined with respect to a direction in which the wire travels linearly.

According to a third aspect of the present invention, there is provided a cutting method using a wire saw according to the first aspect, wherein mutually adjacent surfaces of the magnet block are formed in an arc shape.

According to a fourth aspect of the present invention, there is provided the cutting method using a wire saw according to the first aspect, wherein the mutually adjacent surfaces of the magnet block have a shape in which a plurality of concave and convex shapes are engaged.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described. FIG. 1 is an explanatory view of a wire saw 7 for carrying out a cutting method of the present invention, and FIG. The processing jig 12 to be mounted is shown, and the processing jig 1
2 shows a configuration in which a glass plate 11 is adhered to 2 and a magnet block is adhered to the glass plate 11 to form a magnet row 10, and is a side view seen from the direction of arrow X in FIG. A
Indicates the direction of the magnet block, and indicates the same direction as the arrow A of the magnet block 100 shown in FIG. 7 with respect to the magnet block. In the case of the magnet block 100, the magnet block 100 is stuck upside down with the posture shown in FIG. 3 to 5 are explanatory views showing an embodiment using a magnet array 10 of the cutting method of the present invention.

FIG. 1 is an explanatory view showing the main structure of a wire saw 7. The wire 3 wound around a pay-out reel 4 is pulled out while being held by a guide roller 6, and three wires 3 are arranged in a mutually parallel and rotatable manner. A plurality of wires 3 running parallel to the direction of arrow F are wound around the roller 2. The wire 3 wound around the roller 2 is pulled out and wound while being held by the guide roller 6. The workpiece mounting portion of the wire saw 7 moves up and down from the upper side orthogonal to the parallel running wire 3 with respect to one upper side of a triangle formed by the wire 3 and the three grooved rollers 2, which is wound around the take-up reel 5. A glass plate 11 and a magnet array 10 are attached to a processing jig 12 attached to a workpiece mounting portion. When the magnet array 10 is lowered in the direction of arrow D, the magnet array 10 is elongated in the traveling direction of the wire 3. It abuts the wire 3 parallel running in a posture in which directions are perpendicular to, a method of the magnet array 10 is disconnected from the contact with the wire 3 to the magnet element 1 is the same as the prior art,
In a state where the magnet array 10 is pressed against the wire 3,
The wire 3 travels and cuts while a working liquid containing free abrasive grains flows in the abutted portion.

FIGS. 3 to 5 show a magnet array 10 according to the cutting method of the present invention. FIG. 3 shows a state in which a magnet block 200 is adhered to a glass plate 11, and the surfaces of the magnet block 200 adjacent to each other. Also, the magnet row 10 is adhered, but the linear adjacent portion 201 is inclined with respect to the longitudinal direction of the glass plate 11. The wire 3 for cutting the magnet block 200 is orthogonal to the longitudinal direction of the glass plate 11. Therefore, the adjacent portion 201 is inclined with respect to the wire 3.

FIG. 4 shows a magnet block 30 on a glass plate 11.
0, the surfaces adjacent to each other of the magnet block 300 are also attached to form the magnet row 10.
1 has an arc shape, and mutually adjacent magnet blocks 300 match the adjacent surfaces of the arc shape, that is, one convex arc shape matches the adjacent surface with the concave arc shape of the other. The wire 3 that cuts the magnet block 300 is a straight line perpendicular to the longitudinal direction of the glass plate 11, and the arc-shaped adjacent portion 301 of the wire 3 is in contact with the straight line and the arc, and does not match.

FIG. 5 shows a magnet block 40 on a glass plate 11.
0, the surfaces adjacent to each other of the magnet block 400 are also attached to form the magnet row 10, but the adjacent portion 40
Reference numeral 1 denotes a shape in which a plurality of concave and convex shapes are meshed with each other, and mutually adjacent magnet blocks 400 make the adjacent surfaces of the concave and convex shapes coincide, that is, one convex shape is fitted to the other convex shape and adjacent to each other. The wire 3 that cuts the magnet block 400 so that all of its surfaces coincide with each other is a straight line orthogonal to the longitudinal direction of the glass plate 11, and the adjacent portion 401 to the wire 3.
Does not occur that all of the adjacent planes coincide and become parallel.

In the embodiment shown in FIGS. 3 to 5,
The adjacent portions 201, 301, and 401 do not have a relationship in which all surfaces adjacent to the wire 3 of the wire saw 7 coincide with each other and become parallel. The conventional adjacent portion 101 is parallel to the wire 3. In other words, according to observations by the inventors, the wire 3 is easily fitted into the adjacent portion 101, and when fitted, the wire 3 runs along the adjacent portion 101. , Wire 3
Is hindered by the fitted adjacent portion 101, the adjacent portion 1
01 rarely completely coincides with the position where the wire 3 originally travels, and it can be seen that the travel of the wire 3 is shifted to a different position and does not travel linearly. Of the present invention, the unstable running of the magnet affects the wires 3 running on both sides. If the running of the wires 3 on both sides becomes unstable, the thickness of the magnet piece 1 corresponding to the second sample varies. The adjacent portions 201, 301, and 401 formed by the cutting method can prevent the wires 3 from being fitted into each other, thereby preventing the running of the wires 3 on both sides from becoming unstable. As described above, the magnet block is formed by molding and sintering powder, and has a predetermined shape error and is difficult to completely match. There also have a predetermined shape error, it remains that implementation and its effects of the present invention can be obtained not.

[0015]

According to the cutting method using a wire saw of the present invention, a plurality of blocks for magnets are formed as magnet rows that are in contact with surfaces adjacent to each other. The running is stable without the wires being inserted into the adjacent portions between the surfaces where the blocks are adjacent to each other, and the running of the wires on both sides of the wires is also stable. There is no variation in the magnet pieces corresponding to the two samples, and the magnet pieces excluding the portions including both ends and adjacent portions of the magnet row have thickness accuracy and variation suitable for the magnet pieces without additional processing. As a result, an additional process and time are not required, so that the cost is saved and the delivery time is not lengthened.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a main configuration of a wire saw.

FIG. 2 is a processing jig to be attached to a workpiece attachment portion of a wire saw.

FIG. 3 is a magnet row in which mutually adjacent surfaces of a magnet block are inclined.

FIG. 4 is a magnet row in which mutually adjacent surfaces of a magnet block are formed in an arc shape.

FIG. 5 is a diagram showing a magnet array in which the mutually adjacent surfaces of the magnet block have a shape in which irregularities mesh with each other.

FIG. 6 shows a conventional magnet array in which mutually adjacent surfaces of a magnet block are parallel to wires.

FIG. 7 is a perspective view of a magnet block.

FIG. 8 is a perspective view of a magnet piece.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnet piece 2 Roller 3 Wire 4 Feeding reel 5 Take-up reel 6 Guide roller 7 Wire saw 10 Magnet row 11 Glass plate 12 Processing jig 100, 200, 300, 400 Magnet block 101, 201, 301, 401 Adjacent part A magnet Arrow indicating the direction of the application block. D Arrow in the direction to lower the processing jig. F Arrow in the direction in which the wires travel in parallel. X The direction of the processing jig shown in FIG.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 3C058 AA05 AA07 AA11 AA16 AB04 AC04 BA02 BA07 CA02 DA03 5E062 CE01 CG01

Claims (4)

[Claims] 1. A method of cutting a plurality of magnet blocks into a plurality of magnet pieces by simultaneously forming a plurality of magnet blocks into a magnet row whose surfaces adjacent to each other are in contact with each other and abutting the magnet row on a plurality of wires running in a straight line in parallel. A cutting method using a wire saw, wherein surfaces adjacent to each other of the magnet block are not made to coincide with a direction in which the wire travels linearly. 2. The cutting method using a wire saw according to claim 1, wherein the mutually adjacent surfaces of the magnet block are inclined with respect to a direction in which the wire travels linearly. 3. The cutting method using a wire saw according to claim 1, wherein mutually adjacent surfaces of the magnet block are formed in an arc shape. 4. The cutting method using a wire saw according to claim 1, wherein the mutually adjacent surfaces of the magnet block have a shape in which a plurality of concave and convex shapes are engaged.