JPH07182615A - Method and apparatus for grinding magnetic core block for magnetic head apparatus - Google Patents

Abstract

PURPOSE:To improve the flatness of grinding in a gap depth surface. CONSTITUTION:In a long-sized magnetic core block 1 with a magnetic gap G formed on one plane, the surface at a certain angle of a surface 3 where the magnetic gap is formed is ground planar along the length of the magnetic gap. Other angle surfaces of the magnetic gap forming surface 3 undergo this planar grinding to finish the magnetic gap forming surface 3 as a specified magnetic gap depth D by accomplishing a grinding over multiple surfaces. This makes possible the elimination of variations in gap depth finish dimensions almost completely in a working core block and also allows the use of the same apparatus and jig in the working of core blocks for individual magnetic head apparatuses varied in R shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for polishing a long magnetic core block having a magnetic gap formed in one plane, which can cut out a plurality of magnetic head chips for a magnetic head device, and a polishing apparatus for the same. Is.

[0002]

2. Description of the Related Art First, a conventional method of processing a magnetic core block for a magnetic head device (hereinafter simply referred to as "core block") and its processing apparatus will be described with reference to FIGS. FIG. 4 is a conceptual perspective view of a conventional polishing apparatus for a magnetic core block, and FIG. 5 is a top view of the magnetic core block showing a state of a magnetic gap forming surface polished by the polishing apparatus of FIG. 6 is a side view showing the state of the magnetic gap forming surface in the longitudinal direction, which is also polished by the polishing apparatus of FIG.

In FIGS. 4 and 5, reference numeral 1 indicates a core block. The core block 1 is made of, for example, single crystal ferrite, and has a pair of core halves 2 of a certain length.
a and 2b are abutted against each other so that a magnetic gap G is formed. Reference numeral 3 indicates a plane on which the magnetic gap G is formed (hereinafter, simply referred to as a “gap forming surface”), and the gap forming surface 3 is a portion to be polished in the present invention.

In FIG. 4, reference numeral 100 generally indicates a magnetic core block polishing apparatus (hereinafter simply referred to as "polishing apparatus"). This polishing machine 1
00 is a rotary polishing device 110, and a storage jig 120 in which a holding portion 121 for storing and holding the core block 1 is formed.
A support device (not shown) having a pivot 130 for supporting the storage jig 120, and the storage jig 12
0 is a linear drive device (not shown) that linearly reciprocates in the longitudinal direction (direction of arrow X), and a rotary drive device (illustrated in the drawings) that rotates the storage jig 120 in the direction of arrow Ra. Not included) and a drive device (not shown) that drives the storage jig 120 forward and backward (in the direction of arrow Y) with respect to the rotary polishing device 110.
Other devices than the rotary polishing device 110 are movably mounted on an XY table (not shown). The rotary polishing device 110 polishes the gap forming surface 3 of the core block 1 on the peripheral surface 112 thereof while always rotating around the shaft 111 in the direction of arrow Rb at a constant rotation speed.

In order to grind and grind the gap forming surface 3 of the core block 1 (hereinafter, simply referred to as "polishing") using the grinding apparatus 100 having such a structure, first, the core to be ground is to be ground. With the reinforcing plate 122 applied over the entire length of the back surface of the block 1 and the gap forming surface 3 arranged in a direction facing the rotary polishing device 110,
It is stored and fixed in the holder 121.

Then, the rotary polishing device 110 is rotated, the storage jig 120 is moved to the left of the arrow X with respect to the rotating polishing device 100, and is moved forward in the direction of the arrow Y, and the pivot 130 is moved. The storage jig 120 is rotated around.

[0007] Then, the rotary polishing apparatus 110, as shown in FIG.
, The gap forming surface 3 of the core block 1 is polished from the right end surface 3A thereof.
By moving to the right of arrow X at a constant speed,
The gap forming surface 3 is cylindrically polished over its entire length from the right end to the center and the left end, as shown by the solid line in FIG. 5, and has a gap depth D of a predetermined depth and an arc of a predetermined shape (hereinafter, simply The medium sliding surface 4 is formed by "R shape".

[0008]

However, in this polishing method and apparatus, the core block 1 is stored in the storage jig 1.
Since there is a mechanical error in fixing the holding jig 120 to the holder 20 and a mechanical error in supporting the storage jig 120 with the pivot 130, the rotary polishing apparatus 110 causes the right end surface and the left end of the gap forming surface 3 of the core block 1 to move. When abutting against the surface and applying a larger load than the central surface when polishing, the core block 1 is pushed back by the rotary polishing device 110, albeit very slightly, and as shown in FIG. The right end surface 2A and the left end surface 2C of the medium sliding surface 4 of the core block 1 are ground deeper than the central surface 2B by a dimension T, and the flatness of the medium sliding surface deteriorates.

In practice, the difference T is 10 to 20 μm over the length of 4 to 5 mm at both ends of the core block.
There is a degree of variation, which affects the gap depth D, and it was not possible to uniformly obtain a magnetic head device capable of realizing a predetermined magnetic recording / reproducing characteristic from one core block.

During the polishing process, the size of the gap depth D must be checked from both ends of the core block at all times. Furthermore, the standard of the R shape of the medium sliding surface 4 is R2.65 mm, R
There are many sizes such as 5 mm, R6 mm, R8 mm, etc., and a storage jig 120 corresponding to these is required. An object of the present invention is to solve the inconvenient points described above.

[0011]

Therefore, according to the method of processing a magnetic core block for a magnetic head device of the present invention, the magnetic gap forming surface of a long magnetic core block in which a magnetic gap is formed on one plane is formed. A certain angled surface is polished into a flat surface along the length direction of the magnetic gap, and this flat surface polishing processing is also applied to other angled surfaces of the magnetic gap forming surface to polish the magnetic gap forming surface into multiple surfaces. By doing so, a method for forming a medium sliding surface and finishing to a predetermined magnetic gap depth was adopted.

Further, the polishing apparatus supports a magnetic core block supporting device for supporting both ends of a long magnetic core block having a magnetic gap formed on one plane and rotating the magnetic gap forming surface in multiple steps. A rotary polishing device that has a rotation axis orthogonal to a magnetic gap formed in the lengthwise direction of the magnetic gap forming surface and that polishes the magnetic gap forming surface by rotation; and a rotary polishing device and the magnetic core block supporting device. And a drive device that moves the magnetic core block linearly and relatively in the longitudinal direction of the magnetic core block to realize the processing method and solve the problems.

[0013]

Therefore, the flatness of the sliding surface of the medium can be easily obtained, and the variation in the finished size of the gap depth in the core block to be processed can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a method for polishing a magnetic core block and an apparatus for polishing the same according to the present invention will be described below with reference to FIGS.
Will be explained. 1 is a perspective view of an embodiment of a polishing apparatus of the present invention, and FIG. 2 is a top view of a magnetic core block showing a state of a magnetic gap forming surface polished by the polishing apparatus shown in FIG. 3 is a side view showing a state of the magnetic gap forming surface in the longitudinal direction polished by the polishing apparatus shown in FIG.

First, the polishing apparatus 10 of the present invention will be described with reference to FIG. The polishing apparatus 10 supports the core block 1 and conveys the core block 1 linearly in the longitudinal direction, and the core block 1 vertically and vertically.
Moves back and forth, and the gap forming surface 3 of the core block 1
And a rotary polishing device 40 for rotary polishing in the longitudinal direction.

Further, the transfer device 11 includes a base 12 and a sliding base 13 and a ball screw 14 for moving the sliding base 13 and an X-axis motor 15 for driving the ball screw 14 to rotate. Configured X-axis table 20
And a surface plate 21 fixed to the upper surface of the slide table 13 and bearings 22A and 22 fixed to both side ends of the surface plate 21.
A core block supporting device 30 that is rotatably supported by B and bearings 22A and 22B and that includes a holding device 23 that holds the core block 1 and a motor 24 that rotates the holding device 23 in multiple stages. It consists of and.

On the other hand, the rotary polishing device 40 can move in the Y-axis direction (Y-axis direction indicated by arrow Y) which is orthogonal to the moving direction of the X-axis table 20 (X-axis direction indicated by arrow X), A base 41, a slide 42, and a ball screw 43 for moving the slide 42 and a Y-axis for rotating the ball screw 43, which are provided between the base 41 and the slide 42 so as to be able to move forward and backward with respect to the X-axis table 20. A Y-axis table 45 composed of a motor 44, a base 50 vertically fixed on the upper plane of the slide table 42, and a slide table 51 are present between the two. A ball screw 52 that moves in the axial direction (Z-axis direction indicated by arrow Z) and this ball screw 52.
A Z-axis table 54 composed of a Z-axis motor 53 for rotating and driving, and a rotary whetstone 56 having a whetstone formed on its circumferential surface, which is fixed to the vertical surface of the slide table 51 and rotated by a motor 55. It is configured. That is, this rotary whetstone 56
The rotation axis of is provided with a rotation axis orthogonal to the magnetic gap G formed in the length direction of the gap forming surface 3 of the core block 1.

Next, a polishing method for polishing the gap forming surface 3 of the core block 1 using the polishing apparatus 10 will be described. First, the long core block 1 having the gap forming surface 3 is placed on the reinforcing plate 122 over the entire length of the back surface of the long core block 1 so that the gap forming surface 3 faces the rotary grindstone 56. Board 1
It is fixed to the holding device 23 in a state where both ends of 22 are fixed.

In this way, the holding device 23 to which the core block 1 is fixed is rotated by a certain angle by energizing the motor 24, and the gap forming surface 3 is held in a state of being inclined by that angle. Next, the X-axis motor 15
The surface plate 21 in FIG.
Move it to the left of and move it to the left end. That is, the right end of the core block 1 is located at the lower left of the rotary grindstone 56.

With the core block 1 maintained in such a positional relationship, the motor 55 is energized to rotate the grindstone 56.
While rotating the Y-axis motor 44, the Y-axis motor 44 is energized to move the slide base 42 forward above the core block 1
The shaft motor 44 is stopped. Next, the Z-axis motor 53
To lower the slide base 51, and immediately before the rotary grindstone 56 contacts the gap forming surface 3, the X-axis motor 1
5 is urged in the reverse rotation direction to move the slide base 13 to the right of the arrow X, and then the rotary grindstone 56 is further lowered to move rightward with the grindstone of its circumferential surface. Planar polishing is started from the right end of the gap forming surface 3 of the core block 1.

Then, the X-axis motor 15 is continuously energized to linearly drive the slide base 13, and the planar polishing is continuously performed to the left end of the gap forming surface 3. Therefore, the certain angled surface of the gap forming surface 3 is polished into a flat surface along the length direction of the magnetic gap G over the entire length thereof. For example, the plane indicated by reference numeral 4A in FIG. 2 is formed over the entire length of the core block 1.

When the angled surface of the gap forming surface 3 is ground over its entire length, the Z-axis motor 53 is reversed to raise the rotating grindstone 56 away from the gap forming surface 3, while the motor 24 is turned on again. The holding device 23 is biased to rotate by the next certain angle, and the gap forming surface 3 is held in a state of being inclined by the next certain angle. Then, the X-axis motor 15 is energized and rotated in the reverse direction, and the sliding base 13, and thus the core block 1 is linearly moved backward in the left direction of the arrow X, and at the same time, the motor 55 is rotated in the reverse direction to rotate the rotary grindstone 56. While reversing, the rotary grindstone 56 is lowered again to start the planar polishing from the left end of the gap forming surface 3 of the core block 1 at the next certain angle. This 2
The surface formed by the second plane polishing corresponds to the plane indicated by reference numeral 4B in FIG.

After the completion of the reverse surface polishing, the Z-axis motor 53 and the X-axis motor 15 are reversed, and the motor 24 is energized to incline the gap forming surface 3 at a certain angle. Plane polishing for gap forming surface 3
Of the planes 4C, 4D shown in FIG.
4E is sequentially finished, and the planar polishing is repeatedly performed to polish the magnetic gap forming surface 3 into multiple surfaces to finish the magnetic gap depth D into a predetermined value.

When the polishing method of the present invention as described above is adopted, the load of the rotary grindstone 56 is applied uniformly over the entire length of the gap forming surface 3 of the core block 1, and as shown in FIG. Dimensional difference T between the right end surface 2A and the left end surface 2C of the medium sliding surface 4 and the central surface 2B
Was suppressed to a very small dimension of 1 μm or less, and good flatness of the medium sliding surface was obtained. That is, it was possible to almost eliminate the variation in the finishing dimension of the gap depth D in the processed core block 1.

In the above-described embodiment, the rotary polishing device 40 is moved by the Y-axis table 45 in the Y-axis direction of the arrow Y. However, the rotary polishing device 40 is fixed and the X-axis table 2 is used.
0 may be constituted by an XY axis table, and the core block 1 may be moved toward the rotary polishing device 40. Further, the core block 1 is placed on the Y-axis table so as not to move in the X-axis direction, and the rotary polishing device 4 is used.
It is needless to say that the Y-axis table 45 of 0 may be configured by an XY-axis table, and the rotary grindstone 56 may be moved in the X-axis direction to perform planar polishing.

[0026]

As described above, according to the core block polishing method of the present invention, the flatness of the gap depth surface can be improved by the plane polishing as described above. It was possible to almost eliminate the variation in the gap depth finishing dimension D in the processed core block. Further, the size of the gap depth can be formed by plane polishing, and the R shape of the medium sliding surface can be formed by the tape wrap after assembly, so that the desired shape can be obtained.

Furthermore, since the multi-side processing is performed, the processing of the gap forming surface can be divided into a processing portion requiring high precision and a processing portion requiring less precision. Furthermore, when processing core blocks for magnetic head devices having different R shapes,
It is not necessary to use a dedicated processing jig, and it is possible to deal with the problem by using the same device and jig and only changing the surface of the angled surface of the core block. As described above, the core block polishing method of the present invention provides various excellent effects.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a polishing apparatus for a magnetic core block of a magnetic head according to the present invention.

FIG. 2 is a top view of a magnetic core block showing a state of a magnetic gap forming surface polished by the polishing apparatus shown in FIG.

FIG. 3 is a side view showing a state of a magnetic gap forming surface in the longitudinal direction polished by the polishing apparatus shown in FIG.

FIG. 4 is a conceptual perspective view of a conventional polishing apparatus for a magnetic core block.

5 is a top view of the magnetic core block showing a state of a magnetic gap forming surface polished by the polishing apparatus shown in FIG.

6 is a side view showing a state of a magnetic gap forming surface in the longitudinal direction polished by the polishing apparatus shown in FIG.

[Explanation of symbols]

 G magnetic gap 1 (magnetic) core block 2a core half body 2b core half body 3 gap forming surface 4 medium sliding surface 4A right end surface of medium sliding surface 4 of magnetic core block 4B medium sliding surface 4 of magnetic core block Central surface 4C Left end surface of medium sliding surface 4 of magnetic core block 10 Polishing device 11 Conveying device 20 X-axis table 21 Surface plate 23 Holding device 30 Core block supporting device 40 Rotating polishing device 45 Y-axis table 54 Z-axis table 55 Motor 56 rotating whetstone

Claims (2)

[Claims] 1. A long magnetic core block having a magnetic gap formed in one plane, an angled surface of the magnetic gap forming surface is ground into a plane along the length direction of the magnetic gap, The magnetic core block for a magnetic head device, characterized in that the flat surface polishing process is performed on other angled faces of the magnetic gap forming face to polish the magnetic gap forming face into a multi-faceted surface to obtain a predetermined magnetic gap depth. Polishing method. 2. A magnetic core block supporting device for supporting both ends of a long magnetic core block having a magnetic gap formed in one plane and rotating the magnetic gap forming surface in multiple steps, and the magnetic gap forming surface. Of the magnetic core block, the rotary polishing device having a rotation axis orthogonal to the magnetic gap formed in the longitudinal direction of the magnetic gap forming surface, the rotary polishing device for rotationally polishing the magnetic gap forming surface, the rotary polishing device and the magnetic core block supporting device. A polishing apparatus comprising a driving device that moves linearly in the longitudinal direction and relatively.