JPH097109A - Apparatus for production of head piece of magnetic head and its production - Google Patents

Abstract

PURPOSE: To improve the flatness of the cut surface of a head piece of magnetic head and to lower the surface roughness by providing a production apparatus with a second magnet for additionally working the cut surface at the time when a block body is cut by a first magnet. CONSTITUTION: The apparatus for producing magnetic head has a rough grinding wheel 14 which is the first magnet 14, a fine grinding wheel 15 which is the second magnet and a motor M which is a driving means. A magnetic head block 13 which is the block body is fixed attachably and detachably to a block fixing jig 16 of a holding means 90. A jig 16 is fixed to a magnet table 17 of the holding means 90 and is made movable in arrow X direction by a moving means 51. The rough grinding wheel 14 and the fine grinding wheel 15 are mounted at a grinding wheel flange 12 via a space 19 and is held in a mounting section 77. The mounting sec 77 is made movable and positionable at every prescribed pitch in arrow Y direction by the motor M and further, the mounting section 77 is made movable and positionable along arrow Z direction by a moving mEans 71. A grinding water supplying section 18 is capable of discharging grinding water 18a to the rough grinding wheel 14 and the fine grinding wheel 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus such as a video tape recorder (VTR), or a manufacturing apparatus and a manufacturing method for manufacturing a head piece of an optimum magnetic head using the reproducing apparatus. It is a thing.

[0002]

2. Description of the Related Art For example, a video tape recorder has a rotary magnetic head device, and this rotary magnetic head device comprises a fixed drum and a rotary drum rotating with respect to the fixed drum. The rotary drum has, for example, an induction type magnetic head. This magnetic head can be used for recording information on a video tape, reproducing information on the video tape, or erasing information on the video tape. As shown in FIG. 22, the magnetic head has a magnetic head piece 202 attached to a head base 201 by adhesion or the like. In this type of magnetic head, the accuracy of the dimension value 203 from the reference surface of the head base 201 to the head gap G shown in FIG. 23 is strictly required. The dimension value 203 is strict as described above because, for example, a rotary magnetic head device including this magnetic head is used.
This is for allowing the magnetic head piece 202 to record information on a predetermined recording track when recording information on the video tape. The head piece 202 is manufactured by cutting a block body using a disc-shaped grindstone.

[0003]

However, in the conventional method of manufacturing a head piece by cutting a block body with a disc-shaped grindstone, the flatness of the cut surface is poor and the cut surface is rough. The dimensional value 203 at the position from the cut surface 202a to the head gap G varies. FIG. 20 shows a conventional disk-shaped grindstone 210.
It shows a state in which the block body 230 is cut to manufacture a plurality of magnetic head pieces 202. This cutting surface 202
The roughness of a is shown in FIG. 21, and the cut surface 202a is
Poor flatness and rough cut surface. For this,
Conventionally, the dimension value 203 from the cut surface 202a to the head gap G is measured one by one, and the quality of the magnetic head chip is ranked. The bending of the cut surface 202a of the cut magnetic head piece has a problem that it is difficult to obtain an accurate dimension value 203 from the cut surface 202a to the position of the head gap G. Therefore, the present invention has been made to solve the above problems, and provides a magnetic head manufacturing apparatus and a magnetic head head piece that can improve the flatness of the cut surface of the magnetic head and reduce the surface roughness. It is intended to provide a manufacturing method.

[0004]

According to the invention of claim 1, the above object is to hold a block body in a headpiece manufacturing apparatus for manufacturing a headpiece of a magnetic head by cutting the block body. A holding means for cutting, a first grindstone for cutting the block body by rotating, and a second grindstone rotating in synchronization with the first grindstone, wherein the first grindstone is the block body. A second grindstone for additionally processing a cutting surface of the block body which is already formed by the first grindstone with a part of the block body sandwiched between the first grindstone and the first grindstone; This is achieved by an apparatus for manufacturing a head piece of a magnetic head, which is provided with a first grindstone and a driving means for rotating the second grindstone. In the invention of claim 2, preferably, the second grindstone has a coarser grain size than that of the first grindstone. In the invention of claim 3, the second grindstone preferably has the same grain size as the first grindstone. In a fourth aspect of the present invention, preferably, in the head piece manufacturing method for manufacturing the head piece of the magnetic head by cutting the block body, the block body is held, and the first grindstone and the second grindstone. When the first grindstone cuts the block body, the second grindstone and the first grindstone sandwich a part of the block body by rotating the second grindstone.
The whetstone of No. 1 additionally processes the cut surface of the block body which has already been formed by the first whetstone. In the invention of claim 5,
Preferably, the second grindstone has a coarser grain size than the first grindstone. In the invention of claim 6, preferably, the second grindstone has the same grain size as that of the first grindstone.

[0005]

According to the present invention, the holding means holds the block body and the first grindstone rotates to cut the block body. The second grindstone rotates in synchronization with the first grindstone, and when the first grindstone cuts the block body, the first grindstone
The cutting surface of the block body already formed by the first grindstone is additionally processed in such a manner that a part of the block body is sandwiched between the grindstone and the grindstone. As a result, the first grindstone and the second grindstone sandwich the part of the block body so that the first grindstone cuts the block body and the second grindstone cuts the already formed block body. The surface is additionally processed. In other words, the first grindstone and the second grindstone simultaneously perform the cutting process of the block body and the additional process of the already formed surface thereof, so that a part of the block body does not escape. Therefore, when the cut surface of the block body on which the second grindstone has already been formed is additionally processed, the second grindstone can be processed so as to secure the flatness of the cut surface and reduce the surface roughness. .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Note that the embodiments described below are
Since it is a preferred specific example of the present invention, various technically preferable limitations are attached, but the scope of the present invention is, unless otherwise stated to limit the present invention, in the following description.
It is not limited to these modes. FIG. 1 shows an example of a magnetic head provided with a magnetic head piece 2 produced by the apparatus for manufacturing a head piece of a magnetic head of the present invention. In this magnetic head, a magnetic head piece (head piece) 2 is fixed to a head base 1 with an adhesive. The head base 1 is, for example, a brass base. FIG. 2 shows a state in which the magnetic head piece 2 is bonded to the head base 1. A head gap G is formed on the sliding surface of the magnetic head piece 2 on the video tape. The head gap G is a portion for recording information on a recording track of a video tape, for example.

The dimension value 3 between the cut surface 13a of the magnetic head piece 2 and the head gap G must be set strictly. Since the cut surface 13a serves as an adhesion reference surface of the magnetic head piece 2, the flatness (the curvature of the cut surface) and the surface roughness of the cut surface 13a (see FIG. 14) are reduced and finished. There is a need to.

The structure of the magnetic head manufacturing apparatus of the present invention will be described with reference to FIGS. The magnetic head manufacturing apparatus includes a holding means 90, a coarse grindstone 14 that is a first grindstone, a fine grindstone 15 that is a second grindstone, and a motor M that is a drive means. The magnetic head block 13, which is a block body, is detachably fixed to the block fixing jig 16 of the holding means 90. The block fixing jig 16 is fixed to the magnet table 17 of the holding means 90. The magnet table 17 can be moved and positioned in the arrow X direction by the moving means 51, for example.

The coarse grindstone 14 and the fine grindstone 15 are provided with a spacer 19
Is attached to the grindstone flange 12 via
Is held in. The mounting portion 77 can be continuously rotated in the arrow R direction by the motor M. The mounting portion 77 and the motor M can be moved and positioned at predetermined pitches in the arrow Y direction by the moving means 70, for example. Furthermore, the mounting part 7
The moving unit 71 can be moved and positioned in the vertical direction along the arrow Z direction by the moving unit 71. Grinding water supply unit 18
Can discharge the grinding water 18a to the rough grindstone 14 and the fine grindstone 15 sides.

The coarse grindstone 14 and the fine grindstone 15 constitute a so-called multi-grinding stone. The rough whetstone 14 is the whetstone flange 1
A rough-processed metal grindstone is formed for No. 2. The grindstone flange 12 has, for example, a diameter of 95 mm,
The thickness of the rough-worked metal grindstone is, for example, 0.177 mm, and the abrasive grain size is # 600. On the other hand, the fine grindstone 15 is also formed by forming a metal grindstone with a fine grain size # 2000 on the grindstone flange 12.
The thickness of this metal grindstone is, for example, 0.177 mm. Coarse grindstone 14 and fine grindstone 1 made in this way
The outer diameter of each of 5 is, for example, 101 mm.

Next, a method for manufacturing a magnetic head by the above-described apparatus for manufacturing a head piece of a magnetic head will be described. First, FIG. 6 shows the ferrite substrate 4 before processing. The flattening process is first performed on the ferrite substrate 4. FIG. 7 shows a state in which the glass setting groove 5 and the winding groove 6 are formed on the ferrite substrate 4. The glass setting groove 5 and the winding groove 6 are formed along the longitudinal direction of the ferrite substrate 4. 8 is shown in FIG.
The track width regulation groove 7 is further formed on the ferrite substrate 4 of FIG. The track width regulation groove 7 is a groove as shown in FIG. 14, and is a groove for regulating the width GW of the head gap G. In FIG. 8, the side of the ferrite substrate 4 on which the track width regulating groove 7 is formed is further mirror-finished.

Next, as shown in FIG. 9, the ferrite substrate 4 shown in FIG. 8 is cut from its central portion along the longitudinal direction. FIG. 10 shows two split ferrite substrates 4 that have been cut.
a and 4a are shown, and these divided ferrite substrates 4 are shown.
The metal film sputtering process and the gap film sputtering process are performed on a and 4a. As a result, the gap film 9 and the magnetic metal film 10 are formed. Then, as shown in FIG. 11, 2
The two divided ferrite substrates 4a, 4a are adhered to each other, and the fused glass 11 is melted and injected into the glass set groove 5 and the winding groove 6. As a result, the magnetic head block 13 as shown in FIG. 11 is completed.

In the magnetic head block 13, the sliding surface 13d of the video tape is formed into a predetermined curved surface as shown in FIG. The magnetic head block 13 of FIG.
The magnetic head piece 2 is divided into individual magnetic head pieces 2 as shown in FIG. 4 by being held by the holding means 90 as shown in FIG. 12 and being cut by the coarse grindstone 14 and the fine grindstone 15. FIG. 5 shows how the magnetic head block 13 is cut by the rough grindstone 14 and the fine grindstone 15. The cut surface 13a of the obtained magnetic head piece 2 is bonded to the head base 1 with an adhesive as shown in FIGS.

Next, the apparatus for manufacturing the head piece of the magnetic head shown in FIGS. 12 and 13 individually cuts the magnetic head block 13 into the magnetic head pieces 2 as shown in FIGS. 4 and 5. I will explain the situation. As shown in FIG.
The coarse grindstone 14 and the fine grindstone 15 are attached to the grindstone flange 12 via a spacer and are held by the mounting portion 77. By driving the motor M shown in FIGS. 12 and 13,
The coarse grindstone 14 and the fine grindstone 15 are synchronized, for example, 5000
The magnetic head block 13 of FIG. 3 is rotated by 30 mm / min.
It cuts at a cutting speed of min. FIG. 14 shows the magnetic head block 13, the coarse grindstone 14, and the fine grindstone 15. The magnetic head block 13 is arranged at a predetermined angle θ so that the head gap G is inclined at a predetermined azimuth angle.

The magnetic head block 13 includes a rough grindstone 1.
4 and fine grindstone 15 are processed simultaneously. That is,
The feed pitch P of the coarse grindstone 14 and the fine grindstone 15 in the substantially longitudinal direction of the magnetic head block 13 is, for example, 397 μm.
It is. The interval P1 between one surface of the rough grindstone 14 and one surface of the fine grindstone 15 is set to 377 μm, for example. The coarse grindstone 14 has a thickness D1 of 177 μm, for example, and the fine grindstone 15 has a thickness D2 of 177 μm, for example. The spacer width DS is, for example, 200 μm. When the rough grindstone 14 and the fine grindstone 15 are cut into the magnetic head block 13 arranged at an inclination with a predetermined cut depth, the rough grindstone 14 forms a cut surface 13a. At the same time, the fine grindstone 15 performs side surface finishing while cutting the cut surface 13a (shown by a chain double-dashed line) already cut by the rough grindstone 14 with the cut depth DD. This depth of cut D
D indicates the cutting portion 13b, which is, for example, 20 μm.

Thus, the rough grinding wheel 14 forms the cutting surface 13a, and at the same time, the fine grinding stone 15 performs side surface finishing on the already roughly cut cutting surface 13a to form the side surface finishing surface 13c. be able to. In such a processing method, since the coarse grindstone 14 and the fine grindstone 15 perform the processing in such a manner that the portion 13d of the magnetic head block 13 is sandwiched from both sides, there is no escape of the sandwiched portion 13d. Therefore, since the obtained magnetic head piece 2 does not fall, a good cut surface 13c of the magnetic head piece 2 is obtained.
The flatness can be secured and the surface roughness can be reduced.

FIG. 15 shows the properties of the roughened cutting surface 13a thus formed, and FIG. 16 shows the properties of the laterally finished cutting surface 13c. The cutting speed is 30m.
An example of cutting at m / min is shown. As shown in FIG. 15, the finished cut surface 13c has a higher degree of flatness than the conventional cut surface 13c. Moreover, as shown in FIG. 16, the finished cut surface 13c is
Low roughness and high flatness.

FIG. 17 shows an example of measuring the grinding resistance when the grindstones 14 and 15 process the ferrite substrate 13 in the X, Y and Z directions. The grinding resistance is recorded in the recorder 102 via the amplifier 101. In this case, as shown in FIG. 18, the grooving depth d1 of the grindstones 14 and 15 is, for example, 2.
3 mm, and the width d2 of the protrusion 103 is 1.1 m, for example.
m.

The grinding resistance shown in FIG. 19 increases only slightly when the grinding speed is increased from 32 mm / min to 79 mm / min, for example, and the tilt of the magnetic head piece 2 in FIG. 15 during grinding is reduced. . By adopting the multi-grinding stone in which the coarse grindstone 14 and the fine grindstone 15 having a finer count than the coarse grindstone are combined, the thickness and the cutting depth of the magnetic head piece 2 are set to the optimum conditions in the cutting by the multi-grinding stone By this, about 80
Even at a feed speed of mm / min, the magnetic head piece 2 can be cut so as not to fall. This can improve the flatness of the cut surface 13c of the magnetic head piece and reduce the surface roughness.

As described above, in the apparatus and method for manufacturing the head piece of the magnetic head of the present invention, the side surface of the magnetic head chip once processed by the metal grindstone for rough cutting is finer than that of the grindstone for rough cutting. The cutting portion 13b of FIG. 14 is cut and processed with a metal grindstone having an abrasive grain size. As a result, the surface roughness of the finished cut surface 13c can be reduced, and the flatness is improved. Thereby, the cut surface 13a of FIG. 2 can be used as an adhesion reference surface for adhering the magnetic head piece 2 to the head base 1. Since the flatness and surface roughness of the cut surface 13c can be improved, it is possible to reduce variations in the dimensional accuracy of the dimension value 3 of the head gap G and the cut surface 13a in FIG.

When the roughness of the cut surface 13c of the magnetic head piece 2 is required to be, for example, 1 μm or less, it is general to process with a fine cutting (fine cutting) processing grindstone with a fine abrasive grain size, and usually rough cutting. If the processing speed is not reduced as compared with the processing, the magnetic head piece will be chipped or the magnetic head piece will collapse, so it is considered that stable processing cannot proceed. However, the rough grindstone 14 and the fine grindstone 1 of the present invention
5 are combined and rotated synchronously, and the part 13d of the magnetic head block 13 of FIG.
In addition, the fine grindstone 15 is machined with a cutting amount of only 20 μm, which corresponds to the side surface roughness of the rough grindstone 14. The fine grindstone 15 for processing is the cutting surface 13.
It is possible to side-process a. Therefore, the cutting speed does not decrease. The present invention is not limited to the above embodiment. In the above-mentioned embodiment, the method of manufacturing the magnetic head of the video tape recorder is explained.
Not limited to this, it is possible to manufacture a head piece of a magnetic head used in a digital audio tape recorder, a data streamer, or the like.

[0022]

As described above, the flatness of the cut surface of the head piece of the magnetic head can be improved and the surface roughness can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a magnetic head including a magnetic head piece obtained by a head piece manufacturing apparatus for a magnetic head of the present invention.

FIG. 2 is a front view showing the magnetic head of FIG.

FIG. 3 is a perspective view showing an example of a magnetic head block for manufacturing a magnetic head piece.

4 is a perspective view showing a magnetic head piece obtained by cutting the magnetic head block of FIG.

5 is a view showing a cutting example for obtaining the magnetic head piece of FIG.

6 is a perspective view showing an example of a ferrite substrate for producing the magnetic head block of FIG.

FIG. 7 is a view showing a state where a glass setting groove and a winding groove are formed on the ferrite substrate of FIG.

FIG. 8 is a diagram showing a state in which track width regulating grooves are formed on the ferrite substrate of FIG.

9 is a diagram showing a state in which the ferrite substrate of FIG. 8 is cut into two along the length direction.

FIG. 10 is a view showing a state in which a gap film and a magnetic metal film are formed on two ferrite substrates.

FIG. 11 is a diagram in which two ferrite substrates are overlapped and bonded to form a magnetic head block.

FIG. 12 is a side view showing an apparatus for manufacturing a head piece of a magnetic head of the present invention.

13 is a front view of the manufacturing apparatus in FIG.

FIG. 14 is a view showing a positional relationship between a magnetic head block and a coarse grindstone and a fine grindstone.

FIG. 15 is a view showing a property of a surface processed by a rough grindstone.

FIG. 16 is a view showing a property of a processed surface with a fine grindstone.

FIG. 17 is a diagram showing measured amounts of grinding resistance in X, Y, and Z directions with a grindstone.

FIG. 18 is a view showing the shape of a ferrite substrate and a grindstone.

FIG. 19 is a diagram showing the grinding resistance measurement amount of FIG. 17;

FIG. 20 is a view showing an example of cutting a magnetic head block with a conventional grindstone.

FIG. 21 is a diagram showing the nature of the cut surface of the magnetic head piece in the conventional cutting example of FIG. 20.

FIG. 22 is a perspective view showing a normal magnetic head.

FIG. 23 is a front view of the magnetic head of FIG. 22.

[Explanation of symbols]

 1 Base 2 Magnetic Head Piece 3 Dimensional Values of Cut Surface and Head Gap 4 Ferrite Substrate 5 Glass Setting Groove 6 Winding Groove 7 Track Width Regulating Groove 9 Gap Film 10 Magnetic Metal Film 11 Welding Glass 13 Magnetic Head Block (Block Body) 14 Coarse Grindstone (first grindstone) 15 Fine grindstone (second grindstone) 16 Block fixing jig 17 Magnet table 19 Spacer 90 Holding means M Motor (driving means)

Claims (6)

[Claims] 1. A headpiece manufacturing apparatus for cutting a block body to manufacture a headpiece of a magnetic head, and holding means for holding the block body, and for cutting the block body by rotating. First of
And a second grindstone that rotates in synchronization with the first grindstone, wherein a part of the block body is sandwiched by the first grindstone when the first grindstone cuts the block body. A second grindstone for additionally processing the cutting surface of the block body already formed by the first grindstone, and a drive means for rotating the first grindstone and the second grindstone,
An apparatus for manufacturing a head piece of a magnetic head, comprising: 2. The apparatus for manufacturing a head piece of a magnetic head according to claim 1, wherein the second grindstone has a coarser grain size than that of the first grindstone. 3. The apparatus for manufacturing a head piece of a magnetic head according to claim 1, wherein the second grindstone has the same grain size as the first grindstone. 4. A method of manufacturing a head piece for cutting a block body to manufacture a head piece of a magnetic head, wherein the block body is held, and a first grindstone and a second grindstone are rotated, When the first grindstone cuts the block body, the second grindstone forms a part of the block body with the first grindstone, and the second grindstone is already formed by the first grindstone of the block body. A method for manufacturing a head piece of a magnetic head, characterized in that an additional cut surface is additionally processed. 5. The method of manufacturing a head piece of a magnetic head according to claim 4, wherein the second grindstone has a coarser grain size than that of the first grindstone. 6. The method of manufacturing a headpiece of a magnetic head according to claim 4, wherein the second grindstone has the same grain size as the first grindstone.