JPH0531685Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a magnetic head, and in particular, a sliding block is fixed to the front surface of a metal head case.
This invention relates to a sliding block mounting structure for a VTR or audio magnetic head.

(Prior art) For example, in a magnetic head for a VTR, two cores are arranged in a head case spaced apart in the transverse direction with respect to the traveling direction of the magnetic medium, and the magnetic medium is exposed on the entire surface of the case and the magnetic medium is inserted between these cores. A wear-resistant sliding block (hereinafter referred to as a front block) with which the front block comes into sliding contact is joined and fixed. As shown in FIG. 5, the front face 1a of the head case 1, which is usually made of metal, is provided with window holes 2 and 3 through which the front parts of the audio and control cores are exposed. A recess 5 with a bottom is formed, and the front block 4 is bonded and fixed to this recess 5 with a bottom. After the inside of the case is fixed with resin, the front surface of the case is polished in R, and the magnetic medium runs in the direction of arrow A in FIG. 5 in contact with the front surface of the core and the front block 4. Insert the front block 4 into the recess 5 of the case 1.
In order to reliably fix the front block 4 in the correct position with respect to the case window hole, conventionally the case is held in a jig, the front block 4 is positioned by sliding it into the bottomed recess 5, and then the front block 4 is fixed with instant adhesive. It was stuck.

(Problem to be solved by the invention) In the conventional structure described above, the recess 5 on the front of the case
The bottom surface 5a of the front block 4 and the joint surface (back surface) of the front block 4 are flat, solid surfaces, and there is no locking means for the front block in the direction transverse to the running direction of the magnetic medium. In some cases, the front block 4 may shift to one side and be glued. If the core is inserted into the window hole from the rear of the case in this state, one side of the core will come into tight contact with the end 7 of the front block 4, resulting in poor product characteristics, especially impedance characteristics. In extreme cases, an accident may occur where the front end of the core hits the front block 4 and cannot enter the window hole. Furthermore, even if the front block is glued in the correct position at the time of gluing, when it is put in the dryer in the subsequent process, the front block may shift laterally due to heat deformation, resulting in a poor yield overall and the need for rework. It had the disadvantage of high costs, such as requiring a lot of work.

(Means for Solving the Problems) The present invention provides a front block mounting structure that eliminates the above-mentioned drawbacks and enables automatic assembly of the front block to the head case, in which forming at least one side wall of the bottomed recess into a curved shape, and bending the side of the front block to which the bottomed recess is fixed so as to fit into the curved side wall of the bottomed recess; The front block is positioned by fitting the curved portion.

(Examples) Next, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view showing a head case 1 according to an embodiment of the present invention with a front block 4 fixed to its front surface, and FIG. 2 is a sectional view taken along the line - in FIG. be. In this example,
The plate-shaped front block 4 is connected to arrow A during recording and playback.
The side portion 4a on the downstream side in the traveling direction of the magnetic medium traveling in the direction is formed in a straight line, and the side portion 4b on the opposite side, that is, the side portion 4b on the upstream side in the traveling direction of the magnetic medium, is curved in a concave shape. There is. Also head case 1
A side wall 1b on the downstream side in the magnetic medium running direction of the front block mounting recess (bottomed recess) on the front surface 1a of the front block is formed into a straight line, and the opposite side wall 1c on the upstream side in the magnetic medium running direction is formed into a straight line. It is formed into a convex curved shape corresponding to the concave curved side portion 4b of No. 4. In this embodiment, the case 1 and the front block 4 are symmetrical with respect to the center line in the running direction of the magnetic medium. The dimensions of each part are determined so that each protrudes by a predetermined amount with the same length d into the core insertion window holes 2 and 3 of the case 1.

When the front block 4 is installed in the front block mounting recess on the front surface 1a of the case, the engagement between the side walls 1b and 1c of the recess and both sides 4a and 4b of the front block 4 is such that one side is linear and the other is straight. The front block 4 is engaged in the longitudinal direction (arrow A
without causing any misalignment in the lateral direction)
At the position where both are fitted, the front block 4 can be fixed with high positional accuracy using instant adhesive or the like. There is no need for complicated positioning work during fixing, and even in the process after fixing, the front block does not shift due to the above-mentioned uneven fitting. In FIG. 1, a separate erasing head 10 attached to one side of the head case 1 is shown by imaginary lines.

FIG. 3 is a plan view of a head case equipped with a front block according to another embodiment of the present invention.
In this embodiment, contrary to the embodiment shown in FIG.
b and 1c are concavely curved on the downstream side in the magnetic medium running direction A, and straight on the opposite side. Correspondingly, the front block 4 has a convex curved side portion 4a on the downstream side in the magnetic medium running direction, and a straight side portion 4b on the opposite side. Similar to the embodiment shown in FIG. 1, the front block 4 is prevented from shifting due to the uneven fitting.

In each of the above-mentioned embodiments, one side of the front block 4 is linear as in the conventional case, so when manufacturing the front block 4 by molding, the reference plane of the mold is aligned with the linear side of the front block. can be used without causing any problems in manufacturing. Further, as shown in FIG. 4, this type of recording/playback magnetic head 11 usually has an erasing head 1 on one side thereof.
0 is fixed thereto, and a recording magnetic head 12 is disposed alongside this, and during recording and reproduction, a magnetic medium 13 travels from the erasing head 10 side to the recording magnetic head 12 via the magnetic head 11. By running the magnetic medium 13 in this manner, the recording/reproducing magnetic head 11
The front surface opposite to the erasing head 10, that is, the region on the downstream side in the direction of travel of the magnetic medium, tends to be in strong sliding contact with the magnetic medium 13. In the present invention, in all embodiments, the surface of the front block 4 is expanded toward the downstream side compared to the upstream side in the magnetic medium running direction, so that the side shape of the front block 4 can be adjusted on both sides. Even if the magnetic head is made different, there is no problem in contact with the magnetic medium, and excessive wear on the front surface of the magnetic head due to this does not occur.

(Effects of the invention) As explained above, according to the invention, the front block can be easily positioned by fitting the curved side parts together, and the front block can be easily attached to the front of the case. Automated installation is possible. There is no misalignment when gluing the front block or during post-processes such as drying after gluing, and there is no inability to insert the core due to misalignment of the front block, which conventionally occurred by around 10%, or impedance failure due to core pressure welding. Product yield is significantly improved. This has the effect of improving the adhesion strength of the front block. There is no problem from the sliding contact of the magnetic medium.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a head case to which a front block is fixed according to an embodiment of the present invention, FIG. Plan view, Figure 4
FIG. 5 is a perspective view showing the assembled state of a conventional head case, and FIG. 6 is a plan view of the head case with the front block shifted. 1...Head case, 1a...Case front, 1
b, 1c...Side wall, 2, 3...Window hole, 4...Front block, 4a, 4b...Side part, 5...Bottomed recess (front block mounting recess), 10...
...Erasing head, 11...Magnetic head for recording and playback,
13...Magnetic medium, A...Magnetic medium traveling direction.

Claims (1)

[Claims for Utility Model Registration] (1) In a magnetic head in which a slidable block is fixed to a bottomed recess on the front surface of the head case, at least one side wall of the bottomed recess is formed into a curved shape, and the A front block mounting structure for a magnetic head, characterized in that a side portion of the sliding block is curved so as to fit into the curved side wall of the bottomed recess. (2) The upstream side wall in the magnetic medium running direction of the bottomed recess is formed into a convex curved shape, and the downstream side wall in the magnetic medium running direction is formed in a straight shape, corresponding to the shape of the side wall of the bottomed recess. A front block mounting structure for a magnetic head as set forth in claim 1 of the registered utility model claim, characterized in that one side of the slidable block has a concave curved shape and the other side has a straight shape. . (3) The front block mounting structure for a magnetic head as set forth in claim 1, wherein the side wall of the bottomed recess on the downstream side in the magnetic medium running direction is formed into a concave curved shape.