JPH0525051Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a shield cover mounting structure for a magnetic head, and particularly to a shield cover mounting structure for a large magnetic head such as an audio magnetic head for a VTR.

[Background of the idea]

Conventionally, a magnetic head assembly consisting of an erasing magnetic head, known as an audio magnetic head for VTRs, and a recording/playback magnetic head (hereinafter referred to as the recording/reproduction magnetic head) has been designed to be unaffected by external magnetic fields. A shield cover is attached to the side opposite to the magnetic tape sliding surface.

In a simple version, a shield cover made of permalloy material is fixed only to the back of the recording/playback magnetic head by gluing or press-fitting it, but in recent years it has become more complicated as it is easily affected by external magnetic fields. A shield cover with a similar shape is attached.

1 and 2 show a shield cover mounting structure of a conventional audio magnetic head for a VTR, with FIG. 1 being a perspective view showing an assembled state, and FIG. 2 being an exploded perspective view.

In the drawing, 1 and 2 are magnetic heads, for example, 1 is a recording/reproducing magnetic head, 2 is an erasing magnetic head,
Shield cases 1a and 2a for both magnetic heads 1 and 2
are combined to form a magnetic head assembly A. 4 is a terminal for both magnetic heads 1 and 2; 5 is a mounting plate to which this magnetic head assembly A is attached; 6 is a shield cover made of permalloy, for example, that covers the magnetic head assembly A; 1. Shield case 1a of erasing magnetic head 2,
A top plate 6a that covers the top surfaces 1a ₁ and 2a ₂ of 2a, a back plate 6b that covers the back surfaces 1a ₂ and 2a ₂ , and side surfaces 1a ₃ and 2a ₃
and a side plate 6c that covers the. Note that the width B of the back surface of the top plate 6a of the shield cover 6 is formed to be slightly larger than the width C of the magnetic head assembly A, and the back plate 6b of the shield cover 6 has a magnetic head, although not shown. Holes are provided through which the first and second terminals 4 can be inserted.

7 is a printed circuit board on which a conductive pattern (not shown) is formed on the back surface, 14 is a fitting hole for the terminal 4 of the magnetic heads 1 and 2, and 8 is an insulator fixed to one end of the surface of the printed circuit board 7. connector housing,
9 is a connector implanted in the housing 8; 10 is a mounting hole provided in the top plate 6a of the shield cover 6;
11 is the shield case 1 of the recording/playback magnetic head 1
12 is a mounting hole provided on the mounting plate ₅ ; 13 is a screw for screwing the shield case 1a of the recording/recycling magnetic head 1 to the mounting plate 5; 17 is a shield. Screws 15 and 16 for attaching the cover 6 are the cores of the magnetic heads 1 and 2.

Next, the procedure for attaching the shield cover 6 to the magnetic head assembly A will be explained.

First, insert the screw 13 through the mounting hole 12 of the mounting plate 5 to attach the shield case 1a of the recording/reproduction magnetic head 1.
screw into the screw hole (not shown), and then screw the magnetic head assembly A to the mounting plate 5.

Next, after overturning the shield cover 6 on the magnetic head assembly A from the direction of arrow D in FIG.
The shield cover 6 is fixed to the magnetic head assembly A by passing through the mounting hole 10 provided in the top plate 6a of the shield cover 6 and screwing into the tap hole 11 provided in the shield case 1a.

Next, the printed circuit board 7 with the connector housing 8 attached
The surface of the shield cover 6 is overlapped with the back plate 6b of the shield cover 6, and the terminal 4 penetrates the fitting hole 14 of the printed circuit board 7 and protrudes to the back surface, and the terminal 4 is formed into a conductive pattern (not shown) on the back surface of the printed circuit board 7. The printed circuit board 7 was fixed to the shield cover 6 by soldering.

However, the above conventional example had the following drawbacks.

(1) The shield cover 6 must have a mounting hole 10, and the shield case 1a must have a tap hole 11, and after screwing the shield cover 6 to the shield case 1a with screws 17,
Lock paint must be applied to prevent loosening.

(2) Since the mounting hole 10 must be provided in the shield cover 6, the press mold becomes complicated.

(3) Since the shield case 1a is made of a hard material such as permalloy, the tap is likely to break when the tap hole 11 is formed.

The overall workability of (1), (2), and (3) above is poor.

(4) Screws 17 for mounting are required, which increases the number of parts.

[Purpose of invention]

The present invention aims to provide a shield cover mounting structure for a magnetic head that is easy to work with and requires a small number of parts.

[Example of idea]

3 and 4 show an embodiment of the present invention, with FIG. 3 being a perspective view showing an assembled state, and FIG. 4 being an exploded perspective view.

Note that the same parts as in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

In these figures, 1 and 2 are magnetic heads;
For example, 1 is a recording/reproducing magnetic head, 2 is an erasing magnetic head, and the shield cases 1a and 2a of both magnetic heads 1 and 2 are combined to form the magnetic head assembly A.
It consists of 4 is a terminal for both magnetic heads 1 and 2; 5 is a mounting plate to which this magnetic head assembly A is attached; 6 is a shield cover made of permalloy, for example, that covers the magnetic head assembly A; , a top plate 6 that covers the top surfaces 1a ₁ and 2a 1 of the shield cases 1a and _2a of the erasing magnetic head 2.
a, a back plate 6b that covers the back surfaces 1a ₂ and 2a ₂ , and a pair of side plates 6c and 6c that cover the side surfaces 1a ₃ and 2a ₃ . A pair of side plates 6 of this shield cover 6
For example, a protrusion 6 is provided on the lower edge of the protrusion 6 as an engaging portion.
b ₁ and 6b ₁ extend downward, respectively. On the other hand, the projection 6 of the shield cover 6 is attached to the mounting plate 5.
Fitting holes 18, 18, . . . into which b ₁ , 6b _{1 . .} . are inserted are provided. Note that the width dimension B of the back surface of the top plate 6a of the shield cover 6 is formed to be slightly larger than the width dimension C of the magnetic head assembly A.
The rear plate 6b of the shield cover 6 is provided with holes (not shown) through which the terminals 4 of the magnetic heads 1 and 2 can be inserted.

7 is a printed circuit board with a conductive pattern (not shown) formed on the back side, 14 is a fitting hole for the terminal 4 of the magnetic heads 1 and 2, and 8 is a connector made of an insulator fixed to one end of the surface of the printed circuit board 7. 9 is a connector implanted in the connector housing 8, 12 is a mounting hole provided in the mounting plate 5, and 13 is a screw for screwing the shield case 1a of the recording/reproduction magnetic head 1 to the mounting plate 5. , 15 and 16 are cores provided in the magnetic heads 1 and 2.

The mounting position of the connector housing 8 on the printed circuit board 7 is such that the terminals 4 of the magnetic heads 1 and 2 are fitted into the fitting holes 14 of the printed circuit board 7, and the tips of the terminals 4 are connected to the conductive pattern on the back surface of the printed circuit board 7. The lower surface 8a of the connector housing 8 is set at a position to press the upper surface 6a of the shield cover 6 when soldering. Therefore, after soldering, the upper surface plate 6a of the shield cover 6 contacts the lower surface 8a of the connector housing 8, and the lower surface 8a of the connector housing 8 and the upper surface 1a of the shield cases 1a, 2a of the magnetic head assembly A. _1,2
The shield cover 6 is sandwiched between the top plate _6a and the side plates 6c, 6.
The lower edge of connector c contacts and is held between the lower surface 8a of the connector housing 8 and the upper surface of the mounting plate 5, and is securely fixed.

Next, the assembly procedure for the shield cover mounting structure of the head assembly of the present invention will be explained.

For example, first, insert the screw 13 into the mounting hole 1 of the mounting plate 5.
2 and screwed into a screw hole (not shown) in the shield case 1a of the recording/reproducing magnetic head 1, and the magnetic head assembly A is screwed and fixed to the mounting plate 5. Next, the shield cover 6 is placed over the magnetic head assembly A in the direction of arrow D so that the terminals 4 protrude outward from holes (not shown) in the back plate 6b of the shield cover 6, and then each of the lower protrusions 6b ₁ , 6b ₁
... into the fitting holes 18, 18... of the mounting plate 5, and further insert the protrusion 6b ₁ into the fitting hole 18 until the bottom surface 6c ₁ of the side plate 6c comes into contact with the surface of the mounting plate 5 to shield Attach the cover 6 to the mounting plate 5.

Then, the terminals 4 of the magnetic heads 1 and 2 are inserted into the fitting holes 14 of the printed circuit board 7 to which the connector housing 8 is attached, and the surface of the printed circuit board 7 is overlapped with the back plate 6b of the shield cover 6. terminal 4
is soldered to a conductive pattern (not shown) on the back side of the printed circuit board 7. By this soldering, the printed circuit board 7 is fixed to the magnetic head assembly A fixed to the mounting plate 5 by sandwiching the rear plate 6b of the shield cover 6.

The shield cover 6 is attached to the magnetic head assembly A as described above, but when it is attached, the connector housing 8 is installed in advance so that the lower surface 8a contacts and presses the upper surface plate 6a of the shield cover 6. Therefore, the upper surface plate 6a of the shield cover 6 is sandwiched between the lower surface 8a of the connector housing 8 and the mounting plate 5, that is, they are sandwiched and securely fixed while contacting each other. In addition, the shield cover 6 has an upper surface of the top plate 6a and a lower edge of the side plates 6c, 6c.
The lower surface 8a of the connector housing 8 and the upper surface of the mounting plate 5 are held in contact with each other and are securely fixed.

According to the present invention, the following effects are achieved.

(1) There is no need for the conventional tap holes in the shield case 1a.

(2) Since the shield cover 6 does not require the conventional mounting holes, the press mold can be simplified.

(3) The work of screwing the shield cover 6 is eliminated.

Combining the above (1), (2), and (3), workability is improved compared to the conventional method.

(4) Screw 17 for attaching shield cover 6
is no longer necessary, reducing the number of parts.

(5) Attach the protrusion 6b ₁ provided on the shield cover to the mounting plate 5
Since the shield cover 6 is fitted into the fitting hole 18 provided in the shield cover 6, the shield cover 6 can be easily positioned during installation. In the above embodiment, the recording/reproducing magnetic head 1 and the erasing magnetic head 2 constitute the magnetic head assembly A, and the shield cover 6 is provided to cover the magnetic head assembly A. However, the present invention is not limited to this, and the above-described shield cover mounting structure may be provided to the recording/reproducing magnetic head 1 or the erasing magnetic head 2 provided separately. .

[Effect of idea]

As detailed above, the magnetic head shield cover mounting structure of the present invention has a configuration in which the shield cover is sandwiched between the connector housing fixed to the printed circuit board and the mounting plate, so it is easy to work with and is easy to use for parts. This has the effect of requiring fewer points.

[Brief explanation of the drawing]

Figures 1 and 2 show the shield cover mounting structure of a conventional audio magnetic head for a VTR. Figure 1 is a perspective view showing an assembled state, Figure 2 is an exploded perspective view, and Figures 3 and 4. shows an embodiment of the present invention,
FIG. 3 is a perspective view showing the assembled state, and FIG. 4 is an exploded perspective view. 1...Magnetic head for recording/reproduction, 2...Magnetic head for erasing, 1a, 2a...Shield case, 1a ₁ ,
2a ₁ ... top surface, 1a ₂ , 2a ₂ ... back surface, 1a ₃ , 2a ₃
...Side surface, A...Magnetic head assembly, 4...Terminal, 5...Mounting plate, 6...Shield cover, 6a
...Top plate, 6b...Back plate, 6b ₁ ...Protrusion, 6
c...Side plate, 6c ₁ ...Bottom surface, 7...Printed circuit board, 8...Connector housing, 8a...Bottom surface, 9...
Connector, 10, 12... Mounting hole, 11... Tap hole, 13, 17... Screw, 14, 18... Fitting hole, 15, 16... Core.

Claims (1)

[Scope of utility model registration request] A magnetic head, a mounting plate fixed to the magnetic head, a shield cover covering the magnetic head, a printed circuit board having a conductive pattern attached to the shield cover and connected to a terminal of the magnetic head, and the printed circuit board. and a connector housing fixed to the magnetic head, wherein the connector housing and the shield cover are connected and the shield cover is sandwiched between the connector housing and the mounting plate. Mounting structure.