JPH0246706A - Coil bobbin - Google Patents

Abstract

PURPOSE:To simplify the grounding structure and assembly of a core by a method wherein an elastic earth terminal is fixed on flange formed on one end of a bobbin main body to form a thick-wall part on one end part of the flange if necessary. CONSTITUTION:A bobbin main body 2 around which a coil 4 is to be wound is provided with a cylindrical winding part 6 on both ends of which flanges 8 are formed respectively in specified width. Then, a prism-like thick-wall part 10 in the same width as that of the flanges 8 is formed on one side flange 8 to fix a plate type earth terminal 12. This flange 8 is formed into one body with the bobbin main body 2 while a part of the earth terminal 12 is integratedly buried in the thick wall part 10 when the bobbin main body 2 is formed. The earth terminal 12 formed of a band type metallic plate whose one end is protruded from the thick wall part 10 in the end direction of the bobbin main body 2 likewise the other end in the side direction. Finally, the one end part in the contact side with a core is bent to form an S type coated part 12A while the other end part is formed into a flat type leading-out part 12B.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coil bobbin used in a head for a floppy disk device (FDD) and the like.

[Conventional technology]

Conventionally, a core used in an FDD head has its surface coated with a conductive resin or the like to prevent static electricity and is grounded.

Further, an FDD head includes a front core and a back core, which are positioned with high precision using a positioning jig or the like and fixed with an adhesive.

[Problem to be solved by the invention]

However, since the core used in such a head is small, applying a conductive resin to the surface and wiring for grounding complicates the grounding structure and the work involved.

In addition, after positioning each head, it is very troublesome to maintain that position and fix it with adhesive, making the assembly work troublesome as the fixing positions between the cores may become incorrect. This also makes the quality unstable.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a coil bobbin that can simplify the core grounding structure and core assembly.

[Means to solve the problem]

In the coil bobbin of the present invention, an elastic ground terminal is fixed to a flange formed at the end of a bobbin body around which a coil is wound, and one end of the ground terminal is brought into contact with a core attached to the bobbin body using elasticity. , the other end can be connected to the ground wiring side.

In addition, the coil bobbin of the present invention has a thick wall portion formed at one end of the flange formed at the end of the bobbin body, and a plate-shaped ground terminal is connected to the thick wall portion toward the core inserted into the bobbin body. This is embedded, and one end of this ground terminal is pulled out to the core side.

[For production]

When an elastic ground terminal is fixed to the flange formed at the end of the bobbin body, the elasticity of the ground terminal can be used to electrically contact the core, and the core can be grounded via the ground terminal. In addition, the ground terminal can be used as a positioning jig to set the core fixing position, so each bobbin has its own positioning jig, which simplifies assembly work and allows for highly accurate positioning. The quality can be stabilized.

In addition, by forming a thick part at one end of the flange formed at the end of the bobbin body and embedding a plate-shaped ground terminal in this thick part, the elasticity of the ground terminal is increased, and the plate-shaped Therefore, the contact area with the core is wide, and sufficient fixing force can be obtained when assembling the core, and highly accurate positioning can be obtained.

〔Example〕

FIG. 1 shows an embodiment of the coil bobbin of the present invention.

As shown in FIG. 1A, the bobbin body 2 is provided with a cylindrical winding part 6 for winding the coil 4 and for inserting the core therein, and both ends of the winding part 6 are Flanges 8 are each formed with a constant width. For example, the bobbin body 2 can be integrally molded into a rectangular tube shape using an insulating synthetic resin.

A prismatic thick part 10 having the same width as the flange 8 is formed at the edge of one flange 8 by extending the flange 8 in the width direction. A plate-shaped ground terminal 12 is fixed to this thick portion 10 . The flange 8 is molded integrally with the bobbin body 2 from synthetic resin, and a portion of the ground terminal 12 is integrally embedded in the thick portion 10 when the bobbin body 2 is molded.

The ground terminal 12 is formed of a band-shaped metal plate having appropriate elasticity and conductivity, and has one end protruding from the thick wall portion 10 toward the end surface of the bobbin body 2 and the other end toward the side surface of the bobbin body 2. There is. The ground terminal 12 has a curved surface on the side that contacts the core at one end, and an S-shaped contact portion 12A to maintain sufficient elastic force, and the other end is grounded. For convenience of connection with the side,
A flat drawer portion 12B is formed.

In the FDD head, as shown in FIG. 1B, coil bobbins are installed on the read/write core side and the erase core side. That is, the coil 4A on the read/write side is attached to the winding part 6 of the bobbin body 2 of each coil bobbin.
, the erase side coil 4B is wound. Each bobbin body 2 has a front core 14 on the read/write side.
A, the front core 14B on the erase side is inserted, and the front cores 14A, 14B form a U-shape, and between the legs of each front core 14A, 14B, a back core 16A,
16B is fixed. Each of the front cores 14A, 14B and the back cores 16A, 1 and 6B is coated with a conductive synthetic resin made by mixing silver powder as a filler into an epoxy resin to give conductivity. Conductivity is obtained on the surfaces of the cores 14A, 14B, 16A, and 16B.

In this case, each leg of the front core 14A and the back core 1
6A, one end of the ground terminal 12 fixed to the thick part lO of the coil bobbin is brought into contact, and the elastic force of the ground terminal 12 is used to connect the back core 16A to the leg side of the front core 14A. By applying the force, the front core 14A and the back core 16A are joined together. and,
The front core 14A and the back core 16A are fixed together with an adhesive placed on their joint surfaces. This type of configuration is the front core 14B and the back core 16B.
The same applies to the sides, and the front core 14A and the front core 14B and the back core 16A and the back core 16B are integrally fixed with adhesive 18.

Since one end of each ground terminal 12 is in contact with the back cores 16A and 16B, the back cores 16A and 16B are
Front cores 14A, 14B and each ground terminal 12 are electrically connected through 16B.

A support frame 2 made of ceramic, for example, is provided on the side of each front core 14A, 14B on the sliding surface side with the FDD.
0A and 20B are fixed, and the sides of the coils 4A and 4B are covered.

As shown in FIG. 2, a gimbal plate 22 made of a metal spring plate is attached to the end surfaces of the support frames 20A and 20B, and the ground conductor 26 of the wiring board 24 attached to the upper surface of the gimbal plate 22 The ground terminal 12 is electrically connected by solder 28. Therefore, each front core 14A, 14B2 and back core 16A116B connect to the wiring board 2 through the ground terminal 12.
It is electrically connected to four ground conductors 26 and grounded, thereby preventing each core 14A to 16B from being charged.

In addition, since a highly rigid metal can be used for the ground terminal 12, sufficient elastic force can be obtained, and the front core 1
The back cores 16A and 116B are strongly urged against the bobbin body 2 and the front coils 14A and 14B, and the front cores 14A and 14B are pressed against the bobbin body 2. It can also prevent sagging. During assembly work, the ground terminal 12 also serves as a fixing jig, so
Positioning and fixing work becomes easier, work efficiency is improved, and heads with stable quality can be mass-produced.

[Effects of the Invention] According to the present invention, the core can be electrically contacted by utilizing the elasticity of the ground terminal fixed to the flange, and the core can be grounded via the ground terminal. It can be used as a positioning jig to set the position.
Assembly work becomes easier, positioning can be performed with high precision, and heads with stable quality can be mass-produced.

Further, according to the present invention, a thick wall portion is formed at one end of the flange formed at the end of the bobbin body, and a plate-shaped ground terminal is embedded in this thick wall portion, thereby setting the elasticity of the ground terminal to be high. At the same time, a sufficient contact area with the core can be ensured, and when assembling the core, sufficient fixing strength allows highly accurate positioning and a stable fixed state.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 shows an embodiment of the coil bobbin of the present invention, (A
) is a perspective view showing a coil bobbin, (B) is a perspective view showing an FDD head using the coil bobbin, and FIG. 2 is a partial sectional view of the FDD head shown in FIG. 1. 2...Bobbin body 4. 6, 8, 10, 12, 14A. 6A1 A, 4B...Coil, winding part, flange, thick wall part, ground terminal 14B...Front core 16B...Back core (A) Figure (B)

Claims (2)

[Claims] 1. An elastic ground terminal is fixed to a flange formed at the end of the bobbin body around which the coil is wound, one end of which is brought into contact with the core attached to the bobbin body using elasticity, and the other end is connected to the ground wire. Coil bobbin that can be connected to the side. 2. A thick-walled part is formed at one end of the flange formed at the end of the bobbin body, and a plate-shaped ground terminal is embedded in this thick-walled part toward the core that is inserted into the bobbin body. Coil bobbin pulled out to the core side.