JPH0593014U - High frequency variable coil core holder fixing device - Google Patents

Abstract

(57) [Abstract] [Purpose] To securely fix the core holder of the high frequency variable coil to the case. [Structure] A drum core 16 is fixedly mounted on a base 11, a case 15 is exteriorly mounted on the base 11, and a cap core 1 is provided.
4 is screwed into the core holder 13 and attached to the case 15 so as to be retractable. Then, a vertical convex portion 23 is provided on the outer surface of the side plate 13a of the core holder 13 which faces the side plate 15a of the case 15, and the core holder 13 and the case 15 are press-fitted and fixed to each other.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a high frequency variable coil, and more particularly, to a small-sized high frequency variable coil core holder fixing device formed for surface mounting.

[0002]

[Prior Art]

 A conventional high frequency variable coil of this type will be described with reference to FIGS. Terminals 2, 2, 2, 2 are embedded in the base 1, and a drum core 4 around which a coil 3 is wound is fixedly mounted on the upper surface of the base 1. Engagement portions 5 and 5 are provided at opposite positions on the bottom surface of the base 1. On the other hand, a cap core 7 is screwed into a core holder 6 having an internal thread portion engraved on the inner surface thereof, and a case 8 made of metal or resin is mounted. Lugs 9 and 9 are vertically provided at the central portions of both side surfaces of the case 8, and the lugs 9 and 9 are bent to the engaging portion 5 on the bottom surface of the base 1 and crimped. In this way, the case 8 externally mounted on the base 1 is fixed to the bottom surface of the base 1, and the core holder 6 is also fixed by abutting on the base 1.

[0003]

[Problems to be solved by the device]

 In the conventional high frequency variable coil described above, the lugs 9, 9 of the case 8 are bent to fix the case 8 together with the core holder 6 to the base 1. However, if the caulking of the lugs 9, 9 is insufficient, the core holder 6 is loosened due to vibration or the like, or even if the caulking is good, the heat of the solder reflow causes the base 1 and the core holder 6 However, the cap core 7 may slightly move with respect to the drum core 4 due to temporary expansion, resulting in a change in inductance. Therefore, the corner portions 6a, 6a, 6a, 6a of the core holder 6 and the bottom surface of the base 1 are fixed to each other with the adhesive material 10 to prevent the core holder 6 from rattling. Therefore, the bonding work is required, and the adhesive material 10 may come off, resulting in lack of reliability.

Therefore, there arises a technical problem to be solved in order to securely fix the core holder to the case, and the present invention aims to solve this problem.

[0005]

[Means for Solving the Problems]

 This invention has been proposed to achieve the above-mentioned object, and a drum core is fixedly mounted on a base, a case is fixed to the base for exterior mounting, and a cap core is screwed into a core holder to emerge. In the high-frequency variable coil freely attached to the case, the side plate of the case is formed to have a diameter substantially the same as or slightly larger than the outer diameter of each side plate of the core holder that faces the inner diameter. In addition, a vertical projection is formed on the outer surface of each side plate of the core holder, and the core holder is press-fitted into the inner surface of the case to bond the both, and the core holder is fixed to the case. An object of the present invention is to provide a core holder fixing device for a high frequency variable coil.

[0006]

[Action]

 According to this invention, a vertical projection is provided on the outer surface of the side plate of the core holder, and the inner diameter of the side plate of the case, which faces the side plate of the core holder, is approximately the same as the outer diameter of the side plate of the core holder. Alternatively, since it has a slightly larger diameter, the side plate of the core holder can be inserted into the inner surface of the case. At this time, since the vertical convex portion provided on the side plate of the core holder is pressed against the inner side surface of the case and forcedly inserted, the case and the core holder are integrally fixed. Thus, there is no risk of backlash due to vibration and heat from the outside. Therefore, the linearity when rotating the cap core to change the inductance is improved, and the inductance can be maintained constant after the cap core is adjusted.

[0007]

【Example】

 An embodiment of the present invention will be described below in detail with reference to FIGS. In FIGS. 1 and 2, one end of each of terminals 12, 12, 12, 12 is embedded in a synthetic resin base 11, and a cap core 14 is attached to a core holder 13 provided above the base 11. It is screwed. Further, a metal case 15 is fixedly attached to the base 11 for exterior packaging.

FIG. 3 is a vertical sectional view taken along the line AB of FIG. 1, in which the drum core 16 is fixedly installed in the recess of the upper surface of the base 11. The drum core 16 is made of an insulating material such as synthetic resin or ferrite, and is wound with a coil 17 formed by winding a coated wire such as a polyurethane copper wire or a tetron winding or a tinned copper wire. It is glued to the top surface. Further, a cap core 14 having a hollow cylindrical recess 18 is provided at a slight gap from the drum core 16, and a male screw portion 19 engraved on the outer surface of the cap core 14 and the core holder 13 are provided. The female screw portion 20 on the inner surface is screwed together. Then, the front end of the driver is inserted into the long hole 21 formed in the central portion of the cap core 14 and rotated to either the left or the right, so that the cap core 14 is retracted from the case 15 and the drum core 16 is retracted. It is formed so that the polymerization position with and can be changed.

FIG. 4 shows the side surfaces of the case 15 and the core holder 13, respectively. The case 15 has a lug 22 at the center of each of the side plates 15a, 15a, 15a, 15a facing each other. , 22 are provided vertically. The side plates 13a, 13a, 13a, 13a of the core holder 13 fitted to the inner surface of the case 15 are formed to face the side plates 15a, 15a, 15a, 15a of the case 15, respectively. The diameter of the inner surface of the side plates 15a, 15a, 15a, 15a facing each other of the case 15 is substantially equal to or slightly larger than the outer diameter of each of the side plates 13a, 13a, 13a, 13a of the core holder 13 facing each other. Is formed in.

Further, vertical protrusions 23, 23, 23, 23 are provided on the outer surface of each side plate 13a, 13a, 13a, 13a of the core holder 13. Therefore, when the core holder 13 is inserted into the inner side surface of the case 15, the case 15 is pressed outward by the convex portions 23, 23, 23, 23 of the vertical strips and at the same time the core holder 13 is The protrusions 23, 23, 23, 23 are crimped, and the case 15 and the core holder 13 are integrally and firmly fixed. After that, the cap core 14 is screwed into the core holder 13, and as shown in FIG. 3, the lug 22 of the case 15 is bent and crimped into the fastening recess 24 on the bottom surface of the base 11.

Thus, the core holder 13 and the case 15 are securely fixed to the base 11, and there is no risk of rattling of the core holder 13 due to external vibration, and the gap between the cap core 14 and the drum core 16 is slightly moved. This can prevent the inductance from changing. The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified version.

[0012]

[Effect of the device]

 As described in detail in the above-mentioned one embodiment of the present invention, when the core holder is press-fitted into the case, the side wall of the core holder has a vertical projection formed on the outer surface thereof. Crimping them to fix them together. Therefore, the core holder is firmly engaged with the case and the base, and there is no risk of rattling due to external vibration or heat from soldering. Therefore, after adjusting the cap core, there is no fear that the cap core will slightly move with respect to the drum core to change the inductance, and the accuracy of the product can be improved and the product can be made thinner. In addition, the conventional work of bonding the core holder to the base is not required, which reduces the man-hours and contributes to cost reduction.

[Brief description of drawings]

FIG. 1 is a plan view of a high frequency variable coil.

FIG. 2 is a side view of FIG.

FIG. 3 is a cross-sectional view taken along the line AB of FIG.

FIG. 4 is a side view of a case and a core holder.

FIG. 5 is a partially cutaway vertical side view of a conventional high frequency variable coil.

FIG. 6 is a bottom view of the same.

[Explanation of symbols]

 11 Base 13 Core Holder 13a Side Plate 14 Cap Core 15 Case 15a Side Plate 23 Convex Strip

Claims (1)

[Scope of utility model registration request] 1. A high frequency variable coil in which a drum core is fixed to a base, a case is fixed to the base for exterior mounting, and a cap core is screwed into a core holder so as to be retractable and attached to the case. The side plates of the case are formed so as to have a diameter substantially the same as or slightly larger than the outer diameter of each side plate of the core holder, which faces the inner diameter of the case. Forming the convex part of the strip,
Further, the core holder fixing device for a high-frequency variable coil, wherein the core holder is press-fitted into the inner surface of the case so as to bond the both, and the core holder is fixed to the case.