JP3448721B2 - Inductance coil device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductance coil device such as a choke coil. 2. Description of the Related Art FIG. 4 shows a conventional inductance coil device. This coil device comprises a bobbin 1 in which a coil 2 is wound around a cylindrical portion 1a, and inner legs 3a, 4a connected to the cylindrical portion 1a. A pair of Es assembled to the bobbin 1 so as to be inserted into
The joint surfaces of the outer legs 3b, 4b are fixed by an adhesive, and a gap 5 is formed between the ends of the inner legs 3a, 4a. [0003] In the above-described coil device in which the magnetic saturation of the cores 3 and 4 is prevented by the gap 5, since the inductance greatly changes depending on the size of the gap 5, a predetermined inductance value is set. The gap size is designed in advance so as to obtain. That is, since the size of the gap 5 is determined by the length of the inner legs 3a and 4a of the E-shaped cores 3 and 4, the length of the inner legs 3a and 4a is adjusted so that the gap 5 having a predetermined size is formed. Then, the cores 3 and 4 are molded. However, errors may occur in the inductance value of each product due to a dimensional error of the core, a dimensional error at the time of forming the gap, or an error of the magnetic permeability of the core. Since there is a case where a target inductance value cannot be obtained, there is a problem that a product is wasted and a lot of trouble is required for product inspection. [0005] In view of the above-mentioned circumstances, an object of the present invention is to develop an inductance coil device having a simple configuration and capable of obtaining a highly accurate inductance value. In order to achieve the above-mentioned object, according to the present invention, a bobbin made of a synthetic resin material provided with a coil is provided on a cylindrical winding portion. The bobbin is provided with a coil, and the bobbin is provided with a coil so that the inner hole of the winding portion faces each side, so that the bobbin is formed in the endless frame-shaped quadrilateral core. Is provided on the quadrilateral core, and a hole is formed in the bobbin so as to communicate with the inner hole of the winding portion. The present invention proposes an inductance coil device characterized in that an insertion length of an I-shaped core is determined by cutting a portion to adjust an inductance. A bobbin on which a coil is wound is disposed in an endless frame-shaped quadrilateral core such that an inner hole of a winding portion of the bobbin communicates with a hole formed in the quadrilateral core. On the inner surface of the winding portion of the bobbin, a convex portion formed along the cylinder axis direction is provided, and the I-shaped core is formed from the hole-shaped portion to the inner portion of the winding portion at the tip of the I-shaped core. Insert as if cutting. The I-shaped core is inserted until the inductance value that changes according to the insertion length of the I-shaped core reaches a predetermined value, and then the I-shaped core is fixed to the bobbin. The coil device thus configured can easily adjust the inductance and obtain a high-precision inductance. Therefore, the coil device is suitable for mass production, and the reliability of the device is improved and management becomes easy. Next, an embodiment of the present invention will be described with reference to the drawings. 1 is a longitudinal sectional view of the coil device of the present invention, FIG. 2 is a bottom view of the coil device, and FIG. 3 is a perspective view of an outer core and a middle core provided in the device. In these drawings, a bobbin 20 made of a synthetic resin material has a rectangular tubular winding portion 21, and a coil 22 is wound around the winding portion 21. In addition, bobbin 2
Numeral 0 has flanges 20a and 20b at both ends, and a terminal pin 23 is implanted on one of the flanges 20a formed to be thick. Reference numeral 24 denotes an outer core made of a ferrite material. As shown in FIG. 3A, the outer core 24 has a quadrangular endless frame shape, and has a winding inner hole 21 of the bobbin 20 on one side.
A hole portion 24a formed so as to communicate with a is provided. The middle core 25 is an I-shaped core as shown in FIG. 3 (B), and is formed of a ferrite material like the outer core 24. On the other hand, the winding portion 21 of the above-described bobbin 20 is provided with a ridge 26 formed on the side surface of the inner hole 21a along the cylinder axis direction. The projecting ridge 26 is formed by the winding 2
1 are formed from one end side to the other end side, and as shown in FIG. 4, two are formed on the opposing surface where the inner hole 21a is formed. The ridge 26 is a synthetic resin material formed integrally with the winding 21. To configure the coil device of the present invention, a coil 22 is wound around a winding portion 21 of a bobbin 20, and the bobbin 20 is wound inside an endless frame-shaped outer core 24 by a winding portion inner hole 21a.
The bobbin 20 is fixed to the outer core 24 with an adhesive 27 or the like. A terminal pin 23 is fixed to a flange 20a projecting laterally from one inner surface of the outer core 24. Next, the middle core 25 is inserted into the inner hole 21a of the winding part 21 from the outside of the outer core 24 through a hole 24a formed in the outer core 24. At this time, the insertion of the middle core 25 is temporarily prevented because the tip of the middle core 25 contacts the protruding ridge 26, but the protruding ridge 26 of the synthetic resin material is
The core 25 is inserted in such a manner that the core 25 is cut at the end of the core. In the state shown in FIG. 1 in which the middle core 25 is pushed into the inside of the winding part 21 by about 1/3, the insertion of the middle core 25 is temporarily stopped, and the inductance value of this coil device is measured at the terminal pin 23. Connect a measuring device. At this time, the middle core 25 is pressed against the cut portion of the ridge 26 and is temporarily fixed at the above position, and a gap B is formed immediately above the middle core 25. After a measuring instrument is connected to the terminal pin 23, the medium core 25 is gradually pushed into the winding portion 21 while measuring the inductance value with the measuring instrument, and a predetermined inductance value is obtained. Then, the insertion of the middle core 25 is stopped. The middle core 2 temporarily fixed by the ridge 26
At the position 5 described above, an adhesive is injected into the winding portion inner hole 21a, and the middle core 25 is fixed to the bobbin 20. Since the inductance of the coil device is adjusted by the insertion length of the middle core 25, the configuration is extremely simple. When the insertion of the middle core 25 is stopped, the middle core 25 is temporarily moved by the ridge 26. Because it is stopped
The fixation of the middle core 25 is facilitated, and a desired inductance can be easily obtained. By the way, according to the present embodiment, a coil device having an inductance tolerance of 1.0% or less can be realized. In the above embodiment, the ridge 26 is
Is formed from one end side to the other end side along the cylinder axis direction, but may be formed partially between one end side and the other end side. Although two are formed on the side surface, they may be formed on the entire side surface of the inner hole 21a. As described above, in the coil device according to the present invention, the inductance is adjusted by the insertion length of the I-shaped core inserted so as to cut the ridge formed on the inner surface of the bobbin winding. With this configuration, the inductance can be easily adjusted, and a highly accurate inductance can be obtained. In addition, since the device has a simple structure and has a high-precision and uniform inductance irrespective of the dimensional error of each core and the error of the magnetic permeability of the core, the device is suitable for mass production and management. If easy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged longitudinal sectional view showing a coil device according to an embodiment of the present invention. FIG. 2 is a bottom view of the coil device. FIG. 3 is a perspective view of an outer core and a middle core provided in the embodiment, FIG. 3 (A) is a perspective view of the outer core, and FIG. 3 (B) is a perspective view of the middle core. FIG. 4 is a sectional view taken along line AA in FIG. FIG. 5 is a longitudinal sectional view of a conventional coil device. [Description of Signs] 20 Bobbin 21 Winding part 22 Coil 23 Terminal pin 24 Outer core 24a Perforated part 25 Medium core 26 Convex ridge

Claims (1)

(57) [Claim 1] A bobbin made of a synthetic resin material provided with a coil is provided on a cylindrical winding portion. In addition to providing the formed ridge,
This bobbin is equipped with a coil, and is arranged in an endless frame-shaped quadrilateral core such that the inner hole of the winding part faces each side, and the quadrilateral core communicates with the inner hole of the bobbin winding part. A configuration in which an insertion length of the I-shaped core is determined by cutting the protruding portion at the tip end of the I-shaped core inserted into the inner hole of the winding portion from the hole-shaped portion, thereby determining the insertion length of the I-shaped core. An inductance coil device, characterized in that: