JPH05299273A - Choke coil - Google Patents

Abstract

PURPOSE:To assemble a split magnetic core which is high in quality and simple in structure. CONSTITUTION:Split magnetic cores 2A and 2B of the same shape are made to bear against each other making the side end faces 3a of legs 3 which extend in the lengthwise direction of the cores 2A and 2B overlap each other so as to be joined into an integral structure. When a bobbin 5 previously wound with a winding 4 is mounted on the legs 3 by fitting, the bearing surfaces 3a are welded to each other by pressure without being polished with an energizing means provided to the bobbin 5 to fix the cores 2A and 2B together.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a choke coil,
Particularly, the present invention relates to a choke coil in which a split magnetic core can be easily manufactured and the core is integrally assembled.

[0002]

2. Description of the Related Art Generally, in a choke coil as an inductor element, selection of a core material and winding number of windings are standardized in order to obtain a predetermined inductance. Then, coils of various shapes have been developed and manufactured in order to process and manufacture coil components according to various standards. Among them, the toroidal coil is commonly used. In this toroidal coil, a winding can be wound around a ring-shaped toroidal core to create a predetermined inductance, but it is necessary to manually wind the winding around the core at equal intervals. Therefore, there is also proposed a choke coil in which a bobbin is mechanically wound to facilitate winding, or a bobbin in which a winding is preliminarily wound is attached to a split magnetic core.

FIG. 9 is a perspective view showing an example of a choke coil in which the magnetic core 50 is formed in a Chinese character "Japanese" shape. A bobbin 51 is loosely fitted to the central leg core 50a of the choke coil, and a winding separator 52 and a gear 53 are fixed to both ends of the bobbin 51. To wind the winding 54 around the bobbin 51, the drive gear of a winding machine (not shown) and the gear 53 of the bobbin are engaged with each other, the bobbin 51 is rotated at a predetermined speed, and the winding 54 is wound around the bobbin 51. It is designed to let you.

Further, in FIG. 10, a rectangular bobbin 55, in which a winding 54 is mechanically wound beforehand, is formed into a U-shaped split magnetic core 56.
2 shows an example of a choke coil which is fitted to the end portion of and the core is integrally joined. In this choke coil, the divided cores are joined, so that the joint end face 56a of the core is mirror-polished to minimize the gap in order to prevent deterioration of the characteristics of the choke coil.

[0005]

However, in the choke coil of the type in which the winding is wound around the bobbin by the gear shown in FIG. 9, a large diameter winding cannot be used, and the winding size used is limited. As a result, there is a problem that the choke coil characteristic can be applied only to the current capacity of 3 A or less. Further, in the choke coil shown in FIG. 10, the AL value is lowered unless the core joint surface is mirror-polished, so mirror-polishing is an essential work. For this reason, the labor in the manufacturing process increases, which leads to an increase in cost.

Therefore, an object of the present invention is to solve the problems of the above-mentioned conventional techniques, to freely set the diameter of the winding to be used, to eliminate mirror polishing work, and to provide an inexpensive and high quality choke coil. To do.

[0007]

In order to achieve the above object, the present invention integrates the split magnetic cores of the same shape by abutting the side end surfaces of the leg portions extending in the longitudinal direction so as to overlap each other. In a choke coil, which is joined to the bobbin and is fitted and fitted with a winding wound in advance on the bobbin, the contact surface of the leg portion is unpolished and is provided on a part of the bobbin. It is characterized in that they are pressed against each other.

[0008]

According to the present invention, the split magnetic cores of the same shape are integrally joined by abutting the side end surfaces of the leg portions extending in the longitudinal direction so as to overlap each other, and the cores are integrally joined to the bobbin in advance. In a choke coil in which the wound winding is fitted and mounted, the cores are fixed to each other by pressing them against each other by urging means provided in a part of the bobbin without polishing the contact surfaces of the leg portions. In joining the split cores, a large joining area can be secured, and the joining surfaces can be brought into close contact with each other to minimize the characteristic deterioration due to the gap.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the choke coil according to the present invention will be described below with reference to FIGS. In FIG. 1, reference numeral 1 indicates the entire choke coil, and the magnetic core 2 of the choke coil 1 is composed of a core in which substantially U-shaped split magnetic cores are joined so that the leg portions 3 overlap each other. Further, a bobbin 5 in which the winding wire 4 is wound in advance by a winding machine is attached to the core joint portion. Core 2
Is composed of a combination of two magnetic cores 2A, 2B of the same shape as shown in FIG. 2, and the side surfaces of the two leg portions 3 extending in the longitudinal direction are in contact with each other with a wide joint area. Is becoming At this time, the thickness of the leg portion 3 is almost half that of the base portion 2a, and the core portion 2 having a uniform thickness is formed by stacking the leg portions 3 of the two magnetic cores 2A and 2B. At this time, the core material is preferably Mn-Zn ferrite, Ni-Zn ferrite, or carbonyl iron dust for high frequencies, and a predetermined inductance can be obtained due to the relationship between these materials and the number of turns of the winding.

FIG. 3A shows one of the split magnetic cores 2A and 2B.
It shows a piece. At this time, the joint surface 3 of the leg portion 3
"a" is finished with normal finishing surface accuracy. That is, compared to the small joint area of only the end face as shown in FIG.
The cores can have a wide joint surface, which can minimize the gap at the core discontinuity surface. FIG. 3B shows a modified example in which the leg portion 3 corresponding to the joint portion is formed in a wedge shape. In this modification, the wedge effect can further enhance the pressure contact effect of the bobbin 5 fitted in the joint portion.

4 and 5 are partial sectional views showing an example of the biasing means formed on the inner peripheral surface of the bobbin. This urging means is a bobbin 5 in which the winding is previously wound by a machine.
Is fixed to a predetermined portion of the core 2, and plays a role of increasing the degree of adhesion of the joint surface of the leg portion 3 of the core 2 that abuts.

In FIG. 4, two tongue-shaped plates 6, 6 are integrally formed with the bobbin 5 on the inner surfaces of the bobbin 5 facing each other. The bobbin 5 is made of a synthetic resin having a high insulating property, and the tongue plate 6 also exhibits elasticity, and is biased toward the core 2 when mounted on the core 2 as shown in the figure. This ensures the pressed state of the joint surface 3a of the core.

FIG. 5 shows a modification in which the protrusion 7 is provided on the inner surface of the bobbin 5. In the same figure, a notch 8 is formed at the base of the protrusion 7, and the distance between the opposing protrusions 7 is set to be slightly smaller than the thickness of the core 2 into which the protrusion 7 is fitted. In this state, the protrusion 7 is slightly deformed toward the notch 8, and a reaction force for pressing the core surface acts on the head of the protrusion 7. As a result, the joint surface 3 of the core 2
It is possible to press a. The same figure (b) shows the protrusion 7 on one side.
It shows a modified example in which a notch is formed only in. According to this modification, since the core is pressed only in one direction,
The mounting stability of the bobbin 5 is extremely improved.

Next, as another embodiment, an example will be described in which a part of the bobbin 5 is locked by a leaf spring-like clip member and the bobbin 5 is fixed to the core joint surface 3a. FIG. 6 uses a leaf spring-like clip member to join and fix the split magnetic cores 2A and 2B shown in FIG. 1 to sandwich the locking projection integrally formed at the end of the bobbin 5 and the core at a time. This shows the state in which the bobbin 5 is fixed to the core leg portion 3 and the core is pressed. The leaf spring-shaped clip member 10 shown in the figure is a substantially U-shaped resin leaf spring in which the plate width of the tip portion is set to be slightly wider than the root portion, and it is U-shaped as shown in FIG. 7A. The core 2 and the locking projection of the bobbin 5 are sandwiched by slightly expanding the tip of the. At this time, the leaf spring-shaped clip member 10 can also serve as a winding separator. Further, as shown in FIG. 3B, a flange 10a is formed on the end portion of the clip member 10 so that the clip member 10 can be used as a fixing member to a substrate or the like.

FIG. 8 shows a modification of the leaf spring clip member. The figure shows an E-shaped split magnetic core 2
A and 2B are shown. The magnetic cores 2A and 2B are configured such that the bobbin 5 is attached to the joint portion of the central leg portions 3A and 3B, and the leaf spring clip member 20 is attached to the leg portion 3 so as to sandwich the end surface of the bobbin 5 from both sides. The core legs 3 of both ends are fixed by the notch springs 20a at the ends.
The core joint surface 3a can be pressed against each other by sandwiching. According to this modification, by using the leaf spring-shaped clip member 20 having a relatively large size, the bobbin 5 can be fixed and the cores can be pressed against each other reliably.

[0016]

As is apparent from the above description, according to the present invention, the split magnetic core can be assembled with a simple structure so as not to cause the characteristic deterioration, and the winding portion can be easily mounted. The characteristics and manufacturing efficiency are surely improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a choke coil according to the present invention.

FIG. 2 is a perspective view showing the magnetic core shown in FIG.

FIG. 3 is a perspective view showing one piece of a magnetic core.

FIG. 4 is a longitudinal sectional view showing an embodiment of a biasing means for fixing the bobbin of the choke coil according to the present invention.

5 is a vertical cross-sectional view showing a modified example of the urging means shown in FIG.

FIG. 6 is a perspective view showing another embodiment of the choke coil according to the present invention.

7 is an exploded perspective view showing the configuration of the biasing means of the choke coil shown in FIG.

8 is an exploded perspective view showing a modified example of the choke coil shown in FIG.

FIG. 9 is a perspective view showing an example of the configuration of a conventional choke coil.

FIG. 10 is a perspective view showing an example of the configuration of a conventional choke coil.

[Explanation of symbols]

 1 choke coil 2 magnetic core 3 leg 3a joint surface 4 winding 5 bobbin 6 tongue plate 7 protrusions 10 and 20 leaf spring clip member 11 locking protrusion

Claims (1)

[Claims] 1. A split magnetic core of the same shape is integrally joined by abutting the side end faces of leg portions extending in the longitudinal direction so as to overlap each other, and the core is integrally wound around a bobbin in advance. A choke coil for fitting and mounting a winding, wherein the contact surfaces of the leg portions are pressed against each other in a non-polished state by a biasing means provided on a part of the bobbin.