JPH09283354A - Line filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability without generation of cracks or breakage in a yoke by forming holders integrated with a base at both length ends of the base, the holders having the same sectional shape as that of a yoke of a closed magnetic path core so as to cover the entire yoke. SOLUTION: The line filter has a split cylindrical bobbin 1 holding one magnetic leg of a square closed magnetic path core 2 made of a high-permeability material e.g. ferrite. A yoke 2-1 of the core 2 is inserted between two U-shaped holders 6 integrated with a base 4 having buried pin terminals 5, the holders 6 are fixed by a holder of an automatic winder to winding a wire round a bobbin l to form a coil. This prevents the yoke from cracking by an external force or damages due to mutual contact to thereby improve the reliability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line filter which is inserted into a power supply line of an electronic device or the like to prevent noise from entering the electronic device and leaking noise from the electronic device.

[0002]

2. Description of the Related Art A line filter has a closed magnetic circuit core made of a magnetic material having a high magnetic permeability such as ferrite, a split type cylindrical bobbin and a coil wound around the bobbin, and a plurality of pin terminals embedded therein. It is composed of a resin base. This line filter is inserted into a power supply line of an electronic device or the like and serves to attenuate common mode noise generated between a pair of power supply lines and the ground.

A conventional line filter will be described with reference to FIG. As shown in FIG. 4, in the conventional general line filter, one magnetic leg of the square-shaped closed magnetic circuit magnetic core 9 is sandwiched by a split type cylindrical bobbin 10, and one of the closed magnetic circuit magnetic cores 9 is inserted. The coil joint 14 or the two coil joints 9-1 are fixed by the holder of the automatic winding machine, and the coil 14 is wound around the bobbin 10.
Further, the other magnetic leg of the closed magnetic circuit magnetic core 9 is placed on the base 11 in which the plurality of pin terminals 12 are embedded, both ends 15 of the coil 14 are bent to the pin terminals 12, and soldering treatment 16 is performed.
The magnetic joint 9-1 of the closed magnetic circuit magnetic core 9 and the base 11 are bonded together by an adhesive 1
It is fixed at 3.

[0004]

As described above, in the conventional line filter, when winding, the magnetic joint 9-1 of the closed magnetic circuit core 9 is directly fixed by the holding portion of the automatic winding machine. Therefore, an external force for fixing may be directly applied to the magnetic joint 9-1 of the closed magnetic circuit magnetic core 9 to cause cracks or the like.

Further, in recent years, electronic parts have become high performance and small in size with the progress of various technologies. Therefore, the mounting on the printed circuit board has been automated by a mounting machine. Therefore, electronic parts can be stored in a taping product or a stick-shaped case in which the terminal portions are fixed with tape so that the electronic parts can be easily mounted on a mounting machine. Since the line filter is difficult to mount on a mounting machine as a taping product due to its shape, a method is adopted in which the magnetic joints of the adjacent line filters face each other and are housed in a case.

However, in the line filter having the conventional structure, when the line filter is housed in the case, the magnetic joints come into contact with each other, so that cracks may occur in the magnetic joints.
There was a risk of damage. In addition, in order to remove the damaged line filter from the case mounted on the mounting machine, the mounting machine must be stopped and removed, which is time-consuming and requires a long mounting time. Secondary problems such as high cost also occur.

The present invention eliminates these drawbacks by:
Improves reliability by eliminating the risk of cracks or damage to the magnetic joints of the magnetic cores that make up the line filter,
An object of the present invention is to provide a line filter having a structure capable of preventing the occurrence of the above-mentioned secondary problem.

[0008]

According to the present invention, a magnetic leg of a closed magnetic circuit magnetic core is partially held by a split type cylindrical bobbin, the bobbin is wound, and a plurality of pin terminals are embedded. In a line filter having a structure in which another magnetic leg portion of the closed magnetic circuit core is mounted on the base, a cross-sectional shape is formed at both ends in the longitudinal direction of the base so as to cover the entire magnetic joint portion of the closed magnetic circuit core. A receiving portion having the same shape as the cross-sectional shape of the magnetic joint portion is integrally formed with the base.

[0009]

According to the structure of the present invention, when the magnetic leg of the closed magnetic circuit core is placed on the base, the entire magnetic relay portion of the closed magnetic circuit core is covered by the receiving portion. Since the external force of the holding part does not directly act on the magnetic joint part,
There is no occurrence of cracks or the like in the magnetic joint, and when the magnetic joint is housed in a stick-shaped case, the magnetic joints do not directly contact each other due to the receiving portion, or cracks or the like occur in the magnetic joint. As a result, it is possible to prevent the breakage, so that the reliability is improved and the line filter without the above-mentioned secondary problem can be obtained.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view of a line filter according to the present invention. 2 is an exploded perspective view of a line filter according to the present invention, and FIG. 3 is a side view showing a state in which a plurality of line filters of the present invention are housed in a row in a stick-shaped case.

As shown in FIG. 2, the line filter of the present invention comprises a split type cylindrical bobbin 1 and one magnetic leg of a closed magnetic circuit magnetic core 2 having a square V shape and made of a magnetic material having a high magnetic permeability such as ferrite. To pinch. Then, the magnetic joint 2-1 of the closed magnetic circuit magnetic core 2.
Is inserted between two receiving portions 6 which are integrally formed with the base 4 in which a plurality of pin terminals 5 are embedded and whose cross-sectional shape is U-shaped, and which are held by the automatic winding machine. Then, the bobbin 1 is wound and the coil 3 is formed. Furthermore, tie both ends 3-1 of the coil 3 to the pin terminals 5 of the base 4,
Perform solder processing.

As shown in FIG. 1, in the line filter 8 of the present invention, the two magnetic joints 2-1 of the closed magnetic circuit core 2 are entirely covered with the magnetic receiving portions 6, so that the magnetic receiving portions 6 are formed. It works to protect -1. As a result, a line filter with improved reliability was obtained without the occurrence of cracks or the like in the magnetic relay portion 2-1 due to the external force of the holding portion of the automatic winding machine.

As shown in FIG. 3, the line filter 8 of the present invention is arranged in a row in a stick-shaped case 7 so that the magnetic joints of the adjacent line filters 8 face each other via the receiving portion 6. It is stored. Since the receiving portion 6 is interposed so as to cover the entire magnetic joint portion of the closed magnetic circuit magnetic core,
Adjacent magnetic joints do not come into direct contact with each other, and there is no risk of cracks or breakage in the magnetic joints, and an electronic component for an automatic mounting machine with improved reliability is possible.

In this example, the square-shaped closed magnetic circuit magnetic core has been described. However, by forming the receiving portion for accommodating the magnetically connecting portions at both ends as the base, the closed V-shaped magnetic core is used. Similarly, a line filter with improved reliability can be obtained.
In addition, the cross-sectional shape of the receiving portion is formed to match the cross-sectional shape of the magnetic joint portion of the closed magnetic circuit magnetic core.

[0015]

According to the line filter of the present invention, the occurrence of cracks due to external force in the magnetic joint of the closed magnetic circuit core, damage due to mutual contact, etc. is eliminated, reliability is improved, and the time and effort required during mounting are reduced. It is possible to obtain a line filter which can reduce the cost by reducing

[Brief description of drawings]

FIG. 1 is a perspective view showing a line filter according to the present invention.

FIG. 2 is an exploded perspective view of the line filter shown in FIG. 1 before winding.

FIG. 3 is a side view showing a state in which a large number of line filters according to the present invention are housed in a row in a stick-shaped case.

FIG. 4 is a perspective view showing a conventional line filter.

[Explanation of symbols]

 1, 10 Bobbin 2, 9 Closed magnetic circuit magnetic core 2-1, 9-1 Magnetic joint 4, 11 Base 5, 12 Pin terminal 6 Receptor 7 Case 8 Line filter 13 Adhesive 14 Coil

Claims (1)

[Claims] 1. A magnetic core of a closed magnetic circuit core is partially sandwiched by a cylindrical bobbin of a split type, the bobbin is wound, and the closed magnetic circuit magnetic core is attached to a base in which a plurality of pin terminals are embedded. In a line filter having a structure in which another magnetic leg portion is placed, at both ends in the longitudinal direction of the base, the cross-sectional shape is such that the cross-sectional shape of the magnetic-joint portion covers the entire magnetic-joint portion of the closed magnetic circuit magnetic core. A line filter characterized in that a receiving portion of the same shape is formed integrally with the base.