JP3938988B2 - Flux intrusion prevention structure for electromagnetic relay - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a terminal surface sealing structure of a flux-resistant electromagnetic relay mounted on a printed wiring board.
[0002]
[Prior art]
In general, the electromagnetic structure of the electromagnetic relay is such that the coil 12 is wound around the body of the coil bobbin 4, the iron core 1 is inserted into the center hole 4 a of the coil bobbin 4, and the yoke 3 is attached to the iron core 1 as a component forming a magnetic circuit. The armature 2 is provided so as to bridge the head 1a of the iron core 1 of the electromagnet and the other end of the yoke 3, and is held by a plate-like hinge spring 6 made of an elastic body. The armature 2 is rotatably mounted to constitute an electromagnet structure.
The electromagnetic relay attracts the armature 2 to the head 1a of the iron core 1 when a current is passed through the coil terminal 5 and the coil 12 is excited, and the movable contact spring 7 is operated via the card 10 to contact the contacts 7a, 8a. Opening and closing is to be performed.
[0003]
This electromagnetic relay is mounted on a printed wiring board, and the electromagnetic relay is fixed by attaching solder to the terminal part that is led out to the outside through the board through the high-temperature solder layer. The flux may rise and enter the electromagnetic relay, and when this flux enters, it adheres to the contact and causes contact failure. In order to prevent this, an operation of sealing the terminal portion led out of the base block 9, that is, the low surface sealing portion 9b is performed.
[0004]
Further, in order to configure an electromagnetic relay in which the bottom surface sealing portion 9b with terminals is sealed, in addition to the derived terminal portion, the lower portion 1b of the iron core 1 exposed at the bottom surface sealing portion 9b of the base block 9 The L-shaped yoke 3 must also be filled and sealed. As a structure for sealing this portion, means for sealing the bottom surface sealing portion 9b of the base block 9 by injecting the liquid sealing agent 13 into the exposed portion with the lower surface of the coil block 9 facing upward. is required. As one means for this, there is one in which a liquid sealant 13 is applied to the exposed portion and cured by heat treatment and sealed.
Thereafter, the electromagnetic relay main body is covered with the case 11 and fixed at the fitting portion with the base block 9.
[0005]
[Problems to be solved by the invention]
In this conventional fixing means, as shown in FIG. 5, since the head 1a of the iron core 1 and the flange 4b above the coil bobbin 4 are closely attached, the outer peripheral surface of the iron core 1 and the central hole of the coil bobbin 4 There is a gap 14 between the inner peripheral surface of 4a, and when the liquid sealant 13 is filled in the lower part of the base block 9 and heated, the gas in the gap 14 expands by heating. When the liquid sealing agent 13 is cured after heating, bubbles are generated, and there is a problem that the pinhole 13a is generated and the sealing structure is not formed.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a ventilation groove 4c in the flange portion 4b of the coil bobbin 4 so that the gas in the gap 14 between the outer peripheral surface of the iron core 1 and the inner peripheral surface of the center hole 4a of the coil bobbin 4 can be obtained. However, when the liquid sealing agent 13 is heat-cured, the gas expands and escapes to the outside, thereby facilitating the sealing operation.
A coil bobbin 4 formed integrally with the base block 9 or a separate part is placed on the base block 9, a ventilation groove 4 c is formed at the inlet of the flange 4 b of the center hole 4 a of the coil bobbin 4, and the iron core is sandwiched between the coil bobbins 4. The bottom surface of the base block 9 has a structure in which there is a gap between the head 1a of the iron core 1 and the flange 4b of the coil bobbin 4 even after the lower part 1b of 1 is fixed to the fitting hole 3a provided in the yoke 3. The portion of the lower portion 1b of the iron core 1 exposed to the sealing portion 9b and the fitting hole 3a of the yoke 3 is sealed.
[0007]
1 to 4 show the structure of the electromagnetic relay of the present invention, and FIG. 1 is an assembled perspective view of the electromagnetic relay of the present invention. 2 is an exploded perspective view of FIG. FIG. 3 is a perspective view of an iron core, a yoke, and a base block. FIG. 3A is an exploded perspective view, and FIG. 3B is an assembled perspective view thereof. 4 is a front view of the electromagnet, FIG. 4A is a front sectional view, and FIG. 4B is a bottom view thereof. FIG. 5 is a conventional one, FIG. 5A is a front sectional view, and FIG. 5B is a bottom view thereof.
[0008]
The assembly process of the electromagnetic relay of the present invention will be described with reference to FIG. 2. The coil bobbin 4 may be disposed on the base block 9 made of an insulating material, and the coil bobbin 4 may be integrally formed with the base block 9. The coil 12 is wound around the coil bobbin 4, the iron core 1 is inserted into the center hole 4a of the coil bobbin 4, the lower part 1b is penetrated to the lower part of the base block 9, and then the L-shaped yoke 3 is The fitting hole 3a provided in the yoke 3 by inserting into the through hole 9a from the lower part of the base block 9 is fitted and fixed to the lower end 1b of the iron core 1.
[0009]
Thereafter, the hinge spring 6 is attached to the yoke 3. At this time, the hinge 2 can be attached to the yoke 2 in advance. Next, after the movable contact spring 7 and the fixed contact spring 8 are inserted and fixed in the base block 9, the armature 2 is engaged with the free end 6a of the hinge spring 6 at a position facing the head 1a of the iron core 1. After that, the card 10 is locked and attached to the armature 2 and the movable contact spring 7.
The coil terminal 5 can be attached by simultaneous molding in the process of molding the base block 9. Then, the assembly of the electromagnetic relay is completed by covering the case 11.
[0010]
Next, the structure of the iron core 1, the yoke 3, and the base block 9, which are the main parts of the present invention, and the sealing means thereof will be described in detail with reference to FIGS. 3 and 4. The base block 9 is shown in FIG. In this way, the ventilation groove 4c is formed in the flange portion 4b of the coil bobbin 4 by molding. The lower surface of the head 1a of the iron core 1 is in close contact with and locked to the flange 4b having the ventilation groove 4c.
[0011]
As shown in FIG. 4 (a), these fitting states can be assembled with a clearance between the head 1a of the iron core 1 by a ventilation groove 9c provided in the base block 9.
[0012]
【The invention's effect】
As is apparent from the above description, the present invention surrounds the iron core 1 and the iron core 1 by providing the base block 9 with the ventilation groove 4c so that there is a gap 14 between the head 1a of the iron core 1. Since the gas existing between the coil bobbin 4 can escape from the ventilation groove 4c before the liquid sealing agent 13 is cured and the bottom sealing portion 9b of the base block 9 can be sealed without generating bubbles, There is a great effect that work without pinholes is smooth and workability is improved.
[Brief description of the drawings]
FIG. 1 is an assembled perspective view of an electromagnetic relay according to the present invention.
FIG. 2 is an exploded perspective view showing the structure of the electromagnetic relay of the present invention.
3A and 3B show an electromagnet of the present invention, in which FIG. 3A is a perspective view thereof, and FIG. 3B is an assembled perspective view thereof.
4A is an electromagnet, FIG. 4A is a front sectional view thereof, and FIG. 4B is a bottom view thereof.
FIGS. 5A and 5B show a configuration of a conventional electromagnet, in which FIG. 5A is a front view thereof and FIG. 5B is a bottom view thereof.
[Explanation of symbols]
1 ... Iron core 1a ... Iron core head 1b ... Iron core bottom 2 ... Armature 3 ... yoke 3a ··· yoke fitting hole 4 ··· coil bobbin 4a ··· coil bobbin center hole 4b ··· coil bobbin flange 4c ··· Ventilation groove 5 of coil bobbin ..... Coil terminal 6 ..... Hinge spring 6a ..... Free end 7 provided on the hinge spring ..... Movable contact spring 7a ··············································· Fixed spring 9a ··········································· Through-hole 9b ... Base block bottom seal 11 ... Case 12 ... Coil 13 ... Liquid sealant 13a ... The gap between the ... pin hole 14 ...... iron core and the coil bobbin

Claims (1)

A coil bobbin integrally molded or placed on the base block, and a groove through which the gas in the central hole of the coil bobbin can be ventilated at a position where the upper part of the coil bobbin is in contact with the lower part of the iron core head are provided. Flux intrusion prevention structure for electromagnetic relays.

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