JP3952582B2 - Electromagnetic relay - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic relay, and more particularly to an electromagnetic relay having a long life.
[0002]
[Prior art]
Conventionally, as an electromagnetic relay, for example, there is a configuration shown in FIGS.
That is, an electromagnetic relay in which an electromagnet block 3, a movable block 4, and the like are accommodated in an internal space formed by the base 1 and the case 2.
The electromagnet block 3 placed and fixed on the base 1 has an iron core 3c inserted into the center hole of a spool 3b around which a coil 3a is wound, and one end projecting is used as a magnetic pole while the other projecting end is used. The bent yoke 5 is fixed by caulking. In addition, the movable block 4 formed by integrally molding the movable contact piece 6 and the movable iron piece 7 in a non-contact state in a substantially parallel manner is rotatably supported by the horizontal tip of the yoke 5 via a coil spring 8. Yes.
When the movable iron piece 7 of the movable block 4 is attracted to and separated from the magnetic pole portion of the iron core 3 c by the excitation / demagnetization of the electromagnet block 3, the movable block 4 is horizontal against the yoke 5. It rotates with the tip as a fulcrum. And the movable contact 6a provided in the free end part of the movable contact piece 6 contacts / separates alternately with the normally closed fixed contact 6b or the normally open fixed contact 6c, and opens and closes an electric circuit.
[0003]
[Problems to be solved by the invention]
In this type of electromagnetic relay, the movable contact piece 6 and the lead wire 9 were connected by soldering. However, in order to protect the global environment and improve the productivity of the connecting portion, both were welded and connected. The connection structure does not use solder. Further, in this connection structure, the connection portion is covered with a molded resin material in order to prevent disconnection of the connection portion, that is, disconnection due to a tensile force, a bending force, or the like applied to the lead wire 9. For this reason, the length dimension of the movable contact piece 6 must be shortened.
[0004]
However, the movable contact piece having a short length as described above operates as shown in FIGS. 8A to 8D. In particular, the movable block 4 is overshooted by inertia force during the return operation ( FIG. 8 (c)). As a result, the movable contact piece 6 protruding from the movable block main body 4a is greatly bent and stress is concentrated on the base thereof, so that fatigue failure is likely to occur and the mechanical life is short.
Further, since the movable contact piece 6 is shortened, the return bounce time during the return operation is lengthened, and so-called chattering is likely to occur. For this reason, an arc is generated between the contacts during the return operation, and the contacts are likely to be worn out, so that there is a problem that the electrical life is short.
[0005]
In order to solve these problems, for example, it is conceivable to reduce the amount of displacement of the movable contact piece 6 by reducing the gap between the movable contact piece 6 and the movable block body 4a. However, this method requires a mold such as a thin side core for molding, and the mold life is shortened, so that the productivity is lowered.
[0006]
In view of the above problems, an object of the present invention is to provide an electromagnetic relay having a long mechanical and electrical life and high productivity.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an electromagnetic relay according to the present invention rotates a movable block formed by integrating a movable iron piece and a movable contact piece substantially in parallel in a non-contact state based on excitation and demagnetization of the electromagnetic block. the movable contact provided at the free end of the movable contact piece protruding from the movable block, in the electromagnetic relay approaching and moving away from the fixed contact, only the rear middle portion of the movable contact piece only when the overshoot of the movable contact piece In addition to restricting the position by pressure contact, a protrusion that does not come into contact with the rear intermediate portion of the movable contact piece at the time of return to normal operation is provided on the protruding portion that extends in parallel with the movable contact piece from the movable block.
[0008]
The movable block may be obtained by integrating a movable iron piece, which is insert-molded separately, into a movable contact piece, which is primarily molded, by secondary molding.
The protrusion may be provided on a protrusion of a movable block formed by covering one end of the movable iron piece with a synthetic resin material.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings of FIGS.
That is, the electromagnetic relay according to the present embodiment is generally composed of a base 10, an electromagnet block 20, a movable block 30, and a case 40, as shown in FIG.
[0010]
The base 10 has a substantially rectangular plate shape, and a pair of pedestal portions 12 and 13 that face each other with a groove therebetween are formed in the vicinity of one end thereof. The pedestals 12 and 13 are provided with slits (not shown) at a predetermined pitch in a direction perpendicular to the paper surface. The fixed contact terminals 14 and 15 are press-fitted so as to oppose each position divided by the slit. A normally open fixed contact 14a and a normally closed fixed contact 15a provided at the upper ends of the fixed contact terminals 14 and 15 are opposed to each other at a predetermined interval.
[0011]
The electromagnet block 20 has an iron core 23 inserted into a center hole of a spool 22 around which a coil 21 is wound, and a protruding one end portion is used as a magnetic pole portion 23a, while a protruding other end portion is bent into a substantially L shape. The vertical portion 24a is fixed by caulking. The electromagnet block 20 is fixed by press-fitting the flange portion 22 a of the spool 22 and the vertical portion 24 a of the yoke 24 into the base 10.
The coil 21 is electrically connected to the coil terminal 16 via a relay terminal 25 press-fitted into the spool 22.
[0012]
The movable block 30 is formed by insert-molding the movable block body 31 and the movable contact piece 33 into the movable block main body 31 by arranging them substantially in parallel in a non-contact state (FIGS. 2A and 2B). The movable contact piece 33 having the movable contact 33 a at the free end is electrically connected to the movable contact terminal 17 through the lead wire 35 at the upper end. Further, of the protrusion 34 of the movable block main body 31 formed by covering the lower end portion of the movable iron piece 32 with a synthetic resin material, the lower end edge portion of the outward surface thereof can be brought into contact with the back surface of the movable contact piece 33. A position restricting projection 34a is provided. The protrusion 34a presses against the intermediate portion of the back surface of the movable contact piece 33 during overshoot during the return operation, thereby restricting the position of the movable contact piece 33. For this reason, the protrusion 34a can reduce the bending angle at the base portion of the movable contact piece 33 protruding from the movable block main body 31, thereby preventing stress concentration and preventing so-called chattering.
The movable block 30 is rotatably supported by the horizontal tip 24b of the yoke 24, so that the movable contact 33a faces the normally open fixed contact 14a and the normally closed fixed contact 15a so as to be alternately contactable and disengageable. . Furthermore, the movable contact piece 33 is biased outward by locking the uppermost end portion of the movable iron piece 32 to the electromagnet block 20 via the coil spring 36.
[0013]
The case 40 has a substantially rectangular parallelepiped shape that can be fitted to the base 10, and a positioning pressing portion 41 projects from the ceiling surface. When the case 40 is assembled to the base 10, the positioning pressing portion 41 comes into contact with the horizontal tip 24 b of the yoke 24 assembled to the electromagnet block 20. As a result, the electromagnet block 20 is sandwiched from above and below by the base 10 and the case 40 and is stabilized.
[0014]
Next, the operation of the electromagnetic relay having the above-described configuration will be described.
First, when no voltage is applied to the coil 21 of the electromagnet block 20, the movable block 30 is urged counterclockwise in FIG. 1 by the spring force of the coil spring 36, so the movable contact 33a. Is in contact with the normally closed fixed contact 15a.
[0015]
When the coil 21 is excited by applying a voltage, the magnetic pole portion 23a of the iron core 23 attracts the movable iron piece 32, so that the movable block 30 resists the spring force of the coil spring 36, and in FIG. Rotate in the direction. For this reason, after the movable contact 33 a contacts the normally open fixed contact 14 a (FIG. 4A), the movable iron piece 32 is attracted to the magnetic pole portion 23 a of the iron core 23.
[0016]
Next, when the application of voltage to the coil 21 is stopped and the above-described excitation is released, the movable block 30 is rotated in the reverse direction by the spring force of the coil spring 36. For this reason, the movable contact 33a is separated from the normally open fixed contact 14a and returned (FIG. 4B). Then, after the movable contact 33a comes into contact with the normally closed fixed contact 15a, the protrusion 34a of the movable block 30 is brought into contact with the back intermediate portion of the movable contact piece 33 when the movable block 30 is rotated by an inertial force to be in an overshoot state. Press contact. For this reason, the base of the movable contact piece 33 does not bend at a large angle as in the conventional example. Further, since the protrusion 34a is pressed against and pressed against the rear middle portion of the movable contact piece 33, so-called chattering can be prevented. Finally, while the movable contact 33a is in contact with the normally closed fixed contact 15a, the movable block 30 is slightly swung back by the spring force of the movable contact piece 33, and the protrusion 34a is separated from the movable contact piece 33 and returns to the return state. (FIG. 4 (d)).
[0017]
The movable block 30 does not need to insert-mold the movable iron piece 32 and the movable contact piece 33 at the same time in the movable block main body 31. For example, as shown in FIG. 3, after connecting the lead wire 35 to the movable contact piece 33, insert molding is performed by primary molding. In addition, the movable iron piece 32 that is insert-molded separately may be secondarily molded and integrated. According to this embodiment, positioning of the movable contact piece 33 and the movable iron piece 32 is facilitated, and there is an advantage that productivity and component accuracy are improved.
Further, the position restricting protrusion may be applied when the position of the movable contact piece is restricted only during operation. Furthermore, the movable contact does not have to be alternately connected to and separated from the pair of fixed contacts, and may be a case where only the single fixed contact is contacted or separated.
[0018]
【Example】
(Example)
The operation characteristics during the return operation were measured by providing the electromagnetic relay shown in FIG. 1 with a protrusion having a shape determined based on the equation shown in FIG. The measurement results are shown in the graph of FIG.
(Comparative example)
The operating characteristics were measured in the same manner when no protrusion was provided. The measurement results are shown in FIG.
In addition, the graph shown in FIG. 5 or FIG. 9 is measured on the basis of the outward side surface of the movable block. Therefore, in order for the movable contact to reliably contact the normally closed fixed contact, the displacement needs to be about 0.45 or more in FIG. 5 or FIG. Means that it is separated from the normally closed fixed contact.
[0019]
By comparing FIG. 5 which is the measurement result of the present example and FIG. 9 of the conventional example, it is understood that the present example has a smaller displacement during the return operation, particularly an amplitude at the time of overshoot, than the comparative example. It was. For this reason, it turned out that the bending angle in the base part of a movable contact piece becomes small, and stress concentration does not arise easily.
Further, as is apparent from FIG. 5, even if there is a swingback from the overshoot state, the swingback amplitude does not become 0.45 or less. For this reason, the movable contact does not leave the fixed contact, and so-called chattering does not occur. As a result, no arc was generated between the contacts, and contact wear was remarkably reduced, and it was found that the electrical life was extended.
[0020]
In addition, the protrusion concerning an Example is formed by calculating roughly based on the equation shown in FIG. However, the equation in FIG. 6 can be used to roughly calculate the shape and position of the protrusion of the movable block having the most typical component configuration, and is not necessarily limited to the protrusion of the position and shape derived from this equation. Not what you want.
[0021]
【The invention's effect】
As is apparent from the above description, according to the electromagnetic relay of claim 1 of the present invention, even after the movable contact comes into contact with the fixed contact, the movable block is further rotated by an inertial force to be in an overshoot state. The protrusions of the movable block are pressed against only the rear middle portion of the movable contact piece to restrict the position. For this reason, the base portion of the movable contact piece does not bend at a large angle as in the conventional example, and fatigue failure is less likely to occur, thereby extending the mechanical life.
In addition, since the protrusions are pressed against only the rear intermediate portion of the movable contact piece and indirectly press the movable contact, so-called chattering does not occur and the electrical life is extended.
Furthermore, since the protrusion is provided on the movable block, it is not necessary to reduce the gap between the movable block main body and the movable contact piece. For this reason, a mold such as a thin side core is not required, the mold life is extended, and the productivity is improved.
[0022]
According to the second aspect of the present invention, the movable block is formed by integrating the movable iron piece, which is separately insert-molded with the movable contact piece, which is primarily molded, by the secondary molding. For this reason, positioning with a movable contact piece and a movable iron piece becomes easy, and productivity and component precision improve.
[0023]
According to the third aspect, the protrusion is provided on the protrusion of the movable block formed by covering one end of the movable iron piece with the synthetic resin material. For this reason, since the movable iron piece serves as a core material and the protrusion is not easily deformed, the protrusion is not easily deformed even if the protrusion is in contact with the movable contact piece. As a result, it is possible to perform position regulation as designed, and there is an effect that there is no variation in operating characteristics.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an electromagnetic relay according to an embodiment of the present invention.
2 shows the movable block shown in FIG. 1, FIG. 2 (a) is an enlarged side view, and FIG. 2 (b) is an enlarged sectional view.
FIG. 3 is a modification of FIG.
4 is a schematic diagram for explaining the operation of the movable block shown in FIG. 1; FIG.
FIG. 5 is a graph showing the operation of the movable block.
FIG. 6 is a schematic view showing an example for specifying an external dimension of the embodiment.
FIG. 7 is a cross-sectional view showing an electromagnetic relay according to a conventional example.
FIG. 8 is a schematic diagram for explaining the operation of the movable block shown in FIG. 7;
FIG. 9 is a graph showing the operation of a movable block according to a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Base, 14a ... Normally open fixed contact, 15a ... Normally closed fixed contact, 20 ... Electromagnetic block, 23 ... Iron core, 23a ... Magnetic pole part, 30 ... Movable block, 31 ... Movable block main body, 32 ... Movable iron piece, 33 ... movable contact piece, 33a ... movable contact, 34 ... projection, 34a ... position regulating projection.

Claims (3)

A movable block formed by integrating a movable iron piece and a movable contact piece in a non-contact state substantially in parallel is rotated based on excitation and demagnetization of the electromagnet block, and is moved to the free end of the movable contact piece protruding from the movable block. In the electromagnetic relay that contacts and separates the provided movable contact from the fixed contact,
Thereby restricting position in pressure contact with only the back middle portion of the movable contact piece only when the overshoot of the movable contact piece, a projection that does not contact the rear middle portion of the movable contact piece during normal operation returning, from said movable block An electromagnetic relay, characterized in that the electromagnetic relay is provided on a protruding portion extending in parallel with the movable contact piece .   The electromagnetic relay according to claim 1, wherein the movable block is obtained by integrating a movable iron piece, which is separately insert-molded, with a movable contact piece, which is primarily molded, by secondary molding.   3. The electromagnetic relay according to claim 1, wherein the protrusion is provided on a protrusion of the movable block formed by covering one end of the movable iron piece with a synthetic resin material.

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