JPH05182572A - Electromagnetic relay - Google Patents

Abstract

PURPOSE:To provide an electromagnetic relay which, although a fixed contact plate is of such rigidity that the work of adjusting its contact position is possible, can enhance fusion resistant performance when switching a load through which a large rush current flows in a short time. CONSTITUTION:When a housing is formed using a base 1 and a case 10, a movement restraining portion 10b which presses the end portion of a fixed contact plate 2 to restrain movement of the contact plate 2 is provided inside the upper surface of the case 10, the fixed contact plate 2 being provided with a fixed contact 3 being supported by the base in a cantilever manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic relay which solves the problems caused by contact bounce.

[0002]

2. Description of the Related Art There is a general electromagnetic relay having a structure shown in FIG. In the figure, reference numeral 1 is a base, on which a fixed contact plate 2 also serving as a fixed contact terminal and a movable contact terminal 4 are fixed, and an electromagnet device 7 is mounted. Fixed contact plate 2
The base end (intermediate part if integrally formed with the fixed contact terminal) is supported by the base 1 in a cantilever manner, and the fixed contact 3 is provided at the tip. Further, the movable contact terminal 4 is fixedly provided with a base end portion of a movable spring 5. This movable spring
Reference numeral 5 shows a state in which the base end is supported by the movable contact terminal 4 in a cantilever manner, and the movable contact 6 which can be brought into contact with and separated from the fixed contact 3 is provided at the tip. The electromagnet device 7 is movable by holding the armature, which is a movable member, at the tip of a movable frame 9 rotatably supported by the coil frame 8 and controlling the excitation of the coil wound around the coil frame 8. Rotate the frame 9. Movable frame 9
Is a drive unit for driving the movable spring 5 in its middle part.
With 9a. Therefore, when the excitation of the electromagnet device 7 is controlled, the movable frame 9 rotates to drive the movable spring 5, whereby the contacts 3 and 6 open and close (contact and separate).

In such an electromagnetic relay, during the contact closing operation, the movable contact 6 collides with the fixed contact 3 to cause contact bounce, and if a large inrush current flows at that time, welding occurs. There are cases. Therefore, various measures have been taken to reduce the contact bounce and shorten the bounce time to improve the welding resistance performance.

Generally, in the structure described above, as shown in FIG. 13, the movable spring 5 of the movable frame 9 is moved closer to the movable contact 6 within a range where the OT amount can be secured, and the movable frame 6 is moved.
9 is designed to suppress the rebound of the movable spring 5.
According to this means, the drive position of the movable spring 5 is such that the movable contact 6
Bounce time shown in dashed line in Figure 14 when away from
It is possible to eliminate the contact bounce occurring at t1 = several hundreds of microseconds or t2 = several msec. In other words, even if contact bounce occurs, it can be about several tens of microseconds. In terms of the contact material, a material having a high surface hardness may be used so that contact welding is less likely to occur.

Further, Japanese Patent Application Laid-Open No. 63-124324 discloses a proposal in which the movable springs are of a twin type and the lengths of the movable springs are changed to make the vibration frequencies different so that contact chattering (bounce) is prevented. ing. In addition, actual development Sho 62-3
7149 and Japanese Utility Model Laid-Open No. 62-88337 disclose a proposal to reduce the vibration of the movable spring by forming a shock absorbing portion in the movable spring or providing a shock absorbing member.

[0006]

FIG. 15 shows the mechanism by which contact bounce occurs in the structure shown in FIG.
A brief description will be given with reference to (a) to (e). (a) Open contact
When the movable frame 9 operates to drive the movable spring 5 in the (opened) state, the movable contact 6 collides with the fixed contact 3 to reach the state (b). At this time, repulsive forces in opposite directions are applied to both contacts 3 and 6.
Since f is generated, a gap is created between both contacts as shown in (c). Now, the displacement amount of the movable frame 9 is x1, the displacement amount of the fixed contact plate 2 due to the repulsive force f is x2, the absolute displacement amount (reverse displacement amount) at the contact position of the movable spring 5 is x3, and the movable spring 5 due to the repulsive force f.
X4 is the displacement at the contact point position of the movable frame, and k is the coefficient that converts the displacement of the movable frame 9 into the displacement amount at the contact position.
= X4-kx1, the absolute position of the movable contact 6 remains almost unchanged. In other words, the movable contact 6 hardly returns to the reverse. On the other hand, the fixed contact plate 2 is slightly displaced due to the repulsive force f and also because it is supported in a cantilever manner, and the fixed contact plate 2 is tens of μs
A short contact bounce of about c occurs. Therefore fixed contact plate
When 2 returns, the contact closes (contact) as shown in (d), and
It stays in the closed (contact) state of (e). Mentioned above
FIG. 16 is a time chart showing (a) to (e). Further, when a material having a high surface hardness is used as the contact material, the coefficient of restitution increases, so that the displacement of the fixed contact plate 2 also increases.

Further, JP-A-63-124324 and JP-A-62-3714
Even with the configuration disclosed in Japanese Utility Model Laid-Open No. 62-88337, although the vibration of the movable spring can be reduced, it is not possible to suppress the minute displacement of the fixed contact plate, and the bounce time of about several tens of microseconds is still required. Contact bounces are likely to occur.

By the way, when the electric circuit is opened and closed by the electromagnetic relay, if the load is a capacitor load or a lighting fixture load, a large inrush current flows in a short time. In the case of contact bounce with a bounce time of several tens of microseconds, which has been described so far, when such a load is opened and closed, an arc of large energy is generated during the contact bounce and the contacts may be welded. It is effective to increase the rigidity by increasing the thickness of the fixed contact plate to eliminate the contact bounce of about several tens of microseconds, but such fixed contact plate makes it difficult to adjust the contact position of the electromagnetic relay. Poor feasibility due to problems such as aging and complicated press work.

The present invention has been made in view of the above circumstances. An object of the present invention is to provide a fixed contact plate with a rigidity such that the contact position adjustment work thereof can be performed, but a large inrush current is generated in a short time. It is an object of the present invention to provide an electromagnetic relay having improved welding resistance performance when opening and closing a flowing load.

[0010]

In order to solve the above problems, an electromagnetic relay according to the present invention comprises a base, a fixed contact plate having a base end fixed to the base and a fixed contact provided at the tip, and a base end. A movable spring that is fixedly mounted on a member and provided with a movable contact at a tip end thereof that can be brought into contact with and separated from a fixed contact, and is opened and closed by being driven by a movable member of an electromagnet device; and a base for housing these members. In an electromagnetic relay having a case forming a housing, the case is provided with a movement suppressing portion that suppresses movement of the fixed contact plate in the plate thickness direction when the housing is formed.

Further, it is preferable that the movement restraining portion elastically presses the fixed contact plate.

[0012]

According to this structure, since the fixed contact plate has a general rigidity, the contact position adjustment work can be performed as in the conventional case.
In the completed state as an electromagnetic relay, the fixed contact plate can be restrained from moving as if its rigidity was greatly increased by the movement restraining part of the case, and contact bounce of several tens of microseconds is hardly caused.

Further, if the movement restraining portion elastically presses the fixed contact plate, it is possible to reduce the risk that the appropriate positional relationship in which the contact position adjusting work is performed changes.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. The members having the same basic functions as those of the conventional example are designated by the same reference numerals, but the base 1,
The fixed contact plate 2, the movable spring 5, the electromagnet device 7, the movable frame 9 and the like are substantially the same.

That is, the base 1 has a fixed contact plate 2 also serving as a fixed contact terminal and a movable contact terminal 4 fixedly mounted, and an electromagnet device 7 mounted thereon. In addition, a fixing protrusion 1a for fixing a case described later is provided on the side surface. Fixed contact plate
2 is a state in which the base end portion (the middle portion when integrally formed with the fixed contact terminal) is supported by the base 1 in a cantilever manner, and the fixed contact 3 is provided at the tip end portion. The movable contact terminal 4 is provided with a fixed end of a movable spring 5. The movable spring 5 has a base end supported in a cantilevered manner by the movable contact terminal 4, and a movable contact 6 capable of coming into contact with and separating from the fixed contact 3 is provided at the tip. The electromagnet device 7 moves by controlling the excitation of the coil wound around the coil frame 8 by holding the armature, which is a movable member, at the tip of the movable frame 9 rotatably supported by the coil frame 8. Rotate the frame 9. The movable frame 9 has a drive portion 9a for driving the movable spring 5 in its intermediate portion. Therefore, when the excitation of the electromagnet device 7 is controlled, the movable frame 9 rotates to drive the movable spring 5, whereby the contacts 3 and 6 open and close (contact and separate).

Reference numeral 10 denotes a case, which is formed of a plastic material and has a box shape whose lower surface is opened.
It has a fixing hole 10a into which the fixing protrusion 1a is fitted. In this case 10, a housing is formed by both members by fitting the fixing protrusion 1a into the fixing hole 10a so as to cover the base 1, and the above-mentioned member is housed in the housing. Further, at the position corresponding to the fixed contact plate 2 inside the upper surface, a movement suppressing portion 10b for suppressing the movement of the fixed contact plate 2 in the plate thickness direction when the housing is formed is provided in a protruding manner. The cross-sectional shape of the movement suppressing portion 10b is substantially the same as or slightly larger than that of the fixed contact plate 2, and the height thereof can surely press the tip end surface of the fixed contact plate 2 when the housing is formed.

Since the rigidity of the fixed contact plate 2 is general in this case, the contact position adjustment work can be performed as in the conventional case.
In the completed state as an electromagnetic relay, the fixed contact plate 2 can be restrained from moving as if the rigidity was greatly increased by the movement restraining portion 10b of the case 10 and almost no contact bounce of about several tens μsec occurs.

Next, a second embodiment of the present invention will be described with reference to FIGS.
It will be explained based on. This is different from the first embodiment in the shape of the tip of the fixed contact plate 2 and the movement restraining portion 10b of the case 10.

That is, the fixed contact plate 2 has a sharp taper portion 2a at its tip, that is, a taper portion 2a which gradually becomes thinner in the thickness direction. On the other hand, the case 10 forms a plurality of rectangular movement restraining portions 10b that are long in the plate thickness direction of the fixed contact plate 2. In this case, when the housing is formed by the base 1 and the case 10, the sharp portion of the tapered portion 2a pierces the end face of the movement suppressing portion 10b, and the movement of the fixed contact plate 2 can be further suppressed.

Next, a third embodiment of the present invention will be described with reference to FIGS.
It will be explained based on. This is also different from the first embodiment in the shape of the tip of the fixed contact plate 2 and the movement restraining portion 10b of the case 10.

That is, the fixed contact plate 2 has a sharp conical portion 2b continuously formed at its tip, that is, thin in both the thickness and width directions. On the other hand, the case 10 forms a movement restraining portion 10b corresponding to the conical portion 2b of the fixed contact plate 2 and having a slightly wide area and a slight depression. In this case, when the housing is formed by the base 1 and the case 10, the sharp portion of the conical portion 2b pierces the end face of the movement restraining portion 10b, and like the second embodiment, the fixed contact plate 2 has a more stable shape. Movement can be suppressed.

Next, a fourth embodiment of the present invention will be described with reference to FIGS.
It will be explained based on. This is also different from the first embodiment in the shape of the tip of the fixed contact plate 2 and the movement restraining portion 10b of the case 10.

That is, the fixed contact plate 2 has a narrow projection 2c continuously formed at its tip. On the other hand, the case 10 forms a movement restraining portion 10b having a slightly wider area corresponding to the protrusion 2c of the fixed contact plate 2 and a recess 10c having an opening 10c slightly larger than the protrusion 2c. This one is the base
When the housing is formed by 1 and the case 10, the protrusion 2c is inserted into the opening 10c, and in this state, the protrusion 2c is adhered by the adhesive 10d to fix the protrusion 2c to the movement suppressing portion 10b. Therefore, similarly to the second embodiment, it is possible to further suppress the movement of the fixed contact plate 2 and reduce the risk of changing the appropriate positional relationship in which the contact position adjustment work is performed.

Next, a fifth embodiment of the present invention will be described with reference to FIGS.
It will be explained based on. This is also different from the first embodiment in the shape of the tip of the fixed contact plate 2 and the movement restraining portion 10b of the case 10.

That is, the fixed contact plate 2 has inclined portions 2d, 2d formed by chamfering both sides in the width direction of the fixed contact plate 2. On the other hand, the case 10 includes the inclined parts 2d, 2 of the fixed contact plate 2.
Two thin-walled movement suppressing portions 10b having elasticity corresponding to d are formed. This one has a base 1 and a case
When the housing is formed by 10, the movement suppressing portion 10b
Is elastically fixed while bending along the slopes 2d, 2d
Press 2. Therefore, it is possible to achieve the same effects as those of the first embodiment, and reduce the risk that the appropriate positional relationship where the contact position adjustment work is performed changes. Note that FIG. 11 is a modification of the fifth embodiment, in which the inclined portion 2d of the fixed contact plate 2 is formed only on one side in the width direction, and the movement suppressing portion 10b of the case 10 is
Only individual pieces are formed.

The present invention can be applied to any member corresponding to the electromagnet device or the movable frame as long as the fixed contact plate is cantilevered.

[0027]

In the electromagnetic relay of the present invention, since the rigidity of the fixed contact plate is general, the contact position adjustment work can be performed as in the conventional case, and the fixed contact plate restrains the movement of the case when completed as an electromagnetic relay. The movement can be suppressed as if the rigidity became extremely large due to the part, and the contact bounce of about several tens of μsec is hardly caused, and if this movement suppression part elastically presses the fixed contact plate, It is possible to reduce the risk of changing the appropriate positional relationship when the contact position adjustment work is performed, so the fixed contact plate is rigid enough to allow the contact position adjustment work, but a load with a large inrush current flows in a short time. The welding resistance performance when opening and closing the will be improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part thereof.

FIG. 3 is an exploded perspective view of essential parts showing a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of the relevant part.

FIG. 5 is an exploded perspective view of essential parts showing a third embodiment of the present invention.

FIG. 6 is a cross-sectional view of the relevant part.

FIG. 7 is an exploded perspective view of essential parts showing a fourth embodiment of the present invention.

FIG. 8 is a cross-sectional view of the relevant part.

FIG. 9 is an exploded perspective view of essential parts showing a fifth embodiment of the present invention.

FIG. 10 is a cross-sectional view of the relevant part.

FIG. 11 is a main-portion cross-sectional view showing a modification thereof.

FIG. 12 is a perspective view showing a conventional example.

FIG. 13 is a schematic diagram illustrating a configuration near the contact.

FIG. 14 is a time chart of the contact bounce.

15A to 15E are explanatory views for explaining the mechanism of the contact bounce.

16 is a time chart of contact bounce corresponding to FIG. 15.

[Explanation of symbols]

 1 Base 2 Fixed contact plate 3 Fixed contact 4 Moving contact terminal 5 Moving spring 6 Moving contact 7 Electromagnet device 8 Coil frame 9 Movable frame 10 Case 10b Case movement restraining part

Claims (2)

[Claims] 1. A base, a fixed contact plate having a base end fixed to the base and a fixed contact provided at a tip end, and a movable contact part having a base end fixed to an appropriate member and capable of contacting and separating from the fixed contact at the tip end. An electromagnetic relay having a movable spring, which is provided with a contact and is opened / closed by being driven by a movable member of an electromagnet device, and a case which forms a housing together with a base so as to accommodate these members. An electromagnetic relay characterized by comprising a movement suppressing portion for suppressing the movement of the fixed contact plate in the plate thickness direction when formed. 2. The electromagnetic relay according to claim 1, wherein the movement suppressing portion elastically presses the fixed contact plate.