JPH0896686A - Overcurrent relay - Google Patents

Abstract

(57) [Summary] [Purpose] In an overcurrent relay, regardless of whether or not the normally closed contact is welded, the normally open contact always closes when an overcurrent flows in the main circuit. [Structure] The toggle mechanism A is a connection point 27 of the operating lever 23.
A spring member 29 is provided between the drive member 25 and the drive member 25. The normally closed switch mechanism B is provided on the upper right side of the drive member 25, and the normally open side switch mechanism C is provided on the upper left side of the drive member 25. . Normally, the normally-closed movable contact plate 3 is driven by the drive member 25.
When 0 is pressed, the normally closed contacts 31 and 32 are closed and the normally open contacts 34 and 36 are open. When an overcurrent flows in the main circuit, the drive member 25 reverses and separates from the normally closed movable contact plate 30 regardless of whether the normally closed contacts 31 and 32 are welded, and the normally open contacts 34 and 36 are always closed. The alarm is connected to the normally-open side switch mechanism, and the abnormality of the main circuit is notified to the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overcurrent relay for oscillating displacement of a movable member to switch contacts when an overcurrent flows in a main circuit.

[0002]

2. Description of the Related Art A conventional example of this type of overcurrent relay will be described with reference to FIGS. 3 and 4 schematically show a mechanical portion provided in the case of the overcurrent relay, in which reference numeral 1 is an actuating member made of bimetal, which is not shown in the drawings and is connected to the main circuit. -Data is attached. As a result, the operating member 1 is bent and deformed as shown by the chain double-dashed line in FIG. 3 due to heat generation of the heater when an overcurrent flows in the main circuit, and the operation plate 2 engaged with the lower end side thereof. Is displaced to the left.

An operating lever-3 is provided on the left side of the operation plate 2, and is swingable with the shaft 4 as a fulcrum when the operation plate 2 is displaced. A movable contact plate 5 is provided above the operation lever 3 so as to be swingable about a shaft 6 at the lower end, and a normally closed side movable contact 7 is provided at the upper end. Then, between the connection point 8 at the tip of the operation lever 3 and the connection point 9 located in the middle of the movable contact plate 5,
The spring member 10 is suspended. With this, the toggle mechanism is configured, and the movable contact plate 5 moves from the neutral position (the position indicated by the chain double-dashed line in FIG. 3) along with the swing displacement of the operating lever-3.
It is designed to be swingably displaced to the left and right respectively.

On the other hand, in the upper right portion of the movable contact plate 5, the normally closed side fixed contact 1 which comes in contact with and separates from the normally closed side movable contact 7 is provided.
1 is provided with a normally-closed side switch mechanism including a fixed contact plate 12 and the like, and a main circuit is connected to the normally-closed side switch mechanism. The fixed contact plate 12 is made of a conductive material having elasticity, and is fixed at its upper end so that it can be flexibly deformed. As shown by the solid line in FIG. 3, when the movable contact plate 5 is located on the right side by the spring force of the spring member 10, the normally closed side movable contact 7 contacts the normally closed side fixed contact 11 to close the contact. The fixed contact plate 12 is flexed and deformed to the right. The maximum amount of flexural deformation of the fixed contact plate 12 to the right is regulated by the regulation member 13.

Further, a normally open side fixed contact 14 and a normally open side fixed contact 14 are provided at an upper left portion of the movable contact plate 5.
A normally-open side movable contact plate 16 made of an elastic conductive material having a normally-open side movable contact 15 that comes into contact with and separated from the normally open side movable contact plate 15 and a normally open side switch mechanism including an insulating piece 18 that swings around a shaft 17 as a fulcrum are provided. An alarm device or the like is connected to the normally open side switch mechanism. The normally-open side contacts 14 and 15 are normally open, and as shown in FIG. 4, when the operating lever 3 crosses the neutral position to the left and the movable contact plate 5 is displaced to the left, The movable contact plate 5 is flexibly deformed to the left by the movable contact plate 5 via the insulating piece 18, and the contacts 14 and 15 are deformed.
Is to be closed.

As described above, normally, as shown by the solid line in FIG. 3, the normally closed contacts 7 and 11 are closed and the normally open contacts 14 and 15 are open. And
When an overcurrent flows in the main circuit, the operation lever is operated via the operation plate 2.
When the connecting point 8 of 3 is displaced to the left and exceeds the neutral position, the movable contact plate 5 is reversed, the normally closed contacts 7 and 11 are opened, and the normally open contacts 14 and 15 are closed. It is supposed to be done. Therefore, the connection between the normally closed side switch mechanism and the main circuit is cut off, and an abnormality of the main circuit can be notified to the outside by an alarm device or the like connected to the normally open side switch mechanism.

[0007]

However, in the conventional structure as described above, the movable contact plate 5 is oscillated and displaced so as to close the normally open side contacts 14 and 15 based on the overcurrent of the main circuit. Since the normally-closed side movable contact 7 is provided at the upper end portion, if the normally-closed side contacts 7 and 11 are welded by the overcurrent, the overcurrent flows in the main circuit and the connection point 8 of the operation lever 3 is reached. Normally-closed side contact 7, even if is displaced to the left and exceeds the neutral position
Since 11 is inseparable, the movable contact plate 5 does not reverse and the normally open contacts 14 and 15 cannot be closed. Therefore, in this case, the overcurrent relay cannot disconnect the electrical connection of the main circuit, and cannot notify the abnormality of the main circuit to the outside. Could continue to flow, causing load burnout and overcurrent relay body burnout.

The present invention has been made in view of the above circumstances, and an object thereof is to close a normally open side contact when an overcurrent flows in a main circuit regardless of whether or not the normally closed side contact is welded. An object of the present invention is to provide an overcurrent relay that can notify the abnormality of the main circuit to the outside.

[0009]

In order to achieve the above object, an overcurrent relay according to the present invention comprises a normally closed fixed contact member having a normally closed fixed contact, and an elastic normally closed fixed contact member. A normally-closed side movable contact plate having a normally-closed side movable contact having a normally-closed side movable contact arranged to be movable toward and away from the member and reciprocally displaced to and from the normally-closed side fixed contact; A normally open side fixed contact member having a normally open side fixed contact, and an elastic member which is displaceably provided in a direction toward and away from the normally open side fixed contact member and reciprocally moves to the normally open side fixed contact member. A normally-open side movable contact plate including a normally-open side movable contact plate having a normally-open side movable contact that comes into contact with and separates from the normally-open side movable contact plate, and the normally-closed side movable contact plate is swingably provided and is displaced to one side. To press the normally closed side movable contact into pressure contact with the normally closed side fixed contact. A driving member that presses the normally-open movable contact plate when it is oscillated and displaced to the other side to press the normally-open movable contact into pressure contact with the normally-open fixed contact, and a bimetal that is displaced based on an overcurrent. An operating member, an operating plate that interlocks with the displacement of the operating member, an operating lever that is swung by the operating plate, and one side and the other side of the driving member according to the swing position of the operating lever. And a toggle mechanism including a spring member for oscillating displacement.

[0010]

According to the overcurrent relay of the present invention, when the actuating member is displaced due to the overcurrent of the main circuit, the actuating lever is swung accordingly, regardless of whether the normally-closed side contact is welded or not. The drive mechanism is reversed by the toggle mechanism to separate from the normally closed side movable contact plate. Then, the drive member presses the normally open side movable contact plate to close the normally open side contact, and an alarm device connected to the normally open side switch mechanism notifies the outside of the abnormality of the main circuit.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2 schematically show the mechanical portion provided in the case of the overcurrent relay according to the present embodiment, and 21 is an operating member made of bimetal, which is connected to the main circuit. A not shown heater is attached. As a result, when an overcurrent flows in the main circuit, the heat generated by the heater causes the operating member 21 to be curved and deformed to the left as shown by the chain double-dashed line in FIG. The operation plate 22 of is displaceable to the left.

An operating lever 23 is provided on the left side of the operation plate 22.
Is provided, and is swingable about the shaft 24 as a fulcrum according to the displacement of the operation plate 22. This operating lever
A drive member 25 made of an insulating material, such as plastic, is provided above 23 to be swingable about a shaft 26 at the lower end. A spring member 29 made of a tension coil spring is hung between a connecting point 27 at the tip of the actuating lever 23 and a connecting point 28 located in the middle of the driving member 25. Thus, the toggle mechanism A is configured and the drive member 2
5 is pivotally displaced from the neutral position (the position where the shaft 26 and the connecting points 27 and 28 are aligned in a straight line as shown by the chain double-dashed line in FIG. 1) to the left and right in accordance with the pivotal displacement of the operating lever 23. It has become so.

On the other hand, in the upper right portion of the driving member 25, the normally closed movable contact plate 3 pressed by the driving member 25.
0 is provided. The normally-closed movable contact plate 30 is made of a conductive material having elasticity, for example, a metal leaf spring, has an upper end fixed and is deformable by bending, and a normally-closed movable contact 31 is provided at the lower end. . A normally closed side fixed contact member 33 having a normally closed side fixed contact 32 with which the normally closed side movable contact 31 comes in and out is fixedly provided on the right side of the normally closed side movable contact plate 30. The switch mechanism B is configured. The normally-closed fixed contact member 33 is made of a conductive material and also functions as a restricting member that restricts the normally-closed movable contact plate 30 from bending to the right. The normally-closed movable contact plate 30 has an elastic force in a direction away from the normally-closed fixed contact member 33. However, the normally-closed movable contact plate 30 is normally pressed by the drive member 25, The closed contacts 31, 32 are closed.

A main circuit is connected to the normally closed switch mechanism B. Further, a normally open side fixed contact member 35 having a normally open side fixed contact 34 and a normally open side movable contact 36 which comes in contact with and separates from the normally open side fixed contact 34 are provided at an upper left portion of the drive member 25. A normally open side switch mechanism C including a side movable contact plate 37 is provided. The normally open side movable contact plate 37 is made of a conductive material having elasticity, for example, a metal leaf spring, and normally has an elastic force in a direction of separating the normally open side movable contact plate 37 from the normally open side fixed contact member 35. By doing so, the contacts 34, 36 are open. As shown in FIG. 2, when the actuating lever 23 crosses the neutral position to the left and the driving member 25 swings to the left, the driving member 25 causes the normally-open side movable contact plate 37 to move to the left. It is flexibly deformed so that the contacts 34 and 36 are closed. The leftward deflection of the normally open side movable contact plate 37 is restricted by the normally open side fixed contact member 35 made of a conductive material.

An alarm device (not shown) equipped with a buzzer, a display lamp and the like is connected to the normally open side switch mechanism C. Next, the operation of the above configuration will be described.

In a normal state, as shown by a solid line in FIG. 1, the driving member 25 is oscillated and displaced rightward from the neutral position by the spring force of the spring member 29, and the driving member 25 has a normally-closed movable contact. When the plate 30 is pressed, the normally closed side movable contact 31
Is closed to the normally closed side fixed contact 32, the normally open side contacts 34 and 36 are open, and the main circuit is closed by the normally closed side switch mechanism B.

When an overcurrent flows in the main circuit, the connecting point 27 of the operating lever 23 is displaced to the left via the operating plate 22, and when it exceeds the neutral position, as shown in FIG. Is inverted and pressed by this, the normally open side movable contact plate 37
Bends and deforms to the left to close the normally-open side contacts 34 and 36, and the alarm device connected to the normally-open side switch mechanism C operates to notify the abnormality of the main circuit to the outside. At this time, when the normally closed side movable contact plate 30 is separated from the normally closed side fixed contact member 33 by its elastic force, the normally closed side contacts 31 and 32 are opened and the normally closed side switch mechanism B opens the main circuit. , If the normally closed contacts 31 and 32 are welded due to overcurrent,
The normally closed contacts 31 and 32 remain closed and the connection between the normally closed switch mechanism B and the main circuit is continued.

As described above, according to this embodiment, the driving member 2
Since 5 is made of plastic as an insulating material and is not related to the electrical connection between the normally closed switch mechanism B and the main circuit, even if the normally closed contacts 31 and 32 are welded due to overcurrent, The influence does not reach the toggle mechanism A including the drive member 25. When an overcurrent flows in the main circuit, the drive member 25 is always inverted and separated from the normally closed side movable contact plate 30, and the normally open side movable contact plate. 37 to press the normally open contact 34,
36 is closed. Therefore, since the alarm connected to the normally open side switch mechanism C can reliably notify the abnormality to the outside, the connection between the main circuit and the normally closed side switch mechanism B can be continued without the abnormality of the main circuit being detected forever. It is possible to prevent the burnout of the load and the burnout of the overcurrent relay body due to the above.

The drive member 25 is made of metal,
An insulating member may be attached to the back surface of the normally closed movable contact plate 30 and the back surface of the normally opened movable contact plate 37 with which the driving member 25 contacts. The insulating member for preventing current from flowing is the driving member 25, the normally closed side movable contact plate 30, and the normally open side movable contact plate 3.
7, between the driving member 25 and the spring member 29, the shaft 26, or between the driving member 25 and the case of the overcurrent relay.

[0020]

As is apparent from the above description, the overcurrent relay of the present invention has the following effects. That is, the drive member is not electrically connected even if it comes into contact with the normally-closed side switch mechanism and the normally-closed side switch mechanism. Since the side movable contact plate is pressed, even if the normally closed side contacts are welded due to overcurrent, if overcurrent flows in the main circuit and the operating lever swings and moves beyond the neutral position, The driving member is always inverted and separated from the normally-closed movable contact plate to press the normally-open movable contact plate. Therefore, since the normally open side contact is closed, the normally open side switch mechanism operates to reliably notify the abnormality to the outside, and it is possible to prevent the burnout of the load and the burnout of the overcurrent relay body.

[Brief description of drawings]

FIG. 1 is a schematic front view of a main part in a normal state, showing an embodiment of the present invention.

FIG. 2 is a schematic front view of a main part showing a state when an overcurrent flows in a main circuit.

FIG. 3 is a view corresponding to FIG. 1 showing a conventional example.

FIG. 4 is a view corresponding to FIG. 2 showing a conventional example.

[Explanation of symbols]

1, 21 are operating members, 2, 22 are operating plates, 3, 23 are operating levers, 5 are movable contact plates, 7, 31 are normally closed side movable contacts, 10 and 29 are spring members, and 14 and 34 are normally. Open side fixed contacts, 15 and 36 are normally open side movable contacts, 25 is a driving member, 2
9 is a spring member, 30 is a normally closed side movable contact plate, 32 is a normally closed side fixed contact, 33 is a normally closed side fixed contact member, 35 is a normally opened side fixed contact member, 37 is a normally opened side movable contact plate, A Is a toggle mechanism, B is a normally closed switch mechanism, and C is a normally open switch mechanism.

Claims (1)

[Claims] 1. A normally-closed fixed contact member having a normally-closed fixed contact, and an elastic member which is displaceable in a direction in which the normally-closed fixed contact member comes into contact with and separates from the normally-closed fixed contact member. The normally-closed side movable contact plate having the normally-closed side movable contact that comes in and out of contact with the side fixed contact, the normally-open side fixed contact member having the normally-open side fixed contact, and the elastic And a normally open side movable contact plate having a normally open side movable contact which is provided so as to be displaceable in a direction in which the normally opened side fixed contact member is brought into contact with and separated from the normally opened side fixed contact member, and which is reciprocally displaced so as to be brought into contact with and separated from the normally open side fixed contact. The normally open side switch mechanism is swingably provided, and when it is swingably displaced to one side, the normally closed side movable contact plate is pressed to bring the normally closed side movable contact into pressure contact with the normally closed side fixed contact. , When it is oscillated and displaced to the other side, it pushes the normally open side movable contact plate and A drive member for pressing the side movable contact to the normally open side fixed contact, an actuating member made of bimetal that is displaced based on an overcurrent, an operation plate interlocked with the displacement of the actuating member, and a swinging operation by the operation plate. Overcurrent relay comprising an operating lever and a toggle mechanism including a spring member for oscillating and displacing the drive member to one side and the other side according to the swing position of the operating lever.