JPH1140013A - Pressure contact mechanism of switchgear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a bending moment generated together with a breaking operation at a link rod for linking a movable contact and a swinging lever and realize miniaturization of an entire constitution due to downsizing of a link rod. SOLUTION: A link pin 66 parallel to a support shaft 40 of a swinging arm 4 is erected at a lower end part of a lower rod 63 of a link rod. An elongated hole 65 is formed at a link bracket 61 connected to an end part of the swinging arm 4, and the link pin 66 is inserted through this elongated hole 65 to link between a link rod 60 and a link bracket 61. A contact pressure spring 6 is built-in between an intermediate part of the link rod 60 and an insulation plate 64 so that collision together with energy discharge of the contact pressure spring 6 is generated between the link pin 66 and an upper rim of the elongated hole 65 during breaking operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact pressure mechanism for applying pressure to a movable contact so as to maintain a contact pressure with a fixed contact when a main contact is turned on in a power switch such as a circuit breaker or a switch.

[0002]

2. Description of the Related Art In a switching device such as a circuit breaker or a switch, a movable contact is pressed against a fixed contact when a main contact obtained by bringing the movable contact into contact with the fixed contact is applied to the fixed contact. It is necessary to maintain the contact pressure, for example, as disclosed in Japanese Patent Publication No. 63-55737, the contact pressure spring interposed in the operating mechanism of the movable contact is charged during the operation for closing, and A contact pressure mechanism is used in which a movable contact is pressed by an accumulating force to obtain a contact pressure on a fixed contact.

FIGS. 5 and 6 are side sectional views of a conventional circuit breaker having a configuration similar to that disclosed in Japanese Patent Publication No. 63-55737. FIG. 5 shows a closed state, and FIG. Each shows a cut-off state.

This circuit breaker is configured as a vacuum circuit breaker having a fixed contact 10 and a movable contact 11 inside a vacuum switch tube 1. An end of the fixed contact 10 protruding above the vacuum switch tube 1 is connected to a main circuit conductor 20 insulated and supported on the upper part of the insulating frame 2, and a movable contact 11 to the lower part of the vacuum switch tube 1. The protruding portion is connected to a main circuit conductor 21 insulated and supported by an intermediate portion of the insulating frame 2 via a flexible connection conductor 22.

[0005] A swinging lever 4, which is supported halfway by a substantially horizontal support shaft 40, is arranged inside a gantry 3 that supports a lower portion of the insulating frame 2. One end of the swing lever 4 is connected to a drive device 5 supported on a gantry 3 side by side with the insulating frame 2.
The swing lever 4 is pushed and pulled by the link 50 in response to the operation of the driving device 5 and swings around the axis of the support shaft 40. .

On the other hand, the other end of the swing lever 4 reaching the lower part of the insulating frame 2 is connected to the lower end of the movable contact 11 via a contact pressure mechanism. FIG. 7 is an enlarged sectional view of the contact pressure mechanism. As shown in FIG.
Connecting rod 70 connected to the lower end of
And a contact pressure spring 7 interposed between them.

The connecting rod 70 coaxially connects the upper rod 72 and the lower rod 73 via a connecting plate 74 made of an insulating material, and the lower end of the movable contact 11 is screwed with the end of the upper rod 72. Fixed and connected. The connection bracket 71 is a plate material having an L-shaped bent shape, and one side thereof is connected to an end of the swing lever 4 via a connection pin 75. The lower portion of the lower rod 73 is Is inserted through a hole passing through the other side, and is prevented from coming off by a stopper plate 77 fixed to an end by a bolt.

The contact pressure spring 7 is a coil spring inserted into the outside of the lower rod 73, and the lower end thereof is connected to the connecting bracket 71.
The other side and the upper end of the lower rod 73 are elastically pressed against a push plate 78 provided so as to project outward in the middle of the lower rod 73, and the spring force of the push plate 78 biases the two in a direction away from each other. It has been done.

In the conventional circuit breaker having the contact pressure mechanism configured as described above, when in the closed state shown in FIG.
The lower part of the lower rod 73 is in a state of protruding sufficiently below the connection bracket 71 pushed upward by the swing lever 4, and the contact pressure springs 7
The movable contact 11, which is compressed and stored between the push plate 78 and the fixed contact 10 inside the vacuum switch tube 1, is provided with a contact pressure spring 7 applied upward to the push plate 78.
Is applied via the connecting rod 70, and is pressed against the fixed contact 10 with a sufficient contact pressure, so that a reliable closing state is obtained.

In such a closed state, when the drive device 5 performs a shut-off operation, the swing lever 4 swings clockwise in the figure by pulling up the connecting portion of the link 50, and the swing is connected by this swing. The bracket 71 is pulled downward to come into contact with the stopper plate 78 at the lower end of the lower rod 73, and the connecting rod 70 is pulled down by further swinging of the swinging lever 4, and connected to the upper end of the connecting rod 70. The movable contact 11 is detached from the fixed contact 10, and the cutoff state shown in FIG. 6 is obtained.

Further, when the driving device 5 performs the closing operation in such a cutoff state, the swing lever 4 swings counterclockwise in the figure by pushing down the connecting portion of the link 50, and The connection bracket 71 is pushed upward by the swing, and the contact pressure spring 7 is compressed between the push plate 78 provided on the lower rod 73 and the compression reaction force.
The connection rod 70 is pushed up by the swing of the movable contact 11 connected to the upper end of the connection rod 70 and the fixed contact 10
Contact After this contact occurs, the connection rod 70 stops moving, but the connection bracket 71 continues to be pushed up and approaches the push plate 78, so that the contact pressure spring 7
Are strongly compressed and accumulate, and a sufficient contact pressure is obtained between the movable contact 11 and the fixed contact 10 by the spring force of the contact pressure spring 7 as described above.

The above-described circuit breaker is a movable contact of a main contact provided for each of three phases for three-phase AC.
Are connected to respective swinging levers 4, 4 arranged in parallel in the axial direction of the support shaft 40 via the same contact pressure mechanism.

[0013]

By the way, in the circuit breaker provided with such a contact pressure mechanism, when the switching from the closing state to the closing state is performed as described above, the swing lever 4 is required.
As a result of the lowering of the connecting bracket 71 caused by the swing of the spring, the spring force of the contact pressure spring 7 which is in the pressure accumulated state in the closed state is released, so that the connecting bracket 71 is
It will collide with the stopper plate 77 at the lower end at a high speed.

FIG. 7 shows a state at the time of the collision. At this time, when the connecting bracket 71 and the stopper plate 77 collide with each other due to the action of the spring force F of the contact pressure spring 7, the connecting bracket 71 is connected. Except for the case where the direction of the swing lever 4 and the direction of the spring force F are orthogonal to each other correctly, it generally occurs at one point in the circumferential direction of the stopper plate 77 as shown as point A in the drawing. When such a collision occurs, a bending moment is generated in the entire connecting rod 70 including the lower rod 73 due to the action of the spring force F concentratedly applied to the collision point A separated by a distance L from the axis of the lower rod 73. Therefore, it is necessary to ensure that each member constituting the connecting rod 70 has strength to withstand the bending moment, which leads to an increase in the size of the contact pressure mechanism and an increase in the weight of the movable member, thereby increasing the weight of the movable member. Drive of 5 has a problem that the operating energy increases.

In the circuit breaker for three-phase alternating current, the contact pressure springs 7 at the time of closing are supplied to the respective three-phase contact pressure mechanisms.
An adjustment operation is required to adjust the compression size of each of the phases and to match the input and output timings in each phase. In the conventional energy storage mechanism shown in FIG.
Unlock the adjustment nut 79 provided in the middle of
The length of the lower rod 73 is adjusted by the procedure of adjusting the length of screwing into the lower half where the is formed, and retightening the adjusting nut 79, as shown in FIGS. 5 and 6. An adjustment window hole 23 is opened at a corresponding position on the back surface of the insulating frame 2, and the adjustment nut 79 is operated through the window hole 23.

However, since the window hole 23 is provided, it is necessary to make the insulating frame 2 thicker to compensate for the reduction in strength due to the opening, which causes an increase in the weight of the apparatus and the opening of the window hole 23. The position is close to the position where the connecting portion 22 and the charging portion such as fixing bolts for the connecting portion 22 are provided inside the insulating frame 2, and the air between the connecting portion 22 and the conductor component such as the ground metal disposed on the back of the circuit breaker. Due to the necessity of securing an insulation distance, shortening of the depth dimension of the circuit breaker is limited, which has been a factor that hinders miniaturization of the circuit breaker.

The present invention has been made in view of such circumstances, and reduces a bending moment generated in a connecting rod due to a breaking operation, thereby realizing a reduction in the size of the connecting rod and a reduction in the overall configuration. It is another object of the present invention to provide a pressure accumulating mechanism that can adjust a contact pressure spring at a position away from a charged portion inside an insulating frame and can reduce a depth dimension of an opening and closing device.

[0018]

According to a first aspect of the present invention, there is provided a pressure accumulating mechanism for an opening / closing device, wherein one of a connecting rod connected to a movable contact and a connecting bracket connected to the swing lever supports a swing lever. Place the connecting pin approximately parallel to the axis,
This connecting pin is inserted into an elongated hole formed on the other side to connect the connecting rod and the connecting bracket.

According to the present invention, the pressure accumulation of the contact pressure spring is performed within the range of the sliding length of the connecting pin with respect to the long hole,
The collision between the connecting rod side and the connecting bracket side due to the release of the contact pressure spring during the shut-off operation is caused to occur on the substantially axial center of the connecting rod as a collision of the connecting pin with the end face of the elongated hole. The bending moment generated in the connecting rod is reduced accordingly.

According to a second aspect of the present invention, there is provided a pressure accumulating mechanism for an opening / closing device, wherein a connecting portion between the connecting bracket and the swing lever is provided with a means for adjusting a projecting length of the connecting bracket on the swing lever. is there.

In the present invention, the compression length of the contact pressure spring can be adjusted by adjusting the length of the connecting portion between the swing lever and the connecting bracket, that is, the position inside the insulating frame that is sufficiently away from the charged portion. You.

According to a third aspect of the present invention, there is provided a pressure accumulating mechanism for an opening / closing device, wherein a recess as a spring seat of a contact pressure spring is provided on a surface of the spring plate facing the pressing plate.

In the present invention, a recess is provided in the spring plate of the connection bracket, and a contact pressure spring is elastically contacted with the recess,
Prevents unnecessary displacement of the contact pressure spring on the spring plate.

According to a fourth aspect of the present invention, in the pressure accumulating mechanism for an opening / closing device, the connecting position of the connecting rod and the connecting bracket by the connecting pin is defined by a perpendicular line which is lowered from the swing center of the swing lever to the axis of the connecting rod. It is set near.

According to the present invention, when the swing lever swings, the movement trajectory of the connecting portion with the connecting rod does not largely depart from the axis of the connecting rod, and the connecting rod and the movable contact associated with the swing of the swing lever. Vibration during operation of the child is reduced.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. 1 and 2 are side sectional views of a circuit breaker provided with a contact pressure mechanism according to the present invention. FIG. 1 shows a closed state, and FIG. 2 shows a closed state.

This circuit breaker, like the circuit breaker shown in FIG. 5 and FIG. 6, has a vacuum switch tube 1 which is maintained in a vacuum and has a fixed contact 10 and a movable contact 11 opposed to each other in a vertical direction. It is configured as a vessel. The vacuum switch tube 1 is
The fixed contact 10 is suspended and supported inside the insulating frame 2 with the fixed contact 10 as a support, and the end of the fixed contact 10 protruding above the vacuum switch tube 1 is connected to the main circuit insulated and supported above the insulating frame 2. Connected to conductor 20.

The movable contact 11 is supported by the vacuum switch tube 1 so as to be movable in a direction in which the movable contact 11 comes into contact with and separates from the fixed contact 10. A protruding portion of the movable contact 11 to a lower portion of the vacuum switch tube 1 is connected to a main circuit conductor 21 insulated and supported at an intermediate portion of the insulating frame 2 via a flexible connection conductor 22. By the contact and separation between the fixed contact 10 and the movable contact 11, a closed state in which the main circuit conductor 20 and the main circuit conductor 21 are electrically connected and a cut-off state in which the main circuit conductor 20 and the main circuit conductor 21 are cut off are obtained. is there.

A swinging lever 4, which is supported halfway by a substantially horizontal support shaft 40, is arranged inside a gantry 3 that supports a lower portion of the insulating frame 2. One end of the swing lever 4 is connected via a link 50 to the inside of a drive device 5 arranged in parallel with the insulating frame 2 above the gantry 3.
Is pushed and pulled by the link 50 in response to the operation of the driving device 5 and swings around the support shaft 40.

The other end of the swing lever 4 reaching the lower part of the insulating frame 2 is connected to the lower end of a movable contact 11 protruding below the vacuum switch tube 1 via a contact pressure mechanism according to the present invention. Have been. FIG. 3 is an enlarged cross-sectional view of the contact pressure mechanism according to the present invention, and FIG. 4 is a view taken along the line IV-IV in FIG. The contact pressure mechanism includes a connection rod 60 connected to the lower end of the movable contact 11, a connection bracket 61 connected to the other end of the swing lever 4, and a contact pressure spring interposed therebetween. 6 is provided.

The connecting rod 60 is formed by coaxially connecting an upper rod 62 and a lower rod 63 via an umbrella-shaped insulating plate 64. As shown in FIGS.
Is screwed and fixed to the lower end of the movable contact 11. The upper rod 62 has an upper half 62 a and a lower half 62 b connected to a connecting pin 6 parallel to the support shaft 40 of the swing lever 4.
It is configured by being connected by 2c.

The connection bracket 61 has a screw shaft 61a protruding from one side thereof. As shown in FIG. 4, the swing lever 4 has a U-shaped cross section having a horizontal portion along the lower edge for securing the bending strength and connecting the connecting portion 61. The bracket 61 has the screw shaft 61a inserted into the horizontal portion of the swing lever 4, and this inserted portion is connected by being tightened from above and below by adjusting nuts 61b and 61c screwed into the screw shaft 61a. With this connection structure, the adjusting nuts 61b and 61c are loosened, the insertion length of the screw shaft 61a is adjusted, and then the adjusting nuts 61b and 61c are tightened again. It can be adjusted appropriately.

In the upper part of the connecting bracket 61, there is formed a concave portion 61d having a size capable of inserting the lower rod 63, and the concave portion 61d facing the direction of the support shaft 40 of the swing lever 4 is formed. On both side walls, elongated holes 65, 65 having a predetermined length in the axial direction of the screw shaft 61a are formed. On the other hand, in the vicinity of the lower end of the lower rod 63, a connecting pin 66 is driven in substantially parallel to the support shaft 40 of the swing lever 4, and the connecting rod 60 and the connecting bracket 61 The lower end is inserted into the concave portion 61d of the connection bracket 61, and both ends of the connection pin 66 are inserted into the long holes 65, 65 to be connected.

A connecting bracket 61 having long holes 65 formed therein.
As shown in FIG. 3, a mountain-shaped convex portion 61e having a top at the center thereof is formed on the upper edge of both side walls of the rim. This protrusion 6
1e is a disk-shaped spring plate 67 inserted through the lower rod 63,
It is supported by contact from below.

The contact pressure spring 6 is a coil spring inserted into the outside of the lower rod 63. The lower end of the spring 6 is supported by the spring plate 67 supported on the connecting bracket 61 as described above. The insulating plate 64 is resiliently contacted above the plate 67, and is urged in a direction away from each other by its spring force. A concave portion 67a is formed on the upper surface of the spring plate 67 so as to border the periphery thereof, and a lower end of the contact pressure spring 6 is fitted into the concave portion 67a,
At the time of accumulating and releasing, which will be described later, the elastic contact position on the spring plate 67 does not shift.

In this embodiment, the upper end of the contact pressure spring 6 is elastically contacted with the insulating plate 64, and the insulating plate 64 is also used as a pressing plate for pressing the contact pressure spring 6 in the operation described later. However, similarly to the push plate 78 in the conventional contact pressure mechanism shown in FIG. 7, a dedicated push plate may be provided in the middle of the lower rod 63.

In the circuit breaker having the contact pressure mechanism configured as described above, when in the closed state shown in FIG. 1, the lower end of the lower rod 63 is connected to the connecting bracket 61 pushed upward by the swing lever 4. The connecting pin 66 that has entered the concave portion 61d and is driven into the lower rod 63 slides along the long hole 65 formed in the connecting bracket 61, and is in a state of being close to the lower edge of the long hole 65. Become. At this time, the contact pressure spring 6 includes a spring plate 67 supported by the connection bracket 61 and an insulating plate 64 as a pressing plate.
The movable contact 11 which is compressed and accumulates between the movable contact 11 and the fixed contact 10 inside the vacuum switch tube 1 receives the spring force of the contact pressure spring 6 applied upward to the insulating plate 64 by the upper rod. Acting via 62, the fixed contact 10
To obtain a reliable input state.

When the drive device 5 performs a shut-off operation in such a closed state, the swing lever 4 swings clockwise in the drawing by pulling up the connecting portion of the link 50, and the swing is connected by the swing. The bracket 61 is pulled down. This lowering is caused by sliding of the connecting pin 66 generated along the elongated hole 65 formed in the connecting bracket 61.
Within the length range of 65, it is allowed without being transmitted to the lower rod 63. However, after the connecting pin 66 abuts on the upper edge of the long hole 65, further swinging of the swing lever 4 causes lower rod 63 The movable contact 11 connected via the insulating plate 63 and the upper rod 62 is disengaged from the fixed contact 10, and the cutoff state shown in FIG. 2 is obtained.

Further, when the driving device 5 performs the closing operation in such a cut-off state, the swing lever 4 swings counterclockwise in the drawing by pushing down the connecting end of the link 50. , Connecting bracket 61 connected to the other end
Push up. This pushing up causes the connection bracket 61
The spring plate 67 supported above approaches the insulating plate 64, the contact pressure spring 6 is compressed between the two, and the upper rod 62 is pushed up through the insulating plate 64 by the action of the compression reaction force. The movable contact 11 connected to the upper end of the upper rod 62 moves upward and comes into contact with the fixed contact 10.

After this contact occurs, the movement of the connecting rod 60 is stopped by the restraint from the movable contact 11 side, but the connecting bracket 61 is connected to the connecting pin 66 formed along the elongated hole 65 formed in the connecting bracket. The lower rod 63 slides into the recess 61d by sliding.
Is pushed up while increasing the approach length of the lower end. As a result, the spring plate 67 supported on the connecting bracket 61 is pushed up and approaches the insulating plate 64, and the contact pressure spring 6 is strongly compressed and accumulated between the two, and the spring force of the contact pressure spring 6 is increased. Is applied to the movable contact 11 via the connecting rod 60, and a sufficient contact pressure with the fixed contact 10 is obtained.

In the transition from the closed state to the closed state performed as described above, in the contact pressure mechanism according to the present invention, the connection bracket 61 is lowered by the swinging of the swing lever 4 so that the connecting bracket 61 is lowered in the closed state. Contact pressure spring 6 in accumulating state
As a result, the spring force F of the connecting bracket 61 is released.
Is strongly pushed downward by the spring force F acting via the spring plate 67, and the connecting pin 66 connecting the connecting bracket 61 and the lower rod 63 slides along the elongated hole 65, and the elongated hole 65 Collides with the upper rim.

FIGS. 3 and 4 show the state at the time of the collision. In the contact pressure mechanism according to the present invention, the collision caused by the release of the contact pressure spring 6 causes the long hole 65 formed in the connection bracket 61 and the connection pin 66 driven into the lower rod 63 as described above. Between the swing levers 4
The collision point A where the spring force F is concentrated substantially coincides with the axis of the lower rod 63 as shown in FIG.

Accordingly, the bending moment generated in the entire connecting rod 60 including the lower rod 63 due to the collision is small, and when designing the strength of each member constituting the connecting rod 60,
It is not necessary to consider the influence of the bending moment, and the downsizing of the connecting rod 60 makes it possible to significantly reduce the size of the entire pressure contact mechanism, and further reduces the weight of the movable member including the connecting rod 60. As a result, it is possible to reduce the size of the drive device 5 for closing / closing, and to reduce the size of the entire circuit breaker.

In the above embodiment, a long hole 65 is formed in the connecting bracket 61 and a connecting pin is formed in the lower rod 63.
The configuration in which 66 was cast was described, but conversely, a long hole 65 was formed in the lower rod 63, a connecting pin 66 was driven into the connecting bracket 61, and the latter was inserted by inserting the latter into the former. The state may be obtained.

In the contact pressure mechanism according to the present invention,
As described above, the protruding length of the connecting bracket 61 on the swing lever 4 can be adjusted by operating the adjusting nuts 61b and 61c, and the length of the contact pressure mechanism including the connecting rod 60 can be adjusted by this adjustment. Therefore, an adjustment operation for adjusting the compression dimension of the contact pressure spring 6 for adjusting the closing and closing timings can be performed at the connection position between the swing lever 4 and the connection bracket 61, as shown in FIGS. As described above, the window hole 23 for the adjustment operation can be opened below the insulating frame 2, that is, at a position sufficiently distant from the charged portion inside the insulating frame 2. Thereby, it is easy to secure a necessary air insulation distance between the conductor part arranged on the back surface of the circuit breaker and the live part, and it is possible to greatly reduce the depth dimension of the circuit breaker and further reduce the size. Is achieved.

Further, the connecting bracket 61 by the connecting pin 66
As shown in FIG. 3, the connection position between the lower rod 63 and
It is set in the vicinity of a perpendicular line lowered from the center of the support shaft 40, which is the center of swing of the swing lever 4, to the axis of the connecting rod 60 including the lower rod 63. As a result, the movement trajectory of the connecting portion due to the swinging of the swinging lever 4 is generated without largely separating from the axis of the connecting rod 60, and the swing amount of the connecting rod 60 during the closing and closing operations is kept at a low level. And stable operation becomes possible.

[0047]

As described above in detail, in the contact pressure mechanism of the opening and closing device according to the first aspect of the present invention, the connecting rod connected to the movable contact and the connecting bracket connected to the swing lever are formed by these components. Since the connecting pin, which is driven in substantially parallel to the support shaft of the swing lever, is inserted into the elongated hole formed on the other side and connected to the connecting rod, the connecting rod side is released by the release of the contact pressure spring at the time of the breaking operation. Collision with the connecting bracket side occurs on the approximate axis of the connecting rod due to the collision of the connecting pin with the end face of the long hole, and the bending moment generated on the connecting rod due to this collision is reduced. Accordingly, downsizing is achieved by downsizing the movable member including the connecting rod.

In the contact pressure mechanism of the opening and closing device according to the second aspect of the present invention, the connecting portion between the connection bracket and the swing lever is provided with a means for adjusting a protruding length of the connection bracket on the swing lever. Therefore, the compression length of the contact pressure spring can be adjusted at a position sufficiently distant from the charged portion inside the insulating frame, and it is easy to secure an air-insulated distance from the conductor parts arranged on the back side, and the switching device Can be reduced in depth dimension.

Further, in the contact pressure mechanism of the switching device according to the third aspect of the present invention, a recess is provided on the surface of the spring plate facing the pressing plate, and this recess is used as a spring seat of the contact pressure spring.
In storing and releasing the contact pressure spring, unnecessary displacement of the contact pressure spring on the spring plate can be prevented, and stable operation can be performed.

According to a fourth aspect of the present invention, the connecting position of the connecting rod and the connecting bracket by the connecting pin is lowered from the swing center of the swing lever to the axis of the connecting rod. Because it was set near the vertical line,
The movement trajectory of the connecting portion due to the swinging of the swing lever does not largely deviate from the axis of the connecting rod, the swing during the operation of the connecting rod and the movable contact can be reduced, and a stable operation can be performed. The present invention has excellent effects.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a closed state of a circuit breaker provided with a contact pressure mechanism according to the present invention.

FIG. 2 is a side sectional view showing a circuit breaker provided with a contact pressure mechanism according to the present invention in a cut-off state.

FIG. 3 is an enlarged sectional view of a contact pressure mechanism according to the present invention.

FIG. 4 is a view taken along line IV-IV in FIG. 3;

FIG. 5 is a side sectional view showing a closed state of a circuit breaker provided with a conventional contact pressure mechanism.

FIG. 6 is a side sectional view showing a cut-off state of a circuit breaker provided with a conventional contact pressure mechanism.

FIG. 7 is an enlarged sectional view of a conventional contact pressure mechanism.

[Explanation of symbols]

4 swing lever, 6 contact pressure spring, 10 fixed contact, 11
Movable contact, 60 connecting rod, 61 connecting bracket, 64
Insulating plate, 65 long hole, 66 connecting pin, 67 spring plate.

Claims (4)

[Claims] 1. A connecting rod having one end connected to a movable contact of an opening / closing device, a swing lever swinging around an axis in response to a closing or opening operation, and one end connected to the swing lever. The connecting bracket and the connecting rod or the other end of the connecting bracket are driven into the other end of the connecting lever substantially in parallel with the axis of the swinging lever, and the other end of the connecting bracket or the connecting rod is formed in an elongated hole. A connecting pin that is inserted to connect the connecting bracket and the connecting rod by allowing contact and separation in the axial direction within the length range of the long hole, and is fixed to an intermediate portion of the connecting rod. A pressing plate, a spring plate opposed to the pressing plate and supported at the other end of the connection bracket,
A contact pressure mechanism for an opening and closing device, comprising: a contact pressure spring interposed therebetween. 2. The contact pressure mechanism for an opening and closing device according to claim 1, further comprising means for adjusting a projecting length of the connection bracket on the swing lever at a connection portion between the connection bracket and the swing lever. 3. The contact pressure mechanism for an opening and closing device according to claim 1, wherein the spring plate has a recess as a spring seat of a contact pressure spring on a surface facing the pressing plate. 4. The connecting position of the connecting rod and the connecting bracket by the connecting pin is set near a vertical line lowered from the swing center of the swing lever to the axis of the connecting rod. 3. The contact pressure mechanism of the switching device according to any one of 3.