JPH0158816B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an electromagnetic repulsion contact device used in circuit breakers and the like.

[Background technology]

In an electromagnetic repulsion contact device, a movable contact and a fixed contact, which are pivotally supported by a contact support frame, are arranged substantially in parallel so that the current directions are opposite to each other.
As a result, when a short circuit current flows, an electromagnetic repulsion force acts between both contacts, speeding up the opening operation and enhancing the current limiting effect.

Conventional contact devices of this type use a tension coil spring as a contact pressure spring, which is tension-suspended between a movable contact and a contact support frame, and as a result, rotational force is applied to the movable contact, increasing the contact pressure at the time of contact. (contact pressure). In addition, when a short circuit current flows and electromagnetic repulsion acts on both contacts, the movable contact rotates against the spring force of the contact pressure spring, and when this reaches a predetermined amount, the contact pressure spring The direction of the rotational force applied to the electrode is reversed and now contributes to the opening operation.

As a model that adopted this basic configuration,
54-137865, 53-123170, 51-83660, 51
-77575, etc., and various improvements have been made.

However, according to this basic configuration, there is an extremely large deviation between the acting direction of the spring force of the contact pressure spring and the actually required contact pressure direction (the tangential direction of the contact rotation locus), resulting in variations in the set contact pressure. becomes larger. Moreover, from this, in order to reliably secure the required contact pressure, it is necessary to increase the spring force. Furthermore, the reversal operation in the direction of the rotational force applied to the movable contact of the contact pressure spring also becomes more variable. In any case, it is difficult to design and manufacture the contact pressure spring, and it is difficult to obtain stable operation when the contact is opened.

[Purpose of the invention]

The present invention has been made in view of the above points, and its purpose is to provide an electromagnetic repulsion contact device that facilitates the design and manufacture of contact pressure springs and improves the stability of opening operation. There is something to do.

[Disclosure of the invention]

Embodiment Hereinafter, an embodiment of the present invention applied to a circuit breaker will be described based on FIGS. 1 to 7.

FIG. 1 shows the overall structure of a circuit breaker, where 1 is a stand and 2 is a cover. 3 is a power supply side terminal, 4 is a fixed contact, 5 is a fixed contact, 6 is a movable contact, 7 is a movable contact, 8 is a copper stranded wire, 9 is an overcurrent sensor, and 10 is a load side terminal. Thus, an electric path is constructed.

11 is a contact support frame, 12 is a link that drives the movable contact 7 to open and close, 13 is a reversing link, 14 is a latch metal fitting, 15 is a handle link, 16 is a return spring, 17 is a tripping metal fitting, 18 is a handle, 19 20 is a contact pressure spring; 21 is a movable contact holding plate; 22 is an interlocking shaft connecting the contact support frames 11 of each phase; 23 is a locking member; 31 is a reset member.

FIG. 1 shows the circuit breaker in the on state. When a short-circuit current flows in the electrical path between the terminals 3 and 10 in this state, a large electromagnetic repulsive force acts between the fixed contact 4 and the movable contact 7, and the movable contact resists the spring force of the contact pressure spring 20. The child 7 rotates and starts the opening operation. On the other hand, the movable iron piece 9a is attracted by the coil of the overcurrent sensor 9, the tripping fitting 17 is tripped, the latch fitting 14 is released, and a complete opening operation is performed by the action of the return spring 16. Further, the arc generated between the contacts 5 and 6 is driven toward the arc extinguishing grid 19 and is finally extinguished.

Next, the main parts of the present invention will be explained in detail with reference to FIGS. 2 to 7.

The fixed contact 4 has a U-shaped folded shape, and a fixed contact 5 is provided at the end. The electric circuit section provided with the fixed contact 5 is located in a substantially parallel relationship with the movable contact 7 so that the current direction is opposite.

The contact support frame 11 has a U-shape as a whole consisting of opposing pieces and a connecting piece, and the tip portion is shaped like only both opposing pieces. The base end portion is fixed to an interlocking shaft 22, and is rotatable about the interlocking shaft 22, that is, the base end portion, as a fulcrum. A shaft pin 25 is provided on the fixed contact side of the distal end of the support frame 11 through both opposing pieces, and the base end of the movable contact 7 is pivotally supported on this. 28 is a stopper shaft provided at the base end.

Furthermore, a locking recess 11 is provided at the tip of the support frame 11.
A long hole 11a having a diameter b is formed. Specifically, the elongated hole 11a is formed with a predetermined radius and a predetermined arc length from the center of the pivot portion (axis pin 25) toward the tip side and the opposite side of the fixed contact, and the locking recess 11b is
The elongated hole 11a is formed so as to continue from the movable contact side end in a substantially orthogonal direction to the opposite side of the fixed contact. Furthermore, the support frame 11 has this elongated hole 11.
A lock member 23, which can move within the elongated hole while being guided by the lock member a, is provided in the direction in which the locking recess 11b is located and is biased by a lock member return spring 26.

The movable contact holding plate 21 has a shape in which opposing pieces are connected to the proximal end and the intermediate part of a long plate-like base. The facing piece at the base end is pivotally supported by a shaft pin 25, and therefore, the presser plate 21 is attached to the contact support frame 1 so that the base end is coaxial with the pivot portion of the movable contact 7.
It will be supported by 1.

Further, the opposing piece at the intermediate portion is located at a position overlapping the elongated hole 11a having the locking recess 11b of the support frame 11, and has a loose fitting hole 2 larger than the outer diameter of the locking member 23.
1b is formed. By inserting the locking member 23 into the loose fitting hole 21b, the presser plate 21 engages with the locking member 23 with a predetermined gap at the intermediate portion thereof.

Furthermore, the tip faces the tip of the movable contact 7 at a predetermined distance, and a contact pressure spring fixing stud 21a is fixed at a position corresponding to the movable contact 6.

The contact pressure spring 20 is formed in a coil shape, and one side thereof is inserted into the contact pressure spring fixing stud 21a, and is compressed and suspended between the movable contact holding plate 21 and each tip of the movable contact 7.

The movable contactor 7 basically has a long plate shape, and reinforcing plates 7a are overlapped and bonded to each other. A shaft stopper having a semicircular recess is fixed to the upper surface of the base end of the reinforcing plate 7a, and the reinforcing plate 7a and the semicircular recess form a shaft hole 7c into which the shaft pin 25 can be inserted. be done. Therefore, the base end of the movable contactor 7 is pivotally supported by the shaft pin 25, that is, the tip of the support frame 11, and a contact pressure is applied by the above-mentioned contact pressure spring.

Further, from the side of the reinforcing plate 7a located in the middle part as the movable contact 7, there is a protrusion 29 whose tip end surface is located near the locking recess 11b of the contact support frame 11.
is formed by bending it. Specifically, the tip surface of the protruding piece 29 is in a normal state, that is, in an on state or a manually turned off state, and when the lock member 23 is locked in the locking recess 11b, the lock member 2
3, when a short circuit current flows and the movable contact 7 rotates under electromagnetic repulsion, the locking member 23 that is locked in the locking recess 11b is locked. This is to remove the . Therefore, the tip end surface of the protruding piece 29 becomes a pushing part that pushes the locking member 23.

(Operation) FIG. 2a shows an on state, FIG. 2b shows an off state, and FIG. 2c shows an open state when a short circuit current flows.

In the on state, the locking member 23 is in the locking recess 11.
b, so the movable contact holding plate 21
The shaft pin 25 and the lock member 23 make it impossible to rotate with respect to the support frame 11. Therefore, the movable contact 7 receives a rotational force due to the spring force of the contact pressure spring 20, and the movable contact 6 is in contact with the fixed contact 5 with a predetermined contact pressure.

In the OFF state due to manual operation, the locking member 23 remains locked in the locking recess 11b, but the movable contact 6 separates from the fixed contact 5, so the base end of the movable contact 7 touches the stopper shaft 28. Rotate counterclockwise until it makes contact. This amount of rotation becomes overtravel.

Next, a case where a short circuit current flows in the on state will be explained. First, before the mechanism is unlatched due to the operation of the overcurrent sensor 9, the movable contact 7, which has received an electromagnetic repulsive force, rotates clockwise about the shaft pin 25, and the opening operation is performed. Start. As a result, as shown in FIG. 7b, the pushing portion of the protrusion 29 comes into contact with the locking member 23, which then pushes the locking member 23 to release it from the locking recess 11b. In this case, since the play hole 21b of the presser plate 21 is larger than the outer diameter of the lock member 23, the lock member 23 can move.

When the locking member 23 is released, the presser plate 2
1 is rotatable, holding plate 21 and movable contact 7
Both open at high speed, as shown in FIG. 7c. Thereafter, when the mechanism section becomes unlatched due to the operation of the overcurrent sensor 9, the contact support frame 11 also rotates and the opening operation is completed.

The reset operation of locking the locking member 23 in the locking recess 11b again is performed by manual operation, as shown in FIG. 2b.
Rotate it to the off position. As a result, the tip of the presser plate 21 comes into contact with the stopper member 31 and rotates relatively counterclockwise.
b moves the locking member 23 to engage the locking recess 11b.
It locks in.

FIGS. 8 and 9 show other embodiments in which the opening speed of the previous embodiment is further increased.

In this device, an opening spring support shaft 32 is provided on the projecting piece 29 of the movable contact 7, and an opening spring 33 is tensioned and suspended between the support shaft 32 and the stopper shaft 28. The support shaft 32 is provided so as to be located approximately on an extension line connecting the stopper shaft 28 and the shaft pin 25 when the movable contact holding plate 21 is in a non-rotatable state. is in contact with the top surface of the Therefore, a clockwise rotational force is applied to the movable contactor 7, but this is not so large, and if the spring force of the contact pressure spring 20 is slightly increased,
The required contact pressure can be secured.

FIG. 8a shows the on state, and FIG. 8b shows the open state when a short circuit current flows. In the on state, when a short circuit current flows, the movable contact 7 receives electromagnetic repulsion and rotates to start an opening operation. Then, when the position of the opening spring support shaft 32 moves and the angle formed by the support shaft 32, the shaft pin 25, and the stopper shaft 28 becomes smaller than 180°, the opening spring 33
The clockwise rotational force of the movable contactor 7 increases due to this. Since this rotational force increases as the rotation of the movable contactor 7 progresses, the opening operation is promoted along with the disappearance of the anti-opening force due to unlocking, thereby increasing the speed of the opening operation.

〔effect〕

Since the electromagnetic repulsion contact device of the present invention is configured as described above, the direction of action of the spring force of the contact pressure spring and the actually necessary contact pressure direction (the tangential direction of the rotation locus of the contact) are As a result, the variation in the set contact pressure can be reduced, and there is no need to reverse the direction of the rotational force applied to the movable contact of the contact pressure spring as in the conventional case, so that the contact pressure of the contact pressure spring can be This facilitates design and manufacturing, and improves the stability of the opening operation.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the present invention applied to a circuit breaker, Figs. , a perspective view of the main parts; FIG. 5 is a perspective view of a movable contact holding plate;
Figure 6 is a perspective view of the movable contact, Figures 7a, b,
8c is an enlarged explanatory diagram of the operation, FIGS. 8a and 8b are explanatory diagrams of the operation of another embodiment of the present invention, and FIG. 9 is a plan view of the main part thereof. 4... Fixed contact, 5... Fixed contact, 7... Movable contact, 6... Movable contact, 29... Projection piece, 11... Contact support frame, 11a... Elongated hole, 11b... Locking recess, 25...
Shaft pin, 28...Stopper shaft, 20...Contact pressure spring,
21... Movable contact holding plate, 21b... Playing hole, 23
...Lock member, 31...Reset member.

Claims (1)

[Scope of Claims] 1. A contact support frame that is rotatable about a base end and a movable contact that is provided with a movable contact at its distal end and whose base end is pivotally supported on the distal end of the contact support frame. A fixed contact is provided with a fixed contact at the end and has a substantially parallel electric circuit portion in which the current direction is opposite to that of the movable contact, and a movable contact is provided with a spring to apply contact pressure when both contacts are in contact. In an electromagnetic repulsion contact device including an urging contact pressure spring, an elongated hole having a locking recess is formed in the contact support frame, and the elongated hole can move within the elongated hole while being guided by the elongated hole. A lock member is added which is biased by a spring in the direction in which the locking recess is located, and the base end is pivoted on the contact support frame so as to be coaxial with the pivot part of the movable contact, and the intermediate part is A movable contact holding plate is added which engages with the locking member with a predetermined distance and whose tip faces the tip of the movable contact at a predetermined distance, and the contact pressure spring is connected to the movable contact holding plate. A pushing part is suspended between the plate and each tip of the movable contact, and the movable contact has a pushing part that releases the locking member that is locked in the locking recess when it rotates under electromagnetic repulsion. An electromagnetic repulsion contact device formed by: