JP7175572B2 - circuit breaker for wiring - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker for wiring that operates a movable contactor by raising and lowering a crossbar.

A circuit breaker for wiring in which contacts of a plurality of poles are simultaneously turned on and off by a crossbar is disclosed in Patent Document 1, for example. Such a circuit breaker for wiring incorporates a movable contact with a movable contact at the tip and a lead wire connected to the base end. A structure is adopted in which the contacts are brought into contact with the fixed contacts below.

FIG. 10 is an explanatory diagram showing a first conventional structure. In FIG. 10, 50 is a movable contact, 51 is a movable contact, 52 is a fixed contact, and 53 is a crossbar. The movable contact 50 is urged upward by a spring 54, and the movable contact 51 is separated from the fixed contact 52 when the crossbar 53 can be raised. However, when the crossbar 53 moves downward, the point of contact between the base end 56 of the movable contactor 50 and the movement restricting portion 55 provided on the breaker body or the cover serves as a fulcrum, and the movable contactor 50 descends and rotates. , bring the movable contact 51 into contact with the fixed contact 52 .

In this manner, the movable contact 50 descends while rotating, and the position of the fulcrum, which is the center of rotation of the movable contact 50, is not fixed. As a result, when the movable contact 50 descends, it moves so as to be slightly pushed forward (to the left in FIG. 10). It could have slipped to the side.

After the movable contact 51 and the fixed contact 52 are in contact with each other, more specifically, when the movable contact 51 of the movable contact 50 is below the contact point between the upper end of the spring 54 and the movable contact 50, the spring 54 is It acts so as to move the movable contact 50 so as to be pushed backward by the resilience.

In this first conventional structure, the movable contactor 50 can be prevented from moving forward by the movement restricting portion 55 . However, when the crossbar 53 rises and the movable contactor 50 opens, there is a risk that the movable contactor 50 may move backward (rightward in FIG. 10).

In addition, the movable contactor 50 having the first conventional structure also has a problem during assembly. That is, as shown in FIG. 11, the movable contact 50 is passed through the crossbar 53, and the proximal end 56 of the movable contact 50 is moved under the movement restricting portion 55 while the movable contact 50 is in contact with the spring 54. It is necessary to introduce it so as to slip into the At this time, the spring 54 is compressed, and a force is applied in the biasing direction to move the movable contactor 50. As a result, the crossbar 53 is disengaged from the movable contactor 50, resulting in poor assembling workability. rice field.

In order to solve the above problems, in the second conventional structure, as shown in FIG. A third conventional structure is also adopted in which movement of the movable contactor 50 is restricted by sandwiching both sides of the contactor 58 . However, in this structure, it is necessary to rotate the movable contactor 50 having the protrusion 57 by 90 degrees, pass it through the opening 58 of the crossbar 53, and then return it horizontally to assemble it.

Furthermore, in the second conventional structure, since the protrusions 57 are formed on the left and right sides of the movable contactor 50, there are many wasteful parts when stamping the movable contactor 50 from the copper plate, resulting in a poor material yield. There was also a problem. 14, the movable contactor 50 is inserted horizontally from the wide portion and moved upward to the narrow portion. , the opening 58 becomes large, and there is a possibility that the strength of the crossbar 53 is lowered and the insulation distance between the adjacent movable contacts 50 is lowered.

JP-A-2000-251558

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a circuit breaker for wiring which solves the above-described problems of the prior art, has good assembling workability of the movable contact, and is capable of preventing the movement of the movable contact.

A circuit breaker for wiring according to the present invention, which has been made to solve the above problems, comprises a movable contact having a movable contact at its tip, a cross bar having an opening into which the movable contact is inserted , and a movable contact. The movable contact has recessed locked portions formed at both side ends in the width direction . A convex locking portion is formed, and the opening includes a wide portion having an opening width larger than the maximum width dimension between the tip of the movable contact and the locked portion, and an upper side of the wide portion. and a narrow portion formed between the opposing engaging portions in the above, wherein the engaging portion is engaged with the engaged portion of the movable contact inserted into the opening. It is something to do.

In addition, it is preferable to form the locking portion on the base end side of the movable contact in the thickness direction of the crossbar.

According to the present invention, even when the crossbar moves up and down, the movable contactor is always locked by the locking portion of the crossbar, so that the movable contactor can be prevented from moving forward and backward. can. In addition, since it is only necessary to pass the movable contactor through the opening of the crossbar and lift it upward during assembly, the workability of assembly is excellent. Furthermore, since the engaged portion of the movable contact is concave and does not have a projection, the yield of materials can be improved.

According to the present invention, it is possible to prevent the movable contact from tilting in the width direction when it is pushed down by the crossbar. According to the second aspect of the invention, since the locking portion is formed on the base end side of the movable contact in the thickness direction of the crossbar, the rotational stroke of the movable contact during operation is smaller than that on the tip side. . Therefore, it is possible to reduce the amount of protrusion of the locking portion.

It is an external appearance perspective view of the circuit breaker for wiring of embodiment. FIG. 4 is a cross-sectional view showing a contact open state; FIG. 5 is a cross-sectional view showing a state in the middle of contact closure; FIG. 4 is a cross-sectional view showing a contact closed state; It is an exploded perspective view showing a crossbar and a movable contact. FIG. 4 is an assembled perspective view showing a crossbar and a movable contact; FIG. 2 is a cross-sectional view of the essential parts of the first embodiment; FIG. 10 is a cross-sectional view of a main part of the second embodiment; FIG. 11 is a cross-sectional view of a main part of a third embodiment; It is an explanatory view showing a first conventional structure. It is an explanatory view showing a problem of the first conventional structure. It is an explanatory view showing a second conventional structure. It is an explanatory view showing a problem of the second conventional structure. It is an explanatory view showing a third conventional structure.

Preferred embodiments of the present invention are described below.
FIG. 1 is an external perspective view of a three-pole circuit breaker according to an embodiment, and FIG. 2 is a cross-sectional view of the contact open state. In FIG. 1, 10 is a base, 11 is a cover, 12 is a handle projecting upward from the cover 11, 13 is a power supply side terminal, and 14 is a load side terminal.

As shown in FIG. 2 , a fixed contact 16 is provided at the tip of a fixed contact 15 extending from the power supply side terminal 13 . A crossbar 17 and a movable contactor 18 are provided above it. A movable contact 19 is provided at the tip of the movable contact 18 . The proximal end of the movable contactor 18 is an open end 29 that is bent upward into an L-shape, and is in contact with a movement restricting portion 20 attached to an instantaneous tripping mechanism. Details of the crossbar 17 and the movable contactor 18 will be described later.

A stranded wire 21 is connected to the proximal end of the movable contact 18 , the other end of the stranded wire 21 is connected to the lower end of a spiral coil 22 , and the upper end of the coil 22 is connected to the load side terminal 14 . . A movable iron core 23 is arranged in the center of the spiral coil 22, and a movable iron piece 24 is arranged above it. The movable iron piece 24 is attracted to the movable iron core 23 by a magnetic force generated when a large current flows through the circuit, and constitutes an instantaneous tripping mechanism that operates a known tripping mechanism 25 . Note that the movable iron piece 24 is normally held at a position away from the movable iron core 23 by a spring 28 . An instantaneous tripping mechanism may not be formed. In that case, the movement restricting portion 20 is formed on the base 10 .

A well-known opening/closing mechanism 26 is incorporated below the handle 12 . When the handle 12 is tilted toward the power supply side from the contact open state shown in FIG. 2, the state shown in FIG. The movable contact 18 of the pole is rotated counterclockwise in the drawing to bring the movable contact 19 into contact with the fixed contact 16 . In this state, the power supply side terminal 13 and the load side terminal 14 are in a conductive state, and power is supplied to the load.

However, when a large current flows through the circuit, the above-described instantaneous tripping mechanism operates, and when an overcurrent flows, the overcurrent detection mechanism operates and the crossbar 17 and the movable contactor 18 are released by springs. 27 forces it to move upwards. As a result, the movable contact 19 is separated from the fixed contact 16 and the current is interrupted.

The spring 27 is arranged below the movable contactor 18 and at an intermediate position between the open end 29 and the crossbar 17 . By disposing the spring 27 away from the movable contact 19 in this manner, the spring 27 can be prevented from being exposed to arcs generated when the contacts are opened.

The structure and operation of the circuit breaker for wiring described above are the same as the conventional ones. However, the relationship between the crossbar 17 and the movable contactor 18, which will be described below, is a novel structure not found in the prior art.

As shown in FIGS. 5 and 6, also in this embodiment, the crossbar 17 is formed with openings 30 for three poles, into which three-pole movable contacts 18 are inserted. However, unlike the prior art, recessed engaged portions 31 are formed at both side end portions in the width direction of the movable contactor 18 . A convex locking portion 32 is formed correspondingly to the upper end of the opening 30 of the crossbar 17, and as shown in FIG. The locking portion 32 of the opening 30 of 17 is locked. By providing the engaged portion 31 and the engaging portion 32 on both the left and right sides, it is possible to prevent the movable contactor 18 from tilting in the left-right direction.

The engaging portion 32 may be formed in the thickness direction of the crossbar 17, but is preferably formed on the base end side of the movable contactor 18. In the first embodiment shown in FIG. , the locking portion 32 is formed at the proximal end of the crossbar 17 in the thickness direction. However, in the second embodiment shown in FIG. 8, the engaging portion 32 is formed slightly closer to the proximal side than the center of the crossbar 17 in the thickness direction. Since the movable contactor 18 rotates around the base end side, the rotation stroke during operation on the base end side is smaller than that on the tip end side. Therefore, as described above, the protrusion amount of the locking portion 32 can be reduced.

As described above, in the present invention, the engaging portion 32 of the opening 30 of the crossbar 17 is engaged with the engaging portion 31 of the movable contact 18, so that the movable contact 18 is always integral with the crossbar 17. It can be restrained from moving in the longitudinal direction as in the conventional art. Therefore, the movable contact 19 comes into contact with the fixed contact 16 correctly. Since the movable contactor 18 is always urged upward by the spring 27, the locked portion 31 will not come off from the locking portion 32 even if the crossbar 17 moves up and down. In the present invention, since the engaged portion 31 is formed in a concave shape, it is possible to suppress material loss during punching of a copper plate as in the conventional case. However, if the size of the engaged portion 31 is increased, the current carrying capacity is lowered. In addition, the movable contactor 18 can be easily incorporated into the crossbar 17, which is excellent in assembly workability.

The operation of the circuit breaker for wiring according to the present invention constructed as described above is summarized as follows.

(close operation)
When the handle 12 is operated in the ON direction, the opening/closing mechanism 26 pushes down the crossbar 17 . As a result, the open end 29 side of the movable contactor 18 in contact with the spring 27 becomes a fulcrum, the movable contact 19 side rotates downward, and the movable contact 19 comes into contact with the fixed contact 16 as shown in FIG. When the handle 12 is operated, the crossbar 17 is further lowered, and the open end 29 side of the movable contactor 18 is lowered while compressing the spring 27, resulting in the state shown in FIG. In this state, the base end side of the movable contactor 18 is pushed up by the spring 27 with the engaged portion 31 as a fulcrum, so that the movable contact 19 on the tip side is pressed against the fixed contact 16 to maintain the contact pressure.

In order to allow the crossbar 17 to be lowered sufficiently in this way, it is preferable to form the crossbar storage space 33 below the fixed contact 16 as shown in FIGS. In this state, the power supply side terminal 13 and the load side terminal 14 are in a conductive state, and power is supplied to the load.

(open operation)
When the handle 12 is operated in the OFF direction or when an overcurrent or a second current is detected, the opening/closing mechanism 26 is released from the crossbar 17, and the movable contact 18 is moved to the crossbar 17 by the elastic force of the spring 27. to raise Since the crossbar 17 is located near the movable contact 19, the contact between the movable contact 19 and the fixed contact 16 can be immediately released. Since the movable contactor 18 is always urged upward by the spring 27, it is possible to prevent the crossbar 17 from coming off even if the crossbar 17 moves up and down.

In addition, as shown in FIG. 9, a movable contact is provided at the lower end of the opening 30 of the crossbar 17 so that the engaging portion 32 of the crossbar 17 and the engaged portion 33 of the movable contactor 18 are not disengaged. A lower protrusion 34 is formed on the tip side of the contactor 18 . Even if the locking portion 32 of the crossbar 17 and the locked portion 33 of the movable contactor 18 are disengaged, the movable contactor 18 abuts against the lower projection 34 to restrict movement. The locking portion 32 is locked with the locked portion 33 by the resilience of the spring 27 . Specifically, since the space x between the engaging portion 32 and the lower protrusion 34 is formed narrower than the thickness t of the movable contact 18, movement can be restricted. Further, since the space z between the engaging portion 32 and the lower end of the opening 30 is formed wider than the thickness t of the movable contact 18, insertion of the movable contact is not hindered.

10 Base 11 Cover 12 Handle 13 Power supply side terminal 14 Load side terminal 15 Fixed contact 16 Fixed contact 17 Crossbar 18 Movable contact 19 Movable contact 20 Movement regulating part 21 Stranded wire 22 Coil 23 Movable iron core 24 Movable iron piece 25 Tripping mechanism 26 Open/close mechanism 27 Spring 28 Spring 29 Open end 30 Opening 31 Locked portion 32 Locking portion 33 Crossbar storage space 34 Lower protrusion 50 Movable contact 51 Movable contact 52 Fixed contact 53 Crossbar 54 Spring 55 Movement restriction Part 56 Base end 57 Protrusion 58 Opening

Claims (2)

A movable contact with a movable contact at the tip, a crossbar with an opening into which the movable contact is inserted, and a spring that raises the movable contact,
The movable contact has recessed locked portions formed at both widthwise end portions ,
A convex locking portion corresponding to the locked portion is formed on both left and right sides of the upper end of the opening,
The opening is
a wide portion having an opening width larger than the maximum width dimension between the tip of the movable contact and the locked portion;
a narrow portion formed between the engaging portions facing each other on the upper side of the wide portion;
A circuit breaker for wiring , wherein the locking portion is locked to the locked portion of the movable contact inserted into the opening . 2. The wired circuit breaker according to claim 1, wherein the locking portion is formed on the base end side of the movable contact in the thickness direction of the crossbar.

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