JP3348599B2 - Circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker such as a wiring breaker, and more particularly to an engagement structure of a spring member which is engaged with a movable contact and applies a pressing force.

[0002]

2. Description of the Related Art FIG.
FIG. 11 is a partially cutaway front view showing a configuration of a movable contact portion of a conventional circuit breaker shown in Japanese Unexamined Patent Publication, FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. 10, and FIG. FIG.
FIG. 4 is a cross-sectional view illustrating a configuration of a circuit breaker in which a movable contact portion at 0 is incorporated. In the figure, reference numeral 1 denotes a movable contact made of a plate-like conductor, which is rotatably disposed around a support shaft 3 whose both ends are supported by a holder 2, and a movable contact 1a is provided at one rotating end, for example. It is fixed by brazing or the like. Reference numeral 4 denotes a fixed contact made of a plate-shaped conductor fixed on the case 5, and a fixed contact 4a is fixed at a position corresponding to the movable contact 1a by, for example, brazing.

Reference numeral 6 denotes a connecting conductor made of a plate-like conductor. The connecting conductor 6 is a flat mounting portion 6a and is set up from the mounting portion 6a at a predetermined interval to elastically move the movable contact 1 near the support shaft 3. It is constituted by a pair of arms 6b which are sandwiched and slidably contact both side surfaces of the movable contact 1. Reference numeral 7 denotes a contact spring member which is fitted at both ends of the support shaft 3 and comprises a compression spring, and presses both arm portions 6b of the connection conductor 6 against both side surfaces of the movable contact 1 with a predetermined force. Reference numeral 8 denotes a current limiting pin which penetrates the other rotating end of the movable contact 1 and is disposed so as to protrude on both sides. 9a and a pair of left and right arms 9b below the V-shaped portion 9a are integrally formed of a plate material, and the current limiting latch 11 is supported by the holder 2 via a pin 10 inserted through the arm 9b. Is a current limiting spring member which is engaged between the V-shaped portion 9a of the current limiting latch 9 and a predetermined position of the holder 2 and comprises a compression spring.

[0004] The movable contact portion configured as described above is
It is incorporated in a circuit breaker as shown in FIG. Then, the current flows from the fixed contact 4 integrated with the power supply terminal to the fixed contact 4a → the movable contact 1a → the movable contact 1 → the connecting conductor 6 → the overcurrent trip device 12 in this order, and the conductor integrated with the load side terminal. 13 flows. In order to change from the closed state as shown in FIG. 12 to the open state, when the operation handle 14 is tilted rightward in the figure, the opening / closing mechanism 15 is activated and the toggle link 16 is activated.
Is rotated clockwise, and the movable contact 1 is separated.

On the other hand, when the current becomes an overcurrent state, the opening / closing mechanism 15 is actuated by the action of the overcurrent trip device 12, and the movable contact 1 is separated. In this case, when a large current, such as a short-circuit current, flows, the movable contact 1 and the fixed contact 4 arranged in parallel to each other flow in opposite directions as indicated by arrows in the drawing. The movable contact 1 is driven by an electromagnetic repulsion generated between currents flowing through the contact 1 and the fixed contact 4, respectively, and the overcurrent trip device 1
2 is rapidly opened prior to the operation by the action of 2.

[0006]

The movable contact portion of the conventional circuit breaker is constructed as described above, and biases the force of the current limiting spring member 11 to the current limiting pin 8 via the current limiting latch 9. Therefore, it is necessary to assemble and hold the current limiting latch 9 with the pin 10 in advance.
Further, as is apparent from FIG. 10, the current limiting pin 8 engages with the current limiting latch 9 from the distance from the pin 10 to the position where the line of force of the current limiting spring member 11 crosses the current limiting latch 9. Since the distance to the position is larger, the force acting on the current limiting pin 8 is smaller than the biasing force of the current limiting spring member 11. Therefore, in order to secure the contact pressure of the movable contact 1 necessary as a circuit breaker, However, the biasing force of the current-limiting spring member 11 must be considerably increased, and the mechanical strength of the holder 2 that receives one end of the current-limiting spring member 11 must be ensured accordingly. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a circuit breaker in which the movable contact portion can be easily assembled and the mechanical strength required for the holder can be reduced. It is intended to provide.

[0008]

A circuit breaker according to a first aspect of the present invention is provided so as to be rotatable around a support shaft supported by a holder, and a movable contact is fixed to one of the rotation ends. The movable contact is disposed between the operating pin and a position opposed to both ends of the operating pin of the holder. In a circuit breaker provided with a spring member that urges a child in a direction in which a movable contact is pressed by a pair of fixed contacts, the circuit breaker is engaged with both ends of an operation pin at a position on a force line of the spring member. A holding member for receiving one end of the spring member is provided.

According to a second aspect of the present invention, there is provided a circuit breaker according to the first aspect, wherein the movable contact and the holding member abut against respective opposing positions to restrict the rotation of the holding member to thereby restrict the spring. An engaging portion for stably holding the direction of the line of force of the member is formed.

According to a third aspect of the present invention, there is provided a circuit breaker according to the first aspect, wherein flat portions are formed at both ends of the operating pin via step portions, and the flat portions are engaged with the holding member. The movement of the operating pin in the axial direction is restricted by bringing the step into contact with a predetermined portion of the holding member.

According to a fourth aspect of the present invention, in the circuit breaker according to the first aspect, when the movable contact is in the open state, the position of the force line of the spring member is different from the engagement position of the spring member with the holder. It is configured such that it is shifted in the opening direction from a line connecting the center of the support shaft.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 FIG. 1 is a partially cutaway front view showing a configuration of a movable contact portion of a circuit breaker according to Embodiment 1 of the present invention, and FIG. 2 is a holding member constituting a main part of the movable contact portion in FIG. FIG. 3 is a front view showing a movable contact constituting a main part of the movable contact in FIG.

In FIG. 1, reference numeral 18 denotes a plate-shaped conductor, which is fitted through a hole 18a to a support shaft 20, both ends of which are supported by a holder 19, so as to be rotatable about the support shaft 20. Movable contact, one of which has a movable contact 18
b is fixed by, for example, brazing or the like, and a contact surface 18c that contacts a holding member described later is formed at the other rotating end. Reference numeral 21 denotes a fixed contact made of a plate-shaped conductor fixed on the case 22, and a fixed contact 21a is fixed to a position corresponding to the movable contact 18b by, for example, brazing. 2
Reference numeral 3 denotes a connection conductor made of a plate-like conductor, which is raised from a flat attachment portion 23a and a predetermined interval from the attachment portion 23a, similarly to the conventional connection conductor shown in FIGS.
The movable contact 18 is elastically clamped near the support shaft 20,
A pair of arm portions 23 that are in sliding contact with both side surfaces of the movable contact 18
b.

Although not shown, these arms 23
“b” is pressed against both side surfaces of the movable contact 18 with a predetermined force by contact spring members formed of compression springs fitted at both ends of the support shaft 20. 24 is the contact surface 18 of the movable contact 18
An operating pin, which penetrates a predetermined position in the vicinity of c and protrudes from both sides, is a holding member 25 formed of a plate material as shown in FIG. A connecting portion 26 having a hole 26a through which the hole 24 penetrates, and a contact surface 26b for contacting the contact surface 18c of the movable contact 18 on the side surface of each side portion, and an upper portion of both side portions of the connection portion 26 Are bent at right angles in opposite directions from each other, are formed in a reverse U-shaped cross section, and have a receiving surface 27a inwardly receiving one end of each of both spring members described later, and a hole 26a outwardly.
Surface 27b which engages with the end of the operating pin 24 which has passed through
And a pair of engaging portions 27 formed respectively. Reference numeral 28 denotes a spring member formed of a compression spring whose one end is received by each of the receiving surfaces 27 a of the two engaging portions 27 of the holding member 25 and whose other end is received at a predetermined position facing the holder 19.

In the movable contact portion of the circuit breaker according to the first embodiment configured as described above, the spring member 28
Is transmitted to the operating pin 24 via the holding member 25 and urges the movable contact 18 with a predetermined contact pressure. Then, when a large current such as a short-circuit current flows, the movable contact 18 is driven in the opening direction by the above-described electromagnetic repulsive force, and overcomes the moment due to the compressive force F of the spring member 28, and Rotating around and rapidly separating.

As described above, according to the first embodiment, one end of the spring member 28 is received by the receiving surface 27a of the engaging portion 27 of the holding member 25 engaged with both ends of the operating pin 24. The position of the operating pin 24 is
And the entire compressive force F of the spring member 28 is urged by the movable contact 18, so that the required compressive force F of the spring member 28 is reduced as compared with the conventional case. As a result, the reaction pressure applied to the holder 19 receiving the other end of the spring member 28 is also reduced, and the mechanical strength required for the holder 19 can be reduced, thereby improving the reliability. Also becomes possible.

In addition, since parts such as the current limiting latch in the related art can be eliminated, the number of parts is reduced, so that the cost is reduced and the assembly is facilitated. Furthermore, the contact surface 18c of the movable contact 18 and the connecting portion 26 of the holding member 25
Is made to abut against the contact surface 26, so that the rotation of the spring member 28 in the counterclockwise direction is regulated, so that the force line of the spring member 28 is stabilized and the moment of the movable contact 18 is also constant. , And a stable opening and closing operation can be performed.

Embodiment 2 FIG. FIG. 4 is a partially cutaway front view showing a configuration of a movable contact portion of a circuit breaker according to Embodiment 2 of the present invention, and FIG. 5 is an operating pin constituting a main part of the movable contact portion in FIG. FIG. 6 is a perspective view showing a state in which the operating pin in FIG. 5 is engaged with the holding member. In the figure, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. 29 is a flat portion 29b at both ends via a step portion 29a.
Are operating pins formed respectively.

In the second embodiment configured as described above, flat portions 29b are formed at both ends of the operating pin 29 via step portions 29a, and both flat portions 29b are held as shown in FIG. Engaging surface 27 of each engaging portion 27 of member 25
Since the holding member 25 and the operating pin 29 are rotated while maintaining the relative positional relationship constant, the force line of the spring member 28 is stabilized, and the opening and closing operation is also stabilized. In addition, since the two step portions 29a abut on the inner side surfaces of the respective engaging portions 27 of the holding member 25, the axial movement of the operating pin 29 is restricted. Can be prevented.

In the structure of the second embodiment, the stepped portion 29a of the operating pin 29 is brought into contact with the inner side surface of each of the engaging portions 27 of the holding member 25 to prevent the operating pin 29 from coming off. I try to prevent it,
As shown in FIG. 7, a regulating portion 27c may be formed to be bent outward from the outer side surface of each engaging portion 27 of the holding member 25. In this case, the operation in the first embodiment is performed. It goes without saying that the present invention can be applied to the pin 24.

Embodiment 3 FIG. 8 is a partially cutaway front view showing the configuration of the closed state of the movable contact portion of the circuit breaker according to Embodiment 3 of the present invention, and FIG. 9 is a movable contact portion of the circuit breaker shown in FIG. FIG. 3 is a front view showing a configuration in an open state of FIG. In the figure, the same parts as those in the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted. Reference numeral 30 denotes an operating pin that penetrates a predetermined position of the movable contact 18 and protrudes from both sides, and is engaged with one end of a spring member 28 via a holding member 25.
When the movable contact 18 is in the open state as shown in FIG.
The line of force of the spring member 28 is a line A connecting the other end of the spring member 28 with the engaging portion 19 a of the holder 19 and the center of the support shaft 20.
It is provided at a position that is more shifted in the opening direction.

In the movable contact portion of the circuit breaker according to the third embodiment configured as described above, when a short-circuit current flows in a closed state as shown in FIG. 8, the movable contact 18 is moved by electromagnetic repulsion. Rotating in the counterclockwise direction in the figure results in an open state as shown in FIG. That is, in this state, the line of force of the spring member 28 is displaced in the opening direction from the line A connecting the support shaft 20 with the engaging portion 19a between the other end of the spring member 28 and the holder 19 and the support shaft 20. In the closed state, the moment l ₁ × F ₁ acting in the clockwise direction disappears, and the counterclockwise moment l ₂ × F ₂ acts, so that the separated state can be easily maintained.

[0023]

As described above, according to the first aspect of the present invention, the movable contact is fixed to one of the rotating ends while being rotatably disposed about the support shaft supported by the holder. The movable contact is disposed between the operating pin and a position opposed to both ends of the operating pin of the holder. In a circuit breaker provided with a spring member which urges and rotates in a direction in which a movable contact is pressed by a pair of fixed contacts, a spring member is engaged with both ends of an operation pin at a position on a force line of the spring member. Is provided with a holding member for receiving one end of the circuit breaker, whereby a circuit breaker capable of easily assembling the movable contact portion and suppressing the mechanical strength required by the holder can be provided.

According to a second aspect of the present invention, in the first aspect, the rotation of the holding member is regulated by abutting the opposing positions of the movable contact and the holding member so that the force of the spring member is reduced. Since the engaging part that stably holds the direction of the wire is formed, it is easy to assemble the movable contact part and it is possible to suppress the mechanical strength required for the holder, as well as stable opening and closing. A circuit breaker capable of performing an operation can be provided.

According to a third aspect of the present invention, in the first aspect, flat portions are formed at both ends of the operating pin via step portions, and the flat portions are engaged with the holding member.
Since the stepped portion is brought into contact with a predetermined portion of the holding member to restrict the movement of the operating pin in the axial direction, the movable contact portion can be easily assembled and the mechanical strength required for the holder is reduced. Of course, it is possible to suppress
It is possible to provide a circuit breaker in which the operation pin can be easily prevented from coming off.

According to a fourth aspect of the present invention, in the first aspect, when the movable contact is in the separated state, the position of the line of force of the spring member is determined by the position of the spring member engaging with the holder and the position of the support shaft. Since it is configured to be displaced in the opening direction from the line connecting the center, it is of course possible to easily assemble the movable contact portion and to reduce the mechanical strength required by the holder,
A circuit breaker that can easily maintain an open state can be provided.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a configuration of a movable contact portion of a circuit breaker according to Embodiment 1 of the present invention.

FIG. 2 is a perspective view showing an appearance of a holding member constituting a main part of the movable contact portion in FIG.

FIG. 3 is a front view showing a movable contact constituting a main part of the movable contact in FIG. 1;

FIG. 4 is a front view showing a configuration of a movable contact portion of a circuit breaker according to Embodiment 2 of the present invention, with a part thereof cut away.

FIG. 5 is a perspective view showing an appearance of an operation pin constituting a main part of the movable contact portion in FIG.

FIG. 6 is a perspective view showing a state in which the operation pin in FIG. 4 is engaged with a holding member.

FIG. 7 is a perspective view showing an external appearance of a modification of a holding member constituting a main part of the movable contact portion in FIG.

FIG. 8 is a partially cutaway front view showing a configuration of a closed state of a movable contact portion of a circuit breaker according to Embodiment 3 of the present invention.

9 is a partially cutaway front view showing a configuration of the movable contact portion of the circuit breaker in FIG. 8 in a closed state.

FIG. 10 is a front view showing a configuration of a movable contact portion of a conventional circuit breaker, partially cut away.

FIG. 11 is a sectional view showing a section taken along line XI-XI in FIG. 10;

12 is a cross-sectional view illustrating a configuration of a circuit breaker in which the movable contact unit in FIG. 10 is incorporated.

[Explanation of symbols]

18 movable contact, 18a, 26a hole, 18b movable contact, 18c, 26b contact surface, 19 holder, 20
Support shaft, 24, 29 operating pin, 29a step, 29b
Flat part, 25 holding member, 26 connecting part, 27 engaging part, 27a receiving surface, 27b engaging surface, 28 spring member.

Claims (4)

(57) [Claims] 1. A movable contact is fixedly mounted on one of the rotation ends around a support shaft supported by a holder, and an operation pin passes through the other rotation end so as to project from both sides. The movable contact is locked between the operation pin and a position of the holder facing the both ends of the operation pin, and the movable contact is fixed to the movable contact via the operation pin. In a circuit breaker provided with a spring member that is urged and rotated in a pressing direction, a holding member that is engaged with both ends of the operating pin and receives one end of the spring member at a position on the force line of the spring member A circuit breaker comprising: 2. An engaging portion for restricting the rotation of the holding member by abutting on opposing positions of the movable contact and the holding member to stably hold the direction of the force line of the spring member. The circuit breaker according to claim 1, wherein: 3. A flat portion is formed at each end of the operating pin via a step portion, and the flat portion is engaged with a holding member, and the step portion is brought into contact with a predetermined portion of the holding member. 2. The circuit breaker according to claim 1, wherein the operation pin is restricted from moving in the axial direction. 4. A structure in which the position of the line of force of the spring member is displaced in the separating direction from the line connecting the engagement position of the spring member with the holder and the center of the support shaft in the separated state of the movable contact. The circuit breaker according to claim 1, wherein the circuit breaker is used.