JP2003068183A - Trip for circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a trip for circuit breaker having high sensitivity in spite of a small size by reducing the force of the direction of weakening the electromagnetic attractive force acting between a first iron core and a second iron core. SOLUTION: The upper end part of a bimetal 42 is fixed in a fixed position, and the first iron core 41 is arranged on the bimetal 42 in opposition thereto. When an overcurrent is carried to a current-carrying cable run including the bimetal 42, the lower end part of the bimetal 42 is displaced in the direction of getting close to the first iron core 41. The second iron core 44 is arranged on the first iron core 41 in the form that its lower end is in contact with the first iron core 41, and it encloses a part of the bimetal 42 with the first iron core 41. The bimetal 42 and the first iron core 41 are mutually connected through a holding spring 43 formed of a plate spring, and the fixing position of the first iron core 41 and bimetal 42 with the holding spring 42 is set so that the load received from a working plate 33 by the first core 41 acts on the holding spring 43 as tensile load.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention passes through a current-carrying electric line in order to forcibly open a contact inserted in the current-carrying electric circuit when an abnormal current flows in the current-carrying electric circuit between a power source and a load. The present invention relates to a trip device for a circuit breaker that detects an abnormal current.

[0002]

2. Description of the Related Art Generally, a circuit breaker is locked by a spring or the like in a state in which a force in the opening direction is stored with a contact inserted in an energizing electric path between a power source and a load being closed, and an When an abnormal current such as a current or a short-circuit current passes through the energizing circuit, the tripping device for detecting the abnormal current releases the locked state and the contacts are forcibly opened.

As a trip device, for example, Japanese Unexamined Patent Publication No. Hei 6
As disclosed in Japanese Patent Laid-Open No. 162910/1992, there is known a configuration in which an attracting piece is attached to a bimetal inserted in an energizing electric path, and a latch movable piece made of a magnetic material is arranged to face the attracting piece. The circuit breaker stores the force in the direction to open the contact when the contact inserted in the energizing circuit is closed and puts it in the locked state.When the locked state is released, the stored force is released to force the contact. An opening / closing mechanism for opening the contact is provided, and the latch movable piece is provided with a locking portion for locking a part of the opening / closing mechanism to keep it in a locked state. Then, the latch movable piece is brought into contact with one end of the bimetal, and when an overcurrent flows in the energization circuit and the bimetal bends due to self-heating, the latch movable piece bends together with the bimetal to release the locked state.
Further, when a short-circuit current flows in the energizing circuit, the attracting piece attracts the latch movable piece by magnetic force to release the latch. As described above, the configuration is adopted in which the deflection due to the self-heating of the bimetal is used for the overcurrent and the magnetic force is used for the short circuit current.

However, in the trip device described in the above publication, there is a problem that the space for disposing the trip device itself becomes large because the suction piece and the latch movable piece are separated from each other, and There is a problem that the suction force between the suction iron piece and the latch movable piece is weak and the sensitivity is low.

In order to solve this kind of problem, a tripping device 4 having the structure shown in FIG. 9 has been proposed (Japanese Patent Application No. 2000).
-207585). In the trip device 4, the first iron core 45 is connected to the lower end of the plate-shaped bimetal 42 via the holding spring 43 formed of a leaf spring, and the second iron core 44 is contacted with a part of the first iron core 41. Are arranged.

The first iron core 41 is provided with a main iron core 41b formed in a U shape or a U shape surrounding one side surface and both side surfaces of the bimetal 42 in the thickness direction.
A fixing piece 41c is projected from the lower end of b. One end of the holding spring 43 is caulked and fixed to the fixed piece 41c, and the other end of the holding spring 43 is caulked and fixed to the lower end of the bimetal 42. A locking piece 41a is provided on the outer surface of the first iron core 41 so that a part of the opening / closing mechanism 3 described later can be locked to the locking piece 41a.

By the way, since the main iron core 41b of the first iron core 41 is formed in a U shape or a U shape as described above, the left end surface of the main iron core 41b is opened and the magnetic pole surface 41f (see FIG. 10) is formed. Is forming. The second iron core 44 is the magnetic pole surface 41.
A mounting spring 4 which is arranged so as to face f and is formed of a leaf spring.
It is coupled to the first iron core 41 via 5. That is,
The mounting spring 45 is fixed to the second iron core 44, and a portion of the mounting spring 45 that extends toward the first iron core 41 is engaged with the outer surface of the main iron core 41b of the first iron core 41, so that the second iron core 44 is connected to the first iron core 41.

In this way, the holding spring 4 is attached to the bimetal 42.
Since the first iron core 41 is connected to the first iron core 41 via the mounting spring 45, the first iron core 41 is connected to the first iron core 41 via the mounting spring 45, the first iron core 41, the bimetal 42, the holding spring 43, and the second iron core 44. The trip spring 4 is integrated with the mounting spring 45,
It can be handled as one member. Further, the bimetal 42 is surrounded by the main iron core 41 b of the first iron core 41 and the second iron core 44, and the magnetic flux formed around the bimetal 42 with the energization of the bimetal 42 causes the first iron core 41 and the second iron core 44. It passes through. Further, as shown in FIG. 10, the magnetic pole surface 41f of the first iron core 41 faces the second iron core 44, and when the current does not flow through the bimetal 42, only the lower end portion of the magnetic pole surface 41f and the second iron core 44 is formed. Are abutted against each other and the upper ends thereof are arranged to be separated from each other. As a result, it is possible to bring the first iron core 41 and the second iron core 44 close to each other for downsizing, and to increase the suction force by bringing a part of the first iron core 41 and the second iron core 44 into contact with each other. Has become.

The trip device 4 described above is incorporated in a circuit breaker as shown in FIG. This circuit breaker has a rectangular parallelepiped-shaped container body 1 which is a synthetic resin molded product, and is arranged inside the container body 1 side by side in the width direction (direction orthogonal to the plane of FIG. 1) of the container body 1. Two sets of contacts 2a, 2b, an opening / closing mechanism 3 for collectively opening and closing the contacts 2a, 2b, and contacts 2a, 2 when an abnormal current passes through the energizing circuit in which the contacts 2a, 2b are inserted.
A trip device 4 for actuating the opening / closing mechanism 3 so as to forcibly open b is housed. The contacts 2a and 2b are provided with two fixed contacts 21a and 21b fixed to the body 1, and movable contacts 22a and 22b that are brought into contact with and separated from the fixed contacts 21a and 21b.

The fixed contact 21a is fixed to one end of the terminal plate 23a, and a locking spring 24 is arranged at the other end of the terminal plate 23a. The locking spring 24 is formed by bending one end of a strip-shaped leaf spring in the longitudinal direction into a J shape to form a locking piece 24a and bending the other end into an S shape into a contact piece 24b. The locking piece 24a and the contact piece 24b are arranged so as to face a part of the terminal plate 23a. Therefore, the body 1
When the electric wire inserted into the body 1 through the electric wire insertion hole 11 formed in the side wall of the terminal is inserted between the locking piece 24a and the contact piece 24b and the terminal plate 23a, the springs of the locking piece 24a and the contact piece 24b. The electric wire is sandwiched between the terminal plate 23a and the terminal plate 23a by the force, and the electric wire is electrically connected to the terminal plate 23a. Further, the locking piece 24a bites into the electric wire to prevent the electric wire from being pulled out. This type of terminal structure is known as a quick-connect terminal.

In order to release the locked state of the electric wire held by the terminal plate 23a and the locking spring 24, the body 1
A release handle 25 is provided so that the operating portion 25a is exposed from the exposure window 12 provided on the upper surface of the. Release handle 25
The lower part is pivotally supported with respect to the body 1, and when the operating part 25a is tilted to the left side in the drawing, the release projection 25c provided on the lower part of the release handle 25 pushes the tip end of the locking piece 24a downward to push it from the terminal plate 23a. The locking piece 24a is pulled away to release the locked state of the electric wire. In this state, the electric wire can be pulled out.

On the other hand, the fixed contact 21b is fixed to a terminal plate 23b provided separately from the terminal plate 23a. Terminal board 23b
Holds a locking spring at one end like the terminal plate 23a.
Further, a release handle is provided on the body 1 to release the locked state of the electric wire connected to the locking spring.

The movable contacts 22a and 22b corresponding to the fixed contacts 21a and 21b are held at the ends of the movable contacts 26a and 26b connected to the opening / closing mechanism 3, respectively.
In the movable contacts 26a, 26b, the movable contacts 22a, 2
The end provided with 2b is driven by the opening / closing mechanism 3 to move up and down.

The opening / closing mechanism 3 has a handle 31 having an operating portion 31a which is undulated through a window hole 14 which is opened on the upper surface of the body 1, and a rotary portion 31b is integrally formed at one end of the operating portion 31a. The rotating part 31b includes a handle shaft 31c supported by the body 1 inside the window hole 14. Therefore, the handle 31 can be erected between a position where the operating portion 31 a is substantially flush with the opening surface of the window hole 14 and a position where the operating portion 31 a projects from the window hole 14.

An upper end of a U-shaped link 32 is pivotally attached to the rotating portion 31b of the handle 31, and an operating plate 33 as a latch plate of the opening / closing mechanism 4 is pivotally attached to the lower end of the link 32. Further, the opening / closing mechanism 3 includes a holder 34 made of a synthetic resin molded product that holds the movable contacts 26a and 26b.
4, a shaft portion 34c is provided so as to project from the upper end side surface of the shaft 4.
Is rotatably supported by the body 1. An opening spring 35 composed of a coil spring is held between the lower end of the holder 34 and the bottom of the body 1, and the holder 34 is urged clockwise by the spring force of the opening spring 35 in FIG. ing. Here, the movable contact 26b is formed in a strip shape by a conductive metal plate having rigidity, and an intermediate portion in the longitudinal direction is inserted into a cut groove 34b provided on one side surface (back surface in FIG. 1) of the holder 34, A contact pressure spring 36 formed of a coil spring is sandwiched between the lower surface of the movable contact 26b and the holding body 34. In addition, the kerf 34 provided on the other side surface (front surface of FIG. 1) of the holder 34.
The intermediate portion of the movable contact 26a formed of a thin conductive metal plate is inserted into a. The above-mentioned handle 31,
Link 32, operating plate 33, holder 34, opening spring 35,
The contact pressure spring 36 constitutes the opening / closing mechanism 3.
Operates in cooperation with the trip device 4 to open and close the contacts 2a, 2b.

By the way, the actuating plate 33 has a main piece 33a formed in a strip shape, and is provided with bearing pieces 33b which are vertically provided on both sides of an intermediate portion in the longitudinal direction of the main piece 33a. Bearing piece 33b
Has a distal end portion formed in an arc shape, and can come into contact with a protrusion 34d provided on the upper surface of the holding body 34 so as to protrude closer to the contacts 2a and 2b than the shaft 34c. One end of the main piece 33a on the side of the contacts 2a and 2b can abut the tip of the projection 34d, and the other end of the main piece 33a is a locking piece 41a as a locking part provided in the trip device 4. It can be locked (described later).

A terminal block 50 that can be connected to a conductive bar (not shown) provided in the distribution board is provided on the right side of the body 1. The terminal block 50 has insertion grooves 51a to 51c at three upper and lower positions.
And the blade receiving springs 52a, 52c corresponding to the two upper and lower insertion grooves 51a, 51c of the respective insertion grooves 51a-51c.
c is arranged. Each of the blade receiving springs 52a and 52b includes a pair of upper and lower spring pieces, and a conductive bar is sandwiched between the spring pieces to be electrically connected to the conductive bar.
One end of the movable contact 26a is fixed to the upper blade receiving spring 52a. On the other hand, a bimetal fixing plate 53 extended upward is fixed to the lower blade receiving spring 52b. The bimetal fixing plate 53 is extended to the upper part of the body 1, and the upper end of the bimetal 42 constituting the trip device 4 is fixed to the upper end of the bimetal fixing plate 53. That is, the upper end of the bimetal 42 becomes the fixed end of the bimetal, and the lower end becomes the free end of the bimetal 42.

The upper end of the bimetal 42 provided on the trip device 4 is connected to the blade receiving spring 52c via the bimetal fixing plate 53 as described above. Further, the lower end portion of the bimetal 42 is connected to one end portion of the movable contact 26b via the braided wire 47. Therefore, between the blade receiving spring 52c and the terminal plate 23b (not shown), the bimetal fixing plate 53, the bimetal 42, the braided wire 47, the movable contact 26b, and the movable contact 2 are provided.
A current-carrying electric path of the path of 2b-fixed contact 21b is formed.
Further, a current-carrying electric path of the movable contact 26a-movable contact 22a-fixed contact 21a is formed between the blade receiving spring 52a and the terminal plate 23.

The operation will be briefly described below. FIG. 10 shows a state in which the operating portion 31a of the handle 31 is tilted to close the contacts 2a and 2b. At this time, the upper end of the link 32 is located on the left side of the handle shaft 31c. Link 32
The left end of the operating plate 33 connected to the lower end of the
It comes into contact with the projection 34d provided on the base plate and receives the rotational force in the clockwise direction around the joint with the link 32 by the spring force of the opening spring 35. Here, the right end of the operating plate 33 is the first iron core 4
1, the operating plate 33 does not rotate, and as a result, the holder 34 compresses the opening spring 35 to move the movable contact 26a, 26b is pressed downward, and the movable contacts 22a and 22b are fixed contact 2
It contacts 1a and 21b. At this time, the force of pushing up the operating plate 33 acts by the spring force of the opening spring 35, but since the upper end of the link 32 is located on the left side of the handle shaft 31c, a clockwise rotating force acts on the handle 31. However, the handle 31 is kept in the tilted position. Also,
When the upper wall of the cut groove 34a presses the movable contact 26a from above, the contact pressure of the movable contact 22a to the fixed contact 21a is obtained, and the movable contact 26b also has the cut groove 3a.
The spring force of the contact pressure spring 36 acts on the fixed contact 2 of the movable contact 22b in a state where a part of the movable contact 22b contacts the upper wall of the movable contact 22b.
A contact pressure for 1b is obtained.

On the other hand, when the handle 31 is raised from the closed state of FIG. 1, the upper end of the link 32 is pulled up so as to be located on the right side of the handle shaft 31c, and the operating plate 33 is pulled up, so that the holding body 34 is activated. The plate 33 is no longer in contact with the plate 33, and the spring force of the opening spring 35 causes the holder 34 to rotate in the clockwise direction. As a result, the movable contacts 26a and 26b held by the holder 34 are pulled up, and the movable contacts 22a and 22b are separated from the fixed contacts 21a and 21b upward and open. That is, the operating state 31a of the handle 31 is raised to open the contact.

When an overcurrent larger than the rated current passes through the current-carrying circuit including the bimetal 42 in the closed state, the bimetal 42 bends so as to displace the lower end portion to the right as shown in FIG. Since the lower end of the first iron core 41 connected via the spring 43 moves to the right with respect to the upper end, the locking piece 41a and the operating plate 33 are moved.
The locked state with is released. As a result, the operating plate 33 becomes rotatable around the lower end of the link 32, and the opening spring 35
The holding body 34 rotates clockwise by the spring force, and the movable contacts 22a and 22b open from the fixed contacts 21a and 21b. At this time, the operating plate 33 freely rotates around the lower end of the link 32, so that the spring force of the opening spring 35 is not transmitted to the handle 31 and the operating portion 3 of the handle 31 is not transmitted.
1a is kept in a fallen state. That is, a so-called trip-free state is set. In this state, the holding body 34 comes into contact with the partition wall 13 to regulate the rotational position.

Further, when a large current such as a short-circuit current flows in the energizing circuit including the bimetal 42 in the closed state, the magnetic field generated around the bimetal 42 attracts between the first iron core 41 and the second iron core 44. Power acts. First
Since the lower end portion of the magnetic pole surface 41f of the iron core 41 is in contact with the second iron core 44, a suction force acts between the upper portion of the first iron core 41 and the second iron core 44, so that the upper portion of the first iron core 41 is illustrated. Move 10 to the right rapidly. As a result, the locking piece 41a of the first iron core 41 is disengaged from the actuating plate 33, and the movable contacts 22a, 22b are fixed to the fixed contacts 21a, 2 as in the case where an overcurrent flows.
The contact is opened from 1b. In this case as well, the trip is free.

[0023]

In the trip device described above, a part of the magnetic pole surface 41f of the first iron core 41 is part of the second iron core 44.
The electromagnetic attraction is large due to the fact that the first core 41 and the second core 44 are in contact with each other, so that the volumes of the first iron core 41 and the second iron core 44 can be reduced, and as a result, downsizing is possible.

By the way, the first iron core 41 receives a downward force from the opening / closing mechanism 3 in the locked state where one end of the operating plate 33 is locked to the locking piece 41a, and the bimetal 42 and the first iron core 41 are A force from the opening / closing mechanism 3 acts on the holding spring 43 that connects the. Since the middle portion of the holding spring 43 is bent in an L shape, it may be bent by a downward force acting on the first iron core 41, and in order to reduce the bending of the holding spring 43, the holding spring 43 may be bent. It is necessary to increase the spring constant. The holding spring 43 has a function of connecting the bimetal 42 and the first iron core 41, and the first iron core 41 is opened after the contacts 2a and 2b are opened by attracting the first iron core 41 to the second iron core 44. Since it also has a function of separating from the second iron core 44 and returning it to the original position, the returning force is applied in the direction of weakening the suction force between the first iron core 41 and the second iron core 44, and the spring of the holding spring 43. The larger the constant, the smaller the electromagnetic attraction force between the first iron core 41 and the second iron core 44. That is, in order to increase the electromagnetic attraction force due to the short-circuit current and increase the sensitivity, it is necessary to increase the volumes of the first iron core 41 and the second iron core 44, and the degree of downsizing of the trip device 4 is insufficient. It becomes something.

The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the force for weakening the electromagnetic attraction force acting between the first iron core and the second iron core, thereby reducing the size. Another object is to provide a trip device for a circuit breaker having high sensitivity.

[0026]

According to a first aspect of the present invention, a contact inserted in an energizing electric path between a power source and a load and a force for opening the contact when the contact is closed are stored and locked. It is used in a circuit breaker equipped with an opening and closing mechanism for forcibly opening the contact by the force when the contact state is released, and when a large current flows in the energizing circuit when the contact is closed, A tripping device that releases the stop state and forcibly opens the contacts, one end of which is fixed at a fixed position to form a part of the energization circuit and the other end of which is displaced when an overcurrent flows in the energization circuit. A bimetal and a locking portion that holds the opening / closing mechanism in the locking state are integrally provided, and the bimetal and the locking portion are arranged so as to face the bimetal, and a pusher that works as the other end of the bimetal is displaced in the direction of decreasing the distance. When the pressure is transmitted, the locked state is released. The iron core and one end of a pair of side pieces are integrally connected, and are arranged so as to surround a part of the bimetal together with the first iron core. One end side of the first iron core abuts on both side pieces and the other end side A second iron core separated from both side pieces, and a leaf spring having one end fixed to the bimetal and the first iron core, and fixed to the bimetal so that the load applied to the first iron core from the opening / closing mechanism acts as a tensile load. The part is composed of a holding spring located closer to the fixed end of the bimetal than the part fixed to the first iron core, and the first iron core on the side where the first iron core and the second iron core are separated from each other when a large current flows in the current-carrying circuit. The second
It is characterized in that the contacts are forcibly opened by drawing the iron core to release the locked state between the opening / closing mechanism and the locking portion.

According to a second aspect of the present invention, in the first aspect of the present invention, the engaging portion is an engaging piece formed by cutting and raising the first iron core, and an end of a latch plate provided in the opening / closing mechanism. A through hole through which the locking piece can be inserted is provided through the portion, and in the locked state, the leading end surface of the locking piece abuts between the edge of the latch plate and the through hole, and the locked state is released. At this time, one of a state in which the locking piece is disengaged toward the edge of the latch plate and a state in which the locking piece is inserted into the through hole is selected.

According to a third aspect of the present invention, in the first aspect of the present invention, the engaging portion is an engaging piece formed by cutting and raising the first iron core, and an end of a latch plate provided in the opening / closing mechanism. A recessed portion into which the locking piece can be inserted is provided in the portion, and in the locked state, the leading end surface of the locking piece abuts between the edge of the latch plate and the recessed portion, and the locked state is released. In this case, one of a state in which the locking piece is disengaged from the edge of the latch plate and a state in which the locking piece is inserted into the recess is selected.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the locking portion is a locking projection projecting from an inner peripheral edge of an insertion hole penetrating the first iron core. The end portion of the latch plate provided on the side of the latch plate is formed with a notch portion which can be inserted into the insertion hole and into which the locking projection can be inserted. And a state in which the locking projection is disengaged to the end edge side of the latch plate and the state where the locking projection is disengaged to the cutout side is selected. To do.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the locking portion is a locking projection piece provided on both side edges of the first iron core, and the latch plate is provided on the opening / closing mechanism. A concave groove into which the first iron core can be inserted is formed at the end portion, and mounting protrusions that can come into contact with the locking protrusion are formed on both inner side surfaces of the opening of the concave groove. Then, the mounting projection abuts on the locking projection, and when the locked state is released, the locking projection retreats from the groove and disengages from the mounting projection and the locking projection enters the groove. It is characterized in that one of the state of being inserted and detached from the mounting projection is selected.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the latch plate is a metal plate, and the latch plate body is crossed from both side edges of one end portion of the latch plate body and both ends of the latch plate body are tied. A pair of arm pieces extending in the same direction, the groove is surrounded by the latch plate body and both arm pieces, and the mounting projection is bent such that the tip ends of the arm pieces approach each other. It is characterized by being formed.

According to a seventh aspect of the present invention, in the first to sixth aspects of the present invention, a pusher for transmitting a pressing force generated by the displacement of the other end of the bimetal to the first iron core is provided. To do.

The invention of claim 8 is characterized in that, in the invention of claim 7, the pusher is a pressing projection fixed to one of the other end of the bimetal and the first iron core. To do.

According to a ninth aspect of the present invention, in the seventh aspect, the pusher is a push piece formed by bending at least one of the other end of the bimetal and the end of the first iron core. Characterize.

According to a tenth aspect of the present invention, the contact inserted into the energizing electric path between the power source and the load and the force in the direction of opening the contact when the contact is closed are stored in the locked state to set the locked state. It is used in a circuit breaker equipped with an opening and closing mechanism that forcibly opens contacts by the force when released, and releases the locked state when a large current flows in the energizing circuit when the contacts are closed. A tripping device for forcibly opening contacts, one end of which is fixed at a fixed position to form a part of the energizing electric circuit, and the other end of which displaces when overcurrent flows in the energizing electric circuit, and an opening / closing mechanism. A first iron core integrally provided with a locking portion to be in the locked state, arranged to face the bimetal, and releasing the locked state when a tensile force accompanying the displacement of the other end of the bimetal is transmitted. , A shape in which one end of a pair of side pieces is integrally connected And a second iron core arranged so as to surround a part of the bimetal together with the first iron core, one end side of the first iron core abuts on both side pieces and the other end side is separated from the both side pieces, and displacement of the other end portion of the bimetal. Of the bimetal so that the load received from the opening / closing mechanism on the first core acts as a tensile load. The fixed part is composed of a holding spring located closer to the fixed end of the bimetal than the fixed part with the first iron core, and when the large current flows in the energizing electric path, the first part is provided on the side separated from the first iron core and the second iron core. It is characterized in that the contact is forcibly opened by drawing the iron core to the second iron core to release the locked state between the opening / closing mechanism and the locking portion.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION The trip device described below as an embodiment of the present invention will be described assuming that it is applied to the circuit breaker described as a conventional structure, but the circuit breaker having another structure will be described. Does not prevent the application of.

(First Embodiment) The trip device 4 of the present embodiment has the structure shown in FIG. 1, and has a first iron core 41 and a second iron core 44 as in the conventional structure. A part of the bimetal 42 is surrounded, and the bimetal 42 and the first iron core 41 are connected via a holding spring 43 which is a leaf spring. Here, the first iron core 41 is provided with a locking piece 41a as a locking portion for locking one end of the operating plate 33 as a latch plate provided in the opening / closing mechanism 3. In this embodiment, the first iron core 41 is formed in a flat plate shape, and the second iron core 44 is bent in a U shape or a U shape. The tip surfaces of both side pieces of the second iron core 44 face the first iron core 41 as magnetic pole surfaces 44a. In the present embodiment, the lower end of the magnetic pole surface 44a contacts the first iron core 41, and the upper end of the magnetic pole surface 44a contacts the first iron core 41.
It is arranged so as to be separated from. Also, the second iron core 4
4 is fixed in a fixed position of the body 1 (see FIG. 10),
By tilting the upper end of the first iron core 41 toward the second iron core 44 with the lower end of the magnetic pole surface 44a as the center,
Can be closely attached to the magnetic pole surface 44a.
The body 1 is provided with a position regulating protrusion 1a. When the first iron core 41 is separated from the magnetic pole surface 44a, the position regulating protrusion 1a comes into contact with the upper end portion of the first iron core 41. Is regulated.

The bimetal 42 is inserted into the space surrounded by the first iron core 41 and the second iron core 44, and is arranged so as to face the first iron core 41. Similar to the conventional configuration, the bimetal 42 has a fixed end at the upper end in FIG. 1 and a free end at the lower end. Further, when an overcurrent passes through the energization circuit including the bimetal 42, the free end of the bimetal 42 is deformed so as to approach the first iron core 41. At the free end of the bimetal 42, a pusher 42a is provided as a pressing projection toward the first iron core 41. When the bimetal 42 is not deformed, the tip of the pusher 42a is separated from the first iron core 41. ing. A screw may be used as the pusher 42a, and when the screw is used, the protrusion size of the pusher 42a from the bimetal 42 can be adjusted, and the pusher 42a contacts the first iron core 41 when the bimetal 42 is deformed. It becomes possible to adjust the timing to do.

The holding spring 43 is arranged between the facing surfaces of the first iron core 41 and the bimetal 42, and one end of the holding spring 43 has the first iron core 41.
And the other end is fixed to the bimetal 42. Here, the first iron core 41 and the bimetal 42 and the holding spring 43 are fixed to each other by spot welding, or the dowels protruding from the first iron core 41 and the bimetal 42 are inserted into the holding spring 43 and caulked to fix them. To do.
The fixing part of the holding spring 43 to the bimetal 42 is the first
It is located above the fixing portion of the holding spring 43 to the iron core 41. This is because when the operating plate 33 is locked to the locking piece 41a and a downward load is applied from the operating plate 33 to the first iron core 41, this load acts as a tensile load on the holding spring 43. This is to allow it. That is,
Since the load acting from the opening / closing mechanism 3 on the first iron core 41 acts on the holding spring 43 as a tensile load, the holding spring 43 does not bend in the thickness direction, and as a result, the holding spring 4
As 3, it is possible to use one having a small spring constant. In addition, in the intermediate portion connecting the first iron core 41 and the bimetal 42 in the holding spring 43, both sides may be bent as necessary to provide the reinforcing piece 43a. By providing the reinforcing piece 43a, the holding spring 43 may be provided. Can be made more difficult to bend.

In the structure of this embodiment, however, when an overcurrent flows through the current-carrying circuit including the bimetal 42, the bimetal 4
The lower end of 2 bends toward the first iron core 41,
The lower end of the first iron core 41 is pushed by the 2a, so that the first iron core 41 moves to the second position around the position regulating protrusion 1a.
It rotates in a direction away from the iron core 44. Since the pressing force generated by the displacement of the free end of the bimetal 42 is transmitted to the first iron core 41 via the pusher 42a, the holding spring 43 is compared with the case where it is transmitted via the holding spring 43 as in the conventional configuration.
Therefore, the spring constant of the holding spring 43 can be reduced. Also,
When a short-circuit current passes through the bimetal 42, the first iron core 41
And the electromagnetic attraction force acting between the second iron core 44,
When the first iron core 41 rotates about the lower end of the magnetic pole surface 44a, the first iron core 41 is brought into close contact with the magnetic pole surface 44a. Thus, the center and position of rotation of the first iron core 41 change depending on whether overcurrent or short-circuit current passes through the bimetal 42. Approaching 33, the first when short-circuit current
The iron core 41 separates from the operating plate 33.

Therefore, in the present embodiment, as shown in FIG. 2, a through hole 33c is provided in an end portion of the operating plate 33 close to the first iron core 41, and the locking piece 41a of the first iron core 41 is cut and raised. I am doing it. In the locked state, the distal end surface of the locking piece 41a abuts between the end edge of the operating plate 33 and the through hole 33c, and the locking piece 41a can be inserted into the through hole 33c. There is. With this configuration,
When the first iron core 41 approaches the actuating plate 33 during overcurrent, the locked state shifts to a state in which the locking piece 41a is inserted into the through hole 33c, and during the short-circuit current, the first iron core 4 moves.
When 1 is separated from the operating plate 33, the locking state shifts to a state in which the locking piece 41a is disengaged from one end of the operating plate 33. In this way, the locked state can be released regardless of which direction the first iron core 41 moves. The contact angle is set so that the tip surface of the locking piece 41a and the contact surface of the operating plate 33 are in close contact with each other, and thus the locking piece 41 due to the load applied from the operating plate 33 to the locking piece 41a.
The deformation of “a” is suppressed, and the variation in operation sensitivity to overcurrent and short-circuit current is suppressed. Other configurations and operations are similar to the conventional configuration.

(Second Embodiment) This embodiment is shown in FIG.
As shown in FIG. 3, a hollow portion 33d is provided instead of the through hole 33c. The recess 33d is formed by denting the lower surface side of the operating plate 33 so that the tip of the locking piece 41a can be inserted, and substantially functions like the through hole 33c. However, when the locking piece 41a is inserted into the through hole 33c, the insertion dimension of the locking piece 41a into the through hole 33c becomes relatively large, whereas the recessed portion 33d has the locking piece 4a.
Since the insertion amount of 1a is regulated, it becomes easy to guide the locking piece 41a to the position where it is locked to the operating plate 33 in the operation of returning from the trip-free state described as the conventional configuration to the locked state. Other configurations and operations are similar to those of the first embodiment.

(Third Embodiment) This embodiment is shown in FIG.
As shown in FIG. 7, instead of providing the locking piece 41a on the first iron core 41, a rectangular insertion hole 41e is provided so as to penetrate, and locking projections 41g as locking portions are formed on both side edges of the insertion hole 41e. . On the other hand, a notch 33e is formed at one end of the operating plate 33 on both sides, and the notch 33e is formed so that the locking projection 41g can be inserted therein.

In this configuration, in the locked state, the locking projection 41 is provided at a portion between the end of the operating plate 33 and the notch 33e.
g is abutting, and when the first iron core 41 moves toward the operating plate 33, the locking projection 41g comes off to the notch 33e side, and when the first iron core moves away from the operating plate 33, the locking projection 41g. Will come off to the edge side of the operating plate 33. That is, as in the first embodiment, the first iron core 41
When moving so as to approach the operating plate 33,
In either case, the opening / closing mechanism 3 can be operated by releasing the locked state.

In the structure of this embodiment, since the locking piece 41a is not cut and raised, the locking piece 41a can be easily processed, and the end of the actuating plate 33 is inserted into the insertion hole 41e to operate. The movement range of the plate 33 is restricted, and stable operation can be expected. Other configurations and operations are similar to those of the first embodiment.

(Fourth Embodiment) In this embodiment, as shown in FIGS. 5 and 6, a concave groove 33f is formed at one end of the operating plate 33, and both inner side surfaces of the opening of the concave groove 33f are formed. The mounting projection 33g is provided on the first projection 33g.
In order to lock the iron core 41, the first iron core 41
A pair of locking projections 41h are provided on both side edges of the locking projections as locking parts. The width dimension of the recessed groove 33f is larger than the width dimension between both ends of the locking projection piece 41h.
The locking projection 41h can be inserted into a gap between the locking projection 41h and 3g.

In this structure, when the mounting projection 33g is in contact with the locking projection 41h in the locked state and the first iron core 41 moves due to overcurrent or short-circuit current, the first iron core 41 moves. Depending on the direction of movement, the locking projection 41
h is inserted from the mounting protrusion 33g into the concave groove 33f, and
It is disengaged to the 3f side, or the locking projection 41h is formed into the concave groove 33.
It exits from f and comes off to the edge side of the operating plate 33. That is, as in the first embodiment, the first iron core 41
When moving so as to approach the operating plate 33,
In either case, the opening / closing mechanism 3 can be operated by releasing the locked state.

Further, in the structure of this embodiment, instead of providing the presser 42a which is a separate member from the bimetal 42, the presser 42b is formed as a presser piece having the free end of the bimetal 42 bent, and this presser 42b is formed. The tip of the child 42b is brought into contact with the first iron core 41. Therefore, when the bimetal 42 bends due to overcurrent passing through the energization circuit, the first iron core 4
The pressing force directly acts on 1 to move the first iron core 41, and it is possible to operate it with high sensitivity.

As described above, in this embodiment, the locking protrusion 41h is used as the locking portion, and since the first iron core 41 has no hole, the magnetic resistance in the first iron core 41 is small. As a result, magnetic flux leakage is reduced, and as a result, a relatively large electromagnetic attraction force can be applied between the first iron core 41 and the second iron core 44.
If the volumes of the second iron core 44 and the second iron core 44 are similar to those of the other embodiments, the operation sensitivity can be increased. Moreover, the strength of the first iron core 41 is increased by the absence of holes in the first iron core 41. Other configurations and operations are similar to those of the first embodiment.

(Fifth Embodiment) In the fourth embodiment, the operating plate 33 is formed by punching out the concave groove 33f, but in the present embodiment, as shown in FIG. 7, the operating plate is formed. 33 is formed by a sheet metal, and a part of the sheet metal is bent to form the recessed groove 33f and the mounting projection 3
3 g have been formed.

That is, the latch plate 33 has a pair of arm pieces 33i extending in a direction intersecting the latch plate body 33h from both side edges of one end of the latch plate body 33h and connecting both ends of the latch plate body 33h. It is formed in a shape, and the portion surrounded by both arm pieces 33i and the latch plate body 33h functions as a groove 33f. Further, the tip ends of the arm pieces 33i are bent so that they approach each other, and the tip side of the bent portion is formed so as to function as the placement projection piece 33g.

This embodiment is the same as the fourth embodiment except that the latch plate 33 is formed by bending a metal plate. By adopting the configuration of this embodiment, the mounting plate 33g and the arm 33i are attached to the latch plate body 3
Since the dimension of 3h in the thickness direction can be made larger than that in the fourth embodiment, it is possible to suppress deformation of the latch plate 33 and reduce variations in operation sensitivity. Other configurations and operations are similar to those of the first embodiment.

(Sixth Embodiment) This embodiment is shown in FIG.
In the configuration of the fourth embodiment, as shown in FIG.
The upper end side of the magnetic pole surface 44a of the iron core 44 is in contact with the first iron core 41, and the lower end side of the magnetic pole surface 44a is separated from the first iron core 41. Further, the direction in which the bimetal 42 is deformed when the overcurrent passes through the energization circuit is set to the direction away from the first iron core 41, and between the bimetal 42 and the first iron core 41, when the bimetal 42 is deformed, A tension plate 46 for moving the first iron core 41 together with the bimetal 42 is added. The tension plate 46 is the first iron core 41.
The first metal core 41 is not connected to the first iron core 41 when the bimetal 42 is deformed.

In the present embodiment, however, the free end of the bimetal 42 causes the free end of the bimetal 42 to flow when the overcurrent flows through the energizing circuit.
Since the lower end portion of the first iron core 41 receives a tensile force from the bimetal 42 via the tension plate 46 at this time, the first iron core 41 moves away from the latch plate 33 with the position regulating projection 1a as a fulcrum. It will rotate in the direction. In addition, when a short-circuit current flows in the energizing circuit, the second
When the first iron core 41 is attracted to the magnetic pole surface 44a of the iron core 44, the first iron core 44 rotates in a direction away from the latch plate 33 with the position regulating projection 1a as a fulcrum. That is,
The first iron core 44 moves in the same direction regardless of whether it is an overcurrent or a short circuit current.

In the configuration of this embodiment, the first iron core 41 moves in a direction away from the actuation plate 33 in both cases of overcurrent and short circuit current. As the relationship with the plate 33, it is possible to adopt the same structure as the conventional structure, and the structure of this portion becomes simple as compared with the above-described respective embodiments. Other configurations and operations are similar to those of the first embodiment.

In each of the above-described embodiments, the working plate 33 is locked to the first iron core 41, and the working plate 33 is used.
However, depending on the configuration of the circuit breaker, a movable contact may be used as the latch plate instead of the actuation plate 33, and one end of the movable contact may be locked. . Further, although the example in which the pushers 42a and 42b are provided on the bimetal 42 is shown, the pushers 42a and 42b may be provided on the first iron core 41.

[0057]

According to the first aspect of the present invention, there is provided an opening / closing mechanism and a bimetal, one end of which is fixed at a fixed position to form a part of the energizing electric path, and the other end of which is displaced when an overcurrent flows through the energizing electric path. It is equipped with a locking part that is in a stopped state and is arranged facing the bimetal, and when the pressing force acting as the other end of the bimetal is displaced in the direction of decreasing the distance is transmitted, the locking state is achieved. The first iron core for releasing the first core and the one end of the pair of side pieces are integrally connected, and the first iron core is arranged so as to surround a part of the bimetal. A second iron core that is in contact with the other end and is separated from both side pieces, and a leaf spring having one end fixed to the bimetal and the first iron core so that the load received from the opening / closing mechanism on the first iron core acts as a tensile load. The first iron core is the part that is fixed to the bimetal. Of consists of a holding spring located bimetal fixed end nearer adhesions, first in spaced side between the first core and the second core when a large current flows to the conduction path 1
The contact is forcibly opened by attracting the iron core to the second iron core to release the locked state between the opening / closing mechanism and the locking portion. The load received by the first iron core from the opening / closing mechanism is a tensile load on the holding spring. Since the fixing portion of the bimetal and the holding spring is located closer to the fixed end of the bimetal than the fixing portion of the first iron core and the holding spring, the holding spring is bent by the load from the opening / closing mechanism. There is no need to use a holding spring having a spring constant that gives a restoring force to the bimetal or the first iron core, and as a result, the spring constant of the holding spring can be reduced. As a result, the electromagnetic attraction force between the first iron core and the second iron core can be reduced, and the volume of the first iron core and the second iron core can be reduced, leading to downsizing. Further, if the size is not reduced, the electromagnetic attraction force acting between the first iron core and the second iron core is increased, and the sensitivity can be increased.

According to a second aspect of the present invention, in the first aspect of the present invention, the locking portion is a locking piece formed by cutting and raising the first iron core, and the locking plate is provided at the end of the latch plate provided in the opening / closing mechanism. A through hole through which the locking piece can be inserted is provided, and in the locked state, the tip surface of the locking piece abuts between the end edge of the latch plate and the through hole,
When the locked state is released, one of the state in which the locking piece is disengaged from the edge of the latch plate and the state in which the locking piece is inserted into the through hole is selected. By adopting a configuration in which the moving direction of the first iron core and the moving direction of the first iron core when the first iron core is attracted to the second iron core by the accompanying moving direction of the first iron core are opposite to each other, it is possible to detect the overcurrent and the short-circuit current. It is possible to select a state in which the locking piece is inserted into the through hole and a state in which the locking piece is disengaged from the edge of the latch plate.

According to a third aspect of the present invention, in the first aspect of the present invention, the engaging portion is an engaging piece formed by cutting and raising the first iron core, and an end portion of the latch plate provided in the opening / closing mechanism is provided. A recessed portion through which the locking piece can be inserted is provided, and in the locked state, the tip end surface of the locking piece abuts between the end edge of the latch plate and the recessed portion,
When the locked state is released, one of the state in which the locking piece is disengaged from the edge of the latch plate and the state in which the locking piece is inserted into the recess is selected. By adopting a configuration in which the moving direction of the first iron core and the moving direction of the first iron core when the first iron core is attracted to the second iron core by the accompanying moving direction of the first iron core are opposite to each other, it is possible to detect the overcurrent and the short-circuit current. It is possible to select a state in which the locking piece is inserted into the recess portion and a state in which the locking piece is disengaged from the end edge side of the latch plate. Moreover, it is easier to return to the locked state when the locking piece is inserted into the recess than when the locking piece is inserted into the through hole.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the locking portion is a locking projection provided on the inner peripheral edge of the insertion hole penetrating the first iron core and provided in the opening / closing mechanism. At the end of the latch plate, a notch is formed in the side part that can be inserted into the insertion hole and into which the locking protrusion can be inserted.In the locked state, the locking protrusion is between the edge of the latch plate and the notch. When the contact state is released and the locking state is released, one of the state in which the locking protrusion is disengaged to the edge of the latch plate and the state in which the locking protrusion is disengaged to the cutout side is selected. If a configuration is adopted in which the moving direction of the first iron core and the moving direction of the first iron core when the first iron core is attracted to the second iron core due to the deformation of the The state where the locking projection comes off to the notch side and the state where the locking projection comes off to the edge side of the latch plate It is possible to select a. Moreover, since the end portion of the latch plate is inserted into the insertion hole, the movement direction of the end portion of the latch plate is restricted by the insertion hole, and stable operation can be expected.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the engaging portion is an engaging protrusion projecting from both side edges of the first iron core, and the engaging portion is provided at the end of the latch plate provided in the opening / closing mechanism. Is formed with a concave groove into which the first iron core can be inserted, and mounting projections that can contact the locking projections are formed on both inner side surfaces of the opening of the concave groove. When the piece comes into contact with the locking projection and the locked state is released, the locking projection retreats from the groove and comes off the mounting projection, and the locking projection is inserted into the groove and mounted. One of the state in which the first core moves away from the projecting piece is selected, and the first core moves when the first core is attracted to the second core due to the moving direction of the first core due to the deformation of the bimetal due to overcurrent and the short-circuit current. By adopting a configuration in which the moving direction of is opposite to that of the mounting projection, the locking projection will retreat from the concave groove at the time of overcurrent and short-circuit current. Disengaged state and the engaging protrusion is possible to select and which deviates from 置突 piece mounting is inserted in the groove. Moreover, since the locking projections are provided on both side edges of the first core, no holes are formed in the first core, and as a result, the magnetic resistance and the magnetic leakage can be reduced. The electromagnetic attraction force acting between the first iron core and the second iron core can be increased.

According to a sixth aspect of the present invention, in the invention of the fifth aspect, the latch plate is a metal plate, and a direction intersecting the latch plate body from both side edges of one end portion of the latch plate body and connecting both end portions of the latch plate body. A pair of arm pieces that are extended to each other, the groove is surrounded by the latch plate body and both arm pieces, and the mounting projection piece is formed by bending the tip ends of the arm pieces toward each other. Since the arm piece is bent in the direction intersecting with the latch plate body, the arm piece and the mounting projection piece can have a large dimension in the direction in which the load acts, and the arm piece and the mounting projection piece can be mounted in a locked state. It is possible to suppress the deformation of the projecting piece and the arm piece, and to reduce the variation in operation sensitivity.

According to a seventh aspect of the present invention, in the first to sixth aspects of the present invention, since a pusher for transmitting the pressing force generated by the displacement of the other end of the bimetal to the first iron core, the bimetal is deformed. The pressing force can be directly transmitted to the first iron core, and the spring constant of the holding spring can be reduced as compared with the case where the pressing force is transmitted via the holding spring. As a result, the electromagnetic attraction force acting between the first iron core and the second iron core is hardly reduced by the holding spring, and if the sensitivity is the same, the trip device can be downsized.
If the size is the same, the sensitivity of the trip device can be increased.

According to the invention of claim 8, in the invention of claim 7, since the pusher is a pressing protrusion fixed to one of the other end of the bimetal and the first iron core, the pressing protrusion is By adjusting the protrusion size of the portion, it is possible to adjust the amount of deformation of the bimetal required to release the locked state between the first iron core and the opening / closing mechanism, and it is possible to adjust the sensitivity of the trip device.

According to a ninth aspect of the invention, in the invention of the seventh aspect, since the pusher is a push piece formed by bending at least one of the other end of the bimetal and the end of the first iron core, a separate member is provided. The pusher can be configured without using it, and there is an advantage that material cost and processing cost are low.

According to a tenth aspect of the invention, one end is fixed to a fixed position to form a part of the energizing electric path, and the other end is displaced when an overcurrent flows in the energizing electric path. Of the pair of side pieces and a first iron core that is integrally provided with a locking portion and that is arranged to face the bimetal and that releases the locked state when the tensile force accompanying the displacement of the other end of the bimetal is transmitted. A second iron core having a shape in which one ends thereof are integrally connected and arranged so as to surround a part of the bimetal together with the first iron core, and one end side of the first iron core abuts on both side pieces and the other end side is separated from both side pieces; , A tension plate for transmitting the displacement of the other end of the bimetal to the first iron core, and a leaf spring having one end fixed to the bimetal and the first iron core, wherein the load received from the opening / closing mechanism on the first iron core is a tensile load. Solid with bimetal to act as The part is composed of a holding spring located closer to the fixed end of the bimetal than the part fixed to the first iron core, and the first iron core on the side where the first iron core and the second iron core are separated from each other when a large current flows in the current-carrying circuit. The contact is forcibly opened by attracting to the second iron core to release the locked state between the opening / closing mechanism and the locking portion, and the load received by the first iron core from the opening / closing mechanism is applied to the holding spring as a tensile load. Since the fixing portion of the bimetal and the holding spring is positioned closer to the fixed end of the bimetal than the fixing portion of the first iron core and the holding spring so that the holding spring may be bent by the load from the opening / closing mechanism. Instead, a holding spring having a spring constant that gives a restoring force to the bimetal or the first iron core may be used.
As a result, the spring constant of the holding spring can be reduced. As a result, the electromagnetic attraction force between the first iron core and the second iron core can be reduced, and the volume of the first iron core and the second iron core can be reduced, leading to downsizing. Further, if the size is not reduced, the electromagnetic attraction force acting between the first iron core and the second iron core is increased, and the sensitivity can be increased.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view of the above.

3A and 3B show a second embodiment of the present invention, in which FIG. 3A is a perspective view of an essential part, and FIG.

FIG. 4 is a partially cutaway perspective view showing a third embodiment of the present invention.

FIG. 5 is a perspective view showing a fourth embodiment of the present invention.

FIG. 6 is a partially cutaway perspective view of the above.

FIG. 7 is a perspective view showing an operating plate used in a fifth embodiment of the present invention.

FIG. 8 is a perspective view showing a sixth embodiment of the present invention.

FIG. 9 is a perspective view showing a conventional configuration.

FIG. 10 is a side view showing the closed state of the circuit breaker with the body opened.

FIG. 11 is a side view showing the opened state of the circuit breaker showing an open state due to overcurrent.

[Explanation of symbols]

1 body 2a, 2b contact 3 open / close mechanism 4 Tripping device 33 Actuation plate 33c through hole 33d depression 33e Notch 33f groove 33g mounting protrusion 33h Latch plate body 33i arm piece 41 No. 1 iron core 41a locking piece 41e insertion hole 41g locking protrusion 41h locking protrusion 42 bimetal 42a pusher 42b pusher 43 Holding spring 44 No. 2 iron core 44a Magnetic pole surface 45 mounting spring 46 Tension plate

Claims (10)

[Claims] 1. A contact inserted into an energizing electric path between a power source and a load, and a force in a direction for opening the contact when the contact is closed to store a force to bring the contact into a locked state and the locked state is released. Used in a circuit breaker equipped with an opening and closing mechanism that forcibly opens contacts by force, when the contact is closed and a large current flows into the energizing circuit, the locked state is released and the contacts are forcibly opened. A tripping device, in which one end is fixed at a fixed position to form a part of the energizing circuit and the other end is displaced when an overcurrent flows in the energizing circuit; When the pressing force acting as the other end of the bimetal is displaced in the direction of reducing the distance is transmitted, the locking state is integrally provided. The first iron core to be released and one end of the pair of side pieces are integrated A second iron core having a shape connected to the first iron core and surrounding the part of the bimetal together with the first iron core, wherein one end side of the first iron core abuts on both side pieces and the other end side is separated from both side pieces; A leaf spring having one end fixed to the first iron core, and a portion fixed to the bimetal is more bimetallic than a portion fixed to the first iron core so that a load applied to the first iron core from the opening / closing mechanism acts as a tensile load. And a holding spring located near the fixed end of the first core, and when a large current flows in the energizing circuit, the first core is attracted to the second core on the side of separation between the first core and the second core to engage with the opening / closing mechanism. A trip device for a circuit breaker, characterized in that a contact is forcibly opened by releasing a locked state with a stop portion. 2. The locking portion is a locking piece formed by cutting and raising the first iron core, and the locking piece can be inserted into an end portion of a latch plate provided in the opening / closing mechanism. When the locking hole is formed, the leading end surface of the locking piece abuts between the end edge of the latch plate and the through hole in the locked state, and when the locked state is released, the locking piece moves toward the edge side of the latch plate. 2. The trip device for a circuit breaker according to claim 1, wherein one of a state in which the locking piece is disengaged and a state in which the locking piece is inserted into the through hole is selected. 3. The engaging portion is an engaging piece formed by cutting and raising the first iron core, and a recess into which the engaging piece can be inserted at an end of a latch plate provided in the opening / closing mechanism. When the locking state is released, when the locking state is released, the leading end surface of the locking piece abuts between the edge of the latch plate and the recess. 2. The trip device for a circuit breaker according to claim 1, wherein one of a state in which the locking piece is disengaged and a state in which the locking piece is inserted in the recess is selected. 4. The locking portion is a locking projection protruding from an inner peripheral edge of an insertion hole penetrating the first iron core, and an end portion of a latch plate provided in the opening / closing mechanism is inserted into the insertion hole. A notch is formed on the side that can be inserted and the locking projection can be inserted,
In the locked state, the locking projection abuts between the edge of the latch plate and the notch, and when the locked state is released, the locking projection is disengaged from the edge of the latch plate and the locking projection is notched. 2. The trip device for a circuit breaker according to claim 1, wherein one of a state of being detached to the side of the part is selected. 5. The locking portion is a locking projection piece provided on both side edges of the first iron core, and the first iron core can be inserted into an end portion of a latch plate provided in the opening / closing mechanism. The concave groove is formed, and the mounting projections capable of contacting the locking projections are formed on both inner side surfaces of the opening of the concave groove, and the mounting projections contact the locking projections in the locked state. When contacting and releasing the locked state, there are a state in which the locking projection retreats from the groove and disengages from the mounting projection, and a state in which the locking projection is inserted into the groove and disengages from the mounting projection. The trip device for a circuit breaker according to claim 1, wherein one of them is selected. 6. The latch plate is a metal plate, and has a pair of arm pieces extending in a direction intersecting the latch plate body from both side edges of one end of the latch plate body and connecting both ends of the latch plate body. 6. The recessed groove is surrounded by the latch plate body and both arm pieces, and the placing projection piece is formed by bending the leading end portions of the arm pieces toward each other. The trip device for the circuit breaker described. 7. The presser for transmitting a pressing force generated by the displacement of the other end of the bimetal to the first iron core, according to any one of claims 1 to 6. Circuit breaker trip device. 8. The trip of the circuit breaker according to claim 7, wherein the pusher is a pressing projection fixed to one of the other end of the bimetal and the first iron core. apparatus. 9. The circuit breaker according to claim 7, wherein the pusher is a push piece formed by bending at least one of the other end of the bimetal and the end of the first iron core. Tripping device. 10. A contact inserted into an energizing electric path between a power source and a load, and a force in a direction for opening the contact when the contact is closed to store the contact and release the unlocked state. Used in a circuit breaker equipped with an opening and closing mechanism that forcibly opens contacts by force, when the contact is closed and a large current flows into the energizing circuit, the locked state is released and the contacts are forcibly opened. A tripping device, in which one end is fixed at a fixed position to form a part of the energizing circuit and the other end is displaced when an overcurrent flows in the energizing circuit; A locking portion that is integrally provided and that is disposed so as to face the bimetal, and that releases the locked state when a tensile force accompanying the displacement of the other end of the bimetal is transmitted.
The iron core and one end of a pair of side pieces are integrally connected, and are arranged so as to surround a part of the bimetal together with the first iron core. One end side of the first iron core abuts on both side pieces and the other end side A second iron core separated from both side pieces, a tension plate for transmitting the displacement of the other end of the bimetal to the first iron core, and a leaf spring having one end fixed to the bimetal and the first iron core. So that the load applied to the first iron core from the first core acts as a tensile load, the part fixed to the bimetal is composed of a holding spring located closer to the fixed end of the bimetal than the part fixed to the first core, and a large current is applied to the energizing circuit. Forcibly opening the contacts by attracting the first iron core to the second iron core on the side where the first iron core and the second iron core are separated when flowing, and releasing the locked state between the opening / closing mechanism and the locking portion. A device for tripping a circuit breaker.