JP3374699B2 - 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, and more particularly to improvement of its opening / closing mechanism.

[0002]

2. Description of the Related Art FIG. 8 is a front sectional view showing a conventional circuit breaker disclosed in, for example, Japanese Patent Laid-Open No. 1-56493, showing a closed state. 9 is a front sectional view showing the circuit breaker of FIG. 8 in an open circuit state, FIG. 10 is a front sectional view showing the circuit breaker of FIG. 8 at the moment of trip operation, and FIG. 11 is a diagram. 8 is a front sectional view showing a state in which the contacts of the circuit breaker of FIG. 8 are in a welded state.

In FIG. 8, reference numeral 1 denotes a base, which is made of synthetic resin. 2 is a shaft 1a protruding from the base 1
The handle is rotatably supported around the. Reference numeral 3 denotes a torsion spring mounted on the shaft 1a, one end of which is engaged with the base 1 and the other end of which is engaged with the handle 2 to bias the handle 2 in the counterclockwise direction. Reference numeral 4 denotes a U-shaped connecting pin, one leg of which is rotatably inserted into a through hole 2b provided in a protrusion 2a protruding from the handle 2.

Reference numeral 5 is a movable contactor, which is rotatably supported by a shaft 6 fixed to the base 1 and has a pair of first and second latch surfaces 5a and 5a at one of the rotating end portions. 5b, and the movable contact 5c is fixed to the other end. Reference numeral 7 is a locking lever having a locking portion 7a, which is rotatably supported by the shaft 6 like the movable contact 5 and is biased by the twist spring 8 wound around the shaft 6 Always biased in the opposite direction. Reference numeral 9 denotes a roller, which is rotatably inserted into the other leg portion of the connecting pin 4 and is normally held between the first latch surface 5a and the second latch surface 5b and the locking portion 7a.

Reference numeral 12 is a first spring hook shaft fixed to the movable contactor 5, 13 is a second spring hook shaft fixed to the base 1, and 14 is the first spring hook shaft 12 and the second spring hook shaft 1.
It is a tension spring stretched between 3 and 3. Reference numeral 15 is a fixed contact fixed to the base 1, and a fixed contact 15a is fixed so as to face the movable contact 5c. Reference numeral 16 is an electromagnetic tripping device, 17 is a yoke attached to the base 1 to form a magnetic path of the electromagnetic tripping device 16, and 18 is an electromagnetic coil. One end of the electromagnetic coil 18 is the fixed contact 1
5, the other end is electrically connected to the load side terminal 19.

20 is a wire retainer, 21 is a terminal screw,
An external conductor (not shown) is connected to the load side terminal 19. Reference numeral 22 denotes a plunger that is attracted to the left in the figure against the biasing force of the push spring 23 when the electromagnetic coil 18 is excited, and 24 is a rod that is driven to the left when the plunger 22 is attracted. is there. Reference numeral 29 denotes a flexible conductor, one end of which is electrically connected to the movable contact 5 and the other end of which is electrically connected to the bimetal 30. Reference numeral 31 is a power supply side terminal electrically connected to the bimetal 30, and is used to connect an external conductor (not shown) by a wire retainer 32 and a terminal screw 33. Reference numeral 34 is an arc extinguishing device that extinguishes the arc generated between the contacts 5c and 15a.

In such a conventional circuit breaker,
In both the circuit-breaker closed state shown in FIG. 8 and the circuit-breaker opened state shown in FIG. 9, the roller 9 includes the first latch surface 5a and the second latch surface 5 of the movable contact 5.
The connecting pin 4 is locked by being sandwiched between b and the locking portion 7a of the locking lever 7. When the handle 2 is turned on in the clockwise direction from the open state of the circuit breaker shown in FIG. 9, the toggle link mechanism formed by the protrusion 2a of the handle 2 and the connecting pin 4 extends beyond the dead point, and the movable contact is made. The child 5 rotates counterclockwise around the shaft 6 to move the movable contact 5c.
Comes into contact with the fixed contact 15a, and the circuit is closed as shown in FIG.

Next, when the handle 2 is turned OFF counterclockwise from the closed state of the circuit breaker shown in FIG. 8, the toggle link mechanism formed by the projection 2a of the handle 2 and the connecting pin 4 will reach a dead point. It bends over and the movable contact 5 rotates clockwise around the shaft 6, the movable contact 5c is separated from the fixed contact 15a, and the open state shown in FIG. 9 is established.

Next, in the closed state of the circuit breaker shown in FIG. 8, when an overcurrent flows in the electric circuit, the bimetal 3
The free end 30a of 0 is curved and one end 7b of the locking lever 7 is bent.
, Or the plunger 22 is actuated to press the other end 7c of the locking lever 7 with the rod 24 to rotate the locking lever 7 clockwise about the shaft 6,
Is clamped between the first latch surface 5a and the second latch surface 5b of the movable contact 5 and the locking portion 7a of the locking lever 7 is released. When the roller 9 is released, the connection pin 4 is unlocked, the movable contact 5 is rotated clockwise about the shaft 6 by the urging force of the pulling spring 14, and the movable contact 5c is separated from the fixed contact 15a. Then, the trip instantaneous state as shown in FIG. 10 is obtained.

After that, the handle 2 is rotated counterclockwise by the biasing force of the torsion spring 3, and the roller 9 causes the first latch surface 5a and the second latch surface 5b and the locking portion 7a of the locking lever 7 to rotate. Between the first latch surface 5 and the roller 9
a and the second latch surface 5b and the locking portion 7a, the connecting pin 4 is locked, the handle 2 moves to a position similar to the open state shown in FIG. 9, and is automatically reset. It is something.

In the circuit breaker as described above, when the circuit breaker shown in FIG. 8 is in the closed state, an abnormal current flows and the movable contact 5c is welded to the fixed contact 15a and cannot be opened. When the above-mentioned overcurrent tripping operation is performed in this state, the pinching of the roller 9 is released and the connecting pin 4 is released.
Is released, and the toggle link mechanism formed by the projection 2a of the handle 2 and the connecting pin 4 is bent by the turning force of the handle 2 in the counterclockwise direction to bend beyond the dead point and lock. The lever 7 is rotated clockwise about the shaft 6, and the position of the handle 2 is almost the same as the OFF position, as shown in FIG.

Further, even when the OFF operation by the handle 2 is performed in a state where the movable contact 5c and the fixed contact 15a are welded, the toggle link mechanism similarly formed by the protrusion 2a of the handle 2 and the connecting pin 4 is formed. Bend beyond the dead point from the extended state, and the locking lever 7
The center of the handle 2 is rotated clockwise, and the handle 2 is at almost the same position as the OFF position, as shown in FIG.

[0013]

In the conventional circuit breaker as described above, even when the circuit breaker trips due to an overcurrent flowing in the electric path and the bimetal 30 or the electromagnetic tripping device 16 is activated, the trip occurs. Since the handle 2 is automatically reset later, the handle 2
The position of is the same as that of the open state, and it is difficult to identify which of the multiple electrical circuits the circuit breaker has tripped when the circuit is checked after the trip, and it takes time to check. There was a problem.

Further, even when the movable contact 5c and the fixed contact 15a are welded together due to an abnormal current or the like, the handle 2 is located at substantially the same position as the OFF position, and therefore the appearance is as if the circuit breaker is in an open state, that is, both contacts. 5c, 15
There is a problem that it may be misidentified as if a is in a separated state.

Further, even if the handle is reset while the movable contact 5c and the fixed contact 15a are welded by an abnormal current or the like, the separating force cannot be applied between the movable contact 5c and the fixed contact 16. Therefore, the movable contact 5c cannot be separated from the fixed contact 15a even if it is slightly welded so that it can be reused.
There is also a problem that the circuit breaker cannot be used.

The present invention has been made to solve the above problems, and after the trip due to overcurrent or the like, the handle 2 is stopped at a trip position which is an intermediate position between the ON position and the OFF position, and the circuit In addition to displaying that the circuit breaker is in a trip state, if the movable contact 5c and the fixed contact 15a are welded, the handle 2 is stopped at the ON position and both contacts 5c and 15a are in a conductive state. The purpose is to obtain a circuit breaker that can be displayed.

Further, even when the movable contact 5c and the fixed contact 15a are welded to each other due to an overcurrent or the like, the OF
To obtain a circuit breaker capable of returning to a reusable state by causing the movable contact 5c to be separated from the fixed contact 15a in the case of slight welding by applying an opening force between the contacts by the F operation and causing slight welding. With the goal.

[0018]

In the circuit breaker according to the present invention, an insulating casing including a base and a cover, and a handle disposed inside the insulating casing and capable of being turned on and off from the outside are provided. A fixed contact mounted on the base of the insulating housing, a movable contact facing the fixed contact and moving away from the fixed contact, a crossbar driving the movable contact, and an arm engaging with the crossbar. A circuit provided with a handle arm having one end engaged with the arm and the other end engaged with the handle to form a toggle link mechanism, and an overcurrent trip device that operates the toggle link mechanism in response to an overcurrent. A circuit breaker, a guide plate pivotally supported by the handle, a handle spring that engages with the guide plate and the handle, and always biases the guide plate and the handle to a predetermined relational position,
And a connecting pin having one end rotatably supported by the guide plate and the other end rotatably supported by the crossbar.

Further, a leakage trip device is provided for operating the toggle link mechanism in response to the unbalanced current.

Further, a guide plate pivotally supported by the handle, a handle spring which engages with the guide plate and the handle and always urges the guide plate and the handle to a predetermined relational position, and one end of which is rotatable with respect to the guide plate. A connecting pin that is pivotally supported on the other end and is rotatably supported by the crossbar on the other end, is provided on the other pole of the back surface of the base that is adjacent to the opening / closing mechanism part that is disposed on the front surface of the base. .

Furthermore, a protrusion is formed on the end surface of the handle, and the protrusion engages with the guide plate when the handle is turned in the OFF operation direction, so that the movable contact can move through the connecting pin and the crossbar. The contact is separated from the fixed contact of the fixed contact.

[0022]

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1. FIG. 1 is a front sectional view showing the inside by cutting out a part of a circuit breaker according to an embodiment of the present invention, in which the circuit breaker shows a closed state. 2 is a front sectional view showing the circuit breaker of FIG. 1 in an open state, FIG. 3 is a front sectional view showing the circuit breaker of FIG. 1 in a trip state, and FIG. 4 is a circuit breaker of FIG. FIG. 6 is a front cross-sectional view showing a state where the contacts of the container are welded and the opening / closing mechanism trips. 5 is a rear sectional view showing the circuit breaker of FIG. 1 in a closed state, FIG. 6 is a rear sectional view showing the circuit breaker of FIG. 1 in an open state, and FIG. 7 is a circuit breaker of FIG. FIG. 7 is a rear cross-sectional view showing a case where the container is in a trip state.

1 to 4, 40 is a first cover, 41 is a base, and 42 is a second cover (shown in FIG. 5).
And both are made of synthetic resin. Reference numeral 43 is an insulating housing composed of the first cover 40, the base 41, and the second cover 42. Reference numeral 44 is a fixed contact, 45 is a fixed contact fixed to the fixed contact 44, and 46 is a movable contact having a movable contact 47 that faces the fixed contact 45 and separates from it.

Reference numeral 48 denotes a crossbar made of synthetic resin, one end of which is rotatably supported by a shaft 71 described later and holds one end of each movable contactor 46 arranged in parallel on all poles. . 49 is a contact pressure spring which is interposed between the movable contact 46 and the crossbar 48 to constantly urge the movable contact 46 toward the fixed contact 45, and 50 is a cross which urges the crossbar 48 clockwise. It is Verbane. Reference numeral 51 is a flexible conductor, one end of which is connected to the movable contactor 46 and the other end of which is a free end 6 of a bimetal 62 of an overcurrent trip device 60 described later.
2a. Reference numeral 52 is an arc extinguishing device that extinguishes the arc generated between the contacts 45 and 47.

Reference numeral 60 is an overcurrent trip device. Reference numeral 61 denotes a power supply side terminal formed by bending a conductive material such as copper or copper alloy, and includes a horizontal terminal portion 61a and a vertical terminal portion 61.
b, an inclined terminal portion 61c, and a hanging terminal portion 61d that hangs from the root of the inclined terminal portion 61c, and is inserted into the groove 41a of the base 41. Reference numeral 62 denotes a flat bimetal, one end of which is an inclined terminal portion 61 of the power supply side terminal 61.
It is welded to c. Reference numeral 63 is a fixed iron piece, which is formed by bending a magnetic material such as an iron plate into a U-shape,
3a is disposed between the vertical terminal portion 61b of the power supply side terminal 61 and the depending terminal portion 61d.

Reference numeral 64 denotes a movable iron piece disposed so as to face the fixed iron piece 63, which is formed of a magnetic material such as an iron plate and has a central portion rotatably supported by a shaft 65 held by a frame 70 described later. Has been done. Reference numeral 66 is an adjusting screw screwed to the fixed iron piece 63, which acts on the vertical terminal portion 61b of the power source side terminal 61 to deform the base of the inclined terminal portion 61c, and the free end 62a of the bimetal 62 and a locking lever described later. 1st of 72
The gap G with the engaging piece 72a of is adjusted.

Reference numeral 69 is an opening / closing mechanism. Reference numeral 70 denotes a frame that supports the opening / closing mechanism portion 69, and a part of the frame 70 is cut away, but is supported by a shaft 65 and a shaft 92 mounted between the base 41 and the first cover 40. . 72
Is a locking lever, and the free end 62a of the bimetal 62 is engaged at one end thereof with the first engaging piece 7 when bent in the direction of the arrow.
2a, an L-shaped second engaging piece 72b that engages with a roller 79, which will be described later, and a third engaging piece 72c with which a trip bar 92, which will be described later, engages are formed on the other end of the shaft 65. It is pivotally supported.

Reference numeral 73 denotes an arm, which is formed with a guide groove 73a for guiding a roller pin 75 pivotally supported by a handle arm 74, which will be described later, and a pressing portion 73b for pressing the protruding portion 48a of the crossbar 48, which is rotated around the shaft 65. It is rotatably supported. A handle arm 74 is engaged with the guide groove 73a via a roller pin 75 pivotally supported at one end. Reference numeral 76 denotes a handle made of synthetic resin, which has a first protrusion 76a protruding from the outer peripheral surface, a second protrusion 76b protruding from the end surface, and a third protrusion 76c protruding from the end surface of the back surface portion. It is provided inside the insulating housing 43 and can be turned on and off from the outside.
It is interlocked with the handle arm 74 via a shaft 77 fitted in 6a. Reference numeral 78 denotes a handle shaft that is axially fixed to the frame 70, and rotatably supports the handle 76.
Reference numeral 79 is a roller, which is rotatably attached to a roller pin 75 attached to the handle arm 74.

Reference numeral 80 designates a fixed contact 44 to a load side terminal 81.
Reference numeral 82 is a zero-phase current transformer through which the conductor 80 penetrates to detect an unbalanced current in the electric path. Reference numeral 83 denotes a control circuit unit that controls a secondary current proportional to the current detected by the zero-phase current transformer 82, and is composed of electronic components such as resistors, capacitors and ICs mounted on the board.
Reference numeral 84 denotes an earth leakage trip device, which includes an electromagnet portion 87, a plunger 88, and an upper end surface 41a of the base 41 during an earth leakage operation.
It is composed of a trip display button 89 that projects from the display and indicates that the leakage operation has been performed, a display button spring 90 that urges the trip display button 89 in a direction to project, and the like.

Reference numeral 91 denotes a trip lever, which is a plunger engaging portion 91a that abuts against the tip of the plunger 88, and a latch portion 89 formed at one end of the trip display button 89.
It is formed by a latch engagement portion 91b that engages with a and a lever engagement portion 91c that engages with the third engagement piece 72c of the locking lever 72, and is rotatably supported by a shaft 92. . 9
Reference numeral 3 denotes a trip lever spring mounted on the shaft 92, which constantly biases the trip lever 91 counterclockwise.

The base 41 of the circuit breaker shown in FIGS.
On the back side of the above, terminals of the other pole adjacent to the opening / closing mechanism section 69 on the front side, a current-carrying member including an overcurrent trip device and the like, and a display auxiliary member are configured. In the figure, 44-
Reference numerals 52, 60 to 66, 80, 81 are the same as those shown in FIG. 1, and the description thereof will be omitted.

Reference numeral 95 is a guide plate pivotally supported by the handle 76, and 96 is a handle which engages between the guide plate 95 and the handle 76 and urges the guide plate 95 and the handle 76 to always hold them in a predetermined relational position. Spring, 9
Reference numeral 7 is a U-shaped connecting pin that rotatably connects the guide plate 95 and the crossbar 48. Guide plate 9
5, the handle spring 96 and the connecting pin 97 are insulated from the opening / closing mechanism portion 69 on the front surface by the pole spacing wall 41b of the base 41.

The guide plate 95, the handle spring 96, and the connecting pin 97 are directly engaged with one end of an insulating member such as the handle 76 and the crossbar 48. Reference numeral 98 is a trip bar, which has a free end 6 of the bimetal 62 at one end.
A first protrusion 98a that engages when the 2a is bent and a second protrusion 98b that protrudes to the front surface shown in FIG. ing.

Next, the operation will be described. When the handle 76 is turned off in the clockwise direction while the circuit breaker shown in FIG. 1 is closed, the toggle link mechanism formed by the protrusion 76a of the handle 76, the handle arm 74, and the shaft 77 bends beyond the dead point. Then, the urging force of the crossbar spring 50 causes the crossbar 48 to rotate clockwise about the shaft 71, so that the movable contact 47 of the movable contactor 46 held by the crossbar 48 is fixed as shown in FIG. Four
5, the end surface 7 of the frame 70 is rotated further.
0a and the end surface 48b of the crossbar 48 are brought into contact with each other, and the contact opening operation is completed.

Next, in the closed state of FIG. 1, when an overcurrent flows in the electric path, the free end 62a of the bimetal 62 bends in the direction of the arrow to press the first engaging piece 72a of the locking lever 72. Alternatively, when the movable iron piece 64 is attracted to the fixed iron piece 63, the lower end portion 64a of the movable iron piece 64 is moved to the trip bar 9
When the first engagement piece 72a is pressed through the second protrusion 98b of No. 8, the locking lever 72 rotates counterclockwise about the shaft 65, and the second contact between the roller 79 and the second locking lever 72. The engagement with the engagement piece 72b is released.

When the handle arm 74 is disengaged, the crossbar 48 is rotated clockwise about the shaft 71 by the urging force of the crossbar spring 50 as shown in FIG. The contact 47 is separated from the fixed contact 45,
Further rotation, it stops at the position where the end surface 70a of the frame 70 and the end surface 48b of the crossbar 48 contact, and the contact opening operation is completed.

At this time, at the other poles adjacent to each other shown in FIG. 7, the handle 76 is urged by the handle spring 96 so as to be always held in the same relation position with the guide plate 95, so that it is connected to the crossbar 48. Interlocked with the movement of the guide plate 95 of the link mechanism constituted by the pin 97 and the guide plate 95, the handle spring 96 rotates in the OFF position direction by the urging force of the handle spring 96 to turn it on as shown in FIGS. 7 and 3. Stops at the trip position, which is an intermediate position between OFF and OFF, and indicates that the circuit breaker has tripped.

In the circuit breaker as described above, when the circuit breaker shown in FIG. 1 is in the closed state, an abnormal current flows and the movable contact 47 is welded to the fixed contact 45 and cannot be opened. In this state, when the above-mentioned overcurrent trip operation is performed, that is, the bimetal 62 or the movable iron piece 6
4 operates, the locking lever 72 rotates counterclockwise around the shaft 65, and the roller 79 and the second locking lever 72 are rotated.
The engagement with the engaging piece 72b is released.

As a result, the engagement between the locking lever 72 and the handle arm 74 is released, and the cross bar 48 tries to rotate clockwise about the shaft 71 by the urging force of the cross bar spring 50. Since the contacts 45 and 47 are in the welded state, the movable contact 46 prevents the opening operation of the crossbar 48, and the crossbar 48 is maintained in the closed position as shown in FIG.

Therefore, the connecting pin 97 and the guide plate 95, which are formed on the adjacent poles and interlock with the crossbar 48, are also kept in the closed position similar to that shown in FIG.
6 is turned on as shown in FIG. 4 by the urging force of the handle spring 96.
Holds in position to indicate that the contacts are in conduction.

When the contact points 45, 47 are in a slightly welded state, the handle 76 is turned off,
As shown in FIG. 6, the third protrusion 7 on the handle 76 is
6 bc contacts the end surface 95a of the guide plate 95,
Guide plate 95, connecting pin 97, cross bar 4
8, the movable contact 46 is actuated to open, the movable contact 47 is opened from the fixed contact 45, and the contact is opened. After the reset operation of the handle 76, the circuit breaker is opened.

Next, the operation of the earth leakage trip device 84 will be described. When the circuit breaker shown in FIG. 1 is in the closed state and an unbalanced current flows in the circuit, a secondary current signal proportional to the current detected by the zero-phase current transformer 82 is sent to the control circuit section 83, and this control circuit section is sent. Reference numeral 83 excites the electromagnetic coil 87 in the earth leakage trip device 84 when the value of the secondary current exceeds a predetermined value.

When the plunger 88 is attracted in the direction of the arrow by the excitation of the electromagnetic coil 87, the tip end of the plunger 88 rotates the trip lever 91 clockwise around the shaft 92, and at the same time, the lever of the trip lever 91 is rotated. The third engaging piece 72c of the locking lever 72 is pressed by the engaging portion 91c, and the roller 79 and the second engaging piece 72b of the locking lever 72 are pressed.
Is disengaged and the opening / closing mechanism section 6 is released in the same manner as shown in FIG.
9 is tripped.

At the same time, the latch portion 89a formed at one end of the trip display button 89 and the trip lever 91
FIG. 3 shows a latch mechanism configured with the latch engagement portion 91b of FIG.
When the display button 89 is released as shown by the alternate long and short dash line in FIG.
The urging force of 0 projects from the upper end surface 41a of the base 41 to indicate that the electric leakage has occurred.

Next, when the handle 76 is rotated clockwise (in FIG. 1) and the reset operation is performed after eliminating the cause of the electric leakage accident, the second operation of the handle 76 is performed in parallel with the reset operation of the opening / closing mechanism section 69. The protruding portion 76b is the display button 8
9, the receiving portion 89b is pressed to lower the display button 89 against the biasing force of the display button spring 90, and the latch engagement portion 91b of the trip lever 91 and the latch portion 89a of the display button 89 move to the trip lever spring 93 and The urging force of the display button spring 90 brings the circuit into the engaged state again, completes the reset operation, and brings the circuit breaker into the open circuit state shown in FIG.

According to the embodiment of the present invention, the guide plate 95 pivotally supported by the handle 76 and the guide plate 95 engaged with the guide plate 95 and the handle 76 are provided.
And a handle spring 96 that constantly urges the handle 76 to a predetermined relational position, and a connecting pin 97 whose one end is rotatably supported by the guide plate 95 and the other end is rotatably supported by the crossbar 48. If the circuit breaker trips due to overcurrent, the handle 76 is stopped at the trip position which is an intermediate position between the ON position and the OFF position, and the fact that the circuit breaker has tripped is displayed. This makes it easier to check the circuit after tripping. Further, when an abnormality such as contact welding occurs, the handle 76 is held at the ON position, and it can be displayed that the movable contact 47 and the fixed contact 45 are in the conductive state, so that the display of contact welding becomes clear.

Further, the guide plate 95, the handle spring 96 and the connecting pin 97 are connected to the other pole adjacent to the opening / closing mechanism portion 69 arranged on the front surface of the base 41, that is, the rear surface of the base 41 of the insulating housing 43. Since they are provided in the base 41, they can be easily insulated from the opening / closing mechanism 68 by the pole spacing wall 41b of the base 41, and they are directly engaged with one end of an insulating member such as the handle 76 and the crossbar 48. Therefore, it is possible to display the steering wheel position with low transmission loss and high reliability.

Further, a third protrusion 76c is formed on the end face of the handle 76, and when the handle 76 is rotated in the OFF operation direction, the third protrusion 76c engages with the end face 95d of the guide plate 95, Connecting pin 97 and crossbar 4
Since the movable contact 47 of the movable contact 46 is separated from the fixed contact 45 of the fixed contact 44 via 8, even if welding occurs between both contacts, the OFF operation of the handle 76 causes the contact between the contacts. Since the opening force can be applied,
When the welded state of the contact is slight, the welded state of the contact can be released and the circuit breaker can be returned to a reusable state.

[0049]

Since the present invention is constructed as described above, it has the following effects.

According to the circuit breaker of the present invention, the guide plate pivotally supported by the handle, the handle spring that engages with the guide plate and urges the guide plate and the handle to a predetermined relational position at all times, Since one end is provided with a connecting pin that is rotatably supported by the guide plate and the other end is rotatably supported by the crossbar, if the circuit breaker trips due to overcurrent, the handle Stop at the trip position, which is an intermediate position between the ON position and the OFF position, and display that the circuit breaker has tripped. Also, if an abnormality such as contact welding occurs during trip operation, the handle can be held at the ON position, and it can be displayed that the movable contact and the fixed contact are in conduction.
The display of contact welding becomes clear.

Further, according to the circuit breaker of the present invention, the guide plate, the handle spring, and the connecting pin are provided on the other pole of the back surface portion of the base adjacent to the opening / closing mechanism portion arranged on the front surface portion of the base. Therefore, these can be easily insulated from the opening / closing mechanism by the pole spacing wall of the base, and since they are directly engaged with one end of the insulating member such as the handle and the crossbar, the transmission loss is reduced. It is possible to display the position of the steering wheel with high reliability.

Furthermore, according to the circuit breaker of the present invention, a protrusion is formed on the end surface of the handle, and the handle is OF'ed.
Since the protrusion engages with the guide plate when it is rotated in the F operation direction, the movable contact of the movable contact is separated from the fixed contact of the fixed contact through the connecting pin and the crossbar. Even if welding occurs between the contacts, if the welding state is slight, the welding state of the contacts can be released and the circuit breaker can be returned to a reusable state.

[Brief description of drawings]

FIG. 1 is a front sectional view showing the inside by cutting away a part of a circuit breaker according to a first embodiment of the present invention.

FIG. 2 is a front sectional view showing the circuit breaker of FIG. 1 in an open circuit state.

FIG. 3 is a front sectional view showing the circuit breaker of FIG. 1 in a trip state.

FIG. 4 is a front cross-sectional view showing a state where the contacts of the circuit breaker of FIG. 1 are welded and the opening / closing mechanism is tripped.

5 is a rear sectional view showing the circuit breaker of FIG. 1 in a closed state.

FIG. 6 is a rear cross-sectional view showing the circuit breaker of FIG. 1 in an open circuit state.

FIG. 7 is a rear cross-sectional view showing the circuit breaker of FIG. 1 in a trip state.

FIG. 8 is a front sectional view showing a conventional circuit breaker.

9 is a front cross-sectional view showing when the circuit breaker of FIG. 8 is in an open circuit state.

FIG. 10 is a front cross-sectional view showing when the circuit breaker of FIG. 8 is in a trip state.

11 is a front cross-sectional view showing a state where the contacts of the circuit breaker of FIG. 8 are welded.

[Explanation of symbols]

40 1st cover, 41 base, 42 2nd cover, 43 Insulation case, 44 Fixed contact, 45 Fixed contact, 46 Movable contact, 47 Movable contact, 48 Crossbar, 60 Overcurrent trip device, 69 Opening and closing mechanism section,
73 arm, 74 handle arm, 76 handle, 76c third protrusion, 84 earth leakage trip device,
95 guide plate, 96 handle spring, 97 connecting pin

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01H 73/50 H01H 71/12 H01H 83/02

Claims (4)

(57) [Claims] 1. An insulating casing comprising a base and a cover, a handle disposed inside the insulating casing and capable of being turned on and off from the outside, and a fixed contact mounted on the base of the insulating casing. A movable contactor that faces the fixed contactor and separates from the fixed contactor, a crossbar that drives the movable contactor, an arm that engages the crossbar, and one end that engages this arm and the other end that A handle arm that engages with the handle to configure a toggle link mechanism, an overcurrent trip device that operates the toggle link mechanism in response to an overcurrent, a guide plate pivotally supported by the handle, and this guide. A handle spring that engages the plate and the handle and always biases the guide plate and the handle to a predetermined relational position; one end is rotatably supported by the guide plate and the other end is the claw. A circuit breaker, comprising: a connecting pin pivotally supported by a loss bar. 2. The circuit breaker according to claim 1, further comprising an earth leakage tripping device which operates the toggle link mechanism in response to the unbalanced current. 3. A guide plate pivotally supported by a handle, a handle spring which engages with the guide plate and the handle and always urges the guide plate and the handle to a predetermined relational position, and one end of the guide plate. A connecting pin rotatably rotatably supported at its other end and rotatably rotatably supported at the other end by the crossbar on the other pole of the rear surface of the base adjacent to the opening / closing mechanism arranged at the front of the base. The circuit breaker according to claim 1 or 2, wherein the circuit breaker is provided in the. 4. A protrusion is formed on the end face of the handle, and when the handle is turned in the OFF operation direction, the protrusion engages with the guide plate, and the protrusion of the movable contact is connected via the connecting pin and the crossbar. The movable contact is separated from the fixed contact of the fixed contactor.
The circuit breaker according to any one of 3 above.