JPH0824026B2 - Circuit breaker for wiring - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a circuit breaker for wiring.

[Background Art] Conventionally, in this type of circuit breaker for wiring, it was usual to screw a holding frame holding the trip device to the bottom of the casing of the circuit breaker body, but the assembly work is complicated and the productivity is high. In addition, the problem is that the insulation resistance is inferior because it is fixed with screws inserted from the outside of the bottom of the housing.

[Object of the Invention] The present invention has been made in view of the above problems, and an object of the present invention is to provide a circuit breaker for wiring which is easy to assemble and has excellent insulation resistance.

DISCLOSURE OF THE INVENTION In order to achieve the above object, according to the present invention, an excessive current passes through a breaker main body which is composed of a housing and a lid body attached to an opening of the housing. Then, a tripping device that is driven, and a trip device that mounts a plurality of links on the holding frame and performs a trip operation when the tripping device is driven,
A crossbar that includes a movable contactor that has a movable contact point inserted in a main circuit and is connected to a trip device, and a contactor holding portion that insulates and stores the movable contactor and is rotatably held in the housing. In the wiring circuit breaker containing the contact device composed of, the contact device is arranged on the bottom side of the housing,
One of a plurality of frame fixing portions protruding in both directions of the holding frame is a shaft member penetrating the holding frame,
The shaft member is protruded toward the abutting surface side from a recess formed in the opening edge of the housing abutted with the lid body, and the outer peripheral surface of the shaft member is pressed by the lid body.

 The present invention will be described below with reference to examples.

Examples In the following examples, a 3-pole breaker is shown.
As shown in FIG. 1, basically, a trip device 10 that is driven when an overcurrent passes, a trip device 40 that performs a trip operation when the trip device 10 is driven, and a trip device 40 that trips. A contact device 110 that is momentarily opened when the contactor is opened and an arc extinguishing device 130 that extinguishes the arc generated when the contact device 110 is opened are housed in the circuit breaker body 1. From the top of the main body 1, trip device 40
The handle 100 interlocked with protrudes freely. The trip device 10, the contact device 110, and the arc extinguishing device 130 are provided for each pole, and the trip device 40 is provided so as to share three poles. The circuit breaker main body 1 is composed of a housing 1a and a lid 1b fitted on the housing 1a, and a handle 10 is inserted through a handle insertion hole 2 formed in a central portion of the lid 1b.
0 projects outside the circuit breaker body 1. Further, an exhaust plate 9 that connects the inside and outside of the circuit breaker body 1 is fitted on the side surface of the circuit breaker body 1 on the arc extinguishing device 130 side.

The trip device 10 includes an electromagnetic trip device 10a and a thermal trip device 10b. The electromagnetic trip device 10a is
It includes a coil 11, a yoke 12, a plunger 13, a return spring 14, and a bush 15. The coil 11 is formed by bending a short sheet metal, and constitutes a half-turn coil in which a terminal piece 18 is integrally extended at the right end. Terminal strip 18
The terminal screw 19 is screwed into the center of the
The fixed screw 20 is screwed into the end portion on the 11 side from the outside of the housing 1a. Thus, the plunger 13 is inserted through the yoke 12 having the bush 15 attached thereto, and the return spring 14 is provided with the spring accommodating recess 25 corresponding to the first horizontal piece 12a and the second horizontal piece 12b of the yoke 12. When the spring 13 is mounted in the spring housing recess 25 from the side, the upper and lower ends of the return spring 14 make elastic contact with the first horizontal piece 12a of the yoke 12 and the bush 15, respectively, and when the plunger 13 moves up and down. 14 is compressed, and the plunger 13 is given a restoring force. The lower end of the plunger 13 is a vertical piece of the coil 11.
11b and the first vertical piece 12d of the yoke 12 are arranged between the coil
Plunger 13 is configured to be sucked downward by energizing 11. With this configuration, the coil 11 can be finally placed in the yoke 12 from the side of the yoke 12 with the plunger 13 attached to the yoke 12, and compared with the case where the plunger 13 is inserted into the coil 11. As a result, the assemblability is improved. The thermal trip device 10b is coupled to the projecting piece 21 formed at one end of the coil 11.

The thermal release device 10b includes a heater plate 31, a bimetal plate 3
2, and the pressing screw 33. The heater plate 31 and the bimetal plate 32 are provided at the lower ends of the coil 11 with protrusions of the coil 11.
21 has an insertion hole into which the bimetal plate 32 is placed on the electromagnetic tripping device 10a side, the heater plate 3 and the bimetal plate 32 are laminated, and the projection 21 is inserted into the insertion hole to remove the projection 21. By tightening, the heater plate 31 and the bimetal plate 32 are integrally fixed to the coil 11. Heater plate 31
In the state where the bimetal plate 32 and the bimetal plate 32 are stacked, the right end portion of the bimetal plate 32 projects above the upper end of the heater plate 31, and the pressing screw 33 is inserted into the screw hole formed in this protruding portion.
Are screwed together so that they can move back and forth. As shown in FIG. 1, a connecting wire 37 made of a braided wire is connected to the upper end of the heater plate 31, and the heater plate 31 is heated by the current supplied to the heater plate 31.
When is heated, the upper end of the bimetal plate 32 is bent toward the electromagnetic trip device 10a.

The trip device 10 configured as described above is the first
As shown in the figure, the terminal piece 18 is arranged so as to be exposed to the outside of the circuit breaker main body 1, and is fixed in a fixed position of the circuit breaker main body 1 by fixing screws 20 and 4 screwed from the lower surface of the housing 1a. To be done. The trip device 10 is provided for each pole, and operates independently of each other.

As shown in FIG. 2, the trip device 40 includes a holding frame 41 formed in a shape in which a pair of substantially parallel support plates 41a that are separated from each other in the left and right are integrally connected. Holding frame 41
A latch link 51 is pivotally supported by a link pin 52 at the end portion on the trip device 10 side so as to be swingable.

The latch link 51 has a spring receiving projecting piece 53 projecting downward at a portion closer to the tripping device 10 than the shaft supporting portion, and projecting upward at the end of the spring receiving projecting piece 53 and the holding frame 41. A compression spring (54) is sandwiched between the spring receiving projection (42) provided. A latch piece 55 extends from an end of the latch link 51 near the trip device 10, and the latch piece 55 is
Is inserted into the holding groove 62 formed at the bottom. Latch link 51
At the end, a holding piece 56 extends at an end farther from the trip device 10 than the pivot portion, and the lower end of the holding piece 56 contacts the upper end of the locking lever 71.

The interlocking lever 61 is spaced apart from the three axial positions at substantially equal intervals so that the pressing piece 63 and the hooking piece 64 project in a direction substantially orthogonal to each other, and the pressing piece 63 is substantially orthogonal to the central portion in the axial direction. Is formed in a shape in which the locking piece 65 is projected in the direction of
Both ends of the interlocking bar 61 in the axial direction are rotatably supported at fixed positions on the inner surface of the circuit breaker body 1. The pressing piece 63 is arranged corresponding to the tip of the pressing screw 33 of the thermal tripping device 10b, and the hooking piece 64 is arranged on the lower surface side of the hooking piece at the tip of the plunger 13 of the electromagnetic tripping device 10a. It When the plunger 13 is pulled downward or the bimetal plate 32 bends away from the heater plate 31, the interlock bar 61 rotates counterclockwise in FIG. Where the interlocking bar 61
Since the pressing pieces 63 and the hooking pieces 64 are provided at the three positions, the interlocking bar 61 rotates and the trip device 40 rotates when any one of the tripping devices 10 provided for each pole operates. To operate. The locking piece 65 is formed with a holding groove 62 whose side surface and front end surface are open.
At the tip of 65, the upper wall of the holding groove 62 forms an inclined surface 66 that gently rises and inclines toward the tip of the locking piece 65.

The lower end of the locking lever 71 is pivotally attached to the holding frame 41 by a link pin 72, and the spring receiving protruding piece 73 is positioned above the pivoted portion in a direction away from the trip device 10.
Is protruding. This spring receiving protrusion 73 is a holding frame
A compression spring 74 is sandwiched between a spring receiving protruding piece 43 protruding at a top end of the 41 and approaching the trip device 10.
A notch hole 75 is formed in the locking lever 71, and an inclined piece 76 that rises and inclines in a direction away from the trip device 10 extends from a lower edge of the notch hole 75. A locking projection 82 extending from a cradle 81 is inserted into the cutout hole 75 of the locking lever 71.

The cradle 81 is bent into a substantially U-shape having legs substantially parallel to both support plates 41a of the holding frame 41, and is provided with a link pin.
The lower end is pivotally attached to the holding frame 41 by the pivot 83. A shaft projection 84 is stamped on the inner peripheral surface of the upper end of the cradle 81, and the shaft projection 84 has a cylindrical shape, and a part of the peripheral surface of the cylinder is cut off by a plane 85 parallel to the axial direction, and the peripheral surface is formed in a superior arc shape. Is formed. The upper end of the first link 91 is rotatably mounted on the shaft projection 84. The first link 91 is formed in a substantially U shape in which the distance between the outer peripheral surfaces of both leg pieces is set to be substantially equal to the distance between the inner peripheral surface of both leg pieces of the cradle 81, and a shaft projection 84 is formed at the upper end portion of both leg pieces. It has a bearing groove 92 that is cut out in an arc shape with a substantially equal diameter, and this bearing groove 92 is rotatably connected to the shaft projection 84. Thus, the bearing groove 92 of the first link 91 is inserted into the shaft projection 84 from a direction parallel to the plane 85 of the shaft projection 84 in a plane orthogonal to the axial direction of the shaft projection 84, and then the first link
If 91 is rotated around the axis of the shaft protrusion 84, the first link 91
Is held by the cradle 81 so that it can be swung freely while being retained. Here, the position of the plane 85 on the shaft protrusion 84 is the first in the operating range of the cradle 81 and the first link 91.
The link 91 is provided at a position where it does not fall off the cradle 81. With this configuration, the cradle 81
Since the first link 91 and the first link 91 can be swingably connected, the structure is simple, and it is possible to prevent the first link 91 from being easily disengaged after the two are coupled. In both legs of the cradle 81, a pressing protrusion 86 is provided at the end opposite to the locking protrusion 82.
Is extended.

The lower end of the first link 91 is, as shown in FIG.
The link 94 is rotatably connected to the upper end of the link 94 by a link pin 93. One end of a tension spring 102 is connected to the link pin 93. The other end of the tension spring 102 is connected to a hook hole 103 at the upper end of the handle link 101. Handle link 101
Is formed in a substantially U-shape opened downward, and an upper end portion is integrally connected to the handle 100 so as to swing as the handle 100 is turned upside down. That is, the lower end portion of the hand link 101 has a substantially U-shaped bearing groove 104 that is opened downward and engages with a shaft protrusion 44 provided on the outer surface of the support plate 41a of the holding frame 41. It can be swung around the protrusion 44 together with the handle 100. A stopper protrusion 45 that restricts the rotation range of the handle link 101 is provided at a position different from the shaft protrusion 44 on the outer surface of the support plate 41a. In addition, the holding frame 4 in the handle link 101
A pressing pin 105 is attached to a portion projecting above 1. An arcuate surface 106 is formed on the upper surface of the lower end of the handle 100 along the arcuate surface 6 formed on the inner peripheral surface around the handle insertion hole 2 at the upper end of the circuit breaker body 1. 1
Both 06 are arcs centered on the shaft protrusion 44. By the way, a substantially U-shaped connecting groove 95 is formed at the lower end of the second link 94, and the connecting groove 95 is a contact device 110.
Linked to

The contact device 110 includes a movable contact 111 provided with a movable contact 112.
And a crossbar 121 for holding the movable contact 111, and a compression spring 11 interposed between the crossbar 121 and the movable contact 111.
3 and fixed contacts integrally provided on the arc extinguishing device 130 described later.
It has 131 and. The movable contact 111 is connected to the heater plate 31 at the other end of a connection line 37, one end of which is connected to the heater plate 31.
The crossbar 121 is pivotally supported at a fixed position on the inner peripheral surface of the circuit breaker main body 1, and simultaneously drives the movable contacts 111 of the other poles. In other words, the interlocking bar described above
Similar to 61, the crossbar 121 holds the movable contacts 111 of each pole at the same time, and when any one of the movable contacts 111 operates, the remaining movable contacts 111 interlock. The crossbar 121 is formed of an insulating material such as a synthetic resin molded product, and has contact holders 122 at three locations in the axial direction. The contact holder 122 is a crossbar
The holding body 122b has a shape in which the outer shape of the base body 122a is substantially triangular when viewed from the axial direction of the holding body 121a.
The tip of 2b is separated in the axial direction of the crossbar 121. The base body 122a is formed in a shape in which the protruding surface of the holding body 122b and the surface on the opposite side are open. Base body
The side surface of the lower wall of 122a on the holding body 122b side forms a first spring receiving surface 123 which is a plane in the vertical direction, and the first spring receiving surface 1
A second spring receiving surface 124 is formed at the upper end of the upper surface 23 and is inclined upward and away from the holder 122b. That is, the edge 125 is formed between the first spring receiving surface 123 and the second spring receiving surface 124. A spring receiving protrusion 126 is provided on the lower wall of the base body 122a and extends obliquely upward so as to straddle the edge 125, and the protruding direction of the spring receiving protrusion 126 is substantially orthogonal to the second spring receiving surface 124. Is set to the direction. The vertical width of the opening of the base body 122a opposite to the holding body 122b is set to be larger than the vertical width of the movable contact 111. On the inner peripheral surface of the holding body 122b, a holding groove 128 that is open to the inside of the holding body 122b and the base body 122a side is formed, and the upper peripheral wall of the holding groove 128 is a lower peripheral wall as it approaches the base body 122a. Sloped away from. In addition, the holding groove 128
In, the tip end farthest from the base body 122a has a substantially constant width. An inward retaining projection 129 protrudes inward at the distal end of the holding body 122b, and the space between the distal end of the retaining groove 128 and the retaining projection 129 is the width of the second link 94 around the connection groove 95. They are set approximately equal. By the way, the movable contactor 111 has a shaft pin 114 inserted through a substantially central portion in the longitudinal direction, and a spring receiving tongue 115 protruding toward the base body 122a side is formed at the lower part of the end portion on the side of the base body 122a and a spring. The spring receiving pin 116 is inserted into the receiving tongue 115. Compression spring 11
Numeral 3 is sandwiched between the spring receiving projection 126 of the base body 122a and the spring receiving tongue 115 of the movable contact 111, and the end on the movable contact 111 side contacts the spring receiving pin 116. Since the spring receiving projection 126 is inserted into the compression spring 113, the compression spring 11
3 is swingable between a position where its axial direction is orthogonal to the first spring bearing surface 123 and a position orthogonal to the second spring bearing surface 124, and an edge 125 is formed between both spring bearing surfaces 123 and 124. By being formed, the compression spring 113 is reliably positioned at either one of the above two positions.
The shaft pin 114 is inserted into the holding groove 128, and the spring force of the compression spring 113 biases the movable contact 111 so that the shaft pin 114 moves toward the tip of the holding groove 128. Axis pin 114
A second link 94 is rotatably engaged with the second link 94.
Is a retaining protrusion 129 and a shaft pin due to the spring force of the compression spring 113.
It is sandwiched between 114 and. Therefore, the trip device 40
In assembling the contact device 110 with the contact device 110, after the contact device 110 is assembled, the compression spring 113 is compressed to retract the shaft pin 114 from the tip of the holding groove 128, and in that state, the trip device 40
After mounting the shaft pin 114 in the connecting groove 95 of the second link 94 of
If the compressive force applied to the compression spring 113 is removed, the second link 94 is sandwiched between the retaining protrusion 129 and the shaft pin 114, and the second pin 94 is retained.
The retaining in the direction orthogonal to 114 is performed. Also, in the direction along the shaft pin 114, the movable contact 111 and the holding body 122b are clamped to prevent the retainer from coming off.

The fixed contact 131, which forms a contact together with the movable contact 112, is provided on the upper surface of the fixed contact plate 132 of the arc extinguishing device 130, and an arc traveling plate 133 is provided at one end of the fixed contact plate 132. One end of an arc drive coil 134 is connected to an end of the fixed contact plate 132 opposite to the arc traveling plate 133 with the fixed contact 131 interposed therebetween. The arc drive coil 134 is bent in a substantially U-shape that is open downward, and is arranged so that the fixed contact 131 is located at a position corresponding to between the two leg pieces. The other end of the arc driving coil 134 is connected to the fixed plate 135.
The fixing plate 135 is bent in a stepwise manner, and the lower side thereof is the fixing piece 135a, and the fixing screw 7 inserted from the lower surface of the housing 1a is screwed into the fixing piece 135a, so that the fixing plate 135 is formed. It is fixed to the housing 1a. The upper side of the fixed plate 135 is a screw piece 135b exposed on the outer surface of the circuit breaker body 1, and the terminal screw 136 is screwed into the terminal piece 135b. An arc extinguisher 137 is provided above the arc traveling plate 133. The arc extinguisher 137 is formed by a plurality of grid plates 138 that are conductive plates and are arranged in parallel in the vertical direction with a small gap therebetween, and a holding frame 139 formed of an insulating material that holds the grid plates 138. And the bottom grid plate 138
Are arranged so as to face the arc traveling plate 133.

As described above, the terminal strip 18, the coil 11, the heater plate 3
1, connection wire 37, movable contact 111, movable contact 112, fixed contact 1
A main electrical path passing through the fixed contact plate 132, the arc driving coil 134, and the fixed plate 135 is formed.

Moreover, by having the above-mentioned structure, the circuit breaker main body 1
In assembling each device into the inside, first, the arc extinguishing device 130 that forms the main electric path is installed in the housing 1, then the trip device 10 and the contact device 110 are installed, and then the trip device 4
It is only necessary to incorporate 0, and at that time the trip device 40
The second link 94 and the shaft pin 114 of the contact device 110 are connected. Here, the tripping device 10 has both ends of the link pin 83 penetrating the holding frame 41 and both ends of the pin 87 also penetrating the holding frame 41 at the upper edges of both side walls of the opening of the housing 1a, that is, the lid body. The tripping device 10 and the contact device 110 connected to the tripping device 10 are suspended by fitting into the front and rear recesses 88 respectively formed on the abutting surfaces with respect to the lower edge of the 1b. Then, the outer peripheral edges of the pins 83 and 87 projecting upward from the upper edge of the recess 88 are pressed by the lower edge of the lid 1b to be fixed and fixed as shown in FIG. Here, the casing 1a is formed of a thermosetting resin in consideration of insulation and the like, and the lid 1b is formed of a thermoplastic resin. Therefore, the pressing of the pins 83 and 87 by the lid 1b is performed by the lid 1b. Since this is performed by the elasticity of 1b, the pins 83 and 87 can be reliably fixed without a gap between the abutting surfaces of the lid 1b and the casing 1a. Further, the recess 88 is the casing 1a.
Since it is formed at the edge of the opening of the recessed portion, the shape of the recessed portion 88 can be accurately formed when the housing 1a is formed by the upper and lower molds.
Therefore, the pins 83, 87 can be fitted into the recess 88 without rattling. Further, since it is not necessary to screw the lower end of the holding frame 41 to the bottom of the housing 1a with a screw, the vertical length of the holding frame 41 can be shortened.

The operation will be described below. Thus, when the handle 100 is tilted toward the trip device 10, the movable contact 112 and the fixed contact 131 are separated. In this state, the latch piece 55 of the latch link 51 is inserted into the holding groove 62 of the interlocking bar 61, and the latch link 51 is biased counterclockwise around the link pin 52 by the compression spring 54. Latch link
The lower surface of the pressing piece 56 of the 51 is in contact with the upper edge of the locking lever 71, and the locking lever 71 is fixed by the compression spring 74 to the link pin 72.
It is urged clockwise around. Here, since the latch link 51 and the locking lever 71 are in contact with each other, rotation of both is stopped. The locking projection 82 of the cradle 81 is inserted into the notch hole 75 of the locking lever 71, and the rotation of the cradle 81 is stopped. On the other hand, the straight line connecting both ends of the tension spring 102 passes on the right side of the shaft protrusion 84, and the upward spring force acts on the link pin 93 that connects the first link 91 and the second link 94. 91 is biased counterclockwise around the shaft projection 84. Therefore, the second link 94 and the movable contact 111 connected to the second link 94 are pulled upward in the upper right direction so that the movable contact 112 and the fixed contact 131 are separated from each other, and the crossbar 121 is attached clockwise. Energized. Since the locking surface 8 corresponding to the base body 122a of the crossbar 121 is formed on the base 1a, the rotation angle of the crossbar 121 is regulated by the contact of the base body 122a with the locking surface 8. Here, the straight line connecting both ends of the compression spring 113 is the shaft pin 1
Since it passes through the right side of 14 and the spring force of the compression spring 113 acts upward, the movable contact 111 is biased counterclockwise.
That is, the movable contactor 111 is in contact with the lower surface of the upper wall of the base body 122a.

Next, as shown in FIG. 1, the handle 100 is attached to the arc extinguishing device 1
When tilted to the 30 side (left side in the figure), the straight line connecting both ends of the tension spring 102 passes the left side of the shaft protrusion 44 and the spring force acts downward, so that the handle link 101 is biased counterclockwise and the handle The state where 100 is pushed down to the left side is maintained.
Here, the handle link 101 is in contact with the stopper protrusion 45, whereby the maximum rotation angle is restricted. Also,
In this state, the straight line connecting both ends of the tension spring 102 passes on the right side of the link pin 83 that supports the cradle 81, and the spring force acts upward, so that the cradle 81 is urged counterclockwise. . Here cradle 81, locking lever
The 71, the latch link 51, and the interlocking bar 61 are maintained in the same state as the above-described contact opening state. On the other hand, the first link 91 and the second link 91
Since the link pin 93 connecting the link 94 is pulled to the left by the spring force of the tension spring 102, the first link 91
And the second link 94 are substantially aligned on a straight line.
The movable contact 111 connected to the lower end of the link 94 is pressed downward to close the movable contact 112 and the fixed contact 131. Further, since a straight line connecting both ends of the compression spring 113 passes through the right side of the shaft pin 114 and the spring force acts upward, a sufficient contact pressure can be obtained. In this way, when the handle 100 is tilted to the left, it is in a set state in which the spring force of the tension spring 102 is accumulated.

When an extremely large current such as a short-circuit current flows in the main circuit with the contacts closed as described above, the movable contact 112 and the fixed contact 131 are momentarily separated by the electromagnetic repulsive force. At this time, since the straight line connecting both ends of the compression spring 113 passes under the shaft pin 114 and the spring force acts leftward, the movable contact 112 is attached in a direction away from the fixed contact 131 by the spring force of the compression spring 113. Will be encouraged. At this position, the compression spring 113 abuts the first spring receiving surface 123, and the first spring receiving surface 123 and the second spring receiving surface 124.
Since the edge 125 is formed between and, the reversing operation of the compression spring 113 is easily performed. Further, since the compression spring 113 contacts the first spring receiving surface 123, the acting direction of the spring force is accurately set.
As described above, the compression spring 113 acts as a reversing spring so as to apply the contact pressure when the contacts are closed and accelerate the opening of the contacts when the contacts are opened. Here, an arc is generated when the contacts are opened.
The Lorentz force acting between the magnetic field generated around the arc and the arc strongly urges the arc toward the arc extinguisher 137, and the arc length is rapidly extended.

Following the opening of the contact by the electromagnetic repulsion, the trip device 40 is driven by the electromagnetic trip device 10a. The electromagnetic tripping device 10a operates when not only a short-circuit current but a large current of several times or more of the rated current flows. That is, when a large current passes through the coil 11 of the electromagnetic trip device 10a, the plunger 13 is pulled downward against the spring force of the return spring 14, and a hook piece 24 formed at the upper end of the plunger 13 is formed.
As a result, the hooking piece 64 of the interlocking bar 61 is pulled downward. As a result, the interlocking bar 61 rotates counterclockwise as shown in FIG. 12, and the latch piece 55 of the latch link 51 is
Is pressed downward. That is, since the latch link 51 rotates right by the spring force of the compression spring 54 and the pressing force to the locking lever 71 is released, the locking lever 71 rotates left by the spring force of the compression spring 74, and the cradle 81 The locking projection 82 is the locking lever 71
From the notch hole 75. Cradle 81, as described above,
Since it is biased counterclockwise by the spring force of the tension spring 102, when the engagement with the locking lever 71 is released, it rotates counterclockwise and pulls up the first link 91 to the upper left. When the first link 91 is pulled up, the second link 94 is pulled up to the upper right along with the contraction of the tension spring 102, and the movable contact 112
The movable contact 111 is pulled up so as to separate from the fixed contact 131. These operations are instantaneous,
The so-called trip operation is performed. When the movable contact 112 separates from the fixed contact 131 in this way, the arc length is extended, the arc is divided by the grid plate 138 of the arc extinguisher 137, and the arc is rapidly extinguished. Further, the high-pressure arc gas accompanying the arc generation is discharged to the outside of the circuit breaker body 1 through the exhaust plate 9. Here, the rotation of the crossbar 121 is stopped by the lower end of the base body 122a of the crossbar 121 abutting on the locking surface 8 formed on the bottom surface of the base 1a as described above. Thus, the movable contact 11
1 is restricted by bringing the crossbar 121 into contact with the locking surface 8 of the base 1a.
Is held on the crossbar 121 by the shaft pin 114 and the compression spring 113, so that the impact force when the crossbar 121 abuts on the locking surface 8 is reduced, and the impact on the movable contact 111 and the trip device 40 is reduced. When the trip device 40 operates and the contacts are separated, the impact on the movable contact 111 and the trip device 40 can be reduced while regulating the rotation angle of the movable contact 111. is there. At the contact opening position, the compression spring 113 contacts the second spring receiving surface 124,
A straight line connecting both ends of the compression spring 113 passes through the right side of the shaft pin 114, and the spring force acts upward so that the movable contact 111 is biased counterclockwise.

As described above, when a large current of several times the rated value or more passes, the electromagnetic trip device 10a operates and the trip device 40 is driven, but an overcurrent of a slightly larger value than the rated value is applied for a long time. When heated, the heater plate 31 heats the bimetal plate 32 to bend the bimetal plate 32, and the pressing screw 33 presses the pressing piece 63 of the interlocking bar 61 to rotate the interlocking bar 61 counterclockwise. The contact can be opened by operating the trip device 40 in the same manner as described above.

In this way, when the trip device 40 operates, the cradle
Since 81 is disengaged from the locking lever 71, it is necessary to reset the contact in order to close the contact again. The reset is performed by tilting the handle 100 to the right as much as possible. That is, when the handle 100 is tilted to the right to the maximum, the pressing pin 105 provided on the handle link 101 presses the pressing protrusion 86 of the cradle 81 to the right, and the cradle 81 rotates counterclockwise. By this operation, the locking projection piece 828 of the cradle 81 is inserted into the cutout hole 75 along the inclined piece 76 extending to the lower edge of the cutout hole 75 of the locking lever 71.
The pressing lever 81 rotates the locking lever 71 counterclockwise. Therefore, the upper end of the locking lever 71 comes into contact with the lower surface of the pressing piece 56 of the latch link 51.

EFFECTS OF THE INVENTION The present invention has a contact device arranged on the bottom side of a housing, and one of a plurality of frame fixing parts projecting in both sides of a holding frame as a shaft member penetrating the holding frame. The outer peripheral surface of the shaft member is pressed by the lid body so that the holding frame is attached to the bottom of the housing as in the conventional case, because the member is projected toward the abutting surface side from the recess formed in the opening edge of the housing that abuts the lid body. Since it is not necessary to fix it by screwing, it can be assembled and fixed simply by fitting the shaft member into the recess, which facilitates the assembly work. Moreover, since the fixing position is the abutting surface part of the housing and the lid, the insulation distance is large. The effect is that the insulation resistance is improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is an exploded perspective view of a trip device and a contact device used in the same as above, and FIG. 3 is a trip device, a contact device and a case used in the same as above. Partly omitted and broken perspective view, FIG. 4 is an enlarged cross-sectional view of the main part for explaining the above assembly, where 1 is a circuit breaker body, 1a is a housing, and 1b is
Is a lid, 10 is a tripping device, 40 is a trip device, 41 is a holding frame, 83 is a link pin, 87 is a pin, 88 is a recess, 11
0 is a contact device.

Claims (3)

[Claims] 1. A trip device driven when an excessive current passes and a holding frame in a circuit breaker main body composed of a casing and a lid attached to an opening of the casing. A trip device that performs a trip operation when a plurality of links are mounted and the trip device is driven, a movable contactor that has a movable contact inserted in the main electric path and is connected to the trip device, and the movable contactor is insulated and stored. In a circuit breaker for wiring, which includes a contact device that includes a contact holding unit that is rotatably held in the housing, and the contact device is arranged on the bottom side of the housing. A concave portion formed at the edge of the opening of the casing, which is a shaft member penetrating the holding frame, and one of the plurality of frame fixing portions protruding in both directions of the holding frame is formed through the holding frame. The shaft is made to project to the butting surface side Circuit breaker, characterized in that formed by pressing in the lid of the outer peripheral surface of the. 2. The circuit breaker according to claim 1, wherein the casing is formed of a thermosetting resin and the lid is formed of a thermoplastic resin. 3. The wiring breaker according to claim 1, wherein a link pin is used as the shaft member.