JPS62163235A - Wiring breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field 1 The present invention relates to a molded circuit breaker.

[BACKGROUND TECHNOLOGY] The circuit breaker core structure of this type of molded circuit breaker is shown in a 12M1 shaft, with arc drive coils 69 installed on both sides of a fixed contact plate 67 with a built-in grid plate 75 of an arc extinguishing device 80. was provided, and the height position of the arc drive coil 69 was set as the top dead center position when the movable contactor 8 was opened. Therefore, the diameter of the coil becomes larger and the position is further away from the contact point between the fixed contact 38 and the movable contact 8, and as a result, magnetic driving force is not effectively applied to the arc generated between the contacts 38 and 8, and the arc voltage There was a problem that the rise of the current was slow and the current limiting property was poor.

[Object of the invention] The present invention has been made in view of the above-mentioned problems, and its purpose is to be able to efficiently interrupt short-circuit current at high speed and with a high current limit, and to significantly improve the interrupting capacity. To provide molded circuit breakers.

[Disclosure 1 of the Invention] The present invention provides an electromagnetic drive means that drives a plunger by an electromagnetic drive force when a short-circuit current is applied, a movable contact that is directly pushed and driven in the opening direction by the plunger of the electromagnetic drive means, and a movable A cut-off mechanism is constructed by a fixed contact plate that is equipped with a fixed contact that makes contact with and opens the contact, and is provided with a 7-track drive coil in the vicinity of the fixed liquid, and an arc extinguisher disposed on the opposite side of the movable contact. The height position of the arc drive coil of the rotating contact plate is set at approximately the same level or slightly above the movable contact position when the movable contact is reversed and opened, and the movable contact It is characterized in that an electromagnetic driving force is generated by the magnetic field generated by the arc driving coil to cause the contacts to open and open at high speed using electromagnetic driving means, and to constantly advance the arc generated between the movable contact and the fixed contact forward.

(Example) In the following example, a three-pole breaker is shown. As shown in FIG. 1, a tripping device 10 is basically activated when an excessive current such as a short circuit current or an overcurrent passes through.
The trip device 40 performs a trip operation when the trip device 10 is driven, the contact device 79 opens instantaneously when the trip device 40 performs the trip operation, and the contact device 79 is opened when the contact device 79 is opened. An arc extinguishing device 80 for extinguishing an arc is housed in the housing 1,
A handle 78 interlocked with the trip device 40 protrudes from the upper surface of the housing 1 so as to be freely raised and lowered.

In contact with the trip device 10, an α device 79 and an arc extinguishing device 80 are provided for each type, and the trip device 40 has three
It is set up so that the poles are shared. The housing 1 is composed of a base 1a and a cover 1b fitted over the base 1a, and a handle 78 projects to the outside of the housing 1 through a handle insertion hole 2 formed in the center of the cover 1b.

As shown in FIGS. 4 and 5, the trip device 10 includes an electromagnetic trip device 10a and a thermal trip device 10b.
It consists of The electromagnetic trip device 10a includes a coil 11, a yoke 12, a plunger 13, a return spring 14,
and a bush 15. The coil 11 is constructed by bending a rectangular flat plate 17 having an oval-shaped cutout groove 16 into an L-shape, and has a half-turn shape with a terminal piece 18 integrally extended at the right end. A coil 11 is formed. Here, in the coil 11, the side closer to the terminal piece 18 along the electric path becomes the horizontal piece 11a, and the side farther from the terminal piece 18 becomes the vertical piece 11b. A terminal screw hole 19 is formed in the center of the terminal piece 18, and the fill 11gA of the terminal piece 18
A screw hole 20 is formed in the '4 part. Also, fill 1
A projecting piece 21 is provided at the tip of the vertical piece 11b. As shown in FIG. 5, the yoke 12 is formed of a magnetic material bent into a substantially S-shape, and includes both horizontal pieces 12a, 12b, a first horizontal piece 12a in the upper stage and a second horizontal piece 12b in the middle stage. There are rectangular through holes 22a on a straight line in the vertical direction.

A screw hole 23 is formed in the portion. Therefore, the second i piece 12b
The fill 11 is interposed between the coil 11 and the third horizontal piece 12c, so that the horizontal piece 11a of the coil 11 faces the third horizontal piece 12c, and the vertical piece 11b of the coil 11 and the first
The R piece 12d is arranged to face the coil 11 with the horizontal piece 11& interposed therebetween.

Further, the bushing 15 is attached to the through hole 22b formed in the second horizontal piece 12b. The bushing 15 is formed of a non-magnetic material such as a synthetic resin molded product into a rectangular parallelepiped shape with a slightly concave upper surface, and a rectangular through hole 27 is opened in the center of the bottom surface.
An insertion protrusion 28 is provided protruding from the entire lower surface of the opening periphery of the through hole 27 . However, the insertion protrusion 28 is
By press-fitting into 2b, the bushing 15 is attached to the yoke 12.
It is fixed to . Here, the through hole 27 is the first horizontal piece 1
It is formed to have approximately the same dimensions as the through hole 22a of 2a. The plunger 13 is made of a magnetic material, and the upper end thereof is bent into an oval shape to form a hooking piece 24, a spring storage recess 25 opened laterally is formed in the center, and the lower end has a recess 1 that engages one end of a movable contact 8, which will be described later.
3a is provided. Is the vertical width of the bone storage recess 25 the first one of the yoke 12? The width is set approximately equal to the width between the ilt piece 12a and the second horizontal piece 12b. The spring storage recess 25 holds the return spring 14 between the spring holding protrusions 26 protruding from both the upper and lower end surfaces.
It is designed to be installed. The center and lower end of the plunger -13 are formed into a rectangular cross section corresponding to the through hole 22a formed in the mi horizontal piece 12a of the yoke 12 and the through hole (L27) of the bushing 15, and are formed in both way holes 22a and 27. It is inserted so that it can be moved up and down.

Then, insert the plant gear 13 into the yoke 12 with the bushing 15 attached, and connect the first horizontal piece 12a and the second w of the yoke 12.
If the return spring 14 is attached to the spring storage recess 25 with the spring storage recess 25 corresponding to the L piece 1.2b, both upper and lower ends of the return spring 14 will be connected to the #&1 horizontal piece 12 of the yoke 12.
a and the second i-piece 12b, respectively, and the plant
When 13 moves up and down, the return spring 14 is compressed,
A restoring force acts on the plunger 13. The center part of the plant gear 13 is disposed between the vertical piece 11b of the coil 11 and the $1 vertical piece 12d of the yoke 12,
The plunger 13 is configured to be sucked downward when energized.

By the way, a thermal tripping device 10b is coupled to a protrusion 21 formed at one end of the coil 11.

The thermal tripping device 10b is composed of a heater plate 31, a bimetal plate 32, and a pressure adjustment screw 33. The heater plate 31 and the bimetal plate 32 each have insertion holes 34 and 35 at their lower ends into which the protruding piece 21 is inserted, and the heater plate 31 and the bimetal plate 32 are stacked with the bimetal plate 32 on the side of the electromagnetic tripping device 10a. and insertion hole 34.3
The heater plate 31 and the bimetal plate 32 are integrally fixed to the fill 11 by inserting the protrusion 21 into the filter 5 and caulking the protrusion 21. When the heater plate 31 and the bimetal plate 32 are stacked, the upper end of the bimetal plate 32 protrudes above the upper end of the heater plate 31, and the pressure adjustment screw 33 is inserted into the screw hole 36 formed in this protruding part. They screw together. At the upper end of the heater plate 31, as shown in FIG.
37 is connected, 〜゛ −
When the heater plate 31 is heated due to an overcurrent exceeding the rated value, the upper end of the bimetal plate 32 is activated by the electromagnetic tripping device 1.
It is designed to bend towards the 0a side. With this configuration, the heater plate 31 and the bimetal plate 32 are connected to the coil 11.
This makes it easier to handle during assembly.

As shown in FIG. 1, the tripping device 10 configured as described above is arranged so that the terminal piece 18 is exposed to the outside of the housing 1, and the fixing screws 3 and 4 are screwed into the bottom surface of the base 1a. The distal end portion of the terminal piece 18 is screwed into a screw hole 19 formed in the terminal piece 18 and a screw hole 23 formed in the yoke 12, thereby being fixed in a fixed position on the base 1a.

Furthermore, a terminal screw 29 is screwed into the terminal screw hole 19 of the terminal piece 18 . This tripping device 10 is provided for each type of device, and operates independently of each other.

As shown in FIGS. 1 and 2, the trip device 40 is equipped with 7 holding frames 4 formed in a shape in which a pair of substantially parallel support plates 41 & spaced left and right are integrally connected. The lower ends of the plates 41a are each bent inward to form a fixed piece 41t+. A fixing plate 47 is disposed so as to straddle both of the defining pieces 41b, and a fixing screw 5 inserted from the lower surface of the base 1a is screwed into a pair of screw holes 41a formed in the fixing plate 47. , holding frame 41
is fixed to the base 1a.

A latch link 51 is rotatably attached to the end of the holding frame 41 on the side of the tripping device 10 by a link pin 52 . The launch link 51 has a spring bearing protruding piece 53 that protrudes downward in a portion closer to the tripping device 10 than the pivoting portion, and this spring bearing is connected to the protruding piece 53 and the holding frame 41.
A spring holder protruding upward from the end of the spring holder holds a compression spring 54 between the spring holder and the protruding piece 42 . A latch piece 55 extends from the end of the latch link 51 near the tripping device 10, and the latch piece 55 is inserted into a holding groove 62 formed in the interlocking bar 61.

The interlocking bar 61 has a pressing piece 63 and a hooking piece 64 protruding from each other at approximately equal intervals from three dark places in the axial direction, and a suppressing piece 63 at the center in the axial direction. A locking piece 65 is formed to protrude in the orthogonal direction, and both ends of the interlocking bar 61 in the axial direction are rotatably supported at fixed positions on the inner surface of the hashing 1. Pressing piece 6
3 is disposed corresponding to the tip of the pressure adjusting screw 33 of the thermal tripping device 10b, and the hooking piece 64 is disposed on the lower surface side of the hooking piece 24 of the electromagnetic tripping device 10a. When the plunger 13 is pulled downward or the bimetal plate 32 is bent away from the heater plate 31, the interlocking bar 61 rotates counterclockwise in FIG. Here, since the pressing piece 63 and the hooking piece 64 are provided at three locations on the interlocking bar 61, when any one of the tripping devices 10 provided for each type operates, the interlocking bar 61 rotates. That's what I do. The locking piece 65 is formed with the above-mentioned holding groove 62 which is open at the side and the tip end, and at the tip of the locking piece 65, the upper wall of the holding groove 62 gently rises toward the tip of the locking piece 65. An inclined surface 66 is formed. A holding piece 56 extends from the end of the latch link 51 that is farther from the tripping device 10 than the pivot portion, and the upper end of the locking lever 71 comes into contact with the lower surface of the holding piece 56.

The lower end of the locking lever 71 is rotatably pivoted to the holding frame 41 by a link pin 72, and above the pivoted portion, a protruding piece 73 of the spring receiver protrudes in the direction away from the tripping device 10. It is set up.

The spring receiver holds the compression spring 74 between the protruding piece 73 and the protruding piece 53, which is provided at the upper end of the holding frame 41 and protrudes in a direction approaching the tripping device 10. Further, the locking lever 71 is formed with a notch 7 hole '1, and from the lower edge of the notch hole 98, an inclined piece 76 that rises and slopes in a direction away from the tripping device 10 is provided. A locking protrusion 8 is provided with a fredle 81 extending in the notch hole 78 of the locking lever 71.
2 is inserted.

The fredle 81 is bent into a substantially U-shape with leg pieces substantially parallel to both support plates 41a of the holding frame 41, and its lower end is pivotally attached to the holding frame 41 by a link pin 83. A shaft protrusion 8 is provided on the inner peripheral surface of the upper end of the fredle 81.
4 is stamped out, and the shaft protrusion 84 has a cylindrical shape, and is formed by cutting a part of the curved surface of the cylinder with a plane 85 parallel to the axial direction, so that the circumferential surface has a substantially arcuate shape. This shaft protrusion 84
The upper end of the first link 86 is rotatably attached to the upper end of the first link 86 .

The first link 86 is formed into a substantially U-shape similar to the fredle 81, and has a bearing groove 87 cut out in an arcuate shape having approximately the same diameter as the shaft protrusion 84 at the upper end of both legs. A groove 87 is rotatably coupled to the shaft protrusion 84 . The opening width of the bearing groove 87 is set to be larger than the minimum width of the shaft projection 84 in a plane orthogonal to the axial direction of the shaft projection 84, and smaller than the diameter of the shaft projection 84. Therefore, the bearing groove 87 of the first link 86 is inserted into the shaft projection 84 from a direction parallel to the plane 85 of the shaft projection 84 within a plane orthogonal to the axial direction of the shaft projection 84, and then the first link 86 is inserted into the shaft projection 84. When rotated around the axis, the first link 86 is held by the fredle 81. Here, the position of the flat surface 85 on the shaft protrusion 84 is provided at a position where the opening edge of the bearing groove 87 and the flat surface 85 are not perpendicular to each other within the operating range of the fredle 81 and the first link 86. Both are designed to prevent them from falling off within the operating range.

The lower end of the first link 86 is rotatably connected to the upper end of the eight second links via a link bridge 88. One end of a tension spring 92 is coupled to the link pin 88 . The other end of the tension spring 92 is connected to a hook hole 93 at the upper end of the handle link 91. As shown in FIG. 2, the handle link 91 is formed in a substantially F-shape that is open downward, and its upper end is integrally connected to the handle 78 so that it swings as the handle 78 is raised and lowered. It has become.

That is, the lower end of the handle link 91 has a substantially U-shaped bearing groove 9=i that is open downward and engages with the shaft protrusion 44 protruding from the outer surface of the support plate 41a of the holding frame 41. , is rotatable around the shaft protrusion 44 together with the handle 78. A stopper protrusion 45 that restricts the rotation range of the handle link 91 is provided at a position different from the shaft protrusion 44 on the outer surface of the support plate 41a.

Further, a bottle 95 is attached to a portion of the handle link 91 that projects upward from the seven holding frames 41.

A circular arc surface 96 is formed on the upper surface of the lower end of the handle 78 along the circular arc surface 6 formed on the inner circumferential surface of the /% unong 1. It is a circular arc. By the way, the lower end of the second link 89 is connected to the contact device 79.

The contact device 79 includes a movable contact 8 having a movable contact 7;
It includes a crossbar 9 that holds a movable contact 8 and a fixed contact 38 that is integrally provided with an arc extinguishing device 80 that will be described later. The movable contactor 8 has one end connected to the heater plate 31 and the other end of the MiA cap 37 connected to the rear end 8a.
The plunger 13 extends rearward so as to be pushed and driven by engaging the recess 13 at the lower end of the plunger 13 of the electromagnetic device 10a. The crossbar 9 is pivotally supported at a fixed position on the inner peripheral surface of the housing 1, and is connected to the movable contact 8 of the other pole.
are designed to be driven at the same time. In other words, similar to the interlocking bar 61 described above, the crossbar 9 is used for various movable contacts 8.
are held at the same time, so that when any one movable contact 8 operates, the remaining movable contacts 8 also operate in the same way. The cross spar 9 is made of an insulating material such as a synthetic resin molded product, and is provided with contact holding portions 39 at three locations in the axial direction. The contact holding parts 3 have a substantially triangular outer shape when viewed from the axial direction of the crossbar 9, and pass through the upper center of the movable contact 8, and insert a torsion spring 100 for contact pressure into the pongee pin 101. The movable contact 8 is rotatably supported by supporting the movable contact 8, and the second link 89
The movable contact 8 is inserted between both sides of the lower end thereof, and is connected to the front lower part of the contact holding part 39 by being rotatably supported on the pongee pin 57.

The fixed contact 38, which constitutes a contact together with the movable contact 7, is provided on the upper surface of a fixed contact plate 67 constituting the arc extinguishing device 80, and an arc running plate 68 is provided at one end of the fixed contact plate 67. One end of an arc drive coil 69 is connected to the end of the fixed contact plate 67 on the opposite side of the arc running plate 68 with the fixed contact 38 in between. Arc drive coil 6
9 is bent into a substantially U-shape that is open downward, and is arranged so that the fixed contact 38 is located at a position corresponding to between both legs. The other end of the arc drive coil 69 is a fixed plate 70
connected to. The fixed plate 70 is bent in a step-like manner,
On the lower side is the base 1a.

The fixing plate 70 is fixed to the base 1a by screwing together the fixing screws 7 inserted from the bottom surface.

The upper side of the fixing plate 70 is a terminal piece 70 exposed on the outer surface of the housing 1. a, and the terminal screw 73 is attached to the terminal piece 70a.
are screwed together. An arc extinguisher 74 is disposed above the arc travel plate 68. The arc extinguisher 74 includes a plurality of grid plates 75 which are electrically conductive plates arranged in parallel with each other spaced apart from each other in the vertical direction.
and the holding frame 7γ formed of an insulating material that holds the grid plate 75. As described above, the terminal pieces 181, the coil 11, the heater plate 31, the braid #i37, the movable contact 8, the movable contact 7, An electric path is formed that passes through the fixed contact 38, the fixed contact plate 67, the arc drive coil 69, the fixed plate 70, and its decorative piece 70b.

(Operation) The operation will be explained below. First, as shown in Figure 11,
When the handle 78 is tilted toward the tripping device 10 (right side in FIG. 11), the movable contact 7 and the fixed contact 38 are separated. In this state, the latch piece 55 of the Lγ link 51 is latched in the holding groove 62 of the interlocking bar 61, and the latch link 51 is held by the link pin 5 by the compression spring 54.
2, it is biased counterclockwise. The lower surface of the holding piece 56 of the latch link 51 is in contact with the upper edge of the locking lever 7-1, and the locking lever 71 is biased clockwise around the link pin 72 by a compression spring 97. Here, since the latch link 51 and the locking lever 7'' are in contact with each other, rotation of both is stopped. The locking protrusion 82 of the fredle 81 is inserted into the notch hole 98 of the locking lever 71, and the rotation of the fredle 81 is stopped. On the other hand, since the straight line connecting both ends of the tension spring 92 passes closer to the 75 side than the shaft protrusion 84, and an upward spring force acts on the link pin 88 connecting the first link 86 and the second link 89, the first Link 86 is biased counterclockwise around shaft projection 84 . Therefore, the second link 89 is pulled upward to the right together with the movable contact 8 connected via the cross par 9, and the movable contact 7 and the fixed contact 38 are separated.A') The cross par 9 moves clockwise. energized.

Next, as shown in FIG.
When tilted to the 0 side (left side in the figure), the straight line connecting both ends of the tension spring 92 passes to the left of the shaft protrusion 44, and the spring force acts downward, so the handle link 91 is biased counterclockwise. , the handle 78 remains tilted to the left. Here, the handle link 91 is connected to the stopper projection 4
5, the maximum rotation angle is regulated. In addition, in this state, the straight line connecting both ends of the tension spring 92 passes to the right of the link pin 83 that pivotally supports the fredle 81, and the spring force acts upward, so the fredle 81 is urged counterclockwise. It turns out. Here, the fredle 81, the locking lever 71, the latch link 51, and the interlocking bar 61 are maintained in the same state as the opened state of the contacts described above. On the other hand, since the link pin 88 connecting the first link 86 and the second link 89 is pulled to the left by the spring force of the tension spring 92, the first link 86 and the second link 89
are arranged substantially in a straight line, and the movable contact 8 connected to the second link 89 via the crossbar 9 is pressed downward, and the movable contact 7 and the fixed contact 38 are closed. At this time, sufficient contact pressure can be obtained by the spring force of the screw spring 100. In this closed state, the movable contact 8
The rear end 8a enters between the horizontal piece 12b and the horizontal piece 11a of the coil 11 via the notch groove 12d of the horizontal piece 12c of the yoke 12 of the electromagnetic tripping device 10a and the notch groove 11 of the fill 11, and the planar It is in a state where it is engaged with the recess 13a of No. 13.

Is there a short circuit when the contacts are closed as described above? 4
When an extremely large current flows, the planter 13 of the electromagnetic tripping device 10a moves downward when
s 口nor' I Q-1,-7-[人l り+
, L +Kmb The rear end 8a of the 8 is pushed down as shown in FIG. 6, the movable contact 8 is rotated clockwise around the shaft pin 101, and the movable liquid, α7, and the fixed liquid, α
38 are momentarily separated. Here, an arc is generated as the movable contact 7 opens, but the arc drive coil 69
Due to the Lorentz force acting between the magnetic field generated around the arc and the arc, the arc is strongly urged toward the grid plate 75 of the arc extinguisher 74, and the arc length is rapidly extended. FIGS. 7(a) to 7(d) are drawings showing the magnetic drive of the arc when the movable contact 7 is opened as described above, and in the closed state shown in FIGS. As shown in FIG. 6(b), an arc is generated between the movable liquid α7 and the fixed contact 38, and the arc is caused by the driving force of the magnetic field generated by the 7-way drive coil 69. As shown in Figure (C), the arc is stretched in the direction of the grid plate 75, and the arc length shown in Figure (D) is rapidly extended. Here, the transition of the arc in the direction of the grid plate 75 is most efficient when the movable contact 7 is opened by about 1 to 5++ on, so the height position of the arc drive coil 69 is the height of the movable contact 7 separated by rpA. The reason why the arc is set at a position substantially equal to or slightly above the arc position is to promote arc migration most efficiently. Figure 8 shows a comparison of the change characteristics of arc voltage, arc current, and opening time between the conventional example and this example, and as shown by curve A in the figure, the current limit for the arc current of this example is It takes place in a short time, and the arc voltage rises quickly as shown by the line. On the other hand, in the conventional example, the arc current is limited slowly as shown by the convex curve, and therefore the arc voltage rises slowly as shown by the dihedral line.

Now, following the opening of the contacts performed by the rotation of the movable contactor 8 due to the pushing drive of the plunger 13,
The trip device 40 is driven by the electromagnetic trip device 10a. The electromagnetic trip device 10a not only handles short circuit current,
It is activated when a large current several times higher than the rated value flows.6 In other words, when a large current passes through the coil 11 of the electromagnetic tripping device 10a, the plunger 13 resists the spring force of the return spring 14 and moves downward ( When the plunger 13 is pulled in, the hook piece 64 of the interlocking bar 61 is pulled downward by the hook piece 24 formed on the upper i part of the plunger 13. As a result, the interlocking bar 61
rotates counterclockwise as shown in FIG. That is, the latch link 51 is rotated clockwise by the spring force of the compression spring 54 and the pressing force on the locking lever 71 is released, so that the locking lever 71 is rotated clockwise by the spring force of the compression spring 54.
The locking protrusion 82 of the fredle 81 is removed from the recessed hole 98 of the locking lever 71 by rotating to the left by the spring force of 7. fredl 81
As described above, since it is biased counterclockwise by the spring force of the tension spring 92, when the engagement with the locking lever 71 is released, it rotates counterclockwise and moves the first link 86 to the upper left. pull it up towards you. Further, when the first link 86 is pulled up, the second link 89 is pulled up to the upper right as the tension spring 92 contracts, and the movable contact 8 is pulled up so as to separate the movable contact 7 from the fixed contact 38. After moving in this manner, when α7 separates from the fixed liquid and α38, the arc length is extended as shown in FIG. 7(d), and the arc is divided by the grid plate 75 and extinguished. . Further, high-pressure arc gas generated by arc generation is exhausted to the outside of the housing 1 through the exhaust plate 99.

As described above, when a large current several times the rating or more passes through, the electromagnetic trip device Wlloa is activated and the trip device 40 is driven, but an overcurrent that is slightly larger than the rating is applied for a long time. When the heater plate 31 heats the bimetal plate 32, the bimetal plate 3
2 is bent, and the suppression screw 33 is the pressing piece 63 of the interlocking bar 61.
By pressing , the interlocking bar 61 can be rotated counterclockwise, and the trip device 40 can be actuated to open the contacts in the same manner as described above.

As described above, when the trip device 40 is activated, the fredle 81 is disengaged from the locking lever 71, so it is necessary to perform a reset in order to close the contact again. To reset, as shown in FIG. 10, when the handle 78 is tilted to the right as much as possible, the pressing protrusion 86 of the fredle 81 is pressed to the right by the pin 95 provided on the handle link 91. Then, the fredle 81 rotates clockwise. By this operation, the locking protrusion 8 of the fredle 81
2 is inserted into the notch hole 98 along the inclined piece 76 extending from the lower edge of the notch hole 98 of the locking lever 71, and the fredle 8
The locking lever 71 rotates counterclockwise due to the pressing force from 1. Therefore, the upper end of the locking lever 71 comes into contact with the lower surface of the holding piece 56 of the latch link 51, and if the force for tilting the handle 78 to the right is removed, the state shown in FIG. 1I is restored.

[Effects of the Invention] The present invention provides an electromagnetic drive means for driving a planter by an electromagnetic drive force when a short-circuit current is applied, a movable contact that is directly pushed and driven in the opening direction by a puff of the electromagnetic drive means, and a movable contact. A shielding FT mechanism is constituted by a fixed contact plate having a fixed contact that comes into contact with and separates from the child and provided with an arc drive fill near the fixed contact, and an arc extinguisher disposed on the opposite side of the movable contact; Since the height position of the arc drive fill of the fixing liquid 7 plate is set at approximately the same level or slightly above the movable contact position when the movable contact is reversed and opened, when a short circuit current flows, the movable contact can be rapidly driven in the separating direction by electromagnetic driving force,
Since the movable contact is close to the arc drive coil at the time of opening, a driving force always acts to drive the arc generated between the movable contact and the fixed contact toward the arc extinguisher, and the arc is extinguished at high speed. As a result, the short circuit current can be efficiently interrupted at high speed and with a high current limit, and as a result, the interrupting capacity can be significantly increased.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the contact and my closed state of the embodiment of the present invention, Fig. 2 is an exploded perspective view of a trip device and a contact device used in the above, and Fig. 3 is a contact used in the same. A partially omitted top view of the device and arc extinguisher, Figure 4 is a perspective view of the tripping device used in the same, Figure 5 is an exploded perspective view of the tripping device used in the same, Figure 6 is a short circuit in the same as the above. △ A cross-sectional view showing a state in which current is applied, FIGS. 7 and 8 are explanatory diagrams of the same operation as above, FIG. 11 is a sectional view showing the reset state, and FIG. 11 is a sectional view showing the off state in the same as above.
Figure 2 is a partially omitted side view of a conventional arc extinguisher and contact α device. 67 is the movable contact, 8 is the movable contact, 10a
1 is an electromagnetic drawer, 13 is a plunger, 13 is a recess, 7
4 is an arc extinguisher, 69 is an arc drive coil, and 75 is a grid plate. Agent Patent Attorney Ishi 1) 议 7th figure 3' 4th figure 5th figure 6th figure 0m (mS)

Claims (1)

[Claims] (1) An electromagnetic drive means that drives a plunger by an electromagnetic drive force when a short circuit current is applied, a movable contact that is directly pushed and driven in the opening direction by the plunger of the electromagnetic drive means, and a movable contact that makes contact with the plunger to open the plunger. A breaking mechanism is constituted by a fixed contact plate which is provided with a fixed contact to be separated and an arc drive coil is provided near the fixed contact, and an arc extinguisher disposed on the opposite side of the movable contact, and A molded circuit breaker characterized in that the height position of the arc drive coil is set at a position approximately equal to or slightly above the position of the movable contact when the movable contact is reversed and opened.