JP3117075B2 - 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 used for controlling a motor and protecting wiring in a low-voltage distribution line.

[0002]

2. Description of the Related Art Conventionally, protection of a motor circuit and the like is generally performed by using a circuit breaker 110 and an electromagnetic switch 1 as shown in FIG.
20, the load-side terminal of the circuit breaker 110 and the power-supply-side terminal of the electromagnetic switch 120 are connected to the respective phases (in the figure, three phases) by the conducting wire 130. FIG. 34 is an internal connection diagram of FIG. In FIG. 34, a circuit breaker 110 for wiring
Has a contact (hereinafter, referred to as disconnecting contact) 111 for interrupting an overcurrent in each phase conduction path and an overcurrent trip device 112. The disconnecting contact 111 is opened and closed by manual operation of the opening and closing mechanism 113. The opening / closing mechanism 113 is opened by a trip command from the overcurrent trip device 112.

That is, when the operating handle 113a is opened and closed in a reset state (a state in which the latch is locked), the action of the opening and closing spring on the toggle link (not shown) is reversed to open and close the disconnecting contact point 111. . When the latch is unlocked by the trip command of the overcurrent trip device 112, the opening / closing mechanism 113 releases the force accumulated in the opening / closing spring to open the disconnecting contact point 111. The overcurrent tripping device 112 includes a time extension tripping section 112a and an instantaneous tripping section 112b. The time extension tripping section detects an overload current and issues a tripping command after a lapse of time according to the current value. Give to 113. On the other hand, the instantaneous trip unit 112b detects a large current such as a short-circuit current,
A trip command is given to the opening / closing mechanism 113 instantaneously.

In FIG. 34, an electromagnetic switch 120 is used.
Has a contact (hereinafter, referred to as an on-off contact) 121 for opening and closing a load current and a thermal relay 122 in an energizing path, and opens and closes the on-off contact 121 by an operating electromagnet 123. When an overload current occurs, the control circuit of the operating electromagnet 123 is opened by the thermal relay 122 and the on-off contact 121 is opened.

[0005]

In the prior art described above, since the circuit breaker for wiring and the electromagnetic switch are connected by a conductor,
A wiring space is required between the two, and the wiring work is complicated. In addition, the circuit breaker 110 for wiring and the electromagnetic switch 120
Since each of them has independent overcurrent protection means, both protection means overlap in the overload protection area, resulting in waste. An object of the present invention is to eliminate the need for wiring work for connecting a disconnecting contact and an on-off contact, and to avoid duplication of overcurrent protection means between the two contacts.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a phase conducting path in which a disconnecting contact and an opening / closing contact are arranged in series, an opening / closing mechanism for opening the disconnecting contact by releasing a force accumulated by a reset operation, and a control signal. An operating electromagnet that opens and closes the switching contact and an overcurrent trip device that detects an overcurrent in the current path and gives a trip command to the switching mechanism and the operating electromagnet are integrally housed in the same insulating container. Circuit breaker. In this circuit breaker, the disconnecting function and the opening / closing function are housed in the same insulating container, so that connection work between them is not required, and both functions are integrated in a compact manner, and the installation space is reduced. Further, the disconnecting contact and the opening / closing contact are controlled by the common overcurrent trip device, and the duplication of the overload protection means is avoided.

The above-mentioned circuit breaker disconnects only the switching contact after a lapse of a specified time after the overcurrent tripping device detects the overload current, and instantaneously disconnects the disconnecting contact and the switching contact after detecting the short-circuit current. Both shall be separated. When a short-circuit current is generated, the disconnecting contact and the switching contact are simultaneously opened, whereby the arc voltage is shared between the disconnecting contact and the switching contact, and the arc energy per contact is reduced, thereby extending the contact life. When an overload current occurs, the operating electromagnet demagnetizes the electromagnetic coil by opening the control circuit to open and close the switching contact.However, when a short-circuit current occurs, the switching electromagnet mechanically opens and closes the switching contact. It can be.
Further, also in this case, if the control circuit of the operating electromagnet is opened at the same time, the disconnection of the on-off contact becomes more reliable and the disconnection state after the trip operation is ensured.

[0008] Even when the overcurrent trip device detects an overload current that is equal to or less than the instantaneous trip operating current, both the disconnecting contact and the on-off contact may be opened after a specific time has elapsed. By doing so, it is possible to extend the life of the on-off contact in a duty such as a six-fold closing of the rated current, which is a duty of normal motor operation, and a duty such as a six-fold closing and a six-fold breaking, which is a condition more severe than the one-time breaking. it can.

If an intermediate terminal for external connection is provided for each phase in the insulating container, and the intermediate terminal is connected between the disconnecting contact and the open / close contact of each phase conduction path, the intermediate terminal is used separately. By connecting the electromagnetic relay, it is possible to provide a plurality of switching contacts for one disconnection function.

When the movable contacts of the disconnecting contact and the opening / closing contact are respectively held by holders made of insulating material, it is preferable that the two holders have a common rotation center and are rotatably supported by the insulating container. Accordingly, when the center of rotation is separated, a space generated therebetween is not required, and the circuit breaker can be made compact. The arc-extinguishing chamber of each of the disconnecting contact and the on-off contact preferably connects the arc-extinguishing space to each other, thereby expanding the arc-extinguishing space and improving the arc-extinguishing performance. In this case, if a commutation plate is provided that straddles both arc extinguishing chambers, the arc current is commutated from the original current path to the commutation plate during the instantaneous trip operation, and the conductive components in the current path become excessive. Can be protected from damage caused by the passage of a large amount of current.

[0011]

FIG. 1 is an internal connection diagram of a three-phase circuit breaker 1 showing an embodiment of the present invention. In FIG. 1, a disconnection contact 5 and an on-off contact 6 are arranged in series on each phase conduction path from the power supply terminal 2 to the load terminal 3 with a thermodynamic / electromagnetic type overcurrent trip device 4 interposed therebetween. These are housed together with the opening / closing mechanism 7 and the operating electromagnet 8 in the same insulating container 9. The disconnecting contact 5 is opened and closed by manual operation of the operation handle 7a in the reset state of the opening and closing mechanism 7.
The switching contact 6 is closed when the operating electromagnet 8 is excited by a control signal applied from the outside, and is opened when the control signal disappears.

When an overload current flows through the current path, the control contact 11 consisting of a normally closed contact inserted in the control circuit of the operating electromagnet 8 is opened by the operation of the time extension tripping part 4a of the overcurrent tripping device 4. Then, the control signal disappears and the switching contact 6 is opened. On the other hand, when a short-circuit current flows in the conduction path, the latch (not shown) of the opening / closing mechanism 7 is unlocked by the operation of the instantaneous tripping section 4b of the overcurrent tripping device 4, and the force accumulated in the opening / closing spring is released to disconnect the disconnecting contact. 5 and the switching contact 6 are simultaneously opened. In this case, as will be described later, the opening / closing mechanism 7 is mechanically connected to the operation electromagnet 8 in a structure that does not hinder the opening / closing operation. Operating electromagnet 8 is open / close contact 6
To separate.

In FIG. 1, an intermediate terminal 12 for external connection is provided for each phase in the insulating container 9, and these intermediate terminals 12 are connected between the overcurrent trip device 4 of each phase conduction path and the switching contact 6. Between the disconnecting contact 5 and the switching contact 6. The intermediate terminal 12 is configured as a plug-in connection type, and is disposed on the back surface (mounting surface) of the circuit breaker 1.

FIG. 2 is an internal connection diagram showing an embodiment of a circuit breaker 1 provided with an electronic overcurrent trip device. The overcurrent tripping device 13 detects the current flowing through the current transformer 14 and, when an overload current flows through the current path, operates the tripping relay 15 to open the relay contact 16 inserted into the control circuit of the operation electromagnet 8. Let go. As a result, the control signal disappears and the switching contact 6 is opened. When a short-circuit current flows through the current path, the overcurrent trip device 13 operates the trip electromagnet 17. Thereby, the latch of the opening / closing mechanism 7 is unlocked, and the disconnecting contact 5 and the opening / closing contact 6 are simultaneously opened as in the case of FIG.

FIG. 3 is a longitudinal sectional view showing a specific structure of the circuit breaker 1 of FIG. In FIG. 3, the circuit breaker is integrally formed in an insulating container 9 including a case 18 and a cover 19, and a bottom plate 18a of the case 18 is detachable. The cover 19 is divided into a cover 19a also serving as a unit case of the overcurrent trip device 4 and a cover 19b also serving as a cover for the operation electromagnet 8. A disconnecting contact 5 and an opening / closing contact 6 are provided in series on each phase conduction path. The disconnecting contact 5 includes a fixed contact 20 having a fixed contact and a movable contact 21 having a movable contact. Is composed of a fixed contact 22 having a fixed contact and a movable contact 23 having a movable contact. Fixed contacts 20 and 2
The power supply side terminal 2 and the load side terminal 3 are formed integrally with each other, and both are fixed to the case 18 by fitting.

The movable contacts 21 and 23 are respectively provided with pins 26 and 25 on holders 24 and 25 each having a substantially fan-shaped cross section made of an insulating material.
And 27, are rotatably supported by contact springs (not shown) toward the fixed contacts 20 and 22, respectively, that is, the movable contact 21 is clockwise in FIG. 3, and the movable contact 23 is counterclockwise. Has been energized. The holders 24 and 25 are formed symmetrically with each other, and are integrally connected between the phases by opening and closing shafts 28 and 29 having a sector cross section. As will be described later in detail, at one portion of the opening / closing shafts 28 and 29 corresponding to the main portion of the sector, a projection is formed integrally with the other, and a concave portion fitted with the projection is formed integrally with the other. Therefore, the holders 24 and 25 have the protrusions and recesses butted against each other as shown in the figure, and are concentric with the semicircular bearing groove (not shown) of the case 18 via the outer peripheral surfaces of the open / close shafts 28 and 29 with the center of rotation being concentric. It is rotatably supported.

FIG. 10 shows a movable contact 23 of the switching contact 6 via the overcurrent trip device 4 from the movable contact 21 of the disconnecting contact 5.
FIG. 4 is a perspective view showing an energization path leading to the power supply. 3 and 10, the movable contact 2 supported by the holders 24 and 25
1 and 23 are slidably contacted with connection plates 30 and 31 fixed to the case 18, respectively, and are electrically connected.
As shown in FIG. 10, the connection plates 30 and 31 are formed in a forked shape, and elastically sandwich the supporting ends of the movable contacts 21 and 23 from the left and right, and are inserted between the holders 24 and 25. The movable contacts 21 and 23 are pressed against each other by a compression spring (not shown). In addition, the movable contact 21
And 23 are provided with arc-shaped elongated holes 30a and 31a (FIG. 10) so as to escape the movement trajectories of the pins 26 and 27 accompanying the rotation of the holders 24 and 25, respectively. In FIG. 3, an intermediate terminal 12 is provided at the bottom of the case 18 so as to face the outside. Intermediate terminal 12
As shown in FIG. 10, is formed integrally with the connection plate 31 on the switching contact 6 side in a clip shape, and is connected to an external connection terminal by insertion connection.

FIG. 4 shows that the opening / closing mechanism 7 and the operating electromagnet 8 are turned on.
FIG. 5 is a perspective view showing a trip crossbar portion of the main part in a state. 3, 4, and 5, the movable contact 21 of the disconnecting contact 5 is driven to open and close by manual operation of the opening and closing mechanism 7, and the movable contact 23 of the opening and closing contact 6 is driven to open and close by remote control of the operating electromagnet 8. . First, the configuration and operation of the opening / closing mechanism 7 will be described below. The opening / closing mechanism 7 is mounted on a frame 32 composed of two left and right side plates (only one side is shown in FIGS. 4 and 5) fixed to the case 18, and is rotatably supported by the frame 32 by pins 33. L-shaped latch 34, which is rotatably supported by frame 32 with pins 35, L-shaped latch receiver 36 for locking the tip of latch 34, and is rotatably supported by overcurrent trip device 4, 36 tip 3
Trip cross bar 37 (FIGS. 3 and 5) for locking 6a with pawl 37a, and first link 3 connected to each other by pin 38
9a and the second link 39b, and the first link 39a
Is connected to the latch 34 by a pin 40, and the second link 39b
Is a toggle link 39 connected to the holder 24 of the movable contact 21 by a pin 41, a handle lever 43 rotatably supported on the frame 32 by a pin 42, and an operation handle 7a (FIG. 3) mounted on the head. One end is handle lever 4
3 and the other end is a toggle link 3
An opening / closing spring 44 (FIG. 3) composed of a tension spring hung on a pin 38 of the ninth embodiment. Note that the latch 3
4, the first link 39a, the second link 39b, and the handle lever 43 are all bifurcated with a pair of left and right arms as shown in FIG. 4 (the handle lever 43 is also cut from the center in FIG. Shown).

6 to 9 are perspective side views of the main part for explaining the opening / closing operation of the circuit breaker 1. FIG. 6 shows an ON state, FIG. 7 shows a disconnecting contact ON and an opening / closing contact OFF state, and FIG. FIG. 9 shows an OFF / reset state. Figure 3,
In the ON state of FIGS. 4 and 6, the opening / closing spring 44 is in a state of accumulating force, that is, in a tension state, and the handle lever 43 receives a rotational force in the counterclockwise direction with the pin 42 as a fulcrum and is held at the ON position in the figure. ing. Toggle link 39
The first link 39a receives a rotational force clockwise about the pin 40, applies a clockwise rotational force to the holder 24 via the second link 39b, and moves the movable contact 21 to the fixed contact 20.
Is pressed. On the other hand, the latch 34, which receives the force of the opening / closing spring 44 via the first link 39a, receives a rotational force in the counterclockwise direction with the pin 33 as a fulcrum. Have been. Latch 3
The latch receiver 36, which is pressed by a locking slope (not shown) on the rear surface thereof, receives a rotational force in the clockwise direction with the pin 35 as a fulcrum.
(FIG. 3) to prevent rotation.

When the operating handle 7a is tilted rightward from the ON state in FIG. 6 and the handle lever 43 is rotated clockwise about the pin 42 as a fulcrum, the center line of the opening / closing spring 44 becomes the first.
With the point passing through the center line of the link 39a from right to left in the drawing as a dead point, the action of the opening / closing spring 44 on the first link 39a is reversed. Therefore, the first link 39a rotates counterclockwise about the pin 40, and simultaneously rotates the holder 24 counterclockwise via the second link 39b.
Thereby, the movable contact 21 is separated from the fixed contact 22 (OFF operation). FIG. 9 shows this OFF state. When the operation handle 7a is tilted to the left from this state, the OFF state is obtained.
The state shown in FIG. 6 is obtained again by an operation reverse to the operation (ON operation).

FIG. 11 is a perspective view of the operation electromagnet 8, FIG. 12 is a perspective view showing a state in which an operation link described later is connected to the armature of the operation electromagnet 8, FIG. 13 is a view of FIG. FIG. 13 is a view in which the operation link of FIG. 12 is connected to the holder 25 of the switching contact 6. 3, 4, 11 to 14, and particularly FIG. 4, the operating electromagnet 8 is formed of a monostable polarized electromagnet, and a rotating plate 46 a having an armature 46 fitted at both ends between a pair of upper and lower yokes 45. Is rotatably supported by the case 18 of the circuit breaker body via
An electromagnetic coil 47 is arranged around a rotation axis of the armature 46. Outside the yoke 45, a permanent magnet 64 is closely arranged.

A U-shaped groove 4 is provided on one end of the armature 46 on both sides.
A pair of left and right hooks 48 having 8a (FIG. 11) is fixed, and a pin 50 fixed to the upper ends of a pair of left and right operation links 49 is fitted into the U-shaped groove 48a. Holder 25 holding movable contact 23
It is connected to. The spring hook 65 at the upper end of the operation link 49 and the spring hook 6 fixed to the operation electromagnet 8
6 (FIG. 13), a return spring 51 (FIG. 3) formed of a tension spring is stretched over, and the pin 50 is inserted into the U-shaped groove 48a.
And the armature 46 is receiving a rotational force in the counterclockwise direction of FIG. A part 49a (FIG. 4) of the upper end of the operation link 49 bulges toward the opening / closing mechanism 7 side, and a trip link 53 is fixed to a pin 52 fixed to this part 49a.
One end of FIGS. 3 and 14 is hooked through a long hole 53a (FIG. 14), and the other end of the trip link 53 is connected to the latch 34 together with the first link 39a by a pin 40.

The electromagnetic coil 47 is connected to a control circuit box 67 (FIG. 1).
1), an operation signal (voltage) is externally applied to the control circuit via the coil terminal 54 in the state shown in FIG. 3, and the armature 46 is connected to the electromagnetic coil 47 and the permanent magnet 64. As shown in the figure, the magnetic flux is attracted to the yoke 45 against the return spring 51 by both magnetic fluxes.
The holder 25 to which a rotational force is applied in a counterclockwise direction via the operation link 49 presses the movable contact 23 against the fixed contact 22. (For details of the monostable type polarized electromagnet, refer to -284262). When the operation signal is cut off from this state, the spring force of the return spring 51 exceeds the attraction force of the permanent magnet 64 alone, and the armature 46 is driven counterclockwise by the return spring 51. Thereby, the holder 25 is connected to the operation link 4
9, the movable contact 23 is separated from the fixed contact 22 as shown in FIG.
operation).

FIG. 15 is a plan view of the overcurrent trip device, and FIG.
6 is a side view thereof, and FIG. 17 is a right front view thereof. 3 and FIGS. 15 to 17, the overcurrent trip device 4 is housed in a cover 19a of the circuit breaker main body, is unitized, and is detachably mounted on the case 18 from above. . The overcurrent tripping device 4 comprises a time tripping part 4a comprising a thermal tripping mechanism and an instantaneous tripping part 4b comprising an electromagnetic tripping mechanism. The time tripping part 4a is a bimetal support comprising an L-shaped bracket. The heater conductor 58 is wound around the outside of the bimetal 57 supported by the cantilever at the left end in FIG. Further, the instantaneous trip portion 4b is provided with a plunger 56 slidably inside the trip coil 55 held in the U-shaped yoke 104, facing the fixed iron core 105 (FIG. 16) fixed to the yoke 104. The plunger 56 is biased by a return spring (not shown) and is held at a position shown in FIG.

As shown in FIG. 10, one end of the trip coil 55 is connected to the connection plate 30 via the plug terminal 68 and the relay conductor 69, and the other end is connected to one end of the heater conductor 58. The other end of the heater conductor 58 is connected to the connection plate 31 via the plug terminal 70 and the relay conductor 71. Here, the relay conductors 69 and 71 are formed in an L shape, and one of the horizontal legs in FIG.
It is fastened with screws (not shown) to 0 and 31, respectively.
The other vertical leg is folded back into a U-shape, and the bent portion is provided with holes for passing plug terminals 68 and 70, respectively. On the other hand, the plug terminals 68 and 70 are strip-shaped and the upper end is tripped, and the coil 55 and the heater conductor 58
And the lower end is detachably insertable.
And 71 are inserted and connected respectively to the folded portions. The overcurrent tripping device 4 is configured to be biased to the right (T-phase side) in the case 18, and the opening / closing mechanism 7 is configured to be biased to the left (R-phase side) as shown in FIG. Thus, the opening / closing mechanism 7 is disposed in a positional relationship shown by a two-dot chain line in FIG. 15 with respect to the overcurrent trip device 4.

In FIGS. 3 and 10, the current flows from the power source terminal 2 to the fixed contact 2 as shown by the broken line arrow in FIG.
0, movable contact 21, connection plate 30, relay conductor 69, plug terminal 68, trip coil 55, heater conductor 58, plug terminal 70, relay conductor 71, connection plate 31, movable contact 2
3. It flows to the load side terminal 3 via the fixed contact 22. When an overload state occurs in the process, the control contact 11 (FIG. 1) is operated by the bending of the bimetal 57 heated by the Joule heat of the current flowing through the heater conductor 58, and the electromagnetic coil 4
The control circuit 7 is opened, the suction of the armature 46 is released, and the switching contact 6 is opened by the spring force of the return spring 51. At that time, the operation link 49 is the trip link 5
Since the pin 52 is freely moved in the long hole 53a (FIG. 14) of the tripping link 53 while swinging the pin 3 around the pin 40 as a fulcrum, the operation of the operation link 49 becomes the tripping link 53.
It is not hindered by

The following describes the time extension operation in more detail. As shown in FIGS. 15 to 17, particularly, FIG. 17, two upper and lower differential shifters 72 and 73 are arranged to face each other near the tip of the bimetal 57, and can be slid right and left in FIG. Supported. In the differential shifters 72 and 73, the contact portions 72a and 73a projecting in a comb-like shape are in contact with both side surfaces of the bimetal 57 with the distal end portion interposed therebetween. 24 and 25 (FIG. 25 is an exploded view of FIG. 24) is provided on the upper and lower differential shifters 72 and 73 with upper and lower projecting shafts 75a.
And 75b. Shifter operating plate 75
An operation section 75c is provided at the lower end of the operation section 75.
One end of a contact operating mechanism 76 for operating the control contact 11 is opposed to c with a certain gap. Here, in FIG. 11, the control contact 11 is provided in the control circuit box 67,
It comprises a movable contact 11a and a fixed contact 11b. Although not shown in detail, the fixed contact 11b is always used.
The movable contact 11a that comes into contact with the movable contact 11a is operated by the contact operating mechanism 76 and is separated from the fixed contact 11b.

Now, when a current flows through the current path of the circuit breaker including the heater conductor 58, the tip of the bimetal 57 heated by the heater conductor 58 bends rightward in FIG. As a result, the differential shifter 73 is pushed rightward, and accordingly, the shifter operation plate 75 and the differential shifter 72 also move rightward in the illustrated posture. In this case, the shifter operating plate 75 is operated by the operating unit 75c if the supplied current is equal to or less than the rated current.
Stops moving before contacting the contact operating mechanism 76,
When the current exceeds the rated current, the contact operating mechanism 76 is pushed rightward in FIG. 17 after the elapse of the delay time according to the current value. As a result, the control contact 11 is opened, and the open / close contact 6 is opened as described above. The differential shifter 72 is provided to open the control contact 11 in a shorter time when a phase loss occurs in the circuit than in the case of a three-phase overload. That is, if any phase is lost, the bimetal 57 of that phase does not bend, so that even when the differential shifter 73 moves to the right, the differential shifter 72 is prevented from moving by the bimetal 57 of the missing phase. As a result, the shifter operating plate 75
17 rotates counterclockwise in FIG. 17 around the protruding shaft 75a, and the differential shifter 75 is rotated by the ratio of the length of the arm between the protruding shafts 75a and 75b and the length of the arm from the protruding shaft 75a to the operation section 75c. The displacement is enlarged, and the control contact 11 is opened in a shorter time than when a normal overload occurs.

On the other hand, in FIG. 3, when a large current such as a short-circuit current flows through the current path, the instantaneous trip portion 4b instantaneously attracts the plunger 56 to the left in FIG. 3 and trips via the link mechanism. The crossbar 37 is rotated clockwise. As a result, the latch 37 is unlocked by the pawl 37a, the latch receiver 36 is rotated clockwise, the latch 34 is unlocked by the latch receiver 36, and the latch 34 is deflected by the spring force of the open / close spring 44. Rotate clockwise.
As a result, the toggle link 39 moves downward, the holder 24 rotates counterclockwise, and the disconnecting contact 5 is opened. When the latch 34 rotates, the operation link 49 is pulled counterclockwise through the trip link 53, and the pin 50
From the U-shaped groove 48a of the hook 48. for that reason,
The operation link 49 is moved downward by the spring force of the return spring 51, and as shown in FIG. 8, the holder 25 rotates clockwise and the on-off contact 6 is also released (instantaneous tripping operation). In addition,
The handle lever 43 rotates clockwise about the pin 42 as the toggle link 39 is lowered, and the operation handle 7a
Moves to an intermediate position between the ON position and the OFF position to display a trip.

The following describes the instantaneous trip operation in more detail. Here, FIGS. 18 to 22 show the overcurrent tripping device 4 in which the time extension tripping part 4a is omitted for simplicity, FIG. 18 is a plan view before an instantaneous tripping operation, and FIG. FIG. 20 is a plan view after the instantaneous trip operation, FIG. 21 is a side view thereof, and FIG. 22 is a right front view thereof. A flange 56a is formed at the tip of the plunger 56 of each phase, and the flange 56a is engaged with the tip of the arm 77a for each phase of the instant cross bar 77 having the shape shown in FIG. Central Minister's Arm 7
7a is provided with a connecting portion 78 for connecting an instant interlocking plate described later. A hook 77b is provided at one end of the instant crossbar 77, and an extension of the shaft end of the shaft portion 77c is a hollow hole 79 of the trip button crossbar 79.
c so as to be rotatable (see FIG. 18). The trip button crossbar 79 is provided with an arm portion 79a and a hook 79b. The hook 79b is connected to the hook 77b with the instant crossbar 77 inserted into the hollow hole 79c of the trip button crossbar 79 as shown in FIG. They are adjacent. The instant crossbar 77 is rotatably supported in the overcurrent trip device 4, and the trip button crossbar 79 is rotatably supported on the shaft end of the instant crossbar 77.

As shown in FIG. 21, in order to link the instant cross bar 77, the trip button cross bar 79 and the trip cross bar 37, the sub cross bar 80 is rotatable about the support shaft 80a. Is provided. The sub crossbar 80 has a rectangular plate shape as shown in FIG. 22, and the upper end faces the hooks 77b and 79b, and the lower end faces the operation piece 37b of the trip crossbar 37. 18 and 19, the shifter operating plate 75
A rotation interlocking plate 81 having a shape shown in FIGS. 24 and 25 is provided in the vicinity of the lower end operation portion 75c so as to be rotatable in a horizontal plane with the shaft portion 81a as a fulcrum. The operation unit 75c faces the lower step portion. An instant interlocking plate 82 is provided between the rotation interlocking plate 81 and the instant cross bar 77, and one end of the instant interlocking plate 82 is provided with a slit 81c of the rotation interlocking plate 81 through a projection 82a.
, And the other end is fitted via a pin 83 into a hole 78a (FIG. 23) of the connecting portion 78 of the instant crossbar 77. Further, as shown in FIG.
A trip button 84 is provided on the upper surface of the device so as to be able to be pushed in together with a return spring (not shown), and an arm portion 79a of a trip button crossbar 79 faces a lower end surface thereof.

In such a configuration, the plunger 56
Is sucked, as shown in FIG.
Turns the instant crossbar 77 clockwise through the arm 77a, and the instant crossbar 77 turns the sub crossbar 80 counterclockwise through the hook 77b. As a result, the sub crossbar 80 rotates the trip crossbar 37 clockwise through the operation protrusion 37b, and disengages the pawl 37a from the latch receiver 36. As a result, as described above, the disconnecting contact 5 and the switching contact 6 associated therewith are opened. At this time, as shown in FIG. 20, the instant crossbar 77 rotates the rotation interlocking plate 81 counterclockwise via the instant interlocking plate 82, and the rotation interlocking plate 81 rotates through the arm 81b as shown in FIG. As shown in FIG.
Rotate counterclockwise around 5a. As a result, the contact operating mechanism 76 is pushed, the control contact 11 is opened, and the control circuit is opened. The switching contact 6 is opened in conjunction with the disconnecting contact 5, and at this time, the control circuit of the operating electromagnet 8 is also opened at the same time, so that the disconnection of the switching contact 6 and the disconnection state after the tripping operation are reliably maintained. Become.

In FIG. 8, in order to reset the opening / closing mechanism 7 having performed the instantaneous trip operation, the operating handle 7a is moved rightward from the trip position to the OFF position. As a result, the latch 34 is lifted by the pin 63 at the tip of the handle lever 43, and rotates clockwise to engage the latch receiver 36 again. At this time, the operation link 49 is pushed rightward by the latch 34 via the pin 52, and the armature 46 is a projection 46b protruding toward the opening / closing mechanism 7.
(FIG. 11) is pushed by the overhang portion 43a (FIG. 4) of the handle lever 43 and rotates counterclockwise, so that the pin 50 enters the U-shaped groove 48a of the hook 48 of the armature 46, and FIG. To the OFF state (reset state). Thereafter, when the operation handle 7a is moved to the left toward the ON position, the opening / closing spring 44 is stretched and the power is accumulated, and the disconnecting contact 5 is turned ON again in FIG. Although not shown, the latch receiver 36 and the trip crossbar 37 are provided with return springs that constantly urge counterclockwise, and cooperate with the reset operation.

In FIG. 3, a disconnecting contact 5 and a switching contact 6
Has an arc-extinguishing grid 59 made of a U-shaped magnetic plate.
Arc extinguishing chambers are provided in which the arc extinguishing grids 59 and 60 are stacked. The arc extinguishing grids 59 and 60 are joined by caulking at both left and right ends to a pair of left and right insulator side walls 61 extending integrally between the two contacts 5 and 6. And the space between the arc-extinguishing grids 59 and 60 communicates. Thus, the arc-extinguishing chambers formed inside the left and right side plates 61 share an arc-extinguishing space between the disconnecting contact 5 and the on-off contact 6, and have an arc-extinguishing chamber independent of each other. As a result, the arc extinguishing space of each of the contacts 5 and 6 is substantially expanded, and the arc extinguishing performance is improved accordingly. Also,
In the arc-extinguishing chamber, a commutation plate 62 made of a strip-shaped conductor bent in the illustrated shape so as to straddle between the arc-extinguishing grids 59 and 60.
Is provided. The commutation plate 62 is movable when a large current is interrupted.
This is for commutating the foot on the movable contact side of the arc generated between the fixed contacts, and thereafter, the current flows by bypassing the commutation plate 62, and a large current flows through the original current path of the circuit breaker. This prevents the overcurrent trip device 4 from being damaged.

According to the above-described embodiment, since the circuit breaker 1 has the disconnecting contact 5 and the switching contact 6 in the same insulating container, there is no need for connection work and wiring space therebetween. Further, at the time of short circuit, both the disconnecting contact 5 and the switching contact 6 are simultaneously opened, so that a large short-circuit current can be interrupted. Furthermore, since there are intermediate terminals 12 for external connection connected between the disconnecting contact 5 and the switching contact 6, respectively, the intermediate terminal 1
By connecting an electromagnetic contactor to 2, a plurality of switching contacts can be connected to the same disconnecting contact.

Next, a holder having a concentric center of rotation will be described in detail with reference to FIGS. 26 is a plan view of the movable contact portion, FIG. 27 is a perspective view of the movable contact portion, and FIG. 28 is an exploded perspective view partially showing an opening / closing shaft supported on the phase gap wall. The opening / closing shafts 28 and 29 integrally connected with each other are formed in a fan shape with the pivot center as a main part. A concave portion 28a formed of an arc surface and a columnar projection 28b are formed at the center of rotation of one opening / closing shaft 28, and the projection 28b is fitted to the center of rotation of the other opening / closing shaft 29. A concave portion 29a having an arcuate surface and a columnar protrusion 29b fitted into the concave portion 28a are formed. Further, semicircular insulating plates 86 and 87 having a central angle slightly larger than 180 degrees are formed integrally with the opening / closing shafts 28 and 29 in the axial direction.

The right and left holders 24 and 25 are formed by mutually opposing concave portions 28a and 29a and projecting portions 28b and 28b, respectively, to form a common center of rotation 85. As shown in FIG. And 29, it is rotatably supported on the phase space wall 18a of the case 18. A pair of upper and lower semi-circular bearing grooves 88 are formed on the mating surface of the phase space wall 18a of the case 18 and the phase space wall of the cover (not shown).
Are formed respectively, but each inter-phase wall 18a of FIG.
The bearing groove 88 shows only the case 18 side.

In FIG. 28, the left and right opening / closing shafts 28 and 29 formed independently of each other are inserted into bearing grooves 88,
The two opening / closing shafts 28 and 29 are rotationally supported independently of each other with a common rotation center 85 by the sliding contact between the fan-shaped outer peripheral circle and the inner peripheral surface of the bearing groove 88. Insulating plates 86 and 87
Are accommodated in the recess 89, but the left and right insulating plates 86, 87 are displaced from each other in the axial direction, and the left and right opening / closing shafts 28, 2
In a state where the members 9 abut against each other, as shown in FIG. 26, they overlap with each other and slide with the rotation of the open / close shafts 28 and 29.

FIGS. 29A and 29B show how the left and right insulating plates 10 overlap. FIG. 29A shows that both contacts 5 and 6 are closed, and FIG.
Indicates that both contacts 5 and 6 are open, (C) indicates that disconnecting contact 5 is closed and switching contact 6 is open, and left and right insulating plates 86 and 87 overlap each other in the shaded portion. . As shown, the left and right insulating plates 86, 87 overlap in any state to form a complete circle. Thereby, a large creepage distance 90 (FIG. 26) is obtained between adjacent phases. As described above, the holder 24 of the disconnecting contact 5 and the switching contact 6,
By making the rotation centers 85 of the 25 concentric, the longitudinal dimension of the circuit breaker is reduced as compared with the case where the respective rotation centers are separately located at intervals.

FIGS. 30 to 32 show an electronic overcurrent trip device that detects an overcurrent by a current transformer and outputs a trip signal. FIG. 30 is viewed from the switching contact side (load side). FIG. 31 is a perspective view, FIG. 31 is a sectional view taken along the line AA of FIG. 30, and shows a non-operating state, and FIG. 32 shows the same operating state. The electronic overcurrent trip device 13 includes a current transformer 14 of each phase, a main circuit conductor 91, a printed board 92 on which an electronic circuit is mounted, a trip electromagnet 17, and the like.
Are integrated. The main circuit conductors 91 of each phase are located before and after the current transformer 14, that is, on the power supply side and the load side, and two flat connection conductors 94 and 95 sandwiching the current transformer 14 from the left and right; 14 and a through conductor 96 formed of a round bar extending between the connection conductors 94 and 95. The ends of the connection conductors 94 and 95 are fastened to the connection plates 30 and 31 of the disconnecting contact 5 and the switching contact 6, respectively. Terminal portions 94a and 95a are formed, respectively.

In FIGS. 31 and 32, the tripping electromagnet 17 is configured as a magnetic holding type.
Is always attracted to the fixed iron core 100 by the magnetic flux of the permanent magnet 98 while compressing the trip spring 99. When a trip signal is input to the trip coil 101 and the magnetic flux weakens the magnetic flux of the permanent magnet 98, the spring force of the trip spring 99 exceeds the attraction force, and the movable iron core 97 is driven downward, and the head Pushing the arm 37c of the trip cross bar 37 via the trip plate 102 attached to the, the clockwise rotation of the trip cross bar 37 releases the engagement between the pawl 37a and the latch receiver 36 (FIG. 3). . As a result, the disconnecting contact 5 and the switching contact 6 are opened in the same manner as in the case of the thermodynamic / electromagnetic type overcurrent trip device 4. Here, the trip crossbar 37 is composed of a thermal-electromagnetic overcurrent trip device 4 and an electronic overcurrent trip device 13.
The arm 37c on which the trip plate 102 of the overcurrent trip device 13 acts as shown in FIG.
The tripping plate 102 is also formed in a gate shape so that the latch receiver 36 that rotates clockwise during the tripping operation does not come into contact, and the trip plate 102 is also formed in a gate shape. It is designed to be pressed.

The electronic overcurrent tripping device 13 is shown in FIG.
Is used in place of the thermal-electromagnetic overcurrent trip device 4 and is screwed to the connection plates 30 and 31 via the terminals 94a and 95a, respectively. The thermal-electromagnetic type overcurrent trip device 4 is provided with a cover 19 for the circuit breaker body.
The electronic overcurrent trip device 13 is mounted by being inserted into the relay conductors 69 and 71 and attached, as described above, and a separate main body cover (not shown) is attached from above. The current transformer 14 detects a current flowing through the through conductor 96 constituting a part of the current path as a current signal and outputs the current signal to an electronic circuit on the printed board 92. When the electronic circuit determines from the current signal that the supplied current is in an overcurrent state, the electronic circuit outputs a trip signal after a lapse of time according to the current value.

In this case, when the current is overloaded, the trip signal is input to the trip relay 15 (FIG. 2), and the relay contact 16 inserted in the control circuit of the operating electromagnet 8 is opened and closed. The contact 6 is opened. When a large current such as a short-circuit current flows, a tripping signal is input to the tripping electromagnet 17 to disconnect the disconnecting contact 5 and the switching contact 6 as described above. Note that, even in an overcurrent state, when the current value exceeds a certain level, the tripping electromagnet 17 can be operated to open both the disconnecting contact 5 and the switching contact 6.

As described above, the present invention has the following effects. (1) Since the disconnecting function and the opening / closing function are housed in the same insulating container, both functions are compactly integrated, so that connection work between them is not required and the installation space is reduced. (2) When a short circuit occurs, both the disconnecting contact and the switching contact are simultaneously opened, so that an arc voltage is generated in series, the current limiting effect is increased, and a large short-circuit current can be interrupted. (3) An intermediate terminal for external connection is provided between the disconnection contact and the on-off contact of each phase current path.By connecting a branch system electromagnetic contactor to this intermediate terminal, the same disconnection function can be achieved. A plurality of opening and closing functions can be easily connected.

[Brief description of the drawings]

FIG. 1 is an internal connection diagram of a circuit breaker showing an embodiment of the present invention.

FIG. 2 is an internal connection diagram of a circuit breaker showing another embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing an internal configuration of the circuit breaker of FIG.

FIG. 4 is a perspective view showing an opening / closing mechanism and an operation electromagnet in the circuit breaker of FIG. 3;

FIG. 5 is a perspective view showing a trip crossbar in the circuit breaker of FIG. 3;

FIG. 6 is a perspective side view in an ON state illustrating an operation of the circuit breaker of FIG. 3;

FIG. 7 is a switching contact O for explaining the operation of the circuit breaker of FIG. 3;
It is a perspective side view of FF state.

FIG. 8 is a perspective side view illustrating an operation of the circuit breaker of FIG. 3 in an instantaneous trip state.

FIG. 9 is a perspective side view in a reset state illustrating the operation of the circuit breaker of FIG. 3;

10 is a perspective view showing an energizing path of an overcurrent trip device in the circuit breaker of FIG.

11 is a perspective view showing an operating electromagnet in the circuit breaker of FIG.

12 is a perspective view showing a state where an operation link is connected to the operation electromagnet of FIG. 11;

FIG. 13 is a perspective view showing FIG. 12 from the opposite side.

14 is a perspective view showing a state in which the operation link of FIG. 13 is connected to a movable contact holder of an on-off contact.

FIG. 15 is a plan view of an overcurrent trip device in the circuit breaker of FIG. 3;

16 is a side view of FIG.

FIG. 17 is a right front view of FIG. 16;

18 is a plan view showing the overcurrent trip device of FIG. 15 without a bimetal.

19 is a side view of FIG.

20 is a plan view showing a state in which the overcurrent trip device of FIG. 18 operates.

FIG. 21 is a side view of FIG. 20.

FIG. 22 is a right front view of FIG. 21.

23 is an exploded perspective view of the instant crossbar and the trip button crossbar in FIG. 18.

24 is a perspective view of the shifter operation plate and the instant interlocking plate in FIG. 18.

FIG. 25 is an exploded view of FIG. 24.

26 is a plan view of a movable contact portion in the circuit breaker of FIG.

FIG. 27 is an exploded perspective view of FIG. 26.

28 is a perspective view of an opening / closing shaft portion of FIG. 27.

FIG. 29 is a side view showing an overlapping state of the insulating plates of the movable contact portion in FIG. 26, (A) both the disconnecting contact and the on-off contact are open, (B) is both closed, and (C) is Disconnect contacts closed,
The open / close contact indicates an open state.

FIG. 30 is a perspective view of an electronic overcurrent trip device.

FIG. 31 is a cross-sectional view of FIG. 30 taken along the line AA.

32 is a diagram when the trip coil unit in FIG. 31 operates.

FIG. 33 is a front view of a circuit breaker and an electromagnetic switch 120 showing a conventional example.

FIG. 34 is an internal connection diagram of FIG. 33.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 4 Overcurrent tripping device 4a Extended tripping part at 4a Instantaneous tripping part 5 Disconnection contact 6 Switching contact 7 Switching mechanism 7a Operation handle 8 Operating electromagnet 9 Insulating container 12 Intermediate terminal 13 Overcurrent tripping device 14 Current transformer 17 Tripping Electromagnet 20 Fixed contact 21 Movable contact 22 Movable contact 23 Opening / closing mechanism 24 Holder 25 Holder 34 Latch 36 Latch receiver 39 Toggle link 43 Handle lever 45 Yoke 46 Armature 47 Electromagnetic coil 49 Operation link 51 Return spring 53 Trip link 62 Commutation Board

Continuation of the front page (72) Inventor Katsunori Kuboyama 1-1, Tanabe-Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fuji Electric Co., Ltd. (72) Inventor Hiroaki Tosaka 1-1-1, Tanabe-Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Fuji Inside Electric Co., Ltd. (72) Inventor Kentaro Toyama 1-1-1, Tanabe Nitta, Kawasaki-ku, Kawasaki, Kanagawa Prefecture Inside Fuji Electric Co., Ltd. (72) Inventor Koji Nomura 1-1-1, Tanabe Nitta, Kawasaki-ku, Kawasaki-ku, Kanagawa Fuji Inside Electric Machinery Co., Ltd. (72) Inventor Isamu Nagahiro 1-1-1, Tanabe Nitta, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture Inside Fuji Electric Co., Ltd. (56) References JP-A-4-75227 (JP, A) JP-A-4- 163823 (JP, A) JP-A-63-141218 (JP, A) JP-A-8-148067 (JP, A) JP-A-1-172247 (JP, U) JP-A-48-38379 (JP, Y1) (58) Field surveyed (Int.Cl. ⁷ , DB name) H01H 73/36 H01H 9/02 H01H 33/59

Claims (9)

(57) [Claims] An open / close mechanism for opening the disconnection contact by releasing a force accumulated by a reset operation; and an operation for opening / closing the open / close contact by a control signal. A circuit breaker, wherein an electromagnet and an overcurrent trip device that detects an overcurrent in the current path and outputs a trip command to the switching mechanism and the operating electromagnet are integrally housed in the same insulating container. . 2. The circuit breaker according to claim 1, wherein only the switching contact is opened after a lapse of a specific time after the overcurrent trip device detects the overload current. 3. The circuit breaker according to claim 1, wherein both the disconnecting contact and the on-off contact are instantaneously opened after the overcurrent trip device detects the short-circuit current. 4. The circuit breaker according to claim 2, wherein the operating electromagnet opens and closes the on-off contact when the control circuit opens. 5. The circuit breaker according to claim 2, wherein the operating electromagnet mechanically works with the switching mechanism to open and close the switching contact. 6. The circuit breaker according to claim 1, wherein both the disconnecting contact and the on-off contact are opened after a lapse of a specific time after the overcurrent trip device detects the overload current. 7. An intermediate terminal for external connection is provided for each phase in the insulating container, and the intermediate terminal is connected between a disconnecting contact and a switching contact of each phase conducting path. The described circuit breaker. 8. The movable contact of the disconnecting contact and the opening / closing contact are respectively held by holders made of insulating material, and both holders are rotatably supported by an insulating container with a common rotation center. The circuit breaker according to claim 1, wherein 9. An arc extinguishing space of an arc extinguishing chamber for a disconnecting contact and an on-off contact is communicated with each other, and a commutation plate is provided in the arc extinguishing space so as to straddle the two arc extinguishing chambers. The circuit breaker according to claim 1.