JPH04230927A - Circuit breaker - Google Patents

Abstract

PURPOSE:To easily perform a switching action test by providing the TEST mode while the disconnecting contact of a main current path is opened. CONSTITUTION:When a control handle 79 is turned to a TEST or ISOL device, an eccentric cam 76 is also turned, and the first lever 105 is turned counterclockwise. A three-pole interlocking disconnecter 109 coupled with a lever 107 is lifted upward as the lever 105 is turned, a conductor 25 is separated from a power source side terminal conductor 16 and a solid conductor 12, and a main current path is cut off. In the TEST mode, a monitor action can be performed because a limit switch 118 is turned on, while in the ISOL mode, no monitor action can be performed because the limit switch 118 is turned off. The switching action test of circuit cutoff can be thereby easily performed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker, and more particularly to a circuit breaker having both a circuit breaking function and an electromagnetic switching function.

0002

2. Description of the Related Art Generally, circuit breakers are intended to protect electrical circuits and system equipment against overload currents or short circuit currents. When the load is frequently switched, an electromagnetic switch connected in series with the circuit breaker is provided, and the load is switched by the electromagnetic switch, which has long switching durability.

FIG. 23 is a block diagram showing the circuit configuration of a conventional circuit breaker. The conventional circuit breaker shown in FIG. 23 has a main contact S and a disconnection contact D in each of the three main current paths.
S is provided. The main contacts S are opened and closed by the operation of the electromagnet 150. The electromagnet 150 is connected to a power source E, and is turned on/off by a limit switch 152 and a switch 153 provided in the circuit. The circuit of the disconnection contact DS is made conductive or disconnected by a mechanical opening/closing means. The operating mode of the circuit breaker is selected by a switching handle 151. Handle 1
Table 1 shows the circuit open/close states in each operating mode of the circuit breaker selected by 51.

0004

[Table 1]

When the handle 151 is in the "AUTO" position, the disconnection contact DS is in a conductive state, the limit switch 152 is turned on, and current can be applied to the load via the circuit breaker. The handle 151 is “
In the "OFF" position, the limit switch 152 is set to OFF, the electromagnet 150 is de-energized, and the main contact S is in an open state. At this time, disconnection contact DS
is in a closed state. Furthermore, the handle 151 is
In the "OL" position, the disconnection contact DS is opened and closed, the limit switch 152 is set to the OFF state, the electromagnet 150 is de-energized, and the main contact S is opened and closed. Note that when an overcurrent occurs in the circuit and the overcurrent response device is activated, the limit switch 152 is automatically turned OFF, the electromagnet 150 is de-energized, and the main contact S
is released. At this time, the handle 151 automatically
RIP” position. In addition, in order to return from the "TRIP" state to the "AUTO" state, press the handle 1.
51 to "RESET", then "AUTO"
You can set it to the position.

[0006]

SUMMARY OF THE INVENTION In a circuit breaker, it is necessary to perform a test to confirm the operation of the electromagnetic switching means of the main contact S using an electromagnet 150 or the like. However, the conventional circuit breaker described above does not have an operating mode for testing the circuit breaker. In testing a circuit breaker, it is necessary to check the electromagnetic switching operation of only the main contact S with the main current path disconnected. However, none of the five modes shown in Table 1 satisfy this condition. Therefore, in order to test such a conventional circuit breaker, the handle 151 must be rotated to the "ISOL" position to disconnect the disconnect contact DS, and then some method must be taken to disconnect the disconnect contact D.
While maintaining the open state of S, turn the handle 151 again.
I had to turn it to the ``AUTO'' position. However, this method is not based on the original function of the circuit breaker, and is not only difficult to test, but also impossible depending on the structure of the circuit breaker. .

[0007] Therefore, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a circuit breaker having a structure that allows easy testing of the opening/closing operation of the contacts of the circuit breaker. With the goal.

[0008]

[Means for Solving the Problem] A circuit breaker according to claim 1 includes a disconnecting contact and a fixed contact provided in series in the middle of a main current path connecting a power supply side circuit terminal and a load side circuit terminal. , a movable contact that performs a circuit opening/closing operation by contacting and separating from a fixed contact, and an electromagnet for causing the movable contact to perform a circuit opening/closing operation. Furthermore, a transmission device is provided between the electromagnet and the movable contact to transmit the operation of the electromagnet to the movable contact. moreover,
A lock position that engages with the transmission device and holds the transmission device in a state where the movable contact and the fixed contact are separated, and a lock that returns the transmission device to a state where the movable contact and the fixed contact can be brought into contact. A locking device movable between the locking device and the release position, a disconnecting contact opening/closing means including a movable conductor that moves to connect or disconnect the disconnecting contact, and engaging the locking device and the disconnecting contact switching device. It has an operation switching device. The operation switching device has a first position in which the circuit switching device connects the disconnecting contact and the locking device is held in the unlocked position, and a first position in which the disconnecting contact switching device disconnects the disconnecting contact and the locking device is held in the unlocked position. and a second position.

In the circuit breaker according to claim 2, the operation switching device further includes a third position in which the disconnection contact opening/closing device connects the disconnection contact and the locking device is held in the locked position; and a fourth position in which the switching device disconnects the disconnecting contact and the locking device is held in the locked position.

0010

In the circuit breaker according to the present invention, by setting the operation switching device to the second position, the opening/closing operation of the circuit breaker can be tested using an electromagnet. That is, when the operation switching device is in the second position, the disconnection switching device disconnects the disconnection contact. Therefore, continuity between the circuit breaker and the current path is broken. Further, by holding the locking device in the unlocked position, the movable contact becomes operable, and opening/closing operations can be performed by the electromagnet.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an external perspective view of a three-pole type circuit breaker having an overload short-circuit protection function according to an embodiment of the present invention. The housing of the circuit breaker is composed of six parts: a base 1, an operating mechanism unit housing 3, a tripping unit housing 4, and three independent switching unit housings 2 for each pole. Further, FIG. 22 is a circuit configuration block diagram showing a schematic configuration of the circuit breaker. Referring to FIG. 22, the circuit breaker has three independent main current paths, and there is a disconnection contact D in the middle of each path.
A main contact S, an electromagnet ST for forced opening in the event of a short circuit, a current transformer CT for current detection, and a zero-phase current transformer ZCT are provided. Three opening/closing means are provided as contact opening/closing means for opening/closing the main contact S. The first opening/closing means is a means for opening/closing the main contact S using an electromagnet 60 for opening/closing operation. The second opening means opens the main contact S by a spring release mechanism 75b that operates in response to a detection signal from a current detection current transformer CT or a zero-phase current transformer ZCT provided in the main current path. It is something to do. The third opening means is a means for opening the main contact S by the operation of a forced opening electromagnet ST provided in the main current path. The structure of a circuit breaker having such a circuit configuration and mechanism will be described below.

FIG. 2 is a sectional view of the center side of the circuit breaker shown in FIG. 1 in the closed state, and FIG. 3 is a cross-sectional view of the circuit breaker shown in FIG.
It is a top view from the direction along X. Referring to both figures,
The circuit breaker includes a hollow base 1 made of a molded insulator, an independent opening/closing unit housing 2 for each pole made of a molded insulator inserted from the bottom of the base 1, and a circuit breaker housing 2 on one side of the top of the base 1. An operating mechanism unit housing 3 made of a formed insulator and a trip unit housing 4 made of a molded insulator formed on the other side of the upper part of the base 1 are attached.

The opening/closing unit housing 2 has an elongated shape, and a power supply side terminal conductor 16 disposed at one end passes through a disconnection section 13 to a first fixed conductor 12, a main contact section 5, and a second fixed conductor 14. A current path leading to is constructed. Arc extinguishers 7, 7 are arranged on both sides of the main contact portion 5. The main contact part 5 includes a pair of fixed contacts 10, 10 provided on a first fixed conductor 12 and a second fixed conductor 14,
A movable contact 8 is located at a position opposite to the fixed contacts 10, 10.
8 and a bridging type movable contact 9 and this movable contact 9
The contact spring 11 supports the movable contact 8 from below and always presses the movable contact 8 against the fixed contact, and the opening/closing lever 17 extends in the vertical direction and is connected to the movable contact 9. The opening/closing operation of the main contact section 5 is performed by pushing down the opening/closing operation lever 17 to open the space between the fixed contacts 10, 10 and the movable contacts 8, 8, and the return operation is performed by the restoring force of the contact spring 11 between the fixed contacts 10 and 10. This is done by making contact with the movable contact 8.

One end of the first fixed conductor 12 having one fixed contact 10 extends to the upper part of the arc extinguishing device 7 to form an arc horn, and the other end extends to the disconnecting section 13. Also, a second fixed conductor 1 having the other fixed contact 10
4 has one end extended to the top of the arc extinguishing device 7 to form an arc horn, and the other end folded back and extended along the top of the housing 2 to connect to the tripping unit through the through hole of the base 1. It is provided so as to be exposed in the groove of the housing 4.

[0015] Also, this opening/closing/blocking unit housing 2
An interlocking mechanism 18 for forced opening in the event of a short circuit is provided near the top of the main contact 5 in the main contact 5. This will be discussed later.

Further, an arc runner 15 provided along the bottom wall of the switching/closing unit housing 2 connects the fixed contacts 10 and 10 of the first fixed conductor 12 and the second fixed conductor 14.
They are provided at the lower part of the arc extinguishing devices 7, 7 in correspondence with the arc runner portion formed to extend to the side.

The interior of the trip unit housing 4 includes an electromagnet 30 for forced opening in the event of a short circuit, a zero-phase current transformer 40, a current transformer 41 for current detection, and a load-side terminal conductor 43, each of which is connected in series. Configure the main current path.

The electromagnet 30 for forced opening in the event of a short circuit is a plunger type electromagnet composed of a fixed iron core 32, a corresponding movable iron core 33, a return spring 34, a magnetic yoke 35, and an exciting coil 36. A protruding rod 31 is integrally attached to the movable iron core 33. The tip of the protruding rod 31 passes through a through hole provided in the tripping unit housing 4, the base 1, and the opening/closing blocking unit housing 2, and comes into contact with the first lever 19 of the interlocking mechanism 18 for forced opening in the event of a short circuit. The input end of the excitation coil 36 is connected to the second fixed conductor 14 exposed at the top of the opening/closing unit housing 2.
is connected by a screw 24 to the output conductor 39.
The iron core 4 of the current detecting current transformer 41 is passed through the through hole of one zero-phase current transformer 40 for common use with three poles provided as necessary.
2 as a primary coil.

The lead-out end of the primary coil of the current detecting current transformer 41 is connected to one end of the load-side terminal conductor 43. A secondary coil 44 is located on the other side of the iron core 42 of the current detecting current transformer 41.
is wound, and the lead-out wire of the secondary coil is connected as an input to an electronic overcurrent relay 45 disposed above the secondary coil.

With the above configuration, a main current path from the power supply side terminal conductor 16 to the load side terminal conductor 43 is constructed.

Next, the configuration of the three separating means of the main contact 5 will be explained. First, a configuration using the opening/closing electromagnet 60 as the first contact opening means will be described. Figure 2
Referring to FIGS. 4 to 4, the opening/closing electromagnet 60 is arranged in the operation mechanism unit housing 3 together with the operation control mechanism 75. The opening/closing electromagnet 60 is composed of an E-shaped fixed core 61, a corresponding E-shaped movable core 62, and an excitation coil 63 and an attraction/release spring 64 that are wound around the central leg of each core. Ru. The fixed core 61 of the opening/closing operation electromagnet 60 is attached to the end cover 3 of the operating mechanism unit housing together with the fixed frame 65 by a plate spring 66 inserted into a through hole 61a provided in the fixed core 61.
It is fixedly supported by a. The movable core 62 is movably attached to the fixed frame 65 via a suction release spring 64 by a spring installation plate 69 that is integrally attached to the movable core 62 . The suction release spring 64 always urges the movable iron core 62 in a direction away from the fixed iron core 61. The movable core 62 has a movable core operating pin 73 that passes through the movable core 62 and moves integrally with the movable core 62.
is formed. Furthermore, an electromagnet operating lever 71 that engages with this movable core operating pin 73 is provided at one end of the fixed frame 65.
is mounted rotatably about a shaft 72. A cross bar 74 is attached to one end of the electromagnet operating lever 71. The cross bar 74 connects three opening/closing unit housings 2, 2, 2 arranged in parallel inside the base 1.
It is composed of an integral molded body that simultaneously contacts the heads of the opening/closing operation levers 17, 17, 17, which respectively protrude from the opening/closing levers.

Furthermore, FIG. 2 shows the second contact opening means.
, will be explained with reference to FIGS. 3, 5, and 6. Figure 5 shows
FIG. 4 is an enlarged plan view of a main part near the release type electromagnet 46 in FIG. 3; Further, FIG. 6 is a cross-sectional structural diagram taken from the direction of the cutting line Y in FIG. 2. In FIG. The second contact opening means passes from one end of the secondary coil 44 of the current detecting current transformer 41 to the electronic overcurrent relay 45 and the release type electromagnet 46, and further via the operation control mechanism 75 to the three-pole interlocking crossbar. It is composed of up to 74 devices. Referring to FIG. 5, release type electromagnet 4
Reference numeral 6 denotes a U-shaped frame 47 made of a magnetic material, a permanent magnet 48 disposed within the U-shaped frame, a tripping coil 49 wound around one end of the U-shaped frame 47, an armature 50, and an armature 50. It is composed of a rotatably supported support member 51 and a tripping spring 52. Release type electromagnet 4
6, the armature 50 is attracted and held by the leg portion of the U-shaped frame 47 against the acting force of the tripping spring 52 by the magnetic flux constantly applied by the permanent magnet 48. When an output signal from the electronic overcurrent relay 45 is input to the tripping coil 49 in this state, magnetic flux is generated in a direction that cancels the magnetic flux of the permanent magnet 48, and the armature 50 is opened from the legs of the U-shaped frame 47. Let go. One end of the armature 50 contacts a tripping transmission plate 54 that transmits the opening movement of the armature 50,
The other end of the tripping transmission plate 54 further abuts one end of the response transmission plate 103. The other end of the response transmission plate 103 is in contact with one end of the overload response trip actuation plate 102. The overload responsive trip actuation plate 102 rotates around the shaft 101. And overload response trip actuating plate 10
The other end of 2 corresponds to the secondary hook 99 of the operation control mechanism 75 shown in FIG. The transmission mechanism shown in FIG. 5 converts an excessive current detection signal generated in the main current path into a mechanical signal.

Next, referring to FIG. 6, the operation control mechanism 75
We will explain the structure of The operation control mechanism 75 is roughly divided into a handle mechanism section 75a operated by a control handle 79, and a spring release mechanism section 75b for mechanically opening and closing the main contact. Handle mechanism section 75
a is a control handle 79, a camshaft 77 attached to this control handle 79, and a camshaft 77;
The eccentric cam 76 is connected to the eccentric cam 76, and the slide plate 84 is connected to the eccentric cam 76 and performs a sliding movement. The control handle 79 is rotatably supported, and the control handle 79 is rotatably supported.
"TO", "TRIP", "OFF", "RESET",
It has six switching positions: "TEST" and "ISOL". 8, 12 and 1 on the lower surface of the eccentric cam 76.
A cam groove 76a shown in 6 is formed, and the tip of a slide plate sliding pin 83 is inserted into this cam groove. The slide plate sliding pin 83 passes through a linear guide hole provided in the fixed frame 80 and is caulked to one end of the slide plate 84. A portion of the slide plate 84 has an ear portion 84a bent into an inverted U shape. With this structure, when the control handle 79 is rotated, the rotational movement is converted into a linear movement of the slide plate 84 by the action of the eccentric cam 76.

The spring release mechanism 75b includes a secondary hook 99, a primary hook 97, and a releasable lever 93 in the order of engagement.
, link 92, link 90 and crossbar control lever 87. The bent piece 99a of the secondary hook 99 is provided at a position corresponding to one end of the overload responsive trip actuating plate 102, and receives the rotational movement of the overload responsive trip actuating plate 102. Further, the tip of the crossbar control lever 87 is in contact with the head 74a of the three-pole interlocking crossbar 74.

The secondary hook 99 is rotatably supported by a shaft 100, one end of which is releasably butt-engaged with the upper end of the primary hook 97, and the other end is provided with a bent piece 99a. 1
The second hook 97 is rotatably supported by a shaft 98, and a clockwise rotational force is applied by a spring. Additionally, a locking pin 9 movable along the elongated hole is provided in the center of the primary hook 97.
7a is installed. One end of the releasable lever 93 is rotatably supported by a shaft 96 fixed to the fixed frame 80, and a claw portion 93a at the other end is connected to the latching pin 9 of the primary hook 97.
7a and is releasably engaged. A link 92 whose one end is rotatably connected by a shaft 94 is connected to the upper end of the releasable lever 93 . The other end of the link 92 is connected to a link 90 via a toggle shaft 91, and one end of the link 90 is connected via a shaft 89 to one end of a crossbar control lever 87 rotatably supported on a shaft 88. has been done. A toggle link mechanism is constituted by these two links 90 and 92, a toggle shaft 91 between them, and an expansion spring 95 connected between the toggle shaft 91 and the top of the opening/closing control lever 86. The opening/closing control lever 86 is a fixed bar 13 whose lower end is fixed to the fixed frame 80.
0 and is rotatably provided around this fixed bar 130.

This opening/closing control lever 86 has ears 84a of the slide plate 84 in grooves 86a provided at the upper portions of both sides thereof.
A pin 84b provided at the tip of is slidably inserted. This connects the spring release mechanism 75b and the handle operation mechanism 75a. This operation control mechanism 75
is a mechanism for operating the three-pole interlocking crossbar 74 by vertical movement of the crossbar control lever 87 to open and close the main contacts of the main current path, and there are two command input systems as its operation command system. One is a system in which a spring release mechanism 75b is operated by operating a handle 79 via a handle control mechanism 75a. As another system, an abnormal signal detected by a current detection current transformer 41 is transmitted to a release type electromagnet 4.
In this system, after the signal is converted into a mechanical signal by 6, the secondary hook 99 is operated via the overload response trip actuating plate 102.

Furthermore, regarding the third contact opening means, FIG.
Explain using. The protruding rod 31 of the electromagnet 30 for forced opening in the event of a short circuit arranged in series in the main current path corresponds to the first lever 19 of the interlocking mechanism 18 for forced opening in the event of a short circuit provided inside the opening/closing unit housing 2. are in contact with each other. The first lever 19 is rotatably supported at its center by a rotating shaft 20 . The other end of the first lever 19 is a second lever 21
is engaged in. The second lever 21 has a shaft 23 at its center.
It is rotatably supported by, and a force to rotate clockwise is applied by a spring 22. Also, the second lever 21
The other end is inserted into a hollow part formed in the upper part of the opening/closing operation lever 17. The electromagnet 30 for forced opening in the event of a short circuit is operated by moving the opening/closing operation lever 17 via the interlocking mechanism 18 for forced opening in the event of a short circuit by the operation of the protruding rod 31, thereby connecting the fixed contact 10 and the movable contact 8. Open the gap and cut off the main current path.

Next, the contact opening/closing operation of the circuit breaker according to the present invention will be explained. First, the contact opening/closing operation using the opening/closing electromagnet 60, which is the first opening/closing means, will be explained with reference to FIG. The opening/closing electromagnet 60 operates in response to opening/closing commands from an ON/OFF switch or the like provided outside the circuit breaker. When the excitation coil 63 of the opening/closing electromagnet 60 is de-energized in response to an external signal, the movable core 62 moves away from the fixed core 61 due to the restoring force of the attraction/release spring 64. In response to this, a movable core operating pin 73 provided on the movable core 62 rotates the electromagnet operating lever 71 clockwise about the shaft 72 . Then, the crossbar 74 opens and closes the opening/closing operation lever 17.
is pushed down, and accordingly, the movable contact 8 and the fixed contact 10 of the movable contactor 9 are opened. This breaks the circuit.

In the return operation, when the excitation coil 63 is energized again, the movable core 62 is attracted to the fixed core 61, and
Accordingly, the electromagnet actuation lever 71, the crossbar 74, and the opening/closing operation lever 17 return to their original positions.

Next, the breaking operation of the main contact of the spring release mechanism, which is the second separating means, will be explained with reference to FIGS. 2, 5, and 7 to 18. Here, FIGS. 7, 11 and 15 are plan views of the control handle, and FIGS. 8 and 12 are plan views of the control handle.
16 is a plan structural view showing the positional relationship between the eccentric cam and the slide plate 84. Further, FIGS. 9, 13, and 17 are cross-sectional structural views of the handle control mechanism section in each operating state. 10, 14 and 18 each illustrate a spring release mechanism 75 corresponding to the handle control mechanism described above.
FIG.

First, referring to FIGS. 7 to 10, when the main current path of the circuit breaker is closed, the control handle 79 is in the "AUTO" or "TEST" position, and the spring release mechanism is in the "AUTO" or "TEST" position. The portion 75b is the claw portion 9 of the releasable lever 93.
3a is engaged with the latching pin 97a of the primary hook 97, and the upper end of the primary hook 97 and one end of the secondary hook 99 are in an engaged state. A toggle shaft 91 connecting the two toggle links 90 and 92 is in tension via the upper end of the opening/closing control lever 86 and an expansion spring 95, and the upper part of the link 90 is locked by the shaft 96. Therefore, the toggle links 90 and 92 are extended substantially in a straight line, and one end of the crossbar control lever 87 is pushed down, and the side that contacts the three-pole interlocking crossbar 74 is pushed up, and the interlocking pin 74a of the crossbar 74 is pushed up. It is in a state separated from.

[0032] The control handle 79 is now in the "AUTO" position.
position, and the main contacts 8 and 10 are in the "on" state, an overload current flows in the main current path, and when the release type electromagnet 46 operates in response to the output signal of the electronic overcurrent relay 45, The armature 50 opens, presses and slides the trip transmission plate 54 and the overload response transmission plate 103, and further rotates the overload response trip actuation plate 102, so that the trip transmission plate 54 and the overload response transmission plate 103 are rotated. The bent piece 99a is pressed and moved.

Referring to FIG. 14, the secondary hook 99 is attached to the shaft 1.
When rotated clockwise around 00, the secondary hook 9
The primary hook 97, which is disengaged from the primary hook 97, rotates clockwise about the shaft 98, and the engagement between the latch pin 97a and the releasable lever 93 is disengaged. The freely releasable lever 93 rotates counterclockwise about the shaft 96 and the toggle link 90
, 92 and pull up one end of the crossbar control lever 87. Therefore, the crossbar control lever 87
8 as a fulcrum and rotates clockwise to push down the interlocking pin 74a of the cross bar 74. When the crossbar 74 is pushed down, the operating lever 1 of each pole that is in contact with the crossbar 74
7, 17, 17 are pushed down, the main contacts are opened,
It will be in the "off" state. At this time, as the opening/closing control lever 86 is rotated, the slide plate 84 that engages with the bent lug 86a is slid, and the eccentric cam 76 and the control handle 79 are rotated, and the control handle 79 is set to "TRIP". It is rotated to the indicated position (see FIGS. 11, 12 and 13).

Further, with reference to FIGS. 15 to 18, "
In order to return to the openable/closeable state from the "TRIP" state, the opening/closing control lever 86 rotates clockwise by forcibly rotating the control handle 79 to the "RESET" position, and one end of the opening/closing control lever 86 is rotated clockwise. The releasable lever 93 is rotated clockwise by the pin 86b attached to the releasable lever 93, so that the claw portion 93a of the releasable lever 93 engages the primary hook 97.
, and returns to the reset state in which the primary hook 97 and the secondary hook 99 are engaged. If you let go of the control handle 79 in this state, it will automatically rotate to the "OFF" instruction position, and furthermore, the "AU"
To return to the "TO" state, simply force the lever back to the "AUTO" position in Figures 7 to 10.
The state shown in is restored.

Next, the circuit breaking operation performed via the short circuit forced opening electromagnet 30 and the short circuit forced opening interlocking mechanism 18, which are the third breaking means, will be described with reference to FIG. The electromagnets 30 for forced opening in the event of a short circuit are connected in series to each of the three main current paths. Now, when an excessive current, such as a short circuit current, occurs in the main current path, the short circuit forced opening electromagnet 30 operates instantaneously, causing the protruding rod 31 to protrude downward. In response to the operation of the protruding rod 31, the first lever 19 rotates clockwise, pushes up the right end of the second lever 21 against the rotational force of the spring 22, and rotates it counterclockwise. Then, the left end of the second lever 21 is the opening/closing operation lever 1.
Push down on 7. As a result, the fixed contact 10 and the movable contact 8 are separated, the contacts are opened, and the current is cut off. When the current is cut off, the short-circuit forced opening electromagnet 30 connected in series to this main current path is de-energized, the protruding rod returns upward, and the first lever 19 and second lever 2
1 returns to its original position. However, the overcurrent response devices 45 and 46 that have detected the overcurrent operate accordingly, and the opening/closing operation lever 17 is maintained in a downwardly pressed state by the spring release mechanism 75b.

This opening means using the electromagnet 30 for forced opening in the event of a short circuit and the interlocking mechanism 18 is advantageous because the electromagnet 30 for forced opening in the event of a short circuit has a fast response speed, the mechanism is simple, and the inertia force is small. Instant cut-off operation is possible. Therefore, it is possible to protect circuits and equipment by instantly interrupting excessive current that occurs during a short circuit.

Next, a second embodiment of the interlocking mechanism 18 for forcibly opening at the time of a short circuit included in the third opening means will be described with reference to FIGS. 19 and 20. This second embodiment uses a link mechanism as an interlocking mechanism for forced opening in the event of a short circuit. FIG. 19 is a partially enlarged structural diagram showing a standby state of the interlocking mechanism for forced contact opening at the time of short circuit according to the second embodiment, and FIG. 20 is a partially enlarged sectional view showing the operating state.

First, referring to FIG. 19, the protruding rod 31 of the electromagnet 30 for forced opening in the event of a short circuit is connected to the first lever 110 of the interlocking mechanism for forced opening in the event of a short circuit provided inside the opening/closing unit housing 2. are in contact. The first lever 110 is rotatably supported at its center by a rotating shaft 111. The other end of the first lever 110 is connected to a link member 112, and the other end of the link member 112 is connected to a second lever 113. The second lever 113 has a substantially L-shape, and its central portion is rotatably supported by a shaft 114. The first lever 110, the link member 112, and the second lever 113 constitute a so-called dead center link mechanism. At one end of the first lever 110,
A return spring 115 is provided that always biases the protruding rod 31 of the electromagnet 30 for forced opening in the event of a short circuit in the direction of pushing back. Further, the tip of the second lever 113 is inserted into a hollow portion formed in the upper part of the opening/closing operation lever 17 of the main contact.

Referring to FIG. 20, if a current exceeding the operating current value of the electromagnet 30 for forced opening in the case of a short circuit occurs in the main current path, the electromagnet 30 for forced opening in the case of a short circuit operates instantly. Then, the protruding rod 31 is made to protrude downward. In response to the operation of the protruding rod 31, the first lever 110 releases the return spring 115.
It rotates clockwise around the shaft 111 so as to compress it. In response to the rotation of this first lever 110, the link material 112
is pushed upward, and the second lever 113 is pushed up against the shaft 11.
It is rotated counterclockwise around 4. Then, the tip of the second lever 113 pushes the opening/closing operation lever 17 downward. As a result, the fixed contact 10 and the movable contact 8 are separated and the contacts are opened. When the main current path is cut off, the short circuit forced opening electromagnet 30 connected in series to the main current path is also deenergized, and the protruding rod 31 returns upward. At this time, the link mechanism receives a counterclockwise restoring force from a return spring 115 at one end of the first lever 110, and a contact spring 11 provided at the bottom of the opening/closing operation lever 17 at the other end of the second lever 113. receives a restoring force that rotates clockwise. The link material 112 receives restoring forces from both in opposite directions, and maintains the open state of the contacts by canceling these forces. That is, this interlocking mechanism for forced opening in the event of a short circuit constitutes a self-holding link mechanism. The return operation of the link mechanism in the illustrated self-holding state is performed by the overcurrent response device 45 that detects the overcurrent.
, 46, the opening/closing operation lever 17 is pushed down by the spring release mechanism 75b, which is activated by the operation of the spring release mechanism 75b. When the opening/closing operation lever 17 is pushed down slightly, the second lever 113 is released to a powerless state. and,
The first lever 110 is rotated counterclockwise by the return spring 115, and the link mechanism returns to the state shown in FIG. 19 accordingly.

When the interlocking mechanism for forced opening in the event of a short circuit according to the second embodiment is used, when the electromagnet for forced opening in the event of a short circuit operates, the contacts are opened by the above-described self-holding link mechanism, and the contact is opened. Since the separated state is maintained, safety against re-contact after separation is ensured, and short-circuit breaking performance is improved.

Further, the circuit breaker according to the present invention has a mode of "TEST" or "ISOL" selected by the control handle 79, in which case the main current path is disconnected. The "TEST" mode is a mode for performing a circuit breaker monitoring operation. However, "ISOL" cannot perform monitor operation. In these modes, the disconnector 13 is turned off to disconnect the main current path. FIG. 21 is a diagram of a disconnection contact opening/closing mechanism showing the opening/closing mechanism of this disconnection section 13. As shown in FIG. Referring to FIGS. 2 and 14, the disconnection section opening/closing mechanism includes a pair of first levers 105, one end of which is in contact with the eccentric cam 76 and rotatably supported by a shaft 106; an L-shaped second lever 107 that is engaged with and rotatably supported by a shaft 108; and a three-pole interlocking disconnection lever 10 that is engaged with the tip of the second lever 107 and is made of an insulator.
9. A conductor 25 connected to the first fixed conductor 12 and the power supply side terminal conductor 16 is mounted inside the three-pole interlocking disconnection lever 109 .

In operation, the control handle 79 is
When rotated to the ``EST'' or ``ISOL'' position,
The eccentric cam 76 also rotates in a similar manner, causing the first lever 105 in contact therewith to rotate counterclockwise. First lever 105
In response to the rotation, the second lever 107 is rotated clockwise, and the three-pole interlocking disconnection lever 109 that is engaged with the second lever 107 is lifted upward. As a result, the conductor 2
5 is separated from the power supply side terminal conductor 16 and the first fixed conductor 12, and the main current path is disconnected. Also, as shown below,
In the "TEST" mode, the limit switch 118 is in the "on" state and a monitoring operation is possible, and in the "ISOL" mode, the limit switch 118 is in the "off" state and therefore the monitoring operation cannot be performed.

Next, referring to FIG. 22, an electrical operating circuit for a switch using the switching electromagnet 60 will be described. The operation connection terminals 115, 116, and 117 are installed on the upper terminal shelf of the operation mechanism unit housing 3, and from one side the power supply connection terminal 115, the excitation coil of the opening/closing electromagnet 60, the limit switch 118, and the self of the opening/closing electromagnet 60. A holding microswitch 119 is connected in series, and the other power connection terminal 11 is connected via a remote control OFF push button 120 provided outside the switch.
5a. A power source E is connected between the power source connection terminals 115 and 115a. In addition, connection terminals 116 and 117
ON push-pin 121 for remote control provided externally between
are connected in parallel. The limit switch 118 is set to be "on" when the control handle 79 is in the "AUTO" or "TEST" position, and to be "off" at other switching positions. That is, this limit switch 118 is attached to the fixed frame 80 of the operation control mechanism 75, and is attached so that the operating lever of this limit switch comes into contact with the bent lug 87a of the crossbar control lever 87. Then, for example, the limit switch 118 is held in the "ON" state in the "AUTO" position, that is, with the toggle links 90 and 92 extended.

The microswitch 119 for self-holding of the electromagnet 60 for opening/closing operation is attached to the outer surface of the fixed frame 65 in the operation mechanism unit housing 3, and the electromagnet 60 for opening/closing operation
The end of a movable core operating pin 73 provided on the movable core 62 is attached so as to correspond to the microswitch operating lever. When the movable core 62 is attracted to the fixed core 61, the movable core operating pin 73 moves to maintain the microswitch operating lever in the "on" state. Disconnector 13, main contact 5 and limit switch 11 at each switching position of control handle 79
The relationship between "on" and "off" with 8 is summarized in Table 2.

[0045]

[Table 2]

As described above, the circuit breaker according to the present invention includes the fixed contacts 10, 10, and the movable contact 9 having the movable contacts 8, 8 arranged so as to be able to open and close the fixed contacts 10, 10. A contact spring 11 is attached to the movable contact 9 so as to connect the contacts 8, 8 to the fixed contacts 10, 10, and an opening/closing operation lever (a third opening/closing lever) is engaged for each pole to operate the movable contact 9. (1) connecting means) 17, a second connecting means consisting of an electromagnet operating lever 71 and a cross bar 74 that operate the opening/closing operation lever 17 of each pole simultaneously, and an electromagnet 60 for opening/closing operation common to each pole; It is provided with three types of opening means consisting of a common spring release mechanism 75b and a short-circuit forced opening electromagnet 30 for each pole, and overcurrent response devices 45 and 46 that detect and respond to overcurrent. If the control handle 79 is normally placed in the "AUTO" position and the opening/closing electromagnet 60 is energized, the contact spring 11 causes the movable contacts 8, 8 to come into contact with the fixed contacts 10, 10. is in a state of

When the opening/closing electromagnet 60 is deenergized, the second connecting means 71 and 74 are operated to push down the first connecting means 17 of each pole and open the movable contacts 8 and 8. Keep it in the "off" state. That is, the opening/closing operation of the main current path is performed by the opening/closing electromagnet 60.

Further, when an overload current flows in the above-mentioned "on" state, the electronic overcurrent relay 45 detects the overcurrent and outputs a detection signal, and upon receiving the output signal, the release type electromagnet 4
6 operates to connect the primary hook 9 via the transmission plates 54 and 103.
7. Disengage the secondary hook 99. Then, the spring release mechanism 75b is released and the crossbar control lever 87 is rotated to push down the first connecting means 17. This pushes the movable contactor 9 downward and opens the main current path. Further, due to the rotation of the crossbar control lever 87, the limit switch 118 is turned off, and the electromagnet 60 for opening/closing operation is turned off.
The excitation coil 63 is deenergized. And the movable iron core 62
is separated from the fixed iron core 61 and follows the second connecting means 71 and 74 which have already been moved to the separated position. In this way, in response to an overload current, the circuit is broken by the collapse of the spring release mechanism 75b, which operates at a high speed, so that the overload current breaking performance can be improved compared to conventional circuit breakers.

Furthermore, when a large current such as a short-circuit current occurs, the electromagnet 30 for forced opening in the event of a short circuit is energized instantaneously, and the protruding rod 31 operates the interlocking mechanism 18 for forced opening in the event of a short circuit. The connecting means 17 is pushed down to open the contacts. Further, at the same time, the electronic overcurrent relay 45 detects a short circuit current, and the release type electromagnet 46 and the spring release mechanism 75b are activated by the output signal, and the second connecting means 71, 74 is activated.
is operated to restrain the first connecting means 17 in the open position. Therefore, the electromagnet 30 for forced opening in the event of a short circuit operates early and guides the movable contact 9 to the open position, and then the electromagnet 30 for forced opening in the event of a short circuit is deenergized, and the movable contact 9 moves to the movable contact spring. 11 to reclose the circuit, the high-speed spring release mechanism 75b operates to maintain the open position of the movable contact 9. Therefore, there is no need to provide the electromagnet 30 for forced opening in the event of a short circuit with a special latch mechanism or reset mechanism for preventing reclosing. In addition, by providing the interlocking mechanism 18 for forced opening in the event of a short circuit in the opening/closing cutoff housing unit 2, the electromagnet 30 for forced opening in the event of a short circuit is connected to the current transformer 41 for current detection related to the rated current of the circuit breaker and the overcurrent. It can be provided in the trip unit housing 4 together with overcurrent response means consisting of response devices 45 and 46. The tripping unit housing 4 can be easily removed by removing the screw 24 at the input end of the excitation coil 36 of the electromagnet 30 for forced opening in the event of a short circuit. As a result, it is possible to replace the electromagnet 30 for forced opening at the time of short circuit and the overcurrent response means as a pair, which have a current capacity and an operation setting value according to the rated current.

Furthermore, when the rated current is small, the current capacity of the excitation coil 36 of the electromagnet 30 for forced opening in the event of a short circuit is reduced, the number of turns of the coil is increased, the resistance value is increased, and the passing short circuit current is extremely reduced. be able to.

[0051]

Effects of the Invention As described above, the circuit breaker according to the present invention has a "TES" which maintains the main contact in a state where the main contact can be opened and closed by an electromagnet while the disconnection contact of the main current path is opened.
By configuring the circuit breaker to include the "T" mode, it is possible to easily test the opening/closing operation of the circuit breaker.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of a circuit breaker according to an embodiment of the present invention.

FIG. 2 is a cross-sectional structural diagram of the circuit breaker shown in FIG. 1.

FIG. 3 is a plan view of the structure taken along the cutting line XX in FIG. 2;

FIG. 4 is a partial structural diagram showing the first contact opening means of the circuit breaker.

FIG. 5 is a plan structural diagram for explaining a release type electromagnet 46 and a transmission mechanism connected thereto.

FIG. 6 is a cross-sectional structural diagram showing the operation control mechanism.

FIG. 7 is a plan view of the control handle in “AUTO” mode.

8 is a plan view of the eccentric cam and the slide plate in the operation mode shown in FIG. 7; FIG.

9 is a cross-sectional structural diagram of a handle control mechanism corresponding to the operation mode of FIG. 7; FIG.

10 is a sectional structural view of the spring release mechanism in an operating mode corresponding to FIG. 7; FIG.

FIG. 11 is a plan view of the control handle in “TRIP” mode.

FIG. 12 is a plan view of the eccentric cam and slide plate in the operation mode shown in FIG. 11;

13 is a cross-sectional structural diagram of the handle control mechanism section in the operation mode shown in FIG. 11. FIG.

FIG. 14 is a cross-sectional structural view of the spring release mechanism in the operating mode shown in FIG. 11;

FIG. 15 is a top structural view of the control handle in “RESET” mode.

16 is a plan structural view of the eccentric cam and slide plate in the operation mode shown in FIG. 15. FIG.

FIG. 17 is a cross-sectional structural diagram of the handle control mechanism section in the operation mode of FIG. 15;

FIG. 18 is a cross-sectional structural view of the spring release mechanism in the operating mode shown in FIG. 15;

FIG. 19 is a structural diagram showing a self-holding state of the link mechanism of the interlocking mechanism for forced opening at the time of short circuit according to the second embodiment.

20 is a structural diagram showing a contact open state of the interlocking mechanism for forced opening in the event of a short circuit shown in FIG. 19; FIG.

FIG. 21 is a diagram of a disconnection contact opening/closing mechanism showing a disconnection contact opening/closing mechanism.

FIG. 22 is a circuit block diagram of a circuit breaker according to the present invention.

FIG. 23 is a circuit block diagram of a conventional circuit breaker.

[Explanation of symbols]

1 Base 2　Opening/closing cutoff unit housing 3 Operation mechanism unit housing 4 Tripping unit housing 8 Movable contact 9 Movable contact 10 Fixed contact 12 First fixed conductor 13 Disconnection section 14 Second fixed conductor 18 Interlocking mechanism for forced opening during short circuit 30 Electromagnet for forced opening during short circuit 40 Electric phase current transformer 41 Current transformer for current detection 45 Electronic overcurrent relay 46 Release type electromagnet 60　Electromagnet for opening/closing operation 71 Electromagnetic activation lever 74 Cross bar for 3-pole interlocking 75 Operation control mechanism 75a Handle control mechanism section 75b Spring release mechanism part 76 Eccentric cam 87 Crossbar control lever 105 First lever 107 Second lever 109 3-pole interlocking disconnection lever

Claims (2)

[Claims] 1. A fixed contact and a disconnection contact provided in series in the middle of a main current path connecting a power supply side circuit terminal and a load side circuit terminal; A movable contact for opening and closing a circuit, an electromagnet for causing the movable contact to open and close the circuit, and a movable contact provided between the electromagnet and the movable contact to control the operation of the electromagnet to the movable contact. a locking position that engages with the transmission means and holds the transmission means in a state where the movable contact and the fixed contact are separated; a locking means movable between an unlocking position and an unlocking position for returning the transmission means to a state where the transmission means can come into contact with the disconnection contact; and a disconnection contact including a movable conductor that moves to connect or disconnect the disconnection contact. opening/closing means; and at least a first position that engages the locking means and the disconnection contact opening/closing means so that the disconnection opening/closing means connects the disconnection contact and the locking means is held in the unlocked position. . A circuit breaker comprising operation switching means for moving between a second position in which the disconnection contact opening/closing means disconnects the disconnection contact and the locking means is held in the unlocked position. 2. The operation switching means has a third position in which the disconnection switching means connects the disconnection contact and the locking means is held in the locked position; and a third position in which the disconnection switching means disconnects the disconnection contact. and a fourth position in which the locking means is held in the locked position.