JP3329033B2 - Neutral device for circuit breakers - 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 neutral device for electrically opening and closing a ground side line of the circuit breaker.

[0002]

2. Description of the Related Art In general, when power is supplied from a power supply to a load, the power is supplied to a main breaker in a distribution board, and then branched from the main breaker to each branch breaker and then supplied to the load.

[0003] That is, the connection bar on the power supply side of the main breaker is connected to the input terminal of each branch breaker, and the connection bar on the ground side of the main breaker is connected to a neutral switch provided in the distribution board. The power supply side line is connected to the load from the output terminal, and the ground side line is connected to the load from the neutral switch.

However, in this case, the power supply side line leading to the load is led from the output terminal of the branch breaker, and the ground side line is led from a neutral switch provided at a position distant from the branch breaker. It is necessary to change the length of each of the pair of electric wires, ie, the power supply side wire and the grounding side wire, and to connect the wires by routing the inside of the distribution board.

For this reason, the present applicant has proposed a circuit breaker provided with a neutral device (Japanese Patent Application No. 5-102).
No. 067). The neutral device of the circuit breaker includes a fixed contact, a movable contact that has a movable contact that can be brought into contact with and separated from the fixed contact, and a movable contact that is spring-biased in a direction in which the movable contact contacts the fixed contact. And an operation handle for driving the movable contact and bringing the movable contact portion into and out of contact with the fixed contact.

[0006] The fixed contact is electrically connected to the input terminal of the grounding side line, and is disposed so as to face the movable contact portion of the movable contact. The movable contact is a seesaw shape formed by bending a sheet of conductive material, has a substantially center fixed, has a contact portion at one end that comes into contact with and separates from the fixed contact, and a contact portion that contacts the operation handle at the other end. And one end thereof is urged by a coil spring in a direction of contacting the fixed contact. The operation handle has an operation part that can be operated by protruding from the circuit breaker and a drive part that contacts the contact part of the movable contact and drives the movable contact, and the movable contact is fixed by rotating. It is possible to contact and separate from the contact.

[0007]

However, in the above-described circuit breaker, the movable contact has a substantially conductive see-saw shape formed by bending a sheet of conductive material, and has a substantially fixed center and a fixed contact at one end. It has a contact portion that comes into contact with and separates from the contact, and has a contact portion that contacts the operation handle at the other end, and one end is urged by a coil spring in a direction to contact the fixed contact, so that the movable contact There has been a problem that the electromagnetic repulsive force due to the current flowing through the contact and the fixed contact is large, and the contact reliability is reduced.

The present invention has been made in view of the above circumstances, and has as its object to reduce the electromagnetic repulsion of each contact by dividing the current flowing through the fixed contact and the movable contact. Accordingly, it is an object of the present invention to provide a neutral device for a circuit breaker having improved contact reliability.

[0009]

According to a first aspect of the present invention, there is provided a neutral device for a circuit breaker having a fixed contact and a movable contact which can be moved toward and away from the fixed contact. A circuit breaker comprising: a movable contact that is spring-biased in a direction in which the movable contact comes into contact with the fixed contact; and an operation handle that drives the movable contact and brings the movable contact into and out of contact with the fixed contact. In the neutral device, the movable contact is formed in a substantially U-shape with a cutting groove at least substantially at the center from the base end to the distal end of the movable contact portion.
When a fixed contact is formed on the inner surface to form a movable contact
In both cases, another fixed contact is made on the outer surface of the other
Form a movable contact that allows the contactor to come and go, from one side to the other
The arrangement is such that the spring is biased toward the one piece .

According to a second aspect of the present invention, there is provided a neutral device for a circuit breaker according to the first aspect, wherein the movable contact is provided with a movable contact portion.
The configuration is such that one side of the coil spring is disposed in contact with the kerf .

[0011]

[0012]

According to the structure of the first aspect, the current flowing from one of the fixed contacts is moved by one of the movable contact portions of the movable contact divided by the cut groove and the movable contact portion by the cut groove.
After flowing to the movable contact on the other side of the contact, the other fixed contact
Flow to the tentacles.

[0013] According to the second aspect, according to claim 1
In addition to the action, the movable contact is split into two parts by a kerf
One side of the coil spring abuts the movable contact part on both sides
The biasing force acts, for example, the fixed contact of the movable contact part on both sides
If the distance from the
The movable contact portion has a stronger spring force.

[0014]

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the circuit breakers shown in FIGS. The circuit breaker housing 1 is formed of an insulating material such as a synthetic resin, and is provided with power supply side connection terminals 2, 3 and ground side connection terminals 4, 5 on both sides of the circuit breaker. It has a rectangular handle projection 6 for projecting the power supply side handle, and has attachment parts 7, 7 on both sides near the lower surface for fixing to the distribution board. The bottom surface (mounting surface) is fixed to the distribution board by fitting the fixing member (not shown). The handle projection 6 has a rectangular window hole 9 into which a power supply side handle described later is inserted,
The outside has a large diameter and the inside has a small through hole 2
And two operation holes 10 and 11 are provided. As shown in FIG. 4, the housing 1 has a body 12 having an opening on a side surface and having components fitted sideways, a first cover 13 for closing an opening on the front of the body 12, and a opening on the back of the body 12. 2nd cover
14 and is composed of.

The inside of the body 12 has a partition wall 12h substantially at the center.
A link mechanism 15 for interrupting an electric circuit by an arc and an arc extinguishing chamber (arc extinguishing member) 16 for separating and cooling the arc are provided.
It is divided into a section 12A and a second section 12B in which a leakage detection device 17 for detecting a leakage current and a test button 18 are provided. The first section 12A has a concave terminal groove 12a for mounting the ground-side connection terminal 4, and a concave terminal groove 12b for mounting the power supply-side connection terminal 2 of the electric circuit below the terminal groove 12a.
And an arc extinguishing chamber (arc extinguishing member) below the terminal groove 12b.
And an exhaust port 12c for exhausting the gas generated in the exhaust gas. Further, an insulating plate 19 for separating power-supply-side and ground-side connection terminals 2 and 4 from a bimetal, which will be described later, is provided behind the terminal groove 12a. Further, a fitting portion 20 for fitting and fixing an arc traveling plate described below is provided below the arc extinguishing chamber (arc extinguishing member) 16. Also, the first section 12A
In the vicinity of the bottom surface (mounting surface), a ground-side connection conductor housing 21 in which a ground-side connection conductor described later is provided is formed.

The second section 12B has a concave terminal groove 12d for mounting the power supply side connection terminal 3, and a concave terminal groove for mounting the ground side connection terminal 5 above the terminal groove 12d. 12e. Cut grooves 12f and 12g are formed in the upper surface and the lower surface of the second section 12B, respectively. Furthermore, partition walls
A hook shaft 22 for hooking a tension spring to be described later is formed on the side surface of 12h. On the upper part of the partition wall 12h, an electric leakage display device 23 for displaying an electric leakage state is provided.

The first cover 13 covers the front opening of the body 12, and the first cover 13 closes the opening of the body 12.
A link mechanism 15, an arc extinguishing chamber 16 (arc extinguishing device), an electric leakage detecting device 17, a test button 18, an electric leakage display device
And so on. The second cover 14 closes the back opening of the body 12, and holds the neutral device 24, the ground-side connection conductor 24a, and the like disposed in the body 12 with the opening of the body 12 closed. is there.

The link mechanism 15 includes an opening / closing mechanism for manually opening and closing the electric circuit, and an abnormal current detecting unit for opening the electric circuit when an abnormal current flows. The opening / closing mechanism is a power-side movable contact whose intermediate portion is pivotally supported by a frame described later.
25, an opening spring 26 for urging the power supply side movable contact 25 in the opening direction, a connection link 27 having one end connected to the power supply side movable contact 25, and a shaft supported by the frame together with the power supply side handle 28. A latch link 30 having a slit 30a for swingably supporting a movable shaft 29 held at the other end of the connection link 27, a trip link 31 pivotally supported by a frame to latch the latch link 30, and one end is movable. A handle link 33 connected to a connection link 27 via a shaft 29 and the other end connected to a power supply side handle 28 via a movable shaft 32; and a latch link to the frame.
A power supply side handle 28 held together with the power supply 30, a frame 34 holding these members, and a power supply side contact 35 interposed between the power supply side connection terminals 2 and 3 are provided.

The power supply side movable contact 25 has an intermediate
An elliptical slit 25a is provided so as to be axially supported by a pair of legs, and a pair of legs parallel to each other and a connecting piece connecting the legs are formed in a substantially U shape, and a movable contact 25b is provided at one end of the connecting piece.
And a projection for hooking one end of the opening spring 26 at the other end of the connecting piece. In addition, in the approximate center of the connecting piece, there is formed a damper hole (not shown) through which a movable iron core to be described later is inserted for forcibly opening the power supply side movable contact 25 in the opening direction. This power side movable contact
25 is electrically connected to frame 34 via copper strands 36. The opening spring 26 is formed in a coil shape, and has one end hooked to the projection of the power supply side movable contact 25 and the other end hooked to a second yoke to be described later. It is energizing.

The connecting link 27 is composed of a pair of parallel leg pieces having shaft holes at both ends and a connecting piece connecting the leg pieces from near the shaft hole at one end of the leg piece. The movable link 37 is connected to the power supply side movable contact 25 via the movable shaft 37, and the shaft link at the other end is connected to the latch link 30 and the handle link 33 via the movable shaft 29. The latch link 30 has a shaft hole supported by the frame 34 and
And a pair of leg pieces which are formed in a substantially rectangular shape in a side view and are parallel to each other, and a connecting piece for connecting the leg pieces. That is, the connecting link 27 and the handle link 33 are swingably held by the slit 30a via the movable shaft 29.

The trip link 31 is composed of a standing piece and a side piece that is integrally connected at an intermediate portion of the standing piece, and forms an ear piece on the opposite side to the side piece, and is formed on the side piece and the ear piece. Through the bearing hole. Also, this trip link
A locking portion for locking the connecting piece of the latch link 30 is formed at the tip of the side piece of the 31. Further, there is provided a torsion coil spring 38 which is inserted and supported by the frame 34, is engaged with the side piece and a first yoke described later, and urges the side piece toward the connection side of the latch link 30. At the upper end of the standing piece, a bimetal interlocking portion interlocking with the deformation of the bimetal 39 and a protruding piece provided in a direction intersecting with the bimetal interlocking portion and to which an opening of a first lever described later is attached are provided. At the lower end of the standing piece, a movable core interlocking plate is provided for interlocking movement of a movable iron core to be described later.

The handle link 33 is composed of a pair of leg pieces having shaft holes at both ends and being parallel to each other, and a connecting piece for connecting the leg pieces from the center of the leg pieces.
The shaft hole at the other end is connected to a power supply side handle 28 via a movable shaft 32. The power supply side handle 28 is formed of an insulating material such as a synthetic resin, and swings the operation portion protruded from the handle protrusion 6 on the upper surface of the housing 1 and the window hole 9 of the housing 1, and is viewed from the side. A fan-shaped swinging portion, a base portion serving as a center of rotation having a shaft hole for holding the latch link 30 in the frame 34 and a spring shaft hole into which one end of a spring described later is inserted, and , Is composed of. In addition, a protruding portion having a shaft hole to which a handle link 33 is connected via a movable shaft 32 is provided at one end of the swing portion.

The frame 34 comprises a frame body provided integrally with the first yoke 40, and a frame cover connected to the frame body via three fixed shafts 41, 42, 43. The frame main body is formed in a substantially triangular shape with an opening inside when viewed from the side, and has a shaft hole into which the fixed shafts 41, 42, and 43 are inserted at the apexes and two bases, respectively. The first yoke 40 is provided integrally. Like the frame body, the frame cover is formed in a substantially triangular shape with an opening inside when viewed from the side, and has shaft holes into which fixed shafts 41, 42, and 43 are inserted at both ends of the apex and the bottom. are doing. From one end of the bottom side, a leg piece extending downward and a side piece extending in the direction of the frame main body from the tip of the leg piece are continuously provided. By welding one of the copper stranded wires 36 to the frame cover and welding the other of the copper stranded wires 36 to the power supply side movable contact 25, the frame 34 and the power supply side movable contact 25 are electrically connected. .

The power supply side contact 35 includes a movable contact 25b fixed to the power supply side movable contact 25 and a fixed contact fixed to the connection member 44.
44a, and is interposed between the power supply side connection terminals 2 and 3. The movable contact 25b is provided at one end of the connecting piece of the power supply side movable contact 25 as described above. Fixed contact 44a
Is provided at one end of the connection member 44. Connection member 44
Is formed in a substantially L-shape from a connecting member main body 45 connected to the power supply side connection terminal 3 and a fixed contact portion 46 hanging from the connecting member main body 45. The connecting member main body 45 has one end connected to the power supply side connection terminal 3, has an insulating material such as vinyl attached in the center, is inserted into a zero-phase current transformer described later, and has the other end connected to the partition wall 12h.
Holding in. The fixed contact portion 46 has a fixed contact 44a, and is disposed in a state where the fixed contact 44a is fitted in a fitting hole formed in an arc traveling plate described later. The fixed contact 44a is generated by the heat of the arc generated when the power supply side contact 35 is forcibly opened by an abnormal current such as a short-circuit current.
Even if it is melted, it is prevented from leaking to the outside through the fitting hole, so that it can be easily reused even after forcibly opening the electrode by an abnormal current.

The abnormal current detecting section comprises a bimetal 39 for detecting an overcurrent and a detecting electromagnet 47 for detecting a short circuit current. Bimetal 39 has two different thermal expansion coefficients.
The thin plates are integrally laminated, and the whole is bent substantially in an L shape from the vertical piece and the horizontal piece, and generates heat and deforms in accordance with the supplied current. At the upper end of the vertical piece, a screw hole into which the gap adjusting screw is screwed is provided. This bimetal 39
The power supply side connection terminal is welded to the frame
2 Placed near. The detection electromagnet 47 includes a first yoke 40 provided integrally with the frame 34, a fixed core 48 provided on the first yoke 40, a trip link drive rod 49 penetrating the fixed core 48, and a movable core 50. Spring 51 for urging the power supply side movable contact 25 side, a movable core 50 forcibly opening the power supply side movable contact 25, a coil cylinder 52 covering them, and a coil for winding the coil cylinder 52 53, and a second yoke 54 connected to the first yoke 40. 1st yoke
The upper piece 40 is formed in a substantially U-shape with a facing upper piece and a lower piece via a connecting piece, and the upper piece is provided integrally with the frame 34. The fixed iron core 48 has a through hole, the tip of which is the first hole.
The yoke 40 is fitted into the fitting hole formed in the connecting piece from the inside and caulked and fixed.

The trip link drive rod 49 is entirely formed in a column shape longer than the fixed core 48, and is swingably inserted into a through hole of the fixed core 48. The return spring 51 is formed in a coil shape, and is compressed and erected between the fixed core 48 and the movable core 50,
The movable core 50 is biased toward the power supply side movable contact 25. The movable iron core 50 is slidably fitted in the coil cylinder 52,
A forced opening rod protruding from one end protrudes outside from the small diameter portion of the coil cylinder 52, a flange is formed at the tip thereof, and penetrates through the Daruma hole of the power supply side movable contact 25. The coil cylinder 52 is
It has a through-hole and is composed of a large-diameter portion and a small-diameter portion. The small-diameter portion is fitted into a fitting hole of a second yoke 54 described later from inside. The coil 53 is wound around a coil cylinder 52, and one end of the coil 53 is bent back in the axial direction and welded to a terminal plate on the power supply side described later. In addition, one end of the copper stranded wire 36 is welded to the other end of the coil 53, and the copper stranded wire 36 is attached to the vertical piece of the bimetal 39.
The other end is electrically connected to the bimetal 39 by welding. The second yoke 54 is composed of a lower piece and side pieces connected to the lower piece, and has a fitting hole into which the small diameter portion of the coil cylinder 52 is fitted. At the tip of the side piece, a latching portion is provided for latching the opening spring 51 to urge the power supply side movable contact 25 in the opening direction.

The arc extinguishing chamber 16 (arc extinguishing device) has an arc traveling plate 55 for moving an arc generated at the time of short-circuit interruption from a power source side contact 35 composed of a movable contact 25b and a fixed contact 44a. The separated and cooled gas is exhausted from the exhaust port 12c. The arc traveling plate 55 is formed in a substantially L-shape with a vertical piece and a horizontal piece, and the horizontal piece is fitted to the fitting portion 20 above the ground-side connection conductor housing 21 near the bottom (mounting surface) of the body 12. The vertical pieces are fitted side by side with the ground side connection conductor 24a with the vertical pieces fitted to the partition wall 12h.
5) The magnetic field caused by the current flowing through the
4a) is less susceptible to the magnetic field due to the current flowing through it. For this reason, the arc generated when an abnormal current flows and the movable contact 25b is forcibly opened from the fixed contact 44a can be easily extended by the arc traveling plate 55, and the adverse effect of the ground-side connection conductor 24a can be reduced. As shown in FIG. 1, the vertical piece has, at its center, a fitting hole 55a for fitting the fixed contact 44a, and for example, the movable contact 25b is closed by an abnormal current such as a ground fault current or a short-circuit current. Even if the fixed contact 44a melts due to the heat of the arc generated when forcibly opening, the fitting hole
From 55a, it becomes difficult to flow, and it can be reused even after forced opening. In addition, a protruding rib 55b is provided on the center line of the horizontal piece of the arc traveling plate 55 to facilitate traveling of the arc and avoid sticking.

Next, the operation principle of the link mechanism 15 will be described with reference to FIGS. 3, 8, and 9. FIG. That is, when the power supply side handle 28 is tilted from the off state side shown in FIG. 3 to the on state side shown in FIG.
The movable shaft 29 moves from the upper side to the lower side through the slit 30a of the latch link 30 in a state where the movable shaft 29 is latched by the link 31, and the connecting link 27 is moved by the movable shaft 29. Then, when the movable shaft 29 moves beyond a straight line connecting the movable shaft 29 and the fixed shaft 42, the movable shaft 29 is rapidly inverted, and the power supply side movable contact 25 connected to the connection link 27 is moved around the fixed shaft 41. Then, as shown in FIG. 8, the movable contact 25b comes into contact with the fixed contact 44a. At this time, the fixed shaft 41 is located in the middle of the elliptical slit 25a provided in the middle of the power supply side movable contact 25, and the movable contact
A contact pressure is applied to 25b. In the overcurrent trip among the trip states, when an overcurrent flows in the electric circuit in the ON state shown in FIG. 3, the trip link 31 is gradually pressed by the self-heating of the bimetal 39, and the connecting piece of the latch link 30 is engaged. The latch link 30 is rotated by the opening spring 26 and the power supply side movable contact 25 is rotated about the fixed shaft 41 in a direction away from the fixed contact 44a. Then, as shown in FIG. 9, the power supply side contact 35 is opened. In the short-circuit trip, when a short-circuit current flows in the electric circuit in the ON state shown in FIG. 3, the movable core 50 of the detecting electromagnet 47 is attracted to the fixed core 48. As a result, the trip link drive rod 49 is pushed out and pushes the movable core interlocking plate of the trip link 31, and the trip link 31 rotates, releasing the latch link 30 and opening the power supply side movable contact 25 as described above. Operate. However, before the power supply side movable contact 25 is opened by such link interlocking, that is, at the same time as the operation of the movable core 50, the flange of the movable core 50 is locked to the power supply side movable contact 25 and The movable contact 25b is pulled away from the fixed contact 44a. That is, just before the latch link 30 is tripped, the power supply side movable contact 25 rotates about the fixed shaft 41 as a fulcrum in the direction of compressing the opening spring 26 to perform the opening operation.

As shown in FIG. 10, the leakage detecting device 17
A zero-phase current transformer 56 for detecting an unbalanced current in the electric circuit, a control circuit unit (not shown) for amplifying the output of the zero-phase current transformer 56,
A movable contact plate 57 for holding the test button 18 so as to protrude from the housing 1 and an unbalanced current flowing to the zero-phase current transformer 56 via a test circuit unit (not shown) by contacting the movable contact plate 57. And a leakage detection board 59 to which these components are attached. The leakage detection board 59 is arranged near the ground-side connection terminal 5.

The grounding connection conductor 24 is
a forms a slit through which it can pass. The upper end of the earth leakage detection board 59 is formed in the kerf 12f of the body 12 and the lower end is formed in the body.
The earth leakage detecting device 17 is disposed in the housing 1 by being mounted on the 12 kerfs 12g. In addition, the control circuit section includes an amplifier that outputs a signal when an unbalanced current flowing through the electric circuit exceeds the sensitivity current, and a switching element configured with a thyristor that turns on when an output signal of the amplifier is output. It is composed of

The test button 18 is actually operated from the upper surface of the housing 1 and comprises a substantially cylindrical operating portion and legs extending from the lower surface of the operating portion.
Operation hole 11 so that the operation part protrudes from the upper surface of housing 1.
Attached to. In addition, at the tip of the leg portion, a contact portion which has elasticity by having a cut groove in the center and which locks inside the operation hole 11 when inserted into the operation hole 11 and contacts the movable contact plate 57 when inserted into the operation hole 11 is provided. Provided. When the test button 18 is pressed, the movable contact plate 57 comes into contact with the fixed contact shaft 58, and generates an unbalanced current in the zero-phase current transformer 56 via the test circuit. The test circuit section includes a current limiting resistor for limiting a current, and a test winding.

The electric leakage display device 23 is provided with a housing
1 and a spring 61 for projecting the leakage indicator 60 from the operation hole 10 of the housing 1.
First and second transmission levers 62 and 63 for rotating the trip link 31 to trip the opening and closing mechanism, and a tension spring 64 for pulling the second transmission lever 63 toward the lower surface of the body 12.
And an electromagnet device 65 for rotating the second transmission lever 63 by the current amplified by the control circuit of the leakage detecting device 17. The leakage display member 60 has a columnar shape, and has a display portion that protrudes from the operation hole 10 of the housing 1 when an electric leakage occurs, and a substantially prismatic shape that can be advanced and retracted into the operation hole 10, and one end of a spring 61 is inserted. Kerf and first transmission lever
And a leg portion having a piece to be locked which is locked to 62. The spring 61 is formed in a coil shape, is inserted into the fixed shaft 42, and one end is inserted into the spring shaft hole of the power supply side handle 28, and the other end is inserted into the cut groove of the electric leakage display member 60. It is attached so that it is urged. At the other end, the power supply side handle 28 is in a neutral position, and has a contact portion that comes into contact with the other end of the swing portion of the power supply side handle 28 when the power supply handle 28 is shifted to the open position. are doing. The first transmission lever 62 is composed of a vertical piece having an opening, and an engagement piece having an engagement portion that is provided in series with the vertical piece and engages with the engagement portion of the second transmission lever 63. Be composed. A fixed shaft of the frame 34 is provided between these vertical pieces and the engagement pieces.
An insertion recess into which the first transmission lever 62 is inserted is provided with a fixed shaft 43 inserted into the insertion recess and a projecting piece of the trip link 31 inserted into the opening.
It is held at 34 so that it can rotate.

The second transmission lever 63 has a slant having a locking portion at its tip for locking the locked portion of the leakage indicating member 60, and a first transmission lever 62 connected to the slant. An engaging piece having an engaging portion for engaging the engaging portion; and an engaging piece continuously provided below the locking portion of the oblique piece and provided in a direction intersecting the oblique piece. It is composed of a hook shaft to be hooked on the portion, and a locking piece that is provided on a side surface of the oblique piece and locks a movable iron core of the electromagnet device 65 described later. A fixed shaft 41 of the frame 34 is provided between the connection of these oblique pieces and the engagement pieces.
Is provided, and the second transmission lever 63 is rotatably held by the frame 34 by mounting the fixed shaft 41 in the insertion recess. According to the present embodiment, the transmission lever for transmitting the output of the leakage detection device to the cutoff mechanism is constituted by two members, but the transmission lever can be applied by any number of members.

The tension spring 64 is formed in a coil shape,
Is hooked on the hook shaft of the transmission lever 63 and the hook shaft 22 of the body 12. The electromagnet device 65 includes a coil bobbin 66 around which a coil is wound, a fixed core 67, a movable core 68, and a yoke 69.
It is composed of The coil terminals at both ends of the coil bobbin 66 are connected to the control circuit unit and the test circuit unit of the leakage detecting device 17 via lead wires (not shown). Fixed iron core
Reference numeral 67 denotes a coil bobbin 66 which is formed in a substantially cylindrical shape and has a cut groove.
And is held by the yoke 69. The movable core 68 includes a columnar movable core body, a continuous shaft connected to the movable core body, and a locked part locked by a locking piece of the second transmission lever 63. It is inserted into a through hole formed in the coil bobbin 66 and the movable core body is prevented from falling off by the holding recess of the yoke 69, so that the movable core 68 does not fall off the coil bobbin 66. yoke
69, the upper piece and the lower piece facing each other are formed in a substantially U-shape via a connecting piece, and the upper piece and the lower piece are unevenly fitted to the flange of the coil bobbin 66, so that the coil bobbin 66 Be attached. Further, the upper piece and the lower piece are provided with holding recesses for holding the cut grooves of the fixed core 67 and the movable core body so as not to fall out of the through holes.

When an unbalanced current flows in the electric circuit, the circuit breaker detects the unbalanced current by the zero-phase current transformer 56, generates a secondary output, amplifies it with an amplifier, turns on the switching element, and excites the electromagnet by exciting the coil. When the movable iron core 68 of the device 65 is attracted to the fixed iron core 67 side and the movable iron core 68 pushes up the second transmission lever 63, the second transmission lever 63 rotates about the fixed shaft 41, and the second transmission lever 63 is the first transmission lever 62
, The first transmission lever 62 rotates about the fixed shaft 41, and the trip link 31 inserted into the first transmission lever 62 rotates about the fixed shaft 43. After this,
Similar to the trip operation of the link mechanism 15 described above, the movable contact
25b is pulled off from the fixed contact 44a, and the power supply side contact 35 is opened. When the second transmission lever 63 rotates, the leakage indicating member 60 protrudes from the operation hole 10 of the housing 1 and the power supply side handle 28 is held at the neutral position. Further, when performing a leakage test, the test button 18 is pressed, the movable contact plate 57 is brought into contact with the fixed contact shaft 58, and a signal is given to the test circuit section. Then, the electromagnet device 65 operates and the movable iron core 68 is attracted. Therefore, as described above, by the link mechanism 15,
The movable contact 25b is detached from the fixed contact 44a.

When the power leakage handle 60 is displaced toward the opening position when the power leakage display member 60 protrudes from the operation hole 10 of the housing 1 and the power supply side handle 28 is in the neutral position due to the electric leakage, the power supply side The other end of the swinging portion of the handle 28 comes into contact with a contact portion 61a formed on the spring 61, and the other end 61b of the spring 61 moves downward in FIG. As a result, the leakage display member 60 into which the other end 61b of the spring 61 is inserted is displaced inward of the housing 1, and the leakage display member 60 is locked to the second transmission lever 63 by this displacement. According to this embodiment, when the leakage display member protrudes from the operation hole of the housing and the power supply side handle is at the neutral position, the power leakage side handle is moved toward the opening position to move the leakage display member to the second position. Is locked to the transmission lever of
The present invention can also be applied to a device that locks the leakage indicating member to the second transmission lever by moving the power supply side handle toward the closing position.

Terminals are power supply side connection terminals 2 and 3 (input / output terminals)
And ground-side connection terminals 4 and 5. The power supply side line connection terminal 2 is a terminal screw with a screwdriver operation hole.
A terminal plate 71 having a screw hole 71a into which the terminal screw 70 is screwed and having a protruding piece 71b connected to the coil 53 of the detecting electromagnet 47; and a nut 72 into which the terminal screw 70 is screwed.
And is arranged in the terminal groove 12b of the first section 12A. Like the power supply side connection terminal 2, the power supply side connection terminal 3 has a terminal screw 73 having an operating hole for a screwdriver and having a chevron shaped contact, and a screw hole 74a into which the terminal screw 73 is screwed. A terminal plate 74 connected to the terminal 44 and a nut 75 into which the terminal screw 73 is screwed.
It is arranged in the terminal groove 12d of 12B.

The ground-side connection terminal 4 has a terminal screw 76 having a driver operation hole, a screw hole 77a into which the terminal screw 76 is screwed, and a projection 77b to which the ground-side connection conductor 24a is welded. And a nut 78 into which the terminal screw 76 is screwed, and is disposed in the terminal groove 12a of the first section 12A. The ground-side connection terminal 5 has a terminal screw 79 having a driver operation hole and a mountain-shaped contact, a screw hole 80a into which the terminal screw 79 is screwed, and a fixed contact described later. The second section is composed of a terminal plate 80 and a nut 81 into which a terminal screw 79 is screwed.
It is arranged in the terminal groove 12e of 12B.

As shown in FIG. 11, the neutral device 24 includes a first neutral fixed contact 90 (fixed contact) connected to the ground-side connection terminal 5 at one end, and a first neutral fixed contact 90 connected to the first neutral fixed contact 90. A second neutral fixed contact 91 (another fixed contact) arranged in parallel and a neutral movable contact 92 which comes into contact with and separates from each of the neutral fixed contacts 90, 91
(Movable contact) and a contact spring 93 for urging the neutral movable contact 92 in the direction of each neutral fixed contact 90,91.
And a neutral handle 94 (operation handle) for bringing the neutral movable contact 92 into and out of contact with each of the neutral fixed contacts 90 and 91 against the bias of the spring, and a ground connection at the other end welded to the other fixed contact 91. And a ground-side connection conductor 24a welded to the terminal 4.

The first neutral fixed contact 90 is continuously provided so as to protrude from the terminal plate 80 of the ground-side connection terminal 5 at one end. As shown in FIG. 11, the second neutral fixed contact 91 is arranged in parallel with the fixed contact 90, and is electrically connected to the other ground side connection terminal 4 via the ground side connection conductor 24a. .

Neutral movable contact 92 (movable contact)
Is connected to and separated from the first neutral fixed contact 90 while the one piece 92
A and the other piece that comes into contact with and separates from the second neutral fixed contact 91
92B and a connecting piece 92C connecting the one piece 92A and the other piece 92B are formed in a substantially U-shape. On the other hand 92A
Has a spring receiving portion 92a for mounting the contact spring 93 on the substantially central rear surface thereof, so that the contact spring 93 can be mounted between the main body 12 and the spring. On the other hand, the piece 92A is
A movable contact portion 92b is provided on the inner surface of the distal end, and the movable contact portion 92b is opposed to the first neutral fixed contact 90 so as to be able to contact and separate from the first neutral fixed contact 90. On the other hand, the piece 92B is
A contact portion of a neutral handle 94 (operation handle) described later abuts on the tip 92c, and the neutral handle 94
By rotating the (operating handle), the neutral movable contact 92 can be moved toward and away from the neutral fixed contacts 90 and 91. The other piece 92B also has a movable contact portion 92d on the outer surface of the base end thereof, and can move toward and away from the second neutral fixed contact 91 by being opposed to the second neutral fixed contact 91. This neutral movable contact 92 has one piece 92A.
A cut groove 92e is formed in the approximate center of the movable contact portion 92b from the movable contact portion 92b of the other piece 92B to the movable contact portion 92d of the other piece 92B. The electromagnetic repulsive force of the neutral fixed contacts 90 and 91 and the neutral movable contact 92 is weakened, and the contact reliability can be improved. In other words, since the electromagnetic repulsion is proportional to the square of the current,
Although the electromagnetic repulsion force is で at ×× １ ／, there are two places where the poles are opened, so the actual value is ４ × 2 and the original 1
/ 2. According to the present embodiment, the kerf is formed substantially at the center from one movable contact portion to the other movable contact portion, but at least the first neutral fixed contact and the second neutral fixed contact are formed. If it is provided in the movable contact portion with which the child contacts, the current flowing through each of the neutral fixed contact and the neutral movable contact can be divided, thereby improving the contact reliability.

The contact spring 93 is formed by a coil spring.
One side is fitted in the spring receiving portion 92a of the neutral movable contact 92 so as to be in contact with the notch 92e of the movable contact portion 92b, and as shown in FIG. 13, the movable contact portions 92b, If the distance between the first fixed contact 92b and the first neutral fixed contact 90 is shifted from each other, a strong spring force acts on the movable contact portion 92b farther from the first neutral fixed contact 90, and the balance of contact reliability can be maintained. . Also. The other side of the contact spring 93 is in contact with the body 12, and the neutral movable contact 92 is connected to each neutral fixed contact 9
It is biased in the 0,91 direction. Neutral handle 94
The (operating handle) has a knitted center cam shape, has a shaft hole 94a rotatably held by a bearing (not shown) of the body 12, and has an operating portion 94b and a contact portion 94c at predetermined peripheral positions. Have. As shown in FIG. 11, the ground-side connection conductor 24a has one side welded to the other fixed contact 91 and the other side welded to the ground-side connection terminal 4 at the other end, and has a neutral handle 94 (operation handle). 11 is electrically connected to the ground-side connection terminals 4 and 5 at both ends. Also, this ground side connection conductor 24a is
The other fixed contact 91 is inserted through the zero-phase current transformer 56, drawn inside the ground-side connection conductor housing 21 formed in the body 12, and welded to the ground-side connection terminal 4 at the other end, and By being arranged in the connection conductor housing 21, the heat is generated in the ground-side connection conductor 24a when it is arranged in contact with the bottom surface (mounting surface) of the body 12 and is attached to a distribution board or the like. The heat is easily radiated to the outside, so that the operation of each member (particularly, bimetal) inside the body 12 is hardly hindered.

In the neutral device 24, when the operating portion 94b of the neutral handle 94 (operating handle) is oriented vertically, the contact portion 94c does not contact the neutral movable contact 92 as shown in FIG. Due to the spring force of the spring 93, the movable contact portion 92b of the one piece 92A contacts the fixed contact 90, and the movable contact portion 92d of the other piece 92B contacts the other fixed contact 91. 4 and 5 become conductive. From this state, when the operation portion 94b of the neutral handle 94 (operation handle) is rotated in the horizontal direction,
Contact portion 94c of neutral handle 94 (operation handle)
Abuts against the tip 92c of the other piece 92B. Further, if the rotation operation is continued, the fixed movable contact 90 moves from the fixed movable contact 90 to the neutral movable movable contact 92.
The one piece 92A is separated from the other fixed contact 91 by the other piece 92B of the neutral movable contact 92. At this time, the neutral handle 94 (operation handle) is frictionally locked while the contact spring 93 is compressed by the neutral movable contact 92.

According to this embodiment, the fixed contact is 2
Although it is formed of three members (the first neutral fixed contact and the second neutral fixed contact), if the number is one, the number of poles to be opened is reduced, and the electromagnetic repulsion force is 1/4 of the original. And the contact reliability is further improved.

[0046]

According to the first aspect of the present invention, the current flowing from one of the fixed contacts is cut off.
One movable contact part of the movable contact divided by the groove
And the other end of the movable contact divided by the notch
After flowing to the contact part, it flows to the other fixed contact.
It is possible to reduce the size while securing the opening distance by dot cutting.

According to the neutral device for the circuit breaker of the second aspect, the movable contact is divided into two parts by the cut groove.
One side of the coil spring abuts the point, and the movable contact on both sides
Biasing force, for example, fixed contact between movable contact parts on both sides
If the distance from the
Claim 1 because the far movable contact portion has a stronger spring force.
In addition to the effects described above, a well-balanced contact pressure is applied to the movable contact
And the contact reliability is further improved.

[0048]

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a circuit breaker to which the present invention is applied.

FIG. 2 is an exploded perspective view showing a state where the inside of the body of FIG. 1 is assembled.

FIG. 3 is a perspective view showing a state where the device shown in FIG. 1 is assembled.

FIG. 4 is a perspective view showing a state where the first cover of FIG. 3 is attached.

FIG. 5 is a side view of the neutral device shown in FIG. 4;

FIG. 6 is a top view of that of FIG.

FIG. 7 is a side view of FIG. 4 on the side opposite to the neutral device side.

FIG. 8 is a front view showing the ON state of FIG. 3;

FIG. 9 is a front view showing a tripped state of FIG. 3;

FIG. 10 is a diagram illustrating a trip operation due to electric leakage, and is a side view showing a state in which a first cover of FIG. 4 is removed.

FIG. 11 is a rear view showing the state of FIG. 4 with the second cover removed.

FIG. 12 is a perspective view showing a neutral movable contact (movable contact) of FIG. 10;

FIG. 13 is a side sectional view showing a biasing force applied to the neutral movable contact by the contact spring of FIG.

[Explanation of symbols]

24 Neutral device 90 1st neutral fixed contact (fixed contact) 91 2nd neutral fixed contact (other fixed contact) 92 Neutral movable contact (movable contact) 92b, 92d movable contact 92e kerf 93 contact Spring 94 Neutral handle (operation handle)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-211526 (JP, A) JP-A-59-207517 (JP, A) JP-A-2-74734 (JP, U) JP-A-1 137019 (JP, U) Actually open sho 59-129141 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 73/04

Claims (2)

(57) [Claims] 1. A movable contact having a fixed contact, a movable contact that can be brought into contact with and separated from the fixed contact, and a spring biased in a direction in which the movable contact comes into contact with the fixed contact; An operating handle for driving the movable contact portion to contact and separate the movable contact portion from the fixed contact member, wherein the movable contact portion is cut at least substantially at the center in the direction from the base end of the movable contact portion to the tip end of the movable contact portion. Formed in a generally U-shape with grooves
On the other hand, a movable contact part on which the fixed contact
And on the outer surface of the other side facing this one side
The other fixed contact forms a movable contact that can be separated
A neutral device for a circuit breaker, which is disposed in a state of being biased by a spring from one side to the other side . 2. The movable contact is provided in a groove of a movable contact portion.
The neutral device for a circuit breaker according to claim 1, wherein one side of the coil spring is disposed in contact with the coil spring .