JPH06338247A - Circuit breaker - Google Patents

Abstract

PURPOSE:To extinguish an arc speedily with a simple constitution by extending the arc generated in opening a movable contact from a fixed contact toward an arc commutation protrusion by a holding wall or the like. CONSTITUTION:A terminal connection part 35 with which an input terminal screw 34 is threaded is formed at one input terminal plate 6, and a fixed contact 36 is installed on the other. A movable contact member 16 having a movable contact 50 facing the fixed contact 36 to get closer to/apart from it freely, and a handle capable of external operation of the movable contact 16 are connected, and a switching mechanism part 15 for forcedly opening the movable contact 50 when an abnormal current flows between contacts 14 is contained in a body 1 having a surrounding wall 8 surrounding a screw part of the input terminal screw 34. A protrusion 38 to commutates an are is provided on the movable contact side of the input terminal plate 6, and a holding wall 12 covering around the protrusion is provided holding this protrusion 38. The generated arc can thus be extended from the movable contact 50 toward the protrusion 38, thereby the arc can be applied to the protrusion 38 to be extinguished.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker for forcibly opening contacts when an abnormal current such as an overcurrent flows.

[0002]

2. Description of the Related Art As a circuit breaker of this type, Jikkou 55
There is one shown at -15246. This is a movable contactor having an input terminal plate on one side of which a terminal connecting portion to which an input terminal screw is screwed and a fixed contact is attached, and a movable contact facing the fixed contact in a freely contactable and separable manner. An enclosing wall that encloses the screw part of the input terminal screw, and an opening / closing mechanism part that connects the movable contactor and an externally operable handle and forcibly opens the movable contact when an abnormal current flows between the contacts. It is stored in the body with.

A horseshoe-shaped arc extinguishing grid is arranged near the fixed contacts so that the arc generated when the movable contacts are opened can be extended to extinguish the arc.

[0004]

According to the circuit breaker described above, the arc generated when the movable contact opens from the fixed contact is extinguished by the horseshoe-shaped arc extinguishing grid. The arc can be extinguished quickly. However, there is a problem that extra material such as an arc-extinguishing grid is required, resulting in high material cost.

The present invention has been made in view of the above circumstances. An object of the present invention is to provide a circuit breaker capable of quickly extinguishing an arc with a simple structure, thereby reducing material costs. To do.

[0006]

In order to solve the above problems, a circuit breaker according to a first aspect of the present invention has a terminal connecting portion on one side of which an input terminal screw is screwed and a fixed contact on the other side. The input terminal board, the movable contact that has a movable contact that faces the fixed contact so that it can come into contact with and separate from the fixed contact, and the movable contact and the handle that can be operated externally are connected to move when an abnormal current flows between the contacts. The opening and closing mechanism that forcibly opens the contacts is housed in a body that has an enclosing wall that surrounds the screw part of the input terminal screw, and a protrusion that commutes an arc is provided on the movable contact side of the input terminal plate. The body is provided with a holding wall that covers the periphery of the protrusion with the body sandwiched.

According to a second aspect of the circuit breaker, the body of the first aspect has a structure in which an exhaust port for exhausting the arc gas is provided in the vicinity of the terminal connecting portion via the surrounding wall.

[0008]

According to the structure of the first aspect, the arc generated when the movable contact is opened from the fixed contact is extended from the movable contact in the projection direction, and the arc hits only the projection around the projection.

According to the second aspect of the invention, in addition to the function of the first aspect, the arc gas of the arc generated when the movable contact is opened from the fixed contact is circulated around the surrounding wall and discharged from the exhaust port. It

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. That is, the housing of this circuit breaker is formed of an insulating material such as synthetic resin, has a side opening, and has a body 1 in which the components are laterally fitted, and the body 1
Has a first cover 2 for closing the front opening of the body 1 and a second cover 3 for closing the side of the body 1 opposite to the front opening,
It connects with each connection hole through the connection pin.
As shown in FIGS. 2 and 3, the body 1 has both ends formed in a stepped shape with the outer side being the upper stage, and the ground side terminals 4,5 of the electric line and the power source side terminals (the input / output terminals) of the electric line are respectively arranged in the upper stages. ) 6,
7 are provided. Each of these terminals is composed of a terminal plate and a terminal screw that is screwed onto the terminal plate. The terminal screw is screwed onto the terminal plate while the electric wire conductor is in contact with the terminal plate, and the electric wire conductor can be connected. . Further, the body 1 near the input / output terminals 6 and 7 is provided with surrounding walls 8 and 9 surrounding the screw portions of the input terminal screw and the output terminal screw.
A handle hole 10 through which a handle described later is projected is formed.

On the side surface of the body 1 near the outside of the surrounding wall 8 of the input terminal 6, there is provided an exhaust port 11 for discharging the arc gas generated at the contact point, which will be described later. Prevents dust from adhering. Further, a clamping wall 12 for clamping a projection of an input terminal plate, which will be described later, is provided near the inside of the surrounding wall 8, and the arc is made to hit only the projection in the vicinity of the projection. The arc is extinguished quickly. Inside the body 1, a handle 13, a contact point 14 (a contact point portion, an opening / closing mechanism portion 15, a contact point drive plate 16 (movable contactor), a bimetal 17 (abnormal current detection device), and the like are housed.

The ground side terminals 4 and 5 are connected to the ground side wire switch section 18
It is possible to conduct electricity by checking the insulation. As shown in FIG. 5, the ground side wire switch unit 18 includes a conductive plate 19, a seesaw plate 20, and an operation knob 21.
Have and. The conductive plate 19 is arranged such that one end thereof is integrally connected to the terminal plate of the ground side terminal 4 and the other end thereof is located near the ground side terminal 5. The seesaw plate 20 is bent in a V shape and has a bearing hole 22 at its bent portion, and has a contact portion 23 at one end facing the other end of the conductive plate 19 so as to be contactable and separable. Bearing hole 22
A spring receiver 24 is provided between the two, and a horizontal portion 25 is provided at the other end. An inclined plate 26 is extended in the inclined direction from the terminal plate of the ground side terminal 5 and a fulcrum protrusion 27 is provided at the tip thereof, and the bearing hole 22 is fitted into the fulcrum protrusion 27 to support the seesaw plate 20 so that it can swing. There is.
A contact pressure spring 28 is compressed between the bearing protrusion 27 and the body 1 to bring the contact portion 23 into contact with the other end of the conductive plate 19.

The operation knob 21 is of an eccentric cam type, has a shaft 29 projecting from one side, and has a knob piece at a predetermined peripheral position.
30, a first flat surface portion 31, a second flat surface portion 32 and a retaining projection 33 are formed. The operation knob 21 has a shaft 29 rotatably held in a recess (not shown) formed in the body 1. That is, when the operation knob 21 is set to the position indicated by the solid line, the first flat surface portion 31 faces the horizontal portion 25 of the seesaw plate 20,
Since the first flat portion 31 is separated from the horizontal portion 25, the contact portion 23 is in contact with the other end of the conductive plate 19 by the spring force of the contact pressing spring 28. Further, when the operation knob 21 is set to the position of the imaginary line, the second flat portion 32 presses the horizontal portion 25, the seesaw plate 20 rotates to compress the contact pressing spring 28, and the contact portion 23 causes the conductive plate 19 to move.
It is separated from the other end and is locked at the position of the imaginary line by frictional locking. Therefore, by operating the knob piece 30, the ground side switch portion 18 is operated on and off.

The input / output terminals 6 and 7 consist of an input terminal connected to a branch bar of a distribution board (not shown) and an output terminal connected to each external load. Each is arranged. The input terminal 6 includes an input terminal screw 34 for fixing a branch bar, an electric wire conductor, etc., and a terminal connecting portion 35 with which the input terminal screw 34 is screwed on one side, and a fixed contact 36 attached on the other side. And a plate 37. The input terminal plate 37 is provided with a projection 38 that commutates the arc between the terminal connecting portion 35 and the fixed contact 36 to rapidly extinguish the arc. The output terminal 7 is, like the input terminal 6, an output terminal screw 39 for fixing the wire conductor connected to the load,
It has a terminal connecting portion 40 with which the output terminal screw 39 is screwed on one side and an L-shaped output terminal plate 42 to which a braided wire 41 is connected on the other side.

The handle 13 is formed of an insulating material such as plastic, has a shaft hole 43 at the center thereof, and has a link connecting projection 45 (which is locked to a knob 44 and a locking portion which will be described later) at a predetermined position on the peripheral portion. It has a locked portion) and a spring receiver 46. As shown in FIG. 10, the handle 13 has a shaft 47a at one end of a U-shaped link 47 fitted in the shaft hole 43 and a shaft 47 at the other end.
b fits into the shaft hole 48a of the link piece 48, and
As shown in FIG. 4, 47c is positioned and fitted and supported by a positioning groove 49 that is inclined in a predetermined direction with respect to the bottom surface formed on the body 1. As a result, the handle 13 and contact drive plate
Each of the 16 is supported by the body 1 via a fixed shaft. The knob 44 can be operated between on and off for projecting from the handle hole 10 of the body 1 to the outside and contacting and separating the contact point 14.

The contact 14 (contact part) is the input terminal plate described above.
It is composed of a fixed contact 36 attached to 37, and a movable contact 50 facing the fixed contact 36 so as to freely come into contact with and separate from the fixed contact 36. The movable contact 50 is fitted into the contact drive plate 16 from the upper surface of the bimetal 17 in a state where the bimetal 17 is in contact with the contact drive plate 16.
A rivet 50a is formed so that the bimetal 17 can be fixed by a rivet.

The opening / closing mechanism portion 15 is the above-mentioned U-shaped link.
47, the opening spring 51, the link spring 52, and the tripping member 53
And have. As described above, the link 47 connects the shaft 47a at one end to the handle 13 and the shaft at the other end.
47b is connected to the contact drive plate 16 and the center of rotation of each is fixed to the body 1. The opening spring 51 is a compression coil spring, and is interposed between the handle 13 and the contact drive plate 16. The link spring 52 is formed by bending both ends of a torsion coil spring in the axial direction as shown in FIG.
The shaft 52a, 52b is passed through a guide plate 54 having an elongated hole to regulate the maximum opening of the shaft 52a, 52b by a torsion coil spring, and the shaft 52a is formed in the shaft hole of the link connecting protrusion 45 of the handle 13.
The shaft 52b is fitted in the shaft hole 53a of the removing member 53. The locking piece 55 is locked to the locking member 56 by the spring force within the restricted range of the guide plate 54 of the link spring 52.

The tripping member 53 is formed by a substantially U-shaped plate as shown in FIG. 10, one end of the intermediate piece thereof is extended to form a locking piece 55, and the contact driving plate is formed in the middle portion of both side pieces. It has a shaft hole 53b for connecting to 16, and a shaft hole 53a for connecting the handle is formed at the other end of both side pieces.
The tripping member 53 is connected to the contact drive plate 16 via the connecting shaft 57 in the shaft hole 53b, and the rotation of the tripping member 53 causes the locking piece 55 (latch) to move in the same direction as the longitudinal direction of the bimetal 17. It can be locked to a locking member 56 described later.

The contact drive plate 16 is made of a magnetic material such as iron,
The connecting piece 58 and the pair of facing pieces 59 are formed in a substantially U-shape. The connecting piece 58 has one end extending in the direction intersecting with the facing piece 59 and forming an inclined portion 58a at its tip, and a protruding piece 60 (fixed portion) for arc commutation and wobble prevention is formed at the tip of the inclined portion 58a. Has been done. The facing piece 59 includes a bent portion 61 bent from the connecting piece 58, and a link piece 48 extending from the bent portion 61 so as to incline toward the locking member 56 side. A positioning protrusion 62 is formed at the tip of the bent portion 61, shaft holes 48a and 48b are formed at the middle and tip of the link piece 48, and an abnormal current trips at a predetermined position on the side edge in the middle. Since the handle neutrality restricting protrusion 63 (locking portion) that locks the handle 13 in a state in which it is positioned substantially in the center between on and off, the trip state can be displayed with a simple configuration. Further, the contact drive plate 16 has an opening / closing mechanism 15
An isolation member 64 is provided to isolate the contact point 14 from the contact point 14, and when the arc generated when the movable contact 50 is opened from the fixed contact 36 flies in the direction of the opening / closing mechanism section 15, the arc is applied to the isolation member 64, The operation of each member of the opening / closing mechanism section 15 is made difficult to be disturbed.

The isolating member 64 is made of an arc-extinguishing gas generating material such as polymethylpentene resin or polymethylmethacrylate resin. When the arc hits, the arc extinguishes gas by the heat to extinguish the arc quickly. I am trying. The separating member 64 is formed in a substantially inverted T shape from the horizontal pieces 65 and 66 and the vertical piece 67. The horizontal piece 65 is the opening spring 51.
A pair of bent portions 61 serve as spring seats for receiving the
In addition to having a locking hole 65a for locking the positioning projection 62 over the same, a spring receiving projection 65b is provided at the center of the horizontal piece 65. An opening spring 51 is compressed and interposed between the spring receiving protrusion 65b and the spring receiving 46 of the handle 13. In addition,
Since the horizontal piece 65 is constantly pressed against the bent portion 61 by the opening spring 51, the horizontal piece 65 does not have to be caulked on the positioning protrusion 65b.
Since it does not come off, the means for fixing the isolation member 64 can be simplified. The horizontal piece 66 is an enclosing piece of the movable contact 50, and has a notch 66a at the tip and positions the movable contact 50 in the notch 66a so as to narrow the arc flying direction and quickly extinguish the arc. I am trying. Further, the vertical piece 67 is located on the side of the opening spring 51 to separate the movable contact 50 and the opening spring 51 from each other to prevent the influence of the arc.

The bimetal 17 (abnormal current detection device) has an engaging hole 68 into which the projection 60 of the contact drive plate 16 fits, and a hole 69 to be riveted to the contact drive plate 16 by the movable contact 50 at one end thereof. ing. In addition, the other end of this bimetal 17 is bent and the other end is connected to the output terminal 7 by a braided wire.
One end of 41 is welded, and a locking member 56 that locks the tripping member 53 at a position on the one end side from the position where the braided wire 41 is welded, that is, a position where the bimetal 17 is not deformed due to the welding of the braided wire 41 ( (See FIG. 11). Therefore, a locking member 56 that locks (latches) the tripping member 53.
The amount of engagement of the (latch engagement part) does not easily change, so the contact
14 is forcibly opened The operating current is hard to change, and it is possible to cut off accurately when an abnormal current flows.

The locking member 56 is composed of a rotating body in which a peripheral edge 56a is formed stepwise from an insulating material, and the locking piece 55 of the tripping member 53 is locked to the peripheral edge 56a so as to be released. Since the displacement amount of the bimetal 17 with which the member 53 is opened can be adjusted, the work of adjusting the operating current for opening the contact 14 is simplified. Also, since it is made of an insulating material, the contacts
It is possible to prevent a current from flowing from 14 to the opening / closing mechanism section 15, and it becomes easy to understand the characteristic operating current that the bimetal 17 is displaced. Further, the locking member 56 has a central portion 56b which is located at the other end side of the bimetal 17 by the caulking jig 70 so that the locking amount for locking the locking piece 55 of the tripping member 53 can be adjusted. It is attached to the mounting hole 71 and can be freely rotated.
The amount to lock 53 can be adjusted easily.

This bimetal 17 is shown in FIGS. 12 (a) and 12 (b).
As shown in FIG. 2, first, the inclined portion 58a of the contact drive plate 16 is superposed on the side of the one end which is in the warp direction, and the movable contact 50 is formed with the protrusion 60 of the contact drive plate 16 fitted in the engagement hole 68. 69 and the hole 58b of the inclined portion 58a of the contact drive plate 16 are penetrated. Next, by caulking the rivet 50a of the movable contact 50, the bimetal 17, the inclined portion 58a, and the movable contact 50 are integrally connected at the same time. As a result, the inclined portion 58a is overlaid on the bimetal 17, and a gap is formed between the bimetal 17 and the connecting piece 58. Therefore, the bimetal 17 can be warped toward the gap side due to the overcurrent flowing through the bimetal 17, and the short-circuit current flows through the bimetal 17 along with the connecting piece.
The 58 can be electromagnetically attracted to the bimetal 17.

Next, the operation of this circuit breaker will be described.
That is, in FIG. 1, the movable contact 50 is in contact with the fixed contact 36 so that the input / output terminals 6 and 7 are electrically connected, and when the ground side wire switch unit 18 is turned on, the ground side terminals 4 and 5 are connected. Conducts. When the handle 13 is in the ON state, the shaft 52a is positioned higher than the straight line connecting the shafts 47a and 52b, so that the force of the link spring 52 holds the handle 13 against the edge of the handle hole 10. When the handle 13 is tilted from the on position to the off position shown in FIG. 13, the shaft 52a of the link spring 52 is
Is inverted below the straight line connecting the shafts 47a and 52b, the spring force of the link spring 52 causes the handle 13 to be locked to the other edge of the handle hole 10, and the contact drive plate 16 to rotate counterclockwise. The movable contact 50 is rotated to open the fixed contact 36.

When an abnormal current such as an overcurrent flows between the contacts 36 and 50 in the ON state, the bimetal 17 is heated and bent to the connecting piece 58 side. Therefore, the locking member 56 moves in accordance with the warping motion of the bimetal 17 and separates from the locking piece 55, and the tripping member 53 is rotated around the shaft 57 by the link spring 52 in the direction of the clockwise hand in FIG. At the same time, the contact drive plate 16 is an opening spring
By the action of 51, the movable contact 50 is rotated counterclockwise about the shaft 47b, the movable contact 50 is separated from the fixed contact 36, and the trip state shown in FIG. Further, in this operation, the handle 13 starts to turn to the off side by the action of the opening spring 51, and the link connecting protrusion 45 (locked portion) moves, but the neutral position regulating protrusion 63
It is locked by the (locking portion) and stopped, and the trip display is performed by the handle 13.

The trip mechanism 15 is reset in the trip state by tilting the handle 13 to the off side as shown in FIG. That is, the link connecting projection 45 of the handle 13 pushes over the neutral position restricting projection 63 to rotate the contact drive plate 16 in the clockwise direction to get over the neutral position restricting projection 63, and with the rotation of the link connecting projection 45, the link spring 52 Through, the tripping member 53 rotates counterclockwise about the shaft 57, the locking piece 55 of the tripping member 53 moves to the locking side of the locking member 56,
It is turned off. When the handle 13 is pushed from this off state to the on state of FIG. 1, as described above, the linking spring 52 is locked with the locking piece 55 of the tripping member 53 being locked to the locking member 56 via the link spring 52. The contact drive plate while the shaft 52a rotates to the reverse position and the opening spring 51 is compressed.
The movable contact 50 contacts the fixed contact 36 by rotating 16 in the clockwise direction.

Further, when a short-circuit current flows through the bimetal 17 in the ON state, a magnetic flux generated around the bimetal 17 due to the large current flows through the contact drive plate 16 of the magnetic body, and the connecting piece
The suction force acts between the 58 and the bimetal 17,
The connecting piece 58 is sucked by the bimetal 17 faster than the warping of the locking piece 55 and the locking piece 55 separates from the locking member 56. When the locking piece 55 separates from the locking member 56, the movable contact 50 is opened from the fixed contact 36 by the above-mentioned operation.

[0028]

According to the circuit breaker of the first aspect of the present invention, the arc generated when the movable contact is opened from the fixed contact is extended from the movable contact in the projection direction, and the arc is generated only around the projection in the vicinity of the projection. Since it hits, the arc can be extinguished quickly with a simple structure, and the material cost is less likely to occur.

According to the circuit breaker of the second aspect, the arc gas of the arc generated when the movable contact is opened from the fixed contact is circulated around the surrounding wall and discharged from the exhaust port. In addition to the effects described above, it becomes difficult for dust and dirt to adhere to the contacts from the exhaust port.

[Brief description of drawings]

FIG. 1 is a front view of an ON state with a first cover removed according to an embodiment of the present invention.

FIG. 2 is a side view showing a state in which a first cover is attached to the one shown in FIG.

FIG. 3 is a top view of that of FIG.

FIG. 4 is an exploded perspective view of that of FIG.

5 is a rear view showing the ground side wire switch unit of FIG. 4 with the second cover removed. FIG.

FIG. 6 is an exploded perspective view in which a holding wall portion of FIG. 4 is enlarged.

FIG. 7 is an enlarged front sectional view of an input terminal portion of the one shown in FIG.

FIG. 8 is a side sectional view showing a state in which the protrusion of FIG. 7 is sandwiched between the sandwiching walls.

FIG. 9 is a perspective view showing an opening / closing mechanism of the one shown in FIG.

10 is an exploded perspective view of that of FIG. 9. FIG.

11 is a perspective view showing a locking member of the one shown in FIG.

FIG. 12 is an explanatory diagram showing a method of fixing the bimetal of FIG. 10 to the contact drive plate.

13 is a front view showing the off or reset state of the one shown in FIG. 1. FIG.

FIG. 14 is a front view showing the trip state of the one shown in FIG.

[Explanation of symbols]

 1 Body 6 Input terminal 8 Enclosing wall 12 Clamping wall 13 Handle 14 Contact 15 Open / close mechanism 16 Contact drive plate (movable contact) 34 Input terminal screw 35 Terminal connection 36 Fixed contact 38 Protrusion 50 Moving contact

Claims (2)

[Claims] 1. A movable contact having an input terminal plate on one side of which a terminal connecting portion to which an input terminal screw is screwed and a fixed contact is attached, and a movable contact facing the fixed contact so that the fixed contact can be separated from the fixed contact. An enclosure that encloses the screw part of the input terminal screw, and the opening and closing mechanism part that connects the movable contact part and the handle that can be operated externally and forcibly opens the movable contact when an abnormal current flows between the contacts. It is characterized in that it is housed in a body having a wall, a projection for commuting an arc is provided on the movable contact side of the input terminal plate, and a holding wall that covers the periphery of the projection is provided in the body while sandwiching the projection. Circuit breaker. 2. The circuit breaker according to claim 1, wherein the body is provided with an exhaust port for exhausting the arc gas near the terminal connection portion via the surrounding wall.