JPH0623145U - Circuit breaker - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a circuit breaker capable of trapping most metal melts without reducing the discharge efficiency of arc gas. [Structure] A straight part 2b that connects the exhaust passage 2 formed in the case 1 to the operation space S of the fixed and movable contacts 7 and 9 at the inner end.
And a bent portion 2c whose inner end is connected to the outer end of the straight portion 2b and which communicates with the outer end and is located off the extension line of the straight portion 2b, and is further formed by extending the straight portion 2b. A reservoir 2d that is located on the line and is connected to the outer end of the straight portion 2b is provided, and a trap 5 that traps the metal melt Y 1 is disposed in the reservoir 2d.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a circuit breaker having an improved arc gas exhaust structure.

[0002]

[Prior art]

 As a general circuit breaker, there is one having a configuration shown in FIG. In the figure, 3 is a body that constitutes the case 1 made of an insulating material such as plastic together with the cover 4, and has a box-like shape with one surface open. 6 is a fixed contactor having a fixed contact 7, 8 is a movable contactor having a movable contact 9, 10 is a handle, 11 is a handle for opening and closing the fixed contacts 7 and 9 by operating the handle 10. An opening / closing mechanism section including 10 and 15 is an abnormal current detecting means that acts on the opening / closing mechanism section 10 to perform a trip operation when an abnormal current flows.

The case 1 also has an exhaust passage 2 for communicating the space in which the fixed and movable contacts 7 and 9 are opened and closed to the outside. Further, the exhaust passage 2 is for exhausting a plurality of gases. An exhaust plate 2a having holes is attached.

In the case of a circuit breaker, when a short circuit break is performed, an arc A generated between both contacts 7 and 9 has a diameter of 1 to 1 by melting its grid or the like in the case of having a contact point, a contactor and an arc extinguishing device. It may be about 2 mm granular. Such a metal melt Y is extremely high in temperature and tends to be ejected from the exhaust passage 2 to the outside by the high-pressure arc gas G. The exhaust passage 2 and the exhaust plate 2a described above function so as to quickly discharge the arc gas G and capture the metal melt Y that is about to be ejected to the outside.

On the other hand, Japanese Utility Model Laid-Open No. 56-86746 proposes a U-shaped heat absorber composed of an assembly of fine wires and wire nets in the exhaust passage to reliably capture the metal melt Y. .

[0006]

The above-mentioned conventional circuit breaker attempts to ensure the capture of the metal melt Y by making the gas exhaust holes of the exhaust plate small, the fine wire of the heat absorber and the density of the wire mesh. Increasing the value hinders the discharge of arc gas. If this becomes extreme, the pressure of the arc gas will cause damage to the case and deterioration of insulation.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a circuit breaker capable of trapping most metal melts without reducing the discharge efficiency of arc gas. It is in.

[0008]

[Means for Solving the Problems]

 In order to solve such a problem, the circuit breaker according to claim 1 has a fixed contact having a fixed contact, a movable contact having a movable contact, and a fixed and movable opening / closing operation of the movable contact by a handle operation. It has an opening / closing mechanism including a handle, an abnormal current detection means that acts on the opening / closing mechanism to perform a trip operation when an abnormal current flows, and an exhaust passage for accommodating the above-mentioned members and discharging arc gas. In a circuit breaker provided with a case made of an insulating material, the exhaust passage has a straight portion whose inner end communicates with the working space of the fixed and movable contacts and an inner end which is the outer end of the straight portion. The outer end of the straight portion is formed by a bent portion whose connecting outer end communicates with the outer portion and is located off the extension line of the straight portion, and which is located on the extension line of the straight portion. A reservoir part that connects to That it has a structure in which is disposed a captor for capturing the metal melt Mari unit.

A circuit breaker according to a second aspect of the present invention includes a fixed contactor having a fixed contact, a movable contactor having a movable contact, and a handle for opening and closing the fixed contact and the movable contact by operating the handle. It is made of an insulating material that has an opening / closing mechanism, an abnormal current detector that acts on the opening / closing mechanism to perform a trip operation when an abnormal current flows, and an exhaust passage for accommodating each member and exhausting an arc gas. In the circuit breaker having the case of, the inner end of the exhaust passage is connected to the operation space of the fixed and movable contacts, and the inner end is connected to the outer end of the straight part. Is formed by a bent portion that communicates with the outside and is located off the extension line of the straight portion, and that is located on the extension line of the straight portion and that is connected to the outer end of the straight portion. We set up and collect money in this pool A heat absorber for absorbing the heat of the metal melt is provided.

[0010]

[Action]

 According to the structure of claim 1, the exhaust passage for discharging the arc gas does not have a member for obstructing it, so that the discharge efficiency does not decrease, and the metal melt is trapped by the trap body arranged in the reservoir. Does not gush out.

According to the structure of the second aspect, since there is no member that obstructs the arc gas in the exhaust path for exhausting the arc gas, the exhaust efficiency does not decrease, and the metal melt is trapped in the pool portion and distributed there. Even if the metal melt spouts through the exhaust passage for some reason, the temperature will be low due to the heat absorber installed, and it will not cause a fire.

[0012]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The members having the same basic functions as those of the conventional one are designated by the same reference numerals.

Reference numeral 1 denotes a case, which is composed of a body 3 and a cover 4 which are molded with an insulating material such as phenol resin. The body 3 is in the shape of a box with one surface open, and the handle opening 3b is formed on the upper wall surface, and the fixed contact mounting portion 3c and the terminal board mounting portion 3d are formed on the left and right side walls so as to be cut out from the opening end surface. ing. The upper and lower walls and the left and right side walls are not of uniform wall thickness, and the inner wall side is designed appropriately considering the arrangement, fixing, positioning, etc. of the members to be housed, and the outer wall side is designed considering the attachment of terminal members, etc. . These thick-walled parts, together with tapping screws 23, 23, prep holes 3e, 3e, for fixing the cover and relief parts 3f, 3f for the terminal screw, communicate the operating space of the fixed and movable contacts, which will be described later, to the outside. A slightly longer recess 3a is provided as an exhaust path 2 for the purpose of doing so. That is, the exhaust passage 2 is formed by closing the recess 3a with the cover 4. Further, a fulcrum portion 2h of the handle, a support portion 2j of the frame, etc. are provided on the bottom portion.

Explaining the exhaust passage 2 and its peripheral structure in detail, the exhaust passage 2, that is, the recess 3a, has a straight portion 2b whose inner end communicates with the operating space S of the fixed and movable contacts and a straight portion whose inner end is a straight portion. The bent portion 2c is connected to the outer end of 2b, the outer end communicates with the outside, and is located off the extension line of the straight portion 2b. Further, as shown in FIG. 2, a reservoir 2d connected to the outer end of the linear portion 2b is provided on the extension line of the linear portion 2b, and the bottom of the reservoir 2d is provided with a trap body or the like described later. A mounting portion 2e is provided. As shown in FIG. 2, reference numeral 5 denotes a capturing body, which is a rectangular plate-like member having a certain thickness such that a metal plate 5a made of an iron plate or a wire mesh and a metal tape 5b having an adhesive property can be fitted to the mounting part 2e. Is formed in.

The cover 4 has a flat plate shape that closes the opening of the body 3 and has insertion holes for the tapping screws 23, 23, at positions corresponding to the lower holes 3e, 3e ,.

Reference numeral 6 denotes a fixed contact, which has a length extending from the inside of the body 3 to the outside when mounted on the fixed contact mounting portion 3c and is formed by bending. The fixed contact 6 has a fixed contact 7 fixed to one end located on the inner side of the body 3, and the other end on the outer side also serves as a terminal plate. Therefore, the terminal screw 24 is screwed.

Reference numeral 8 denotes a movable contact, which has a fixed contact 7 and a movable contact 9 for contacting and separating operation fixedly attached to one end located below, and a handle rotatably supported to the other end located above. A rotating shaft 8a and a spring bearing 8b of a reversing spring are provided in the middle part.

Reference numeral 10 denotes a handle, which is interlocked with the movable contactor 8 in cooperation with an opening / closing mechanism portion described later. The handle 10 has a pivoting fulcrum 10h located below it supported by the fulcrum 3h of the body 3, an operating part 10b located above it protruding from the handle opening 3b, and a cradle pressing part to be described later in the middle. 10c, and supports the movable contact 8 described above.

Reference numeral 11 denotes an opening / closing mechanism portion including the handle 10, which opens and closes the fixed and movable contacts 7 and 9 by operating the handle 10 and performs a trip operation when an abnormal current detecting means described later is activated. The opening / closing mechanism unit 11 includes a cradle 12, a frame 13 that supports the cradle 12, a reversing spring 14, and the like. The frame 13 has a fitting portion 13j that fits into the support portion 3j of the body 3 on the base portion 13a, and the support piece 13b of the cradle 12 and a bimetal support piece 13c described later are formed by bending.

The cradle 12 has a generally V-shape, one end of which is movably supported by a support piece 13b of the frame 13, and the other end of which is a locked portion 12a which is locked by an abnormal current detecting means described later, and an intermediate portion. The portion has a spring receiver 12b of a reversing spring and a pressed portion 12c corresponding to the pressing portion 10c of the handle 10. The reversing spring 14 has a coil shape and is compressed and suspended between the movable contact 8 and the spring receivers 8b and 12b of the cradle 12. Therefore, the reversing spring 14 normally biases the cradle 12 in the counterclockwise direction, and biases the movable contact 8 in the contact contact direction or the contact open direction depending on the positions of the handle 10 and the cradle 12. There is.

Reference numeral 15 denotes an abnormal current detection means, which acts on the opening / closing mechanism 11 to perform a trip operation when an abnormal current flows in the electric path. The abnormal current detecting means 15 is composed of a bimetal 16, a suction piece 17, a locking piece 18, an elastic piece 19 and the like. The base end of the bimetal 16 is fixed to the by-metal support piece 13c of the frame 13, the base end of the elastic piece 19 is fixed to the tip end, and the suction piece 17 is held in the middle part. The attracting piece 17 is a U-shaped magnetic plate material. The locking piece 18 has a long plate shape made of a magnetic plate material, and a rectangular opening is provided at the center so that its upper end surface serves as a locking portion of the locked portion 12a of the cradle 12, and the base end of the elastic piece 19 is formed. Sticks to the tip. In this case, the locking piece 18 is located so as to face the end surface of the suction piece 17.

In the abnormal current detection means 15, when an overcurrent flows in the bimetal 16 and it is deformed, the locking piece 18 also moves accordingly, and a short-circuit current flows in the bimetal 16 to cause a large magnetic flux in the adsorption piece 17. When flows, the locking piece 18 is immediately attracted to the end surface of the suction piece 17 and moves. That is, when an abnormal current such as an overcurrent or a short-circuit current flows in the electric circuit, the locked portion 12a of the cradle 12 is released from the locking portion of the locking piece 18 in order to perform the trip operation.

Reference numeral 20 is a terminal plate, 21 is a braided wire connecting the terminal plate 20 and the bimetal 16, and 22 is a braided wire connecting the bimetal 16 and the movable contact 8.

FIG. 1 shows a state immediately after the trip operation. That is, when an abnormal current flows in the electric path in the ON state, the abnormal current detection means 15 operates to release the locked portion 12a of the cradle 12 from the locking portion of the locking piece 18, and the spring force of the reversing spring 14 is released. Rotate cradle 12 counterclockwise. When this cradle 12 rotates a certain amount, its spring receiver 12b reaches a position where the spring biasing direction of the reverse spring 14 with respect to the movable contact 8 is reversed, and the spring biasing direction of the reverse spring 14 is the contact opening direction. It is reversed to.

This trip operation, that is, when both contacts 7 and 9 are opened, an arc A and an arc gas G are generated, and in the case where the contacts 7 and 9, the contacts 6 and 8 and the arc extinguishing device are provided, The grid etc. may be melted to form a granular metal melt Y 1 having a diameter of about 1 to 2 mm. Such a metal melt Y tends to be ejected from the operating space S to the outside by the high-pressure arc gas G, but is sent to the pool portion 2d located on the extension of the straight portion 2b of the exhaust passage 2 and mounted there. The trapped body 5 thus captured is more finely captured by the metal tape 5b and is not ejected to the outside.

On the other hand, the arc gas G passes through the exhaust passage 2, that is, the straight portion 2b and the bent portion 2c, and is discharged to the outside. Since there is no member that hinders gas discharge in the exhaust passage 2, its discharge efficiency is sufficiently high.

The trapping body 5 is capable of various deformations, and also includes one in which an adhesive coating agent (for example, liquid molybdenum) is applied to the wall surface of the reservoir 2d.

Next, another embodiment of the present invention will be described with reference to FIG. This one is equipped with a heat absorber 5A that absorbs the heat of the metal melt Y.sub.1 in place of the trapper in the previous embodiment. The heat absorber 5A is formed of an iron plate, a wire mesh or the like into a rectangular plate shape having a certain thickness that can be fitted into the mounting portion 2e.

When this trip operation is performed, the metal melt Y also tries to be ejected from the operation space S to the outside by the high-pressure arc gas G, but is located on the extension of the straight portion 2b of the exhaust passage 2. It is sent to the pool part 2d, and touches the heat absorber 5A mounted there. Then, most of the metal melt Y is captured in the pool 2d. In addition, for some reason, a part of the metal melt Y may be ejected to the outside, but it is not high enough to cause a fire. The discharge efficiency of the arc gas G is sufficiently high as in the previous example.

The operation of the heat absorber 5A will be described in more detail. The material of the metal melt Y is copper (contact etc.), silver (contact etc.), iron (arc extinguishing grid etc.), etc. The melting points are 1083 ° C, 960 ° C and 1530 ° C. Now, assuming that the metal melt Y is the hottest iron, which is assumed to be spherical with a diameter of 2 mm, the heat quantity Q1 is Q1 = m × C × V × T1 = 33.8 [J] When 5A is an iron plate with a thickness of 5 mm × 20 mm × 1 mm and the room temperature is T2 = 25 ° C, the heat quantity Q2 of the heat absorber 5A is Q2 = m × C × V × T2 = 13.2 [J] where m is The specific gravity is 7.86, the specific heat is 0.67 [J / g · ° C], and the V is volume.

Since the volume of the heat absorber 5A is sufficiently larger than that of the metal melt Y, it can be approximately said that the heat absorber 5A can continue to take infinite heat from the metal melt Y. That is, when the metal melt Y comes into contact with the heat absorber 5A in view of the above-mentioned thermal energy gradient, the metal melt Y becomes sufficiently low temperature in a very short contact time.

[0032]

[Effect of device]

 In the circuit breaker according to claim 1, since there is no member for blocking the arc gas in the exhaust path, the discharge efficiency does not decrease, and the metal melt is trapped by the trap body arranged in the reservoir. Does not gush out.

In the circuit breaker according to the second aspect, since there is no member that blocks the arc gas in the exhaust passage that discharges the arc gas, the discharge efficiency does not decrease, and the metal melt is trapped in the reservoir and is distributed there. Even if the metal melt spouts through the exhaust passage for some reason, the temperature will be low due to the heat absorber installed, and it will not cause a fire.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention with a cover cut away.

FIG. 2 is an exploded perspective view of a main part thereof.

FIG. 3 is an exploded perspective view of an essential part of another embodiment of the present invention.

FIG. 4 is a side view showing a conventional example with a cover cut away.

[Explanation of symbols]

 1 Case 2 Exhaust passage provided in the case 2b Exhaust passage straight line portion 2c Exhaust passage bent portion 2d Exhaust passage connecting portion 2e Retaining portion mounting portion 3 Body that constitutes the case 3a Body that substantially constitutes the exhaust passage Recess 4 Cover that constitutes the case 5 Capturer 5a Capturer substrate 5b Capturer metal tape 5A Heat absorber 6 Fixed contact 7 Fixed contact 8 Movable contact 9 Movable contact 10 Handle 11 Opening / closing mechanism 12 Opening / closing Cradle that constitutes the mechanism section 13 Frame that constitutes the opening and closing mechanism section 14 Reversing spring that constitutes the opening and closing mechanism section 15 Abnormal current detection means 16 Bimetal that constitutes the abnormal current detection means 17 Adsorption piece that constitutes the abnormal current detection means 18 Abnormal current Locking piece constituting detection means 19 Elastic piece constituting abnormal current detection means S Operating space of S contact A arc G arc gas

Claims (2)

[Scope of utility model registration request] 1. A fixed contact having a fixed contact, a movable contact having a movable contact, an opening / closing mechanism section including a handle for opening and closing the fixed and movable contacts by operating a handle, and an abnormal current flowed. In a circuit breaker provided with an abnormal current detection means that sometimes acts on the opening / closing mechanism to perform a trip operation, and a case made of an insulating material having an exhaust passage for accommodating each member and discharging arc gas, In the exhaust passage, the inner end communicates with the operating space of the fixed and movable contacts, and the inner end connects to the outer end of the straight part, the outer end communicates with the outside, and from the extension of the straight part. A trap body that is formed by a bent portion that is located apart from the bent portion and that is located on the extension line of the straight portion and that is provided with a pool portion that is connected to the outer end of the straight portion, and that traps the metal melt Has been installed Circuit breaker characterized by. 2. A fixed contact having a fixed contact, a movable contact having a movable contact, an opening / closing mechanism section including a handle for opening and closing the fixed and movable contacts by operating a handle, and an abnormal current flows. In a circuit breaker provided with an abnormal current detection means that sometimes acts on the opening / closing mechanism to perform a trip operation, and a case made of an insulating material having an exhaust passage for accommodating each member and discharging arc gas, In the exhaust passage, the inner end communicates with the operating space of the fixed and movable contacts, and the inner end connects to the outer end of the straight part, the outer end communicates with the outside, and from the extension of the straight part. A bent portion that is located away from the bent portion, which is formed on the extension line of the straight portion and is connected to the outer end of the straight portion is provided, and the heat of the metal melt is absorbed in this reserved portion. With heat absorber A circuit breaker characterized by that.