WO2003065396A1

WO2003065396A1 - Air circuit breaker

Info

Publication number: WO2003065396A1
Application number: PCT/JP2002/000739
Authority: WO
Inventors: Hiroshi Okashita; Junichi Kawakami
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 2002-01-31
Filing date: 2002-01-31
Publication date: 2003-08-07
Also published as: CN1494727A; TW540078B; DE60211562D1; CN1253909C; KR20030090691A; EP1471553B1; KR100552413B1; ES2262784T3; JPWO2003065396A1; EP1471553A1; DE60211562T2; JP4138665B2; EP1471553A4

Abstract

An air circuit breaker capable of suppressing the temperature rise of a make and break contactor and energized bodies around the contact by a heat generation due to the energization of the contact, comprising, in a cabinet (1), a fixed conductor (3) having a fixed contact (4) fixed thereto, a movable element (6) having a movable contact (5) moving close to and apart from the fixed contact (4) fixed thereto, and an arc-extinguishing device (17) inductively extinguishing an arc generated between both contacts, a discharge window (1c) for discharging arc gas to the outside of the cabinet, vent holes (1d) opened at a position opposed to the discharge window (1c) and forming an air passage inside the cabinet, a valve member (21) closing the vent holes (1d) when a pressure inside the cabinet rises, an arc block (22) having a fixed side arc contactor (22a) extended from the fixed contact (4) to allow an electricity and a heat to be transferred thereto, and the movable side arc contactor (6) extended from the movable contact (5) to allow an electricity and a heat to be transferred thereto.

Description

Technical Manual Air Circuit Breaker Technical Field

The present invention relates to suppression of a temperature rise of a switching contact and a current-carrying conductor around the contact when the air circuit breaker is normally energized. Background technology,

FIG. 3 is a side sectional view of a conventional air circuit breaker described in, for example, Japanese Patent Application Laid-Open No. 5-309390.

In the figure, reference numeral 1 denotes a base case, which is composed of a main base 1a and a sub base 1b formed of an insulating material. Reference numeral 1c denotes an arc gas discharge window provided in the base case 1. Reference numeral 2 denotes a cover housing, 3 denotes a fixed conductor in which several poles of the air circuit breaker are arranged side by side on the sub-base 1 b, and a fixed contact 4 is fixed to one end, and the other end is outside the base housing 1. To form the power supply terminal 3a. Reference numeral 5 denotes a movable contact opposed to and separated from the fixed contact 4, 6 denotes a mover to which the movable contact 5 is fixed, 7 denotes a contact arm that rotatably holds the mover 6, and 8 denotes an unnecessary part of the mover 6. The mover stopper pin 9 prevents movement of the arm, and 9 is a contact arm shaft for supporting the contact arm 7 to the base housing 1. Reference numeral 10 denotes a terminal conductor, and a portion fixed to the main base 1a and led out to the base housing 1 forms a load-side terminal 10a. 1 1 is a flexible conductor movably connecting the movable element 6 to the terminal conductor 1 0 ₀ -

1 2 is a contact pressure panel that urges the mover 6 in the opening direction, 13 is an opening / closing mechanism, and opens the mover 6 linked to the contact arm 7 by the shaft 14. Close. 15 is a trip relay section. The opening / closing mechanism section 13 is formed of a well-known todal link mechanism, and is locked by a D-shaped latch 16 that engages with the trip relay section 15. Reference numeral 17 denotes an arc extinguishing device, which is opened so that the arc gas can be discharged to the outside through an arc gas discharge window 1c. Reference numeral 18 denotes an input panel in which the input driving force of the opening / closing mechanism unit 13 is stored, and reference numeral 19 denotes a ratchet mechanism for compressing and storing the input panel 18 using the handle 20 or a motor (not shown).

Such an air circuit breaker detects an overcurrent or an overcurrent due to an accident, etc., in the connected load and releases the bow.1.Relay 15 releases the lock of the D-type latch 16. The contact arm 7 is pushed up about the contact arm axis 9 by the force of the contact pressure panel 12, and the mover 6 is moved counterclockwise about the axis 14. By rotating, the fixed contact 4 and the movable contact 5 are opened to cut off the current between both contacts. At that time, the arc between the contacts is attracted to the arc extinguishing device 17 to extinguish the arc, and the arc gas generated at this time is emitted through the arc gas emission window 1c.

Such an air circuit breaker has a rated current of 1,000 to several thousand amps, and the upper limit temperature of the energized part is specified in the standard in order to prevent the temperature rise due to the application of the rated current from deteriorating each part. In the conventional air circuit breaker as described above, the fixed contact point 4 and the movable contact 5 and the surrounding conductive paths such as the mover 6 are used to insulate the current-carrying part and shield the arc generated when excessive current is interrupted, and arc gas. The switch is located in a closed space with only the arc gas discharge window 1c to prevent leakage into the switchgear 13 so that when the rated current is applied, the contact resistance between the fixed contact 4 and the movable contact 5 and the movable element 6, etc. The heat generated by the resistance of the peripheral conductive passages causes a large rise in the temperature inside the base 1, causing a problem that the rise in the temperature of the current-carrying part exceeds the upper limit temperature.

The present invention has been made to solve such a problem. The purpose is to suppress the temperature rise of the current-carrying part inside the air circuit breaker by effectively dissipating the heat inside the medium circuit breaker. Disclosure of the invention

An air circuit breaker according to the present invention includes a fixed conductor having a fixed contact fixed thereto, a movable element having a movable contact fixed to and separated from the fixed contact by an opening / closing mechanism, and extinguishing an arc generated between the two contacts. An arc extinguishing device, which is provided in a part of the case and discharges an arc gas to the outside of the case, and an air passage formed in a portion facing the discharge window to form an air passage inside the case. A vent hole is provided.

Further, a valve member for closing the ventilation hole when the pressure inside the housing rises is provided to the above.

Also. An arc block with a fixed-side arc contact extending from the fixed contact to the arc-extinguishing device so that it can conduct electricity and heat, and a movable-side arc that contacts the fixed-side arc contact when both contacts open. The contact is provided so as to extend from the movable contact to the arc extinguishing device side so as to be capable of conducting and conducting heat.

Further, one pole is opened and closed by a plurality of movers, and a movable-side arc contact is extended to the arc extinguishing device side for each of the plurality of movers. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a sectional view of a main part of an air circuit breaker according to the present invention.

FIG. 2 is a transparent perspective view of an energizing portion of the air circuit breaker of the present invention.

FIG. 3 is a side sectional view of a conventional air circuit breaker. BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1

FIG. 1 is a cross-sectional view of a main part of an air circuit breaker according to Embodiment 1 of the present invention, and FIG. 2 is a transparent perspective view of a current-carrying portion of the air circuit breaker according to Embodiment 1.

In the figure, 1, 3 to 13 and 17 are the same as those of the above-mentioned conventional apparatus, and the description thereof is omitted. 1 d is a ventilation hole opened in the base case 1 on the opposite side of the arc extinguishing device 17. 2 1 is a valve member with a ventilation hole 1d, which always allows ventilation from the outside to the inside of the base case 1, and closes the ventilation hole 1d when the pressure inside the base case 1 rises I do. Reference numeral 6a denotes a movable-side arc contact provided with a mover conductor extending from a fixed portion of the movable contact 5 of the mover 6 toward the tip. Reference numeral 2 denotes an arc block mounted in the direction of the arc extinguishing device 17 for the fixed conductor 3. One surface is fixedly attached to the fixed conductor 3 and the other orthogonal surface is attached to the bottom surface of the base housing 1, respectively. The arc block 22 has a fixed-side arc contact 22a at a position facing the movable-side arc contact 6a. Then, as shown in FIG. 2, a plurality of movers 6 are arranged in parallel to constitute a one-pole open / close unit. The arc block 22 is provided with a concave groove 22b at a portion not in contact with the movable arc contact 6a.

Such an air circuit breaker is installed with the power supply side terminal 3a facing upward, and the arc extinguisher 17 side is located upward and the ventilation hole 1d is located downward as shown in the figure. Therefore, an air passage is formed between the ventilation hole 1d and the arc gas discharge window 1c.

As a result, the heat generated in the contact portion between the fixed contact 4 and the movable contact 5 and the surrounding conductive passages such as the mover 6 during energization is cooled by natural convection from the ventilation hole 1 d to the arc gas discharge window 1 c. The temperature rise of the inside is suppressed. In addition, the valve member 21 closes the ventilation hole 1 d due to the arc gas pressure generated when the conduction current is interrupted. To prevent

Next, the operation of the movable-side arc contact 6a and the fixed-side arc contact 22a will be described. The mover 6 connected to the opening / closing mechanism 13 is turned on. ■ The contact arm 7, the mover pin 8, and the contact arm shaft 9 are in a positional relationship so as to move when the armature is off. During the ON operation, first, the movable-side arc contact 6a and the fixed-side arc contact 22a come into contact with each other and energization is started. When the opening / closing mechanism is further pushed, the contact point serves as a fulcrum, and the movable contact 5 and the fixed contact 4 come into contact with each other. This time, since the contact surface between the movable contact 5 and the fixed contact 4 is the fulcrum and the pushing is continued, the movable arc contact 6 a and the fixed arc contact 2 2 a are separated, and the conduction current is fixed. It flows on all contact surfaces between 4 and movable contact 5.

During the current interruption operation, the movable contact 5 is slightly separated from the fixed contact 4 as the movable element 6 of the switching mechanism is pulled up, and an electric current is applied between the two contacts by an arc. The mover 6 is rotated clockwise about the axis 14 by the pressing force of the contact pressure panel 12, and the movable-side arc contact 6a comes into contact with the fixed-side arc contact 22a. At this point, the current flows in parallel with the arc current between the two contacts and the contact point between the movable-side arc contact 6a and the fixed-side arc contact 22a. By further raising the opening / closing mechanism, the movable contact 5 and the fixed contact 4 are largely separated from each other with the contact point between the movable-side arc contact 6a and the fixed-side arc contact 22a kept in contact. The arc between the contacts is elongated. As the arc is extended, the arc resistance increases and the main current flows to the contact point between the movable-side arc contact 6a and the fixed-side arc contact 22a. The contact point between the movable arc contact 6a and the fixed arc contact 22a is opened by further opening operation of the opening / closing mechanism, and the arc generated here is attracted to the arc extinguishing device 17 and extinguished. You.

As described above, the movable-side arc contact Since no current flows through 6a and the fixed-side arc contact 22a, there is no heat generated by energization in this area. However, heat conduction from the contact point is possible, which has the effect of increasing the heat dissipation area.

The movable-side arc contact 6a and the arc block 22 connected to the contact surfaces of the movable contact 5 and the fixed contact 4, which are the main heat generating parts, are provided in the ventilation flow path between the ventilation hole 1d and the arc gas discharge window 1c. Cooled by convection air as a heat dissipating member, it suppresses temperature rise in the current-carrying part.

In addition, since the plurality of movers 6 including the movable-side arc contact 6a are arranged in parallel at the one-pole opening / closing section, the movable-side arc contact 6a increases the heat radiation area as a whole. In addition, the arc block 22 has a concave groove 22b provided along the ventilation direction to increase the heat radiation area and enhance the heat radiation effect.

The arc block 22 constituting the fixed-side arc contact 2 2a is attached to one side of the fixed conductor 3 and the other side is attached to the bottom of the base housing 1, so that the heat of the fixed contact 4 is fixed conductor. The heat is transmitted to the arc block 22 via 3 and the heat radiation by the above convection air and the heat radiation to the outside air from the back surface through the bottom surface of the base case 1 are promoted, and the temperature rise of the conducting part is suppressed. . At this time, if the bottom rear surface of the base housing 1 is corrugated to increase the heat radiation area of the bottom rear surface, the heat radiation effect can be further improved, and industrial applicability is possible.

As described above, the air circuit breaker according to the present invention includes a fixed conductor having a fixed contact fixed thereto, a movable element having a movable contact fixed to and separated from the fixed contact fixed thereto, and an arc extinguishing the arc between the two contact points. An arc extinguishing device is provided in the housing, and a vent hole is provided in a part of the housing and opposed to the discharge window that discharges the arc gas to the outside of the housing. The contact and the current-carrying body around the contact are cooled by air convection from the hole to the discharge window, and the temperature caused by the heat generated The rise is suppressed.

In addition, a valve member is provided to close the ventilation hole when the pressure in the housing increases, so that the valve member prevents the arc gas from escaping from the ventilation hole when the fault current is shut off. ,

An arc block having a fixed-side arc contact extending from the fixed contact so as to be able to conduct and conduct heat, and an arc block having a movable-side arc contact extending from the movable contact so as to conduct and conduct heat, are provided. The arc block and the movable-side arc contact, which are not energized in the normal contact closed state, can increase the heat radiation area and perform cooling effectively.

In addition, since one pole is opened and closed as a plurality of movers, and the movable-side arc contacts are extended to each of the plurality of movers, all the movable-side arc contacts become radiation fins. The heat radiation area can be further increased. Therefore, it is possible to suppress the temperature rise of the current-carrying part of the air circuit breaker within the upper limit temperature of the specification.

Claims

The scope of the claims

1. A fixed conductor with a fixed contact fixed thereto, a movable element with a movable contact fixed to and separated from the fixed contact by an opening / closing mechanism, and a extinction for inducing and extinguishing an arc generated at the movable contact and the fixed contact 阇. In an air circuit breaker provided with an arc device in a housing, an emission window provided in a part of the housing for discharging the arc gas in the housing to the outside of the housing, and a portion facing the emission window. An air circuit breaker, characterized by having a vent hole which is opened and forms an air passage inside the housing.

2. The air circuit breaker according to claim 1, further comprising: a vent hole that closes when the pressure inside the housing rises. .

3. An arc block including a fixed-side arc contact extending from the fixed contact to the arc-extinguishing device so as to be able to conduct electricity and heat, and the fixed-side arc contact at least when the two contacts are opened. The air circuit breaker according to claim 1 or 2, wherein a movable arc contact contacting with the arc-extinguishing device is provided extending from the movable contact to the arc extinguishing device so as to be capable of conducting and conducting heat. _(4. performs with the opening and closing of one pole of a plurality of movable elements, according to claim 3 air circuit breaker according to, characterized in that by extending the movable arcing contact to each of the plurality of movable elements.