JP5149667B2 - Contact device - Google Patents

Description

  The present invention relates to a contact device used for a circuit breaker or a switch.

  Conventionally, a contact device having means for preventing thermal energy from increasing between contacts due to an arc generated when an overcurrent such as a short-circuit current or an overload current flows and forcibly opens is known. Some are disclosed in Document 1. The contact device described in Patent Document 1 includes a plurality of power supply side terminal portions and load side terminal portions respectively disposed on both sides of the container body, contact portions disposed on the power supply side terminal section side, and the interior of the container body. An open / close mechanism that opens and closes the contact device in conjunction with the operation of an externally operated operating handle, and is opened and closed when an overcurrent such as a short-circuit current or overload current flows through the contact portion. And an overcurrent interruption mechanism that releases the mechanism and forcibly opens the contact portion. In addition, this contact device is equipped with a contact portion, a power supply side terminal portion, a load side terminal portion, and an overcurrent cutoff mechanism at each pole, and each overcurrent cutoff mechanism has a switching mechanism including an operation handle in common with each pole. And it becomes the structure linked with a contact part.

  The contact portion is fixed to a fixed contact fixed to a terminal plate extending from the power supply side terminal portion, and a movable contact that is rotatable between a position in contact with the fixed contact and a position away from the fixed contact. It consists of movable contacts that are placed opposite to each other. The movable contact of each pole is housed in the body so as to straddle each pole, and is rotatably held by each pole-linked crossbar that rotates around the shaft portion according to the operation of the operation handle. ing.

In the vicinity of the movable contact in the movable contact, there is a fixed contact so that the distance between the fixed contact and the movable contact is smaller than the separation distance between the fixed contact and the movable contact with the opening operation of the movable contact. Electrode pieces made of a conductive material always facing each other at intervals are provided. Thus, the arc current generated at the time of forced opening spreads not only to the movable contact but also to the electrode piece, so that an increase in arc voltage can be suppressed, and the current is reduced to a substantially zero point while suppressing an increase in thermal energy. It can be blocked at the position.
Japanese Patent No. 2734615

  By the way, when the overcurrent breaking mechanism is forced to open, if an overcurrent flows, an electromagnetic repulsive force is generated between the contacts, and this electromagnetic repulsive force causes a phenomenon in which the fixed contact and the movable contact are separated, causing an arc to occur. Occur. At the same time as this phenomenon occurs, the overcurrent cutoff mechanism works to force the contacts to open.

  However, in the above conventional example, since it takes time until the arc is extinguished by completely separating the contacts by the overcurrent interruption mechanism after the contact opening phenomenon due to the electromagnetic repulsive force occurs, the arc is generated. There is a problem that the time is increased, and the life of the contact is shortened by depleting the fixed contact and the movable contact.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a contact device that can prevent a fixed contact, a movable contact, and the like from being consumed by an arc generated during forced opening. .

In order to achieve the above object, the invention according to claim 1 is a pair of terminal portions corresponding to input / output, a terminal plate having a fixed contact and connected to one terminal portion, and a movable contacting and separating from the fixed contact. A contact spring that has a contact and a movable contact that is connected to the other terminal portion is housed in a container for each of one or more poles, and applies a contact pressure when each movable contact contacts each fixed contact A crossbar that supports each movable contact while holding it between each movable contact and operates each movable contact in conjunction with the handle, and a handle that is rotatable between an on position and an off position. An opening / closing mechanism composed of a plurality of link members that contact and separate each movable contact with each fixed contact by transmitting the turning operation of the handle to the crossbar, and a force accumulated in a direction that breaks the balance of the opening / closing mechanism. Latch member that holds the balance of the open / close mechanism and fixed When an overcurrent flows between the point and the movable contact, the contact device includes an overcurrent interruption mechanism that drives the latch member to break the balance of the switching mechanism and forcibly opens the movable contact from the fixed contact, The overcurrent cutoff mechanism consists of a fixed core wound with a coil connected to a movable contact, a yoke that is attached to the fixed core and forms a magnetic path with the fixed core, and is supported by the yoke and contacts the fixed core. The latch member is positioned on the trajectory of rotation of the armature and is overcurrent. It is those that are driven to rotate in the direction in which the armature when the flow is in contact with the fixed iron core Ko' the urging force of the return spring, the two vent above the crossbar in the device body It was formed through and penetrated the introduction hole above the armature in the device body, these vents and inlet holes, the arc gas caused by the arcing armature a ventilation path that leads to be pressed to the fixed iron core side It is formed in a container.

  According to the present invention, the air passage that guides the arc gas generated by the generation of the arc so that the armature is pressed toward the fixed iron core is formed in the body, so that the armature is fixed by the gas pressure of the arc gas when the contact is forcibly opened. The time until the armature drives the latch member can be shortened by being accelerated in the direction toward the iron core. Therefore, since the time required until the contact is forcibly opened can be shortened, the arc generation time can be shortened and the fixed contact and the movable contact can be prevented from being consumed.

  Hereinafter, embodiments of the contact device according to the present invention will be described. In the following description, the top, bottom, left, and right in FIG. In this embodiment, the three poles are opened and closed by a single opening / closing mechanism. As shown in FIGS. 1 (a), 1 (b) and 2, each of the left and right ends of the substantially rectangular parallelepiped container 1 is provided. A terminal block 13 is formed, and the left terminal block 13 is provided with three power supply side terminal portions A along the width direction of the body 1 (one in the drawing), and the right terminal block 13 has a load side. Three (1 in the figure) terminal portions B are arranged in parallel along the width direction of the container body 1. Each terminal block 13 is formed with an insulating wall 13a that insulates between adjacent power supply side terminal portions A and between load side terminal portions B. Between each of the poles, between the power supply side terminal portion A and the load side terminal portion B, there is a terminal plate 2 having a fixed contact 2a connected to the power supply side terminal portion A, and a fixed contact connected to the load side terminal portion B. A movable contact 3 having a movable contact 3a that contacts and separates from 2a is housed. The container 1 also includes an opening / closing mechanism 4 that opens and closes the contacts of each pole and an overcurrent blocking mechanism 5 that forcibly opens the contacts when an overcurrent flowing between the contacts is detected when the contacts are closed. Has been.

  The container body 1 is covered with a flat base 10 made of a synthetic resin molded product, a substantially rectangular parallelepiped body 11 made of a synthetic resin molded product disposed above the base 10, and an upper surface of the body 11. A box-shaped cover 12 made of a synthetic resin molded product having an open bottom surface is coupled to each other. An insulating wall 11a (see FIG. 4B) that divides the internal space for each pole is formed inside the body 11, and insulation between adjacent poles is achieved. Further, a substantially rectangular window hole 12a is provided in the upper surface of the cover 12 so as to expose an operation portion of the handle 40 described later. As shown in FIGS. 1 (a) and 1 (b), two substantially rectangular vent holes 11b are formed above the cross bar 30 (to be described later) of the body 11 and above the armature 53 (to be described later). An introduction hole 11c is provided. The vent hole 11b and the introduction hole 11c form a vent path for guiding the arc gas generated when the arc is generated to the armature 53.

  As shown in FIGS. 4A and 4B, the terminal plate 2 is made of a conductive material such as copper, and has a screw hole 20a into which the terminal screw 14 of the power supply side terminal portion A is screwed. The terminal piece 20, the contact piece 21 to which the fixed contact 2 a made of a conductive material having higher arc resistance than copper such as silver, for example, is fixed, and the extended piece 22 that couples the terminal piece 20 and the contact piece 21. It is comprised by the substantially Z shape. The extension piece 22 has an insulating valve plate 23 made of an insulating material having elasticity, and a plurality of (four in the figure) substantially rectangular exhaust holes 24 a that are closed by the valve plate 23. An exhaust plate 24 made of a material is attached. Further, the extension piece 22 is provided with a substantially rectangular escape hole 22a through which arc gas generated by the generation of the arc is released at a position facing the operating range of the movable contact 3a.

  The valve plate 23 is bent outward due to the gas pressure of the arc gas generated when the arc is generated, and discharges the arc gas to the outside through the exhaust holes 24 a of the exhaust plate 24. Since the valve plate 23 closes the exhaust hole 24a except when an arc is generated, the valve plate 23 functions to prevent foreign matters such as dust from entering the inside of the vessel 1.

  The exhaust plate 24 is disposed so as to overlap the thickness direction of the exhaust plate 24. The arc extinguishing gas generating plate 24b generates arc extinguishing gas by the heat of the arc generated when the contact is opened, and the arc extinguishing gas generating plate 24b. A plurality (three in the figure) of grids 24c held by the exhaust plate 24 are provided. For this reason, the arc gas generated with the generation of the arc is discharged out of the body through the exhaust hole 24a of the exhaust plate 24, and the arc is divided and cooled by the grid 24c, and the arc extinguishing generated from the arc extinguishing gas generating plate 24b. The arc is extinguished by sex gas. Further, the contact piece 21 is provided with a contact protection plate 25 which is disposed so as to surround the fixed contact 2a to protect the fixed contact 2a and prevent the arc from re-igniting.

  As shown in FIG. 3A, the movable contact 3 is formed in a long flat plate shape from a conductive material such as copper, for example, and has an arc resistance higher than that of copper such as silver at one end portion in the longitudinal direction. A movable contact 3a made of a highly conductive material is fixed so as to face the fixed contact 2a. Further, in the vicinity of the movable contact 3a, an electrode piece 3b made of a conductive material having a melting temperature higher than that of the movable contact 3, such as iron, is provided. The electrode piece 3b is arranged so that the distance between the fixed contact 2a and the electrode piece 3b is smaller than the distance between the contacts during the opening operation of the contacts, and an arc generated at the time of opening is generated. An increase in arc voltage is suppressed so as to spread toward the electrode piece 3b, and an increase in thermal energy is suppressed. Connected to the other end in the longitudinal direction of the movable contact 3 is a connection line 31 composed of a braided wire that is electrically connected to the load side terminal portion B and a coil 51 described later. Thus, at the time of closing, the power supply side terminal portion A and the load side terminal portion B are electrically connected via the terminal plate 2, the movable contact 3 and the connection line 31.

  A rotary shaft 33 is provided at substantially the center of the movable contact 3, and the rotary shaft 33 is rotatably held by being held inside a cross bar 30 provided continuously across the poles. As shown in FIG. 4 (a), the cross bar 30 connects a plurality of (three in the drawing) holding portions 30b that hold the movable contact 3 of each pole at a predetermined interval to each other by a shaft portion 30a. In each holding portion 30b, a contact pressure spring 32 (see FIG. 3A) formed of a coil spring is held in a compressed state between the inner surface of the holding portion 30b and the other end portion of the movable contact 3. Yes.

  As shown in FIG. 3A, the urging direction of the contact pressure spring 32 includes a point a where the holding portion 30b and the contact pressure spring 32 are in contact, and a point b where the movable contact 3 and the contact pressure spring 32 are in contact. And the point c of the rotary shaft 33. That is, when the normal contact is opened and closed, the movable contact 3 is biased counterclockwise because the point b is positioned above the straight line connecting the point a and the point c. Due to the electromagnetic repulsive force between the contacts, the movable contact 3 rotates clockwise against the urging force of the contact pressure spring 32, and the point b is located below the straight line connecting the points a and c. Therefore, the movable contact 3 is urged clockwise.

  The opening / closing mechanism 4 is connected to the handle 40, which is rotatably held by the body 11, and has an operating portion protruding outside through the window hole 12 a of the cover 12, and the handle 40 and the crossbar 30. And a plurality of link members 41 for interlocking the crossbar 30 in accordance with the rotational movement. The handle 40 is rotatable between an ON position (see FIGS. 3A and 3B) for closing the contact and an OFF position (see FIGS. 3C and 3D) for opening the contact. When the handle 40 is turned to the on position, the cross bar 30 is turned counterclockwise, and when the handle 40 is turned to the off position, the cross bar 30 is turned clockwise. . Thus, in conjunction with the closing operation of the handle 40, the opening / closing mechanism 4 rotates the cross bar 30 counterclockwise about the shaft portion 30a, so that the movable contact 3a comes into contact with the fixed contact 2a, and the contact pressure A contact pressure is applied between the contacts by the biasing force of the spring 32. Further, in conjunction with the opening operation of the handle 40, the opening / closing mechanism 4 rotates the cross bar 30 clockwise about the shaft portion 30a, whereby the movable contact 3a is separated from the fixed contact 2a. In addition, since the structure of such an opening-and-closing mechanism 4 is known, detailed description shall be abbreviate | omitted here.

  As shown in FIG. 3A, the overcurrent interrupting mechanism 5 includes a fixed core 50 disposed on the terminal plate 6 of the load side terminal portion B so that the longitudinal direction is along the vertical direction, and the fixed core 50. One end is provided at the upper end of the yoke 52 so as to face the upper end of the fixed coil 50, the coil 52 wound around the coil 51, the yoke 52 attached to the side of the fixed core 50. An armature 53 that is supported and urged clockwise by a return spring 54 that is a coil spring, and a latch member 55 that is positioned on the locus of rotation of the armature 53 and that interlocks with the link member 41 of the opening / closing mechanism 4. Composed.

  The armature 53 is located away from the upper end portion of the fixed core 50 by the urging force of the return spring 54 except when an overcurrent is generated. However, when an overcurrent is generated, the fixed core 50 is caused by an overcurrent flowing through the coil 51. Is excited and attracts the armature 53, so that the armature 53 rotates counterclockwise against the urging force of the return spring 54 and comes into contact with the upper end portion of the fixed iron core 50. At this time, in the process in which the armature 53 comes into contact with the upper end portion of the fixed iron core 50, the other end portion of the armature 53 comes into contact with the latch member 55 to rotate the latch member 55 clockwise. The latch member 55 holds the balance of the opening / closing mechanism 4 in a state where the force in the direction of breaking the balance of the opening / closing mechanism 4 is accumulated. When the latch member 55 is driven as described above, The force in the direction of breaking the balance is released, and the opening / closing mechanism 4 rotates the cross bar 30 clockwise to forcibly open the contact.

  Hereinafter, the operation at the time of forced opening of the present embodiment will be described. First, when an overcurrent such as a short-circuit current flows between the contacts at the time of closing, the electromagnetic repulsive force generated between the contacts due to the overcurrent exceeds the urging force of the contact pressure spring 32 so that the movable contact 3 rotates clockwise. Then, the contact is released and an arc is generated. Simultaneously with the above phenomenon, the fixed iron core 50 is excited by the overcurrent flowing through the coil 51, and the armature 53 rotates counterclockwise against the urging force of the return spring 54 to contact the tip of the fixed iron core 50. . At this time, in the process in which the armature 53 comes into contact with the tip of the fixed iron core 50, the armature 53 comes into contact with the latch member 55 and rotates the latch member 55 clockwise. The opening / closing mechanism 4 rotates the cross bar 30 clockwise to forcibly open the contact.

  Here, in this embodiment, since the ventilation hole 11b and the introduction hole 11c are provided in the body 11, it is generated by the thermal energy of the arc generated when the contact is separated and fills the arc extinguishing space around the fixed contact 2a. The arc gas is guided to the armature 53 through a ventilation path including the ventilation hole 11b and the introduction hole 11c. As shown in FIG. 1A, the introduction hole 11 c is provided so as to be connected to the space above the armature 53, so that the arc gas guided through the air passage fills the space above the armature 53. The armature 53 is pressed downward by the gas pressure, that is, toward the fixed iron core. For this reason, the armature 53 is accelerated in the direction toward the fixed iron core 50, and the time required for the armature 53 to rotate the latch member 55 can be shortened. As a result, the time required until the contact is forcibly opened. Can be shortened.

  As described above, in the present embodiment, the air passage that guides the arc gas generated by the generation of the arc so that the armature 53 is pressed toward the fixed iron core 50 is formed in the body 1. With this gas pressure, the armature 53 is pressed and accelerated in the direction toward the fixed iron core 50, and the time until the armature 53 drives the latch member 55 can be shortened. Therefore, since the time required until the contact is forcibly opened can be shortened, the arc generation time can be shortened, and the fixed contact 2a, the movable contact 3a, and the like can be prevented from being consumed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows embodiment of the contact apparatus which concerns on this invention, (a) is a perspective view which shows a closing state, (b) is a perspective view which shows an opening state. It is a perspective view which shows the state which attached the cover same as the above. (A), (b) is sectional drawing which shows a closing state same as the above, (c), (d) is sectional drawing which shows an opening state same as the above. (A) is a disassembled perspective view of a power supply side terminal part, (b) is a perspective view of a power supply side terminal part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Body 2 Terminal board 2a Fixed contact 3 Movable contactor 3a Movable contact 30 Crossbar 4 Opening / closing mechanism 40 Handle 41 Link member 5 Overcurrent interruption mechanism 50 Fixed iron core 51 Coil 52 Yoke 53 Armature 54 Return spring 55 Latch member A Power supply side Terminal part B Load side terminal part

Claims (1)

A pair of terminal portions corresponding to input / output, a terminal plate having a fixed contact and connected to one terminal portion, and a movable contact having a movable contact contacting and separating from the fixed contact and connected to the other terminal portion Is housed in the container for each of one or more poles, and each movable contact is movable while holding a contact pressure spring between each movable contact to apply contact pressure when each movable contact contacts each fixed contact. By having a crossbar for supporting the contactor and operating each movable contactor in conjunction with each other, and a handle that can be rotated between an on position and an off position, and transmitting the rotation of the handle to the crossbar. An opening / closing mechanism composed of a plurality of link members that bring each movable contact into and out of each fixed contact, a latch member that maintains the balance of the opening / closing mechanism in a state in which the force in the direction that breaks the balance of the opening / closing mechanism is accumulated, a fixed contact, and a movable Latch when overcurrent flows between contacts The contact device is provided with an overcurrent interruption mechanism that drives the material to break the balance of the switching mechanism and forcibly opens the movable contact from the fixed contact, and the overcurrent interruption mechanism is connected to the movable contactor. Between a fixed core around which a coil is wound, a yoke that is attached to the fixed core and forms a magnetic path with the fixed core, and a position that is supported by the yoke and that is in contact with and away from the fixed core The latch member is located on the trajectory of rotation of the armature and the armature is energized by the return spring when an overcurrent flows. It is those that are driven to be rotated in a direction to contact the fixed iron core Ko' to and penetrated two vents above the crossbar in the device body, above the armature in the device body The entry apertures were formed through, these vents and inlet hole, characterized in that the arc gas caused by the arcing armature formed in the air passage of the device body guide it is pressed against the fixed core side contact apparatus.

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