JP4285261B2 - Switch - Google Patents

Description

  The present invention relates to a switch. More specifically, the case or the like constituting the arc extinguishing chamber of the switch is prevented or reduced from being melted by the heat of the arc generated between the contacts during the opening operation of the switch, and the case or the like is deformed so that the case is deformed. The present invention relates to a device in which the temperature rise value of the contact when the main circuit is energized does not fall within the standard value due to troubles in operation or attachment of wrinkles to the contact.

For example, in a gas switch, a stationary contact (power source side contact) is accommodated and fixed in each arc-extinguishing chamber, and a through hole provided in a case constituting the arc-extinguishing chamber passes through the stationary contact. The movable contact (load side contact) that has been made is connected.
When the switch is opened, an arc is generated so as to connect the two contacts between the fixed contact and the movable contact. Since the heat of the arc is extremely high and adversely affects the surroundings, various means have been conventionally used to extinguish the arc instantaneously in the arc extinguishing chamber.

As one of such means, there is a shutter system in which an arc extinguishing shutter is provided corresponding to a through hole of a case constituting the arc extinguishing chamber (reference: FIGS. 1 and 2).
The shutter system is an open operation, that is, the movable contact is pulled out from the fixed contact and exits the arc extinguishing chamber, and at the same time, the shutter is closed and the arc is cut off to extinguish the arc. However, in the arc extinguishing chamber, the resin case is melted by the generated arc heat, and soot and the like adhere to the inner surface. Moreover, this wrinkle adheres similarly to each contact, especially a fixed contact.

When the case is melted, the periphery of the through-hole through which the movable contact penetrates is likely to be deformed, and the deformed through-hole may hinder the movement of the movable contact and hinder the operation of the switch.
Moreover, when wrinkles or the like adhere to the contact, when the switch is turned on, the electrical resistance (contact resistance) at the contact portion between the movable contact and the fixed contact increases, and the amount of heat generated when energized also increases. This makes it difficult for the temperature rise value of each contact to fall within the standard value, and in extreme cases, the temperature rises too much, causing the risk of accidents such as each contact and its surrounding members melting at high temperatures. Sex cannot be denied.
In particular, when a switch with a large load switching capability is generated, the generated arc becomes larger, and the above tendency becomes remarkable, and the temperature rise value of the contact when the main circuit of the switch is energized is within the standard value by design. It was difficult to fit in.

(Object of the present invention)
The present invention prevents or reduces the melting of the case or the like constituting the arc extinguishing chamber of the switch due to the heat of the arc generated between the contacts during the opening operation of the switch, and the operation of the switch by deforming the case To provide a switch that prevents the temperature rise of the contact from falling within the standard value when the main circuit of the switch is energized due to contact with the contact, such as wrinkles With the goal.

Means taken by the present invention to solve the above problems are as follows.
In the present invention,
A mounting portion is provided inside the arc extinguishing chamber case that forms an arc extinguishing chamber that extinguishes the arc generated between the contacts of the main circuit during the opening operation ,
The mounting portion, the inner surface of the arc extinguishing chamber protected from the arc heat, no eddy currents during energization of the main circuit in the closed state, the protective cover made of non-magnetic material and the inner surface of the arc-extinguishing chamber case It is placed between fixed contacts and mounted.
The protective cover is composed of a rectangular top and side portions provided on its four sides, and the top is provided with a through-hole that has the same rectangular shape as the through-hole of the arc extinguishing chamber case and matches the position. And
The protective cover is deformed inward on each side and is fixed to the mounting part using its repulsive force.
It is a switch.

  The protective cover may cover the entire inner surface of the arc extinguishing chamber, or may cover only a part thereof. In order to protect the inner surface of the arc extinguishing chamber from arc heat and prevent the case constituting the arc extinguishing chamber from being melted or to prevent adhesion to a contact such as a flaw, the area covered with a protective cover However, there is no particular limitation on the area to be covered, the area, and the like. For example, among the cases constituting the arc extinguishing chamber, at least the top portion where the through-hole through which the movable contact passes is provided is covered.

  Various known means can be adopted as means for providing the protective cover inside the arc extinguishing chamber. For example, a fitting part is provided inside the case constituting the arc extinguishing chamber, and a removable cover that fits and fixes a separate protective cover into the fitting part, and using a fastener such as a bolt on the fitting part One that is fixed, or one that is fixed by insert molding that is integrally molded when the case is manufactured. Further, the protective cover may be in close contact with the inner surface of the arc extinguishing chamber, or a space may be provided between the inner surface of the arc extinguishing chamber and the inner surface as long as the inner surface of the arc extinguishing chamber can be protected from arc heat.

As a material for the protective cover, for example, stainless steel (18-8 stainless steel, etc.), high manganese steel, aluminum alloy, copper alloy, titanium alloy, nickel alloy (Inconel, etc.), etc. Can be adopted.
The material of the protective cover is not limited to the above metals, and other materials such as synthetic resins and ceramics should be used as long as they have excellent heat resistance that does not melt even with the heat of the arc. You can also. A plated material can also be used.

  Furthermore, it is possible to provide the same function by forming, for example, the case itself constituting the arc extinguishing chamber with the above material. In addition, the form of the protective cover is not limited to a simple plate-like form, and may be a net-like (including punching metal), etc., as long as it can protect the arc extinguishing chamber by reducing arc heat. Can also be adopted.

  When the protective cover is formed in, for example, a rectangular box shape, and the arc extinguishing chamber opening after the movable contact is pulled out is closed by the arc extinguishing shutter, the arc generated by opening the contact is It will be sealed in a protective cover. The protective cover is made of a material that can sufficiently withstand the thermal expansion of its arc energy, and has sufficient structural strength.

(Function)
The operation of the switch according to the present invention will be described. In addition, here, in order to make the explanation easy to understand, each constituent element of the present invention will be described by correspondingly assigning a reference numeral given to each part in the embodiment described later. It is for reference and does not mean the limitation of each component to the above-mentioned parts.

  The switch (S) has an arc inside the arc extinguishing chamber (719) that extinguishes the arc generated between the contacts (4, 5) of the main circuit during the opening operation, and the inner surface of the arc extinguishing chamber (719). Since the protective cover (73) made of a nonmagnetic material that protects from heat is provided, it is possible to prevent the inner surface from being exposed to the heat of the arc.

If the main circuit is energized with the switch turned on, the protective cover will cover the periphery of the movable contact, so if the protective cover is made of a magnetic material such as steel, Magnetic flux generated around the conductor goes around the protective cover, and Joule heat is generated by the eddy current generated thereby.
Since the protective cover (73) according to the present invention is made of a nonmagnetic material, no eddy current is generated in the protective cover (73). Therefore, there is no generation of Joule heat due to eddy current, and the protective cover (73) is not heated to a high temperature.

Therefore, when the switch (S) is opened, it is possible to prevent or reduce the melting of the inner surface of the arc extinguishing chamber (719) due to the heat of the arc generated between the contacts (4, 5). As a result, for example, the case (71) constituting the arc extinguishing chamber (719) is deformed, thereby obstructing the operation of the switch (S) by inhibiting the movement of the movable contact (5). Can be prevented.
In addition, the case (71) and the like can be prevented or reduced from melting due to the heat of the arc and the generation of wrinkles, and the wrinkles and the like are less likely to adhere to the contacts (4, 5). As a result, the temperature rise value of the contact (4.5) when the main circuit is energized after turning on the switch can be suppressed, and the temperature can be prevented from falling within the standard value.

(A) The switch according to the present invention is a non-magnetic material that protects the inner surface of the arc extinguishing chamber from arc heat inside the arc extinguishing chamber that extinguishes the arc generated between the contacts of the main circuit during the opening operation. Since the protective cover made is provided, it is possible to prevent the inner surface from being exposed to the heat of the arc.
In addition, since the protective cover is made of a non-magnetic material, no eddy current is generated in the protective cover when the main circuit is energized when the switch is turned on, and no Joule heat is generated, so the protective cover is heated to a high temperature. There is nothing.
Therefore, it is possible to prevent or reduce the melting of the inner surface of the arc extinguishing chamber of the switch by the arc heat generated when the contact is opened. For example, the case constituting the arc extinguishing chamber can be moved by deformation. It is possible to prevent the operation of the switch from being hindered by obstructing the movement of the contact.

(B) Since the case can be prevented or reduced from melting due to the heat of the arc to generate wrinkles or the like, the wrinkles or the like hardly adhere to the contact. As a result, when the switch is turned on, an increase in electrical resistance (contact resistance) at the contact portion between the movable contact and the fixed contact can be suppressed.
Therefore, the temperature rise of the contact when the main circuit is energized can be suppressed, and the temperature rise of the contact can be prevented from falling within the standard value even when used for a long time.

  The present invention will be described in detail based on the embodiments shown in the drawings.

FIG. 1 is a cross-sectional explanatory view of a stationary contact side of a switch according to the present invention,
2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is a partial cross-sectional view of the arc extinguishing chamber case in FIG.
FIG. 4 is an explanatory view showing the structure of the protective cover, (a) is a front view, (b) is a plan view, (c) is a left side view,
FIG. 5 is a perspective explanatory view showing the internal structure of the switch according to the present invention,
FIG. 6 is an explanatory view showing the appearance of the switch according to the present invention, (a) is a front view, and (b) is a left side view.

  The structure of the switch S according to the present embodiment will be described. The switch S has a general structure other than the arc extinguishing section 7 which will be described later, which is a characteristic part of the present invention. Therefore, the outline of these structures is only described or omitted. .

The switch S includes a case 1, bushings 2, 3 for connecting a distribution line, a fixed contact 4 connected to a distribution line introduced through the bushing 2, and a rotatable contact within the case 1. A curved plate-shaped movable contact 5 that opens and closes the fixed contact 4, a drive mechanism unit 6 that rotates each movable contact 5, and an arc-extinguishing unit 7 that covers each fixed contact 4. In addition, it has a configuration including a handle 8 for operating the driving mechanism 6 to manually turn on and open the movable contacts 5.
Note that a control unit that is connected to the case 1 and that automatically turns on and off the movable contacts 5 is not shown.

The arc extinguishing part 7 of the switch S employs a shutter system that extinguishes when the movable contact 5 exits an arc extinguishing chamber 719, which will be described later, by closing the shutter member 723 and cutting off the arc when opening. Yes.
Each arc extinguishing part 7 is constituted by a fixed contact base member 70, an arc extinguishing chamber case 71, an arc extinguishing shutter part 72, and a protective cover 73 provided in the arc extinguishing chamber case 71.

  Each fixed contact base member 70 is made of an insulating resin, and is fixedly provided in parallel to a mounting seat member 74 attached to the inner wall portion of the case 1 with a bolt 740. The side of the fixed contact base member 70 opposite to the side fixed to the mounting seat member 74 is opened, and the fixed contact 4 is provided on the open side.

  The stationary contact 4 is fixed to the conductor 40 that constitutes the distribution line. The conductor 40 is introduced into the fixed contact base member 70 and fixed with two bolts 49. The stationary contact 4 is composed of a bottom portion 41 fixed to the conductor 40 with two bolts 48, and rising portions 42 provided so as to be inclined so that the tip side approaches both sides thereof. The tip of 42 is rounded inward.

  In the fixed contact 4, an in-contact sesame 43 is provided so as to be located inside each rising portion 42. A contact spring 44 that reinforces the spring property of the fixed contact 4 is provided in close contact with the outer surface side of the fixed contact 4. Further, both end portions (upper end portions in FIG. 1) of the contact spring 44 are positioned at substantially the same position as the top portion of the rising portion 42.

  An arc-extinguishing chamber case 71 made of insulating resin having an opening at the lower side is fixed to the opening side of the fixed contact base member 70 by four bolts 700. A packing 75 is interposed between the lower part of the arc-extinguishing chamber case 71 and the fixed contact base member 70. A rectangular through-hole 710 through which the movable contact 5 passes is provided at the top of the arc extinguishing chamber case 71. An arc extinguishing chamber 719 is formed by the opening side of the fixed contact base member 70 and the internal space of the arc extinguishing chamber case 71.

  A mounting part 711 for mounting the protective cover 73 is provided inside the arc extinguishing chamber case 71. The protective cover 73 is made of stainless steel, which is a nonmagnetic material. As shown in FIG. 4, the protective cover 73 includes a rectangular top portion 730 and side portions 731, 732, 733, and 734 provided on four sides thereof. The top portion 730 is provided with a through-hole 739 having the same rectangular shape as the through-hole 710 of the arc-extinguishing chamber case 71 and matching the position.

The side portions 732 and 734 on both long sides are inclined so as to expand slightly downward. Further, the side portion 731 on one short side is inclined so as to expand slightly downward, the side portion 733 on the other side is provided at a right angle to the top portion 730, and the middle portion of the lower end side is outward. It is tilted.
The protective cover 73 is fixed to the mounting portion 711 by deforming the side portions 731, 732, and 734 inward and using the repulsive force. The protective cover 73 can be removed from the mounting portion 711 and can be easily replaced.
With this structure, the protective cover 73 is provided between the inner surface of the arc-extinguishing chamber case 71 (that is, the inner surface of the arc-extinguishing chamber 719) and the stationary contact 4, and Can cover most.

  An arc extinguishing shutter 72 made of insulating resin is fixed to the upper part of the arc extinguishing chamber case 71 with two bolts 720. The arc extinguishing shutter part 72 is open at the top and has a shutter chamber 721 at the bottom. Further, the arc extinguishing shutter portion 72 is curved in accordance with the shape of the movable contact 5 as shown in FIG. The lower part of the shutter chamber 721 is open and communicates with the through-hole 710. In the upper part of the shutter chamber 721, a rectangular through hole 722 which is the same as the through holes 710 and 739 is provided.

  A shutter member 723 is provided in the shutter chamber 721 against the opposite. Each shutter member 723 is urged in the contact direction by a spring 724. When the movable contact 5 is in an open state, the shutter members 723 are in close contact with each other at positions that match the through holes 710 and 722. Further, each shutter member 723 expands when the movable contact 5 is in the closed state, and is in close contact with the side surface of the movable contact 5.

(Function)
With reference to FIG. 1 thru | or FIG. 6, the effect | action of the switch S which concerns on this Embodiment is demonstrated.
When the fixed contact 4 and the movable contact 5 of the switch S are opened, an arc is generated between the contacts 4 and 5. The arc is generated so as to be connected between the stationary contact 4 and the movable contact 5 about to exit from the arc extinguishing chamber 719, and the arc extinguishing chamber 719 is also filled.

Inside the arc extinguishing chamber 719 of the switch S, a protective cover 73 made of stainless steel, which is a nonmagnetic material, is provided so as to cover the inner surface of the arc extinguishing chamber case 71 (or the arc extinguishing chamber 719). The arc-extinguishing chamber case 71 is disposed between the inner surface of the arc-extinguishing chamber case 71 and the stationary contact 4.
Thereby, the protective cover 73 can prevent the inner surface of the arc extinguishing chamber case 71 from being exposed to the heat of the arc.
Further, since the protective cover 73 is made of a non-magnetic material, no eddy current is generated in the protective cover 73 when the main circuit is energized in the on state. Therefore, there is no generation of Joule heat due to eddy current, and thus the protective cover 73 is not heated to a high temperature.

  Therefore, it is possible to prevent or reduce the melting of the inner surface of the arc extinguishing chamber case 71 constituting the arc extinguishing chamber 719 of the switch S by the heat of the arc generated when the contacts 4 and 5 are opened. For example, it is possible to prevent the operation of the switch S from being hindered by, for example, inhibiting the movement of the movable contact 5 by deforming the vicinity of the through-hole 710 of the arc extinguishing chamber case 71.

  Further, the arc extinguishing chamber case 71 can be prevented or reduced from melting due to the heat of the arc, and the soot is prevented from being reduced, so that the soot is not easily attached to the contacts 4 and 5, particularly the fixed contact 4. This suppresses an increase in electrical resistance (contact resistance) when the fixed contact 4 and the movable contact 5 are inserted and connected, and suppresses a temperature rise of the contacts 4 and 5 when the main circuit is energized. it can. Thereby, it is possible to prevent the temperature rise values of the contacts 4 and 5 from falling within the standard value even during long-term use.

  Note that the terms and expressions used in the present specification are merely explanatory and not restrictive, and do not exclude terms and expressions equivalent to the above terms and expressions. The present invention is not limited to the illustrated embodiment, and various modifications can be made within the scope of the technical idea.

Cross-sectional explanatory drawing by the side of the stationary contact of the switch concerning this invention. AA sectional drawing in FIG. The BB partial arrow directional view of the arc-extinguishing chamber case in FIG. It is explanatory drawing which shows the structure of a protective cover, (a) is a front view, (b) is a top view, (c) is a left view. The perspective explanatory view showing the internal structure of the switch concerning the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the external appearance of the switch concerning this invention, (a) is a front view, (b) is a left view.

Explanation of symbols

DESCRIPTION OF SYMBOLS S Switch 1 Case 2, 3 Bushing 4 Fixed contact 40 Conductor 41 Bottom 42 Raising part 43 Contact inner sesame 44 Contact spring 48 Bolt 49 Bolt 5 Movable contact 6 Drive mechanism part 7 Arc extinguishing part 70 Fixed contact stand member 700 Bolt 71 Arc-extinguishing chamber case 710 Through-hole 711 Mounting part 719 Arc-extinguishing chamber 72 Arc-extinguishing shutter part 720 Bolt 721 Shutter chamber 722 Through-hole 723 Shutter member 724 Spring 73 Protective cover 730 Top part 731, 732, 733 734 Side part 739 Through-hole 74 Mounting seat member 740 Bolt 75 Packing 8 Handle

Claims (1)

A mounting portion (711) is provided inside the arc extinguishing chamber case (71) that forms an arc extinguishing chamber (719) that extinguishes the arc generated between the contacts (4, 5) of the main circuit during the opening operation. And
The mounting portion (711) has a protective cover (73) made of a non-magnetic material that protects the inner surface of the arc extinguishing chamber (719) from arc heat and does not generate eddy current when the main circuit is energized in the on state. ) Is arranged and mounted between the inner surface of the arc extinguishing chamber case (71) and the stationary contact (4),
The protective cover (73) is composed of a rectangular top part (730) and side parts (731, 732, 733, 734) provided on its four sides, and the top part (730) has a through-hole in the arc extinguishing chamber case (71) ( (739) is provided with a through-hole (739) that is almost the same rectangular shape as in (710)
The protective cover (73) deforms each side part (731,732,734) inward, and is fixed to the mounting part (711) using the repulsive force.
Switch.

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