JPH06131937A - Structure for disconnecting switch opening/closing contact section - Google Patents

Abstract

PURPOSE:To omit the polishing cleaning of a contact face performed while excitation is stopped to prevent the defective excitation or fusion loss caused by a compound generated on the contact face when no opening/closing action is made on a disconnecting switch opening/ closing contact section for a long period. CONSTITUTION:The fixed contact piece base 1b of a fixed contact piece 1 is inserted between a shape memory coil 3 and a bias spring 4 and fixed to a fixed section base 6 with a fixing bolt 7. The electric circuit between the fixed section base 6 and the fixed contact piece 1 is a parallel circuit of the shape memory alloy coil 3 and a flexible conductor 5, and the current at the time of excitation flows to the fixed contact piece 1 from the fixed section base 6 via the shape memory coil 3 and the flexible conductor 5. The temperature of the shape memory alloy coil 3 is changed above or below the shape- memory temperature by the increase or decrease of the current, the shape memory alloy coil 3 is deformed, and the fixed contact piece 1 is vertically moved accordingly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an opening / closing contact portion (hereinafter referred to as a contact portion) of a disconnector.

[0002]

2. Description of the Related Art Conventionally, when the contact portion is closed, the movable contact piece and the finger are in contact with each other and the contact surface does not move.

[0003]

Since the conventional contact part does not move for a long period of time when the contact part is closed for a long period of time, the chlorine or its compound or the sulfur or its compound in the atmosphere may be changed over time. The metal on the contact surface reacts with each other to form a compound of the metal on the contact surface and chlorine or sulfur (hereinafter referred to as a compound). Since the compound has a large electric resistance, it is electrically closed at the contact surface of the contact portion. Alternatively, the metal on the contact surface is melted by heat generated by energization. In order to prevent this, the contact surface is regularly polished to remove the compound. For this reason, there is a drawback that it takes time and labor for stopping the energization and for polishing.

The present invention was devised to solve the above-mentioned drawbacks of the prior art.
For example, the object is to remove the compound on the contact surface by moving the contact surface and slidingly polishing it by changing the energizing current in the daytime and nighttime.

[0005]

In order to achieve the above object, a fixed contact piece of a contact portion is interposed between a shape memory alloy and a bias spring to be fixed to a fixed portion base, and the energizing current is the shape memory alloy. A circuit in which all or part of the current flows, and the shape that has been memorized (hereinafter referred to as memory shape) and the shape that is in a non-memory state (hereinafter referred to as non-memory shape) are associated with changes in the temperature of the shape memory alloy due to changes in the energizing current during the day and night. Note)
In the invention of claim 1, the contact surface moves on the finger, and in the invention of claim 2, the contact surface moves on the movable contact edge.

[0006]

[Function] At night when the amount of electricity is small, the shape memory alloy forming a part of the energizing circuit is lower than the shape memory temperature and has a non-memory shape. Then, the fixed contact piece is pushed up by the restoring force exceeding the stress of the bias spring, and the contact surface slides on the finger. Alternatively, the fixed contact piece is rotated in one direction, and the contact surface slides on the edge of the movable contact piece. At night when the amount of electricity is small, the shape memory alloy falls below the shape memory temperature, loses the stress of the bias spring and shrinks to a non-memory shape, and the fixed contact piece descends. At this time as well, the contact surface slides on the fingers. Alternatively, the fixed contact piece rotates in the opposite direction, and the contact surface also slides on the movable contact piece at this time.

If the change in the applied current is day or night as described above, the contact surface is slid and polished once a day to remove the compound. By repeating this, the restoring force of the shape memory alloy decreases, and the stress in the non-memory shape decreases (hereinafter, the restoring force and the decrease in stress are referred to as deterioration). Therefore, in the memory shape, the length of the bias spring, which is greater than the stress of the bias spring and extends, is smaller than that before the deterioration (hereinafter referred to as the initial stage). In addition, the non-memory shape is also deteriorated due to the stress of the bias spring and contracted from the initial stage. Therefore, the sliding range of the contact surface moves downward, or moves in the direction turning to the right.
Therefore, the contact surface does not slide on the same part of the finger or on the same part of the movable contact edge, but by moving within the range, wear of the finger due to sliding or wear of the movable contact edge is reduced. .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an example of a contact portion of the present invention, in which a fixed contact piece comprises a finger 1a and a fixed contact piece base 1b. The fixed contact piece 1 is fixed to the fixed portion base 6 by placing the fixed contact piece base 1b between the shape memory alloy coil 3 mounted on the fixing bolt 7 and the bias spring 4. The flexible conductor 5 is provided between the fixed base 6 and the fixed contact piece 1 in the energizing path.
And the shape memory alloy coil 3 form a parallel circuit.

FIG. 1 (a) shows the shape memory alloy coil 3 in a non-memory shape at a temperature below the shape memory temperature, that is, in a contracted state where full compression is not achieved. When the energization amount increases and the current flowing through the shape memory alloy coil 3 also increases and the shape memory alloy coil 3 reaches the shape memory temperature or higher, the shape memory alloy coil 3 is deformed into a memorized shape and recovered as shown in FIG. 1B. The force overcomes the stress of the bias spring 4 and pushes the fixed contact piece 1 upward.

When the amount of energization decreases and the shape memory alloy coil 3 falls below the shape memory temperature, the shape memory alloy coil 3 contracts due to the stress of the bias spring 4 and becomes a non-memory shape.
The fixed contact piece 1 moves downward. The contact surface 8 slides on the finger 1a as the fixed contact piece 1 moves up and down based on the increase / decrease in the amount of energization, and the movable contact piece 2 and the portion forming the contact surface 8 of the finger 1a are polished to remove the compound.

By repeating this, the shape memory alloy coil 3 is gradually deteriorated. Along with this, in the memory shape, the length of the bias spring 4 that extends beyond the stress of the bias spring 4 becomes smaller.
Also, the stress in the non-memory shape gradually decreases, and accordingly, the stress in the bias spring 4 causes the non-memory shape to shrink from the initial state. Therefore, the finger 1a shown in FIG.
The sliding range A of the upper contact surface 8 gradually moves to the sliding range B of the contact surface 8 as shown in FIG. In this way, the sliding range A of the contact surface 8 on the finger 1a gradually moves to the sliding range B, and wear of the finger 1a due to sliding is reduced.

FIG. 3 shows another example of the contact portion of the present invention. The fixed contact piece 1 comprises a finger 1a and a fixed contact piece base 21b. The fixed contact piece base 21b has a fixed contact piece bolt hole 11 that is sized to move through the fixed bolt 27. The fixing fitting 29 has a fixing fitting bolt hole 10 through which the fixing bolt 27 can pass. The fixing bracket 299 is a flexible conductor 25.
And is fixed to the fixed portion base 6. The fixed contact piece base 21b is fixed to a fixing metal fitting 29 with a fixing bolt 27 via a shape memory alloy coil 23 and a bias spring 24. The fixed bolt 27 forms an arc having a radius R from the center O of the movable contactor to the fixed contact piece bolt hole 11. The edge 12 of the movable contact piece is at the center O of the movable contact piece.
It forms an arc centered at. The shape memory alloy coil 23 is provided between the fixed contact piece 1 and the fixed portion base 6 in the energization path.
And the flexible conductor 25 form a parallel circuit.

FIG. 3 (a) shows the shape memory alloy coil 23 in a non-memory shape below the shape memory temperature, that is, in a contracted state which does not reach full compression. The amount of energization increases, the current flowing through the shape memory alloy coil 23 also increases, and the shape memory alloy coil 23 increases.
Is deformed into a memory shape as shown in FIG. 3B when the temperature exceeds the shape memory temperature, and the restoring force is the bias spring 24.
The fixed contact piece 1 is rotated to the left overcoming the stress of.

When the amount of energization decreases and the shape memory alloy coil 23 falls below the shape memory temperature, the shape memory alloy coil 23 contracts due to the stress of the bias spring 24 and becomes a non-memory shape, and the fixed contact piece 1 rotates to the right and is again drawn. The state shown in FIG. By rotating the fixed contact piece 1 to the left or right based on the increase or decrease in the amount of energization, the contact surface 8 slides on the movable contact edge portion 12, and the portions forming the contact surface 8 of the finger 1a and the movable contact piece 2 are polished. Remove the compound. By repeating this, the shape memory alloy coil 23 deteriorates. Accordingly, in the memory shape, the length of extension of the bias spring against the stress of the bias spring becomes smaller. Further, the stress in the non-memory shape gradually decreases, and accordingly, the stress of the bias spring 24 reduces from the initial value. Therefore, the sliding range C of the contact surface 8 on the movable contact piece 1 shown in FIG. 4A gradually increases as shown in FIG. 2C.
Move clockwise to.

[0015]

According to the present invention, the compound generated on the contact surface of the disconnector can be removed by changing the amount of electric current to prevent the occurrence of a closed circuit at the contact portion caused by the compound or the heat generation melting loss.

[Brief description of drawings]

FIG. 1 is an example of a contact portion of the present invention, in which (a) is a small amount of electricity, the shape memory alloy coil is lower than the shape memory temperature, the shape memory alloy coil has a non-memory shape, and the fixed contact portion is Shows the state below. (B) shows a state in which the energization amount is large, the temperature of the shape memory alloy coil becomes higher than the shape memory temperature, and the shape becomes a memory shape, the restoring force thereof exceeds the stress of the bias spring, and the fixed contact portion is above.

FIG. 2 shows the left half of the fixed contact piece. (A)
(B) shows the initial non-memory shape and the memory shape of the shape memory alloy coil, respectively. A shows the sliding range of the contact surface due to the shape change of the shape memory alloy coil shown in (a) and (b). (C) and (d) show the non-memory shape and the memory shape of the deteriorated shape memory alloy coil, respectively. B shows the sliding range of the contact surface due to the shape change of the shape memory alloy coil shown in (c) and (d).

FIG. 3 shows another example of the contact portion of the present invention,
(A) shows a state in which the energization amount is small, the shape memory alloy coil is lower than the shape memory temperature, the shape memory alloy coil has a non-memory shape, and the fixed contact portion is rotated to the right. (B) is a state in which the energization amount is large, the shape memory alloy coil has a temperature higher than the shape memory temperature, and has a memory shape, and the restoring force overcomes the stress of the bias spring to compress it and the fixed contact portion rotates to the left. Indicates.

4A and 4B show the contact portion, and FIGS. 4A and 4B respectively show a non-memory shape and a memory shape in the initial state of the shape memory alloy coil. (C) and (d) show the non-memory shape and the memory shape of the deteriorated shape memory alloy coil, respectively. C shows the sliding range of the contact surface due to the shape change of the shape memory alloy coil shown in (a) and (b). D shows the sliding range of the contact surface due to the shape change of the shape memory alloy coil shown in (c) and (d).

[Explanation of symbols]

 1 Fixed Contact Piece 1a Finger 1b Fixed Contact Piece Base 2 Movable Contact Piece 3 Shape Memory Alloy Coil 4 Bias Spring 5 Flexible Conductor 6 Fixed Part Base 7 Fixing Bolt 8 Contact Surface 9 Fixing Bracket 10 Fixing Bracket Bolt 11 Fixed Contact Piece Bolt Hole 12 Movable contact piece edge 21b Fixed contact piece base 23 Shape memory alloy coil 24 Bias spring 25 Flexible conductor 27 Fixing bolt A A contact part sliding range B contact part sliding range C contact surface sliding range D contact surface sliding Range O Center of movable contact piece

Claims (2)

[Claims] 1. A fixed contact piece is interposed between a shape memory alloy and a bias spring in a disconnecting switch opening / closing contact portion and fixed to a base of the fixed portion. The contact surface of the finger and the movable contact piece (hereinafter referred to as the contact surface) is expanded in the original non-shape memory shape by contracting due to the stress of the bias spring in the original non-shape memory, and contracted in the middle of full compression. The structure of the disconnecting switch opening / closing contact part that moves in parallel on the fingers and slides and polishes the contact surface. 2. A fixed contact piece of a disconnecting switch opening / closing contact part is interposed between a shape memory alloy and a bias spring and fixed to a fixed part base. It expands with an excellent recovery force, and in the original non-shape memory shape, the contact surface of the finger and the movable contact piece is reduced by the stress of the bias spring to the middle of full compression so that the contact surface of the finger and the movable contact piece is The structure of the disconnecting switch opening and closing contact part that slides and polishes the contact surface by reciprocating the edge part.