JPH09115568A - Energizing contact - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make both the stationary portion of a movable contact and a mounting/demounting mechanism at the movable contact side small in size by letting the energizing contact be brought into contact with specified pressure at the time of energization, reducing force required for mounting/demounting with contact pressure lowered at the time of no voltage applied. SOLUTION: An energizing spring part 5a energizing a slide contact 4 shall be made out of a shape memory alloy, when a main circuit is energized, the energizing spring 5a made out of the shape memory allowy is deformed because of heat conduction by heat generation at a contact part, and its spring force is increased so as to allow the specified pressure of the contact part to be increased, and when the main circuit is not energized, since the energizing spring 5a made out of the shape memory alloy is deformed because the temperature drops, and spring force is thereby lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention connects a main circuit terminal of a device to a main circuit wiring of a switchboard or the like by pressure contact so that a contact portion can be attached and detached as the device moves back and forth when no voltage is applied. Regarding current-carrying contacts.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram of a conventional energizing contact. In FIG. 3, 2 is a fixed contactor, 3 is a movable contactor, 4 is a pressure contact with the movable contactor 3, and a sliding contactor 5 makes a sliding pressure contact when the fixed contactor 2 is attached or detached. An urging spring for urging the sliding contactor 4 from the back side under pressure, 6 is a sliding contactor 4
Is a fixing plate for fixing the guide plate 6 to the movable contactor 3, and 7 is a housing arranged outside the biasing spring 5. Reference numeral 1 denotes an energizing contactor, which is composed of the movable contactor 3, the sliding contactor 4, a biasing spring 5, a guide plate 6, a fixing bolt 6a, and a housing 7. In FIG. 3, the fixed contactor 2 is fixedly attached to either the main circuit wiring or the main circuit terminal of the equipment connected to the main circuit wiring. For example, when the fixed contactor 2 is fixed to the main circuit wiring. The movable contact 3 is fixed to the main circuit terminal of the device. The sliding contactor 4 pressurizes and contacts the outer circumferences of both the fixed contactor 2 and the movable contactor 3 to form an electric path when the device is connected to the main circuit wiring. In the holding space of the dynamic contactor 4,
The urging spring 5 presses the inner surface from the back surface and holds it. A guide plate 6 having a gear-shaped groove on the outer peripheral side is provided at the tip of the movable contactor 3 on the fixed contactor 2 side, and the fixed bolt 6a is provided.
The gear-shaped groove regulates the moving range of the sliding contact 4 so that the sliding contact 4 does not shift in the circumferential direction.

[0003]

This type of current-carrying contactor has a current-carrying capacity of, for example, 600 A to 2000 A, and the force applied to the portion where the contactor makes contact with the fixed contactor is approximately one current-carrying contactor. Since it is 100 to 300 N, which is three times that in three phases, a large force is required to attach and detach the energizing contact and the fixed contact, and the fixed portion of the fixed contact and the movable contact, and the movable contact. It was necessary to strengthen the attachment / detachment mechanism on the child side. The present invention has been made to solve the above problems, and its purpose is to make a pressure contact with a predetermined pressure when energized, and reduce the contact pressure when not energized to reduce the force required for attachment / detachment. Another object of the present invention is to provide a current-carrying contactor in which the fixed part of the movable contactor and the attaching / detaching mechanism on the movable contactor side can be downsized.

[0004]

According to the first aspect of the present invention,
A state where the fixed contact fixedly attached to either the main circuit wiring or the main circuit terminal of the equipment connected to it, the movable contact fixedly attached to the other, and the equipment connected to the main circuit wiring , A sliding contactor that pressurizes both the fixed contactor and the movable contactor to form an electric path, and an urging spring portion that urges the sliding contactor toward the fixed contactor and the movable contactor. The shape of the urging spring part for urging the sliding contact is made of a shape memory alloy, and when the corresponding main circuit is conducting,
The shape memory alloy spring is deformed by heat transfer from the heat generated in the contact part, increasing the spring force and applying a predetermined contact pressure to the contact part, and when the corresponding main circuit is not energized, the temperature of the shape memory alloy spring The energizing contact is such that the spring force is reduced by the deformation caused by the drop.

With the above structure, when the main circuit using the current-carrying contactor starts conduction, the contact pressure at the contact portion of the current-carrying contactor is lower than the rated value, and therefore the contact pressure becomes approximately 0.4 to 1.0. The contact resistance increases in inverse proportion to the amount of heat generated at that portion, and the heat transfer from that portion deforms the shape memory alloy spring portion to increase the spring force and press the contact portion with a predetermined contact pressure. .
Further, when the main circuit is not energized, the contact portion does not generate heat, so that the temperature of the shape memory alloy spring portion is deformed to reduce the spring force, so that the fixed contactor, the fixed portion of the movable contactor, and The attachment / detachment mechanism on the movable contact side can be downsized accordingly.

According to a second aspect of the present invention, in the current-carrying contactor according to the first aspect, the biasing spring portion abuts the sliding contactor, and both side walls are substantially straight at a predetermined temperature or more and the cross-sectional shape is parallel. A current-carrying contactor is formed of a shape memory alloy spring receiver which forms a quadrangle and whose side walls are deformed at a predetermined temperature or lower so that the upper and lower surfaces forming a parallelogram come close to each other, and a coil spring.

With the above structure, when the main circuit using the current-carrying contactor starts conducting, the contact pressure at the contact portion of the current-carrying contactor is lower than the rated value, so that the contact pressure is approximately 0.4 to 1.0. The contact resistance increases in inverse proportion to the amount of heat generated at that portion, and the heat transfer from that portion deforms the side wall of the spring receiver that makes up the shape memory alloy spring part so that the upper and lower surfaces are separated, A predetermined contact pressure is applied to the contact portion by compressing and increasing the spring force. Further, when the main circuit is not energized, there is no heat generation in the contact portion, so the temperature of the shape memory alloy spring receiver is lowered and the spring receiver is deformed so that the upper and lower surfaces of the spring receiver come closer to each other to extend the spring and reduce the spring force. Therefore, the fixed contactor, the fixed portion of the movable contactor, and the attachment / detachment mechanism on the movable contactor side can be downsized accordingly.

According to a third aspect of the present invention, there is provided a fixed contact fixedly attached to either the main circuit wiring or a main circuit terminal of a device connected thereto, and a movable contact fixedly attached to the other. A sliding contact having a contact portion inside the opening with a bottomed cylindrical body that pressurizes and contacts the fixed contact to form an electric path in a state where the device is connected to the main circuit wiring,
The sliding contactor is provided on the back side of the sliding contactor with a metal cylindrical body closely attached to the back side of the sliding contactor, and the sliding contactor and the metallic cylindrical body are provided with slits extending from the opening end to the bottom. The metal cylindrical body is made of shape memory alloy, and when the corresponding main circuit is conducting, heat is transferred from the heat generated at the contact part to extend the metal cylindrical body made of shape memory alloy and bend it inwardly to the sliding contact that adheres to it. Apply a force to apply a predetermined contact pressure to the contact part, and when the corresponding main circuit is not energized, the metal cylinder made of shape memory alloy shrinks due to the temperature drop and the contact pressure of the contact part decreases. It is the energized contactor.

With the above structure, when the main circuit using the current-carrying contactor starts conduction, the contact pressure of the contact portion of the current-carrying contactor is lower than the rated value, and therefore the contact pressure is approximately 0.4 to 1.0. Inversely, the contact resistance increases, the amount of heat generated at that portion increases, and the heat transfer from that portion deforms the shape memory alloy cylindrical body to press the contact portion to a predetermined contact pressure. Further, when the main circuit is not energized, the contact portion does not generate heat, so that the temperature of the shape memory alloy cylindrical body lowers and restores and deforms to reduce the pressure applied to the contact portion. The fixed part and the attachment / detachment mechanism on the side of the movable contact can be downsized accordingly.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1] FIG. 1A is a configuration diagram of a main part of an embodiment of the inventions 1 and 2, and FIG. 1B is a ¼ partial view of a guide plate viewed from an arrow side. 1 (a) and 1 (b), members denoted by the same reference numerals as those of the conventional example have approximately the same functions, and therefore description thereof will be omitted. This figure 1
In (a) and (b), 1 is a current contactor, 2 is a fixed contactor, 3 is a movable contactor, 4 is a pressure contact with the movable contactor 3, and a sliding force is applied when the fixed contactor 2 is attached or detached. Sliding contactor for pressure contact, 5a is a biasing spring made of a shape memory alloy for biasing the sliding contactor 4 from the back side, 6 is a guide plate for regulating the position of the sliding contactor 4, and 6a is a guide. A fixing bolt for fixing the plate 6 to the movable contactor 3 and a housing 7 arranged outside the biasing spring 5a.

In FIGS. 1 (a) and 1 (b), the fixed contact 2 is fixedly attached to either the main circuit wiring or the main circuit terminal of the equipment connected to the main circuit wiring. When the fixed contact 2 is fixed,
The movable contact 3 is fixed to the main circuit terminal of the device. The sliding contactor 4 pressurizes and contacts the outer circumferences of both the fixed contactor 2 and the movable contactor 3 to form an electric path when the device is connected to the main circuit wiring. A biasing spring 5 made of a shape memory alloy is placed in the holding space of the dynamic contactor 4 from the back side.
It is pressed against the inner surface side at a and held. A guide plate 6 having a gear-like groove on the outer peripheral side is fixed to the tip of the movable contactor 3 on the fixed contactor 2 side by a fixing bolt 6a, and the gear-like groove has a sliding contactor 4 in the circumferential direction. The movement range is regulated so that it does not shift to.

In the energizing contact 1, the biasing spring 5a made of a shape memory alloy is set to a predetermined temperature or lower and the spring pressure is set low when the energization is started. Therefore, the sliding contact 4 and the fixed contact 2, Also, the contact resistance of each contact portion of the sliding contact 4 and the movable contact 3 becomes high, the amount of heat generation at that portion increases, and the heat transfer from there causes the shape memory alloy biasing spring 5 to overheat. Then, when the temperature exceeds the predetermined temperature, the biasing spring 5a made of the shape memory alloy is deformed to increase the spring force and bring the contact pressure of the contact portion to the rated value. Further, when the energization current becomes zero and the heat generation at the contact portion disappears, the shape memory alloy urging spring 5a falls below a predetermined temperature and is restored and deformed to reduce the spring force. The child 3 can be attached and detached with a correspondingly weak force. The predetermined temperature in the above is 313-
It is set between 390K. Further, the contacting force of the contact portion varies depending on the energizing capacity of the energizing contactor 1, but is approximately 100 to 300 N per energizing contactor, and in the non-energized state, it can be reduced to a contact pressure that does not spark at the start of energization.

The energizing contactor 1 comprises a movable contactor 3, a sliding contactor 4, a bias spring 5a made of a shape memory alloy, a guide plate 6, a fixing bolt 6a and a housing 7. Further, instead of the shape memory alloy biasing spring 5a, the spring steel spring and both side walls become substantially straight at a predetermined temperature or more to form a parallelogram, and both side walls are deformed at a predetermined temperature or less. It is also possible to use it in combination with a shape memory alloy spring bearing in which the upper and lower surfaces forming the parallelogram are close to each other.

In the above example, the cylindrical current-carrying contactor 1 is described, but the fixed contactor may be formed in a flat plate shape, and the movable contactor may be arranged on the upper and lower surfaces thereof to have a flat structure. [Embodiment 2] FIG. 2 is a block diagram showing the main part of an embodiment of the invention 3. In FIG. 2, 1a is a current-carrying contactor, 2 is a fixed contactor, 3 is a movable contactor, and 4a is a bottomed cylindrical body having a contact portion inside the opening, and from the opening side toward the bottom. A sliding contact having a plurality of slits 4b cut,
Reference numeral 8 denotes a cylindrical body made of a shape memory alloy, which is closely attached to the outer peripheral side of the sliding contactor 4a and has a slit 8a of substantially the same length cut at the same position as the slit 4b of the sliding contactor 4a.

In FIG. 2, the energizing contact 1a has a temperature of the shape memory alloy cylinder 8 at a predetermined temperature or less at the start of energization, so that the spring pressure for pressing the sliding contact 4a against the fixed contact 2 is applied. Since it is set low, the contact resistance of the contact portion between the sliding contact 4a and the fixed contact 2 becomes high,
When the amount of heat generated in that portion increases and the heat transfer from there heats the shape-memory alloy cylindrical body 8 to a predetermined temperature or higher, the shape-memory alloy cylindrical body 8 deforms and the spring force increases. Then, the contact pressure of the contact portion is set to the rated value. Further, when the energization current becomes zero and the heat generation at the contact portion disappears, the shape memory alloy cylindrical body 8 is restored to a predetermined temperature or less and is deformed to reduce the spring force, so that the fixed contact and the movable contact are separated from each other. It can be attached and detached with a weak force.

Further, instead of the cylindrical body 8, the sliding contact 4
You may use the metal whose expansion coefficient is larger than a.

[0017]

According to the present invention, since the force required for attaching and detaching the current-carrying contactor when no current is applied can be weakened, the mechanism for attaching and detaching the current-carrying contactor can be made inexpensive and compact.

[Brief description of the drawings]

FIG. 1A is a configuration diagram of a main part of an embodiment of the inventions 1 and 2, and FIG. 1B is a ¼ partial view of a guide plate seen from an arrow side.

FIG. 2 is a configuration diagram of main parts of an embodiment of invention 3;

FIG. 3 is a configuration diagram of a conventional example.

[Explanation of symbols]

 1, 1a Energizing contactor 2 Fixed contactor 3 Movable contactor 4, 4a Sliding contactor 4b Slit 5, 5a Energizing spring 6 Guide plate 6a Fixing bolt 7 Housing 8 Cylindrical body 8a Slit

Claims (3)

[Claims] 1. A fixed contact fixedly attached to either one of a main circuit wiring or a main circuit terminal of a device connected to the main circuit wiring, a movable contact fixedly attached to the other, and a device to the main circuit wiring. Connected, presses both the fixed contact and the movable contact to form an electric path, and the sliding contact is biased toward the fixed contact and the movable contact. The shape memory alloy spring is provided as the urging spring portion for urging the sliding contact, and the shape memory alloy spring is formed by heat transfer from heat generated at the contact portion when the corresponding main circuit is conducting. Characterized by deforming and increasing the spring force to apply a predetermined contact pressure to the contact part, and when the corresponding main circuit is not energized, the spring force is reduced by the deformation due to the temperature drop of the shape memory alloy spring And energizing contactor. 2. The current-carrying contactor according to claim 1, wherein the biasing spring portion abuts the sliding contactor, and both side walls are substantially straight at a predetermined temperature or more and a cross-sectional shape forms a parallelogram. A current-carrying contactor comprising: a shape memory alloy spring retainer whose side walls are deformed at a predetermined temperature or lower so that upper and lower surfaces forming a parallelogram come close to each other, and a coil spring. 3. A main circuit wiring, or a fixed contact fixedly attached to either one of the main circuit terminals of equipment connected to the main circuit wiring, a movable contact fixedly attached to the other, and equipment for the main circuit wiring. When the is connected, the sliding contactor that has a contact part inside the opening is a cylindrical body with a bottom that pressurizes and contacts the fixed contactor to form an electric path, and adheres closely to the rear side of the sliding contactor. And a metal cylinder arranged in a manner such that the sliding contact and the metal cylinder are provided with a slit extending from the opening end to the bottom,
The metal cylindrical body placed on the back surface of the sliding contact is made of shape memory alloy, and when the corresponding main circuit is conducting, the heat transfer from the heat generated at the contact portion causes the shape of the metal cylindrical body made of shape memory alloy to extend and adhere to it. When the main circuit in question is not energized, the metal cylinder made of shape memory alloy shrinks due to temperature drop when a bending contact force is applied to the sliding contact to apply a predetermined contact pressure to the contact part. An energizing contactor characterized in that the contact pressure of the contact portion is reduced.