JP6926732B2 - Gas sealed magnetic contactor - Google Patents

Description

The present invention relates to a gas-sealed electromagnetic contactor in which a fixed contactor having a fixed contact and a movable contactor having a movable contact are arranged in an arc extinguishing chamber filled with gas.

In the gas sealed electromagnetic contactor, the contact part is sealed in a closed container, and hydrogen gas that enhances the breaking performance is sealed in this closed container, so that the product size is smaller and the voltage and current are higher. It has the advantage of being able to block. In addition, by opening and closing the contacts inside the closed container, the sparks of the arc do not scatter outside the product, so there is no risk of fire, and dust does not enter from the outside, so it is excellent in safety and contact reliability.

On the other hand, Patent Document 1 below describes a contact member made of a CuW alloy containing at least one metal material having a melting point higher than that of Cu or a metal material having a heat of vaporization higher than that of Cu, and Cu or Cu. It is composed of an alloy containing the main component or a conductor made of steel or an alloy containing steel as the main component, and a layer made of Cu or Cu alloy is interposed on the joint surface of both members to integrally join the members. The arc contacts made of copper are disclosed.

Further, in Patent Document 2 below, in a method of impregnating a temporary sintered body with an infiltrating material having a melting point lower than that of the temporary sintered body to produce a contact material, a recess is provided in the center of the lower surface of the temporary sintered body. The contact material is formed, a conductive metal is placed in the concave portion, and an infiltrating material is arranged on the upper surface of the temporary sintered body, and the upper surface infiltrating material is heated to impregnate the calcined body with the contact material. A method for producing a contact material, which is characterized by obtaining the above, is disclosed.

Japanese Unexamined Patent Publication No. 2001-138609 Japanese Unexamined Patent Publication No. 6-203692

The gas-sealed electromagnetic contactor has the above-mentioned excellent features, but since hydrogen gas, etc., which enhances the blocking performance is sealed in the closed container, a material with a low melting point (copper) on the contact surface. There was a problem that (such as silver and silver) was easily consumed. Then, when the material having a low melting point is consumed, only the material having a high melting point (tungsten, chromium, etc.) remains, and there is a problem that the contact resistance becomes large.

The above-mentioned Patent Document 1 is composed of a contact member made of a CuW alloy and a conductor made of Cu or an alloy containing Cu as a main component, or steel or an alloy containing steel as a main component, and joins both members. An arc contactor in which a layer made of Cu or a Cu alloy is interposed on the surface and the members are integrally joined to each other is disclosed, but it is not disclosed that the member is used as a contactor of a gas-sealed electromagnetic contactor. ..

Further, in Patent Document 2, a recess is formed in the center of the lower surface of the temporary sintered body, a conductive metal is arranged in the recess, and a infiltrating material is arranged on the upper surface of the temporary sintered body. It is described that the calcined material is impregnated into the calcined body to obtain a contact material by heating the infiltrated material, but it relates to a method for manufacturing a contact material for a vacuum valve, and is a contact of a gas-sealed electromagnetic contactor. It is not disclosed for use as a child.

Therefore, an object of the present invention is to solve the problem that a material having a low melting point (copper, silver, etc.) on the contact surface is easily consumed in a gas-sealed electromagnetic contactor, and to maintain a low contact resistance for a long period of time. To be.

In order to achieve the above object, the present invention provides a gas-sealed electromagnetic contacter in which a fixed contact having a fixed contact and a movable contact having a movable contact are arranged in an arc extinguishing chamber filled with gas. The fixed contact and the movable contact include a mixed layer in which a high melting point contact material is mixed with a low melting point contact material having a melting point lower than that of the high melting point contact material, and a low melting point layer composed of only the low melting point contact material. The mixed layer is arranged on the surface side of the fixed contact and the movable contact, the low melting point layer is arranged inside the mixed layer, and the mixed layer is a mating contact. Provided is a gas-sealed electromagnetic contactor characterized in that it is configured to be in contact with and separated from the gas.

According to the present invention, as the low melting point contact material in the mixed layer is consumed, the low melting point contact material in the low melting point layer melts and moves to the mixed layer, so that the low melting point contact material in the mixed layer is replenished. , The contact resistance can be maintained well for a long period of time.

In the present invention, it is preferable that a recess is formed in the central portion on the back surface side of the mixed layer, and the low melting point layer is filled in the recess. According to this aspect, since the low melting point layer is filled in the recess formed in the central portion on the back surface side of the mixed layer, the low melting point contact material can be evenly replenished from the low melting point layer to the entire mixed layer. The increase in contact resistance can be suppressed more effectively.

Further, the mixed layer preferably contains 90 to 10% by mass of the high melting point contact material and 10 to 90% by mass of the low melting point contact material. According to this aspect, the contact resistance between the fixed contact and the movable contact can be lowered, and the durability can be improved.

Further, the mixed layer preferably contains the high melting point contact material in an amount of 40 to 60% by mass and the low melting point contact material in an amount of 60 to 40% by mass. According to this aspect, the contact resistance between the fixed contact and the movable contact can be lowered, and the durability can be further improved.

The gas sealed in the arc extinguishing chamber is preferably a mixed gas of hydrogen gas and nitrogen gas. According to this aspect, by using a mixed gas of hydrogen gas and nitrogen gas as the gas sealed in the arc extinguishing chamber, the cooling effect on the arc can be enhanced and the arc extinguishing ability can be enhanced. On the other hand, hydrogen gas in particular tends to accelerate the consumption of the low melting point contact material, but in the present invention, the low melting point contact material of the low melting point layer melts as the low melting point contact material in the mixed layer is consumed. Since it moves to the mixed layer, the contact resistance can be maintained well.

Further, the gas sealed in the arc extinguishing chamber preferably contains 30% (v / v) or more of hydrogen gas. By using a gas containing 30% (v / v) or more of hydrogen gas as the gas sealed in the arc extinguishing chamber, the cooling effect on the arc can be enhanced and the arc extinguishing ability can be enhanced. On the other hand, hydrogen gas in particular tends to accelerate the consumption of the low melting point contact material, but in the present invention, the low melting point contact material of the low melting point layer melts as the low melting point contact material in the mixed layer is consumed. Since it moves to the mixed layer, the contact resistance can be maintained well.

Furthermore, the thickness of the mixed layer is preferably 0.2 to 1 mm. According to this aspect, when the thickness of the mixed layer is 0.2 to 1 mm, heat is easily transferred to the low melting point layer, and as the low melting point contact material in the mixed layer is consumed, the low melting point layer becomes The low melting point contact material can be melted and easily transferred to the mixed layer.

Furthermore, the total thickness of the fixed contact and the movable contact composed of the mixed layer and the low melting point layer is preferably 0.5 to 3 mm. According to this aspect, the strength of the fixed contact and the movable contact can be maintained, and the contact resistance can be maintained well.

According to the present invention, as the low melting point contact material in the mixed layer is consumed, the low melting point contact material in the low melting point layer melts and moves to the mixed layer, so that the low melting point contact material in the mixed layer is replenished. , The contact resistance can be maintained well for a long period of time.

It is schematic cross-sectional view which shows an example of the gas closed type electromagnetic contactor to which this invention is applied. It is a perspective view which shows typically the fixed contactor and the movable contactor in the gas closed type electromagnetic contactor of this invention. It is sectional drawing which shows typically the structure of the contact | contact in the gas closed type electromagnetic contactor of this invention. It is a figure which shows the result of having measured the change of the contact resistance (mΩ) by the current time product (AS) of the gas closed type electromagnetic contactor of Example 1.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.

FIG. 1 shows an example of a gas sealed magnetic contactor to which the present invention is applied. Since the structure of the gas-sealed electromagnetic contactor 10 is described in detail in, for example, Japanese Patent Application Laid-Open No. 2016-201304, the main part thereof will be briefly described here.

The gas sealed magnetic contactor 10 includes a contact mechanism 20, an electromagnet unit 30 for driving the contact mechanism 20, and a sealed arc extinguishing chamber 40 for accommodating the contact mechanism 20.

The contact mechanism 20 has a first fixed contact 21, a second fixed contact 22, and a movable contact 23. The movable contact 23 is supported and attached to a connecting shaft 25 mounted on the movable plunger 24. The movable plunger 24 is urged upward by the return spring 26. Further, the movable contact 23 is urged downward by the contact spring 27, and when it comes into contact with the first fixed contact 21 and the second fixed contact 22, the contact spring 27 is compressed and elastic. It is designed to come into contact with.

The electromagnet unit 30 has an exciting coil 31 arranged on the lower outer periphery of the movable plunger 24 and a permanent magnet 32 arranged on the upper outer periphery of the movable plunger 24.

The arc extinguishing chamber 40 includes a metal square cylinder 41, an insulating cylinder 42 arranged inside the metal square cylinder 41, a fixed contact support insulating substrate 43 whose lower surface is joined to the upper end of the square cylinder 41, and a square cylinder. It is surrounded and sealed with a magnetic yoke 44 joined to the lower surface of the body 41. A permanent magnet 45 for arc extinguishing is arranged on the outer circumference of the square cylinder 41.

The inside of the arc extinguishing chamber 40 is filled with a gas such as hydrogen gas, nitrogen gas, a mixed gas of hydrogen and nitrogen, air, and SF _6. The gas to be filled in the arc extinguishing chamber 40 is not particularly limited, but it is preferable to contain hydrogen gas in order to enhance the cooling effect on the arc and enhance the arc extinguishing ability, and the hydrogen gas is 30% (v / v) or more. It is more preferable to contain it. Further, in order to secure the withstand voltage, a mixed gas of hydrogen gas and nitrogen gas is preferably used.

As shown in FIG. 2, fixed contacts 28 are joined to fixed contacts 21 and 22, and movable contacts 29 are joined to movable contacts 23.

Explaining the operation of the gas-sealed electromagnetic contactor 10, the exciting coil 31 of the electromagnet unit 30 is in a non-excited state, and the electromagnet unit 30 is in a released state in which an attractive force for lowering the movable plunger 24 is not generated. In this case, the movable plunger 24 is in a position raised by the urging force of the return spring 26 and the attractive force of the permanent magnet 32, and the movable contact 23 does not come into contact with the first fixed contact 21 and the second fixed contact 22. The contacts open and open.

Next, when the exciting coil 31 of the electromagnet unit 30 is energized, an attractive force is generated by the electromagnet unit 30, and the movable plunger 24 descends against the urging force of the return spring 26 and the attractive force of the permanent magnet 32. do. As a result, the movable contact 23 is also lowered, and the movable contact 29 (see FIG. 2) provided on the movable contact 23 is a fixed contact provided on each of the first fixed contact 21 and the second fixed contact 22. In contact with 28, the first fixed contact 21 and the second fixed contact 22 are made conductive. As a result, a large current of the power supply source is supplied to the load device through the first fixed contact 21, the movable contact 29, and the fixed contact 28, and is in a closed state.

Then, when the energization of the electromagnet unit 30 to the exciting coil 31 is released again, the downward attractive force of the electromagnet unit 30 with respect to the movable plunger 24 disappears, and the urging force of the return spring 26 and the attractive force of the permanent magnet 32 cause the movable plunger. 24 is raised, the movable contact 23 is separated from the first fixed contact 21 and the second fixed contact 22, and the contacts are opened to open the pole. At this time, an arc is generated between the fixed contact 28 of the fixed contacts 21 and 22 and the movable contact 29 of the movable contact 23, and this arc is generated by the current flow of the arc and the permanent magnet 45 for extinguishing the arc. Due to the relationship with the magnetic flux generated in, it is stretched and extinguished by the Lorentz force generated by Fleming's left-hand rule.

At this time, there is a problem that the low melting point metal which is the material of the fixed contact 28 and the movable contact 23 is sublimated and the low melting point metal is consumed. The consumption of the low melting point metal tends to be particularly severe when the gas filled in the arc extinguishing chamber 40 contains hydrogen gas having a high cooling effect on the arc. In order to solve such a problem, the present invention is characterized in that the structures of the fixed contacts 28 of the fixed contacts 21 and 22 and the movable contacts 29 of the movable contacts 23 are, for example, the following structures. There is.

That is, as shown in FIG. 3, the fixed contact 28 and the movable contact 29 in the present invention are a mixed layer in which the high melting point contact material 52 and the low melting point contact material 51 having a lower melting point than the high melting point contact material 52 are mixed. The 50 and the low melting point layer 53 made of only the low melting point contact material are joined to each other, and the mixed layer 50 is arranged on the surface side of the fixed contact 28 and the movable contact 29. It is arranged inside the mixing layer 50, and is configured so that the mixing layer 50 comes into contact with and separates from the mating contact.

In the case of this embodiment, a recess is formed in the central portion on the back surface side of the mixed layer 50, and the low melting point layer 53 is filled in the recess. With such a structure, the low melting point layer 53 is filled in the recess formed in the central portion on the back surface side of the mixed layer 50, so that the entire mixed layer 50 is evenly covered with the low melting point layer 53 to the low melting point contact material. Can be replenished, and the increase in contact resistance can be suppressed more effectively.

However, the structures of the fixed contact 28 and the movable contact 29 in the present invention are not limited to the above structure, and for example, a low melting point layer also formed in a plate shape on the lower surface of the mixed layer 50 formed in a plate shape. The shape may be a stack of 53.

As the high melting point contact material 52, for example, tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), tungsten carbide (WC) and the like are preferably used. Further, as the low melting point contact material 51 and the low melting point layer 53 (hereinafter, both materials are referred to as "low melting point contact materials"), for example, copper (Cu), silver (Ag) and the like are preferably used.

As a method for producing the mixed layer 50, a method in which a high melting point contact material and a low melting point contact material are mixed and press-molded and then sintered, or a method in which the high melting point material is press-molded and sintered in advance and then sintered. A method of melting the low melting point material and impregnating the gaps between the high melting point materials can be adopted.

Further, the low melting point layer 53 is formed by cutting the back surface side of the mixed layer 50 into a recess, and melting and pouring the low melting point contact material into the recess, or molding the low melting point contact material into a shape suitable for the recess. Then, a method of inserting the molded low melting point contact material into the recess and welding it can be mentioned.

The mixed layer 50 preferably contains 90 to 10% by mass of the high melting point contact material 52 and 10 to 90% by mass of the low melting point contact material 51, and 40 to 60% by mass of the high melting point contact material 52 and the low melting point contact material. It is more preferable to contain 51 in an amount of 60 to 40% by mass. As a result, the contact resistance between the fixed contact and the movable contact can be lowered, and the durability can be improved. If the melting point contact material 52 is less than 10% by mass, the strength as the contact material tends to be insufficient, and if the melting point contact material 52 exceeds 90% by mass, the contact resistance tends to increase.

As a more preferable embodiment of the mixed layer 50, W is used as the high melting point contact material 52 and Cu is used as the low melting point contact material 51.

The thickness of the mixed layer 50 is preferably 0.2 to 1 mm. As a result, heat is easily transferred to the low melting point layer 53, and as the low melting point contact material 51 in the mixed layer 50 is consumed, the low melting point contact material of the low melting point layer 53 melts and easily moves to the mixed layer 50. can do. If the thickness of the mixed layer 50 is less than 0.2 mm, the strength and durability as a contact material tend to be insufficient, and if it exceeds 1 mm, heat is less likely to be transferred to the low melting point layer 53, and the low melting point of the mixed layer 50 is low. When the contact material 51 is consumed, it becomes difficult for the low melting point material to be replenished from the low melting point layer 53.

Further, the total thickness of the fixed contact 28 and the movable contact 29 composed of the mixed layer 50 and the low melting point layer 53 is preferably 0.5 to 3 mm. As a result, the strength of the fixed contact 28 and the movable contact 29 can be maintained, and the contact resistance can be maintained satisfactorily. If the total thickness of each contact is less than 0.5 mm, the strength and durability tend to be insufficient, and if it exceeds 3 mm, the heat conduction tends to be weakened and the effect tends not to be exhibited.

According to the gas-sealed electromagnetic contactor of the present invention configured in this way, when an arc is generated when the contacts are opened and the low melting point contact material 51 in the mixed layer 50 is sublimated and consumed. Since the low melting point contact material of the low melting point layer 53 melts and moves to the mixed layer 50 to replenish the consumed low melting point contact material 51, the consumption of the low melting point contact material 51 in the mixed layer 50 is suppressed and the contact resistance. Can be kept low for a long period of time.

The embodiment shown in FIG. 1 is an example of a gas-sealed electromagnetic contactor to which the present invention is applied. The present invention is characterized by a contact structure and is a gas-sealed electromagnetic contactor. The structure itself is not limited, and can be applied to gas-sealed magnetic contactors having other structures.

[Example 1]
A contact formed by joining a mixed layer and a low melting point layer is attached to an electromagnetic contactor (magnet switch) that is not a gas-sealed type, and this electromagnetic contactor is placed in a gas chamber, filled with nitrogen gas, and gas-sealed. An environment similar to that of a conventional magnetic contactor was created, and the change in contact resistance (mΩ) due to the current-time product (AS) when an arc was generated by turning the current on and off was measured. As the mixed layer 50, W was used as the high melting point contact material 52, Cu was used as the low melting point contact material 51, and Cu: W = 50: 50 was used. Cu was used as the low melting point layer 53.

The result is shown in FIG. As shown in FIG. 4, the contact resistance could be kept low until the current-time product reached 600 AS.

10 Sealed electromagnetic contactor 20 Contact mechanism 21 First fixed contactor 22 Second fixed contactor 23 Movable contactor 24 Movable plunger 25 Connecting shaft 26 Return spring 27 Contact spring 28 Fixed contact 29 Movable contact 30 Electromagnet unit 31 Exciting coil 32 Permanent magnet 40 Arc extinguishing chamber 41 Square cylinder 42 Insulated cylinder 43 Fixed contact support Insulated substrate 44 Magnetic yoke 45 Permanent magnet for arc extinguishing

Claims (7)

In a gas-sealed electromagnetic contactor in which a fixed contactor having a fixed contact and a movable contactor having a movable contact are arranged in an arc extinguishing chamber filled with gas.
The fixed contact and the movable contact include a mixed layer in which a high melting point contact material is mixed with a low melting point contact material having a lower melting point than the high melting point contact material, and a low melting point layer composed of only the low melting point contact material. It is made up of joints and
The mixed layer is arranged on the surface side of the fixed contact and the movable contact, the low melting point layer is arranged inside the mixed layer, and the mixed layer is configured to be in contact with and separated from the mating contact. Ori,
A gas-sealed electromagnetic contactor characterized in that the thickness of the mixed layer is 0.2 to 1 mm. In a gas-sealed electromagnetic contactor in which a fixed contactor having a fixed contact and a movable contactor having a movable contact are arranged in an arc extinguishing chamber filled with gas.
The fixed contact and the movable contact include a mixed layer in which a high melting point contact material is mixed with a low melting point contact material having a lower melting point than the high melting point contact material, and a low melting point layer composed of only the low melting point contact material. It is made up of joints and
The mixed layer is arranged on the surface side of the fixed contact and the movable contact, the low melting point layer is arranged inside the mixed layer, and the mixed layer is configured to be in contact with and separated from the mating contact. Ori,
A gas-sealed electromagnetic contactor characterized in that a recess is formed in a central portion on the back surface side of the mixed layer, and the low melting point layer is filled in the recess. The gas-sealed electromagnetic contactor according to claim 1 or 2, wherein the mixed layer contains 90 to 10% by mass of the high melting point contact material and 10 to 90% by mass of the low melting point contact material. The gas-sealed magnetic contactor according to claim 3, wherein the mixed layer contains 40 to 60% by mass of the high melting point contact material and 60 to 40% by mass of the low melting point contact material. The gas-sealed electromagnetic contactor according to any one of claims 1 to 4, wherein the gas sealed in the arc extinguishing chamber is a mixed gas of hydrogen gas and nitrogen gas. The gas-sealed electromagnetic contactor according to any one of claims 1 to 5, wherein the gas sealed in the arc extinguishing chamber contains 30% (v / v) or more of hydrogen gas. The gas-sealed electromagnetic wave according to any one of claims 1 to 6 , wherein the total thickness of the fixed contact and the movable contact composed of the mixed layer and the low melting point layer is 0.5 to 3 mm. Contactor.

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