Direct current contactor with arc extinguishing structure

Abstract

The direct current contactor with the arc extinguishing structure comprises a shell, the shell is divided into two cavities through a magnetic pole plate, a driving mechanism and a contact system are located in the different cavities in the shell respectively, and the cavity where the contact system is located is a sealed cavity; the contact system comprises a moving contact and a static contact, and the moving contact and one end of the static contact which is switched on and switched off with the moving contact are located in the sealed cavity; a part or all of the peripheries of the moving contact and the static contact in the sealed chamber are provided with a breathable arc extinguishing structure, and an insulation distance is reserved between the arc extinguishing structure and the contact system. Through the arrangement of the arc extinguishing structure, the gas temperature in the sealed chamber where the contact system is located is reduced, the arc extinguishing speed and the arc extinguishing efficiency are improved, and the breaking capacity is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit protection, specifically to the DC technology in circuit protection, and more particularly to a DC contactor with an arc extinguishing structure. Background Art

[0002] A DC contactor is a switching device that needs to frequently break and close a DC circuit. In the field of new energy applications, for example, pure electric vehicles usually use DC contactors to be responsible for connecting and disconnecting the power battery system, and can disconnect the battery system in case of an accident. During the process of the electrical contact from closing to opening, there will be a discharge phenomenon and an arc will be generated. The generation of the arc will delay the opening of the circuit, and a relatively high arc energy may even burn the electrical contact, causing the electrical contact to be welded, and in severe cases, it may lead to the ignition and explosion of the contactor.

[0003] At present, the DC contactor products used in new energy vehicles are small in size, high in operating load, and the contact system is sealed in a ceramic cavity, and a gas arc extinguishing medium is filled for arc extinguishing. For example, the high-voltage DC contactor with the function of monitoring the working state of the main circuit and short-circuit resistance disclosed in Chinese Patent Application CN118231189A has a good arc extinguishing effect when the fault circuit is small. However, when the contactor breaks a large fault current, due to the small size of the contactor and limited arc extinguishing space, the arc burning time will be relatively long or even the arc cannot be effectively extinguished, ultimately resulting in the failure of the contactor or it cannot be used again after one operation. Therefore, there is a need for a highly efficient and reliable contactor with an arc extinguishing structure to improve the arc extinguishing ability of the contactor and the ability to break fault current, and extend the service life of the contactor under extreme working conditions. Summary of the Invention

[0004] The object of the present invention is to provide a DC contactor with an arc extinguishing structure. Through the arc extinguishing structure, when the contactor closes and opens, the arc extinguishing ability is improved by combining the arc extinguishing structure with a gas arc extinguishing medium, the breaking ability of the contactor is improved, and the service life of the contactor under extreme working conditions is extended.

[0005] To achieve the above object, the technical solution provided by the present invention is a DC contactor with an arc extinguishing structure, including a housing. The housing is divided into two chambers by a magnetic pole plate, and a driving mechanism and a contact system are respectively located in different chambers of the housing. The chamber where the contact system is located is a sealed chamber. The contact system includes a moving contact and a static contact. One end of the moving contact and the static contact that closes and opens with the moving contact is located in the sealed chamber. A breathable arc extinguishing structure is provided on part or all of the outer periphery of the moving contact and the static contact in the sealed chamber, and an insulating distance is reserved between the arc extinguishing structure and the contact system.

[0006] Preferably, when an arc extinguishing structure is provided on the outer peripheral portions of the moving contact and the static contact in the sealed chamber, the arc extinguishing structure includes two arc extinguishing members. The two arc extinguishing members are relatively spaced apart and disposed outside both ends where the moving contact contacts the static contact. The arc extinguishing member surrounds the end portion and both sides of one end where the moving contact contacts the static contact in the displacement path direction of the moving contact, and a part of the outer periphery of the static contact corresponding to the area surrounded by the moving contact. An insulating distance is reserved between the arc extinguishing member and the static contact and the moving contact.

[0007] Preferably, the arc extinguishing member includes a mounting portion, and the mounting portion is located on the side facing the driving mechanism at the opening position of one end where the moving contact contacts the static contact.

[0008] Preferably, magnetic steels capable of generating a magnetic field are respectively provided on opposite sides inside or outside the sealed chamber.

[0009] Preferably, magnetic steel frames that are magnetically conductive are respectively provided on the outer peripheries of opposite sides of the ceramic cover, and the magnetic steels are provided on the magnetic steel frames.

[0010] Preferably, the magnetic steel frame is an inverted U-shaped structure formed by splicing magnetic conductive plates. The color steel is located at the bottom of the inverted U-shaped magnetic steel frame, and the magnetic steel is located between the magnetic steel frame and the ceramic cover.

[0011] Preferably, bumps are respectively provided on the top and surface of the side of the magnetic steel frame facing the ceramic cover. Corresponding to the bumps, notches are provided on the top of the magnetic steel, and grooves are provided on the surface of the magnetic steel facing the bumps. The bumps cooperate with the notches and the grooves to form a limit for the magnetic steel.

[0012] Preferably, a ceramic cover is hermetically connected to the top of the magnetic pole plate to form the sealed chamber. The arc extinguishing structure is installed on an insulating base in the ceramic cover, and the insulating base is installed on the magnetic pole plate.

[0013] Preferably, the arc extinguishing structure is a porous structure or a breathable structure formed by extruding or weaving metal wires.

[0014] Preferably, a gas arc extinguishing medium is filled in the sealed chamber.

[0015] In the contactor of the present invention, an arc extinguishing structure and magnetic members are provided on the outer periphery of the static contact and the moving contact and on the outer periphery of the displacement path of the moving contact. The arc is guided to the arc extinguishing structure for arc extinguishing. At the same time, heat exchange is performed through the arc extinguishing structure to reduce the gas temperature in the sealed chamber where the contact system is located, improve the arc extinguishing speed and arc extinguishing efficiency, and improve the breaking capacity.

[0016] The arc extinguishing structure is arranged on the outer periphery of the moving contact displacement path, the outer periphery of the end where the moving contact contacts the static contact, and the outer periphery of the static contact, so that the arc generated during opening and closing can be guided to the arc extinguishing structure as much as possible, and the arc extinguishing structure participates in cooling and arc extinguishing.

[0017] Through the insulation base setting, the end during opening and closing of the contactor and the low-voltage end where the driving mechanism works are insulated and isolated, improving the working reliability and safety of the contactor.

[0018] The chamber where the contact system is located is sealed by a metal sleeve, a ceramic cover and a magnetic pole plate, and a gas arc extinguishing medium is filled in the chamber, so that the arc generated during opening and closing can be extinguished through the gas arc extinguishing medium. Combining with the arc extinguishing structure, the arc extinguishing ability and breaking ability are further improved. Brief Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of the contactor of the present invention.

[0020] Figure 2 It is a schematic structural diagram of the ceramic cover.

[0021] Figure 3 It is a schematic structural diagram of the static contact.

[0022] Figure 4 It is a schematic structural diagram of the moving contact.

[0023] Figure 5 It is a schematic structural diagram of the magnetic steel frame and the magnetic steel structure. Figure A is the magnetic steel frame and Figure B is the magnetic steel.

[0024] Figure 6 It is a schematic structural diagram of the installation of the push rod and the moving contact.

[0025] Figure 7 It is a schematic structural diagram of the arc extinguishing structure.

[0026] Figure 8 It is a schematic structural diagram of the insulation base.

[0027] Figure 9 It is a schematic structural diagram of the insulation base installed with the arc extinguishing structure.

[0028] Reference Signs:

[0029] Magnetic pole plate 10, driving coil 11, magnetic conduction cylinder 12, metal sleeve 13, moving iron core 14, push rod 15, moving contact 16, static contact 17, ceramic cover 18, mounting hole 181, insulation base 19, U-shaped yoke 20, mounting base 21, contact spring 22, magnetic conduction part 23, pressing plate 24, arc extinguishing structure 25, arc extinguishing part 25a, magnetic steel frame 26, magnetic steel 27. Detailed Embodiments

[0030] The DC contactor with an arc extinguishing structure according to the present invention includes a housing, which is divided into two chambers by a magnetic pole plate. A driving mechanism and a contact system are respectively located in different chambers of the housing, and the chamber where the contact system is located is a sealed chamber. The contact system includes a moving contact and a static contact, and one end of the moving contact and the static contact that opens and closes with the moving contact is located in the sealed chamber. A breathable arc extinguishing structure is provided on a part or all of the outer periphery of the moving contact and the static contact in the sealed chamber, and an insulating distance is reserved between the arc extinguishing structure and the contact system.

[0031] The following gives preferred embodiments and specific descriptions in conjunction with the drawings. The orientation words involved are only based on the orientation shown in the drawings and do not constitute a limitation to the technical solution of the present invention.

[0032] Refer to Figures 1 to 9 , the DC contactor includes a housing, a driving mechanism, a contact system, and an arc extinguishing structure. The housing 10 divides the cavity in the housing into two independent cavities through the magnetic pole plate 10. The driving mechanism and the contact system are respectively located in different cavities. The driving mechanism is located in the bottom cavity, and the contact system is located in the top cavity. The driving mechanism includes a driving coil 11, a magnetic guide cylinder 12, a moving iron core 13, and a push rod 14. The contact system includes a moving contact 16 and a static contact 17.

[0033] A ceramic cover 18 is provided on the magnetic pole plate 10 in the top cavity where the contact system is located. The ceramic cover 18 is hermetically connected to the magnetic pole plate 10, and an installation hole for installing the static contact 17 is opened at the top of the ceramic cover 18. An insulating base 19 is provided on the magnetic pole plate 10 in the ceramic cover 18. Through the insulating base, the end where the contact system is located is insulated from the low-voltage end where the driving mechanism is located, and a sufficient insulating distance is reserved from the low voltage.

[0034] The driving system is located in the bottom cavity. A magnetic guide cylinder 12 is provided in the hollow part of the driving coil 11, and a U-shaped yoke 20 is provided on the outer periphery of the driving coil 11. The magnetic guide cylinder 12 is fixedly connected to the U-shaped yoke. A metal sleeve 21 is passed through the hollow parts of the driving coil 11 and the magnetic guide cylinder 12. One end of the metal sleeve 21 is open and the other end is closed. The closed end of the metal sleeve 21 is located in the magnetic guide cylinder 12, and the open end is located at the magnetic pole plate 10 and is hermetically connected to the magnetic pole plate 10. A sealed cavity is formed among the metal sleeve 21, the ceramic cover 18, and the magnetic pole plate 10, and a gas arc extinguishing medium is filled in the sealed cavity.

[0035] The moving iron core 14 is inserted into the metal sleeve 13 and can be displaced relative to the metal sleeve 13. One end of the push rod 15 is fixedly connected to the moving iron core 14 in a threaded connection manner, and the other end of the push rod 15 passes through the magnetic pole plate 10 and the insulating base 19 and is located in the cavity where the contact system is located. An installation base 21 is provided on the push rod 15, a contact spring 22 is provided on the installation base 21, a magnetic conduction member 23 is provided on the contact spring 22, a moving contact 16 is provided in the magnetic conduction member 23, a pressing plate 24 is provided on the magnetic conduction member 23, and the pressing plate 24 is connected to the installation base 21 to form positioning of the moving contact 16. The contact spring 22 is always in a compressed state.

[0036] An installation hole 181 for the static contact 17 to pass through and be fixed is formed in the ceramic cover 18. The static contact 17 is provided with a limiting step, is installed in the installation hole of the ceramic cover 18, and is hermetically fixed on the ceramic cover 18 by welding or pasting to seal the installation hole. One end of the static contact 17 passes through the housing and is located outside the contactor, serving as the wiring terminal of the contactor, and the end located inside the ceramic cover is used for making and breaking contact with the moving contact.

[0037] An arc extinguishing structure 25 is installed on the insulating base 19 inside the ceramic cover 18. The arc extinguishing structure 25 can completely surround the outer peripheries of the moving contact and the static contact inside the ceramic cover 18, or partially surround the outer periphery of the static contact and the end of the moving contact in contact therewith. An insulating distance is reserved between the arc extinguishing structure 25 and the moving contact and the static contact. In this embodiment, the arc extinguishing structure 25 partially surrounds the outer periphery of the static contact and the end of the moving contact in contact therewith. The arc extinguishing structure 25 includes two arc extinguishing members 25a. The two arc extinguishing members 25a are spaced apart and installed on both sides of the insulating base 19. The two arc extinguishing members 25a are respectively arranged on the outer peripheries of the ends of the static contact and the moving contact in contact therewith located in the ceramic cover, surrounding the end and both sides of the end of the static contact and the moving contact in contact therewith, so as to achieve partial surrounding and protection of the outer peripheries of the static contact and the moving contact inside the protective cover. In this embodiment, the arc extinguishing member 25a includes an inverted U-shaped structure surrounding the outer periphery of the end of the moving contact and the static contact in contact therewith and an installation portion located below the inverted U-shaped structure. The inverted U-shaped structure is fixedly connected to the installation portion, and the installation portion of the arc extinguishing member 25a is arranged on the insulating base 19.

[0038] The arc extinguishing structure is a breathable structure for facilitating air permeability, such as a porous structure, a wire mesh structure and other breathable structures that are easy to breathe, or a breathable structure formed by extruding one metal wire or multiple metal wires with a density less than that of the metal wire itself. The arc extinguishing structure of this type conducts current with low resistance and can dissipate energy. The material of the arc extinguishing structure is a metal material or a non-metal conductive material.

[0039] Magnetic steel 27 is respectively arranged on the opposite outer sides between the ceramic cover and the housing. Magnetic steel frames 26 are arranged on the opposite two sides of the outer periphery of the ceramic cover. The magnetic steel frame 26 is an inverted U-shaped structure formed by splicing three magnetic conduction plates. The magnetic steel 27 is in a plate-like structure and is arranged on the bottom of the inverted U-shaped magnetic steel frame 26 on the outer peripheral side of the ceramic cover. The magnetic steel 27 is supported by the magnetic steel frame 26, and the magnetic field of the magnetic steel is concentrated by the inverted U-shaped magnetic steel frame 26. In this embodiment, the magnetic steel frame 26 is in an inverted U-shaped structure, surrounding one end of the outer side of the ceramic cover, forming a semi-surrounding structure for one end of the outer side of the ceramic cover. The magnetic steel 27 is arranged on the magnetic steel frame 26, that is, as shown in the drawings, the magnetic steel 27 is arranged in pairs on the opposite left and right sides of the outer periphery of the ceramic cover. Protrusions are respectively arranged on the top and the side surface of the side of the magnetic steel frame 26 facing the ceramic cover. Corresponding to the protrusions on the magnetic steel frame 26, notches corresponding to the protrusions are arranged on the top of the magnetic steel 27, and grooves corresponding to the protrusions are arranged on the surface of the magnetic steel 27. When the magnetic steel 27 is installed on the side surface of the magnetic steel frame 26, the notch of the magnetic steel 27 just catches on the protrusion of the magnetic steel frame 26, and the protrusion on the magnetic steel frame 26 catches into the groove on the surface of the magnetic steel, forming a limit. The magnetic steel can be arranged in pairs on the opposite two sides in the length direction of the ceramic cover or can be arranged in pairs on the opposite two sides in the width direction of the ceramic cover.

[0040] When the driving mechanism drives the moving contact 16 to displace for closing or opening with the static contact 17, an arc is generated. The arc is elongated towards the arc extinguishing structure 25 under the magnetic field force of the magnetic steel 27. Due to the elongation of the arc, the gas arc extinguishing medium filled in the sealed cavity participates in arc extinguishing in a large range. During the elongation of the arc, the temperature of the arc extinguishing medium gas rises instantaneously. The gas with the increased temperature passes through the breathable arc extinguishing structure for heat energy exchange. Since the arc extinguishing structure is a breathable structure and has a large heat exchange surface area, the temperature of the gas can be quickly reduced through the arc extinguishing structure, and the energy can be dissipated. At the same time, the elongated arc flows through the arc extinguishing part with low resistance, and the arc is quickly extinguished.

[0041] The arc extinguishing structure surrounds the displacement path of the moving contact and the contact surface between the static contact and the moving contact during closing and opening, that is, the position where the arc is generated for the first time, so that the arc can be completely elongated towards the arc extinguishing structure under the action of the magnetic field force, improving the arc extinguishing efficiency. When the arc extinguishing structure completely surrounds the static contact and the displacement path of the moving contact, the arc extinguishing effect is better.

Claims

1. A DC contactor with an arc extinguishing structure, characterized in that: The invention comprises a shell, which is divided into two chambers by a magnetic pole plate, wherein a driving mechanism and a contact system are respectively located in different chambers in the shell, and the chamber where the contact system is located is a sealed chamber; the contact system comprises a moving contact and a stationary contact, and the moving contact and one end of the stationary contact for opening and closing the switch with the moving contact are located in the sealed chamber; a breathable arc extinguishing structure is partially or completely provided on the periphery of the moving contact and the stationary contact in the sealed chamber, and an insulation distance is retained between the arc extinguishing structure and the contact system.

2. The DC contactor according to claim 1, characterized in that: When an arc extinguishing structure is provided on the peripheral parts of the moving contact and the static contact in the sealed chamber, the arc extinguishing structure includes two arc extinguishing members, which are relatively spaced apart and arranged outside the two ends where the moving contact and the static contact are in contact, and the arc extinguishing members surround the end and both sides of the end of one end where the moving contact and the static contact are in contact in the direction of the moving contact displacement path, and a part of the periphery of the static contact corresponding to the area surrounded by the moving contact; an insulation distance is retained between the arc extinguishing members and the static contact and the moving contact.

3. The DC contactor according to claim 2, characterized in that: The arc extinguishing member comprises a mounting portion, and the mounting portion is located at a side of an opening position of one end of the moving contact contacting the static contact facing the driving mechanism.

4. The DC contactor according to claim 1, characterized in that: Magnetic steels capable of generating a magnetic field are respectively arranged on opposite sides of the interior or the periphery of the sealed chamber.

5. The DC contactor according to claim 4, characterized in that: Magnetic steel frames with magnetic conductivity are respectively arranged on the outer peripheries of two opposite sides of the ceramic cover, and the magnetic steel is arranged on the magnetic steel frames.

6. The DC contactor according to claim 5, characterized in that: The magnetic steel frame is an inverted U-shaped structure formed by splicing magnetic conductive plates, the colored steel is located at the bottom of the magnetic steel frame of the inverted U-shaped structure, and the magnetic steel is located between the magnetic steel frame and the ceramic cover.

7. The DC contactor according to claim 6, characterized in that: Bumps are respectively arranged on the top and surface of the side of the magnetic steel frame facing the ceramic cover. Corresponding to the bumps, a notch is arranged on the top of the magnetic steel, and a groove is arranged on the surface of the magnetic steel facing the bump. The bump cooperates with the notch and the groove to limit the magnetic steel.

8. The DC contactor according to claim 1, characterized in that: A ceramic cover is sealed on the magnetic pole plate to form the sealed chamber. The arc extinguishing structure is installed on an insulating base in the ceramic cover, and the insulating base is installed on the magnetic pole plate.

9. The DC contactor according to any one of claims 1 to 8, characterized in that: The arc extinguishing structure is a porous structure, or a breathable structure extruded or woven from metal wires.

10. The DC contactor according to claim 1, characterized in that: The sealed chamber is filled with arc extinguishing gas.

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