Short-circuit-current-resistant direct-current contactor

Abstract

The utility model relates to the field of high-voltage direct-current circuit protection, in particular to an anti-short-circuit-current direct-current contactor which comprises an electromagnetic driving mechanism, a static contact and a moving contact structure. The moving contact structure comprises a base, a U-shaped bracket movably clamped on the base, a contact spring positioned between the base and the U-shaped bracket, a U-shaped bracket, a moving contact bridge, an upper magnetizer and a lower magnetizer; the push rod is arranged on the base. The two sides of one end, facing the static contact, of the U-shaped support are fixedly connected with an upper magnetizer and an elastic piece. The movable contact bridge is located between the upper magnetizer and the lower magnetizer; the two ends of the contact spring abut against the lower magnetizer and the base respectively. An air gap is reserved between the upper magnetizer and the lower magnetizer, a gap is reserved between the U-shaped support and the base in the moving contact bridge displacement path direction, and the gap is smaller than the overtravel distance. When the switch is switched on, the gap between the U-shaped support and the base is eliminated, so that the air gap between the upper magnetizer and the lower magnetizer is minimum, and the capability of resisting short-circuit current is strongest.

Description

Technical Field

[0001] The invention relates to the field of high-voltage direct current circuit protection, in particular to a short-circuit current resistant direct current contactor. Background Art

[0002] A DC contactor is a mechanical device that uses electromagnetic principles to close and release the moving and static iron cores, thereby connecting and disconnecting the moving contact and the static contact.

[0003] The existing DC contactor contact structure is mostly a direct-acting structure. For example, Chinese patent CN216671512U discloses a DC contactor contact structure that is easy to automatically assemble. A DC contactor contact structure that is easy to automatically assemble includes a static contact, a moving contact arranged in a vertical direction corresponding to the static contact, a contact spring that provides an upward elastic support force for the moving contact, an upper magnetic yoke that is placed above the moving contact, a lower magnetic yoke that is placed between the moving contact and the upper end of the contact spring, and an upper magnetic A magnetic conductive circuit is formed between the yoke and the lower magnetic yoke, and the contact and separation of the static contact and the moving contact realize the on and off of the contactor. A boss is provided on the U-shaped basket assembly, and a limit surface corresponding to the boss is provided on the push rod assembly. The boss and the limit surface are installed in coordination. The U-shaped basket assembly includes a U-shaped basket, and insulating connectors are fixedly mounted on both side walls of the U-shaped basket. The push rod assembly includes a push rod, and an insulating member is fixedly mounted on the upper end of the push rod. The insulating connector and the insulating member are connected together by a latch pin, so that the U-shaped basket assembly and the push rod assembly (7) form a frame structure.

[0004] In the contact structure of the above technical solution, a magnetic circuit is formed by connecting the upper and lower magnetic yokes, and an attraction is generated between the upper and lower magnetic conductors to resist the electric repulsion so that the moving and static contacts do not bounce. This structure is very effective when the air gap between the upper and lower magnetic conductors is small, but the existing contactor structure has limited ability to resist large short-circuit currents due to the existence of overtravel, which greatly weakens the electromagnetic attraction. In addition, the U-shaped blue component structure is relatively complex and difficult to manufacture. Summary of the invention

[0005] The purpose of the present invention is to provide a short-circuit current resistant DC contactor, which can improve the ability to resist short-circuit current by increasing the gap between the upper and lower magnetic conductors when the gap between the U-shaped bracket and the base compensates for overtravel.

[0006] To achieve the above-mentioned purpose, the technical solution provided by the present invention is a short-circuit current resistant DC contactor, comprising an electromagnetic drive mechanism, a static contact, and a movable contact structure that can be displaced relative to the static contact; the movable contact structure comprises a base, a push rod, a contact spring, a U-shaped bracket, a movable contact bridge, an upper magnetic conductor and a lower magnetic conductor;

[0007] The base and the push rod are integrally formed or the push rod is glued and fixed to the base; the push rod is fixedly connected to the electromagnetic drive mechanism;

[0008] The U-shaped bracket is movably clamped on the base, and the contact spring, the upper magnetic conductor, the lower magnetic conductor and the moving contact bridge are located between the U-shaped bracket and the base; an elastic member that can contact the top of the DC contactor is arranged at one end of the U-shaped bracket facing the static contact;

[0009] The upper magnetic conductor is fixedly connected to the U-shaped bracket;

[0010] The two ends of the contact spring abut against the lower magnetic conductor and the base respectively; the moving contact bridge is located between the lower magnetic conductor and the upper magnetic conductor, and is located on the lower magnetic conductor;

[0011] In the initial position before closing, an air gap is retained between the upper magnetic conductor and the lower magnetic conductor, and the upper magnetic conductor and the lower magnetic conductor can form a magnetic circuit; in the direction of the displacement path of the moving contact bridge, a gap is retained between the U-shaped bracket and the base, and the gap is smaller than the overtravel distance.

[0012] Preferably, the base includes a base body and cantilevers located on opposite sides of the base body, the base body and the cantilever are integrally connected by a connecting piece, a U-shaped slot is formed between the base body and the cantilever, the U-shaped bracket is clamped in the U-shaped slot between the base body and the cantilever, and the gap is retained between the U-shaped bracket and the connecting piece.

[0013] Preferably, the U-shaped bracket includes a bottom plate that can contact the moving contact bridge and side plates integrally formed at both ends of the bottom plate, and a notch is provided at the end surface of the free end of the side plate to form a U-shaped plug structure, and the U-shaped plug structure is inserted in the U-shaped slot, and the gap is retained between the notch and the connecting piece, and the end of the free end of the U-shaped plug structure is bent in a movable manner and overlapped on the base body.

[0014] Preferably, a limiting step is provided at one end of the base body facing the electromagnetic drive mechanism, and the end of the free end of the U-shaped insert structure is bent and movably overlapped at the limiting step.

[0015] Preferably, the U-shaped plug-in structure includes two pin pieces integrally formed on the free end of the side panel and arranged at intervals, the two pin pieces are parallel and the free ends of the two pin pieces are bent outward to opposite sides respectively; when the U-shaped plug-in structure is inserted into the U-shaped slot, the free ends of the two pin pieces are bent and overlapped at the limit step.

[0016] Preferably, a limiting groove is provided on the end surface of one end of the base body facing the moving contact bridge, a limiting boss is provided on the end surface of the lower magnetic conductor corresponding to the limiting groove, one end of the contact spring is located in the limiting groove, and the other end is located on the outer periphery of the limiting boss.

[0017] Preferably, an arc extinguishing chamber is arranged at the periphery where the static contact and the moving contact structure are located, and the arc extinguishing chamber is filled with an arc extinguishing medium; and the end of the static contact in contact with the moving contact bridge passes through the arc extinguishing chamber.

[0018] Preferably, the elastic member is a spring sheet, and at least one spring sheet is arranged on the end surface of the U-shaped bracket facing the static contact, and the spring sheet protrudes from the end surface of the static contact and is arranged obliquely.

[0019] Preferably, when there are two spring sheets and they are spaced apart, the two spring sheets are integrally formed.

[0020] Preferably, the lower magnetic conductor has a U-shaped structure, the moving contact bridge is located in the U-shaped groove of the lower magnetic conductor, and the lower magnetic conductor and the moving contact bridge are matched with each other through a concave-convex mortise and tenon structure.

[0021] The short-circuit current resistant DC contactor of the present invention has a gap between an elastic member and a U-shaped bracket and a base. When the switch is closed, the elastic member contacts the top of the contactor to form an extrusion to generate an elastic force. Under the action of the elastic force, the U-shaped bracket moves toward the base with the upper magnetic conductor to eliminate the gap between the U-shaped bracket and the base. As the gap between the U-shaped bracket and the base is eliminated, the air gap between the upper magnetic conductor and the lower magnetic conductor is reduced to a minimum. At this time, the electromagnetic attraction between the upper magnetic conductor and the lower magnetic conductor is the largest, which can resist a very large short-circuit current and improve the ability to resist short-circuit current.

[0022] The short-circuit current resistant DC contactor of the present invention has a small number of moving contact structure parts and a small number of assembly processes, which facilitates automatic assembly and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the DC contactor of the present invention.

[0024] Figure 2 It is a schematic diagram of the moving contact structure.

[0025] Figure 3 It is a schematic diagram of the cross-sectional structure of the moving contact structure.

[0026] Figure 4 It is a schematic diagram of the base and push rod structure.

[0027] Figure 5 It is a schematic diagram of the U-shaped bracket structure.

[0028] Reference numerals:

[0029] Base 1, limiting step 101, arc extinguishing chamber 102, static contact 103, base body 10, cantilever 11, connector 12, U-shaped slot 13, limiting groove 14, push rod 2, U-shaped bracket 3, bottom plate 31, side plate 32, pin sheet 321, notch 3211, moving contact bridge 4, contact spring 5, electromagnetic coil 61, moving iron core 62, static iron core 63, upper magnetic conductor 7, lower magnetic conductor 8, limiting boss 81, elastic member 9. DETAILED DESCRIPTION

[0030] The short-circuit current resistant DC contactor of the present invention comprises an electromagnetic drive mechanism, a stationary contact, and a moving contact structure that can move relative to the stationary contact; the moving contact structure comprises a base, a push rod, a contact spring, a U-shaped bracket, a moving contact bridge, an upper magnetic conductor, and a lower magnetic conductor;

[0031] The base and the push rod are integrally formed or the push rod is glued and fixed on the base; the push rod is fixedly connected to the electromagnetic drive mechanism;

[0032] The U-shaped bracket is movably clamped on the base, and the contact spring, the upper magnetic conductor, the lower magnetic conductor and the moving contact bridge are located between the U-shaped bracket and the base; an elastic member that can contact the top of the DC contactor is arranged at one end of the U-shaped bracket facing the static contact;

[0033] The upper magnetic conductor is fixedly connected to the U-shaped bracket;

[0034] The two ends of the contact spring abut against the lower magnetic conductor and the base respectively; the moving contact bridge is located between the lower magnetic conductor and the upper magnetic conductor, and is located on the lower magnetic conductor;

[0035] In the initial position before closing, an air gap is retained between the upper magnetic conductor and the lower magnetic conductor, and the upper magnetic conductor and the lower magnetic conductor can form a magnetic circuit; in the direction of the displacement path of the moving contact bridge, a gap is retained between the U-shaped bracket and the base, and the gap is smaller than the overtravel distance.

[0036] With respect to the above technical solution, a preferred embodiment is now given and specifically described in conjunction with the drawings. Figures 1 to 5 .

[0037] The DC contactor comprises an electromagnetic drive mechanism, a moving contact structure, a stationary contact and a housing. The electromagnetic drive mechanism, the moving contact structure and the stationary contact 103 are located in different cavities in the housing.

[0038] The electromagnetic drive mechanism includes an electromagnetic coil 61, a moving iron core 62, and a static iron core 63. The static iron core 63 is located between the moving iron core 62 and the static contact 103. The electromagnetic drive mechanism is a prior art and will not be described in detail herein.

[0039] The moving contact structure includes a base 1, a push rod 2, a U-shaped bracket 3, a moving contact bridge 4, a contact spring 5, an upper magnetic conductor 7, a lower magnetic conductor 8, and an elastic member 9. Among them:

[0040] The base 1 is an integrally molded structure made of insulating material and is integrally molded by injection molding. The base 1 includes a base body 10 and cantilevers 11 located on the outer sides of the base body 10 on opposite sides. The base body 10 and the cantilever 11 are integrally molded through a connecting piece 12, and a U-shaped slot 13 is formed between the base body 10 and the cantilever 11. One end face of the base body 10 is integrally molded with the push rod 2. In other embodiments, the push rod 2 and the base body are molded separately, and the push rod 2 is adhered to the base body 10. A limiting groove 14 is formed on the end face of the other end of the base body 10, that is, the end face facing the static contact. Limiting steps 101 are formed on both sides of the end of the base body 10 facing the push rod 2, see Figure 4 The limiting step 101 is adjacent to the U-shaped slot 13. In other embodiments, the limiting step 101 can also be formed on the end surface of the cantilever 11 facing the push rod 2. The cantilever 11 is in the shape of a baffle. The limiting step 101 on the cantilever 11 and the base body limits the position of the U-shaped bracket inserted into the U-shaped slot 13 to prevent the U-shaped bracket from falling out of the base 1.

[0041] The U-shaped bracket 3 is an integrally formed structure, and the U-shaped bracket 3 includes a bottom plate 31 and side plates 32 integrally formed with both ends of the bottom plate 31. The bottom plate 31 and the side plates 32 located at both ends of the bottom plate 31 form the U-shaped bracket 3. The bottom plate 31 is a planar structure that can fit with the dynamic contact bridge 4. A notch is provided at the free end of the side plate 32 to form a U-shaped insert structure. The U-shaped insert structure includes two pin pieces 321 located on both sides of the notch. The two pin pieces 321 are arranged in parallel, and the free ends of the two pin pieces are bent toward the outside of the opposite sides, respectively, see FIG. Figure 5 A notch 3211 for the free end of the pin piece to bend again is provided at the bending portion of the pin piece 321. In other embodiments, the two pin pieces 321 are arranged in parallel, and the notch 3211 for the free end of the pin piece to bend is provided near the free ends of the two pin pieces 321.

[0042] The side plates 32 of the U-shaped bracket 3 are inserted into the U-shaped slots 13 on both sides of the base body 10, and the connector 12 at the U-shaped slots 13 is located in the notch of the U-shaped insert structure. The free ends of the two pins 321 of the U-shaped bracket 3 are bent toward the side of the limiting step 101, and the free ends of the bent pins 321 overlap the limiting step 101. The position of the U-shaped bracket 3 is limited by the cantilever and the limiting step to prevent it from detaching from the base. In the displacement direction of the moving contact bridge 4, a gap △mm is retained between the notch of the U-shaped insert structure of the U-shaped bracket 3 and the connector 12 of the base 1, and the gap △mm is less than the overtravel distance.

[0043] The moving contact bridge 4 is located between the U-shaped bracket 3 and the base body 10. An upper magnet 7 is arranged above the moving contact bridge 4, and the upper magnet 7 is fixedly connected to the U-shaped bracket 3. A lower magnet 8 is arranged below the moving contact bridge 4, and the lower magnet 8 is in a U-shaped structure. The moving contact bridge 4 is located in the U-shaped groove of the lower magnet 8, and the moving contact bridge 4 and the bottom of the U-shaped groove of the lower magnet 8 are matched through a concave and convex mortise and tenon structure. A limiting boss 81 is arranged on the end surface of the lower magnet 8 facing the base 1, corresponding to the limiting groove 14. One end of the contact spring 5 is located in the limiting groove 14 of the base 1, and the other end is located at the outer periphery of the limiting boss 81 of the lower magnet 8, and contacts with the end surface where the limiting boss 81 of the lower magnet 8 is located. In the initial position before closing, an air gap (air gap) is retained between the lower magnet 8 and the upper magnet 7.

[0044] An elastic member 9 is fixedly arranged in the middle of the end surface of the U-shaped bracket 3 facing the static contact, and the two ends of the elastic member 9 are spring structures 91, which are tilted and tilted toward the static contact, so that when the moving contact structure and the static contact are closed, the spring on the U-shaped bracket 3 contacts the top of the shell where the static contact is located, and the top of the shell squeezes the spring to generate elastic force. Under the action of the elastic force, the U-shaped bracket is driven to drive the upper magnet relative to the base to move, reduce the air gap between the upper magnet and the lower magnet, and improve the electromagnetic attraction between the upper magnet and the lower magnet. The elastic member 9 can be a U-shaped spring structure, or two separate spring structures are tilted, or multiple spring structures are set, as long as it is satisfied that when the moving contact bridge moves toward the static contact, the spring structure is squeezed by the top of the shell to generate elastic force, and under the action of the elastic force, the U-shaped bracket is driven to drive the upper magnet relative to the base to move, reduce the air gap between the upper magnet and the lower magnet, and improve the electromagnetic attraction between the upper magnet and the lower magnet.

[0045] In order to improve the arc extinguishing effect, an arc extinguishing chamber 102 is provided in the housing cavity where the static contact and the moving contact bridge are located, and the arc extinguishing medium is filled in the arc extinguishing chamber 102. The end of the static contact 103 that contacts the moving contact bridge passes through the arc extinguishing chamber 102. When the moving contact bridge and the static contact are closed, the elastic member 9 of the moving contact structure can contact and act on the top of the arc extinguishing chamber 102 to generate elastic force. Under the action of the elastic force, the components composed of the upper magnetic conductor, the U-shaped bracket and the spring are pushed down. At this time, the notch of the U-shaped bracket contacts the connecting member at the base, eliminating the gap between the U-shaped bracket and the insulating member, shortening the air gap between the upper magnetic conductor and the lower magnetic conductor. At this time, the air gap is the smallest. When the short-circuit current comes, the electromagnetic attraction between the upper magnetic conductor and the lower magnetic conductor is extremely large, which can resist very large short-circuit current.

Claims

1. A short-circuit current DC contactor, characterized in that: It includes an electromagnetic drive mechanism, a static contact, and a moving contact structure that can move relative to the static contact; the moving contact structure includes a base, a push rod, a contact spring, a U-shaped bracket, a moving contact bridge, an upper magnetic conductor, and a lower magnetic conductor; The base and the push rod are integrally formed or the push rod is glued and fixed to the base; the push rod is fixedly connected to the electromagnetic drive mechanism; The U-shaped bracket is movably clamped on the base, and the contact spring, the upper magnetic conductor, the lower magnetic conductor and the moving contact bridge are located between the U-shaped bracket and the base; an elastic member that can contact the top of the DC contactor is arranged at one end of the U-shaped bracket facing the static contact; The upper magnetic conductor is fixedly connected to the U-shaped bracket; The two ends of the contact spring abut against the lower magnetic conductor and the base respectively; the moving contact bridge is located between the lower magnetic conductor and the upper magnetic conductor, and is located on the lower magnetic conductor; In the initial position before closing, an air gap is retained between the upper magnetic conductor and the lower magnetic conductor, and the upper magnetic conductor and the lower magnetic conductor can form a magnetic circuit; in the direction of the displacement path of the moving contact bridge, a gap is retained between the U-shaped bracket and the base, and the gap is smaller than the overtravel distance.

2. The short-circuit current resistant DC contactor according to claim 1, characterized in that: The base includes a base body and cantilevers located on opposite sides of the base body. The base body and the cantilever are integrally connected via a connecting piece, forming a U-shaped slot between the base body and the cantilever. The U-shaped bracket is clamped at the U-shaped slot between the base body and the cantilever, and the gap is retained between the U-shaped bracket and the connecting piece.

3. The short-circuit current resistant DC contactor according to claim 2, characterized in that: The U-shaped bracket includes a bottom plate that can contact the moving contact bridge and side plates integrally formed at both ends of the bottom plate. A notch is provided at the free end surface of the side plate to form a U-shaped plug structure. The U-shaped plug structure is inserted into the U-shaped slot. The gap is retained between the notch and the connecting piece. The end of the free end of the U-shaped plug structure is bent and movably overlapped on the base body.

4. The short-circuit current resistant DC contactor according to claim 3, characterized in that: A limiting step is arranged at one end of the base body facing the electromagnetic drive mechanism, and the free end of the U-shaped insert structure is bent and movably overlapped at the limiting step.

5. The short-circuit current resistant DC contactor according to claim 4, characterized in that: The U-shaped plug-in structure includes two pin pieces integrally formed on the free end of the side plate and arranged at intervals, the two pin pieces are parallel and the free ends of the two pin pieces are bent outward to opposite sides respectively; when the U-shaped plug-in structure is inserted into the U-shaped slot, the free ends of the two pin pieces are bent and overlapped at the limiting step.

6. The short-circuit current resistant DC contactor according to claim 1, characterized in that: A limiting groove is provided on one end surface of the base body facing the moving contact bridge, a limiting boss is provided on the end surface of the lower magnetic conductor corresponding to the limiting groove, one end of the contact spring is located in the limiting groove, and the other end is located on the periphery of the limiting boss.

7. The short-circuit current resistant DC contactor according to claim 1, characterized in that: An arc extinguishing chamber is arranged at the periphery where the static contact and the moving contact structure are located, and the arc extinguishing chamber is filled with an arc extinguishing medium; one end of the static contact in contact with the moving contact bridge passes through the arc extinguishing chamber.

8. The short-circuit current resistant DC contactor according to claim 1, characterized in that: The elastic member is a spring sheet. At least one spring sheet is arranged on the end surface of the U-shaped bracket facing the static contact. The spring sheet protrudes from the end surface of the static contact and is arranged obliquely.

9. The short-circuit current resistant DC contactor according to claim 8, characterized in that: When there are two spring sheets and they are spaced apart, the two spring sheets are integrally formed.

10. The short-circuit current resistant DC contactor according to any one of claims 1 to 9, characterized in that: The lower magnetic conductor has a U-shaped structure, the moving contact bridge is located in the U-shaped groove of the lower magnetic conductor, and the lower magnetic conductor and the moving contact bridge are matched with each other through a concave-convex mortise and tenon structure.

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