A moving contact assembly of a DC contactor and the DC contactor

Abstract

A moving contact assembly of a DC contactor comprises a moving contact (41) and a push rod mechanism (42), wherein the moving contact (41) is mounted on the top of the push rod mechanism (42), and is characterized in that: a ferromagnetic fan blade (43) is arranged on the push rod mechanism (42), and the ferromagnetic fan blade (43) is located between a pair of permanent magnets (3, 3'). By adding a fan blade structure, the ferromagnetic fan blade is rotated due to uneven force in the arc blowing magnetic field to disturb the gas inside the arc extinguishing chamber, so that hydrogen and nitrogen are fully mixed, and effective arc extinguishing at a higher voltage is achieved. At the same time, the rotation of the fan blade can drive the moving contact to move, change the contact position when the contact is closed, avoid local concentrated ablation of the contact, and extend the service life of the product.

Description

Technical Field

[0001] The invention belongs to the field of low-voltage electrical technology, and specifically relates to a moving contact assembly of a DC contactor. Background Art

[0002] DC contactors are generally composed of coils and external magnetic circuits, arc extinguishing chambers, static contacts, moving contacts, movable shaft components, permanent magnets and plastic shells, and are mainly used in electric vehicles, charging piles, photovoltaics and energy storage. At present, common DC contactor products usually achieve rapid arc extinguishing through permanent magnet magnetic blowing and inert gases such as hydrogen or nitrogen. The working voltage is generally 450V and 750V, and the maximum working current can reach 300-400A. However, with the increasing requirements for the endurance of electric vehicles, DC contactors are required to have a working voltage of 1000V-1500V, and the working current needs to reach 800-1000A. However, it is difficult for current DC contactor products to meet such requirements. The main reason is that most DC contactor products are filled with single hydrogen or nitrogen. Hydrogen has a strong deionization effect and is easier to extinguish arcs, but its insulation strength is lower than that of nitrogen, which is easy to cause heavy breakdown and arc reignition under high voltage; although the insulation strength of nitrogen is high, it is weaker than the performance of hydrogen in arc extinguishing. Therefore, the use of a mixture of hydrogen and nitrogen is often considered in high-voltage and high-current DC contactor products. However, due to the different densities of the two gases, it is necessary to consider how to avoid the two gases from stratifying and not working effectively during actual use. On the other hand, the current DC contactor contact structure is prone to rapid reduction in life due to the transfer of contact metal materials during the breaking process. Summary of the invention

[0003] The purpose of the present invention is to provide a moving contact assembly of a DC contactor and the DC contactor in view of the technical defects of the above-mentioned existing DC contactors, which disturbs the gas inside the arc extinguishing chamber by adding a fan blade structure and utilizing the uneven force of the ferromagnetic fan blades in the arc blowing magnetic field to rotate, so as to fully mix the hydrogen and nitrogen and achieve effective arc extinguishing at a higher voltage. At the same time, the rotation of the fan blades can drive the moving contact to move, change the contact position when the contact is closed, avoid local concentrated ablation of the contact, and extend the service life of the product.

[0004] Technical Solution

[0005] In order to achieve the above technical objectives, the present invention provides a moving contact assembly of a DC contactor, including a moving contact and a push rod mechanism, wherein the moving contact is mounted on the top of the push rod mechanism, and is characterized in that: a ferromagnetic fan blade is provided on the push rod mechanism, and the ferromagnetic fan blade is located between a pair of permanent magnets.

[0006] Furthermore, the ferromagnetic blades are capable of rotating, and the ferromagnetic blades are capable of driving the moving contact to rotate during the rotation process.

[0007] Furthermore, the push rod mechanism includes an upper movable shaft, the moving contact is fixedly mounted on the top end of the upper movable shaft, the lower end of the upper movable shaft is tightly fitted into the inner cavity of the insulating support, a miniature bearing is embedded in the groove at the bottom of the inner cavity of the insulating support, the top end of the lower movable shaft is fixedly mounted in the inner ring hole of the miniature bearing, and the contact spring is sleeved on the upper movable shaft, with one end abutting against the lower surface of the moving contact and the other end abutting against the upper surface of the insulating support.

[0008] Furthermore, an open retaining ring and a gasket are installed on the end of the upper movable shaft on the outside of the moving contact to limit the freedom of the moving contact. The lower end of the upper movable shaft is step-shaped. The lower end of the upper movable shaft is installed in the inner cavity of the insulating support through a through hole on the upper surface of the insulating support. The lower end of the stepped upper movable shaft abuts against the step surface corresponding to the inner cavity of the insulating support.

[0009] Furthermore, a shoulder is provided on the top of the lower movable shaft and located on the outer side of the bottom of the miniature bearing, and the lower surface of the miniature bearing abuts against the shoulder so that the inner ring hole of the miniature bearing is tightly mounted on the lower movable shaft, one end of the miniature bearing abuts against the step surface of the slot, and the other end is fixedly embedded in the inner cavity of the insulating support member through an open retaining ring installed at the bottom of the inner cavity of the insulating support member.

[0010] Furthermore, the lower end of the lower movable shaft extends out of the second through hole at the bottom of the inner cavity of the insulating support member.

[0011] Furthermore, the ferromagnetic blades are installed in the slots in the circumferential direction of the insulating support or are an integrated structure with the insulating support.

[0012] Preferably, the number of the ferromagnetic blades is not less than one, and they are made of pure iron magnetic conductive material.

[0013] Preferably, the number of the ferromagnetic blades is 3, the angles between them are unequal, and one of the angles is equal to 120°.

[0014] Preferably, the insulating support is made of plastic or ceramic insulating material.

[0015] Furthermore, a pair of permanent magnets are arranged on both sides of a line connecting a pair of stationary contacts, and the polarities of the facing surfaces are opposite.

[0016] Furthermore, the moving contact is a circular sheet structure.

[0017] A DC contactor comprises the moving contact assembly described above, characterized in that it also includes a ceramic cavity, a pair of stationary contacts, an external magnetic circuit portion and a kovable frame, wherein the pair of stationary contacts are mounted on the ceramic cavity, a pair of permanent magnets are mounted on both sides of the ceramic cavity and are parallel to a center line connecting the pair of stationary contacts, and the upper portion of the moving contact assembly is located inside a cavity formed by the ceramic cavity, the pair of stationary contacts and the kovable frame.

[0018] Furthermore, the external magnetic circuit part includes a yoke plate, a yoke tube, a coil, a core sleeve, a static iron core, a reaction spring, a coil frame and a moving iron core. The static iron core is connected and fixed to the yoke plate, and the moving iron core is sleeved on the lower movable shaft. The lower end of the lower movable shaft passes through the center hole of the static iron core. The reaction spring is installed on the lower movable shaft, one end of which is connected to the static iron core, and the other end is connected to the moving iron core. The static iron core and the moving iron core are installed in the core sleeve, the coil frame is sleeved on the core sleeve, the coil is installed on the coil frame, and the yoke tube is installed on the coil frame and is located below the yoke plate.

[0019] Beneficial Effects

[0020] The present invention provides a moving contact assembly of a DC contactor and the DC contactor, wherein the rotation of the ferromagnetic blades can disturb the gas inside the arc extinguishing chamber when the product is disconnected, so that hydrogen and nitrogen are fully mixed, the medium recovery speed is increased, and effective arc extinguishing is achieved at a higher voltage. At the same time, in addition to the arc being elongated under the action of the magnetic field, the rotation of the moving contact can also elongate the arc, thereby accelerating the extinguishing of the arc. On the other hand, after the contact rotates, the contact contact position changes when it is connected next time, and is no longer the position that has just been ablated, thereby avoiding local concentrated ablation of the contact, extending the service life of the contact, and effectively improving the electrical life of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 2 is a product diagram of a DC contactor in an embodiment of the present invention.

[0022] Figure 2 Schematic diagram of the structure of a DC contactor in an embodiment of the present invention.

[0023] Figure 3 It is a product picture of the moving contact assembly in an embodiment of the present invention.

[0024] Figure 4 Schematic diagram of the structure of the moving contact assembly in an embodiment of the present invention.

[0025] Figure 5 2 is a product diagram of a contact system in an embodiment of the present invention.

[0026] Figure 6 Schematic diagram of the structure of the contact system in the embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0028] Example

[0029] As attached Figure 1 and 2 As shown, a DC contactor comprises a moving contact assembly 4, a ceramic cavity 1, a pair of stationary contacts 2, 2', an external magnetic circuit portion 5 and a kovar frame sheet 6, wherein the pair of stationary contacts 2, 2' are mounted on the ceramic cavity 1, a pair of permanent magnets 3, 3' are mounted on both sides of the ceramic cavity 1 and are parallel to the central line connecting the pair of stationary contacts 2, 2', and the upper part of the moving contact assembly 4 is located inside the cavity formed by the ceramic cavity 1, the pair of stationary contacts 2, 2' and the kovar frame sheet 6. A pair of permanent magnets 3, 3' are arranged on both sides of the line connecting the pair of stationary contacts 2, 2', and the polarities of the opposite faces are opposite.

[0030] The outer magnetic circuit part 5 includes a yoke plate 51, a yoke tube 52, a coil 53, a core sleeve 54, a static iron core 55, a reaction spring 56, a coil frame 57 and a moving iron core 58. The static iron core 55 is connected and fixed to the yoke plate 51, and the moving iron core 58 is sleeved on the lower movable shaft 424. The lower end of the lower movable shaft 424 passes through the center hole of the static iron core 55. The reaction spring 56 is installed on the lower movable shaft 424. One end of the reaction spring 56 is connected to the static iron core 55, and the other end is connected to the moving iron core 58. The static iron core 55 and the moving iron core 58 are installed in the core sleeve 54, the coil frame 57 is sleeved on the core sleeve 54, the coil 53 is installed on the coil frame 57, and the yoke tube 52 is installed on the coil frame 57 and is located below the yoke plate 51.

[0031] As attached Figure 3 and 4 As shown, the moving contact assembly 4 includes a moving contact 41 and a push rod mechanism 42, wherein the moving contact 41 is mounted on the top of the push rod mechanism 42, wherein the push rod mechanism 42 is provided with a ferromagnetic blade 43, and the ferromagnetic blade 43 is located between a pair of permanent magnets 3, 3'. The ferromagnetic blade 43 can rotate, and the ferromagnetic blade 43 can drive the moving contact 41 to rotate during the rotation process. The ferromagnetic blade 43 is installed in the circumferential groove 422d of the insulating support 422 or is an integrated structure with the insulating support 422. The number of the ferromagnetic blade 43 is not less than 1, and it is made of pure iron-type magnetic conductive material, and the insulating support 422 is made of plastic or ceramic insulating material. In this embodiment, the number of ferromagnetic blades 43 is 3, and the angles between them are not equal. One of the angles is equal to 120°, and the other two angles can be set according to the rotation conditions so that the ferromagnetic blades 43 as a whole are subjected to a suitable magnetic torque, and the rotation angle of the moving contact 41 better meets the requirements.

[0032] In detail, as attached Figure 4 As shown, the push rod mechanism 42 includes an upper movable shaft 421, and a moving contact 41 is fixedly mounted on the top of the upper movable shaft 421. In this embodiment, the moving contact 41 is a circular sheet structure. The lower end of the upper movable shaft 421 is tightly fitted and extends into the inner cavity of the insulating support 422. A miniature bearing 423 is embedded in the slot 422a at the bottom of the inner cavity of the insulating support 422. The top end of the lower movable shaft 424 is fixedly mounted in the inner ring hole of the miniature bearing 423. The contact spring 425 is sleeved on the upper movable shaft 421, with one end abutting against the lower surface of the moving contact 41 and the other end abutting against the upper surface of the insulating support 422.

[0033] An open retaining ring 426 and a gasket 427 are installed on the end of the upper movable shaft 421 on the outer side of the moving contact 41 to limit the freedom of the moving contact 41. The lower end of the upper movable shaft 421 is stepped, and the lower end of the upper movable shaft 421 is installed in the inner cavity of the insulating support 422 through a through hole 422b on the upper surface of the insulating support 422. The lower end of the stepped upper movable shaft 421 abuts against the step surface corresponding to the inner cavity of the insulating support 422.

[0034] The top of the lower movable shaft 424 passes through the inner ring hole of the micro bearing 423 and is provided with an open retaining ring 2 428. The lower movable shaft 424 is provided with a shoulder 424a on the outer side of the bottom of the micro bearing 423. The lower surface of the micro bearing 423 abuts against the shoulder 424a so that the inner ring hole of the micro bearing 423 is tightly mounted on the lower movable shaft 424. One end of the micro bearing 423 abuts against the step surface of the slot 422a, and the other end is fixedly embedded in the inner cavity of the insulating support 422 through an open retaining ring 3 installed at the bottom of the inner cavity of the insulating support 422. The lower end of the lower movable shaft 424 extends out of the through hole 2 422c at the bottom of the inner cavity of the insulating support 422.

[0035] The working process of this embodiment is as follows: Figure 1 and 2 As shown, when the coil 53 is energized, the moving iron core 58 overcomes the spring forces of the reaction spring 56 and the contact spring 425 in turn under the action of the electromagnetic force, driving the lower movable shaft 424 to move toward the static iron core 55, so that the moving contact 41 of the moving contact assembly 4 contacts with a pair of static contacts 2, 2' and maintains contact pressure under a certain level, thereby realizing reliable connection of the main circuit of the contactor;

[0036] When the coil 53 is energized, the moving iron core 58 will drive the moving contact 41 to rotate a certain angle under the action of a lateral component force during the rising process, thereby changing the contact position between the moving contact 41 and a pair of stationary contacts 2, 2', reducing the degree of ablation and wear at the same position of the moving contact 41 and improving the electrical life of the product.

[0037] When the coil is powered off, the electromagnetic attraction disappears, and the moving iron core 58 is quickly separated from the static iron core 55 under the action of the reaction spring 56 and the spring force of the contact spring 425 and its own gravity, and drives the moving contact assembly 4 to move downward to disconnect the moving contact 41 from a pair of static contacts 2, 2', thereby disconnecting the main circuit of the contactor.

[0038] After the coil is powered off, the spring pressure disappears because the moving contact 41 in the moving contact assembly 4 is separated from the stationary contact 2. Figure 5 and 6 As shown, the moving contact assembly 4 moves in the circumferential direction in the magnetic field of a pair of permanent magnets 3, 3', and the ferromagnetic blades 43 are subjected to magnetic torque as a whole in the magnetic field. Due to the uneven distribution of the permanent magnet magnetic field and the influence of the residual magnetic field of the external magnetic circuit part 5, even if the ferromagnetic blades 43 are in a relatively balanced position in the structure in the magnetic field, the overall magnetic torque to which the ferromagnetic blades 43 are subjected can still enable the ferromagnetic blades to drive the moving contact assembly 4 to rotate around the micro bearing 423, thereby driving the rotation of the moving contact 41. As the moving contact assembly 4 descends, the ferromagnetic blades 43 gradually leave the magnetic field formed by the pair of permanent magnets 3, 3', and the magnetic field force to which the ferromagnetic blades 43 are subjected gradually decreases, and the moving contact assembly 4 will eventually stop rotating.

[0039] The structures, proportions, sizes, quantities, etc. illustrated in the accompanying drawings of the embodiments of the present invention are only used to match the contents disclosed in the specification so as to be understood and read by those familiar with the technology, and are not used to limit the limiting conditions that the present invention can be implemented, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects that the present invention can produce and the purposes that can be achieved. At the same time, the terms such as "upper", "lower", "left", "right", "middle", "clockwise", "counterclockwise", etc. cited in this specification are only for the convenience of narration, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of the relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

Claims

1. A moving contact assembly of a DC contactor, comprising a moving contact (41) and a push rod mechanism (42), wherein the moving contact (41) is mounted on the top of the push rod mechanism (42), characterized in that: The moving contact (41) is a circular sheet structure, and the push rod mechanism (42) is provided with a ferromagnetic fan blade (43), and the ferromagnetic fan blade (43) is located between a pair of permanent magnets (3, 3'); The ferromagnetic blade (43) can rotate in a magnetic field formed by a pair of permanent magnets (3, 3'), and the ferromagnetic blade (43) can drive the moving contact (41) to rotate during the rotation process; The push rod mechanism (42) includes an upper movable shaft (421), the movable contact (41) is fixedly mounted on the top end of the upper movable shaft (421), the lower end of the upper movable shaft (421) is tightly fitted and extends into the inner cavity of the insulating support (422), a miniature bearing (423) is embedded in the groove (422a) at the bottom of the inner cavity of the insulating support (422), the top end of the lower movable shaft (424) is fixedly mounted in the inner ring hole of the miniature bearing (423), and the contact spring (425) is sleeved on the upper movable shaft (421), one end of which abuts against the lower surface of the movable contact (41) and the other end of which abuts against the upper surface of the insulating support (422).

2. The moving contact assembly of a DC contactor according to claim 1, characterized in that: An open retaining ring (426) and a gasket (427) are installed on the end of the upper movable shaft (421) on the outer side of the movable contact (41) to limit the freedom of the movable contact (41); the lower end of the upper movable shaft (421) is stepped; the lower end of the upper movable shaft (421) is installed in the inner cavity of the insulating support (422) through a through hole (422b) on the upper surface of the insulating support (422); the lower end of the stepped upper movable shaft (421) abuts against the step surface corresponding to the inner cavity of the insulating support (422).

3. The moving contact assembly of a DC contactor according to claim 1, characterized in that: The top end of the lower movable shaft (424) passes through the inner ring hole of the micro bearing (423) and is equipped with an open retaining ring 2 (428). The lower movable shaft (424) is provided with a shoulder (424a) located on the outer side of the bottom of the micro bearing (423). The lower surface of the micro bearing (423) abuts against the shoulder (424a) so that the inner ring hole of the micro bearing (423) is tightly mounted on the lower movable shaft (424). One end of the micro bearing (423) abuts against the step surface of the slot (422a), and the other end is fixedly embedded in the inner cavity of the insulating support (422) through an open retaining ring 3 (429) installed at the bottom of the inner cavity of the insulating support (422).

4. The moving contact assembly of a DC contactor according to claim 3, characterized in that: The lower end of the lower movable shaft (424) extends out of the second through hole (422c) at the bottom of the inner cavity of the insulating support member (422).

5. The moving contact assembly of a DC contactor according to claim 1, characterized in that: The ferromagnetic fan blade (43) is installed in a slot (422d) in the circumferential direction of the insulating support member (422) or is an integrated structure with the insulating support member (422).

6. The moving contact assembly of a DC contactor according to claim 1, characterized in that: The number of the ferromagnetic blades (43) is no less than one and they are made of pure iron-based magnetic conductive material.

7. The moving contact assembly of a DC contactor according to claim 6, characterized in that: The number of the ferromagnetic blades (43) is 3, and the angles between them are unequal, with one angle being equal to 120°.

8. A moving contact assembly of a DC contactor as claimed in claim 1, 2 or 3, characterized in that: The insulating support member (422) is made of plastic or ceramic insulating material.

9. A moving contact assembly of a DC contactor as claimed in claim 1, 2 or 3, characterized in that: A pair of permanent magnets (3, 3') are arranged on both sides of a line connecting a pair of stationary contacts (2, 2'), and the polarities of the facing surfaces are opposite.

10. A DC contactor, comprising the moving contact assembly (4) according to any one of claims 1 to 9, characterized in that: It also includes a ceramic cavity (1), a pair of stationary contacts (2, 2'), an external magnetic circuit portion (5) and a kovar frame (6), wherein the pair of stationary contacts (2, 2') are mounted on the ceramic cavity (1), a pair of permanent magnets (3, 3') are mounted on both sides of the ceramic cavity (1) and are parallel to a center line connecting the pair of stationary contacts (2, 2'), and the upper portion of the moving contact assembly (4) is located inside a cavity formed by the ceramic cavity (1), the pair of stationary contacts (2, 2') and the kovar frame (6).

11. A DC contactor according to claim 10, characterized in that: The outer magnetic circuit part (5) comprises a yoke plate (51), a yoke cylinder (52), a coil (53), an iron core sleeve (54), a static iron core (55), a reaction spring (56), a coil frame (57) and a moving iron core (58). The static iron core (55) is connected and fixed to the yoke plate (51). The moving iron core (58) is sleeved on the lower movable shaft (424). The lower end of the lower movable shaft (424) passes through the center hole of the static iron core (55). The reaction spring (56) ) is mounted on the lower movable shaft (424), one end of the reaction spring (56) is connected to the static iron core (55), and the other end is connected to the moving iron core (58), the static iron core (55) and the moving iron core (58) are mounted in the iron core sleeve (54), the coil frame (57) is sleeved on the iron core sleeve (54), the coil (53) is mounted on the coil frame (57), and the yoke tube (52) is mounted on the coil frame (57) and is located below the yoke plate (51).

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