Short-circuit-current-resistant DC contactor moving contact assembly and DC contactor

Abstract

The utility model provides a DC contactor moving contact assembly resistant to short-circuit current, which comprises a support, an upper magnetic conductive block is arranged at the top of the inner side of the support, a moving contact, a contact spring and a push rod assembly are sequentially arranged below the upper magnetic conductive block, and the push rod assembly is arranged at the lower part of the inner side of the support. The utility model also provides a DC contactor comprising the above DC contactor moving contact assembly resistant to short-circuit current. According to the utility model, the upper magnetic conductive block is arranged above the moving contact, the upper magnetic conductive block can be easily magnetized in a magnetic field, and the magnetic field generated after the upper magnetic conductive block is magnetized can weaken the magnetic field intensity generated during short-circuit current or impact current, so that the magnetic induction intensity borne by the moving contact is reduced, the Lorentz force borne by the moving contact is reduced, and the moving contact is prevented from bouncing off; and the static contact is separated from the static contact, so that the circuit is disconnected abnormally.

Description

Technical Field

[0001] The utility model relates to the technical field of contactors, in particular to a short-circuit current-resistant DC contactor moving contact assembly and a DC contactor. Background Art

[0002] The contactor generates a magnetic field by energizing the coil, causing the electromagnetic system to generate electromagnetic attraction. When the electromagnetic attraction is greater than the spring reaction force on the moving iron core, the moving iron core begins to move, driving the moving contact to move, causing the moving contact and the static contact to contact, and the contactor enters the on state; when the coil is de-energized, the electromagnetic attraction disappears, and under the action of the spring reaction force, the moving iron core resets, the moving contact and the static contact separate, and the contactor is in the off state.

[0003] Existing contactors usually have a double-breakpoint bridge contact structure, that is, a structure with one moving contact and two stationary contacts. When the contactor is working, the moving contact and the stationary contact are in contact, and the current passes between the moving and stationary contacts. Due to the influence of the contraction resistance and the magnetic field, the moving contact will be subjected to the Holm force and the Lorentz force, that is, the electromotive repulsion. When the rated current passes between the moving and stationary contacts, the electromotive repulsion is very small and will not affect the normal operation of the contactor; however, when a short-circuit current or an impact current occurs, the electromotive repulsion on the moving contact will be greater than the contact force, causing the moving contact to bounce off and lose contact with the stationary contact, resulting in abnormal disconnection of the circuit, which will have serious consequences for the electrical system and the contactor.

[0004] In order to improve the short-circuit current resistance performance of the contactor and reduce the influence of the electric repulsion on the contactor, magnetic blocks are usually placed above and below the moving contact of the contactor, and the number of upper and lower magnetic blocks is generally one or two each; usually the upper magnetic block is riveted to the push rod assembly, and the lower magnetic block is linked to the moving contact. When the moving and static contacts are energized, the lower magnetic block is subjected to the upward electromagnetic attraction generated by the upper magnetic block. Since the upper magnetic block is fixed on the push rod assembly, and the lower magnetic block is linked to the moving contact, the electromagnetic attraction acts on the moving contact, thereby resisting the downward electric repulsion. The above-mentioned prior art resists or reduces the electric repulsion by the electromagnetic attraction between the upper and lower magnetic blocks, and the structure is relatively complex and the production process is cumbersome. Utility Model Content

[0005] In order to solve the above problems, the utility model aims to provide a short-circuit current resistant DC contactor moving contact assembly and a DC contactor. By arranging an upper magnetic conductive block above the moving contact, the upper magnetic conductive block is easily magnetized in the magnetic field. The magnetic field generated after the upper magnetic conductive block is magnetized can weaken the magnetic field strength generated by the short-circuit current or the impact current, reduce the magnetic induction intensity of the moving contact, reduce the Lorentz force on the moving contact, and prevent the moving contact from bouncing off and losing contact with the static contact, thereby causing abnormal disconnection of the circuit.

[0006] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0007] A short-circuit current resistant DC contactor moving contact assembly comprises a bracket, an upper magnetic conductive block is installed on the inner top of the bracket, a moving contact, a contact spring and a push rod assembly are installed in sequence below the upper magnetic conductive block, and the push rod assembly is installed on the inner lower part of the bracket.

[0008] Furthermore, the bracket is a U-shaped bracket, a through hole is formed on the U-shaped bracket, and a first boss corresponding to and matching the through hole is provided on the upper magnetic conductive block.

[0009] Furthermore, the push rod assembly includes a shaft, a steel sheet and a plastic base. The steel sheet is installed horizontally through the interior of the plastic base, and the shaft is vertically installed at the inner center of the plastic base. Both sides of the steel sheet protrude out of the plastic base and are riveted to the slots on both sides of the U-shaped bracket.

[0010] Furthermore, a circular groove is provided on the upper part of the plastic base, a circular boss is provided at the center of the circular groove, the circular boss corresponds to and matches the inner circle of the contact spring, and the circular groove corresponds to and matches the outer circle of the contact spring.

[0011] Furthermore, a stamped second boss is provided at the lower portion of the moving contact, and the second boss corresponds to and matches the inner circle of the contact spring.

[0012] Furthermore, a plurality of stamping bosses are provided at the lower portion of the moving contact, and the plurality of stamping bosses correspond to and match the outer circle of the contact spring.

[0013] Furthermore, when the moving contact is in a free state, the contact spring is in a compressed state and drives the moving contact to contact the upper magnetic conductive block.

[0014] Furthermore, the upper magnetic conductive block is a DT4 material magnetic block.

[0015] In order to achieve the above-mentioned purpose, the utility model also provides a DC contactor, including the above-mentioned short-circuit current-resistant DC contactor moving contact assembly.

[0016] Beneficial effect: The utility model arranges an upper magnetic block above the moving contact. The upper magnetic block is easily magnetized in the magnetic field. The magnetic field generated by the magnetization of the upper magnetic block can weaken the magnetic field strength generated by short-circuit current or impact current, reduce the magnetic induction intensity of the moving contact, reduce the Lorentz force on the moving contact, and prevent the moving contact from bouncing away and losing contact with the static contact, which would cause abnormal disconnection of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0018] Figure 1 This is a schematic structural diagram of a moving contact assembly of a DC contactor capable of withstanding short-circuit current according to an embodiment of the utility model;

[0019] Figure 2 This is a schematic diagram of the installation of a moving contact assembly of a DC contactor capable of withstanding short-circuit current according to an embodiment of the utility model;

[0020] Figure 3 This is a schematic diagram of the installation of a push rod assembly of a moving contact assembly of a DC contactor capable of withstanding short-circuit current according to an embodiment of the utility model;

[0021] Figure 4 The moving contact structure of the moving contact assembly of the short-circuit current resistant DC contactor according to the embodiment of the utility model is shown in FIG. Figure 1 ;

[0022] Figure 5 The moving contact structure of the moving contact assembly of the short-circuit current resistant DC contactor according to the embodiment of the utility model is shown in FIG. Figure 2 ;

[0023] Figure 6 The present invention is a schematic diagram of the working state principle of the moving contact assembly of a short-circuit current resistant DC contactor according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0025] Example 1

[0026] See also Figure 1-5 A short-circuit current resistant DC contactor moving contact assembly comprises a bracket 1, an upper magnetic conductive block 2 is installed on the inner top of the bracket 1, a moving contact 3, a contact spring 4 and a push rod assembly 5 are installed in sequence below the upper magnetic conductive block 2, and the push rod assembly 5 is installed on the inner lower part of the bracket 1.

[0027] When the contactor is in action, due to the effect of the magnetic field, the moving iron core of the push rod assembly moves upward, driving the push rod assembly to move upward. Since the overall structure is fixedly installed with the push rod assembly, the overall structure moves upward until the moving contact and the static contact come into contact, and the moving contact stops moving. The bracket, the upper magnetic block, the contact spring and the push rod assembly will stop moving after continuing to travel the overtravel distance. Since the upper magnetic block of this embodiment is easily magnetized in the magnetic field, the magnetic field generated after the upper magnetic block is magnetized can weaken the magnetic field strength generated by short-circuit current or impulse current, reduce the magnetic induction strength of the moving contact, reduce the Lorentz force on the moving contact, and prevent the moving contact from bouncing off and losing contact with the static contact, thereby causing abnormal disconnection of the circuit.

[0028] In this embodiment, the magnetic field generated by the upper magnetic block weakens the magnetic field on the moving contact, thereby reducing the Lorentz force on the moving contact and the electromotive repulsion on the moving contact. Compared with the traditional short-circuit current-resistant structure, the moving contact and the static contact are guided to contact through the mutual attraction between the upper and lower magnetic blocks; the lower magnetic block is omitted and only the upper magnetic block is retained, and the structure is simpler, so the product cost is lower and the assembly efficiency is higher.

[0029] In a specific example, the bracket 1 is a U-shaped bracket, a through hole 101 is opened on the U-shaped bracket, and a first boss 201 corresponding to and matching the through hole is provided on the upper magnetic conductive block 2.

[0030] The U-shaped bracket of this embodiment is provided with a through hole for riveting with the first boss of the upper magnetic conductive block.

[0031] In a specific example, the push rod assembly 5 includes a shaft 501, a steel sheet 502 and a plastic base 503. The steel sheet 502 is installed horizontally through the interior of the plastic base 503, and the shaft 501 is vertically installed at the inner center of the plastic base 503. Both sides of the steel sheet 502 protrude from the plastic base 503 and are riveted to the slots 102 on both sides of the U-shaped bracket.

[0032] It should be noted that the push rod assembly of this embodiment is composed of a shaft, a steel sheet and a plastic base, wherein the shaft and the steel sheet do not contact each other through the plastic base and are insulated from each other; the shaft and the contact spring also do not contact each other through the plastic base and are insulated from each other.

[0033] In a specific example, a circular groove 5031 is provided on the upper part of the plastic base 503 , a circular boss 5032 is provided at the center of the circular groove 5031 , the circular boss 5032 corresponds to and matches the inner circle of the contact spring 4 , and the circular groove 5031 corresponds to and matches the outer circle of the contact spring 4 .

[0034] The circular groove and circular boss design on the upper part of the plastic base of this embodiment can facilitate the stable installation of the contact spring, so that the moving contact assembly of this embodiment is more stable when working.

[0035] In a specific example, a stamped second boss 301 is provided at the lower portion of the moving contact 3 , and the second boss 301 corresponds to and matches the inner circle of the contact spring 4 .

[0036] It should be noted that the boss is inserted into the inner circle of the contact spring, so that the upper end of the contact spring can support the starting contact.

[0037] In a specific example, a plurality of stamping bosses 302 are provided at the lower portion of the moving contact 3 , and the plurality of stamping bosses 302 correspond to and match the outer circle of the contact spring 4 .

[0038] It should be noted that the lower part of the moving contact in this embodiment is arranged in another structural form. During assembly, the stamping boss and the outer circle of the contact spring are matched, and the contact spring is placed in the middle of a plurality of stamping bosses.

[0039] In a specific example, when the moving contact 3 is in a free state, the contact spring 4 is in a compressed state and drives the moving contact 3 to contact the upper magnetic conductive block 2 .

[0040] In a specific example, the upper magnetic conductive block 2 is a DT4 material magnetic block.

[0041] like Figure 6 As shown: Working principle description: Usually the moving contact and the static contact of the contactor are placed vertically. When the contactor is working, the moving and static contacts are in contact, and the current passing through the moving and static contacts will generate a magnetic field. Since the current-carrying conductor will be subjected to the Lorentz force (Ampere force) in the magnetic field, the moving contact will be subjected to the downward Lorentz force. When the current is the rated current, the Lorentz force on the moving contact is small, and the contactor can be connected normally. When a short-circuit current or an impact current passes through, the Lorentz force on the moving contact may exceed the contact force, causing serious consequences. In this embodiment, an upper magnetic conductive block is placed above the moving contact. The upper magnetic conductive block is made of DT4 material and is easily magnetized in a magnetic field. The magnetic field generated after the magnetic conductive block is magnetized can weaken the original magnetic field strength and reduce the magnetic induction intensity on the moving contact, thereby reducing the Lorentz force on the moving contact.

[0042] Example 2

[0043] In order to achieve the above-mentioned purpose, the present embodiment further provides a DC contactor, comprising the above-mentioned short-circuit current-resistant DC contactor moving contact assembly.

[0044] The advantages of the DC contactor of this embodiment and the above-mentioned short-circuit current-resistant DC contactor moving contact assembly over the prior art are the same, which will not be described in detail here.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A short-circuit current resistant DC contactor moving contact assembly, characterized in that: The invention comprises a bracket (1), an upper magnetic conductive block (2) is installed on the inner top of the bracket (1), a moving contact (3), a contact spring (4) and a push rod assembly (5) are installed in sequence below the upper magnetic conductive block (2), the push rod assembly (5) is installed on the inner lower part of the bracket (1), the bracket (1) is a U-shaped bracket, a through hole (101) is opened on the U-shaped bracket, a first boss (201) corresponding to the through hole is provided on the upper magnetic conductive block (2), the push rod assembly (5) comprises a shaft (501), a steel sheet (502) and a plastic base (503), the steel sheet (502) is installed transversely through the interior of the plastic base (503), the shaft (501) is vertically installed at the inner center of the plastic base (503), both sides of the steel sheet (502) protrude from the outside of the plastic base (503) and are connected to the U-shaped bracket. The slots (102) on both sides of the interior are riveted together, a circular groove (5031) is provided on the upper part of the plastic base (503), a circular boss (5032) is provided in the center of the circular groove (5031), the circular boss (5032) corresponds to and matches the inner circle of the contact spring (4), the circular groove (5031) corresponds to and matches the outer circle of the contact spring (4), a stamped second boss (301) is provided on the lower part of the moving contact (3), the second boss (301) corresponds to and matches the inner circle of the contact spring (4), a plurality of stamped bosses (302) are provided on the lower part of the moving contact (3), the plurality of stamped bosses (302) correspond to and match the outer circle of the contact spring (4), and when the moving contact (3) is in a free state, the contact spring (4) is in a compressed state and drives the moving contact (3) to contact the upper magnetic conductive block (2).

2. The short-circuit current-resistant DC contactor moving contact assembly according to claim 1, characterized in that: The upper magnetic conductive block (2) is a magnetic block made of DT4 material.

3. A DC contactor, characterized in that: It comprises a short-circuit current-resistant DC contactor moving contact assembly as claimed in any one of claims 1 to 2.

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