Contact structure resistant to electric repulsive force of contact

Abstract

The utility model belongs to the technical field of manufacturing and application of low-voltage electric appliance products, and particularly relates to a contact structure resistant to contact electro-dynamic repulsive force, which comprises a shell, a static contact assembly, a moving contact assembly and a contact supporting piece, and is characterized in that one end, close to a central hole, of a static contact piece is bent downwards to form a static contact part, and the other end of the static contact piece is bent downwards to form a moving contact part; the static contact parts and the parallel surface form an included angle a, the movable contact piece assembly is arranged between the two static contact pieces, the two ends of the movable contact piece are bent upwards to form movable contact parts, and the movable contact parts and the parallel surface form an included angle a. By designing the included angle between the movable and static contact pieces and the parallel surface, the capability of resisting the electric repulsive force of the contact after closing is improved; under the same output suction force, compared with a traditional parallel contact structure, the structure can tolerate larger contact electric repulsive force; the contactor based on the structure can obtain stronger impact current resistance, reduces the damage of large impact current to the contactor, and improves the reliability.

Description

Technical Field

[0001] The utility model belongs to the technical field of manufacturing and application of low-voltage electrical appliances, and particularly relates to a contact structure resistant to electric repulsion of contacts. Background Art

[0002] With the iteration of motors and the promotion of energy-saving motors, their starting current multiples and the reverse electromotive force when the power supply is vacant are getting larger and larger. In engineering applications, the reverse electromotive force of the new generation of motors connected to the power supply can reach an impact current of 22-27 times the rated current. Therefore, the contact electromotive force caused by the impact current that the AC contactor that connects and disconnects them needs to withstand is getting larger and larger.

[0003] Traditional contactors with a flat-type contact structure can generally only withstand 10-15 times their rated current. However, in engineering applications, due to the increase in inrush current, the short-circuit setting value of the circuit breaker of the line is often increased to a ratio far greater than the default 12 times. In this way, in application, the excessive inrush current will cause the closed contactor contacts to open and arc due to their contact electromotive force, resulting in abnormal contact wear and even welding of the moving and static contacts. Utility Model Content

[0004] In order to solve the above problems, the present invention proposes a contact structure that is resistant to the electric repulsion of contacts, so as to solve the problems mentioned in the above background technology.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is a contact structure resistant to electric repulsion of contacts, comprising a housing, a static contact assembly, and a dynamic contact assembly. A center hole is vertically opened in the middle of the housing and passes through the housing. The static contact assembly includes a static contact piece, which is respectively arranged on both sides of the center hole. One end of the static contact piece near the center hole is bent downward to form a static contact portion. The static contact portion forms an angle a with the parallel surface of the static contact piece. A static contact point is welded on the upper surface of the static contact portion.

[0006] The dynamic contact assembly is arranged between the static contact pieces, and the dynamic contact assembly includes a dynamic contact piece, which is arranged between the two static contact pieces. The two ends of the dynamic contact piece are bent upward to form a dynamic contact portion. The dynamic contact portion forms an angle a with the parallel surface of the dynamic contact piece. The lower surface of the static contact portion is welded with a dynamic contact point, and the dynamic contact point is capable of contacting the static contact point.

[0007] The specific value of the angle a between the static contact portion, the dynamic contact portion and the parallel plane can be determined according to specific practical requirements.

[0008] Further preferably, an opening groove is formed at the upper end of the shell in the same extending direction as the long side of the shell.

[0009] Further preferably, the static contact head assembly is fixed in the grooves on both sides of the central opening of the housing by a combination screw.

[0010] Further preferably, the static contact head assembly further includes a static connecting piece, the static connecting piece is arranged in the grooves on both sides of the central hole of the housing, and the static contact piece is arranged above the static connecting piece and contacts the upper surface of the static connecting piece.

[0011] Further preferably, a contact structure resistant to electric repulsion of contacts further includes a contact support member, the contact support member is arranged at the central hole of the housing, a groove with a downward opening is vertically upwardly formed at the bottom end of the contact support member, and a through hole penetrating the contact support member is vertically upwardly formed at the central position of the bottom wall of the groove.

[0012] Further preferably, the moving contact head assembly includes a bracket, a spring piece, a moving contact piece and a contact spring, the bottom end of the bracket passes through the through hole of the contact support member and is movably arranged in the groove of the contact support member, the spring piece, the moving contact piece and the contact spring are all arranged in the bracket, and the spring piece is arranged between the top end of the bracket and the moving contact piece, the contact spring is arranged below the moving contact piece, and one end of the contact spring is stuck at the bottom of the groove of the contact support member, and the other end of the contact spring is fixed on the inner wall of the bottom end of the bracket.

[0013] Further preferably, the moving contact piece and the moving contact parts at both ends form a bridge-shaped structure with an upward opening.

[0014] The beneficial effects of using the utility model are as follows:

[0015] 1. By designing the included angle between the static and moving contact pieces and the parallel plane, the ability to resist the electric repulsion of contacts after closing is improved;

[0016] 2. Under the same output suction force, compared with the traditional parallel contact structure, this structure can withstand a greater electric repulsion of contacts;

[0017] 3. The contactor based on this structure can obtain a stronger ability to withstand impact current, reduce the damage of large impact current to the contactor, and improve the reliability. Description of the Drawings

[0018] Figure 1 is an exploded view of a contact structure resistant to electric repulsion of contacts;

[0019] Figure 2 is a schematic diagram of the overall structure of a contact structure resistant to electric repulsion of contacts;

[0020] Figure 3 is a schematic diagram of the structure in the closing state of a contact structure resistant to electric repulsion of contacts;

[0021] Figure 4 A repulsion diagram for a contact structure resistant to electric repulsion of contacts;

[0022] Reference numerals include:

[0023] 1-housing, 2-static connecting piece, 3-static contact piece, 31-static contact part, 32-static contact point, 4-bracket, 5-spring piece, 6-moving contact piece, 61-moving contact part, 62-moving contact point, 7-contact spring, 8-combination screw, 9-contact support. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of this technical solution more clear, the following technical solution is further described in detail in conjunction with specific implementation methods. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of this technical solution.

[0025] Reference Figure 1 to Figure 4 As shown, Figure 1 An exploded view of a contact structure resistant to electric repulsion of contacts; Figure 2 A schematic diagram of the overall structure of a contact structure resistant to electric repulsion of contacts; Figure 3 A schematic diagram of the structure of a contact structure resistant to electric repulsion of contacts in a closed state; Figure 4 A contact structure resistant to electric repulsion of contacts comprises a housing 1, a static contact assembly, a dynamic contact assembly and a contact support 9.

[0026] The utility model proposes a contact structure resistant to electric repulsion of contacts, including a shell 1, which is rectangular. An open groove is provided at the upper end of the shell 1 in the same direction as the extension direction of the long side of the shell 1, and a center hole is vertically opened in the middle position of the shell 1 and penetrates the shell 1. Static contact head assemblies are respectively provided in the grooves on both sides of the center opening of the shell 1, and the static contact head assemblies are fixed in the shell 1 by a combination screw 8.

[0027] The static contact assembly includes a static connecting piece 2 and a static contact piece 3. The static connecting piece 2 is arranged in the grooves on both sides of the center hole of the shell 1. A static contact piece 3 is provided above the static connecting piece 2 and contacts the upper surface of the static connecting piece 2. The end of the static contact piece 3 close to the center hole is bent downward to form a static contact portion 31. The static contact portion 31 forms an angle a with the parallel surface of the static contact piece 3. A static contact point 32 is welded on the upper surface of the contact portion 31.

[0028] At the central hole of the housing 1, a contact support 9 is provided. The shape of the cross-section of the contact support 9 matches the central hole of the housing 1. At the bottom end of the contact support 9, a groove with a downward opening is vertically opened upwards, and a through hole penetrating the contact support 9 is vertically opened upwards at the central position of the bottom wall of the groove.

[0029] A moving contact assembly is provided between the two static contact assemblies. The moving contact assembly includes a bracket 4, a spring piece 5, a moving contact piece 6, and a contact spring 7. The bottom end of the bracket 4 passes through the through hole of the contact support 9 from top to bottom and is movably arranged in the groove inside the contact support 9. The spring piece 5, the moving contact piece 6, and the contact spring 7 are all arranged inside the bracket 4. And the spring piece 5 is arranged between the top end of the bracket 4 and the moving contact piece 6. The connecting arm of the spring piece 4 is in contact with the upper surface of the moving contact part 61 of the moving contact piece 6. The contact spring 7 is arranged below the moving contact piece 6, and one end of the contact spring 7 is stuck at the bottom of the groove of the contact support 9, and the other end is fixed on the inner wall of the bottom end of the bracket 4.

[0030] The moving contact piece 6 is arranged between two static contact pieces 3. The two ends of the moving contact piece 6 are bent upwards to form moving contact parts 61. The moving contact piece 6 and the two moving contact parts 61 at both ends form a bridge-shaped structure with an upward opening. The angle formed by the moving contact part 61 and the parallel plane of the moving contact piece 6 is the same as the angle formed by the contact part 31 and the parallel plane of the static contact piece 3, both being an α angle. A moving contact 62 is welded on the lower surface of the moving contact part 61. When the moving contact piece 6 moves towards the static contact piece 3, the moving contact 62 on the lower surface of the moving contact part 61 can be in contact with the static contact 32 on the static contact piece 3.

[0031] The spring piece 5 includes a semi-circular connecting section with a downward opening. The two ends of the connecting section are respectively connected with connecting arms. The two connecting arms at both ends extend towards the direction away from the connecting section, and an arc transition design is adopted at the connection between the connecting section and the connecting arms.

[0032] Working principle:

[0033] When the contactor using this structure is closed, as shown in the attachment Figure 3 shows, the contact support 9 acts downward, presses the moving contact piece 6 through the contact spring 7, the bracket 4, and the spring piece 5, so that the moving contact 62 welded on the lower surface of the moving contact part 61 is in contact with the fixed static contact 32. At this time, the current is conducted from the static connection piece 2 on one side, the static contact piece 3, the static contact 32, and the moving contact 62 through the moving contact piece 6 to the moving contact 62, the static contact 32, the static contact piece 3, and the static connection piece 2 on the other side to conduct the current.

[0034] When a large impact current is generated in the conducting loop, a contact electro-magnetic repulsive force perpendicular to the contact surface will be generated between the static contact 32 and the moving contact 62 in contact with each other. As shown in the attachment Figure 4As shown in F1, since there is an angle a between the angle at which the static contact portion 31 bends downward and the horizontal plane, the resultant force of F1 that repels the contact is greater than F3. For the traditional parallel contact structure, the contact can be repelled as long as the contact electric repulsion force is greater than F3. Therefore, when the downward force F3 of the contact support 9 is the same (the same attracting coil), when a = 30°, this structure is 115% of the traditional structure's resistance to contact electric repulsion force; when a = 45°, this structure is 141% of the traditional structure's resistance to contact electric repulsion force.

[0035] A contact structure resistant to contact electric repulsion force provided by the present utility model changes the magnitude of the resultant force of the contact electric repulsion forces F1 on both sides by changing the angle between the contact surface formed by the static contact point 32 and the moving contact point 62 and the horizontal plane of the contact surface, so that the resultant force of the contact electric repulsion forces F1 on the two outer sides is less than the downward force F3 of the contact support 9 (the same attracting coil), enabling the contact structure of the present utility model to withstand a greater contact electric repulsion force, thereby reducing the damage to the contactor caused by large impact currents and improving reliability.

[0036] The above content is only the preferred embodiment of the present utility model. For those of ordinary skill in the art, based on the idea of the technical content of the present application, many changes can be made in the specific implementation manner and application scope. As long as these changes do not depart from the concept of the present utility model, they all fall within the protection scope of this patent.

Claims

1. A contact structure resistant to electric repulsive force of contacts, comprising a housing, a static contact head assembly and a moving contact head assembly. A central hole penetrating the housing is vertically formed at the middle position of the housing. It is characterized in that: The static contact head assembly includes static contact pieces which are respectively arranged on both sides of the central hole. One end of the static contact piece close to the central hole is bent downward to form a static contact portion. An included angle a is formed between the plane parallel to the static contact piece and the static contact portion. A static contact point is welded on the upper surface of the static contact portion. The moving contact head assembly is arranged between the static contact pieces. The moving contact head assembly includes a moving contact piece which is arranged between two static contact pieces. Both ends of the moving contact piece are bent upward to form moving contact portions. An included angle a is formed between the plane parallel to the moving contact piece and the moving contact portions. A moving contact point is welded on the lower surface of the static contact portion. The moving contact point can contact with the static contact point. The specific value of the included angle a between the static contact portion and the moving contact portion and the parallel plane can be determined according to specific actual requirements.

2. The contact structure resistant to contact electric repulsion according to claim 1, characterized in that: An opening groove extending in the same direction as the long side of the housing is formed at the upper end of the housing.

3. The contact structure resistant to contact electric repulsive force according to claim 1 or 2, characterized in that: The static contact head assembly is fixed in the grooves on both sides of the central opening of the housing by combination screws.

4. The contact structure resistant to the electric repulsive force of the contact tip according to claim 1, characterized in that: The static contact head assembly further includes static connection pieces which are arranged in the grooves on both sides of the central hole of the housing. The static contact pieces are arranged above the static connection pieces and contact with the upper surfaces of the static connection pieces.

5. The contact structure resistant to electric repulsive force of the contact as claimed in claim 1, wherein: The contact structure resistant to electric repulsive force of contacts further includes a contact support. The contact support is arranged at the central hole of the housing. An opening-downward groove is vertically formed at the bottom end of the contact support. A through hole penetrating the contact support is vertically formed at the central position of the bottom wall of the groove.

6. The contact structure resistant to the electric repulsive force of the contact tip according to claim 1, characterized in that: The moving contact head assembly includes a bracket, a spring piece, a moving contact piece and a contact spring. The bottom end of the bracket passes through the through hole of the contact support and is movably arranged in the groove of the contact support. The spring piece, the moving contact piece and the contact spring are all arranged in the bracket. The spring piece is arranged between the top end of the bracket and the moving contact piece. The contact spring is arranged below the moving contact piece. One end of the contact spring is stuck at the bottom of the groove of the contact support, and the other end of the contact spring is fixed on the inner wall of the bottom end of the bracket.

7. The contact structure resistant to the electric repulsive force of the contact tip according to claim 6, characterized in that: The moving contact piece and the moving contact portions at both ends form a bridge-shaped structure with an upward opening.

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