Low-impact vacuum circuit breaker

Abstract

The invention relates to a low-impact vacuum circuit breaker, and belongs to the technical field of circuit breakers, the low-impact vacuum circuit breaker comprises a fixed cylinder, an overtravel spring and a pull rod, the fixed cylinder is located above a moving contact assembly, and the bottom end of the fixed cylinder is fixed on the moving contact assembly; the bottom end of the fixed cylinder is a closed end; the over-travel spring is arranged in the fixed cylinder, and the bottom end of the over-travel spring is in contact with the closed end of the fixed cylinder; the pull rod slides in the fixed cylinder, the bottom end of the pull rod contacts with the top end of the over-travel spring, and the top end of the pull rod slidably penetrates out of the top end of the fixed cylinder, so that after the pull rod is downwards pushed by external force, the moving contact assembly is firstly pushed to contact with the static contact assembly, and then the over-travel spring is compressed. According to the invention, the over-travel spring is arranged in the fixed cylinder, and then the pull rod slides in the fixed cylinder and is in contact with the over-travel spring, so that during closing, the moving contact assembly is pushed to be in contact with the static contact assembly, and then the over-travel spring is compressed, so that the contact impact force between the moving contact assembly and the static contact assembly is reduced; and the service lives of the moving contact assembly and the static contact assembly are prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit breakers, in particular to a low-impact vacuum circuit breaker. BACKGROUND

[0002] The vacuum circuit breaker is generally of a flat plate structure. In order to make the closing more reliable, compared with the ordinary SF6 arc extinguishing chamber, an overtravel compensation structure needs to be added to the transmission system. This structure makes the circuit breaker suddenly accelerate from zero speed before opening to high speed after opening. The transmission member needs to bear a great impact, which is easy to cause damage to the transmission member.

[0003] The current patent “202311715980.9 High-voltage alternating-current vacuum circuit breaker transmission system” proposes a three-phase linkage open type vacuum circuit breaker system. The system reduces the opening and closing bounce and impact by reducing the transmission gap, setting adjustable inter-phase connecting rods, and setting oil buffers at the tail. The patent “202311466522.6 Transmission device and intelligent vacuum circuit breaker using the device” proposes a method of using a buffer liquid to reduce the impact in the movement process of the vacuum circuit breaker. This method can also well improve the impact problem in the operation process of the vacuum circuit breaker.

[0004] The patent “201520806302.8 Buffer for transmission connection of vacuum circuit breaker” proposes a buffer for transmission connection of a vacuum circuit breaker. A counterweight composed of a balance sheet and a buffer pad is arranged between the pull rod and the driving crank arm to release the impact energy of the moving and stationary contact assembly at the moment of closing, and eliminate the closing bounce.

[0005] However, the following problems still exist in the applied patents: (1) Although the device of the buffer liquid can well offset the whole process impact, a damping buffer needs to be added to the transmission system, which not only has high cost, but also is difficult to guarantee the opening process characteristics. (2) Although the impact caused by the opening and closing bounce is eliminated, the great impact still exists at the moment after opening.

[0006] Therefore, how to design a low-cost, low-closing impact, and low-opening impact vacuum circuit breaker is a problem that needs to be solved by those skilled in the art. SUMMARY

[0007] The present application provides a low-impact vacuum circuit breaker, which solves the technical problems of large opening impact and large closing impact of the existing vacuum circuit breaker.

[0008] The technical scheme for solving the above technical problems is as follows: a low-impact vacuum circuit breaker, comprising: a fixed seat, a static contact assembly and a dynamic contact assembly, the static contact assembly is fixed on the fixed seat; the dynamic contact assembly is located above the static contact assembly; further comprising: a fixed cylinder, an over-travel spring and a pull rod, The fixed cylinder is located above the dynamic contact assembly and the bottom end thereof is fixed on the dynamic contact assembly; the bottom end of the fixed cylinder is a closed end; the over-travel spring is arranged in the fixed cylinder and the bottom end thereof is in contact with the closed end of the fixed cylinder; the pull rod is slidably arranged in the fixed cylinder and the bottom end thereof is in contact with the top end of the over-travel spring, and the top end thereof is slidably arranged out of the top end of the fixed cylinder, so that, after the pull rod is pushed downward by an external force, the dynamic contact assembly is first pushed into contact with the static contact assembly, and then the over-travel spring is compressed.

[0009] The beneficial effects of the present application are: the structure of the traditional vacuum circuit breaker is improved, the over-travel spring is first arranged in the fixed cylinder, and then the pull rod is slidably arranged in the fixed cylinder and in contact with the over-travel spring, so that, when the circuit breaker is closed, the dynamic contact assembly is first pushed into contact with the static contact assembly, and then the over-travel spring is compressed, thereby reducing the contact impact force of the dynamic contact assembly and the static contact assembly and prolonging the service life of the dynamic contact assembly and the static contact assembly.

[0010] On the basis of the above technical scheme, the present application can also be improved as follows.

[0011] Further, the fixed cylinder has an inner hole which is divided into an upper inner hole section and a lower inner hole section, the diameter of the upper inner hole section is smaller than that of the lower inner hole section, and the connection part between the two sections is an inclined surface; the pull rod is slidably arranged in the upper inner hole section and has a cavity arranged along the axial direction thereof in the interior thereof, the side wall of the pull rod is provided with a long strip sliding hole arranged along the axial direction thereof, both side walls of the pull rod are provided with cavities, the long strip sliding hole and the cavities are in communication with the cavity, the limiting block is fixed on the fixed seat and slidably arranged through the long strip sliding hole and into the cavity, two balls are respectively arranged in the two cavities and can be clamped at the inclined surface, and the elastic member is arranged in the cavity and the top end thereof can be in contact with the limiting block, the two side walls of the elastic member are inwardly inclined inner concave curved surfaces from the two ends of the shaft to the middle part of the shaft, and the two inner concave curved surfaces are respectively in contact with the two balls, so that, after the pull rod is pulled upward by an external force, the two balls are linked to move over the inclined surface, and the over-travel spring in the compressed state is restored to the initial state.

[0012] The above further beneficial effects are: the two balls are first linked to move away from the inclined surface by pulling the pull rod upward, and then the over-travel spring is used to release the over-travel compression pre-tightening spring, so that, when the circuit breaker is opened, the pull rod and the fixed cylinder are avoided from colliding, the opening collision is prevented, and the service life of the pull rod and the fixed cylinder is prolonged.

[0013] Furthermore, the elastic element includes a preload spring and a mandrel, the preload spring being placed within the cavity; the mandrel being placed within the cavity with its bottom end contacting the top end of the preload spring; the limiting block being able to contact the top end of the mandrel; and the two concave arc surfaces being the two sides of the mandrel.

[0014] Furthermore, it also includes an arc-extinguishing chamber, the top of which is provided with an ejector hole and the bottom of which is provided with a bottom outlet hole; the stationary contact assembly is located inside the arc-extinguishing chamber and its bottom end extends out of the bottom outlet hole; the moving contact assembly is located inside the arc-extinguishing chamber and its top end slides out of the ejector hole.

[0015] The further beneficial effect of adopting the above is that arranging both the moving contact assembly and the stationary contact assembly in the arc-extinguishing chamber can reduce the burning of the stationary contact assembly and the moving contact assembly by the opening arc.

[0016] Furthermore, the pull rod is made of insulating material. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the internal structure of a low-impact vacuum circuit breaker according to the present invention; Figure 2 This is a schematic diagram illustrating the opening and closing actions of a low-impact vacuum circuit breaker according to the present invention.

[0018] The attached diagram lists the components represented by each number as follows: 1. Stationary contact assembly; 2. Moving contact assembly; 3. Fixed cylinder; 31. Inclined surface; 4. Overtravel spring; 5. Pull rod; 51. Cavity; 6. Limiting block; 7. Elastic element; 71. Preload spring; 72. Mandrel; 721. Concave arc surface; 8. Ball bearing; 9. Arc extinguishing chamber. Detailed Implementation

[0019] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0020] like Figure 1 As shown, a low-impact vacuum circuit breaker includes: a fixed base, a stationary contact assembly 1, and a moving contact assembly 2, wherein the stationary contact assembly 1 is fixed on the fixed base; the moving contact assembly 2 is located above the stationary contact assembly 1; it also includes: a fixed cylinder 3, an overtravel spring 4, and a pull rod 5. The fixed cylinder 3 is located above the moving contact assembly 2 and its bottom end is fixed to the moving contact assembly 2; the bottom end of the fixed cylinder 3 is a closed end; the overtravel spring 4 is placed inside the fixed cylinder 3 and its bottom end is in contact with the closed end of the fixed cylinder 3; the pull rod 5 slides inside the fixed cylinder 3 and its bottom end is in contact with the top end of the overtravel spring 4, and its top end slides out of the top end of the fixed cylinder 3 so that after the pull rod 5 is pushed down by an external force, the moving contact assembly 2 is first pushed to contact the stationary contact assembly 1, and then the overtravel spring 4 is compressed.

[0021] In some embodiments, the fixed cylinder 3 is provided with a limiting block 6, an elastic member 7 and two balls 8. The inner hole of the fixed cylinder 3 is divided into an upper inner hole section and a lower inner hole section. The diameter of the upper inner hole section is smaller than that of the lower inner hole section, and the connection between the two sections is an inclined surface 31. The pull rod 5 slides in the upper inner hole section and is provided with a cavity 51 arranged along the axial direction of the pull rod 5. The side wall of the pull rod 5 is provided with a long strip sliding hole arranged along the axial direction of the pull rod 5. The two side walls of the pull rod 5 are provided with cavities, and the long strip sliding hole and the cavities are in communication with the cavity 51. The limiting block 6 is fixed on the fixed seat and slides through the long strip sliding hole to extend into the cavity 51. The two balls 8 are respectively arranged in the two cavities and can be clamped at the inclined surface 31. The elastic member 7 is arranged in the cavity 51 and the top end of the elastic member 7 can be in contact with the limiting block 6. The two side walls of the elastic member 7 are inwardly inclined inner concave arc surfaces 721 from the two ends of the shaft 72 to the middle part of the shaft 72. The two inner concave arc surfaces 721 are respectively in contact with the two balls 8. When an external force pulls the pull rod 5 upward, the two balls 8 are linked to overcome the inclined surface 31, so that the over-travel spring 4 in the compressed state returns to the initial state.

[0022] In some embodiments, the elastic member 7 includes a pre-tightening spring 71 and a shaft 72. The pre-tightening spring 71 is arranged in the cavity 51. The shaft 72 is arranged in the cavity 51 and the bottom end of the shaft 72 is in contact with the top end of the pre-tightening spring 71. The limiting block 6 can be in contact with the top end of the shaft 72. The two inner concave arc surfaces 721 are the two side walls of the shaft 72.

[0023] As shown in Figure 1 In some embodiments, the arc-extinguishing chamber 9 can also be included. The top end of the arc-extinguishing chamber 9 is provided with a top hole and the bottom end of the arc-extinguishing chamber 9 is provided with a bottom hole. The stationary contact assembly 1 is located in the arc-extinguishing chamber 9 and the bottom end of the stationary contact assembly 1 extends out of the bottom hole. The movable contact assembly 2 is located in the arc-extinguishing chamber 9 and the top end of the movable contact assembly 2 extends out of the top hole.

[0024] Specifically, the pull rod 5 is made of insulating material.

[0025] As shown in Figure 2 The opening process is described as follows: ①In the closing state, as shown in Figure 2 a, the two balls 8 are clamped at the inclined surface 31, the pull rod 5 is pressed downward, the over-travel spring 4 is compressed, and the fixed cylinder 3, the over-travel spring 4, the pull rod 5, the shaft 72, the pre-tightening spring 71 and the two balls 8 are in the self-locking state; ②In the opening process, as shown in Figure 2 b, the pull rod 5 is pulled upward by an external force. Since the fixed cylinder 3, the over-travel spring 4, the pull rod 5, the shaft 72, the pre-tightening spring 71 and the two balls 8 are in the self-locking state, the fixed cylinder 3, the over-travel spring 4, the pull rod 5, the shaft 72, the pre-tightening spring 71 and the two balls 8 do not change the relative position, and only the movable contact assembly 2 moves upward to separate from the stationary contact assembly 1; ③In the opening process, as shown in Figure 2As shown in FIG. 1c, the external force continues to pull the pull rod 5 upward, when the mandrel 72 contacts the limit block 6, the mandrel 72 no longer continues to move upward with the pull rod 5, starts to compress the pre-tightening spring 71, and the two balls 8 continue to move upward with the pull rod 5, over the inclined surface 31, so that the over-travel spring 4 loses the pressure of the mandrel 72, and restores to the natural state, releasing the over-travel.

[0026] As shown in FIG. 1a, the external force pulls the pull rod 5 upward to the predetermined position, and then stops pulling upward, at this time, because one side of the two balls 8 contacts the upper inner hole section and the other side respectively contacts the low position of the inner concave arc surface 721, it will extrude the mandrel 72 to compress the pre-tightening spring 71, so that the pull rod 5, the mandrel 72, the pre-tightening spring 71 and the two balls 8 are in the self-locking state. Figure 2 As shown in FIG. 1d, the closing process is described as follows: ③ The opening state, as shown in FIG. 1d, the external force pulls the pull rod 5 upward to the predetermined position, and then stops pulling upward, at this time, because one side of the two balls 8 contacts the upper inner hole section and the other side respectively contacts the low position of the inner concave arc surface 721, it will extrude the mandrel 72 to compress the pre-tightening spring 71, so that the pull rod 5, the mandrel 72, the pre-tightening spring 71 and the two balls 8 are in the self-locking state. Figure 2 As shown in FIG. 1d, the external force pulls the pull rod 5 upward to the predetermined position, and then stops pulling upward, at this time, because one side of the two balls 8 contacts the upper inner hole section and the other side respectively contacts the low position of the inner concave arc surface 721, it will extrude the mandrel 72 to compress the pre-tightening spring 71, so that the pull rod 5, the mandrel 72, the pre-tightening spring 71 and the two balls 8 are in the self-locking state. Figure 2 As shown in FIG. 1e, the external force pushes the pull rod 5 downward to move downward, at this time, because the limit block 6 is out of contact with the mandrel 72, the pull rod 5, the mandrel 72, the pre-tightening spring 71 and the two balls 8 are in the self-locking state, it will first contact the moving contact assembly 2 and the static contact assembly 1, and then compress the over-travel spring 4. Figure 2 As shown in FIG. 1e, the external force pushes the pull rod 5 downward to move downward, at this time, because the limit block 6 is out of contact with the mandrel 72, the pull rod 5, the mandrel 72, the pre-tightening spring 71 and the two balls 8 are in the self-locking state, it will first contact the moving contact assembly 2 and the static contact assembly 1, and then compress the over-travel spring 4.

[0027] The above is only the preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A low-impact vacuum circuit breaker, comprising: The fixed base, the stationary contact assembly (1), and the moving contact assembly (2) are provided, wherein the stationary contact assembly (1) is fixed on the fixed base; The moving contact assembly (2) is located above the stationary contact assembly (1); characterized in that it further includes: A fixed cylinder (3) is located above the moving contact assembly (2) and its bottom end is fixed to the moving contact assembly (2); The overtravel spring (4) has a closed end at the bottom of the fixed cylinder (3); the overtravel spring (4) is placed inside the fixed cylinder (3) and its bottom end is in contact with the closed end of the fixed cylinder (3); Pull rod (5), the pull rod (5) slides inside the fixed cylinder (3) and its bottom end contacts the top end of the overtravel spring (4), and its top end slides out of the top end of the fixed cylinder (3) so that after the pull rod (5) is pushed down by an external force, the moving contact assembly (2) is first pushed to contact the stationary contact assembly (1), and then the overtravel spring (4) is compressed.

2. The low-impact vacuum circuit breaker according to claim 1, characterized in that, It also includes a limiting block (6), an elastic element (7), and two balls (8). The inner hole of the fixed cylinder (3) is divided into an upper inner hole section and a lower inner hole section. The diameter of the upper inner hole section is smaller than that of the lower inner hole section, and the connection between the two is an inclined surface (31). The pull rod (5) slides in the upper inner hole section and has a cavity (51) arranged along its axial direction inside. Its side wall has a long sliding hole arranged along its axial direction, and both its side walls have accommodating holes. The long sliding hole and the accommodating holes are connected to the cavity (51). The limiting block (6) is fixed on the fixed seat and slides through the long sliding hole into the cavity (51). Each ball (8) is placed in one of the two holes and can be engaged with the inclined surface (31); the elastic element (7) is placed in the cavity (51) and its top end can contact the limiting block (6). The two sides of the elastic element (7) are concave arc surfaces (721) that slope inward from both ends of the spindle (72) to the middle of the spindle (72). The two concave arc surfaces (721) contact the two balls (8) respectively, so that after the external force pulls the pull rod (5) upward, the two balls (8) will move across the inclined surface (31) and the overtravel spring (4) in the compressed state will return to the initial state.

3. A low-impact vacuum circuit breaker according to claim 1, characterized in that, The elastic element (7) includes a preload spring (71) and a spindle (72). The preload spring (71) is placed inside the cavity (51). The spindle (72) is placed inside the cavity (51) and its bottom end contacts the top end of the preload spring (71). The limiting block (6) can contact the top end of the spindle (72). The two concave arc surfaces (721) are the two sides of the spindle (72).

4. A low-impact vacuum circuit breaker according to claim 1, characterized in that, It also includes an arc-extinguishing chamber (9), which has an ejector hole at its top and a bottom hole at its bottom; the stationary contact assembly (1) is located inside the arc-extinguishing chamber (9) and its bottom end protrudes through the bottom hole; the moving contact assembly (2) is located inside the arc-extinguishing chamber (9) and its top end slides out of the ejector hole.

5. A low-impact vacuum circuit breaker according to claim 1, characterized in that, The tie rod (5) is made of insulating material.

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