A current limiting automatic opening device

Abstract

The present invention discloses a current-limiting automatic tripping device, which belongs to the technical field of circuit breaker operating mechanisms. The present invention mainly includes a rotating shaft, a tripping half shaft, a lower connecting rod and a tripping assembly. When a short circuit occurs in the circuit breaker, the main shaft, the lower connecting rod and the tripping assembly are linked in sequence to perform current limiting protection on the circuit breaker. The characteristics are as follows: the tripping assembly includes a side plate, a rotating shaft and an elastic member; the side plate is mounted on the main structure of the circuit breaker through the rotating shaft; a rolling member is provided on the side plate, one end of the elastic member abuts against the rolling member, and the other end is fixed to the side plate. The present invention utilizes the electric repulsive force generated and transmitted to the lower connecting rod of the circuit breaker when the circuit breaker is short-circuited, so that the lower connecting rod pushes the bearing of the automatic tripping device to move, and the tripping is completed by separating the lower connecting rod from the bearing. The number of times the electric power is transmitted is small, and a faster and more accurate tripping can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of circuit breaker operating mechanisms, and in particular relates to a current limiting automatic opening device for a circuit breaker. Background Art

[0002] A circuit breaker is a switch device that can close, carry and disconnect current under normal circuit conditions and close, carry and disconnect current under abnormal circuit conditions within a specified time. When the circuit is short-circuited, the huge current will damage the circuit breaker, so it is necessary to set a current limiting automatic opening device to ensure that the circuit can be disconnected in time to protect the circuit breaker from damage.

[0003] Chinese patent application 99111495.7 discloses a single-pole or multi-pole circuit breaker, including a moving contact device, having a bracket that moves between an open position and a closed position and one or more contact fingers that move between a contact position and a retracted position. The electromagnetic compensation device keeps the contact fingers in contact with other contact devices. The electromagnetic limiting device drives the contact fingers to the retracted position. When the current intensity flowing into the contact device is less than the limit threshold, the contact fingers remain in contact with other contact devices. When it is higher than the above threshold, the contact fingers are driven to the retracted position. When the current intensity flowing into the moving contact device reaches the limit threshold, the resultant force applied by the bracket to the moving connection device is less than the high-speed opening threshold. However, in this invention, the short-circuit current has to undergo multiple conductions before it can reach the operating mechanism, and there are certain deficiencies in the accuracy and speed of the opening. Summary of the invention

[0004] The purpose of the present invention is to provide a novel current-limiting automatic opening device to address the problem of insufficient opening accuracy in the prior art, which can achieve automatic opening and current limiting more accurately.

[0005] Specifically, the present invention is implemented by adopting the following technical solutions:

[0006] A current-limiting automatic tripping device comprises a rotating shaft, a tripping half shaft, a lower connecting rod and a tripping assembly. When a short circuit occurs in a circuit breaker, the main shaft, the lower connecting rod and the tripping assembly are linked in sequence to perform current-limiting protection on the circuit breaker. The tripping assembly comprises a side plate, a rotating shaft and an elastic member; the side plate is mounted on a main structure of the circuit breaker through the rotating shaft; a rolling member is arranged on the side plate, one end of the elastic member abuts against the rolling member, and the other end is fixed to the side plate.

[0007] Furthermore, the lower connecting rod is provided with a concave curved surface which can cooperate with the rolling element. In the closed state, the rolling element abuts against the concave portion of the curved surface. When a short circuit occurs in the circuit breaker, the rotation of the lower connecting rod causes the rolling element to gradually roll out along the concave curved surface, thereby completing the opening of the circuit.

[0008] Furthermore, a bearing slideway is provided on the side plate, and the center axis of the rolling element is limited in the bearing slideway and can move along the bearing slideway.

[0009] Furthermore, the length extension direction of the bearing slideway is consistent with the force direction of the lower connecting rod on the needle bearing during the circuit breaker opening process.

[0010] Furthermore, a slide plate is provided at one end of the elastic member close to the rolling member, the slide plate is provided with a concave curved surface, and the concave curved surface abuts against the rolling member; and / or a fixing plate fixed to the side plate is provided at one end of the elastic member away from the rolling member.

[0011] Furthermore, the skateboard and / or the fixed plate are provided with a boss; when the skateboard is provided with a boss, the side plate is also provided with a skateboard slide, and the boss is limited in the skateboard slide and can move along the skateboard slide; when the fixed plate is provided with a boss, the side plate is also provided with a fixed plate mounting hole, and the boss is installed in the fixed plate mounting hole.

[0012] Furthermore, the rotating shaft is provided with a clearance groove, and the elastic member is installed through the clearance groove.

[0013] Furthermore, a rotating shaft reinforcement piece is provided at the rotating shaft position corresponding to the giving way groove.

[0014] Furthermore, the axial dimension of the rotating shaft reinforcement member along the rotating shaft is larger than the axial dimension of the clearance groove, and the radial dimension is larger than the radius of the rotating shaft.

[0015] Furthermore, the side panel is approximately parallelogram-shaped.

[0016] The beneficial effects of the present invention are as follows:

[0017] The present invention utilizes the electric repulsive force generated when the circuit breaker is short-circuited and transmitted to the lower connecting rod of the circuit breaker, so that the lower connecting rod pushes the bearing of the automatic opening device to move, and the opening is completed by separating the lower connecting rod from the bearing. The number of times the electric force is transmitted is small, and faster and more accurate opening can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the main circuit closing state of the circuit breaker.

[0019] Figure 2 It is a schematic diagram of the critical state of current limiting and opening of the circuit breaker.

[0020] Figure 3 It is a schematic diagram of the structural assembly of a specific embodiment of the present invention.

[0021] Figure 4 It is a schematic structural diagram of a rotating shaft in a specific embodiment of the present invention.

[0022] Figure 5 It is a structural orthographic projection diagram of a specific embodiment of the present invention.

[0023] Numbers in the figure: 1-moving contact, 2-static contact, 3-lower connecting rod, 4-automatic opening device, 5-needle bearing, 6-side plate, 7-rivet column, 8-rotating shaft, 9-compression spring slide plate slide, 10-needle bearing slide, 11-rotating shaft mounting hole, 12-compression spring fixing plate, 13-compression spring slide plate, 14-compression spring, 15-riveting hole, 16-compression spring fixing plate mounting hole, 17-compression spring clearance groove, 18-rotating shaft reinforcement, 19-side plate end, 20-side plate tail, 21-lower connecting rod curved surface, 22-opening half shaft, 23-spring, 24-circuit breaker bracket, 25-mounting shaft, 26-boss, 27-limiting column, mounting column. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with embodiments and with reference to the accompanying drawings. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0025] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0027] Embodiment 1:

[0028] First, regarding the opening working principle of this embodiment. For the specific working state of the current limiting automatic opening device in the circuit breaker, refer to Figure 1 and Figure 2 , Figure 1It is a schematic diagram of the circuit breaker in the closed state. When the main circuit of the circuit breaker is closed, the concave surface 21 at the top of the lower connecting rod 3 abuts against the outer ring of the needle bearing 5, and the end 19 of the side plate abuts against the opening half shaft 22. When a short circuit occurs in the circuit breaker, the short circuit current will generate a strong electric force between the moving contact 1 and the static contact 2. The electric force acts on the circuit breaker mechanism and is then transmitted to the lower connecting rod 3. The linkage relationship between the other components of the circuit breaker and the lower connecting rod 3 belongs to the scope of the prior art (see Chinese patent with authorization number CN101373686B), which will not be repeated here. The electric force will push the lower connecting rod 3 to rotate clockwise around its mounting axis 25 ( Figure 1 The curved surface 21 at the top of the lower connecting rod 3 pushes the needle bearing 5 on the automatic opening device 4 along the needle bearing slideway 10 (see Figure 3 ) moves upward, and the lower connecting rod 3 moves to Figure 2 The position shown is in a critical state, after which the lower connecting rod 3 continues to rotate clockwise and separates from the needle bearing 5, thereby completing the opening action.

[0029] Next, the specific structure of this embodiment is described. Figures 3 to 5 1 is a schematic diagram of the specific structure of the automatic opening device 4. The automatic opening device 4 mainly includes a needle bearing 5, two side plates 6, a rotating shaft 8 and a compression spring 14. The two side plates 6 have the same structure. Figure 1 and Figure 2 As shown, the side plate 6 is generally parallelogram-shaped and is provided with a side plate end 19 and a side plate tail 20. The side plate end 19 is in contact with the circuit breaker opening half shaft 22; the side plate tail 20 is provided with a spring 23 connected to the circuit breaker bracket 24. Two rivet holes 15 are provided at the middle position near the upper edge of the side plate 6 and the side plate tail 20, which are riveted together by rivet columns 7. One end of the spring 23 is connected to the circuit breaker bracket 24, and the other end is provided on the rivet column 7 between the side plate tail 20. Figure 3 As shown, a shaft mounting hole 11 is provided near the lower edge of the side plate 6 and near the side plate tail 20. The shaft 8 passes through the shaft mounting hole 11 of the two side plates 6 and is mounted on the circuit breaker bracket 24. The specific structure of the shaft 8 is as follows Figure 4As shown, a section of semicircular cylinder is cut off from the middle of the rotating shaft 8 to form a compression spring clearance groove 17, and the length of the cut semicircular cylinder is slightly larger than the outer diameter of the compression spring 14. In order to ensure the strength of the rotating shaft 8, a rotating shaft reinforcement 18 is added to the side of the rotating shaft 8 where the compression spring clearance groove 17 is not provided. The rotating shaft reinforcement 18 is in a semicircular arc shape and is close to the side of the rotating shaft 8, and the width of the rotating shaft reinforcement 18 along the central axis of the rotating shaft 8 is greater than the distance between the two side plates 6. Therefore, the rotating shaft mounting hole 11 on the side plate 6 is matched with the shape of the middle part of the rotating shaft 8, and it is a shape of two semicircles with different radii concentrically spliced ​​together, wherein the smaller semicircle radius is equal to the outer diameter of the rotating shaft 8, and the larger semicircle radius is equal to the outer diameter of the rotating shaft reinforcement 18. A waist-shaped through hole, a needle roller bearing slideway 10, is provided on the side plate 6 near the lower edge and near the end 19 of the side plate, and a waist-shaped compression spring slideway 9 is provided on each side of the needle roller bearing slideway 10. The long sides of the needle bearing slide 10 and the compression spring slide 9 are parallel to each other, and are parallel to the direction of force applied by the lower connecting rod 3 to the needle bearing 5 in the aforementioned working principle. A needle bearing 5 is installed in the middle of the two side plates 6, and the two ends of the central axis of the needle bearing 5 are respectively inserted into the needle bearing slide 10 on each side. Two compression springs 14 are provided above the needle bearing 5 and along the direction of the needle bearing slide 10. The positions of the two compression springs 14 are defined by the compression spring slide 13 and the compression spring fixing plate 12. The compression spring 14 close to the rotating shaft 8 passes through the compression spring clearance groove 17 of the rotating shaft 8, and the generatrix of the compression spring 14 is parallel to the bottom plane of the compression spring clearance groove 17. The two are close but not in contact to prevent increased friction. The compression spring slide 13 and the compression spring fixing plate 12 have the same structure. As Figure 5, the compression spring slide plate 13 and the compression spring fixing plate 12 are each provided with two conical or truncated cone-shaped bosses 26 on the side close to the compression spring, and the two ends of the two compression springs 14 are sleeved on the outside of the bosses 26. The compression spring slide plate 13 is provided with a concave arc surface on the side away from the compression spring 14, which cooperates with the side of the needle bearing 5 and abuts against the side of the needle bearing 5. The side of the compression spring fixing plate 12 away from the compression spring 14 may be provided with an arc surface or not. The compression spring slide plate 13 is perpendicular to the two sides of the side plate 6, and each extends a section of limit column 27 outward along the side line, which is respectively inserted into the corresponding compression spring slide slideway 9. Similarly, the compression spring fixing plate 12 is perpendicular to the two sides of the side plate 6, and each extends a section of mounting column 28 outward along the side line, and compression spring fixing plate mounting holes 16 are provided at the corresponding positions of the two side plates 6. The mounting columns 28 of the compression spring fixing plate 12 are inserted into the corresponding compression spring fixing plate mounting holes 16 for fixing. The end of the needle roller bearing slideway 10 away from the compression spring 14 is farther than the end of the compression spring slideway 9 away from the compression spring 14, ensuring that when the central axis of the needle roller bearing 5 is located at this end in the closed state, the compression spring slideway 13 abuts against the needle roller bearing 5, and the limit column 27 is also just located at the end of the compression spring slideway 9 away from the compression spring 14, and the compression spring 14 is in a compressed state. The length of the needle roller bearing slideway 10 and the compression spring slideway 9 is greater than the distance that the lower connecting rod 3 pushes the rolling bearing 5 to move during the opening process.

[0030] Although the present invention has been disclosed as above with preferred embodiments, the embodiments are not intended to limit the present invention. Any equivalent changes or modifications made without departing from the spirit and scope of the present invention also belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the content defined by the claims of this application.

Claims

1. A current limiting automatic tripping device, comprising a rotating shaft, a tripping half shaft, a lower connecting rod and a tripping assembly. When a short circuit occurs in the circuit breaker, the rotating shaft, the lower connecting rod and the tripping assembly are linked in sequence to perform current limiting protection on the circuit breaker, characterized in that: The opening switch assembly includes a side plate, a rotating shaft and an elastic member; the side plate is installed on the main structure of the circuit breaker through the rotating shaft, and when the main circuit of the circuit breaker is closed, the end of the side plate abuts against the opening switch half-shaft; a rolling member is provided on the side plate, one end of the elastic member abuts against the rolling member, and the other end is fixed to the side plate; a concave curved surface that can cooperate with the rolling member is provided on the lower connecting rod, and in the closed state, the rolling member abuts against the concave part of the curved surface, and when a short circuit occurs in the circuit breaker, the rotation of the lower connecting rod causes the rolling member to gradually roll out along the concave curved surface, thereby completing the opening switch.

2. The current limiting automatic opening device according to claim 1 is characterized in that: The side plate is provided with a bearing slideway, and the center axis of the rolling element is limited in the bearing slideway and can move along the bearing slideway.

3. The current limiting automatic opening device according to claim 2 is characterized in that: The length extension direction of the bearing slideway is consistent with the force direction of the lower connecting rod on the needle bearing during the circuit breaker opening process.

4. The current limiting automatic opening device according to claim 1 is characterized in that: A slide plate is arranged at one end of the elastic member close to the rolling member, and a concave surface is arranged on the slide plate, and the concave surface abuts against the rolling member; and / or a fixing plate fixed to the side plate is arranged at one end of the elastic member away from the rolling member.

5. The current limiting automatic opening device according to claim 4 is characterized in that: The skateboard and / or the fixed plate are provided with a boss; when the skateboard is provided with a boss, the side plate is also provided with a skateboard slide, and the boss is limited in the skateboard slide and can move along the skateboard slide; when the fixed plate is provided with a boss, the side plate is also provided with a fixed plate mounting hole, and the boss is installed in the fixed plate mounting hole.

6. The current limiting automatic opening device according to claim 1 is characterized in that: The rotating shaft is provided with a clearance groove, and the elastic member is installed through the clearance groove.

7. The current limiting automatic opening device according to claim 6, characterized in that: A rotating shaft reinforcement piece is also provided at the rotating shaft position corresponding to the giving way groove.

8. The current limiting automatic opening device according to claim 7, characterized in that: The axial dimension of the rotating shaft reinforcement member along the rotating shaft is larger than the axial dimension of the clearance groove, and the radial dimension is larger than the radius of the rotating shaft.

9. The current limiting automatic opening device according to claim 1, characterized in that: The side plate is approximately parallelogram-shaped.

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