A current limiting automatic opening device

Abstract

The present invention discloses a current-limiting automatic opening device, comprising an opening half shaft, a double-blade assembly and an elastic element, wherein the double-blade assembly comprises two double-blade current-limiting unlocking pieces and a double blade, which act on each other through the elastic element. The double blade adopts an integrated structure, which reduces the cost and reduces the manufacturing and assembly processes. The elastic element contacts the double blade through a rotatable joint device composed of a circular groove arranged on the double blade and a round-headed conical boss matched with the circular groove, so that the elastic element will not be distorted during the compression process, and the position of the elastic element is prevented from being misplaced during the compression process. The head of the double blade in contact with the opening half shaft is a double-clamp design, which is conducive to reducing friction and is more conducive to rapid opening of the mechanism.

Description

Technical Field

[0001] The invention relates to the field of circuit breakers, and in particular to a current limiting automatic opening device. Background Art

[0002] The breaking capacity of a circuit breaker is an important parameter of the circuit breaker performance index. The breaking capacity depends largely on the breaking capacity of the tripping device. According to the breaking test, when a short circuit occurs in a circuit breaker, the current will instantly increase by more than 20 times the normal value, or even more, thus generating a strong additional electric force between the moving contact and the static contact. In this case, the circuit breaker should be quickly tripped by the tripping device, otherwise it will easily damage the internal mechanism of the circuit breaker.

[0003] Chinese patent CN99111495.7 discloses a circuit breaker and a current limiting automatic tripping device arranged in the circuit breaker. The current limiting automatic tripping device mainly includes an opening pawl, which is mainly composed of a pair of supporting flanges, a guide plate fixed to the supporting flanges, a limiting lever hinged to the supporting flanges, and two compression springs installed between the guide plate and the limiting lever. The end of the limiting lever is provided with a nose that matches the latch. When the latch is unlocked with the nose at the end of the limiting lever, the circuit breaker can be quickly tripped. The length of the unlocking time between the latch and the nose is controlled by the degree of compression of the two compression springs.

[0004] However, the automatic opening device in the above system has certain disadvantages: during the opening process, the limiting lever rotates around the rotating axis instead of moving vertically up and down, which causes the spring to not be compressed linearly during the compression process. Due to the offset of the spring position, long-term operation can easily cause functional failure, thereby reducing the breaking capacity of the circuit breaker. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a current limiting automatic opening device in order to overcome the deficiencies of the above-mentioned prior art.

[0006] Specifically, the technical solution adopted in the present invention is as follows: a current limiting automatic opening device, comprising a closing half-shaft, a double-knife assembly and an elastic element; the double-knife assembly comprises two double-knife current limiting unlocking pieces and double blades, the double blades are rotatably installed between the two double-knife current limiting unlocking pieces through the double-knife assembly rotating shaft, and are limited by the double-blade limiting shaft; the double-knife current limiting unlocking piece and the double blades act on each other through the elastic element, and the elastic element contacts the double blades through a rotatable joint device.

[0007] Furthermore, the double blades are of an integrated structure.

[0008] Furthermore, the elastic element is a current limiting spring.

[0009] Furthermore, the rotatable joint device is a circular groove arranged on the double blades and a round-headed conical boss matching the circular groove.

[0010] Furthermore, a current limiting spring fixing device is provided on the double-pole current limiting unlocking piece.

[0011] Furthermore, the current limiting spring fixing device is a current limiting spring mounting seat.

[0012] Furthermore, the current limiting spring mounting seat is provided with a cylindrical hole, one end of the current limiting spring is mounted in the cylindrical hole, and the other end is mounted on the round-headed conical boss.

[0013] Furthermore, the current limiting spring, the circular groove, the round-headed conical boss and the current limiting spring mounting seat are each a pair of two.

[0014] Furthermore, the heads of the double blades contacting the opening half shaft are double clamping heads.

[0015] Correspondingly, a circuit breaker adopts the above-mentioned current limiting automatic opening device.

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

[0017] 1. The double blades adopt an integrated structure, which reduces costs and reduces manufacturing and assembly processes.

[0018] 2. The elastic element contacts the double blades by adopting a joint device, so that the elastic element will not be distorted during the compression process, thereby preventing the elastic element from being misplaced during the compression process.

[0019] 3. The head where the double blade contacts the opening half shaft is a double clamp, which is divided into two parts, which is beneficial to reduce friction and is more conducive to rapid opening of the mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an exploded view of the double-blade assembly of the present invention.

[0021] Figure 2 It is a schematic diagram of the double blade of the present invention.

[0022] Figure 3 This is another angle schematic diagram of the double blade of the present invention.

[0023] Figure 4 It is a schematic diagram of the round-headed conical boss of the present invention.

[0024] Figure 5 It is a top view of the current limiting spring mounting seat of the present invention.

[0025] Figure 6 It is a side cross-sectional view of the current limiting spring mounting seat of the present invention.

[0026] Figure 7 It is a three-dimensional diagram of the current limiting spring mounting seat of the present invention.

[0027] Figure 8 It is a schematic diagram of the closing state of the opening device of the present invention.

[0028] Fig. 9 It is a schematic diagram of the opening state of the opening device of the present invention.

[0029] Numbers in the figure: 1—disconnecting half-axis; 2—double-blade current limiting unlocking piece; 3—double blade; 4—double blade limiting shaft; 5—double blade assembly rotating shaft; 6—current limiting spring; 7—circular groove; 8—round-head conical boss; 9—current limiting spring mounting seat; 10—double clamp. DETAILED DESCRIPTION

[0030] In order to facilitate those skilled in the art to understand and implement the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0031] One embodiment of the present invention is a current limiting automatic tripping device, which is used in a matching circuit breaker to achieve rapid tripping of the circuit breaker.

[0032] like Figure 1 , 8 As shown in Figures 9 and 10, the current limiting automatic opening device of this embodiment has an opening half shaft 1, a double-blade current limiting unlocking piece 2, a double blade 3, etc. Among them, the double-blade current limiting unlocking piece 2 has two pieces, and the double blade 3 is an integrated structure, which can reduce costs and manufacturing and assembly processes. It is installed on the two double-blade current limiting unlocking pieces 2 through the double-blade assembly shaft 5, thereby forming a double-blade assembly. The double blade 3 can rotate in the two double-blade current limiting unlocking pieces 2 by means of the double-blade assembly shaft 5, but is limited by the double blade limit shaft 4 installed between the two double-blade current limiting unlocking pieces 2.

[0033] A current limiting spring 6 is also provided between the two double-pole current limiting unlocking pieces 2. In this embodiment, there are two current limiting springs 6. The current limiting spring mounting seat 9 is installed between the two double-pole current limiting unlocking pieces 2, such as Figure 5 , 6 As shown in FIG. 7 , it is a rectangular parallelepiped with two cylindrical holes in the seat. The bottom end of each current limiting spring 6 is installed in each cylindrical hole of the current limiting spring mounting seat 9, and the other end is sleeved under a round-headed conical boss 8. The shape of the round-headed conical boss 8 is as shown in FIG. Figure 4 Correspondingly, the double blade 3 is provided with two circular grooves 7, which match the round-headed conical boss 8, as shown in FIG. Figure 2In this way, when the current limiting spring 6 is compressed, the round head portion of the round-headed conical boss 8 can rotate in the circular groove 7, thereby preventing the current limiting spring 6 from being misplaced during the compression process, so that the current limiting spring 6 will not be compressed during the compression process.

[0034] like Figure 3 As shown, the head of the double blade 3 in contact with the opening half shaft 1 is divided into two parts, forming a double clamp 10. This is conducive to reducing friction and is more conducive to rapid opening of the mechanism.

[0035] like Figure 6 As shown, when there is no short-circuit fault in the line where the circuit breaker is located, the mechanism is closed. At this time, under the action of the current limiting spring 6, the double clamp 10 of the double blade 3 contacts the opening half shaft 1 and is in a locked state. If a short-circuit fault occurs in the line, a short-circuit current is generated in the line. Under the action of the short-circuit current, a strong electric repulsive force is generated between the moving and static contacts of the circuit breaker, and the force is finally transmitted to the current limiting automatic opening device. At this time, this additional force will compress the current limiting spring 6. When the current limiting spring 6 is compressed to a certain state, it will drive the double-blade current limiting unlocking piece 2 to rotate, and cause the opening half shaft 1 and the double clamp 10 of the double blade 3 to unlock. At this time, the circuit breaker can be quickly opened, thereby disconnecting the short-circuit fault current.

[0036] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the concept of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A current limiting automatic opening device, comprising an opening half shaft (1), a double knife assembly and an elastic element; the double knife assembly comprises two double knife current limiting unlocking pieces (2) and a double blade (3); the double blade (3) is rotatably mounted between the two double knife current limiting unlocking pieces (2) through a double knife assembly rotating shaft (5) and is limited by a double blade limiting shaft (4); the double knife current limiting unlocking piece (2) and the double blade (3) act on each other through the elastic element, characterized in that: The elastic element contacts the double blade (3) via a rotatable joint device; the elastic element is a current limiting spring (6); the rotatable joint device is a circular groove (7) arranged on the double blade (3) and a round-headed conical boss (8) matching the circular groove (7); a current limiting spring fixing device is provided on the double-blade current limiting unlocking piece (2); the current limiting spring fixing device is a current limiting spring mounting seat (9); the current limiting spring mounting seat (9) is provided with a cylindrical hole, one end of the current limiting spring (6) is mounted in the cylindrical hole, and the other end is mounted on the round-headed conical boss (8).

2. A current limiting automatic opening device according to claim 1, characterized in that: The double blades (3) are of an integrated structure.

3. A current limiting automatic opening device according to claim 1, characterized in that: The current limiting spring (6), the circular groove (7), the round-headed conical boss (8) and the current limiting spring mounting seat (9) are each a pair of two.

4. A current limiting automatic opening device according to any one of claims 1 to 3, characterized in that: The head of the double blade (3) in contact with the opening half shaft (1) is a double clamping head (10).

5. A circuit breaker, characterized in that: A current limiting automatic opening device as described in any one of claims 1 to 4 is adopted.

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