Tripping mechanism and circuit breaker

Abstract

The utility model discloses a tripping mechanism which comprises a support, a lock catch, a jump pin and a movable contact piece, the lock catch is pivoted to the middle of the support, the lock catch is provided with a kidney-shaped groove below the support, the jump pin is pivoted to the upper end of the support and matched with the lock catch in a hasp mode, the movable contact piece is pivoted to the lower end of the support, the movable contact piece is provided with a protruding block inserted into the kidney-shaped groove, and the protruding block can slide in the kidney-shaped groove. And when the movable contact is repelled by the electric repulsive force, the convex block drives the lock catch to rotate at the same time for tripping. The utility model also discloses a circuit breaker with the tripping mechanism. According to the utility model, through the cooperation of the convex block and the waist-shaped groove, when the movable contact member is repelled by an electric repulsive force, the lock catch can rotate at the same time for tripping, so that the phenomenon that the movable contact member falls back after being repelled by a short-circuit current is effectively prevented, and the breaking capacity is further improved.

Description

Technical Field

[0001] This utility model relates to the field of circuit breaker technology, and in particular to a tripping mechanism and a circuit breaker. Background Technology

[0002] Circuit breakers are commonly used switching devices in power systems. They are capable of carrying, closing, and disconnecting current in a circuit during normal operation, and can also carry, close, and interrupt abnormal currents, such as short-circuit currents, within a specified time. Circuit breakers mainly consist of a casing, operating mechanism, contact system, arc-extinguishing system, and short-circuit protection. Under normal operating conditions, the circuit breaker's contact system is closed, and the circuit is connected. When an overload or short circuit occurs in the circuit, the short-circuit protection section quickly disconnects the circuit to protect equipment and personnel. Simultaneously, the arc-extinguishing system activates to ensure that the electric arc is quickly extinguished.

[0003] The breaking capacity of a circuit breaker directly determines the safety and stability of circuits and equipment. Existing short-circuit protection is usually achieved through thermal trip units or electromagnetic trip units. There is a certain reaction time from the generation of short-circuit current to the tripping of the operating mechanism. If the fault current cannot be cut off in time, the fault range will expand.

[0004] To improve breaking speed, some circuit breakers utilize the electrostatic repulsion force generated by the fault current to directly separate the moving and stationary contacts to cut off the circuit. However, if the moving contact is repelled before the short-circuit protection can activate, the moving contact may fall back after being repelled by the short-circuit current, causing the system to close again, resulting in arc reignition or even contact burnout, severely affecting the circuit breaker's breaking capacity. Utility Model Content

[0005] The purpose of this utility model is to provide a tripping mechanism and a circuit breaker to improve the breaking capacity of the circuit breaker.

[0006] To achieve the above objectives, the technical solution proposed by this utility model is as follows:

[0007] A release mechanism includes a bracket, a latch, a jump catch, and a movable contact. The latch is pivotally connected to the middle of the bracket and has an oblong groove at the bottom of the bracket. The jump catch is pivotally connected to the upper end of the bracket and engages with the latch. The movable contact is pivotally connected to the lower end of the bracket and has a protrusion that inserts into the oblong groove. The protrusion can slide within the oblong groove. When the movable contact is repelled by an electric repulsive force, the protrusion drives the latch to rotate simultaneously, thus releasing the latch.

[0008] Preferably, the latch includes a first front side plate and a first rear side plate disposed opposite to each other, and a first connecting plate connecting the first front side plate and the first rear side plate. The first front side plate and the first rear side plate are coaxially provided with a first intermediate shaft hole. The first front side plate is provided with the waist-shaped groove, which is located below the first intermediate shaft hole. The bracket is disposed between the first front side plate and the first rear side plate. The bracket includes a second front side plate and a second rear side plate disposed opposite to each other, and a second connecting plate connecting the second front side plate and the second rear side plate. The second front side plate and the second rear side plate are coaxially provided with a second upper shaft hole, a second intermediate shaft hole and a second lower shaft hole from top to bottom. The second upper shaft hole is located on the side of the first intermediate shaft hole away from the latch. The bracket is pivotally connected to the latch through an intermediate rotating shaft passing through the first intermediate shaft hole and the second intermediate shaft hole. The intermediate rotating shaft is used to pivotally connect the tripping mechanism to the housing of the circuit breaker. The trip latch has a first upper shaft hole at one end and a locking latch at the other end for connection to the circuit breaker's operating handle. The trip latch is pivotally connected to the bracket via an upper rotating shaft passing through the first and second upper shaft holes. The movable contact is located between the second front and second rear side plates. The movable contact has a first lower shaft hole located above the protrusion. The movable contact is pivotally connected to the bracket via a lower rotating shaft passing through the first and second lower shaft holes.

[0009] Preferably, the upper end of the moving contact has a hook portion located between the first connecting plate and the intermediate rotating shaft, the hook portion being used for limiting engagement with the intermediate rotating shaft.

[0010] Preferably, the outer surface of the first front side plate is formed with a convex ring surrounding the first intermediate shaft hole, and a torsion spring is sleeved on the convex ring. The first front side plate is provided with a first locking block below the first intermediate shaft hole, and one end of the torsion spring is locked with the first locking block. The second front side plate is provided with a second locking block above the second intermediate shaft hole, and the other end of the torsion spring is locked with the second locking block.

[0011] Preferably, the movable contact includes a movable contact arm pivotally connected to the bracket and a movable contact disposed at the lower end of the movable contact arm, wherein the length of the movable contact is 4-5 mm.

[0012] A circuit breaker, characterized in that it has the tripping mechanism of this utility model.

[0013] Preferably, the stationary contact includes a stationary contact arm and a stationary contact connected to the stationary contact arm. The portion of the moving contact arm that connects to the moving contact and the portion of the stationary contact arm that connects to the stationary contact are configured to be parallel and aligned when the circuit is closed, and both are configured to have a length of 6 to 12 mm.

[0014] Preferably, the length of the stationary contact is 4-5 mm.

[0015] The beneficial effects of this utility model by adopting the above technical solution are as follows: This utility model has a waist-shaped groove on the latch of the tripping mechanism and a protrusion on the moving contact. By the cooperation of the protrusion and the waist-shaped groove, when the moving contact is pushed open by the electric repulsive force, the latch can rotate at the same time to trip, so as to effectively prevent the moving contact from falling back after being pushed open by the short circuit current, thereby improving the breaking capacity. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the internal structure of the circuit breaker in this embodiment.

[0017] Figure 2 for Figure 1 A front view diagram of the tripping mechanism.

[0018] Figure 3 for Figure 2 An exploded view of the tripping mechanism.

[0019] Figure 4 for Figure 1 A schematic diagram showing the tripping state of the tripping mechanism, operating handle, electromagnetic trip unit, and stationary contact.

[0020] Figure 5 for Figure 1 A schematic diagram showing the closed state of the tripping mechanism, operating handle, electromagnetic trip unit, and stationary contact.

[0021] Wherein: 1. Tripping mechanism; 11. Bracket; 111. Second front side plate; 112. Second rear side plate; 113. Second connecting plate; 114. Second upper shaft hole; 115. Second intermediate shaft hole; 116. Second lower shaft hole; 117. Second locking block; 12. Lock; 121. Waist-shaped groove; 122. First front side plate; 123. First rear side plate; 124. First connecting plate; 125. First intermediate shaft hole; 126. Protruding ring; 127. First locking block 1. Block; 13. Jumper; 131. First upper shaft hole; 14. Moving contact; 141. Protrusion; 142. First lower shaft hole; 143. Hook; 144. Moving contact arm; 145. Moving contact; 15. Upper rotating shaft; 16. Middle rotating shaft; 17. Lower rotating shaft; 18. Torsion spring; 2. Housing; 3. Operating handle; 4. Arc extinguishing system; 5. Electromagnetic trip unit; 6. Thermal trip unit; 7. Stationary contact; 71. Stationary contact arm; 72. Stationary contact; 8. Terminal block. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] like Figure 1As shown, this embodiment provides a circuit breaker, which includes a housing 2, an operating handle 3, an arc extinguishing system 4, an electromagnetic trip unit 5, a thermal trip unit 6, a stationary contact 7, a terminal block 8, and a tripping mechanism 1 installed within the housing 2. The positions and transmission relationships of the above components are common knowledge in the art and will not be described in detail here. In other embodiments of this utility model, the circuit breaker may also be other types of circuit breakers.

[0024] Combination Figures 2-5 The release mechanism 1 of this embodiment includes a bracket 11, a latch 12, a snap fastener 13, and a movable contact 14. The latch 12 is pivotally connected to the middle of the bracket 11 and has a waist-shaped groove 121 at the bottom of the bracket 11. The snap fastener 13 is pivotally connected to the upper end of the bracket 11 and engages with the latch 12. The movable contact 14 is pivotally connected to the lower end of the bracket 11 and has a protrusion 141 that inserts into the waist-shaped groove 121. The protrusion 141 can slide within the waist-shaped groove 121.

[0025] Reference Figure 4 When the circuit breaker is in the open state, the protrusion 141 is located at the left end of the slot 121. During the process of switching the circuit breaker from the open state to the closed state, the protrusion 141 moves from the left end to the right end of the slot 121, as follows: Figure 5 As shown. In the closed state, when the moving contact 14 is repelled by the electric repulsive force, the protrusion 141 drives the latch 12 to rotate simultaneously to release the latch, thereby effectively preventing the moving contact 14 from falling back after being repelled by the short-circuit current, thus improving the breaking capacity and current limiting capacity.

[0026] Combination Figure 3 Specifically, the latch 12 in this embodiment includes a first front side plate 122 and a first rear side plate 123 disposed opposite to each other, and a first connecting plate 124 connecting the first front side plate 122 and the first rear side plate 123. The first front side plate 122 and the first rear side plate 123 are coaxially provided with a first intermediate shaft hole 125, and an oblong groove 121 is provided on the first front side plate 122, and the oblong groove 121 is located below the first intermediate shaft hole 125.

[0027] In this embodiment, the bracket 11 is disposed between the first front side plate 122 and the first rear side plate 123. It includes a second front side plate 111 and a second rear side plate 112 disposed opposite to each other, and a second connecting plate 113 connecting the second front side plate 111 and the second rear side plate 112. The second front side plate 111 and the second rear side plate 112 are coaxially provided with a second upper shaft hole 114, a second intermediate shaft hole 115 and a second lower shaft hole 116 from top to bottom. The second upper shaft hole 114 is located on the side of the first intermediate shaft hole 125 away from the latch 12. The bracket 11 is pivotally connected to the latch 12 through an intermediate rotating shaft 16 passing through the first intermediate shaft hole 125 and the second intermediate shaft hole 115. The intermediate rotating shaft 16 is used to pivotally connect the tripping mechanism 1 inside the circuit breaker housing 2, so that the latch 12 mechanism can rotate relative to the housing 2 around the intermediate rotating shaft 16.

[0028] In this embodiment, one end of the jump buckle 13 is provided with a first upper shaft hole 131, and the other end of the jump buckle 13 is engaged with the lock buckle 12 and used to connect with the operating handle 3 of the circuit breaker (such as through a connecting rod to the operating handle 3 for transmission). The jump buckle 13 is pivotally connected to the bracket 11 through an upper rotating shaft 15 passing through the first upper shaft hole 131 and the second upper shaft hole 114.

[0029] In this embodiment, the movable contact 14 is disposed between the second front side plate 111 and the second rear side plate 112. The movable contact 14 has a first lower shaft hole 142 located above the protrusion 141. The movable contact 14 is pivotally connected to the bracket 11 through a lower rotating shaft 17 passing through the first lower shaft hole 142 and the second lower shaft hole 116. The upper end of the movable contact 14 has a hook portion 143 located between the first connecting plate 124 and the intermediate rotating shaft 16. The hook portion 143 is used to limit the rotation angle of the movable contact 14 by engaging with the intermediate rotating shaft 16.

[0030] This embodiment also includes a torsion spring 18 to assist in the reset of the latch 12, which can improve the sensitivity of the latch 12's action. To facilitate the assembly of the torsion spring 18, this embodiment forms a convex ring 126 surrounding the first intermediate shaft hole 125 on the outer surface of the first front side plate 122, and the torsion spring 18 is sleeved on the convex ring 126. The first front side plate 122 has a first locking block 127 below the first intermediate shaft hole 125, and one end of the torsion spring 18 is locked with the first locking block 127. The second front side plate 111 has a second locking block 117 above the second intermediate shaft hole 115, and the other end of the torsion spring 18 is locked with the second locking block 117.

[0031] Combination Figure 4 and Figure 5In this embodiment, the moving contact 14 includes a moving contact arm 144 pivotally connected to the bracket 11 and a moving contact 145 disposed at the lower end of the moving contact arm 144. The aforementioned protrusion 141, first lower shaft hole 142, and hook portion 143 are all located on the moving contact arm 144. In this embodiment, the stationary contact 7 includes a stationary contact arm 71 and a stationary contact 72 disposed on the stationary contact arm 71. The portion a of the moving contact arm 144 connecting to the moving contact 145 and the portion b of the stationary contact arm 71 connecting to the stationary contact 72 are configured to be parallel and aligned when the circuit is closed. The electro-repulsive force experienced by the moving contact 145 is related to the breaking speed of the contact system. The electro-repulsive force between the contacts includes the circuit electro-repulsive force and the inter-contact electro-repulsive force. The resultant force of these two forces constitutes the force for the moving contact to open rapidly. The electro-repulsive force in the circuit is mainly caused by the conductive circuit of the circuit breaker. The interaction of the current flowing between the contacts and contact arms is the main reason for the generation of the electro-repulsive force. Therefore, in order to interrupt the fault current more quickly, the electro-repulsive force can be increased by lengthening the lengths of a and b. The lengths of a and b are preferably 6-12 mm. The electro-repulsive force between contacts is the electro-repulsive force caused by the contraction of the current lines at the contact point. Its magnitude is related to the current, the contact area between the contacts, and the contact area between the contacts and contact arms. The larger the contact area between the contacts and contact arms, the greater the electro-repulsive force between the contacts. Therefore, the electro-repulsive force can be increased by lengthening the length L1 of the moving contact 145 and the length L2 of the stationary contact 72. The lengths of L1 and L2 are preferably 4-5 mm.

[0032] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims are within the scope of protection of the present invention.

Claims

1. A trip unit, comprising: include: Support (11); The latch (12) is pivotally connected to the middle part of the bracket (11), and the latch (12) has a waist-shaped groove (121) below the bracket (11). The jump buckle (13) is pivotally connected to the upper end of the bracket (11) and engages with the lock (12); The movable contact (14) is pivotally connected to the lower end of the bracket (11). The movable contact (14) is provided with a protrusion (141) that inserts into the waist-shaped groove (121). The protrusion (141) can slide within the waist-shaped groove (121). The movable contact (14) can be disengaged by rotating the latch (12) simultaneously through the protrusion (141) when it is repelled by an electric repulsive force.

2. The tripping mechanism according to claim 1, characterized in that, The latch (12) includes a first front side plate (122) and a first rear side plate (123) disposed opposite to each other, and a first connecting plate (124) connecting the first front side plate (122) and the first rear side plate (123). The first front side plate (122) and the first rear side plate (123) are coaxially provided with a first intermediate shaft hole (125). The first front side plate (122) is provided with the waist-shaped groove (121), which is located below the first intermediate shaft hole (125). The bracket (11) is located between the first front side plate (122) and the first rear side plate (123). The bracket (11) includes: a second front side plate (111) and a second rear side plate (112) arranged opposite to each other, and a second connecting plate (113) connecting the second front side plate (111) and the second rear side plate (112). The second front side plate (111) and the second rear side plate (112) are coaxially provided with a second upper shaft hole (114), a second intermediate shaft hole (115) and a second lower shaft hole (116) from top to bottom. The second upper shaft hole (114) is located on the side of the first intermediate shaft hole (125) away from the latch (12). The bracket (11) is pivotally connected to the latch (12) through an intermediate rotating shaft (16) passing through the first intermediate shaft hole (125) and the second intermediate shaft hole (115). The intermediate rotating shaft (16) is used to pivotally connect the tripping mechanism (1) to the housing (2) of the circuit breaker. The jump buckle (13) has a first upper shaft hole (131) at one end and a lock buckle (12) at the other end for connecting with the operating handle (3) of the circuit breaker. The jump buckle (13) is pivotally connected to the bracket (11) through an upper rotating shaft (15) passing through the first upper shaft hole (131) and the second upper shaft hole (114). The movable contact (14) is located between the second front side plate (111) and the second rear side plate (112). The movable contact (14) has a first lower shaft hole (142) located above the protrusion (141). The movable contact (14) is pivotally connected to the bracket (11) through a lower rotating shaft (17) passing through the first lower shaft hole (142) and the second lower shaft hole (116).

3. The trip unit of claim 2, wherein, The upper end of the moving contact (14) is formed with a hook portion (143) located between the first connecting plate (124) and the intermediate rotating shaft (16), and the hook portion (143) is used to limit the engagement with the intermediate rotating shaft (16).

4. The trip unit of claim 2 wherein, The outer surface of the first front side plate (122) is formed with a convex ring (126) surrounding the first intermediate shaft hole (125). A torsion spring (18) is sleeved on the convex ring (126). The first front side plate (122) is provided with a first snap-fit ​​block (127) below the first intermediate shaft hole (125). One end of the torsion spring (18) is snapped with the first snap-fit ​​block (127). The second front side plate (111) is provided with a second snap-fit ​​block (117) above the second intermediate shaft hole (115). The other end of the torsion spring (18) is snapped with the second snap-fit ​​block (117).

5. The trip unit of any of claims 1-4, wherein: The movable contact (14) includes a movable contact arm (144) pivotally connected to the bracket (11) and a movable contact (145) disposed at the lower end of the movable contact arm (144), wherein the length of the movable contact (145) is 4 to 5 mm.

6. A circuit breaker characterized by, It has a tripping mechanism (1) as described in any one of claims 1 to 5.

7. The circuit breaker of claim 6, wherein, The stationary contact (7) of the circuit breaker includes a stationary contact arm (71) and a stationary contact (72) disposed on the stationary contact arm (71), wherein the length of the stationary contact (72) is 4-5 mm.

8. The circuit breaker of claim 6, wherein, The stationary contact (7) of the circuit breaker includes a stationary contact arm (71) and a stationary contact (72) disposed on the stationary contact arm (71); the moving contact (14) of the tripping mechanism includes a moving contact arm (144) pivotally connected to the bracket (11) and a moving contact (145) disposed at the lower end of the moving contact arm (144); the part of the moving contact arm (144) connected to the moving contact (145) and the part of the stationary contact arm (71) connected to the stationary contact (72) are configured to be parallel and aligned when the circuit is closed, and the length of each part is configured to be 6-12mm.

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