Arc extinguish chamber pressure relief structure and circuit breaker

Abstract

The invention relates to the technical field of switch equipment, in particular to an arc extinguish chamber pressure relief structure and a circuit breaker. The arc extinguish chamber pressure relief structure comprises a cylinder body and a pull rod which is arranged in the cylinder body and is fixed relative to the cylinder body, a piston is further arranged in the cylinder body, the pull rod penetrates through the piston in a sealing mode to define an air compression chamber in the cylinder body, and a pressure relief groove extending in the movement direction of the cylinder body is formed in one of the inner circumferential face, corresponding to the air compression chamber, of the cylinder body and the outer circumferential face of the piston. The piston is in sealing fit with the inner circumferential face of the cylinder body through the outer sealing piece, when the cylinder body moves to the position right opposite to the pressure relief groove and the outer sealing piece, sealing between the piston and the cylinder body is relieved, and the pressure relief groove is communicated with an external air chamber to achieve opening pressure relief. A pressure release valve with a complex structure does not need to be arranged in the air compression chamber, the structure of the arc extinguish chamber is simplified, the problem that the short-circuit current breaking capacity of the circuit breaker is affected due to the fact that the function of the pressure release valve is prone to failure is solved, and the fault rate of the circuit breaker is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of switchgear, and in particular to an arc extinguishing chamber pressure relief structure and a circuit breaker. Background Art

[0002] The arc extinguishing chamber in the circuit breaker can be divided into compressed air type arc extinguishing chamber and self-energy type arc extinguishing chamber according to the arc extinguishing principle. The compressed air type arc extinguishing chamber has the problem of large mechanism operation work, while the self-energy type arc extinguishing chamber requires less operation work and has relatively high mechanical reliability. The Chinese invention patent with authorization announcement number CN109767950B discloses a self-energy type arc extinguishing chamber and a circuit breaker using the arc extinguishing chamber. The arc extinguishing chamber includes a shell, a piston cylinder and a piston cylinder bottom are provided in the shell, the piston cylinder bottom is fixedly connected to one end of the piston cylinder, a piston structure is provided in the piston cylinder, the piston structure and the piston cylinder and the piston cylinder bottom form a compressed air chamber, a moving arc contact, a nozzle and an expansion chamber are provided on the piston structure, an air inlet valve that can make the compressed air chamber and the expansion chamber connected is provided on the expansion chamber, a pressure relief channel and an air supply channel are provided on the piston cylinder bottom, a pressure relief valve is provided on the pressure relief channel, and an air supply valve is provided on the air supply channel, and both the pressure relief valve and the air supply valve are connected through The spring controls the opening pressure; when the circuit breaker is closed, the air pressure in the compressed air chamber drops sharply. When the pressure difference between the compressed air chamber and the external air chamber is greater than the spring preload of the air supply valve, the air supply valve opens, and the gas in the external air chamber enters the compressed air chamber to complete the closing and air supply operation, balance the internal and external pressure difference, and reduce the closing operation work; when the circuit breaker is opened, the air pressure in the compressed air chamber rises sharply. When the pressure in the compressed air chamber is greater than the pressure in the expansion chamber, the air inlet valve opens, and the gas in the compressed air chamber can enter the expansion chamber, forming a compressed air arc extinguishing mode. When the pressure difference between the compressed air chamber and the external air chamber is greater than the spring preload of the pressure relief valve, the pressure relief valve opens, and the gas in the compressed air chamber is discharged, realizing the opening pressure relief and reducing the opening operation work.

[0003] In order to reduce the operation work of opening the switch, the existing arc extinguishing chamber is provided with a pressure relief channel and a pressure relief valve on the bottom of the piston cylinder of the compressed air chamber. The pressure relief valve needs to be controlled by a spring. The pressure relief valve has a large number of parts and a complex matching relationship, which leads to a complex overall structure of the arc extinguishing chamber. Moreover, after the pressure relief valve is opened and closed many times, the pressure relief spring is prone to fatigue failure, which affects the ability of the circuit breaker to break the short-circuit current and poses a huge safety hazard. Summary of the invention

[0004] The object of the present invention is to provide a pressure relief structure for an arc extinguishing chamber, so as to solve the problem that the arc extinguishing chamber of the existing arc extinguishing chamber reduces the opening operation work by arranging a pressure relief channel on the compressed air chamber and configuring a pressure relief valve, and the pressure relief valve has a complex structure, resulting in a complex overall structure of the arc extinguishing chamber and the pressure relief valve is prone to functional failure, thereby affecting the short-circuit current breaking capacity of the circuit breaker; the object of the present invention is also to provide a circuit breaker, so as to solve the problem that the arc extinguishing chamber of the existing circuit breaker reduces the opening operation work by arranging a pressure relief channel on the compressed air chamber and configuring a pressure relief valve, and the pressure relief valve has a complex structure, resulting in a complex overall structure of the arc extinguishing chamber and the pressure relief valve is prone to functional failure, thereby affecting the short-circuit current breaking capacity of the circuit breaker.

[0005] The arc extinguishing chamber pressure relief structure of the present invention adopts the following technical solutions: A pressure relief structure for an arc extinguishing chamber comprises a cylinder body and a pull rod arranged inside the cylinder body and fixed relatively to the cylinder body, a piston is also arranged inside the cylinder body, the pull rod seal passes through the piston to form a compressed air chamber inside the cylinder body, a pressure relief groove extending along the movement direction of the cylinder body is provided on one of the inner circumference of the cylinder body corresponding to the compressed air chamber and the outer circumference of the piston, and an external seal is provided on the other, the piston and the inner circumference of the cylinder body are sealed by the external seal, when the cylinder body moves to the position where the pressure relief groove and the external seal are facing each other, the piston and the cylinder body are released from the seal, and the pressure relief groove is connected with the external air chamber to realize the pressure relief of the gate.

[0006] Furthermore, the pressure relief groove is arranged on the inner circumferential surface of the cylinder body corresponding to the compressed air chamber, and the outer sealing member is an outer sealing ring, which is sleeved on the outer circumferential surface of the piston close to one end of the compressed air chamber to achieve sealing cooperation between the piston and the circumferential surface of the cylinder body, and the outer diameter of the piston is smaller than the inner diameter of the cylinder body to form a gas channel between the piston and the cylinder body.

[0007] Furthermore, the outer seal cooperates with the inner peripheral surface of the cylinder body to guide the movement of the cylinder body.

[0008] Furthermore, an inner seal is provided on the inner circumference of one end of the piston close to the air compression chamber, and the piston and the outer circumference of the pull rod are sealed through the inner seal, and the inner seal cooperates with the outer circumference of the pull rod to guide the movement of the pull rod.

[0009] Furthermore, the pressure relief groove is a rectangular groove, and there are more than two pressure relief grooves which are evenly spaced along the circumference of the cylinder body or the piston where the pressure relief grooves are located.

[0010] Furthermore, the cylinder body and the pull rod are an integrated structure.

[0011] Furthermore, the piston is a sleeve structure, the end of the sleeve structure facing the compressed air chamber has a closed end cover, and the end away from the compressed air chamber is open. The closed end cover of the piston is provided with an air supply hole connecting the compressed air chamber with the external air chamber. The air supply hole is provided with an air supply valve for opening when the arc extinguishing chamber is closed to supply air to the compressed air chamber.

[0012] Furthermore, the air supply valve is a one-way valve, which includes an air supply valve plate arranged at an orifice of one end of the air supply hole facing the air compression chamber and an air supply valve plate baffle for limiting the air supply valve plate. The air supply valve plate baffle is fixed on the closed end cover. When the pressure in the air compression chamber is lower than the pressure in the external air chamber, the air supply valve plate opens under the action of the internal and external pressure difference to supply air to the air compression chamber.

[0013] Furthermore, a gas-inflating valve plate support seat is provided on the closed end cover. The gas-inflating valve plate is an annular valve plate. The gas-inflating valve plate is movably mounted on the gas-inflating valve plate support seat. The gas-inflating valve plate baffle is fixedly connected to the gas-inflating valve plate support seat.

[0014] Beneficial effects: The arc extinguishing chamber pressure relief structure of the present invention is a pioneering invention. The cylinder body and the pull rod are relatively fixed, and the pull rod is used to connect the operating mechanism, thereby driving the cylinder body to move synchronously. A compressed air chamber is enclosed in the cylinder body. One of the inner circumference of the cylinder body corresponding to the compressed air chamber and the outer circumference of the piston is provided with a pressure relief groove extending along the movement direction of the cylinder body, and the other is provided with an outer seal. When the switch is opened, the pull rod drives the cylinder body to move synchronously, and the air pressure in the compressed air chamber rises sharply. When the cylinder body moves to the point where the pressure relief groove and the outer seal are directly opposite, due to the gap between the outer seal and the pressure relief groove, the piston and the cylinder body are unsealed at this time, and the pressure relief groove is connected to the external air chamber. The gas in the compressed air chamber can flow from the pressure relief groove to the external air chamber, realizing the opening of the switch and reducing the opening operation work. The present invention does not need to configure a pressure relief valve with a complex structure in the compressed air chamber, which not only simplifies the arc extinguishing chamber structure, but also directly avoids the problem that the pressure relief valve is prone to functional failure and affects the short-circuit current breaking capacity of the circuit breaker, thereby reducing the failure rate of the circuit breaker.

[0015] The circuit breaker of the present invention adopts the following technical solution: The circuit breaker comprises an arc extinguishing chamber, which comprises an arc extinguishing chamber shell. An arc extinguishing chamber pressure relief structure is arranged in the arc extinguishing chamber shell. The arc extinguishing chamber pressure relief structure comprises a cylinder body and a pull rod arranged inside the cylinder body and fixed relatively to the cylinder body. A piston is also arranged in the cylinder body. The pull rod seal passes through the piston to form a compressed air chamber inside the cylinder body. A pressure relief groove extending along the movement direction of the cylinder body is arranged on one of the inner circumference of the cylinder body corresponding to the compressed air chamber and the outer circumference of the piston, and an external seal is arranged on the other. The piston and the inner circumference of the cylinder body are sealed by the external seal. When the cylinder body moves to the position where the pressure relief groove and the external seal are directly opposite, the piston and the cylinder body are released from the seal, and the pressure relief groove is connected with the external air chamber to realize the opening pressure relief.

[0016] Furthermore, the pressure relief groove is arranged on the inner circumferential surface of the cylinder body corresponding to the compressed air chamber, and the outer sealing member is an outer sealing ring, which is sleeved on the outer circumferential surface of the piston close to one end of the compressed air chamber to achieve sealing cooperation between the piston and the circumferential surface of the cylinder body, and the outer diameter of the piston is smaller than the inner diameter of the cylinder body to form a gas channel between the piston and the cylinder body.

[0017] Furthermore, the outer seal cooperates with the inner peripheral surface of the cylinder body to guide the movement of the cylinder body.

[0018] Furthermore, an inner seal is provided on the inner circumference of one end of the piston close to the air compression chamber, and the piston and the outer circumference of the pull rod are sealed through the inner seal, and the inner seal cooperates with the outer circumference of the pull rod to guide the movement of the pull rod.

[0019] Furthermore, the pressure relief groove is a rectangular groove, and there are more than two pressure relief grooves which are evenly spaced along the circumference of the cylinder body or the piston where the pressure relief grooves are located.

[0020] Furthermore, the cylinder body and the pull rod are an integrated structure.

[0021] Furthermore, the piston is a sleeve structure, the end of the sleeve structure facing the compressed air chamber has a closed end cover, and the end away from the compressed air chamber is open. The closed end cover of the piston is provided with an air supply hole connecting the compressed air chamber with the external air chamber. The air supply hole is provided with an air supply valve for opening when the arc extinguishing chamber is closed to supply air to the compressed air chamber.

[0022] Furthermore, the air supply valve is a one-way valve, which includes an air supply valve plate arranged at an orifice of one end of the air supply hole facing the air compression chamber and an air supply valve plate baffle for limiting the air supply valve plate. The air supply valve plate baffle is fixed on the closed end cover. When the pressure in the air compression chamber is lower than the pressure in the external air chamber, the air supply valve plate opens under the action of the internal and external pressure difference to supply air to the air compression chamber.

[0023] Furthermore, a gas-inflating valve plate support seat is provided on the closed end cover. The gas-inflating valve plate is an annular valve plate. The gas-inflating valve plate is movably mounted on the gas-inflating valve plate support seat. The gas-inflating valve plate baffle is fixedly connected to the gas-inflating valve plate support seat.

[0024] Beneficial effects: The circuit breaker of the present invention is an improved invention. A new arc extinguishing chamber pressure relief structure is adopted. The cylinder body and the pull rod of the arc extinguishing chamber pressure relief structure are relatively fixed. The pull rod is used to connect the operating mechanism, thereby driving the cylinder body to move synchronously. A compressed air chamber is formed in the cylinder body. One of the inner circumference of the cylinder body corresponding to the compressed air chamber and the outer circumference of the piston is provided with a pressure relief groove extending along the movement direction of the cylinder body, and the other is provided with an outer seal. When the switch is opened, the pull rod drives the cylinder body to move synchronously, and the air pressure in the compressed air chamber rises sharply. When the cylinder body moves to the position where the pressure relief groove and the outer seal are directly opposite, there is a gap between the outer seal and the pressure relief groove. At this time, the piston and the cylinder body are unsealed, and the pressure relief groove is connected with the external air chamber. The gas in the compressed air chamber can flow from the pressure relief groove to the external air chamber, so as to realize the pressure relief of the switch opening and reduce the switch opening operation work. The present invention does not need to configure a complicated pressure relief valve in the compressed air chamber, which not only simplifies the arc extinguishing chamber structure, but also directly avoids the problem that the pressure relief valve is prone to functional failure and affects the short-circuit current breaking capacity of the circuit breaker, thereby reducing the failure rate of the circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a pressure relief structure of an arc extinguishing chamber in an embodiment of a circuit breaker of the present invention; Figure 2 It is a structural schematic diagram of the cylinder body; Figure 3 It is a structural schematic diagram of the piston part; Figure 4 It is a schematic diagram of the connection between the compression chamber and the expansion chamber of the circuit breaker in the early stage of breaking the short-circuit current; Figure 5 It is a schematic diagram of the connection between the pressure relief groove and the external air chamber during the continuous breaking process of the circuit breaker; Figure 6 for Figure 5 The enlarged schematic diagram at A in the middle; Figure 7 It is a schematic diagram of the connection between the pressure relief groove and the external air chamber before the circuit breaker is closed; Figure 8 for Figure 7 The enlarged schematic diagram of point B in the middle; Fig. 9 It is a schematic diagram of the air supply valve being opened to connect the compressed air chamber and the external air chamber during the continuous closing process of the circuit breaker; In the figure: 1. cylinder part; 101. cylinder body; 102. vent hole; 103. pressure relief groove; 104. pull rod; 105. intake valve plate; 106. intake valve plate baffle; 107. intake valve plate support seat; 2. piston part; 201. piston; 202. outer sealing member; 203. air supply hole; 204. air supply valve plate; 205. air supply valve plate baffle; 206. air supply valve plate support seat; 207. inner sealing member; 301. expansion chamber; 302. compression chamber; 303. external air chamber. DETAILED DESCRIPTION

[0026] The existing arc extinguishing chamber realizes the pressure relief of the opening gate by setting a pressure relief channel on the compressed air chamber and configuring a pressure relief valve to reduce the operation work of the opening gate. However, the pressure relief valve needs to be controlled by a spring, and the number of parts is large and the matching relationship is complex, resulting in a complex overall structure of the arc extinguishing chamber. Moreover, after the pressure relief valve is opened and closed many times, the pressure relief spring is prone to fatigue failure and affects the ability of the circuit breaker to break the short-circuit current, which poses a huge safety hazard. In view of the problems existing in the prior art, the present invention provides an arc extinguishing chamber pressure relief structure and a circuit breaker, which do not need to be configured with a pressure relief valve with a complex structure, which can not only simplify the arc extinguishing chamber structure, but also directly avoid the problem that the pressure relief valve is prone to functional failure and affects the ability of the circuit breaker to break the short-circuit current. The function is more stable and reliable, thereby reducing the failure rate of the circuit breaker.

[0027] The basic inventive concept of the present invention is that the arc extinguishing chamber pressure relief structure includes a cylinder body, a pull rod and a piston are arranged in the cylinder body, the pull rod is relatively fixed to the cylinder body to drive the cylinder body to move synchronously, the piston, the cylinder body and the pull rod are sealed and cooperate to form a compressed air chamber inside the cylinder body, a pressure relief groove extending along the movement direction of the cylinder body is arranged on one of the inner circumference of the cylinder body corresponding to the compressed air chamber and the outer circumference of the piston, and an external seal is arranged on the other one, when the switch is opened, the pull rod drives the cylinder body to move synchronously, when the cylinder body moves to the position where the pressure relief groove and the external seal are opposite, there is a gap between the external seal and the pressure relief groove, so the piston and the cylinder body are unsealed, and at this time, the pressure relief groove is connected with the external air chamber, so that the switch is opened and the pressure relief is realized, thereby reducing the switch opening operation work.

[0028] Based on the above inventive concept, the embodiments of the present invention are described in detail below.

[0029] Embodiment of the circuit breaker of the present invention: The circuit breaker includes an arc extinguishing chamber and an operating mechanism. The arc extinguishing chamber includes an arc extinguishing chamber housing, and an arc extinguishing chamber pressure relief structure is arranged in the arc extinguishing chamber housing. Figure 1-3 As shown, the arc extinguishing chamber pressure relief structure includes a cylinder part 1 and a piston part 2. The piston part 2 is arranged inside the cylinder part 1. The cylinder part 1 is cylindrical as a whole, including a cylinder 101 and a pull rod 104 arranged inside the cylinder 101 and relatively fixed to the cylinder 101. The pull rod 104 is connected to the operating mechanism of the circuit breaker by transmission to drive the cylinder 101 to move synchronously. In this embodiment, the cylinder 101 and the pull rod 104 are an integrated structure, which reduces the matching relationship between parts and simplifies the arc extinguishing chamber structure. The cylinder 101 is separated into an expansion chamber 301 and a compressed air chamber 302 by a partition. The partition and the cylinder 101 are an integrated structure. The partition is provided with an air vent 102 connecting the expansion chamber 301 and the compressed air chamber 302. An air inlet valve is provided at the air vent 102, which is used to open when the pressure in the expansion chamber 301 is low in the early stage of opening the switch to allow the gas in the compressed air chamber 302 to enter the expansion chamber 301 to provide air blowing. As shown Figure 2 As shown in , the intake valve is a one-way valve, including an intake valve plate 105 arranged at the opening of one end of the vent hole 102 facing the expansion chamber 301 and an intake valve plate baffle 106 for limiting the intake valve plate 105. The pull rod 104 is provided with an intake valve plate support seat 107. The intake valve plate 105 is an annular valve plate. The intake valve plate 105 is movably mounted on the intake valve plate support seat 107. The intake valve plate baffle 106 is fixedly connected to the intake valve plate support seat 107. The intake valve plate baffle 106 is annular, and the inner hole is a threaded hole, which is threadedly connected to the intake valve plate support seat 107. The intake valve plate 105 floats along the axial direction of the pull rod 104 under the pressure difference between the expansion chamber 301 and the compression chamber 302. The intake valve itself has a simple structure and does not need to be controlled by a spring, which avoids the problem of fatigue failure of the spring.

[0030] In the early stage of breaking the short-circuit current, the pressure accumulated in the expansion chamber 301 is lower than the pressure in the compression chamber 302. At this time, the gas in the compression chamber 302 can flow into the expansion chamber 301 through the vent 102, and the intake valve plate 105 is in an open state. At this time, the intake valve plate baffle 106 limits the intake valve plate 105; as the arc burning time increases, when the pressure accumulated in the expansion chamber 301 is greater than the pressure in the compression chamber 302, the intake valve plate 105 is close to the vent 102, and the vent 102 is closed, so that the compression chamber 302 and the expansion chamber 301 are isolated.

[0031] like Figure 1 As shown, the piston part 2 includes a piston 201, and the piston 201 is sealed with the inner circumference of the cylinder body 101 and the outer circumference of the pull rod 104 to enclose a compressed air chamber 302 inside the cylinder body 101. One of the inner circumference of the cylinder body 101 corresponding to the compressed air chamber 302 and the outer circumference of the piston 201 is provided with a pressure relief groove 103 extending along the movement direction of the cylinder body 101, and the other is provided with an outer seal 202, and the piston 201 and the inner circumference of the cylinder body 101 are sealed through the outer seal 202. When the cylinder body 101 moves to the position where the pressure relief groove 103 and the outer seal 202 are directly opposite, there is a gap between the outer seal 202 and the pressure relief groove 103, at this time, the piston 201 and the cylinder body 101 are unsealed, the pressure relief groove 103 is connected with the external air chamber 303, and the gas in the compressed air chamber 302 can flow from the pressure relief groove 103 to the external air chamber 303, so as to realize the pressure relief of the gate. In this embodiment, the pressure relief groove 103 is arranged on the inner circumferential surface of the cylinder body 101 corresponding to the compressed air chamber 302, the outer seal 202 is an outer sealing ring, and a mounting groove is provided on the outer circumferential surface of the end of the piston 201 close to the compressed air chamber 302. The outer seal 202 is arranged in the mounting groove to achieve sealing cooperation between the piston 201 and the inner circumferential surface of the cylinder body 101. The outer diameter of the piston 201 is slightly smaller than the inner diameter of the cylinder body 101, and a gas channel is formed between the piston 201 and the cylinder body 101, which facilitates the arrangement of the outer seal 202. The outer seal 202 can be directly mounted on the piston 201, which is easy to install and not easy to loosen.

[0032] The pressure relief groove 103 is a rectangular groove. There are more than two pressure relief grooves 103 and they are evenly spaced along the circumference of the cylinder body 101. In this embodiment, there are four pressure relief grooves 103. When the pressure relief groove 103 moves to the outer seal 202, four pressure relief channels can be formed on the circumference of the cylinder body 101 to accelerate the pressure relief. The length direction of the pressure relief groove 103 is consistent with the axial direction of the cylinder body 101. The groove depth is less than the thickness of the cylinder body 101. The length of the groove depends on the stroke of the moving end of the arc extinguishing chamber to ensure that the pressure chamber 302 can effectively relieve pressure from the pressure relief position to the end of the opening. The position of the groove is determined according to the preset pressure relief pressure. According to the required pressure relief pressure, the relative position of the piston 201 and the cylinder body 101 is calculated, and the end position of the pressure relief groove 103 is determined based on this.

[0033] There is a gap between the piston 201 and the inner circumference of the cylinder body 101. The piston 201 is sealed with the inner circumference of the cylinder body 101 through the outer seal 202 to avoid direct contact between the outer circumference of the piston 201 and the cylinder body 101 to cause scratches. The outer seal 202 provided on the piston 201 is made of polytetrafluoroethylene and has a certain hardness, so that the outer seal 202 is guided with the inner circumference of the cylinder body 101 to guide the movement of the cylinder body 101 and ensure the coaxiality of the cylinder body 101 and the piston 201. A mounting groove is also provided on the inner circumference of the piston 201 near the compressed air chamber 302, and an inner seal 207 is provided in the mounting groove. The inner seal 207 is specifically an inner sealing ring. There is a gap between the piston 201 and the outer circumference of the pull rod 104. The piston 201 is sealed with the outer circumference of the pull rod 104 through the inner seal 207 to avoid direct contact between the piston 201 and the outer circumference of the pull rod 104 to cause scratches. The inner seal 207 is also made of polytetrafluoroethylene, has a certain hardness, and has a certain extension length in the axial direction, so that the inner seal 207 cooperates with the outer peripheral surface guide of the pull rod 104 to guide the movement of the pull rod 104 and ensure the coaxiality of the pull rod 104 and the piston 201. Since the cylinder body 101 and the pull rod 104 are an integrated structure in this embodiment, the outer seal 202 and the inner seal 207 jointly guide the cylinder body part 1 to ensure the coaxiality of the cylinder body part 1 and the piston part 2.

[0034] The piston 201 is a sleeve structure, and the end of the sleeve structure facing the compressed air chamber 302 has a closed end cover, and the end away from the compressed air chamber 302 is open. The closed end cover of the piston 201 is provided with an air supply channel connecting the compressed air chamber 302 and the external air chamber 303. The air supply channel includes more than two air supply holes 203, and all the air supply holes 203 are evenly spaced on the same circumference. The air supply holes 203 are provided with air supply valves, which are used to open when the arc extinguishing chamber is closed to supply air to the compressed air chamber 302. Figure 3As shown in , the air supply valve is a one-way valve, including an air supply valve plate 204 and an air supply valve plate baffle 205. The air supply valve plate 204 is arranged at the opening of the air supply through hole 203 at one end facing the air pressure chamber 302. The air supply valve plate support seat 206 is arranged on the closed end cover of the piston 201. The air supply valve plate 204 is an annular valve plate. The air supply valve plate 204 is movably mounted on the air supply valve plate support seat 206, and can block all the air supply through holes 203 at the same time. The air supply valve plate baffle 205 is fixedly connected to the air supply valve plate support seat 206. The air supply valve plate baffle 205 is located at the front side of the air supply valve plate 204 to limit the air supply valve plate 204. The air supply valve plate baffle 205 is annular, and the inner hole is a threaded hole. It is threadedly connected to the air supply valve plate support seat 206, and is easy to assemble. The air supply valve plate 204 floats left and right under the pressure difference between the compressed air chamber 302 and the external air chamber 303. When the pressure in the compressed air chamber 302 is lower than the pressure in the external air chamber 303, the air supply valve plate 204 opens under the pressure difference between the inside and the outside to supply air to the compressed air chamber 302. The overall structure of the air supply valve is simple, and the assembly is convenient. It does not need to be controlled by a spring, which avoids the problem of fatigue failure of the spring.

[0035] During the opening process, the air supply valve plate 204 is always close to the air supply through hole 203, and the gas in the compressed air chamber 302 cannot flow out from the air supply through hole 203; during the closing process, when the pressure of the external air chamber 303 is greater than the pressure of the compressed air chamber 302, the air supply valve plate 204 opens, and the air supply valve plate baffle 205 limits the air supply valve plate 204, and the compressed air chamber 302 is connected with the external air chamber 303, ensuring that the air pressure in the compressed air chamber 302 is consistent with the outside during the closing process, thereby reducing the operating work of the mechanism.

[0036] like Figure 4 As shown in the figure, in the early stage of breaking the short-circuit current, the arcing energy of the circuit breaker is small, the pressure accumulated in the expansion chamber 301 is less than the pressure in the compressed air chamber 302, and the pressure relief groove 103 of the cylinder body 101 has not reached the outer seal 202. The large arrow in the figure shows the movement direction of the pull rod 104. As the pull rod 104 moves, the pressure in the compressed air chamber 302 continues to increase with the compression. At this time, the intake valve plate 105 opens under the pressure difference between the compressed air chamber 302 and the expansion chamber 301, and the gas in the compressed air chamber 302 enters the expansion chamber 301 to assist in arc extinguishing. Figure 4 The small arrows indicate the direction of the air flow. As the opening and closing process continues, the pressure in the expansion chamber 301 increases and becomes greater than the pressure in the compression chamber 302. Figure 5 As shown, the air intake valve plate 105 is closed, the compressed air chamber 302 is isolated from the expansion chamber 301, and when the pressure relief groove 103 moves to the outer seal 202, the pressure relief groove 103 begins to communicate with the external air chamber 303, and the gas in the compressed air chamber 302 flows to the external air chamber 303 through the pressure relief groove 103, as shown in FIG. Figure 6 The small and medium arrows indicate the direction of airflow, which serves to relieve pressure. This process continues until the disconnection is completed.

[0037] like Figure 7-8 As shown, in the early stage of closing the circuit breaker, the pressure relief groove 103 is connected to the external air chamber 303. At this time, the pressure in the compressed air chamber 302 is the same as that in the external air chamber 303, which does not affect the closing process. Figure 7 The middle arrow indicates the movement direction of the pull rod 104; as the pull rod 104 moves, Fig. 9 As shown, when the pressure relief groove 103 and the outer seal 202 are misaligned, the piston 201 forms a sealing fit with the inner circumference of the cylinder body 101 again, and the compressed air chamber 302 is isolated from the external air chamber 303. When the valve is further closed, the pressure in the compressed air chamber 302 will be lower than the pressure in the external air chamber 303. Under the pressure difference between the external air chamber 303 and the compressed air chamber 302, the air supply valve plate 204 is opened to connect the compressed air chamber 302 with the external air chamber 303, and the gas in the external air chamber 303 can enter the compressed air chamber 302. Fig. 9 The small and medium arrows indicate the direction of air flow, which ensures that the air pressure in the compressed air chamber 302 is consistent with that outside during the closing process, thereby ensuring that the entire closing process proceeds smoothly.

[0038] The present invention adopts a simpler and more reliable pressure relief principle, eliminates the traditional complex pressure relief structure, and does not need to configure a complex pressure relief valve in the compressed air chamber. It not only simplifies the arc extinguishing chamber structure and reduces production costs, but also directly avoids the problem that the pressure relief valve is prone to functional failure and affects the short-circuit current breaking capacity of the circuit breaker. It is more stable and reliable, reduces the failure rate of the circuit breaker, and increases the service life of the circuit breaker, which is conducive to promoting the popularization and application of new environmentally friendly circuit breakers.

[0039] Of course, the present invention is not limited to the implementation methods in the above embodiments.

[0040] For example, in other embodiments, a pressure relief groove extending along the axial direction of the piston can be provided on the outer circumferential surface of the piston, and an outer seal can be fixedly provided on the inner circumferential surface of the cylinder body. The piston and the inner circumferential surface of the cylinder body are sealed by the outer seal. When the cylinder body moves to the point where the pressure relief groove and the outer seal are facing each other, the piston and the cylinder body are released from the seal, and the pressure relief groove is connected to the external air chamber to realize the pressure relief of the gate.

[0041] For example, in other embodiments, an outer seal is provided on the outer circumferential surface of the piston, and the outer seal is in sealing cooperation with the inner circumferential surface of the cylinder body. A guide structure is additionally provided on the piston to guide the movement of the cylinder body.

[0042] For example, in other embodiments, an inner seal is provided on the inner circumference of the piston, the piston and the outer circumference of the pull rod are sealed through the inner seal, and a guide structure is additionally provided on the inner circumference of the piston to guide the movement of the pull rod.

[0043] For example, in other embodiments, the number of the pressure relief grooves can be flexibly adjusted, and can be one, three, five or more. Preferably, all the pressure relief grooves are evenly spaced in the circumferential direction.

[0044] For example, in other embodiments, the cylinder body and the pull rod may also be a split structure, and the two are fixedly connected together.

[0045] For example, in other embodiments, the air supply valve may also be a one-way valve commonly used in the prior art and controlled by a spring.

[0046] For example, in other embodiments, the air supply valve plate support seat may not be provided, and a protrusion may be provided in the center of the closed end cover of the piston, and the air supply valve plate may be directly movably mounted on the protrusion, and the air supply valve plate baffle may also be directly fixed on the protrusion.

[0047] The present invention further provides an embodiment of an arc extinguishing chamber pressure relief structure, the specific structure of which is the same as that of the arc extinguishing chamber pressure relief structure in the above-mentioned circuit breaker embodiment, and will not be described in detail here.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. An arc extinguishing chamber pressure relief structure, characterized in that: It includes a cylinder body and a pull rod arranged inside the cylinder body and fixed relatively to the cylinder body. A piston is also arranged in the cylinder body. The pull rod seal passes through the piston to form a compressed air chamber inside the cylinder body. A pressure relief groove extending along the movement direction of the cylinder body is provided on one of the inner circumference of the cylinder body corresponding to the compressed air chamber and the outer circumference of the piston, and an external seal is provided on the other. The piston and the inner circumference of the cylinder body are sealed by the external seal. When the cylinder body moves to the position where the pressure relief groove and the external seal are opposite, the piston and the cylinder body are released from the seal, and the pressure relief groove is connected with the external air chamber to realize the pressure relief of the gate.

2. The arc extinguishing chamber pressure relief structure according to claim 1, characterized in that: The pressure relief groove is arranged on the inner circumferential surface of the cylinder body corresponding to the compressed air chamber. The outer sealing member is an outer sealing ring. The outer sealing ring is sleeved on the outer circumferential surface of the piston close to one end of the compressed air chamber to achieve sealing cooperation between the piston and the inner circumferential surface of the cylinder body. The outer diameter of the piston is smaller than the inner diameter of the cylinder body to form a gas channel between the piston and the cylinder body.

3. The arc extinguishing chamber pressure relief structure according to claim 2, characterized in that: The outer sealing member cooperates with the inner peripheral surface of the cylinder body to guide the movement of the cylinder body.

4. The arc extinguishing chamber pressure relief structure according to any one of claims 1 to 3, characterized in that: An inner seal is provided on the inner circumference of one end of the piston close to the air compression chamber. The piston and the outer circumference of the pull rod are sealed through the inner seal. The inner seal cooperates with the outer circumference of the pull rod to guide the movement of the pull rod.

5. The arc extinguishing chamber pressure relief structure according to any one of claims 1 to 3, characterized in that: The pressure relief groove is a rectangular groove, and more than two pressure relief grooves are provided and are evenly spaced along the circumference of the cylinder body or the piston where the pressure relief grooves are located.

6. The arc extinguishing chamber pressure relief structure according to any one of claims 1 to 3, characterized in that: The cylinder body and the pull rod are an integrated structure.

7. The arc extinguishing chamber pressure relief structure according to any one of claims 1 to 3, characterized in that: The piston is a sleeve structure, which has a closed end cover on one end facing the compressed air chamber and an open end away from the compressed air chamber. The closed end cover of the piston is provided with an air supply hole connecting the compressed air chamber with the external air chamber. The air supply hole is provided with an air supply valve which is opened when the arc extinguishing chamber is closed to supply air to the compressed air chamber.

8. The arc extinguishing chamber pressure relief structure according to claim 7, characterized in that: The air supply valve is a one-way valve, which includes an air supply valve plate arranged at the orifice of one end of the air supply hole facing the air compression chamber and an air supply valve plate baffle for limiting the air supply valve plate. The air supply valve plate baffle is fixed on the closed end cover. When the pressure in the air compression chamber is lower than the pressure in the external air chamber, the air supply valve plate opens under the action of the internal and external pressure difference to supply air to the air compression chamber.

9. The arc extinguishing chamber pressure relief structure according to claim 8, characterized in that: The closed end cover is provided with an air supply valve plate support seat, the air supply valve plate is an annular valve plate, the air supply valve plate is movably sleeved on the air supply valve plate support seat, and the air supply valve plate baffle is fixedly connected to the air supply valve plate support seat.

10. A circuit breaker comprising an arc extinguishing chamber, the arc extinguishing chamber comprising an arc extinguishing chamber housing, characterized in that: An arc extinguishing chamber pressure relief structure as claimed in any one of claims 1 to 9 is arranged in the arc extinguishing chamber housing.

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