A direct-acting single-pole double-breakpoint DC frame circuit breaker

Abstract

The invention discloses a direct-acting single-pole double-breakpoint DC frame circuit breaker, which relates to the technical field of wind power and energy storage equipment. The static contact system comprises a busbar, a static arc-striking contact and a static contact, wherein the static contact is fixed to the busbar, and the static arc-striking contact is rotatably connected to the static contact through a pin shaft. A torsion spring is sleeved on the pin shaft and abuts against the back of the static arc-striking contact to drive the static arc-striking contact to achieve reset. The static arc-striking contact is rotatably connected to the static contact through the pin shaft and reset with the help of the torsion spring. The moving contact assembly comprises a moving arc-striking contact and a plurality of bridge contacts arranged side by side for connecting corresponding ones. The bridge contact and the corresponding two groups of static contacts form a double-breakpoint structure. The static arc-striking contact can automatically return to its original position after being acted upon by the moving contact system. The double-breakpoint mode improves the breaking capacity and arc-striking effect. At the same time, the arc-striking contact achieves the purpose of arc-striking after being separated, thereby reducing the problem of poor contact caused by wear of the arc-striking contact, and can be used to achieve large current breaking.

Description

Technical Field

[0001] The invention relates to the technical field of wind power and energy storage, and in particular to a direct-acting single-pole double-breakpoint DC frame circuit breaker. Background Art

[0002] In the field of low-voltage power supply and distribution, large-capacity DC systems have developed rapidly in urban subways, photovoltaic power generation, ship power and other fields. The voltage level of the power supply system has also been greatly increased to DC1500V or even DC2000V. DC frame circuit breaker products with high-performance breaking capacity and derived DC disconnector products have emerged at the corresponding voltage level. At present, DC frame circuit breakers basically adopt the reverse arc method, that is, when the arc voltage is higher than the system voltage, the arc current will be forced to decrease and gradually drop to zero. In actual engineering, the arc voltage is generally increased by stretching, cooling, and cutting the arc in a metal grid arc extinguishing chamber. The higher the system voltage, the more difficult it is for the circuit breaker to break. Under high voltage conditions, it is of great significance to ensure that the circuit breaker volume remains unchanged or even miniaturized to achieve high-performance breaking under high DC voltage conditions. Although the existing DC frame circuit breakers can meet the needs of the power system to a certain extent, they are usually used in DC circuits in multi-pole series connection and other methods. Summary of the invention

[0003] The object of the present invention is to provide a direct-acting single-pole double-breakpoint DC frame circuit breaker, which is used to solve the disadvantages of a traditional DC frame circuit breaker adopting a multi-pole series connection mode and a large volume.

[0004] To achieve the above-mentioned object, the present invention provides the following technical solutions: A direct-acting single-pole double-breakpoint DC frame circuit breaker, comprising a housing, and an operating mechanism arranged on one side of the housing, wherein the housing is provided with at least one set of single-pole chambers, wherein the single-pole chambers include a moving contact system and two sets of stationary contact systems in contact with the moving contact system, wherein the stationary contact system includes a busbar, a stationary arc-striking contact, and a stationary contact, wherein the stationary contact is fixed to the busbar, and the stationary arc-striking contact is rotatably connected to the stationary contact through a pin shaft, and a torsion spring is sleeved on the pin shaft The movable contact system comprises a contact support which performs horizontal reciprocating motion toward the static arc-striking contact and a movable contact assembly in the contact support, the movable contact assembly comprises a movable arc-striking contact and a plurality of bridge contacts which are arranged side by side for connecting corresponding ones, the bridge contact and the corresponding two groups of static contacts form a double breakpoint structure, the movable contact system is symmetrically provided with arc-extinguishing chambers at the upper and lower ends, the movable arc-striking contact and the static arc-striking contact are located at the slit of the arc-extinguishing chamber.

[0005] Preferably, the monopole chamber is assembled from two side plates, wherein two sets of upper and lower racetrack-shaped hole grooves are provided in the side plates, and the contact bracket realizes horizontal movement in the hole grooves through bearings, and the length of the hole grooves is the moving stroke of the contact bracket. An opening is provided on one side of an assembly surface of the monopole chamber, and the contact bracket is located at the opening.

[0006] Preferably, the operating mechanism comprises a connecting rod and a push-pull plate, wherein the push-pull plate is sleeved on the connecting rod and has an interference fit with the connecting rod, and the push-pull plate is provided with an oblique connecting portion toward the direction of the monopolar chamber.

[0007] Preferably, the contact bracket is provided with a push-pull groove in the opening direction toward the single-pole chamber, the connecting portion of the push-pull plate extends into the push-pull groove through the opening and is connected to the contact bracket through a pin shaft to synchronously drive the contact system to move horizontally when the operating mechanism is operated.

[0008] Preferably, the moving contact system also includes a spring sheet, which includes an arched portion and two contact feet, and the spring sheet is arranged between the contact bracket and the moving contact assembly, wherein the arched portion abuts against the contact bracket, and the contact feet abut against the upper and lower ends of the moving contact assembly respectively, and the number of the spring sheets is the same as the number of moving arc-striking contacts and bridge contacts in the moving contact assembly, wherein the width of the spring sheet abutting against the back side of the moving arc-striking contact is larger than the spring sheet abutting against the back side of the bridge contact, and the contact bracket is extended toward the side of the static contact system and is provided with a moving contact insulating cover.

[0009] Preferably, the static contact system also includes a cover shell and a static contact insulating cover, the cover shell is arranged on the outside of the static contact, an inclined portion is arranged above the cover shell toward the moving contact system, the inclined portion and the static arc-striking contact form a bell mouth, the static contact insulating cover is arranged below the cover shell and a reset spring is arranged at one end of the static contact insulating cover to drive the static contact insulating cover to reset.

[0010] Preferably, the arc extinguishing chamber includes an arc extinguishing grid, an arc striking plate, and an arc extinguishing cover, wherein the arc striking plates are arranged on both sides of the arc extinguishing grid and the arc striking plates are divided into dynamic arc striking plates and static arc striking plates, wherein the static arc striking plates are arranged in the trumpet mouth formed by the inclined portion and the static arc striking contact, and the dynamic arc striking plates are arranged on the back of the dynamic arc striking contact.

[0011] Preferably, arc-striking contacts and auxiliary contacts are provided at upper and lower ends of the movable arc-striking contact, and main contacts are provided at both sides of the bridge-shaped contact, wherein the auxiliary contacts and the main contacts are in the same plane.

[0012] Preferably, a static arc contact is provided on the static arc-striking contact, and a long strip-shaped static main contact is provided on the static contact.

[0013] Preferably, an installation area is also provided on the side panel, and a limiting structure is provided below the installation area, wherein the busbar is arranged in the installation area, the cover shell is slidably assembled in the limiting structure, and the cover shell forms an insertion margin between the limiting structure for inserting the moving contact insulating cover.

[0014] Compared with the prior art, the beneficial effects of the present invention are: (1) The static arc-striking contact is rotatably connected to the static contact through a pin shaft and is reset with the help of a torsion spring. This design enables the static arc-striking contact to automatically return to its original position after being acted upon by the moving contact system. The bridge-shaped contact and the corresponding two groups of static contacts form a double-breakpoint structure. The double-breakpoint mode improves the breaking capacity and arc-striking effect. At the same time, the arc-striking contact achieves the purpose of arc-striking by realizing rear separation, reducing the problem of poor contact caused by wear of the arc-striking contact, and can be used to achieve large current breaking.

[0015] The double breakpoint mode is realized by cooperating with the bridge contact and two sets of static contacts, which effectively increases the opening distance of the DC frame circuit breaker and the number of arc extinguishing grids while effectively reducing the volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0017] Figure 2 A schematic diagram of the internal structure of the operating mechanism of an embodiment of the present invention;

[0018] Figure 3 It is a schematic diagram of the structure of the shell part of an embodiment of the present invention;

[0019] Figure 4 This is a schematic diagram of the internal structure of a monopolar chamber according to an embodiment of the present invention;

[0020] Figure 5 A side view of a monopolar chamber according to an embodiment of the present invention;

[0021] Figure 6 for Figure 5 CC section view;

[0022] Figure 7 It is a partial structural schematic diagram of a moving contact assembly according to an embodiment of the present invention;

[0023] Figure 8 1 is a top view of a moving contact according to an embodiment of the present invention.

[0024] In the figure:

[0025] 10. operating mechanism; 101. connecting rod; 102. push-pull plate;

[0026] 20, housing; 201, single-pole chamber; 2011, opening; 2012, hole slot; 2013, installation area; 202, arc extinguishing chamber; 2021, arc-striking plate; 203, moving contact system; 2031, contact support; 20311, push-pull slot; 2032, spring sheet; 2033, moving contact assembly; 20331, moving arc-striking contact; 203311, arc-striking contact; 203312, auxiliary contact point; 20332, bridge contact; 203321, main contact; 2034, moving contact insulation cover; 204, bearing; 205, static contact system; 2051, busbar; 2052, static arcing contact; 20521, static arcing contact; 20522, static main contact; 2053, static contact insulation cover; 2054, reset spring; 2055, torsion spring; 2056, static contact; 2057, cover. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] See also Figure 1-Figure 8 A direct-acting single-pole double-breakpoint DC frame circuit breaker includes a housing 20 and an operating mechanism 10 arranged on one side of the housing 20. The housing 20 is provided with at least one set of single-pole chambers 201. The single-pole chambers 201 include a moving contact system 203 and two sets of stationary contact systems 2056 in contact with the moving contact system 203. The stationary contact system 2056 includes a bus bar 2051, a stationary arc-striking contact 2052, and a stationary contact 2056. The stationary contact 2056 is fixed to the bus bar 2051, and the stationary arc-striking contact 2052 is rotatably connected to the stationary contact 2056 through a pin shaft. A torsion spring 2055 is sleeved on the pin shaft and abuts against the stationary arc-striking contact 2051. The back side of 052 is used to drive the static arc-striking contact 2052 to achieve reset, and the moving contact system 203 includes a contact bracket 2031 that performs horizontal reciprocating motion toward the static arc-striking contact 2052 and a moving contact assembly 2033 located in the contact bracket 2031, and the moving contact assembly 2033 includes a moving arc-striking contact 20331 and a plurality of bridge contacts 20332 arranged side by side for connecting corresponding ones, and the bridge contact 20332 and the corresponding two groups of static contacts 2056 form a double breakpoint structure, and the moving contact system 203 is symmetrically provided with arc-extinguishing chambers 202 at the upper and lower ends, and the moving arc-striking contact 20331 and the static arc-striking contact 2052 are located at the slit of the arc-extinguishing chamber 202.

[0029] It should be noted that the modularization is achieved by adopting the structure of the single-pole housing 20, which can be assembled according to the needs, which is conducive to the realization of assembling multiple poles. It can be assembled into two poles, three poles, four poles, and multiple poles. In each single-pole chamber 201, the moving contact system 203 and the static contact system 205 work together to realize the connection and disconnection of the circuit. The static contact system 205 consists of a bus bar 2051, a static arc-striking contact 2052, and a static contact 2056. The bus bar 2051 is made of a high conductivity material as the main transmission path of the current to ensure the current transmission efficiency. The static contact 2056 is firmly fixed on the bus bar 2051 to play a supporting and connecting role. The static arc-striking contact 2052 is rotatably connected with the static contact 2056 through a pin shaft. This design allows the static arc-striking contact 2052 to have a certain rotation range when it is subjected to the force of the moving contact system 203, thereby increasing the reliability and durability of the contact. The torsion spring 2055 installed on the pin abuts against the back of the static arc-striking contact 2052, providing a continuous reset force for the static arc-striking contact 2052. When the moving contact system 203 is removed, the torsion spring 2055 drives the static arc-striking contact 2052 to quickly return to the initial position, ensuring good conductivity and rapid response during the next contact. The moving contact system 203 is composed of a contact support 2031 and an internal moving contact assembly 2033. The contact support 2031 is designed to be able to reciprocate in the horizontal direction. This linear motion method simplifies the mechanical structure and improves the accuracy and stability of the disconnection. The moving contact assembly 2033 includes a moving arc-striking contact 20331 and a plurality of bridge contacts 20332 arranged side by side. The bridge contacts 20332 are made of high-quality copper alloy materials, have good conductivity and wear resistance, and ensure stable operation even under high current density. Efficient arc extinguishing chambers 202 are symmetrically arranged at the upper and lower ends of the moving contact system 203. The arc extinguishing chamber 202 is designed with slits inside, and the arc generated by the moving arc-striking contact 20331 and the static arc-striking contact 2052 when they are in contact or separated will be guided into these slits. The slits are filled with gas-generating blocks and magnets to further guide the arc into the slits to extinguish the arc and protect the circuit breaker from arc erosion.

[0030] refer to Figure 4 The single-pole chamber is assembled by two side plates, wherein two sets of upper and lower racetrack-shaped slots 2012 are arranged in the side plates, and the contact bracket 2031 is horizontally moved in the slots 2012 through the bearings 204. The length of the slots 2012 is the moving stroke of the contact bracket 2031. An opening 2011 is arranged on one side of an assembly surface of the single-pole chamber, and the contact bracket 2031 is located at the opening 2011.

[0031] It should be noted that inside the side plate, the upper and lower sets of racetrack-shaped slots 2012 not only provide tracks for the contact bracket 2031 to move horizontally, but also ensure the stability and accuracy of the contact bracket 2031 during movement. The shape design of the racetrack-shaped slots 2012 enables the contact bracket 2031 to transition smoothly during movement, avoiding failures caused by friction or jamming, thereby achieving reliable closing and opening of the circuit.

[0032] The operating mechanism 10 comprises a connecting rod 101 and a push-pull plate 102 , wherein the push-pull plate 102 is sleeved on the connecting rod 101 and has an interference fit with the connecting rod 101 , and the push-pull plate 102 is provided with an oblique connecting portion toward the direction of the monopolar chamber.

[0033] It should be noted that the connecting rod 101 and the push-pull plate 102 convert the external operating force into the moving power of the moving contact system 203 through the matching and transmission mechanism. The push-pull plate 102 is sleeved on the connecting rod 101 and realizes an interference fit with the connecting rod 101. This interference fit ensures the firmness and stability of the push-pull plate 102 on the connecting rod 101, and avoids transmission failure caused by looseness or displacement. The push-pull plate 102 is provided with an oblique connection portion toward the direction of the single-pole chamber, so that when the push-pull plate 102 is subjected to the thrust or pulling force of the connecting rod 101, it can generate an oblique driving force, which is converted into the horizontal movement of the moving contact system 203 through the transmission mechanism, avoiding excessive lateral force on the moving contact system 203, and ensuring the stability and life of the moving contact system 203. When the external operating force acts on the operating mechanism 10, the connecting rod 101 starts to move, and drives the push-pull plate 102 to move together through the interference fit. The oblique connection portion on the push-pull plate 102 then generates an oblique driving force, which is transmitted to the moving contact system 203, causing it to move in the horizontal direction to achieve the closing or opening of the circuit.

[0034] The contact bracket 2031 is provided with a push-pull groove 20311 toward the opening 2011 of the single-pole chamber, and the connecting portion of the push-pull plate 102 extends into the push-pull groove 20311 through the opening 2011 and is connected to the contact bracket 2031 through a pin shaft to synchronously drive the contact system 203 to move horizontally when the operating mechanism 10 is operated.

[0035] It should be noted that when the operating mechanism 10 is subjected to an external operating force, the connecting rod 101 starts to move, and drives the connecting part to move together through the push-pull plate 102. Since the connecting part extends into the push-pull slot 20311 of the contact bracket 2031 and is connected to the contact bracket 2031 through the pin shaft, the movement of the connecting part will synchronously drive the contact bracket 2031 and the moving contact system 203 to move horizontally. This transmission mechanism not only realizes the precise control of the moving contact system 203, but also improves the flexibility and accuracy of the operation.

[0036] refer to Figure 6 , Figure 8 The moving contact system 203 also includes a spring sheet 2032, which includes an arched portion and two contact feet. The spring sheet 2032 is arranged between the contact bracket 2031 and the moving contact assembly 2033, wherein the arched portion abuts against the contact bracket 2031, and the contact feet abut against the upper and lower ends of the moving contact assembly 2033 respectively. The number of the spring sheets 2032 is the same as the number of the moving arc-striking contacts 20331 and the bridge contacts 20332 in the moving contact assembly 2033, wherein the width of the spring sheet 2032 abutting against the back side of the moving arc-striking contact 20331 is greater than that of the spring sheet 2032 abutting against the back side of the bridge contact 20332, and a moving contact insulating cover 2034 is provided on the side of the contact bracket 2031 extending toward the static contact system 205.

[0037] It should be noted that the spring sheet 2032 includes an arched portion and two contact feet. This design enables the spring sheet 2032 to provide effective support and buffering between the contact bracket 2031 and the moving contact assembly 2033. The arched portion has a certain elasticity and can be tightly abutted against the contact bracket 2031 to ensure the stability of the moving contact system 203 during movement. At the same time, the elasticity of the arched portion can also absorb some of the impact and vibration during operation, thereby extending the service life of the moving contact system 203. The two contact feet are respectively abutted against the upper and lower ends of the moving contact assembly 2033 to provide stable support for the moving arc-striking contact 20331 and the bridge contact 20332. This design not only ensures the precise alignment of the moving arc-striking contact 20331 and the bridge contact 20332 during operation, but also improves the electrical contact performance between them. It is worth noting that the number of spring pieces 2032 is the same as the number of moving arc-striking contacts 20331 and bridge-shaped contacts 20332 in the moving contact assembly 2033, so as to ensure that each moving arc-striking contact 20331 and bridge-shaped contact 20332 can be fully supported. In addition, according to the different sizes and weights of the moving arc-striking contacts 20331 and the bridge-shaped contacts 20332, the width of the spring pieces 2032 is also adjusted accordingly. Specifically, the width of the spring piece 2032 abutting against the back side of the moving arc-striking contact 20331 is greater than the spring piece 2032 abutting against the back side of the bridge-shaped contact 20332. This design can better adapt to the size difference between the moving arc-striking contact 20331 and the bridge-shaped contact 20332, and ensure stable contact and transmission between them. The present invention adds a moving contact insulation cover 2034 on the side of the contact support 2031 facing the static contact system 205, which effectively prevents the arc pressure from moving backward.

[0038] refer to Figure 4The cover shell 2057 is arranged on the outside of the static contact 2056, and an inclined portion is arranged above the cover shell 2057 toward the moving contact system 203, and the inclined portion and the static arc-striking contact 2052 form a bell mouth, and the insulating cover 2053 of the static contact 2056 is arranged below the cover shell 2057 and a reset spring 2054 is arranged at one end of the insulating cover 2053 of the static contact 2056 to drive the insulating cover 2053 of the static contact 2056 to reset.

[0039] It should be noted that the cover 2057 is arranged on the outside of the static contact 2056, providing a certain degree of protection for the static contact 2056, and preventing direct damage to the static contact 2056 by external factors. An inclined portion is arranged above the cover 2057 toward the moving contact system 203, and the inclined portion and the static arc-striking contact 2052 together form a trumpet shape. This design allows the static arc-striking contact 2052 to have a better rotation range, thereby realizing the conversion of contact force. An insulating cover 2053 of the static contact 2056 is added below the cover 2057 to effectively prevent the arc pressure from moving backward. A reset spring 2054 is arranged at one end of the insulating cover 2053 of the static contact 2056, so that the insulating cover 2053 of the static contact 2056 can be retracted inward when subjected to external force, thereby completing the contact between the static contact 2056 and the moving contact assembly 2033.

[0040] refer to Figure 6 The arc extinguishing chamber 202 includes an arc extinguishing grid, an arc striking plate, and an arc extinguishing cover. The arc striking plates are arranged on both sides of the arc extinguishing grid and are divided into dynamic arc striking plates and static arc striking plates. The static arc striking plates are arranged in the trumpet mouth formed by the inclined portion and the static arc contact, and the dynamic arc striking plates are arranged on the back of the dynamic arc striking contact 20331.

[0041] It should be noted that the arc-striking pieces are divided into moving arc-striking pieces and static arc-striking pieces, which are respectively arranged on both sides of the arc-extinguishing grid so that the arc can be more efficiently guided to the arc-extinguishing grid, thereby improving the arc-extinguishing efficiency. The static arc-striking piece is arranged in the bell mouth formed by the inclined portion and the static arc contact. When the moving contact system 203 contacts or separates from the static contact 2056 system 205, the generated arc will first be guided to the static arc-striking piece through the bell mouth, and then quickly transferred to the arc-extinguishing grid through the static arc-striking piece. The guiding path of the arc also reduces the direct damage of the arc to the static contact 2056 system 205. The moving arc-striking piece is directly arranged on the back of the moving arc-striking contact 20331. When the moving arc-striking contact 20331 separates from the static arc-striking contact 2052, the generated arc will be immediately captured by the moving arc-striking piece and guided to the arc-extinguishing grid. This design ensures that the arc can be extinguished quickly and effectively, thereby improving the breaking capacity and electrical life of the circuit breaker.

[0042] refer to Figure 7The moving arc-striking contact 20331 is provided with arc-striking contacts 203311 and auxiliary contacts 203312 at the upper and lower ends, and the main contacts 203321 are provided at both sides of the bridge contact 20332, wherein the auxiliary contacts 203312 and the main contacts 203321 are in the same plane.

[0043] It should be noted that when the moving contact system 203 moves toward the stationary contact 2056 system 205, the arc-striking contact 203311 first contacts the stationary arc contact 20521 in the stationary contact 2056 system 205 to generate an arc. At this time, the arc is quickly guided to the arc extinguishing chamber 202 for extinguishing. As the moving contact system 203 continues to move, the auxiliary contact 203312 and the main contact 203321 successively contact the stationary main contact 20522 in the stationary contact 2056 system 205 to form a stable electrical connection.

[0044] When the circuit breaker is disconnected, the auxiliary contact 203312 and the main contact 203321 are first separated from the static main contact 20522 in the static contact 2056 system 205, and the arc is generated again. Similarly, the arc is quickly guided to the arc extinguishing chamber 202 for extinguishing. The arc-starting contact 203311 is the last contact to be separated, ensuring the complete extinguishing of the arc and the safe disconnection of the circuit breaker.

[0045] A static arc contact 20521 is provided on the static arc-striking contact 2052 , and a long strip static main contact 20522 is provided on the static contact.

[0046] It should be noted that a static main contact 20522 is provided on the static contact 2056, which is responsible for forming a stable electrical connection with the corresponding contact in the moving contact system 203 when the circuit breaker is closed, ensuring smooth transmission of current. At the same time, a static arc contact 20521 is provided on the static contact 2056. This static arc contact 20521 corresponds to the arc-starting contact 203311 in the moving contact system 203, and is responsible for guiding and extinguishing the arc when the circuit breaker is disconnected. Thereby more effectively absorbing and dissipating the arc energy, improving the arc extinguishing efficiency. When the circuit breaker is closed, the static main contact 20522 is in close contact with the corresponding contact in the moving contact system 203 to form a stable electrical connection. At this time, the current is smoothly transmitted through the static main contact 20522, ensuring the normal operation of the power system. When the circuit breaker is disconnected, the moving contact system 203 and the static contact 2056 system 205 begin to separate first, generating an arc. As the moving contact system 203 continues to move, the arcing contact 203311 and the static arcing contact 20521 also begin to separate. At this time, the arc is extinguished by the arcing contact 203311 and the static arcing contact 20521. In this way, the circuit breaker can disconnect the circuit safely and reliably.

[0047] An installation area 2013 is also provided on the side panel, and a limiting structure is provided below the installation area 2013, wherein the busbar 2051 is provided in the installation area 2013, the cover shell 2057 is slidably assembled in the limiting structure, and the cover shell 2057 forms an insertion margin between the limiting structures for inserting the moving contact insulating cover 2034.

[0048] It should be noted that, during the assembly process of the circuit breaker, the design of the present invention enables the busbar 2051, the cover 2057 and the moving contact insulation cover 2034 and other components to be quickly and accurately assembled together in a predetermined order and manner. First, the busbar 2051 is installed in the installation area 2013 of the side plate and fixed by fasteners. Then, the cover 2057 is slidably assembled into the limiting structure, and the insertion margin between it and the limiting structure is ensured to meet the requirements through appropriate adjustments. Finally, when the moving contact insulation cover 2034 needs to be installed, it only needs to be inserted into the insertion margin between the cover 2057 and the limiting structure. At the same time, the setting of the insertion margin makes the moving contact insulation cover 2034 fully in the insertion margin when the moving and static contacts are in contact, thereby avoiding the influence of the moving contact insulation cover 2034 on the contact.

[0049] This assembly method not only simplifies the assembly process of the circuit breaker and improves the assembly efficiency, but also ensures the close fit and good connection between the various components. At the same time, due to the existence of the insertion margin, the replacement and maintenance of the moving contact insulation cover 2034 also become more convenient and quick.

[0050] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A direct-acting single-pole double-breakpoint DC frame circuit breaker, characterized in that: It includes a shell and an operating mechanism arranged on one side of the shell, the shell is provided with at least one group of single-pole chambers, the single-pole chamber includes a moving contact system and two groups of static contact systems in contact with the moving contact system, the static contact system includes a busbar, a static arc-striking contact, and a static contact, wherein the static contact is fixed to the busbar, the static arc-striking contact is rotatably connected to the static contact through a pin shaft, a torsion spring is sleeved on the pin shaft and abuts against the back of the static arc-striking contact to drive the static arc-striking contact to reset, the moving contact system includes a contact bracket that makes horizontal reciprocating motion toward the static arc-striking contact and a moving contact assembly located in the contact bracket, the moving contact assembly includes a moving arc-striking contact and a plurality of bridge contacts arranged side by side for connecting corresponding ones, the bridge contact and the corresponding two groups of static contacts form a double breakpoint structure, arc-extinguishing chambers are symmetrically arranged at the upper and lower ends of the moving contact system, the moving arc-striking contact and the static arc-striking contact are located in the arc-extinguishing chamber At the slit, the moving contact system also includes a spring sheet, the spring sheet includes an arched portion and two contact feet, the spring sheet is arranged between the contact bracket and the moving contact assembly, wherein the arched portion abuts against the contact bracket, and the contact feet abut against the upper and lower ends of the moving contact assembly respectively, the number of the spring sheets is the same as the number of moving arc-striking contacts and bridge contacts in the moving contact assembly, wherein the width of the spring sheet abutting against the back side of the moving arc-striking contact is greater than the spring sheet abutting against the back side of the bridge contact, the contact bracket is extended toward the side of the static contact system to be provided with a moving contact insulating cover, the static contact system also includes a cover shell and a static contact insulating cover, the cover shell is arranged on the outside of the static contact, and an inclined portion is arranged above the cover shell towards the moving contact system, the inclined portion and the static arc-striking contact form a trumpet mouth, the static contact insulating cover is arranged below the cover shell and is used to drive the static contact insulating cover to reset by arranging a reset spring at one end of the static contact insulating cover.

2. The direct-acting single-pole double-breakpoint DC frame circuit breaker according to claim 1 is characterized in that: The monopole chamber is assembled by two side plates, wherein two sets of upper and lower racetrack-shaped hole grooves are arranged in the side plates, and the contact bracket can realize horizontal movement in the hole grooves through bearings. The length of the hole grooves is the moving stroke of the contact bracket. An opening is arranged on one side of an assembly surface of the monopole chamber, and the contact bracket is located at the opening.

3. The direct-acting single-pole double-breakpoint DC frame circuit breaker according to claim 1 is characterized in that: The operating mechanism comprises a connecting rod and a push-pull plate, wherein the push-pull plate is sleeved on the connecting rod and has an interference fit with the connecting rod, and the push-pull plate is provided with an oblique connecting portion toward the direction of the monopolar chamber.

4. The direct-acting single-pole double-breakpoint DC frame circuit breaker according to claim 2 or 3, characterized in that: The contact bracket is provided with a push-pull groove in the opening direction toward the single-pole chamber, the connecting portion of the push-pull plate extends into the push-pull groove through the opening and is connected to the contact bracket through a pin shaft to synchronously drive the contact system to move horizontally when the operating mechanism is operated.

5. The direct-acting single-pole double-breakpoint DC frame circuit breaker according to claim 1 is characterized in that: The arc extinguishing chamber includes an arc extinguishing grid, an arc striking plate, and an arc extinguishing cover. The arc striking plates are arranged on both sides of the arc extinguishing grid and are divided into a dynamic arc striking plate and a static arc striking plate. The static arc striking plate is arranged in a trumpet mouth formed by the inclined portion and the static arc striking contact, and the dynamic arc striking plate is arranged on the back of the dynamic arc striking contact.

6. The direct-acting single-pole double-breakpoint DC frame circuit breaker according to claim 1, characterized in that: The moving arc-striking contact is provided with arc-striking contacts and auxiliary contacts at the upper and lower ends, and the bridge-shaped contact is provided with main contacts at both sides, wherein the auxiliary contacts and the main contacts are in the same plane.

7. The direct-acting single-pole double-breakpoint DC frame circuit breaker according to claim 1 is characterized in that: The static arc-striking contact is provided with a static arc contact, and the static contact is provided with a long strip static main contact.

8. The direct-acting single-pole double-breakpoint DC frame circuit breaker according to claim 2 is characterized in that: The side plate is also provided with an installation area, a limiting structure is provided below the installation area, wherein the busbar is provided in the installation area, the cover shell is slidably assembled in the limiting structure, and the cover shell forms an insertion margin between the limiting structures for inserting the moving contact insulating cover.

Images