Double-breakpoint circuit breaker for direct current system

Abstract

A double-breakpoint circuit breaker for a direct current system is characterized in that the double-breakpoint circuit breaker comprises an operating handle (1), the operating handle (1) is linked with a rotating shaft (3) through an upper connecting rod (2), a jump pin (6) and a lock catch (7), the rotating shaft (3) is connected with a double-breakpoint moving contact system (a) through a lower connecting rod (4), and the rotating shaft (3) can be driven to rotate through the upper connecting rod (2), the jump pin (6) and the lock catch (7) in the rotating process of the operating handle (1). And the rotating shaft (3) can drive the double-breakpoint moving contact system (a) to move up and down through the lower connecting rod (4) in the rotating process, so that the double-breakpoint moving contact system (a) and the corresponding double-breakpoint static contact system (b) are contacted and separated to realize the on-off of the circuit breaker. According to the circuit breaker, the rotation of the handle is converted into the up-and-down movement of the moving contact system through the improvement of the rotating shaft structure and the installation position, the purpose of double breakpoints is achieved, and the up-and-down movement of the double-breakpoint moving contact system is not required to be linear movement. The moving contact keeps a trend of rotating towards two sides under the action of the pressure spring so as to realize close contact with the static contact assembly, the installation difficulty of a product is simplified, the reliability and the stability of motion transmission are improved, meanwhile, due to the layout of the whole circuit breaker, more arc extinguishing grid sheets can be arranged in the circuit breaker, and the breaking capacity of the circuit breaker is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of low-voltage electrical appliances, and specifically relates to a double-breakpoint circuit breaker for a direct current system. Background Art

[0002] The word switch means opening and closing. It refers to a component that can open a circuit, interrupt the current or make it flow to another circuit. The most common switch is an electromechanical device operated by humans, which has one or more contacts. The "closed" contact means that the contact is conducting and allows current to flow; the "open" switch means that the contact is not conducting and forms an open circuit, and does not allow current to flow. The development history of switches has evolved from the original knife switch that requires manual operation to the current intelligent switch used in various large-scale electrical control equipment. The functions of switches are increasing and the safety is also increasing.

[0003] With the development of DC power systems such as photovoltaics, energy storage, rail transit, and data centers, the application of switches in DC systems has become more and more widespread. In the prior art, the circuit breakers originally used for AC systems cannot be used in DC systems, or can be used in DC systems after being improved, but the existing circuit breakers for DC systems cannot meet the requirements of fast disconnection in existing DC power systems. Even if there are some double-breakpoint circuit breakers that can be used in DC systems, they adopt a rotary structure, that is, two different moving contacts are installed on the same rotating shaft, and the rotation of the rotating shaft drives the moving contact to contact the static contact assembly during the rotation process, thereby achieving the purpose of double breakpoints. This type of rotary double-breakpoint circuit breaker is large in size, and it is difficult to arrange more arc-extinguishing grids, which results in limited arc-extinguishing ability of the circuit breaker and weak breaking ability.

[0004] Chinese Patent 202111275819.5 discloses a double-breakpoint contact electric switch, which belongs to the field of electric switch technology, and includes a shell, wherein an operating mechanism and a double-breakpoint contact mechanism are provided in the shell; at least one row of arc extinguishing chambers are respectively provided on both sides of the double-breakpoint contact mechanism; the operating mechanism includes an operating handle and a driving member connected to the operating handle, the driving member is connected to the moving contact frame of the double-breakpoint contact mechanism through a connecting rod, and a jump structure is connected to the driving member, and the jump structure has an elastic force that enables the driving member to move quickly when the driving member moves from the closing position to the opening position or from the opening position to the closing position; the double-breakpoint contact electric switch, through the cooperation of the operating mechanism and the double arc extinguishing chambers, enables the DC high voltage to be quickly cut off, and the arc is quickly cut and extinguished through the double grid plates, thereby improving the arc extinguishing performance and service life of the electric switch. However, the motion transmission structure of the switch is complex, especially the transmission structure that converts the rotation of the handle into the up and down movement of the moving contact is too complex, resulting in the inability to effectively arrange more arc-extinguishing grids to improve the arc-extinguishing capacity. It also has strict requirements on motion transmission and is difficult to process and assemble. Utility Model Content

[0005] The purpose of the utility model is to provide a double-breakpoint circuit breaker for a DC system in view of the defects of the circuit breaker used in the DC power system, such as complex motion transmission structure, difficult assembly, poor reliability, large product size and poor breaking performance. By improving the shaft structure and the installation position, the rotation of the handle can be converted into the up and down movement of the moving contact system, thereby achieving the purpose of double breakpoints, simplifying the installation difficulty of the product, and improving the reliability and stability of motion transmission. At the same time, the layout of the entire circuit breaker enables more arc extinguishing grids to be arranged in the circuit breaker, thereby improving the breaking capacity of the circuit breaker.

[0006] Technical Solution

[0007] In order to achieve the above technical objectives, the utility model provides a double-breakpoint circuit breaker for a DC system, characterized in that: it includes an operating handle, the operating handle is linked to a rotating shaft through an upper connecting rod, a trip buckle and a lock buckle, the rotating shaft is connected to a double-breakpoint moving contact system through a lower connecting rod, and during the rotation of the operating handle, the rotating shaft can be driven to rotate through the upper connecting rod, the trip buckle and the lock buckle, and during the rotation of the rotating shaft, the double-breakpoint moving contact system can be driven to move up and down through the lower connecting rod, so that the double-breakpoint moving contact system and the corresponding double-breakpoint static contact system are in contact and separation, thereby realizing the on and off of the circuit breaker.

[0008] In one of the embodiments, the operating handle is arranged above the inner cavity of the shell, and the operating end of the operating handle extends out of the shell, the rotating shaft is arranged at the right side below the operating handle, the double-breakpoint moving contact system is arranged at the position directly below the operating handle and can move in the shell space on the left side of the rotating shaft, the jumper and the lock are arranged on the rotating shaft, and the two sides of the double-breakpoint moving contact system are located in the shell space below the rotating shaft, and an arc-strike structure group and an arc-extinguishing chamber group are arranged in sequence up and down, the double-breakpoint static contact system corresponds to the double-breakpoint moving contact system, and a magnetic tripping system is installed on the outer side of the right arc-extinguishing chamber in the arc-extinguishing chamber group on one side of the shell where the rotating shaft is installed, and a thermal tripping system is installed on the outer side of the left arc-extinguishing chamber in the arc-extinguishing chamber group on the other side of the shell away from the installation of the rotating shaft, and the bimetallic strip in the thermal tripping system extends to the bottom position above the double-breakpoint moving contact system and is linked to the tripping rod extended from the lock.

[0009] Furthermore, a right wiring terminal is installed in the shell and located outside the magnetic tripping system.

[0010] In one embodiment, the jump buckle and the lock buckle are arranged on the rotating shaft.

[0011] In one of the embodiments, the operating handle drives the jump buckle to rotate via an upper connecting rod, and the jump buckle can be linked with the lock buckle to lock the operating mechanism during the rotation process.

[0012] Furthermore, the lock buckle can release the lock of the trip buckle under the action of a thermal trip system or a magnetic trip system.

[0013] Furthermore, the rotating shaft is rotatably installed in the inner cavity of the shell, the jump buckle is rotatably installed on the rotating shaft, the lock buckle is rotatably installed on the rotating shaft, and the reset torsion spring is installed on the lock buckle, with one end abutting against the raised platform on the rotating shaft and the other end abutting against the raised platform on the lock buckle. One end of the upper connecting rod is pivotally connected to the operating handle, and the other end is pivotally connected to the driving hole on the jump buckle. A linkage arm extends from the lock buckle, and a linkage step corresponding to the linkage arm is provided on the jump buckle.

[0014] Furthermore, a cantilever extends from the rotating shaft, one end of a lower connecting rod is mounted on the end of the cantilever, and the other end is mounted on the contact seat of the double-breakpoint moving contact system.

[0015] Furthermore, the rotating shaft is connected with a reaction spring for accelerating the opening speed.

[0016] In one of the embodiments, the double-breakpoint moving contact system includes a contact base, and a left moving contact and a right moving contact are rotatably mounted on both sides of the contact base. The outer surfaces of the contact parts of the left moving contact and the right moving contact are provided with insulating parts, and the two ends of the pressure spring respectively press against the inner sides of the corresponding insulating parts. The left moving contact and the right moving contact are connected by a soft connection.

[0017] Furthermore, the protruding contact portions provided on the left moving contact and the right moving contact expose the insulating member and correspond to the double-breakpoint static contact system.

[0018] Furthermore, the contact seat can slide up and down on the housing through a sliding groove structure.

[0019] Furthermore, the contact seat is connected to a switch-off acceleration spring.

[0020] Furthermore, the mounting portions of the left moving contact and the right moving contact are rotatably mounted in the moving contact mounting grooves on both sides of the inner cavity of the contact seat through contact shafts.

[0021] In one embodiment, the magnetic tripping system includes a coil bracket, a coil is mounted on the coil bracket, a moving iron core is installed in the inner cavity of the coil bracket, a push rod is installed at the upper end of the moving iron core, and a yoke is connected to the lower end of the moving iron core located on the outside of the coil bracket, the coil is connected to the right terminal, and a tripping piece is installed on the push rod, and the tripping piece is linked with the lock to unlock the lock.

[0022] Furthermore, one end of the magnetic yoke is mounted on the lower end of the moving iron core located outside the coil support, and the other end extends to the outside of the coil.

[0023] Furthermore, one end of the release member is fixed on the push rod, and the other end extends to one side of the lock to be linked with the lock.

[0024] Furthermore, the release member includes a frame-shaped push rod linkage portion and a lock unlocking push portion, the frame-shaped push rod linkage portion is placed on the push rod, one side of the frame-shaped push rod linkage portion is bent toward the lock direction to form a lock unlocking push portion for linkage with the lock, and a support portion is provided on one side of the frame-shaped push rod linkage portion.

[0025] In one embodiment, the thermal trip system includes a left terminal, one end of the connector is connected to the left terminal, and the other end is connected to one end of a bimetallic strip, and the other end of the bimetallic strip corresponds to a trip rod extending from the lock.

[0026] Furthermore, after the tripping rod extends from the lock buckle, it extends from the rear end of the cantilever on the rotating shaft to a position corresponding to the other end of the bimetallic strip.

[0027] Furthermore, the position of the connecting piece is adjustable.

[0028] Furthermore, the left wiring terminal includes a left wiring frame, which is installed in a left wiring terminal installation slot in the shell, and the left wiring screw is installed on the left wiring frame. One end of the left wiring board is connected to the left wiring frame, and the other end is connected to the connecting piece.

[0029] In one embodiment, the arc-striking structure group includes an upper magnetic conductive sheet arranged on the back of the arc-striking part of the static contact assembly in the double-breakpoint static contact system, and a front ceramic sheet and a rear ceramic sheet are respectively arranged on the front and rear sides of the arc-striking part, and the front and rear magnetic conductive sheets are respectively installed on the outer sides of the front ceramic sheet and the rear ceramic sheet, and the front ceramic sheet, the rear ceramic sheet, the arc-striking part, the upper magnetic conductive sheet, and the front and rear magnetic conductive sheets constitute an arc-striking channel, and the arc outlet of the arc-striking channel corresponds to the arc inlet of the arc extinguishing chamber group, and the arc inlet of the arc-striking channel corresponds to the contact position of the double-breakpoint moving contact system and the double-breakpoint static contact system.

[0030] Furthermore, the static contact assembly comprises an arc-striking portion, the tail of the arc-striking portion is connected to a static arc-striking plate bent downward, the front of the arc-striking portion extends a contact portion bent upward, and a static silver point is mounted on the contact portion.

[0031] Furthermore, the static arc-striking plate extends to the top ends of the corresponding arc-extinguishing grids of the left arc-extinguishing chamber and the right arc-extinguishing chamber.

[0032] Furthermore, a moving arc-striking plate is arranged at one side end of the left arc-extinguishing chamber and the right arc-extinguishing chamber corresponding to the left moving contact and the right moving contact respectively.

[0033] In one embodiment, the left arc extinguishing chamber and / or the right arc extinguishing chamber in the arc extinguishing chamber group are horizontally or obliquely arranged on both sides of the double-breakpoint moving contact system to independently extinguish the arc generated when the corresponding left moving contact and right moving contact in the double-breakpoint moving contact system a are disconnected.

[0034] Furthermore, the arc inlets of the left arc extinguishing chamber and the right arc extinguishing chamber respectively correspond to the arc outlets of the corresponding arc striking channels, and the arc outlets of the left arc extinguishing chamber and the right arc extinguishing chamber correspond to the corresponding exhaust ports on the shell.

[0035] Beneficial Effects

[0036] The utility model provides a double-breakpoint circuit breaker for a DC system, comprising an operating handle, wherein the operating handle is connected to a rotating shaft through an upper connecting rod, a trip buckle and a lock buckle, and the rotating shaft is connected to a double-breakpoint moving contact system through a lower connecting rod. During the rotation of the operating handle, the rotating shaft can be driven to rotate through the upper connecting rod, the trip buckle and the lock buckle, and during the rotation of the rotating shaft, the double-breakpoint moving contact system can be driven to move up and down through the lower connecting rod, so that the double-breakpoint moving contact system and the corresponding double-breakpoint static contact system are brought into contact and separated, thereby realizing the on and off of the circuit breaker. The circuit breaker converts the rotation of the handle into the up and down movement of the moving contact system by improving the shaft structure and the installation position, thereby achieving the purpose of double breakpoints. The up and down movement of the double breakpoint moving contact system does not require linear motion. The moving contact relies on the pressure spring to maintain the tendency to rotate to both sides, which can achieve close and reliable contact with the static contact assembly, simplifying the installation difficulty of the product and improving the reliability and stability of motion transmission. At the same time, the layout of the entire circuit breaker enables more arc extinguishing grids to be arranged in the circuit breaker. The double breakpoint structural design increases the total opening distance of the circuit contacts and improves the breaking capacity of the circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0038] Attached Figure 1a This is the product front view of the circuit breaker in Example 1 of the utility model.

[0039] Attached Figure 1b It is a top view of the circuit breaker in Example 1 of the utility model.

[0040] Attached Figure 2 It is a structural schematic diagram of the circuit breaker in the open state in Example 1 of the utility model.

[0041] Attached Figure 3 It is a structural schematic diagram of the circuit breaker in the closed state in Example 1 of the utility model.

[0042] Attached Figure 4 It is a schematic diagram of the rotating shaft product in Example 1 of the utility model.

[0043] Attached Figure 5 This is schematic diagram 1 of the lock product in Example 1 of the utility model.

[0044] Attached Figure 6 This is the lock product schematic diagram of the first embodiment of the utility model Figure 2.

[0045] Attached Figure 7 This is the front view of the lock in Example 1 of the utility model.

[0046] Attached Figure 8 It is a front view of the double-breakpoint moving contact system in Example 1 of the utility model.

[0047] Attached Fig. 9 It is a schematic diagram of the exploded view of the double-breakpoint moving contact system in Example 1 of the utility model.

[0048] Attached Fig.10 It is a schematic diagram of the internal installation structure of the double-breakpoint moving contact system in Example 1 of the utility model.

[0049] Attached Fig.11 It is a schematic diagram of the exploded connection relationship between the left moving contact and the right moving contact of the double-breakpoint moving contact system in Example 1 of the utility model.

[0050] Attached Fig.12 It is an axonometric diagram of the positional relationship between the double-breakpoint moving contact system and the double-breakpoint static contact system in Example 1 of the utility model.

[0051] Attached Fig.13 It is a schematic diagram of the position relationship between the double-breakpoint moving contact system and the double-breakpoint static contact system in Example 1 of the utility model.

[0052] Attached Fig.14 This is a schematic diagram of the installation of the thermal trip system in Example 1 of the utility model.

[0053] Attached Fig.15 It is a schematic diagram of the structure of the thermal tripping system in Example 1 of the utility model.

[0054] Attached Fig.16a This is a schematic diagram of the installation of the magnetic tripping system in Example 1 of the present utility model.

[0055] Attached Fig.16b It is a schematic diagram of the internal structure of the magnetic tripping system in Example 1 of the present utility model.

[0056] Attached Fig.17 It is a schematic diagram of the magnetic tripping system of the circuit breaker in the open state in Example 1 of the utility model.

[0057] Attached Fig.18 It is a schematic diagram of the installation of the arc extinguishing chamber group in Example 1 of the utility model.

[0058] Attached Fig.19 It is a schematic diagram of the positional relationship among the double-breakpoint moving contact system, the arc striking structure group and the arc extinguishing chamber group in Embodiment 1 of the present utility model.

[0059] Attached Fig. 20This is the first schematic diagram of the decomposition of the arc striking structure assembly in Example 1 of the present utility model.

[0060] Attached Fig.21 This is a schematic diagram of the arc-starting structure assembly in Example 1 of the utility model. Figure 2 .

[0061] Attached Fig. 22 This is a schematic diagram of the installation of the arc extinguishing chamber group in Example 2 of the utility model. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0063] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0064] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0065] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, a first feature being “above”, “above” or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below” or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0066] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0067] Example 1

[0068] In the prior art, circuit breakers used in DC power systems generally do not have a double breakpoint function. Even now, some circuit breakers with a double breakpoint function for DC power systems have appeared. The more common double breakpoint circuit breakers, in consideration of the installation space of the circuit breaker and the arc extinguishing space required by the double breakpoint circuit breaker, change the moving contact system of the double breakpoint circuit breaker from traditional rotation to linear motion. However, in the prior art solution, the rotation of the operating mechanism handle is converted into the linear motion of the double breakpoint moving contact system, the motion transmission structure is complex, the assembly precision requirements are high, the reliability is poor, the transmission is prone to jamming, the arc extinguishing effect is limited, and the breaking performance is poor.

[0069] In order to solve the above problems, the attached Figure 1a , 1b, 2 and 3, the present embodiment provides a double-breakpoint circuit breaker for a DC system, which includes an operating handle 1, and the operating handle 1 is linked to a rotating shaft 3 through an upper connecting rod 2, a tripping buckle 6 and a locking buckle 7. The rotating shaft 3 is connected to a double-breakpoint moving contact system a through a lower connecting rod 4. During the rotation of the operating handle 1, the rotating shaft 3 can be driven to rotate through the upper connecting rod 2, the tripping buckle 6 and the locking buckle 7. During the rotation of the rotating shaft 3, the double-breakpoint moving contact system a can be driven to move up and down through the lower connecting rod 4, so that the double-breakpoint moving contact system a and the corresponding double-breakpoint static contact system b are in contact and separation, thereby realizing the on and off of the circuit breaker. This embodiment utilizes the structure of a cantilever 302 extending from the rotating shaft 3. When the rotating shaft rotates, the cantilever drives the double-moving point moving contact system a to move. The up and down movement of the double-break point moving contact system a is not a completely linear movement, and there is also left and right movement (generally speaking, the left and right movement amplitude of the double-break point moving contact system a is relatively small), that is, the double-break point moving contact system a can also achieve contact with the double-break point static contact system b by slightly deflecting it to the left and right, which effectively reduces the difficulty of assembly and improves the reliability of motion transmission.

[0070] In this embodiment, the circuit breaker, especially the functional components of the circuit breaker, are further rearranged. Specifically, as shown in the attached Figure 2 and 3As shown, the operating handle 1 is arranged above the inner cavity of the shell 5, and the operating end of the operating handle 1 extends out of the shell 1. The rotating shaft 3 is arranged at the right position below the operating handle 1. The double-breakpoint moving contact system a is arranged directly below the operating handle 1 and can move in the shell 5 space on the left side of the rotating shaft 3. In this embodiment, the double-breakpoint moving contact system a is arranged directly below the operating handle 1. It does not require that the centers of the double-breakpoint moving contact system a and the operating handle 1 must be aligned. Generally speaking, as long as it is in the vertical direction up and down, it is considered to be directly below. The jump buckle 6 and the lock buckle 7 are arranged on the rotating shaft 3. The two sides of the double-breakpoint moving contact system a are located in the shell 5 space below the rotating shaft 3, and the arc striking structure group 8 and the arc extinguishing chamber group 9 are arranged in sequence from top to bottom, as shown in the attached figure. Fig.12 and 13 As shown, the double-breakpoint static contact system b corresponds to the double-breakpoint moving contact system a, a magnetic tripping system 10 is installed on the side of the housing 5 where the rotating shaft 3 is installed and located outside the right arc extinguishing chamber 901 in the arc extinguishing chamber group 9, and a thermal tripping system 11 is installed on the side of the housing 5 away from the rotating shaft 3 and located outside the left arc extinguishing chamber 902 in the arc extinguishing chamber group 9, and a bimetallic strip 1103 in the thermal tripping system 11 extends from the top of the corresponding side of the double-breakpoint static contact system b to the top bottom position of the double-breakpoint moving contact system a and is linked to the tripping rod 701 extending from the lock 7, and a corresponding side of the double-breakpoint static contact system b is provided with an avoidance gap to avoid the bimetallic strip 1103. The bimetallic strip 1103 and the static contact components b01, b01' in the double-breakpoint static contact system b are connected through a soft connection to form a circuit.

[0071] The housing 5 is provided with a right terminal 1006 outside the magnetic tripping system 10. Under the above layout structure, the housing 5 is in a convex shape to ensure that the volume of the circuit breaker is minimized. The double-breakpoint circuit breaker according to the above internal layout achieves the purpose of increasing the number of arc-extinguishing grids. Next, the structure and working principle of each functional component are further described in detail in conjunction with the accompanying drawings.

[0072] As attached Figure 2 and 3As shown, in the operating mechanism of the circuit breaker, the operating handle 1 drives the trip button 6 to rotate through the upper connecting rod 2, and the trip button 6 can be linked with the lock button 7 during rotation to lock the operating mechanism. The lock button 7 can release the lock of the trip button 6 under the action of the thermal trip system 11. Similarly, the lock button 7 can also release the lock of the trip button 6 under the action of the magnetic trip system 10. Further, the rotating shaft 3 is rotatably mounted in the inner cavity of the shell 5, the trip button 6 is rotatably mounted on the rotating shaft 3, the lock button 7 is rotatably mounted on the rotating shaft 3, and the reset torsion spring 12 is mounted on the lock button 7, one end of which is against the raised platform 301 on the rotating shaft 3, and the other end is against the raised platform 702 on the lock button 7. One end of the upper connecting rod 2 is pivotally connected to the operating handle 1, and the other end is pivotally connected to the driving hole 601 on the trip button 6, as shown in the attached figure. Figure 5 ,6 and 7, a linkage arm 703 extends from the lock buckle 7, and a linkage step 602 corresponding to the linkage arm 703 is provided on the jump buckle 6. In this embodiment, specifically, the rotating shaft 3 is rotatably mounted on the rotating shaft mounting shaft 504 on the housing 5, the jump buckle 6 is rotatably mounted on the jump buckle mounting shaft 303 on the rotating shaft 3, and the lock buckle 7 is rotatably mounted on the lock buckle mounting shaft 304 on the rotating shaft 3. As shown in the attached Figure 4 As shown, a cantilever 302 extends from the rotating shaft 3, one end of the lower connecting rod 4 is mounted on the end of the cantilever 302, and the other end is mounted on the contact seat a1 of the double-breakpoint moving contact system a. It should be noted that: in order to ensure that the left-right movement amplitude of the double-breakpoint moving contact is small, the rotation center o1 of the rotating shaft 3 rotatably mounted in the inner cavity of the housing 5 should be as far away as possible from the connection point o2 of one end of the lower connecting rod 4 and the end of the cantilever 302, so that the rotation of the rotating shaft is converted by the cantilever 302, ensuring that the double-breakpoint moving contact system a moves up and down as much as possible and the left-right movement amplitude is small. In addition, one end of the upper connecting rod 2 is pivotally connected to the operating handle 1, and the other end is pivotally connected to the driving hole 601 on the trip latch 6. The rotating shaft 3 is rotatably installed in the inner cavity of the shell 5. The trip latch 6 is rotatably installed on the trip latch mounting shaft 303 on the rotating shaft 3. The upper connecting rod 2, the trip latch 6, the lock latch 7 and the rotating shaft 3 form a connecting rod mechanism. The rotation of the operating handle 1 can drive the rotating shaft 3 to rotate through the upper connecting rod 2, the trip latch 6 and the lock latch 7, thereby driving the movement of the double breakpoint moving contact system a.

[0073] As attached Figure 2 and 3As shown, when an overload current appears in the circuit, in order to realize the opening of the operating handle 1, the rotating shaft 3 is connected with a reaction spring 13, one end of which abuts against the inner cavity of the housing 5, and the other end abuts against the rotating shaft 3. That is, when the operating handle 1 is closed, the reaction spring 13 is compressed to store energy, and when an overload current appears in the circuit and the operating handle 1 is about to change from the closed state to the open state, the reaction spring 13 is released, accelerating the rotation of the rotating shaft 3 to facilitate the opening.

[0074] As attached Figure 8 , 9, 10 and 11, in this embodiment, the double-breakpoint moving contact system a includes a contact seat a1, and the left moving contact a2 and the right moving contact a3 are rotatably mounted on both sides of the contact seat a1, and the left moving contact a2 and the right moving contact a3 are connected by a soft connection a8. In this embodiment, the mounting parts of the left moving contact a2 and the right moving contact a3 are rotatably mounted in the moving contact mounting grooves a101, a101' on both sides of the inner cavity of the contact seat a1 through contact shafts a7, a7'. As shown in the attached Fig.10 and 11As shown, in order to prevent the arc generated when the circuit breaker is disconnected from damaging the contact seat a1, the outer surface of the contact portion of the left moving contact a2 and the right moving contact a3 is equipped with insulating parts a5, a5', and the two ends of the pressure spring a4 are respectively against the inner side of the corresponding insulating parts a5, a5', and the pressure spring a4 is installed in the pressure spring installation groove a102 on the contact seat a1. The two ends of the pressure spring a4 are respectively placed in the pressure spring grooves a501, a501' on the inner side of the corresponding insulating parts a5, a5' and against the bottom of the pressure spring grooves a501, a501', and the upper ends of the insulating parts a5, a5' are provided with protruding angles a502, a502' for increasing the creepage distance. At the same time, the protruding contact parts a201, a301 provided on the left moving contact a2 and the right moving contact a3 expose the insulating parts a5, a5' and correspond to the double-breakpoint static contact system b. The left moving contact a2 and the right moving contact a3 are limited in their rotational travel by the moving contact mounting grooves a101, a101'. With this structure, during the up and down movement of the contact seat a1, the contact seat a1 is driven to move by the cantilever 302 of the rotating shaft 3. During the rotation of the rotating shaft 3, the cantilever 302 drives the contact seat a1 to move up and down. Since the contact seat does not move in a straight line up and down, the left moving contact a2 and the right moving contact a3 always have a tendency to rotate outward under the action of the pressure spring a4. During the upward movement of the left moving contact a2 and the right moving contact a3 with the contact seat, the protruding contact parts a201, a301 provided on the left moving contact a2 and the right moving contact a3 will respectively contact the static silver points b01c, b01c' corresponding to the contact parts b01b, b01b' of the double-breakpoint static contact system b, and at the contact parts b01 b, b01 b', it slightly rotates inwards under the action of the corresponding static silver points b01c, b01c', so as to realize the close contact between the protruding contact parts a201, a301 and the corresponding static silver points b01c, b01c' of the contact parts b01b, b01b'. At the same time, the rotating installation of the left moving contact a2 and the right moving contact a3 and the coordination of the up and down non-linear movement of the contact seat make it unnecessary for the left moving contact a2 and the right moving contact a3 to be symmetrically installed in the middle, which reduces the difficulty of assembling the double-breakpoint moving contact system a, improves the reliability of motion transmission, and is not prone to jamming.

[0075] In this embodiment, for smooth and convenient movement, the contact seat a1 can slide up and down on the housing 5 through the slide groove 501 structure. Generally speaking, if the slide groove 501 structure is installed on the housing 5, the slide rail needs to be installed on the contact seat a1. On the contrary, if the slide groove 501 structure is installed on the contact seat a, the slide rail needs to be installed on the housing 5.

[0076] In this embodiment, as shown in the attached Figure 2As shown, in order to guide and limit the movement process of the left moving contact a2 and the right moving contact a3, guide and limit shafts 505, 505' are provided at corresponding positions on the shell 5 outside the left moving contact a2 and the right moving contact a3, and the guide and limit shafts 505, 505' can provide inward rotation pressure to the left moving contact a2 and the right moving contact a3 during the movement process.

[0077] The contact seat a1 includes a contact base a103 and a contact upper cover a104, and the contact base a103 and the contact upper cover a104 are locked together. The contact seat a1 is connected with a switch-off acceleration spring a6. When the switch-off acceleration spring a6 is placed above the contact seat a1, the switch-off acceleration spring a6 is a tower spring or a compression spring, and when the switch-off acceleration spring a6 is placed at the bottom of the contact seat a1, the switch-off acceleration spring a6 is a tension spring. In this embodiment, the switch-off acceleration spring a6 is arranged in a spring mounting groove 503 on the housing 5 between the left arc extinguishing chamber 902 and the right arc extinguishing chamber 901 on both sides of the double-break moving contact system a, one end of which is connected to the contact seat a1, and the other end is fixedly mounted on the bottom of the spring mounting groove 503 on the housing 5. The left arc extinguishing chamber 902 and the right arc extinguishing chamber 901 are separated by the spring mounting groove 503 on the housing 5. The opening acceleration spring a6 provides a downward force to the contact seat a1, causing it to have a tendency to move downward.

[0078] As attached Fig.16a , 16b and 17, in this embodiment, the magnetic tripping system 10 includes a coil bracket 1001, a coil 1002 is sleeved on the coil bracket 1001, a moving iron core 1003 is installed in the inner cavity of the coil bracket 1001, a push rod 1004 is installed at the upper end of the moving iron core 1003, and the lower end of the moving iron core 1003 located on the outer side of the coil bracket 1001 is connected with a yoke 1005, the coil 1002 is connected to the right wiring terminal 1006, and the right wiring terminal 1006 is installed in the right terminal mounting groove 506 on the right side of the shell 5, and a tripping member 1007 is installed on the push rod 1004, and the tripping member 1007 is connected to the outer side of the coil bracket 1001. Figure 5 ,6,7 shown in the lock buckle 7 linkage can unlock the lock buckle 7. Specifically, one end of the yoke 1005 is mounted on the lower end of the moving iron core 1003 located outside the coil support 1001, and the other end extends to the outside of the coil 1002. One end of the release member 1007 is fixed to the push rod 1004, and the other end extends to the outer side of the coil support 1001 as shown in the attached figure. Figure 6 One side of the lock buckle 7 is linked to the release step 705 on the lock buckle 7. Fig.16bAs shown, one end of the moving iron core 1003 located in the inner cavity of the coil support 1001 is fixedly connected to a moving iron core stopper 1008, and a static iron core 1009 is placed in the inner cavity of the coil support 1001 and corresponds to the moving iron core 1003. One end of the moving iron core stopper 108 is fixedly connected to the moving iron core 1003, and the other end passes through the static iron core 1009 and extends out of the coil support 1001. The iron core spring 1010 is sleeved on the moving iron core stopper 1008, one end of which abuts against the moving iron core 1003, and the other end abuts against the static iron core 1009. A stopper 1008a is provided on one end of the moving iron core stopper 1008 extending out of the coil support 1001 to limit the movement stroke of the moving iron core stopper 1008. In this embodiment, the release member 1007 is an elastic release member. The release member 1007 includes a frame-shaped push rod linkage part 1007a and a lock unlocking push part 1007b. The frame-shaped push rod linkage part 1007a is provided with a push rod linkage slot (not shown in the drawings). The push rod 1004 is located in the push rod linkage slot and can drive the release member 1007 to move through the push rod linkage slot. One side of the frame-shaped push rod linkage part 1007a is bent toward the lock 7 to form a lock unlocking push part 1007b for linkage with the lock 7. One side of the frame-shaped push rod linkage part 1007a is provided with a support part 1007c. The release member 1007 is installed on the shaft 1007c01 on the housing 5 through the shaft hole on the support part 1007c (not shown in the drawings) and can rotate around the shaft 1007c01. As shown in the attached figure Fig.18 As shown, in the power-on state, the coil induces a magnetic field, and the moving iron core 1003 moves downward under the action of the magnetic field, driving the push rod 1004 to move downward, thereby driving the tripping member 1007 to release the lock 7, so that the circuit breaker is tripped and opened as shown in the attached figure. Figure 2 and 17 shown.

[0079] As attached Fig.14 and 15 As shown, the thermal trip system 11 in this embodiment includes a left wiring terminal 1101, one end of a connector 1102 is connected to the left wiring terminal 1101, and the other end is connected to one end of a bimetallic strip 1103, and the other end of the bimetallic strip 1103 corresponds to a tripping rod 701 extending from the lock buckle 7. The tripping rod 701 is installed as shown in the attached Figure 6On the trip rod shaft 704 on the lock buckle 7 shown, the trip rod 701 extends from the lock buckle 7 and then extends from the rear side end of the cantilever 302 on the rotating shaft 3 to the position corresponding to the other end of the bimetallic strip 1103. The position of the connecting piece 1102 is adjustable. The adjusting screw 1104 is mounted on the upper surface of the housing 5 and corresponds to the connecting piece 1102 to adjust the position of the connecting piece 1102 and then adjust the position of the bimetallic strip 1103. The left wiring terminal 1101 includes a left wiring frame 1101a, the left wiring frame 1101a is installed in the left wiring terminal installation groove 505 in the housing 5, the left wiring screw 1101b is installed on the left wiring frame 1101a, one end of the left wiring board 1101c is connected to the left wiring frame 1101a, and the other end is connected to the connecting piece 1102. The thermal trip system 11 is placed on a side of the housing of the circuit breaker away from the operating mechanism, which effectively utilizes the space in the housing, reduces the volume of the circuit breaker, and is conducive to arranging the corresponding arc extinguishing chamber of the double-breakpoint moving contact system.

[0080] In a circuit breaker with a dual breakpoint function, the arc extinguishing capability is required to be high, so the breaking arc needs to be quickly introduced into the arc extinguishing chamber for extinguishing. Therefore, in this embodiment, Fig.19 As shown in FIG. 1 , an arc striking structure group 8 is provided at the entrance of the arc extinguishing chamber. Fig. 20 and 21 As shown, the arc-striking structure group 8 includes an upper magnetic conductive sheet 801, 801' on the back of the arc-striking portion b01a, b01a' of the static contact assembly b01, b01' in the double-breakpoint static contact system b, and the front and rear sides of the arc-striking portion b01a, b01a' are respectively provided with a front ceramic sheet and a rear ceramic sheet, and the outer sides of the front ceramic sheet 806, 806' and the rear ceramic sheet 807, 807' are respectively provided with a front magnetic conductive sheet 802, 802' and a rear magnetic conductive sheet 803, 803', and the front ceramic sheet 806, 806', the rear ceramic sheet 807, 807', the arc-striking portion b01a, b01a' a', the upper magnetic conductive sheet 801, 801' and the front magnetic conductive sheet 802, 802' and the rear magnetic conductive sheet 803, 803' constitute an arc-striking channel 805, 805', the arc outlet of the arc-striking channel 805, 805' corresponds to the arc inlet 901a, 902a of the arc-extinguishing chamber group 9, and the arc inlet of the arc-striking channel 805, 805' corresponds to the contact part of the double-breakpoint moving contact system a and the double-breakpoint static contact system b. In such a structure, the front magnetic conductive sheet 802, 802' and the rear magnetic conductive sheet 803, 803' can further quickly introduce the breaking arc into the corresponding left arc-extinguishing chamber 902 and right arc-extinguishing chamber 901 along the arc-striking channel 805, 805' under the action of the magnetic field.

[0081] Further, as attached Fig. 20 and 21As shown, in this embodiment, the static contact assembly b01, b01' comprises an arc-striking portion b01a, b01a', the tail of the arc-striking portion b01a, b01a' is connected to a static arc-striking plate 804, 804' bent downward, the front of the arc-striking portion b01a, b01a' extends a contact portion b01b, b01b' bent upward, and the contact portion b01b, b01b' is provided with a static silver point b01c, b01c'. The static arc-striking plate 804, 804' extends to the top of the corresponding arc-extinguishing grids of the left arc-extinguishing chamber 902 and the right arc-extinguishing chamber 901. The static arc-striking plates 804, 804', the arc-striking parts b01a, b01a' and the contact parts b01b, b01b' are installed together or in an integrated form. In this embodiment, the static arc-striking plates 804, 804', the arc-striking parts b01a, b01a' and the contact parts b01b, b01b' are in an integrated form. Figure 2 As shown, the left arc extinguishing chamber 902 and the right arc extinguishing chamber 901 are respectively provided with moving arc-striking plates 808, 808' at one side end corresponding to the left moving contact a2 and the right moving contact a3. The structure of the static contact assembly b01, b01' can effectively contact with the protruding contact parts a201, a301 provided on the left moving contact a2 and the right moving contact a3 in the contact seat a1 that moves up and down, and can also match with the position of the arc-striking structure group 8, which is conducive to breaking the arc and quickly entering the arc extinguishing chamber.

[0082] As attached Fig.18 As shown, the left arc extinguishing chamber 902 and / or the right arc extinguishing chamber 901 in the arc extinguishing chamber group 9 are arranged obliquely on both sides of the double-breakpoint moving contact system a to independently extinguish the arc generated when the corresponding left moving contact a2 and right moving contact a3 in the double-breakpoint moving contact system a are disconnected. The arc inlets of the left arc extinguishing chamber 902 and the right arc extinguishing chamber 901 correspond to the arc outlets of the corresponding arc striking channels 805, 805', respectively, and the arc outlets of the left arc extinguishing chamber 902 and the right arc extinguishing chamber 901 correspond to the corresponding exhaust ports 502, 502' on the housing 5. The arc generated by the disconnection of the left moving contact a2 and the right moving contact a3 in the double-breakpoint moving contact system a and the corresponding static contact assemblies b01, b01' in the double-breakpoint static contact system b enters the corresponding left arc extinguishing chamber 902 and the right arc extinguishing chamber 901 through the corresponding arc-starting channels 805, 805', and then is discharged from the housing through the corresponding exhaust ports 502, 502' after arc extinguishing. Different moving contacts correspond to different arc extinguishing chambers, which effectively improves the arc extinguishing capacity of the arc extinguishing chamber and improves the breaking performance of the circuit breaker.

[0083] The working principle of the above-mentioned circuit breaker is as follows: when normal current passes through the circuit, the circuit breaker is in a closed state, the lock catch 7 and the trip catch 6 are buckled together, and the reaction spring 13 cannot push the rotating shaft 3 to rotate, thereby avoiding accidental closing of the circuit; when the circuit breaker needs to be manually opened, the rotation of the operating handle 1 drives the upper connecting rod 2 to move, and the upper connecting rod 2, the trip catch 6, the lock catch 7 and the rotating shaft 3 form a connecting rod mechanism, so the movement of the upper connecting rod 2 will drive the rotating shaft 3 to rotate, thereby driving the disconnection of the double-breakpoint moving contact system a and the double-breakpoint static contact system b to realize the circuit breaker opening.

[0084] When a small overload current appears in the circuit, the bimetal strip 1103 in the thermal trip system 11 is deformed by heat and hits the trip rod 701, and the lock 7 rotates to release the lock on the trip button 6; when a large instantaneous current appears in the circuit, the magnetic trip system 10 is energized, and the trip part 1007 pushes the lock 7 to rotate to release the lock on the trip button 6. When a fault abnormal current appears in these two circuits, the lock of the trip button is released, and the shaft 3 can rotate under the action of the reaction spring 13 to drive the disconnection of the double-breakpoint moving contact system a and the corresponding double-breakpoint static contact system b. In this process, the opening acceleration spring a6 provides a downward pulling force to the contact seat a1, making it tend to move downward, thereby accelerating the opening speed.

[0085] Example 2

[0086] As attached Fig. 22 As shown, in this embodiment, the left arc extinguishing chamber 902 and / or the right arc extinguishing chamber 901 in the arc extinguishing chamber group 9 are horizontally arranged on both sides of the double-breakpoint moving contact system a. Other structures and working principles are the same as those in Embodiment 1.

[0087] The embodiment of the utility model provides a double-breakpoint circuit breaker for a DC system. The circuit breaker converts the rotation of the handle into the up and down movement of the moving contact system through the improvement of the rotating shaft structure and the installation position, thereby achieving the purpose of double breakpoints. The up and down movement of the double-breakpoint moving contact system does not require linear motion. The moving contact relies on the pressure spring to maintain the tendency to rotate to both sides to achieve close contact with the static contact assembly, which simplifies the installation difficulty of the product and improves the reliability and stability of motion transmission. At the same time, the layout of the entire circuit breaker enables more arc-extinguishing grids to be arranged in the circuit breaker, thereby improving the breaking capacity of the circuit breaker. It should also be noted that the above technical solution can not only be used for circuit breakers, but any technical solution inspired by the technical idea of ​​the utility model should be deemed to fall within the protection scope of the utility model.

[0088] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0089] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A double-breakpoint circuit breaker for a DC system, characterized in that: It comprises an operating handle (1), wherein the operating handle (1) is linked to a rotating shaft (3) through an upper connecting rod (2), a tripping buckle (6) and a locking buckle (7); a cantilever (302) extends from the rotating shaft (3); one end of a lower connecting rod (4) is mounted on the end of the cantilever (302), and the other end is mounted on a contact seat (a1) of a double-breakpoint moving contact system (a); the rotating shaft (3) is connected to the double-breakpoint moving contact system (a) through the lower connecting rod (4); during the rotation of the operating handle (1), the rotating shaft (3) can be driven to rotate through the upper connecting rod (2), the tripping buckle (6) and the locking buckle (7); during the rotation of the rotating shaft (3), the double-breakpoint moving contact system (a) can be driven to move up and down through the lower connecting rod (4), so that the double-breakpoint moving contact system (a) and the corresponding double-breakpoint static contact system (b) are in contact and separated, thereby realizing the on and off of the circuit breaker.

2. A double breakpoint circuit breaker for a DC system according to claim 1, characterized in that: The operating handle (1) is arranged above the inner cavity of the housing (5), and the operating end of the operating handle (1) extends out of the housing (5); the rotating shaft (3) is arranged at a right position below the operating handle (1); the double-breakpoint moving contact system (a) is arranged directly below the operating handle (1) and is capable of moving in the housing (5) space on the left side of the rotating shaft (3); arc striking structure groups (8) and arc extinguishing chamber groups (9) are arranged in sequence in the housing (5) space below the rotating shaft (3) on both sides of the double-breakpoint moving contact system (a); and the double-breakpoint static contact system (b) is provided at a right position below the operating handle (1) and is capable of moving in the housing (5) space on the left side of the rotating shaft (3). Corresponding to the double-break moving contact system (a), a magnetic tripping system (10) is installed on one side of the housing (5) where the rotating shaft (3) is installed and located on the outside of the right arc extinguishing chamber (901) in the arc extinguishing chamber group (9), and a thermal tripping system (11) is installed on one side of the housing (5) away from the rotating shaft (3) and located on the outside of the left arc extinguishing chamber (902) in the arc extinguishing chamber group (9). The bimetallic strip (1103) in the thermal tripping system (11) extends to the bottom position above the double-break moving contact system (a) and is linked to a tripping rod (701) extending from the lock (7).

3. A double breakpoint circuit breaker for a DC system as claimed in claim 2, characterized in that: A right wiring terminal (1006) is installed inside the housing (5) and outside the magnetic tripping system (10).

4. A double breakpoint circuit breaker for a DC system as claimed in claim 2, characterized in that: The jump buckle (6) and the lock buckle (7) are arranged on the rotating shaft (3).

5. A double breakpoint circuit breaker for a DC system according to claim 1, characterized in that: The operating handle (1) drives the jump buckle (6) to rotate via the upper connecting rod (2); during the rotation of the jump buckle (6), the jump buckle (6) can be linked with the lock buckle (7) to achieve locking of the operating mechanism.

6. A double breakpoint circuit breaker for a DC system as claimed in claim 5, characterized in that: The lock buckle (7) can release the lock of the trip buckle (6) under the action of a thermal tripping system (11) or a magnetic tripping system (10).

7. A double breakpoint circuit breaker for a DC system as claimed in claim 3, characterized in that: The rotating shaft (3) is rotatably mounted in the inner cavity of the shell (5), the jump buckle (6) is rotatably mounted on the rotating shaft (3), the lock buckle (7) is rotatably mounted on the rotating shaft (3), and the reset torsion spring (12) is mounted on the lock buckle (7), one end of which abuts against the raised platform (301) on the rotating shaft (3), and the other end abuts against the raised platform (702) on the lock buckle (7). One end of the upper connecting rod (2) is pivotally connected to the operating handle (1), and the other end is pivotally connected to the driving hole (601) on the jump buckle (6). A linkage arm (703) extends from the lock buckle (7), and a linkage step (602) corresponding to the linkage arm (703) is provided on the jump buckle (6).

8. A double breakpoint circuit breaker for a DC system as claimed in claim 7, characterized in that: The rotating shaft (3) is connected to a reaction spring (13) for accelerating the opening speed.

9. A double breakpoint circuit breaker for a DC system according to claim 1 or 2, characterized in that: The double-breakpoint moving contact system (a) comprises a contact seat (a1), a left moving contact (a2) and a right moving contact (a3) ​​are rotatably mounted on both sides of the contact seat (a1), the outer surfaces of the contact parts of the left moving contact (a2) and the right moving contact (a3) ​​are provided with insulating parts (a5, a5'), the two ends of the pressure spring (a4) respectively press against the inner sides of the corresponding insulating parts (a5, a5'), and the left moving contact (a2) and the right moving contact (a3) ​​are connected via a soft connection (a8).

10. A double breakpoint circuit breaker for a DC system according to claim 9, characterized in that: The protruding contact parts (a201, a301) arranged on the left moving contact (a2) and the right moving contact (a3) ​​expose the insulating parts (a5, a5') and correspond to the double-breakpoint static contact system (b).

11. A double breakpoint circuit breaker for a DC system as claimed in claim 9, characterized in that: The contact seat (a1) can slide up and down on the housing (5) through the sliding groove (501).

12. A double breakpoint circuit breaker for a DC system as claimed in claim 9, characterized in that: The contact seat (a1) is connected to a switch-off acceleration spring (a6).

13. A double breakpoint circuit breaker for a DC system as claimed in claim 9, characterized in that: The mounting parts of the left moving contact (a2) and the right moving contact (a3) ​​are rotatably mounted in the moving contact mounting grooves (a101, a101') on both sides of the inner cavity of the contact seat (a1) via contact shafts (a7, a7').

14. A double breakpoint circuit breaker for a DC system as claimed in claim 6, characterized in that: The magnetic tripping system (10) comprises a coil support (1001), a coil (1002) is sleeved on the coil support (1001), a moving iron core (1003) is mounted in an inner cavity of the coil support (1001), a push rod (1004) is mounted on the upper end of the moving iron core (1003), a yoke (1005) is connected to the lower end of the moving iron core (1003) located outside the coil support (1001), the coil (1002) is connected to a right wiring terminal (1006), a tripping member (1007) is mounted on the push rod (1004), and the tripping member (1007) is linked with the lock (7) to unlock the lock (7).

15. A double breakpoint circuit breaker for a DC system as claimed in claim 14, characterized in that: One end of the magnetic yoke (1005) is mounted on the lower end of the moving iron core (1003) located outside the coil support (1001), and the other end extends to the outside of the coil (1002).

16. A double breakpoint circuit breaker for a DC system as claimed in claim 14, characterized in that: One end of the release member (1007) is fixed on the push rod (1004), and the other end extends to one side of the lock buckle (7) to be linked with the lock buckle (7).

17. A double breakpoint circuit breaker for a DC system as claimed in claim 14, characterized in that: The release member (1007) comprises a frame-shaped push rod linkage portion (1007a) and a lock unlocking push portion (1007b); the frame-shaped push rod linkage portion (1007a) is placed on the push rod (1004); one side of the frame-shaped push rod linkage portion (1007a) is bent toward the lock (7) to form a lock unlocking push portion (1007b) for linkage with the lock (7); and a support portion (1007c) is provided on one side of the frame-shaped push rod linkage portion (1007a).

18. A double breakpoint circuit breaker for a DC system as claimed in claim 6, characterized in that: The thermal trip system (11) comprises a left wiring terminal (1101), one end of a connecting piece (1102) is connected to the left wiring terminal (1101), and the other end is connected to one end of a bimetallic strip (1103), and the other end of the bimetallic strip (1103) corresponds to a trip rod (701) extending from a lock buckle (7).

19. A double breakpoint circuit breaker for a DC system as claimed in claim 18, characterized in that: The tripping rod (701) extends from the lock buckle (7) and then from the rear end of the cantilever (302) on the rotating shaft (3) to a position corresponding to the other end of the bimetallic strip (1103).

20. A double breakpoint circuit breaker for a DC system as claimed in claim 18, characterized in that: The position of the connecting member (1102) is adjustable.

21. A double breakpoint circuit breaker for a DC system as claimed in claim 18, characterized in that: The left wiring terminal (1101) comprises a left wiring frame (1101a), the left wiring frame (1101a) is installed in a left wiring terminal installation slot (505) in a housing (5), a left wiring screw (1101b) is installed on the left wiring frame (1101a), and a left wiring board (1101c) is connected to the left wiring frame (1101a) at one end and connected to a connecting piece (1102) at the other end.

22. A double breakpoint circuit breaker for a DC system as claimed in claim 2, characterized in that: The arc-striking structure group (8) comprises an upper magnetic conductive sheet (801, 801') arranged at the back of an arc-striking portion (b01a, b01a') of a static contact assembly (b01, b01') in the double-breakpoint static contact system (b), a front ceramic sheet (806, 806') and a rear ceramic sheet (807, 807') are respectively arranged at the front and rear sides of the arc-striking portion (b01a, b01a'), a front magnetic conductive sheet (802, 802') and a rear magnetic conductive sheet (803, 803') are respectively arranged on the outer sides of the front ceramic sheet (806, 806') and the rear ceramic sheet (807, 807'), the front ceramic sheet (806, 806'), the rear ceramic sheet (807, 807'), the arc-striking portion (b01a, b01a') a'), an upper magnetic conductive sheet (801, 801'), a front magnetic conductive sheet (802, 802') and a rear magnetic conductive sheet (803, 803') form an arc striking channel (805, 805'), an arc outlet of the arc striking channel (805, 805') corresponds to an arc entrance of an arc extinguishing chamber group (9), and an arc entrance of the arc striking channel (805, 805') corresponds to a contact position of a double-breakpoint moving contact system (a) and a double-breakpoint static contact system (b).

23. A double breakpoint circuit breaker for a DC system as claimed in claim 22, characterized in that: The static contact assembly (b01, b01') comprises an arc-striking portion (b01a, b01a'), the tail of the arc-striking portion (b01a, b01a') is connected to a static arc-striking plate (804, 804') bent downward, the front of the arc-striking portion (b01a, b01a') extends a contact portion (b01b, b01b') bent upward, and a static silver point (b01c, b01c') is installed on the contact portion (b01b, b01b').

24. A double breakpoint circuit breaker for a DC system as claimed in claim 23, characterized in that: The static arc-striking plates (804, 804') extend to the top ends of the corresponding arc-extinguishing grids of the left arc-extinguishing chamber (902) and the right arc-extinguishing chamber (901).

25. A double breakpoint circuit breaker for a DC system as claimed in claim 24, characterized in that: Moving arc-striking plates (808, 808') are arranged at one side end of the left arc-extinguishing chamber (902) and the right arc-extinguishing chamber (901) corresponding to the left moving contact (a2) and the right moving contact (a3), respectively.

26. A double breakpoint circuit breaker for a DC system as claimed in claim 2, characterized in that: The left arc extinguishing chamber (902) and / or the right arc extinguishing chamber (901) in the arc extinguishing chamber group (9) are arranged horizontally or obliquely on both sides of the double-breakpoint moving contact system (a) to independently extinguish the arc generated when the corresponding left moving contact (a2) and right moving contact (a3) ​​in the double-breakpoint moving contact system (a) are disconnected.

27. A double breakpoint circuit breaker for a DC system as claimed in claim 26, characterized in that: The arc inlets of the left arc extinguishing chamber (902) and the right arc extinguishing chamber (901) respectively correspond to the arc outlets of the corresponding arc striking channels (805, 805'), and the arc outlets of the left arc extinguishing chamber (902) and the right arc extinguishing chamber (901) correspond to the corresponding exhaust ports (502, 502') on the housing (5).

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