A contact system for a circuit breaker

Abstract

The application discloses a contact system of a circuit breaker, which comprises a first current-carrying copper bar, a second current-carrying copper bar, a static main contact, a dynamic main contact, a static arc contact, a dynamic arc contact assembly, a dynamic contact rod, a spring mechanism and a flexible connection mechanism; the first current-carrying copper bar and the second current-carrying copper bar are fixedly installed on the frame of the circuit breaker; the static main contact and the static arc contact are fixedly installed on the first current-carrying copper bar, and the static arc contact is located above the static main contact; one end of the spring mechanism is rotationally connected with the frame of the circuit breaker, and the other end is rotationally connected with the dynamic contact rod; the dynamic main contact is fixedly installed on the side surface of the top end of the dynamic contact rod, and the dynamic arc contact assembly is installed on the top end of the dynamic contact rod and electrically connected with the second current-carrying copper bar through the flexible connection mechanism; the dynamic arc contact assembly comprises a dynamic arc contact, the dynamic arc contact can move within a certain range, and the dynamic arc contact is located above the dynamic main contact; the dynamic main contact and the dynamic arc contact can move along with the rotation of the dynamic contact rod.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of switchgear, in particular to a contact system of a circuit breaker. BACKGROUND

[0002] For a circuit breaker, the contact system is a core component. In order to ensure that the circuit breaker operates stably and reliably for a long time, the following must be achieved: 1) when the contact system passes through the rated current for a long time, the temperature rise does not exceed the value specified in the national standard, and the temperature rise remains stable for a long time; 2) when the contact system passes through a short-circuit current below the setting trip value, the contact contact part does not fuse or relax; 3) during the breaking process of the circuit breaker, the loss of the contact material should be as small as possible; 4) during the closing process of the circuit breaker, the contact contact part should not fuse and cannot be opened, and the surface of the contact should not have serious deformation or damage.

[0003] Based on the above basic requirements, the design of the contact structure of the circuit breaker is particularly important. In the design process of the circuit breaker, how to ensure the stability of the contact resistance, reduce the contact closing bounce, and reduce the fusion and wear of the contact material has always been the core of studying the circuit breaker. The existing contact system of the circuit breaker is usually difficult to well complete the above requirements. SUMMARY

[0004] In order to solve the problems raised in the background art, the purpose of the present application is to provide a contact system of a circuit breaker.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is:

[0006] A contact system of a circuit breaker, comprising a first current-carrying copper bar, a second current-carrying copper bar, a static main contact, a dynamic main contact, a static arc contact, a dynamic arc contact assembly, a dynamic contact rod, a spring mechanism and a soft connection mechanism;

[0007] The first current-carrying copper bar and the second current-carrying copper bar are both fixedly installed on the frame of the circuit breaker;

[0008] The static main contact and the static arc contact are both fixedly installed on the first current-carrying copper bar, and the static arc contact is located above the static main contact;

[0009] One end of the spring mechanism is rotatably connected with the frame of the circuit breaker, and the other end is rotatably connected with the dynamic contact rod;

[0010] The dynamic main contact is fixedly installed on the side surface of the top end of the dynamic contact rod, and the dynamic arc contact assembly is installed on the top end of the dynamic contact rod, and the dynamic arc contact assembly is electrically connected with the second current-carrying copper bar through the soft connection mechanism;

[0011] The movable arc contact assembly comprises a movable arc contact capable of moving within a range, which is above the movable main contact;

[0012] Both the movable main contact and the movable arc contact are capable of moving with the rotation of the movable contact rod, thereby being in contact with or disconnected from the static main contact and the static arc contact, respectively.

[0013] In some embodiments, the movable arc contact assembly further comprises a stop sheet, a spring, a spring support rod, a flexible connecting part, and a disc spring assembly;

[0014] The movable arc contact is fixed with the top end of the flexible connecting part, and the bottom end of the flexible connecting part is fixedly connected with the flexible connecting mechanism;

[0015] The movable arc contact is further rotationally connected with the movable contact rod through a rotating shaft;

[0016] The end of the movable arc contact away from the static arc contact is fixedly connected with the stop sheet;

[0017] One end of the spring is fixedly connected with the stop sheet, and the other end of the spring is fixed on the movable contact rod, and the spring is sleeved on the spring support rod;

[0018] One end of the spring support rod is fixedly connected with the movable contact rod, the other end of the spring support rod passes through the through hole on the stop sheet and the movable arc contact, and is fixedly connected with the disc spring assembly above the stop sheet.

[0019] In some embodiments, the movable arc contact assembly further comprises a mounting sheet and a protective sleeve;

[0020] The top end of the movable arc contact, the mounting sheet, and the flexible connecting part are fixed together by a fastening bolt, and the top surface of the mounting sheet is used to provide a planar support for the fastening bolt;

[0021] The rotating shaft passes through the side surface of the mounting sheet, and the side surface of the mounting sheet is used to limit the axial displacement of the rotating shaft;

[0022] The protective sleeve is arranged between the spring support rod and the spring, and is used to prevent the spring support rod and the spring from being abraded.

[0023] In some embodiments, a first arc striking horn and a second arc striking horn fixedly installed on the frame of the circuit breaker are further included, and the installation positions of the first arc striking horn and the second arc striking horn correspond to the static arc contact and the movable arc contact, respectively.

[0024] In some embodiments, an insulating support block and an arc region partition plate are further included;

[0025] Two ends of the insulating support block are fixedly connected with the first current-carrying copper bar and the static arc contact respectively, and are located at the other end of the contact end of the static arc contact, and the insulating support block is used for supporting the static arc contact;

[0026] The arc area partition plate is fixed on the moving contact rod and is used for playing an electric isolation role to avoid the electric arc from entering the flexible connection mechanism.

[0027] In some embodiments, the static main contact and the moving main contact are both made of silver alloy material, and the static arc contact and the moving arc contact are both made of copper alloy material.

[0028] Compared with the prior art, the circuit breaker contact system has the following beneficial effects:

[0029] The circuit breaker contact system provided by the application designs the contact system as main and arc two-grade contacts, can realize zero bounce of the contact system during closing, can effectively avoid electric damage generated in the closing process of the circuit breaker contact system, preferentially ablates the arc contact during breaking of the circuit breaker, can effectively protect the main contact, reduces ablation and fusion welding of the main contact caused by breaking, and thus ensures stability of the contact resistance of the circuit breaker. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 Fig. 1 is a transient schematic diagram of the circuit breaker contact system provided by the application at the moment when the arc contact just contacts during closing;

[0031] Figure 2 Fig. 2 is a schematic diagram of the circuit breaker contact system provided by the application after closing is stable; Figure 1

[0032] Fig. 3 is a schematic diagram of the circuit breaker contact system provided by the application in a breaking state; Figure 3 Figure 1 Fig. 4 is a schematic diagram of the moving arc contact assembly in the circuit breaker contact system provided by the application;

[0033] Figure 4 Figure 1 Fig. 5 is a schematic diagram of a part of structure of the moving arc contact assembly in the circuit breaker contact system provided by the application.

[0034] Figure 5 Fig. 6 is a sectional view of the part of structure of the moving arc contact assembly in the circuit breaker contact system provided by the application. Figure 4

[0035] Legend of reference signs:

[0036] ​​​1, first current-carrying copper bar; 2, second current-carrying copper bar; 3, static main contact; 4, dynamic main contact; 5, static arc contact; 6, dynamic arc contact assembly; 7, first arc leading angle; 8, second arc leading angle; 9, dynamic contact rod; 10, spring mechanism; 11, flexible connection mechanism; 12, insulating support block; 13, arc area partition plate; 14, rotating shaft; 61, dynamic arc contact; 62, mounting piece; 63, spring support rod; 64, flexible connection part; 65, disc spring assembly; 66, stop piece; 67, spring; 68, protective sleeve. DETAILED DESCRIPTION

[0037] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the following will further describe how the present application is implemented in combination with the drawings and specific embodiments.

[0038] Referring to Figures 1-3 The present application provides a contact system of a circuit breaker, comprising a first current-carrying copper bar 1, a second current-carrying copper bar 2, a static main contact 3, a dynamic main contact 4, a static arc contact 5, a dynamic arc contact assembly 6, a dynamic contact rod 9, a spring mechanism 10 and a flexible connection mechanism 11; the first current-carrying copper bar 1 and the second current-carrying copper bar 2 are both fixedly installed on the frame of the circuit breaker; the static main contact 3 and the static arc contact 5 are both fixedly installed on the first current-carrying copper bar 1, and the static arc contact 5 is located above the static main contact 3; one end of the spring mechanism 10 is rotatably connected with the frame of the circuit breaker, and the other end is rotatably connected with the dynamic contact rod 9; the dynamic main contact 4 is fixedly installed on the side surface of the top end of the dynamic contact rod 9, and the dynamic arc contact assembly 6 is installed on the top end of the dynamic contact rod 9, and the dynamic arc contact assembly 6 is electrically connected with the second current-carrying copper bar 2 through the flexible connection mechanism 11; the dynamic arc contact assembly 6 comprises a dynamic arc contact 61, the dynamic arc contact 61 can move within a certain range, and the dynamic arc contact 61 is located above the dynamic main contact 4; the dynamic main contact 4 and the dynamic arc contact 61 can both move with the rotation of the dynamic contact rod 9, so as to be in contact or disconnected with the static main contact 3 and the static arc contact 5 respectively.

[0039] Further, the contact system of the circuit breaker further comprises a first arc leading angle 7 and a second arc leading angle 8 which are fixedly installed on the frame of the circuit breaker, and the installation positions of the first arc leading angle 7 and the second arc leading angle 8 correspond to the static arc contact 5 and the dynamic arc contact 61 respectively.

[0040] Preferably, the contact system of the circuit breaker further comprises an insulating support block 12 and an arc area partition plate 13; the two ends of the insulating support block 12 are fixedly connected with the first current-carrying copper bar 1 and the static arc contact 5 respectively, and are located at the other end of the contact end of the static arc contact 5, and the insulating support block 12 is used for supporting the static arc contact 5; the arc area partition plate 13 is fixed on the dynamic contact rod 9, and is used for playing an electrical isolation role to avoid the arc entering the flexible connection mechanism 11.

[0041] Preferably, the static main contact 3 and the dynamic main contact 4 are made of silver alloy material, and the static arc contact 5 and the dynamic arc contact 61 are made of copper alloy material.

[0042] Further referring to Figure 4 and Figure 5 Preferably, the dynamic arc contact assembly 6 further comprises a stop sheet 66, a spring 67, a spring support rod 63, a flexible connecting part 64 and a disc spring assembly 65; the dynamic arc contact 61 and the top end of the flexible connecting part 64 are fixed together, and the bottom end of the flexible connecting part 64 is fixedly connected with the flexible connecting mechanism 11; the dynamic arc contact 61 is further rotationally connected with the dynamic contact rod 9 through the rotating shaft 14; the end of the dynamic arc contact 61 away from the static arc contact 5 is fixedly connected with the stop sheet 66; the stop sheet 66 is fixedly connected with one end of the spring 67, and the other end of the spring 67 is fixed on the dynamic contact rod 9, and the spring 67 is sleeved on the spring support rod 63; one end of the spring support rod 63 is fixedly connected with the dynamic contact rod 9, and the other end of the spring support rod 63 passes through the through hole on the stop sheet 66 and the dynamic arc contact 61, and is fixedly connected with the disc spring assembly 65 located above the stop sheet 66.

[0043] It can be understood that the contact surface between the dynamic arc contact 61 and the static arc contact 5 is an arc surface, which can not only ensure the concentration of contact pressure, but also provide an effective path for the arc flow to the second arc guiding horn 8 when the circuit breaker is broken. The flexible connecting part 64 and the flexible connecting mechanism 11 can be threadedly fastened to ensure the effective conduction of the loop during the transient process when the main contacts are not in contact during the closing and opening of the circuit breaker. The disc spring assembly 65 can reduce the impact of the dynamic arc contact 61 on the spring support rod 63 during the repeated closing and opening of the circuit breaker.

[0044] Preferably, the dynamic arc contact assembly 6 further comprises a mounting sheet 62 and a protective sleeve 68; the dynamic arc contact 61, the mounting sheet 62 and the top end of the flexible connecting part 64 are fixed together by fastening bolts, and the top surface of the mounting sheet 62 is used to provide a planar support for the fastening bolts; the rotating shaft 14 passes through the side surface of the mounting sheet 62, and the side surface of the mounting sheet 62 is used to limit the axial displacement of the rotating shaft 14; the protective sleeve 68 is arranged between the spring support rod 63 and the spring 67 to prevent wear between the spring support rod 63 and the spring 67.

[0045] When the circuit breaker is not working, the contact system is in the open state, as shown in Figure 3 When the control system issues a closing command, the circuit breaker performs a closing action, and the dynamic contact rod 9 drives the dynamic main contact 4, the dynamic arc contact assembly 6 and the flexible connecting mechanism 11 to move towards the static main contact 3. Due to the existence of two-stage contacts and the main arc time sequence difference, and under the comprehensive action of the contact mechanism, the closing process of the circuit breaker can be divided into the following steps:

[0046] 1) The moving arc contact 61 collides and makes contact with the stationary arc contact 5. At this time, the moving main contact 4 and the stationary main contact 3 have not yet made contact due to the timing difference of the main arc. At this time, the circuit current of the circuit breaker is conducted through the arc contact section, and the current flow direction is as follows: Figure 1 As shown.

[0047] 2) The moving contact rod 9 continues to move towards the stationary main contact 3. The moving arc contact 61 and the stationary arc contact 5 bounce due to the collision. The moving arc contact 61 separates from the stationary arc contact 5. The moving arc contact 61 rotates around the rotating shaft 14 by one end distance and compresses the spring 67. At this time, the movement of the moving contact rod 9 causes the moving main contact 4 to collide with the stationary main contact 3, and the current is transferred. The circuit breaker circuit current is conducted through the main contact part.

[0048] 3) Due to mechanical collision, the moving main contact 4 bounces, separating from the stationary main contact 3. At this time, the collision and bouncing of the arc contact part ends, and the moving arc contact 61 contacts the stationary arc contact 5 again, and the current is transferred again, with the current flow returning to its original direction. Figure 1 The state shown.

[0049] 4) After the collision and bouncing of the moving main contact ends, the moving arc contact 61 and the moving main contact 4 simultaneously contact the stationary arc contact 5 and the stationary main contact 3, respectively. The spring 67 and the spring mechanism 10 provide electrical contact pressure, and the current flows as follows: Figure 2 As shown.

[0050] As can be seen, the present invention adopts a two-stage contact design, which cancels out the closing bounce during the collision contact process of the circuit breaker, achieving zero contact bounce during closing and seamless current switching and transfer. The contact part will not separate due to bounce, so no electric arc will be generated, effectively avoiding electrical damage caused by the circuit breaker contact system closing process.

[0051] Similarly, in the opening process of the circuit breaker, the control system issues an opening command, and the circuit breaker performs an opening action. Under the action of the spring force of the spring mechanism 10, the movable contact rod 9 drives the movable main contact 4, the movable arc contact assembly 6, and the flexible connection mechanism 11 to move away from the static main contact 3. Due to the existence of the main arc timing difference, when the circuit breaker is broken, the main contact part is separated first, at this time, the arc contact part is still in the contact state, and the loop current is conducted through the arc contact part. With the separation of the arc contact, an electric arc is generated in the circuit breaker wall, which enters the arc extinguishing chamber along the arc leading angle under the action of the electric force, and the breaking is realized. Since the last conducting part of the circuit breaker loop is the arc contact part, the arc contact is at the downstream of the electric arc path, and the electric arc only erodes and welds the arc contact part, effectively protecting the main contact. The main contact part is composed of silver alloy material, and the arc contact part is composed of copper alloy material. The conductivity of silver alloy is better than that of copper alloy, and the electric contact pressure provided by the spring mechanism 10 is much larger than that provided by the spring 67, so that the contact resistance of the main contact part is much smaller than that of the arc contact part. The erosion and welding of the arc contact basically have no effect on the contact resistance of the circuit breaker after closing, so the stability of the contact resistance of the circuit breaker is ensured.

[0052] In summary, the contact system of the circuit breaker provided by the present application designs the contact system as a main contact and an arc contact, which can realize zero bounce of the contact closing, and can effectively avoid the electric damage generated in the closing process of the contact system of the circuit breaker. In the breaking process of the circuit breaker, the arc contact is preferentially eroded, which can effectively protect the main contact and reduce the erosion and welding of the main contact caused by breaking, thereby ensuring the stability of the contact resistance of the circuit breaker.

[0053] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A contact system for a circuit breaker, characterized by The utility model relates to a circuit breaker, including first current-carrying copper bar (1), second current-carrying copper bar (2), static main contact (3), dynamic main contact (4), static arc contact (5), dynamic arc contact assembly (6), dynamic contact rod (9), spring mechanism (10) and soft connection mechanism (11); The first current-carrying copper bar (1) and the second current-carrying copper bar (2) are fixedly installed on the frame of the circuit breaker; The static main contact (3) and the static arc contact (5) are both fixedly installed on the first current-carrying copper bar (1), and the static arc contact (5) is located above the static main contact (3); One end of the spring mechanism (10) is rotatably connected with the frame of the circuit breaker, and the other end is rotatably connected with the dynamic contact rod (9); The dynamic main contact (4) is fixedly installed on the side surface of the top end of the dynamic contact rod (9), and the dynamic arc contact assembly (6) is installed on the top end of the dynamic contact rod (9), and the dynamic arc contact assembly (6) is electrically connected with the second current-carrying copper bar (2) through the soft connection mechanism (11); The dynamic arc contact assembly (6) includes a dynamic arc contact (61), which can move within a certain range, and the dynamic arc contact (61) is located above the dynamic main contact (4); The dynamic main contact (4) and the dynamic arc contact (61) can move with the rotation of the dynamic contact rod (9), so as to be in contact with or disconnected from the static main contact (3) and the static arc contact (5) respectively; The dynamic arc contact assembly (6) further includes a stop sheet (66), a spring (67), a spring support rod (63), a soft connection part (64), and a disc spring assembly (65); The dynamic arc contact (61) and the top end of the soft connection part (64) are fixed together, and the bottom end of the soft connection part (64) is fixedly connected with the soft connection mechanism (11); The dynamic arc contact (61) is further rotatably connected with the dynamic contact rod (9) through a rotating shaft (14); One end of the dynamic arc contact (61) away from the static arc contact (5) is fixedly connected with the stop sheet (66); The stop sheet (66) is fixedly connected with one end of the spring (67), and the other end of the spring (67) is fixed on the dynamic contact rod (9), and the spring (67) is sleeved on the spring support rod (63); One end of the spring support rod (63) is fixedly connected with the dynamic contact rod (9), and the other end of the spring support rod (63) passes through the through hole on the stop sheet (66) and the dynamic arc contact (61), and is fixedly connected with the disc spring assembly (65) located above the stop sheet (66); The utility model further includes a first arc guiding horn (7) and a second arc guiding horn (8) fixedly installed on the frame of the circuit breaker, and the installation positions of the first arc guiding horn (7) and the second arc guiding horn (8) correspond to the static arc contact (5) and the dynamic arc contact (61) respectively.

2. The contact system of a circuit breaker according to claim 1, characterized in that The dynamic arc contact assembly (6) further includes a mounting sheet (62) and a protective sleeve (68); The top ends of the dynamic arc contact (61), the mounting sheet (62), and the soft connection part (64) are fixed together by a fastening bolt, and the top surface of the mounting sheet (62) is used for providing a planar support for the fastening bolt. The rotating shaft (14) penetrates through the side of the mounting piece (62) for limiting the axial displacement of the rotating shaft (14); The protective sleeve (68) is arranged between the spring supporting rod (63) and the spring (67) for preventing the spring supporting rod (63) and the spring (67) from being abraded.

3. The contact system of a circuit breaker of claim 1, wherein, Further comprising an insulating supporting block (12) and an arc area partition plate (13); Two ends of the insulating supporting block (12) are fixedly connected with the first current-carrying copper bar (1) and the static arc contact (5) respectively, and are located at the other end of the contact end of the static arc contact (5), the insulating supporting block (12) is used for supporting the static arc contact (5); The arc area partition plate (13) is fixed on the moving contact rod (9) and is used for playing an electric isolation role to avoid the electric arc entering the soft connection mechanism (11).

4. The contact system of a circuit breaker of claim 1, wherein, The static main contact (3) and the moving main contact (4) are made of silver alloy material, and the static arc contact (5) and the moving arc contact (61) are made of copper alloy material.

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