CN216928456U

CN216928456U - Double-breakpoint moving contact device and double-breakpoint moulded case circuit breaker breaking unit

Info

Publication number: CN216928456U
Application number: CN202123101008.1U
Authority: CN
Inventors: 赵瑞峰; 刘俭; 王世慧
Original assignee: Shanghai Renmin Electrical Apparatus Works Co Ltd
Current assignee: Shanghai Renmin Electrical Apparatus Works Co Ltd
Priority date: 2021-12-11
Filing date: 2021-12-11
Publication date: 2022-07-08
Anticipated expiration: 2031-12-11

Abstract

The utility model relates to a double-breakpoint moving contact device and a breaking unit of a double-breakpoint molded case circuit breaker, wherein the breaking unit comprises a double-breakpoint moving contact device (3), two static contact devices (2) and two arc extinguishing chambers (4), wherein the two static contact devices and the two arc extinguishing chambers are symmetrically arranged along the center of the double-breakpoint moving contact device (3). The static contact device (2) comprises a static contact bridge (23), the static contact bridge (23) is in a flat cylindrical shape and is in a U-shaped bending and overturning structure, and a stress balance groove (231) is arranged on the inner side of the overturning arc. A double-breakpoint movable contact device, which comprises a main rotating shaft (31), wherein the center of the main rotating shaft (31) is provided with a central shaft (314); a movable contact bridge (32) is arranged in the main rotating shaft (31), a long strip-shaped waist hole (324) is formed in the center of the movable contact bridge (32), and the movable contact bridge is rotatably arranged in the main rotating shaft (31) through a central shaft (314). Compared with the prior art, the static contact structure has the advantages that the stress deformation of the static contact can be reduced, the use is not influenced, and the like.

Description

Double-breakpoint moving contact device and breaking unit of double-breakpoint molded case circuit breaker

Technical Field

The utility model relates to the field of low-voltage electric appliances, in particular to a double-breakpoint moving contact device and a breaking unit of a double-breakpoint molded case circuit breaker.

Background

The circuit breaker is a switching device capable of closing, carrying, and opening/closing a current under a normal circuit condition and a current under an abnormal circuit condition for a predetermined time. The breaking unit is a core component for realizing the segmentation of the circuit breaker, but the breaking unit of the existing circuit breaker has a complex structure and is troublesome to assemble, so that the circuit breaker has higher cost.

At present, a plurality of breaker breaking unit static contact bridge systems and movable contact bridge systems in the market can generate head pressure due to contacts when in contact so as to lead to deformation of a bending part of a static contact and incapability of recovering to cause virtual contact problems of the whole breaker system. The two pairs of movable contact bridges and the static contact bridges are repeatedly impacted and separated, and if the two pairs of impacting and separating rhythms are asynchronous, one pair of the movable contact bridges and the static contact bridges can be damaged and accelerated. The problem of synchronization of the two pairs of strikes, i.e. the problem of balancing the forces of the rebounding of the strikes, is therefore also an important problem for present-day circuit breakers.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects in the prior art, provide a double-breakpoint moving contact device and a double-breakpoint molded case circuit breaker breaking unit which can reduce the stress deformation of a fixed contact and do not influence the use, and solve the problem that the normal breaking of the whole circuit breaker system is influenced by the deformation of the fixed contact under the stress after the existing circuit breaker breaking system works for a long time.

The purpose of the utility model can be realized by the following technical scheme:

a double-breakpoint moving contact device comprises a main rotating shaft, wherein a central shaft is arranged in the center of the main rotating shaft;

a movable contact bridge is arranged in the main rotating shaft, a strip-shaped waist hole is arranged in the center of the movable contact bridge, and the movable contact bridge is rotatably arranged in the main rotating shaft through a central shaft,

the strip-shaped waist holes are used for adjusting the position of the movable contact bridge in the main rotating shaft in the working process, and the pressure distribution balance of the upper and lower movable contacts and the upper and lower static contact bridges is ensured.

Furthermore, two open slots and two first mounting positioning holes which are centrosymmetric relative to the central shaft are sequentially arranged on the side edge of the axial end surface of the main rotating shaft along the central shaft;

two springs penetrating through the center of the main rotating shaft are arranged on two end faces of the main rotating shaft in parallel respectively; a spring shaft used for mounting one end of a spring is arranged in the open slot in a penetrating manner; a small connecting rod for mounting the other end of the spring is inserted into the first mounting positioning hole;

arc guide grooves are arranged on two sides of the movable contact bridge; the spring shaft is abutted against the arc-shaped guide groove and the open groove;

the middle part of the side wall of the main rotating shaft along the radial direction is provided with two arc-shaped slots which are centrosymmetric relative to the central shaft; the movable contact bridge passes through the arc-shaped slot and is rotatably arranged in the main rotating shaft through the central shaft.

Furthermore, the main rotating shaft is of a flat cylindrical structure, and the movable contact bridge and the arc-shaped guide groove are both arranged in central symmetry relative to the center of the movable contact bridge; the adjacent small connecting rods and the spring shaft are riveted together through connecting pieces.

Furthermore, two second mounting positioning holes which are centrosymmetric relative to the central shaft are sequentially arranged on the side edge of the axial end surface of the main rotating shaft; a screen board for covering is arranged on the end surface of the main rotating shaft along the axial direction; the screen board is fixedly connected with the main rotating shaft through a second mounting positioning hole;

a spring containing cavity is formed between the screen board and the main rotating shaft, and the spring is located in the spring containing cavity.

A breaking unit of a double-breakpoint molded case circuit breaker comprises a double-breakpoint movable contact device, two static contact devices and two arc extinguish chambers, wherein the two static contact devices and the two arc extinguish chambers are symmetrically arranged along the center of the double-breakpoint movable contact device.

Furthermore, the static contact device comprises a static contact bridge which is in a flat cylindrical shape and is in a U-shaped bending and overturning structure, and a stress balance groove is arranged on the inner side of the overturning arc.

Furthermore, the static contact device also comprises a magnetic conduction mechanism arranged on the static contact bridge and used for guiding the electric arc to enter the arc extinguish chamber, and the magnetic conduction mechanism is in interference fit with the static contact bridge during assembly;

the end part of the movable contact bridge is provided with a movable contact, and the end part of the static contact bridge is provided with a static contact which is used for contacting with the movable contact; and the end part of the static contact bridge is also provided with an arc striking sheet.

The magnetic conduction mechanism comprises a magnetic conduction rod and a magnetic conduction sheet arranged on the outer side of the other end of the arc extinguish chamber opposite to the magnetic conduction rod.

Furthermore, the static contact device also comprises an insulating bush which is wrapped outside the turnover arc of the static contact bridge; the insulating bush is provided with an inclined baffle plate for limiting the position of the magnetic conduction mechanism.

Furthermore, the breaking unit also comprises two cover plates for loading the double-breakpoint moving contact device, the static contact device and the arc extinguish chamber, wherein a central shaft hole is formed in the middle of each cover plate, and two waist-shaped holes are formed in two sides of each central shaft hole;

the central shaft passes through the central shaft hole; the main rotating shaft is provided with a sliding shaft which is arranged in the waist-shaped hole in a penetrating way and slides in the waist-shaped hole.

The two cover plates are connected together through screws to form an independent box body unit, and a cavity is formed inside the box body unit; two static contacts are installed in the cavity of box body unit in a diagonal mode, and the wiring end of each static contact extends out of the box body unit.

Compared with the prior art, the utility model has the following advantages:

(1) the static contact bridge is provided with the stress balance groove, the structure is simple, the whole structure is not required to be changed, the stress generated in the collision can be well offset, and the deformation of the static contact bridge is avoided;

(2) the movable contact bridge system used by the utility model realizes the stress transmission of the contact through the pair of parallel springs, and has simple structure and stable contact structure; meanwhile, the movable contact bridge is matched with the strip-shaped waist hole, so that certain eccentric rotation can be performed according to the actual condition, and the balance of impact is better ensured;

(3) the utility model well solves the problem of force balance, fully ensures the synchronous collision of the two opponent parts, and improves the service life and the reliability of the circuit breaker.

Drawings

FIG. 1 is an assembly view of a circuit breaker according to an embodiment;

fig. 2 is a schematic diagram of the internal structure of the circuit breaker;

FIG. 3 is a schematic diagram of a moving bridge system of a breaking unit;

FIG. 4 is a schematic structural diagram of a moving contact bridge of a breaking unit;

FIG. 5 is a schematic view of a static contact bridge of the breaking unit;

FIG. 6 is a schematic structural diagram of an arc extinguishing chamber;

FIG. 7 is a schematic view of a rotating shaft structure;

FIG. 8 is a schematic view of a static bridge insulation bushing;

FIG. 9 is an assembled view of the static bridge insulation bushing;

FIG. 10 is a schematic view of a shaft panel assembly;

the reference numbers in the figures indicate: the device comprises a cover plate 1, a central shaft hole 11, a sliding shaft 12, a kidney-shaped hole 13, a static contact device 2, a static contact 21, an arc striking plate 22, a static contact bridge 23, a stress balance groove 231, an insulating bush 24, an inclined baffle 241, a double-breakpoint movable contact device 3, a main rotating shaft 31, an open groove 311, a first installation positioning hole 312, an arc-shaped groove 313, a central shaft 314, a second installation positioning hole 315, a movable contact bridge 32, an arc-shaped guide groove 321, a movable contact 322, a kidney-shaped hole 324, a spring shaft 33, a spring 34, a small connecting rod 35, a connecting plate 36, a screen plate 37, an arc extinguish chamber 4, an arc isolating wall 41, a slide way 411, an arc extinguish grid plate 42 and a magnetic conduction mechanism 6.

Detailed Description

The utility model is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

Examples

A breaking unit of a double-breakpoint molded case circuit breaker is shown in figures 1-2 and comprises a double-breakpoint movable contact device 3, two static contact devices 2 and two arc extinguishing chambers 4, wherein the two static contact devices and the two arc extinguishing chambers are symmetrically arranged along the center of the double-breakpoint movable contact device 3.

The breaking unit also comprises two cover plates 1 used for loading a double-breakpoint moving contact device 3, a static contact device 2 and an arc extinguish chamber 4, wherein the middle part of each cover plate 1 is provided with a central shaft hole 11, and two sides of each central shaft hole 11 are provided with two waist-shaped holes 13; the central shaft 314 passes through the central shaft hole 11; the main shaft 31 is provided with a sliding shaft 12, and the sliding shaft 12 is inserted into the kidney-shaped hole 13 and slides in the kidney-shaped hole 13. The two cover plates 1 are connected together through screws to form an independent box body unit, and a cavity is formed inside the box body unit; two static contacts 2 are installed in the cavity of the box body unit in a diagonal mode, and wiring terminals of the static contacts extend out of the box body unit.

As shown in fig. 3, 4 and 7, the double-break movable contact device 3 includes a main rotating shaft 31, and a central shaft 314 is disposed in the center of the main rotating shaft 31; the movable contact bridge 32 is arranged in the main rotating shaft 31, the center of the movable contact bridge 32 is provided with a strip-shaped waist hole 324, and the movable contact bridge is rotatably installed in the main rotating shaft 31 through the central shaft 314, and the strip-shaped waist hole 324 is used for adjusting the position of the movable contact bridge 32 in the main rotating shaft 31 in the working process, so that the pressure distribution balance between the upper and lower movable contacts and the upper and lower static contact bridges is ensured.

The main shaft 31 is provided with two opening grooves 311 and two first mounting positioning holes 312 along the axial end surface side thereof in turn, wherein the two opening grooves 311 are centrosymmetric relative to the central shaft 314; two springs 34 penetrating the center of the main rotating shaft 31 are respectively arranged on two end faces of the main rotating shaft 31 in parallel; a spring shaft 33 for mounting one end of a spring 34 penetrates through the opening groove 311; a small connecting rod 35 for mounting the other end of the spring 34 is inserted into the first mounting positioning hole 312;

arc-shaped guide grooves 321 are formed in two sides of the movable contact bridge 32; the spring shaft 33 abuts against the arc-shaped guide groove 321 and the open groove 311; the main rotating shaft 31 is provided with two arc-shaped open slots 313 which are centrosymmetric relative to the central shaft 314 along the middle part of the radial side wall; the movable contact bridge 32 passes through the arc-shaped slot 313 and is rotatably installed in the main rotating shaft 31 through the central shaft 314.

The main rotating shaft 31 is of an oblate cylindrical structure, and the shape of the movable contact bridge 32 and the arc-shaped guide groove 321 are arranged in central symmetry relative to the center of the movable contact bridge 32; the adjacent small connecting rods 35 and the spring shafts 33 are riveted together by connecting pieces 36. Two second mounting positioning holes 315 which are centrosymmetrically arranged relative to the central shaft 314 are sequentially arranged along the axial end surface side of the main rotating shaft 31.

As shown in fig. 10, a screen 37 for covering is provided on an end surface of the main shaft 31 along the axial direction thereof; the screen panel 37 is fixedly connected with the main rotating shaft 31 through a second mounting positioning hole 315; the shroud 37 forms a spring pocket with the main shaft 31, and the spring 34 is located in the spring pocket.

As shown in fig. 8-9, the static contact device 2 includes a static contact bridge 23, the static contact bridge 23 is a flat cylindrical shape and has a U-shaped bent and inverted structure, and a stress balance groove 231 is disposed inside the inverted arc. The static contact device 2 further comprises a static contact bridge 23, a magnetic conducting mechanism 6 is arranged in the turnover arc and used for guiding the electric arc to enter the arc extinguish chamber 4, and the magnetic conducting mechanism 6 is in interference fit with the static contact bridge 23 during assembly; the end part of the movable contact bridge 32 is provided with a movable contact 322, and the end part of the static contact bridge 23 is provided with a static contact 21 which is used for contacting with the movable contact 322; the end of the static contact bridge 23 is also provided with an arc striking plate 22. The magnetic conducting mechanism 6 comprises a magnetic conducting rod and a magnetic conducting sheet arranged outside the other end of the arc extinguish chamber 4 opposite to the magnetic conducting rod. The static contact device 2 further comprises an insulating bush 24 wrapped outside the turnover arc of the static contact bridge 23; the insulating bush 24 is provided with an inclined stopper 241 for restricting the position of the magnetic conductive mechanism 6.

As shown in fig. 6, the arc extinguishing chamber 4 is provided with arc isolating walls 41 arranged at intervals, and a plurality of arc extinguishing grids 42 are combined with the arc isolating walls 41 to form an arc extinguishing chamber; the two ends of the movable contact bridge 32 are positioned in the middle of the arc extinguishing grid pieces 42; and mounting grooves are formed in two sides of the arc isolating wall 41 and used for mounting and fixing the static contact bridge 23. The open end of the fixed hinge of the static contact bridge is used for fixing the static contact bridge 23 to prevent left and right shaking, and the closed end is clamped into the grooves at the two sides of the arc partition wall 41 to be fixed.

When the circuit breaker is in an initial state, the movable contact 322 makes the movable contact 322 contact with the fixed contact 21 under the combined action of the spring 34, the spring shaft 33 and the small link 35. When a circuit is in fault, electric repulsion force is generated between the moving contact and the static contact, the moving contact 322 is stressed to rotate, the spring shaft 33 enters the arc-shaped guide grooves 321 on the two sides of the moving contact bridge 32 under the action of the spring 34 and the arc-shaped open groove 313, the spring shaft 33 is tightly clamped, the function of repelling and locking the moving contact 322 is realized, and the moving contact 322 is effectively prevented from falling back. The structure is simple, the structure of the moving contact system is stable, and the contact can be quickly and stably repelled under the condition of short-circuit current.

In the working process, the moving contact 322 generates contact pressure on the static contact bridge 23, the stress concentration condition exists at the overturning part of the static contact bridge 23, and the plastic deformation of the static contact can be caused after the static contact bridge is broken for a plurality of times for a long time, so that the problems of virtual contact, poor contact and the like are caused. Through the mode that sets up stress balance groove 231 at quiet touch bridge 23 upset portion, promoted the resilience surplus of quiet touch bridge 23 after the pressurized, dispersed the condition of concentrating on a certain point at pressurized in-process stress, promoted life.

The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the utility model may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.

Claims

1. A breaking unit of a double-breakpoint molded case circuit breaker is characterized by comprising a double-breakpoint movable contact device (3), two static contact devices (2) and two arc extinguish chambers (4), wherein the two static contact devices and the two arc extinguish chambers are symmetrically arranged along the center of the double-breakpoint movable contact device (3);

the static contact device (2) comprises a static contact bridge (23), the static contact bridge (23) is in a flat cylindrical shape and is in a U-shaped bending and overturning structure, and a stress balance groove (231) is arranged on the inner side of the overturning arc; the double-breakpoint moving contact device (3) comprises a main rotating shaft (31), wherein a central shaft (314) is arranged at the center of the main rotating shaft (31);

a movable contact bridge (32) is arranged in the main rotating shaft (31), a long strip-shaped waist hole (324) is formed in the center of the movable contact bridge (32), and the movable contact bridge is rotatably installed in the main rotating shaft (31) through a central shaft (314).

2. The breaking unit of the double-breakpoint molded case circuit breaker according to claim 1, wherein the main rotating shaft (31) is sequentially provided with two open slots (311) and two first mounting positioning holes (312) which are centrosymmetric with respect to the central axis (314) along an axial end surface side thereof;

two springs (34) penetrating through the center of the main rotating shaft (31) are arranged on two end faces of the main rotating shaft (31) in parallel respectively; a spring shaft (33) used for installing one end of a spring (34) penetrates through the opening groove (311); a small connecting rod (35) for mounting the other end of the spring (34) is inserted into the first mounting positioning hole (312);

arc-shaped guide grooves (321) are arranged on two sides of the movable contact bridge (32); the spring shaft (33) is abutted against the arc-shaped guide groove (321) and the open groove (311);

the middle part of the side wall of the main rotating shaft (31) along the radial direction is provided with two arc-shaped open slots (313) which are centrosymmetric relative to the central shaft (314); the movable contact bridge (32) passes through the arc-shaped slot (313) and is rotatably arranged in the main rotating shaft (31) through the central shaft (314).

3. The breaking unit of the double-breakpoint molded case circuit breaker according to claim 2, wherein the main rotating shaft (31) has a flat cylindrical structure, and the movable contact bridge (32) and the arc-shaped guide groove (321) are both arranged in a central symmetry manner with respect to a center of the movable contact bridge (32); the adjacent small connecting rods (35) and the spring shaft (33) are riveted together through connecting pieces (36).

4. The breaking unit of the double-breakpoint molded case circuit breaker according to claim 2, wherein the main rotating shaft (31) is sequentially provided with two second mounting positioning holes (315) which are centrosymmetric with respect to the central shaft (314) along the axial end surface side; a screen board (37) for covering is arranged on the end surface of the main rotating shaft (31) along the axial direction; the screen plate (37) is fixedly connected with the main rotating shaft (31) through a second mounting positioning hole (315);

a spring containing cavity is formed between the screen plate (37) and the main rotating shaft (31), and the spring (34) is located in the spring containing cavity.

5. The breaking unit of the double-breakpoint molded case circuit breaker according to claim 1, wherein the static contact device (2) further comprises a magnetic conducting mechanism (6) arranged on the static contact bridge (23) and used for guiding the electric arc to enter the arc extinguishing chamber (4), and the magnetic conducting mechanism (6) is in interference fit with the static contact bridge (23) when being assembled;

a moving contact (322) is arranged at the end part of the moving contact bridge (32), and a static contact (21) which is used for contacting with the moving contact (322) is arranged at the end part of the static contact bridge (23); the end part of the static contact bridge (23) is also provided with an arc striking sheet (22).

6. The breaking unit of the double-breakpoint breaker with plastic case as claimed in claim 5, wherein the static contact device (2) further comprises an insulating bushing (24) wrapped outside the turning arc of the static contact bridge (23); the insulating bush (24) is provided with an inclined baffle (241) for limiting the position of the magnetic conduction mechanism (6).

7. The breaking unit of the double-breakpoint molded case circuit breaker according to claim 4, wherein the breaking unit further comprises two cover plates (1) for loading the double-breakpoint movable contact device (3), the static contact device (2) and the arc-extinguishing chamber (4), a central shaft hole (11) is formed in the middle of each cover plate (1), and two kidney-shaped holes (13) are formed in two sides of each central shaft hole (11);

the central shaft (314) passes through the central shaft hole (11); the main rotating shaft (31) is provided with a sliding shaft (12), and the sliding shaft (12) penetrates through the waist-shaped hole (13) and slides in the waist-shaped hole (13).