CN212461576U - Breaking unit of double-breakpoint molded case circuit breaker - Google Patents

Abstract

The utility model relates to a two breakpoint moulded case circuit breaker's disconnected unit of dividing, including two apron, inside formation cavity, two static contacts, a rotation type double break point moving contact system, it includes the pivot, touches the bridge, two spring shafts, two springs and two little connecting rods, the both sides of touching the bridge are equipped with the arc guide slot, the tip of touching the bridge is equipped with the movable contact, in the open slot of pivot is worn to establish to spring shaft axial, the spring is located the pivot along its two axial terminal surfaces on, the both ends of spring are connected on the spring shaft, are connected through the connecting rod between spring shaft and the little connecting rod. The arc extinguishing chamber comprises two arc isolating walls and a plurality of arc extinguishing grid pieces, and the arc isolating walls are provided with magnetic conduction plates at one ends of the openings of the arc extinguishing chambers. Compared with the prior art, the utility model discloses divide disconnected unit to improve the breaking capacity of product, can prevent the moving contact from falling back at extreme position with the quick chucking of mechanism, the explosion chamber can also be to electric arc rapid arc extinguishing.

Description

Breaking unit of double-breakpoint molded case circuit breaker

Technical Field

The utility model relates to a circuit breaker technical field, concretely relates to disconnected unit of double break moulded 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 breaking of the circuit breaker, but the breaking unit of the existing circuit breaker has complex structure and troublesome assembly, and causes higher cost of the circuit breaker.

At present, the rotating double-breakpoint moving contact system of the molded case circuit breaker is one of the developing directions, the existing double-breakpoint moving contact system has many parts and a complex structure, after a contact bridge is repelled by electric repulsive force, because the electric repulsive force is reduced, the moving contact can be closed secondarily or closed for many times due to shaking under the action of spring tension, and if a clamping device cannot rapidly clamp the contact bridge at the limit position, the contact bridge can be very unfavorable for breaking.

In addition, during the breaking process of the circuit breaker, the voltage between the contacts causes air dielectric discharge to form electric arcs, so in the circuit breaker switch, an arc extinguishing chamber is usually used for arc extinguishing to ensure the safe operation of the electric appliance. However, the arc striking effect of the existing arc extinguishing chamber is not good, so that the electric arc cannot enter the arc extinguishing chamber structure more quickly, and the better arc extinguishing effect cannot be achieved.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a two breakpoint moulded case circuit breaker's disconnected unit exactly in order to solve above-mentioned problem, solve the problem that current circuit breaker moving contact can't effectively drop off to and the explosion chamber can not reach the problem of preferred arc extinguishing effect.

The purpose of the utility model is realized through the following technical scheme:

a breaking unit of a double-breakpoint molded case circuit breaker, comprising:

the two cover plates are connected to form an independent box body unit, and a cavity is formed inside the box body unit;

the two static contacts are arranged 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;

a rotation type double break point moving contact system, the pivoted is installed in the cavity of box body unit to be located between two static contacts, it includes:

the rotating shaft is of a flat cylindrical structure, a central shaft is arranged at the center of the rotating shaft, two arc-shaped open grooves which are centrosymmetric relative to the central shaft are arranged in the middle of the radial side wall of the rotating shaft, and two open grooves which are centrosymmetric relative to the central shaft and two first installation positioning holes are sequentially arranged on the side of the axial end face of the rotating shaft;

the contact bridge penetrates through the arc-shaped open groove and is rotatably installed on the rotating shaft through the central shaft, a round hole is formed in the center of the contact bridge, arc-shaped guide grooves are formed in two sides of the contact bridge, a movable contact is arranged at the end part of the contact bridge, and the shape of the contact bridge, the arc-shaped guide grooves and the movable contact are arranged in central symmetry relative to the center of the contact bridge;

the two spring shafts are used for installing springs and respectively and axially penetrate through the open grooves of the rotating shaft;

the two springs are respectively arranged on two end faces of the rotating shaft along the axial direction of the rotating shaft, and two ends of each spring are connected to the spring shaft;

the two small connecting rods axially penetrate through the first mounting positioning holes of the rotating shaft respectively, and the adjacent spring shafts are connected with the small connecting rods through connecting rods;

two explosion chambers are installed in the box body unit cavity of rotation type double break point moving contact system both sides, it includes:

the two arc isolating walls are arranged at intervals, and a plurality of slideways are arranged on the inner side edges of the arc isolating walls; and

the arc extinguishing grid pieces are embedded into the slide ways of the two arc isolating walls;

the arc-extinguishing grid pieces and the two arc-insulating walls are combined to form an arc-extinguishing chamber, and the arc-insulating walls are provided with magnetic conductive plates at one end of an opening of the arc-extinguishing chamber;

the two end parts of the contact bridge are positioned in the middle of the arc extinguishing grid plate.

Preferably, the two cover plates comprise a first cover plate and a second cover plate, the first cover plate and the second cover plate are connected together through screws, a central shaft hole is formed in the middle of each of the first cover plate and the second cover plate, and two waist-shaped holes are formed in two sides of each central shaft hole;

the rotary double-breakpoint moving contact system is rotatably installed in the box body unit cavity through a central shaft penetrating through the central shaft hole, a second installation positioning hole is formed in the end face of the rotating shaft along the axial direction of the rotating shaft, a sliding shaft is installed in the second installation positioning hole, and the sliding shaft penetrates through the waist-shaped hole and slides in the waist-shaped hole.

Preferably, the first cover plate and the second cover plate are symmetrically provided with square sinking grooves respectively, first air outlets are arranged in the square sinking grooves, and second air outlets corresponding to the first air outlets are arranged on the arc isolating wall, so that gas generated in the arc extinguishing chamber can be discharged out of the cover plates and enter the pneumatic protection device of the circuit breaker.

Preferably, the rotating shaft is provided with a screen board for covering along the axial end face of the rotating shaft, a screen board boss is arranged on the inner side of the screen board, the connecting rod is clamped between the screen board boss and the rotating shaft, a spring containing cavity is formed between the screen board and the end face of the rotating shaft, and the spring is located in the spring containing cavity to avoid the flying-out of the connecting rod in the moving process.

Preferably, the rotating shaft is provided with a groove matched with the connecting rod in shape along the axial end face of the rotating shaft, one side of the groove is linear, and the other side of the groove is arc-shaped.

Preferably, the connecting rod is the shuttle form, and two terminal surface shapes are different, and one end is circular-arc, and one end is the toper form, and both ends circular arc transitional coupling is as an organic whole, and circular-arc one end is located the arc side of recess, and toper form one end is located the straight line shape side of recess, and this structural design helps controlling the turned position of connecting rod, effectively prevents the excessive rotation of connecting rod.

Preferably, the cross section of the open slot is in an arc structure, bosses are arranged at two ends of the contact bridge on one side corresponding to the movable contact, and a roller is sleeved in the middle of the spring shaft.

Preferably, the small connecting rod passes through the connecting rod and the rotating shaft respectively and is riveted with the connecting rod and the rotating shaft together.

Preferably, the fixed contact is U-shaped, a magnetic conducting rod is placed in the U-shaped groove of the fixed contact, a magnetic conducting plate is arranged on the outer side of the other end of the arc extinguish chamber opposite to the magnetic conducting rod, and the magnetic conducting rod and the magnetic conducting plate can form a closed magnetic circuit, so that the arc is more easily attracted into the arc extinguish chamber under the action of a magnetic field, and effective arc extinction is achieved. Preferably, the magnetic conductive plate is arranged on the arc-isolating wall at a side edge opposite to the insertion end of the arc-extinguishing grid piece, the arc-isolating wall is provided with a groove, and the magnetic conductive plate is embedded in the groove.

Preferably, the slideway is a plurality of groups of groove-shaped structures which are arranged in parallel on the inner wall of the arc-isolating wall, the arc-extinguishing grid pieces are sequentially inserted into the slideway at intervals in parallel, the upper part of the inner wall of the arc-isolating wall along the insertion end of the arc-extinguishing grid pieces is an open U-shaped slideway, and the lower part of the inner wall of the arc-isolating wall is an installation cavity;

preferably, the magnetic conductive plate is a strip-shaped rectangular plate, the length direction of the magnetic conductive plate is parallel to the arrangement direction of the arc-extinguishing grid pieces, and the length of the magnetic conductive plate is consistent with the arrangement width of the arc-extinguishing grid pieces;

the arc extinguishing bars are metal sheets provided with U-shaped arc extinguishing grooves, the U-shaped arc extinguishing grooves are formed by connecting multiple sections of arc lines, and an invaginated notch is formed in the middle of each U-shaped arc extinguishing groove.

The utility model discloses a principle does, when the circuit breaker was in initial condition, the moving contact made moving contact and static contact under spring, spring shaft and little connecting rod combined action. When a circuit breaks down, electric repulsion force is generated between the moving contact and the fixed contact, the moving contact is stressed to rotate, the spring shaft enters the arc-shaped guide grooves on the two sides of the contact bridge under the action of the spring and the arc-shaped grooves, the spring shaft is tightly clamped, the function of repelling and locking the moving contact is realized, and the moving contact is effectively prevented from falling back. The utility model discloses simple structure, contact stable in structure, under the short-circuit current condition, the contact can be rapidly stable repulsion.

In addition, through setting up the magnetic conduction board in the bottom of explosion chamber flash barrier, electric arc gets into the arc extinguishing bars piece fast under the electromagnetic force effect, electric arc is introduced the arc extinguishing bars piece of the top after, the even cutting electric arc of arc extinguishing bars piece, a long arc is cut apart into the multistage short arc, reach the best arc extinguishing effect, and flash barrier both sides have set up the gas outlet, guarantee that the hot gas flow that produces can in time cool off and disperse when the arc extinguishing, be convenient for effectively carry out the arc extinguishing, thereby reach preferred arc extinguishing effect.

Compared with the prior art, the utility model discloses specifically have following beneficial effect:

1. the utility model discloses moving contact system realizes the transmission of contact atress through a pair of spring, reduces part quantity, simple structure, and contact stable in structure, when short-circuit current produced electric repulsion, the moving contact atress rotated, under the spring action, the separation is with higher speed, and then improves the breaking capacity of product, and there is the arc guide slot in the both sides of touching the bridge, and the spring shaft gets into the arc guide slot along the arc fluting, with the mechanism rapid chucking at extreme position, prevents that the moving contact from falling back.

2. The small connecting rod, the connecting rod and the rotor are welded together, so that the stability of the structure is improved, and the manufacturability is good.

3. The boss screen board that sets up on the screen board, boss and pivot laminating are at the both ends of connecting rod, avoid the departure of connecting rod in the motion process.

4. The planar shape of both sides of the connecting rod is different, and in the motion process, the planar surface effectively prevents the excessive rotation of the connecting rod, and is helpful for controlling the rotating position of the connecting rod.

5. The arc-isolating wall bottom is equipped with the magnetic conduction board, has not only shortened the length of arc extinguishing bars piece, and reduce cost makes simple structure, makes electric arc can get into the explosion chamber more fast moreover, and after electric arc was introduced into the arc extinguishing bars piece, the even cutting electric arc of arc extinguishing bars piece, a long electric arc is cut apart into the short electric arc of multistage, reaches best arc extinguishing effect, guarantees to extinguish the arc rapidly.

6. The arc-extinguishing grid piece is installed on the arc-isolating wall, the sliding grooves are formed in the edges of the sliding grooves and the arc-extinguishing grid pieces, the installation and the disassembly are very convenient, the assembly mode is simple, the maintenance is very convenient, the arc-extinguishing grid pieces in different forms can be installed on the structure according to design requirements, and the whole arc-extinguishing chamber is flexible and changeable.

7. Be equipped with the gas outlet on the lateral wall of flash barrier, guarantee that the hot gas flow that produces can in time cool off and disperse when the arc extinguishing, and the gas outlet can blow the system cooperation with the magnetism of circuit breaker, strengthen the magnetism greatly and blow the effect.

Drawings

FIG. 1 is a schematic view of the overall structure of a breaking unit;

FIG. 2 is a schematic view of an internal structure of a breaking unit;

FIG. 3 is a schematic structural diagram of a rotary double-break moving contact system;

FIG. 4 is a schematic structural diagram of a rotating shaft of a rotary double-breakpoint moving contact system;

fig. 5 and 6 are schematic views of a connection structure of a rotary double-breakpoint moving contact system;

FIG. 7 is a schematic structural diagram of a contact bridge of a rotary double-breakpoint moving contact system;

FIG. 8 is a schematic structural diagram of an arc extinguishing chamber;

FIG. 9 is a schematic structural view of an arc-isolating wall of the arc-extinguishing chamber;

FIG. 10 is a schematic structural view of the moving and stationary contacts in an initial contact state;

FIG. 11 is a schematic view of a structure for repelling a moving contact and a stationary contact under a large current;

fig. 12 is a schematic view of the arrangement and operation of the magnetic conducting rod and the magnetic conducting plate.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1 and 2, a breaking unit of a double-breakpoint molded case circuit breaker includes two cover plates 101, two fixed contacts 102, a rotary double-breakpoint movable contact system 103, and two arc extinguishing chambers 104. Wherein, the two cover plates 101 form an independent box body unit, and a cavity is formed inside the box body unit; the two fixed contacts 102 are diagonally arranged in the cavity of the box body unit, the wiring terminals of the fixed contacts 102 extend out of the box body unit, and the rotary double-breakpoint moving contact system 103 is rotatably arranged in the cavity of the box body unit and is positioned between the two fixed contacts 102; two arc-extinguishing chambers 104 are installed in the box unit cavities on both sides of the rotary double-breakpoint moving contact system 103.

The stationary contact 102 is U-shaped, as shown in fig. 2 and 12, a magnetic conducting rod 106 is disposed in the U-shaped groove of the stationary contact 102, a magnetic conducting plate 105 is disposed outside the other end of the arc extinguish chamber 104 opposite to the magnetic conducting rod 106, and the magnetic conducting rod 106 and the magnetic conducting plate 105 can form a closed magnetic circuit, so that the arc is more easily attracted into the arc extinguish chamber under the action of the magnetic field, thereby achieving effective arc extinction. Specifically, the two cover plates 101 include a first cover plate and a second cover plate, the first cover plate and the second cover plate are connected together through screws, a central shaft hole 1011 is arranged in the middle of the first cover plate and the second cover plate, and two waist-shaped holes 1012 are arranged on two sides of the central shaft hole 1011; the rotary double-break moving contact system 103 is rotatably installed in the cavity of the box body unit through a central shaft 10314 penetrating through the central shaft hole 1011, the rotary double-break moving contact system 103 is provided with a sliding shaft 1013, and the sliding shaft 1013 penetrates through the waist-shaped hole 1012 and slides in the waist-shaped hole 1012. The first cover plate and the second cover plate are symmetrically provided with square sinking grooves respectively, air outlet holes 1014 corresponding to the air vent holes 205 in the slide block accommodating chamber are arranged in the square sinking grooves, and the air outlet holes 1014 on the first cover plate and the second cover plate are asymmetrically arranged.

The structure of the rotary double break point moving contact system 103 is shown in fig. 3-7, and comprises:

a rotating shaft 1031, as shown in fig. 4, the rotating shaft 1031 is in an oblate cylindrical structure, a central shaft 10314 is disposed at the center of the rotating shaft 1031, two arc slots 10313 which are centrosymmetric with respect to the central shaft 10314 are disposed in the middle of the radial sidewall of the rotating shaft 1031, and two open slots 10311 which are centrosymmetric with respect to the central shaft 10314 and two first mounting positioning holes 10312 are sequentially disposed on the rotating shaft 1031 along the axial end surface side;

a contact bridge 1032, as shown in fig. 7, the contact bridge 1032 passes through the arc-shaped slot 10313, and is rotatably mounted on the rotating shaft 1031 through the central shaft 10314, a circular hole is arranged at the center of the contact bridge 1032, arc-shaped guide grooves 10321 are arranged at both sides of the contact bridge 1032, a movable contact 10322 is arranged at the end of the contact bridge 1032, and the shape of the contact bridge 1032, the arc-shaped guide grooves 10321, and the movable contact are all arranged in central symmetry with respect to the center of the contact bridge 1032;

two spring shafts 1033, as shown in fig. 3 and 6, for mounting the springs 1034, and axially penetrate through the opening grooves 10311 of the rotating shaft 1031, respectively;

two springs 1034 respectively arranged on two end faces of the rotating shaft 1031 along the axial direction thereof, and two ends of each spring 1034 are connected to the spring shaft 1033; and

two small connecting rods 1035 axially penetrate through the first mounting positioning hole 10312 of the rotating shaft 1031, and the adjacent spring shafts 1033 and the small connecting rods 1035 are connected through a connecting rod 1036.

In addition, as shown in fig. 6, a screen 1037 for covering is arranged on an end surface of the rotating shaft 1031 along the axial direction thereof, a screen boss 10371 is arranged on the inner side of the screen 1037, the connecting rod 1036 is clamped between the screen boss 10371 and the rotating shaft 1031, a spring accommodating cavity is formed between the screen 1037 and the end surface of the rotating shaft 1031, and the spring is located in the spring accommodating cavity; the screen panel is installed on the rotation shaft 1031 through the second installation positioning hole 10315; the cross section of the open slot 10311 is in an arc structure, the two ends of the contact bridge 1032 are provided with a boss 10323 at one side corresponding to the movable contact 10322, and the middle of the spring shaft 1033 is sleeved with a roller 1038; the small link 1035 passes through the connecting rod and the rotating shaft 1031, respectively, and is riveted with the connecting rod and the rotating shaft 1031.

When the circuit breaker is in an initial state, as shown in fig. 10, the contact bridge makes the movable contact and the fixed contact under the combined action of the spring, the spring shaft and the small connecting rod. When a circuit breaks down, electric repulsion force can be generated between the moving contact and the static contact, the contact bridge is stressed to rotate, as shown in fig. 11, at the moment, the spring shaft enters the arc-shaped guide grooves 10321 at the two sides of the contact bridge 1032 under the action of the spring and the arc-shaped grooves of the contact bridge 1, the spring shaft is tightly clamped, the moving contact is repelled and locked, the moving contact is effectively prevented from falling back, the tripping action is smoothly completed, and the problem that the moving contact can be closed for a second time or closed for a plurality of times due to shaking under the action of spring tension is solved.

As shown in fig. 8 and 9, the arc extinguishing chamber 104 includes:

the two arc isolating walls 1041 are arranged alternately, and a plurality of slideways 10412 are arranged on the inner side edge of the arc isolating walls 1041; and

a plurality of arc-extinguishing grid plates 1042 embedded in the slide rails 10412 of the two arc-isolating walls 1041;

the arc-extinguishing grid plates 1042 and the two arc-extinguishing walls 1041 are combined to form an arc-extinguishing chamber, the arc-extinguishing chamber is provided with a magnetic conducting plate 1043 at one open end of the arc-extinguishing chamber by the arc-extinguishing walls 1041, and two end parts of the contact bridge 1032 are positioned in the middle of the arc-extinguishing grid plates 1042.

The magnetic conduction plate 1043 is arranged on the side edge of the arc-isolating wall 1041 opposite to the insertion end of the arc-extinguishing grid 1042, a groove is arranged on the arc-isolating wall 1041, and the magnetic conduction plate 1043 is embedded in the groove; the slideway 10412 is a multi-group of groove-shaped structures which are arranged in parallel on the inner wall of the arc-isolating wall 1041, the arc-extinguishing grid plates 1042 are inserted into the slideway 10412 in sequence at intervals, the upper part of the inner wall of the arc-isolating wall 1041 along the insertion end of the arc-extinguishing grid plate 1042 is an open U-shaped slideway 10412, and the lower part is an installation cavity; the magnetic conducting plate 1043 is a strip-shaped rectangular plate, the length direction of the magnetic conducting plate is parallel to the arrangement direction of the arc-extinguishing grid plates 1042, the length of the magnetic conducting plate 1043 is consistent with the arrangement width of the arc-extinguishing grid plates 1042, and the arc-insulating wall 1041 is provided with a second air outlet hole 10411. The arc-extinguishing grid 1042 is a metal sheet provided with a U-shaped arc-extinguishing groove, the U-shaped arc-extinguishing groove is formed by connecting a plurality of sections of arc lines, and an invaginated notch is formed in the middle of the U-shaped arc-extinguishing groove.

The explosion chamber is through being equipped with the magnetic conduction board on the flash barrier wall, the arc striking is carried out to the electric arc that produces, thereby make electric arc can get into in the explosion chamber sooner, electric arc is introduced behind the arc extinguishing bars piece of the top, arc extinguishing bars piece evenly cuts electric arc, a long electric arc is cut apart into the short electric arc of multistage, reach best arc extinguishing effect, be equipped with the gas outlet on the lateral wall of flash barrier wall, guarantee that the hot gas flow that produces can in time cool off and disperse when the arc extinguishing, and the gas outlet can cooperate with the magnetic blow-out system of circuit breaker, strengthen the magnetic blow-out effect greatly.

The embodiments described above are intended to facilitate the understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention according to the disclosure of the present invention.

Claims (10)

1. The utility model provides a two breakpoint moulded case circuit breaker's disconnected unit which characterized in that includes:

the box body comprises two cover plates (101), wherein the two cover plates (101) form an independent box body unit, and a cavity is formed inside the box body unit;

the two static contacts (102) are arranged in a cavity of the box body unit in a diagonal mode, and wiring terminals of the static contacts (102) extend out of the box body unit;

a rotary double-breakpoint moving contact system (103) rotatably installed in the cavity of the box body unit and located between two fixed contacts (102), comprising:

the rotating shaft (1031) is of an oblate cylindrical structure, a central shaft (10314) is arranged at the center of the rotating shaft (1031), two arc-shaped open grooves (10313) which are centrosymmetric relative to the central shaft (10314) are formed in the middle of the radial side wall of the rotating shaft (1031), and two open grooves (10311) and two first mounting positioning holes (10312) which are centrosymmetric relative to the central shaft (10314) are sequentially formed in the rotating shaft (1031) along the axial end surface side of the rotating shaft (1031);

the contact bridge (1032) penetrates through the arc-shaped open slot (10313) and is rotatably mounted on the rotating shaft (1031) through the central shaft (10314), a round hole is formed in the center of the contact bridge (1032), arc-shaped guide grooves (10321) are formed in two sides of the contact bridge (1032), a movable contact (10322) is arranged at the end part of the contact bridge (1032), and the shape of the contact bridge (1032), the arc-shaped guide grooves (10321) and the movable contact are arranged in a central symmetry mode relative to the center of the contact bridge (1032);

two spring shafts (1033) for mounting springs (1034) and axially penetrating into the opening grooves (10311) of the rotating shaft (1031), respectively;

the two springs (1034) are respectively arranged on two end faces of the rotating shaft (1031) along the axial direction of the rotating shaft, and two ends of each spring (1034) are connected to the spring shaft (1033); and

two small connecting rods (1035) axially penetrate through the first mounting positioning hole (10312) of the rotating shaft (1031), and the adjacent spring shafts (1033) are connected with the small connecting rods (1035) through connecting rods (1036);

two explosion chambers (104) are installed in the box body unit cavity of rotation type double break moving contact system (103) both sides, and it includes:

the two arc isolating walls (1041) are arranged at intervals, and a plurality of slideways (10412) are arranged on the inner side edge of each arc isolating wall (1041); and

the arc extinguishing grid pieces (1042) are embedded into the slide ways (10412) of the two arc isolating walls (1041);

the arc extinguishing grid plates (1042) and the two arc isolating walls (1041) are combined to form an arc extinguishing chamber, and the arc isolating walls (1041) are provided with magnetic conductive plates (1043) at one end of an opening of the arc extinguishing chamber;

the two ends of the contact bridge (1032) are positioned in the middle of the arc extinguishing grid plate (1042).

2. The breaking unit of the double break molded case circuit breaker according to claim 1,

the two cover plates (101) comprise a first cover plate and a second cover plate, the first cover plate and the second cover plate are connected together through screws, a central shaft hole (1011) is formed in the middle of the first cover plate and the middle of the second cover plate, and two waist-shaped holes (1012) are formed in two sides of the central shaft hole (1011);

the rotary double-breakpoint moving contact system (103) is rotatably installed in the cavity of the box body unit through a central shaft penetrating through the central shaft hole (1011), the rotary double-breakpoint moving contact system (103) is provided with a sliding shaft (1013), and the sliding shaft (1013) penetrates through the waist-shaped hole (1012) and slides in the waist-shaped hole (1012).

3. The breaking unit of the double-breakpoint molded case circuit breaker according to claim 2, wherein the first cover plate and the second cover plate are symmetrically provided with a square sink groove, the square sink groove is provided with a first air outlet hole (1014), and the arc barrier wall is provided with a second air outlet hole (10411) corresponding to the first air outlet hole (1014).

4. The breaking unit of the double-breakpoint molded case circuit breaker according to claim 1, wherein a shroud (1037) for covering is arranged on an end surface of the rotating shaft (1031) along an axial direction thereof, a shroud boss (10371) is arranged on an inner side of the shroud (1037), the shroud boss (10371) and the rotating shaft (1031) clamp the connecting rod (1036) in the middle, a spring accommodating cavity is formed between the shroud (1037) and the end surface of the rotating shaft (1031), and the spring is located in the spring accommodating cavity.

5. The breaking unit of the double-break molded case circuit breaker according to claim 1, wherein the cross-section of the open slot (10311) is an arc structure, the two ends of the contact bridge (1032) are provided with a boss (10323) at the side corresponding to the moving contact (10322), and the middle of the spring shaft (1033) is sleeved with a roller (1038).

6. The breaking unit of the double break molded case circuit breaker according to claim 1, wherein the small link (1035) passes through a connecting rod and a rotating shaft (1031), respectively, and is riveted with the connecting rod and the rotating shaft (1031).

7. The breaking unit of the double-breakpoint molded case circuit breaker according to claim 1, wherein the fixed contact (102) is U-shaped, a magnetic conductive rod (106) is disposed in the U-shaped groove of the fixed contact (102), and a magnetic conductive sheet (105) is disposed outside the arc extinguish chamber (104) at the other end opposite to the magnetic conductive rod (106).

8. The breaking unit of the double-breakpoint molded case circuit breaker according to claim 1, wherein the magnetic conductive plate (1043) is disposed on a side of the arc-isolating wall (1041) opposite to the insertion end of the arc-extinguishing grid plate (1042), a groove is disposed on the arc-isolating wall (1041), and the magnetic conductive plate (1043) is embedded in the groove.

9. The breaking unit of the double-breakpoint molded case circuit breaker according to claim 1, wherein the chute (10412) is a plurality of sets of groove structures disposed in parallel on an inner wall of the arc barrier (1041), the arc chute plates (1042) are sequentially inserted into the chute (10412) at intervals, an upper portion of the inner wall of the arc barrier (1041) along an insertion end of the arc chute plates (1042) is an open U-shaped chute (10412), and a lower portion thereof is an installation cavity.

10. The breaking unit of the double-breakpoint molded case circuit breaker according to claim 1, wherein the magnetic conductive plate (1043) is a rectangular plate with a long bar shape, a length direction of the magnetic conductive plate is parallel to an arrangement direction of the arc chute plates (1042), and a length of the magnetic conductive plate (1043) is consistent with an arrangement width of the arc chute plates (1042);

the arc extinguishing grid piece (1042) is a metal sheet provided with a U-shaped arc extinguishing groove, the U-shaped arc extinguishing groove is formed by connecting a plurality of sections of arc lines, and an invaginated notch is formed in the middle of the U-shaped arc extinguishing groove.

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