阅读说明：本技术 断路器 (Circuit breaker ) 是由 郭得道 袁从飞 于 2020-06-30 设计创作，主要内容包括：本发明提供一种断路器,其包括壳体、触头支持件、反力弹性件、动触头、静触头、锁扣、手柄、连杆以及脱扣器。触头支持件包括本体部、驱动部以及弹性储能部,本体部通过支点转轴转动连接于壳体,驱动部和弹性储能部分别位于支点转轴的两侧,驱动部通过连杆连接于手柄。动触头连接于弹性储能部,在手柄超程转动时,动触头抵接静触头,本体部相对动触头运动,弹性储能部的两端产生位移差并弯曲,产生指向静触头的回弹力以将动触头压紧于静触头。(The invention provides a circuit breaker, which comprises a shell, a contact support, a counter-force elastic element, a moving contact, a static contact, a lock catch, a handle, a connecting rod and a release. The contact supporting piece comprises a body part, a driving part and an elastic energy storage part, the body part is rotatably connected to the shell through a fulcrum rotating shaft, the driving part and the elastic energy storage part are respectively positioned on two sides of the fulcrum rotating shaft, and the driving part is connected to the handle through a connecting rod. The moving contact is connected in elasticity energy storage portion, and when the handle over-travel rotated, the moving contact butt static contact, the relative moving contact motion of this somatic part, the both ends of elasticity energy storage portion produced the displacement difference and crooked, produced the resilience force of directional static contact in order to compress tightly the moving contact in the static contact.)

1. The utility model provides a circuit breaker, its characterized in that includes casing, contact supporting member, reaction elastic component, moving contact, static contact, hasp, handle, connecting rod and release, wherein:

the contact supporting piece comprises a body part, a driving part and an elastic energy storage part, wherein the body part is rotatably connected to the shell through a fulcrum rotating shaft, the driving part and the elastic energy storage part are respectively positioned at two sides of the fulcrum rotating shaft, and the driving part is connected to the handle through a connecting rod;

the moving contact is connected in elasticity energy storage portion, and when the handle over-travel rotated, moving contact butt static contact, the relative moving contact motion of this somatic part, the both ends of elasticity energy storage portion produced the displacement difference and crooked, produced the resilience force of directional static contact in order to compress tightly the moving contact in the static contact.

2. The circuit breaker of claim 1, wherein the movable contact is connected to the elastic energy storage portion in an overlapping manner, a portion of the elastic energy storage portion connected to the movable contact in an overlapping manner is a resilient force adjustment area, and the resilient force is adjusted by adjusting the length of the resilient force adjustment area.

3. The circuit breaker according to claim 2, wherein the contact holder further comprises a connecting portion connecting the body portion and the elastic energy storing portion, and the connecting portion is bent and extended in a thickness direction with respect to the body portion and then connected to the elastic energy storing portion.

4. The circuit breaker of claim 1, wherein the latch is rotatably connected to the contact supporter and forms a linkage state or a release state with the driving part to lock or unlock a link connected to the handle, and the latch elastic member is connected between the latch and the contact supporter.

5. The circuit breaker according to claim 4, wherein the latch comprises a latch body, a trip trigger portion, a hook portion and a locking portion, the latch body is rotatably connected to the body portion of the contact support, the trip trigger portion and the hook portion are respectively located at two sides of the latch body, the locking portion is formed on the hook portion and protrudes towards the inner side of the hook portion, the latch body, the hook portion and the locking portion enclose a first bayonet, the driving portion is provided with a second bayonet opposite to the first bayonet, and in a linkage state, the outer side wall of the locking portion and the side wall of the second bayonet respectively abut against and lock two sides of the other end of the connecting rod; under the tripping state, the locking part releases the locking of the other end of the connecting rod, and the other end of the connecting rod stops in the first clamping opening.

6. The circuit breaker according to claim 5, wherein the other end of the driving portion opposite to the first bayonet is provided with at least one groove, and the latch elastic member is sleeved and fixed between the two grooves or between one of the grooves and an outer side wall of the driving portion.

7. The circuit breaker according to claim 1 or 4, wherein the latch further comprises a rotation triggering portion, the rotation triggering portion is disposed on the trip triggering portion and extends to a side where the contact supporting member is located, and the rotation triggering portion is located between the stationary contact and the elastic energy storage portion.

8. The circuit breaker of claim 1, wherein the trip unit comprises a thermal trip unit, the thermal trip unit comprises a bimetallic strip and a trip bar, a bottom of the bimetallic strip abuts against the double-gold adjusting screw, and an included angle between a surface of the bimetallic strip at the abutment and an axis of the double-gold adjusting screw is greater than or equal to 75 degrees and less than or equal to 105 degrees.

9. The circuit breaker of claim 8, wherein the bimetal comprises a first portion, a second portion and a third portion from bottom to top, the first portion abuts against the double-gold adjusting screw, an included angle between the surface of the first portion and an axis of the double-gold adjusting screw is greater than or equal to 75 degrees and less than or equal to 105 degrees, the second portion is bent towards one side where the fixed contact is located relative to the first portion, and the third portion is bent towards one side away from the fixed contact relative to the second portion.

10. The circuit breaker of claim 1, further comprising an arc extinguish chamber disposed in the housing, and a plurality of exhaust guide pieces located at one side of the arc extinguish chamber, wherein an air guide channel is formed between the exhaust guide pieces, and gas generated after the arc extinguish chamber is exhausted through the air guide channel.

Technical Field

The invention relates to the technical field of low-voltage electrical appliance protection, in particular to a circuit breaker.

Background

A circuit breaker is a switching device capable of closing, carrying, and opening a current under a normal circuit condition, and carrying and opening a current under an abnormal circuit condition within a prescribed time. The traditional circuit breaker generally comprises a shell, a handle, a connecting rod, a static contact, a moving contact, a contact support, a jump buckle, a lock catch, a lever, a lock catch spring, a contact spring, a reset spring, an electromagnetic release, a thermal release, an arc extinguishing system and the like, and has the disadvantages of complex structure, difficult assembly and high cost.

In order to solve the problems, the circuit breaker which utilizes the combination of the driving wheel and the tripping frame to make the moving contact and the fixed contact or separate is also provided in the market at present, the driving wheel and the tripping frame in the circuit breaker with the structure replace the functions of a plurality of parts such as a jump buckle, a lock catch, a lever, a contact support and the like in the traditional circuit breaker, and the structure is simplified. However, in such a circuit breaker using the driving wheel and the trip, in order to achieve the over travel of the moving contact and the stationary contact in the locked state to ensure the reliable closing of the moving contact and the stationary contact, a contact pressure spring needs to be installed between the driving wheel and the moving contact to press the moving contact against the stationary contact. When the static contact is worn, burnt or electrically repulsive force occurs, the moving contact can be tightly pressed on the static contact by the counter force of the contact pressure spring, and therefore effective closing is achieved. In order to realize the installation of the contact pressure spring, a containing groove needs to be formed in the driving wheel, the moving contact is fixed in the containing groove, and two ends of the contact pressure spring are respectively installed between the moving contact and the inner wall of the containing groove. The installation of the moving contact and the contact pressure spring is difficult, the installation efficiency is low, and the quality after the installation is difficult to control. In addition, when the contact pressure needs to be adjusted, springs with different elastic forces and different lengths need to be replaced, and the contact pressure is limited by the space of the accommodating groove, so that the adjustment of the contact pressure is very difficult.

In addition, the volume of the driving wheel is increased due to the arrangement of the accommodating groove, the strength of the driving wheel is weakened due to the arrangement of the accommodating groove, particularly, the driving wheel with a plastic structure is obvious, and the thickness or the width of the driving wheel needs to be increased in order to ensure that the driving wheel has certain strength, so that the volume of the driving wheel is further increased. The tripping frame is rotationally buckled with the driving wheel, and the volume of the driving wheel is increased to ensure that the volume of the tripping frame is also increased. Therefore, the entire circuit breaker is bulky and costly.

Disclosure of Invention

The invention provides a breaker with simple structure and small volume to overcome the defects of the prior art.

In order to achieve the above object, the present invention provides a circuit breaker, which includes a housing, a contact support, a counter-force elastic element, a moving contact, a stationary contact, a latch, a handle, a connecting rod, and a release. The contact supporting piece comprises a body part, a driving part and an elastic energy storage part, the body part is rotatably connected to the shell through a fulcrum rotating shaft, the driving part and the elastic energy storage part are respectively positioned on two sides of the fulcrum rotating shaft, and the driving part is connected to the handle through a connecting rod. The moving contact is connected in elasticity energy storage portion, and when the handle over-travel rotated, the moving contact butt static contact, the relative moving contact motion of this somatic part, the both ends of elasticity energy storage portion produced the displacement difference and crooked, produced the resilience force of directional static contact in order to compress tightly the moving contact in the static contact.

According to an embodiment of the invention, the movable contact is connected with the elastic energy storage part in an overlapped manner, the part of the elastic energy storage part, which is connected with the movable contact in an overlapped manner, is a resilience force adjusting area, and the length of the resilience force adjusting area is adjusted to adjust the size of the resilience force.

According to an embodiment of the invention, the contact support further includes a connecting portion connecting the body portion and the elastic energy storing portion, and the connecting portion is bent and extended in a thickness direction of the body portion relative to the body portion and then connected to the elastic energy storing portion.

According to an embodiment of the present invention, the latch is rotatably connected to the contact support and forms a linkage state or a release state with the driving part to lock or unlock the link connected to the handle, and the latch elastic member is connected between the latch and the contact support.

According to an embodiment of the invention, the lock catch comprises a lock catch body, a tripping trigger part, a hook part and a locking part, wherein the lock catch body is rotationally connected to the body part of the contact support member, the tripping trigger part and the hook part are respectively positioned at two sides of the lock catch body, the locking part is formed on the hook part and protrudes towards the inner side of the hook part, the lock catch body, the hook part and the locking part surround to form a first bayonet, the driving part is provided with a second bayonet opposite to the first bayonet in direction, and in a linkage state, the outer side wall of the locking part and the side wall of the second bayonet are respectively abutted against two sides of the other end of the connecting rod and; under the tripping state, the locking part releases the locking of the other end of the connecting rod, and the other end of the connecting rod stops in the first clamping opening.

According to an embodiment of the present invention, the other end of the driving portion opposite to the first bayonet has at least one groove, and the locking elastic member is sleeved and fixed between the two grooves or between one of the grooves and the outer sidewall of the driving portion.

According to an embodiment of the invention, the latch further includes a rotation triggering portion, the rotation triggering portion is disposed on the trip triggering portion and extends toward a side where the contact supporting member is located, and the rotation triggering portion is located between the static contact and the elastic energy storage portion.

According to one embodiment of the invention, the release comprises a thermal release, the thermal release comprises a bimetallic strip and a trip rod, the bottom of the bimetallic strip abuts against the double-gold adjusting screw, and an included angle between the surface of the bimetallic strip at the abutting position and the axis of the double-gold adjusting screw is greater than or equal to 75 degrees and less than or equal to 105 degrees.

According to an embodiment of the present invention, the bimetal includes a first portion, a second portion and a third portion from bottom to top, the first portion abuts against the double-gold adjusting screw, an included angle between a surface of the first portion and an axis of the double-gold adjusting screw is greater than or equal to 75 degrees and less than or equal to 105 degrees, the second portion is bent toward a side where the fixed contact is located with respect to the first portion, and the third portion is bent toward a side away from the fixed contact with respect to the second portion.

According to an embodiment of the invention, the circuit breaker further comprises an arc extinguish chamber arranged in the shell and a plurality of exhaust guide pieces positioned on one side of the arc extinguish chamber, an air guide channel is formed among the exhaust guide pieces, and gas generated after the arc extinguish chamber is extinguished is exhausted through the air guide channel.

In summary, the contact support in the circuit breaker provided by the invention includes a body portion, a driving portion and an elastic energy storage portion, and the elastic energy storage portion is connected to the moving contact. When the handle rotates in an overtravel mode, the handle drives the body part to continue rotating through the connecting rod and the driving part, and the moving contact is limited by the abutting of the static contact. The relative motion between the body part and the moving contact enables the two ends of the elastic energy storage part to generate displacement difference, the elastic energy storage part bends and generates resilience force pointing to the static contact, and the resilience force compresses the moving contact on the static contact. When the static contact is worn, burnt or electrically repulsive force occurs, the elastic deformation part of the elastic energy storage part is restored to compensate the distance generated by the factors such as the wear, the burning or the electrically repulsive force of the static contact, so that the moving contact can be tightly abutted against the static contact, and the reliability of closing is ensured. The circuit breaker provided by the invention can realize reliable contact of the moving contact and the fixed contact without arranging a contact pressure spring, the structure of the contact supporting piece is very simple, only the moving contact is connected to the elastic energy storage part when the circuit breaker is installed, the assembly is very easy, the assembly efficiency is high, and the reliability and the consistency of the assembled product are good. In addition, the omission of the contact pressure spring also greatly simplifies the volume of the contact support, thereby realizing the miniaturization of the circuit breaker.

Furthermore, in the circuit breaker provided by the invention, the lengths of the parts which are bent and deformed on the elastic energy storage part are adjusted to be different, and the pressure applied to the moving contact during overtravel is also different; therefore, the contact pressure can be adjusted by adjusting the length of the bending deformation part on the elastic energy storage part. The length of the bending deformation part can be adjusted freely without any space limitation, so that the circuit breaker can be well matched with circuit breakers with different contact pressure requirements, and the design universality is better.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 is a schematic structural diagram of a circuit breaker in a trip state according to an embodiment of the present invention.

Fig. 2 is an enlarged schematic view of a portion a of fig. 1.

Fig. 3 is a schematic structural view illustrating the movable and stationary contacts of the circuit breaker shown in fig. 1.

Fig. 4 is an enlarged schematic view of fig. 3 at B.

Fig. 5 is a schematic structural diagram of fig. 3 from another view angle.

Figure 6 is an exploded view of the contact support and latch of figure 1.

Fig. 7 is a schematic view showing a structure in which the contact holder is mounted on the housing.

Fig. 8 is a schematic view showing the connection between the contact support and the movable contact.

Fig. 9 is a schematic structural view of the lock catch.

Fig. 10 is a schematic diagram showing the connection of the contact support, the latch, and the thermal trip unit of fig. 1.

Fig. 11 is a schematic structural view of the bimetal and the double-gold adjusting screw in fig. 1.

Detailed Description

As shown in fig. 1 to 10, the circuit breaker provided in this embodiment includes a housing 1, a contact support 2, a reaction elastic element 3, a movable contact 4, a stationary contact 5, a latch 6, a handle 7, a link 8, and a release 9. The contact support 2 comprises a body 21, a driving part 22 and an elastic energy storage part 23, the body 21 is rotatably connected to the housing 1 through a fulcrum rotating shaft 101, the driving part 22 and the elastic energy storage part 23 are respectively positioned at two sides of the fulcrum rotating shaft 101, and the driving part 22 is connected to the handle 7 through a connecting rod 8. The moving contact 4 is connected in the elastic energy storage part 23, when the handle 7 rotates in an over-travel mode, the moving contact 4 is abutted to the static contact 5, the body part 21 moves relative to the moving contact 4, the two ends of the elastic energy storage part 23 generate displacement difference and bend, and resilience force pointing to the static contact is generated to compress the moving contact 4 to the static contact 5.

Fig. 1 and 2 are schematic structural diagrams of the circuit breaker in a tripping state, and fig. 3 and 4 are schematic structural diagrams of the circuit breaker in a linkage state. The working principle of the circuit breaker closing and tripping will be explained in detail with reference to fig. 1 to 4. The terms "clockwise", "counterclockwise", "left", "right", "up" and "down" are used in reference to the corresponding drawings, respectively, and are only used for convenience of describing the operation principle of the circuit breaker in detail, and are not intended to limit the present invention. The direction indicated by the arrow K in fig. 1 and 3 is clockwise, and the direction opposite thereto is counterclockwise.

The circuit breaker can generate abrasion after the moving contact and the static contact are continuously separated and combined in the using process; the contact may be burnt after the load is switched on and off; or electric repulsion can be generated between the moving contact and the static contact after the moving contact and the static contact are contacted and electrified. In order to ensure that the moving contact and the static contact can be reliably contacted when the above conditions occur, the moving contact needs to be tightly pressed on the static contact to realize reliable closing. In the circuit breaker provided in this embodiment, the contact support 2 has an elastic energy storage portion 23, and the movable contact 4 is connected to the elastic energy storage portion 23. In the process of closing the switch, the handle 7 acts on the driving portion 22 through the connecting rod 8 to enable the contact supporting member 2 to rotate clockwise around the fulcrum rotating shaft 101, and the elastic energy storage portion 23 drives the movable contact 4 to gradually move towards the fixed contact 5. When the moving contact 4 abuts against the static contact 5, the handle 7 enters an over-travel state. In the over travel state, the drive portion 22 and the body portion 21 of the contact support continue to follow the movement of the link 8; and the moving contact 4 is limited by the abutting of the fixed contact 5 and does not move any more. The relative movement of the body 21 and the movable contact 4 causes a displacement difference between two ends of the elastic energy storage part 23, and the displacement difference causes the elastic energy storage part 23 to bend and deform. In the present embodiment, in the orientation shown in fig. 3, the elastic energy storage portion 23 is convexly curved to the right (the side where the static contact is located), the bending deformation of the elastic energy storage portion 23 generates a resilient force pointing to the static contact 5 on the movable contact 4, and the resilient force is stored in the bending deformation, so that the movable contact 4 is tightly pressed on the static contact 5. When a gap is generated between the moving contact and the static contact due to abrasion, burning loss or repulsive force, the elastic deformation part of the elastic energy storage part 23 is recovered, the moving contact 4 moves towards the static contact 5 to compensate the gap between the moving contact and the static contact, and the residual elastic deformation stored rebound force continuously presses the moving contact 4 on the static contact 5, so that reliable switching-on of the moving contact and the static contact is realized.

Compare the reliable combined floodgate under the circumstances such as traditional adoption contact pressure spring counter-force between the contact pressure spring realizes sound contact wearing and tearing, scaling loss or electronic repulsion, the circuit breaker that this embodiment provided is realized through the produced resilience force of deformation and this deformation on the release elasticity energy storage portion 23, and the structure of whole product is very simple and very easily assembles. Because need not to set up the contact pressure spring in the circuit breaker that this embodiment provided, consequently can solve the installation degree of difficulty that causes among the current circuit breaker because of the contact pressure spring big, the circuit breaker is bulky and with high costs scheduling problem well.

The magnitude of the return force depends on the modulus of elasticity of the elastic energy storing portion 23 and the length of the deformed portion thereof in the case where the over-travel range of the handle is determined. Therefore, the resilience can be adjusted by adjusting the length of the deformed part on the elastic energy storage part 23 during design; for example, for a circuit breaker with a large electric repulsive force between a moving contact and a stationary contact, the repulsive force needs to be increased to overcome the electric repulsive force so as to realize reliable contact between the moving contact and the stationary contact. In this embodiment, the movable contact 4 is connected to the elastic energy storage portion 23 in an overlapped manner, and since the movable contact 4 is made of a rigid material, after the movable contact is connected to the elastic energy storage portion 23 in an overlapped manner, the connection portion is not bent any more, so that the length of the deformation portion can be adjusted by adjusting the length of the connection portion. Specifically, when the length of the elastic energy storage portion 23 is constant, the shorter the length of the connection portion between the elastic energy storage portion 23 and the movable contact 4 is, the longer the length of the deformed portion is, the greater the repulsive force due to the deformation is.

In the embodiment, the movable contact 4 and the elastic energy storage part 23 are connected in an overlapped manner, so that the movable contact and the elastic energy storage part are reliably connected; furthermore, the connection mode also greatly simplifies the adjustment of the resilience force, so that the circuit breaker provided by the embodiment has good universality.

In the present embodiment, as shown in fig. 7, the movable contact 4 includes a contact body 41 and a contact connecting portion 42 connected to the elastic energy storage portion 23. The contact body 41 is bent toward the side where the stationary contact 5 is located with respect to the contact connecting portion 42, and the angle formed by the bending is α. As shown in fig. 1 and 3, the smaller the bending angle α between the contact body 41 and the contact connecting portion 42, the earlier the movable contact 4 will abut against the stationary contact 5 during rotation, and the overtravel is made by the movement of the handle once the movable contact abuts against the stationary contact. Therefore, the smaller the bending angle α, the greater the over travel distance will be, and the more the elastic energy storage portion 23 will be deformed, and therefore the greater the contact pressure will be generated. Therefore, the pressure of the contact can be adjusted by adjusting the bending angle of the moving contact and the bending deformation of the elastic energy storage part 23 during design, and the design is very flexible.

In this embodiment, the elastic energy storing portion 23 is connected to the main body 21 through the main body connecting portion 24, and the main body connecting portion 24 is bent and extended in the thickness direction of the main body 21 and then connected to the elastic energy storing portion 23. The arrangement of the body connecting portion 24 greatly increases the connecting surface area of the body portion 21 and the elastic energy storage portion 23 without increasing the thickness of the body portion 21, thereby greatly improving the connecting strength of the body portion 21 and the elastic energy storage portion. Preferably, the driving portion 22, the body portion 21, the connecting portion 24 and the elastic energy storing portion 23 are integrally formed and made of an elastic thin metal material. However, the present invention is not limited thereto. In other embodiments, the elastic energy storage portion can be detachably connected to the main body portion.

In this embodiment, the reaction elastic element 3 is a torsion spring sleeved on the fulcrum shaft 101 and fixedly connected to the driving portion 22 of the contact support, and the contact support has a torsion spring end fixing hole. Compared with a tension spring connected between the rotating wheel and the shell in the existing circuit breaker, the installation of the torsion spring sleeved on the fulcrum rotating shaft 101 and positioned below the contact supporting piece 2 is simpler and more convenient, and the additional installation space in the shell 1 is not occupied, so that the size of the circuit breaker is further reduced. In addition, when tripping, compare the reverse restoring force that traditional compression extension spring provided, the restoring force of torsional spring can make moving contact 4 and static contact 5 separate more rapidly after the energy storage, effectively prevents moving contact 4 shake and arouses the secondary arcing. However, the present invention is not limited thereto. In other embodiments, the counter-force elastic element may also be a tension spring as in a conventional circuit breaker.

In the circuit breaker provided by the embodiment, the arrangement of the elastic energy storage part 23 simplifies the installation steps and improves the installation efficiency under the condition of meeting the requirements of the traditional circuit breaker; in addition, this arrangement also greatly simplifies the structure of the contact support 2, and the miniaturization of the contact support 2 further simplifies the structure of the latch connected thereto. Specifically, in the present embodiment, the latch 6 includes a trip triggering portion 61, a latch body 62, a hook portion 63, and a locking portion 64. The latch body 62 is rotatably connected to the body 21 by a latch rotating shaft 65, and the trip triggering part 61 and the hook part 63 are respectively located at two sides of the latch body 62. The locking portion 64 is formed on the hook portion 63 and protrudes toward the inner side of the hook portion 63, the latch body 62, the hook portion 63, and the locking portion 64 enclose a first bayonet 601, and the driving portion 22 of the contact support has a second bayonet 201 facing opposite to the first bayonet 601. In a linkage state, the outer side wall of the locking part 64 and the side wall of the second bayonet 201 respectively abut against and lock two sides of the other end 81 of the connecting rod; in the released state, the locking portion 64 releases the locking of the other end 81 of the link, and the other end 81 of the link comes to rest in the first notch 601.

In order to realize the linkage between the latch 6 and the contact support 2, in this embodiment, as shown in fig. 1, a latch elastic member 10 is disposed between the latch 6 and the contact support 2, the handle 7 drives the contact support 2 to rotate around the fulcrum shaft 101, and the latch elastic member 10 pushes the latch 6 to rotate along with the contact support 2 and to engage with the driving portion 22 to form a linkage state. In this embodiment, the latch elastic member 10 is a compression spring, and in order to further reduce the volume of the contact support member 2, the other end of the driving portion 22 opposite to the second latch 201 is provided with two grooves 202, and a compression spring positioning boss 203 is formed between the two grooves. One end of the pressure spring is fixed on the pressure spring positioning boss 203, and the other end is fixed on the lock catch body 62. The arrangement of the pressure spring positioning boss 203 not only simplifies the fixing mode of the locking elastic piece 10, but also greatly facilitates the installation of the locking elastic piece 10. However, the present invention does not set any limit to the number of grooves. In other embodiments, the driving portion may have only one groove.

As shown in fig. 1 and 2, in the tripped state, the side walls of the locking portion 64 and the second bayonet 201 are both located on the same side of the other end 81 of the connecting rod, and the other end 81 of the connecting rod rests in the first bayonet 601. When pushing away handle 7 and overcoming the counter-force of handle torsional spring so that the relative casing 1 clockwise motion of handle, the other end 81 of connecting rod supports the lateral wall of second bayonet 201 fast, and the right side wall of locking portion 64 supports the left side of the connecting rod other end 81, and the right side wall of locking portion 64 and the lateral wall of second bayonet 201 support the both sides that lean on the connecting rod other end 81 respectively. The pre-pressure generated by the latch elastic member 10 connected between the latch 6 and the contact support 2 in a pre-pressed state will make the right sidewall of the locking portion 64 and the sidewall of the second bayonet 201 lock the other end 81 of the connecting rod to the second bayonet 201 to ensure that the connecting rod 8 is not slipped, and the handle 7 pushes the contact support 2 and the latch 6 to link clockwise through the connecting rod 8.

When the moving contact 4 and the static contact 5 are just contacted, the connecting line of the two ends of the connecting rod 8 is positioned above the rotating center of the handle 4, if the force acting on the handle 7 is removed at the moment, the handle 7 can rotate anticlockwise relative to the shell 1 to restore to the original position under the action of the handle torsion spring and the counter-force elastic element 3. The contact support 2 and the lock catch 6 are also restored to the original positions, the moving contact 4 is separated from the static contact 5, and the two can not realize stable closing. Therefore, when the movable contact 4 and the fixed contact 5 are just in contact, the handle 7 needs to be rotated continuously (handle overtravel) so that the connecting line of the two ends of the connecting rod 8 is located below the rotation center of the handle 4. At this time, the reaction force of the reaction elastic member 3 is a force that rotates the handle 7 clockwise and the force is larger than the counterclockwise restoring force of the handle torsion spring, and at this time, the force acting on the handle 7 is removed, and the handle 7 does not automatically return to the original position, thereby realizing closing. When the handle 7 enters an over travel state, the body part 21 continues to rotate clockwise along with the handle 7, and the movable contact 4 is limited by the abutting of the fixed contact 5 and does not rotate along with the body part 21. The relative movement between the body 21 and the moving contact 4 causes the two ends of the elastic energy storage part 23 to have a displacement difference, the elastic energy storage part 23 bends and protrudes towards one side where the static contact 5 is located, the bending deformation generates a resilience force towards the static contact on the moving contact, and the resilience force tightly presses the moving contact 4 on the static contact 5 without separation, as shown in fig. 3 and 4.

When a short circuit or overload occurs in the circuit, the release 9 triggers the release triggering part 61 in the state of fig. 3 to rotate the latch 6 counterclockwise, the locking part 64 releases the locking of the left side of the other end 81 of the connecting rod, and the space between the latch 6 and the driving part 22 is in a release state. At this time, the reaction force of the reaction force elastic member 3 cannot act on the handle 7 through the link 8 any more, and the handle 7 is returned by the handle torsion spring. Meanwhile, the reaction elastic element 3 drives the contact support element 2, the lock catch 6 and the moving contact 4 to move anticlockwise, and the moving contact 4 is separated from the static contact 5. The circuit breaker returns to the state shown in fig. 1.

In this embodiment, as shown in fig. 6, the latch 6 further includes a rotating trigger portion 66, the rotating trigger portion 66 is disposed on the trip trigger portion 61 and extends toward the side where the contact support 2 is located, and the rotating trigger portion 66 is located between the static contact 5 and the elastic energy storage portion 23. When the tripping triggering portion 61 is triggered by the tripping device 9 to rotate the latch 6 counterclockwise, the rotation triggering portion 66 will rapidly touch the elastic energy storage portion 23, and the elastic energy storage portion 23 rapidly drives the moving contact 4 to rotate counterclockwise, so as to accelerate the separation of the moving contact 4 and the static contact 5, and further reduce the possibility of secondary arcing.

In the present embodiment, as shown in fig. 1, the trip unit 9 includes a short-circuit trip unit 91 and an overheat trip unit 92. The short circuit release 91 is an electromagnetic release and is arranged opposite to the release trigger part 61, the static contact 5 is connected to the electromagnetic release, when a short circuit fault occurs in the circuit, the ejector rod 911 on the short circuit release moves to one side of the lock catch 6 and triggers the release trigger part 61, the lock catch 6 and the driving part 22 are in a release state, and the movable contact 4 is separated from the static contact 5.

The thermal release 92 comprises a bimetallic strip 921, a trip bar 924 and a double-gold adjusting screw 925, wherein the bottom of the bimetallic strip 921 abuts against the double-gold adjusting screw 925, and an included angle between the surface of the bimetallic strip 921 at the abutting position and the axis of the double-gold adjusting screw 925 is greater than or equal to 75 degrees and less than or equal to 105 degrees. Preferably, the angle θ between the surface of the bimetal 921 and the axis of the double-gold adjusting screw 925 is set equal to 95 degrees. However, the present invention is not limited thereto. In other embodiments, the angle between the surface of the bimetal and the axis of the bimetal adjusting screw may be other angles within 75 degrees to 105 degrees.

In the existing thermal release, the longitudinal section of the bimetallic strip is an inclined plane, and when the bimetallic adjusting screw is rotated to adjust the thermal release sensitivity, the tail end of the bimetallic adjusting screw moves along the surface of the inclined bimetallic strip, so that the sensitive adjustment is difficult to realize. In the thermal trip 92 provided in this embodiment, the included angle θ between the surface of the bimetal 921 and the axis of the bimetal adjusting screw 925 is equal to 95 degrees, the force generated by the movement of the bimetal adjusting screw 925 acts on the surface of the bimetal mainly in the vertical direction, and the fine adjustment on the bimetal adjusting screw can be converted into the displacement of the top of the bimetal, so that the thermal trip has good adjusting sensitivity and the bimetal adjusting screw does not move along the surface of the bimetal any more during adjustment.

In this embodiment, as shown in fig. 11, the bimetal 921 includes a first portion 9211, a second portion 9212 and a third portion 9213 from bottom to top, the first portion 9211 is clamped by the connecting piece 922 and the arc runner 923, the double-gold adjusting screw 925 is disposed at the outer side of the connecting piece 922 in an abutting manner, and an included angle between the surface of the first portion 9211 and the axis of the double-gold adjusting screw 925 is equal to 95 degrees. The second portion 9212 is bent toward the side of the fixed contact 5 with respect to the first portion 9211, and the third portion 9212 is bent toward the side away from the fixed contact 5 with respect to the second portion 9212. The present embodiment provides a bi-metal strip 921 having two turns. However, the present invention is not limited thereto. In other embodiments, the bimetal may not have the third portion. Specifically, when the double-gold adjusting screw 925 pushes the first portion 9211 inward (moves leftward in fig. 11), the second portion 9212 and the third portion 9213 will move (move rightward) away from the stationary contact 5 under the action of the metal connecting piece 922 and the arc runner 923. When double-gold adjusting screw 925 is rotated out, first portion 9211 is reset to the right and corresponding second portion 9212 and third portion 9213 are moved to the left.

As shown in fig. 3, the housing 1 has a guide groove 102 opened to a turn of the trip lever. One end of the trip lever 924 is fixed to the trip triggering portion 61, and the other end of the trip lever 924 is bent and extends into the guide groove 102, and the third portion 9213 of the bimetal is disposed opposite to the other end of the trip lever 924. When the circuit is overloaded, the bimetal 921 is heated to bend to the side far away from the static contact 5 (bend to the right side in fig. 3) and pulls the trip lever 924 to the right, and the trip lever 924 drives the trip trigger part 61 to rotate counterclockwise, so as to realize overheating trip. The arrangement of the guide groove 102 guides and limits the motion track of the trip lever 924 caused by the deformation of the bimetallic strip 921, so that the force generated by the micro deformation of the bimetallic strip 921 can be rapidly applied to the trip triggering part 61 through the trip lever 924, and the fault response speed of the circuit breaker is greatly improved.

In this embodiment, as shown in fig. 1, an arc extinguishing chamber 11 is further disposed in the housing 1, and one end of the arc striking plate 923, which is far away from the bimetal 921, is disposed in the arc extinguishing chamber 11 to guide the arc to enter the arc extinguishing chamber 11 for arc extinguishing. A plurality of exhaust guide plates 12 are arranged at one side of the arc extinguish chamber 11, an air guide channel 120 is formed among the exhaust guide plates 12, and the gas generated after the arc extinguish chamber 11 is exhausted through the air guide channel 120.

In summary, the contact support in the circuit breaker provided by the invention includes a body portion, a driving portion and an elastic energy storage portion, and the elastic energy storage portion is connected to the moving contact. When the handle rotates in an overtravel mode, the handle drives the body part to continue rotating through the connecting rod and the driving part, and the moving contact is limited by the abutting of the static contact. The relative motion between the body part and the moving contact enables the two ends of the elastic energy storage part to generate displacement difference, the elastic energy storage part bends and generates resilience force pointing to the static contact, and the resilience force compresses the moving contact on the static contact. When the static contact is worn, burnt or electrically repulsive force occurs, the elastic deformation part of the elastic energy storage part is restored to compensate the distance generated by the factors such as the wear, the burning or the electrically repulsive force of the static contact, so that the moving contact can be tightly abutted against the static contact, and the reliability of closing is ensured. The circuit breaker provided by the invention can realize reliable contact of the moving contact and the static contact without arranging a contact pressure spring. The structure of the contact supporting piece is very simple, only the moving contact needs to be connected to the elastic energy storage part during installation, the assembly is very easy, the assembly efficiency is high, and the reliability and consistency generated after the assembly are good. In addition, the omission of the contact pressure spring also greatly simplifies the volume of the contact support, thereby realizing the miniaturization of the circuit breaker.

Furthermore, in the circuit breaker provided by the invention, the lengths of the parts which are bent and deformed on the elastic energy storage part are adjusted to be different, and the pressure applied to the moving contact during overtravel is also different; therefore, the contact pressure can be adjusted by adjusting the length of the part of the elastic energy storage part which is bent and deformed. The length of the bending deformation part can be adjusted freely without any space limitation, so that the circuit breaker can be well matched with circuit breakers with different contact pressure requirements, and the design universality is better.

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.