circuit breaker

Abstract

The application provides a circuit breaker, which comprises a shell, a contact support, a counterforce spring, a movable contact, a static contact, a lock catch, a handle, a connecting rod and a trip unit. The contact support comprises a body part, a driving part and an elastic energy storage part, the body part is rotationally connected to the shell through a fulcrum shaft, the driving part and the elastic energy storage part are respectively located on two sides of the fulcrum shaft, and the driving part is connected to the handle through the connecting rod. The movable contact is connected to the elastic energy storage part, when the handle is rotationally over-traveled, the movable contact abuts against the static contact, the body part moves relative to the movable contact, the two ends of the elastic energy storage part are displaced and bent, and a rebound force directed to the static contact is generated to press the movable contact against the static contact.

Description

Technical Field

[0001] This invention relates to the field of low-voltage electrical protection technology, and particularly to a circuit breaker. Background Technology

[0002] A circuit breaker is a switching device capable of closing, carrying, and interrupting current under normal circuit conditions, and capable of carrying and interrupting current under abnormal circuit conditions within a specified time. Traditional circuit breakers generally include a housing, handle, linkage, stationary contact, moving contact, contact support, trip latch, locking latch, lever, locking spring, contact spring, return spring, electromagnetic trip unit, thermal trip unit, arc extinguishing system, etc., which are complex in structure, difficult to assemble, and costly.

[0003] To address the aforementioned issues, a circuit breaker has emerged on the market that utilizes a drive wheel and trip frame to allow the moving and stationary contacts to contact or separate. In this type of circuit breaker, the drive wheel and trip frame replace the functions of multiple components in traditional circuit breakers, such as the trip lever, locking mechanism, lever, and contact support, simplifying the structure. However, in these circuit breakers employing a drive wheel and trip unit, to ensure reliable closing of both the moving and stationary contacts by allowing them to extend beyond their travel range in the locked state, a contact spring needs to be installed between the drive wheel and the moving contact to press the moving contact firmly against the stationary contact. When the stationary contact experiences wear, burnout, or electrostatic repulsion, the reaction force of the contact spring will press the moving contact tightly against the stationary contact, thus achieving effective closing. To accommodate the contact spring, a receiving groove needs to be created on the drive wheel. The moving contact is fixed within the receiving groove, and the two ends of the contact spring are respectively installed between the moving contact and the inner wall of the receiving groove. Due to space constraints within the receiving groove, the installation of the moving contact and contact spring is extremely difficult, inefficient, and the quality after installation is hard to control. Furthermore, when adjusting the contact pressure, springs with different spring strengths and lengths must be replaced; again, due to space constraints within the receiving groove, adjusting the contact pressure is very difficult.

[0004] Furthermore, the inclusion of the receiving slot itself increases the volume of the drive wheel and weakens its strength, especially noticeable in drive wheels with plastic structures. To ensure sufficient strength, the thickness or width of the drive wheel needs to be increased, further increasing its volume. Since the trip frame is rotatably engaged with the drive wheel, the increased volume of the drive wheel inevitably leads to an increase in the volume of the trip frame. Therefore, the overall circuit breaker is large and expensive. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a circuit breaker with a simple structure and small size.

[0006] To achieve the above objectives, the present invention provides a circuit breaker comprising a housing, a contact support, a reaction elastic member, a moving contact, a stationary contact, a latch, a handle, a connecting rod, and a trip unit. The contact support includes a body, a drive unit, and an elastic energy storage unit. The body is rotatably connected to the housing via a pivot shaft. The drive unit and the elastic energy storage unit are located on opposite sides of the pivot shaft. The drive unit is connected to the handle via a connecting rod. The moving contact is connected to the elastic energy storage unit. When the handle is rotated beyond its travel range, the moving contact abuts against the stationary contact. The body moves relative to the moving contact, and the two ends of the elastic energy storage unit generate a displacement difference and bend, generating a restoring force pointing towards the stationary contact to press the moving contact firmly against the stationary contact.

[0007] According to one embodiment of the present invention, the moving contact and the elastic energy storage part are connected in an overlapping manner, and the part where the elastic energy storage part and the moving contact are connected in an overlapping manner is a rebound force adjustment area. The rebound force is adjusted by adjusting the length of the rebound force adjustment area.

[0008] According to one embodiment of the present invention, the contact support further includes a connecting portion connecting the body portion and the elastic energy storage portion, wherein the connecting portion is bent and extended relative to the body portion in the thickness direction and then connected to the elastic energy storage portion.

[0009] According to one embodiment of the present invention, the latch is rotatably connected to the contact support and forms a linkage state or a disengaged state with the drive unit to lock or unlock the linkage connected to the handle, and the latch elastic member is connected between the latch and the contact support.

[0010] According to an embodiment of the present invention, the latch includes a latch body, a release trigger part, a hook part, and a locking part. The latch body is rotatably connected to the body part of the contact support member. The release trigger part and the hook part are respectively located on both sides of the latch body. The locking part is formed on the hook part and protrudes inward from the hook part. The latch body, the hook part, and the locking part together form a first latch. The drive part has a second latch facing opposite to the first latch. In the linkage state, the outer wall of the locking part and the side wall of the second latch abut against both sides of the other end of the connecting rod and lock them. In the release 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 latch.

[0011] According to one embodiment of the present invention, the drive part has at least one groove on the other end opposite to the first bayonet, and the locking elastic element is sleeved and fixed between the two grooves or between one of the grooves and the outer wall of the drive part.

[0012] According to one embodiment of the present invention, the latch further includes a rotation trigger portion, which is disposed on the trip trigger portion and extends toward the side where the contact support is located, and the rotation trigger portion is located between the stationary contact and the elastic energy storage portion.

[0013] According to an embodiment of the present invention, the trip unit includes a thermal trip unit, which includes a bimetallic strip and a trip lever. The bottom of the bimetallic strip abuts against a bimetallic adjusting screw. The angle between the surface of the bimetallic strip at the abutment and the axis of the bimetallic adjusting screw is greater than or equal to 75 degrees and less than or equal to 105 degrees.

[0014] According to an embodiment of the present invention, the bimetallic strip includes a first part, a second part and a third part from bottom to top. The first part abuts against the bimetallic adjusting screw. The angle between the surface of the first part and the axis of the bimetallic adjusting screw is greater than or equal to 75 degrees and less than or equal to 105 degrees. The second part is bent relative to the first part toward the side where the stationary contact is located. The third part is bent relative to the second part toward the side away from the stationary contact.

[0015] According to one embodiment of the present invention, the circuit breaker further includes an arc-extinguishing chamber disposed within the housing and a plurality of exhaust guide plates located on one side of the arc-extinguishing chamber, wherein an exhaust guide channel is formed between the plurality of exhaust guide plates, and the gas generated after the arc-extinguishing chamber extinguishes the arc is discharged through the exhaust guide channel.

[0016] In summary, the contact support component in the circuit breaker provided by this invention includes a body, a drive unit, and an elastic energy storage unit, with the elastic energy storage unit connected to the moving contact. When the handle is rotated beyond its travel range, the handle drives the body to continue rotating via the connecting rod and the drive unit, while the moving contact is already abutted and limited by the stationary contact. The relative movement between the body and the moving contact causes a displacement difference between the two ends of the elastic energy storage unit, causing the elastic energy storage unit to bend and generate a rebound force pointing towards the stationary contact. This rebound force presses the moving contact firmly against the stationary contact. When the stationary contact experiences wear, burning, or electro-repulsive forces, the elastic deformation portion of the elastic energy storage unit recovers to compensate for the gap caused by wear, burning, or electro-repulsive forces, ensuring that the moving contact can tightly abut against the stationary contact and guaranteeing the reliability of closing. The circuit breaker provided by this invention achieves reliable contact between moving and stationary contacts without the need for contact springs. Furthermore, the structure of the contact support is extremely simple; during installation, the moving contact is simply connected to the elastic energy storage section, making assembly very easy. This results in high assembly efficiency and excellent reliability and consistency of the assembled product. In addition, the omission of the contact springs significantly reduces the size of the contact support, thereby achieving miniaturization of the circuit breaker.

[0017] Furthermore, in the circuit breaker provided by this invention, the pressure applied to the moving contact during overtravel will vary depending on the length of the bending deformation portion on the elastic energy storage section; therefore, the contact pressure can be adjusted by changing the length of the bending deformation portion on the elastic energy storage section. The adjustment of the length of the bending deformation portion is very flexible and not limited by any space, thus it can be well matched to circuit breakers with different contact pressure requirements, i.e., it has better design versatility.

[0018] To make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 The diagram shown is a schematic representation of the circuit breaker in the tripped state according to an embodiment of the present invention.

[0020] Figure 2 As shown Figure 1 Enlarged diagram of point A in the middle.

[0021] Figure 3 As shown Figure 1 The diagram shows the structure of the circuit breaker's moving and stationary contacts.

[0022] Figure 4 As shown Figure 3 Enlarged diagram of point B in the middle.

[0023] Figure 5 As shown Figure 3 A structural diagram from another perspective.

[0024] Figure 6 As shown Figure 1 Exploded view of the middle contact support and the latch.

[0025] Figure 7 The diagram shows the structure of the contact support mounted on the housing.

[0026] Figure 8 The diagram shows the connection between the contact support and the moving contact.

[0027] Figure 9 The diagram shown is a schematic of the latch structure.

[0028] Figure 10 As shown Figure 1 A schematic diagram showing the connection of the middle contact support, latch, and thermal trip unit.

[0029] Figure 11 As shown Figure 1 A schematic diagram of the structure of the bimetallic strip and the bimetallic adjusting screw. Detailed Implementation

[0030] like Figures 1 to 10As shown, the circuit breaker provided in this embodiment includes a housing 1, a contact support 2, a reaction elastic member 3, a moving contact 4, a stationary contact 5, a latch 6, a handle 7, a connecting rod 8, and a trip unit 9. The contact support 2 includes a body 21, a drive 22, and an elastic energy storage part 23. The body 21 is rotatably connected to the housing 1 via a pivot shaft 101. The drive 22 and the elastic energy storage part 23 are located on opposite sides of the pivot shaft 101. The drive 22 is connected to the handle 7 via the connecting rod 8. The moving contact 4 is connected to the elastic energy storage part 23. When the handle 7 rotates beyond its travel range, the moving contact 4 abuts against the stationary contact 5. The body 21 moves relative to the moving contact 4, and the two ends of the elastic energy storage part 23 generate a displacement difference and bend, generating a rebound force pointing towards the stationary contact to press the moving contact 4 against the stationary contact 5.

[0031] Figure 1 and Figure 2 The diagram shown is a schematic of the circuit breaker in the tripped state. Figure 3 and Figure 4 The diagram shown is a structural schematic of the circuit breaker in the interlocked state. The following will combine... Figures 1 to 4 This paper elaborates on the working principles of circuit breaker closing and tripping. The terms "clockwise," "counterclockwise," "left," "right," "up," and "down" used in this paper refer to the corresponding diagrams and are only for the purpose of explaining the working principle of the circuit breaker in detail; they are not intended to limit the invention. Figure 1 and Figure 3 The direction indicated by the middle arrow K is clockwise, and the opposite direction is counterclockwise.

[0032] During operation, the moving and stationary contacts of a circuit breaker experience wear due to repeated opening and closing; the contacts may also burn out after the load is applied; or an electric repulsion force may be generated between the moving and stationary contacts after they come into contact and are energized. To ensure reliable contact between the moving and stationary contacts in these situations, the moving contact needs to be firmly pressed against the stationary contact to achieve reliable closing. In the circuit breaker provided in this embodiment, the contact support 2 has an elastic energy storage section 23, and the moving contact 4 is connected to the elastic energy storage section 23. During the closing process, the handle 7 acts on the drive section 22 through the connecting rod 8, causing the contact support 2 to rotate clockwise around the fulcrum shaft 101. The elastic energy storage section 23 drives the moving contact 4 to gradually move towards the stationary contact 5. When the moving contact 4 abuts against the stationary contact 5, the handle 7 enters an overtravel state. In the overtravel state, the drive section 22 and the body section 21 of the contact support continue to move with the connecting rod 8; while the moving contact 4 is stopped by the abutment of the stationary contact 5 and no longer moves. The relative movement between the main body 21 and the moving contact 4 causes a displacement difference between the two ends of the elastic energy storage section 23, which causes the elastic energy storage section 23 to bend and deform. In this embodiment, using... Figure 3In terms of orientation, the elastic energy storage section 23 protrudes and bends to the right (on the side where the stationary contact is located). The bending deformation of the elastic energy storage section 23 generates a rebound force on the moving contact 4 pointing towards the stationary contact 5, and this rebound force is stored in the bending deformation, thereby pressing the moving contact 4 tightly against the stationary contact 5. When a gap occurs between the moving and stationary contacts due to wear, burning, or repulsive force, the elastic deformation of the elastic energy storage section 23 partially recovers, and the moving contact 4 moves towards the stationary contact 5 to compensate for the gap between them. The rebound force stored in the remaining elastic deformation continues to press the moving contact 4 tightly against the stationary contact 5, thereby achieving reliable closing of the circuit.

[0033] Compared to traditional circuit breakers that rely on the reaction force between contact springs to ensure reliable closing under conditions of contact wear, burnout, or electro-repulsion, the circuit breaker provided in this embodiment achieves this by releasing the deformation of the elastic energy storage section 23 and the resulting rebound force. The overall structure of the product is very simple and easy to assemble. Since the circuit breaker provided in this embodiment does not require contact springs, it effectively solves the problems of difficult installation, large circuit breaker size, and high cost caused by contact springs in existing circuit breakers.

[0034] With the handle overtravel range determined, the magnitude of the rebound force depends on the elastic coefficient of the elastic energy storage section 23 and the length of its deformed portion. Therefore, the rebound force can be adjusted during design by modifying the length of the deformed portion of the elastic energy storage section 23. For example, for circuit breakers with a large electro-repulsive force between the moving and stationary contacts, the rebound force needs to be increased to overcome the electro-repulsive force and achieve reliable contact between the moving and stationary contacts. In this embodiment, the moving contact 4 is connected to the elastic energy storage section 23 in an overlapping manner. Since the moving contact 4 is made of a rigid material, the connection portion will no longer bend after it is connected to the elastic energy storage section 23 in an overlapping manner. Therefore, the length of the deformed portion can be adjusted by modifying the length of the connection portion. Specifically, when the length of the elastic energy storage section 23 is constant, the shorter the length of the connection portion between the elastic energy storage section 23 and the moving contact 4, the longer the length of the deformed portion, and the greater the rebound force generated by the deformation.

[0035] In this embodiment, the overlapping connection between the moving contact 4 and the elastic energy storage part 23 not only achieves a reliable connection between the two, but also greatly simplifies the adjustment of the rebound force, thereby making the circuit breaker provided in this embodiment highly versatile.

[0036] In this embodiment, as Figure 7 As shown, the moving 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 relative to the contact connecting portion 42 toward the side where the stationary contact 5 is located, and the angle formed by the bending is α. Figure 1 and Figure 3As shown, the smaller the bending angle α between the contact body 41 and the contact connection part 42, the earlier the moving contact 4 will contact the stationary contact 5 when rotating. Once contact is made, the movement of the handle enters overtravel. Therefore, the smaller the bending angle α, the greater the overtravel distance, and the more severe the deformation of the elastic energy storage part 23, resulting in greater contact pressure. Thus, the contact pressure can also be adjusted by changing the bending angle on the moving contact and the bending deformation of the elastic energy storage part 23, making the design very flexible.

[0037] In this embodiment, the elastic energy storage unit 23 is connected to the main body 21 via the main body connecting part 24. The main body connecting part 24 is bent and extended relative to the main body 21 in the thickness direction before connecting to the elastic energy storage unit 23. The provision of the main body connecting part 24 greatly increases the connection surface area between the main body 21 and the elastic energy storage unit 23 without increasing the thickness of the main body 21, thereby greatly improving the connection strength between the two. Preferably, the driving part 22, the main body 21, the connecting part 24, and the elastic energy storage unit 23 are integrally formed and made of a thin, elastic metal material. However, the present invention does not limit this in any way. In other embodiments, the elastic energy storage unit may also be detachably connected to the main body.

[0038] In this embodiment, the reaction elastic element 3 is a torsion spring sleeved on the fulcrum shaft 101 and fixedly connected to the drive part 22 of the contact support member, with a fixing hole at the end of the torsion spring on the contact support member. Compared to the tension spring connected between the wheel and the housing in existing circuit breakers, the torsion spring sleeved on the fulcrum shaft 101 and located below the contact support member 2 is easier and more convenient to install and does not occupy additional installation space in the housing 1, thus further reducing the size of the circuit breaker. In addition, during tripping, compared to the reverse restoring force provided by a traditional compression tension spring, the restoring force of the torsion spring after energy storage will more quickly separate the moving contact 4 and the stationary contact 5, effectively preventing the moving contact 4 from shaking and causing secondary arcing. However, the present invention does not limit this. In other embodiments, the reaction elastic element can also be a tension spring from a conventional circuit breaker.

[0039] In the circuit breaker provided in this embodiment, the flexible energy storage section 23 simplifies the installation steps and improves installation efficiency while meeting the requirements of conventional circuit breakers. Furthermore, this configuration 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 to it. Specifically, in this embodiment, the latch 6 includes a trip trigger section 61, a latch body 62, a hook section 63, and a locking section 64. The latch body 62 is rotatably connected to the body section 21 via a latch pivot 65. The trip trigger section 61 and the hook section 63 are located on opposite sides of the latch body 62. The locking section 64 is formed on the hook section 63 and protrudes inward from the hook section 63. The latch body 62, the hook section 63, and the locking section 64 together form a first bayonet 601. The driving section 22 of the contact support has a second bayonet 201 facing opposite to the first bayonet 601. In the linkage state, the outer wall of the locking part 64 and the side wall of the second bayonet 201 abut against the two sides of the other end 81 of the connecting rod and lock them; in the disengagement state, the locking part 64 releases the lock on the other end 81 of the connecting rod, and the other end 81 of the connecting rod stops in the first bayonet 601.

[0040] To achieve linkage between the latch 6 and the contact support 2, in this embodiment, as follows: Figure 1 As shown, a locking elastic element 10 is provided between the latch 6 and the contact support 2. The handle 7 drives the contact support 2 to rotate around the pivot shaft 101, and the locking elastic element 10 pushes the latch 6 to rotate with the contact support 2 and engage with the drive part 22 to form a linkage state. In this embodiment, the locking elastic element 10 is a compression spring. To further reduce the volume of the contact support 2, two grooves 202 are provided on the other end of the drive part 22 opposite to the second bayonet 201, and a compression spring positioning boss 203 is formed between the two grooves. One end of the compression spring is fixed to the compression spring positioning boss 203, and the other end is fixed to the latch body 62. The setting of the compression spring positioning boss 203 not only simplifies the fixing method of the locking elastic element 10, but also greatly facilitates the installation of the locking elastic element 10. However, the present invention does not limit the number of grooves. In other embodiments, the drive part may also have only one groove.

[0041] like Figure 1 and Figure 2As shown, in the disengaged state, the side walls of the locking part 64 and the second latch 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 latch 601. When the handle 7 is pushed and the reaction force of the handle torsion spring is overcome to make the handle move clockwise relative to the housing 1, the other end 81 of the connecting rod quickly abuts against the side wall of the second latch 201, the right side wall of the locking part 64 abuts against the left side of the other end 81 of the connecting rod, and the right side wall of the locking part 64 and the side wall of the second latch 201 abut against the two sides of the other end 81 of the connecting rod, respectively. The pre-pressure generated by the pre-pressed locking elastic member 10 connected between the latch 6 and the contact support 2 will cause the right side wall of the locking part 64 and the side wall of the second latch 201 to lock the other end 81 of the connecting rod in the second latch 201 to ensure that the connecting rod 8 does not slip. The handle 7 pushes the contact support 2 and the latch 6 clockwise through the connecting rod 8.

[0042] When the moving contact 4 and the stationary contact 5 just make contact, the line connecting the two ends of the connecting rod 8 is above the rotation center of the handle 7. If the force acting on the handle 7 is removed at this time, under the action of the handle torsion spring and the reaction elastic element 3, the handle 7 will rotate counterclockwise relative to the housing 1 to return to its original position. The contact support 2 and the latch 6 will also return to their original positions, and the moving contact 4 will separate from the stationary contact 5, making stable closing impossible. Therefore, when the moving contact 4 and the stationary contact 5 just make contact, the handle 7 needs to be rotated further (handle overtravel) so that the line connecting the two ends of the connecting rod 8 is below the rotation center of the handle 7. At this time, the reaction force of the reaction elastic element 3 is a force that makes the handle 7 rotate clockwise, and this force is greater than the counterclockwise restoring force of the handle torsion spring. If the force acting on the handle 7 is removed at this time, the handle 7 will not automatically return to its original position to achieve closing. When the handle 7 enters the overtravel state, the main body 21 continues to rotate clockwise following the handle 7, while the moving contact 4, limited by the contact of the stationary contact 5, no longer rotates with the main body 21. The relative movement of the main body 21 and the moving contact 4 causes a displacement difference between the two ends of the elastic energy storage section 23. The elastic energy storage section 23 bends and protrudes towards the side where the stationary contact 5 is located. This bending deformation generates a rebound force on the moving contact towards the stationary contact. This rebound force presses the moving contact 4 tightly against the stationary contact 5 without separating it. Figure 3 and Figure 4 As shown.

[0043] When a short circuit or overload occurs in the circuit, the trip unit 9 is triggered. Figure 3 In the tripping state, the tripping trigger 61 causes the latch 6 to rotate counterclockwise, and the locking part 64 releases the lock on the left side of the other end 81 of the connecting rod, putting the latch 6 and the drive part 22 in a tripped state. At this time, the reaction force of the reaction elastic element 3 can no longer act on the handle 7 through the connecting rod 8, and the handle 7 returns to its original position under the action of the handle torsion spring. Simultaneously, the reaction elastic element 3 drives the contact support 2, the latch 6, and the moving contact 4 to move counterclockwise, separating the moving contact 4 from the stationary contact 5. The circuit breaker returns to normal. Figure 1The state shown.

[0044] In this embodiment, as Figure 6 As shown, the latch 6 also includes a rotation trigger part 66, which is disposed on the trip trigger part 61 and extends towards the side where the contact support 2 is located. The rotation trigger part 66 is located between the stationary contact 5 and the elastic energy storage part 23. When the trip trigger part 61 is triggered by the trip unit 9 to rotate the latch 6 counterclockwise, the rotation trigger part 66 will quickly touch the elastic energy storage part 23. The elastic energy storage part 23 will quickly drive the moving contact 4 to rotate counterclockwise, accelerating the separation of the moving contact 4 and the stationary contact 5, and further reducing the possibility of secondary arcing.

[0045] In this embodiment, as Figure 1 As shown, the trip unit 9 includes a short-circuit trip unit 91 and an overheat trip unit 92. The short-circuit trip unit 91 is an electromagnetic trip unit and is disposed opposite to the trip trigger unit 61. The stationary contact 5 is connected to the electromagnetic trip unit. When a short-circuit fault occurs in the circuit, the push rod 911 on the short-circuit trip unit moves to the side where the latch 6 is located and triggers the trip trigger unit 61. The latch 6 and the drive unit 22 are in a tripped state, and the moving contact 4 and the stationary contact 5 are separated.

[0046] The thermal trip unit 92 includes a bimetallic strip 921, a trip lever 924, and a bimetallic adjusting screw 925. The bottom of the bimetallic strip 921 abuts against the bimetallic adjusting screw 925, and the angle between the surface of the bimetallic strip 921 and the axis of the bimetallic adjusting screw 925 at the abutment point 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 bimetallic strip 921 and the axis of the bimetallic adjusting screw 925 is set to 95 degrees. However, the present invention does not limit this. In other embodiments, the angle between the surface of the bimetallic strip and the axis of the bimetallic adjusting screw can be other angle values ​​within the range of 75 degrees to 105 degrees.

[0047] In existing thermal trip units, the longitudinal section of the bimetallic strip is inclined. When rotating the bimetallic adjusting screw to adjust the thermal trip sensitivity, the end of the adjusting screw moves along the inclined surface of the bimetallic strip, making it difficult to achieve sensitive adjustment. In the thermal trip unit 92 provided in this embodiment, the angle θ between the surface of the bimetallic strip 921 and the axis of the bimetallic adjusting screw 925 is equal to 95 degrees. The force generated by the movement of the bimetallic adjusting screw 925 mainly acts on the surface of the bimetallic strip in the vertical direction. A slight adjustment on the bimetallic adjusting screw can be converted into a displacement of the top of the bimetallic strip. Therefore, it has good adjustment sensitivity, and the bimetallic adjusting screw no longer moves along the surface of the bimetallic strip during adjustment.

[0048] In this embodiment, as Figure 11As shown, the bimetallic strip 921 includes a first part 9211, a second part 9212, and a third part 9213 from bottom to top. The first part 9211 is held by a connecting piece 922 and an arc-inducing piece 923. A bimetallic adjusting screw 925 is abutted against the outside of the connecting piece 922. The angle between the surface of the first part 9211 and the axis of the bimetallic adjusting screw 925 is equal to 95 degrees. The second part 9212 is bent relative to the first part 9211 toward the side where the stationary contact 5 is located, and the third part 9212 is bent relative to the second part 9212 toward the side away from the stationary contact 5. The bimetallic strip 921 provided in this embodiment has two bends. However, the present invention does not limit this. In other embodiments, the bimetallic strip may not have a third part. Specifically, when the bimetallic adjusting screw 925 pushes the first part 9211 inward ( Figure 11 When the first part 9211 moves to the left, under the action of the metal connecting piece 922 and the arc-starting piece 923, the second part 9212 and the third part 9213 will move away from the stationary contact 5 (move to the right). When the bimetallic adjusting screw 925 is rotated out, the first part 9211 returns to the right, and the corresponding second part 9212 and the third part 9213 will move to the left.

[0049] like Figure 3 As shown, the housing 1 has a guide groove 102 with an opening facing the bend of the trip lever. One end of the trip lever 924 is fixed to the trip trigger part 61, and the other end is bent and extends into the guide groove 102. The third part 9213 of the bimetallic strip is positioned opposite to the other end of the trip lever 924. When the circuit is overloaded, the bimetallic strip 921 is heated and bends away from the stationary contact 5. Figure 3 The trip lever 924 is pulled to the right (bending from center to right), causing the trip trigger part 61 to rotate counterclockwise, thus achieving overheat tripping. The guide groove 102 guides and limits the movement trajectory of the trip lever 924 caused by the deformation of the bimetallic strip 921, so that the force generated by the slight deformation on the bimetallic strip 921 can be quickly applied to the trip trigger part 61 through the trip lever 924, greatly improving the fault response speed of the circuit breaker.

[0050] In this embodiment, as Figure 1 As shown, an arc-extinguishing chamber 11 is also provided inside the casing 1. The end of the arc-initiating plate 923 away from the bimetallic strip 921 is located inside the arc-extinguishing chamber 11 to guide the electric arc into the arc-extinguishing chamber 11 for arc extinguishing. Multiple exhaust guide plates 12 are located on one side of the arc-extinguishing chamber 11, and a gas guiding channel 120 is formed between the multiple exhaust guide plates 12. The gas generated after the arc is extinguished in the arc-extinguishing chamber 11 is discharged through the gas guiding channel 120.

[0051] In summary, the contact support component in the circuit breaker provided by this invention includes a body, a drive unit, and an elastic energy storage unit, with the elastic energy storage unit connected to the moving contact. When the handle is rotated beyond its travel range, the handle drives the body to continue rotating via the connecting rod and the drive unit, while the moving contact is already abutted and limited by the stationary contact. The relative movement between the body and the moving contact causes a displacement difference between the two ends of the elastic energy storage unit, causing it to bend and generate a rebound force pointing towards the stationary contact. This rebound force presses the moving contact firmly against the stationary contact. When the stationary contact experiences wear, burning, or electro-repulsive forces, the elastic deformation portion of the elastic energy storage unit recovers to compensate for the gap caused by wear, burning, or electro-repulsive forces, ensuring the moving contact is tightly abutted against the stationary contact and guaranteeing reliable closing. The circuit breaker provided by this invention achieves reliable contact between the moving and stationary contacts without the need for contact springs. The contact support has a very simple structure. During installation, the moving contact simply needs to be connected to the elastic energy storage section, making assembly very easy. This results in high assembly efficiency and excellent reliability and consistency after assembly. Furthermore, the omission of the contact spring greatly simplifies the size of the contact support, thus enabling the miniaturization of the circuit breaker.

[0052] Furthermore, in the circuit breaker provided by this invention, the pressure applied to the moving contact during overtravel will vary depending on the length of the bending deformation portion on the elastic energy storage section. Therefore, the contact pressure can be adjusted by regulating the length of the bending deformation portion on the elastic energy storage section. The adjustment of the length of the bending deformation portion is very flexible and not limited by any space, thus it can be well matched with circuit breakers with different contact pressure requirements, i.e., it has better design versatility.

[0053] Although the present invention has been disclosed above by way of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of protection claimed in the claims.

Claims

1. A circuit breaker, characterized in that, It includes a housing, contact support, reaction elastic element, moving contact, stationary contact, latch, handle, connecting rod, and trip unit, wherein: The contact support includes a body, a drive unit, and an elastic energy storage unit. The body is rotatably connected to the housing via a pivot shaft. The drive unit and the elastic energy storage unit are located on both sides of the pivot shaft, and the drive unit is connected to the handle via a connecting rod. The moving contact is connected to the elastic energy storage unit. When the handle is rotated beyond its travel range, the moving contact abuts against the stationary contact. The main body moves relative to the moving contact, and the two ends of the elastic energy storage unit generate a displacement difference and bend, generating a rebound force pointing towards the stationary contact to press the moving contact tightly against the stationary contact. The moving contact and the elastic energy storage unit are connected in an overlapping manner. The part where the elastic energy storage unit and the moving contact are connected in an overlapping manner is the rebound force adjustment area. The magnitude of the rebound force is adjusted by adjusting the length of the rebound force adjustment area.

2. The circuit breaker according to claim 1, characterized in that, The contact support also includes a connecting part that connects the body part and the elastic energy storage part. The connecting part is bent and extended relative to the body part in the thickness direction and then connected to the elastic energy storage part.

3. The circuit breaker according to claim 1, characterized in that, The latch is rotatably connected to the contact support and forms a linkage or disengagement state with the drive unit to lock or unlock the linkage connected to the handle. The latch elastic element is connected between the latch and the contact support.

4. The circuit breaker according to claim 3, characterized in that, The latch includes a latch body, a release trigger, a hook, and a locking part. The latch body is rotatably connected to the body of the contact support. The release trigger and the hook are located on both sides of the latch body. The locking part is formed on the hook and protrudes inward from the hook. The latch body, the hook, and the locking part together form a first latch. The drive part has a second latch facing opposite to the first latch. In the linkage state, the outer wall of the locking part and the side wall of the second latch abut against both sides of the other end of the connecting rod and lock them. In the release state, the locking part releases the lock on the other end of the connecting rod, and the other end of the connecting rod stops in the first latch.

5. The circuit breaker according to claim 4, characterized in that, The drive unit has at least one groove on the other end opposite to the first bayonet, and the locking elastic element is sleeved and fixed between the two grooves or between one of the grooves and the outer wall of the drive unit.

6. The circuit breaker according to claim 1 or 3, characterized in that, The latch also includes a rotation trigger part, which is disposed on the trip trigger part and extends toward the side where the contact support is located. The rotation trigger part is located between the stationary contact and the elastic energy storage part.

7. The circuit breaker according to claim 1, characterized in that, The trip unit includes a thermal trip unit, which includes a bimetallic strip and a trip lever. The bottom of the bimetallic strip abuts against a bimetallic adjusting screw. The angle between the surface of the bimetallic strip and the axis of the bimetallic adjusting screw at the abutment point is greater than or equal to 75 degrees and less than or equal to 105 degrees.

8. The circuit breaker according to claim 7, characterized in that, The bimetallic strip comprises a first part, a second part, and a third part from bottom to top. The first part abuts against the bimetallic adjusting screw. The angle between the surface of the first part and the axis of the bimetallic adjusting screw is greater than or equal to 75 degrees and less than or equal to 105 degrees. The second part is bent relative to the first part toward the side where the stationary contact is located. The third part is bent relative to the second part toward the side away from the stationary contact.

9. The circuit breaker according to claim 1, characterized in that, The circuit breaker also includes an arc-extinguishing chamber disposed within the housing and multiple exhaust guide plates located on one side of the arc-extinguishing chamber. An exhaust guide channel is formed between the multiple exhaust guide plates, and the gas generated after the arc-extinguishing chamber extinguishes the arc is discharged through the exhaust guide channel.

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