Adjustable overload release for molded case circuit breaker

Abstract

The invention discloses an adjustable overload release for a plastic shell type circuit breaker. The adjustable overload release comprises a bimetallic strip, a connecting plate, an adjusting screw, a thermal element, a support and a fixed iron core, wherein the thermal element, the support and the fixed iron core are sequentially attached and fixed together to form a release main body; the bimetallic strip is arranged on one side of the release body in a sliding mode, and a lower threaded hole is formed in the lower portion of the bimetallic strip. The connecting plate is positioned on the other side of the release main body, and the upper end of the connecting plate is fixedly connected with the thermal element; a fixed iron core screw hole is formed in the fixed iron core, and a fixed iron core limiting notch is formed in the fixed iron core; the rod portion of the adjusting screw is in threaded connection with the lower threaded hole, the head portion of the adjusting screw is rotationally arranged in the fixed iron core limiting notch and cannot move axially, and a polygonal driving groove is formed in the side, facing the fixed iron core screw hole, of the head portion of the adjusting screw. The device is good in adaptability and universality, can adapt to different currents, does not need to replace thermal elements made of different materials when the currents are changed, does not affect the production cost and turnover, and does not reduce the batch production efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of circuit breakers, and in particular to an adjustable overload release for a plastic case circuit breaker. Background Art

[0002] The overload release of the overload adjustable plastic case circuit breaker (hereinafter referred to as MCCB) on the market generally uses a thermal element to generate heat, and then deforms the double metal by conduction, pushing the traction rod or the tripping part to trip the main mechanism of the circuit breaker to disconnect the main circuit; products with different rated power require the use of thermal elements of different materials, and such thermal elements often use low-resistance alloy materials. The price of such alloys is relatively high, which affects production costs and turnover. Secondly, such thermal elements have poor versatility, and different currents require the use of alloys of different materials, which reduces the efficiency of mass production. Summary of the invention

[0003] To solve the above problems, the object of the present invention is to provide an adjustable overload release for a plastic case circuit breaker which does not require replacement of thermal elements of different materials, has good versatility and can adapt to different currents.

[0004] The purpose of the present invention is achieved through the following technical solutions: An adjustable overload release for a plastic case circuit breaker comprises a bimetallic strip, a connecting plate, an adjusting screw, and a thermal element, a bracket and a fixed iron core which are fitted and fixed together in sequence to form a main body of the releaser; the bimetallic strip is slidably arranged on one side of the main body of the releaser and can bend after being heated to push the main mechanism of the circuit breaker to complete the tripping action, and a lower threaded hole is arranged at the lower part of the bimetallic strip; the connecting plate is located on the other side of the main body of the releaser and its upper end is fixedly connected to the thermal element; a fixed iron core screw hole is arranged on the fixed iron core, and a fixed iron core limiting notch is arranged on the side of the fixed iron core facing the bracket opposite to the lower threaded hole; the rod of the adjusting screw is movable through the preset screw holes on the bracket and the thermal element in sequence and then is threadedly connected to the lower threaded hole, the head of the adjusting screw is rotatably arranged in the fixed iron core limiting notch and cannot move axially, and an inwardly concave polygonal driving groove is arranged on the side of the head of the adjusting screw facing the fixed iron core screw hole.

[0005] Furthermore, in order to adjust the distance between the bimetallic strip and the traction rod (a rotating structure for driving the main mechanism of the circuit breaker to trip), an adjusting bolt is threadedly connected to the upper part of the bimetallic strip.

[0006] Furthermore, the bimetallic strip is slidably arranged on one side of the release body through the following structure: two bimetallic cantilevers located on both sides of the thermal element are arranged on both sides of the lower part of the bimetallic strip toward the release body, and two bracket avoidance positions corresponding to the two bimetallic cantilevers are arranged on the bracket, and two fixed iron core limiting holes corresponding to the two bimetallic cantilevers are arranged on the fixed iron core; the bimetallic cantilevers are slidably arranged in the corresponding bracket avoidance positions and the corresponding fixed iron core limiting holes in turn, and their ends extend out of the fixed iron core limiting holes.

[0007] Furthermore, in order to limit the sliding distance of the bimetallic strip, the present invention provides the following structure: a limit block is provided at the end of the bimetallic strip cantilever to limit the bimetallic strip cantilever from being completely retracted into the fixed iron core limit hole, so as to limit the maximum distance between the bimetallic strip and the thermal element.

[0008] Furthermore, in order to limit the sliding distance of the bimetallic strip, the present invention provides another structure as follows, wherein the adjustable overload release for the plastic housing circuit breaker also includes a limit armature front wall plate, and the limit armature front wall plate is arranged on the side of the bimetallic strip facing away from the release body, and is used to block the bimetallic strip, prevent the bimetallic strip from detaching from the adjusting screw, and limit the maximum distance between the bimetallic strip and the thermal element, so that the bimetallic strip can only move back and forth between the release body (thermal element).

[0009] Furthermore, in order to realize the short-circuit protection function of the circuit breaker and limit the sliding distance of the bimetallic strip, the present invention provides the following structure, in which a bracket plate is provided on each side of the bracket facing the thermal element, and the two bracket plates are located on both sides of the bimetallic strip and the thermal element (the bimetallic strip and the thermal element are surrounded in the bracket). In addition, the adjustable overload release for the plastic housing circuit breaker also includes a shaft, an armature and a spring; the armature includes an armature front wall plate and an armature side wall plate; the armature front wall plate is located on the side of the bimetallic strip facing away from the release body, and is used to block the bimetallic strip, prevent the bimetallic strip from detaching from the adjusting screw, and limit the maximum distance between the bimetallic strip and the thermal element; the armature side wall plate is composed of two pieces and is respectively fixed on both sides of the armature front wall plate, and the two armature side wall plates are respectively attached to the outside of the bracket plates on both sides of the bracket, and one of the armatures is The side wall plate extends upward to a position corresponding to the position of the main mechanism of the circuit breaker and can push the main mechanism of the circuit breaker to complete the tripping action under the drive of the electromagnet. In the event of a short circuit, the function of the main mechanism of the circuit breaker tripping is realized; the spring is located between the two bracket plates, one end of which is installed on the wall plate, and the other end is installed on the bracket (the bracket hook preset on the bracket plate) for resetting the armature; the shaft is installed between the two bracket plates and its two ends respectively pass through the two armature side wall plates outward, and the shaft is located on the side of the bimetallic strip facing away from the releaser body.

[0010] Furthermore, in order to realize the installation and limiting of the armature front wall plate on the armature, the lower part of the two bracket plates is provided with a bracket lower hook corresponding to the armature front wall plate, and the lower part of the armature front wall plate is arranged in the bracket lower hook of the two bracket plates, and the armature front wall plate can swing back and forth in the bracket lower hook.

[0011] The present invention has good adaptability and versatility, can adapt to different currents, and when the current changes, there is no need to replace thermal elements of different materials, which will not affect production costs and turnover, and will not reduce mass production efficiency. At the same time, the present invention also has overload tripping protection and short-circuit tripping protection functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The structure of the present invention is further described in detail below in conjunction with the accompanying drawings.

[0013] Figure 1 The figure is a schematic structural diagram of the adjustable overload release for the plastic case circuit breaker of the present invention.

[0014] Figure 2 This is an exploded structural diagram of the plastic case circuit breaker of the present invention.

[0015] Figure 3 It is a schematic diagram of the structure of the bimetallic strip described in the present invention.

[0016] Figure 4 It is a schematic diagram of the structure of the thermal element of the present invention.

[0017] Figure 5 It is a structural schematic diagram of the connecting plate of the present invention.

[0018] Figure 6 It is a schematic diagram of the structure of the support described in the present invention.

[0019] Figure 7 It is a schematic diagram of the structure of the adjusting screw of the present invention.

[0020] Figure 8 It is a structural schematic diagram of the fixed iron core described in the present invention.

[0021] Fig. 9 It is a schematic diagram of the structure of the armature of the present invention.

[0022] Fig.10 It is a schematic structural diagram of the spring described in the present invention.

[0023] Fig.11 It is a schematic structural diagram of the traction rod of the present invention.

[0024] As shown in the figure: 100-bimetallic strip, 101-upper threaded hole, 102-lower threaded hole, 200-thermal element, 201-thermal element threaded hole, 202-thermal element welding surface, 203-thermal element rivet hole, 204-thermal element screw hole, 300-adjusting bolt, 400-connecting plate, 401-connecting plate welding surface, 402-connecting plate screw hole, 500-axis, 600-bracket, 601-bracket axis hole, 602-bracket screw hole, 603-bracket lower hook, 604-bracket upper hook, 605-bracket rivet hole, 606-bracket avoidance position, 607-bracket plate, 700-adjusting screw, 7 01-adjusting screw head, 702-polygonal driving groove, 800-fixed iron core, 801-fixed iron core limiting hole, 802-fixed iron core side plate, 803-fixed iron core limiting notch, 804-fixed iron core rivet hole, 805-fixed iron core screw hole, 900-rivet, 1000-armature, 1001-armature shaft hole, 1002-armature notch, 1003-armature front wall plate, 1004-armature side wall plate, 1005-armature head, 1100-spring, 1101-spring first cantilever, 1102-spring inner hole, 1103-spring second cantilever, 1200-traction rod, 1201-traction rod release force surface. DETAILED DESCRIPTION

[0025] The following is an explanation of the implementation of the present invention by specific specific embodiments. People familiar with the technology can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. It should be noted that the terms "include", "comprise" or any other variants are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or device. Example 1

[0027] like Figure 1 and Figure 2As shown, this embodiment provides an adjustable overload release for a plastic case circuit breaker, comprising a bimetallic strip 100, a thermal element 200, an adjusting bolt 300, a connecting plate 400, a bracket 600, an adjusting screw 700, a fixed iron core 800 and a rivet. The thermal element 200, the bracket 600 and the fixed iron core 800 are sequentially fitted and fixed together to form a release body.

[0028] like Figure 1 and Figure 3 As shown, the bimetallic strip 100 is slidably arranged on one side of the release body close to the thermal element 200, and slides back and forth in the direction away from or close to the thermal element 200. The bimetallic strip 100 can bend after being heated (receiving heat transfer from the thermal element 200) and push the traction rod tripping force surface 1201 of the traction rod 1200 to make the traction rod swing 1200. After the traction rod 1200 swings, it pushes the circuit breaker main mechanism to complete the tripping action. The upper part of the bimetallic strip 100 corresponds to the position of the traction rod tripping force surface 1201 and is provided with an upper threaded hole 101. The adjusting bolt 300 is threadedly connected in the upper threaded hole 101 of the bimetallic strip 100; the lower part of the bimetallic strip 100 is provided with a lower threaded hole 102; and two bimetallic strip cantilevers 103 located on both sides of the thermal element 200 are provided on both sides of the lower part of the bimetallic strip 100 facing the release body. The bimetallic strip 100 is of conventional structure, with its passive layer facing the traction rod release force surface 1201, and the active layer connected to the thermal element 200. The material of the active layer mainly includes manganese-nickel-copper alloy, nickel-chromium-iron alloy, nickel-manganese-iron alloy and nickel, etc.; the material of the passive layer is mainly nickel-iron alloy with a nickel content of 34-50%.

[0029] like Figure 1 and Figure 4 As shown, the thermal element 200 is located on the side of the release body facing the bimetal 100, a thermal element welding surface 202 for welding the connecting plate 400 is provided on the upper side of the thermal element 200 facing away from the bimetal 100, a thermal element screw hole 204 is provided at the lower part of the thermal element 200 directly opposite to the lower threaded hole 102, and a thermal element rivet hole 203 is also provided at the lower part of the thermal element 200; a mounting plate mounted on the MCCB base is integrally fixed to the bottom of the thermal element 200, and a thermal element threaded hole 201 is provided on the mounting plate. The screw spirally passes through the thermal element threaded hole 201, and the thermal element 200 is installed on the MCCB base. The thermal element 200 transfers heat to the bimetal 100 by means of radiation heat transfer.

[0030] like Figure 1 and Figure 5As shown, the connecting plate 400 is located on the other side of the trip unit body close to the fixed iron core 800 and its upper end is fixedly connected to the thermal element 200; the upper part of the connecting plate 400 is provided with a connecting plate welding surface 401 facing the thermal element welding surface 202 of the thermal element 200, and the connecting plate 400 is welded to the thermal element welding surface 202 of the thermal element 200 through the connecting plate welding surface 401, so as to achieve a fixed connection between the two. A connecting plate screw hole 402 is provided at the bottom of the connecting plate 400, and a screw spirally passes through the connecting plate screw hole 402 to install the connecting plate 400 on the MCCB base.

[0031] like Figure 1 and Figure 6 As shown, the bracket 6 is fixed on the side of the thermal element 200 facing away from the bimetallic strip 100 and is located below the connecting plate 400; a bracket screw hole 602 is provided on the bracket 600 directly opposite to the lower threaded hole 102, and a bracket rivet hole 605 is provided on the bracket 600 directly opposite to the rivet hole 203 of the thermal element. A bracket plate 607 is provided on both sides of the bracket 600 facing the thermal element 200, and the two bracket plates 607 are located on both sides of the bimetallic strip 100 and the thermal element 200, and the bimetallic strip 100 and the thermal element 200 are surrounded in the bracket 600; a bracket shaft hole 601 is provided on both bracket plates 607, and a bracket upper hook 604 is also provided on the upper part of the side of the bracket plate 607 facing away from the bimetallic strip 100. Two bracket avoidance positions 606 corresponding to the two bimetallic strip cantilevers 103 are provided on the bracket 600, and the bimetallic strip cantilevers 103 can slide back and forth along the bracket avoidance positions 606.

[0032] like Figure 1 and Figure 8 As shown, the fixed iron core 800 is fixed on the side wall of the bracket 6 facing away from the thermal element 200; a fixed iron core screw hole 805 is provided on the fixed iron core 800 directly opposite to the lower threaded hole 102, and a fixed iron core rivet hole 804 is provided on the fixed iron core 800 directly opposite to the bracket rivet hole 605, and at the same time, a fixed iron core limiting notch 803 connected to the fixed iron core screw hole 805 is provided on the side of the fixed iron core 800 facing the bracket 600 directly opposite to the lower threaded hole 102 (inwardly concave). Two fixed iron core limiting holes 801 corresponding to the two bimetallic cantilevers are provided on the fixed iron core 800, and the bimetallic cantilevers 103 are slidably arranged in the corresponding bracket avoidance position 606 and the corresponding fixed iron core limiting hole 801 in sequence, and the end thereof extends out of the fixed iron core limiting hole 801. Thin-walled fixed iron core side plates 802 are provided on both sides of the fixed iron core 800 for limiting the fixed iron core side plates 802.

[0033] like Figure 1 and Figure 7As shown, the rod of the adjusting screw 700 moves through the preset screw holes (the bracket screw hole 602 and the thermal element screw hole 204) on the bracket 600 and the thermal element 200 in sequence and then is threadedly connected with the lower threaded hole 102. The head of the adjusting screw 700 (i.e., the adjusting screw head 701) is rotatably arranged in the fixed iron core limit notch 803 facing the fixed iron core screw hole 805 and cannot move axially. The adjusting screw 700 drives the bimetallic strip 100 to approach or move away from the thermal element 200 through the forward and reverse axial rotation, thereby achieving The distance between the bimetallic strip 100 and the thermal element 200 is adjustable, and an inwardly concave polygonal driving groove 702 is provided on the side of the head of the adjusting screw 700 (adjusting screw head 701) facing the fixed iron core screw hole 805. The polygonal driving groove 702 is a hexagonal hole and is directly opposite to the fixed iron core screw hole 805 (connected with and aligned with the fixed iron core screw hole 805). The diameter of the circumscribed circle of the polygonal driving groove 702 is smaller than the diameter of the fixed iron core screw hole 805, and the diameter of the fixed iron core screw hole 805 is smaller than the diameter of the head of the adjusting screw 700.

[0034] The thermal element 200, the bracket 600 and the fixed iron core 800 are sequentially attached together and then riveted together to form a release body by rivets 900 that penetrate the fixed iron core rivet hole 804, the bracket rivet hole 605 and the thermal element rivet hole 203 in sequence. The assembly steps are as follows:

[0035] During assembly, the connecting plate welding surface 401 of the connecting plate 400 and the thermal element welding surface 202 of the thermal element 200 are welded together to form the main circuit in the releaser; the adjusting screw 700 is pre-placed between the bracket screw hole 602 and the limiting notch 803 of the fixed iron core 800, and the rivet 900 passes through the thermal element rivet hole 203, the bracket rivet hole 605, and the fixed iron core rivet hole 804 to fix the three together to form the releaser body; the bimetallic cantilever 103 at the bottom of the bimetallic strip 100 passes through the bracket avoidance position 606 and the fixed iron core limiting hole 801 in turn, and the rod (threaded end) of the adjusting screw 700 passes through the bracket screw hole 602 and the thermal element screw hole in turn. After the hole 204 is formed, it is matched with the lower threaded hole 102 of the bimetallic strip 100 through the tool hexagonal adjusting screwdriver (the hexagonal adjusting screwdriver passes through the fixed iron core screw hole 805 and extends into the polygonal driving groove 702, driving the adjusting screw 700 to rotate and screw into the lower threaded hole 102), forming an adjustable distance function with the releaser body, and then the adjusting bolt 300 is installed at the upper threaded hole 101 of the bimetallic strip 100 to form an overload tripping structure, and finally the releaser is installed in the MCCB base by using screws through the thermal element threaded hole 201 and the connecting plate threaded hole 402, and the fixed iron core side plates 802 with thin walls on both sides of the fixed iron core 800 are synchronously limited in the corresponding features of the base. Here’s how it works:

[0036] The overload current of the MCCB main circuit flows through the thermal element 200 of the release, generating a large amount of heat. The thermal element 200 transfers the heat energy to the bimetallic strip 100 by radiation. The bimetallic strip 100 bends due to the heat (bends toward the traction rod tripping force surface 1201 of the traction rod 1200), driving the traction rod 1200 to rotate. The traction rod 1200 drives the MCCB main mechanism to complete the tripping action, thereby achieving the overload protection function.

[0037] In this embodiment, the distance between the bimetallic strip 100 and the thermal element 200 is adjustable. Under the premise that the materials of the bimetallic strip 100 and the thermal element 200 are not replaced, by adjusting the distance between the bimetallic strip 100 and the thermal element 200, the heat generated by the overload current passing through the thermal element 200 is always transferred to the bimetallic strip 100 with constant energy, so that the bimetallic strip 100 is bent and the traction rod 1200 is driven to rotate, thereby completing the MCCB tripping function. Example 2

[0038] In order to limit the sliding distance of the bimetallic strip 100, this embodiment adds the following settings on the basis of the first embodiment.

[0039] The end of the bimetal cantilever 103 is provided with a limit block for limiting the bimetal cantilever 103 from being completely retracted into the fixed core limit hole 801, which is used to limit the maximum distance between the bimetal 100 and the thermal element 200. By setting the limit block, the maximum distance between the bimetal 100 and the thermal element 200 is limited, thereby preventing the bimetal 100 from being separated from the adjusting screw 700. Example 3

[0040] In order to limit the sliding distance of the bimetallic strip 10, this embodiment adds another structure based on the first embodiment.

[0041] The adjustable overload release for the plastic case circuit breaker also includes a limit armature front wall plate 1003, which is arranged on the side of the bimetallic strip 100 facing away from the release body, and is used to block the bimetallic strip 100, prevent the bimetallic strip 100 from being separated from the adjusting screw 700, and limit the maximum distance between the bimetallic strip 100 and the thermal element 200, so that the bimetallic strip 100 can only move back and forth between the limit armature front wall plate 1003 and the release body (thermal element 200); the limit armature front wall plate 1003 is provided with a clearance hole for supporting the end of the rod of the adjusting screw 700. Example 4

[0042] In order to realize the short-circuit protection function of the circuit breaker and limit the sliding distance of the bimetallic strip 100, this embodiment adds the following settings on the basis of the first embodiment.

[0043] The adjustable overload release for a molded case circuit breaker further includes a shaft 500 , an armature 1000 and a spring 1100 .

[0044] like Figure 1 and Fig. 9 As shown, the armature 1000 includes an armature front wall plate 1003 and an armature side wall plate 1004; the armature front wall plate 1003 is located on the side of the bimetallic strip 100 facing away from the release body, and is used to block the bimetallic strip 100, prevent the bimetallic strip 100 from being separated from the adjusting screw 700, and limit the maximum distance between the bimetallic strip 100 and the thermal element 200. The limit armature front wall plate 1003 is provided with a clearance hole for supporting the rod of the adjusting screw 700; the armature side wall plate 1004 is composed of two pieces and is respectively fixed on both sides of the armature front wall plate 1003, and the two armature side wall plates 1004 are respectively attached to the support 600 on both sides. Outside the frame plate 607 (and can rotate relatively), one of the armature side wall plates 1004 extends upward to the position corresponding to the position of the circuit breaker main mechanism to form an armature head 1005. The armature 1000 can rotate toward the traction rod tripping force surface 1201 of the traction rod 1200 under the drive of the electromagnet, so that the armature head 1005 contacts the traction rod tripping force surface 1201 to push the traction rod 1200 to rotate, and then the traction rod 1200 pushes the circuit breaker main mechanism to complete the tripping action, realizing the function of the circuit breaker main mechanism tripping when short circuit occurs. The armature front wall plate 1003 and the armature side wall plate 1004 surround the releaser body therein. The armature front wall plate 1003 is provided with an armature notch 1002, and the two armature side wall plates 1004 are provided with armature shaft holes 1001, and all the armature shaft holes 1001 and all the bracket shaft holes 601 are located on the same straight line.

[0045] like Figure 1 and Fig.10 As shown, the spring 1100 is located between the two bracket plates 607. The spring 1100 is a double torsion spring used for resetting the armature 1000. It has a first spring cantilever 1101, a spring inner hole 1102 and a second spring cantilever 1103. The first spring cantilever 1101 of the spring 1100 is installed on a bracket hook 604 preset on the bracket plate 607, and the second spring cantilever 1103 of the spring 1100 is installed in the armature notch 1002 of the armature front wall plate 1003.

[0046] like Figure 1 As shown, the shaft 500 is installed between the two bracket plates 607 (the two ends of the shaft 500 are located in the bracket shaft hole 601) and its two ends respectively pass through the armature shaft holes 1001 on the two armature side wall plates 1004, and the shaft 500 is located on the side of the bimetallic strip 100 facing away from the release body. When short-circuited, the armature 1000 rotates around the shaft 500, so that its upper end rotates toward or away from the traction rod release force surface 1201.

[0047] The shaft 500, the armature 1000, the spring 1100 and the electromagnet constitute a short-circuit tripping structure. During installation, the shaft 500 passes through the armature shaft hole 1001, the bracket shaft hole 601 and the spring inner hole 1102, the first cantilever 1101 of the spring is placed on the hook 604 on the bracket, and the second cantilever 1103 of the spring is placed on the armature notch 1002, thereby forming a short-circuit tripping structure. When the MCCB main circuit is short-circuited, the coil of the electromagnet generates a magnetic field to push the movable iron core sleeved in the coil to move toward the armature 1000, push the armature 1000 to rotate, and make the armature head 1005 rotate toward the traction rod tripping force surface 1201 of the traction rod 1200, thereby pushing the traction rod 1200 to rotate, so that the traction rod 1200 pushes the circuit breaker main mechanism to complete the tripping action.

[0048] The short-circuit release structure is installed on the overload release structure through the shaft 500 to form a complete overload and short-circuit release. The short-circuit release structure and the overload release structure coexist in parallel without interfering with each other. Example 5

[0049] In order to realize the installation and positioning of the armature front wall plate 1003 on the armature 1000, this embodiment adds the following settings on the basis of the fourth embodiment.

[0050] A bracket lower hook 603 is provided at the lower part of the two bracket plates 607 corresponding to the armature front wall plate 1003 , and the lower part of the armature front wall plate 1003 is arranged in the bracket lower hook 603 of the two bracket plates 607 , and the armature front wall plate 1003 can swing back and forth in the bracket lower hook 603 .

[0051] Other aspects of the present invention that are not described in detail are all conventional techniques known to those skilled in the art.

[0052] It should be noted that the terms "comprises", "includes" or any other variations are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0053] The protection scope of the present invention is not limited to the technical solutions disclosed in the specific implementation methods. Any modifications, equivalent replacements, improvements, etc. made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. An adjustable overload release for a plastic case circuit breaker, characterized in that: The invention comprises a bimetallic strip (100), a connecting plate (400), an adjusting screw (700), and a thermal element (200), a bracket (600), and a fixed iron core (800) which are sequentially fitted and fixed together to form a tripper body; the bimetallic strip (100) is slidably arranged on one side of the tripper body and can be bent after being heated to push the circuit breaker main mechanism to complete the tripping action; a lower threaded hole (102) is provided at the lower part of the bimetallic strip (100); the connecting plate (400) is located on the other side of the tripper body and its upper end is fixedly connected to the thermal element (200); a fixed iron core screw (102) is provided on the fixed iron core (800); A nail hole (805) is provided on the fixed iron core (800) on the side facing the bracket (600) and facing the lower threaded hole (102); the rod of the adjusting screw (700) is movably passed through the screw holes preset on the bracket (600) and the thermal element (200) in sequence and is threadedly connected with the lower threaded hole (102); the head of the adjusting screw (700) is rotatably arranged in the fixed iron core limiting notch (803) and cannot move axially; and a concave polygonal driving groove (702) is provided on the side of the head of the adjusting screw (700) facing the fixed iron core screw hole (805).

2. The adjustable overload release for a plastic case circuit breaker according to claim 1, characterized in that: The thermal element (200), the bracket (600) and the fixed iron core (800) are sequentially attached and fixed together by means of rivets (900) that sequentially penetrate the fixed iron core (800), the bracket (600) and the thermal element (200) to form a releaser body.

3. The adjustable overload release for a plastic case circuit breaker according to claim 1, characterized in that: An adjusting bolt (300) is threadedly connected to the upper portion of the bimetallic strip (100).

4. The adjustable overload release for a plastic case circuit breaker according to claim 1, characterized in that: Two bimetallic cantilevers (103) located on both sides of the thermal element (200) are provided on both sides of the lower part of the bimetallic strip (100) towards the release body, and two bracket avoidance positions (606) corresponding one-to-one to the two bimetallic cantilevers (103) are provided on the bracket (600), and two fixed iron core limiting holes (801) corresponding one-to-one to the two bimetallic cantilevers are provided on the fixed iron core (800); the bimetallic cantilevers (103) are slidably arranged in the corresponding bracket avoidance positions (606) and the corresponding fixed iron core limiting holes (801) in sequence, and their ends extend out of the fixed iron core limiting holes (801).

5. The adjustable overload release for a plastic case circuit breaker according to claim 4, characterized in that: A limiting block is provided at the end of the bimetallic cantilever (103) to limit the bimetallic cantilever (103) from being completely retracted into the fixed iron core limiting hole (801).

6. The adjustable overload release for a plastic case circuit breaker according to claim 1, characterized in that: It also comprises a limiting armature front wall plate (1003), wherein the limiting armature front wall plate (1003) is arranged on a side of the bimetallic strip (100) facing away from the releaser body.

7. The adjustable overload release for a plastic case circuit breaker according to claim 1, characterized in that: A support plate (607) is provided on both sides of the support (600) facing the thermal element (200), respectively. The two support plates (607) are located on both sides of the bimetallic strip (100) and the thermal element (200).

8. The adjustable overload release for a plastic case circuit breaker according to claim 7, characterized in that: The device also includes a shaft (500), an armature (1000) and a spring (1100); the armature (1000) includes an armature front wall plate (1003) and an armature side wall plate (1004); the armature front wall plate (1003) is located on the side of the bimetallic strip (100) facing away from the releaser body; the armature side wall plates (1004) are in two pieces and are respectively fixed on both sides of the armature front wall plate (1003); the two armature side wall plates (1004) are respectively attached to the outside of the bracket plates (607) on both sides of the bracket (600), and one of the armature side wall plates (1004) is fixed to the outside of the bracket plates (607) on both sides of the bracket (600). The iron side wall plate (1004) extends upward to a position corresponding to the position of the circuit breaker main mechanism and can push the circuit breaker main mechanism to complete the tripping action under the drive of the electromagnet; the spring (1100) is located between the two bracket plates (607), one end of which is mounted on the wall plate (1003) and the other end is mounted on the bracket (600); the shaft (500) is installed between the two bracket plates (607) and the two ends of which respectively pass through the two armature side wall plates (1004) outwardly, and the shaft (500) is located on the side of the bimetallic strip (100) that is away from the tripper body.

9. The adjustable overload release for a plastic case circuit breaker according to claim 8, characterized in that: The spring (1100) is a linear spring or a torsion spring.

10. The adjustable overload release for a plastic case circuit breaker according to claim 8, characterized in that: The lower parts of the two bracket plates (607) are provided with bracket lower hooks (603) corresponding to the armature front wall plate (1003); the lower parts of the armature front wall plate (1003) are arranged in the bracket lower hooks (603) of the two bracket plates (607); and the armature front wall plate (1003) can swing back and forth in the bracket lower hooks (603).

Images