A molded case circuit breaker

Abstract

This application provides a molded case circuit breaker, belonging to the field of electrical equipment technology. The molded case circuit breaker includes a base, an operating mechanism, a traction rod, support members, and a stationary contact assembly. The base is a U-shaped structure formed by sequentially connecting a first side plate, a bottom plate, and a second side plate. The operating mechanism is fixedly connected to the base. The traction rod is rotatably connected to the operating mechanism, and a boss is provided at the end of the traction rod. Two support members are respectively disposed on the side of the first and second side plates away from the bottom plate, and both support members are provided with limiting grooves, with the boss located within the limiting grooves. The stationary contact assembly drives the traction rod to rotate. The support members limit the end of the traction rod in a first direction. The two support members can form a symmetrical constraint on the traction rod, thus reducing the possibility of axial displacement of the traction rod during rotation. This allows the traction rod to reliably engage the tripping mechanism even under long span conditions, thereby improving the reliability of the overload delay protection action of the molded case circuit breaker.

Description

Technical Field

[0001] This application relates to the field of electrical equipment technology, and more particularly to a molded case circuit breaker. Background Technology

[0002] Molded case circuit breakers, also known as modular circuit breakers, have all their components sealed within a plastic housing. They mainly consist of a contact system, an arc-extinguishing chamber, a trip unit, and an operating mechanism.

[0003] Molded case circuit breakers typically include two functions: overload time-delay protection and short-circuit instantaneous protection. Overload time-delay protection works by thermally deforming the bimetallic strip; when the circuit breaker is overloaded, the resulting overheating causes the bimetallic strip to bend and deform, triggering the tripping rod. Short-circuit instantaneous protection works by the sudden surge in current during a short circuit, causing the moving and stationary iron cores on the tripping rod to separate, thus breaking the circuit. However, in current technology, molded case circuit breakers suffer from low reliability in providing overload time-delay protection. Utility Model Content

[0004] This application provides a molded case circuit breaker to improve the reliability of the molded case circuit breaker during overload time delay protection.

[0005] In a first aspect, this application provides a molded case circuit breaker. The molded case circuit breaker includes a base, an operating mechanism, a traction rod, a support member, and a stationary contact assembly. The base includes a first side plate, a second side plate, and a bottom plate, which are sequentially connected to form a U-shaped structure. The operating mechanism is partially disposed within the cavity of the U-shaped structure and is fixedly connected to the base. The traction rod is disposed on the side of the first and second side plates away from the bottom plate, and is rotatably connected to the operating mechanism. A boss is provided at the end of the traction rod. There are two support members, each disposed on the side of the first and second side plates away from the bottom plate. Both support members have a limiting groove, and the boss is located within the limiting groove. The stationary contact assembly is disposed within the cavity of the U-shaped structure and is located on one side of the traction rod, driving the traction rod to rotate. The support member limits the end of the traction rod in a first direction, wherein the first direction is parallel to the arrangement direction of the stationary contact assembly and the traction rod.

[0006] With the above-described design, the two support members are respectively positioned on the first and second side plates. When the boss at the end of the traction rod is located within the limiting groove, the two support members can provide symmetrical constraints on the traction rod, thus reducing the possibility of axial displacement during rotation. This directional constraint mechanism allows the traction rod to maintain a stable rotation trajectory even under long-span support conditions, reducing the occurrence of motion instability caused by excessive distance between support points. This ensures that the traction rod can reliably engage the tripping mechanism even under long-span conditions, thereby improving the accuracy and reliability of the overload delay protection action of the molded case circuit breaker.

[0007] In one possible design, the limiting groove is a through hole on the support member along the first direction. The through hole is circular, and the boss is cylindrical. When the traction rod rotates, the boss rotates within the through hole.

[0008] The above solution can solve the problem of the traction rod shifting due to the distance between the support point and the force point, ensuring that the traction rod maintains a stable axial position during rotation, thereby reliably transmitting the driving force to the tripping mechanism. This can improve the accuracy and consistency of the overload protection action of the molded case circuit breaker, and thus improve the reliability of the molded case circuit breaker in overload delay protection.

[0009] In one possible design, the limiting groove is a through groove formed on the support member along a first direction, with the groove opening facing away from the base plate. The bottom of the through groove is curved, and the boss is cylindrical. When the traction rod rotates, the boss rotates within the through groove.

[0010] The above solution reduces the likelihood of the traction rod deviating along the first direction under stress, ensuring that the thrust of the stationary contact assembly is fully converted into rotational torque. The stability of the traction rod's rotation trajectory is improved, reducing the probability of rotational failure due to excessive distance between support points. This allows for reliable linkage of the tripping mechanism during overload protection, thereby enhancing the reliability of the molded case circuit breaker during overload delay protection.

[0011] In one possible design, the height of the side of the through slot away from the stationary contact assembly in a second direction is higher than the height of the side of the through slot closer to the stationary contact assembly in the second direction. Here, the second direction is the direction from the base plate to the operating mechanism.

[0012] With the above scheme, when the stationary contact assembly pushes the traction rod to rotate, the boss slides along the arc surface within the through groove. Since the groove edge on the side away from the stationary contact assembly has a higher position in the second direction, this side edge forms a blocking surface, restricting the traction rod from shifting away from the stationary contact assembly, while the groove edge on the side closer to the stationary contact assembly has a lower height, making it easier to install the traction rod.

[0013] In one possible design, both the first and second side plates have mounting grooves on the side furthest from the base plate, with the openings of the mounting grooves facing away from the base plate. Support members are inserted into these mounting grooves.

[0014] Through the above-described solution, this application enables the support member to withstand the lateral force generated by the rotation of the traction rod, thereby forming a distributed load transfer between the mounting groove wall and the contact surface of the support member, preventing stress concentration and resulting tilting of the support member. The mounting groove simplifies the installation process of the support member, thus reducing the time cost required for installing molded case circuit breakers.

[0015] In one possible design, the mounting groove is a trapezoidal groove, with the groove opening width greater than the groove bottom width.

[0016] With the above scheme, when the support member is inserted into the trapezoidal groove, the side wall of the support member and the inclined groove wall of the trapezoidal groove generate contact pressure. As the support member is pushed towards the bottom of the groove, the constraint force of the two side walls on the support member gradually increases, forming a progressive engagement. When the traction rod rotates and generates a lateral load, the inclined side wall of the trapezoidal groove can also convert the lateral component of the force into a normal force perpendicular to the groove wall, counteracting the displacement tendency of the support member through friction. Furthermore, since the mounting groove is a trapezoidal groove, the width of the groove opening is greater than the width of the groove bottom, which facilitates the installation of the support member from the groove opening into the groove. This not only retains the limiting effect of the mounting groove on the support member but also simplifies the installation of the support member.

[0017] In one possible design, the base also includes multiple partitions spaced apart within the U-shaped structure, creating multiple installation spaces within the U-shaped structure. Each partition has a support platform on its side away from the base plate, which supports the traction rod.

[0018] Through the above-described solution, this application can prevent the axial displacement of the multi-stage traction rod due to the lever effect when under force, ensuring the stability of the traction rod's rotation trajectory, thereby improving the reliability of the linkage between the traction rod and the stationary contact assembly. When the stationary contact assembly pushes the traction rod, multiple support platforms work together to limit the radial displacement of the traction rod, avoiding rotational jamming caused by rod twisting, ensuring accurate triggering of overload protection, and thus improving the reliability of the molded case circuit breaker during overload time delay protection.

[0019] In one possible design, the support platform has an arc-shaped groove, and the side wall of the traction rod contacts the groove wall of the arc-shaped groove.

[0020] Through the above scheme, when the traction rod rotates under the force of the stationary contact assembly, its sidewall forms a continuous surface contact with the curved surface of the arc-shaped groove. This contact method ensures that the supporting force is evenly distributed along the curved surface of the groove, avoiding stress concentration caused by local point contact. During the rotation of the traction rod, the curved surface of the groove continuously provides radial constraint, preventing the traction rod from dislodging from the support position due to force offset, while allowing free rotation around the axis. This effectively prevents radial offset of the traction rod during rotation, ensuring the reliability of the traction rod, reducing the occurrence of abnormal tripping action of the molded case circuit breaker due to support failure, and thus improving the reliability of the overload delay protection function of the molded case circuit breaker.

[0021] In one possible design, the traction rod is equipped with limiting elements, each with a groove. The number of limiting elements corresponds to the number of partitions, and the support platform is positioned within the groove when supporting the traction rod.

[0022] Through the above solution, this application solves the problem of traction rod misalignment caused by excessive distance between the support point and the force application point, ensuring that the traction rod maintains a stable rotation trajectory under the push of the stationary contact assembly. The mating structure between the groove and the support platform increases the contact area between the traction rod and the support platform, reduces local stress concentration, and extends the service life of the components. In addition, the overlapping structure formed by the support platform embedded in the groove increases the creepage distance between adjacent phase poles, which can reduce the short-circuit risk between adjacent phase poles, thereby improving the reliability of the molded case circuit breaker during overload time delay protection.

[0023] In one possible design, the molded case circuit breaker also includes a center cover, which is mounted on the base. The center cover has a clearance groove to accommodate support members and bosses.

[0024] Through the above solution, this application solves the problem of motion deviation caused by the obstruction of the middle cover during the rotation of the traction rod, ensuring that the rotation angle of the traction rod is completely transmitted to the tripping mechanism, improving the triggering reliability of the overload protection action, and thus improving the reliability of the molded case circuit breaker in overload delay protection. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the molded case circuit breaker provided in this embodiment of the application after removing the middle cover.

[0026] Figure 2 This is an assembly diagram of the base and traction rod provided in an embodiment of this application.

[0027] Figure 3 This is a schematic diagram of the structure of the base provided in an embodiment of this application.

[0028] Figure 4 This is a schematic diagram of the structure of the traction rod provided in an embodiment of this application.

[0029] Figure 5 A schematic diagram of the structure of the support member provided in an embodiment of this application in one design.

[0030] Figure 6 A schematic diagram of the support member provided in an embodiment of this application in another design.

[0031] Figure 7 This is a schematic diagram of the overall structure of the molded case circuit breaker provided in the embodiments of this application.

[0032] Figure 8 This is a schematic diagram of the structure of the cover provided in an embodiment of this application.

[0033] Explanation of reference numerals in the attached figures: 100. Base; 110. First side plate; 120. Second side plate; 130. Bottom plate; 140. Mounting groove; 150. Partition plate; 151. Support platform; 200. Operating mechanism; 300. Towing rod; 310. Boss; 320. Limiting component; 321. Groove; 400. Support component; 410. Limiting groove; 500. Stationary contact assembly; 600, middle cover; 610, clearance groove; OX, first direction; OY, second direction. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0036] The terms "comprising" and "having," and any variations thereof, used in the specification, claims, and drawings of this application are intended to cover without excluding other meanings. The words "a" or "an" do not exclude the presence of multiples.

[0037] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the phrase "embodiment" in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0038] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0039] The directional terms appearing in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. For example, in the description of this application, terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0040] Furthermore, the terms "first," "second," etc., in the specification and claims of this application or in the aforementioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0041] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, "connection" or "joining" in mechanical structures can refer to a physical connection. A physical connection can be a fixed connection, such as a connection secured by fasteners, such as a connection secured by screws, bolts, or other fasteners; a physical connection can also be a detachable connection, such as a snap-fit ​​or interlocking connection; a physical connection can also be an integral connection, such as a connection formed by welding, bonding, or integral molding. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0042] In existing technologies, when overload delay protection is required for the neutral (N) pole of a four-pole circuit breaker, the traditional solution of simply extending the length of the traction rod results in an excessive distance between the N pole support point and the stress point. This structural defect causes lateral displacement when the bimetallic strip pushes the traction rod, leading to reliability issues such as traction rod rotation jamming and tripping mechanism linkage failure, severely restricting the stability of the overload protection function of the four-pole circuit breaker.

[0043] To address the aforementioned problems, this application provides a molded case circuit breaker. To enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0044] Figure 1 This is a schematic diagram of the molded case circuit breaker provided in this embodiment of the application after removing the middle cover. Figure 2 This is an assembly diagram of the base and traction rod provided in an embodiment of this application. Figure 3 This is a schematic diagram of the structure of the base provided in an embodiment of this application. Figure 4 This is a schematic diagram of the structure of the traction rod provided in an embodiment of this application. Figures 1 to 4 As shown, this application provides a molded case circuit breaker. The molded case circuit breaker includes a base 100, an operating mechanism 200, a traction rod 300, a support member 400, and a stationary contact assembly 500.

[0045] The base 100 includes a first side plate 110, a second side plate 120, and a bottom plate 130, which are sequentially connected to form a U-shaped structure. The operating mechanism 200 is partially housed within the cavity of the U-shaped structure and is fixedly connected to the base 100. A traction rod 300 is located on the side of the first side plate 110 and the second side plate 120 away from the bottom plate 130, and is rotatably connected to the operating mechanism 200. A boss 310 is provided at the end of the traction rod 300. There are two support members 400, each located on the side of the first side plate 110 and the second side plate 120 away from the bottom plate 130. Each support member 400 has a limiting groove 410, and the boss 310 is located within the limiting groove 410. The stationary contact assembly 500 is disposed within the inner cavity of the U-shaped structure and is located on one side of the traction rod 300. The stationary contact assembly 500 drives the traction rod 300 to rotate. The support member 400 limits the end of the traction rod 300 in the first direction OX, wherein the first direction OX is parallel to the arrangement direction of the stationary contact assembly 500 and the traction rod 300.

[0046] The U-shaped structure refers to a frame-like base composed of a first side plate 110, a second side plate 120, and a base plate 130, which forms a stable installation platform. The support member 400 can be a limiting device installed on the first side plate 110 and the second side plate 120. The limiting groove 410 refers to a guide structure on the support member 400, which can be in the form of a through hole or a through groove. The axial direction of the limiting groove 410 can be parallel to the axial direction of the traction rod 300.

[0047] The traction rod 300 can be a long rod-shaped structure, and the boss 310 can be a positioning structure set at the end of the traction rod 300. The boss 310 can be cylindrical or elliptical cylindrical in design, and a clearance fit can be formed between the boss 310 and part of the limiting groove 410.

[0048] The stationary contact assembly 500 is disposed on one side of the traction rod 300, and the first direction OX can be parallel to the arrangement direction of the stationary contact assembly 500 and the traction rod 300. A bimetallic plate can be disposed on the side of the stationary contact assembly 500 near the traction rod 300, and an adjusting screw can be disposed on the bimetallic plate, which can contact the traction rod 300.

[0049] Specifically, when the bimetallic plate in the stationary contact assembly 500 deforms due to heat, the adjusting screw on the bimetallic plate can push the traction rod 300, allowing the traction rod 300 to rotate around the fulcrum on the operating mechanism 200. At this time, the boss 310 at the end of the traction rod 300 can rotate within the limiting groove 410. Since the axis of the limiting groove 410 is consistent with the direction of force, it effectively restricts the displacement of the traction rod 300 along the first direction OX.

[0050] In summary, the arrangement of the two support members 400, respectively located on the first side plate 110 and the second side plate 120, allows the two support members 400 to provide symmetrical constraints on the traction rod 300 when the boss 310 at the end of the traction rod 300 is located within the limiting groove 410. This reduces the possibility of axial displacement of the traction rod 300 during rotation. This directional constraint mechanism enables the traction rod 300 to maintain a stable rotation trajectory even under long-span support conditions, reducing the occurrence of motion instability caused by excessive distance between support points. Consequently, the traction rod 300 can reliably engage the tripping mechanism even under long-span conditions, thus improving the accuracy and reliability of the overload delay protection action of the molded case circuit breaker.

[0051] There are several possible configurations for the limiting groove 410. Two of them will be explained in detail below with reference to the attached diagram.

[0052] Figure 5 A schematic diagram of the support member provided in an embodiment of this application in one design. The first configuration is as follows: Figures 2 to 5As shown, the limiting groove 410 can be a through hole opened on the support member 400 along the first direction OX. The through hole can be a circular hole, and the boss 310 is cylindrical. When the traction rod 300 rotates, the boss 310 rotates within the through hole.

[0053] The through hole can be a hole-like structure that penetrates both sides of the support member 400. The axial direction of the through hole can be parallel to the axial direction of the traction rod 300, which is used to limit the displacement of the end of the traction rod 300 in the first direction OX.

[0054] A circular hole refers to a through hole with a circular cross-section. The inner wall of the through hole can be a continuous and smooth cylindrical surface, which is used to form contact with the cylindrical boss 310 and to evenly distribute the frictional stress during rotation.

[0055] The cylindrical boss 310 refers to the cylindrical protrusion structure provided at the end of the traction rod 300. The axis of the boss 310 can coincide with the rotation axis of the traction rod 300. In this way, the boss 310 can rotate around its own axis in the through hole, avoiding radial displacement of the boss 310 during rotation.

[0056] Specifically, the cylindrical boss 310 at the end of the traction rod 300 can be embedded in the circular through hole of the support member 400, and the inner wall of the through hole forms a continuous circumferential contact with the cylindrical surface of the boss 310. When the stationary contact assembly 500 applies a thrust, the traction rod 300 rotates around its axis, and the boss 310 rotates within the through hole by sliding friction. Since the inner wall of the through hole is circular, the displacement of the boss 310 along the first direction OX can be limited by the inner wall of the through hole, allowing only rotational movement around the axis. During this process, the contact surface between the boss 310 and the inner wall of the through hole is always a uniformly distributed annular area, so that the traction rod 300 will not tilt or shift laterally due to uneven force during rotation.

[0057] When the limiting groove 410 is in the first setting form, it can solve the problem of the traction rod 300 offset due to the distance between the support point and the force point, and ensure that the traction rod 300 maintains a stable axial position during rotation, thereby reliably transmitting the driving force to the tripping mechanism. This can improve the accuracy and consistency of the overload protection action of the molded case circuit breaker, and thus improve the reliability of the molded case circuit breaker in overload delay protection.

[0058] Figure 6 A schematic diagram of the support member provided in an embodiment of this application in another design. The second configuration is as follows... Figures 1 to 4 as well as Figure 6 As shown, the limiting groove 410 can be a through groove opened on the support member 400 along the first direction OX, with the groove opening facing away from the bottom plate 130. The bottom of the through groove is an arc surface, and the boss 310 is cylindrical. When the traction rod 300 rotates, the boss 310 rotates in the through groove.

[0059] The through groove refers to an open groove extending along a second direction OY, which can be the direction from the base plate 130 to the operating mechanism 200. The groove opening facing away from the base plate 130 reduces assembly difficulty. The arc-shaped groove bottom refers to the bottom of the through groove having a concave, arc-shaped structure for rolling contact with the cylindrical boss 310. The cylindrical boss 310 refers to the axially extending column at the end of the traction rod 300; the sidewall of the boss 310 can form line contact with the arc-shaped groove bottom.

[0060] Specifically, when the stationary contact assembly 500 pushes the traction rod 300, the boss 310 rolls along the bottom of the arc-shaped groove within the through slot. Due to the geometric matching between the arc-shaped groove bottom and the cylindrical surface of the boss 310, rolling friction, rather than sliding friction, is generated during the rotation of the traction rod 300. This rolling contact method reduces motion resistance. The open structure of the through slot allows the boss 310 to be directly embedded into the slot during assembly, reducing the assembly difficulty of the traction rod 300.

[0061] When the limiting groove 410 is configured in the second way, it can reduce the possibility of the traction rod 300 deviating along the first direction OX when under force, ensuring that the thrust of the stationary contact assembly 500 is completely converted into rotational torque. The stability of the rotation trajectory of the traction rod 300 is improved, reducing the probability of rotational failure caused by excessive distance between support points, enabling the tripping mechanism to reliably link when the overload protection is activated, thereby improving the reliability of the molded case circuit breaker in overload time delay protection.

[0062] Furthermore, such as Figure 1 as well as Figure 6 As shown, the height of the side of the through slot away from the stationary contact assembly 500 in the second direction OY is higher than the height of the side of the through slot close to the stationary contact assembly 500 in the second direction OY.

[0063] The second direction OY refers to the spatial direction perpendicular to the plane of the base plate 130 and pointing towards the location of the operating mechanism 200. Specifically, this can be achieved by arranging the operating mechanism 200 in the top area of ​​the base 100. The groove opening height difference refers to the vertical drop between the two edges of the groove in the second direction OY. Specifically, this can be achieved by performing asymmetrical cutting on the opening end of the groove during the machining of the support member 400, forming an inclined limiting boundary.

[0064] In summary, when the stationary contact assembly 500 pushes the traction rod 300 to rotate, the boss 310 slides along the arc surface within the through groove. Since the groove edge on the side of the through groove away from the stationary contact assembly 500 has a higher position in the second direction OY, this edge forms a blocking surface, restricting the traction rod 300 from shifting away from the stationary contact assembly 500. Conversely, the groove edge on the side closer to the stationary contact assembly 500 has a lower height, making it easier to install the traction rod 300.

[0065] like Figure 3 , Figure 5 as well as Figure 6 As shown, both the first side plate 110 and the second side plate 120 have mounting grooves 140 on the side away from the base plate 130, with the openings of the mounting grooves 140 facing away from the base plate 130. The support member 400 is inserted into the mounting groove 140.

[0066] The mounting groove 140 refers to the groove structure opened on the top of the first side plate 110 and the second side plate 120 to accommodate the support member 400. The mounting groove 140 can be integrally formed with the first side plate 110 and the second side plate 120, or the mounting groove 140 can be set on the first side plate 110 and the second side plate 120 by cutting or carving after the first side plate 110 and the second side plate 120 are formed.

[0067] Inserting the support member 400 into the mounting groove 140 means inserting the support member 400 into the groove along the opening direction of the mounting groove 140. Specifically, this can be achieved by using an interference fit or a snap-fit ​​structure, and the support member 400 is constrained in three dimensions by the side wall of the groove.

[0068] Specifically, the mounting groove 140 is located at the top edge of the first side plate 110 and the second side plate 120, with the depth direction of the groove parallel to the second direction OY. After the support member 400 is inserted into the mounting groove 140, its bottom surface contacts the bottom of the groove, its two sides contact the groove wall of the mounting groove 140, and its top is exposed outside the groove opening. When the traction rod 300 rotates, the support member 400 is subjected to a radial force from the boss 310. At this time, the groove wall of the mounting groove 140 bears this force through surface contact, effectively limiting the displacement of the support member 400 in the first direction OX. Since the depth direction of the groove is perpendicular to the force direction, the position of the support member 400 in the first direction OX is completely constrained by the bottom of the groove, thereby forming a stable spatial positioning.

[0069] In summary, this application enables the support member 400 to withstand the lateral force generated by the rotation of the traction rod 300, thereby forming a distributed load transfer between the groove wall of the mounting groove 140 and the contact surface of the support member 400, and avoiding the tilting of the support member 400 caused by stress concentration. The installation groove 140 simplifies the installation process of the support member 400, thereby reducing the time cost required for the installation of molded case circuit breakers.

[0070] Furthermore, please continue to refer to Figure 3 , Figure 5 as well as Figure 6 As shown, the mounting groove 140 can be a trapezoidal groove, and the width of the groove opening of the mounting groove 140 is greater than the width of the groove bottom of the mounting groove 140.

[0071] A trapezoidal groove structure refers to a groove structure with a trapezoidal cross-section. This can be achieved by gradually narrowing the groove walls towards the bottom, creating a geometric shape that is wider at the top and narrower at the bottom. This structure utilizes the tilt angle of the groove walls to create a self-locking effect, ensuring that the support member 400° makes surface contact with the groove wall after insertion.

[0072] In summary, when the support member 400 is inserted into the trapezoidal groove, the sidewall of the support member 400 and the inclined groove wall of the trapezoidal groove generate contact pressure. As the support member 400 is pushed towards the bottom of the groove, the constraint force of the two side walls on the support member 400 gradually increases, forming a progressive engagement. When the traction rod 300 rotates and generates a lateral load, the inclined sidewall of the trapezoidal groove can also convert the lateral component force into a normal force perpendicular to the groove wall, counteracting the displacement tendency of the support member 400 through friction. Furthermore, since the mounting groove 140 is a trapezoidal groove, the width of the groove opening of the mounting groove 140 is greater than the width of the groove bottom. This facilitates the installation of the support member 400 from the groove opening into the mounting groove 140, which not only retains the limiting effect of the mounting groove 140 on the support member 400, but also simplifies the installation of the support member 400.

[0073] To further improve the stability of the traction bar 300 installation, the following improvements have been made, please refer to them. Figures 1 to 4 As shown, the base 100 also includes multiple partitions 150, which are spaced apart within the cavity of the U-shaped structure, creating multiple installation spaces within the U-shaped structure. Each of the multiple partitions 150 has a support platform 151 on the side away from the base plate 130, which supports the traction rod 300.

[0074] The partition 150 refers to a plate-like structure vertically installed inside the U-shaped structure along the opposite direction of the second direction OY. It can be integrally molded with the base 100 using injection molding. The thickness of the partition 150 can be 3-5mm, and its height can be two-thirds of the inner height of the base 100. The function of the partition 150 is to divide the interior of the circuit breaker into multiple independent areas, achieving physical isolation between different pole components. The support platform 151 directly supports the traction rod 300, forming multiple support points distributed along the axial direction of the traction rod 300.

[0075] Specifically, multiple partitions 150 can be arranged equidistantly along the width of the base 100, with adjacent partitions 150 forming independent chambers for mounting the contact system. Each partition 150 has a support platform 151 extending from its top, the surface of which contacts the side wall of the traction rod 300. When the stationary contact assembly 500 pushes the traction rod 300, the support platform 151 provides a constraint force in the radial direction of the traction rod 300's rotation axis, ensuring the traction rod 300 remains axially stable during rotation. For example, in a four-pole circuit breaker embodiment, three partitions 150 can divide the base 100 into four installation spaces, with the support platform 151 on top of each partition 150 corresponding to the middle section of the traction rod 300, forming a three-point support structure. Thus, when the traction rod 300 is subjected to lateral thrust from the stationary contact assembly 500, the support platform 151 reduces the risk of rod bending deformation caused by single-point stress by distributing the support force.

[0076] Through the above technical solution, this application can prevent the axial displacement of the multi-stage traction rod 300 due to the lever effect when under force, ensuring the stability of the rotation trajectory of the traction rod 300, thereby improving the reliability of the linkage between the traction rod 300 and the stationary contact assembly 500. When the stationary contact assembly 500 pushes the traction rod 300, multiple support platforms 151 work together to limit the radial displacement of the traction rod 300, avoiding the rotation jamming problem caused by rod body twisting, so that the overload protection action is accurately triggered, thereby improving the reliability of the molded case circuit breaker in overload time delay protection.

[0077] Furthermore, please continue to refer to Figures 1 to 4 As shown, the support platform 151 is provided with an arc-shaped groove, and the side wall of the traction rod 300 is in contact with the groove wall of the arc-shaped groove.

[0078] The arc-shaped groove 321 refers to the continuous curved surface structure formed by machining the surface of the support platform 151. Specifically, it can be achieved by using an arc-shaped contour that matches the outer diameter of the traction rod 300, with a radius of curvature ranging from 3 to 8 mm. This arc-shaped groove forms a circumferential constraint by wrapping around the side wall of the traction rod 300, thus limiting the radial offset of the traction rod 300.

[0079] In summary, when the traction rod 300 rotates under the force of the stationary contact assembly 500, its sidewall forms a continuous surface contact with the curved surface of the arc-shaped groove. This contact method ensures that the supporting force is evenly distributed along the curved surface of the arc-shaped groove, avoiding stress concentration caused by local point contact. During the rotation of the traction rod 300, the curved surface of the arc-shaped groove continuously provides radial constraint, preventing the traction rod 300 from dislodging from the support position due to force offset, while allowing free rotation around the axis. This effectively prevents radial offset of the traction rod 300 during rotation, ensuring the reliability of the traction rod 300, reducing the occurrence of abnormal tripping action of the molded case circuit breaker due to support failure, and thus improving the reliability of the overload delay protection function of the molded case circuit breaker.

[0080] To improve the reliability of molded case circuit breakers, such as Figure 1 , Figure 3 as well as Figure 4 As shown, the traction rod 300 is also provided with a limiting member 320, and the limiting member 320 is provided with a groove 321. The number of limiting members 320 corresponds to the number of partitions 150. When the support platform 151 supports the traction rod 300, the support platform 151 is located in the groove 321.

[0081] The limiting member 320 is a structural component fixed to the surface of the traction rod 300. The limiting member 320 is used to form a constraint structure that cooperates with the support platform 151. The groove 321 is a recessed structure opened on the surface of the limiting member 320. Specifically, it can be formed by machining or injection molding into an annular groove around the limiting member 320, which is used to accommodate the support platform 151 and limit the lateral displacement of the traction rod 300.

[0082] The correspondence between the number of limiting members 320 and the number of partitions 150 means that the distribution of the number of limiting members 320 and the number of partitions 150 are in a one-to-one correspondence. Specifically, this can be achieved by arranging the limiting members 320 at equal intervals along the axial direction of the traction rod 300, ensuring that each support platform 151 can be embedded in the corresponding groove 321.

[0083] Specifically, when the support platform 151 supports the traction rod 300, the support platform 151 is embedded in the groove 321 of the limiting member 320, and the side wall of the groove 321 and the side wall of the support platform 151 form a clearance fit. When the traction rod 300 rotates due to the thrust of the stationary contact assembly 500, the fit between the groove 321 and the support platform 151 restricts the radial displacement of the traction rod 300, thus keeping the rotation axis of the traction rod 300 stable. Since the number of limiting members 320 corresponds to the number of partitions 150, each support platform 151 forms an independent constraint on the traction rod 300 through the groove 321, avoiding deviation of the rotation trajectory due to the lack of local support points.

[0084] Through the above technical solution, this application solves the problem of displacement of the traction rod 300 caused by the excessive distance between the support point and the force-bearing point, ensuring that the traction rod 300 can maintain a stable rotation trajectory under the push of the stationary contact assembly 500. The mating structure between the groove 321 and the support platform 151 increases the contact area between the traction rod 300 and the support platform 151, reduces local stress concentration, and extends the service life of the components. In addition, the overlapping structure formed by the support platform 151 embedded in the groove 321 increases the creepage distance between adjacent phase poles, which can reduce the short-circuit risk between adjacent phase poles, thereby improving the reliability of the molded case circuit breaker during overload time delay protection.

[0085] Figure 7 This is a schematic diagram of the overall structure of the molded case circuit breaker provided in the embodiments of this application. Figure 8 This is a schematic diagram of the structure of the cover provided in an embodiment of this application. Figure 1 , Figure 7 as well as Figure 8 As shown, the molded case circuit breaker also includes a middle cover 600, which is mounted on the base 100. The middle cover 600 is provided with a clearance groove 610, which provides clearance for the support member 400 and the boss 310.

[0086] The middle cover 600 refers to the enclosed component that covers the top of the base 100. This component maintains the overall structural integrity of the molded case circuit breaker while also providing space for the internal moving parts of the molded case circuit breaker to move.

[0087] The clearance groove 610 refers to a localized recessed area formed on the middle cover 600. It can be achieved by milling or molding, and its shape can be rectangular, circular, or irregular. The size of the clearance groove 610 can be slightly larger than the outer contour of the support member 400 and the rotation trajectory range of the boss 310. This structure eliminates the possibility of contact between the middle cover 600 and moving parts through spatial avoidance.

[0088] Specifically, the middle cover 600 forms a closed cavity after covering the base 100, protecting the operating mechanism 200 and the traction rod 300. The clearance groove 610 is recessed in the middle cover 600 at the installation position of the support member 400 and in the rotation path area of ​​the boss 310. When the traction rod 300 rotates under the drive of the stationary contact assembly 500, the limiting groove 410 of the support member 400 constrains the rotation trajectory of the boss 310, while the clearance groove 610 of the middle cover 600 provides clearance for the spatial displacement of the support member 400 and the boss 310 during rotation. During this process, a gap is maintained between the middle cover 600 and the support member 400 to avoid frictional resistance or structural interference caused by rigid contact, ensuring that the rotation angle of the traction rod 300 is completely transmitted to the release mechanism.

[0089] Through the above technical solution, this application solves the problem of motion deviation caused by the obstruction of the middle cover 600 during the rotation of the traction rod 300, ensuring that the rotation angle of the traction rod 300 is completely transmitted to the tripping mechanism, improving the triggering reliability of the overload protection action, and thus improving the reliability of the molded case circuit breaker in overload delay protection.

Claims

1. A molded case circuit breaker, characterized in that, include: The base includes a first side plate, a second side plate, and a bottom plate, wherein the first side plate, the bottom plate, and the second side plate are sequentially connected to form a U-shaped structure. The operating mechanism is partially disposed within the inner cavity of the U-shaped structure, and the operating mechanism is fixedly connected to the base. A traction rod is disposed on the side of the first side plate and the second side plate away from the bottom plate. The traction rod is rotatably connected to the operating mechanism, and a boss is provided at the end of the traction rod. The support member has two parts, which are respectively disposed on the side of the first side plate and the second side plate away from the bottom plate. Each of the two support members is provided with a limiting groove, and the boss is located in the limiting groove. A stationary contact assembly is disposed in the inner cavity of the U-shaped structure and is located on one side of the traction rod. The stationary contact assembly drives the traction rod to rotate. The support member limits the end of the traction rod in a first direction, wherein the first direction is parallel to the arrangement direction of the stationary contact assembly and the traction rod.

2. The molded case circuit breaker according to claim 1, characterized in that, The limiting groove is a through hole opened on the support member along the first direction; The through hole is circular, and the boss is cylindrical. When the traction rod rotates, the boss rotates within the through hole.

3. The molded case circuit breaker according to claim 1, characterized in that, The limiting groove is a through groove opened on the support member along the first direction, and the opening of the through groove faces away from the bottom plate; The bottom of the through groove is an arc surface, and the boss is cylindrical. When the traction rod rotates, the boss rotates within the through groove.

4. The molded case circuit breaker according to claim 3, characterized in that, The height of the side of the through slot away from the stationary contact assembly in the second direction is higher than the height of the side of the through slot close to the stationary contact assembly in the second direction. The second direction is the direction from the base plate to the operating mechanism.

5. The molded case circuit breaker according to any one of claims 1-4, characterized in that, Both the first side plate and the second side plate have mounting grooves on the side away from the bottom plate, and the openings of the mounting grooves face away from the bottom plate. The support member is inserted into the mounting slot.

6. The molded case circuit breaker according to claim 5, characterized in that, The mounting groove is a trapezoidal groove, and the width of the groove opening is greater than the width of the groove bottom.

7. The molded case circuit breaker according to any one of claims 1-4, characterized in that, The base also includes multiple partitions, which are spaced apart in the inner cavity of the U-shaped structure, thus forming multiple installation spaces within the U-shaped structure; Each of the partitions has a support platform on the side away from the base plate, and the support platform supports the traction rod.

8. The molded case circuit breaker according to claim 7, characterized in that, The support platform is provided with an arc-shaped groove, and the side wall of the traction rod contacts the groove wall of the arc-shaped groove.

9. The molded case circuit breaker according to claim 7, characterized in that, The traction rod is provided with a limiting component, and the limiting component is provided with a groove; The number of limiting members corresponds to the number of partitions, and when the support platform supports the traction rod, the support platform is located in the groove.

10. The molded case circuit breaker according to any one of claims 1-4, characterized in that, It also includes a middle cover, which is disposed on the base; The middle cover is provided with a clearance groove, which provides clearance for the support member and the boss.

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