Molded case circuit breaker

Abstract

The utility model discloses a kind of molded case circuit breakers, it is related to the technical field of electrical equipment of circuit protection, wherein, the molded case circuit breaker includes shell and terminal assembly;Shell has wiring end, and includes upper shell and bottom shell of lid combination, and the visual passage extending towards bottom shell direction is equipped in the position of wiring end in upper shell;Terminal assembly is located in shell, and is located wiring end, and terminal assembly is used to crimp fixed external wire;Wherein, visual passage is configured to allow from the visual angle of installation time observe the length of external wire insertion terminal assembly.The utility model provides a kind of molded case circuit breaker structure, which can intuitively observe the length of wire insertion from the usual visual angle of installation (overhead or level view), to improve wiring efficiency and circuit safety.

Description

Technical Field

[0001] This utility model relates to the technical field of electrical equipment for circuit protection, and in particular to a molded case circuit breaker. Background Technology

[0002] As a critical protective electrical appliance in low-voltage power distribution systems, the reliability of the wire crimping of the terminal assemblies of molded case circuit breakers directly affects circuit safety. In related technologies, the casing of molded case circuit breakers typically adopts a closed design, with the terminal assemblies at the inlet and outlet ends completely enclosed by the upper casing. Installers cannot directly observe the depth of external wires (such as copper or aluminum wires) inserted into the terminal assemblies during wiring. If the wires are inserted too shallowly, it may lead to excessive contact resistance, causing overheating or even burning out the terminals. Utility Model Content

[0003] The main objective of this invention is to provide a molded case circuit breaker. The aim is to offer a molded case circuit breaker structure that allows for intuitive observation of the wire insertion length from commonly used installation perspectives (top view or eye view), thereby improving wiring efficiency and circuit safety.

[0004] To achieve the above objectives, this utility model proposes a molded case circuit breaker, comprising: A housing having a terminal block, the housing comprising a capping upper shell and a bottom shell, the upper shell having a viewing channel extending toward the bottom shell at the location of the terminal block; and A terminal assembly, disposed within the housing and located at the wiring terminal, is used to crimp and secure an external wiring connection; wherein the viewing channel is configured to allow observation of the length of the external wiring inserted into the terminal assembly from the viewing angle during installation.

[0005] In one embodiment, the visible channel is a first groove formed by a recess from the bottom of the upper shell toward the top and extending axially to the port of the terminal.

[0006] In one embodiment, the bottom of the upper shell is further provided with a plug-in protrusion that protrudes along the extension direction of the first groove. The terminal has a port for inserting external wiring. The bottom shell is provided with a matching second groove corresponding to the plug-in protrusion. The plug-in protrusion is inserted into the second groove and together with the second groove forms the port.

[0007] In one embodiment, the width of the first groove is greater than the wire diameter of the external wiring and not greater than the width of the terminal assembly.

[0008] In one embodiment, the wall thickness of the insertion protrusion in the recessed direction is less than the recess depth of the first groove.

[0009] In one embodiment, the bottom surface of the first groove is close to or flush with the inlet edge of the terminal assembly, and the bottom surface of the first groove is configured as an observation reference line. When the external wire is inserted, the relative position of the end of the metal core of the external wire observed through the bottom surface of the first groove and the bottom surface of the groove is used to determine the length of the inserted terminal assembly.

[0010] In one embodiment, the terminal assembly includes at least two terminals, which are spaced apart at the terminal along the external wiring insertion direction.

[0011] In one embodiment, the terminal assembly includes a wiring frame and fasteners for external wiring to pass through, and the molded case circuit breaker further includes a crimping plate that is sequentially inserted and located within the wiring frame. The crimping plate and the wiring frame can be driven to move closer together to press the external wiring by tightening any of the fasteners passing through the at least two terminal assemblies.

[0012] In one embodiment, the edge of the crimping plate extends to the bottom edge of the port of the upper shell at the terminal, and the upper shell and the bottom shell are crimped together to fix the crimping plate.

[0013] In one embodiment, the wiring frame has a placement space for external wiring to pass through, and the bottom wall surface of the placement space is provided with anti-slip texture to increase the friction between the external wiring and the bottom wall. The wiring frame has a through-hole groove in the middle area, which extends from the bottom of the wiring frame from both sides to near the top edge.

[0014] In one embodiment, the surface of the crimping plate facing the bottom wall of the wiring frame is provided with an anti-slip structure to enhance the clamping friction of the external wiring.

[0015] In one embodiment, the outer surface of the upper shell is provided with a stripping scale mark and is located near the inlet end and / or the outlet end; the stripping scale mark extends along the insertion direction of the external wire, and the stripping scale mark includes at least one scale line or at least one scale line and a corresponding length value, the length value being configured to indicate the minimum stripping length of the external wire.

[0016] In one embodiment, the visible channel is a through hole penetrating the upper shell, and the axis of the through hole is perpendicular to the insertion direction of the external wiring.

[0017] This invention utilizes a visual channel within the casing, essentially creating a "visual window" on the upper casing. When the circuit breaker is installed in a distribution cabinet or on a wall (a typical installation scenario), the operator's line of sight (e.g., parallel to the front of the circuit breaker, looking up, or looking down) can be directly projected onto the wire insertion point of the terminal assembly through this visual channel, eliminating the need to bend over or disassemble the upper casing. During installation, the wire insertion length can be observed in real time, eliminating the need for repeated plugging and unplugging or disassembling the upper casing for inspection; wiring can be completed in a single operation, improving wiring efficiency. It ensures that the wire's metal core insertion length meets the standard (e.g., at least covering the conductive area of ​​the terminal assembly), preventing excessive contact resistance and overheating / burning of the terminal due to shallow insertion; furthermore, the insertion depth can be controlled by observation to avoid excessively deep insertion that exposes excess wire core. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 A schematic diagram of a structure of an embodiment of the molded case circuit breaker provided by this utility model; Figure 2 for Figure 1 A schematic diagram of the structure after the separation of the upper and middle shells and the bottom shell; Figure 3 for Figure 1 A schematic diagram of the cross-sectional structure; Figure 4 for Figure 3 A partial schematic diagram of point A; Figure 5 A schematic diagram of another embodiment of the molded case circuit breaker provided by this utility model; Figure 6 A schematic diagram of another embodiment of the molded case circuit breaker provided by this utility model; Figure 7 A schematic diagram of an embodiment in which two terminal assemblies are arranged for wiring terminals; Figure 8 for Figure 7 A schematic diagram of one embodiment of the wiring frame.

[0020] Explanation of icon numbers: 100. Housing; 110. Upper housing; 111. Peeling scale mark; 112. First groove; 113. Second groove; 114. Insertion protrusion; 120. Bottom housing; 130. Terminal; 131. Inlet terminal; 132. Outlet terminal; 133. Port; 140. Visual channel; 200. Terminal assembly; 210. Wiring frame; 211. Placement space; 212. Anti-slip texture; 213. Mounting hole; 214. Block plate; 215. Cutout groove; 220. Fastener; 300, crimping plate; 310, anti-slip structure; 400, external wiring; G. Observe the baseline.

[0021] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0023] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0024] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0025] As a critical protective electrical appliance in low-voltage power distribution systems, the reliability of the wire crimping of the terminal assemblies of molded case circuit breakers directly affects circuit safety. In existing technology, the casing of molded case circuit breakers is usually designed as a closed system, with the terminal assemblies at the inlet and outlet ends completely enclosed by the upper casing. Installers cannot directly observe the depth of external wires (such as copper or aluminum wires) inserted into the terminal assemblies during wiring. If the wires are inserted too shallowly, it may lead to excessive contact resistance, causing overheating or even burning out the terminals.

[0026] Therefore, this utility model proposes a molded case circuit breaker. The aim is to provide a molded case circuit breaker structure that allows for intuitive observation of the wire insertion length from commonly used installation perspectives (top view or eye view), thereby improving wiring efficiency and circuit safety.

[0027] This utility model proposes a molded case circuit breaker.

[0028] Molded case circuit breakers typically consist of a housing, contact system, operating mechanism, and tripping mechanism. The housing is usually made of high-strength insulating plastic (such as polyamide or polycarbonate), providing mechanical protection, insulation, and flame retardancy. The upper housing is designed as a sealed structure, encapsulating the internal components. The contact system includes moving and stationary contacts, responsible for switching current. The contact system also integrates arc-extinguishing devices (such as arc-extinguishing chambers or arc-extinguishing grids) to quickly extinguish the arc generated during breaking, preventing short-circuit damage. The operating mechanism controls the opening and closing of the contacts via a lever (manual or electric) driven linkage mechanism. The operating mechanism includes mechanical components such as springs, trip hooks, and latches to switch and maintain the closed-open state. The operating mechanism and the trip unit are linked through a free-trip mechanism to ensure forced tripping in case of a fault; the contact system and the arc-extinguishing chamber work closely together to ensure safe breaking.

[0029] Please see Figure 1 In one embodiment of the present invention, the molded case circuit breaker includes a housing 100 and a terminal assembly 200.

[0030] The housing 100 has a terminal 130, as shown in the reference. Figure 2 The housing 100 includes an upper housing 110 and a bottom housing 120 that fit together. The upper housing 110 has a viewing channel 140 extending toward the bottom housing 120 at the terminal 130. The terminal assembly 200 is disposed inside the housing 100 and located at the terminal 130. The terminal assembly 200 is used to crimp and fix the external wiring 400. The viewing channel 140 is configured to allow the length of the external wiring 400 inserted into the terminal assembly 200 to be observed from a top or level view during installation.

[0031] Continue to refer to Figure 1External wiring 400 refers to external conductors (such as copper or aluminum core wires in a user circuit) that are connected to the incoming terminal 131 or led out from the outgoing terminal 132 outside the circuit breaker, and must form an electrical connection with the terminal assembly 200 of the wiring unit. Terminal 130 refers to the area located on opposite sides of the housing 100 for wiring, and includes an incoming terminal 131 and an outgoing terminal 132.

[0032] Reference Figures 1 to 6 In this embodiment, the upper shell 110 and the bottom shell 120 cooperate to form a closed space to accommodate the internal components. The terminal assembly 200 is a component that fixes the external wiring 400. The visible channel 140 is a first groove 112 extending from the upper shell 110 toward the bottom shell 120 at the position corresponding to the inlet end 131 / outlet end 132. The "visible channel 140" formed by the partial depression at the bottom of the upper shell 110 has an opening direction that matches the upward / horizontal line of sight during installation. The groove is a groove-shaped structure, and its length and width need to cover the wiring area of ​​the terminal assembly 200. The groove extends axially to the wiring area of ​​the terminal assembly 200. In this way, when the wire is inserted into the inlet end 131, the wire and the terminal assembly 200 can be observed from the groove and the mating gap between the upper shell 110 and the bottom shell 120, avoiding the wire being inserted too shallowly, which may cause excessive contact resistance, heat generation, or even burn out the terminal.

[0033] In other embodiments, the viewing channel 140 may also be a through hole provided on the upper housing 110, which extends to the terminal assembly 200, so that the insertion of the wire into the terminal assembly 200 can also be observed.

[0034] The technical solution of this utility model adopts a viewing channel 140 in the housing 100, which is equivalent to opening a "visual window" on the upper housing 110. When the circuit breaker is installed in a distribution cabinet or on a wall (a conventional installation scenario), the operator's line of sight (e.g., parallel to the front of the circuit breaker, looking up, or looking down) can be directly projected onto the wire insertion point of the terminal assembly 200 through the viewing channel 140, without the need to bend over or disassemble the upper housing 110. During installation, the wire insertion length can be observed in real time, eliminating the need for repeated plugging and unplugging or disassembling of the upper housing 110 for inspection. Wiring can be completed in a single operation, improving wiring efficiency. It ensures that the wire metal core insertion length meets the standard (e.g., at least covering the conductive area of ​​the terminal assembly 200), preventing excessive contact resistance and overheating of the terminal due to shallow insertion; moreover, the wire insertion depth can be controlled by observation to avoid excessive depth and exposure of excess wire core.

[0035] Reference Figures 3 to 5Specifically, the bottom of the upper shell 110 is provided with a plug-in protrusion 114 that protrudes along the extension direction of the first groove 112. The terminal 130 has a port 133 for inserting the external wiring 400. The bottom shell 120 is provided with a matching second groove 113 corresponding to the plug-in protrusion 114. The plug-in protrusion 114 is inserted into the second groove 113 and together with the second groove 113 forms the port 133.

[0036] The bottom shell 120 extends from the first groove 112 to the bottom of the terminal 130 of the bottom shell 120. The bottom of the first groove 112 forms a step, that is, the bottom of the first groove 112 in the through direction forms a stepped surface. The bottom surface of the first groove 112 is close to or flush with the edge of the terminal assembly 200 on the wire inlet side. The bottom surface of the first groove 112 is configured as the observation reference line G. When the external wire 400 is inserted, the relative position of the end of the metal wire core of the external wire 400 observed through the bottom surface of the first groove 112 and the bottom surface is used to determine the length of the inserted terminal assembly 200.

[0037] Specifically, the bottom of the upper shell 110 is recessed towards the top to form a first groove 112, which spans the entire bottom of the upper shell 110, ensuring that the wiring area of ​​the bottom shell 120 can be fully seen from a top / level view (without obstruction from the edge of the upper shell 110). The first groove 112 extends to the rear shell but "only partially extends" to form a step. Thus, the surface of the step and the insertion protrusion 114 can form a reference for the insertion length. For example, after the insulation sheath of the external wiring 400 is stripped, the metal wire core and the sheath form a clear "boundary line". During installation, the operator observes through the first groove 112 and aligns the boundary line with the step surface of the second groove 113. If the boundary line is exactly in contact with the step surface, it means that the wire core insertion depth is up to standard (not too shallow). If the boundary line is outside the step surface (the wire core is exposed outside the step), the wire needs to be inserted further until the boundary line is aligned with the step. If the boundary line exceeds the step surface (the wire core is too deep), it needs to be pulled out and adjusted. By using the stepped surface as a reference for wire insertion, the abstract length judgment is transformed into a concrete edge alignment operation, which is suitable for novice operation and offers both ease of installation and circuit safety.

[0038] The height of the stepped surface is aligned with the wire insertion reference line of the terminal assembly 200 (such as the minimum insertion depth boundary of the wire core). For example, if the length of the metal wire core is 10mm, if the outer end of the wire sheath is observed from the first groove 112, it can be considered as just inserted; however, if the metal wire core and the outer end are observed from the stepped surface, it is known that it needs to be inserted further in, thus controlling the insertion length and ensuring accurate wiring. The stepped surface serves as a physical scale for wire insertion, visually indicating the specific alignment position.

[0039] Specifically, the wiring frame 210 of the terminal assembly 200 (i.e., the insulating upper shell 110 that wraps the conductive parts) is close to the edge of the inlet end 131 / outlet end 132, and is aligned (flush) or close (e.g., with a spacing of 0.5mm-3mm) with the inner edge of the first groove 112 of the upper shell 110 in the horizontal direction. This design makes the edge of the first groove 112 and the wiring entrance of the wiring frame 210 approximately form the same horizontal line. The operator can quickly locate the insertion point of the terminal assembly 200 through the edge of the groove and quickly determine the required insertion length.

[0040] Specifically, the edge of the crimping plate 300 extends to the bottom edge of the port 133 of the wiring terminal 130 of the upper shell 110, and the upper shell 110 and the bottom shell 120 crimp and fix the crimping plate 300. Specifically, the width of the first groove 112 is greater than the wire diameter of the external wiring 400, but not greater than the width of the terminal assembly 200. This ensures that when observing the external wiring 400, only the necessary wiring area is considered, while also ensuring the strength of the housing 100.

[0041] Specifically, when the external wire 400 is inserted to the preset stripping length, the first groove 112 exposes at least a portion of the metal core of the external wire 400, and the exposed portion of the metal core does not exceed the step. When the wire is inserted to the preset stripping length (e.g., 10mm), the first groove 112 should show the transition edge between the metal core and the insulation, proving that the core has entered the crimping area of ​​the terminal assembly 200. Using the stepped surface as a reference for wire insertion transforms the abstract length judgment into a concrete edge alignment operation, which is suitable for novice operation, improving installation convenience and circuit safety.

[0042] Reference Figure 1 , Figure 5 and Figure 6To standardize wiring operations and eliminate human error, the outer surface of the upper housing 110 of the circuit breaker body is provided with a stripping dimension mark 111, located near the inlet end 131 and / or outlet end 132. The stripping dimension mark 111 extends along the insertion direction of the external wiring 400 and includes at least one scale line and a corresponding length value, which is configured to indicate the minimum stripping length of the external wiring 400. The stripping dimension mark 111 is a permanent mark on the outer surface (insulating plastic material) of the upper housing 110 of the circuit breaker body, formed by injection molding or laser engraving, and located at the wire insertion point of the inlet end 131 / outlet end 132. The mark extends along the wire insertion direction (i.e., parallel to the wire axis) and includes at least one scale line (such as a raised line in red or black, 0.5mm-2mm wide, 10mm-50mm long) and a corresponding number (such as 10mm, 15mm, 25mm, 30mm), indicating the minimum length of insulation to be stripped from the wire. The minimum length of insulation layer to be stripped before inserting the external wire 400 into the terminal is specified by the length value of the stripping scale mark 111 (e.g., 10mm means stripping 10mm of insulation layer). This ensures the contact area between the core wire and the terminal frame 210 (meets conductivity requirements) while avoiding burning the terminal due to excessively short stripping or exposing the core wire due to excessively long stripping, which could pose a safety hazard.

[0043] Combination Figure 7 and Figure 8 Two terminal assemblies 200 are spaced apart at the inlet end 131 and / or outlet end 132 along the insertion direction of the external wiring 400. Each terminal assembly 200 includes a wiring frame 210 and a fastener 220. The terminal assembly 200 is a component for fixing the external wiring 400, and two are spaced apart along the insertion direction of the external wiring 400 (i.e., the axial direction in which the wire enters the wiring frame 210 from the inlet end 131 / outlet end 132). (For example, two terminal assemblies 200 are provided at the inlet end 131, or two are provided at the outlet end 132, or two are provided at both the inlet end 131 and the outlet end 132). Each terminal assembly 200 consists of a wiring frame 210 and a fastener 220. The wiring frame 210 is a metal structure that carries the wire and the crimping plate 300, and forms an internal space 211 for accommodating the wire. It is usually made of conductive metal (such as brass) and has both fixing and conductive functions. Fasteners 220 are components (such as wiring screws, snap-fit ​​pins, etc.) used to drive the movement of the crimping plate 300 and the wiring frame 210, and achieve the clamping or release of the wires by limiting and fixing them with the wiring frame 210.

[0044] The crimping plate 300 is located inside the circuit breaker body and within the two wiring frames 210; by driving the fasteners 220, the wiring frames 210 and the crimping plate 300 can move relative to each other and move closer to each other.

[0045] In one embodiment, the crimping plate 300 can be brought close to the bottom of the wiring frame 210 by means of fastener 220; that is, the wiring frame 210 remains stationary while the crimping plate 300 moves.

[0046] In one embodiment, the fastener 220 allows the wiring frame 210 to be brought close to the bottom of the crimping plate 300; that is, the crimping plate 300 remains stationary while the wiring frame 210 moves.

[0047] Reference Figure 7 and Figure 8 The bottom of the wiring frame 210 is the lower wall of the internal placement space 211, which cooperates with the crimping plate 300 to form a clamping structure for the wire (the wire is located between the crimping plate 300 and the bottom of the wiring frame 210). The crimping plate 300 is a metal plate disposed within the two wiring frames 210, and the wiring frame 210 can move axially (towards / away from the bottom of the crimping plate 300) by the drive of the fastener 220. In this design, when the fastener 220 is tightened, the wiring frame 210 moves upward and presses the wire against the bottom of the crimping plate 300 to form a stable electrical connection; when loosened, the wiring frame 210 moves downward to release the wire.

[0048] Reference Figure 1 , Figure 5 and Figure 6 The number of wiring units corresponds to the number of poles of the molded case circuit breaker. The number of wiring units matches the number of poles of the molded case circuit breaker (e.g., 1 set of wiring units for a 1P circuit breaker, 2 sets for a 2P circuit breaker, 3 sets for a 3P circuit breaker, and 4 sets for a 4P circuit breaker), and each set of wiring units is arranged independently to adapt to the circuit requirements of different phase numbers (e.g., single-phase and three-phase circuits).

[0049] Reference Figure 8 Specifically, the wiring frame 210 is integrally bent from a metal plate to form a placement space 211, and the crimping plate 300 is disposed within the placement space 211. A fastener 220 is movably inserted through the top of the wiring frame 210. Specifically, the fastener 220 passes through the housing 100 of the circuit breaker body and connects to the wiring frame 210. The crimping plate 300 is fixed within the circuit breaker body. In this embodiment, the crimping plate 300 is clamped and fixed by the upper shell 110 and the lower shell 120, and the wiring frame 210 is movably disposed within the wiring frame 210. In other embodiments, it can also be fixed to the circuit breaker body by integral molding or screw fastening. By driving the fastener 220, the wiring frame 210 can be moved upward relative to the crimping plate 300 in the height direction to press the external wiring 400 or downward to loosen the external wiring 400.

[0050] The wiring frame 210 is formed by integrally molding a single piece of metal sheet (such as brass or copper) through stamping, bending, and other processes, forming a "frame-shaped" structure with a top opening, without the need for welding or splicing. The enclosed internal space is the placement space 211 (used to accommodate the wires and crimping plate 300). The placement space 211 is a closed or semi-closed area within the wiring frame 210 used to define the position of the wires, formed by an integrally bent metal sheet. Fasteners 220 (such as cylindrical head screws) are connected to the wiring frame 210 from outside the circuit breaker body through the pre-set mounting holes 213 (with internal threads) on the top of the wiring frame 210, and the axial movement of the fasteners 220 is unrestricted. "Movable installation" specifically means that the fasteners 220 can rotate and move up and down along their own axis.

[0051] The moving direction of the wiring frame 210 is its own "height direction," specifically the axial direction perpendicular to the bottom wall (i.e., the direction perpendicular to the direction of wire insertion). When the fastener 220 is tightened, the bottom of the crimping plate 300 moves (upwards) along this direction until it contacts and presses against the wire; when loosened, it moves downwards relative to the crimping plate 300 to release the wire. Pressing secures the wire by the clamping force between the crimping plate 300 and the bottom of the wiring frame 210, ensuring full contact between the wire core and the metal wiring frame 210 to guarantee conductivity. The wiring frame 210 is formed by integrally bending and enclosing a metal plate, eliminating the welding and other processes required in traditional wiring frames 210, and also facilitating adaptation to molded case circuit breakers of different current ratings by adjusting the plate thickness and bending angle.

[0052] To improve the wiring reliability of the molded case circuit breaker, the bottom wall surface within the placement space 211 is further provided with anti-slip textures 212 to increase the friction between the external wiring 400 and the bottom wall. The anti-slip textures 212 are an uneven textured structure on the surface of the bottom wall of the placement space 211 of the wiring frame 210. They can be integrally formed using stamping or rolling processes, and specific forms include, but are not limited to, serrated, grid-like, and striped textures. This increases surface roughness and enhances the static friction between the external wiring 400 and the bottom wall. The bottom wall of the placement space 211 is the lower wall surface of the placement space 211 enclosed by the wiring frame 210 (i.e., the bearing surface for wire placement), and is a flat area after the metal plate is integrally bent. The anti-slip textures 212 are directly formed on the entire surface of this area or the wire contact area. The contact between the external wiring 400 and the bottom wall refers to the physical contact between the metal core wire (or the entire wire with insulation, depending on the wiring method) of the external wiring 400 after the insulation layer has been removed and the bottom wall of the wiring frame 210. The anti-slip texture 212 acts directly on the contact interface and achieves anti-slip through mechanical interlocking.

[0053] To improve the wiring reliability and ease of operation of the molded case circuit breaker, specifically, the top wall of the wiring frame 210 is provided with a through mounting hole 213, the inner circumferential surface of the mounting hole 213 is provided with an internal thread, the outer circumferential surface of the fastener 220 is provided with an external thread, and it engages with the thread of the mounting hole 213; by tightening or loosening the fastener 220, the pressure plate 300 is driven to press the external wiring 400 or loosen the external wiring 400.

[0054] The axial through hole opened on the top wall of the wiring frame 210 completely penetrates the wall (extending from the top surface to the interior of the placement space 211). The axis of the hole is consistent with the height direction of the wiring frame 210 (the moving direction of the crimping plate 300), ensuring that the fastener 220 moves vertically along the axial direction.

[0055] Alternatively, the circuit breaker body can have an internal threaded hole, mounting hole 213, or a spiral groove machined on the circuit breaker body that engages with the external thread of fastener 220, converting the rotational motion of fastener 220 into axial linear motion. The fastener 220 (external thread) and the hole (internal thread) in the circuit breaker body or wiring frame 210 achieve a detachable connection through helical surface contact, specifically a "bolt-nut" type fit: fastener 220 acts as the "bolt," and the internal thread acts as the "nut." By manually or with tools rotating fastener 220 (e.g., clockwise tightening, counterclockwise loosening), when tightening, fastener 220 moves axially downward relative to mounting hole 213, pushing wiring frame 210 and pressure plate 300 to press the conductor; when loosening, it moves axially downward, and wiring frame 210 moves under the applied force. In this way, users can achieve fine adjustment of the clamping force by controlling the rotation angle. Compared to snap-fit ​​structures, it is self-locking and prevents loosening, improving long-term connection reliability and ensuring long-term conductive stability.

[0056] Furthermore, because the wiring frame 210 moves on its own, it is located at the bottom of the circuit breaker body between the wire insertion terminal 131 and / or the wire insertion terminal 131. This avoids the gap between the wiring frame 210 and the circuit breaker body in traditional solutions, preventing users from accidentally inserting wires outside the wiring frame 210, causing the wires to connect between the lower outer end of the wiring frame 210 and the circuit breaker body, which could lead to burnout. Also, because the crimping section abuts against the upper casing 110 of the circuit breaker, the wires cannot be inserted between the crimping section and the fastener 220, ensuring that the wires can only be inserted into the placement space 211 of the wiring frame 210, and are located below the crimping plate 300.

[0057] To further address the safety hazards associated with gap insertion in traditional molded case circuit breakers, a baffle plate 214 is formed by bending the bottom edge of the wiring frame 210 near the incoming terminal 131 or outgoing terminal 132 away from the pressure plate 300. The baffle plate 214 prevents the external wiring 400 from being inserted into the gap between the wiring frame 210 and the circuit breaker body. The bottom edge of the wiring frame 210 near the incoming terminal 131 / outgoing terminal 132 (i.e., the entry edge in the direction of wire insertion) is bent in a direction away from the pressure plate 300 (i.e., away from the interior of the placement space 211, usually downwards or outwards, the same as the pressing direction of the pressure plate 300) using a stamping process, forming a vertical or inclined baffle structure. The bending angle and length are determined according to the specific product design. The baffle plate 214 is a plate-shaped protrusion formed by bending the bottom edge, and it is integrally formed with the wiring frame 210 as a metal plate without any seams. Its position is directly opposite the wire insertion path of the incoming terminal 131 / outgoing terminal 132, forming a "physical barrier" to prevent wires from being inserted into the gap between the wiring frame 210 and the circuit breaker body, thus solving the problem that if a wire is accidentally inserted into the gap, it will cause a short circuit in the internal circuit and burn out the terminal assembly 200.

[0058] Furthermore, the inclined or vertical structure of the baffle plate 214 forms a "guide slope" for the inserted wire. When there is a deviation in the insertion angle of the wire (within ±30°), the path can be automatically corrected through the mechanical contact of the baffle plate 214 to ensure that the wire enters the central area of ​​the placement space 211.

[0059] Specifically, the baffle plate 214 and the wiring frame 210 are integrally bent and formed, so that the baffle plate 214 and the wiring frame 210 form a continuous metal structure, while eliminating the need for additional molds and reducing production costs.

[0060] Furthermore, the middle area of ​​the wiring frame 210 is provided with a through-hole groove 215, which extends along the height direction of the wiring frame 210; the middle area of ​​the wiring frame 210 extends along the height direction of the wiring frame 210 (perpendicular to the bottom wall), and is long and strip-shaped, completely penetrating the front and rear walls of the wiring frame 210 ("through" means penetrating from the front to the back of the wiring frame 210), ensuring that the hollow area is maximized without weakening the structural strength, thereby reducing the cost of raw materials; at the same time, it reduces the overall weight of the circuit breaker and makes the wiring frame 210 easier to form.

[0061] Reference Figure 4Specifically, the crimping plate 300 has a horizontally extending crimping section and a connecting section located on the side of the crimping section away from the inlet end 131 or outlet end 132; the crimping section is located within the placement space 211, and the connecting section is bent away from the bottom wall of the placement space 211. The flat structure of the horizontal crimping section ensures that the conductor is subjected to uniform force when crimped, ensuring metal-to-metal contact between the core wire and the crimping plate 300. The horizontally extending crimping section is the main functional area of ​​the crimping plate 300, and is flat and elongated (its length matches the width of the placement space 211), extending in a direction parallel to the bottom wall of the wiring frame 210 (horizontal direction), located within the placement space 211 and in direct contact with the external wiring 400.

[0062] The transition structure, integrally extended from the side of the crimping plate 300 away from the inlet end 131 / outlet end 132 (i.e., the opposite direction of the wire insertion direction), is formed by a stamping process in a direction away from the bottom wall of the placement space 211 (i.e., bent downwards, forming an angle of 90°~135° with the crimping section). This allows for a compact design suitable for miniaturized circuit breakers, while the bending structure prevents interference between the connection section and the wires within the placement space 211.

[0063] To further improve connection reliability while reducing the operating torque requirement and adapting to a wider range of wire types, an anti-slip structure 310 is provided on the side surface of the crimping segment facing the bottom wall of the wiring frame 210 to enhance the clamping friction of the external wiring 400. The anti-slip structure 310 is a textured surface (including but not limited to the surface in contact with the core wire of the external wiring 400) of the crimping segment facing the bottom wall of the wiring frame 210. This textured surface may be formed by stamping, etching, or knurling processes, such as diamond patterns, grooves / protrusions, etc. When the crimping plate 300 is pressed down by the fastener 220, the surface of the anti-slip structure 310 directly contacts and applies pressure to the core wire on the bottom wall of the placement space 211. The anti-slip structure 310 is located on the "front" of the contact surface.

[0064] To ensure relative movement between the wiring frame 210 and the crimping plate 300, specifically, each side edge of the crimping segment is provided with an outwardly protruding first limiting part, which is positioned between two spaced wiring frames 210. The first limiting parts are protruding structures extending outward from the sides of the crimping segment perpendicular to its extension direction (i.e., laterally). These protrusions are integrally stamped from a metal sheet with the crimping segment, and can be rectangular or semi-circular in shape. The limiting parts on both sides are symmetrically distributed, with opposite protrusion directions (left side protrudes to the left, right side protrudes to the right), forming an "ear-like" structure. When the crimping plate 300 is installed, the first limiting parts on both sides are embedded in the gap between the two side walls, forming a "guide rail" constraint, allowing the wiring frame 210 to move only in the vertical direction (cruising / releasing direction).

[0065] Specifically, a second limiting part is provided at one end of the crimping section near the inlet end 131 or the outlet end 132. The second limiting part is located outside the wiring frame 210, and its width along the direction perpendicular to the insertion of the external wiring 400 is greater than the width of the placement space 211, which is used to restrict the crimping plate 300 from entering the placement space 211. The second limiting part is a protruding structure integrally formed at the end of the crimping section near the wire insertion end (inlet end 131 / outlet end 132). The first limiting part can have the same structure as the second limiting part. The second limiting part extends out of the edge of the frame opening of the wiring frame 210; its width is greater than the placement space 211. The setting of the first and second limiting parts also facilitates the upper shell 110 and the bottom shell 120 of the circuit breaker body to cooperate and press and fix the crimping plate, ensuring the stable installation of the crimping plate 300.

[0066] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A molded case circuit breaker characterized by, include: A housing having a terminal block, the housing comprising a capping upper shell and a bottom shell, the upper shell having a viewing channel extending toward the bottom shell at the location of the terminal block; and A terminal assembly, disposed within the housing and located at the wiring terminal, is used to crimp and secure an external wiring connection; wherein the viewing channel is configured to allow observation of the length of the external wiring inserted into the terminal assembly from the viewing angle during installation.

2. The molded case circuit breaker according to claim 1, characterized in that, The visible channel is a first groove, which is formed by the bottom of the upper shell recessing towards the top and extends axially to the port of the terminal.

3. The molded case circuit breaker according to claim 2, characterized in that, The bottom of the upper shell is also provided with a plug-in protrusion that protrudes along the extension direction of the first groove. The terminal has a port for inserting external wires. The bottom shell is provided with a matching second groove corresponding to the plug-in protrusion. The plug-in protrusion is inserted into the second groove and together with the second groove forms the port.

4. The molded case circuit breaker as described in claim 2, characterized in that, The width of the first groove is greater than the wire diameter of the external wiring, but not greater than the width of the terminal assembly; And / or, the wall thickness of the insertion protrusion in the recess direction is less than the recess depth of the first groove.

5. The molded case circuit breaker as described in any one of claims 2 to 4, characterized in that, The bottom surface of the first groove is close to or flush with the edge of the inlet side of the terminal assembly, and the bottom surface of the first groove is configured as an observation reference line. When the external wire is inserted, the relative position of the end of the metal core of the external wire observed through the bottom surface of the first groove and the bottom surface of the groove is used to determine the length of the inserted terminal assembly.

6. The molded case circuit breaker as described in claim 5, characterized in that, The terminal assembly includes at least two, and the at least two terminal assemblies are spaced apart at the terminal along the external wiring insertion direction.

7. The molded case circuit breaker as described in claim 5, characterized in that, The terminal assembly includes a wiring frame and fasteners for external wiring to pass through. The molded case circuit breaker also includes a crimping plate, which is sequentially inserted and located within the wiring frame. By tightening any of the fasteners in the at least two terminal assemblies, the crimping plate and the wiring frame can be driven to move closer together to press the external wiring.

8. The molded case circuit breaker as described in claim 7, characterized in that, The edge of the crimping plate extends to the bottom edge of the port of the upper shell at the wiring terminal, and the upper shell and the bottom shell are crimped together to fix the crimping plate. And / or, the wiring frame has a placement space for external wiring to pass through, and the bottom wall surface of the placement space is provided with anti-slip texture to increase the friction between the external wiring and the bottom wall; The wiring frame has a through-hole groove in the middle area, which extends from both sides from the bottom of the wiring frame to near the top edge; And / or, the surface of the crimping plate facing the bottom wall of the wiring frame is provided with an anti-slip structure to enhance the clamping friction of the external wiring.

9. The molded case circuit breaker as described in claim 1, characterized in that, The outer surface of the upper shell is provided with a stripping scale mark, which is close to the inlet end and / or the outlet end; the stripping scale mark extends along the insertion direction of the external wire, and the stripping scale mark includes at least one scale line or at least one scale line and a corresponding length value, the length value being configured to indicate the minimum stripping length of the external wire.

10. The molded case circuit breaker as described in claim 1, characterized in that, The visible channel is a through hole that penetrates the upper shell, and the axis of the through hole is perpendicular to the insertion direction of the external wiring.

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