A plastic shell circuit breaker with false tripping prevention

Abstract

The application belongs to the technical field of low-voltage power distribution, and particularly relates to a misoperation prevention tripping molded case circuit breaker, which comprises a molded case circuit breaker body, a wiring terminal, a wire pressing screw, a wire pressing plate and a conductive connecting terminal, the conductive connecting terminal comprises an annular mounting portion for being sleeved outside the wire pressing screw and a connecting portion connected with the annular mounting portion; the self-centering mechanism is arranged, the annular mounting portion is coarsely positioned and corrected by means of the tapered guide hole, and then the tapered positioning hole is matched with the upper and lower tapered surfaces of the wire pressing tapered ring to apply the circumferentially uniformly distributed radial pressing force to the annular mounting portion, guide the annular mounting portion to move in the direction of the wire pressing screw axis, eliminate the radial assembly gap between the annular mounting portion and the wire pressing screw, and make the conductive connecting terminal always keep the accurate and stable posture, thereby effectively avoiding the eccentricity, micro swing and micro rotation problems caused by the radial gap, and greatly improving the connection stability and conductive reliability of the wiring terminal.

Description

Technical Field

[0001] This invention belongs to the field of low-voltage power distribution technology, and in particular relates to a molded case circuit breaker that prevents accidental tripping. Background Technology

[0002] Molded case circuit breakers (MCCBs) are important protective components in low-voltage power distribution systems and are widely used in industrial power distribution, building electrical systems, and power control systems. They can automatically disconnect the circuit when overload or short circuit faults occur to protect the safe operation of power supply lines and electrical equipment. In actual use, in addition to normal fault tripping, MCCBs may also trip prematurely when no overload or short circuit fault has occurred. Premature tripping not only causes power outages and affects the continuous operation of equipment, but also reduces the reliability of the power distribution system.

[0003] Studies have found that, in addition to factors such as the performance of the thermal tripping mechanism itself and ambient temperature, the connection stability of the wiring terminals is also one of the important factors affecting the false tripping of molded case circuit breakers. When the contact between the wiring terminals and the conductive connection terminals is unstable, it is easy to increase the contact resistance, cause local heating at the connection point, and the generated heat is further conducted into the molded case circuit breaker, causing the thermal tripping mechanism to reach the action condition in advance, thereby increasing the risk of false tripping.

[0004] Existing molded case circuit breakers typically use crimp screws and crimp plates to crimp and fix conductive connection terminals. The conductive connection terminal includes an annular mounting part for installation with the crimp screw and a connection part for crimping the wire. To meet assembly requirements and machining tolerances, the diameter of the mounting hole in the annular mounting part is usually larger than the outer diameter of the crimp screw. Therefore, there is a certain radial assembly gap between the two. Although the crimp screw can provide axial clamping force after tightening, it cannot eliminate the above-mentioned radial gap. During long-term operation of the equipment, affected by factors such as vibration, electrodynamic impact, and thermal expansion and contraction of the wire, the conductive connection terminal is prone to eccentricity, slight swing, or slight rotation by taking advantage of this gap. This causes the actual contact area between the conductive connection terminal and the wiring terminal to change continuously, resulting in increased wear of the contact interface, fluctuation of contact resistance, and local heating.

[0005] Furthermore, after the conductive connector and the wire are crimped together to form an integral structure, the swaying or torsion caused by the wire during vibration, stress, and thermal expansion and contraction will continue to act on the conductive connector. This can cause slight changes in the orientation of the already crimped and fixed conductive connector, further reducing connection stability and exacerbating poor contact and localized overheating. Therefore, existing technologies cannot simultaneously address both the installation and positioning stability of the conductive connector and the continuous disturbance caused by changes in the wire's orientation to the conductive connector.

[0006] Therefore, there is an urgent need to provide a molded case circuit breaker that prevents accidental tripping, in order to solve the technical problem in the prior art where there is a radial assembly gap between the conductive connection terminal and the wiring terminal, which makes the conductive connection terminal prone to eccentricity, micro-swaying and micro-rotation, and the continuous disturbance of the conductive connection terminal by the change of conductor posture, resulting in decreased contact stability, increased contact resistance and local heating, and thus inducing accidental tripping of the molded case circuit breaker. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a molded case circuit breaker that prevents accidental tripping.

[0008] To achieve the above objectives, the technical solution of the present invention is implemented as follows: This invention discloses a molded case circuit breaker that prevents accidental tripping, comprising a molded case circuit breaker body, wiring terminals, wire screws, wire plate, and conductive connection terminals; The conductive connection terminal includes an annular mounting portion and a wire connection portion connected to the annular mounting portion, and the annular mounting portion is sleeved on the outside of the wire clamping screw. The terminal block is provided with a guide seat, and the guide seat forms a screw hole for the wire clamping screw to pass through and a tapered positioning hole communicating with the screw hole. The tapered positioning hole is used to accommodate the annular mounting part. The pressure plate is provided with a clamping structure on the side facing the annular mounting part that mates with the conical positioning hole, so that when the pressure screw clamps the conductive connection terminal, the annular mounting part automatically adjusts its position along the radial direction of the conical positioning hole and remains centered; The guide seat is also provided with a constraint mechanism, which is used to clamp and limit the wire connection part during the movement of the pressure plate, so as to restrict the swing of the wire connection part.

[0009] Furthermore, a pressure cone ring is fixedly provided at the bottom of the pressure plate. The outer circumferential surface of the pressure cone ring is a conical surface, and the inner wall of the conical positioning hole is a conical surface that matches the pressure cone ring.

[0010] Furthermore, the guide seat is provided with a tapered guide hole, which communicates with the conical positioning hole, and the diameter of the tapered guide hole gradually decreases along the direction close to the conical positioning hole, so as to guide the annular mounting part into the conical positioning hole.

[0011] Furthermore, the cone angle of the tapered positioning hole is smaller than the cone angle of the tapered guide hole.

[0012] Furthermore, the constraint mechanism includes a constraint member slidably disposed on the guide seat and an elastic member for driving the constraint member to reset. When the pressure plate moves, it drives the constraint member to move toward the wire connection portion to form a clamping constraint on the wire connection portion.

[0013] Furthermore, the constraint mechanism includes: A sliding groove is provided at the front end of the guide seat, and two sets of the sliding groove are provided; The reset spring rod is provided in two sets. One end of the reset spring rod in each set slides through the guide seat and extends into the limiting hole, and the other end extends into the corresponding sliding groove. A passive block is fixedly installed at one end of the reset spring rod located in the sliding groove, and the passive block is slidably connected to the sliding groove. The constraint block is fixedly installed at one end of the reset spring rod located in the limiting hole, and is used to abut against the outer periphery of the wire connection part; The driving pressure block is fixedly installed at the bottom of the pressure plate and is set in opposition to the corresponding passive block. The driving pressure block and the passive block are provided with mutually cooperating guide slopes on opposite sides.

[0014] Furthermore, the two sets of constraint blocks are located on both sides of the wire connection portion, and the driving pressure block is located above the wire connection portion. The driving pressure block and the two sets of constraint blocks are distributed in a three-point clamping pattern around the wire connection portion.

[0015] Furthermore, the constraint block has an arc-shaped pressing surface on the side facing the wire connection portion, and the curvature of the arc-shaped pressing surface matches the outer diameter of the wire connection portion.

[0016] Furthermore, a pressing protrusion is fixedly installed at the bottom of the driving pressure block. The pressing protrusion is inclined toward the wire connection part and is used to press against the insulation coating layer of the wire connection part.

[0017] Furthermore, a guide arc surface block is fixedly installed at one end of the constraint block facing the annular mounting portion, and the guide arc surface block has a guide arc surface that is adapted to the inner wall of the conical positioning hole.

[0018] Compared with the prior art, the molded case circuit breaker with anti-mistripping feature of the present invention has the following advantages: 1. This invention, by setting a self-centering mechanism, uses a tapered guide hole to coarsely position and correct the annular mounting part, and then applies a circumferentially uniformly distributed radial clamping force to the annular mounting part through the engagement of the tapered positioning hole and the upper and lower tapered surfaces of the pressure ring, guiding the annular mounting part to move in the direction of the pressure screw axis. This eliminates the radial assembly gap between the annular mounting part and the pressure screw, ensuring that the conductive connection terminal always maintains a stable posture with precise centering. This effectively avoids the problems of eccentricity, micro-swaying, and micro-rotation caused by the existence of radial gaps, and greatly improves the connection stability and conductivity reliability of the terminal.

[0019] 2. This invention, by setting up a constraint mechanism, utilizes the guide slope of the driving block and the passive block to convert the axial movement of the pressure plate into the horizontal movement of the constraint block. This causes the two sets of constraint blocks and the holding protrusions to form a three-point clamping structure around the wire connection part, which restricts the movement trend of the wire connection part in the radial, circumferential, and axial directions. This effectively suppresses the swaying, torsion, and axial movement of the wire caused by vibration, thermal expansion and contraction, and external forces, prevents the continuous disturbance of the conductive connection terminal by changes in the wire posture, and improves the long-term stability of the wiring structure under complex working conditions.

[0020] 3. This invention provides a guide arc surface block at the front end of the constraint block, which forms a guiding fit with the inner wall of the conical positioning hole. When the conductive connection terminal is subjected to residual disturbance and tends to deflect, the guide arc surface block can slide along the conical surface of the conical positioning hole and apply an auxiliary corrective force toward the center of the conical positioning hole to the conductive connection terminal. This enables the constraint mechanism and the self-centering mechanism to form a linkage compensation, ensuring that the annular mounting part and the guide seat always maintain a uniform fit. This effectively suppresses contact resistance fluctuations and local abnormal heating, and avoids premature tripping of the tripping mechanism due to poor contact of the wiring terminals, thereby reducing the risk of accidental tripping of the molded case circuit breaker. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the wiring terminals of the present invention; Figure 3 This is an exploded view of the wire clamping screw and wire clamping plate of the present invention; Figure 4 This is a schematic diagram of the self-centering mechanism of the present invention; Figure 5 This is a schematic diagram of the pressure plate of the present invention; Figure 6 This is a schematic diagram of the constraint mechanism of the present invention; Figure 7 yes Figure 5 A magnified view of part A in the image.

[0022] The markings in the diagram are as follows: 1. Molded case circuit breaker body; 11. Terminal block; 12. Wire clamping screw; 13. Wire clamping plate; 131. Wire clamping cone ring; 14. Conductive connection terminal; 141. Annular mounting part; 142. Conductor connection part; 2. Self-centering mechanism; 21. Guide seat; 22. Screw hole; 23. Tapered positioning hole; 24. Gradient guide hole; 25. Limiting hole; 3. Constraint mechanism; 31. Sliding groove; 32. Return spring rod; 33. Passive block; 34. Constraint block; 35. Drive pressure block; 36. Holding protrusion; 37. Guide arc surface block. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0024] like Figures 1-6As shown, the present invention provides a molded case circuit breaker with anti-misoperation protection, including a molded case circuit breaker body 1, terminals 11, wire screws 12, wire clamping plates 13, and conductive connection terminals 14. The conductive connection terminals 14 include an annular mounting portion 141 for being sleeved on the outside of the wire clamping screws 12 and a wire connection portion 142 connected to the annular mounting portion 141. A self-centering mechanism 2 is disposed on the terminals 11 and is used to drive the annular mounting portion 141 to automatically center itself during the process of the wire clamping screws 12 pressing the conductive connection terminals 14, thereby reducing the risk of misoperation. The radial assembly gap between the small annular mounting part 141 and the wire pressing screw 12; a wire pressing cone ring 131 in the shape of an inverted cone is fixedly installed at the bottom of the wire pressing plate 13. Preferably, the wire pressing cone ring 131 has a continuous annular cone surface, and the central axis of its cone surface coincides with the central axis of the wire pressing screw 12, so as to ensure that the wire pressing cone ring 131 can apply uniform force to the annular mounting part 141 in the circumference during the descent. Moreover, the wire pressing cone ring 131 and the wire pressing plate 13 are integrally formed to ensure the connection rigidity between the two and prevent damage in the long-term compressed state. If loosening occurs, the self-centering mechanism 2 includes a guide seat 21 fixedly installed on the terminal block 11. The guide seat 21 can be connected to the terminal block 11 by integral processing, embedding, or welding to ensure the relative position stability between the guide seat 21 and the terminal block 11. A screw hole 22 is opened through the middle of the guide seat 21 for the wire clamping screw 12 to pass through. A tapered positioning hole 23 is opened in the middle of the guide seat 21 and communicates with the screw hole 22. The large end diameter of the tapered positioning hole 23 is larger than that of the screw. The diameter of hole 22 is used to accommodate the annular mounting part 141 and cooperate with the wire pressing cone ring 131 to radially self-center and press the annular mounting part 141; the tapered guide hole 24 is opened at the top of the guide seat 21 and is connected to the conical positioning hole 23. The diameter of the tapered guide hole 24 gradually decreases along the direction close to the conical positioning hole 23, and is used to guide the annular mounting part 141 into the conical positioning hole 23; the limiting hole 25 is opened on one side of the guide seat 21 and is connected to the conical positioning hole 23, and is used for the wire connecting part 142 to pass through.

[0025] It should be noted that the maximum inner diameter of the tapered positioning hole 23 is larger than the outer diameter of the annular mounting part 141, so that the annular mounting part 141 has a certain radial adjustment space when it enters the tapered positioning hole 23. When the pressure cone ring 131 continues to apply axial pressure, the annular mounting part 141 can move radially under the action of the radial component force of the tapered surface, so as to achieve coaxial correction with the pressure screw 12. When the conductive connection terminal 14 is installed on the terminal block 11, the annular mounting part 141 of the conductive connection terminal 14 is first placed in the tapered guide hole 24 of the guide seat 21, and the wire connection part 142 passes through the limiting hole 25. Then tighten the pressure screw 12. The pressure screw 12 drives the pressure plate 13 to move downward along the axial direction. The pressure cone ring 131 at the bottom of the pressure plate 13 first contacts the annular mounting part 141 and pushes the annular mounting part 141 to move downward along the tapered guide hole 24. Since the diameter of the tapered guide hole 24 gradually decreases along the pressing direction, when there is an assembly deviation in the annular mounting part 141, its outer periphery first contacts the hole wall of the tapered guide hole 24. Under the guidance of the hole wall, the annular mounting part 141 gradually adjusts towards the center position to achieve preliminary guidance and positioning. This process can quickly correct the large radial offset caused by the tolerance of parts or manual placement, complete the coarse positioning correction, and lay the foundation for subsequent precise centering. As the wire clamping screw 12 continues to tighten, the wire clamping cone ring 131 pushes the annular mounting part 141 away from the tapered guide hole 24 and into the conical positioning hole 23. At this time, the outer conical surface of the wire clamping cone ring 131 and the inner conical surface of the conical positioning hole 23 form a corresponding conical surface mating structure. The annular mounting part 141 is clamped between the two coaxial conical surfaces with the same cone angle. Under the axial clamping force of the wire screw 12, the wire clamping cone ring 131 moves downward. Its outer cone surface applies a downward axial force and an outward radial force to the annular mounting part 141, while the inner wall of the fixed conical positioning hole 23 applies an upward axial reaction force and an inward radial reaction force to the annular mounting part 141. Since the conical surface of the conical positioning hole 23 is continuous and coaxial, this setting allows the annular mounting part 141 to be subjected to a radial clamping force distributed along its circumference, thereby being guided and adjusted to a position that is basically coaxial with the wire screw 12. Ultimately, the annular mounting part 141 maintains a stable coaxial positioning state relative to the wire screw 12 and restricts the radial relative movement between the two. This two-stage positioning and clamping structure realizes a continuous transition from coarse positioning to precise centering of the conductive connection terminal 14, greatly improving the terminal positioning accuracy, crimping uniformity, and installation posture stability.

[0026] After the wire screw 12 is tightened, the annular mounting part 141 is stably attached to the inner wall of the tapered positioning hole 23 of the guide seat 21, and the guide seat 21 and the terminal 11 form a stable conductive connection, so that the conductive connection terminal 14 maintains a stable installation posture. In actual assembly, the outer diameter of the annular mounting portion 141 of the conductive connection terminal 14 produced by different manufacturers may vary in tolerance, making it difficult for traditional rigid positioning structures to adapt. However, the tapered guide hole 24 of the present invention is a continuously tapered hole structure with adaptive size adaptation capability. For the annular mounting portion 141 with machining dimensional tolerances, in most cases it can find the corresponding positioning position in the tapered guide hole 24 under the pressing and guiding action of the wire clamping cone ring 131, and the tapered positioning hole 23 completes the final centering and clamping. There is no need to adjust the assembly size or replace the matching parts for conductive connection terminals 14 of different specifications or batches, which effectively broadens the application range of the terminal 11 structure and improves the product's versatility and compatibility.

[0027] In conventional terminal block 11 structures, the mounting hole diameter of the conductive connection terminal 14 is generally larger than the outer diameter of the wire clamping screw 12. Due to factors such as different manufacturers' processing techniques, fluctuations in component dimensional tolerances, and manual assembly errors, the conductive connection terminal 14 is prone to radial eccentricity after assembly, resulting in inconsistent assembly quality in batches. This invention, through a continuous guiding and centering structure of the tapered guide hole 24 and the conical positioning hole 23, can automatically guide and correct the annular mounting part 141 during the dynamic clamping process of wire clamping, reducing manual secondary alignment or fine-tuning operations. Relying on the mechanical structure to adaptively complete centering positioning, it effectively avoids eccentric assembly defects and improves the consistency and yield rate of batch assembly.

[0028] This invention employs a pressing structure with upper and lower conical surfaces. Compared to the traditional single axial pressing mode, it can simultaneously apply axial pressing force and circumferential radial constraint force to the annular mounting part 141, so that the entire end face of the annular mounting part 141 is fully and stably fitted with the inner wall of the conical positioning hole 23 of the guide seat 21 and the pressure cone ring 131, eliminating the poor contact state of local pressing, realizing a stable pressing fit in the entire circumference, and improving the regularity and stability of the pressing fit.

[0029] like Figure 3 As shown, the inner wall of the conical positioning hole 23 is a continuous conical surface. The outer conical surface of the pressure cone ring 131 is correspondingly set with the inner conical surface of the conical positioning hole 23. When the pressure cone ring 131 enters the conical positioning hole 23, it and the conical positioning hole 23 together form a circumferentially stable pressure on the annular mounting part 141.

[0030] The cone angle of the tapered positioning hole 23 is smaller than that of the tapered guide hole 24. It should be noted that the design of this cone angle difference makes the tapered guide hole 24 have a gentler guiding slope, which facilitates the smooth entry of the annular mounting part 141, while the tapered positioning hole 23 has a steeper cone surface, which can generate a larger radial component force within a limited axial stroke, thereby providing a stronger centering and clamping effect.

[0031] like Figures 2-5As shown, a transition connection area is formed between the annular mounting part 141 and the wire connection part 142. The transition connection area is located between the annular mounting part 141 and the wire connection part 142 to ensure the structural continuity between the annular mounting part 141 and the wire connection part 142, and at the same time to provide an auxiliary limiting position for the constraint mechanism 3.

[0032] The constraint mechanism 3 is disposed on the terminal block 11 and is used to drive the constraint member to clamp the insulation-covered section of the wire during the clamping process of the pressure plate 13, so as to limit the swing and rotation of the wire connection part 142 relative to the terminal block 11 and reduce the continuous disturbance of the wire posture change to the annular mounting part 141. The constraint mechanism 3 includes: a sliding groove 31, which is opened at the front end of the guide seat 21, and two sets of sliding grooves 31 are provided; and two sets of return spring rods 32, one end of each set of return spring rods 32 slidingly passes through the guide seat 21 and extends to the limiting hole. Within 25, the other end extends into the corresponding sliding groove 31; the passive block 33 is fixedly installed at one end of the reset spring rod 32 located within the sliding groove 31, and the passive block 33 is slidably connected to the sliding groove 31; the constraint block 34 is fixedly installed at one end of the reset spring rod 32 located within the limiting hole 25, and is used to abut against the outer periphery of the wire connection part 142; the driving pressure block 35 is fixedly installed at the bottom of the pressure plate 13 and is correspondingly set with the corresponding passive block 33, and the driving pressure block 35 and the passive block 33 are provided with mutually cooperating guide slopes on opposite sides. The two sets of constraint blocks 34 are located on both sides of the wire connection part 142, and the driving pressure block 35 is located above the wire connection part 142. The driving pressure block 35 and the two sets of constraint blocks 34 are distributed in a three-point clamping distribution around the wire connection part 142.

[0033] It should be noted that the constraint mechanism 3 is not used to replace the crimping connection between the wire connection part 142 and the conductive connection terminal 14. Its main function is to limit the swing torque generated by the wire when it is subjected to external vibration, tension, or thermal expansion and contraction, reducing the possibility of this disturbance torque being transmitted to the annular mounting part 141, so that the conductive connection terminal 14 can maintain a stable mounting posture for a long time. The size of the limiting hole 25 is larger than the outer diameter of the wire connection part 142, so that the wire connection part 142 can pass through the limiting hole 25 and maintain a certain amount of movement. The constraint block 34 is located within this range of movement and only applies a clamping effect to the insulation covering area of ​​the wire connection part 142 during the crimping process, without participating in the crimping of the conductive contact area of ​​the conductive connection terminal 14. When the crimping screw 12 is tightened, the crimping plate 13 moves downward along the axial direction, and the two sets of driving blocks 35 fixed at the bottom of the crimping plate 13 simultaneously enter the corresponding sliding grooves 31. Since the driving block 35 and the passive block 33 are both provided with guide slopes on opposite sides, when the driving block 35 continues to move downward, it pushes the passive block 33 to move outward along the guide slope.

[0034] After the passive block 33 moves, it drives the reset spring rod 32 to slide synchronously along the radial direction of the guide seat 21, so that the two sets of constraint blocks 34 located in the limiting hole 25 gradually approach the wire connection part 142 and abut against the two sides of the wire connection part 142 respectively.

[0035] As the pressure plate 13 continues to press down, the driving pressure block 35 simultaneously presses down on the upper side of the wire connection part 142. At this time, the two sets of constraint blocks 34 and the driving pressure block 35 together form a three-point clamping structure around the wire connection part 142. This three-point clamping structure constitutes a stable constraint system in geometry, which restricts the movement tendency of the wire connection part 142 in the radial, circumferential and axial directions. This makes the wire connection part 142 fully constrained in both the radial and circumferential directions, which helps to limit the swaying or twisting of the wire connection part 142 under vibration, thermal expansion and contraction and external force, reduces the possibility of micro-rotation of the conductive connection terminal 14 around the pressure screw 12, and improves the long-term stability of the wiring structure.

[0036] It should be noted that the reset spring rod 32 is mainly used to drive the constraint block 34 to reset. When the wire screw 12 is locked, the clamping force of the constraint block 34 on the wire connection part 142 is mainly provided by the wire plate 13.

[0037] like Figure 2 , Figure 3 , Figure 5 and Figure 6 As shown, the constraint block 34 has an arc-shaped pressing surface on the side facing the wire connection part 142. The curvature of the arc-shaped pressing surface is adapted to the outer diameter of the wire connection part 142. The wrap angle of the arc-shaped pressing surface is 60° to 120°, which can increase the contact area between the surface and the wire insulation layer. While ensuring sufficient clamping force, it avoids damage to the wire insulation layer due to excessive local pressure.

[0038] It should be noted that a pressing protrusion 36 is fixedly installed at the bottom of the driving pressure block 35. The pressing protrusion 36 is inclined toward the rear end of the limiting hole 25, and the pressing end of the pressing protrusion 36 is used to abut against the insulation coating of the wire connection part 142.

[0039] As the pressure plate 13 continues to press down under the action of the pressure screw 12, the driving pressure block 35 moves synchronously toward the wire connection part 142. The pressing protrusion 36 located at the bottom of the driving pressure block 35 first contacts the insulation coating of the wire connection part 142 and forms local pressure on the insulation coating during the pressing process. At this time, the contact point between the pressing protrusion 36 and the wire connection part 142, as well as the contact points between the two sets of constraint blocks 34 and the wire connection part 142, together form a three-dimensional constraint network located at different height levels, improving the anti-disturbance capability.

[0040] Since the holding protrusion 36 is inclined toward the rear end of the limiting hole 25, when the wire connection 142 is subjected to an outward pulling force, the wire connection 142 is relatively displaced relative to the holding protrusion 36, and a wedge-tightening effect is formed between the holding protrusion 36 and the insulation coating layer, which further increases the holding force of the holding protrusion 36 on the wire connection 142, which is beneficial to improve the pull-out resistance of the wire connection 142 and suppress the axial movement of the wire connection 142.

[0041] Meanwhile, the pressing protrusion 36 cooperates with the two sets of constraint blocks 34 to form a three-point posture constraint on the wire connection part 142. While restricting the swing and micro-rotation of the wire connection part 142, it can also restrict the wire connection part 142 from moving outward along the axial direction, thereby reducing the continuous disturbance to the conductive connection terminal 14 when the wire is subjected to external force and improving the long-term stability of the wiring structure.

[0042] like Figure 3 , Figure 4 As shown, a guide arc surface block 37 is fixedly installed on one end of the constraint block 34 facing the annular mounting part 141. The guide arc surface block 37 has a guide arc surface that matches the inner wall of the conical positioning hole 23 on one side facing the conical positioning hole 23.

[0043] When the pressure plate 13 continues to press down, the drive block pushes the two sets of constraint blocks 34 to move towards each other, so that the two sets of guide arc surface blocks 37 move closer to the conductive connection terminal 14 in sync. The guide arc surface of the guide arc surface block 37 abuts against the transition connection area between the annular mounting part 141 and the wire connection part 142. When the conductive connection terminal 14 is subjected to external disturbance and has a tendency to shift, the guide arc surface block 37 can form a lateral restraint effect on it, and cooperate with the positioning effect of the tapered positioning hole 23 on the annular mounting part 141, so that the annular mounting part 141 is further attached to the inner wall of the tapered positioning hole 23, thereby providing auxiliary compensation for the self-centering mechanism 2 and improving the overall posture stability of the conductive connection terminal 14.

[0044] The guide arc surface block 37 not only serves to constrain the posture of the wire connection part 142, but also applies a guiding correction force to the transition connection area of ​​the conductive connection terminal 14 by utilizing its guide arc surface that mates with the conical positioning hole 23, thus enabling the constraint mechanism 3 and the self-centering mechanism 2 to form a linkage compensation. The core of this linkage compensation mechanism is that when the wire is subjected to external disturbance, the constraint mechanism 3 first suppresses and attenuates the disturbance; for any residual disturbance that cannot be eliminated, the guide arc surface block 37, in conjunction with the conical positioning hole 23, transforms it into a centripetal correction force on the annular mounting part 141, thereby ensuring that the contact state between the annular mounting part 141 and the guide seat 21 remains relatively stable. When the conductor changes its posture due to vibration, thermal expansion and contraction or external force, the guide arc block 37 can continuously correct the posture of the conductive connection terminal 14, reduce the off-center load of the conductor on the annular mounting part 141, maintain the uniform fit between the annular mounting part 141 and the guide seat 21, improve the stability of conductive contact, and reduce contact resistance fluctuations and local heating, thereby further reducing the risk of false tripping of the molded case circuit breaker.

[0045] Furthermore, after the wire screw 12 is tightened, the annular mounting portion 141 of the conductive connection terminal 14 is precisely centered and pressed by the self-centering mechanism 2, while its wire connection portion 142 is firmly clamped by the constraint mechanism 3. The two work together to reduce the possibility of fretting wear and rotational eccentricity of the conductive connection terminal 14, ensuring the long-term stability of the contact interface and effectively suppressing the abnormal temperature rise caused by the increase in contact resistance, thereby improving the anti-mistripping capability of the molded case circuit breaker under complex working conditions.

[0046] Working principle: When the wire clamping screw 12 is tightened, the wire clamping plate 13 drives the wire clamping cone ring 131 to move downward and contact the annular mounting part 141, pushing it into the tapered guide hole 24. The diameter of the tapered guide hole 24 gradually decreases along the clamping direction. After its inner wall of the cone surface contacts the outer periphery of the annular mounting part 141, it applies a radial component force to the annular mounting part 141, forcing the annular mounting part 141 to slide towards the center. As the wire clamping screw 12 continues to tighten, the wire clamping cone ring 131 pushes the annular mounting part 141 into the conical positioning hole 23. The inner conical surface of the conical positioning hole 23 and the outer conical surface of the wire clamping cone ring 131 form a coaxial conical surface fit, applying a circumferentially evenly distributed radial clamping force to the annular mounting part 141, causing the annular mounting part 141 to move towards the axial direction of the wire clamping screw 12 until the annular mounting part 141 reaches a stable coaxial positioning state, and restricting the radial relative movement between the two. At the same time, when the pressure plate 13 moves downward, it drives the two sets of driving pressure blocks 35 to simultaneously enter the corresponding sliding grooves 31. The guide slope of the driving pressure block 35 slides relative to the guide slope of the passive block 33, converting the axial movement of the driving pressure block 35 into the horizontal movement of the passive block 33. The passive block 33 drives the reset spring rod 32 to slide radially, causing the two sets of constraint blocks 34 to approach the wire connection part 142 from both sides and abut against the outer periphery of the wire connection part 142. The pressure at the bottom of the driving pressure block 35... The protrusion 36 abuts against the insulating coating layer of the wire connection portion 142 from above. The two sets of constraint blocks 34 and the pressing protrusion 36 form a three-point clamping around the wire connection portion 142. The guide arc surface block 37 at the front end of the constraint block 34 abuts against the transition area between the annular mounting portion 141 and the wire connection portion 142. When the conductive connection terminal 14 tends to deflect, the guide arc surface block 37 slides along the inner conical surface of the conical positioning hole 23, applying a corrective force toward the center of the conical positioning hole 23 to the conductive connection terminal 14.

[0047] The molded case circuit breaker disclosed in this application, which prevents accidental tripping, incorporates a self-centering mechanism 2 at the terminal position. This mechanism allows the mounting portion of the conductive connection terminal 14 to adjust its position during the clamping process, guided by the structure. This avoids the eccentricity, slight swaying, and slight rotation caused by assembly gaps between the mounting hole and the clamping component in traditional structures, thus maintaining a more stable installation posture for the conductive connection terminal. Simultaneously, a clamping action-linked constraint mechanism provides auxiliary constraint to the wire connection portion while clamping and fixing the conductive connection terminal. This reduces the transmission of swaying and torsion caused by vibration, tension, thermal expansion and contraction of the wire to the conductive connection terminal, ensuring a relatively stable contact area between the conductive connection terminal and the terminal block. This reduces contact resistance fluctuations caused by changes in the contact surface. This application achieves stable terminal positioning... By combining qualitative improvement with conductor disturbance limitation, the wiring structure is transformed from the traditional method of relying solely on axial compression for fixation to a composite stable connection method with position correction and attitude maintenance capabilities. Without adding complex electrical control and detection structures, the mechanical structure itself achieves installation error compensation and stable operation. This not only improves the assembly consistency and long-term reliability of the wiring parts of the molded case circuit breaker, but also effectively reduces the possibility of abnormal heating, reduces the risk of malfunction of the protection mechanism due to unstable wiring status, and improves the working stability of the molded case circuit breaker under vibration, temperature change, and long-term continuous operation conditions. At the same time, the structure of this solution is mainly based on the optimization and improvement of the existing wiring structure, and has the advantages of strong structural adaptability, low manufacturing difficulty, convenient installation and maintenance, and suitability for mass production applications.

[0048] It should be noted that the improvement of this application focuses on utilizing the clamping action generated during the installation of the conductive connection terminal to simultaneously achieve automatic positioning of the conductive connection terminal and attitude stability control of the wire connection part. By reducing the impact of installation deviation and external disturbance on the conductive connection terminal, the long-term connection stability of the wiring part is improved. In this application, the self-centering mechanism, attitude constraint mechanism, and clamping component form a cooperative working relationship through clamping action, guiding cooperation, and linkage constraint. The specific structural form of each component can be adjusted according to the wiring space, terminal size, and assembly requirements of different specifications of molded case circuit breakers. Its guiding method, constraint method, connection method, installation position, and driving form are not limited to the specific structure described in this embodiment. As long as the conductive connection terminal can be automatically positioned during the clamping installation process, the installation positioning stability of the conductive connection terminal can be improved, and the wire connection part can withstand external vibration, thermal expansion and contraction, or force disturbance. The present application aims to restrict the posture of the conductor connection to reduce the continuous impact of conductor posture changes on the conductive connection terminal, maintain a stable contact state between the conductive connection terminal and the wiring terminal, reduce contact resistance fluctuations and local abnormal temperature rises, and thus reduce the risk of false tripping of the molded case circuit breaker. Furthermore, the functions of automatic centering of the conductive connection terminal, conductor posture constraint, clamping and fixing, elastic reset, motion transmission, and auxiliary limiting can all be implemented using conventional mechanical structures selected by those skilled in the art based on actual application scenarios. The materials, dimensions, shapes, quantities, fit forms, installation methods, and structural parameters of each component can be adaptively designed according to different models of molded case circuit breakers, different wiring terminal specifications, and different conductor connection requirements, without affecting the overall working principle and technical effect of the present application, which improves wiring stability and reduces the risk of false tripping due to poor contact through automatic centering of the conductive connection terminal and coordinated constraint of conductor posture.

[0049] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A molded case circuit breaker with anti-misoperation protection, comprising a molded case circuit breaker body (1), terminals (11), wire clamping screws (12), wire clamping plate (13), and conductive connection terminals (14), characterized in that: The conductive connection terminal (14) includes an annular mounting portion (141) and a wire connection portion (142) connected to the annular mounting portion (141), wherein the annular mounting portion (141) is sleeved on the outside of the wire clamping screw (12); The terminal block (11) is provided with a guide seat (21), and the guide seat (21) forms a screw hole (22) for the wire screw (12) to pass through and a tapered positioning hole (23) communicating with the screw hole (22). The tapered positioning hole (23) is used to accommodate the annular mounting part (141). The pressure plate (13) is provided with a clamping structure that mates with the tapered positioning hole (23) on the side facing the annular mounting part (141), so that when the pressure screw (12) clamps the conductive connection terminal (14), the annular mounting part (141) automatically adjusts its position along the radial direction of the tapered positioning hole (23) and remains centered. The guide seat (21) is also provided with a constraint mechanism (3), which is used to clamp and limit the wire connection part (142) during the movement of the wire plate (13) to limit the swing of the wire connection part (142).

2. The molded case circuit breaker for preventing accidental tripping according to claim 1, characterized in that, The bottom of the pressure plate (13) is fixedly provided with a pressure cone ring (131). The outer circumferential surface of the pressure cone ring (131) is a cone-shaped surface, and the inner wall of the cone positioning hole (23) is a cone-shaped surface that is adapted to the pressure cone ring (131).

3. A molded case circuit breaker with anti-mistripping feature according to claim 2, characterized in that, The guide seat (21) is provided with a tapered guide hole (24), which is connected to the conical positioning hole (23). The diameter of the tapered guide hole (24) gradually decreases in the direction close to the conical positioning hole (23) to guide the annular mounting part (141) into the conical positioning hole (23).

4. A molded case circuit breaker with anti-mistripping feature according to claim 3, characterized in that, The cone angle of the tapered positioning hole (23) is smaller than the cone angle of the tapered guide hole (24).

5. A molded case circuit breaker with anti-mistripping feature according to claim 1, characterized in that, The constraint mechanism (3) includes a constraint member slidably disposed on the guide seat (21) and an elastic member for driving the constraint member to reset. When the pressure plate (13) moves, it drives the constraint member to move toward the wire connection part (142) to form a clamping constraint on the wire connection part (142).

6. A molded case circuit breaker for preventing accidental tripping according to claim 5, characterized in that, The constraint mechanism (3) includes: A sliding groove (31) is provided at the front end of the guide seat (21), and two sets of the sliding groove (31) are provided; The reset spring rod (32) is provided in two sets. One end of each set of the reset spring rod (32) slides through the guide seat (21) and extends into the limiting hole (25), while the other end extends into the corresponding sliding groove (31). A passive block (33) is fixedly installed at one end of the reset spring rod (32) located in the sliding groove (31), and the passive block (33) is slidably connected to the sliding groove (31); The constraint block (34) is fixedly installed at one end of the reset spring rod (32) located in the limiting hole (25) and is used to abut against the outer periphery of the wire connection part (142); The driving pressure block (35) is fixedly installed at the bottom of the pressure plate (13) and is set in correspondence with the corresponding passive block (33). The driving pressure block (35) and the passive block (33) are provided with mutually cooperating guide slopes on opposite sides.

7. A molded case circuit breaker for preventing accidental tripping according to claim 6, characterized in that, The two sets of constraint blocks (34) are located on both sides of the wire connection part (142), and the driving pressure block (35) is located above the wire connection part (142). The driving pressure block (35) and the two sets of constraint blocks (34) are distributed in a three-point clamping distribution around the wire connection part (142).

8. A molded case circuit breaker with anti-mistripping feature according to claim 7, characterized in that, The constraint block (34) has an arc-shaped pressing surface on the side facing the wire connection part (142), and the curvature of the arc-shaped pressing surface matches the outer diameter of the wire connection part (142).

9. A molded case circuit breaker with anti-mistripping feature according to claim 6, characterized in that, The bottom of the driving block (35) is fixedly installed with a pressing protrusion (36), which is inclined toward the wire connection part (142) and is used to press against the insulation coating layer of the wire connection part (142).

10. A molded case circuit breaker with anti-mistripping feature according to claim 8, characterized in that, The constraint block (34) has a guide arc surface block (37) fixedly installed at one end facing the annular mounting part (141), and the guide arc surface block (37) has a guide arc surface that is adapted to the inner wall of the tapered positioning hole (23).

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