A circuit breaker overload protection mechanism

Abstract

The utility model discloses a kind of circuit breaker overload protection mechanism, it is related to circuit breaker technical field, specifically for the right end fixed connection of bimetallic strip has soft wire, the upper surface fixed connection of soft wire has contact plate, the right upper side of contact plate is installed with center lever, the lower fixed connection of bimetallic strip close to left end has load wire, the left end fixed connection of bimetallic strip has fine adjustment screw block, the lower installation of bimetallic strip right end has Z-shaped metal sheet.The circuit breaker overload protection mechanism is cooperatively arranged by bimetallic strip, Z-shaped metal sheet, resistance and alarm wire, when bimetallic strip is bent due to overload in the process of using in circuit breaker, Z-shaped metal sheet will be touched preferentially, current output is achieved through resistance and alarm wire, by connecting alarm wire into alarm or emergency device, thereby played the role of alarming or enabling protection device before overload tripping occurs.

Description

Technical Field

[0001] This utility model relates to the field of circuit breaker technology, specifically to a circuit breaker overload protection mechanism. Background Technology

[0002] Circuit breakers are essential protective devices in power systems and are widely used in various high and low voltage power distribution systems. They can connect and disconnect circuits under normal conditions, and automatically disconnect circuits in the event of overloads, short circuits, or other faults, protecting electrical equipment and lines.

[0003] The overload protection mechanism of a circuit breaker is the core part of the circuit breaker to realize the overload protection function. Its main responsibility is to monitor the current in the circuit in real time. When the current exceeds the rated current of the circuit breaker, that is, when an overload occurs, it takes corresponding measures in time to avoid damage to the circuit and equipment due to excessive current.

[0004] Conventional circuit breakers typically trip the circuit breaker directly when an overload occurs, lacking any prior warning mechanism. Even with the addition of new equipment or abnormally high current due to aging electrical appliances, long-term low-power overloads can still trigger a power outage, causing server shutdowns, data loss or corruption, or scrapping products on automated production lines, resulting in significant time and financial losses. While low-power overloads (above rated power but below maximum power) still pose some safety hazards, alarms can be triggered before a power outage, allowing staff to investigate and prevent unnecessary losses due to sudden tripping. Utility Model Content

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this utility model provides a circuit breaker overload protection mechanism, which solves the problems mentioned in the background section.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, this utility model provides the following technical solution: a circuit breaker overload protection mechanism, comprising a bimetallic strip, a flexible wire fixedly connected to the right end of the bimetallic strip, a contact plate fixedly connected to the top of the flexible wire, a central lever installed on the upper right of the contact plate, a load wire fixedly connected to the lower left end of the bimetallic strip, a fine-tuning screw fixedly connected to the left end of the bimetallic strip, and a Z-shaped metal plate installed below the right end of the bimetallic strip.

[0009] Optionally, an upper fine-tuning bracket is installed above the fine-tuning screw block, and lower fine-tuning brackets are installed on both sides of the fine-tuning screw block. A fine-tuning screw is connected to the internal thread of the fine-tuning screw block, and a fine-tuning retaining ring is fixedly connected to the outer surface of the fine-tuning screw.

[0010] Optionally, the left side of the contact plate is fixedly connected to the inside of the housing, the center of the central lever is movably connected to the housing via a shaft, the upper and lower fine-tuning brackets are fixed to the side of the housing, and the fine-tuning screw is movably connected to the bottom surface of the housing via a fine-tuning retainer.

[0011] Optionally, a resistor is fixedly connected to the lower end of the Z-shaped metal sheet, and an alarm wire is fixedly connected to the lower end of the resistor.

[0012] Optionally, the housing is internally fixedly connected to a metal triangular base, a metal base, a resistor base, and an alarm wire bracket. The bottom edge of the Z-shaped metal piece is engaged between the metal triangular base and the metal base. The resistor is installed on the side of the resistor base. There are two alarm wire brackets. The alarm wire passes through the lower surface of the housing by bending through the alarm wire brackets.

[0013] Optionally, a tie rod bracket is fixedly connected to the lower surface of the bimetallic strip, and the lower end of an overload tie rod is installed below the tie rod bracket. The upper end of the overload tie rod is installed on the upper side of the left arm of the central lever.

[0014] Optionally, a contact spring is fixedly connected to the right end of the contact plate, and the other end of the contact spring is clamped to the lower arm of the central lever through a square frame.

[0015] (III) Beneficial Effects

[0016] This utility model provides an overload protection mechanism for a circuit breaker, which has the following advantages:

[0017] 1. The overload protection mechanism of this circuit breaker, through the setting of the bimetallic strip, enables the Z-shaped metal strip to bend due to the different thermal expansion coefficients of the two metals when the circuit breaker is overloaded. Through the coordinated arrangement of the bimetallic strip, the Z-shaped metal strip, the resistor, and the alarm wire, when the circuit breaker is overloaded and the bimetallic strip bends, it will first contact the Z-shaped metal strip. Current will be output through the resistor and the alarm wire. By connecting the alarm wire to the alarm or emergency device, it can play the role of alarming or activating the protection device before the overload trips, avoiding unnecessary economic losses caused by direct tripping due to low power overloads.

[0018] 2. The overload protection mechanism of this circuit breaker, through the setting of the overload pull rod, enables the overload protection mechanism to cut off the power supply by pulling down the center lever through the overload pull rod when the bimetallic strip is deformed due to overload. Through the cooperation of the fine-adjustment screw and the fine-adjustment retaining ring, the position of the bimetallic strip can be adjusted during use, and the operating current of the trip unit can be precisely set, thereby adjusting the tripping time and avoiding false tripping. For some special loads, such as motors, there will be a large inrush current during startup, but this inrush current is short-lived and does not require immediate tripping protection, thus achieving the purpose of adapting to different working environments. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the internal structure of the present invention;

[0021] Figure 3 This utility model Figure 2 A schematic diagram of the structure of A in the middle;

[0022] Figure 4 This is a schematic diagram of the structure of this utility model.

[0023] In the diagram: 1. Bimetallic strip; 2. Flexible wire; 3. Contact plate; 4. Central lever; 5. Load wire; 6. Fine-tuning screw; 7. Upper fine-tuning bracket; 8. Lower fine-tuning bracket; 9. Fine-tuning screw; 10. Fine-tuning retaining ring; 11. Z-shaped metal strip; 12. Resistor; 13. Alarm wire; 14. Housing; 15. Metal strip triangular base; 16. Metal strip base; 17. Resistor base; 18. Alarm wire frame; 19. Overload pull rod; 20. Pull rod bracket; 21. Contact spring; 22. Manual switch; 23. Operating linkage; 24. Release spring; 25. Arc ignition plate; 26. Arc extinguishing grid. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0025] Example 1

[0026] Please see Figures 1 to 4This utility model provides the following technical solution: A flexible wire 2 is fixedly connected to the right end of a bimetallic strip 1. A contact plate 3 is fixedly connected to the top of the flexible wire 2. A central lever 4 is installed on the upper right side of the contact plate 3. A load wire 5 is fixedly connected to the lower left side of the bimetallic strip 1. A fine-tuning screw 6 is fixedly connected to the left end of the bimetallic strip 1. A Z-shaped metal strip 11 is installed on the lower right side of the bimetallic strip 1. The flexible wire 2 connects the bimetallic strip 1 and the contact plate 3 to ensure current transmission when the bimetallic strip 1 bends. The load wire 5 is used to connect the load device and is the power supply terminal of the circuit breaker. The contact plate 3 itself is made of elastic metal, which allows it to bend when pressed by the central lever 4 and automatically reset when not pressed.

[0027] An upper fine-tuning bracket 7 is mounted above the fine-tuning screw block 6, and lower fine-tuning brackets 8 are mounted on both sides of the fine-tuning screw block 6. A fine-tuning screw 9 is threadedly connected internally to the fine-tuning screw block 6, and a fine-tuning retaining ring 10 is fixedly connected to the outer surface of the fine-tuning screw 9. The fine-tuning brackets 7 and 8 support and position the fine-tuning screw block 6, allowing it to move only within a certain range. The fine-tuning screw 9 is threadedly connected to the fine-tuning screw block 6. Rotating the fine-tuning screw 9 changes the position of the fine-tuning screw block 6, thereby adjusting the position of the bimetallic strip 1. The higher the bimetallic strip 1 is, the greater the time and power required for it to contact the Z-shaped metal strip 11 or trigger the overload lever 19.

[0028] The left side of the contact plate 3 is fixedly connected to the inside of the housing 14. The center of the central lever 4 is movably connected to the housing 14 via a shaft. The upper fine-tuning bracket 7 and the lower fine-tuning bracket 8 are fixed to the side of the housing 14. The fine-tuning screw 9 is movably connected to the bottom surface of the housing 14 via a fine-tuning retaining ring 10. The central lever 4 is movably connected to the housing 14 via a shaft, allowing it to rotate around the shaft. The retaining ring 10 is used to limit the range of motion of the fine-tuning screw 9, and together with the head of the fine-tuning screw 9, it is locked onto the bottom surface of the housing 14, allowing it to rotate but not move.

[0029] A resistor 12 is fixedly connected to the lower end of the Z-shaped metal piece 11, and an alarm wire 13 is fixedly connected to the lower end of the resistor 12. The Z-shaped metal piece 11 is made of elastic metal, which can conduct electricity when the bimetallic plate 1 is bent, and can be pressed down without affecting its bending when further bent. The Z-shaped metal piece 11 automatically resets when the bimetallic plate 1 is reset. The resistor 12 is used to protect the alarm circuit, and the alarm wire 13 leads out the signal of the alarm circuit and connects to the alarm or protection device.

[0030] The housing 14 is internally fixedly connected to a metal triangular bracket 15, a metal base 16, a resistor base 17, and an alarm wire bracket 18. The bottom edge of the Z-shaped metal piece 11 is engaged between the metal triangular bracket 15 and the metal base 16. The resistor 12 is mounted on the side of the resistor base 17. There are two alarm wire brackets 18, and the alarm wire 13 passes through the alarm wire bracket 18, bent, and through the lower surface of the housing 14. The upper fine-tuning bracket 7, lower fine-tuning bracket 8, metal triangular bracket 15, metal base 16, and resistor base 17 are all used to fix other structures. They can be fixedly connected to the housing 14 or directly formed from the housing 14. The metal triangular bracket 15 and metal base 16 can clamp and fix the Z-shaped metal piece 11.

[0031] A tie rod bracket 20 is fixedly connected to the lower surface of the bimetallic strip 1. The lower end of the overload tie rod 19 is installed below the tie rod bracket 20, and the upper end of the overload tie rod 19 is installed on the upper side of the left arm of the central lever 4. When the bimetallic strip 1 deforms due to temperature, the tie rod bracket 20 drives the overload tie rod 19, thereby causing the central lever 4 to rotate.

[0032] As a preferred embodiment of this utility model: a contact spring 21 is fixedly connected to the right end of the contact plate 3, and the other end of the contact spring 21 is clamped to the lower arm of the central lever 4 through a square frame. The contact spring 21 provides a leftward elastic force, which, in conjunction with the release spring 24, maintains the closed and open states.

[0033] In use, this device serves as an overload protection device for circuit breakers and should be operated in accordance with... Figure 4 The structure is located inside the circuit breaker, and the circuit breaker's closing, short-circuit disconnection, wiring, and installation methods all follow common circuit breaker structural principles. In the normal operating state of the device, with the manual opener 22 positioned at the top, operating the linkage 23 releases the tension of the spring 24 to the upper right. In this state, the tension of the contact spring 21 cannot be overcome, and the device remains in the closed state.

[0034] When a low-power overload occurs in the circuit (above rated power, below maximum power), the bimetallic strip 1 generates Joule heat. Due to the different thermal expansion coefficients of the two metals, the right end bends downwards. During this downward bending, the bimetallic strip contacts the Z-shaped metal strip, forming a circuit. After the current in the alarm line 13 is kept at a safe level by resistor 12, the electrical signal is output to the alarm or protection device through the alarm line 13. If the low-power overload is not resolved for an extended period, the bimetallic strip 1 continues to bend. Pulling down the overload lever 19 causes the central lever 4 to rotate counterclockwise, pushing the contact plate 3 away from the arc-extinguishing plate 25 to open the circuit. The arc-extinguishing grid 26 ensures circuit safety. The counterclockwise rotation of the central lever 4 drives the manual switch 22 to trip via the operating linkage 23. Simultaneously, the rotation of the operating linkage 23 changes the direction of the release spring 24 to the upper left, thus overcoming the elasticity of the contact spring 21 and maintaining the open state.

[0035] When a high-power overload occurs (exceeding the maximum power and potentially damaging electrical appliances at any time), the bimetallic strip 1 generates Joule heat at an increased rate due to the increased current, allowing it to bend quickly and shortening the time required to pull the overload lever 19. This enables rapid tripping, ensuring that even with an alarm function, it can still quickly respond to and cut off high-power overload situations, thus guaranteeing the safety of electrical appliances and personnel.

[0036] In summary, this circuit breaker overload protection mechanism, through the arrangement of the bimetallic strip 1, enables the Z-shaped metal strip 11 to bend due to the different thermal expansion coefficients of the two metals when the circuit breaker is overloaded. Through the coordinated arrangement of the bimetallic strip 1, the Z-shaped metal strip 11, the resistor 12, and the alarm line 13, during operation, when the circuit breaker is overloaded and the bimetallic strip 1 bends, it will preferentially contact the Z-shaped metal strip 11. Current will then be output through the resistor 12 and the alarm line 13. By connecting the alarm line 13 to an alarm or emergency device, it serves to alarm or activate the protection device before an overload trip occurs, avoiding unnecessary economic losses caused by direct tripping during low-power overloads. The overload protection mechanism of this circuit breaker, through the setting of the overload pull rod 19, enables the overload protection mechanism to cut off the power supply by pulling down the central lever 4 through the overload pull rod 19 when the bimetallic strip 1 is deformed due to overload. Through the cooperation of the fine-tuning screw block 6 and the fine-tuning retaining ring 10, the position of the bimetallic strip 1 can be adjusted during use to accurately set the trip current, thereby adjusting the tripping time and avoiding false tripping. For some special loads, such as motors, there will be a large inrush current when starting, but this inrush current is short-lived and does not require immediate tripping protection, thus achieving the purpose of adapting to different working environments.

[0037] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A circuit breaker overload protection mechanism, comprising a bimetallic strip (1), characterized in that: A flexible wire (2) is fixedly connected to the right end of the bimetallic strip (1), a contact plate (3) is fixedly connected to the top of the flexible wire (2), a central lever (4) is installed on the upper right of the contact plate (3), a load wire (5) is fixedly connected to the lower left end of the bimetallic strip (1), a fine-tuning screw (6) is fixedly connected to the left end of the bimetallic strip (1), and a Z-shaped metal strip (11) is installed on the lower right end of the bimetallic strip (1).

2. The circuit breaker overload protection mechanism according to claim 1, characterized in that: An upper fine adjustment frame (7) is installed above the fine adjustment screw block (6), and lower fine adjustment frames (8) are installed on both sides of the fine adjustment screw block (6). A fine adjustment screw (9) is connected to the internal thread of the fine adjustment screw block (6), and a fine adjustment retaining ring (10) is fixedly connected to the outer surface of the fine adjustment screw (9).

3. The circuit breaker overload protection mechanism according to claim 2, characterized in that: The left side of the contact plate (3) is fixedly connected to the inside of the outer shell (14), the center of the central lever (4) is movably connected to the outer shell (14) via a shaft, the upper fine adjustment frame (7) and the lower fine adjustment frame (8) are fixed to the side of the outer shell (14), and the fine adjustment screw (9) is movably connected to the bottom surface of the outer shell (14) via a fine adjustment retaining ring (10).

4. The circuit breaker overload protection mechanism according to claim 1, characterized in that: A resistor (12) is fixedly connected to the lower end of the Z-shaped metal sheet (11), and an alarm line (13) is fixedly connected to the lower end of the resistor (12).

5. The circuit breaker overload protection mechanism according to claim 3, characterized in that: The outer casing (14) is internally fixedly connected to a metal plate triangular seat (15), a metal plate base (16), a resistor base (17), and an alarm wire bracket (18). The bottom edge of the Z-shaped metal plate (11) is snapped between the metal plate triangular seat (15) and the metal plate base (16). The resistor (12) is installed on the side of the resistor base (17). There are two alarm wire brackets (18). The alarm wire (13) is bent through the alarm wire bracket (18) and passes through the lower surface of the outer casing (14).

6. The circuit breaker overload protection mechanism according to claim 1, characterized in that: A tie rod bracket (20) is fixedly connected to the lower surface of the bimetallic strip (1). The lower end of an overload tie rod (19) is installed below the tie rod bracket (20), and the upper end of the overload tie rod (19) is installed on the upper side of the left arm of the central lever (4).

7. The circuit breaker overload protection mechanism according to claim 1, characterized in that: The right end of the contact plate (3) is fixedly connected to a contact spring (21), and the other end of the contact spring (21) is connected to the lower arm of the central lever (4) through a square frame.

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