A current limiting device for a quick circuit breaker

Abstract

The present invention discloses a current limiting device for a quick circuit breaker, which includes a housing and a static contact rod and a moving contact rod arranged inside the housing. An elastic pressing mechanism on the housing presses against one side of the moving contact rod. The elastic pressing mechanism consists of a rectangular limiting sleeve fixedly installed on the inner wall of the housing, a rectangular movable plate slidably arranged inside the rectangular limiting sleeve, a screw rod passing through the middle of the rectangular movable plate and threadedly connected to the rectangular movable plate, and a compression spring arranged directly below the rectangular limiting sleeve and fixedly connected to the static contact rod. A pressure sensor is arranged in the middle of the rectangular movable plate, and the pressure sensor is electrically connected to a single-chip microcomputer on the side wall of the housing. The single-chip microcomputer converts the electrical signal received from the pressure sensor into a digital signal and transmits it to an electronic screen arranged outside the housing for display. This device can accurately and quickly adjust the pressing force of the elastic pressing mechanism, withstand the electro-dynamic repulsive force generated by different large currents, so as to facilitate the application of the circuit breaker to different uses.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrical equipment, and particularly relates to a current limiting device for a fast circuit breaker. Background Art

[0002] A circuit breaker refers to a switching device that can close, carry, and break the current under normal circuit conditions and can close, carry, and break the current under abnormal circuit conditions within a specified time. Circuit breakers are divided into high-voltage circuit breakers and low-voltage circuit breakers according to their application scope. The division between high and low voltages is relatively blurred. Generally, those above 3 kV are called high-voltage electrical appliances. Circuit breakers can be used to distribute electric energy, start asynchronous motors infrequently, and protect power supply lines and motors, etc. When they encounter serious overload, short circuit, and undervoltage faults, they can automatically cut off the circuit. Its function is equivalent to the combination of a fuse switch and an over- and under-heat relay, etc. Moreover, generally no components need to be changed after breaking the fault current. At present, it has been widely used.

[0003] The circuit breaker uses a set of contacts to close, separate, and break the current. When a large short-circuit current appears, it is difficult for the contacts to break the electric arc, and it is difficult to achieve high breaking capacity. Especially for circuit breakers with a rated current of 16 A and below, when encountering a large short-circuit current, problems such as damage to the circuit breaker where the coil or heating element is burned out are likely to occur. Therefore, a current limiting device needs to be provided.

[0004] When the circuit breaker is in normal use, through the pressing of the elastic pressing structure, the contacts on the opposite surfaces of the static contact rod and the moving contact rod are pressed against each other to form a path with the external circuit. After a large current passes between the contacts of the static contact rod and the moving contact rod, an electro-dynamic repulsive force is generated to push the contacts of the static contact rod and the moving contact rod away from each other. When they are separated to a certain distance, the short-circuit current is quickly interrupted, thereby protecting the main circuit. When the circuit breaker is applied to different electrical equipment, the large current passing through is different, and the electro-dynamic repulsive force that the elastic pressing structure needs to resist is also different. Designing and manufacturing circuit breakers for different electrical equipment increases costs, consumes manpower and material resources, and the applicability is also insufficient. Therefore, an improved design is needed. Summary of the Invention

[0005] The purpose of the present invention is to provide a current limiting device for a fast circuit breaker to be put into use to solve the problems raised in the above background art.

[0006] To achieve the above object, the present invention provides the following technical solution: A current-limiting device for a fast circuit breaker, comprising a housing and a static contact rod and a moving contact rod disposed inside the housing. An elastic pressing mechanism on the housing presses against one side of the moving contact rod, so that the contacts on the opposite surfaces of the moving contact rod and the static contact rod are pressed together. The elastic pressing mechanism consists of a rectangular limiting sleeve fixedly installed on the inner wall of the housing, a rectangular movable plate slidably disposed within the rectangular limiting sleeve, a screw rod passing through the middle of the rectangular movable plate and threadedly connected to the rectangular movable plate, and a compression spring disposed directly below the rectangular limiting sleeve and fixedly connected to the moving contact rod;

[0007] A pressure sensor is provided in the middle of the rectangular movable plate. The pressure sensor is electrically connected to a single-chip microcomputer on the side wall of the housing. The single-chip microcomputer converts the electrical signal received from the pressure sensor into a digital signal and transmits it to an electronic screen disposed outside the housing for display;

[0008] A movable nut is fixedly provided in the middle of the rectangular movable plate. The movable nut is sleeved outside the screw rod and threadedly connected to the screw rod;

[0009] The threaded sleeve and the housing are of an integrally formed structure, and the housing, the rectangular limiting sleeve, the rectangular movable plate, and the screw rod are all made of insulating rubber material.

[0010] Preferably, a knob is rotatably installed on the side surface of the housing, and the end of the screw rod passes through the housing and is fixedly connected to the middle of the knob.

[0011] Preferably, a buzzer is provided on the housing, and the buzzer is electrically connected to the single-chip microcomputer.

[0012] The technical effects and advantages of the present invention: For this current-limiting device of the fast circuit breaker, by rotating the screw rod to adjust the pressure of the elastic pressing mechanism on the compression spring, thereby adjusting the pressure grams between the moving contact rod and the static contact rod, and adjusting the resistance of the moving contact rod and the static contact rod to the electro-dynamic repulsion force, so that the applicability to different large-current values is different, thus ensuring that the circuit breaker is applicable to various electrical equipment, with stronger practicability, eliminating the step of customizing circuit breakers for different electrical equipment, and saving costs and manpower. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a structural schematic diagram of the present invention;

[0014] Figure 2 is a structural schematic diagram of the elastic pressing mechanism.

[0015] In the figure: 1, housing; 2, static contact rod; 3, moving contact rod; 4, elastic pressing mechanism; 41, rectangular limiting sleeve; 42, rectangular movable plate; 43, screw rod; 44, compression spring;

[0016] 5. Pressure sensor; 6. Single-chip microcomputer; 7. Electronic screen; 8. Buzzer; 9. Knob; 10. Movable nut. Specific embodiments

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] The present invention provides a current-limiting device for a fast circuit breaker as Figure 1-2 shown, which includes a housing 1, a static contact rod 2 and a moving contact rod 3 arranged inside the housing 1. An elastic pressing mechanism 4 on the housing 1 presses on one side of the moving contact rod 3, so that the contacts on the opposite surfaces of the moving contact rod 3 and the static contact rod 2 are pressed together. The elastic pressing mechanism 4 is composed of a rectangular limiting sleeve 41 fixedly installed on the inner wall of the housing 1, a rectangular movable plate 42 slidably arranged in the rectangular limiting sleeve 41, a screw rod 43 passing through the middle of the rectangular movable plate 42 and threadedly connected to the rectangular movable plate 42, and a compression spring 44 arranged directly below the rectangular limiting sleeve 41 and fixedly connected to the moving contact rod 3;

[0019] A pressure sensor 5 is arranged in the middle of the rectangular movable plate 42. The pressure sensor 5 is electrically connected to a single-chip microcomputer 6 on the side wall of the housing 1. The single-chip microcomputer 6 converts the electrical signal received from the pressure sensor 5 into a digital signal and transmits it to an electronic screen 7 arranged outside the housing 1 for display.

[0020] Current limiting device adjustment steps: Rotate the screw 43 clockwise. Since the screw 43 is threadedly connected to the middle of the rectangular movable plate 42, through the mutual acting force between the threads, the rectangular movable plate 42 vertically descends along the screw 43 and squeezes the compression spring 44 on the moving contact rod 3, causing the compression spring 44 to shorten and thus generate a restoring force. Along with the descent of the rectangular movable plate 42, the compression amount of the compression spring 44 increases, thereby generating a greater restoring force, making the pressing force of one end of the compression spring 44 on the moving contact rod 3 increase. At the same time, the restoring forces at both ends of the compression spring 44 are the same, that is, the pressure of the compression spring 44 on the moving contact rod 3 is the same as the pressure of the compression spring 44 on the pressure sensor 5 on the lower side of the rectangular movable plate 42. The pressure sensor 5 converts the pressure signal into a digital signal and transmits it to the single-chip microcomputer 6. The single-chip microcomputer 6 analyzes the electrical signal and then transmits it to the electronic screen 7, where the specific pressure in grams is displayed. By adjusting the pressure in grams of the compression spring 44, the resistance to the electric repulsive force between the moving contact rod 3 and the static contact rod 2 is adjusted, so that the applicability to different large current values is different, thus ensuring that the circuit breaker is suitable for various electrical equipment, with stronger practicability, eliminating the steps of customizing circuit breakers for different electrical equipment, and saving costs and manpower.

[0021] A movable nut 10 is fixedly arranged in the middle of the rectangular movable plate 42. The movable nut 10 is sleeved outside the screw 43 and is threadedly connected to the screw 43. Through the cooperation between the movable nut 10 and the screw 43, it is ensured that during the clockwise or counterclockwise rotation of the screw 43, the rectangular movable plate 42 vertically rises and falls along the screw 43.

[0022] A knob 9 is rotatably installed on the side of the housing 1, and the end of the screw 43 penetrates through the housing 1 and is fixedly connected to the middle of the knob 9. It is convenient for the operator to quickly and conveniently rotate the screw 43 through the knob 9.

[0023] The threaded sleeve and the housing 1 are of an integrally formed structure, and the housing 1, the rectangular limit sleeve 41, the rectangular movable plate 42, and the screw 43 are all made of insulating rubber material to ensure the insulation performance and prevent static electricity from affecting the normal operation of electronic devices such as the pressure sensor 5.

[0024] A buzzer 8 is arranged on the housing 1, and the buzzer 8 is electrically connected to the single-chip microcomputer 6. When the electric repulsive force generated when a large current passes between the moving contact rod 3 and the static contact rod 2 pushes the contacts between the moving contact rod 3 and the static contact rod 2 to move away from each other, extrusion occurs between the upper end of the compression spring 44 and the rectangular movable plate 42, generating an extrusion force. When the pressure detected by the pressure sensor 5 exceeds the set value, the single-chip microcomputer 6 sends a start signal to the buzzer 8, and the buzzer 8 makes a sound to prompt the maintenance personnel.

[0025] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A current limiting device for a quick circuit breaker, comprising a housing (1), a static contact rod (2) and a moving contact rod (3) arranged inside the housing (1), wherein an elastic pressing mechanism (4) on the housing (1) presses on one side of the moving contact rod (3), so that the contacts on the opposite surfaces of the moving contact rod (3) and the static contact rod (2) are pressed together, and it is characterized in that: The elastic pressing mechanism (4) consists of a rectangular limiting sleeve (41) fixedly installed on the inner wall of the housing (1), a rectangular movable plate (42) slidably arranged in the rectangular limiting sleeve (41), a screw rod (43) passing through the middle of the rectangular movable plate (42) and threadedly connected to the rectangular movable plate (42), and a compression spring (44) arranged directly below the rectangular limiting sleeve (41) and fixedly connected to the moving contact rod (3); A pressure sensor (5) is arranged in the middle of the rectangular movable plate (42). The pressure sensor (5) is electrically connected to a single-chip microcomputer (6) on the side wall of the housing (1). The single-chip microcomputer (6) converts the electrical signal received from the pressure sensor (5) into a digital signal and transmits it to an electronic screen (7) arranged outside the housing (1) for display; A movable nut (10) is fixedly arranged in the middle of the rectangular movable plate (42). The movable nut (10) is sleeved outside the screw rod (43) and threadedly connected to the screw rod (43); The threaded sleeve and the housing (1) are of an integrally formed structure, and the housing (1), the rectangular limiting sleeve (41), the rectangular movable plate (42), and the screw rod (43) are all made of insulating rubber material.

2. The current limiting device for a quick circuit breaker according to claim 1, characterized in that: A knob (9) is rotatably installed on the side of the housing (1), and the end of the screw rod (43) passes through the housing (1) and is fixedly connected to the middle of the knob (9).

3. The current limiting device for a quick circuit breaker according to claim 1, characterized in that: A buzzer (8) is arranged on the housing (1), and the buzzer (8) is electrically connected to the single-chip microcomputer (6).

Images