A movable contact device for low voltage circuit breaker

Abstract

The present invention belongs to the technical field of low-voltage circuit breakers and discloses a movable contact device of a low-voltage circuit breaker, comprising a U-shaped plate arranged inside a circuit breaker housing, a shaft being installed between two sides of the U-shaped plate, a first mounting plate, a second mounting plate, a third mounting plate and a first pillar being installed on both sides of the U-shaped plate, two brackets being installed in a mirror-image manner at the bottom of the U-shaped plate, a second pillar being installed on the circuit breaker housing, movable contacts being rotatably installed on both side surfaces of the bracket, a rocker being rotatably installed on the second pillar, the rocker being provided with a fork, a first spring being installed between the rocker and the baffle, a waist-shaped hole being provided at the other end of the rocker, a flat plate being rotatably installed on the first pillar, a pen-type electric push rod being installed on the first mounting plate, a second spring being installed between the lower side of the waist-shaped hole and the upper side of the third mounting plate, and a proximity switch being installed on the second mounting plate.

Description

Technical Field

[0001] The present invention belongs to the technical field of low-voltage circuit breakers, and in particular relates to a movable contact device of a low-voltage circuit breaker. Background Art

[0002] Low-voltage circuit breaker, also known as automatic air switch, is an important control and protection electrical appliance, mainly used in AC and DC low-voltage power grids. Low-voltage circuit breaker can not only manually or electrically open and close circuits, but also protect circuits or electrical equipment from overload, short circuit and undervoltage. It can also be used to start motors infrequently and has certain control and protection functions. Low-voltage circuit breakers are classified in various ways. According to the usage category, it can be divided into selective type (protection device parameters are adjustable) and non-selective type (protection device parameters are not adjustable). According to the arc extinguishing medium, it can be divided into air type and vacuum type. Among them, domestically produced ones are mostly air type. Capacity range: Low-voltage circuit breakers have a wide capacity range, with a minimum of 4A, which can meet the protection needs of circuits of different sizes.

[0003] The invention patent application number 200610141037.1 discloses a movable contact device for a circuit breaker, which has a shunt-free current-carrying mechanism but has high current-carrying capacity, a small size, and stable contact resistance. The invention relates to a device for contacting a plurality of movable contacts (8) arranged side by side at each pole, wherein a positioning unit (8c) is used to position and clamp the inner diameter portion (17a) of an oblique spiral ring spring (17) formed into a ring shape by an inclined spiral spring, and the movable contact (8) is pushed on a connecting conductor (11b) of a movable contact support portion (11) supporting the movable contact (8) by the oblique spiral ring spring (17) to slide. However, the problem is that the currents I1 and I2 between the two movable contacts 11 flow in the same direction, and the electromotive forces F1 and F2 generated by the currents show a mutual attraction. When a large fault current is generated, the electromotive forces F1 and F2 of the fault current may be greater than the acting forces F3 and F4 of the spring 13, so that the contact pressure between the movable contact 11 and the bracket 12 is reduced or even disappears, thereby affecting the stability of the contact resistance.

[0004] Therefore, how to ensure the strength of its contact and how to ensure the stability of its resistance when the spring performance fails are technical issues that need to be considered at present. Summary of the Invention

[0005] In view of the problems raised by the above background technology, the object of the present invention is to provide a movable contact device for a low-voltage circuit breaker.

[0006] In order to achieve the above technical objectives, the technical solutions adopted by the present invention are as follows:

[0007] A movable contact device for a low-voltage circuit breaker includes a U-shaped plate disposed within a circuit breaker housing, an axis mounted between two sides of the U-shaped plate, a first mounting plate, a second mounting plate, a third mounting plate, and a first support column mounted on both sides of the U-shaped plate, two brackets mounted in a mirror-image manner on the bottom of the U-shaped plate, and second supports mounted symmetrically on both sides of the brackets in the circuit breaker housing;

[0008] The shaft passes through the two brackets, and steps are provided at both ends of the shaft. A latch is installed on the shaft at the step, and a baffle is installed between the latch and the side wall of the step. The shaft is rotatably installed with moving contacts on both sides of the bracket, and the second pillar is rotatably installed with a rocker, and one end of the rocker is provided with a fork with a specification matching the shaft, and the fork is located on the outside of the shaft. A first spring is installed between the rocker and the baffle, and the first spring is sleeved on the outside of the shaft. A waist-shaped hole is provided at the other end of the rocker, and a flat plate is rotatably installed on the first pillar. The first mounting plate A pen-type electric push rod is installed, and the output end of the pen-type electric push rod is hinged to one end of the flat plate, and a bottom column is installed at the other end of the flat plate, and the bottom column passes through the third mounting plate, and the bottom column is integrally connected with an inner column, and an outer cylinder is slidably mounted on the inner column, and a guide column is integrally connected to the top of the outer cylinder, and the guide column is located in the waist-shaped hole, and a second spring is installed between the lower side of the waist-shaped hole and the upper side of the third mounting plate, and the second spring is sleeved on the outer side of the outer cylinder and the bottom column, and a proximity switch is installed on the second mounting plate, and the output end of the proximity switch corresponds to the upper side of the waist-shaped hole.

[0009] It is further defined that the pen-type electric push rod adopts a maximum outer diameter of 350mm. Such a design has a small size and good installation adaptability.

[0010] It is further defined that the U-shaped plate and the circuit breaker housing are integrally injection-molded. Such a design ensures structural strength and production efficiency.

[0011] It is further defined that the two brackets are symmetrically provided with four fixing holes. Such a design ensures the fixing effect of the brackets.

[0012] It is further defined that the shaft is made of conductive material, and such a design ensures the current conduction effect.

[0013] It is further defined that the latch is installed by means of a threaded connection, and such a design will not cause the problem of falling out.

[0014] It is further defined that, under normal operating conditions, the proximity switch is in a state of detecting the end of the seesaw. With such a design, when the contact end of the seesaw is pushed away, the proximity switch will not be able to detect the corresponding position, and then transmit a signal to achieve the purpose of maintaining monitoring.

[0015] It is further defined that a blocking disk is installed at the end of the first support, and this design prevents the flat panel from falling out.

[0016] It is further defined that the contact surface between the fork and the shaft is rounded and deburred, and this design prevents scratches caused by friction.

[0017] It is further defined that the outer diameters of the outer cylinder and the bottom column are the same. Such a design prevents interference with the movement of the second spring.

[0018] The beneficial effects of the present invention are as follows:

[0019] In the present invention, under the effect of the first spring and the second spring, the forces of both can finally act on the movable contact, so that the movable contact maintains contact with the bracket, and the movable contact will not be separated from the bracket due to the repulsive force of operation or the strengthening of the electric force, thereby ensuring the stability of the contact resistance;

[0020] The present invention establishes an electric power monitoring element, namely a contact switch. When a problem occurs, the contact switch can react immediately and activate the pen-type electric push rod to force the moving contact to contact the bracket to ensure the stability of the contact resistance. It is suitable for emergency situations where the first spring and the second spring fail due to various problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention can be further illustrated by the non-limiting examples given in the accompanying drawings;

[0022] Figure 1 This is a structural schematic diagram of an embodiment of a movable contact device of a low-voltage circuit breaker according to the present invention;

[0023] Figure 2 This is a schematic cross-sectional view of an embodiment of a movable contact device of a low-voltage circuit breaker according to the present invention;

[0024] The main component symbols are described as follows:

[0025] Circuit breaker housing 1; U-shaped plate 2; shaft 3; first mounting plate 4; second mounting plate 5; third mounting plate 6; first pillar 7; bracket 8; second pillar 9; step 10; latch 11; baffle 12; moving contact 13; rocker 14; fork 15; first spring 16; waist-shaped hole 17; flat plate 18; pen-type electric push rod 19; bottom pillar 20; inner pillar 21; outer cylinder 22; guide pillar 23; second spring 24; proximity switch 25. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0027] like Figure 1、 Figure 2 As shown, a movable contact device for a low-voltage circuit breaker of the present invention includes a U-shaped plate 2 disposed inside a circuit breaker housing 1, a shaft 3 being installed between two sides of the U-shaped plate 2, a first mounting plate 4, a second mounting plate 5, a third mounting plate 6, and a first support 7 being installed on both sides of the U-shaped plate 2, two brackets 8 being installed in a mirror-image manner at the bottom of the U-shaped plate 2, and second supports 9 being symmetrically installed on both sides of the brackets 8 on the circuit breaker housing 1;

[0028] The shaft 3 passes through the two brackets 8, and steps 10 are provided at both ends of the shaft 3. A latch 11 is installed on the shaft 3 at the step 10, and a baffle 12 is installed between the latch 11 and the side wall of the step 10. The shaft 3 is rotatably installed with a moving contact 13 on both sides of the bracket 8. The second pillar 9 is rotatably installed with a rocker 14. One end of the rocker 14 is provided with a fork 15 whose specifications match the shaft 3. The fork 15 is located on the outside of the shaft 3. A first spring 16 is installed between the rocker 14 and the baffle 12. The first spring 16 is sleeved on the outside of the shaft 3. A waist-shaped hole 17 is provided at the other end of the rocker 14. The first pillar 7 is rotatably installed with a flat plate 18. The first mounting plate 4 is installed There is a pen-type electric push rod 19, the output end of the pen-type electric push rod 19 is hinged to one end of the flat plate 18, and a bottom column 20 is installed at the other end of the flat plate 18. The bottom column 20 passes through the third mounting plate 6, and the bottom column 20 is integrally connected to the inner column 21. The inner column 21 is slidably mounted with an outer cylinder 22, and the top of the outer cylinder 22 is integrally connected with a guide column 23. The guide column 23 is located in the waist-shaped hole 17, and a second spring 24 is installed between the lower side of the waist-shaped hole 17 and the upper side of the third mounting plate 6. The second spring 24 is sleeved on the outer side of the outer cylinder 22 and the bottom column 20. The second mounting plate 5 is installed with a proximity switch 25, and the output end of the proximity switch 25 corresponds to the upper side of the waist-shaped hole 17.

[0029] In this embodiment, as one of the embodiments, only the first spring 16 needs to be installed. Under the effect of the first spring 16, the moving contact 13 can be directly pressed against the side of the bracket 8. The arrangement of the latch 11 and the baffle 12 on the step 10 facilitates the installation of the first spring 16.

[0030] As one embodiment, only the first spring 16 and the second spring 24 need to be installed. Under the joint action of the first spring 16 and the second spring 24, the double force ensures that the movable contact 13 contacts the bracket 8. This can effectively resist the electric repulsion force generated on the contact system when the circuit breaker interrupts the fault current, thereby achieving the purpose of ensuring the stability of the contact resistance.

[0031] As one of the embodiments, on the basis of installing the first spring 16 and the second spring 24, a proximity switch 25 and a pen-type electric push rod 19 are further installed. When the first spring 16 and the second spring 24 both fail in a specific situation, under the effect of the electric repulsive force, the end of the rocker 14 with the fork 15 will be pushed toward the baffle 12. Under the effect of the second pillar 9, the other end of the rocker 14 will be away from the sensing end of the proximity switch 25. When the proximity switch 25 cannot sense, the signal is fed back to the terminal in real time. The terminal controls the operation of the pen-type electric push rod 19 to forcibly push the rocker 14 toward the direction of the proximity switch 25. The fork 15 then forcibly pushes the moving contact 13 toward the bracket 8, thereby achieving the purpose of contact and ensuring the stability of the contact resistance.

[0032] In summary, while ensuring the contact strength, it also has the effect of monitoring and handling in emergency situations, ensuring the effectiveness of use.

[0033] It is preferred that the pen-type electric push rod 19 adopts a maximum outer diameter of 350 mm. Such a design has a small volume and good installation adaptability. In fact, the specification selection of the pen-type electric push rod 19 can also be considered according to specific circumstances.

[0034] Preferably, the U-shaped plate 2 and the circuit breaker housing 1 are integrally injection molded. Such a design ensures structural strength and production efficiency. In fact, the molding method of the U-shaped plate 2 and the circuit breaker housing 1 can also be considered according to specific circumstances.

[0035] Preferably, the two brackets 8 are symmetrically provided with four fixing holes. Such a design ensures the fixing effect of the brackets 8. In fact, the fixing method of the brackets 8 can also be considered according to specific circumstances.

[0036] The shaft 3 is preferably made of a conductive material. Such a design ensures the current conduction effect. In fact, the material selection and the shape and structure of the shaft 3 can also be considered according to specific circumstances.

[0037] Preferably, the latch 11 is installed by threaded connection. Such a design will not cause the problem of falling out. In fact, the installation method of the latch 11 can also be considered according to specific circumstances.

[0038] Preferably, under normal operating conditions, the proximity switch 25 is in a state of detecting the end of the rocker 14. With this design, when the contact end of the rocker 14 is pushed away, the proximity switch 25 will not be able to detect the corresponding position, and then transmit a signal to achieve the purpose of maintaining monitoring. In fact, the monitoring state of the proximity switch 25 can also be considered according to specific circumstances.

[0039] Preferably, a blocking disk is installed at the end of the first support 7. Such a design prevents the flat plate 18 from falling out. In fact, anti-falling measures can also be considered according to specific circumstances.

[0040] Preferably, the contact surface between the fork 15 and the shaft 3 is rounded and deburred. This design prevents scratches caused by friction. In fact, anti-scratch treatment measures can also be considered according to specific circumstances.

[0041] Preferably, the outer diameters of the outer cylinder 22 and the bottom column 20 are the same. This design prevents interference with the movement of the second spring 24. In fact, the outer diameters of the outer cylinder 22 and the bottom column 20 can also be considered according to specific circumstances.

[0042] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A movable contact device for a low-voltage circuit breaker, comprising a U-shaped plate (2) disposed inside a circuit breaker housing (1), characterized in that: A shaft (3) is installed between the two sides of the U-shaped plate (2), a first mounting plate (4), a second mounting plate (5), a third mounting plate (6) and a first support (7) are installed on both sides of the U-shaped plate (2), two brackets (8) are installed at the bottom of the U-shaped plate (2) in a mirror-image manner, and the circuit breaker housing (1) is symmetrically installed with second supports (9) on both sides of the brackets (8); The shaft (3) passes through the two brackets (8), and steps (10) are provided at both ends of the shaft (3). A latch (11) is installed on the shaft (3) at the step (10), and a baffle (12) is installed between the latch (11) and the side wall of the step (10). The shaft (3) is rotatably installed with moving contacts (13) on both sides of the bracket (8). The second pillar (9) is rotatably installed with a seesaw (14), and one end of the seesaw (14) is provided with a fork (15) whose specifications match the shaft (3). The fork (15) is located on the outside of the shaft (3). A first spring (16) is installed between the seesaw (14) and the baffle (12), and the first spring (16) is sleeved on the outside of the shaft (3). The other end of the seesaw (14) is provided with a waist-shaped hole (17). The first pillar (7) is rotatably installed with a flat plate (18). The mounting plate (4) is provided with a pen-type electric push rod (19), the output end of the pen-type electric push rod (19) is hinged to one end of the plane plate (18), the other end of the plane plate (18) is provided with a bottom column (20), the bottom column (20) passes through the third mounting plate (6), the bottom column (20) is integrally connected with an inner column (21), the inner column (21) is slidably provided with an outer cylinder (22), the top of the outer cylinder (22) is integrally connected with a guide column (23), the guide column (23) is located in the waist-shaped hole (17), a second spring (24) is provided between the lower side of the waist-shaped hole (17) and the upper side of the third mounting plate (6), the second spring (24) is sleeved on the outer side of the outer cylinder (22) and the bottom column (20), the second mounting plate (5) is provided with a proximity switch (25), the output end of the proximity switch (25) corresponds to the upper side of the waist-shaped hole (17).

2. The movable contact device of a low-voltage circuit breaker according to claim 1, characterized in that: The pen-type electric push rod (19) has a maximum outer diameter of 350 mm.

3. The movable contact device of a low-voltage circuit breaker according to claim 1, characterized in that: The U-shaped plate (2) and the circuit breaker housing (1) are integrally injection-molded.

4. The movable contact device of a low-voltage circuit breaker according to claim 1, characterized in that: The two brackets (8) are symmetrically provided with four fixing holes.

5. The movable contact device of a low-voltage circuit breaker according to claim 1, characterized in that: The shaft (3) is made of conductive material.

6. The movable contact device of a low-voltage circuit breaker according to claim 1, characterized in that: The latch (11) is installed in a threaded connection manner.

7. The movable contact device of a low-voltage circuit breaker according to claim 1, characterized in that: In a normal operating state, the proximity switch (25) is in a state of detecting the end of the rocker (14).

8. The movable contact device of a low-voltage circuit breaker according to claim 1, characterized in that: A blocking disk is installed at the end of the first support (7).

9. The movable contact device of a low-voltage circuit breaker according to claim 1, characterized in that: The contact surface between the fork (15) and the shaft (3) is processed by rounding and deburring.

10. The movable contact device of a low voltage circuit breaker according to claim 1, characterized in that: The outer diameters of the outer cylinder (22) and the bottom column (20) are the same.

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