Magnetic control tripping device of circuit breaker and use method of magnetic control tripping device

Abstract

The invention discloses a magnetic control tripping device of a circuit breaker and a use method of the magnetic control tripping device. The tripping device comprises a lever, a support, an iron core operating rod and a magnetic control assembly, one end of the lever is a tripping action end, the middle of the lever is rotatably arranged on the support, the other end of the lever is movably connected with the iron core operating rod, and the iron core operating rod prizes the lever and is limited in the magnetic control assembly. The tripping device is adopted in the using method. When the external induction device detects that the current value i or the current rise rate di / dt in the main circuit exceeds a preset value, the magnetic control assembly enables the iron core operating rod in the magnetic control assembly to rise, the tripping action end at one end of the lever is driven to descend, and tripping operation is carried out. The device has the beneficial effects that when overload or short-circuit current is detected in a main loop, the device can respond quickly, the tripping speed is high, and the safety of equipment and personnel is protected; the magnetic control principle is matched with the lever principle, the structure is simple, installation is convenient, the number of mechanical parts is small, abrasion loss is small, the service life is long, and reliability is high.

Description

Technical Field

[0001] The present application belongs to the technical field of electrical switches, and in particular relates to a magnetically controlled tripping device for a circuit breaker and a method for using the same. Background Art

[0002] In rail electric traction systems, DC circuit breakers, as switching and protection devices, must not only be able to normally close, carry, and interrupt rated operating currents, but must also be capable of connecting and interrupting short-circuit currents and overload currents. The short-circuit and overload current interruption process on the circuit breaker must first pass through the trip device, which causes the circuit breaker's locking device to trip, allowing the circuit breaker contacts to separate and complete the on-load interruption process. Therefore, the circuit breaker's ability to interrupt short-circuit and overload currents is significantly affected by the trip device. The rapid response and tripping reliability of the trip device significantly impact the circuit breaker's breaking capacity, safety, and the safe operation of the entire power supply system. The trip device's response time and tripping reliability are important indicators for evaluating circuit breaker performance.

[0003] To ensure reliable on-load tripping, circuit breakers are equipped with a variety of trip devices, including shunt trips, indirect trips, undervoltage trips, and overload trips, utilizing different operating principles. These devices improve or guarantee their response time and tripping reliability. However, existing trip devices cannot meet the demand for rapid tripping and are in urgent need of optimization and upgrade. Summary of the Invention

[0004] The purpose of this application is to provide a magnetically controlled tripping device for a circuit breaker and a method for using the same. The device is a type of indirect tripping device and is redundant for the reliable tripping function of the circuit breaker. When an external sensing device senses that the current value i or the current rise rate di / dt in the main circuit exceeds a predetermined value, the external control circuit of the coil in the tripping device is triggered. The device uses the electromagnetic force generated by the electromagnetic principle and the force conversion using the lever principle to achieve tripping, thereby solving the problem that existing tripping devices cannot trip quickly.

[0005] The purpose of this application is achieved through the following technical solutions: A circuit breaker magnetically controlled tripping device comprises a lever, a bracket, an iron core operating rod and a magnetic control assembly. One end of the lever is a tripping action end, the middle part of the lever is rotatably arranged on the bracket, and the other end of the lever is movably connected to the iron core operating rod. The iron core operating rod pries the lever and is limited in the magnetic control assembly.

[0006] Furthermore, the tripping action end is provided with an arc action surface.

[0007] Furthermore, the other end of the lever is provided with a semicircular hole movable groove, and the ball head end of the iron core operating rod is movably arranged in the semicircular hole movable groove.

[0008] Furthermore, by adjusting the relative distance L between the ball head end and the bottom of the semicircular hole movable groove, the position of the ball head end in the semicircular hole movable groove is changed to obtain different force matching relationships.

[0009] Furthermore, the core operating rod includes a ball head end, a push rod housing and a moving iron core. The part of the push rod housing extending out of the magnetic control component is connected to the ball head end, and the part of the push rod housing located at the magnetic control component has the moving iron core built in.

[0010] Furthermore, the magnetic control assembly includes a magnetic yoke, a coil body, a permanent magnet, a magnetic conductive plate and a release spring, the core operating rod is located at the center of the magnetic yoke, the coil body is located inside the magnetic yoke, the magnetic conductive plate is opposite to the bottom end of the core operating rod, the permanent magnet is located at the bottom end of the magnetic conductive plate, and a release spring is provided between the magnetic conductive plate and the core operating rod.

[0011] Furthermore, the coil body includes an enameled wire and a coil frame, the enameled wire is wound on the coil frame, and the lead end of the enameled wire is connected to an external control circuit.

[0012] Furthermore, the top end of the coil skeleton is in contact with the magnetic yoke, and the bottom end of the coil skeleton is in contact with the magnetic conductive plate.

[0013] Furthermore, the magnetron assembly further includes an end cover, a step opening is provided at the bottom end of the magnetic yoke, the end cover is fixed at the step opening, and the permanent magnet is sandwiched between the end cover and the magnetic conductive plate.

[0014] Furthermore, the magnetic control assembly also includes a spring support, which is fixed on the magnetic conductive plate, and the release spring is sleeved on the spring support.

[0015] Furthermore, the stop end surface of the magnetic yoke and the stop end surface of the core operating rod are tapered end surfaces that match each other.

[0016] A method for using a magnetically controlled tripping device for a circuit breaker, using the magnetically controlled tripping device for a circuit breaker; Tripping operation: When the external sensing device detects that the current value i or the current rise rate di / dt in the main circuit exceeds a predetermined value, the external control circuit causes a positive current to flow into the coil body, weakening the electromagnetic holding force on the iron core operating rod. The iron core operating rod is pushed upward by the elastic force of the tripping spring, driving the tripping end of the lever to descend, thus performing the tripping operation; Reset operation: When the tripping action is completed, the external control circuit causes reverse current to flow into the coil body. The iron core operating rod is subjected to a downward electromagnetic force. The iron core operating rod moves downward under the action of the tripping spring, driving the tripping end of one end of the lever to rise. After the magnetic plate and the moving iron core are in contact, the external control circuit cuts off the power to the coil body.

[0017] Beneficial effects of this application: (1) When an overload or short-circuit current is detected in the main circuit, the device can respond quickly and trip quickly to protect the safety of equipment and personnel.

[0018] (2) The device uses the magnetic control principle combined with the lever principle to trip the circuit breaker. It has a simple structure, easy installation, few mechanical parts, small wear, long service life and high reliability.

[0019] (3) Use an external control circuit to perform short-term control on the coil of the device to achieve tripping and resetting operations.

[0020] (4) During the installation process, the relative position of the ball head end of the iron core operating rod and the semicircular hole movable groove of the lever can be adjusted to obtain different position and force matching relationships to meet the use of different types of circuit breakers.

[0021] The aforementioned main solution and its various further options can be freely combined to form multiple solutions, all of which are solutions that can be adopted and protected by this application. Furthermore, in this application, (non-conflicting options) can also be freely combined with each other and with other options. After understanding the solution of this application, those skilled in the art will understand that there are many combinations based on existing technology and common knowledge, all of which are technical solutions to be protected by this application, and these are not exhaustive here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the usage status of this application.

[0023] Figure 2 It is a cross-sectional view of the structure of this application (untripped state).

[0024] Figure 3 It is a cross-sectional view of the structure of this application (tripped state).

[0025] Figure 4 It is the structural appearance diagram of this application.

[0026] Figure 5 It is a structural diagram of the lever of this application.

[0027] Figure 6 It is a structural diagram of the iron core operating rod of this application.

[0028] In the figure: 1. Lever; 2. Bracket; 3. Iron core operating rod; 4. Magnetic yoke; 5. Coil body; 6. End cover; 7. Permanent magnet; 8. Magnetic plate; 9. Spring support; 10. Trip spring; 11. Arc action surface; 12. Semicircular hole movable groove; 31. Ball head end; 32. Push rod housing; 33. Moving iron core; 41. U-shaped groove; 51. Coil skeleton; 111. Shift fork; 112. Moving contact assembly; 113. Static contact assembly. DETAILED DESCRIPTION

[0029] The following non-limiting examples illustrate the present application.

[0030] Example 1 refer to Figures 1 to 6 As shown, a magnetically controlled tripping device for a circuit breaker includes a lever 1, a bracket 2, an iron core operating rod 3 and a magnetic control assembly.

[0031] refer to Figure 1 As shown, the left half of the figure is a schematic diagram of the operating conditions of the circuit breaker's magnetically controlled tripping device. In the diagram, the shift fork 111, through the action of the electromagnetic drive mechanism, causes the moving contact in the moving contact assembly 112 to contact the static contact in the static contact assembly 113, completing the circuit breaker closing operation. When the front end of the shift fork 111 is subjected to the downward force exerted by the lever 1, causing it to move downward to complete the tripping operation, the action of the closing energy storage spring causes the moving contact to separate from the static contact, resulting in the disconnection operation. The entire process, in which the shift fork 111 is forced downward to complete the tripping operation, is the tripping phenomenon.

[0032] One end of lever 1 is the tripping end, which directly contacts and presses against the tripping end to achieve the specific tripping action. The middle portion of lever 1 is pivotally mounted on bracket 2, allowing lever 1 to rotate relative to bracket 2. The other end of lever 1 is movably connected to the core operating rod 3. Changing the position of the core operating rod 3 causes the tripping end of lever 1 to swing up and down by acting on the other end of lever 1.

[0033] When the core operating rod 3 pries lever 1 and is trapped within the magnetic control assembly, the changes in the magnetic field within the magnetic control assembly exert an upward or downward force on the core operating rod 3. Upward movement of the core operating rod 3 pushes the tripping end downward, triggering the tripping action. Downward movement of the core operating rod 3 raises the tripping end, releasing the tripping action and resetting the device. Under normal conditions, the core operating rod 3 remains in a low position, and lever 1 remains in a ready-to-trip position.

[0034] The tripping action end of the lever 1 is provided with an arc action surface 11, which is beneficial to reducing the friction between the contact surface of the lever 1 and the shift fork 111, avoiding tripping stress concentration, reducing sticking, and improving service life and stability.

[0035] refer to Figure 3 and Figure 4The other end of the lever 1 is provided with a semicircular movable groove 12. The cross-section of the semicircular movable groove 12 is semicircular, and a notch is opened on the side of the groove for the core operating rod 3 to pass through. The ball end 31 of the core operating rod 3 is movably arranged in the semicircular movable groove 12. When the core operating rod 3 remains in the unreleased state, the lower part of the ball end 31 of the core operating rod 3 contacts and limits the position of the semicircular movable groove 12; when the core operating rod 3 moves upward, the upper part of the ball end 31 contacts the top of the semicircular movable groove 12, and as the lever 1 rotates, the contact point slides; when the core operating rod 3 moves downward, the lower part of the ball end 31 contacts the notch of the semicircular movable groove 12, and as the lever 1 rotates, the contact point slides.

[0036] The contact area between the ball end 31 and the semicircular movable groove 12 creates low friction, and the downward release movement of the lever 1 is limited, ensuring a release clearance H between the lever 1 and the shift fork 111 to prevent accidental contact. A certain gap δ is also designed above the ball end 31 and the semicircular movable groove 12, ensuring that the core operating rod 3 has idle travel during its initial movement.

[0037] The distance between the lever 1 and the fork 111 is H, and the relative position distance between the ball end 31 of the iron core operating rod 3 and the semicircular hole movable groove 12 of the lever 1 is L. When H and the preload force generated by the tripping spring 10 on the iron core operating rod 3 are constant, according to the lever principle, F1L1=F2L2, F1 is the impact force generated by the iron core operating rod 3 on the lever 1, which is positively correlated with the preload force generated by the tripping spring 10 on the iron core operating rod 3, L1 is the distance from the ball end 31 of the iron core operating rod 3 to the bracket 2, and this distance includes L, F2 is the tripping force generated by one end of the lever 1 on the fork 111, L2 is the distance from one end of the lever 1 to the bracket 2, and the tripping force motion stroke generated by one end of the lever 1 is determined by H, so the magnitude of the tripping force is related to L, and the larger L is, the greater the tripping force is. By adjusting the relative distance L between the ball end 31 and the bottom of the semicircular hole movable groove 12 and changing the different positions of the ball end 31 in the semicircular hole movable groove 12, the magnitude of the tripping force can be adjusted to match the force value when the shift fork 111 in different types of circuit breakers is released.

[0038] The core operating rod 3 comprises a ball end 31, a push rod housing 32, and a movable iron core 33. The portion of the push rod housing 32 extending from the magnetic control assembly is integrally connected to the ball end 31, enabling a movable connection between the core operating rod 3 and the lever 1. The portion of the push rod housing 32 located within the magnetic control assembly houses a movable iron core 33. The magnetic force of the magnetic control assembly acts on the movable iron core 33, achieving magnetically controlled lifting and lowering.

[0039] The magnetron assembly includes a yoke 4, a coil body 5, an end cap 6, a permanent magnet 7, a magnetic plate 8, a spring support 9, and a release spring 10. The yoke 4, end cap 6, and magnetic plate 8 are all made of ferromagnetic material to ensure a stable magnetic circuit and magnetic field. The yoke 4 and end cap 6 are coated with insulating varnish, and the lever 1 is made of a non-metallic material to prevent any inherent electrical conductivity or leakage that could affect the device's operation.

[0040] The iron core operating rod 3 is located at the center of the magnetic yoke 4 and is arranged in a sleeve manner. The coil body 5 is located inside the magnetic yoke 4. The magnetic conductive plate 8 is opposite to the bottom end of the iron core operating rod 3. The permanent magnet 7 is located at the bottom end of the magnetic conductive plate 8. A release spring 10 is provided between the magnetic conductive plate 8 and the iron core operating rod 3.

[0041] In the initial state, the magnetic field causes the moving component, iron core operating rod 3, to contact magnetic plate 8. In the tripping state, a forward current flows through coil body 5, weakening the magnetic flux loop. The action of trip spring 10 causes iron core operating rod 3 to disengage from magnetic plate 8, simultaneously driving lever 1 in motion. In the reset state, a reverse current flows through coil body 5, increasing the magnetic flux loop. The iron core operating rod 3, overcoming the action of trip spring 10, contacts magnetic plate 8 and simultaneously drives lever 1 in motion.

[0042] The coil body 5 comprises enameled wire and a coil bobbin 51. The enameled wire is wound around the coil bobbin 51. A ring groove is defined within the yoke 4 to house the coil bobbin 51. The top of the coil bobbin 51 abuts the yoke 4, while the bottom of the coil bobbin 51 is abutted by the magnetic plate 8, securing the coil bobbin 51 within the yoke 4. A U-shaped groove 41 is defined at the end of the yoke 4, near the coil body 5, to connect the enameled wire lead end to the external control circuit.

[0043] The bottom end of the yoke 4 is provided with a stepped opening, to which the end cap 6 is fixed by riveting. The permanent magnet 7 is sandwiched between the end cap 6 and the magnetic plate 8. That is, the end cap 6 abuts and limits the permanent magnet 7, which in turn abuts and limits the magnetic plate 8, which in turn abuts and limits the coil bobbin 51.

[0044] The spring support 9 is fixed to the magnetic plate 8, and the trip spring 10 is mounted on the spring support 9. The spring support 9 provides guidance and position limiting for the trip spring 10, and the spring support 9 does not move upward with the operating rod. In the initial state, the trip spring 10 is in a pre-compressed state. In the actuated state, the trip spring 10 releases the stored energy, pushing the core operating rod 3 upward.

[0045] The stop end face of the yoke 4 and the stop end face of the core operating rod 3 are conical end faces that match each other. Specifically, the relative end face angles of the core operating rod 3 and the yoke 4 are α and β respectively, and α=β. The purpose is to enable the core operating rod 3 to automatically align during movement, reduce deviation and jamming, and ensure the accuracy and reliability of the movement.

[0046] The advantages of this tripping device are: when an overload or short-circuit current is detected in the main circuit, it can respond quickly and trip quickly to protect the safety of equipment and personnel; the device uses the magnetic control principle and the lever principle to trip the circuit breaker, with a simple structure, easy installation, few mechanical parts, low wear, long service life and high reliability; an external control circuit is used to control the coil of the device for a short time to achieve tripping and resetting operations; during the installation process, the relative position of the ball head end of the operating rod and the semicircular hole movable groove of the lever can be adjusted to obtain different position and force matching relationships to meet the use of different models of circuit breakers.

[0047] Example 2 refer to Figures 1 to 6 As shown, a method for using a magnetically controlled tripping device of a circuit breaker adopts the magnetically controlled tripping device of embodiment 1.

[0048] refer to Figure 1 As shown, the left half of the figure is a schematic diagram of the operating conditions of the circuit breaker's magnetically controlled tripping device. In the diagram, the shift fork 111, through the action of the electromagnetic drive mechanism, causes the moving contact in the moving contact assembly 112 to contact the static contact in the static contact assembly 113, completing the circuit breaker closing operation. When the front end of the shift fork 111 is subjected to the downward force exerted by the lever 1, causing it to move downward to complete the tripping operation, the action of the closing energy storage spring causes the moving contact to separate from the static contact, resulting in the disconnection operation. The entire process, in which the shift fork 111 is forced downward to complete the tripping operation, is the tripping phenomenon.

[0049] In the initial state: the force and movement of the lever 1 on the fork 111 are generated by the lever principle through the movement of the iron core operating rod 3. In the initial state, the position of the lever 1 is as follows: Figure 2 As shown, the magnetic field generated by the permanent magnet 7 forms a magnetic circuit on the yoke 4, the end cover 6, the magnetic conductive plate 8, and the moving iron core 33, so that the iron core operating rod 3 is subjected to a downward electromagnetic attraction. This electromagnetic attraction overcomes the pressure of the trip spring 10 on the iron core operating rod 3, causing the trip spring 10 to be pre-compressed and store energy.

[0050] refer to Figure 3As shown, the tripping operation: When the external sensing device detects that the current value i or the current rise rate di / dt in the main circuit exceeds a predetermined value, the external control circuit causes a short-term (0.5s) positive current to flow into the coil body 5, generating a magnetic field opposite to that of the permanent magnet 7. The electromagnetic holding force on the core operating rod 3 weakens, and the core operating rod 3 is pushed upward by the elastic force of the trip spring 10. In other words, the magnetic control assembly causes the internal core operating rod 3 to rise, driving the tripping end of the lever 1 to descend, thus performing the tripping operation. Specifically, the core operating rod 3 moves through an idle stroke δ and then contacts the lever 1, driving the lever 1 to rotate about the bracket 2, causing the left side of the lever 1 to move downward until it contacts the shift fork 111. The lever 1 continues to move downward until the shift fork 111 completes the tripping, separating the moving contact of the moving contact assembly 112 from the stationary contact of the stationary contact assembly 113. The lever 1 eventually stops due to the inherent travel S of the core operating rod 3.

[0051] Reset operation: After the tripping action is completed, the external control circuit causes a short-time (0.5s) reverse current to flow into the coil body 5, generating the same magnetic field as the permanent magnet 7, increasing the magnetic flux density of the magnetic circuit, and the iron core operating rod 3 is subjected to a downward electromagnetic force. The iron core operating rod 3 moves downward under the action of overcoming the tripping spring 10, driving the tripping action end of one end of the lever 1 to rise. After the magnetic conductive plate 8 is in contact with the moving iron core 33, the external control circuit cuts off the power to the coil body 5, completing the reset operation.

[0052] The aforementioned basic examples and their further selected examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed for protection in this application. In this application, each selected example can be arbitrarily combined with any other basic examples and selected examples.

[0053] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A magnetically controlled tripping device for a circuit breaker, comprising a lever (1), characterized in that: The invention also includes a bracket (2), an iron core operating rod (3) and a magnetic control assembly. One end of the lever (1) is a tripping end. The middle part of the lever (1) is rotatably arranged on the bracket (2). The other end of the lever (1) is movably connected to the iron core operating rod (3). The iron core operating rod (3) pries the lever (1) and is limited in the magnetic control assembly.

2. The magnetically controlled tripping device for circuit breaker according to claim 1, characterized in that: The tripping action end is provided with an arc action surface (11); the other end of the lever (1) is provided with a semicircular hole movable groove (12), and the ball head end (31) of the iron core operating rod (3) is movably arranged in the semicircular hole movable groove (12).

3. The magnetically controlled tripping device for circuit breaker according to claim 2, characterized in that: By adjusting the relative distance L between the ball head end (31) and the bottom of the semicircular hole movable groove (12), the position of the ball head end (31) in the semicircular hole movable groove (12) is changed to obtain different force matching relationships.

4. The magnetically controlled tripping device for circuit breaker according to claim 1, characterized in that: The iron core operating rod (3) comprises a ball end (31), a push rod housing (32) and a moving iron core (33); the part of the push rod housing (32) extending out of the magnetic control component is connected to the ball end (31); the part of the push rod housing (32) located in the magnetic control component has the moving iron core (33) built in.

5. The magnetically controlled tripping device for circuit breaker according to claim 4, characterized in that: The magnetic control assembly comprises a magnetic yoke (4), a coil body (5), a permanent magnet (7), a magnetic conductive plate (8) and a release spring (10), the core operating rod (3) is located at the center of the magnetic yoke (4), the coil body (5) is located inside the magnetic yoke (4), the magnetic conductive plate (8) is opposite to the bottom end of the core operating rod (3), the permanent magnet (7) is located at the bottom end of the magnetic conductive plate (8), and a release spring (10) is provided between the magnetic conductive plate (8) and the core operating rod (3).

6. The magnetically controlled tripping device for circuit breaker according to claim 5, characterized in that: The magnetic control assembly further comprises a spring support (9), the spring support (9) is fixed on the magnetic conductive plate (8), and the release spring (10) is sleeved on the spring support (9).

7. The magnetically controlled tripping device for circuit breaker according to claim 5, characterized in that: The stop end surface of the magnetic yoke (4) and the stop end surface of the iron core operating rod (3) are conical end surfaces that match each other.

8. A method for using a magnetically controlled tripping device of a circuit breaker, characterized in that: The circuit breaker magnetically controlled tripping device according to claim 6 is adopted; Tripping operation: When the external sensing device detects that the current value i or the current rise rate di / dt in the main circuit exceeds a predetermined value, the external control circuit causes the coil body (5) to flow with a positive current, the electromagnetic holding force on the iron core operating rod (3) is weakened, and the iron core operating rod (3) is pushed upward by the elastic force of the tripping spring (10), driving the tripping end of one end of the lever (1) to descend, thereby performing the tripping operation; Reset operation: When the tripping action is completed, the external control circuit causes the reverse current to flow into the coil body (5), and the iron core operating rod (3) is subjected to a downward electromagnetic force. The iron core operating rod (3) moves downward under the action of the tripping spring (10), driving the tripping end of one end of the lever (1) to rise. After the magnetic plate (8) and the moving iron core (33) are in contact, the external control circuit cuts off the power to the coil body (5).

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