Short-circuit protection mechanism for a miniature circuit breaker
By using a skeleton-limited moving iron core in the short-circuit protection mechanism of a miniature circuit breaker, the assembly process is simplified, the problem of complex connection between the push rod and the moving iron core is solved, and efficient assembly and stable operation are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI YONGJI ELECTRICAL HLDG
- Filing Date
- 2025-07-25
- Publication Date
- 2026-07-31
AI Technical Summary
The existing short-circuit protection mechanism of miniature circuit breakers has a complex connection process between the push rod and the moving iron core during assembly, resulting in high assembly difficulty and low efficiency.
A frame is used to limit the movement of the iron core. By installing the frame on the magnetic yoke and setting a limiting groove on the frame, the connection steps between the push rod and the iron core are simplified. The frame provides a stable limiting space and reduces the assembly difficulty.
It improves assembly efficiency, reduces assembly difficulty, ensures that the moving iron core does not come out, and guarantees assembly quality and response speed.
Smart Images
Figure CN224582232U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of circuit breaker technology, and in particular to a short-circuit protection mechanism for a miniature circuit breaker. Background Technology
[0002] When a short circuit occurs, the current in the coil of the short circuit protection mechanism increases sharply, causing the magnetic field strength around the coil to increase rapidly. The stationary iron core is thus magnetized and generates a magnetic field, which attracts the moving iron core to extend the push rod and push the tripping mechanism of the miniature circuit breaker to act, causing the moving and stationary contacts of the miniature circuit breaker to separate, completing the circuit disconnection and realizing short circuit protection.
[0003] After the short circuit fault is cleared, the moving iron core and the push rod will be reset by the spring. In order to prevent the moving iron core from falling out of the short circuit protection mechanism, the moving iron core needs to be connected to the push rod that is limited in the short circuit protection mechanism. This results in an additional step of precise assembly of the push rod and the moving iron core in the short circuit protection mechanism, which is difficult and inefficient. Utility Model Content
[0004] To solve the above-mentioned technical problems, this utility model provides a short-circuit protection mechanism for a miniature circuit breaker that is easy to assemble and has high assembly efficiency.
[0005] The present invention adopts the following technical solution:
[0006] This utility model provides a short-circuit protection mechanism for a miniature circuit breaker, including a magnetic yoke, a frame, a moving iron core, a stationary iron core, a push rod, a spring, and a coil. The frame is mounted on the magnetic yoke and has a through mounting hole along the axis. One end of the mounting hole extends radially into a limiting groove. The moving iron core slides through the mounting hole and abuts against the limiting groove. The stationary iron core is fixed to the end of the mounting hole away from the limiting groove. One end of the push rod abuts against the moving iron core, and the other end of the push rod passes through the stationary iron core and can extend out of the stationary iron core. The spring is housed in the stationary iron core and can simultaneously abut against the push rod and the stationary iron core axially. The coil is wound on the outer circumferential surface of the frame.
[0007] Preferably, the magnetic yoke includes a base plate and side plates, with the two side plates spaced apart and vertically fixed to the base plate to form a U-shaped structure, and the frame located within the U-shaped structure and simultaneously vertically connected to the two side plates.
[0008] Preferably, a baffle is fixedly connected to the outer peripheral surface of the frame, the baffle is positioned close to the limiting groove, the portion of the stationary iron core that protrudes from the mounting hole is fixedly connected to a limiting plate, the end of the frame where the limiting groove is located overlaps a side plate and is attached to the side plate through the baffle, the portion of the stationary iron core that protrudes from the mounting hole overlaps another side plate and is attached to the side plate through the limiting plate, and the limiting plate is also attached to the frame.
[0009] Preferably, the end face of the moving iron core facing the push rod is recessed to form an abutment groove, and the end face of the push rod facing the moving iron core is convex to form a spherical end, which cooperates with the abutment groove.
[0010] Preferably, the stationary iron core is axially connected to form a receiving hole and a through hole. The diameter of the receiving hole is larger than the diameter of the through hole. One end of the push rod facing the stationary iron core passes through the receiving hole and is located in the through hole. The spring is sleeved on the push rod and is received in the receiving hole. One end of the spring abuts axially with the push rod, and the other end of the spring abuts axially with the stationary iron core.
[0011] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0012] The short-circuit protection mechanism of this miniature circuit breaker generates an induced magnetic field at the stationary iron core when the current in the coil increases. This magnetic field attracts the moving iron core, which in turn extends the push rod to activate the tripping mechanism of the miniature circuit breaker, separating the moving and stationary contacts and disconnecting the circuit, thus achieving short-circuit protection. After the short-circuit fault is cleared, the spring inside the stationary iron core pushes the push rod back to its original position, and the attracted moving iron core also resets under the action of the push rod. Furthermore, due to the presence of the upper limit slot in the frame, the moving iron core will not detach from the mounting hole of the frame. Clearly, the short-circuit protection mechanism of this miniature circuit breaker can operate normally and ensure that the moving iron core does not detach.
[0013] In particular, because a frame is used to limit the movement of the iron core, the assembly process can reduce the step of connecting the push rod to the iron core, thus improving assembly efficiency. Furthermore, since the frame is mounted on the magnetic yoke, its shape and position are relatively fixed, providing a relatively stable limiting space for the iron core. This reduces assembly difficulty and minimizes the impact of push rod position deviation on the iron core during assembly, ensuring assembly quality. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the overall structure of the short-circuit protection mechanism of the miniature circuit breaker in this embodiment of the present invention.
[0015] Figure 2 This is a cross-sectional view of the short-circuit protection mechanism of a miniature circuit breaker in an embodiment of this utility model.
[0016] Figure 3 This is a cross-sectional view of the short-circuit protection mechanism of a miniature circuit breaker after removing the top rod and spring, according to an embodiment of this utility model.
[0017] Figure 4 This is a schematic diagram of the structure of the magnetic yoke on the short-circuit protection mechanism of the miniature circuit breaker in an embodiment of this utility model.
[0018] Figure 5This is a schematic diagram of the upper frame structure of the short-circuit protection mechanism of the miniature circuit breaker in this embodiment of the present invention.
[0019] The reference numerals in the attached figures are explained as follows:
[0020] 1. Magnetic yoke; 4. Static iron core
[0021] 101, base plate 401, limit plate
[0022] 102, Side plate 402, Accommodation hole
[0023] 2. Skeleton 403, Extrusion Hole
[0024] 201, Mounting Hole 5, Top Rod
[0025] 202, Limiting groove 501, Spherical end
[0026] 203, baffle plate 6, spring
[0027] 3. Moving iron core; 7. Coil
[0028] 301. Abutment groove Detailed Implementation
[0029] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. These embodiments are only used to illustrate this utility model and are not intended to limit it.
[0030] In the description of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0032] Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0033] See Figure 1 and Figure 2 This embodiment provides a short-circuit protection mechanism for a miniature circuit breaker, including a magnetic yoke 1, a frame 2, a moving iron core 3, a stationary iron core 4, a push rod 5, a spring 6, and a coil 7. The frame 2 is mounted on the magnetic yoke 1. The frame 2 has a mounting hole 201 that runs through the axis. One end of the mounting hole 201 extends radially into a limiting groove 202. The moving iron core 3 slides through the mounting hole 201 and abuts against the limiting groove 202. The stationary iron core 4 is fixed to the end of the mounting hole 201 away from the limiting groove 202. One end of the push rod 5 abuts against the moving iron core 3. The other end of the push rod 5 passes through the stationary iron core 4 and can pass out of the stationary iron core 4. The spring 6 is housed in the stationary iron core 4 and can simultaneously abut against the push rod 5 and the stationary iron core 4 axially. The coil 7 is wound around the outer circumferential surface of the frame 2.
[0034] In this embodiment, the short-circuit protection mechanism of the miniature circuit breaker generates an induced magnetic field at the stationary iron core 4 after the current in the coil 7 increases. This magnetic field attracts the moving iron core 3, causing the push rod 5 to extend and activate the tripping mechanism of the miniature circuit breaker. This separates the moving and stationary contacts, completing the circuit disconnection and achieving short-circuit protection. After the short-circuit fault is cleared, the spring 6 inside the stationary iron core 4 pushes the push rod 5 back to its original position. The attracted moving iron core 3 also resets under the action of the push rod 5. Furthermore, due to the presence of the upper limit slot 202 in the frame 2, the moving iron core 3 will not dislodge from the mounting hole 201 of the frame 2. Obviously, the short-circuit protection mechanism of the miniature circuit breaker in this embodiment can work normally and ensure that the moving iron core 3 does not dislodge.
[0035] In particular, since the frame 2 is used to limit the moving iron core 3, the step of connecting the push rod 5 to the moving iron core 3 can be reduced during the assembly process, thus improving the assembly efficiency. Furthermore, since the frame 2 is installed on the magnetic yoke 1, the shape and position of the frame 2 are relatively fixed, which can provide a relatively stable limiting space for the moving iron core 3, reduce the assembly difficulty and reduce the impact on the moving iron core 3 caused by the position deviation of the push rod 5 during assembly, thus ensuring the assembly quality.
[0036] Preferably, see Figure 2 and Figure 4 The magnetic yoke 1 includes a base plate 101 and a side plate 102. The two side plates 102 are spaced apart and vertically fixed to the base plate 101 to form a U-shaped structure. The frame 2 is located inside the U-shaped structure and is vertically connected to both side plates 102 at the same time.
[0037] Preferably, see Figure 2 and Figure 5A baffle 203 is fixedly inserted into the outer circumferential surface of the frame 2. The baffle 203 is positioned near the limiting groove 202. The portion of the stationary iron core 4 that protrudes from the mounting hole 201 is fixedly inserted into the limiting plate 401. The end of the frame 2 with the limiting groove 202 overlaps with a side plate 102 and is fitted to the side plate 102 through the baffle 203. The portion of the stationary iron core 4 that protrudes from the mounting hole 201 overlaps with another side plate 102 and is fitted to the side plate 102 through the limiting plate 401, which is also fitted to the frame 2. Thus, the frame 2 can be installed on the yoke 1 and the position of the stationary iron core 4 can be fixed.
[0038] Preferably, see Figure 2 and Figure 3 The moving iron core 3 has an inwardly recessed groove 301 on the end face facing the push rod 5, and the push rod 5 has an outwardly protruding spherical end 501 on the end face facing the moving iron core 3. The spherical end 501 cooperates with the groove 301 to make the movement path of the push rod 5 in the magnetic field more ideal. When a large current passes through the coil 7, the push rod 5 can pass through faster under the drive of the moving iron core 3, thereby accelerating the tripping action and improving the response speed.
[0039] Preferably, see Figure 2 and Figure 3 The stationary iron core 4 is axially connected to form a receiving hole 402 and a through hole 403. The diameter of the receiving hole 402 is larger than the diameter of the through hole 403. One end of the push rod 5 facing the stationary iron core 4 passes through the receiving hole 402 and is located in the through hole 403. The spring 6 is sleeved on the push rod 5 and is received in the receiving hole 402. One end of the spring 6 is axially abutting against the push rod 5, and the other end of the spring 6 is axially abutting against the stationary iron core 4.
[0040] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.
Claims
1. A short-circuit protection mechanism for a miniature circuit breaker, characterized in that, The system includes a magnetic yoke (1), a frame (2), a moving iron core (3), a stationary iron core (4), a push rod (5), a spring (6), and a coil (7). The frame (2) is mounted on the magnetic yoke (1). The frame (2) has a through mounting hole (201) along its axis. One end of the mounting hole (201) extends radially into a limiting groove (202). The moving iron core (3) slides through the mounting hole (201) and abuts against the limiting groove (202). The stationary iron core (4)... The core (4) is fixed to the end of the mounting hole (201) away from the limiting groove (202). One end of the push rod (5) abuts against the moving iron core (3). The other end of the push rod (5) passes through the stationary iron core (4) and can pass out of the stationary iron core (4). The spring (6) is housed in the stationary iron core (4) and can simultaneously abut against the push rod (5) and the stationary iron core (4) axially. The coil (7) is wound around the outer circumference of the skeleton (2).
2. The short-circuit protection mechanism of the miniature circuit breaker according to claim 1, characterized in that, The magnetic yoke (1) includes a base plate (101) and side plates (102). The two side plates (102) are spaced apart and vertically fixed on the base plate (101) to form a U-shaped structure. The frame (2) is located inside the U-shaped structure and is vertically connected to both side plates (102).
3. The short-circuit protection mechanism of the miniature circuit breaker according to claim 2, characterized in that, A baffle plate (203) is fixedly connected to the outer circumferential surface of the frame (2). The baffle plate (203) is set close to the limiting groove (202). The part of the stationary iron core (4) that passes through the mounting hole (201) is fixedly connected to the limiting plate (401). The end of the frame (2) where the limiting groove (202) is located overlaps on a side plate (102) and is attached to the side plate (102) through the baffle plate (203). The part of the stationary iron core (4) that passes through the mounting hole (201) overlaps on another side plate (102) and is attached to the side plate (102) through the limiting plate (401). The limiting plate (401) is also attached to the frame (2).
4. The short-circuit protection mechanism of the miniature circuit breaker according to claim 1, characterized in that, The moving iron core (3) has an inwardly recessed groove (301) on the end face facing the push rod (5), and the push rod (5) has an outwardly protruding spherical end (501) on the end face facing the moving iron core (3), and the spherical end (501) cooperates with the groove (301).
5. The short-circuit protection mechanism of the miniature circuit breaker according to claim 1, characterized in that, The stationary iron core (4) is axially connected to form a receiving hole (402) and a through hole (403). The diameter of the receiving hole (402) is larger than the diameter of the through hole (403). One end of the push rod (5) facing the stationary iron core (4) passes through the receiving hole (402) and is located in the through hole (403). The spring (6) is sleeved on the push rod (5) and accommodated in the receiving hole (402). One end of the spring (6) abuts axially with the push rod (5), and the other end of the spring (6) abuts axially with the stationary iron core (4).