A miniature circuit breaker

Abstract

A miniature circuit breaker comprises a middle casing and side covers fixedly connected to both sides of the middle casing respectively, the projected area of the middle casing on a plane perpendicular to the mounting direction of the side covers is smaller than the projected area of the side covers on the plane; the bottom of the side cover extends away from the middle casing, thereby forming a mounting space for accommodating a circuit board between the bottom of the middle casing and the two side covers; the region where the minimum dimension of the middle casing in the height direction is located is set as a thermal tripping region for accommodating a thermal element. The mounting space formed by the middle casing and the side covers is used to accommodate the circuit board, the conventional functions of the circuit breaker are concentrated in the middle casing, and the thermal tripping mechanism is arranged in a smaller space, thereby leaving a larger circuit board mounting space while ensuring the normal arrangement of the thermal tripping mechanism without changing the size of the miniature circuit breaker.

Description

Technical Field

[0001] This utility model relates to the field of low-voltage electrical technology, specifically to a miniature circuit breaker. Background Technology

[0002] A miniature circuit breaker is a switching device capable of closing, carrying, and interrupting current under normal circuit conditions and, within a specified time, closing, carrying, and interrupting current under abnormal circuit conditions. It is used to prevent accidents caused by equipment overload or short circuit. Circuit breakers can be operated manually or automatically disconnect when the current change exceeds a predetermined value.

[0003] Due to the limited internal space of miniature circuit breakers, integrating more functions within that limited space is a development trend in miniature circuit breakers. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a miniature circuit breaker.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A miniature circuit breaker includes a central housing and side covers fixedly connected to its two sides. The projected area of ​​the intermediate housing on a plane perpendicular to the side cover mounting direction is smaller than the projected area of ​​the side cover on that plane. The bottom of the side cover extends away from the intermediate housing, thereby forming an installation space for accommodating the circuit board by together with the two side covers on the outer side of the bottom of the intermediate housing. The maximum dimension H1 of the installation space in the height direction plus the minimum dimension H2 of the intermediate shell in the height direction equals the height dimension H of the main body of the side cover; The area containing the minimum dimension of the intermediate housing in the height direction is designated as a thermal tripping area for accommodating the thermal element.

[0006] The ratio of the maximum height dimension H1 of the installation space to the height dimension H of the main body of the side cover is between 0.4 and 0.6.

[0007] The bottom surface of the intermediate shell has two first planes and a second plane with different heights, and the two are connected by an arc surface.

[0008] The heating element is a bimetallic strip, which has a connecting part that is electrically connected to the terminal block and an actuating part for triggering the lever. The connecting part and the actuating part are connected by a bending part.

[0009] The curved section includes two parallel connecting segments and an arc-shaped segment connecting the two connecting segments at the same end.

[0010] The thermal tripping area is also provided with a support plate covering the area. The surface of the support plate is provided with a guide groove, and a pull rod for transmitting the action of the thermal element can be slidably installed in the guide groove.

[0011] The straight section of the pull rod has a T-shaped cross-section and passes through the guide groove.

[0012] One side of the heating element is provided with an adjusting bolt, and the other side of the heating element is provided with a spring, the other end of which is in contact with the arc-inducing plate.

[0013] The bottom of the thermal release area is provided with a mounting groove, and the spring is placed in the mounting groove.

[0014] The beneficial effects of this utility model are as follows: This application utilizes the installation space formed by the intermediate housing and the side cover to accommodate the circuit board, concentrates the conventional functions of the circuit breaker in the intermediate housing, and uses a smaller space to set up the thermal trip mechanism. While ensuring that the size of the miniature circuit breaker remains unchanged, it can provide a larger installation space for the circuit board, and at the same time ensure the normal setting of the thermal trip mechanism. Attached Figure Description

[0015] Figure 1 This is the front view of the present invention.

[0016] Figure 2 This is a schematic diagram of the internal structure of this utility model.

[0017] Figure 3 This is an internal schematic diagram of the present invention (hidden support plate).

[0018] Figure 4 This is a schematic diagram of the structure of the pull rod of this utility model. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0021] like Figure 1 and Figure 2As shown, this utility model discloses a miniature circuit breaker, which includes a middle housing 100 and side covers 200 fixedly connected to its two sides respectively. A corresponding space is formed between the middle housing and the side covers, which is mainly used to place the operating mechanism, the arc extinguishing mechanism and other mechanisms.

[0022] The projected area of ​​the intermediate housing 100 on a plane perpendicular to the installation direction of the side cover 200 is smaller than the projected area of ​​the side cover 200 on that plane. The bottom of the side cover 200 extends away from the intermediate housing 100, thereby forming an installation space 210 for accommodating the circuit board by enclosing the bottom outer side of the intermediate housing 100 and the two side covers 200. The width of the installation space formed by the side cover and the outer side of the intermediate housing is the same as the width of the circuit breaker, thus leaving a larger space for conventional pin-type components, thereby improving the reliability of the control circuit board and reducing costs.

[0023] The maximum dimension H1 of the installation space 210 in the height direction plus the minimum dimension H2 of the intermediate shell 100 in the height direction equals the height dimension H of the main body of the side cover 200, as shown in the figure. Figure 1 As shown, the area where the minimum dimension of the intermediate housing 100 is located in the height direction is set as the thermal tripping area 130 for accommodating the thermal element. In this embodiment, the height dimensions of the two spaces are close, the lower mounting space is used to accommodate the main body of the circuit board, and the upper intermediate housing is used to place the thermal element.

[0024] The ratio of the maximum height dimension H1 of the installation space 210 to the height dimension H of the main body of the side cover 200 is between 0.4 and 0.6, mainly to ensure that the bottom space is large enough to accommodate the circuit board.

[0025] The bottom surface of the intermediate housing 100 has two first planes 110 and second planes 120 with different heights, and the two are connected by an arc surface. A narrow space is formed between the first plane and the bottom of the side cover, while a larger space is formed between the second plane and the bottom of the side cover. At the same time, the arc surface connection between the two is just right to match the arc-starting plate of the arc-extinguishing chamber. Meanwhile, the circuit board can deform and extend along the installation space, so that the circuit board can be adapted to the entire installation space.

[0026] like Figure 3As shown, the heating element is a bimetallic strip 500. The bimetallic strip 500 has a connecting part 510 electrically connected to the terminal block and an actuating part 520 for triggering the pull rod. The connecting part 510 and the actuating part 520 are connected by a bending part 530. Both ends of the pull rod are provided with hooks. One end of the hook engages with the bimetallic strip, and the other end engages with the release lever of the operating mechanism. Thus, the bimetallic strip can be used to drive the pull rod to actuate, causing the operating mechanism to release.

[0027] The space between the two ends of the intermediate housing and the side cover forms a space for placing the wiring terminals, which is more convenient during overall installation. A small space is used to place the heating element, which can directly contact the terminal block of the wiring terminal on one side. In order to improve the deformation capacity of the heating element so that it can drive the tripping mechanism, a bending section is used to increase the deformation capacity. The bending section 530 includes two parallel connecting sections and an arc-shaped section connecting the two connecting sections at the same end, and the bending section is used to increase the elastic deformation force.

[0028] The thermal tripping area 130 is also provided with a support plate 300 covering the area. The surface of the support plate 300 is provided with a guide groove 310. A pull rod 400 for transmitting the action of the thermal element is slidably disposed in the guide groove 310. The support plate directly covers the thermal tripping area and at the same time supports the pull rod. The pull rod can slide relative to the guide groove, that is, it slides relative to the guide groove under the action of the thermal element and the tripping rod.

[0029] like Figure 4 As shown, in order to fix the pull rod, the straight segment 410 of the pull rod 400 has a T-shaped cross-section and passes through the guide groove 310. After the pull rod passes through the guide groove, the end of its straight segment is restricted by the support plate. At the same time, when the other side cover is engaged with the intermediate housing, the pull rod can be restricted and can move as much as possible relative to the length direction of the guide groove.

[0030] One side of the heating element is provided with an adjusting bolt 600, and the other side of the heating element is provided with a spring 700. The other end of the spring 700 is in contact with the arc-inducing plate 800. The spring can be used as a conductive element and can also cooperate with the adjusting bolt to realize the adjustment of the heating element. This directly realizes the multiple functions of the spring and eliminates the need for wiring of the connecting bimetallic strip in conventional circuit breakers.

[0031] The bottom of the thermal release area 130 is provided with a mounting groove, and the spring is placed in the mounting groove. The mounting groove is used to limit the straightness of the spring, ensuring that the spring is always connected to the bimetallic strip and the arc-guiding plate. In order to ensure the centering of the spring, reinforcing ribs can also be provided on the wall of the mounting groove so that the spring can be aligned with the center position of the arc-guiding plate and the bimetallic strip.

[0032] The miniature circuit breaker provided in this embodiment is a 1P. It can also be used in multi-P circuit breakers, where multiple intermediate housings are used to achieve the multi-P design.

[0033] The embodiments should not be regarded as limitations on the present invention, but any improvements made based on the spirit of the present invention should be within the protection scope of the present invention.

Claims

1. A miniature circuit breaker, characterized in that: It includes an intermediate housing (100) and side covers (200) fixedly connected to its two sides respectively. The projected area of ​​the intermediate housing (100) on a plane perpendicular to the mounting direction of the side cover (200) is smaller than the projected area of ​​the side cover (200) on that plane; The bottom of the side cover (200) extends away from the intermediate housing (100), thereby forming an installation space (210) for accommodating the circuit board between the bottom outer side of the intermediate housing (100) and the two side covers (200). The maximum dimension H1 of the installation space (210) in the height direction plus the minimum dimension H2 of the intermediate shell (100) in the height direction equals the height dimension H of the main body of the side cover (200); The area where the minimum dimension of the intermediate housing (100) is located in the height direction is set as a thermal tripping area (130) for accommodating the thermal element.

2. The miniature circuit breaker according to claim 1, characterized in that: The ratio of the maximum height dimension H1 of the installation space (210) to the height dimension H of the main body of the side cover (200) is between 0.4 and 0.

6.

3. A miniature circuit breaker according to claim 1 or 2, characterized in that: The bottom surface of the intermediate shell (100) has two first planes (110) and second planes (120) with different heights, and the two are connected by an arc surface.

4. A miniature circuit breaker according to claim 1, characterized in that: The heating element is a double metal plate (500), which has a connecting part (510) electrically connected to the terminal block and an actuating part (520) for triggering the lever. The connecting part (510) and the actuating part (520) are connected by a bending part (530).

5. A miniature circuit breaker according to claim 4, characterized in that: The curved portion (530) includes two parallel connecting segments and an arc-shaped segment connecting the two connecting segments at the same end.

6. A miniature circuit breaker according to claim 1, characterized in that: The thermal tripping area (130) is also provided with a support plate (300) covering the area. The surface of the support plate (300) is provided with a guide groove (310). A pull rod (400) for transmitting the action of the thermal element is slidably provided in the guide groove (310).

7. A miniature circuit breaker according to claim 6, characterized in that: The straight section (410) of the pull rod (400) has a T-shaped cross-section and is disposed through the guide groove (310).

8. A miniature circuit breaker according to claim 1, characterized in that: One side of the heating element is provided with an adjusting bolt (600), and the other side of the heating element is provided with a spring (700). The other end of the spring (700) is in contact with the arc-inducing plate (800).

9. A miniature circuit breaker according to claim 8, characterized in that: The bottom of the thermal tripping area (130) is provided with a mounting groove, and the spring is placed in the mounting groove.

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