An overload protection device for a direct current fast circuit breaker

Abstract

The utility model relates to the field of direct current circuit breaker overload protection device discloses a kind of direct current quick circuit breaker overload protection device, including box, the top side of the box is connected with lid, the bottom side of the lid is fixedly connected with multiple inserting rods, the inserting rod is inserted in the top side of box, buckle assembly is arranged between the box and the lid, the bottom side of the inside of the box is fixedly connected with bottom plate, the top side of the bottom plate is fixedly connected with bimetallic strip, the right side of the inside of the box is fixedly connected with fixed plate, the right side of the fixed plate is fixedly connected with static contact, the inside of the box is provided with power-off component. In the utility model, the device can provide power-off protection more directly, and the structure is relatively simple, does not contain electronic component and does not need external device power supply, so as to reduce the maintenance intensity of staff, and the structure inside the device is maintained or replaced by staff, and the protection structure is reset.

Description

Technical Field

[0001] This utility model relates to the field of DC circuit breaker overload protection devices, and in particular to a DC fast circuit breaker overload protection device. Background Technology

[0002] DC circuit breaker overload protection devices are core protection components adapted to the characteristics of DC circuits and ensuring circuit safety, such as power supplies for communication base stations and DC equipment circuits in households. They can monitor circuit current in real time, and when the current continuously exceeds the rated value by 1.2 to 1.5 times, they trigger action based on principles such as thermal effects, cutting off the circuit within 300 milliseconds to 2 seconds to prevent equipment overheating and damage or fire.

[0003] However, the current DC circuit breaker overload protection devices have the following defects: First, some devices contain electronic components or rely on external power supply, which not only makes the structure complex, but may also fail due to electronic component failure or power interruption, increasing the maintenance intensity; Second, some devices are difficult to maintain and replace internal structures, and the reset operation is cumbersome, which does not meet the needs of staff for convenient maintenance and quick reset. In response to this technical problem, this application proposes an overload protection device for a DC fast circuit breaker. Utility Model Content

[0004] The purpose of this utility model is to address the shortcomings of existing technologies by proposing a DC fast circuit breaker overload protection device. The device aims to provide power outage protection more directly, with a simple structure, no electronic components, and no need for external power supply, thereby reducing the maintenance intensity for staff and facilitating the maintenance or replacement of the internal structure and the reset of the protection structure.

[0005] To achieve the above objectives, the present invention provides the following technical solution: An overload protection device for a DC fast circuit breaker includes a housing. A cover is connected to the top side of the housing, and multiple plugs are fixedly connected to the bottom side of the cover. The plugs are inserted into the top side of the housing. A snap-fit ​​assembly is provided between the housing and the cover to fix the cover to the housing. A base plate is fixedly connected to the bottom side of the housing, and a bimetallic strip is fixedly connected to the top side of the base plate. A fixing plate is fixedly connected to the right side of the housing, and a stationary contact is fixedly connected to the right side of the fixing plate. A power-off assembly is provided inside the housing to control the disconnection and connection of the circuit.

[0006] Furthermore, the buckle assembly includes a fixing groove fixedly connected to the left and right sides of the box cover, a locking plate is rotatably connected inside the fixing groove, and the left and right sides of the box body are fixedly connected to the locking groove.

[0007] Furthermore, the bottom side of the card plate abuts against the inside of the card slot, and a protrusion is fixedly connected to the bottom side of the card plate. The protrusion engages inside the card slot. A round rod is slidably connected to one side of the card plate, and the bottom end of the round rod is inserted into the inside of the card slot.

[0008] Furthermore, the power-off assembly includes a square plate fixedly connected to the rear side of the inside of the housing, a sliding rod slidably connected inside the square plate, and a sliding plate fixedly connected to the right end of the sliding rod.

[0009] Furthermore, a moving contact is fixedly connected to the left side of the bottom of the slide plate, the moving contact abutting against the inside of the stationary contact, a pull ring is fixedly connected to the left end of the slide rod, and a top plate is fixedly connected to the rear side inside the box.

[0010] Furthermore, a rotating plate is connected to the bottom side of the top plate via a torsion spring, a buckle post is fixedly connected to the top side of the right side of the rotating plate, the buckle post passes through the middle of the pull ring, and a push plate is fixedly connected to the bottom side of the left side of the rotating plate.

[0011] Furthermore, the left side of the top side of the bimetallic strip abuts against the right side of the push plate, and a spring is sleeved on the outer wall of the slide rod. One end of the spring is connected to the left side of the slide plate, and the other end of the spring is connected to the right side of the square plate.

[0012] Furthermore, wires are connected between the base plate and the fixing plate, and on the left side of the base plate and the right side of the slide plate. The wires on both sides pass through the box and are connected to external circuits.

[0013] This utility model has the following beneficial effects: 1. In this utility model, the bending characteristics of the bimetallic strip are used to push the push plate, which pushes the rotating plate to overcome the resistance of the torsion spring and rotate, causing the buckle post to disengage from the pull ring, thereby releasing the lock on the pull ring. Then, the spring will release the stored elastic potential energy, causing the spring to push the slide plate to slide, thereby causing the moving contact to disengage from the stationary contact, thus breaking the circuit and achieving the effect of power failure protection. This allows the device to provide power failure protection more directly, and the structure is relatively simple, without electronic components and without the need for external power supply, thereby reducing the maintenance intensity of the staff.

[0014] 2. In this utility model, by rotating the card plate so that its bottom side abuts against the inside of the card slot, the protrusion is engaged with the inside of the card slot. Then, the round rod is slid to insert into the card slot to prevent the card plate from rotating, thereby connecting the card slot and the fixing slot together, so that the box cover is fixed to the box body, making the box body easy to open, thus facilitating the staff to maintain or replace the internal structure of the device, and to reset the protective structure. Attached Figure Description

[0015] Figure 1This is a perspective view of an overload protection device for a DC fast circuit breaker proposed in this utility model; Figure 2 This is a schematic diagram of the housing structure of an overload protection device for a DC fast circuit breaker proposed in this utility model; Figure 3 This is a bottom view of the cover of a DC fast circuit breaker overload protection device proposed in this utility model; Figure 4 This is a cross-sectional view of the housing of an overload protection device for a DC fast circuit breaker proposed in this utility model; Figure 5 This is a schematic diagram of the bimetallic strip expansion state of an overload protection device for a DC fast circuit breaker proposed in this utility model; Figure 6 This is a schematic diagram of the card plate structure of an overload protection device for a DC fast circuit breaker proposed in this utility model.

[0016] Legend: 1. Enclosure; 2. Enclosure lid; 3. Wire; 4. Slot; 5. Fixing slot; 6. Top plate; 7. Square plate; 8. Slide plate; 9. Fixing plate; 10. Clamping plate; 11. Insert rod; 12. Base plate; 13. Bimetallic strip; 14. Rotating plate; 15. Push plate; 16. Snap-on post; 17. Slide rod; 18. Spring; 19. Pull ring; 20. Stationary contact; 21. Moving contact; 22. Raised strip; 23. Round rod. Detailed Implementation

[0017] 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.

[0018] Reference Figures 1-3 This utility model provides an embodiment of an overload protection device for a DC fast circuit breaker, comprising a housing 1, a cover 2 connected to the top side of the housing 1, and multiple insert rods 11 fixedly connected to the bottom side of the cover 2. The insert rods 11 are inserted into the top side of the housing 1, and the cover 2 is initially installed on the top side of the housing 1 by inserting the insert rods 11 into the top side of the housing 1. A base plate 12 is fixedly connected to the bottom side inside the housing 1, and a bimetallic strip 13 is fixedly connected to the top side of the base plate 12. The bimetallic strip 13 is made of brass and constantan composite, and its main function is to sense the overload current in the circuit and convert the heat energy generated by the current into the energy of mechanical action. A fixing plate 9 is fixedly connected to the right side inside the housing 1, and a stationary contact 20 is fixedly connected to the right side of the fixing plate 9. (Refer to...) Figure 1 and Figure 6The left and right sides of the cover 2 are fixedly connected to the fixing grooves 5. The inside of the fixing grooves 5 is rotatably connected to the locking plate 10. The left and right sides of the box body 1 are fixedly connected to the locking grooves 4. The bottom side of the locking plate 10 abuts against the inside of the locking groove 4. The bottom side of the locking plate 10 is fixedly connected to the protrusion 22, which is engaged inside the locking groove 4. A round rod 23 is slidably connected to one side of the locking plate 10. The bottom end of the round rod 23 is inserted into the inside of the locking groove 4. By rotating the locking plate 10 so that its bottom side abuts against the inside of the locking groove 4, the protrusion 22 is engaged inside the locking groove 4. Then, the round rod 23 is slid to insert into the locking groove 4 to prevent the locking plate 10 from rotating. This connects the locking groove 4 and the fixing groove 5 together, so that the cover 2 is fixed to the box body 1. This makes it easy to open the box body 1, which facilitates the maintenance or replacement of the internal structure of the device by the staff, and the resetting of the protective structure.

[0019] Reference Figure 2 , Figure 4 and Figure 5 A square plate 7 is fixedly connected to the rear side of the interior of the housing 1. A slide rod 17 is slidably connected inside the square plate 7. A slide plate 8 is fixedly connected to the right end of the slide rod 17. A moving contact 21 is fixedly connected to the left side of the bottom of the slide plate 8. The moving contact 21 abuts against the inside of the stationary contact 20. A pull ring 19 is fixedly connected to the left end of the slide rod 17. A top plate 6 is fixedly connected to the rear side of the interior of the housing 1. A rotating plate 14 is connected to the bottom side of the top plate 6 via a torsion spring. A latching post 16 is fixedly connected to the top side of the right side of the rotating plate 14. A push plate 15 is fixedly connected to the bottom left side of the rotating plate 14, passing through the middle of the pull ring 19. The left side of the top side of the bimetallic strip 13 abuts against the right side of the push plate 15. A spring 18 is sleeved on the outer wall of the slide rod 17. One end of the spring 18 is connected to the left side of the slide plate 8, and the other end of the spring 18 is connected to the right side of the square plate 7. When the overload current enters the base plate 12 through the wire 3 and reaches the bimetallic strip 13, due to the difference in the coefficients of thermal expansion of brass and constantan (the coefficient of thermal expansion of brass is approximately 19 × 10⁻⁶), the overload current will cause a thermal expansion of approximately 19 × 10⁻⁶. -6 At ℃, the coefficient of thermal expansion of constantan is approximately 15 × 10⁻⁶. -6At a temperature of / ℃, the brass side expands more significantly after heating, causing the bimetallic strip 13 to bend towards the constantan side, i.e., towards the push plate 15. The degree of bending increases with the increase of the overload current, thus pushing the push plate 15. This push plate 15 then pushes the rotating plate 14 to overcome the resistance of the torsion spring and rotate, causing the latch post 16 to disengage from the pull ring 19, thereby releasing the lock on the pull ring 19. Afterwards, the spring 18 releases its stored elastic potential energy, causing the spring 18 to push the slide plate 8 to slide, thereby causing the moving contact 21 to disengage from the stationary contact 20, thus breaking the circuit and achieving the effect of power-off protection. After the current can no longer flow, the bimetallic strip 13 will return to its original shape. When it is necessary to reset the disconnect structure, simply flick the lever... The rotating plate 14 disengages the latching post 16 from the moving path of the pull ring 19. Then, the pull ring 19 is pulled to move back above the latching post 16, causing the slide plate 8 to re-engage the moving contact 21 with the interior of the stationary contact 20, thus completing the circuit connection. After that, the rotating plate 14 is released, causing it to rotate automatically under the action of the torsion spring, thereby allowing the latching post 16 to pass through the pull ring 19 again to re-lock the pull ring 19. Wires 3 are connected between the base plate 12 and the fixing plate 9, and on the left side of the base plate 12 and the right side of the slide plate 8. The wires 3 on both sides pass through the housing 1, and the wires 3 on both sides are connected to external circuits. The device and the external circuit are connected in series through the wires 3, thereby achieving the effect of disconnecting or connecting the circuit.

[0020] Working principle: First, wire 3 is connected to an external circuit. When an overload occurs, the overload current flows through wire 3 into the base plate 12 and reaches the bimetallic strip 13. The bimetallic strip 13 then bends towards the push plate 15, and the degree of bending increases with the increase of the overload current, thereby pushing the push plate 15. The push plate 15 then pushes the rotating plate 14 to overcome the resistance of the torsion spring and rotate, causing the latch 16 to disengage from the pull ring 19, thus releasing the lock on the pull ring 19. Afterward, the spring 18 releases its stored elastic potential energy, causing the spring 18 to push the slide plate 8 to slide, thereby causing the moving contact 21 to disengage from the stationary contact 20, thus disconnecting the circuit and achieving the effect of power-off protection. After the current can no longer flow, the bimetallic strip 13 will return to its original position. When a reset is required, the circuit will be disconnected. In the structural configuration, first slide the round rod 23 to disengage it from the slot 4, then move the plate 10 to disengage it from the slot 4, then pull the cover 2 upwards to disengage it from the body 1, then move the rotating plate 14 to disengage the latching post 16 from the moving path of the pull ring 19, then pull the pull ring 19 to move it back above the latching post 16, so that the slide plate 8, with the moving contact 21, re-abuts against the inside of the stationary contact 20, completing the circuit connection. Then release the rotating plate 14, so that the rotating plate 14 rotates automatically under the action of the torsion spring, so that the latching post 16 passes through the pull ring 19 again to re-lock the pull ring 19. Then fix the cover 2 back to the body 1. The body 1 can be opened with heat dissipation holes as needed, but the heat dissipation holes need to be equipped with a filter screen and other protective structures to prevent external dust and other impurities from entering the interior of the body 1.

[0021] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model 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 make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An overload protection device for a DC fast circuit breaker, characterized in that: The enclosure includes a housing (1), a cover (2) connected to the top side of the housing (1), a plurality of insert rods (11) fixedly connected to the bottom side of the cover (2), the insert rods (11) being inserted into the top side of the housing (1), a snap-fit ​​assembly being provided between the housing (1) and the cover (2), the cover (2) being fixed to the housing (1) by the snap-fit ​​assembly, a base plate (12) being fixedly connected to the bottom side inside the housing (1), a bimetallic strip (13) being fixedly connected to the top side of the base plate (12), a fixing plate (9) being fixedly connected to the right side inside the housing (1), a stationary contact (20) being fixedly connected to the right side of the fixing plate (9), and a power-off assembly being provided inside the housing (1), the power-off assembly being used to control the disconnection and connection of the circuit.

2. The DC fast circuit breaker overload protection device according to claim 1, characterized in that: The buckle assembly includes a fixing groove (5) fixedly connected to the left and right sides of the box cover (2), and a card plate (10) is rotatably connected inside the fixing groove (5). The left and right sides of the box body (1) are fixedly connected to the card groove (4).

3. The DC fast circuit breaker overload protection device according to claim 2, characterized in that: The bottom side of the card plate (10) abuts against the inside of the card slot (4). A protrusion (22) is fixedly connected to the bottom side of the card plate (10). The protrusion (22) is engaged in the inside of the card slot (4). A round rod (23) is slidably connected to one side of the card plate (10). The bottom end of the round rod (23) is inserted into the inside of the card slot (4).

4. The DC fast circuit breaker overload protection device according to claim 1, characterized in that: The power-off assembly includes a square plate (7) fixedly connected to the rear side inside the housing (1), a slide rod (17) slidably connected inside the square plate (7), and a slide plate (8) fixedly connected to the right end of the slide rod (17).

5. The DC fast circuit breaker overload protection device according to claim 4, characterized in that: A movable contact (21) is fixedly connected to the left side of the bottom side of the slide plate (8), and the movable contact (21) abuts against the inside of the stationary contact (20). A pull ring (19) is fixedly connected to the left end of the slide rod (17), and a top plate (6) is fixedly connected to the rear side inside the box (1).

6. The DC fast circuit breaker overload protection device according to claim 5, characterized in that: The bottom side of the top plate (6) is connected to a rotating plate (14) by a torsion spring. A buckle post (16) is fixedly connected to the top side of the right side of the rotating plate (14). The buckle post (16) passes through the middle of the pull ring (19). A push plate (15) is fixedly connected to the bottom side of the left side of the rotating plate (14).

7. The DC fast circuit breaker overload protection device according to claim 6, characterized in that: The left side of the top side of the bimetallic strip (13) abuts against the right side of the push plate (15). The outer wall of the slide rod (17) is fitted with a spring (18). One end of the spring (18) is connected to the left side of the slide plate (8), and the other end of the spring (18) is connected to the right side of the square plate (7).

8. The DC fast circuit breaker overload protection device according to claim 4, characterized in that: The base plate (12) and the fixing plate (9) are connected by wires (3), and the left side of the base plate (12) and the right side of the slide plate (8) are connected by wires (3). The wires (3) on the left and right sides pass through the box (1) and are connected to external lines.

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