Power distribution cabinet line protection device

Abstract

The invention relates to the technical field of line protection, and particularly discloses a power distribution cabinet line protection device which comprises a power distribution cabinet, a safe box is fixedly installed on the inner wall of the power distribution cabinet, wiring ends are arranged at the upper end and the lower end of the safe box, a cavity is further formed in the safe box, and a bimetallic strip is arranged in the cavity. According to the invention, the bimetallic strip and the external circuit form an access through the electrifying assembly, and the characteristic that the bimetallic strip is bent and deformed when heated is utilized, so that the electrifying assembly can break the connection with the bimetallic strip when the bimetallic strip is bent under the action of current exceeding a preset value, so that the circuit is disconnected, and the protection of the circuit is completed; and after a maintainer carries out first-aid repair on the circuit, if the bimetallic strip is still in a bending deformation state, the bimetallic strip can be connected with the power-on assembly through the compensation assembly to form an access, so that the bimetallic strip is connected into the circuit in advance, the bimetallic strip does not need to be replaced, and material waste is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of line protection, and specifically provides a line protection device for a power distribution cabinet. Background Art

[0002] The line protection device for a power distribution cabinet is an important device to ensure the safe operation of the power system. Its main function is to monitor the circuit state and cut off the power supply in a timely manner in case of abnormalities to protect the safety of equipment and personnel. Among them, the overload protection device is used to detect whether the current exceeds the set value. When the current exceeds the rated value, the device will automatically cut off the circuit to prevent the equipment from being damaged due to overload. In the prior art, a bimetallic strip is usually used as a thermal sensor. When current passes through the bimetallic strip, heat will be generated, causing the temperature of the bimetallic strip to rise. When the current exceeds the set value, the temperature of the bimetallic strip will rise rapidly, causing it to bend and deform. After the bimetallic strip bends, its horizontal length shortens, thereby disconnecting the circuit connection to achieve the effect of circuit protection.

[0003] For example, Chinese Patent No. CN107039218B discloses a protection switch and a circuit protection device, belonging to the field of electrical switches. The protection switch includes a housing, and a first terminal, a second terminal, a first bimetallic strip, a tripping mechanism, a moving contact, a static contact, and a fuse arranged in the housing. The first terminal is electrically connected to the first bimetallic strip, the first bimetallic strip is electrically connected to the static contact, the moving contact is arranged on the tripping mechanism, the first bimetallic strip is arranged on one side of the tripping mechanism, the second terminal is electrically connected to the moving contact through the fuse. When the circuit is overloaded and the temperature rises, the first bimetallic strip bends towards the tripping mechanism, causing the tripping mechanism to trip, thereby separating the moving contact from the static contact, so that the connection between the first terminal and the second terminal is disconnected, thus playing the role of overload protection. The fuse melts when the circuit is short-circuited, causing the connection between the first terminal and the second terminal to be disconnected, thus playing the role of short-circuit protection.

[0004] However, the bimetallic strip usually needs to cool for one to two hours to return to its original state after being heated and bent. During the short-time emergency repair of the circuit, the bimetallic strip cannot meet the requirement of quickly restoring power supply, and only a new bimetallic strip can be directly replaced, resulting in waste of materials. Summary of the Invention

[0005] The purpose of the present invention is to provide a line protection device for a power distribution cabinet to solve at least one technical problem existing in the above prior art.

[0006] To achieve the above purpose, the present invention provides the following technical solution: A line protection device for a power distribution cabinet, including a power distribution cabinet, a safe is fixedly installed on the inner wall of the power distribution cabinet, wiring terminals are provided at both the upper and lower ends of the safe, a cavity is further opened in the safe, and a bimetallic strip is arranged in the cavity;

[0007] It further includes an energizing component, which is used to connect the bimetal in series with an external circuit through the two side terminal ends, and disconnect the circuit after the bimetal is heated and bent;

[0008] It further includes a compensation component, which is used to reconnect the bimetal after it is deformed by heat into the circuit, and always maintain a stable connection of the circuit during the process of the bimetal restoring to its original state.

[0009] Preferably, the energizing component includes a live wire embedded in the terminal end. The opposite ends of the two side live wires are fixedly connected with fitting ends. The fitting ends are fixedly installed on the side wall of the cavity through connecting parts. An access end is slidably inserted into the fitting end. A connecting piece is rotatably connected between each of the two side access ends and the bimetal. Energizing pieces are fixedly installed at both ends of the bimetal. A path is formed between the access end and the energizing piece through a wire embedded in the connecting piece.

[0010] Preferably, the connecting part includes a sliding block fixedly installed on the outer wall of the terminal end and installed in the cavity and capable of sliding adjustment. The sliding block is made of a light insulating material.

[0011] Preferably, the compensation component includes a fixed frame fixedly installed in the middle of the bimetal. A sliding rod capable of horizontally reciprocatingly sliding in the cavity is fixedly installed on the outer wall of the fixed frame. A connecting rod is rotatably connected between the sliding block and the sliding rod.

[0012] Preferably, a rotary valve is rotatably installed in a rotating groove opened on the side wall of the safe. A pull rod is rotatably connected between the side wall of the rotary valve and the sliding rod. A U-shaped frame is fixedly installed in the cavity. One end of the sliding rod extends into the U-shaped frame and is slidably connected with the side wall of the U-shaped frame.

[0013] Preferably, a rotating handle is fixedly rotatably installed on the inner side wall of the U-shaped frame. Stop pins are fixedly installed on the inner walls of the U-shaped frame on both sides of the rotating handle. A tension spring is arranged between the end of the rotating handle far from the sliding rod and the sliding rod.

[0014] Preferably, two groups of insulating cavities and heat-sensitive cavities are opened in the safe with the bimetal as the axis of symmetry. A sliding rod is slidably installed in a through groove opened between the insulating cavity and the heat-sensitive cavity. A compression spring is arranged between one end of the sliding rod and the inner top surface of the insulating cavity. A sliding plate slidably installed on the inner wall of the heat-sensitive cavity is fixedly installed on the outer wall of the sliding rod located in the heat-sensitive cavity. A piston plate is fixedly installed on the outer wall of the sliding rod located in the insulating cavity. A through groove communicating with the cavity is opened on the side wall of the insulating cavity. The insulating cavity is communicated with an external oil supply circuit. The heat-sensitive cavity is filled with a heat-expandable material.

[0015] Preferably, the horizontal distance between the stop pin on one side of the rotating handle and the rotation point of the rotating handle is less than that on the other side.

[0016] Preferably, when the rotary valve rotates to the maximum rotation angle, the connection point between the pull rod and the rotary valve is still on the same side as the initial position.

[0017] Preferably, a plurality of heat dissipation fins are fixedly installed on the outer wall of the safe.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] First, in the present invention, the energizing component forms a circuit with the bimetal sheet, and by using the property that the bimetal sheet is bent and deformed when heated, when the current received by the bimetal sheet exceeds the preset value and bends, the energizing component can disconnect the connection with the bimetal sheet to form an open circuit, completing the protection of the circuit. After the maintenance personnel rush to repair the circuit, if the bimetal sheet has returned to its original state and is connected to the energizing component, the power supply can be directly restored. If the bimetal sheet is still in the bent and deformed state, at this time, the compensation component can be used to connect the bimetal sheet and the energizing component to form a circuit, so that the bimetal sheet is pre-connected to the circuit, without the need to replace the bimetal sheet, reducing material waste.

[0020] Second, in the present invention, while the external structure drives the sliding rod to slide, it also pulls the bent bimetal sheet to slide together, so that both ends of the bimetal sheet are in the same plane as the access end. While reducing the distance between the fitting end and the access end, the two sliding blocks on both sides are pulled by the connecting rod to approach the fitting end together, and the access end and the fitting end are inserted into each other to form a circuit, so that the bent bimetal sheet can be connected to the circuit until it returns to the vertical state by itself, avoiding the situation that the circuit cannot be restored after the rush repair because the bimetal sheet has not returned to its original state by itself, or the difficulty of rush repair caused by replacing the bimetal sheet and the resulting material waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a three-dimensional structural diagram of the present invention;

[0022] Figure 2 is a three-dimensional structural diagram of the safe in the present invention;

[0023] Figure 3 is a side sectional view of the safe in the present invention;

[0024] Figure 4 in the present invention Figure 3 is an isometric three-dimensional structural diagram;

[0025] Figure 5 is a side sectional view of the cavity in the present invention;

[0026] Figure 6 in the present invention Figure 5 is an isometric three-dimensional structural diagram;

[0027] Figure 7 Schematic diagram of the C-shaped frame and its related structures in the present invention;

[0028] Figure 8 Partial schematic diagram when the bimetallic strip in the present invention is bent and deformed.

[0029] In the figure: 1, power distribution cabinet; 2, safe; 3, terminal; 4, cavity; 5, live wire; 6, fitting end; 7, access end; 8, connecting piece; 9, bimetallic strip; 10, wire; 11, live piece; 12, fixed frame; 13, rotary valve; 14, pull rod; 15, sliding rod; 16, connecting rod; 17, C-shaped frame; 18, turning handle; 19, tension spring; 20, sliding rod; 21, sliding plate; 22, insulating cavity; 23, thermal cavity; 24, sliding block; 25, retaining pin; 26, piston plate. Specific embodiments

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] Please refer to Figures 1 to 8 , the present invention provides a technical solution: a line protection device for a power distribution cabinet, including a power distribution cabinet 1, a safe 2 is fixedly installed on the inner wall of the power distribution cabinet 1, terminals 3 are provided at both the upper and lower ends of the safe 2, a cavity 4 is further opened in the safe 2, and a bimetallic strip 9 is provided in the cavity 4;

[0032] It further includes a power-on assembly, which is used to connect the bimetallic strip 9 in series with the external circuit through the terminals 3 on both sides, and disconnect the circuit after the bimetallic strip 9 is heated and bent;

[0033] It further includes a compensation assembly, which is used to connect the bimetallic strip 9 that has been deformed by heat to the circuit again, and always maintain a stable connection of the circuit during the process of the bimetallic strip 9 restoring to its original state.

[0034] When this device is in use, first, the safe 2 is fixedly installed in the power distribution cabinet 1, and the bimetal 9 is connected to the circuit through the terminal 3 and the energizing component, so that the bimetal 9 is arranged in series with the circuit. Then, the circuit is energized. When a fault occurs somewhere in the circuit and the current in the circuit increases significantly, the amount of current flowing into the bimetal 9 increases, causing the heat in the bimetal 9 to accumulate and start to bend and deform. When the current passing through the bimetal 9 exceeds the preset value, that is, when the bending degree of the bimetal 9 is too large, the energizing component disconnects the connection with the bimetal 9, making the circuit break to form an open circuit, so as to ensure that other facilities in the power distribution cabinet 1 will not be damaged or malfunction under the influence of excessive current, achieving the purpose of protecting the circuit in the power distribution cabinet 1. At this time, the power distribution cabinet 1 reminds the maintenance personnel to carry out emergency repairs through the alarm device. After the emergency repair is completed, if the bimetal 9 has recovered by itself and forms a path with the energizing component again, the power supply can be directly restored. If the bimetal 9 has not recovered to its original state by itself, at this time, the bent bimetal 9 can be connected to the energizing component through the compensation component, making the circuit form a path and restoring the power supply until the bimetal 9 cools down and returns to its original state by itself.

[0035] In this way, through the energizing component, the bimetal 9 forms a path with the external circuit and utilizes the property that the bimetal 9 bends and deforms when heated, so that the energizing component can disconnect the connection with the bimetal 9 when the bimetal 9 is bent by a current exceeding the preset value, making the circuit form an open circuit to complete the protection of the circuit. When the maintenance personnel carry out emergency repairs on the circuit, if the bimetal 9 has recovered to its original state and is connected to the energizing component, the power supply can be directly restored. If the bimetal 9 is still in the bent and deformed state, at this time, the bimetal 9 can be connected to the energizing component through the compensation component to form a path, enabling the bimetal 9 to be connected to the circuit in advance without replacing the bimetal 9, reducing material waste.

[0036] It is worth mentioning that when the bent bimetal 9 is connected to the circuit again, since the bimetal 9 has recovered partially after natural cooling during the emergency repair process, if a fault occurs in the circuit again, the bimetal 9 still has a certain bending space. When the bimetal 9 is heated and bends again, the energizing component will immediately disconnect the connection with the bimetal 9, protecting the circuit for the second time and avoiding the bending degree of the bimetal 9 being too high, resulting in the bimetal 9 being unable to recover to its original state by itself, increasing the sensitivity of the bimetal 9 to current changes and the risk of accidental touch, thereby improving the stability of the device.

[0037] Furthermore, the energizing component includes a live wire 5 embedded in the connection terminal 3. At opposite ends of the two-sided live wire 5, fitting ends 6 are fixedly connected. The fitting ends 6 are fixedly installed on the side wall of the cavity 4 through a connecting portion. A connecting end 7 is slidably inserted into the fitting end 6. Connecting members 8 are rotatably connected between the two-sided connecting ends 7 and the bimetal 9. Energizing pieces 11 are fixedly installed at both ends of the bimetal 9. A circuit is formed between the connecting end 7 and the energizing piece 11 through a wire 10 embedded in the connecting member 8.

[0038] According to the above embodiment, a specific way of the energizing component is provided. When the bimetal 9 is completely in the vertical state, specifically refer to Figure 5 , at this time, the vertical length of the bimetal 9 is the largest, so that the connecting end 7 is completely inserted into the fitting end 6. At this time, the live wires 5, fitting ends 6, connecting ends 7, wires 10 on both sides and the central bimetal 9 form a circuit (a certain length of wire 10 is reserved at the rotating part of the connecting member 8) to achieve the purpose of connecting the bimetal 9 in series into the circuit. When the current in the bimetal 9 exceeds the preset value, the bimetal 9 bends with the midpoint as the center and both ends gather towards the center, causing the vertical lengths on both sides of the bimetal 9 to decrease synchronously, pulling the connecting member 8 to rotate. Since the vertical lengths of both sides of the bimetal 9 and the vertical length of the connecting member 8 are shortened by a certain distance, the two-sided connecting ends 7 are pulled away from the fitting end 6, and an open circuit is formed between the connecting end 7 and the fitting end 6 to complete the power-off protection of the circuit.

[0039] Furthermore, the connecting portion includes a sliding block 24 fixedly installed on the outer wall of the connection terminal 3 and installed in the cavity 4 and capable of sliding adjustment. The sliding block 24 is made of a light insulating material.

[0040] According to the above embodiment, a specific way of the connecting portion is provided. Since a sliding block 24 capable of sliding adjustment in the cavity 4 is fixedly installed on the outer wall of the connection terminal 3, when both sliding blocks 24 are in contact with and against the inner walls on both sides of the cavity 4, if the bimetal 9 is heated and bent at this time and the connecting ends 7 are pulled through the connecting members 8 on both sides, since the fitting end 6 and the sliding block 24 are fixed to the inner wall of the cavity 4 together, at this time, the connecting end 7 breaks through the buckle in the fitting end 6 and disengages from the fitting end 6, and the disconnection of the circuit can be completed.

[0041] Furthermore, the compensation component includes a fixed frame 12 fixedly installed in the middle of the bimetal 9. A sliding rod 15 capable of horizontally reciprocating sliding in the cavity 4 is fixedly installed on the outer wall of the fixed frame 12. A connecting rod 16 is rotatably connected between the sliding block 24 and the sliding rod 15.

[0042] According to the above embodiment, a specific way of the compensation component is provided. Specifically refer to Figure 8, when the bimetallic strip 9 starts to bend due to excessive heat (since the left side of the bimetallic strip 9 is made of a metal with a high coefficient of expansion, the bimetallic strip 9 bends to the right), at this time, the bimetallic strip 9 pulls the access end 7 away from the fitting end 6 through the connecting pieces 8 on both sides to form an open circuit. After the emergency repair is completed, the sliding rod 15 can be driven to move to the left by an external structure. At this time, when the sliding rod 15 slides to the left, the vertical length of the connecting rod 16 shortens, and the connecting rod 16 will pull the two sliding blocks 24 on both sides to move closer to each other, so that the sliding block 24 drives the fitting end 6 to be plugged into the access end 7 again to form a circuit. And because the sliding rod 15 drives the bimetallic strip 9 to slide to the left, the linear distance between the two ends of the bimetallic strip 9 and the access end 7 shortens, that is, the outermost ends on both sides of the bimetallic strip 9 are in the same plane as the access end 7, reducing the sliding distance between the sliding block 24 and the fitting end 6. Since the sliding block 24 is made of a lightweight insulating material, such as heat-resistant plastic, the bimetallic strip 9 can form a circuit with the energized component in the bent state, avoiding the situation where the bimetallic strip 9 fails to recover on its own after the emergency repair, resulting in the inability to restore the circuit or increasing the difficulty of the emergency repair and causing material waste when replacing the bimetallic strip 9. As the bimetallic strip 9 returns to the vertical state on its own, since the vertical lengths of the bimetallic strip 9 and the connecting piece 8 increase, the access end 7 pushes the two fitting ends 6 on both sides to move away from each other, so that the two sliding blocks 24 on both sides pull the sliding rod 15 to move to the right through the connecting rod 16, keeping the fitting end 6 and the access end 7 plugged into each other all the time until the bimetallic strip 9 completely returns to the vertical state, and the sliding block 24 and the fitting end 6 also move synchronously to contact and abut against the inner walls on both sides of the cavity 4, completing the reset inside the device.

[0043] In this way, while driving the sliding rod 15 to slide through an external structure, the bent bimetallic strip 9 is pulled to slide together, so that the two ends of the bimetallic strip 9 are in the same plane as the access end 7, reducing the distance between the fitting end 6 and the access end 7. At the same time, the two sliding blocks 24 on both sides are pulled to move closer to the fitting end 6 through the connecting rod 16, and the access end 7 and the fitting end 6 are plugged into each other to form a circuit, so that the bent bimetallic strip 9 can be connected to the circuit until it returns to the vertical state on its own, avoiding the situation where the bimetallic strip 9 fails to recover on its own after the emergency repair, resulting in the inability to restore the circuit or increasing the difficulty of the emergency repair and causing material waste when replacing the bimetallic strip 9.

[0044] Further, a rotary valve 13 is rotatably installed in the rotary groove opened on the side wall of the safe 2. A pull rod 14 is rotatably connected between the side wall of the rotary valve 13 and the sliding rod 15. A U-shaped frame 17 is fixedly installed in the cavity 4. One end of the sliding rod 15 extends into the U-shaped frame 17 and is slidably connected to the side wall of the U-shaped frame 17.

[0045] According to the above embodiments, when the maintenance personnel complete the emergency repair work on the circuit, if the bimetallic strip 9 has not recovered on its own, the rotary valve 13 can be pulled at this time (for details, see Figure 5) When the rotating handle of the rotary valve 13 rotates downward, it will pull the sliding rod 15 to move leftward together through the pull rod 14, which can drive the sliding rod 15 to drive the bimetal 9 and the sliding block 24 to move synchronously, so that the access end 7 and the fitting end 6 are inserted into each other to form a circuit. During the recovery process of the bimetal 9, the rotary valve 13 will also be reset synchronously. When the bimetal 9 is completely restored, the rotary valve 13 can also complete the reset, improving the reuse rate of the device.

[0046] Furthermore, a rotary handle 18 is fixedly and rotatably installed on the inner side wall of the U-shaped frame 17. Stop pins 25 are fixedly installed on the inner walls of the U-shaped frame 17 on both sides of the rotary handle 18. A tension spring 19 is provided between the end of the rotary handle 18 away from the sliding rod 15 and the sliding rod 15.

[0047] According to the above embodiments, when the bimetal 9 is in a completely vertical state, specifically refer to Figure 5 , at this time, the rotary handle 18 is in close contact with the right stop pin 25 under the action of the tension spring 19. The rotary valve 13 is kept in the initial state by pulling the pull rod 14 through the sliding rod 15. After the bimetal 9 is heated and bent to disconnect the circuit and complete the circuit repair work, at this time, pulling the rotary valve 13 can drive the rotary handle 18 to rotate leftward through the sliding rod 15, and after passing the midpoint, it contacts and abuts against the left stop pin 25. Under the action of the tension spring 19, the sliding rod 15 and the rotary valve 13 are kept in the current state together. At the same time, the sliding blocks 24 on both sides are driven by the connecting rod 16 to approach the fitting end 6 and are inserted into each other with the access end 7 to form a circuit. As the bimetal 9 self-recovers, its restoring force breaks through the limitation of the tension spring 19 and drives the sliding rod 15 to move rightward, and drives the rotary valve 13 to start resetting until the rotary valve 13, the sliding rod 15, and the rotary handle 18 complete the reset together, that is, the bimetal 9 is completely restored to the vertical state, ensuring that the access end 7 and the fitting end 6 can always be inserted during the self-recovery process of the bimetal 9, improving the stability of the circuit.

[0048] Furthermore, two groups of insulating cavities 22 and thermal cavities 23 are provided in the safe 2 with the bimetal 9 as the axis of symmetry. A sliding rod 20 is slidably installed in the through groove opened between the insulating cavity 22 and the thermal cavity 23. A compression spring is provided between one end of the sliding rod 20 and the inner top surface of the insulating cavity 22. A sliding plate 21 slidably installed on the inner wall of the thermal cavity 23 is fixedly installed on the outer wall of the sliding rod 20 located in the thermal cavity 23. A piston plate 26 is fixedly installed on the outer wall of the sliding rod 20 located in the insulating cavity 22. A through groove communicating with the cavity 4 is opened on the side wall of the insulating cavity 22. The insulating cavity 22 is communicated with an external oil supply circuit. The thermal cavity 23 is filled with a heat-expandable material.

[0049] According to the above embodiments, since the optimal operating temperature of the bimetallic strip 9 is between minus twenty degrees and two hundred degrees, in order to ensure that the temperature of the bimetallic strip 9 does not exceed this range, insulating oil can be filled in the cavity 4. The insulating oil absorbs heat to create a constant-temperature space for the bimetallic strip 9, preventing the low specific heat capacity of the air in the cavity 4 from causing the heat dissipation efficiency of the bimetallic strip 9 to be too low, resulting in too high a temperature of the bimetallic strip 9, which causes the bimetallic strip 9 to bend too much and unable to return to its original state normally. And when the heat-expandable material (such as paraffin) in the thermal-sensitive cavity 23 detects that the temperature of the insulating oil in the cavity 4 is too high, the paraffin absorbs heat and expands, pushing the sliding plate 21 to slide while driving the sliding rod 20 and the piston plate 26 to slide together, so that the through grooves on the side walls of the two insulating cavities 22 are both communicated with the cavity 4. For specific reference, Figure 6 , the insulating oil in the cavity 4 can be replaced through an external oil supply circuit, accelerating the heat dissipation of the bimetallic strip 9, further improving the constant-temperature effect in the cavity 4, and at the same time improving the recovery effect of the bimetallic strip 9.

[0050] Furthermore, the horizontal distance between the retaining pin 25 on one side of the turning handle 18 and the rotation point of the turning handle 18 is less than that on the other side.

[0051] According to the above embodiments, since the distance between the retaining pin 25 on one side of the turning handle 18 and the rotation point of the turning handle 18 is less than that on the other side. For specific reference, Figure 7 , in the figure, H1 is the distance between the left retaining pin 25 and the rotation point of the turning handle 18, and H2 is the distance between the right retaining pin 25 and the rotation point of the turning handle 18. Since the length of H1 is less than H2, when the bimetallic strip 9 is restoring, it will first break through the resistance of the tension spring 19 and cause the turning handle 18 to cross the center line when the bimetallic strip 9 is not fully restored. At this time, the tension spring 19 provides a rightward pulling force on the sliding rod 15, that is, a pulling force in the restoring direction for the bimetallic strip 9, further improving the restoring efficiency of the bimetallic strip 9.

[0052] Furthermore, when the rotary valve 13 rotates to the maximum rotation angle, the connection point of the pull rod 14 and the rotary valve 13 is still on the same side as the initial position.

[0053] According to the above embodiments, to prevent the connection point of the pull rod 14 and the rotary valve 13 from forming a dead point with the pull rod 14 when the rotary valve 13 rotates to the maximum rotation angle, resulting in insufficient restoring force of the bimetallic strip 9 to pull the rotary valve 13 back to its original position, causing the circuit to be disconnected during the restoration process of the bimetallic strip 9. Therefore, it is set that when the rotary valve 13 rotates to the maximum rotation angle, the connection point of the pull rod 14 and the rotary valve 13 is still on the same side as the initial position.

[0054] Furthermore, multiple groups of heat dissipation fins are fixedly installed on the outer wall of the safe 2.

[0055] According to the above embodiments, by fixedly installing multiple groups of heat dissipation fins on the outer wall of the safe 2 and cooperating with the insulating oil in the cavity 4, the heat dissipation efficiency of the bimetallic strip 9 is further improved. Moreover, since the outer wall of the bimetallic strip 9 is constantly in contact with the cold air in the power distribution cabinet 1, the water vapor in the power distribution cabinet 1 will gather on the outer wall of the heat dissipation fins. Thus, the water vapor in the power distribution cabinet 1 can be collected by setting a wiping or receiving structure, so as to form a dry and sealed space in the power distribution cabinet 1, further improving the protection function for the circuit.

[0056] The standard parts used in this embodiment can be directly purchased from the market. For the non-standard structural components described in the specification and drawings, they can also be directly processed without any doubt according to the existing technical knowledge. At the same time, the connection methods of each component adopt the mature conventional means in the existing technology, and the machines, parts and equipment all adopt the conventional models in the existing technology. Therefore, no specific description will be made here.

[0057] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A line protection device for a power distribution cabinet, comprising a power distribution cabinet (1), characterized in that: The inner wall of the power distribution cabinet (1) is fixedly installed with a safe (2). Both the upper and lower ends of the safe (2) are provided with wiring terminals (3). A cavity (4) is also formed inside the safe (2), and a bimetallic strip (9) is arranged in the cavity (4). It further includes an energizing component, which is used to connect the bimetallic strip (9) in series with an external circuit through the wiring terminals (3) on both sides, and disconnect the circuit when the bimetallic strip (9) is heated and bent. It further includes a compensation component, which is used to reconnect the bimetallic strip (9) that has been deformed by heat to the circuit again, and always maintain a stable connection of the circuit during the restoration process of the bimetallic strip (9).

2. The line protection device for the power distribution cabinet according to claim 1, wherein: The energizing component includes a live wire (5) embedded in the wiring terminal (3). Opposite ends of the two live wires (5) are fixedly connected with fitting ends (6). The fitting ends (6) are fixedly installed on the side wall of the cavity (4) through a connecting part. An access end (7) is slidably inserted into the fitting end (6). Connecting members (8) are rotatably connected between the two access ends (7) and the bimetallic strip (9). Energizing plates (11) are fixedly installed at both ends of the bimetallic strip (9). A circuit is formed between the access end (7) and the energizing plate (11) through a wire (10) embedded in the connecting member (8).

3. The line protection device for a power distribution cabinet according to claim 2, characterized in that: The connecting part includes a sliding block (24) fixedly installed on the outer wall of the wiring terminal (3) and installed inside the cavity (4) and capable of sliding adjustment. The sliding block (24) is made of a lightweight insulating material.

4. The line protection device for a power distribution cabinet according to claim 3, wherein: The compensation component includes a fixed frame (12) fixedly installed in the middle of the bimetallic strip (9). A sliding rod (15) capable of horizontally reciprocating sliding in the cavity (4) is fixedly installed on the outer wall of the fixed frame (12). A connecting rod (16) is rotatably connected between the sliding block (24) and the sliding rod (15).

5. The line protection device for a power distribution cabinet according to claim 4, wherein: A rotary valve (13) is rotatably installed in a rotary groove formed on the side wall of the safe (2). A pull rod (14) is rotatably connected between the side wall of the rotary valve (13) and the sliding rod (15). A U-shaped frame (17) is fixedly installed in the cavity (4). One end of the sliding rod (15) extends into the U-shaped frame (17) and is slidably connected to the side wall of the U-shaped frame (17).

6. The line protection device for a power distribution cabinet according to claim 5, wherein: A rotary handle (18) is fixedly rotatably installed on the inner side wall of the U-shaped frame (17). Stop pins (25) are fixedly installed on the inner walls of the U-shaped frame (17) on both sides of the rotary handle (18). A tension spring (19) is arranged between the end of the rotary handle (18) away from the sliding rod (15) and the sliding rod (15).

7. The line protection device for the power distribution cabinet according to claim 6, characterized in that: Two sets of insulating cavities (22) and thermal-sensitive cavities (23) are provided in the safe (2) with the bimetal strip (9) as the axis of symmetry. A through groove is provided between the insulating cavity (22) and the thermal-sensitive cavity (23), and a sliding rod (20) is slidably installed in the through groove. A compression spring is provided between one end of the sliding rod (20) and the inner top surface of the insulating cavity (22). A sliding plate (21) that is slidably installed on the inner wall of the thermal-sensitive cavity (23) is fixedly installed on the outer wall of the sliding rod (20) located in the thermal-sensitive cavity (23). A piston plate (26) is fixedly installed on the outer wall of the sliding rod (20) located in the insulating cavity (22). A through slot communicating with the cavity (4) is provided on the side wall of the insulating cavity (22). The insulating cavity (22) is communicated with an external oil supply circuit. The thermal-sensitive cavity (23) is filled with a heat-expandable material.

8. The line protection device for a power distribution cabinet according to claim 6, wherein: The horizontal distance between the retaining pin (25) on one side of the turning handle (18) and the turning point of the turning handle (18) is smaller than that on the other side.

9. The line protection device for the power distribution cabinet according to claim 5, wherein: When the rotary valve (13) rotates to the maximum rotation angle, the connection point of the pull rod (14) and the rotary valve (13) is still on the same side as the initial position.

10. The line protection device for a power distribution cabinet according to any one of claims 1-9, characterized in that: Multiple sets of heat dissipation fins are fixedly installed on the outer wall of the safe (2).

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