Small-sized high-voltage direct-current protector

Abstract

The invention relates to the technical field of line protection, in particular to a small high-voltage direct-current protector which comprises a shell and further comprises pressing frames, a coil, a guide column, a pressing plate, a static piece, a lower through line, a locking piece, a flow guide assembly and an arc extinguishing gate, the two pressing frames are connected to the upper side and the lower side of the shell respectively, the upper end of the coil is connected with the lower side of the upper pressing frame, and the lower end of the coil is connected with the lower side of the lower pressing frame. The guide column is arranged on the inner side of the coil, the pressing plate is connected to the lower side of the guide column, the static piece is connected with the lower end of the coil, the lower through line is connected with the upper side of the lower side pressing frame, the lower through line is attached to the static piece, the locking piece is connected between the pressing plate and the lower through line, and the flow guide assembly is connected with the lower through line. According to the arc extinguishing device, arc extinguishing gas is pressurized through movement of the movable contact, so that the arc extinguishing gas flows through the middle part of an arc, and the arc extinguishing gas flow is inserted into a gap of the arc extinguishing gate to be in contact with the arc, so that the arc extinguishing effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of line protection, and particularly to a small high-voltage DC protector. Background Art

[0002] In new energy vehicles, industrial automation equipment, and various DC power supply systems, high-voltage DC protectors, as key devices to ensure the safe operation of circuits, play a crucial role. It is a device specifically used to protect DC circuits from short-circuit faults. It can quickly cut off the circuit when a fault occurs, preventing the fault from further expanding, thereby protecting other devices in the circuit from current damage.

[0003] When the high-voltage DC protector is working normally, the operating mechanism compresses kinetic energy to keep the two contacts closed, and the circuit conducts normally. When a short-circuit fault occurs in the circuit, the operating mechanism is driven to release the stored mechanical energy, pushing a contact to move, so that the two contacts quickly break, realizing the cutting off of the circuit; at the moment when the contacts break, an arc will be generated between the two contacts. At this time, the arc extinguishing device comes into play. By diverting the arc into the arc extinguishing grid, the arc is cut into small segments by the arc extinguishing grid, increasing the resistance of the arc, and thus realizing arc extinguishing. However, the energy of the high-voltage DC arc is relatively large, and the temperature of the arc can reach thousands of degrees Celsius. This high temperature causes the material of the arc extinguishing grid to heat up rapidly, and the miniaturized design of the high-voltage DC protector leads to a decrease in the heat dissipation capacity of the arc extinguishing grid. When the arc contacts the arc extinguishing grid, it is easy to cause thermal deformation or damage of the material, resulting in poor arc extinguishing effect.

[0004] In view of the above problems, some solutions have been proposed in the prior art. For example, by filling an arc extinguishing gas in the high-voltage DC protector, the arc is extinguished by the combined method of using the arc extinguishing grid to isolate the arc and the arc extinguishing gas to cool the arc. However, the miniaturized design of the high-voltage DC protector results in a short moving distance of the arc towards the arc extinguishing grid. Since the arc only contacts the arc extinguishing gas on the path during the moving process, the short moving distance will cause less contact between the arc extinguishing gas and the arc, resulting in poor arc extinguishing effect.

[0005] Therefore, a small high-voltage DC protector is proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide a small high-voltage DC protector, which solves the problem that in a narrow space, when the arc moves towards the arc extinguishing grid, the arc extinguishing gas contacted by the arc is limited, resulting in poor cooling effect of the arc extinguishing gas on the arc. By using the movement of the moving contact to pressurize the arc extinguishing air flow and making the arc extinguishing air flow act on the arc, the arc is elongated in the path from the arc to the arc extinguishing grid, and after the arc moves onto the arc extinguishing grid, the arc extinguishing air flow penetrates into the gaps of the arc extinguishing grid to contact the arc, effectively reducing the arc temperature and thus improving the arc extinguishing effect.

[0007] To achieve the above object, the present invention provides the following technical solutions: A small high-voltage DC protector includes a housing, and also includes a pressure frame, a coil, a guide post, a pressure plate, a static plate, a lower connecting wire, a locking member, a diversion assembly, and an arc extinguishing grid. The two pressure frames are respectively connected to the upper and lower sides of the housing. The upper end of the coil is connected to the lower side of the upper pressure frame. The guide post is arranged inside the coil. The pressure plate is connected to the lower side of the guide post. The static plate is connected to the lower end of the coil. The lower connecting wire is connected to the upper side of the lower pressure frame and is in contact with the static plate. The locking member is connected between the pressure plate and the lower connecting wire. The diversion assembly is connected to the lower connecting wire. The two ends of the arc extinguishing grid are respectively connected to the static plate and the lower connecting wire. When a short circuit occurs, the coil drives the pressure plate to move upward through the guide post to release the limit on the locking member. The locking member pushes the lower connecting wire downward to disconnect from the static plate. When the lower connecting wire moves downward, the diversion assembly blows pressurized air toward the middle of the arc extinguishing grid.

[0008] Through the above solution, during the process of the arc flowing toward the arc extinguishing grid, the arc is further elongated, thereby increasing the heat dissipation area of the arc and achieving the effect of reducing the arc temperature.

[0009] Preferably, a spring plate is connected to the front end of the pressure plate. The spring plate is arc-shaped. The static plate is bent. A push spring is connected to the top of the guide post.

[0010] Through the above solution, the push spring pushes the guide post to maintain a downward movement state. When a short circuit occurs, the magnetic force generated by the coil increases and drives the guide post to move, changing the position of the pressure plate.

[0011] Preferably, the lower connecting wire includes a spring piece, a moving piece, a diversion piece, and a drainage piece. The right end of the spring piece is connected to the inner cavity of the housing. The moving piece is connected to the left end of the spring piece, and the lower end of the moving piece is connected to the lower pressure frame. The diversion piece is connected to the left side of the moving piece. The drainage piece is slidably connected to the left end of the diversion piece. The connection end of the diversion piece and the moving piece is arc-shaped.

[0012] Through the above solution, the connection end of the diversion piece and the moving piece is arc-shaped. Thus, when the spring piece swings, the diversion piece and the drainage piece can be kept in contact through the deformation of the connection end of the diversion piece and the moving piece.

[0013] Preferably, the locking member includes a knob, a limiting rod, and a torsion spring. The knob is connected to the front end of the housing. The two limiting rods are both connected to the rear side of the knob and are symmetrically arranged about the central axis of the knob. The two ends of the torsion spring are respectively connected to the knob and the housing. The spring plate is arc-shaped. The two limiting rods are respectively in contact with the adjacent sides of the spring plate and the spring piece. The shortest distance from the left side of the spring plate to the longitudinal central plane of the knob is greater than the radius value of the limiting rod. Thus, when the plane formed by the central axes of the two limiting rods is vertical, the spring plate moves downward without contacting the limiting rod.

[0014] Preferably, the flow guiding assembly includes a closed box, a baffle plate, a sliding plate, a magnetic plate and an air film. The closed box is connected to the left side of the inner cavity of the housing, and the closed box is located below the flow guiding vane. The baffle plate is connected to the lower side of the flow guiding vane. The sliding plate is connected to the front and rear sides of the upper surface of the baffle plate. The two magnetic plates are respectively connected to the left and right sides of the inner cavity of the closed box. When the lower lead wire does not move downwards, the lower end surface of the baffle plate is higher than the top surface of the closed box.

[0015] Through the above scheme, the lower end surface of the baffle plate is higher than the top surface of the closed box, so that the arc extinguishing gas can freely move into the closed box, which is convenient for the baffle plate to move downwards to squeeze the closed box to form an air flow.

[0016] Preferably, the lower end surface of the left magnetic plate is higher than the upper end surface of the right magnetic plate, and both ends of the sliding plate have magnetism.

[0017] Through the above scheme, the height change of the positions of the two magnetic plates can realize changing the position of the sliding plate at different heights.

[0018] Preferably, the surfaces of the sliding plate and the baffle plate are both provided with trumpet-shaped air holes with the smaller end facing upwards, and the central axes of the air holes are inclined. When the lower lead wire does not move downwards, the air holes on the surfaces of the sliding plate and the baffle plate are arranged in a staggered manner. A through hole is provided in the middle of the surface of the sliding plate, and the through hole is communicated with the air holes in the middle.

[0019] Through the above scheme, the air holes are trumpet-shaped. When the arc extinguishing gas is discharged through the air holes, the air flow can be gathered to act on the middle part of the arc, and then the bending amplitude of the arc is increased, effectively lengthening the arc.

[0020] Preferably, the arc extinguishing grid includes a mounting frame, a pulling plate, a double-layer metal sheet and grid sheets. The mounting frame is connected to the upper side of the bent sheet. The pulling plate is connected to the mounting frame. The double-layer metal sheet is connected to the top of the flow guiding plate. The grid sheets are connected to the mounting frame in an array. The double-layer metal sheet is composed of two metal sheets with different thermal expansion coefficients, and the thermal expansion coefficient of the right metal sheet is greater than that of the left metal sheet.

[0021] Through the above scheme, the different thermal expansion coefficients of the metal sheets on both sides of the double-layer metal sheet cause the double-layer metal sheet to bend when the arc contacts the double-layer metal sheet, and then drive the grid sheets to move through the pulling plate, realizing the lengthening of the arc. At the same time, the increase in the gap between the grid sheets facilitates the arc extinguishing gas blown out by the air holes to flow into the space between the grid sheets, thereby improving the cooling speed of the grid sheets.

[0022] Preferably, a plurality of clamping blocks are connected to the front end surface of the pulling plate. The clamping blocks correspond to the grid sheets, and the distance values on the left and right sides of the clamping blocks gradually increase from right to left.

[0023] Through the above solution, the clamping blocks gradually increase in size from right to left. When the pull plate drives the clamping blocks to move, the gap between multiple adjacent grid plates can be increased, thereby increasing the arc length of each segment in the arc extinguishing grid and improving the arc extinguishing effect.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention solves the problem that in a narrow space, when the arc moves towards the arc extinguishing grid, the arc extinguishing gas contacted by the arc is limited, resulting in poor cooling effect of the arc extinguishing gas on the arc. By moving the lower through-wire to compress the inner cavity of the closed box, the arc extinguishing gas in the inner cavity of the closed box forms an air flow through the air holes and acts on the arc. On the one hand, it accelerates the contact efficiency between the arc extinguishing gas and the arc, thereby increasing the cooling speed of the arc and realizing the improvement of the arc extinguishing efficiency. On the other hand, the air flow acts on the middle part of the arc to increase the bending amplitude of the arc to stretch the arc, increasing the heat dissipation area of the arc, and thus accelerating the arc extinguishing efficiency. On the third hand, the blowing of the pressurized air flow effectively accelerates the moving speed of the arc towards the arc extinguishing grid, thereby improving the arc extinguishing efficiency of the device.

[0025] 2. By providing the arc extinguishing grid, when the arc contacts the double-layer metal sheet, the high temperature of the arc will cause the double-layer metal sheet to bend, thereby expanding the gap between the grid plates, realizing the stretching of the arc, further increasing the heat dissipation area of the arc, achieving the effect of facilitating arc extinguishing. At the same time, when the distance between the grid plates is increased, the intersection of the hot air flows between adjacent grid plates is reduced, thereby improving the cooling efficiency of the grid plates and realizing the improvement of the arc extinguishing efficiency.

[0026] 3. By providing the magnetic plate, when the guide vane drives the baffle to move downward, it will accelerate the stretching of the arc, thereby increasing the cooling efficiency of the arc. And as the baffle moves downward, the magnetic plate will pull the slide plate to move, making the air holes on the slide plate intersect with the air holes on the baffle, thereby increasing the contact area between the air flow and the arc. At the same time, the air flow will act on the grid plates, improving the cooling efficiency of the grid plates, and thus improving the arc extinguishing efficiency of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of the whole of the present invention; Figure 2 is a schematic structural diagram of the lower through-wire part of the present invention; Figure 3 is a schematic structural diagram of the locking part of the present invention; Figure 4 is a schematic structural diagram of the limiting position of the present invention; Figure 5 is of the present invention Figure 4 the enlarged schematic diagram at A in; Figure 6 is a schematic structural diagram of the guide assembly part of the present invention; Figure 7 This is a schematic structural diagram of the arc extinguishing grid part of the present invention; Figure 8 This is a schematic diagram of the state of the air flow blowing the electric arc in the present invention.

[0028] In the figure: 1. Outer shell; 2. Pressing frame; 3. Coil; 4. Guide post; 401. Push spring; 5. Pressing plate; 501. Spring plate; 6. Static plate; 7. Lower connecting wire; 701. Spring piece; 702. Moving plate; 703. Current guiding piece; 704. Drainage piece; 8. Locking member; 801. Knob; 802. Limit rod; 803. Torsion spring; 9. Current guiding assembly; 901. Enclosed box; 902. Baffle plate; 9021. Air hole; 9022. Through hole; 903. Slide plate; 904. Magnetic plate; 905. Air film; 10. Arc extinguishing grid; 1001. Mounting frame; 1002. Pulling plate; 10021. Block; 1003. Double-layer metal sheet; 1004. Grid sheet. Specific embodiments

[0029] Next, with reference to the accompanying drawings of the embodiments of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described, making its working state and structural features more detailed. Obviously, the described embodiments are only partial embodiments of the present invention, not complete embodiments. Based on the embodiments of the present invention, other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0030] Please refer to Figures 1 to 8 , the present invention provides a small high-voltage DC protector, and the technical solution is as follows: Specifically, please refer to Figures 1 to 8, A small high-voltage DC protector, including a housing 1. The housing 1 is a closed structure, and the inner cavity of the housing 1 is separated from the outside. The inner cavity of the housing 1 is filled with an arc extinguishing gas composed of nitrogen and sulfur hexafluoride. It also includes a pressure frame 2, a coil 3, a guide post 4, a pressure plate 5, a static plate 6, a lower connecting wire 7, a locking member 8, a diversion assembly 9, and an arc extinguishing grid 10. Two pressure frames 2 are respectively connected to the upper and lower sides of the housing 1. The pressure frame 2 is used to communicate with the external circuit. The upper end of the coil 3 is connected to the lower side of the upper pressure frame 2. The guide post 4 is arranged inside the coil 3. When current flows through the coil 3, a magnetic force will be generated. The magnetic force will exert a traction on the guide post 4, causing the guide post 4 to have an upward movement tendency. The pressure plate 5 is fixedly connected to the lower side of the guide post 4. The movement of the guide post 4 will drive the pressure plate 5 to move. The static plate 6 is fixedly connected to the lower end of the coil 3. The lower connecting wire 7 is connected to the upper side of the lower pressure frame 2 and is in contact with the static plate 6. When the lower connecting wire 7 is in contact with the static plate 6, they are connected. The locking member 8 is connected between the pressure plate 5 and the lower connecting wire 7. The diversion assembly 9 is connected to the lower connecting wire 7. The two ends of the arc extinguishing grid 10 are respectively connected to the static plate 6 and the lower connecting wire 7. During a short circuit, the coil 3 drives the pressure plate 5 to move upward through the guide post 4 to release the limit on the locking member 8. The locking member 8 pushes the lower connecting wire 7 to move downward to disconnect from the static plate 6. When the lower connecting wire 7 moves downward, the diversion assembly 9 blows a pressurized air flow towards the middle of the arc extinguishing grid 10.

[0031] By setting the diversion assembly 9, on the one hand, it can effectively accelerate the contact efficiency between the arc extinguishing gas and the arc, thereby rapidly reducing the temperature of the arc, reducing the temperature when the arc contacts the arc extinguishing grid 10, and improving the service life of the arc extinguishing grid 10. On the other hand, the air flow acts on the middle of the arc, thereby increasing the bending amplitude of the arc to elongate the arc, effectively increasing the voltage, making it difficult for the arc to maintain, and at the same time increasing the heat dissipation area of the arc, thereby effectively shortening the arc maintenance time. On the third hand, the blowing of the pressurized air flow effectively speeds up the movement speed of the arc towards the arc extinguishing grid 10, thereby improving the arc extinguishing efficiency of the device.

[0032] As an implementation manner of the present invention, referring to Figure 2 and Figure 8, the front end of the pressing plate 5 is connected to the spring plate 501. The spring plate 501 is arc-shaped. When pressing the spring plate 501 from top to bottom, the spring plate 501 can be deformed. When pressing the spring plate 501 from bottom to top, the spring plate 501 cannot be deformed. The static piece 6 is bent. One end of the static piece 6 is connected to the coil 3, and the other end of the static piece 6 is connected to the arc extinguishing grid 10. A push spring 401 is connected to the top of the guide post 4. When there is no short circuit, the pulling force of the magnetic force of the coil 3 on the guide post 4 is less than the pushing force of the push spring 401 on the guide post 4. The lower connecting wire 7 includes a spring piece 701, a moving piece 702, a current guiding piece 703, and a current guiding piece 704. The right end of the spring piece 701 is connected to the inner cavity of the housing 1. The moving piece 702 is connected to the left end of the spring piece 701, and the lower end of the moving piece 702 is connected to the lower pressing frame 2. The current guiding piece 703 is connected to the left side of the moving piece 702. The current guiding piece 704 is slidably connected to the left end of the current guiding piece 703. The connecting end of the current guiding piece 703 and the moving piece 702 is arc-shaped.

[0033] By providing the lower connecting wire 7, the guide post 4 is moved down to a specified position by the push spring 401, thereby realizing the limiting of the locking member 8. When the spring piece 701 is bent, it will drive the moving piece 702 and the current guiding piece 703 to move. The movement of the current guiding piece 703 increases the gap with the static piece 6, improves the stretching speed of the arc, and thus improves the arc extinguishing efficiency.

[0034] As an implementation manner of the present invention, refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 8, the locking member 8 includes a knob 801, a limiting rod 802 and a torsion spring 803. The knob 801 is connected to the front end of the housing 1. The knob 801 can rotate, and a rubber ring is used for sealing between the knob 801 and the housing 1. Both limiting rods 802 are connected to the rear side of the knob 801. The limiting rod 802 is fixedly connected to the knob 801. The two limiting rods 802 are symmetrically arranged about the central axis of the knob 801. The two ends of the torsion spring 803 are respectively connected to the knob 801 and the housing 1. When the knob 801 is rotated, the torsion spring 803 can be stressed, and one limiting rod 802 slides down from top to bottom over the spring plate 501. The two limiting rods 802 are respectively in contact with the adjacent sides of the spring plate 501 and the reed piece 701. When not short-circuited, the sum of the pulling force of the magnetic force of the coil 3 on the limiting rod 802 and the driving force of the torsion spring 803 to drive the knob 801 to reset is less than the pushing force of the push spring 401 on the limiting rod 802. At this time, when the knob 801 is released, the limiting rod 802 that has slid over the spring plate 501 is limited by the spring plate 501. Furthermore, the torsion spring 803 cannot drive the limiting rod 802 to reset. The shortest distance from the left side of the spring plate 501 to the longitudinal central plane of the knob 801 is greater than the radius value of the limiting rod 802. When the plane passing through the center lines of the two limiting rods 802 is vertical, the spring plate 501 moves downwards and does not contact the limiting rod 802. The diversion assembly 9 includes a closed box 901, a baffle 902, a sliding plate 903, a magnetic plate 904 and an air film 905. The closed box 901 is connected to the left side of the inner cavity of the housing 1, and the closed box 901 is located below the diversion piece 703. The baffle 902 is connected to the lower side of the diversion piece 703. The baffle 902 is slidably connected to the closed box 901. The sliding plate 903 is slidably connected to the front and rear sides of the upper surface of the baffle 902. The two magnetic plates 904 are respectively connected to the left and right sides of the inner cavity of the closed box 901. When the lower lead wire 7 does not move downwards, the lower end surface of the baffle 902 is higher than the top surface of the closed box 901. Furthermore, there is a gap between the baffle 902 and the closed box 901, which is convenient for the arc extinguishing gas to flow into the closed box 901. After the baffle 902 moves downwards into the closed box 901, the inner cavity of the closed box 901 can be partitioned. The lower end surface of the left magnetic plate 904 is higher than the upper end surface of the right magnetic plate 904. Both ends of the sliding plate 903 have magnetism. Furthermore, during the downward movement of the sliding plate 903, the two magnetic plates 904 attract the sliding plate 903 in stages to adjust the position of the sliding plate 903. The surfaces of the sliding plate 903 and the baffle 902 are both provided with air holes 9021. When the lower lead wire 7 does not move downwards, the air holes 9021 on the surfaces of the sliding plate 903 and the baffle 902 are staggered. A through hole 9022 is provided in the middle of the surface of the sliding plate 903. The through hole 9022 is communicated with the middle air hole 9021.

[0035] By setting the locking member 8, when the current is not flowing or in a normal state, the push spring 401 pushes the limit rod 802 downward to a fixed position. At this time, the knob 801 is rotated so that a limit rod 802 slides down the reed plate 501 from top to bottom. At this time, the torsion spring 803 applies an upward force, and the limit rod 802 passing through the reed plate 501 is limited by the reed plate 501. At this time, the reed piece 701 is in a straight state, making the moving piece 702 in contact with the static piece 6, and the circuit is connected. When a short circuit occurs, the magnetism of the coil 3 increases, causing the limit rod 802 to move upward, compressing the push spring 401. Furthermore, the reed plate 501 limits the limit rod 802, and the torsion spring 803 drives the knob 801 to reset. Then, the limit rod 802 rotates and presses the reed piece 701, causing the reed piece 701 to move downward. The downward movement of the reed piece 701 drives the baffle 902 to move into the inner cavity of the closed box 901, causing the air flow in the closed box 901 to be discharged through the air hole 9021. The discharged air hole 9021 acts on the arc, thereby reducing the temperature of the arc. At the same time, due to the action of the air flow, the bending amplitude of the arc increases, and the contact area between the arc and the arc extinguishing gas increases, thereby improving the arc extinguishing speed. At the same time, due to the limited air flow discharged through the air hole 9021, the air film 905 expands to accommodate the air flow.

[0036] As an embodiment of the present invention, referring to Figure 7 and Figure 8 , the arc extinguishing grid 10 includes a mounting frame 1001, a pull plate 1002, a double-layer metal sheet 1003, and grid pieces 1004. The mounting frame 1001 is fixedly connected to the upper side of the bent piece. The mounting frame 1001 is rotatably connected to the outer shell 1. The mounting frame 1001 has strong magnetism. The pull plate 1002 is slidably connected to the mounting frame 1001. The double-layer metal sheet 1003 is connected to the top of the drainage piece 704 and is also connected to the left side of the pull plate 1002. The grid pieces 1004 are arranged in an array on the mounting frame 1001. The double-layer metal sheet 1003 is composed of two metal sheets with different coefficients of thermal expansion, and the coefficient of thermal expansion of the right metal sheet is greater than that of the left metal sheet. Therefore, when the arc contacts the double-layer metal sheet 1003, the double-layer metal sheet 1003 is heated and bent, driving the pull plate 1002 to move. The front end surface of the pull plate 1002 is connected with a plurality of clamping blocks 10021. The clamping blocks 10021 correspond to the grid pieces 1004, and the distance value between the left and right sides of the clamping blocks 10021 gradually increases from right to left. When the double-layer metal sheet 1003 is not heated, the right end of the clamping block 10021 is in contact with the grid piece 1004.

[0037] By providing the arc extinguishing grid 10, when the arc moves into the arc extinguishing grid 10, the double-layer metal sheet 1003 is heated and bends. The lower end of the double-layer metal sheet 1003 is the fixed end. Thus, the upper end of the double-layer metal sheet 1003 deforms and drives the pull plate 1002 to move. The pull plate 1002 elongates the distance between the grid sheets 1004 through the latch 10021, thereby achieving the elongation of the arc, increasing the arc cooling speed, and achieving the purpose of improving the arc extinguishing efficiency. At the same time, the increase in the distance between the grid sheets 1004 reduces the interlacing range of the arc extinguishing gas between adjacent grid sheets 1004, thereby improving the cooling efficiency of the grid sheets 1004.

[0038] Working principle: In the process of arc extinguishing, the present invention continuously elongates the arc to increase the contact area between the arc and the arc extinguishing gas, accelerate the arc cooling speed, and thereby achieve the purpose of improving the arc extinguishing efficiency. Specifically: When the current flows normally, the magnetic force generated by the coil 3 is small. At this time, turn the knob 801 so that a limiting rod 802 slides across the reed plate 501 from the upper side of the reed plate 501. Release the knob 801, and the tendency of the torsion spring 803 to drive the limiting rod 802 to reset through the knob 801 is blocked by the reed piece 701 and cannot be reset. Thus, the circuit remains connected at this time; When a short circuit occurs, the magnetic force generated by the coil 3 increases. At this time, the guide post 4 moves upward, driving the pressure plate 5 to move upward. The pressure plate 5 drives the reed plate 501 to move upward, thereby releasing the limitation on the limiting rod 802. The torsion spring 803 drives the knob 801 to rotate, causing another limiting rod 802 to squeeze the reed piece 701, causing the reed piece 701 to bend. The bending of the reed piece 701 drives the moving piece 702 to separate from the static piece 6. At this time, an arc is generated between the moving piece 702 and the static piece 6, and one end of the arc moves along the static piece 6 towards the arc extinguishing grid 10, and the other end of the arc moves towards the arc extinguishing grid 10 through the current guiding piece 703 and the current guiding piece 704; During the movement of the arc, the reed piece 701 drives the current guiding piece 703 to move downward through the moving piece 702. During the movement of the current guiding piece 703, it drives the baffle 902 to move downward to shield the closed box 901. At this time, the gas in the closed box 901 is discharged through the middle air hole 9021 and the through hole 9022 and acts on the middle of the arc, thereby increasing the bending amplitude of the arc, achieving the elongation of the arc. At the same time, the airflow flowing through the arc accelerates the arc cooling efficiency. When the arc moves to the arc extinguishing grid 10, the arc contacts the double-layer metal sheet 1003. The high temperature of the arc causes the double-layer metal sheet 1003 to bend. Thus, the upper end of the double-layer metal sheet 1003 bends. The double-layer metal sheet 1003 drives the pull plate 1002 to move leftward. The movement of the pull plate 1002 drives the latch 10021 to contact the grid sheets 1004 in sequence and drives the grid sheets 1004 to move, thereby elongating the distance between the grid sheets 1004, achieving the elongation of the arc, thereby increasing the voltage of the arc and increasing the contact area between the arc and the arc extinguishing gas, improving the arc extinguishing efficiency; In order to further improve the arc extinguishing efficiency, in this solution, the air flow accelerates the movement speed of the arc, and when the arc moves to the arc extinguishing grid 10, the acting area of the air flow on the grid plates 1004 is increased, thereby reducing the temperature of the grid plates 1004 and achieving the improvement of the arc extinguishing efficiency. Specifically, when the baffle 902 moves downward, the air flow acts on the middle part of the arc, thereby driving the arc to move towards the arc extinguishing grid 10. As the baffle 902 moves downward, the magnetic plate 904 pulls the slide plate 903 to move to the right, so that the air holes 9021 on the surface of the baffle 902 are communicated with the air holes 9021 on the surface of the slide plate 903. Then, the air flow formed by the arc extinguishing gas is accelerated to be discharged and acts on the grid plates 1004, reducing the temperature of the grid plates 1004. At the same time, the contact between the arc extinguishing gas and the arc at the grid plates 1004 speeds up the arc extinguishing efficiency.

[0039] Although the embodiments of the present invention have been described, for those of ordinary skill in the art, under the understanding of the principles and spirit of the present invention, the embodiments can be changed and modified to obtain other effects. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A small high-voltage DC protector, comprising a housing (1), characterized in that: It further includes a pressure frame (2), a coil (3), a guide post (4), a pressure plate (5), a stationary contact piece (6), a lower connecting wire (7), a locking member (8), a current guiding assembly (9) and an arc extinguishing grid (10). The two pressure frames (2) are respectively connected to the upper and lower sides of the housing (1). The upper end of the coil (3) is connected to the lower side of the upper pressure frame (2). The guide post (4) is arranged inside the coil (3). The pressure plate (5) is connected to the lower side of the guide post (4). The stationary contact piece (6) is connected to the lower end of the coil (3). The lower connecting wire (7) is connected to the upper side of the lower pressure frame (2) and is in contact with the stationary contact piece (6). The locking member (8) is connected between the pressure plate (5) and the lower connecting wire (7). The current guiding assembly (9) is connected to the lower connecting wire (7). The two ends of the arc extinguishing grid (10) are respectively connected to the stationary contact piece (6) and the lower connecting wire (7). During a short circuit, the coil (3) drives the pressure plate (5) to move upward through the guide post (4) to release the limit on the locking member (8). The locking member (8) pushes the lower connecting wire (7) to move downward to disconnect from the stationary contact piece (6). When the lower connecting wire (7) moves downward, the current guiding assembly (9) blows a pressurized air flow towards the middle of the arc extinguishing grid (10).

2. The small high-voltage DC protector according to claim 1, wherein: A spring plate (501) is connected to the front end of the pressure plate (5). The spring plate (501) is arc-shaped. The stationary contact piece (6) is bent. A push spring (401) is connected to the top of the guide post (4).

3. The small high-voltage DC protector according to claim 2, wherein: The lower connecting wire (7) includes a spring piece (701), a movable piece (702), a current guiding piece (703) and a diversion piece (704). The right end of the spring piece (701) is connected to the inner cavity of the housing (1). The movable piece (702) is connected to the left end of the spring piece (701). The current guiding piece (703) is connected to the left side of the movable piece (702). The diversion piece (704) is slidably connected to the left end of the current guiding piece (703). The connection end of the current guiding piece (703) and the movable piece (702) is arc-shaped.

4. The small high-voltage DC protector according to claim 3, wherein: The locking member (8) includes a knob (801), a limiting rod (802) and a torsion spring (803). The knob (801) is connected to the front end of the housing (1). The two limiting rods (802) are both connected to the rear side of the knob (801) and are symmetrically arranged about the central axis of the knob (801). The two ends of the torsion spring (803) are respectively connected to the knob (801) and the housing (1). The spring plate (501) is arc-shaped. The two limiting rods (802) are respectively in contact with the adjacent sides of the spring plate (501) and the spring piece (701). The shortest distance from the left side of the spring plate (501) to the longitudinal central plane of the knob (801) is greater than the radius value of the limiting rod (802).

5. The small high-voltage DC protector according to claim 4, characterized in that: The flow guiding assembly (9) includes a closed box (901), a baffle (902), a sliding plate (903), a magnetic plate (904) and an air film (905). The closed box (901) is connected to the left side of the inner cavity of the outer shell (1), and the closed box (901) is located below the flow guiding vane (703). The baffle (902) is connected to the lower side of the flow guiding vane (703). The sliding plate (903) is connected to the front and rear sides of the upper surface of the baffle (902). The two magnetic plates (904) are respectively connected to the left and right sides of the inner cavity of the closed box (901). When the lower lead wire (7) does not move downward, the lower end surface of the baffle (902) is higher than the top surface of the closed box (901).

6. The small high-voltage DC protector according to claim 5, characterized in that: The lower end surface of the left magnetic plate (904) is higher than the upper end surface of the right magnetic plate (904). Both ends of the sliding plate (903) have magnetism.

7. A small high-voltage DC protector according to claim 5, characterized in that: Horn-shaped air holes (9021) with smaller ends facing upward are formed on the surfaces of the sliding plate (903) and the baffle (902), and the central axes of the air holes (9021) are inclined. When the lower lead wire (7) does not move downward, the air holes (9021) on the surfaces of the sliding plate (903) and the baffle (902) are arranged in an alternating manner. A through hole (9022) is formed in the middle of the surface of the sliding plate (903), and the through hole (9022) is communicated with the middle air hole (9021).

8. The miniaturized high-voltage DC protector according to claim 7, characterized in that: The arc extinguishing grid (10) includes a mounting frame (1001), a pulling plate (1002), a double-layer metal sheet (1003) and grid sheets (1004). The mounting frame (1001) is connected to the upper side of the static vane (6). The pulling plate (1002) is connected to the mounting frame (1001). The double-layer metal sheet (1003) is connected to the top of the flow guiding vane (704). The grid sheets (1004) are connected to the mounting frame (1001) in an array. The double-layer metal sheet (1003) is composed of two metal sheets with different thermal expansion coefficients, and the thermal expansion coefficient of the right metal sheet is greater than that of the left metal sheet.

9. The small high-voltage DC protector according to claim 8, characterized in that: A plurality of clamping blocks (10021) are connected to the front end surface of the pulling plate (1002). The clamping blocks (10021) correspond to the grid sheets (1004), and the distance between the left and right sides of the clamping blocks (10021) gradually increases from right to left.

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