Arc extinguishing system of low-voltage direct-current circuit breaker

Abstract

The invention provides an arc extinguishing system of a low-voltage direct-current circuit breaker, and belongs to the field of arc extinguishing of low-voltage direct-current circuit breakers, the arc extinguishing system comprises a shell and an operating handle arranged in the shell, the shell is internally provided with an arc extinguishing chamber, and the arc extinguishing system further comprises a trigger gas injection mechanism, a trigger gas injection mechanism and an arc extinguishing mechanism, the arc extinguishing mechanism is arranged in the arc extinguishing chamber; according to the invention, through the arrangement of the trigger gas injection mechanism linked with the operating handle, when the low-voltage circuit breaker is powered off, the operating handle trips, nitrogen forms high-speed airflow through an injection channel, the airflow speed can be greatly increased, and the airflow direction and the direction of breaking an arc by the arc extinguishing sheet form an included angle of 45 degrees, so that the low-voltage circuit breaker is powered off. The air flow can blow the surface of the arc more effectively, the contact area between the arc and the surrounding medium is increased, cooling of the arc is facilitated, meanwhile, breaking arc extinguishing is conducted in cooperation with the arc extinguishing mechanism, and the arc extinguishing effect can be improved.

Description

Technical Field

[0001] The present invention relates to the field of arc extinguishing for low-voltage DC circuit breakers, and more particularly, to an arc extinguishing system for low-voltage DC circuit breakers. Background Art

[0002] Low-voltage circuit breakers, also known as automatic air switches, are mainly used in AC and DC low-voltage power grids. They can be manually or electrically operated to break and connect circuits, and can protect circuits or electrical equipment against overload, short circuit, and undervoltage. They can also be used to start motors infrequently. They are an important control and protection electrical appliance. A low-voltage circuit breaker is a switching electrical appliance that can not only connect and disconnect normal load currents and overload currents, but also connect and disconnect short-circuit currents. In addition to its control function in the circuit, a low-voltage circuit breaker also has certain protection functions, such as overload, short-circuit, undervoltage, and leakage protection; In a low-voltage circuit breaker, an arc extinguishing device is usually provided inside to extinguish the arc generated by the contacts in the electrical equipment to ensure the safe operation of the electrical equipment. Most current arc extinguishing devices use multiple sets of arranged arc extinguishing plates to eliminate the arc generated during breaking. When a large current is broken between the moving and static contacts and an arc is generated, the arc will be drawn into the arc extinguishing plates under the action of the contraction force of the magnetic field lines, dividing a long arc into multiple short arcs, which plays a role in cooling the arc and also cools the arc extinguishing gas and deionizes it, thereby achieving the arc extinguishing effect. Research shows that during the arc extinguishing process, the more the number of arc extinguishing plates used to cut the arc in the arc extinguishing chamber, the higher the voltage drop across the arc, and the arc cannot maintain combustion and is quickly extinguished, and the breaking capacity is better; Most current low-voltage circuit breaker arc extinguishing devices improve the effect of breaking the arc by increasing the number of arc extinguishing plates. However, the space inside the arc extinguishing chamber is limited. Increasing multiple sets of arc extinguishing plates will occupy more space, resulting in the blockage of the air flow channel, affecting the cooling effect of the arc, and preventing the arc from being effectively cooled, which will cause the arc extinguishing plates to be ablated or reignited. Seriously, it may cause internal short circuit or fire in the circuit breaker, affecting the arc extinguishing effect. Secondly, when a fire occurs in the arc extinguishing chamber of a current low-voltage circuit breaker, it is difficult to quickly extinguish the fire, which will affect the surrounding electrical equipment and lead to the problem of power system paralysis. How to invent an arc extinguishing system for low-voltage DC circuit breakers to improve these problems has become an urgent problem for those skilled in the art. Summary of the Invention

[0003] To make up for the above deficiencies, the present invention provides an arc extinguishing system for low-voltage DC circuit breakers, aiming to improve the problem that most current low-voltage circuit breaker arc extinguishing devices improve the effect of breaking the arc by increasing the number of arc extinguishing plates. However, the space inside the arc extinguishing chamber is limited. Increasing multiple sets of arc extinguishing plates will occupy more space, resulting in the blockage of the air flow channel, affecting the cooling effect of the arc, and preventing the arc from being effectively cooled.

[0004] The present invention is implemented as follows: The present invention provides an arc extinguishing system for a low-voltage DC circuit breaker, comprising a shell and an operating handle arranged in the shell, wherein an electromagnetic solenoid is arranged in the shell, a contact is arranged at one end of the electromagnetic solenoid, a main contact is arranged in the shell, a line solenoid mechanical structure is arranged in the shell, an adjustment screw is arranged in the shell, a bimetallic strip is arranged at one end of the adjustment screw, a line outlet is arranged at one end of the bimetallic strip, the other end of the electromagnetic solenoid contacts the line solenoid mechanical structure, the line solenoid mechanical structure contacts the main contact, the main contact contacts the bimetallic strip, a vent is provided on the outer side wall of the shell, an arc extinguishing chamber is arranged in the shell, and further comprises: a trigger gas injection mechanism: the trigger gas injection mechanism is arranged in the arc extinguishing chamber; an arc extinguishing mechanism, the arc extinguishing mechanism is arranged in the arc extinguishing chamber; a fire extinguishing mechanism, the fire extinguishing mechanism is arranged in the arc extinguishing chamber.

[0005] Preferably, the trigger gas injection mechanism includes an injection seat provided on the inner wall of the arc extinguishing chamber, six groups of injection channels are opened inside the injection seat, six groups of air intake hoods connected to the injection channels are provided on the side wall of the injection seat, and one end of the six groups of air intake hoods is provided with a connecting pipe, the outer wall of the shell is provided with a fixed pipe, one end of the connecting pipe is connected to the inside of the fixed pipe, the outer wall of the fixed pipe is provided with a gas supply pipe, the outer wall of the shell is provided with an air pressure chamber, one end of the air supply pipe is connected to the air pressure chamber, a one-way solenoid valve is provided inside the air supply pipe, a piston head is slidably provided in the air pressure chamber, and a piston is provided on the side wall of the piston head Rod, the outer wall of the shell is provided with a sleeve, and a movable plate is slidably connected in the sleeve, one end of the piston rod passes through the side wall of the sleeve and is connected to the side wall of the movable plate, and the other side wall of the movable plate is provided with a movable rod, the outer wall of the movable rod is sleeved with a storage spring, one end of the storage spring is connected to the inner wall of the sleeve, and the other end of the storage spring is connected to the side wall of the movable plate, the side wall of the shell is provided with a guide rail, and a guide block is slidably connected in the guide rail, one end of the movable rod passes through the inner wall of the sleeve and is connected to the side wall of the guide block, the guide block side wall is hinged with a connecting rod, and one end of the connecting rod is hinged to the side wall of the operating handle.

[0006] Preferably, the arc extinguishing mechanism includes multiple groups of first arc extinguishing plates, second arc extinguishing plates and third arc extinguishing plates transversely arranged on the inner wall of the arc extinguishing chamber, and splicing plates are arranged on the tops of the multiple groups of first arc extinguishing plates, second arc extinguishing plates and third arc extinguishing plates. A first insulating plate is installed through the multiple groups of the first arc extinguishing plates, a second insulating plate is installed through the multiple groups of the second arc extinguishing plates, and a third insulating plate is installed through the multiple groups of the third arc extinguishing plates, and six groups of cooling fins are arranged on the inner wall of the arc extinguishing chamber.

[0007] Preferably, the six groups of heat dissipation fins are arranged between the first arc-extinguishing plate, the second arc-extinguishing plate and the third arc-extinguishing plate, and are in contact with the side walls of the first arc-extinguishing plate, the second arc-extinguishing plate and the third arc-extinguishing plate.

[0008] Preferably, the heights of the first arc-extinguishing pieces, the second arc-extinguishing pieces and the third arc-extinguishing pieces are arranged in sequence from low to high, and the arrangement spacing between the multiple groups of first arc-extinguishing pieces, the second arc-extinguishing pieces and the third arc-extinguishing pieces is reduced in sequence.

[0009] Preferably, the injection channel is arranged in a Venturi shape, and the injection channel and the first arc-extinguishing piece are arranged at an angle of 45 degrees.

[0010] Preferably, a plurality of groups of guide plates are provided on the inner wall of the arc extinguishing chamber, and the plurality of groups of guide plates are distributed in a linear array on the inner wall of the arc extinguishing chamber, and the guide plates are arranged in an arc shape.

[0011] Preferably, outer walls of the first arc-extinguishing piece, the second arc-extinguishing piece and the third arc-extinguishing piece are all provided with a metal oxide composite coating.

[0012] Preferably, the fire extinguishing mechanism comprises an ultraviolet flame sensor provided on the inner wall of the arc extinguishing chamber, a fire extinguishing tank is provided on the inner wall of the arc extinguishing chamber, a delivery pipe is provided at one end of the fire extinguishing tank, a spray plate is provided on the inner wall of the arc extinguishing chamber, and a plurality of groups of nozzles are provided on the side wall of the spray plate.

[0013] Preferably, the spray plate is arranged in an inclined shape in the arc extinguishing chamber, a plurality of groups of spray heads are distributed in a linear array on the side wall of the spray plate, and the spray heads are made of aluminum alloy material.

[0014] The beneficial effects of the present invention are: 1. The present invention sets a trigger gas injection mechanism linked with the operating handle. When the low-voltage circuit breaker is powered off, the operating handle trips (relative to the separation of the main contacts), and the force storage spring is released, so that the piston head can move quickly and squeeze the nitrogen in the air pressure chamber. The nitrogen forms a high-speed airflow through the injection channel, and the airflow speed is greatly improved. The airflow direction forms a 45-degree angle with the direction in which the arc extinguishing piece breaks the arc, so that the airflow can blow the arc surface more effectively, increase the contact area between the arc and the surrounding medium, help cool the arc, and promote the elongation and diffusion of the arc. The elongated arc increases the arc length, so that the arc voltage increases, and the conductivity of the arc gap is reduced, which is conducive to the extinction of the arc; at the same time, the arc extinguishing mechanism is used to break the arc, which can improve the arc extinguishing effect. Therefore, the combination of the trigger gas injection mechanism and the arc extinguishing mechanism can ensure the internal space of the arc extinguishing chamber, and there is no need to increase the arc extinguishing effect by adding arc extinguishing pieces, so that the airflow channel between the arc extinguishing pieces is smooth, and the arc extinguishing effect is further improved. 2. The present invention provides heat dissipation fins, which can cooperate with high-speed airflow to carry the heat of the arc-extinguishing plate out of the vents, thereby reducing the temperature of the arc-extinguishing plate, preventing the arc from reigniting, avoiding heat accumulation in the arc-extinguishing chamber, reducing the risk of arc-extinguishing plate ablation or reignition, and improving safety; 3. By providing a fire extinguishing mechanism in the present invention, the ultraviolet flame sensor can detect the reignition of the electric arc or open fire. When a fire breaks out in the arc extinguishing chamber, it can quickly extinguish the fire, avoiding the problem that the fire spreads and affects the surrounding electrical equipment, resulting in the paralysis of the power system, and further improving the safety of the low-voltage DC circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0016] Figure 1 is a schematic diagram of the overall structure of a low-voltage DC circuit breaker arc extinguishing system provided by an embodiment of the present invention; Figure 2 is a rear view of the structure of a low-voltage DC circuit breaker arc extinguishing system provided by an embodiment of the present invention; Figure 3 is a schematic diagram of the structure of a trigger gas injection mechanism of a low-voltage DC circuit breaker arc extinguishing system provided by an embodiment of the present invention; Figure 4 is a schematic diagram of the structure of an injection channel and an air inlet hood of a low-voltage DC circuit breaker arc extinguishing system provided by an embodiment of the present invention; Figure 5 is a schematic diagram of the structure of an arc extinguishing mechanism of a low-voltage DC circuit breaker arc extinguishing system provided by an embodiment of the present invention; Figure 6 is a side view of the structure of an arc extinguishing mechanism of a low-voltage DC circuit breaker arc extinguishing system provided by an embodiment of the present invention; Figure 7 is a schematic diagram of the structure of heat dissipation fins of a low-voltage DC circuit breaker arc extinguishing system provided by an embodiment of the present invention; Figure 8 is a schematic diagram of an arc extinguishing piece and a metal oxide composite coating of a low-voltage DC circuit breaker arc extinguishing system structure provided by an embodiment of the present invention; Figure 9 is a low-voltage DC circuit breaker arc extinguishing system provided by an embodiment of the present invention Figure 1 enlarged view of the structure at A in.

[0017] In the figure: 1, housing; 2, operating handle; 3, electromagnetic solenoid; 4, contact; 5, arc extinguishing chamber; 6, trigger gas injection mechanism; 600, connecting rod; 601, guide rail; 602, guide block; 603, movable rod; 604, sleeve; 605, storage spring; 606, movable plate; 607, piston rod; 608, piston head; 609, air pressure chamber; 610, one-way electromagnetic valve; 611, gas delivery pipe; 612, fixed pipe; 613, injection seat; 614, injection channel; 615, air intake cover; 616, connecting pipe; 7, arc extinguishing mechanism; 70 0. First arc-extinguishing plate; 701. First insulating plate; 702. Second arc-extinguishing plate; 703. Second insulating plate; 704. Third arc-extinguishing plate; 705. Third insulating plate; 706. Splicing plate; 707. Heat dissipation fins; 8. Fire extinguishing mechanism; 800. Fire extinguishing tank; 801. Delivery pipe; 802. Spray plate; 803. Spray head; 804. Ultraviolet flame sensor; 9. Ventilation port; 10. Guide plate; 11. Main contact; 12. Adjustment screw; 13. Bimetallic strip; 14. Outlet terminal; 15. Wire coil mechanical structure; 16. Metal oxide composite coating. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Example, see Figures 1-9 A low voltage DC circuit breaker arc extinguishing system comprises a housing 1 and an operating handle 2 arranged in the housing 1, an electromagnetic solenoid 3 is arranged in the housing 1, a contact 4 is arranged at one end of the electromagnetic solenoid 3, a main contact 11 is arranged in the housing 1, a wire solenoid mechanical structure 15 is arranged in the housing 1, an adjusting screw 12 is arranged in the housing 1, a bimetallic strip 13 is arranged at one end of the adjusting screw 12, an outlet terminal 14 is arranged at one end of the bimetallic strip 13, the other end of the electromagnetic solenoid 3 is in contact with the wire solenoid mechanical structure 15, the wire solenoid mechanical structure 15 is in contact with the main contact 11, and the main contact 11 is in contact with the wire solenoid mechanical structure 15. The bimetallic strips 13 are in contact with each other, a vent 9 is provided on the outer wall of the shell 1, an arc extinguishing chamber 5 is provided inside the shell 1, a plurality of guide plates 10 are provided on the inner wall of the arc extinguishing chamber 5, the plurality of guide plates 10 are distributed in a linear array on the inner wall of the arc extinguishing chamber 5, the guide plates 10 are arranged in an arc shape, and with the cooperation of the guide plates 10, the electric arc can be guided into the arc extinguishing chamber 5 for arc extinguishing, and also includes: a triggering gas injection mechanism 6: the triggering gas injection mechanism 6 is arranged in the arc extinguishing chamber 5; an arc extinguishing mechanism 7, the arc extinguishing mechanism 7 is arranged in the arc extinguishing chamber 5; a fire extinguishing mechanism 8, the fire extinguishing mechanism 8 is arranged in the arc extinguishing chamber 5.

[0020] The trigger gas injection mechanism 6 includes an injection seat 613 provided on the inner wall of the arc extinguishing chamber 5, six groups of injection channels 614 are opened inside the injection seat 613, six groups of air inlet covers 615 connected to the injection channels 614 are provided on the side wall of the injection seat 613, and one end of each of the six groups of air inlet covers 615 is provided with a connecting pipe 616, a fixed pipe 612 is provided on the outer wall of the shell 1, one end of the connecting pipe 616 is connected to the inside of the fixed pipe 612, a gas delivery pipe 611 is provided on the outer wall of the fixed pipe 612, an air pressure chamber 609 is provided on the outer wall of the shell 1, one end of the gas delivery pipe 611 is connected to the air pressure chamber 609, a one-way solenoid valve 610 is provided inside the gas delivery pipe 611, a piston head 608 is slidably provided in the air pressure chamber 609, and a piston rod 607 is provided on the side wall of the piston head 608, and the shell A sleeve 604 is provided on the outer wall of the body 1, and a movable plate 606 is slidably connected inside the sleeve 604. One end of the piston rod 607 passes through the side wall of the sleeve 604 and is connected to the side wall of the movable plate 606. A movable rod 603 is provided on the other side wall of the movable plate 606. A force storage spring 605 is sleeved on the outer wall of the movable rod 603. One end of the force storage spring 605 is connected to the inner wall of the sleeve 604, and the other end of the force storage spring 605 is connected to the side wall of the movable plate 606. A guide rail 601 is provided on the side wall of the shell 1. A guide block 602 is slidably connected inside the guide rail 601. One end of the movable rod 603 passes through the inner wall of the sleeve 604 and is connected to the side wall of the guide block 602. The side wall of the guide block 602 is hinged with a connecting rod 600, and one end of the connecting rod 600 is hinged to the side wall of the operating handle 2.

[0021] It should be noted that: when the low-voltage circuit breaker is powered off, the operating handle 2 trips (relative to when the main contact 11 is separated), the force storage spring 605 is released, so that the piston head 608 can move quickly and squeeze the nitrogen in the air pressure chamber 609. The nitrogen forms a high-speed airflow through the injection channel 614, and the airflow speed will be greatly increased. The airflow direction is at a 45-degree angle to the direction in which the arc extinguishing plate breaks the arc, so that the airflow can blow the arc surface more effectively, increase the contact area between the arc and the surrounding medium, help cool the arc, and promote the elongation and diffusion of the arc. The elongated arc increases the arc length, which increases the arc voltage and reduces the conductivity of the arc gap, which is beneficial to the extinction of the arc.

[0022] The arc extinguishing mechanism 7 includes that multiple groups of first arc extinguishing plates 700, second arc extinguishing plates 702 and third arc extinguishing plates 704 are horizontally arranged on the inner wall of the arc extinguishing chamber 5. Splicing plates 706 are provided at the tops of multiple groups of first arc extinguishing plates 700, second arc extinguishing plates 702 and third arc extinguishing plates 704. A first insulating plate 701 is installed through between multiple groups of first arc extinguishing plates 700. A second insulating plate 703 is installed through between multiple groups of second arc extinguishing plates 702. A third insulating plate 705 is installed through between multiple groups of third arc extinguishing plates 704. Six heat dissipation fins 707 are provided on the inner wall of the arc extinguishing chamber 5. The six heat dissipation fins 707 are arranged between the first arc extinguishing plates 700, second arc extinguishing plates 702 and third arc extinguishing plates 704 and are in contact with the side walls of the first arc extinguishing plates 700, second arc extinguishing plates 702 and third arc extinguishing plates 704. The heights of the first arc extinguishing plates 700, second arc extinguishing plates 702 and third arc extinguishing plates 704 are arranged in ascending order, and the arrangement distances between every two of multiple groups of first arc extinguishing plates 700, second arc extinguishing plates 702 and third arc extinguishing plates 704 are gradually reduced in sequence.

[0023] It should be noted that: the heights of the arc extinguishing plates are arranged in ascending order. When the electric arc passes through the arc extinguishing plates, the electric arc will be gradually stretched and dispersed. The stretching of the electric arc increases the arc length, raises the arc voltage, reduces the conductivity of the arc gap, and is beneficial to the extinction of the electric arc. At the same time, when the electric arc passes through the arc extinguishing plates with different heights, it will be divided into shorter arc segments multiple times. These short arc segments are easier to extinguish. Moreover, the arrangement distances between every two of multiple groups of arc extinguishing plates are gradually reduced in sequence, further enhancing the dispersion and stretching effects of the electric arc, improving the arc extinguishing efficiency. At the same time, the flow channels between the arc extinguishing plates will also change and bend, increasing the residence time of the electric arc in the arc extinguishing plates, increasing the contact time between the electric arc and the arc extinguishing plates. A longer contact time means that the electric arc has more opportunities to exchange heat with the arc extinguishing plates. The heat of the electric arc can be absorbed and dispersed by the arc extinguishing plates more quickly, helping to reduce the arc temperature, promote the extinction of the electric arc, and improve the arc extinguishing effect; the arc extinguishing plates will absorb the heat of the electric arc during arc extinguishing. Under the action of the heat dissipation fins 707, the heat can be dissipated, so as to cooperate with the high-speed air flow to carry the heat out from the ventilation port 9, reduce the temperature of the arc extinguishing plates, prevent the electric arc from reigniting, avoid the accumulation of heat in the arc extinguishing chamber 5, reduce the risk of ablation or reignition of the arc extinguishing plates, and improve the safety.

[0024] The injection channel 614 is arranged in a Venturi shape, and the injection channel 614 is arranged at an angle of 45 degrees with the first arc extinguishing plate 700.

[0025] It should be noted that: The injection channel 614 adopts a converging-diverging Venturi structure, and the air flow velocity will increase significantly. When the air flow blows the electric arc at an angle of 45 degrees, the air flow can more effectively blow the surface of the electric arc, increasing the contact area between the electric arc and the surrounding medium, contributing to the cooling of the electric arc, and also promoting the elongation and diffusion of the electric arc. The elongated electric arc increases the arc length, causing the arc voltage to rise, while reducing the conductivity of the arc gap, which is beneficial to the extinction of the electric arc.

[0026] Metal oxide composite coatings 16 are provided on the outer walls of the first arc extinguishing plate 700, the second arc extinguishing plate 702, and the third arc extinguishing plate 704.

[0027] It should be noted that: The metal oxide composite coating 16 has good thermal conductivity and electrical insulation properties. During the arc extinguishing process, when the electric arc is generated, the coating can quickly absorb and disperse the heat generated by the electric arc, reducing the arc temperature, thereby accelerating the extinction of the electric arc. During the combustion process of the electric arc, high temperature and strong electrical corrosion will be generated, causing serious damage to the surface of the arc extinguishing plate. The metal oxide composite coating 16 has good high-temperature resistance and corrosion resistance, and can effectively resist the erosion of the electric arc, extending the service life of the arc extinguishing plate.

[0028] The fire extinguishing mechanism 8 includes an ultraviolet flame sensor 804 provided on the inner wall of the arc extinguishing chamber 5, a fire extinguishing tank 800 provided on the inner wall of the arc extinguishing chamber 5, a delivery pipe 801 provided at one end of the fire extinguishing tank 800, a spray plate 802 provided on the inner wall of the arc extinguishing chamber 5, a plurality of spray nozzles 803 provided on the side wall of the spray plate 802. The spray plate 802 is inclined in the arc extinguishing chamber 5, and the plurality of spray nozzles 803 are linearly arrayed on the side wall of the spray plate 802, and the spray nozzles 803 are made of aluminum alloy material.

[0029] It should be noted that: The ultraviolet flame sensor 804 is electrically connected to an external controller CPU. When the ultraviolet flame sensor 804 detects the re-ignition of the electric arc or a fire, it will quickly send a signal to the CPU. The CPU processes the signal and conveys an instruction to the corresponding actuator (the actuator is the fire extinguishing tank 800). The fire extinguishing agent in the fire extinguishing tank 800 is quickly delivered from the delivery pipe 801 into the spray plate 802, and then sprayed out through the spray nozzles 803, enabling rapid fire extinguishing.

[0030] The working principle of the arc extinguishing system of a low-voltage DC circuit breaker: when a load, short circuit or leakage occurs during the use of the low-voltage DC circuit breaker, the operating handle 2 will trip quickly to cut off the power. At this time, an arc will appear. With the cooperation of the guide plate 10, the arc can be guided to the first arc extinguishing plate 700, the second arc extinguishing plate 702 and the third arc extinguishing plate 704. When the operating handle 2 trips (when it does not trip, the storage spring 605 is in a squeezed state), it will drive the connecting rod 600 to rotate, and the connecting rod 600 will drive the guide block 602 to move on the guide rail 601. Under the action of the elastic force of the storage spring 605, it will quickly drive the movable plate 606 to move, and at the same time, the movable plate 606 drives the piston rod 607 and the piston The piston head 608 moves, and the piston head 608 can squeeze the nitrogen in the air pressure chamber 609. The nitrogen enters the air delivery pipe 611 through the one-way solenoid valve 610, and enters the injection channel 614 through the fixed pipe 612 and the air inlet cover 615. The nitrogen forms a high-speed airflow through the injection channel 614 (the injection channel 614 adopts a gradually contracting-gradually expanding Venturi structure, and the airflow speed will be greatly improved). The airflow direction is at an angle of 45 degrees to the direction in which the arc extinguishing piece breaks the arc, which can accelerate the cooling of the arc. Then, the arc passes through the first arc extinguishing piece 700, the second arc extinguishing piece 702 and the third arc extinguishing piece 704 with gradually decreasing spacing in sequence, so that the arc can be gradually broken and finally extinguished, which can improve the arc extinguishing effect. When the cooled arc passes between the first arc extinguishing plate 700, the second arc extinguishing plate 702 and the third arc extinguishing plate 704, the high-speed airflow will carry the heat emitted by the heat dissipation fins 707 out from the vent 9, thereby reducing the temperature of the arc extinguishing plates, preventing the arc from reigniting, and reducing the risk of arc erosion or reignition of the arc extinguishing plates; The ultraviolet flame sensor 804 can detect the re-ignition of an arc or an open flame. The fire extinguisher in the fire extinguisher tank 800 is quickly transported from the delivery pipe 801 to the spray plate 802, and then sprayed out through the nozzle 803, which can quickly extinguish the fire and prevent the fire from expanding and affecting surrounding electrical equipment.

[0031] It should be noted that the specific model and specifications of the ultraviolet flame sensor need to be selected and determined based on the actual specifications of the device, and the specific selection calculation method adopts the existing technology in this field, so it will not be described in detail.

[0032] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-voltage DC circuit breaker arc extinguishing system, comprising a housing (1) and an operating handle (2) disposed within the housing (1). An electromagnetic solenoid (3) is provided within the housing (1). One end of the electromagnetic solenoid (3) is provided with a contact point (4). A main contact (11) is provided within the housing (1). A wire solenoid mechanical structure (15) is provided within the housing (1). An adjusting screw (12) is provided within the housing (1). One end of the adjusting screw (12) is provided with a bimetallic strip (13). One end of the bimetallic strip (13) is provided with an outgoing line end (14). The other end of the electromagnetic solenoid (3) is in contact with the wire solenoid mechanical structure (15). The wire solenoid mechanical structure (15) is in contact with the main contact (11). The main contact (11) is in contact with the bimetallic strip (13). A ventilation opening (9) is formed on the outer sidewall of the housing (1). An arc extinguishing chamber (5) is provided within the housing (1), characterized in that, Also includes: Trigger gas injection mechanism (6): the trigger gas injection mechanism (6) is arranged in the arc extinguishing chamber (5); An arc extinguishing mechanism (7), wherein the arc extinguishing mechanism (7) is arranged in the arc extinguishing chamber (5); A fire extinguishing mechanism (8), wherein the fire extinguishing mechanism (8) is arranged in the arc extinguishing chamber (5).

2. The arc extinguishing system of a low-voltage DC circuit breaker according to claim 1, characterized in that, The trigger gas injection mechanism (6) comprises an injection seat (613) provided on the inner wall of the arc extinguishing chamber (5), six groups of injection channels (614) are provided inside the injection seat (613), six groups of air inlet covers (615) connected to the injection channels (614) are provided on the side wall of the injection seat (613), and one end of each of the six groups of air inlet covers (615) is provided with a connecting pipe (616), and the outer wall of the shell (1) is provided with a fixing pipe (612), one end of the connecting pipe (616) The fixed tube (612) is connected to the inside of the fixed tube (612), the outer wall of the fixed tube (612) is provided with an air supply pipe (611), the outer wall of the shell (1) is provided with an air pressure chamber (609), one end of the air supply pipe (611) is connected to the air pressure chamber (609), a one-way solenoid valve (610) is provided inside the air supply pipe (611), a piston head (608) is slidably provided inside the air pressure chamber (609), and a piston rod (607) is provided on the side wall of the piston head (608). The outer wall of the housing (1) is provided with a sleeve (604), and a movable plate (606) is slidably connected inside the sleeve (604). One end of the piston rod (607) passes through the side wall of the sleeve (604) and is connected to the side wall of the movable plate (606). The other side wall of the movable plate (606) is provided with a movable rod (603). The outer wall of the movable rod (603) is sleeved with a force storage spring (605), and one end of the force storage spring (605) is slidably connected to the inner wall of the sleeve (604). The other end of the force storage spring (605) is connected to the side wall of the movable plate (606); the side wall of the housing (1) is provided with a guide rail (601); a guide block (602) is slidably connected inside the guide rail (601); one end of the movable rod (603) passes through the inner wall of the sleeve (604) and is connected to the side wall of the guide block (602); the side wall of the guide block (602) is hingedly provided with a connecting rod (600); one end of the connecting rod (600) is hingedly connected to the side wall of the operating handle (2).

3. The arc extinguishing system of a low-voltage DC circuit breaker according to claim 1, characterized in that, The arc extinguishing mechanism (7) comprises a plurality of groups of first arc extinguishing plates (700), second arc extinguishing plates (702) and third arc extinguishing plates (704) arranged transversely on the inner wall of the arc extinguishing chamber (5); a splicing plate (706) is arranged on the top of the plurality of groups of first arc extinguishing plates (700), second arc extinguishing plates (702) and third arc extinguishing plates (704); a first insulating plate (701) is installed through the plurality of groups of the first arc extinguishing plates (700); a second insulating plate (703) is installed through the plurality of groups of the second arc extinguishing plates (702); a third insulating plate (705) is installed through the plurality of groups of the third arc extinguishing plates (704); and six groups of heat dissipation fins (707) are arranged on the inner wall of the arc extinguishing chamber (5).

4. The arc extinguishing system of a low-voltage DC circuit breaker according to claim 3, characterized in that, Six groups of the heat dissipation fins (707) are arranged between the first arc extinguishing plate (700), the second arc extinguishing plate (702) and the third arc extinguishing plate (704), and are in contact with the side walls of the first arc extinguishing plate (700), the second arc extinguishing plate (702) and the third arc extinguishing plate (704).

5. The arc extinguishing system of a low-voltage DC circuit breaker according to claim 3, characterized in that The heights of the first arc extinguishing plate (700), the second arc extinguishing plate (702) and the third arc extinguishing plate (704) are arranged in ascending order, and the arrangement intervals between every two of the multiple groups of the first arc extinguishing plate (700), the second arc extinguishing plate (702) and the third arc extinguishing plate (704) are gradually reduced.

6. The arc extinguishing system of a low-voltage DC circuit breaker according to claim 2, characterized in that, The injection channel (614) is arranged in a Venturi shape, and the injection channel (614) is arranged at an angle of 45 degrees with the first arc extinguishing plate (700).

7. A low-voltage DC circuit breaker arc extinguishing system according to claim 1, characterized in that, A plurality of groups of flow guiding plates (10) are arranged on the inner wall of the arc extinguishing chamber (5), and the plurality of groups of flow guiding plates (10) are distributed in a linear array on the inner wall of the arc extinguishing chamber (5), and the flow guiding plates (10) are arranged in an arc shape.

8. The arc extinguishing system of a low-voltage DC circuit breaker according to claim 3, characterized in that, Metal oxide composite coatings (16) are provided on the outer walls of the first arc extinguishing plate (700), the second arc extinguishing plate (702) and the third arc extinguishing plate (704).

9. The arc extinguishing system of a low-voltage DC circuit breaker according to claim 1, characterized in that, The fire extinguishing mechanism (8) includes an ultraviolet flame sensor (804) provided on the inner wall of the arc extinguishing chamber (5), a fire extinguishing tank (800) provided on the inner wall of the arc extinguishing chamber (5), a delivery pipe (801) provided at one end of the fire extinguishing tank (800), a spray plate (802) provided on the inner wall of the arc extinguishing chamber (5), and a plurality of nozzles (803) provided on the side wall of the spray plate (802).

10. The arc extinguishing system of a low-voltage DC circuit breaker according to claim 9, characterized in that, The spray plate (802) is arranged obliquely in the arc extinguishing chamber (5), the plurality of nozzles (803) are distributed in a linear array on the side wall of the spray plate (802), and the nozzles (803) are made of aluminum alloy material.

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