Direct-current switch cabinet pressure relief device

Abstract

The utility model discloses a direct-current switch cabinet pressure relief device, which mainly relates to the technical field of switch appliances and comprises a switch cabinet top plate, a switch cabinet cover plate and a switch cabinet spring mechanism which are combined to play a role and can be automatically reset after pressure relief. When pressure relief is not needed, the pressure relief cover plate can cover the pressure relief hole to prevent dust and water from entering the switch cabinet to cause a series of problems such as short circuit. When the internal pressure of the switch cabinet is increased, the pressure relief cover plate can be quickly opened, an air spring is arranged in the pressure relief device, the opening speed of the pressure relief cover plate can be increased, after the pressure relief action is completed, the pressure relief cover plate automatically returns to the original state under the action of gravity, and the air spring in the pressure relief device can reduce the resetting speed of the pressure relief cover plate, so that the pressure relief effect is improved. Pressure relief gas in the switch cabinet is exhausted as soon as possible, short-circuit breaking failure of the direct-current switch cabinet caused by incomplete exhaust of the pressure relief gas is prevented, and the safety and reliability of the direct-current switch cabinet are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of switch appliances, in particular to a pressure relief device for a DC switch cabinet. Background Technique

[0002] DC switch cabinets are widely used in DC traction power supply systems of rail transit such as subways and light rails. The rail transit DC switch cabinet is a device that provides monitoring, control, and protection for the traction power supply system in the rail transit field. Generally, it is integrated on devices such as rail transit DC switch cabinets and overhead lines, and is a basic component of rail transit power supply equipment, ensuring the safety of the last line of defense of the rail transit traction power supply system. These switch cabinets are mainly used in rail transit systems such as subways and light rails. With the rapid development of China's economy and the maturity of rail transit technology, more and more Chinese cities have started to build subways, light rails, etc., resulting in an increasing demand for rail transit power supply equipment in China.

[0003] DC switch cabinets play an important role in the subway DC power supply system. Currently, the most commonly used is the 1500V DC switch cabinet. These switch cabinets are mainly used in DC traction power supply systems for DC power distribution, realizing the measurement, control, protection of equipment such as feeders, overhead lines, or contact rails, and bus communication with upper-level monitoring equipment. The structure of the DC switch cabinet includes components such as an incoming line cabinet, a feeder cabinet, and a negative pole cabinet. Among them, the incoming line cabinet is used to install equipment between the positive pole of the rectifier and the DC1500V positive busbar to realize the control of feeding power from the rectifier unit to the DC1500V DC positive busbar.

[0004] A fast self - resetting pressure relief mechanism for a switch cabinet disclosed in the authorized announcement number CN207116928U includes a pressure relief top and a pressure relief flap door. There is a door on the high - voltage chamber of the switch cabinet. The pressure relief top includes a front part and a rear part. The front part of the pressure relief top is connected to the door, and a pressure relief channel opening is provided at the rear part of the pressure relief top. The upper edge of the pressure relief channel opening is connected to the pressure relief flap door through a hinge, and the pressure relief flap door covers the pressure relief channel opening under the action of gravity. This self - resetting pressure relief mechanism has strong protection ability and can automatically recover after pressure relief. However, this self - resetting pressure relief mechanism has a risk that the pressure relief pressure cannot offset the self - weight of the pressure relief cover plate, resulting in the inability to open the pressure relief cover plate.

[0005] For example, a pressure relief and waterproof top for a busbar chamber disclosed in the authorized announcement number CN214428932U includes a pressure relief and waterproof top, a water baffle, a diversion plate and a filter screen. The pressure relief and waterproof top is arranged at the top of the busbar chamber and is communicated with the busbar chamber. A water baffle with a bending treatment is arranged on the long side of the top of the pressure relief and waterproof top, and a diversion plate is arranged on the short side of the top of the pressure relief and waterproof top. A grid is arranged on the side of the pressure relief and waterproof top, and a filter screen is arranged on the surface of the grid. This pressure relief and waterproof top is provided with a dedicated pressure relief channel to timely discharge the fault arc gas. However, the pressure relief and waterproof top needs to be welded with cold-rolled steel plates, with complex processing and high production costs. At the same time, the pressure relief channel is arranged on the side, with a small pressure relief area and limited pressure relief capacity.

[0006] In summary, there are many drawbacks in the existing ones, which are summarized as follows:

[0007] ①When a short-circuit fault occurs inside the DC switchgear or the DC circuit breaker interrupts the short-circuit current, a large amount of arc light and gas will be generated in the DC switchgear, which may cause the DC switchgear to burst under strong pressure, endangering the safety of personnel and equipment;

[0008] ②The existing DC switchgears generally adopt the mode of pressure relief through a mesh plate. There are many problems with pressure relief through a mesh plate. Since there are large mesh holes on the mesh plate, it will cause the protection level of the DC switchgear to decrease, and it cannot prevent dust and dripping water from entering the DC switchgear, resulting in a series of problems such as short circuits;

[0009] ③Some DC switchgears adopt a recoverable pressure relief mechanism, but the structure is complex, and there is a risk that the pressure relief pressure cannot offset the self-weight of the pressure relief cover plate, resulting in the inability to open the pressure relief cover plate. Content of the Utility Model

[0010] In view of the deficiencies of the prior art, the present utility model provides a pressure relief device for a DC switchgear to solve the above problems.

[0011] To achieve the above objectives, the present utility model is realized through the following technical solutions.

[0012] A pressure relief device for a DC switchgear includes a switchgear top plate, a cover plate and a spring mechanism. The switchgear top plate and the cover plate are connected by a hinge. The switchgear top plate is provided with a top plate support and a pressure relief hole. There is a top plate hem around the pressure relief hole. The cover plate is provided with a cover plate support and a cover plate hem. The spring mechanism includes a gas spring, a top plate support and a cover plate support. The top plate support and the cover plate support are connected by a gas spring.

[0013] Preferably, when the gas spring stretches or contracts, it can drive the cover plate to rotate along the hinge.

[0014] Preferably, a limit support is provided on the switchgear top plate.

[0015] Preferably, the limiting support member restricts the movement range of the cover plate connecting hinge to less than 90°, preventing the cover plate from being unable to reset after the pressure relief action.

[0016] Preferably, the limiting support member is fixed to the top plate of the switchgear cabinet by screws.

[0017] Preferably, the gas spring and the top plate support member are movably connected.

[0018] Preferably, the gas spring and the cover plate support member are movably connected.

[0019] Preferably, the spring mechanism is symmetrically arranged on the top plate of the switchgear cabinet.

[0020] Preferably, the top plate hem and the top plate of the switchgear cabinet are processed by steel plate welding, and the cover plate hem and the cover plate are processed by steel plate welding. Steel plate welding does not require drilling holes in the steel, which saves labor and time and does not reduce the cross-sectional area of the material, making full use of the material.

[0021] Preferably, the manufacturing materials of the top plate and the cover plate of the switchgear cabinet are epoxy glass cloth boards. Epoxy glass cloth boards have high mechanical and dielectric properties, good heat resistance and good moisture resistance, etc., and are suitable for the manufacture of high-insulation structural parts for machinery, electrical appliances and electronics.

[0022] Compared with the prior art, the present utility model discloses a pressure relief device for a DC switchgear cabinet, which includes the combination of a switchgear cabinet top plate, a cover plate and a spring mechanism to play a role.

[0023] ① The pressure relief device has high reliability and can be automatically reset after pressure relief. When pressure relief is not required, the pressure relief cover plate can cover the pressure relief hole to prevent dust and dripping water from entering the switchgear cabinet;

[0024] ② When the internal pressure of the switchgear cabinet increases, the pressure relief cover plate can be quickly opened; a gas spring is arranged inside the pressure relief device to accelerate the opening speed of the pressure relief cover plate and prevent the situation that the pressure relief cover plate cannot be opened due to the pressure relief pressure being unable to offset the self-weight of the pressure relief cover plate;

[0025] ③ After the pressure relief action is completed, the pressure relief cover plate automatically returns to the original state under the action of gravity; the gas spring inside the pressure relief device can reduce the reset speed of the pressure relief cover plate, so that the pressure relief gas inside the switchgear cabinet can be discharged as soon as possible, preventing the DC switchgear cabinet from short-circuit breaking failure due to incomplete discharge of the pressure relief gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic front view structure diagram of the whole of the present utility model;

[0027] Figure 2 It is a schematic left view structure diagram of the whole of the present utility model;

[0028] Figure 3 Schematic diagram of the cover plate of the present utility model when it rotates to a certain angle (θ1) along the hinge;

[0029] Figure 4 Schematic diagram of the cover plate of the present utility model when it is reset only by the elastic force of the gas spring and its own gravity;

[0030] Figure 5 Rear view schematic diagram of the whole of the present utility model;

[0031] Figure 6 Schematic diagram of the front view of the whole of the present utility model without pressure relief;

[0032] Figure 7 Schematic diagram of the left view of the whole of the present utility model without pressure relief;

[0033] Figure 8 Schematic diagram of the left view of the whole of the present utility model without the spring structure installed; Detailed implementation manners

[0034] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments.

[0035] Embodiment 1

[0036] A pressure relief device for a DC switch cabinet includes a switch cabinet top plate 1, a cover plate 2, and a spring mechanism. The switch cabinet top plate 1 and the cover plate 2 are connected by a hinge 10. The switch cabinet top plate 1 is provided with a top plate support member 4 and a pressure relief hole 8. A top plate flange 7 is provided around the pressure relief hole 8. The cover plate 2 is provided with a cover plate support member 5 and a cover plate flange 9. The spring mechanism includes a gas spring 3, a top plate support member 4, and a cover plate support member 5. The top plate support member 4 and the cover plate support member 5 are connected by the gas spring 3.

[0037] When the gas spring 3 stretches or contracts, it can drive the cover plate 2 to rotate along the hinge 10.

[0038] The switch cabinet top plate 1 is provided with a limit support member 6.

[0039] The limit support member 6 is fixed to the switch cabinet top plate 1 by screws.

[0040] The limit support member 6 limits the movement range of the cover plate 2 connected to the hinge 10 to be less than 90°, preventing the cover plate from being unable to reset after the pressure relief action.

[0041] The gas spring 3 and the top plate support member 4 are movably connected.

[0042] The gas spring 3 and the cover plate support 5 are movably connected.

[0043] The spring mechanism is symmetrically arranged on the top plate 1 of the switchgear cabinet. The gas spring 3 can be installed and used on both sides of the top plate 1 of the switchgear cabinet and the cover plate 2.

[0044] The top plate hem 7 and the top plate 1 of the switchgear cabinet are processed by steel plate welding. The cover plate hem 9 and the cover plate 2 are processed by steel plate welding. Steel plate welding does not require drilling holes in the steel, which saves time and labor and does not reduce the cross-sectional area of the material, making full use of the material.

[0045] The materials for making the top plate 1 and the cover plate 2 of the switchgear cabinet are epoxy glass cloth boards. Epoxy glass cloth boards have high mechanical and dielectric properties, good heat resistance and good moisture resistance, and are suitable for making high-insulation structural parts for machinery, electrical appliances and electronics.

[0046] The implementation scenario is that when the pressure relief device of the DC switchgear cabinet does not need to relieve pressure, such as Figure 6 , Figure 7 , Figure 8 As shown, the cover plate 2 covers the pressure relief hole 8 under the action of gravity. Since the top plate hem 4 is arranged around the pressure relief hole 8 on the top plate 1 of the switchgear cabinet and the cover plate hem 9 is arranged around the cover plate 2, the top plate hem 4 and the cover plate hem 9 can effectively prevent dust, humid air or external dripping water from entering the switchgear cabinet. When there is no need to relieve pressure, at this time the gas spring 3 is in a compressed state, and the gas spring 3 generates an upward acting force on the cover plate 2. At this time, the elastic force of the gas spring 3 is F3, and the angle between the gas spring 3 and the cover plate 2 is θ3. Then the upward force generated by the gas spring 3 on the cover plate 2 is F3*sin(θ3). As long as the moment generated by this acting force F3*sin(θ3) is less than the moment generated by the self-gravity of the cover plate 2, the cover plate 2 will be in a static state.

[0047] The implementation scenario is that the pressure relief device of the DC switchgear cabinet starts to relieve pressure, such as Figure 1 , Figure 2 , Figure 3 As shown, when a short circuit, arc ignition and other faults occur inside the DC switchgear cabinet and the temperature and internal air pressure in the high-voltage chamber rise sharply, the cover plate 2 is subjected to an upward pressure. When the moment of this pressure and the upward acting force generated by the gas spring 3 on the cover plate 2 is greater than the moment of the self-gravity of the cover plate 2, the cover plate 2 rotates upward along the hinge 10, and the pressure relief device starts to relieve pressure. During the process of the cover plate 2 rotating upward along the hinge 10, the gas spring 3 generates an upward acting force on the cover plate 2. Therefore, the gas spring 3 can accelerate the movement of the cover plate 2, make the cover plate 2 open faster, and improve the pressure relief speed of the pressure relief device.

[0048] The real-time scenario is the reset after pressure relief. The cover plate 2 is no longer subject to the upward pressure relief pressure. At this time, whether the cover plate 2 is reset is only affected by the elastic force of the gas spring 3 and the gravity of the cover plate 2 itself. As Figure 3 and Figure 4 shown, when the cover plate 2 rotates around the hinge 10 to a certain angle (θ1), the limit support 6 can block the cover plate 2 to prevent the cover plate 2 from rotating beyond a certain angle (θ1). At this time, the gravity of the cover plate 2 is F1, the angle between the cover plate 2 and the horizontal plane is (θ1), and the equivalent moment length of the cover plate 2 is L1. Then the moment generated by the gravity of the cover plate 2 for downward rotation is F1 * cos(θ1) * L1. The angle between the gas spring 3 and the cover plate 2 is (θ2), the elastic force of the gas spring 3 is F2, and the moment length of the gas spring 3 is L2. Then the moment generated by the gas spring 3 for upward rotation is F2 * sin(θ2) * L2. When F1 * cos(θ1) * L1 > F2 * sin(θ2) * L2, that is, when the moment generated by the gravity of the cover plate 2 for downward rotation is greater than the moment generated by the gas spring 3 for upward rotation, the cover plate 2 starts to move downward, and the pressure relief device starts the reset action. During the downward movement of the cover plate 2, since the angles θ1 and θ2 are continuously decreasing, cos(θ1) will continuously increase, and sin(θ2) will continuously decrease. By selecting a suitable gas spring 3, it can be ensured that during the downward movement of the cover plate 2, the moment generated by the gravity of the cover plate 2 for downward rotation is always greater than the moment generated by the gas spring 3 for upward rotation, so that the cover plate 2 continues to move downward until the cover plate 2 reaches the horizontal position. Since then, the pressure relief device automatically completes a reset. During this process, since the cover plate 2 is subject to the moment generated by the gas spring 3 for upward rotation, the descending speed of the cover plate 2 will be slower than that without the gas spring 3, so that the pressure relief device can quickly discharge the gas inside the switch cabinet and achieve the function of rapid pressure relief.

[0049] Embodiment 2

[0050] Based on the above Embodiment 1 with other technical features unchanged, the gas spring 3 can be installed and used on one side of the top plate 1 and the cover plate 2 of the switch cabinet.

[0051] It should be noted that the terms used here are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used here, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0052] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of this application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here.

[0053] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. For those skilled in the art, the present utility model can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A pressure relief device for a DC switch cabinet, characterized in that: It includes a switchgear cabinet top plate (1), a cover plate (2) and a spring mechanism. The switchgear cabinet top plate (1) and the cover plate (2) are connected by a hinge (10). The switchgear cabinet top plate (1) is provided with a top plate support (4) and a pressure relief hole (8). There is a top plate hem (7) around the pressure relief hole (8). The cover plate (2) is provided with a cover plate support (5) and a cover plate hem (9). The spring mechanism includes a gas spring (3), a top plate support (4) and a cover plate support (5). The top plate support (4) and the cover plate support (5) are connected by the gas spring (3).

2. The pressure relief device for a DC switch cabinet according to claim 1, wherein: When the gas spring (3) stretches or contracts, it can drive the cover plate (2) to rotate along the hinge (10).

3. The pressure relief device for a DC switch cabinet according to claim 1, characterized in that: A limit support (6) is provided on the switchgear cabinet top plate (1).

4. The pressure relief device for a DC switch cabinet according to claim 3, wherein: The limit support (6) is fixed to the switchgear cabinet top plate (1) by screws.

5. The pressure relief device for a DC switchgear according to claim 3, characterized in that: The limit support (6) limits the movement range of the cover plate (2) connected to the hinge (10) to be less than 90°.

6. The pressure relief device for a DC switch cabinet according to claim 1, wherein: The gas spring (3) is movably connected to the top plate support (4).

7. The pressure relief device for a DC switch cabinet according to claim 1, characterized in that: The gas spring (3) is movably connected to the cover plate support (5).

8. The pressure relief device for a DC switch cabinet according to claim 1, wherein: The spring mechanism is symmetrically arranged on the switchgear cabinet top plate (1).

9. The pressure relief device for a DC switch cabinet according to claim 1, characterized in that: The top plate hem (7) and the switchgear cabinet top plate (1) are processed by steel plate welding. The cover plate hem (9) and the cover plate (2) are processed by steel plate welding.

10. A pressure relief device for a DC switch cabinet according to claim 1, characterized in that: The manufacturing materials of the switchgear cabinet top plate (1) and the cover plate (2) are epoxy glass cloth boards.

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