Plastic explosion-proof pressure release valve

Abstract

The utility model discloses a plastic explosion-proof pressure release valve, and relates to the technical field of pressure release valves. The plastic explosion-proof pressure release valve comprises a main body, a guide column, a gland and a spring, external threads are arranged outside the main body, the interior of the main body is vertically through, a plurality of guide seats are arranged on the inner wall of the main body, the guide column is movably assembled in the main body, and guide grooves matched with protruding structures at the ends of the guide seats are formed in the periphery of the guide column. A pressure relief channel is formed between the whole circumference of the guide column and the main body, the gland is fixedly assembled at the upper end of the guide column, the guide column is sleeved with the spring, the spring abuts against the main body, and the spring is used for driving the gland to make contact with the upper end of the main body so as to close the pressure relief channel. The gland drives the guide column to move relative to the body, the spring is pressed, and the pressure relief channel is opened to achieve pressure relief. The plastic explosion-proof pressure release valve has the advantages of being convenient to assemble, good in protection effect, high in reliability and high in pressure release capacity.

Description

Technical Field

[0001] The present application relates to the technical field of pressure relief valves, and in particular to a plastic explosion-proof pressure relief valve. Background Art

[0002] Common battery packs and enclosed enclosures require dust and water protection, necessitating an internal design that is sealed to the outside. Furthermore, due to its lightweight design, the battery pack enclosure can withstand minimal pressure. When a new energy vehicle or energy storage facility is operating, the battery pack heats up, causing the internal pressure to rise. This results in an imbalance in the pressure difference between the inside and outside of the battery pack, adversely affecting the equipment. When a battery chip unit experiences thermal runaway, the pressure inside the battery pack suddenly rises, damaging the pack and posing a threat to equipment and personnel safety. The solution is to design an appropriate pressure relief valve to balance the pressure difference inside and outside the battery pack, reducing potential risks. This valve also allows for rapid pressure relief in the event of thermal runaway in new energy vehicles or energy storage equipment, minimizing the risk of damage from the battery pack.

[0003] A problem with existing pressure relief valve devices is that when the pressure difference between the battery pack and the external environment is small, the pressure relief valve's low permeability prevents it from effectively balancing the pressure inside and outside the battery pack. In the event of thermal runaway in a battery chip unit, the large amount of gas released is difficult to expel quickly. Utility Model Content

[0004] The purpose of this application is to provide a plastic explosion-proof pressure relief valve, which has air permeability, dustproof, waterproof and fire-retardant effects, can automatically adjust the internal and external pressure difference, and can quickly relieve pressure when the battery pack is thermally runaway; the plastic explosion-proof pressure relief valve has the characteristics of easy assembly, good protection effect, high reliability and strong pressure relief capacity.

[0005] To achieve the above-mentioned objectives, the present application provides a plastic explosion-proof pressure relief valve, including a main body, a guide column, a pressure cover and a spring, the outside of the main body is provided with an external thread, the interior of the main body is connected up and down, and a plurality of guide seats are provided on the inner wall of the main body, the guide column is movably assembled inside the main body, the outer periphery of the guide column is provided with a guide groove that cooperates with the convex structure at the end of the guide seat, and a pressure relief channel is formed between the entire periphery of the guide column and the main body, the pressure cover is fixedly assembled on the upper end of the guide column, the spring is sleeved on the guide column, the spring abuts against the main body, and the spring is used to drive the pressure cover to contact the upper end of the main body to realize the closing of the pressure relief channel, and when the pressure difference between the pressure relief channel and the outside world reaches a set value, the pressure cover drives the guide column to move relative to the main body, the spring is compressed, and the pressure relief channel opens to realize pressure relief.

[0006] In some embodiments, the plastic explosion-proof pressure relief valve further includes a protective sheet, which is fixedly assembled on the gland, and the protective sheet is located on the side of the gland facing the main body.

[0007] In some embodiments, the pressure cover is provided with a sealing surface, an assembly seat and an assembly surface on the side facing the main body, the assembly seat is annular, the sealing surface is located on the outer ring of the assembly seat, the assembly surface is located on the inner ring of the assembly seat, the sealing surface is used for contact and sealing with the main body, the assembly seat is used for fixed assembly with the pressure cover, and the assembly surface is used for fixed assembly with the protective sheet.

[0008] In some embodiments, a connecting hole is provided on the assembly seat, a mounting hole matching the connecting hole is provided on the guide column, and the plastic explosion-proof pressure relief valve further includes an elastic pin, which is installed in the mounting hole and the connecting hole.

[0009] In some embodiments, a positioning groove is further provided on the assembly seat, and a protrusion is provided on the guide column to cooperate with the positioning groove. After the protrusion cooperates with the positioning groove, the elastic pin is used to fix the pressure cover and the guide column.

[0010] In some embodiments, the protective sheet is glued and fixed to the pressure cover.

[0011] In some embodiments, the main body, the guide column and the pressure cover are made of plastic structure, and the protective sheet is made of stainless steel structure.

[0012] In some embodiments, a rubber protrusion is provided on the upper end of the main body. The rubber protrusion is annular and surrounds the upper end opening of the main body. The rubber protrusion is used to contact and seal with the sealing surface.

[0013] In some embodiments, the upper end of the spring and the main body abut against the lower side of the guide seat, the lower end of the guide column is provided with an outwardly protruding frustum, and the lower end of the spring and the guide column abut against the upper side of the frustum.

[0014] In some embodiments, the cross-sectional shape of the interior of the main body is circular, the frustum is loosely fitted with the main body, and the frustum is restricted by the guide seat and moves below the guide seat.

[0015] Compared with the above-mentioned background technology, the plastic explosion-proof pressure relief valve provided in the present application mainly includes a main body, a guide column, a pressure cover and a spring. The outside of the main body is provided with an external thread, the interior of the main body is connected up and down, and a plurality of guide seats are provided on the inner wall of the main body. The guide column is movably assembled inside the main body, and the outer periphery of the guide column is provided with a guide groove that cooperates with the raised structure at the end of the guide seat. A pressure relief channel is formed between the entire circumference of the guide column and the main body. The pressure cover is fixedly assembled on the upper end of the guide column, and the spring is sleeved on the guide column. The spring is in contact with the main body. The spring is used to drive the pressure cover to contact with the upper end of the main body to realize the closure of the pressure relief channel, and when the pressure difference between the pressure relief channel and the outside world reaches the set value, the pressure cover drives the guide column to move relative to the main body, the spring is pressurized, and the pressure relief channel opens to realize pressure relief.

[0016] This plastic explosion-proof pressure relief valve can be applied to structures that need to adjust the internal and external pressure difference and provide explosion-proof pressure relief function, such as battery packs or closed boxes. When in use, the plastic explosion-proof pressure relief valve is installed on the battery pack or closed box through the external thread provided on the outside of the main body; during use, because the main body is installed on the battery pack or closed box, the interior of the main body is connected with the interior of the battery pack or closed box, so the pressure relief channel is connected with the interior of the battery pack or closed box, and the internal pressure of the battery pack or closed box can be reflected in the pressure relief channel; if the internal and external pressure difference is small, that is, the pressure difference between the pressure relief channel and the outside world has not reached the set value, then the pressure cover and the guide column maintain a static motion state under the action of the spring, and the pressure relief channel is closed by the contact between the pressure cover and the upper end of the main body. At this time, the battery pack or closed box can be dustproof, waterproof and fire-resistant; if the internal and external pressure difference is large, that is, the pressure difference between the pressure relief channel and the outside world reaches the set value, the pressure cover and the guide column will overcome the action of the spring under the action of the internal pressure and move, and the pressure cover will open under the guidance of the main body on the guide column. The spring is pressurized and the pressure relief channel opens to achieve pressure relief. At this time, the battery pack or closed box can be breathable; if the battery pack has thermal runaway, the pressure cover will open the pressure relief channel, and since the pressure relief channel is formed between the entire circumference of the guide column and the main body, it is equivalent to increasing the cross-sectional area of ​​the pressure relief channel, thereby achieving the effect of rapid pressure relief.

[0017] Combined with the above structure and process description, it can be seen that the plastic explosion-proof pressure relief valve has at least the following beneficial effects: the plastic explosion-proof pressure relief valve is breathable, dustproof, waterproof, and fire-retardant, can automatically adjust the internal and external pressure difference, and can quickly relieve pressure when the battery pack is thermally runaway; the plastic explosion-proof pressure relief valve has the characteristics of easy assembly, good protection effect, high reliability and strong pressure relief capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0019] Figure 1 A schematic diagram of an explosion of a plastic explosion-proof pressure relief valve provided in an embodiment of the present application;

[0020] Figure 2 A schematic structural diagram of a plastic explosion-proof pressure relief valve provided in an embodiment of the present application;

[0021] Figure 3 This is a diagram of the internal structure of the plastic explosion-proof pressure relief valve provided in an embodiment of the present application;

[0022] Figure 4 A schematic diagram of the effect of the plastic explosion-proof pressure relief valve provided in an embodiment of the present application;

[0023] Figure 5 A schematic structural diagram of a guide post provided in an embodiment of the present application;

[0024] Figure 6 A schematic diagram of the structure of the subject provided in the embodiment of the present application;

[0025] Figure 7 A schematic structural diagram of the gland provided in an embodiment of the present application.

[0026] in:

[0027] 1. Guide column; 2. Spring; 3. Sealing ring; 4. Main body; 5. Elastic pin; 6. Protective sheet; 7. Gland;

[0028] 101, round table; 102, mounting hole; 103, protrusion; 104, guide groove;

[0029] 401, raised structure; 402, rubber raised structure; 403, inner wall;

[0030] 701, sealing surface; 702, connecting hole; 703, positioning groove; 704, assembly surface. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0032] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0033] For pressure relief valves, especially those suitable for battery packs and closed boxes, it is necessary to consider the problem of balancing the pressure difference between the inside and outside of the battery pack, as well as the problem of sudden pressure increase in the battery pack when the battery chip unit experiences thermal runaway. At present, conventional pressure relief valves have the following technical disadvantages: the existing explosion-proof pressure relief valve has a complex structure, requiring multiple parts to be connected through threaded connections, interference fit, gluing, and other processes. There are many parts, the process is complicated, and the cost is high; the valve body and seal of the existing explosion-proof pressure relief valve are independent parts, which are assembled together through the installation process, which has poor protection effect and complicated processes; the existing explosion-proof pressure relief valve has structures or parts in the gas flow direction that occupy the airflow channel, resulting in low reliability of the pressure relief valve and reduced pressure relief capacity.

[0034] In response to the problems existing in the conventional pressure relief valve mentioned above, this application provides a plastic explosion-proof pressure relief valve, please refer to Figures 1 to 3 ,in, Figure 1 This is a schematic diagram of the explosion of the plastic explosion-proof pressure relief valve provided in an embodiment of the present application. Figure 2 This is a structural diagram of a plastic explosion-proof pressure relief valve provided in an embodiment of the present application. Figure 3 This is a diagram of the internal structure of the plastic explosion-proof pressure relief valve provided in an embodiment of the present application.

[0035] The purpose of this application is to provide a pressure relief valve with a waterproof and dustproof rating of IP67. Through high air permeability, it reduces the internal and external pressure difference of the battery pack or closed box, reduces the negative impact of the pressure difference on the battery pack or closed box, and can quickly relieve pressure in the event of thermal runaway of the battery pack. At the same time, the performance of the pressure relief valve developed in this project can be guaranteed to be unaffected when the vehicle is driving on muddy roads, washing vehicles, and in conditions of different temperatures in winter and summer. Under the premise of complying with international standards, it can ensure that the product is breathable, dustproof, waterproof, fire-resistant, and can be recycled and cost-saving.

[0036] Please refer to Figure 5 and Figure 6 , Figure 5 This is a schematic diagram of the structure of the guide column provided in the embodiment of the present application. Figure 6 A schematic diagram of the structure of the subject provided in an embodiment of the present application.

[0037] Combine Figures 1 to 3 ,as well as Figure 5 and Figure 6 It can be seen that the plastic explosion-proof pressure relief valve provided in the embodiment of the present application mainly includes a main body 4, a guide column 1, a pressure cover 7 and a spring 2.

[0038] The main body 4 is divided into an upper end portion and a lower straight shaft portion. The exterior of the main body 4 is provided with external threads located on the straight shaft portion, which can be used to mount the main body 4 on structures requiring pressure relief, such as battery packs and closed boxes. Furthermore, a sealing ring 3 is also mounted on the exterior of the main body 4. The sealing ring 3 passes through the straight shaft portion of the main body 4 and is fixed to the underside of the end portion. When the main body 4 is mounted on a structure requiring pressure relief, such as a battery pack or closed box, the sealing ring 3 is pressed tightly between the end portion of the main body 4 and the structure requiring pressure relief, thereby achieving a seal between the main body 4 and the structure requiring pressure relief, such as a battery pack or closed box.

[0039] The interior of the main body 4 is through-connected from top to bottom, and a plurality of guide seats are provided on the inner wall 403 of the main body 4. In some cases, the number of the guide seats is three, and the three guide seats are preferably evenly arranged on the same circumference, with an angle of 120° between adjacent guide seats.

[0040] Guide post 1 is movably assembled within main body 4. A guide groove 104 is provided on the outer periphery of guide post 1. Guide groove 104 cooperates with a raised structure 401 on the end of the guide seat, allowing guide post 1 to move along main body 4 under the guidance of raised structure 401 on guide groove 104. In some cases, there are three guide grooves 104, preferably evenly arranged on the same circumference, with an angle of 120° between adjacent guide grooves 104. There is a one-to-one correspondence between guide grooves 104 and guide seats.

[0041] It should be noted that a plurality of guide seats are provided on the inner wall 403 of the main body 4. The guide column 1 is limited at the center position of the main body 4 under the action of the protruding structure 401. The guide column 1 can move along the main body 4 under the guiding action of the protruding structure 401 on the guide groove 104, and a pressure relief channel is formed between the guide column 1 and the main body 4 along the entire circumference.

[0042] The pressure cover 7 is fixedly assembled on the upper end of the guide column 1. The pressure cover 7 and the guide column 1 are assembled as one body, which is equivalent to the pressure cover 7 and the guide column 1 being movably assembled with the main body 4. When the pressure cover 7 moves, the pressure cover 7 will drive the guide column 1 to move relative to the main body 4. In some cases, the pressure cover 7 is fixed to the guide column 1 by an elastic pin 5.

[0043] The spring 2 is sleeved on the guide column 1, and the spring 2 is in contact with the main body 4. The spring 2 is always in a compressed state. The spring 2 is used to exert a force to drive the pressure cover 7 to contact the upper end of the main body 4. When the pressure cover 7 contacts the upper end of the main body 4, it is equivalent to the pressure cover 7 closing the upper end opening of the main body 4, thereby realizing the closure of the pressure relief channel; when the pressure difference between the pressure relief channel and the outside world reaches the set value, the pressure cover 7 is affected by the internal pressure, and the pressure cover 7 drives the guide column 1 to move relative to the main body 4, and the spring 2 is compressed, thereby realizing the opening of the pressure relief channel, and the pressure relief function can be realized at this time.

[0044] In this embodiment, the plastic explosion-proof pressure relief valve can be applied to structures that need to adjust the internal and external pressure difference and provide explosion-proof pressure relief functions, such as battery packs or closed boxes. During use, the plastic explosion-proof pressure relief valve is installed on the battery pack or closed box through the external threads provided on the outside of the main body 4. During use, because the main body 4 is installed on the battery pack or closed box, the interior of the main body 4 is connected to the interior of the battery pack or closed box, so the pressure relief channel is connected to the interior of the battery pack or closed box, and the internal pressure of the battery pack or closed box can be reflected in the pressure relief channel. If the internal and external pressure difference is small, that is, the pressure difference between the pressure relief channel and the outside has not reached the set value, the pressure cap 7 and the guide column 1 maintain a stationary motion state under the action of the spring 2, and the pressure cap 7 contacts the upper end of the main body 4 to achieve the closure of the pressure relief channel. At this time, the dustproof, waterproof and fire-retardant effects of the battery pack or closed box can be achieved.

[0045] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the effect of the plastic explosion-proof pressure relief valve provided in an embodiment of the present application.

[0046] If the pressure difference between the inside and outside is large, that is, the pressure difference between the pressure relief channel and the outside world reaches a set value, the pressure cover 7 and the guide column 1 will overcome the action of the spring 2 under the action of the internal pressure and move. The pressure cover 7 opens under the guidance of the main body 4 on the guide column 1, the spring 2 is pressurized, and the pressure relief channel opens to achieve pressure relief. At this time, the battery pack or the closed box can be ventilated. If the battery pack has thermal runaway, the pressure relief channel will be opened by the pressure cover 7, and since the pressure relief channel is formed between the guide column 1 and the main body 4 around the entire circumference, it is equivalent to increasing the cross-sectional area of ​​the pressure relief channel. When the pressure cover 7 is opened, the pressure can be dispersed in the entire circumference, thereby achieving the effect of rapid pressure relief.

[0047] Combined with the above structure and process description, it can be seen that the plastic explosion-proof pressure relief valve has at least the following beneficial effects: the plastic explosion-proof pressure relief valve is breathable, dustproof, waterproof, and fire-retardant, can automatically adjust the internal and external pressure difference, and can quickly relieve pressure when the battery pack is thermally runaway; the plastic explosion-proof pressure relief valve has the characteristics of easy assembly, good protection effect, high reliability and strong pressure relief capacity.

[0048] In some embodiments, the main body 4 , the guide post 1 and the pressure cover 7 are made of plastic.

[0049] In this embodiment, the plastic explosion-proof pressure relief valve adopts a plastic structure. The advantages of such a setting are improved structure and reduced weight.

[0050] In some embodiments, the plastic explosion-proof pressure relief valve further includes a protective sheet 6, which is fixedly mounted on the gland 7 and located on the side of the gland 7 facing the main body 4. In some cases, the protective sheet 6 is preferably made of stainless steel.

[0051] In this embodiment, the protective sheet 6 is assembled into one with the pressure cover 7. The protective sheet 6 is located in the axial direction of the pressure relief channel. The protective sheet 6 is used to improve the structural strength of the pressure cover 7 in the axial direction of the pressure relief channel and improve the resistance of the pressure cover 7 to the air pressure shock in the pressure relief channel.

[0052] Please refer to Figure 7 , Figure 7 A schematic structural diagram of the gland provided in an embodiment of the present application.

[0053] In some embodiments, the gland 7 is provided with a sealing surface 701 , an assembly seat and an assembly surface 704 on the side facing the main body 4 , that is, the lower side of the gland 7 .

[0054] In this embodiment, the assembly seat is annular, with a sealing surface 701 located on the outer ring of the assembly seat and an assembly surface 704 located on the inner ring of the assembly seat. The sealing surface 701 is used for contact and sealing with the main body 4. The assembly seat is used for fixed assembly with the gland 7, and the assembly surface 704 is used for fixed assembly with the protective sheet 6. In some cases, the protective sheet 6 and the gland 7 are fixed by adhesive bonding.

[0055] Furthermore, the assembly seat is provided with a connection hole 702, and the guide column 1 is provided with a mounting hole 102 that matches the connection hole 702. The plastic explosion-proof pressure relief valve also includes an elastic pin 5, which is installed in the mounting hole 102 and the connection hole 702. In some cases, the number of the connection holes 702 and the mounting holes 102 are both three, and the connection holes 702 and the mounting holes 102 are preferably evenly arranged on the same circumference, with the connection holes 702 corresponding to the mounting holes 102 one by one.

[0056] In addition, the assembly seat is further provided with a positioning groove 703, and the guide column 1 is provided with a protrusion 103 that cooperates with the positioning groove 703. After the protrusion 103 cooperates with the positioning groove 703, the gland 7 and the guide column 1 are fixed using the elastic pin 5. In some cases, there are three positioning grooves 703 and three protrusions 103. The positioning grooves 703 and the protrusions 103 are preferably evenly arranged on the same circumference, with one positioning groove 703 and one protrusion 103 corresponding to each other.

[0057] In some embodiments, a rubber protrusion 402 is provided on the upper end of the main body 4 .

[0058] In this embodiment, the rubber protrusion 402 is annular and surrounds the upper opening of the main body 4 . The rubber protrusion 402 is used for contacting and sealing with the sealing surface 701 .

[0059] In some embodiments, the upper end of the spring 2 and the main body 4 abut against the lower side of the guide seat, the lower end of the guide column 1 is provided with an outwardly protruding round table 101, and the lower end of the spring 2 and the guide column 1 abut against the upper side of the round table 101.

[0060] In this embodiment, under the action of the spring 2, the sealing surface 701 contacts the rubber protrusion 402 on the main body 4 to form a seal, thereby achieving a protective effect; when the pressure difference between the inside and outside of the valve reaches the set value, the pressure cover 7 drives the guide column 1 to move and compresses the spring 2. At this time, the seal formed by the pressure cover 7 and the main body 4 is opened, and the gas flows out through the gap, thereby achieving the purpose of rapid pressure relief.

[0061] In some embodiments, the cross-sectional shape of the interior of the main body 4 is circular, the frustum 101 is clearance-fitted with the main body 4 , and the frustum 101 is restricted by the guide seat and moves below the guide seat.

[0062] In this embodiment, the guide seat not only limits the guide column 1 to the center position of the main body 4, but also provides abutment for the spring 2 instead of the main body 4, while limiting the maximum moving distance of the guide column 1 in the main body 4 by blocking the frustum 101.

[0063] During assembly, first put the spring 2 on the guide column 1 so that the lower end of the spring 2 abuts against the upper side of the frustum 101 in the guide column 1; then install the guide column 1 with the spring 2 into the main body 4 from the lower end of the main body 4. At this time, the guide groove 104 of the guide column 1 should be matched with the protruding structure 401 of the guide seat in the main body 4 so that the protruding structure 401 slides relatively into the guide groove 104; then install the lower side structure of the pressure cover 7 with the protective sheet 6 into the main body 4 from the upper end of the main body 4, push the guide column 1 upward, adjust the pressure cover 7 so that the positioning groove 703 of the pressure cover 7 cooperates with the protrusion 103 of the guide column 1, at this time, the connecting hole 702 of the pressure cover 7 is aligned with the mounting hole 102 of the guide column 1, and the pressure cover 7 is fixed to the guide column 1 with the elastic pin 5. At this time, the spring 2 is compressed between the frustum 101 of the guide column 1 and the guide seat of the main body 4.

[0064] In a specific embodiment, the plastic explosion-proof pressure relief valve has the following advantages: adopting a plastic structure, improving the structure, reducing weight, reducing costs, being easy to assemble, having a good protection effect, being highly reliable, and having a strong pressure relief capability.

[0065] It should be noted that many of the components mentioned in this application are universal standard parts or components known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0066] It should be noted that, in this specification, relational terms such as first and second are merely used to distinguish one entity from other entities, but do not necessarily require or imply any actual relationship or order between these entities.

[0067] The above is a detailed introduction to the plastic explosion-proof pressure relief valve provided by the present application. This article uses specific examples to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core ideas of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A plastic explosion-proof pressure relief valve, characterized in that: It includes a main body, a guide column, a pressure cover and a spring. The outside of the main body is provided with an external thread, the inside of the main body is connected from top to bottom, and a plurality of guide seats are provided on the inner wall of the main body. The guide column is movably assembled in the interior of the main body, and the outer periphery of the guide column is provided with a guide groove that cooperates with the convex structure at the end of the guide seat. A pressure relief channel is formed between the entire circumference of the guide column and the main body, and the pressure cover is fixedly assembled on the upper end of the guide column. The spring is sleeved on the guide column, and the spring abuts against the main body. The spring is used to drive the pressure cover to contact with the upper end of the main body to realize the closing of the pressure relief channel, and when the pressure difference between the pressure relief channel and the outside reaches a set value, the pressure cover drives the guide column to move relative to the main body, the spring is pressurized, and the pressure relief channel opens to realize pressure relief.

2. The plastic explosion-proof pressure relief valve according to claim 1, characterized in that: It also includes a protective sheet, which is fixedly assembled on the pressure cover and is located on a side of the pressure cover facing the main body.

3. The plastic explosion-proof pressure relief valve according to claim 2, characterized in that: The gland is provided with a sealing surface, an assembly seat and an assembly surface on the side facing the main body. The assembly seat is annular. The sealing surface is located on the outer ring of the assembly seat. The assembly surface is located on the inner ring of the assembly seat. The sealing surface is used for contact and sealing with the main body. The assembly seat is used for fixed assembly with the gland, and the assembly surface is used for fixed assembly with the protective sheet.

4. The plastic explosion-proof pressure relief valve according to claim 3, characterized in that: The assembly seat is provided with a connecting hole, the guide column is provided with a mounting hole matched with the connecting hole, and the plastic explosion-proof pressure relief valve also includes an elastic pin, which is installed in the mounting hole and the connecting hole.

5. The plastic explosion-proof pressure relief valve according to claim 4, characterized in that: The assembly seat is also provided with a positioning groove, and the guide column is provided with a protrusion matched with the positioning groove. After the protrusion is matched with the positioning groove, the elastic pin is used to fix the pressure cover and the guide column.

6. The plastic explosion-proof pressure relief valve according to claim 2, characterized in that: The protective sheet is adhered and fixed to the pressure cover.

7. The plastic explosion-proof pressure relief valve according to claim 6, characterized in that: The main body, the guide column and the pressure cover are made of plastic structure, and the protective sheet is made of stainless steel structure.

8. The plastic explosion-proof pressure relief valve according to claim 3, characterized in that: A rubber protrusion is provided at the upper end of the main body. The rubber protrusion is ring-shaped and surrounds the upper end opening of the main body. The rubber protrusion is used for contacting and sealing with the sealing surface.

9. The plastic explosion-proof pressure relief valve according to claim 1, characterized in that: The upper end of the spring and the main body are in contact with the lower side of the guide seat, the lower end of the guide column is provided with a round table protruding outward, and the lower end of the spring and the guide column are in contact with the upper side of the round table.

10. The plastic explosion-proof pressure relief valve according to claim 9, characterized in that: The cross-sectional shape of the interior of the main body is circular, the truncated cone is clearance-matched with the main body, and the truncated cone is limited by the guide seat and moves at a position below the guide seat.

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