Explosion-proof valve and battery pack

Abstract

The utility model provides an anti-explosion valve and a battery pack, the anti-explosion valve comprises a valve seat, a guide rod, an elastic piece and a valve cover, the valve seat is used for being installed on a box body of the battery pack, a through hole and exhaust holes are formed in the valve seat, and the exhaust holes are formed in the peripheral side of the through hole; the guide rod is movably arranged in the through hole in a penetrating mode and extends to the position below the valve seat in the first direction. The elastic piece is sleeved on a part of the guide rod below the valve seat; the valve cover is connected to the end, away from the box body, of the guide rod, the valve cover can be tightly pressed on the valve seat to seal the exhaust hole under the action of the elastic piece, and the valve cover can be separated from at least one of the valve seat and the guide rod to expose the exhaust hole when heated and / or pressed. When thermal runaway occurs in the battery pack, the valve cover can be heated due to high-temperature gas generated by thermal runaway or relatively high internal local temperature, and the heated valve cover can be separated from the guide rod, so that the valve cover is separated from the guide rod to expose the exhaust hole, the exhaust area is increased, the exhaust efficiency of a single anti-explosion valve is improved, and the safety of the battery is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to an explosion-proof valve and a battery pack. Background Art

[0002] With the rapid development of the new energy vehicle industry, the safety of power batteries, as the power supply system of electric vehicles, has always been the focus of industry attention.

[0003] The battery energy of a power battery is huge. When the battery thermally runs away, it will release a large amount of high-temperature gas in a short period of time, causing the air pressure in the battery pack to rise rapidly. At this time, it is necessary to quickly discharge the high-temperature and high-pressure gas through an explosion-proof valve, otherwise the battery pack may be in danger of explosion. The exhaust area of ​​the explosion-proof valve in the related technology is limited, which makes the exhaust efficiency of the explosion-proof valve low. A battery pack usually needs to be installed with multiple explosion-proof valves to meet the exhaust requirements when the battery thermally runs away, which increases procurement and maintenance costs. At the same time, there may be a situation where the local temperature in the battery pack is too high, but it does not reach the opening pressure of the explosion-proof valve, or when the temperature in the battery pack is too high, the explosion-proof valve fails, thereby affecting the safety of the battery pack. Utility Model Content

[0004] The utility model aims to provide an explosion-proof valve and a battery pack to solve the technical problems existing in the prior art that a single explosion-proof valve has a limited exhaust area, low exhaust efficiency or cannot exhaust in the event of a fault.

[0005] To achieve the above purpose, the technical solution adopted in this application is:

[0006] In a first aspect, the present application provides an explosion-proof valve, comprising: a valve seat, a guide rod, an elastic member and a valve cover, wherein the valve seat is used to be installed on a box body of a battery pack, the valve seat is provided with a through hole and an exhaust hole, and the exhaust hole is arranged on the peripheral side of the through hole; the guide rod can be movably inserted into the through hole and extends to the bottom of the valve seat along a first direction; the elastic member is sleeved on a portion of the guide rod located below the valve seat; and the valve cover is connected to an end of the guide rod facing away from the box body, and under the action of the elastic member, the valve cover can be pressed onto the valve seat to close the exhaust hole, and the valve cover can be separated from at least one of the valve seat and the guide rod to expose the exhaust hole when heated and / or pressurized.

[0007] In one or more embodiments of the present application, the valve cover includes at least one connector capable of being melted by heat, the guide rod includes a guide rod base, and the at least one connector is connected to the guide rod base around the circumference of the guide rod base to form at least a portion of the valve cover.

[0008] In one or more embodiments of the present application, when the valve cover includes multiple connectors that can be melted by heat, the multiple connectors are arranged in sequence around the guide rod base along the second direction B, and the melting points of the multiple connectors decrease in the direction away from the guide rod base.

[0009] In one or more embodiments of the present application, the melting point T of the connecting member satisfies: 85°C≤T≤200°C.

[0010] In one or more embodiments of the present application, the valve cover also includes a top cover, which is connected to the side of the connecting member away from the guide rod base along the second direction B to form a partial valve cover, and / or the top cover is connected between two adjacent connecting members to form a partial valve cover.

[0011] In one or more embodiments of the present application, the guide rod also includes a guide rod body connected to the guide rod base, the guide rod body can be movably inserted into the through hole and extends to below the valve seat along the first direction, the guide rod base is protruded from the guide rod body to abut against the side wall end surface of the through hole through the guide rod base, and the guide rod base is arranged on the side of the valve seat away from the box body to form a partial valve cover.

[0012] In one or more embodiments of the present application, the connecting surface of the guide rod base and the connecting piece is connected with a concave-convex structure, the connecting surface of the connecting piece and the top cover is connected with a concave-convex structure, and the concave-convex structures on the two connecting surfaces of the same connecting piece are staggered.

[0013] In one or more embodiments of the present application, it also includes: a seal, including a first seal and a second seal, a first sealing groove for installing the first seal is provided on the side of the valve seat facing the housing, the first seal is arranged in the first sealing groove to seal the contact surface between the valve seat and the housing, a second sealing groove for installing the second seal is provided on the side of the valve seat facing away from the housing, the second seal is arranged in the second sealing groove to seal the contact surface between the valve seat and the valve cover.

[0014] In one or more embodiments of the present application, one end of the elastic member abuts against the bottom of the valve seat, and the other end of the elastic member abuts against and is fixed to an end of the guide rod body away from the guide rod base.

[0015] The explosion-proof valve also includes a protection sleeve, which is sleeved on the outer sides of the elastic member and the guide rod body.

[0016] In a second aspect, the present application further provides a battery pack, including batteries and a battery box for accommodating the batteries, the battery box including a box body and the explosion-proof valve described in the first aspect, the explosion-proof valve being sealed and fixed to the box body.

[0017] Based on the above technical solution, the explosion-proof valve and battery pack provided by this application have at least the following beneficial technical effects:

[0018] The explosion-proof valve provided in the present application includes a valve seat, a guide rod, an elastic member and a valve cover. The valve seat is used to be installed on the box body of the battery pack. The valve seat is provided with a through hole and an exhaust hole, and the exhaust hole is arranged on the peripheral side of the through hole; the guide rod can be movably inserted into the through hole and extends to the bottom of the valve seat along a first direction; the elastic member is sleeved on the part of the guide rod located below the valve seat; and the valve cover is connected to the end of the guide rod facing away from the box body. Under the action of the elastic member, the valve cover can be pressed onto the valve seat to close the exhaust hole, and the valve cover can be separated from at least one of the valve seat and the guide rod when heated and / or pressurized to expose the exhaust hole. Furthermore, when thermal runaway occurs in the battery pack and a large amount of high-temperature gas is released, the gas pressure will act on the inner surface of the valve cover, compress the elastic member and push the guide rod to move along its axial direction toward the outside of the battery pack, driving the valve cover to separate from the valve seat, and the gas is discharged to the outside of the battery pack through the gap between the valve cover and the valve seat. At the same time, the high-temperature gas generated by thermal runaway or the high local temperature in the battery pack can further heat the valve cover. The heated valve cover can be separated from the guide rod, so that the valve cover is separated from the guide rod and the exhaust hole is exposed, further increasing the exhaust area, thereby increasing the exhaust area and exhaust capacity of a single explosion-proof valve, and improving the exhaust efficiency. In addition, when the local temperature inside the battery pack is too high but does not reach the opening pressure of the explosion-proof valve, or the temperature inside the battery pack is too high and the explosion-proof valve fails to open normally, the valve cover can be separated from the guide rod under heating, and then the valve cover can be separated from the guide rod to expose the exhaust hole for exhaust, thereby improving the safety of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 A schematic diagram of the three-dimensional structure of an explosion-proof valve according to one or more embodiments of the present application;

[0021] Figure 2 A schematic diagram of the explosion structure of an explosion-proof valve according to one or more embodiments of the present application;

[0022] Figure 3 A schematic diagram of the three-dimensional structure of a valve cover of an explosion-proof valve according to one or more embodiments of the present application;

[0023] Figure 4 A schematic diagram of the three-dimensional structure of an explosion-proof valve from another perspective of one or more embodiments of the present application;

[0024] Figure 5 A schematic diagram of the three-dimensional structure of an explosion-proof valve according to one or more embodiments of the present application;

[0025] Figure 6 A schematic diagram of the three-dimensional structure of a valve cover of an explosion-proof valve according to one or more embodiments of the present application;

[0026] Figure 7 A schematic diagram of the three-dimensional structure of an explosion-proof valve according to one or more embodiments of the present application;

[0027] Figure 8 A schematic diagram of the three-dimensional structure of a valve cover of an explosion-proof valve according to one or more embodiments of the present application;

[0028] Fig. 9 A schematic diagram of a three-dimensional structure of a valve seat from a bottom perspective of one or more embodiments of the present application;

[0029] Fig.10 A schematic diagram of the three-dimensional structure of a valve seat from a top perspective according to one or more embodiments of the present application.

[0030] In the figure: 10-protective sleeve; 11-elastic member; 12-guide rod; 13-valve seat; 14-valve cover; 121-guide rod body; 122-guide rod base; 130-support member; 131-perforation; 132-exhaust hole; 133-first sealing groove; 134-second sealing groove; 141-connecting member; 142-top cover; 1411-bump; 1412-groove; 151-first sealing member; 152-second sealing member. DETAILED DESCRIPTION

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0032] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0033] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] In the related art, the spring explosion-proof valve can usually open the exhaust function in time when the battery in the battery pack has thermal runaway. However, after the guide rod opening reaches the maximum value, it is limited by the gap space between the valve cover and the valve seat. The exhaust area and exhaust capacity of the spring explosion-proof valve in the related art are limited, making the exhaust rate of a single explosion-proof valve not high. The battery pack in the related art may also have a situation where the local temperature in the battery pack is too high, but the air pressure in the battery pack does not reach the opening pressure of the explosion-proof valve, making it impossible for the explosion-proof valve to exhaust. Or when the temperature in the battery pack is too high, the explosion-proof valve fails, making it impossible for the explosion-proof valve to exhaust smoothly. In order to meet the exhaust requirements when the battery pack has thermal runaway, a battery pack usually needs to be installed with multiple spring explosion-proof valves, which increases the procurement and maintenance costs of the battery pack.

[0036] Based on the above considerations, in order to solve the technical problems in the prior art that the exhaust area of ​​the explosion-proof valve is limited, the exhaust efficiency is low, or the exhaust cannot be smoothly discharged due to a fault, the present application provides an explosion-proof valve, which includes: a valve seat, a guide rod, an elastic member and a valve cover, the valve seat is used to be installed on the box body of the battery pack, the valve seat is provided with a through hole and an exhaust hole, and the exhaust hole is arranged on the peripheral side of the through hole; the guide rod can be movably inserted into the through hole and extends to the bottom of the valve seat along a first direction; the elastic member is sleeved on the part of the guide rod located below the valve seat; the valve cover is connected to the end of the guide rod facing away from the box body, and under the action of the elastic member, the valve cover can be pressed onto the valve seat to close the exhaust hole, and the valve cover can be separated from at least one of the valve seat and the guide rod to expose the exhaust hole when heated and / or pressurized. In the technical solution of the embodiment of the present application, when thermal runaway occurs in the battery pack and a large amount of high-temperature gas is released, the gas pressure will act on the inner surface of the valve cover, compress the elastic member and push the guide rod to move along its axial direction toward the outside of the battery pack, driving the valve cover to separate from the valve seat, and the gas is discharged to the outside of the battery pack through the gap between the valve cover and the valve seat. At the same time, due to the high temperature of the high-temperature gas generated by thermal runaway, the valve cover can be further heated. The heated valve cover can be separated from the guide rod, so that the valve cover is separated from the guide rod and the exhaust hole is exposed, further increasing the exhaust area, thereby increasing the exhaust area and exhaust capacity of a single explosion-proof valve, and improving the exhaust efficiency. In addition, when the local temperature inside the battery pack is too high but does not reach the opening pressure of the explosion-proof valve, or the temperature inside the battery pack is too high and the explosion-proof valve fails to open normally, the valve cover can be separated from the guide rod under heating, and then the valve cover can be separated from the guide rod to expose the exhaust hole for exhaust, thereby improving the safety of the battery pack.

[0037] The technical solution of the present application is described in detail below with reference to the accompanying drawings and embodiments.

[0038] First, please refer to Figure 1 and Figure 2 , an embodiment of the present application provides an explosion-proof valve, including: a valve seat 13, a guide rod 12, an elastic member 11 and a valve cover 14, the valve seat 13 is used to be installed on the box body of the battery pack, the valve seat 13 is provided with a through hole 131 and a vent hole 132, and the vent hole 132 is arranged on the peripheral side of the through hole 131; the guide rod 12 can be movably inserted into the through hole 131 and extends to the bottom of the valve seat 13 along the first direction A; the elastic member 11 is sleeved on the part of the guide rod 12 located below the valve seat 13; the valve cover 14 is connected to the end of the guide rod 12 away from the box body, under the action of the elastic member 11, the valve cover 14 can be pressed onto the valve seat 13 to close the vent hole 132, and the valve cover 14 can be separated from at least one of the valve seat 13 and the guide rod 12 when heated and / or pressurized to expose the vent hole 132.

[0039] Among them, the valve seat 13 is the installation base of the explosion-proof valve, and the valve seat 13 is used to be installed on the box of the battery pack. In some embodiments, a through hole for installing the valve seat 13 is provided on the outer wall of the box of the battery pack, and the valve seat 13 is fixedly installed on the through hole of the box by fasteners. A support member 130 is provided inside the valve seat 13 to improve the overall strength. A perforation 131 is formed in the middle of the support member 130, and the perforation 131 is used to allow the guide rod 12 to move through. The exhaust hole 132 is formed around the perforation 131 on the outer peripheral side of the support member 130. The exhaust hole 132 is a through hole connecting the inside and outside of the valve seat 13. The inside is the side of the valve seat 13 away from the valve cover 14, and the outside is the side of the valve cover 14 away from the valve seat 13. The side of the valve seat 13 away from the valve cover 14 corresponds to the inside of the battery pack, and the side of the valve cover 14 away from the valve seat 13 corresponds to the outside of the battery pack, that is, the exhaust hole 132 connects the inside and outside of the battery pack. The first direction A can be the axial direction of the guide rod 12.

[0040] The elastic member 11 is sleeved on the guide rod 12, and the valve cover 14 is connected to the end of the guide rod 12 away from the box body. The elastic member 11 can be a spring or other elastic member with elasticity. In the initial state, the elastic member 11 is in a compressed state, and the elastic member 11 applies an elastic force toward the inside of the box body to the guide rod 12, so that the guide rod 12 drives the valve cover 14 to compress on the valve seat 13 to close the exhaust hole 132. When the valve cover 14 is heated and / or pressurized, it can be understood that the valve cover 14 is subjected to high temperature and / or gas pressure. The valve cover 14 can be separated from at least one of the valve seat 13 and the guide rod 12 to expose the exhaust hole 132 when heated and / or pressurized, which may include the following situations: when heated and / or pressurized, the valve cover 14 is separated from the valve seat 13, or the valve cover 14 is separated from the guide rod 12, or the valve cover 14 is separated from the valve seat 13 and the guide rod 12. When the valve cover 14 is separated from the valve seat 13, it can be understood that in the early stage of opening the explosion-proof valve, under the action of gas pressure, the guide rod 12 is pushed to move along its axial direction toward the outside of the battery pack, and the valve seat 13 is fixed, so the movement of the guide rod 12 drives the valve cover 14 to separate from the valve seat 13, so that a gap is generated between the valve cover 14 and the valve seat 13, and a smaller exhaust area is opened. When the valve cover 14 is separated from the guide rod 12, it can be understood that under the action of high-temperature and high-pressure gas of thermal runaway, or high temperature, the valve cover 14 will be separated from the guide rod 12 to expose a larger area of ​​the exhaust hole 132, opening a larger exhaust area. Of course, when thermal runaway or high temperature occurs in the battery pack, the valve cover 14 will separate from the valve seat 13 and the guide rod 12 at the same time. Based on the intensity of the high-temperature and high-pressure gas, the explosion-proof valve can automatically open different exhaust areas to discharge the gas from the battery pack in time.

[0041] In the technical solution of the embodiment of the present application, the above-mentioned arrangement enables the valve cover 14 to be separated from at least one of the valve seat 13 or the guide rod 12 when heated and / or pressurized to expose the exhaust hole 132. Then, when thermal runaway occurs in the battery pack and a large amount of high-temperature gas is released or the temperature is too high, the gas pressure will act on the inner surface of the valve cover 14, compress the elastic member 11 and push the guide rod 12 to move along its axial direction toward the outside of the battery pack, driving the valve cover 14 to separate from the valve seat 13, and the gas is discharged to the outside of the battery pack through the gap between the valve cover 14 and the valve seat 13. Since the temperature of the high-temperature gas is relatively high (the temperature of the high-temperature gas can reach above 200°C, and for batteries with high energy, the thermal runaway exhaust temperature can reach above 600°C), the valve cover can be further heated, and the heated valve cover 14 can be separated from the guide rod 12, so that the valve cover 14 is separated from the guide rod 12 and the exhaust hole is exposed, further increasing the exhaust area, thereby improving the exhaust area and exhaust capacity of a single explosion-proof valve. The exhaust area and exhaust capacity of the single explosion-proof valve are increased, and the exhaust efficiency is improved, which can reduce the number of explosion-proof valves used in the battery pack and save costs. In addition, when the local temperature inside the battery pack is too high but does not reach the opening pressure of the explosion-proof valve, or the temperature inside the battery pack is too high and the explosion-proof valve fails to open normally, the valve cover can be separated from the guide rod under heat, and then the valve cover can be separated from the guide rod to expose the exhaust hole for exhaust, which improves the safety of the battery pack.

[0042] In some embodiments, please refer to Figure 3 , Figure 6 and Figure 8 The valve cover 14 includes at least one connecting piece 141 that can be melted by heat, the guide rod 12 includes a guide rod base 122, and the at least one connecting piece 141 is connected to the guide rod base 122 around the circumference of the guide rod base 122 to form at least part of the valve cover 14.

[0043] Among them, the connector 141 can be a structural member made of a material that can be melted by heat, and then the connector 141 can melt under the action of high-temperature gas to separate the valve cover 14 from the guide rod base 122. The connector 141 can be made of, for example, PE material (melting point 85-110°C), PS material (melting point around 120°C), ABS material (melting point around 170°C), or other materials with a melting temperature higher than the normal use temperature of the battery pack (the normal use temperature of the battery pack is lower than 60°C). At least one connector 141 is connected to the guide rod base 122 around the circumference of the guide rod base 122 to form a partial valve cover 14. It can be understood that at least one connector 141 is connected to the guide rod base 122 around the circumference of the guide rod base 122 and can serve as a part of the valve cover 14.

[0044] In the technical solution of the embodiment of the present application, the valve cover 14 includes at least one connector 141 that can be melted by heat, and at least one connector 141 is connected to the guide rod base 122 around the circumference of the guide rod base 122 to form at least a portion of the valve cover 14. When thermal runaway occurs in the battery, under the action of high-temperature gas, the connector 141 as a part of the valve cover 14 can be heated and melted, and the valve cover 14 can be separated from the guide rod base 122 under the impact of the high-temperature gas, exposing the exhaust hole 132 of the valve seat 13, thereby increasing the exhaust area of ​​the explosion-proof valve, enhancing the exhaust capacity, and improving the exhaust efficiency.

[0045] In some embodiments, please refer to Figure 7 and Figure 8 When the valve cover 14 includes a plurality of connectors 141 that can be melted by heat, the plurality of connectors 141 are arranged in sequence around the guide rod base 122 along the second direction B, and the melting points of the plurality of connectors 141 decrease in a direction away from the guide rod base 122 .

[0046] It can be understood that the valve cover 14 can be a structure that at least a part of the valve cover is composed of a plurality of connectors 141. Even, the valve cover 14 can have a plurality of connectors 141 to constitute the entire structure of the valve cover 14. The second direction B can be the radial direction of the valve cover 14. The melting points of the plurality of connectors 141 decrease in a direction away from the guide rod base 122, which can be understood as the melting points of the plurality of connectors 141 arranged along the radial direction of the valve cover 14 decrease in sequence from the guide rod base 122 to the outside.

[0047] In the technical solution of the embodiment of the present application, a plurality of connectors 141 capable of melting under heat are provided, and the plurality of connectors 141 are arranged along the radial direction of the valve cover 14 around the guide rod base 122, and the melting points of the plurality of connectors 141 decrease in the direction away from the guide rod base 122. Then, when thermal runaway occurs in the battery pack, the connectors 141 with a lower melting point located on the outer periphery of the valve cover 14 melt first, which can cause part of the structure of the valve cover 14 to detach, exposing part of the exhaust holes 132, while the connectors 141 with a higher melting point located on the inner periphery of the valve cover 14 melt later, which can expose more parts of the exhaust holes 132, and thus the exhaust area of ​​the explosion-proof valve can be increased differently according to the severity of the thermal runaway of the battery in the battery pack, thereby improving the flexibility of the exhaust function of the explosion-proof valve.

[0048] In some embodiments, the melting point T of the connector 141 satisfies: 85° C. ≤ T ≤ 200° C. For example, the melting point T of the connector 141 may be 85° C., 90° C., 95° C., 100° C., 110° C., 120° C., 130° C., 140° C., 150° C., 160° C., 170° C., 180° C., 190° C., or 200° C.

[0049] In the technical solution of the embodiment of the present application, by setting the melting point T of the connector 141 to T satisfying: 85°C ≤ T ≤ 200°C, the connector 141 can melt when thermal runaway occurs in the battery, so as to increase the exhaust area of ​​the valve cover 14 and discharge the gas in time. If the melting point of the connector 141 is relatively small (lower than 85°C), the connector 141 may melt before thermal runaway occurs. If the melting point of the connector 141 is relatively large (higher than 200°C), the connector 141 may be difficult to melt when thermal runaway occurs, thereby affecting the exhaust rate.

[0050] In some embodiments, please refer to Figure 3 and Figure 8 The valve cover 14 also includes a top cover 142, which is connected to the side of the connecting member 141 away from the guide rod base 122 along the second direction B to form a partial valve cover 14, and / or the top cover 142 is connected between two adjacent connecting members 141 to form a partial valve cover 14.

[0051] It is understood that, in some embodiments, the valve cover 14 may be formed by a top cover 142 and a connector 141. The top cover 142 may be made of aluminum alloy or other metal or alloy materials to improve the strength of the valve cover 14.

[0052] In the technical solution of the embodiment of the present application, the valve cover 14 includes a top cover 142, the top cover 142 is connected to the side of the connecting member 141 away from the guide rod 12 to form a partial valve cover 14, and / or, the top cover 142 is connected between two adjacent connecting members 141 to form a partial valve cover 14. On the one hand, the strength of the valve cover 14 can be improved, and on the other hand, when thermal runaway occurs, the connecting member 141 is heated and melted, and the top cover 142 can be separated from the connecting member 141, and then the valve cover 14 can be designed to have different exhaust areas, so that it has different exhaust capacities, thereby improving the flexibility of the exhaust function of the explosion-proof valve.

[0053] In some embodiments, please refer to Figure 2 The guide rod 12 also includes a guide rod body 121 connected to a guide rod base 122. The guide rod body 121 can be movably inserted into the through hole 131 and extends to the bottom of the valve seat 13 along the first direction A. The guide rod base 122 is protruded from the guide rod body 121 so as to abut against the side wall end surface of the through hole 131 through the guide rod base 122. The guide rod base 122 is arranged on the side of the valve seat 13 away from the box body to form a partial valve cover 14.

[0054] The guide rod body 121 and the guide rod base 122 may be an integrated structure, and may be made of aluminum alloy or other metal or alloy materials.

[0055] In the technical solution of the embodiment of the present application, the guide rod body 121 is movably inserted into the through hole 131 and extends to the bottom of the valve seat 13 along the first direction A. The guide rod base 122 is protruded from the guide rod body 121 so as to abut against the side wall end surface of the through hole 131 through the guide rod base 122. The setting of the guide rod base 122 is convenient for connection with the connecting member 141, and then, under the action of the elastic member 11, in the initial state, the guide rod base 122 can abut against the end surface of the through hole 131. The guide rod base 122 is set on the side of the valve seat 13 away from the box body to form a partial valve cover 14, so that when the guide rod body 121 moves along the through hole 131 under the action of the elastic member 11, it can drive the valve cover 14 to move, thereby opening the gap between the valve cover 14 and the valve seat 13 to exhaust in time.

[0056] In some embodiments, please refer to Figure 3 , Figure 6 and Figure 8 The connecting surfaces of the guide rod base 122 and the connecting piece 141 are connected with a concave-convex structure, and the connecting surfaces of the connecting piece 141 and the top cover 142 are connected with a concave-convex structure. The concave-convex structures on the two connecting surfaces of the same connecting piece 141 are staggered.

[0057] The concavo-convex structure may refer to a protrusion 1411 being provided in one of the connection surfaces and a groove 1412 being provided in the other, and the protrusion 1411 matches the groove 1412 so that the protrusion 1411 can be inserted into the groove 1412 to achieve a sealed connection. The staggered arrangement of the concavo-convex structures on the two connection surfaces of the same connector 141 may be understood as the protrusions and the grooves on the two connection surfaces of the connector 141 are not in a straight line so as to reduce the strength of the connector 141.

[0058] In some embodiments, the connector 141 can be pressed between the top cover 142 and the guide rod base 122, or between the top covers 142 and the top covers 142, and the connector 141 is connected to the guide rod base 122 and the top cover 142 through an interference fit caused by the deformation of the connector 141. Alternatively, the connector 141 is used to bond the top cover 142 and the guide rod base 122 or the two top covers 142 together in a molten state, and solidifies and forms after cooling to connect the top cover 142 and the guide rod base 122 or the two top covers 142. The connector 141 can melt when heated again and be separated from the guide rod base 122 and the top cover 142.

[0059] In the technical solution of the embodiment of the present application, the connecting surfaces of the guide rod base 122 and the connecting piece 141 are connected by a concave-convex structure, and the connecting surfaces of the connecting piece 141 and the top cover 142 are connected by a concave-convex structure. The concave-convex structures on the two connecting surfaces of the same connecting piece 141 are staggered to increase the connection area of ​​the connecting surface, improve the connection fixity of the connecting piece 141 and the guide rod base 122 or the top cover 142, and prevent the connecting piece 141 from falling off when not heated.

[0060] In some embodiments, please refer to Figure 2 , Fig. 9 and Fig.10 The explosion-proof valve also includes: a seal, including a first seal 151 and a second seal 152. A first sealing groove 133 for installing the first seal 151 is provided on the side of the valve seat 13 facing the box body. The first seal 151 is arranged in the first sealing groove 133 to seal the contact surface between the valve seat 13 and the box body. A second sealing groove 134 for installing the second seal 152 is provided on the side of the valve seat 13 facing away from the box body. The second seal 152 is arranged in the second sealing groove 134 to seal the contact surface between the valve seat 13 and the valve cover 14.

[0061] In the technical solution of the embodiment of the present application, the first seal 151 is installed in the first sealing groove 133 to achieve sealing of the contact surface between the valve seat 13 and the box body through the first seal 151. The second seal 152 is installed in the second sealing groove 134 to achieve sealing of the contact surface between the valve seat 13 and the valve cover 14 in the initial state.

[0062] In some embodiments, one end of the elastic member 11 abuts against the bottom of the valve seat 13 , and the other end of the elastic member 11 abuts against and is fixed to an end of the guide rod body 121 away from the guide rod base 122 .

[0063] In the technical solution of the embodiment of the present application, through the above-mentioned arrangement, in the initial state, the guide rod base 122 , the connecting member 141 and the top cover 142 are pressed against the valve seat 13 by the pre-tightening force generated by the compression of the elastic member 11 .

[0064] In some embodiments, please refer to Figure 2 The explosion-proof valve further includes a protective sleeve 10 , which is sleeved on the outer sides of the elastic member 11 and the guide rod body 121 .

[0065] In the technical solution of the embodiment of the present application, through the above-mentioned setting, the protective sleeve 10 is sleeved on the outer side of the guide rod body 121 and the elastic member 11. In some embodiments, the protective sleeve 10 is fixed on the valve seat 13, thereby protecting the guide rod body 121 and the elastic member 11, and it is not easy for foreign matter to enter the explosion-proof valve and block the explosion-proof valve.

[0066] The following is an example of the structure of the explosion-proof valve:

[0067] Example 1

[0068] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 The explosion-proof valve provided in this embodiment 1 includes a valve seat 13, a guide rod 12, an elastic member 11, a valve cover 14, a protective sleeve 10, a first sealing member 151 and a second sealing member 152.

[0069] The valve seat 13 is used to be installed on the box of the battery pack. A first sealing groove 133 for installing a first sealing member 151 is provided on the side of the valve seat 13 facing the box. The first sealing member 151 is arranged in the first sealing groove 133 to seal the contact surface between the valve seat 13 and the box. A through hole 131 and a vent hole 132 are provided on the valve seat 13. A support member 130 is provided inside the valve seat 13. The through hole 131 is formed in the middle of the support member 130. The through hole 131 is used to allow the guide rod 12 to movably pass through. The vent hole 132 is formed on the outer peripheral side of the support member 130 around the through hole 131. The guide rod 12 includes a guide rod body 121 and a guide rod base 122. The guide rod body 121 can be movably inserted into the through hole 131. The guide rod base 122 is arranged on the side of the valve seat 13 away from the box to form a partial valve cover 14. The elastic member 11 is sleeved on the guide rod body 121, one end of the elastic member 11 abuts against the bottom of the valve seat 13, and the other end of the elastic member 11 abuts against and is fixed to the end of the guide rod body 121 away from the guide rod base 122. The protective sleeve 10 is sleeved on the outside of the elastic member 11 and the guide rod body 121. The protective sleeve 10 is facing the direction of the inside of the battery pack to seal the valve seat 13 to the box.

[0070] The valve cover 14 is connected to the end of the guide rod 12 away from the box body. Under the action of the elastic member 11, the valve cover 14 can be pressed against the valve seat 13 to close the exhaust hole 132. A second sealing groove 134 for installing a second sealing member 152 is provided on the side of the valve seat 13 away from the box body. The second sealing member 152 is arranged in the second sealing groove 134 to seal the contact surface between the valve seat 13 and the valve cover 14. In the initial state, the contact surface between the valve seat 13 and the valve cover 14 is sealed by the second sealing member 152.

[0071] The valve cover 14 is composed of a top cover 142, a connecting piece 141 connected between the top cover 142 and the guide rod base 122, and the guide rod base 122. The melting point T of the connecting piece 141 is 90°C. The top cover 142 and the connecting piece 141 are arranged around the circumference of the guide rod base 122 to form the valve cover 14. A convex block 1411 is provided on the connecting surface of the guide rod base 122 and the connecting piece 141, and a groove 1412 is provided on the connecting surface of the connecting piece 141 and the guide rod base 122. A groove 1412 is provided on the connecting surface of the top cover 142 and the connecting piece 141, and a convex block 1411 is provided on the connecting surface of the connecting piece 141 and the top cover 142. The groove 1412 and the convex block 1411 on the connecting piece 141 are staggered so as to be connected by the concave-convex structure to increase the connection stability of the connection surface. The connector 141 can be pressed between the top cover 142 and the guide rod base 122, and the connector 141 and the guide rod base 122 are connected by interference fit due to deformation of the connector 141. Alternatively, the connector 141 can be used to bond the top cover 142 and the guide rod base 122 together in a molten state, and solidify and mold after cooling to connect the top cover 142 and the guide rod base 122. The connector 141 can be melted when heated again and separated from the guide rod base 122 and the top cover 142.

[0072] Therefore, when the battery inside the battery pack experiences thermal runaway and rapidly releases a large amount of high-temperature gas, the high-temperature gas acts on the inner surfaces of the guide rod base 122, the connector 141 and the top cover 142, compressing the elastic member 11 and pushing the guide rod body 121, the guide rod base 122, the connector 141 and the top cover 142 to move along the axial direction of the guide rod body 121 toward the outside of the battery pack, and the gas is discharged to the outside of the battery pack through the gap between the top cover 142 and the valve seat 13. When the temperature of the high-temperature gas is above 90°C, the connector 141 can quickly melt under the action of this high-temperature gas and the connection fails, and the top cover 142 is separated from it under the impact of the high-temperature gas. At this time, the exhaust area of ​​the explosion-proof valve increases and the exhaust capacity increases. When the gas production of the battery thermal runaway is too large and the explosion-proof valve has no time to exhaust and release pressure, the gas pressure in the battery pack increases, the gas impact force increases, and it is easier to separate the top cover 142 from the connector 141, thereby rapidly increasing the exhaust capacity of the explosion-proof valve and improving the exhaust efficiency.

[0073] Example 2

[0074] Please refer to Figure 5 and Figure 6 The difference between this embodiment 2 and embodiment 1 is that:

[0075] In the present embodiment 2, the valve cover 14 is composed of a guide rod base 122 and a connector 141, and the structure of the top cover 142 is cancelled. The melting point T of the connector 141 is 105°C. When the battery in the battery pack has thermal runaway, the high-temperature and high-pressure gas directly impacts the connector 141 to separate it from the guide rod base 122. When the temperature in the battery pack reaches above 105°C, the connector 141 can be quickly melted, thereby increasing the exhaust area and exhaust capacity of the explosion-proof valve and improving the exhaust efficiency. Furthermore, by setting the guide rod base 122 and the connector 141 to have different area ratios, different exhaust capacities of the explosion-proof valve can be formed. When the area ratio of the connector 141 is larger, the exhaust area after its separation when the battery is in thermal runaway increases more, and the exhaust capacity is also stronger.

[0076] Example 3

[0077] Please refer to Figure 7 and Figure 8 The difference between this embodiment 3 and embodiment 1 is that:

[0078] In this embodiment 3, the valve cover 14 is composed of a guide rod base 122, a plurality of connecting members 141 and a plurality of top covers 142, for example Figure 7 and Figure 8 The valve cover 14 shown is composed of a guide rod base 122, two connectors 141 and two top covers 142. Of course, the number of connectors 141 and top covers 142 can also be set to three or more, and the number of connectors 141 and top covers 142 can also be different. Among them, the outer side of the guide rod base 122 is connected to the connector 141. Along the radial direction of the valve cover 14 from the guide rod base 122 to the outer side of the valve cover 14, the connectors 141 and the top covers 142 are arranged alternately in sequence, and along the radial direction of the valve cover 14, the melting point of the connector 141 gradually decreases. When the temperature inside the battery pack is too high, the connector 141 with a low melting point located on the outer periphery can melt first, and the top cover 142 located on the outer periphery can be separated first; the connector 141 with a high melting point located on the inner periphery melts later, and the top cover 142 close to the inner periphery is separated later. By setting a multi-stage separation top cover, the explosion-proof valve can increase the maximum exhaust area differently according to the different temperatures in the battery pack, thereby improving the flexibility of the exhaust function of the explosion-proof valve.

[0079] Example 4

[0080] The difference between this embodiment 4 and embodiment 1 is that:

[0081] In the present embodiment 4, the valve cover 14 is composed of a guide rod base 122 and a plurality of connectors 141. The number of connectors 141 may include two or more. The plurality of connectors 141 are sequentially arranged along the radial direction of the valve cover 14, and the melting points of the connectors 141 gradually decrease along the radial direction of the valve cover 14. When the temperature inside the battery pack is too high, the connectors 141 with a low melting point located at the outer periphery may melt first, and the connectors 141 with a high melting point located at the inner periphery may melt later. By providing multiple sections of connectors 141, the maximum exhaust area increased by the explosion-proof valve can be different according to the different temperatures inside the battery pack, thereby improving the flexibility of the exhaust function of the explosion-proof valve.

[0082] In a second aspect, the present application further provides a battery pack, including batteries and a battery box for accommodating the batteries, the battery box including a box body and the explosion-proof valve described in the first aspect, the explosion-proof valve being sealed and fixed to the box body.

[0083] In the technical solution of the embodiment of the present application, the explosion-proof valve of the embodiment of the present application is sealed and fixed to the box body. When thermal runaway occurs in the battery pack or the temperature in the battery pack is too high, the gas can first be discharged to the outside of the battery pack through the gap between the valve cover and the valve seat. The high-temperature and high-pressure gas can further separate the connector of the explosion-proof valve cover from the guide rod, thereby increasing the exhaust area and exhaust rate of a single explosion-proof valve, thereby reducing the number of explosion-proof valves used on the battery pack and saving costs.

[0084] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An explosion-proof valve, characterized in that: include: A valve seat (13) for being mounted on a box body of a battery pack, wherein the valve seat (13) is provided with a through hole (131) and an exhaust hole (132), and the exhaust hole (132) is arranged on a peripheral side of the through hole (131); A guide rod (12), the guide rod (12) being movably disposed in the through hole (131) and extending along a first direction (A) to below the valve seat (13); an elastic member (11) sleeved on a portion of the guide rod (12) located below the valve seat (13); and A valve cover (14) is connected to an end of the guide rod (12) facing away from the box body. Under the action of the elastic member (11), the valve cover (14) can be pressed onto the valve seat (13) to close the exhaust hole (132). When heated and / or pressurized, the valve cover (14) can be separated from at least one of the valve seat (13) and the guide rod (12) to expose the exhaust hole (132).

2. The explosion-proof valve according to claim 1, characterized in that: The valve cover (14) comprises at least one connecting piece (141) capable of being melted by heat, the guide rod (12) comprises a guide rod base (122), and at least one connecting piece (141) is connected to the guide rod base (122) around the circumference of the guide rod base (122) to form at least part of the valve cover (14).

3. The explosion-proof valve according to claim 2, characterized in that: When the valve cover (14) includes a plurality of connecting members (141) capable of melting under heat, the plurality of connecting members (141) are arranged in sequence around the guide rod base (122) along the second direction (B), and the melting points of the plurality of connecting members (141) decrease in a direction away from the guide rod base (122).

4. The explosion-proof valve according to claim 2 or 3, characterized in that: The melting point T of the connecting member (141) satisfies: 85°C≤T≤200°C.

5. The explosion-proof valve according to claim 2 or 3, characterized in that: The valve cover (14) further comprises a top cover (142), wherein the top cover (142) is connected to a side of the connecting member (141) facing away from the guide rod base (122) along a second direction (B) to form a portion of the valve cover (14), and / or the top cover (142) is connected between two adjacent connecting members (141) to form a portion of the valve cover (14).

6. The explosion-proof valve according to claim 5, characterized in that: The guide rod (12) further comprises a guide rod body (121) connected to the guide rod base (122); the guide rod body (121) can be movably inserted into the through hole (131) and extends along the first direction (A) to below the valve seat (13); the guide rod base (122) is protruded from the guide rod body (121) so as to abut against the side wall end surface of the through hole (131) through the guide rod base (122); the guide rod base (122) is arranged on a side of the valve seat (13) away from the box body to form a part of the valve cover (14).

7. The explosion-proof valve according to claim 6, characterized in that: The connecting surfaces of the guide rod base (122) and the connecting piece (141) are connected in a concave-convex structure, and the connecting surfaces of the connecting piece (141) and the top cover (142) are connected in a concave-convex structure. The concave-convex structures on the two connecting surfaces of the same connecting piece (141) are staggered.

8. The explosion-proof valve according to claim 1, characterized in that: Also includes: A seal, comprising a first seal (151) and a second seal (152); a first sealing groove (133) for installing the first seal (151) is provided on the side of the valve seat (13) facing the housing; the first seal (151) is arranged in the first sealing groove (133) to seal the contact surface between the valve seat (13) and the housing; a second sealing groove (134) for installing the second seal (152) is provided on the side of the valve seat (13) facing away from the housing; the second seal (152) is arranged in the second sealing groove (134) to seal the contact surface between the valve seat (13) and the valve cover (14).

9. The explosion-proof valve according to claim 6, characterized in that: One end of the elastic member (11) abuts against the bottom of the valve seat (13), and the other end of the elastic member (11) abuts against and is fixed to an end of the guide rod body (121) away from the guide rod base (122). The explosion-proof valve further comprises a protective sleeve (10), wherein the protective sleeve (10) is sleeved on the outer sides of the elastic member (11) and the guide rod body (121).

10. A battery pack, characterized in that: It comprises a battery and a battery box for accommodating the battery, wherein the battery box comprises a box body and the explosion-proof valve according to any one of claims 1 to 9, and the explosion-proof valve is sealed and fixed to the box body.

Images