Gasket

Abstract

[Problem] To provide a gasket which has high shape conformability to an object to be brought into contact therewith, and has excellent pressure resistance and heat resistance. [Solution] A gasket 1 comprises: a plurality of flow path parts 10, each of which is a cylindrical member and has a pair of openings 11, 12; and a base body 20 which has a front surface 21 and a back surface 22 that constitute a pair of surfaces opposite to each other. The base body 20 has elasticity. The flow path parts 10 are held by the base body 20 so as to form flow paths for a sealing target object such that the openings 11, 12 respectively open in the front surface 21 and the back surface 22 of the base body 20. The hardness of the base body 20 is lower than the hardness of the flow path parts 10.

Description

gasket

[0001] The present invention relates to a gasket.

[0002] A battery module having multiple battery cells, such as a lithium-ion battery module, is provided with a gas release path that guides gas released from an explosion-proof valve provided in each battery cell to the outside. The explosion-proof valve of each battery cell is connected to the gas release path, and gas released from the explosion-proof valve of each battery cell is guided to the outside through the gas release path. In the battery module, when the internal pressure of each battery cell becomes high due to gas generated in the battery cell, the gas is released to the outside through the explosion-proof valve. In addition, a gasket is provided between the explosion-proof valve of each battery cell and the gas release path, and the gasket seals the communication path between the explosion-proof valve and the gas release path, preventing gas released from the explosion-proof valve from leaking outside the gas release path (see, for example, Patent Document 1).

[0003] The gasket of such a battery module must adhere closely to the battery module and the gas release path to seal the gas released from the explosion-proof valve. For this reason, the gasket has a low hardness and low reaction force, and is made of a foam material such as foamed silicone foam or urethane foam. If the gasket has a low hardness, the reaction force generated when the gasket deforms is low, and the gasket can easily conform to the shape of the object it comes into contact with.

[0004] Special Publication No. 2022-500810

[0005] The gas released from the explosion-proof valve is high pressure. The gas released from the explosion-proof valve is also high temperature, sometimes reaching temperatures of 400°C or higher. For this reason, conventional gaskets made from foam materials have a foam structure and are prone to deformation, which can lead to leakage of the high-pressure gas released from the explosion-proof valve. Furthermore, conventional gaskets made from foam materials can melt when exposed to the gas released from the explosion-proof valve.

[0006] Thus, conventional gaskets for explosion-proof valves are required to have a configuration that is highly conformable to the object with which it comes into contact, and has excellent pressure resistance and heat resistance.

[0007] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a gasket that has high conformability to an object with which it comes into contact, and is excellent in pressure resistance and heat resistance.

[0008] In order to achieve the above object, the gasket of the present invention is a gasket for sealing an object to be sealed between two members, and comprises a flow path portion which is a tubular member having a plurality of pairs of openings, and a base having a pair of surfaces facing each other, the base having elasticity, the flow path portion being held on the base so that the pair of openings are respectively open from the pair of surfaces of the base to form a flow path for the object to be sealed, and the hardness of the base is lower than the hardness of the flow path portion.

[0009] In the gasket according to one aspect of the present invention, the base has a hardness that allows it to maintain its shape in a natural state where it is not subjected to external force.

[0010] In the gasket according to one aspect of the present invention, the base has a hardness that generates a reaction force when compressed between the two members.

[0011] In the gasket according to one aspect of the present invention, the base has a hardness that allows it to deform when subjected to pressure from the object to be sealed.

[0012] In a gasket according to one aspect of the present invention, the base is formed from a low-hardness material, and the low-hardness material includes rubber, urethane, and elastomer.

[0013] In the gasket according to one aspect of the present invention, the flow path portion is formed of a heat-resistant material.

[0014] In the gasket according to one aspect of the present invention, the heat resistance of the flow path portion is heat resistance against the temperature of the object to be sealed.

[0015] In a gasket according to one aspect of the present invention, the material is PTFE.

[0016] In the gasket according to one aspect of the present invention, the base has adhesiveness.

[0017] In the gasket according to one aspect of the present invention, the adhesiveness of the base is such that the base can be fixed against a force based on the weight of the gasket itself.

[0018] In a gasket according to one aspect of the present invention, the base has a recess between two adjacent flow path portions, and the recess is recessed in the direction in which the pair of surfaces of the base face each other.

[0019] In a gasket according to one embodiment of the present invention, one of the two components is a plurality of battery cells of a battery module, and the other of the two components is a gas release section that forms a space for guiding gas released from the explosion-proof valves of each of the plurality of battery cells, the object to be sealed is the gas released from the plurality of explosion-proof valves, and the plurality of flow path sections each form a flow path for the gas released from the plurality of explosion-proof valves.

[0020] The gasket according to the present invention can have high conformability to the object with which it comes into contact, and can have excellent pressure resistance and heat resistance.

[0021] FIG. 1 is an exploded perspective view schematically showing a battery module in which a gasket according to a first embodiment of the present invention is used. FIG. 2 is a plan view of the gasket shown in FIG. 1. FIG. 3 is a cross-sectional view of the gasket showing a cross section along line A-A in FIG. 2. FIG. 4 is an enlarged cross-sectional view showing an enlarged view of the vicinity of the flow path portion of the gasket shown in FIG. 3. FIG. 5 is a partial cross-sectional view of a battery module showing a cross section of the gasket in a used state attached to the battery module. FIG. 6 is a partially enlarged cross-sectional view showing a modified example of the gasket according to the first embodiment of the present invention. FIG. 7 is a plan view of a gasket according to a second embodiment of the present invention. FIG. 8 is a cross-sectional view showing a modified example of the gasket according to the second embodiment of the present invention.

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that in the drawings, not all of the components are labeled with reference numerals, and some of the components may be omitted. A gasket according to the present invention is used in a battery module having multiple battery cells, such as a lithium-ion battery module, to seal in gas released from an explosion-proof valve provided in each battery cell.

[0023] Fig. 1 is an exploded perspective view schematically illustrating a battery module 100 using a gasket 1 according to a first embodiment of the present invention. Fig. 2 is a plan view of the gasket 1, and Fig. 3 is a cross-sectional view of the gasket 1 taken along line A-A in Fig. 2. The gasket 1 is a gasket for sealing gas released from the explosion-proof valves 111, which are objects to be sealed, between a plurality of battery cells 110 of the battery module 100 and a discharge pipe 120 serving as a gas release section that forms a space for guiding gas released from the explosion-proof valves 111 of each of the plurality of battery cells 110.

[0024] 1 to 3, the gasket 1 includes a flow path portion 10, which is a cylindrical member having a plurality of pairs of openings 11, 12, and a base 20 having a pair of surfaces, a front surface 21 and a back surface 22, facing each other. The base 20 is elastic. The flow path portion 10 is held by the base 20 such that the openings 11, 12 are open from the front surface 21 and the back surface 22 of the base 20, respectively, to form a flow path for the object to be sealed. The hardness of the base 20 is lower than the hardness of the flow path portion 10. The configuration of the gasket 1 will be described in detail below.

[0025] As shown in FIG. 1 , in a battery module 100, a plurality of battery cells 110 are arranged in a row and fixed by fasteners (not shown). For example, an insulating resin (not shown) is interposed between the battery cells 110. The plurality of battery cells 110 are connected together to form a battery cell group 101. The battery cells 110 are, for example, secondary batteries such as lithium-ion batteries, and are rechargeable. Each battery cell 110 has an external shape that is, for example, rectangular, with a length in the width direction (X direction) longer than the height direction (Z direction) and a thin thickness direction (Y direction). The battery cells 110 are arranged in the Y direction.

[0026] As described above, each battery cell 110 has an explosion-proof valve 111 and a pair of electrodes 112. The explosion-proof valve 111 and the electrodes 112 are provided on the upper surface 110a of the battery cell 110. The pair of electrodes 112 are arranged at both ends in the width direction, one of which serves as a positive electrode and the other as a negative electrode. The explosion-proof valve 111 is arranged in the center in the width direction. In secondary batteries such as lithium-ion batteries, gas may be generated internally due to charging and discharging during use or external factors, causing internal pressure to increase. The explosion-proof valve 111 opens when the internal pressure of the battery cell 110 rises to a certain level, releasing the generated gas. This prevents the internal pressure of the battery cell 110 from rising to an unacceptable level.

[0027] The discharge pipe 120 is an exhaust device that guides gas ejected when the explosion-proof valve 111 is opened. The discharge pipe 120 is fixed to each battery cell 110 via a gasket 1 so as to straddle the battery cells 110 arranged in a row in the Y direction. The gasket 1 is in a compressed state sandwiched between the discharge pipe 120 and the upper surface 110a of each of the arranged battery cells 110. The discharge pipe 120 has openings 122 (see FIG. 5 described later) that correspond to the explosion-proof valves 111 of each battery cell 110. In the discharge pipe 120, gas discharge paths 123 (see FIG. 5 described later) guide the gas that flows in from each opening 122 to the outside. The gas discharge paths 123 open to the outside space through the exhaust port 121. The gas ejected from each explosion-proof valve 111 passes through the flow path 10 of the gasket 1 and is guided to the discharge pipe 120, passes through the corresponding opening and gas discharge path, and is discharged from the exhaust port 121 to the outside space.

[0028] 1 to 3, the gasket 1 has the same number of flow path portions 10 as the explosion-proof valves 111 of the plurality of battery cells 110 in the battery cell group 101 of the battery module 100, and is arranged corresponding to the explosion-proof valves 111 of the plurality of battery cells 110. The plurality of flow path portions 10 are arranged in a row, for example, at equal or approximately equal intervals.

[0029] As shown in FIGS. 1 to 3 , the flow path section 10 has a cylindrical shape extending along the axis x and defines a flow path 13 therein, which is a space extending along the axis x. The axis x extends parallel or approximately parallel to the height direction (Z direction) of the battery module 100. The flow path section 10 has, for example, a cylindrical or approximately cylindrical shape with the axis x as its central axis or approximately central axis. The shape of the flow path section 10 is not limited to a cylindrical shape. For example, the flow path 10 may be a polygonal cylindrical shape. The cross-sectional shape of the flow path 10 perpendicular to the axis x is not limited to a circular shape but may be an ellipse, another circular shape, a polygon, or the like. As shown in FIG. 4 , the flow path section 10 has a pair of end faces in the axis x direction: an upper end face 14 and a lower end face 15. The upper end face 14 defines an opening 11, and the lower end face 15 defines an opening 12. The upper end surface 14 and the lower end surface 15 each extend, for example, along a plane perpendicular to the axis x. The flow path 13 extends between the opening 11 and the opening 12.

[0030] The openings 11 and 12 of the flow path 10 each have a shape corresponding to the explosion-proof valve 111 of the battery cell 110, for example, a shape that can accommodate the explosion-proof valve 111 therein. Specifically, for example, the diameters of the openings 11 and 12 are larger than the width in the width direction (X direction) and the width in the thickness direction (Y direction) of the explosion-proof valve 111, respectively. Note that when the openings 11 and 12 of the flow path 10 each have a shape corresponding to the explosion-proof valve 111 of the battery cell 110 as described above, the gasket 1 can be attached to the battery module 100 regardless of the orientation of the axis x direction of the gasket 1. However, only one of the openings 11 and 12 of the flow path 10 may have a shape corresponding to the explosion-proof valve 111 of the battery cell 110 as described above. In this case, in the battery module 100, the side of the openings 11 and 12 of the flow path 10 that has a shape corresponding to the explosion-proof valve 111 faces the battery cell group 101.

[0031] As shown in FIGS. 1 to 3 , the base 20 has a plate-like shape extending in the direction in which the multiple flow path sections 10 are arranged. The front surface 21 and back surface 22 of the base 20 extend parallel or approximately parallel to each other, as shown in FIG. 3 , for example, and are flat or approximately flat, extending along a plane perpendicular to the axis x. The front surface 21 and back surface 22 of the base 20 do not have to be flat. The front surface 21 and back surface 22 may be curved surfaces, such as curved or wavy surfaces, or may be structured surfaces. A structured surface is a surface having a shape corresponding to a predetermined structure, such as a surface having a shape corresponding to the shape of the upper surface 110a of the battery cell 110 or the shape of the discharge pipe 120.

[0032] 3, the width of the base 20 in the axial x direction is larger than the width of the flow path section 10 in the axial x direction, and the surface 21 of the base 20 is above the upper end surface 14 of the flow path section 10, while the back surface 22 of the base 20 is below the lower end surface 15 of the flow path section 10. The upper side refers to the side toward which the surface 21 faces in the axial x direction, and the lower side refers to the side toward which the back surface 22 faces in the axial x direction. Furthermore, for example, the width in the axial x direction between the upper end surface 14 of the flow path section 10 and the surface 21 of the base 20 and the width in the axial x direction between the lower end surface 15 of the flow path section 10 and the back surface 22 of the base 20 are the same or approximately the same.

[0033] 3 and 4 , the base 20 is formed with a flow hole surface 23 that defines a flow hole 24, which is a through-hole that accommodates the flow section 10. The flow hole surface 23 is a cylindrical surface that corresponds to the outer peripheral surface 10a, which is the outer peripheral surface of the flow section 10, and extends along the axis x. The flow surface 23 extends between the front surface 21 and the back surface 22 of the base 20, and the flow hole 24 penetrates the base 20 between the front surface 21 and the back surface 22. The flow hole surface 23 contacts the outer peripheral surface 10a of the flow section 10, thereby holding the flow path section 10 to the base 20. The flow path section 10 is held to the base 20, for example, by being fitted to the flow hole surface 23. The flow path section 10 is also held to the base 20, for example, by being bonded to the flow hole surface 23. Note that the flow path section 10 may be held in the base 20 in other ways. As described above, the surface 21 of the base 20 is located above the upper end surface 14 of the flow path section 10, and the back surface 22 of the base 20 is located below the lower end surface 15 of the flow path section 10. Therefore, as shown in FIG. 4, the flow hole surface 23 and the flow hole 24 are respectively formed with an upper flow hole surface 23a and an upper flow hole portion 24a, which are portions located above the upper end surface 14 of the flow path 10, and a lower flow hole surface 23b and a lower flow hole portion 24b, which are portions located below the lower end surface 15 of the flow path 10.

[0034] The through-hole surface 23 of the base 20 has a shape corresponding to the outer circumferential surface of the flow passage 10, for example, a cylindrical or approximately cylindrical surface with the axis x as the central axis or approximately the central axis. The through-hole surface 23 of the base 20 is not limited to a cylindrical surface. For example, the through-hole surface 23 may be a polygonal cylindrical surface. The cross-sectional shape of the through-hole surface 23 perpendicular to the axis x is not limited to a circle but may be an ellipse, another circular shape, a polygon, or the like. Furthermore, the shape of the upper through-hole surface 23a of the through-hole surface 23 may be different from that of the portion of the through-hole surface 23 that contacts the outer circumferential surface 10a of the flow passage 10 (contact surface 23c). Similarly, the shape of the lower through-hole surface 23b of the through-hole surface 23 may be different from that of the contact surface 23c of the through-hole surface 23. The shape of the upper through-hole surface 23a and the shape of the downstream passage surface 23b may be the same or different. 4, the upper crushing margin d1, which is the width of the upper through-hole surface 23a of the base 20 in the axial x direction, and the lower crushing margin d2, which is the width of the lower through-hole surface 23b of the base 20 in the axial x direction, are the same or approximately the same. Note that the upper crushing margin d1 and the lower crushing margin d2 may be different from each other.

[0035] The base 20 has an upper flow hole portion 24a and a lower flow hole portion 24b defined by the above-described upper flow hole surface 23a and the lower flow hole surface 23b, respectively. Therefore, in the gasket 1, the opening 11 of the flow path portion 10 is open to the space outside the gasket 1 via the upper flow hole portion 24a of the base 20, and the opening 12 of the flow path portion 10 is open to the space outside the gasket 1 via the lower flow hole portion 24a of the base 20.

[0036] The upper flow hole 23a and the lower flow hole 23b of the base 20 each have a shape corresponding to the explosion-proof valve 111 of the battery cell 110, and for example, have a shape capable of accommodating the explosion-proof valve 111 therein. Specifically, for example, the diameters of the upper flow hole 23a and the lower flow hole 23b are larger than the width in the width direction (X direction) and the width in the thickness direction (Y direction) of the explosion-proof valve 111, respectively. Note that when the upper flow hole 23a and the lower flow hole 23b of the base 20 each have a shape corresponding to the explosion-proof valve 111 of the battery cell 110 as described above, the gasket 1 can be attached to the battery module 100 regardless of the orientation of the gasket 1 in the axial x direction. However, only one of the upper flow hole 23a and the lower flow hole 23b of the base 20 may have a shape corresponding to the explosion-proof valve 111 of the battery cell 110 as described above. In this case, in the battery module 100, the side of the upper communication hole 23a or the lower communication hole 23b of the base 20 having a shape corresponding to the explosion-proof valve 111 is on the battery cell group 101 side.

[0037] As described above, the hardness of the base body 20 is lower than the hardness of the flow path portion 10. Specifically, the base body 20 is a low-hardness member. For example, the base body 20 has a low hardness but a hardness that allows it to maintain its shape in a natural state without receiving external force. Furthermore, for example, the base body 20 has a hardness that generates a reaction force when compressed. Specifically, when the gasket 1 is in use and compressed between the upper surfaces of the plurality of battery cells 110 of the battery cell group 101 and the discharge pipe 120, the base body 20 has a hardness that generates a reaction force on each of the upper surfaces of the plurality of battery cells 110 and the discharge pipe 12. Furthermore, for example, the base body 20 has a hardness that allows it to deform under the pressure of the gas discharged from the sealed object, i.e., the explosion-proof valve 111.

[0038] Specifically, for example, the base 20 is a low-hardness member that has a hardness that allows it to maintain its shape in a natural state where it is not subjected to external force, has a hardness that generates a reaction force when compressed in a state of use, and has a hardness that allows it to deform under the pressure of the gas released from the explosion-proof valve 111. Note that the form of the base 20 is not limited to one having such hardness.

[0039] Furthermore, the hardness of the base body 20 is set to a hardness that allows it to deform in accordance with the shape of the object to which it is attached when assembling the battery module 100. Specifically, the hardness of the base body 20 is set to a low hardness that allows the base body 10 to deform in accordance with the shape of the upper surfaces 110a of the plurality of battery cells 110 and the shape of the discharge pipe 120 when the gasket 1 is attached to the upper surfaces 110a of the plurality of battery cells 110 of the battery cell group 101 and when the gasket 1 is attached to the discharge pipe 120 when assembling the battery module 100. Note that when the gasket 1 is attached to the upper surfaces 110a of the plurality of battery cells 110 of the battery cell group 101, the base body 10 may be pressed against the upper surfaces 110a of the plurality of battery cells 110 or may be pressed against the discharge pipe 120, for example, by the force of an operator or the force of an assembly machine. Furthermore, the deformation of the base 10 corresponding to the shape of the upper surfaces 110a of the plurality of battery cells 110 during installation of the gasket 1 described above does not have to be such that the base 10 completely conforms to the shape of the upper surfaces 110a of the plurality of battery cells 110. For example, this deformation of the base 10 may be such that a portion of the base 10 comes into contact with a portion of the upper surfaces 110a of the plurality of battery cells 110, or such that a portion of the base 10 comes into engagement-capable contact with a portion of the upper surfaces 110a of the plurality of battery cells 110. Similarly, the deformation of the base 10 corresponding to the shape of the discharge pipe 120 during installation of the gasket 1 described above does not have to be such that the base 10 completely conforms to the shape of the discharge pipe 120. For example, this deformation of the base 10 may be such that a portion of the base 10 comes into contact with a portion of the discharge pipe 120, or such that a portion of the base 10 comes into engagement-capable contact with a portion of the discharge pipe 120.

[0040] The base 20 is made of, for example, low-hardness urethane having the hardness described above. However, the material of the base 20 is not limited to urethane. The material of the base 20 may be other elastic materials, such as low-hardness rubber or other elastomers having the hardness described above. For example, the compounding ratio of the compounding components of the material of the base 20 is adjusted so that the hardness of the base 20 becomes the desired low hardness described above. For example, when the material of the base 20 is urethane, the compounding ratio of the isocyanate component is adjusted to make the hardness of the base 20 the desired hardness.

[0041] Furthermore, the flow path portion 10 is heat-resistant and made of a heat-resistant material. For example, the flow path portion 10 is heat-resistant to the temperature of the gas released from the explosion-proof valve 111, which is the object to be sealed. Specifically, the temperature of the gas released from the explosion-proof valve 111 may reach 400°C or higher, and the flow path portion 10 has a heat resistance of, for example, 400°C or higher. The material of the flow path portion 10 is, for example, PTFE (polytetrafluoroethylene). The material of the flow path portion 10 may also be other materials having the above-mentioned heat resistance. Furthermore, the hardness of the flow path portion 10 is higher than the hardness of the base 20. For example, the hardness of the base 20 is such that it does not deform even when subjected to the pressure of the gas released from the explosion-proof valve 111.

[0042] The base body 20 may also have adhesiveness. The adhesiveness of the base body 20 is, for example, adhesiveness that allows the base body 20 to be fixed against a force based on the weight of the gasket 1. Specifically, the adhesiveness of the base body 20 is such that when the base body 20 is attached to the upper surfaces 110 a of the plurality of battery cells 110 of the battery cell group 101 or when the base body 20 is attached to the discharge pipe 120 during assembly of the battery module 100, the adhesiveness of the base body 20 allows the base body 20 to attach to the upper surfaces 110 a of the plurality of battery cells 110 or the discharge pipe 120, and the base body 20 does not separate from the battery cell group 101 or the discharge pipe 120 even when the attitude of the battery cell group 101 or the discharge pipe 120 is changed, for example, by tilting the battery cell group 101 or the discharge pipe 120. Furthermore, for example, the adhesiveness of the base 20 may be such that the base 20 does not separate from the battery cell group 101 or the discharge pipe 120 even when an external force that is not large enough to remove the base 20 is applied, such as when an unintentional worker or the like comes into contact with the base 20.

[0043] The degree of adhesiveness of the base body 20 is adjusted, for example, depending on the desired degree of adhesiveness. Specifically, for example, when the base body 20 is attached to the upper surfaces 110 a of the plurality of battery cells 110 of the battery cell group 101 or when the base body 20 is attached to the discharge pipe 120 during assembly of the battery module 100, the degree of adhesiveness of the base body 20 is adjusted based on the size of the contact area of ​​the base body 20 with the upper surfaces 110 a of the plurality of battery cells 110 or the discharge pipe 120. For example, if the contact area of ​​the base body 20 with the upper surfaces 110 a of the plurality of battery cells 110 or the discharge pipe 120 is large, the degree of adhesiveness of the base body 20 may be low. This is because, when the contact area of ​​the base body 20 with the upper surfaces 110 a of the plurality of battery cells 110 or the discharge pipe 20 is large, the adhesive area is large, and therefore, even if the adhesiveness is low, the base body 20 can be prevented from separating from the battery cell group 101 or the discharge pipe 120. On the other hand, when the contact area of ​​the base 20 with the upper surfaces 110a of the plurality of battery cells 110 or the discharge pipe 120 is small, the adhesive area is small, so it is better to have a high degree of adhesiveness of the base 20. In this way, for example, the degree of adhesiveness of the base 20 is adjusted to a value corresponding to the size of the contact area of ​​the base 20 with the attachment object, for example, to a value proportional to the size of the contact area of ​​the base 20 with the attachment object.

[0044] The degree of adhesiveness of the base 20 is adjusted, for example, by adjusting the material of the base 20. For example, when the material of the base 20 is urethane, the adhesiveness increases as the hardness of the base 20 decreases, and therefore the degree of adhesiveness of the base 20 is adjusted by adjusting the compounding ratio of the isocyanate component.

[0045] Next, a description will be given of the operation of the gasket 1 having the above-described configuration. Fig. 5 is a partial cross-sectional view of the battery module 100 showing a cross section of the gasket 1 in a state where it is attached to the battery module 100 and in use.

[0046] 5 , in use, the gasket 1 is sandwiched between the battery cell group 101 and the discharge pipe 120 to seal the flow path between each explosion-proof valve 111 and the corresponding opening 122 of the discharge pipe 120. Specifically, the surface 21 of the base 20 of the gasket 1 contacts the surface 120a of the discharge pipe 120, and the back surface 22 of the base 20 of the gasket 1 contacts the upper surface 110a of each battery cell 110 of the battery cell group 101, and the gasket 1 is compressed between the upper surface 110a of each battery cell 110 and the discharge pipe 120. In addition, the explosion-proof valve 111 is surrounded by the lower flow hole surface 23b of each flow hole surface 23 of the base 20, and the opening 122 of the discharge pipe 120 is surrounded by the upper flow hole surface 23a of each flow hole surface 23 of the base 20. Furthermore, the surface 21 of the base 20 is in contact with the upper surface 110a around the explosion-proof valve 111 of each battery cell 110, and the back surface 22 of the base 20 is in contact with the surface 120a around each opening 122 of the release pipe 120. In this way, the base 20 of the gasket 1 allows the gas released from the explosion-proof valve 111 to flow into the release pipe 120 through the communication holes 24 without leaking.

[0047] As shown in Fig. 5, in the used state, the base body 20 is compressed in the axial x direction and shrinks, for example, by the width of the upper crushing margin d1 and the lower crushing margin d2 (see Fig. 4). As a result, the upper end surface 14 and the lower end surface 15 of the flow portion 10 contact the surface 120a of the discharge pipe 120 and the upper surface 110a of the corresponding battery cell 110. Therefore, as shown in Fig. 5, in the used state, all or almost all of the flow hole surface 23 of the base body 20 of the gasket 1 is covered by the flow path portion 10. Note that in the used state, the base body 20 compressed in the axial x direction may shrink by a width smaller than the width of the upper crushing margin d1 and the lower crushing margin d2 (see Fig. 4). In this case, only the upper end surface 14 of the circulating portion 10 does not contact the surface 120a of the discharge pipe 120, only the lower end surface 15 of the circulating portion 10 does not contact the upper surface 110a of the corresponding battery cell 110, or both the upper end surface 14 and the lower end surface 15 of the circulating portion 10 do not contact the surface 120a of the discharge pipe 120 and the upper surface 110a of the corresponding battery cell 110, respectively. In this case, in the used state, there will be a portion of one or both of the upper flow hole surface 23a and the lower flow hole surface 23b of the flow hole surface 23 of the base 20 of the gasket 1 that is not covered by the flow path portion 10.

[0048] 5, in the use state, the upper end surface 14 of each flow path section 10 surrounds the corresponding opening 122 of the discharge pipe 120, and the lower end surface 15 of each flow path section 10 surrounds the corresponding explosion-proof valve 111. In the use state, the upper end surface 14 of each flow path section 10 does not have to surround the corresponding opening 122 of the discharge pipe 120, and part or all of the upper end surface 14 of each flow path section 10 may be within the corresponding opening 122 of the discharge pipe 120 when viewed in the direction of the axis x.

[0049] As described above, the through-hole surfaces 23 that define each of the through-holes 24 of the base 20 are covered by the heat-resistant flow path portion 10, and the high-temperature, high-pressure gas released from the explosion-proof valve 111 does not come into direct contact with the through-hole surfaces 23 that define each of the through-holes 24 of the base 20. If the through-hole surfaces 23 that define each of the through-holes 24 of the base 20 are not completely covered by the heat-resistant flow path portion 10, the through-hole surfaces 23 that define each of the through-holes 24 of the base 20 may be slightly exposed to the high-temperature, high-pressure gas released from the explosion-proof valve 111.

[0050] As described above, the base 20 has low hardness. Therefore, the base 20 can easily conform to the shape of the mounting surface of the battery cell group 101 with which the base 20 comes into contact, the upper surface 110a of the battery cell 110, and the surface 120a of the discharge pipe 120. Therefore, the base 20 can be easily attached to the mounting object to which the gasket 1 is attached, and the gasket 1 can be easily attached to the mounting object. In this way, the base 20 has high conformability to the object with which the base 20 comes into contact. Therefore, the gasket 1 can be easily assembled to the mounting object.

[0051] Furthermore, the base 20 has adhesiveness. This allows the base 20 to adhere to the mounting surface of the battery cell group 101 with which the base 20 comes into contact, the upper surface 110a of the battery cell 110, and the surface 120a of the discharge pipe 120. This makes it easy to attach the base 20 to the mounting object to which the gasket 1 is to be attached, and the gasket 1 is easy to attach to the mounting object. This also makes it easy to assemble the gasket 1 to the mounting object.

[0052] Furthermore, because the base 20 has a low hardness, when the flow hole surface 23 of the base 20 is exposed to the high-pressure gas released from the explosion-proof valve 111, the flow hole surface 23 is deformed, and ultimately the base 20 is deformed. When the base 20 is deformed, the sealing ability of the gasket 1 decreases. However, in the gasket 1, the flow hole surface 23 of the base 20 is covered by the flow path portion 10, which has a high hardness, and the high-pressure gas released from the explosion-proof valve 111 does not come into direct contact with the flow hole surface 23 of the base 20. In this way, the flow hole surface 23 of the base 20 is protected from the high-pressure gas released from the explosion-proof valve 111 by the flow path portion 10, which has a higher hardness and a higher pressure resistance than the base 20, and deformation of the flow hole surface 23 due to the high-pressure gas released from the explosion-proof valve 111 is prevented or suppressed. Therefore, in the gasket 1, the hardness of the base 20 can be reduced to improve attachment, etc., and even if the base 20 has such low hardness that it is deformed by the pressure of the gas released from the explosion-proof valve 111, deformation of the flow hole surface 23 due to the high-pressure gas released from the explosion-proof valve 111 is prevented or suppressed. In this way, the gasket 1 has excellent pressure resistance.

[0053] Furthermore, the flow path portion 10 has high heat resistance. Therefore, the heat of the high-temperature gas released from the explosion-proof valve 111 that is transmitted to the flow hole surface 23 of the base 20 is blocked or reduced by the flow path portion 10. As a result, the base 20 is not melted by the high-temperature gas released from the explosion-proof valve 111, or is prevented from melting by the high-temperature gas released from the explosion-proof valve 111. In this way, the gasket 1 has excellent heat resistance.

[0054] As described above, even if the flow path portion 10 does not completely cover the through-hole surface 23 of the base 20, it is possible to reduce the amount of high-pressure gas released from the explosion-proof valve 111 that contacts the through-hole surface 23 of the base 20. Therefore, even with the flow path portion 10 that does not completely cover the through-hole surface 23 of the base 20, it is possible to suppress deformation of the through-hole surface 23 due to the high-pressure gas released from the explosion-proof valve 111. Therefore, even in this case, the gasket 1 has excellent pressure resistance.

[0055] Furthermore, even if the through-hole surface 23 of the base 20 is not completely covered by the flow path portion 10, it is possible to reduce the amount of high-temperature gas released from the explosion-proof valve 111 that contacts the through-hole surface 23 of the base 20. Therefore, even with the flow path portion 10 that does not completely cover the through-hole surface 23 of the base 20, it is possible to suppress melting of the through-hole surface 23 due to the high-temperature gas released from the explosion-proof valve 111. Therefore, even in this case, the gasket 1 has excellent heat resistance.

[0056] As described above, the gasket 1 according to the first embodiment of the present invention can improve conformability to the object with which it comes into contact, and can be made to have excellent heat resistance and pressure resistance.

[0057] In the above-described gasket 1, the entire inner circumferential surface 10b of the flow path portion 10 is exposed to the flow path hole 24, but the inner circumferential surface 10b of the flow path portion 10 may be covered by the base 20. For example, as shown in FIG. 6, the flow path portion 10 may be embedded in the base 20. In this case, the gasket 1 can be easily produced by insert molding. FIG. 6 shows a cross section corresponding to FIG. 4. In this case, one or both of the upper end surface 14 and the lower end surface 15 of the flow path portion 10 may be exposed from the base 20. Furthermore, a portion of the inner circumferential surface 10b of the flow path portion 10 may be covered by the base 20.

[0058] Next, a gasket 2 according to a second embodiment of the present invention will be described. The gasket 2 according to the second embodiment of the present invention has a different base configuration from the above-described gasket 1, and includes a base 30 that is different from the base 20. Hereinafter, regarding the gasket 2, components that have the same or similar functions as the above-described gasket 1 will be assigned the same reference numerals and their description will be omitted, and only different components will be described.

[0059] Fig. 7 is a plan view of a gasket 2 according to a second embodiment of the present invention. As described above, the base 20 of the gasket 1 has a solid portion between two adjacent through-hole surfaces 23, which is filled with the material of the base 20. On the other hand, as shown in Fig. 7, the base 30 of the gasket 2 has a non-solid portion between two adjacent through-hole surfaces 23, and has a recessed portion 31, which is a portion recessed in the axial x direction (recess), formed between the two adjacent through-hole surfaces 23. The recessed portion 31 is, for example, a through-hole penetrating between the front surface 21 and the back surface 22, as shown in Fig. 7.

[0060] 7, the base 30 has a peripheral wall portion 32 formed by a lightening portion 31 around the through hole 24, the peripheral wall portion 32 extending in the direction of the axis x. The peripheral wall portion 32 defines a portion of the through hole surface 23, and has a thickness that increases from the through hole surface 23 toward the outer periphery. Also, as shown in FIG. 7, the base 30 has a pair of side wall portions 33 and 34 formed by the lightening portion 31, the side wall portions 33 and 34 extending in the arrangement direction of the flow path portions 10. The side wall portions 33 and 34 face each other via the peripheral wall portion 32 and are integrally connected to the peripheral wall portion 32. The side wall portions 33 and 34 each define a portion of the through hole surface 23.

[0061] In the gasket 2, as described above, the base body 30 is formed with the lightening hole 31. Therefore, when the base body 30 is compressed while the gasket 2 is in use, the peripheral wall portion 32 and the side wall portions 33, 34 can deform toward the lightening hole 31. Therefore, while the gasket 2 is in use, it is possible to prevent the filling rate of the base body 30 from increasing beyond an allowable range that would cause damage to the base body 30. Meanwhile, it is possible to ensure sealing between the base body 30 and the battery cell group 101 and the discharge pipe 120.

[0062] As described above, for example, the shape of the hollowed-out portion 31 is adjusted, and the thicknesses of the peripheral wall portion 32, the side wall portion 33, and the side wall portion 34 are adjusted so that the filling rate of the base 30 becomes the desired value and the base 30 has the desired sealing properties.

[0063] It should be noted that the cutout portion 31 is not limited to one that penetrates the base 30 as described above. For example, as shown in Fig. 8, the cutout portion 31 may be recessed from the front surface 21 and not penetrate the back surface 22. Also, as shown in Fig. 9, the cutout portion 31 may be recessed from the back surface 22 and not penetrate the front surface 21. It should be noted that Figs. 8 and 9 show a cross section corresponding to the cross section taken along line B-B in Fig. 7.

[0064] Furthermore, the base 30 does not necessarily have to have a cutout 31 between every two adjacent flow hole surfaces 23, and even between two adjacent flow holes 22, there may be a portion where no cutout 24 is arranged.

[0065] Furthermore, the gasket 2 exhibits the same effects as the above-described gasket 1. As described above, the gasket 2 according to the second embodiment of the present invention can improve conformability to the object with which it comes into contact, and can be made to have excellent heat resistance and pressure resistance.

[0066] Although the present invention has been described above through the above embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0067] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the scope of the present invention. Furthermore, the above-described embodiments do not limit the scope of the present invention, and the present invention may include any and all applications. The components of the above-described embodiments, as well as their arrangement, materials, conditions, shape, size, etc., are not limited to those illustrated and may be modified as appropriate. For example, the present invention includes differences that arise during implementation due to manufacturing tolerances, etc. Furthermore, components illustrated in different embodiments may be partially substituted or combined within the scope of technical inconsistency. Furthermore, the various configurations may be selectively combined as appropriate to achieve at least some of the above-described problems and effects.

[0068] 1, 2 Gasket, 10 Flow path portion, 10a Outer peripheral surface, 10b Inner peripheral surface, 11, 12 Opening, 13 Flow path, 14 Upper end surface, 15 Lower end surface, 20, 30 Base, 21 Surface, 22 Back surface, 23 Flow hole surface, 23a Upper flow hole surface, 23b Lower flow hole surface, 23c Contact surface, 24 Flow hole, 24a Upper flow hole portion, 24b Lower flow hole portion, 31 Lightening portion, 32 Peripheral wall portion, 33, 34 Side wall portion, 100 Battery module, 101 Battery cell group, 110 Battery cell, 110a Upper surface, 111 Explosion-proof valve, 112 Electrode, 120 Discharge pipe, 120a Surface, 121 Discharge port, 122 Opening, 123 Gas discharge path, d1, d2 Squeezing margin, x axis line

Claims

1. A gasket for sealing an object between two members, a flow path portion that is a cylindrical member having a plurality of pairs of openings; a base body having a pair of surfaces facing each other; the substrate has elasticity, the flow path portion is held by the base such that the pair of openings are open from the pair of surfaces of the base, respectively, so as to form a flow path for an object to be sealed; the hardness of the substrate is lower than the hardness of the flow path portion; The flow path portion is formed of a heat-resistant material, The material is PTFE. gasket.

2. A gasket for sealing an object between two members, a flow path portion that is a cylindrical member having a plurality of pairs of openings; a base body having a pair of surfaces facing each other; the substrate has elasticity, the flow path portion is held by the base such that the pair of openings are open from the pair of surfaces of the base, respectively, so as to form a flow path for an object to be sealed; the hardness of the substrate is lower than the hardness of the flow path portion; The substrate has adhesive properties. gasket.

3. A gasket for sealing an object between two members, a flow path portion that is a cylindrical member having a plurality of pairs of openings; a base body having a pair of surfaces facing each other; the substrate has elasticity, the flow path portion is held by the base such that the pair of openings are open from the pair of surfaces of the base, respectively, so as to form a flow path for an object to be sealed; the hardness of the substrate is lower than the hardness of the flow path portion; one of the two components is a plurality of battery cells of a battery module; the other of the two members is a gas release portion that forms a space that guides gas released from the explosion-proof valve of each of the plurality of battery cells; the object to be sealed is gas released from the plurality of explosion-proof valves, The plurality of flow path portions respectively form flow paths for gases released from the plurality of explosion-proof valves. gasket.

4. The substrate has a hardness that allows it to maintain its shape in a natural state without being subjected to external force. The gasket according to any one of claims 1 to 3.

5. the substrate has a hardness that generates a reaction force when compressed between the two members; 5. The gasket of claim 4.

6. The base has a hardness that allows it to deform when subjected to pressure from the object to be sealed. The gasket according to any one of claims 1 to 3.

7. the substrate is formed from a low hardness material, The low hardness material includes rubber, urethane, and elastomer. The gasket according to any one of claims 1 to 3.

8. The flow path portion is formed of a heat-resistant material.

4. The gasket according to claim 2 or 3.

9. The heat resistance of the flow path portion is heat resistance against the temperature of the object to be sealed. The gasket according to any one of claims 1 to 3.

10. The material is PTFE.

9. The gasket of claim 8.

11. The substrate has adhesive properties. The gasket according to claim 1 or 3.

12. The adhesiveness of the base is such that the base can be fixed against a force based on the weight of the gasket.

12. The gasket of claim 11.

13. The adhesiveness of the base is such that the base can be fixed against a force based on the weight of the gasket.

3. The gasket of claim 2.

14. the base body has a recess between two adjacent flow path portions, The recess is recessed in a direction in which the pair of surfaces of the base face each other. The gasket according to any one of claims 1 to 3.

15. one of the two components is a plurality of battery cells of a battery module; the other of the two members is a gas release portion that forms a space that guides gas released from the explosion-proof valve of each of the plurality of battery cells; the object to be sealed is gas released from the plurality of explosion-proof valves, The plurality of flow path portions respectively form flow paths for gases released from the plurality of explosion-proof valves.

3. The gasket according to claim 1 or 2.