Pressure release valve for power storage device

Abstract

Provided is a pressure relief valve for a power storage device that achieves a reduction in the number of components and simplification of the structure thereof. This pressure relief valve 10 for a power storage device comprises: a base member 20 for being fixed to a case 1; a seal member 40 for being disposed between the case 1 and the base member 20, the seal member 40 having a vent hole 50 that provides, in conjunction with an opening 3, communication between a space inside the case and a space outside the case; a valve member 60 for opening and closing the vent hole 50; and a coil spring 90 for urging the valve member 60 in such a direction that the valve member 60 abuts the seal member 40. A first seal part 43, which abuts a front peripheral edge portion 4 of the opening 3 of the case, is provided on a back side of the seal member 40. A second seal part 45, which receives releasable abutment of the valve member 60, is provided on a front side of the seal member 40 and along the periphery of the vent hole 50.

Description

[Technical field]

[0001] The present invention relates to a pressure relief valve for an electricity storage device, which is attached to a case opening of a case in which an electricity storage device is housed, and relieves pressure within the case. [Background technology]

[0002] For example, hybrid cars and electric cars use electricity storage devices such as batteries and capacitors, which are housed in a case installed in the vehicle. If the electricity storage device is a battery such as a lithium-ion battery, the chemical reaction of the electrolyte may produce gas, causing the pressure inside the case to rise. In this case, a pressure release valve is attached to the opening of the case to reduce the pressure inside the case.

[0003] For example, Patent Document 1 listed below describes a pressure regulating valve that is installed in a housing to regulate its internal pressure and includes a pressure regulating section that regulates the pressure by discharging gas from the housing when the internal pressure is above a certain pressure, and a cover section that contacts the housing and maintains the pressure regulating section in a sealed state.

[0004] The pressure adjusting part has a base part attached to the opening of the housing, and the base part has legs inserted and fixed in the opening, a bearing part provided inside the legs, and a valve seat part protruding from the outer periphery of the tip of the legs. The cover part has a shaft part protruding from the center of the back side, and the shaft part is inserted into the bearing part of the base part. As a result, the cover part is slidable relative to the base part. A spring is attached to the outer periphery of the shaft part, and the cover part is urged in the direction of contact with the valve seat part.

[0005] An O-ring is attached to the back surface of the cover, and the O-ring comes into contact with the surface of the valve seat to seal the gap between the surface of the valve seat and the back surface of the cover. An O-ring is also attached to the back surface of the valve seat to seal the gap between the back surface of the valve seat and the surface of the housing. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2020-21897 A Summary of the Invention [Problem to be solved by the invention]

[0007] The pressure regulating valve of Patent Document 1 requires two O-rings as sealing members to seal the gap between the surface of the valve seat and the cover, and between the back surface of the valve seat and the surface of the housing, resulting in a large number of parts and a complex structure.

[0008] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a pressure release valve for an electricity storage device that can reduce the number of parts and simplify the structure. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a pressure release valve for an electricity storage device that is attached to a case in which an electricity storage device is housed, the valve comprising: a base member fixed to the case; a sealing member that is disposed between the case and the base member and has an air hole that, together with a case opening formed in the case, communicates an internal space of the case with an external space of the case; a valve member that opens and closes the air hole; and a biasing means that biases the valve member in a direction in which it abuts against the sealing member, a first sealing portion that abuts against a front side peripheral portion of the case opening is provided on the back side of the sealing member, and a second sealing portion that the valve member contacts and separates from is provided on the front side of the sealing member at the peripheral portion of the air hole, the valve member normally abuts against the second sealing portion to close the air hole, and when pressure in the internal space of the case increases, the valve member slides against the biasing force of the biasing means to move away from the second sealing portion and open the air hole. Effect of the Invention

[0010] According to the present invention, a first seal portion which abuts against the front side peripheral portion of the case opening is provided on the back side of the sealing member, and a second seal portion which the valve member contacts and separates from is provided on the front side of the sealing member, at the peripheral portion of the air hole.Therefore, the sealing member alone can ensure sealing against the case opening and sealing against the valve member, and the number of parts can be reduced and the structure simplified. [Brief description of the drawings]

[0011] [Figure 1] 1 is an exploded perspective view showing one embodiment of a pressure release valve for an electricity storage device according to the present invention. [Diagram 2] FIG. 2 is a perspective view of the pressure release valve for the electricity storage device. [Diagram 3] 4 is a perspective view of a base member constituting the pressure release valve for the electricity storage device. FIG. [Figure 4] FIG. [Diagram 5] 4 is a perspective view of a sealing member constituting a pressure release valve for an electricity storage device. FIG. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 2 is a perspective view of a valve member constituting a pressure release valve for an electricity storage device. [Figure 9A] 1 is a plan view showing a valve member constituting a pressure release valve for an electricity storage device. FIG. [Figure 9B] FIG. 2 is a bottom view showing a valve member constituting a pressure release valve for an electricity storage device. [Figure 10] FIG. 4 is a bottom view of the cap that constitutes the pressure release valve for the electricity storage device. [Figure 11] 1 is a cross-sectional view of a state in which a pressure release valve for an electricity storage device is attached to an opening of a case. [Figure 12] 12 is a cross-sectional view showing a state in which the valve member has separated from the second seal portion from the state shown in FIG. 11, and the air vent hole has opened. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (One embodiment of a pressure release valve for an electricity storage device) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, one embodiment of a pressure release valve for an electricity storage device according to the present invention will be described with reference to the drawings.

[0013] As shown in Figures 11 and 12, this pressure release valve 10 for an electricity storage device (hereinafter also simply referred to as "release valve 10") is attached to a case 1 that houses an electricity storage device (not shown) and is intended to release (reduce) the pressure inside the case when the pressure increases.

[0014] Examples of the electricity storage device include batteries (lithium ion batteries, etc.), condensers, and the like used in hybrid vehicles including plug-in hybrid vehicles, electric vehicles, and the like, but are not particularly limited as long as they are devices capable of storing electricity.

[0015] As shown in FIG. 1, the case 1 has a case opening 3. More specifically, the case 1 in this embodiment has a recess 2 formed in a substantially circular recess. A recess having a substantially circular recess deeper than the recess 2 is provided from the bottom of the recess 2, a circular hole is formed in the center of the recess, and a cylindrical portion 3a protrudes from the back side periphery of the circular hole. The cylindrical portion 3a and the inner periphery of the circular hole form the case opening 3. The bottom of the recess deeper than the recess 2 forms the front side periphery 4 of the case opening 3. Furthermore, fixing holes 2a, 2a are formed at the bottom of the recess 2 at locations facing each other in the radial direction. As shown in FIGS. 11 and 12, the internal space of the case 1 forms the case internal space R1, and the external space of the case 1 forms the case external space R2.

[0016] In the following description, the "front side" and "front surface side" refer to the side facing the case 1, and the "rear side" and "rear surface side" refer to the side opposite to the "front side" and "front surface side." This also applies to other members (base member, seal member, valve member, cap, etc.) described later.

[0017] 1 and 11, the release valve 10 in this embodiment is mainly composed of a base member 20 fixed to the case opening 3, a seal member 40 arranged between the case 1 and the base member 20 and having an air hole 50 which, together with the case opening 3, communicates the case internal space R1 and the case external space R2, a valve member 60 arranged slidably relative to the seal member 40 and opens and closes the air hole 50, a biasing means for biasing the valve member 60 in a direction in which it abuts against the seal member 40, and a cap 80 arranged on the front side of the base member 20. The biasing means in this embodiment is a coil spring 90 formed by winding a wire of a predetermined diameter at a predetermined pitch.

[0018] First, the base member 20 will be described with reference to FIGS. 3, 4, and 11.

[0019] The base member 20 has a case fixing portion 21 fixed to the case 1. The case fixing portion 21 has an annular portion 23 having a substantially circular ring shape and a pair of fixing portions 25, 25 extending from radially opposing positions of the annular portion 23. A fixing hole 25a is formed in each fixing portion 25. The base member 20 is fixed to the case opening 3 by screwing a screw (not shown) into the fixing hole 25a and the fixing hole 2a of the recess 2 of the case 1. As a result, the base member 20 is fixed to the case 1, and the entire release valve 10 is attached.

[0020] Furthermore, an annular ceiling portion 27 is disposed at the radial center of the annular portion 23, on the front side in the thickness direction of the base member 20. Furthermore, the annular portion 23 and the ceiling portion 27 are connected to each other by a plurality of ribs 29 that extend radially from the axis of the base member 20. Furthermore, a base opening 31 that connects the internal space and the external space of the base member 20 is formed between adjacent ribs 29, 29.

[0021] 11, a cylindrical portion 33 that presses against the seal member 40 protrudes from the back side of the case fixing portion 21 when the case fixing portion 21 is fixed to the case 1. In this embodiment, the annular cylindrical portion 33 protrudes from the inner periphery of the back side of the annular portion 23 that constitutes the case fixing portion 21. Furthermore, an engagement claw 34 protrudes from the outer periphery of the tip of the cylindrical portion 33 in the protruding direction. The engagement claw 34 is annular and provided continuously around the entire circumference of the cylindrical portion 33, and a tapered surface is formed on the outer periphery.

[0022] 11, the cylindrical portion 33 is inserted into the annular groove 47 of the seal member 40, and the engagement claw 34 engages with the engagement groove 47a of the seal member 40, thereby attaching the seal member 40 to the base member 20. In this state, the tip 33a in the protruding direction of the cylindrical portion 33 presses against the bottom surface of the annular groove 47 of the seal member 40, as shown by the arrow F1 in FIG.

[0023] Furthermore, a generally cylindrical bearing portion 35 protrudes toward the case 1 from the rear peripheral edge of the ceiling portion 27 constituting the case fixing portion 21. The shaft portion 67 of the valve member 60 is inserted into the inside of the bearing portion 35, and a coil spring 90 serving as a biasing means is disposed outside the bearing portion 35 (see FIG. 11).

[0024] 4, a pair of guide grooves 35a, 35a are formed in radially opposing positions on the inner periphery of the bearing portion 35. A guide rib 67b (see FIG. 8) of the valve member 60 is slidably inserted into each guide groove 35a, so that the valve member 60 is slidably guided relative to the base member 20 and its rotation is restricted.

[0025] Next, the seal member 40 will be described with reference to FIGS. 5 to 7, 11, etc.

[0026] This sealing member 40 is formed from an elastic material such as rubber or an elastic elastomer, and has a first sealing portion 43 on its back side that abuts against the front side peripheral portion 4 of the case opening 3, and a second sealing portion 45 on the front side at the peripheral portion of the air hole 50, with which the valve member 60 comes into contact and separates.

[0027] The seal member 40 of this embodiment has a substantially annular base portion 41 whose shape and size are adapted to the annular portion 23 of the case fixing portion 21 of the base member 20. A flat seal surface 41a is provided on the back side of the base portion 41 (see Figs. 7 and 11). In this embodiment, as shown in Figs. 7 and 11, the seal surface 41a and a tapered surface 51a (described later) formed on the outer surface of the extension portion 51 form the first seal portion 43.

[0028] 5, an annular groove 47 is formed on the front side of the base 41 at approximately the center in the radial direction. As shown in FIG. 11, an engagement groove 47a is formed on the radial outer periphery inside the annular groove 47 (inside the thickness direction of the base 41). The cylindrical portion 33 of the base member 20 is inserted into the annular groove 47, and the engagement claw 34 of the base member 20 engages with the engagement groove 47a, thereby mounting the seal member 40 to the base member 20. In addition, with the seal member 40 mounted on the base member 20, the bottom surface of the annular groove 47 is pressed by the tip 33a of the cylindrical portion 33, as shown by the arrow F1 in FIG. 11.

[0029] When the sealing member 40 is attached to the base member 20 and the base member 20 is fixed to the case 1, the sealing member 40 is sandwiched between the base member 20 and the case 1, and as shown in FIG. 11, the first sealing portion 43 abuts against the front peripheral portion 4 of the case opening 3 of the case 1 (here, the sealing surface 41a constituting the first sealing portion 43 abuts against the front peripheral portion 4 of the case opening 3).

[0030] 11, the seal member 40 is provided with a protruding portion 49 that protrudes further into the vent hole 50 than the first seal portion 43, and the second seal portion 45 is provided on this protruding portion 49. In this embodiment, the protruding portion 49 is provided from the inner periphery of the base portion 41 constituting the seal member 40, protruding further into the vent hole 50 than the first seal portion 43. The space inside this protruding portion 49 forms the vent hole 50 in the shape of a circular hole.

[0031] Moreover, the protruding portion 49 has an extending portion 51 extending toward the case internal space R1. In this embodiment, the extending portion 51 is substantially cylindrical and extends from the rear side of the protruding portion 49 so as to enter the inner circumference of the case opening 3. Furthermore, a tapered surface 51a is formed on the outer surface of the extending portion 51 in the range from the base end side to just before the tip. This tapered surface 51a is adapted to come into contact with the inner periphery of the upper opening of the air hole 50 (see FIG. 11).

[0032] As shown in FIG. 11, a recess 53 is provided on the front side of the seal member 40, and the second seal portion 45 is disposed closer to the vent hole 50 than the recess 53. More specifically, as shown in FIG. 4, a recess 53 having a ring-shaped groove shape of a predetermined depth is provided on the front side of the seal member 40, inside the annular groove 47. A ring-shaped protruding second seal portion 45 is provided on the radial inside of the recess 53 (see FIG. 11). As shown in FIG. 11, when the valve member 60 abuts against the second seal portion 45, the protruding portion 49 provided with the second seal portion 45 is pressed by the valve member 60, and a force F2 (hereinafter, also referred to as a "protruding portion pressing force F2") acts on the back side of the protruding portion 49 (here, the tapered surface 51a of the extension portion 51) to bring the back side of the protruding portion 49 (here, the tapered surface 51a of the extension portion 51) into close contact with the inner circumference of the case opening 3, as shown in FIG. 11. The deepest surface of the recess 53 forms the bottom surface 55. Furthermore, on the radially outer side of the recess 53, a plurality of arc-shaped grooves 54 extending in an arc shape along the circumferential direction are formed at predetermined intervals (see FIGS. 5 and 6).

[0033] Next, the valve member 60 will be described with reference to FIGS. 8, 9, 11, etc.

[0034] This valve member 60 has a cylindrical valve body 61 with a bottom, a flange portion 65 that extends from the outer periphery of the tip of the valve body 61 and approaches and moves away from the second seal portion 45, and an axis portion 67 that protrudes from the bottom 62 of the valve body 61.

[0035] More specifically, the valve body 61 is a bottomed tubular member consisting of a substantially annular bottom portion 62 and a tubular portion 63 extending from the outer periphery of the bottom portion 62. The valve body 61 is inserted into the vent hole 50 provided in the annular base portion 41 of the seal member 40, and is slidable (axially movable) in the axial direction of the base member 20 and the seal member 40 (the ascending and descending direction of the valve member 60).

[0036] Furthermore, a generally cylindrical shaft portion 67 protrudes from the inner peripheral edge of the bottom portion 62 of the valve body 61. This shaft portion 67 is slidably inserted into the bearing portion 35 of the base member 20. The bearing portion 35 of the base member 20 and the shaft portion 67 of the valve member 60 are arranged coaxially.

[0037] In relation to this valve body 61, the relationship with the coil spring 90, which is the biasing means, will be described. This coil spring 90 is arranged inside the valve body 61, and is fitted to the exterior of the bearing portion 35 of the base member 20, as shown in Fig. 11. That is, the coil spring 90, which is housed and held in a compressed state inside the valve body 61, is arranged outside the bearing portion 35, and its axial base end is supported by abutting against the bottom portion 62 of the valve body 61, and its axial tip is supported by abutting against the rear peripheral portion of the bearing portion 35 of the ceiling portion 27 of the base member 20.

[0038] Returning to the explanation of the valve member 60, a ceiling surface 67a is disposed at the tip of the shaft portion 67 provided on the valve body 61 in the protruding direction and is closed by the ceiling surface 67a. Furthermore, a protrusion 68 protrudes from the radial center of the ceiling surface 67a, and a strip-shaped retaining piece 68a is connected to the tip of the protrusion 68. As shown in Fig. 11, the protrusion 68 and the retaining piece 68a are inserted into the shaft insertion hole 85a of the cap 80, and the retaining piece 68a is engaged with the front peripheral portion of the shaft insertion hole 85a when the valve member 60 rotates by a predetermined angle, so that the cap 80 is held against the valve member 60 (see Fig. 11).

[0039] A pair of guide ribs 67b, 67b forming protrusions are provided extending along the axial direction at radially opposing locations on the outer periphery of the shaft portion 67. Each guide rib 67b is inserted into a corresponding guide groove 35a (see FIG. 4) of the shaft attachment portion 35 of the base member 20, and guides the valve member 60 to slide relative to the base member 20 and restricts its rotation.

[0040] Furthermore, a plurality of outer ribs 71 protrude radially from the outer periphery of the cylindrical portion 63 of the valve body 61. Each outer rib 71 improves the rigidity of the valve body 61 itself, and the vertical guide surface 71a located on the outer edge thereof is close to the inner periphery of the air hole 50 and the inner periphery of the extension portion 51 of the seal member 40 (see FIG. 11), thereby guiding the sliding of the valve member 60 relative to the seal member 40 and suppressing tilting.

[0041] Moreover, the flange portion 65 has a circular outer periphery and is formed to be larger than at least the inner diameter of the second seal portion 45 of the seal member 40, and its back side portion is capable of coming into contact with and separating from the second seal portion 45. Furthermore, in this embodiment, as shown in Fig. 9A, when the valve member 60 is viewed in the axial direction (the direction in which the valve member 60 moves up and down), the outermost diameter of the valve member 60, here the outer diameter D of the flange portion 65, is set to be equal to or smaller than the inner diameter of the case opening 3.

[0042] 8 and 9A, a plurality of generally fan-shaped recesses 73 are formed on the front side of the flange portion 65. Furthermore, as shown in Fig. 11, the valve member 60 is provided with a seal protrusion 75 that protrudes toward the seal member 40. More specifically, the seal protrusion 75 in the form of an annular projection protrudes from the outer circumferential edge of the back side of the flange portion 65 toward the seal member 40. The seal protrusion 75 is formed so that its inner diameter is larger than the outer diameter of the second seal portion 45 of the seal member 40, and is located radially outward of the second seal portion 45.

[0043] The valve member 60 having the above-described configuration is biased by a coil spring, which serves as a biasing means, and is normally in contact with the second seal portion 45 to block the air vent 50 (see FIG. 11). When the pressure in the case internal space R1 increases, the valve member 60 slides against the biasing force of the biasing means and moves away from the second seal portion 45 to open the air vent 50 (see FIG. 12).

[0044] In this embodiment, as shown in the partially enlarged view of FIG. 11, when the valve member 60 abuts against the second seal portion 45, the seal protrusion 75 abuts against the bottom surface 55 of the recess 53. More specifically, the valve member 60 biased by the coil spring 90 is configured such that a portion inside the outer circumferential edge portion of the back side of the flange portion 65 abuts against the second seal portion 45 of the seal member 40, and the seal protrusion 75 provided on the valve member 60 enters the recess 53 and is disposed outside the second seal portion 45 via a gap S, and abuts against the bottom surface 55 of the recess 53 of the seal member 40. As a result, the vent hole 50 is closed by the flange portion 65 of the valve member 60, and the gap between the outer circumferential edge portion of the vent hole 50 and the flange portion 65 is sealed by two annular seal portions, the annular second seal portion 45 and the annular seal protrusion 75.

[0045] 12, when the valve member 60 slides and the flange portion 65 moves away from the second seal portion 45, the cap 80 moves away from the front side of the base member 20, opening the multiple base openings 31 provided in the base member 20. As a result, the internal space R1 and the external space R2 of the case 1 communicate with each other through the ventilation hole 50 of the seal member 40 and the base openings 31 of the base member 20.

[0046] Next, the cap 80 will be described with reference to FIGS.

[0047] The cap 80 of this embodiment is fixed integrally to the valve member 60, and is provided with an elastic flange portion 87 extending toward the base member 20 on its outer circumferential edge.

[0048] More specifically, the cap 80 has a ceiling portion 81 in the shape of a substantially circular plate, and a curved peripheral wall 83 extending from the outer periphery of the ceiling portion 81 towards the base member 20 .

[0049] A retaining recess 85 having a circular recess of a predetermined depth is formed in the radial center of the front side of the ceiling portion 81. A keyhole-shaped shaft insertion hole 85a is formed in the bottom of the retaining recess 85. A pair of retaining projections 85b, 85b are provided on the outer periphery of the shaft insertion hole 85a at the bottom of the retaining recess 85 (see FIG. 10).

[0050] Then, after the protrusion 68 and the retaining piece 68a of the valve member 60 are inserted into the shaft insertion hole 85a, the cap 80 is rotated 90 degrees to engage the retaining piece 68a with the peripheral portion of the front side of the shaft insertion hole 85a, so that the cap 80 is held in place relative to the valve member 60 and is integrated with the valve member 60. In this state, one end of the retaining piece 68a fits between the pair of retaining protrusions 85b, 85b, so that the cap 80 is prevented from rotating relative to the valve member 60. As a result of the cap 80 being integrated with the valve member 60 in this manner, the cap 80 also moves toward and away from the front side of the base member 20 as the valve member 60 slides relative to the base member 20.

[0051] Also, an elastic flange portion 87 extends obliquely outward from the outer peripheral edge of the leading end of the peripheral wall 83 of the cap 80 in the extending direction toward the base member 20 side. This elastic flange portion 87 extends longer toward the base member 20 side than other parts of the cap 80 (ceiling portion 81, peripheral wall 83, etc.). Then, as shown in FIG. 11, when the flange portion 65 of the valve member 60 abuts against the second seal portion 45, the elastic flange portion 87 abuts against the base member 20. Here, the back side of the elastic flange portion 87 is configured to elastically abut against the outer peripheral edge portion 23a on the front side of the annular portion 23 of the base member 20 while being slightly deformed. Also, only the elastic flange portion 87 of the cap 80 abuts against the base member 20, and the other parts do not abut against the base member 20.

[0052] As described above, when the flange portion 65 of the valve member 60 is in contact with the second seal portion 45 and the elastic flange portion 87 of the cap 80 is in contact with the base member 20, the multiple base openings 31 of the base member 20 are closed by the cap 80 (see FIG. 11). On the other hand, when the valve member 60 slides and the flange portion 65 is separated from the second seal portion 45, the cap 80 separates from the base member 20 and the multiple base openings 31 are open (see FIG. 12).

[0053] (Modification) In the embodiment described above, the case 1 is configured with the case opening 3 at the bottom of a plurality of recesses, but it may be configured without providing recesses and with the case opening directly provided in a wall such as the ceiling wall of the case 1. The case opening may have a rectangular, angular, elliptical or other shape as long as it is a shape to which a release valve can be attached.

[0054] Furthermore, the shapes and structures of the base member, seal member, valve member, cap, and the like that constitute the pressure release valve are not limited to those described above.

[0055] For example, the base member may be in the shape of a long plate, a rectangular plate, an ellipse, or the like, as long as the shape allows the sealing member to be sandwiched between the base member and the case. In this embodiment, the base member 20 is fixed to the case 1 via a screw (not shown), but the base member may be provided with an engagement claw or an engagement leg, which may be engaged with the rear edge of the case opening, or an engagement hole separate from the case opening may be formed in the case, and the engagement claw or the like may be engaged with this hole to fix the base member to the case.

[0056] Also, in this embodiment, the base member 20 and the seal member 40 are separate bodies, but the base member and the seal member may be integrally formed by, for example, molding the base member in a specified mold and then molding the seal member while holding the base member in the same mold, a method known as two-color molding.

[0057] Furthermore, the base member 20 of this embodiment has a plurality of base openings 31, which are opened and closed by the cap 80, but the base member may have no base openings without a cap. In this case, however, it is preferable to form a slot or the like in the peripheral wall of the base member that can communicate with the vent hole of the seal member to allow the gas inside the case to flow. In other words, it is sufficient that the shape and structure can communicate the internal space and external space of the case when the valve member separates from the second seal portion and opens the vent hole.

[0058] Furthermore, the sealing member may be, for example, not only circular, but also rectangular, polygonal, or elliptical, or may be a non-circular disk, rectangular plate, or long plate, etc., as long as it is capable of being positioned between the case and the base member and has an air vent, a first sealing portion, and a second sealing portion.

[0059] Furthermore, the valve member 60 in this embodiment has a valve body 61 capable of accommodating a coil spring as a biasing means, and a flange portion 65 extending from the outer periphery of the tip thereof, but the valve member may be, for example, a circular plate, a rectangular plate, an elliptical plate, etc., as long as it can slide relative to the sealing member to open and close the air hole of the sealing member.

[0060] (Action and effect) Next, the function and effect of the release valve 10 according to the present invention having the above-mentioned configuration will be described.

[0061] First, the assembly process of the release valve 10 will be described.

[0062] That is, the valve body 61 of the valve member 60 is inserted from the front opening of the base portion 41 of the seal member 40, and the coil spring 90 is fitted onto the bearing portion 35 of the base member 20. In this state, the cylindrical portion 33 of the base member 20 is aligned with the annular groove 47 of the seal member 40, and the pair of guide ribs 67b, 67b on the outer periphery of the shaft portion 67 of the valve member 60 is aligned with the pair of guide grooves 35a, 35a (see FIG. 4) of the bearing portion 35 of the base member 20. Thereafter, the base member 20 is pressed into the seal member 40.

[0063] Then, the cylindrical portion 33 of the base member 20 is inserted into the annular groove 47 of the seal member 40, and the engaging claws 34 of the base member 20 engage with the annular groove 47 of the seal member 40, thereby allowing the seal member 40 to be attached to the base member 20.

[0064] At the same time, the shaft portion 67 of the valve member 60 is inserted into the bearing portion 35 of the base member 20 , and the protrusion 68 and the retaining piece 68 a at the tip of the shaft portion 67 are inserted from the front opening of the ceiling portion 27 of the base member 20 .

[0065] Next, the cap 80 is placed on the front side of the base member 20, and the projection 68 and the retaining piece 68a of the valve member 60 are aligned with the shaft insertion hole 85a (see FIG. 10), and then the projection 68 and the retaining piece 68a are inserted and removed from the shaft insertion hole 85a. The cap 80 is then rotated 90° to engage the retaining piece 68a with the front peripheral portion of the shaft insertion hole 85a, and one end of the retaining piece 68a is fitted between the pair of retaining projections 85b, 85b, thereby making it possible to attach the cap 80 to the valve member 60 in a state in which the cap 80 is prevented from coming off and its rotation is restricted with respect to the valve member 60.

[0066] In this manner, the various components are assembled to obtain the release valve 10 as shown in Fig. 2. After that, the pair of fixing holes 25a, 25a of the base member 20 constituting the release valve 10 is aligned with the pair of fixing holes 2a, 2a of the case 1, and then the valve body 61 of the valve member 60 is inserted from the front side of the case opening 3 of the case 1, and the first seal portion 43 of the seal member 40 is brought into contact with the front side peripheral portion 4 of the case opening 3 of the case 1. Thereafter, by screwing a screw (not shown) into each fixing hole 25a of the base member 20 and the corresponding fixing hole 2a of the case 1, the base member 20 can be fixed to the case opening 3 of the case 1, and the entire release valve 10 can be attached to the case opening 3.

[0067] 11, the seal member 40 is sandwiched between the base member 20 and the case 1, with the first seal portion 43 in contact with the front peripheral portion 4 of the case opening 3 of the case 1. At the same time, the valve member 60 is urged toward the seal member 40 by the coil spring 90 held in a compressed state within the valve body 61, so that a predetermined location on the back side of the flange portion 65 of the valve member 60 is in contact with the second seal portion 45 of the seal member 40, and the seal protrusion 75 on the valve member 60 side is in contact with the bottom surface 55 of the recess 53 of the seal member 40, maintaining the air vent 50 of the seal member 40 in a closed state. In this state, the cap 80 integral with the valve member 60 is positioned adjacent to the front side of the base member 20, and its elastic flange portion 87 elastically abuts against the outer peripheral edge portion 23a on the front side of the annular portion 23 of the base member 20, thereby blocking the multiple base openings 31 of the base member 20.

[0068] When gas is generated inside the case due to the power storage device as a result of the power storage device supplying power to the driving source or electrical components, or due to the external or internal environment of the case in which the power storage device is housed (for example, when a power storage device such as a lithium ion battery supplies power by driving a motor or the like, gas is generated due to a chemical reaction in the electrolyte), the following operation occurs.

[0069] In other words, when the pressure in the internal space R1 of the case 1 increases and exceeds the biasing force of the coil spring 90, which is the biasing means, the valve member 60 slides in a direction away from the seal member 40 against the biasing force of the biasing means, and its flange portion 65 moves away from the second seal portion 45 of the seal member 40.

[0070] Then, the vent hole 50 of the seal member 40 opens, and the cap 80 integrated with the valve member 60 moves away from the front side of the base member 20 in conjunction with the valve member 60, opening the multiple base openings 31 of the base member 20. As a result, the internal space R1 and the external space R2 of the case 1 communicate with each other through the vent hole 50 of the seal member 40 and the multiple base openings 31 of the base member 20.

[0071] As a result, as shown by arrow L in Figure 12, gas in the internal space R1 of the case 1 passes through the case opening 3, the ventilation hole 50 in the sealing member 40, and the base opening 31 in the base member 20, and is exhausted to the external space R2 of the case 1, thereby releasing (reducing) the pressure within the case 1.

[0072] In this release valve 10, a first seal portion 43 that abuts against the front side peripheral portion 4 of the case opening 3 is provided on the back side of the sealing member 40, and a second seal portion 45 with which the valve member 60 comes into contact and separates is provided on the front side of the sealing member 40, at the peripheral portion of the air hole 50.Therefore, the sealing ability against the case opening 3 and the sealing ability against the valve member 60 can be ensured by the sealing member 40 alone, and the number of parts of the release valve 10 can be reduced and the structure simplified.

[0073] In this embodiment, the seal member 40 is provided with a protruding portion 49 that protrudes further inwardly into the ventilation hole 50 than the first seal portion 43, and the second seal portion 45 is provided on this protruding portion 49 (see FIG. 11).

[0074] According to the above embodiment, when the valve member 60 comes into contact with the second seal portion 45 on the front side of the protrusion 49, the valve member 60 presses the protrusion 49, so that a protrusion pressing force F2 acts to bring the back side portion of the protrusion 49 into close contact with the inner circumference of the case opening 3, as shown in Fig. 11. As a result, the sealing performance of the first seal portion 43 with respect to the case opening 3 can be improved.

[0075] Furthermore, in this embodiment, as shown in FIG. 11, the protruding portion 49 of the seal member 40 has an extending portion 51 that extends toward the case internal space R1.

[0076] According to the above embodiment, when the valve member 60 abuts and is pressed against the second seal portion 45 on the front side of the protrusion 49 and a protrusion pressing force acts on the protrusion 49, as shown in FIG. 11, the extension portion 51 (here, the tapered surface 51a formed on the outer surface of the extension portion 51) extending toward the case internal space R1 tends to come into close contact with the inner circumference of the case opening 3, and the sealing area of ​​the protrusion 49 with respect to the case opening 3 can be increased, thereby further improving the sealing ability of the first seal portion 43 with respect to the case opening 3.

[0077] In addition, in this embodiment, as shown in FIG. 9A, when the valve member 60 is viewed in the axial direction (the direction in which the valve member 60 rises and falls), the outermost diameter of the valve member 60 (here, the outer diameter D of the flange portion 65) is equal to or smaller than the inner diameter of the case opening 3.

[0078] According to the above embodiment, when the valve member 60 abuts and is pressed against the second seal portion 45 on the front side of the protrusion 49, it is possible to easily apply a protrusion pressing force to the protrusion 49, thereby further improving the sealing ability of the first seal portion 43 against the case opening 3.

[0079] Furthermore, in this embodiment, a recess 53 is provided on the front side of the sealing member 40, the second sealing portion 45 is positioned closer to the air hole 50 than the recess 53, and the valve member 60 is provided with a sealing protrusion 75 that protrudes toward the sealing member 40, and is configured so that when the valve member 60 abuts against the second sealing portion 45, the sealing protrusion 75 abuts against the bottom surface 55 of the recess 53 (see Figure 11).

[0080] According to the above embodiment, when the valve member 60 abuts against the second seal portion 45 of the seal member 40, the seal protrusion 75 enters the recess 53 and abuts against the bottom surface 55, so that the valve member 60 is less likely to shift radially relative to the seal member 40 (even if the valve member 60 attempts to move radially, the seal protrusion 75 that has entered the recess 53 abuts against the inner circumference of the recess 53, restricting further radial movement of the valve member 60), and the valve member 60 can be firmly abutted against the second seal portion 45.

[0081] Furthermore, since the sealing protrusion 75 provided on the valve member 60 abuts against the bottom surface 55 of the recess 53 of the sealing member 40, the air hole 50 is closed by two sealing portions, that is, the second sealing portion 45 and the sealing protrusion 75. Therefore, the sealing property of the valve member 60 with respect to the second sealing portion 45 can be improved.

[0082] Furthermore, in this embodiment, as shown in FIG. 11 , the base member 20 has a case fixing portion 21 that is fixed to the case 1, and a cylindrical portion 33 that protrudes from the back side of the case fixing portion 21 and presses the sealing member 40 when the case fixing portion 21 is fixed to the case 1.

[0083] According to the above embodiment, when the case fixing portion 21 is fixed to the case 1, the sealing member 40 is pressed by the cylindrical portion 33, thereby improving the sealing property between the case opening 3 and the first sealing portion 43 of the sealing member 40.

[0084] In addition, in this embodiment, the valve member 60 has a valve body 61 having a bottomed cylindrical shape, a flange portion 65 that extends 65 from the outer periphery of the tip of the valve body 61 and moves toward and away from the second seal portion 45, and an axis portion 67 protruding from the bottom 62 of the valve body 61, and a bearing portion 35 into which the axis portion 67 is inserted protrudes from the back side of the base member 20, and the biasing means is a coil spring 90, which is arranged within the valve body 61 and is configured to be mounted on the exterior of the bearing portion 35.

[0085] According to the above embodiment, certain portions of each component can be wrapped in the axial direction of the release valve 10 (shaft portion 67, bearing portion 35, coil spring 90), making it possible to thin the release valve 10 in the axial direction and suppressing an increase in the amount of protrusion of the release valve 10 from the outer surface of the case 1.

[0086] Furthermore, in this embodiment, there is a cap 80 arranged on the front side of the base member 20, the cap 80 is fixed to the valve member 60, and has an elastic flange portion 87 extending toward the base member 20 on its outer circumferential edge, the elastic flange portion 87 extending toward the base member 20 further than other parts of the cap 80, and is configured so that when the valve member 60 abuts against the second seal portion 45, the elastic flange portion 87 abuts against the base member 20.

[0087] According to the above embodiment, since the cap 80 is arranged on the front side of the base member 20, when a ventilation opening (base opening 31) is formed in the base member 20, the opening can be covered, making it difficult for water, etc. outside the case to penetrate into the release valve 10.

[0088] In addition, when the valve member 60 abuts against the second seal portion 45, the elastic flange portion 87 provided on the outer peripheral edge of the cap 80 elastically abuts against the base member 20. Therefore, even if the cap 80 abuts against the base member 20, the cap 80 abuts via the elastic flange portion 87 which can be flexibly deformed, and the sealing property between the second seal portion 45 of the seal member 40 and the valve member 60 is unlikely to be affected.

[0089] It should be noted that the present invention is not limited to the above-described embodiment, and various modified embodiments are possible within the scope of the gist of the present invention, and such embodiments are also included in the scope of the present invention. [Explanation of symbols]

[0090] 1 case 3 Case opening 10 Pressure release valve for power storage device (release valve) 20 Base material 21 Case fixing part 23 Circular section 31 Base opening 33 Cylindrical section 35 Bearing section 40 Sealing material 41 Base 43 First seal part 45 Second seal part 49 Protrusion 50 Ventilation holes 51 Extension 53 Recess 55 Bottom 60 Valve member 61 Valve body 65 Flange part 67 Shaft 75 Seal protrusion 80 Cap 87 Elastic flange part 90 Coil spring (biasing means)

Claims

1. A pressure release valve for an electricity storage device, which is attached to a case in which the electricity storage device is housed, A base member fixed to the case; a seal member disposed between the case and the base member, the seal member having an air hole that communicates an internal space of the case with an external space of the case together with a case opening formed in the case; a valve member for opening and closing the vent hole; and a biasing means for biasing the valve member in a direction in which the valve member abuts against the seal member, a first seal portion that abuts against a front-side peripheral edge portion of the case opening is provided on a rear side of the seal member; a second seal portion with which the valve member comes into contact and separates is provided on the front side of the seal member and at the periphery of the air hole, the seal member is attached to the base member; When the base member is fixed to the case, the seal member is disposed in a sandwiched state between the base member and the case, a pressure release valve for an electricity storage device, wherein the valve member is normally in contact with the second seal portion to close the air vent, and when pressure in the case internal space increases, the valve member slides against the biasing force of the biasing means and moves away from the second seal portion to open the air vent.

2. 2. The pressure release valve for an electrical storage device according to claim 1, wherein the sealing member has a protrusion that protrudes further inwardly into the air hole than the first sealing portion, and the second sealing portion is provided on this protrusion.

3. 3. The pressure release valve for an electricity storage device according to claim 2, wherein the protruding portion of the sealing member has an extension portion that extends toward the internal space of the case.

4. 4. The pressure release valve for an electricity storage device according to claim 2, wherein an outermost diameter of the valve member is equal to or smaller than an inner diameter of the case opening when viewed in the axial direction.

5. A pressure release valve for an electricity storage device, which is attached to a case in which the electricity storage device is housed, A base member fixed to the case; a seal member disposed between the case and the base member, the seal member having an air hole that communicates an internal space of the case with an external space of the case together with a case opening formed in the case; a valve member for opening and closing the vent hole; and a biasing means for biasing the valve member in a direction in which the valve member abuts against the seal member, a first seal portion that abuts against a front-side peripheral edge portion of the case opening is provided on a rear side of the seal member; a second seal portion with which the valve member comes into contact and separates is provided on the front side of the seal member and at the periphery of the air hole, the valve member is normally in contact with the second seal portion to close the air vent hole, and when a pressure rises in the case internal space, the valve member slides against the biasing force of the biasing means to move away from the second seal portion to open the air vent hole, A recess is provided on the front side of the seal member, The second seal portion is disposed closer to the air hole than the recess, The valve member is provided with a seal protrusion that protrudes toward the seal member, A pressure release valve for an electricity storage device, characterized in that when the valve member abuts against the second seal portion, the sealing protrusion abuts against a bottom surface of the recess.

6. A pressure release valve for an electricity storage device, which is attached to a case in which the electricity storage device is housed, A base member fixed to the case; a seal member disposed between the case and the base member, the seal member having an air hole that communicates an internal space of the case with an external space of the case together with a case opening formed in the case; a valve member for opening and closing the vent hole; and a biasing means for biasing the valve member in a direction in which the valve member abuts against the seal member, a first seal portion that abuts against a front-side peripheral edge portion of the case opening is provided on a rear side of the seal member; a second seal portion with which the valve member comes into contact and separates is provided on the front side of the seal member and at the periphery of the air hole, the valve member is normally in contact with the second seal portion to close the air vent hole, and when a pressure rises in the case internal space, the valve member slides against the biasing force of the biasing means to move away from the second seal portion to open the air vent hole, A pressure release valve for an electricity storage device, characterized in that the base member has a case fixing portion fixed to the case, and a cylindrical portion protruding from the back side of the case fixing portion and pressing the sealing member when the case fixing portion is fixed to the case.

7. the valve member has a cylindrical valve body with a bottom, a flange portion extending from an outer periphery of a tip of the valve body and coming into contact with and away from the second seal portion, and a shaft portion protruding from a bottom of the valve body, A bearing portion into which the shaft portion is inserted protrudes from the back side of the base member, 7. The pressure release valve for an electricity storage device according to claim 6, wherein the biasing means is a coil spring that is disposed within the valve body and externally attached to the bearing portion.

8. A pressure release valve for an electricity storage device, which is attached to a case in which the electricity storage device is housed, A base member fixed to the case; a seal member disposed between the case and the base member, the seal member having an air hole that communicates an internal space of the case with an external space of the case together with a case opening formed in the case; a valve member for opening and closing the vent hole; and a biasing means for biasing the valve member in a direction in which the valve member abuts against the seal member, a first seal portion that abuts against a front-side peripheral edge portion of the case opening is provided on a rear side of the seal member; a second seal portion with which the valve member comes into contact and separates is provided on a front side of the seal member and at a peripheral portion of the air hole, the valve member is normally in contact with the second seal portion to close the air vent hole, and when a pressure rises in the case internal space, the valve member slides against the biasing force of the biasing means to move away from the second seal portion to open the air vent hole, Further, a cap is disposed on the front side of the base member, The cap is fixed to the valve member, and has an elastic flange portion on an outer periphery of the cap that extends toward the base member. The elastic flange portion extends further toward the base member than other portions of the cap, and when the valve member abuts the second seal portion, the elastic flange portion abuts against the base member.

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