Pressure release valve and pressure release valve attachment structure

Abstract

[Problem] To provide a pressure release valve and a pressure release valve attachment structure that improve the efficiency of installation on a case. [Solution] A pressure release valve 2 comprises a base member 5 that is to be fixed to a case 9 that has an opening 91, a valve member 4 that comes into contact with and separates from the base member 5 and opens and closes a ventilation hole 512 in the base member 5, and an urging member 7 that urges the valve member 4 in the direction in which the valve member 4 comes into contact with the base member 5. The base member 5 has an insertion part that is inserted into the opening 91. The insertion part includes a retention part that keeps the insertion part from coming out of the opening 91 in the direction of the axis A1 of the base member 5, a first stopper part that restricts rotation of the base member 5 in a first direction around the axis A1, and a second stopper part that restricts rotation of the base member 5 in a second direction that is opposite the first direction. The first stopper part is provided further to the second direction side than the retention part. The retention part rotates in the first direction to engage an edge part 92 of the opening 91.

Description

Pressure relief valve and pressure relief valve mounting structure

[0001] The present invention relates to a pressure release valve that is attached to a case that houses, for example, an electricity storage device, and that releases pressure inside the case, and to a pressure release valve mounting structure.

[0002] Hybrid vehicles and electric vehicles generally use power storage devices such as batteries and capacitors. The power storage device is housed inside a case installed inside the vehicle. When the power storage device is a battery such as a lithium-ion battery, a chemical reaction in the battery's electrolyte can generate gas, causing the pressure inside the case to increase. Therefore, a pressure relief valve is attached to the case to reduce the pressure inside the case.

[0003] Patent Document 1 discloses a pressure release valve for an electricity storage device that releases pressure inside a case. In the pressure release valve for an electricity storage device described in Patent Document 1, a fixing hole is formed in each fixing portion of the base member. The base member is fixed to the case by threading a screw into the fixing hole of the base member and the fixing hole of the case. As a result, the pressure release valve for an electricity storage device is fixed to the case.

[0004] However, since the pressure release valve for an electricity storage device described in Patent Document 1 is fixed to the case by threading a screw into the fixing hole of the base member and the fixing hole of the case, there is room for improvement in the pressure release valve for an electricity storage device described in Patent Document 1 in terms of improving the efficiency of the work of attaching the pressure release valve for an electricity storage device to the case.

[0005] International Publication No. 2022 / 255376

[0006] The present invention has been made in view of the above circumstances, and has as its object to provide a pressure release valve and a pressure release valve mounting structure that can improve the efficiency of the mounting work on the case.

[0007] One aspect of the present invention is a pressure release valve comprising: a base member fixed to a case having an opening and having an air vent hole that connects the internal space of the case with the external space of the case; a valve member that moves toward and away from the base member to open and close the air vent hole; and a biasing member that biases the valve member in the direction in which the valve member abuts the base member, wherein the base member has an insertion portion that is inserted into the opening, and the insertion portion has a retaining portion that engages with the edge of the opening to prevent the insertion portion from coming out of the opening in the direction of the axis of the base member, a first stopper portion that restricts the base member from rotating in a first direction around the axis, and a second stopper portion that restricts the base member from rotating in a second direction opposite to the first direction, wherein the first stopper portion is positioned closer to the second direction than the retaining portion, and the retaining portion engages with the edge by rotating in the first direction.

[0008] According to one aspect of the present invention, the base member has an insert portion that is inserted into an opening formed in the case. The insert portion has a retaining portion that prevents the insert portion from being removed from the opening in the case in the axial direction of the base member. The retaining portion engages with the edge of the opening in the case by rotating in a first direction around the axis of the base member. As a result, the pressure release valve of the present invention is attached to the case. In this way, the pressure release valve of the present invention is engaged with and attached to the case by rotating relative to the case, without using fastening members such as screws and bolts. This improves the efficiency of the installation work of the pressure release valve of the present invention to the case.

[0009] According to the present invention, it is possible to provide a pressure relief valve that can improve the efficiency of the installation work on the case.

[0010] 10 is a perspective view showing a pressure release valve and a pressure release valve mounting structure according to a first embodiment of the present invention. FIG. 11 is an exploded view showing a pressure release valve and a pressure release valve mounting structure according to the present embodiment. FIG. 12 is a cross-sectional view taken along the line A-A in FIG. 1. FIG. 13 is a plan view of the base member according to the present embodiment, viewed from a direction perpendicular to the axis. FIG. 14 is a perspective view of the base member according to the present embodiment, viewed from the back side. FIG. 15 is a perspective view of the base member according to the present embodiment, viewed from the front side. FIG. 16 is a plan view of the base member according to the present embodiment, viewed from the back side. FIG. 17 is a plan view of the base member according to the present embodiment, viewed from the front side. FIG. 18 is a cross-sectional view taken along the line B-B in FIG. 9. FIG. 19 is an enlarged view of an area A5 in FIG. 20. FIG. 21 is a plan view of the base member according to the present embodiment, viewed from the edge of the opening of the case. FIG. 22 is a cross-sectional view taken along the line C-C in FIG. 21. FIG. 23 is an enlarged view of an area A6 in FIG. 22. FIG. 23 is a perspective view of a pressure release valve according to a second embodiment of the present invention. FIG. 24 is an exploded view of the pressure release valve according to the present embodiment. FIG. 25 is a cross-sectional view taken along the line G-G in FIG. 1. 29(a) 。 FIG. 29 is a cross-sectional view taken along the line H-H in FIG. 1 . FIG. 29 is a cross-sectional view showing a pressure release valve according to a modified example of this embodiment. FIG. 30 is a perspective view showing a valve member according to this embodiment. FIG. 31 is a perspective view showing a cap according to this embodiment. FIG. 32 is a perspective view showing a state before the cap according to this embodiment is placed on the valve member. FIG. 33 is a perspective view showing a state before the engaging portion of the cap and the engaging portion of the valve member engage with each other. FIG. 34 is a cross-sectional view taken along the line I-I in FIG. 23 . FIG. 35 is a cross-sectional view taken along the line D-D in FIG. 23 . FIG. 36 is a perspective view showing a state after the engaging portion of the cap and the engaging portion of the valve member have engaged with each other. FIG. 37 is a cross-sectional view taken along the line E-E in FIG. 26 . FIG. 38 is a cross-sectional view taken along the line F-F in FIG. 26 . FIG. 39 is a perspective view of a pressure release valve according to a third embodiment of the present invention. FIG. 40 is an exploded view of the pressure release valve according to this embodiment. FIG. 41 is a perspective view of a base member as seen from the back side. FIG. 42 is a cross-sectional view taken along the line J-J in FIG. 29(a) . FIG. 43 is a cross-sectional view taken along the line K-K in FIG. 29(a) . FIG. 44 is a partially enlarged view of the pressure release valve shown in FIG. 33 .

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are preferred specific examples of the present invention, and therefore various technically preferable limitations are applied, but the scope of the present invention is not limited to these aspects unless otherwise specified in the following description to the effect that the present invention is limited. Furthermore, in each drawing, similar components are given the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0012] Fig. 1 is a perspective view showing a pressure relief valve and a pressure relief valve mounting structure according to a first embodiment of the present invention. Fig. 2 is an exploded view showing a pressure relief valve and a pressure relief valve mounting structure according to this embodiment. Fig. 3 is a cross-sectional view taken along the line A-A in Fig. 1.

[0013] The pressure release valve mounting structure according to this embodiment includes a case 9 and a pressure release valve 2. The pressure release valve 2 is attached to the case 9 that houses an electricity storage device or the like, and releases gas inside the case 9 when the pressure inside the case 9 increases, thereby releasing the pressure inside the case 9.

[0014] Examples of the power storage device housed in case 9 include batteries (lithium ion batteries, etc.) used in hybrid vehicles including plug-in hybrid vehicles, electric vehicles, etc. However, the power storage device housed in case 9 is not limited to these. Furthermore, the contents housed in case 9 are not limited to power storage devices.

[0015] As shown in FIG. 2 , the case 9 has an opening 91. An edge 92 of the opening 91 has a flange 922. The flange 922 protrudes radially inward from an inner circumferential surface 921 of the edge 92. Here, in this specification, the term "front side" refers to the side of the case 9 facing the external space S2 (see FIG. 3 ) of the case 9, or the direction from the internal space S1 (see FIG. 3 ) of the case 9 toward the external space S2 of the case 9. Also, in this specification, the term "rear side" refers to the side of the case 9 facing the internal space S1 of the case 9, or the direction from the external space S2 of the case 9 toward the internal space S1 of the case 9.

[0016] As shown in FIG. 2 , the pressure release valve 2 includes a cap 3 , a valve member 4 , a base member 5 , a sealing ring 6 , a biasing member 7 , and a locking member 8 .

[0017] The base member 5 is fixed to the edge 92 of the opening 91 of the case 9 by rotating in a first direction A11 (see FIG. 1) about the axis A1. This will be described in detail later. The base member 5 is released from the edge 92 of the opening 91 of the case 9 by rotating in a second direction A12 (see FIG. 1) about the axis A1, i.e., in the direction opposite to the first direction A11.

[0018] The axis A1 is the axis of the base member 5, as well as the axis of each of the cap 3, the valve member 4, the seal ring 6, the biasing member 7, and the locking member 8. In other words, the axis of the base member 5 coincides with the axis of each of the cap 3, the valve member 4, the seal ring 6, the biasing member 7, and the locking member 8.

[0019] 2 , the base member 5 has an annular portion 51, a ceiling portion 52, and a rib 53. The annular portion 51 has a substantially circular ring shape and forms the radially outermost portion of the base member 5. The annular portion 51 has a valve seat 511. The valve seat 511 has a front surface, i.e., a surface facing the seal portion 42 of the valve member 4.

[0020] The ceiling portion 52 has a disk shape and is provided inside the annular portion 51. Specifically, the ceiling portion 52 is provided on the front side of the annular portion 51 in the radial center of the base member 5. The ceiling portion 52 has a through hole 521. The through hole 521 is formed in the radial center of the ceiling portion 52 and penetrates the ceiling portion 52 in the direction of the axis A1.

[0021] The rib 53 is connected to the ceiling portion 52 and the insertion portion 54 (see FIG. 4). That is, the ceiling portion 52 is connected to the insertion portion 54 via the rib 53. The insertion portion 54 is connected to an inner circumferential surface 513 (see FIG. 6) of the annular portion 51. As a result, the ceiling portion 52 is connected to the annular portion 51 via the rib 53 and the insertion portion 54. Details of the insertion portion 54 will be described later.

[0022] 2 , the base member 5 of this embodiment has a plurality of ribs 53. The plurality of ribs 53 are spaced apart from one another in the circumferential direction. Air vents 512 are formed between adjacent ribs 53. The air vents 512 communicate between an internal space S1 of the case 9 and an external space S2 of the case 9.

[0023] The valve member 4 has a base portion 41 and a seal portion 42. The base portion 41 is formed from a material harder than the material of the seal portion 42, and has a ceiling portion 411, a peripheral wall portion 412, and a flange portion 413. The ceiling portion 411 has a disk shape and is provided in the radial center of the valve member 4. An engagement portion 414 is provided on the front surface of the ceiling portion 411. The engagement portion 414 engages with the engagement portion 312 of the cap 3.

[0024] The peripheral wall portion 412 is connected to the outer peripheral edge of the ceiling portion 411 and extends from the outer peripheral edge of the ceiling portion 411 toward the back side, i.e., the side of the base member 5. The flange portion 413 is connected to the tip end of the peripheral wall portion 412 in the extension direction and extends radially outward from the tip end of the peripheral wall portion 412 in the extension direction.

[0025] The seal portion 42 is made of an elastic material such as rubber or an elastic elastomer, and is formed integrally with the flange portion 413 of the base portion 41. The seal portion 42 extends radially outward from the outer peripheral edge of the flange portion 413 and also extends from the outer peripheral edge of the flange portion 413 toward the back side, i.e., the side of the base member 5. The seal portion 42 moves toward and away from the valve seat 511 of the base member 5 to open and close the vent hole 512.

[0026] The seal portion 42 has a protrusion 421. The protrusion 421 protrudes from the front surface of the flange portion 413 toward the front side. As shown in Fig. 3, the protrusion 421 is interposed between the front surface of the flange portion 413 and the back surface of the cap 3, and biases the cap 3 toward the front side.

[0027] The base 41 further has a shaft 415. The shaft 415 is connected to the radial center of the ceiling 411 and extends from the ceiling 411 along the axis A1 toward the back side, i.e., the side of the base member 5. The shaft 415 is inserted into a through-hole 521 formed in the ceiling 52 of the base member 5 and prevents the valve member 4 from coming off the base member 5. In other words, the shaft 415 is a retaining portion for preventing the valve member 4 from coming off the base member 5. This will be described in detail later.

[0028] 3, the shaft portion 415 has an engaging portion 416. The engaging portion 416 is provided at the tip of the shaft portion 415 in the extension direction, and extends radially outward from the outer circumferential surface of the shaft portion 415. The engaging portion 416 engages with the engaging portion 811 of the locking member 8.

[0029] The cap 3 has a ceiling portion 31, a peripheral wall portion 32, and a flange portion 33. The ceiling portion 31 has a disk shape and is provided in the radial center of the cap 3. The ceiling portion 31 has a through hole 311. The through hole 311 is formed to extend in the circumferential direction near the outer peripheral edge of the ceiling portion 31 and penetrates the ceiling portion 31 in the direction of the axis A1. An engagement portion 312 is provided at the edge of the through hole 311. The engagement portion 312 protrudes from the edge of the through hole 311 toward the inside of the through hole 311 and engages with an engagement portion 414 provided on the ceiling portion 411 of the valve member 4.

[0030] That is, the engaging portion 414 of the valve member 4 is inserted into the through-hole 311 of the cap 3, and the cap 3 is rotated in the first direction A11 (see FIG. 1 ), whereby the engaging portion 312 of the cap 3 engages with the engaging portion 414 of the valve member 4. As a result, the cap 3 is attached to the valve member 4 and covers the valve member 4.

[0031] The peripheral wall portion 32 is connected to the outer peripheral edge of the ceiling portion 31 and extends from the outer peripheral edge of the ceiling portion 31 toward the back side, i.e., the side of the valve member 4. The flange portion 33 is connected to the tip of the peripheral wall portion 32 in the extension direction and extends radially outward from the tip of the peripheral wall portion 32 in the extension direction. As shown in FIG. 3 , when the cap 3 is attached to the valve member 4, the flange portion 33 covers the seal portion 42 of the valve member 4 and the valve seat 511 of the base member 5. This allows the cap 3 to prevent water sprayed from, for example, a high-pressure washer from directly hitting the seal portion 42 of the valve member 4.

[0032] The seal ring 6 is a so-called "O-ring" or the like, and is made of an elastic material such as rubber and has a circular ring shape. As shown in Fig. 3, the seal ring 6 is attached to an annular protrusion 514 formed on the back side of the valve seat 511 of the base member 5. The seal ring 6 is interposed between the base member 5 and the case 9, and biases the base member 5 toward the front side.

[0033] The biasing member 7 is a coil spring formed by winding a wire rod having a predetermined diameter at a predetermined pitch, for example. As shown in Fig. 3, the biasing member 7 is disposed radially outside the shaft portion 415 of the valve member 4 and is supported by the shaft portion 415.

[0034] The locking member 8 has a tubular portion 81 and a flange portion 82. The tubular portion 81 has a generally cylindrical shape and is provided in the radial center of the locking member 8. The tubular portion 81 has an engaging portion 811. The engaging portion 811 is provided inside the tubular portion 81 and extends radially inward from the inner circumferential surface of the tubular portion 81. The engaging portion 811 engages with the engaging portion 416 provided on the shaft portion 415 of the valve member 4 when the locking member 8 rotates in the second direction A12 (see FIG. 1 ). As a result, the locking member 8 is attached to the tip of the shaft portion 415 of the valve member 4, as shown in FIG. 3 .

[0035] The flange portion 82 is connected to the tip of the cylindrical portion 81 in the direction of the axis A1 and extends radially outward from the tip of the cylindrical portion 81. As shown in Fig. 3, the flange portion 82 sandwiches the biasing member 7 together with the ceiling portion 52 of the base member 5. In other words, the biasing member 7 is sandwiched in a contracted state between the flange portion 82 of the locking member 8 and the ceiling portion 52 of the base member 5.

[0036] As a result, the locking member 8 is urged in the direction of arrow A18 shown in Fig. 3, i.e., toward the back side. Because the locking member 8 is attached to the tip of the shaft portion 415 of the valve member 4, the valve member 4 is urged in the direction of arrow A18 shown in Fig. 3, i.e., toward the back side, by the urging member 7 via the locking member 8. Therefore, when the pressure inside the case 9 is normal, the seal portion 42 contacts the valve seat 511 of the base member 5 and closes the air vent 512. This seals the internal space S1 of the case 9.

[0037] When the pressure in the internal space S1 of the case 9 increases, the valve member 4 receives a force toward the front side from the gas inside the case 9 through the vent hole 512. When the pressure in the internal space S1 of the case 9 increases above a predetermined value, the valve member 4, cap 3, and locking member 8 move integrally toward the front side while resisting the biasing force of the biasing member 7. As a result, the gas in the internal space S1 of the case 9 passes through the vent hole 512, passes through the gap formed between the seal portion 42 of the valve member 4 and the valve seat 511 of the base member 5, and passes through the gap formed between the flange portion 33 of the cap 3 and the annular portion 51 of the base member 5, and is released into the external space S2 of the case 9.

[0038] At this time, the maximum movement position (full stroke position) of the valve member 4, cap 3, and locking member 8 is determined by the flange portion 82 of the locking member 8 abutting against the rib 53 of the base member 5. In other words, the locking member 8 attached to the shaft portion 415 of the valve member 4, together with the rib 53 of the base member 5, determines the maximum movement position of the valve member 4, cap 3, and locking member 8. In this way, the shaft portion 415 of the valve member 4 and the locking member 8 prevent the valve member 4 from coming off the base member 5. In other words, the shaft portion 415 of the valve member 4 and the locking member 8 function as a retaining portion for preventing the valve member 4 from coming off the base member 5.

[0039] Next, the base member 5 of this embodiment will be further described with reference to the drawings. Fig. 4 is a plan view of the base member of this embodiment when viewed from a direction perpendicular to the axis. Fig. 5 is a perspective view of the base member of this embodiment when viewed from the back side. Fig. 6 is a perspective view of the base member of this embodiment when viewed from the front side. Fig. 7 is a plan view of the base member of this embodiment when viewed from the back side. Fig. 8 is a plan view of the base member of this embodiment when viewed from the front side.

[0040] 4, the base member 5 has an insertion portion 54. The insertion portion 54 is a portion that is inserted into the opening 91 (see FIG. 2) of the case 9. The insertion portion 54 is connected to the inner circumferential surface 513 (see FIGS. 6 and 8) of the annular portion 51, and has a generally annular shape that fits along the inner circumferential surface 513 of the annular portion 51. The insertion portion 54 has a retaining portion 541, a first stopper portion 542, and a second stopper portion 543.

[0041] 6 and 8 , the retaining portion 541 is formed to protrude radially outward from the outer peripheral surface 549 of the insertion portion 54, and has a retaining surface 541a facing the direction of the axis A1. The normal to the retaining surface 541a is along the axis A1. The retaining surface 541a extends in the circumferential direction along the outer peripheral surface 549 of the insertion portion 54.

[0042] As described above with reference to FIGS. 1 to 3, the base member 5 is fixed to the edge 92 of the opening 91 of the case 9 by rotating in the first direction A11 (see FIG. 1) around the axis A1. At this time, the retaining portion 541 engages with the edge 92 of the opening 91 of the case 9. Furthermore, as the retaining portion 541 rotates in the first direction A11, the retaining surface 541a abuts against the back surface 923 of the flange portion 922 (see FIGS. 11 and 14). This will be described in detail later. As a result, the retaining portion 541 prevents the insertion portion 54 from slipping out toward the front side along the direction of the axis A1.

[0043] The first stopper portion 542 is disposed closer to the second direction A12 than the retaining portion 541. As shown in Figures 6 to 8, the first stopper portion 542 is formed to protrude radially outward from the outer circumferential surface 549 of the insertion portion 54.

[0044] 6 and 8 , the first stopper portion 542 has a first stopper surface 542a facing the first direction A11. The first stopper surface 542a extends radially outward from the outer circumferential surface 549 of the insertion portion 54. In other words, the normal to the first stopper surface 542a is along the tangent to the outer circumferential surface 549 of the insertion portion 54.

[0045] When the base member 5 is fixed to the edge portion 92 of the opening 91 of the case 9 by rotating in the first direction A11, the first stopper portion 542 rotates in the first direction A11, causing the first stopper surface 542a to abut against the first end surface 924 (see FIG. 2 ) of the flange portion 922. This will be described in detail later. In this way, the first stopper portion 542 restricts the rotation of the base member 5 in the first direction A11 around the axis A1. The first end surface 924 of this embodiment is an example of the "one end surface" in the present invention.

[0046] 6, the retaining surface 541a and the first stopper surface 542a are connected to each other. Specifically, the first stopper surface 542a is connected to the end of the retaining surface 541a in the second direction A12 and extends from the end of the retaining surface 541a in the second direction A12 toward the front side along the axis A1. Note that the retaining surface 541a and the first stopper surface 542a do not necessarily have to be connected to each other and may be spaced apart from each other in the circumferential direction along the outer circumferential surface 549 of the insertion portion 54.

[0047] The second stopper portion 543 is disposed closer to the first direction A11 than the retaining portion 541. In other words, the first stopper portion 542 and the second stopper portion 543 are disposed at positions offset from each other in the circumferential direction along the outer circumferential surface 549 of the insertion portion 54, with the retaining portion 541 sandwiched between them. As shown in FIGS. 7 and 8 , the second stopper portion 543 is formed to protrude radially outward from the outer circumferential surface 549 of the insertion portion 54.

[0048] Specifically, the second stopper portion 543 has a base portion 544, an elastic piece 545, and a protrusion portion 546. The base portion 544 is connected to the outer peripheral surface 549 of the insertion portion 54, and is formed to protrude radially outward from the outer peripheral surface 549 of the insertion portion 54.

[0049] The elastic piece 545 is connected to the radially outer tip of the base 544 and extends from the radially outer tip of the base 544 in the circumferential direction along the outer circumferential surface 549 of the insertion portion 54. As shown in FIG. 8 , the elastic piece 545 is spaced apart from the outer circumferential surface 549 of the insertion portion 54. Therefore, as shown by arrow A15 in FIG. 4 , the elastic piece 545 is flexible in the direction of the axis A1. Specifically, the elastic piece 545 is flexible in the direction of the axis A1 so as to rotate approximately around the base 544.

[0050] The protrusion 546 is connected to the tip end in the second direction A12 of the elastic piece 545. As shown in Fig. 4, the protrusion 546 has a shape that protrudes toward the front side beyond the front surface 545a of the elastic piece 545 (see Figs. 11 and 14).

[0051] 5 and 8 , the second stopper portion 543 has a second stopper surface 546a facing the second direction A12. The second stopper surface 546a is an end surface of the protrusion 546 in the second direction A12 and extends radially outward. That is, the normal to the second stopper surface 546a is along a tangent to the outer peripheral surface 549 of the insertion portion 54.

[0052] When the base member 5 rotates in the first direction A11 to be fixed to the edge portion 92 of the opening 91 of the case 9, the second stopper portion 543 rotates in the first direction A11, causing the second stopper surface 546a to abut against the second end surface 925 (see FIG. 2 ) of the flange portion 922. The second end surface 925 in this embodiment is an example of the "other end surface" of the present invention. This will be described in detail later. In this way, the second stopper portion 543 restricts the base member 5 from rotating in the second direction A12 around the axis A1.

[0053] Next, the operation of the base member 5 of this embodiment when it is fixed to the edge 92 of the opening 91 of the case 9 will be described with reference to the drawings. FIG. 9 is a plan view showing the state before the base member of this embodiment is fixed to the edge of the opening of the case. FIG. 10 is a cross-sectional view taken along the line B-B in FIG. 9. FIG. 11 is an enlarged view of region A5 in FIG. 10. FIG. 12 is a plan view showing the state after the base member of this embodiment has been fixed to the edge of the opening of the case. FIG. 13 is a cross-sectional view taken along the line C-C in FIG. 12. FIG. 14 is an enlarged view of region A6 in FIG. 13. Note that FIGS. 9 and 12 are plan views of the base member 5 and the opening 91 of the case 9 viewed from the side of the internal space S1 of the case.

[0054] 9 , before the base member 5 is fixed to the edge portion 92 of the opening 91 of the case 9, the retaining portion 541, the first stopper portion 542, and the second stopper portion 543 are disposed between adjacent flange portions 922 in the circumferential direction. 10 and 11 , before the base member 5 is fixed to the edge portion 92 of the opening 91 of the case 9, the retaining portion 541, the first stopper portion 542, and the second stopper portion 543 are inserted into the opening 91 of the case 9 and disposed behind the rear surface 923 of the flange portion 922.

[0055] 11 , the contact surface 547 of the insertion portion 54 contacts the front surface 93 of the case 9. As shown in FIG. 2 , the front surface 93 of the case 9 is flush with the front surface of the flange portion 922. In addition, the back surface 923 of the flange portion 922 is flush with the back surface of the case 9.

[0056] 10 and 11 , when the base member 5 rotates in the first direction A11 around the axis A1, the flange portion 922 rotates in a direction A21 opposite to the first direction A11 relative to the base member 5. Here, as shown in Fig. 11 , the plate thickness T of the case 9 is thinner in the direction of the axis A1 than the gap S11 between the abutment surface 547 of the insertion portion 54 and the front surface 545a of the elastic piece 545. The front surface of the base 544 is flush with the front surface 545a of the elastic piece 545.

[0057] Therefore, when the base member 5 rotates in the first direction A11, the flange portion 922 enters the gap S11 between the abutment surface 547 of the insertion portion 54 and the front surface 545a of the elastic piece 545. When the base member 5 rotates further in the first direction A11, the protrusion 546 reaches a first end of the flange portion 922. The first end of the flange portion 922 is an end of the flange portion 922 that has a first end surface 924 (see FIG. 2 ) facing the second direction A12, and is an example of "one end" in the present invention.

[0058] 11 , the plate thickness T of the case 9 in the direction of the axis A1 is thicker than the gap S12 between the abutment surface 547 of the insertion portion 54 and the front surface 546b of the protrusion 546. Therefore, when the base member 5 further rotates in the first direction A11, the protrusion 546 abuts against the first end of the flange portion 922.

[0059] 4, the elastic piece 545 is flexible in the direction of the axis A1. Therefore, when the protrusion 546 abuts against the first end of the flange portion 922, the elastic piece 545 is flexible in the direction of the arrow A15 shown in FIGS.

[0060] 12 to 14 , when the second stopper portion 543 rotates in the first direction A11, the elastic piece 545 bends in the direction of arrow A15, causing the second stopper surface 546a to move from the first end side of the flange portion 922 over the flange portion 922 and toward the second end side of the flange portion 922. The second end side of the flange portion 922 is the end of the flange portion 922 having a second end surface 925 (see FIG. 2 ) facing the first direction A11, and is an example of the “other end” of the present invention. When the second stopper surface 546a moves toward the second end side of the flange portion 922, the elastic force of the elastic piece 545 itself causes the elastic piece 545 to return to the state it was in before the protrusion 546 abutted against the first end side of the flange portion 922.

[0061] In this way, the retaining surface 541a of the retaining portion 541 abuts against the back surface 923 of the flange portion 922. As a result, the retaining portion 541 prevents the insertion portion 54 from slipping out toward the front side along the direction of the axis A1. Also, as shown in FIG. 14 , the first stopper surface 542a of the first stopper portion 542 abuts against the first end surface 924 of the flange portion 922. As a result, the first stopper portion 542 restricts the base member 5 from rotating in the first direction A11 around the axis A1.

[0062] 14 , the second stopper surface 546 a of the second stopper portion 543 abuts against the second end surface 925 of the flange portion 922. This causes the second stopper portion 543 to restrict rotation of the base member 5 in the second direction A12 around the axis A1. In other words, the second stopper portion 543 restricts rotation of the flange portion 922 relative to the base member 5 in the direction A22 (see FIGS. 13 and 14 ), which is the same as the first direction A11.

[0063] As described above, in the pressure release valve 2 according to this embodiment, the base member 5 has the insertion portion 54 that is inserted into the opening 91 formed in the case 9. The insertion portion 54 has a retaining portion 541 that prevents the insertion portion 54 from being removed from the opening 91 of the case 9 in the direction of the axis A1. The retaining portion 541 engages with the edge 92 of the opening 91 of the case 9 by rotating in the first direction A11 around the axis A1. As a result, the pressure release valve 2 according to this embodiment is attached to the case 9. In this way, the pressure release valve 2 according to this embodiment is engaged with and attached to the case 9 by rotating relative to the case 9 without using fastening members such as screws or bolts. This improves the efficiency of the attachment work of the pressure release valve 2 according to this embodiment to the case 9.

[0064] Furthermore, the first stopper portion 542 is disposed closer to the second direction A12 around the axis A1 than the retaining portion 541. Therefore, the first stopper portion 542 restricts rotation of the base member 5 in the first direction A11 on the second direction A12 side of the retaining portion 541. Furthermore, the retaining portion 541 prevents the insertion portion 54 from coming out of the opening 91 of the case 9 in the direction of the axis A1 on the first direction A11 side of the first stopper portion 542. This improves the efficiency of the attachment work to the case 9 while stably and reliably restricting rotation of the base member 5 and preventing the insertion portion 54 from coming out, compared to when the first stopper portion 542 and the retaining portion 541 restrict rotation of the base member 5 and prevent the insertion portion 54 from coming out at approximately the same position in the circumferential direction.

[0065] Furthermore, because the retaining surface 541a of the retaining portion 541 and the first stopper surface 542a of the first stopper portion 542 are connected to each other, the strength of the retaining portion 541 and the first stopper portion 542 can be increased compared to a case in which the retaining surface 541a and the first stopper surface 542a are not connected to each other. This makes it possible to improve the force of the retaining portion 541 that prevents the insertion portion 54 from coming out of the opening 91 of the case 9 in the direction of the axis A1 (i.e., the retaining force of the retaining portion 541) and the force of the first stopper portion 542 that restricts rotation of the base member 5 in the first direction A11 around the axis A1 (i.e., the rotation restricting force of the first stopper portion 542).

[0066] Furthermore, the second stopper portion 543 is disposed closer to the first direction A11 around the axis A1 than the retaining portion 541. That is, the first stopper portion 542 and the second stopper portion 543 are disposed at positions offset from each other in the circumferential direction of the insertion portion 54, with the retaining portion 541 sandwiched therebetween. Therefore, the first stopper portion 542 alone restricts the rotation of the base member 5 in the first direction A11. The second stopper portion 543 alone restricts the rotation of the base member 5 in the second direction A12. This improves the durability of the first stopper portion 542 and the second stopper portion 543 compared to when a single stopper portion restricts the rotation of the base member 5 in both the first direction A11 and the second direction A12.

[0067] Furthermore, according to the pressure release valve mounting structure of this embodiment, the elastic piece 545 of the second stopper portion 543 extends in the circumferential direction along the outer circumferential surface 549 of the insertion portion 54, thereby ensuring a longer overall length while miniaturizing the base member 5 compared to when it extends in the radial direction of the insertion portion 54. Therefore, the elastic piece 545 of the second stopper portion 543 can ensure a greater amount of deflection while maintaining strength when the second stopper surface 546a overcomes the flange portion 922. As a result, the pressure release valve mounting structure of this embodiment can improve the efficiency of the installation work on the case 9.

[0068] Furthermore, the plate thickness T of the case 9, in the direction of the axis A1, is thinner than the gap S11 between the abutment surface 547 of the insertion portion 54 and the front surface 545a of the elastic piece 545, and thicker than the gap S12 between the abutment surface 547 of the insertion portion 54 and the front surface 546b of the protrusion 546. This reduces the resistance received from the case 9 when the base member 5 rotates in the first direction A11, while more reliably providing a clicking sensation when the second stopper surface 546a moves from the side of the first end of the flange portion 922 over the flange portion 922 to the side of the second end of the flange portion 922. As a result, the pressure release valve mounting structure according to this embodiment can further improve the efficiency of the installation work on the case 9.

[0069] Next, a second embodiment of the present invention will be described. In addition, in cases where the components of a pressure release valve 2A according to the second embodiment are the same as the components of the pressure release valve 2 according to the first embodiment described above with reference to Figures 1 to 14, redundant explanations will be omitted as appropriate, and the following description will focus on the differences.

[0070] Fig. 15 is a perspective view showing a pressure relief valve according to a second embodiment of the present invention. Fig. 16 is an exploded view showing a pressure relief valve according to this embodiment. Fig. 17 is a cross-sectional view taken along the line G-G in Fig. 15. Fig. 18 is a cross-sectional view taken along the line H-H in Fig. 15.

[0071] The pressure release valve 2A of this embodiment is attached to a case 9 that houses an electricity storage device or the like, and when the pressure inside the case 9 rises, it releases the gas inside the case 9 and releases the pressure inside the case 9.

[0072] Examples of the power storage device housed in case 9 include batteries (lithium ion batteries, etc.) used in hybrid vehicles including plug-in hybrid vehicles, electric vehicles, etc. However, the power storage device housed in case 9 is not limited to these. Furthermore, the contents housed in case 9 are not limited to power storage devices.

[0073] As shown in FIG. 16 , the case 9 has an opening 91. An edge 92 of the opening 91 has a flange 922. The flange 922 protrudes radially inward from an inner circumferential surface 921 of the edge 92. Here, in this specification, the term "front side" refers to the side of the case 9 facing the external space S2 (see FIG. 17 ) of the case 9, or the direction from the internal space S1 (see FIG. 17 ) of the case 9 toward the external space S2 of the case 9. Also, in this specification, the term "rear side" refers to the side of the case 9 facing the internal space S1 of the case 9, or the direction from the external space S2 of the case 9 toward the internal space S1 of the case 9.

[0074] As shown in FIG. 16, the pressure release valve 2A includes a cap 3, a valve member 4, a base member 5, a seal ring 6, a biasing member 7, and a locking member 8.

[0075] The base member 5 is fixed to the edge 92 of the opening 91 of the case 9 by rotating in a third direction A16 (see FIG. 15) about the axis A1. The base member 5 is released from the edge 92 of the opening 91 of the case 9 by rotating in a fourth direction A17 (see FIG. 15) about the axis A1, i.e., in the direction opposite to the third direction A16.

[0076] The axis A1 is the axis of the base member 5, as well as the axis of each of the cap 3, the valve member 4, the seal ring 6, the biasing member 7, and the locking member 8. In other words, the axis of the base member 5 coincides with the axis of each of the cap 3, the valve member 4, the seal ring 6, the biasing member 7, and the locking member 8.

[0077] 16 , the base member 5 has an annular portion 51, a ceiling portion 52, and a rib 53. The annular portion 51 has a generally circular ring shape and forms the radially outermost portion of the base member 5. The annular portion 51 has a valve seat 511. The valve seat 511 has a front surface, i.e., a surface facing the seal portion 42 of the valve member 4. As shown in FIGS. 17 and 18 , when the base member 5 is fixed to the edge portion 92 of the opening 91 of the case 9, the valve seat 511 is disposed on the periphery of the opening 91 of the case 9.

[0078] The ceiling portion 52 has a disk shape and is provided inside the annular portion 51. Specifically, the ceiling portion 52 is provided on the front side of the annular portion 51 in the radial center of the base member 5. The ceiling portion 52 has a through hole 521. The through hole 521 is formed in the radial center of the ceiling portion 52 and penetrates the ceiling portion 52 in the direction of the axis A1.

[0079] The rib 53 is connected to the ceiling portion 52 and the insertion portion 54 (see FIGS. 17 and 18 ). That is, the ceiling portion 52 is connected to the insertion portion 54 via the rib 53. The insertion portion 54 is the portion that is inserted into the opening 91 of the case 9, and is connected to the inner circumferential surface 513 (see FIG. 17 ) of the annular portion 51. As a result, the ceiling portion 52 is connected to the annular portion 51 via the rib 53 and the insertion portion 54.

[0080] 16 , the base member 5 of this embodiment has a plurality of ribs 53. The plurality of ribs 53 are spaced apart from one another in the circumferential direction. Air vents 512 are formed between adjacent ribs 53. The air vents 512 communicate between an internal space S1 of the case 9 and an external space S2 of the case 9.

[0081] The valve member 4 has a base portion 41 and a seal portion 42. The base portion 41 is formed from a material harder than the material of the seal portion 42, and has a ceiling portion 411, a peripheral wall portion 412, and a flange portion 413. The ceiling portion 411 has a disk shape and is provided in the radial center of the valve member 4.

[0082] The peripheral wall portion 412 is connected to the outer peripheral edge of the ceiling portion 411 and extends from the outer peripheral edge of the ceiling portion 411 toward the back side, i.e., the side of the base member 5. The flange portion 413 is connected to the tip end of the peripheral wall portion 412 in the extension direction and extends radially outward from the tip end of the peripheral wall portion 412 in the extension direction.

[0083] The seal portion 42 is made of an elastic material such as rubber or an elastic elastomer, and is formed integrally with the flange portion 413 of the base portion 41. The seal portion 42 extends radially outward from the outer peripheral edge of the flange portion 413 and also extends from the outer peripheral edge of the flange portion 413 toward the back side, i.e., the side of the base member 5. The seal portion 42 moves toward and away from the valve seat 511 of the base member 5 to open and close the vent hole 512.

[0084] The base 41 further includes an engaging portion 414 and a shaft portion 415. The engaging portion 414 is an example of a "first engaging portion" in the present invention. The engaging portion 414 is provided on the front surface of the ceiling portion 411 and is formed to extend in the circumferential direction near the outer periphery of the ceiling portion 411. As shown in FIG. 17 , the engaging portion 414 is provided radially outward of the shaft portion 415 and engages with the engaging portion 312 of the cap 3. For example, the engaging portion 414 is provided radially between the shaft portion 415 and the seal portion 42. This will be described in detail later.

[0085] The shaft portion 415 is connected to the radial center of the ceiling portion 411 and extends from the ceiling portion 411 along the axis A1 toward the back side, i.e., the side of the base member 5. The shaft portion 415 is inserted into a through-hole 521 formed in the ceiling portion 52 of the base member 5 and prevents the valve member 4 from coming off the base member 5. In other words, the shaft portion 415 is a portion that prevents the valve member 4 from coming off the base member 5. This will be described in detail later.

[0086] 18 , the shaft portion 415 has an engaging portion 416. The engaging portion 416 is provided at the tip of the shaft portion 415 in the extension direction, and extends radially outward from the outer circumferential surface of the shaft portion 415. The engaging portion 416 engages with the engaging portion 811 of the locking member 8.

[0087] As shown in Fig. 16 , the protrusion 421 protrudes from the front surface of the flange portion 413 toward the front side. The protrusion 421 of this embodiment is an example of the "biasing portion" of the present invention. The protrusion 421 is provided between the engagement portion 414 and the seal portion 42 in the radial direction. As shown in Fig. 18 , the protrusion 421 is interposed between the front surface of the flange portion 413 and the back surface of the cap 3, and biases the cap 3 toward the front side, i.e., in a direction away from the valve member 4.

[0088] The cap 3 has a ceiling portion 31, a peripheral wall portion 32, and a flange portion 33. The ceiling portion 31 has a disk shape and is provided in the radial center of the cap 3. The ceiling portion 31 has a through hole 311. The through hole 311 is formed near the outer peripheral edge of the ceiling portion 31, extending in the circumferential direction, and penetrates the ceiling portion 31 in the plate thickness direction (i.e., the direction of the axis A1). An engagement portion 312 is provided at the edge of the through hole 311. The engagement portion 312 of this embodiment is an example of a "second engagement portion" of the present invention.

[0089] 17 , the engaging portion 312 protrudes from the edge of the through-hole 311 toward the inside of the through-hole 311 and engages with an engaging portion 414 provided on the ceiling portion 411 of the valve member 4. That is, the engaging portion 414 of the valve member 4 is inserted into the through-hole 311 of the cap 3, and the cap 3 rotates around the shaft portion 415 (i.e., around the axis A1) in the third direction A16 (see FIG. 15 ), whereby the engaging portion 312 of the cap 3 engages with the engaging portion 414 of the valve member 4. This will be described in detail later. In this way, the cap 3 is attached to the valve member 4 and covers the valve member 4.

[0090] The peripheral wall portion 32 is connected to the outer peripheral edge of the ceiling portion 31 and extends from the outer peripheral edge of the ceiling portion 31 toward the back side, i.e., the side of the valve member 4. The flange portion 33 is connected to the tip of the peripheral wall portion 32 in the extension direction and extends radially outward from the tip of the peripheral wall portion 32 in the extension direction. As shown in FIGS. 17 and 18 , when the cap 3 is attached to the valve member 4, the flange portion 33 covers the seal portion 42 of the valve member 4 and the valve seat 511 of the base member 5. This allows the cap 3 to prevent water sprayed from, for example, a high-pressure washer from directly hitting the seal portion 42 of the valve member 4.

[0091] The seal ring 6 is a so-called "O-ring" or the like, and is made of an elastic material such as rubber and has a circular ring shape. As shown in Figures 17 and 18, the seal ring 6 is attached to an annular protrusion 514 formed on the back side of the valve seat 511 of the base member 5. The seal ring 6 is interposed between the base member 5 and the case 9, and biases the base member 5 toward the front side.

[0092] The biasing member 7 is a coil spring formed by winding a wire rod having a predetermined diameter at a predetermined pitch, for example. As shown in Figures 17 and 18, the biasing member 7 is disposed radially outside the shaft portion 415 of the valve member 4 and is supported by the shaft portion 415.

[0093] The locking member 8 has a tubular portion 81 and a flange portion 82. The tubular portion 81 has a generally cylindrical shape and is provided in the radial center of the locking member 8. The tubular portion 81 has an engaging portion 811. The engaging portion 811 is provided inside the tubular portion 81 and extends radially inward from the inner circumferential surface of the tubular portion 81. When the locking member 8 rotates in the fourth direction A17 (see FIG. 15 ), the engaging portion 811 engages with the engaging portion 416 provided on the shaft portion 415 of the valve member 4. As a result, as shown in FIG. 18 , the locking member 8 is attached to the tip of the shaft portion 415 of the valve member 4.

[0094] The flange portion 82 is connected to the tip of the cylindrical portion 81 in the direction of the axis A1 and extends radially outward from the tip of the cylindrical portion 81. As shown in Figures 17 and 18, the flange portion 82 sandwiches the biasing member 7 together with the ceiling portion 52 of the base member 5. In other words, the biasing member 7 is sandwiched in a contracted state between the flange portion 82 of the locking member 8 and the ceiling portion 52 of the base member 5.

[0095] As a result, the locking member 8 is biased in the direction of arrow A18 shown in FIGS. 17 and 18 , i.e., toward the back side. Because the locking member 8 is attached to the tip of the shaft portion 415 of the valve member 4, the valve member 4 is biased in the direction of arrow A18 shown in FIGS. 17 and 18 , i.e., toward the back side, by the biasing member 7 via the locking member 8. Therefore, when the pressure inside the case 9 is normal, the seal portion 42 contacts the valve seat 511 of the base member 5 and closes the vent hole 512. This seals the internal space S1 of the case 9. Furthermore, as shown in FIGS. 17 and 18 , when the seal portion 42 contacts the valve seat 511 of the base member 5 and closes the vent hole 512, the flange portion 33 of the cap 3 covers the seal portion 42 of the valve member 4 and the valve seat 511 of the base member 5.

[0096] When the pressure in the internal space S1 of the case 9 increases, the valve member 4 receives a force toward the front side from the gas inside the case 9 through the vent hole 512. When the pressure in the internal space S1 of the case 9 increases above a predetermined value, the valve member 4, cap 3, and locking member 8 move integrally toward the front side while resisting the biasing force of the biasing member 7. As a result, the gas in the internal space S1 of the case 9 passes through the vent hole 512, passes through the gap formed between the seal portion 42 of the valve member 4 and the valve seat 511 of the base member 5, and passes through the gap formed between the flange portion 33 of the cap 3 and the annular portion 51 of the base member 5, and is released into the external space S2 of the case 9.

[0097] At this time, the maximum movement position (full stroke position) of the valve member 4, cap 3, and locking member 8 is determined by the flange portion 82 of the locking member 8 abutting against the rib 53 of the base member 5. In other words, the locking member 8 attached to the shaft portion 415 of the valve member 4, together with the rib 53 of the base member 5, determines the maximum movement position of the valve member 4, cap 3, and locking member 8. In this way, the shaft portion 415 of the valve member 4 and the locking member 8 prevent the valve member 4 from coming off the base member 5. In other words, the shaft portion 415 of the valve member 4 and the locking member 8 function as a retaining portion for preventing the valve member 4 from coming off the base member 5.

[0098] Figure 19 is a cross-sectional view showing a pressure release valve according to a modification of this embodiment. Figure 19 corresponds to the cross-sectional view taken along the line G-G in Figure 15. Note that in cases where the components of the pressure release valve 2B according to this modification are the same as the components of the pressure release valve 2A according to this embodiment described above with reference to Figures 15 to 18, redundant explanations will be omitted as appropriate, and the following explanation will focus on the differences.

[0099] The valve member 4B of the pressure release valve 2B according to this modification has a base portion 41B and a seal portion 42. The base portion 41B has an engagement portion 416. The engagement portion 416 of this modification is an example of the "first engagement portion" of the present invention. The engagement portion 416 is provided on the outer peripheral surface of the peripheral wall portion 412 of the base portion 41B. In this respect, the valve member 4B of this modification differs from the valve member 4 of the present embodiment described above with reference to FIGS. 15 to 18. The engagement portion 416 projects radially outward from the outer peripheral surface of the peripheral wall portion 412 and extends circumferentially along the outer peripheral surface of the peripheral wall portion 412.

[0100] The cap 3B has a ceiling portion 31, a peripheral wall portion 32B, and a flange portion 33. The peripheral wall portion 32B has a through-hole 321. The through-hole 321 is formed in the circumferential direction along the outer circumferential surface of the peripheral wall portion 32B and penetrates the peripheral wall portion 32B in the thickness direction (i.e., the radial direction). An engagement portion 322 is provided on the edge of the through-hole 321. In this respect, the cap 3B of this modified example differs from the cap 3 of the present embodiment described above with reference to FIGS. 15 to 18. The engagement portion 322 of this modified example is an example of the "second engagement portion" of the present invention.

[0101] The engaging portion 322 protrudes from the edge of the through-hole 321 toward the inside of the through-hole 321 and engages with an engaging portion 416 provided on the peripheral wall portion 412 of the valve member 4B. That is, the engaging portion 416 of the valve member 4B is inserted into the through-hole 321 of the cap 3B, and the cap 3B is rotated in the third direction A16 (see FIG. 15 ) around the shaft portion 415 (i.e., around the axis A1), whereby the engaging portion 322 of the cap 3B engages with the engaging portion 416 of the valve member 4B. In this way, the cap 3B is attached to the valve member 4B and covers the valve member 4B. The rest of the structure is the same as the structure of the pressure release valve 2A according to this embodiment described above with reference to FIGS. 15 to 18 .

[0102] Next, the valve member 4 and the cap 3 of this embodiment will be further described with reference to the drawings. Figure 20 is a perspective view showing the valve member of this embodiment.

[0103] 15 to 18, the engaging portion 414 is provided on the front surface of the ceiling portion 411 and is formed to extend in the circumferential direction near the outer periphery of the ceiling portion 411. The engaging portion 414 is provided radially outward of the shaft portion 415 and has a first wall portion 414a, a second wall portion 414b, and a third wall portion 414c.

[0104] The first wall portion 414 a protrudes from the front surface of the ceiling portion 411 toward the front side, and extends in the circumferential direction along the outer periphery of the ceiling portion 411 .

[0105] The second wall portion 414b is connected to the end of the first wall portion 414a in the third direction A16 and, like the first wall portion 414a, protrudes toward the front side from the front surface of the ceiling portion 411. The height that the second wall portion 414b protrudes from the front surface of the ceiling portion 411 is the same as the height that the first wall portion 414a protrudes from the front surface of the ceiling portion 411. The second wall portion 414b extends radially outward from the end of the first wall portion 414a in the third direction A16.

[0106] The third wall portion 414c is connected to the front end of the first wall portion 414a and the front end of the second wall portion 414b, and similar to the first wall portion 414a, extends in the circumferential direction along the outer periphery of the ceiling portion 411. As shown in Fig. 20 , the third wall portion 414c functions as the ceiling portion of the engagement portion 414.

[0107] The third wall portion 414c has a protrusion 414d. The protrusion 414d is provided at the end of the third wall portion 414c in the fourth direction A17 and protrudes from the rear surface of the third wall portion 414c toward the rear side, i.e., from the rear surface of the third wall portion 414c toward the ceiling portion 411. As shown in FIG. 20 , the end of the engagement portion 414 in the fourth direction A17 does not have a wall portion (the second wall portion 414b in the example shown in FIG. 20 ) like the end of the engagement portion 414 in the third direction A16, but rather opens as an opening.

[0108] 20 has four engaging portions 414. However, the number of engaging portions 414 is not limited to four and may be, for example, three or five or more.

[0109] FIG. 21 is a perspective view showing the cap of this embodiment. As described above with reference to FIGS. 15 to 18 , the engaging portion 312 protrudes from the edge of the through hole 311 toward the inside of the through hole 311. Specifically, the engaging portion 312 is formed on the first hole edge 311a of the through hole 311 and protrudes from the first hole edge 311a toward the inside of the through hole 311. The first hole edge 311a is an edge portion on the outer periphery of the through hole 311 that extends in the circumferential direction. The engaging portion 312 extends in the circumferential direction along the first hole edge 311a of the through hole 311. The engaging portion 312 has a thickness that allows it to fit into the engaging portion 414 of the valve member 4. This will be described in detail later.

[0110] 21 , the engaging portion 312 is spaced apart from the second hole edge 311b of the through hole 311 in the circumferential direction. That is, a gap 311c exists between the engaging portion 312 and the second hole edge 311b of the through hole 311. The second hole edge 311b of the through hole 311 is an edge portion of the through hole 311 that is located closer to the fourth direction A17 than the first hole edge 311a, and is formed to extend in the radial direction. As will be described later, a protrusion 414d of the engaging portion 414 of the valve member 4 fits into the gap 311c.

[0111] Note that the engaging portion 312 does not necessarily have to be spaced apart from the second hole edge 311b in the circumferential direction, as long as a groove or space is provided in which the protrusion 414d of the engaging portion 414 of the valve member 4 fits. For example, the engaging portion 312 may be connected to the second hole edge 311b, and a recess into which the protrusion 414d of the engaging portion 414 of the valve member 4 can fit may be provided at the connection portion between the engaging portion 312 and the second hole edge 311b.

[0112] 21 has four engaging portions 312. However, the number of engaging portions 312 is not limited to four, and may be, for example, three or five or more.

[0113] Next, the action when the engaging portion 312 of the cap 3 and the engaging portion 414 of the valve member 4 engage with each other will be described with reference to the drawings. FIG. 22 is a perspective view showing the state before the cap of this embodiment is placed on the valve member. FIG. 23 is a perspective view showing the state before the engaging portion of the cap and the engaging portion of the valve member engage with each other. FIG. 24 is a cross-sectional view taken along section I-I in FIG. 23. FIG. 25 is a cross-sectional view taken along section D-D in FIG. 23. FIG. 26 is a perspective view showing the state after the engaging portion of the cap and the engaging portion of the valve member have engaged with each other. FIG. 27 is a cross-sectional view taken along section E-E in FIG. 26. FIG. 28 is a cross-sectional view taken along section F-F in FIG. 26.

[0114] 22 , the cap 3 is placed on the valve member 4 with the seal portion 42 of the valve member 4 in contact with the valve seat 511 of the base member 5 to close the vent hole 512. At this time, the position of the through-hole 311 of the cap 3 is aligned with the position of the engagement portion 414 of the valve member 4.

[0115] 23, the engaging portion 414 of the valve member 4 is inserted into the through-hole 311 of the cap 3. In this state, as shown in Fig. 25, the flange portion 33 of the cap 3 covers the seal portion 42 of the valve member 4 and the valve seat 511 of the base member 5. Also, as shown in Figs. 24 and 25, the engaging portion 414 of the valve member 4 is located inside the through-hole 311 on the side of the third direction A16 relative to the engaging portion 312 of the cap 3. In other words, the engaging portion 312 of the cap 3 is not yet engaged with the engaging portion 414 of the valve member 4.

[0116] Subsequently, when the cap 3 rotates in the third direction A16 around the axis A1, the engaging portion 312 of the cap 3 moves in the third direction A16 around the axis A1 and approaches the engaging portion 414 of the valve member 4. In other words, the engaging portion 414 of the valve member 4 moves in the fourth direction A17 around the axis A1 inside the through-hole 311 relative to the cap 3 and approaches the engaging portion 312 of the cap 3.

[0117] 25 , in the direction of axis A1, the distance between the front surface of the ceiling portion 411 and the back surface of the third wall portion 414c is longer than the thickness of the engaging portion 312 of the cap 3. In addition, in the direction of axis A1, the distance between the front surface of the ceiling portion 411 and the back end of the protrusion portion 414d is the same as the thickness of the engaging portion 312 of the cap 3 or slightly shorter than the thickness of the engaging portion 312 of the cap 3.

[0118] Therefore, as the end of the third wall portion 414c on which the protrusion 414d is provided bends toward the front side along the direction of the axis A1, the engaging portion 312 of the cap 3 passes between the front surface of the ceiling portion 411 and the rear end of the protrusion 414d. In other words, as the end of the third wall portion 414c on which the protrusion 414d is provided bends toward the front side along the direction of the axis A1, the protrusion 414d climbs over the engaging portion 312 from the end side of the engaging portion 312 in the third direction A16 and moves toward the end side of the engaging portion 312 in the fourth direction A17.

[0119] Next, when the cap 3 is further rotated in the third direction A16 around the axis A1, as shown in Figures 26 to 28, the engaging portion 312 of the cap 3 fits between the front surface of the ceiling portion 411 and the back surface of the third wall portion 414c. Also, as shown in Figure 28, the protrusion 414d of the engaging portion 414 of the valve member 4 fits into the gap 311c formed between the engaging portion 312 of the cap 3 and the second hole edge 311b of the through-hole 311. In this way, as shown in Figures 26 to 28, the engaging portion 312 of the cap 3 engages with the engaging portion 414 of the valve member 4.

[0120] 27 and 28 , when the engaging portion 312 of the cap 3 engages with the engaging portion 414 of the valve member 4, the second hole edge 311b of the through hole 311 abuts against the end of the engaging portion 414 of the valve member 4 in the fourth direction A17. As a result, the second hole edge 311b of the through hole 311 restricts further rotation of the cap 3 in the third direction A16 around the axis A1.

[0121] On the other hand, as shown in Figures 27 and 28, when the engagement portion 312 of the cap 3 is engaged with the engagement portion 414 of the valve member 4, the inner surface of the second wall portion 414b (i.e., the inner surface facing the fourth direction A17) is spaced apart from the engagement portion 312 of the cap 3 in the circumferential direction.

[0122] 27, when the engaging portion 312 of the cap 3 is engaged with the engaging portion 414 of the valve member 4, the inner surface of the second wall portion 414e may abut against the engaging portion 312 of the cap 3. In this embodiment, the second wall portion 414e shown by the dashed two-dot line is an example of the "stopper portion" of the present invention, which is provided at the end of the engaging portion 414 of the valve member 4 in the third direction A16.

[0123] As described above, in the pressure release valve 2A according to this embodiment, the engaging portion 414 of the valve member 4 is provided radially outward of the shaft portion 415 of the valve member 4. The engaging portion 312 of the cap 3 engages with the engaging portion 414 of the valve member 4 by rotating in the third direction A16 around the shaft portion 415. In this way, the cap 3 having the engaging portion 312 engages with the valve member 4 having the engaging portion 414 by rotating in the third direction A16 around the shaft portion 415 of the valve member 4. As a result, the height of the pressure release valve 2A according to this embodiment in the direction of the axis A1 can be kept low compared to when the cap 3 is attached to the valve member 4 along the axis A1.

[0124] Furthermore, the second hole edge 311b of the through hole 311, which is located closer to the fourth direction A17 than the first hole edge 311a of the through hole 311, where the engaging portion 312 of the cap 3 is formed, abuts against the engaging portion 414 of the valve member 4, thereby restricting rotation of the cap 3 in the third direction A16. Therefore, the pressure release valve 2A of this embodiment can restrict rotation of the cap 3 in the third direction A16 inside the through hole 311 of the cap 3. This allows the height of the pressure release valve 2A of this embodiment to be even lower in the direction of the axis A1.

[0125] 27, the second wall portion 414e comes into contact with the engaging portion 312 formed on the first hole edge 311a of the through hole 311 of the cap 3, and functions as a stopper. Therefore, in this case, the pressure release valve 2A according to this embodiment can restrict rotation of the cap 3 in the third direction A16 inside the through hole 311 of the cap 3. This allows the height of the pressure release valve 2A according to this embodiment in the direction of the axis A1 to be further reduced.

[0126] Furthermore, the engaging portion 414 of the valve member 4 moves in the fourth direction A17 inside the through hole 311 of the cap 3 relative to the cap 3 and engages with the engaging portion 312 of the cap 3. Therefore, the engaging portion 414 of the valve member 4 can guide the rotation of the engaging portion 312 formed on the first hole edge 311a of the through hole 311 of the cap 3. This improves the efficiency of the work of attaching the cap 3 to the valve member 4.

[0127] Furthermore, the protrusion 421 of the valve member 4 is provided radially between the engaging portion 414 of the valve member 4 and the seal portion 42 of the valve member 4, and urges the cap 3 in a direction away from the valve member 4. Therefore, the protrusion 421 of the valve member 4 can urge the cap 3 in a direction away from the valve member 4 in the vicinity of the engaging portion 414 of the valve member 4 and the engaging portion 312 of the cap 3. This makes it possible to suppress vibration of the cap 3 relative to the valve member 4 when the engaging portion 312 of the cap 3 is engaged with the engaging portion 414 of the valve member 4.

[0128] Next, a third embodiment of the present invention will be described. In addition, in cases where the components of the pressure release valve 10 according to the third embodiment are the same as the components of the pressure release valve 2 according to the first embodiment described above with reference to Figures 1 to 14 and the pressure release valve 2A according to the second embodiment described above with reference to Figures 15 to 28, redundant explanations will be omitted as appropriate, and the following description will focus on the differences.

[0129] Figure 29 is a perspective view of a pressure release valve 10 according to a third embodiment of the present invention. Figure 29(a) shows the pressure release valve 10 as seen from the front side, and Figure 29(b) shows the pressure release valve 10 as seen from the back side. The pressure release valve 10 is provided in a case of an electricity storage device. The electricity storage device is, for example, a driving power source mounted on a vehicle. The pressure release valve 10 is normally closed and opens when the pressure in the internal space of the case reaches or exceeds a predetermined value.

[0130] The pressure release valve 10 comprises a lid member 12, a valve body 14, a base member 16, a cover member 18, a locking member 20, a biasing member 22, and a sealing member 24. The valve body 14 of this embodiment is an example of the "valve member" of the present invention. The back surface of the pressure release valve 10 shown in Figure 29(b) is seated around the opening of the case in accordance with its position. On the front side of the case, as shown in Figure 29(a), the lid member 12 is located on the top surface, and the cover member 18 covers the side surface of the pressure release valve 10.

[0131] Figure 30 is an exploded view of the pressure release valve 10 of this embodiment. The cover member 12 is formed in a dish shape and covers the upper surface of the pressure release valve 10. The cover member 12 has connecting holes 26 and protrusions 28. The connecting holes 26 are formed to connect to the valve body 14, and multiple connecting holes 26 are formed spaced apart in the circumferential direction. The protrusions 28 are formed inside the connecting holes 26 and are hooked onto the valve body 14.

[0132] The valve element 14 is provided so as to be movable in the axial direction. The axial direction is the direction along the central axis of the valve element 14 and also the direction along the central axis of the pressure release valve 10. The valve element 14 has a first valve element 14a and a second valve element 14b. The first valve element 14a and the second valve element 14b are integrally formed by two-color molding. The first valve element 14a is formed from a harder material than the second valve element 14b, and the second valve element 14b is formed from a rubber material.

[0133] The first valve body 14a has a hook portion 30 and a cylindrical portion 39. A plurality of hook portions 30 are formed and are inserted into the connecting hole portion 26 of the cover member 12 to catch on the protrusion portion 28. This prevents the cover member 12 from coming off.

[0134] The cylindrical portion 39 is located at the center of the first valve body 14a and penetrates it in the axial direction. A breather (not shown) is provided to cover the upper part of the cylindrical portion 39. The breather opens slightly at a pressure lower than the pressure at which the valve body 14 moves.

[0135] The second valve body 14b is provided on the outer periphery of the first valve body 14a and is formed in an annular shape. The second valve body 14b is formed so as to hang radially outward toward the base member 16. The seal end 34 of the second valve body 14b abuts against the base member 16 over the entire circumference, thereby assuming a closed valve state.

[0136] The base member 16 will be described with reference to new drawings. Figure 31 is a perspective view of the base member 16 as seen from the back side. The base member 16 is placed in the opening of the case. The base member 16 has a tubular portion 36, a flange portion 38, an insertion hole portion 40, and an annular protrusion 43. The tubular portion 36 of this embodiment is an example of the "insertion portion" of the present invention.

[0137] The tubular portion 36 is formed in a cylindrical shape. The insertion hole 40 is formed in the center of the tubular portion 36, and the valve body 14 can be inserted therein. The insertion hole 40 is formed with a smaller diameter than the inner circumferential surface of the tubular portion 36. The tubular portion 36 has a hook portion 46 for fixing the tubular portion 36 to the case. The hook portion 46 in this embodiment is an example of the "retaining portion" of the present invention.

[0138] The hook portions 46 are formed in plurality on the outer peripheral surface of the cylindrical portion 36 and are cantilevered pieces extending in the circumferential direction. Each hook portion 46 has a claw portion 46a at its tip. The claw portion 46a protrudes toward the flange portion 38 and hooks onto the edge of the opening of the case. The hook portions 46 are hooked onto the edge of the opening of the case by rotation of the pressure release valve 10 around its axis.

[0139] The flange portion 38 projects radially outward from the cylindrical portion 36. The surface of the flange portion 38 functions as a valve seat 48, on which the seal end portion 34 of the valve body 14 is seated. The outer periphery of the flange portion 38 is formed in a hexagonal shape. The outer periphery of the flange portion 38 is not limited to a hexagonal shape and may be a polygonal shape.

[0140] The flange portion 38 has protrusions 44 on its outer circumferential edge. A plurality of the protrusions 44 are formed at intervals in the circumferential direction and protrude radially outward. The flange portion 38 is disposed at the corner positions of a polygon.

[0141] The annular protrusion 43 is formed from the base end of the cylindrical portion 36 to the flange portion 38, and protrudes outward from the outer circumferential surface of the cylindrical portion 36. The annular protrusion 43 hangs down from the inner edge of the flange portion 38.

[0142] Returning to Figure 30, the cover member 18 is connected to the base member 16 and protects the seal member 24 from the outside in the radial direction. The cover member 18 has an encircling portion 50, an inward protruding portion 57, and a locking portion 59. The encircling portion 50 has a polygonal outer periphery and is formed like a wall that surrounds the outer periphery of the seal member 24. Because the outer periphery of the cover member 18 is polygonal, an operator can use a tool to rotate the pressure release valve 10 around its axis and easily hook the hook portion 46 onto the opening edge of the case.

[0143] The inward protrusion 57 protrudes radially inward from the encircling portion 50 and is formed in an annular shape. The inward protrusion 57 has a circular inner surface. The locking portion 59 stands upright toward the base member 16 and locks onto the base member 16. The locking portion 59 is a flexible elastic claw that locks onto the protrusion 44 of the base member 16. The locking portion 59 is disposed at a corner position of the polygonal cover member 18. The locking portion 59 is located radially outward from the encircling portion 50. The encircling portion 50 is recessed at the corner position where the locking portion 59 is formed, allowing the protrusion 44 of the base member 16 to be inserted therein.

[0144] The seal member 24 is formed in an annular shape and is, for example, an O-ring. The seal member 24 seals between the case and the base member 16 fixed to the case. Using a versatile O-ring helps reduce costs.

[0145] The locking member 20 is fixed to the tip of the cylindrical portion 39 of the first valve body 14a. The locking member 20 has a plurality of small through holes formed therein, so that the tip of the cylindrical portion 39 is not blocked. The locking member 20 has a spring bearing portion 56, a pillar portion 58, and a protruding portion 60.

[0146] The protruding portion 60 protrudes radially outward from one end of the column portion 58 and catches on the cylindrical portion 39. This makes the locking member 20 integral with the valve body 14. The spring bearing portion 56 protrudes radially outward from the other end of the column portion 58 and receives the biasing member 22.

[0147] The biasing member 22 abuts against the base member 16 and the locking member 20, and biases the valve body 14 in the closing direction via the locking member 20. This keeps the valve body 14 in the closed state.

[0148] Figure 32 is a cross-sectional view of the pressure release valve 10 shown in Figure 29(a) taken along line J-J. The pressure release valve 10 shown in Figure 32 is shown attached to a case 62 of an electricity storage device. The case 62 has an opening 62a, and the pressure release valve 10 is provided so as to close the opening 62a. The opening 62a may be formed in a side surface or in the top surface of the case 62.

[0149] The cover member 12 is connected to the valve body 14 by the hook portion 30 and the protrusion portion 28. The protrusion portion 60 of the locking member 20 is hooked onto the engaging portion 39a of the cylindrical portion 39, and the valve body 14 and the locking member 20 are integrated.

[0150] The biasing member 22 biases the valve element 14 via the locking member 20 so as to press it against the surface of the base member 16. This causes the seal end 34 of the valve element 14 to seat on the valve seat 48 of the base member 16, bringing it into a closed state. A breather 66 is placed in the center of the front side of the valve element 14, closing one end of the cylindrical portion 39. Because there is a small gap between the breather 66 and the cover member 12, the breather 66 can slightly release the pressure in the internal space of the case 62. When the valve element 14 receives pressure from the case 62 that is equal to or greater than a predetermined value, it opens against the biasing member 22.

[0151] The locking portion 59 is a resilient claw extending away from the surface of the case 62 and engages with the protrusion 44 of the base member 16. The direction away from the surface of the case 62 refers to the orientation when attached to the case 62. The locking portion 59 extends axially from the back side of the flange portion 38 to the front side and engages with the front side of the flange portion 38. The protrusion 44 is sandwiched between the locking portion 59 and the surrounding portion 50. This connects the cover member 18 to the base member 16. The flange portion 38 has a through-hole 55 that penetrates axially. The through-hole 55 forms part of the water flow path 68. This prevents water from accumulating inside the pressure release valve 10. The through-hole 55 is formed along the locking portion 59, making the locking portion 59 more flexible and also functions as a void for forming the claw of the locking portion 59.

[0152] The cylindrical portion 36 is inserted into the opening 62a of the case 62. The hook portion 46 hooks onto the back surface of the case 62. The annular protrusion 43 abuts against the surface of the case 62. As a result, the annular protrusion 43 and the hook portion 46 sandwich the periphery of the opening 62a of the case 62, and the base member 16 is attached to the case 62. Because the cover member 18 is connected to the base member 16, it is fixed to the case 62 together with the cover member 18.

[0153] The sealing member 24 abuts against the surface of the case 62 and the rear surface of the flange portion 38, thereby sealing between the surface of the case 62 and the base member 16. This prevents water from entering between the case 62 and the base member 16 when the base member 16 is attached to the case 62.

[0154] The cover member 18 is disposed radially outward of the seal member 24 and surrounds the seal member 24. The accommodation groove 64 is defined by the base member 16 and the cover member 18 and accommodates the seal member 24 therein.

[0155] The accommodation groove 64 is defined by the annular protrusion 43, the rear surface of the flange portion 38, and the inward protrusion 57. The annular protrusion 43 and the inward protrusion 57 are opposed to each other in the radial direction and limit the radial movement of the seal member 24.

[0156] Because the cover member 18 is separate from the base member 16, the design freedom of the base member 16 and the cover member 18 is increased. The constraints on the mold for forming the base member 16 and the cover member 18, i.e., the constraints on axial and radial sliding when the mold is parted, are reduced, allowing the hook portion 46 and the accommodating groove 64 to be closer together. This allows the pressure release valve 10 to be made more compact in the radial direction. Forming the hook portion 46 of the base member 16 requires radial sliding of the mold. Forming the accommodating groove 64 separately requires axial sliding of the mold, and a radial distance is required to avoid interference with the radial sliding used to form the hook portion 46. Because the accommodating groove 64 is not formed separately from the base member 16, axial sliding of the mold to form the accommodating groove 64 is not required.

[0157] When the pressure release valve 10 is attached to the case 62, the cover member 18 is sandwiched between the surface of the case 62 and the flange portion 38. This prevents the cover member 18 from coming off even if the cover member 18 is damaged by high-pressure water during a car wash.

[0158] The locking portion 59 locks onto the protruding portion 44 radially outward of the seal member 24, and locks onto the protruding portion 44 radially outward of the seal end 34 of the valve body 14. As a result, the gap between the base member 16 and the cover member 18 is positioned radially outward of the seal member 24 and the valve body 14.

[0159] FIG. 33 is a cross-sectional view of the pressure release valve 10 shown in FIG. 29( a) taken along line K-K. FIG. 34 is a partially enlarged view of the pressure release valve 10 shown in FIG. 33. As shown in FIG. 34, a gap 70a is formed between the outer peripheral surface of the flange portion 38 and the inner peripheral surface of the surrounding portion 50, and a gap 70b is formed between the back surface of the flange portion 38 and the surface of the inward protrusion 57. In this manner, gaps 70a and 70b that form a water flow path 70 are provided between the cover member 18 and the flange portion 38. The flow path 70 is located radially outward of the seal member 24. Note that the gap 70b may be formed by the flange portion 38 being pressed by the seal member 24 in the attached state.

[0160] The power storage device is placed under the floor of the vehicle compartment and may be exposed to high-pressure water 72 when the vehicle is washed. When high-pressure water 72 is sprayed from the side of the pressure release valve 10, the water enters the pressure release valve 10. At this time, the flow path 70 discharges the water 72, thereby preventing the water 72 from accumulating inside the pressure release valve 10. The through-hole portion 55 shown in FIG. 32 also constitutes part of the flow path 70.

[0161] The cover member 18 surrounds the seal member 24, thereby preventing the high-pressure water 72 from directly hitting the seal member 24. The cover member 18 can prevent the high-pressure water 72 from hitting the seal member 24, deforming the seal member 24, and entering the inside of the seal member 24.

[0162] The present invention is not limited to the above-described embodiments, and various modifications such as design changes may be made to the embodiments based on the knowledge of those skilled in the art, and such modified embodiments may also be included within the scope of the present invention.

[0163] For example, the accommodation groove 64 may be defined only by the cover member 18. That is, the cover member 18 may form at least a part of the accommodation groove 64. In this case, the seal member 24 abuts against the surfaces of the cover member 18 and the case 62.

[0164] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the claims. The configurations of the above embodiments can be partially omitted or arbitrarily combined in a different manner from the above.

[0165] 2: Pressure release valve, 2A: Pressure release valve, 2B: Pressure release valve, 3: Cap, 3B: Cap, 4: Valve member, 4B: Valve member, 5: Base member, 6: Seal ring, 7: Biasing member, 8: Locking member, 9: Case, 10: Pressure release valve, 12: Lid member, 14: Valve body, 16: Base member, 18: Cover member, 20: Locking member, 22: Biasing member, 24: Seal member, 26: Connecting hole portion, 28: Projection portion, 30: Hook portion, 31: Ceiling portion, 32: Peripheral wall portion, 32B: Peripheral wall portion, 33: Flange portion, 34: Seal end portion, 36: Cylindrical portion, 38: Flange portion, 39: Cylindrical portion, 39a: Engagement portion, 40: Insertion hole portion, 41: Base portion, 41B: base, 42: seal portion, 43: annular protrusion, 44: protruding portion, 46: hook portion, 48: valve seat, 50: surrounding portion, 51: annular portion, 52: ceiling portion, 53: rib, 54: insertion portion, 55: through hole portion, 56: spring receiving portion, 57: inward protruding portion, 58: pillar portion, 59: engaging portion, 60: protruding portion, 62: case, 62a: opening, 64: accommodation groove, 66: breather, 70: flow path, 70a, 70b: gap, 81: cylindrical portion, 82: flange portion, 91: opening, 92: edge portion, 93: surface, 311: through hole, 311a: first hole edge, 311b: second hole edge, 311c: gap, 312: Engaging portion, 321: Through hole, 322: Engaging portion, 411: Ceiling portion, 412: Peripheral wall portion, 413: Flange portion, 414: Engaging portion, 414a: First wall portion, 414b: Second wall portion, 414c: Third wall portion, 414d: Protrusion portion, 414e: Second wall portion, 415: Shaft portion, 416: Engaging portion, 421: Protrusion portion, 511: Valve seat, 512: Vent hole, 513: Inner peripheral surface, 514: Protrusion portion, 521: Through hole, 541: Retaining portion, 541a: Retaining surface, 542: First stopper portion, 542a: First stopper surface, 543: Second stopper portion, 544: Base portion, 545: Elastic piece, 545a: surface, 546: protrusion, 546a: second stopper surface, 546b: surface, 547: abutment surface, 549: outer circumferential surface, 811: engagement portion, 921: inner circumferential surface, 922: flange portion, 923: surface, 924: first end surface, 925: second end surface

Claims

1. A pressure release valve comprising: a base member fixed to a case having an opening and having an air vent hole that connects the interior space of the case with the exterior space of the case; a valve member that moves toward and away from the base member to open and close the air vent hole; and a biasing member that biases the valve member in the direction in which the valve member abuts against the base member, wherein the base member has an insertion portion that is inserted into the opening, and the insertion portion has: a retaining portion that engages with the edge of the opening to prevent the insertion portion from slipping out of the opening in the direction of the axis of the base member; a first stopper portion that restricts the base member from rotating in a first direction around the axis; and a second stopper portion that restricts the base member from rotating in a second direction opposite to the first direction, wherein the first stopper portion is positioned closer to the second direction than the retaining portion, and the retaining portion engages with the edge when rotated in the first direction.

2. The pressure release valve according to claim 1, wherein the retaining portion has a retaining surface facing in the direction of the axis, the first stopper portion has a first stopper surface facing in the first direction, and the retaining surface and the first stopper surface are connected to each other.

3. A pressure release valve as described in claim 1, characterized in that the first stopper portion and the second stopper portion are each formed by projecting radially outward from the outer circumferential surface of the insertion portion, and the second stopper portion is positioned on the first direction side of the retaining portion.

4. A device comprising: a case having an opening; and a pressure release valve attached to the case, wherein the case has a flange portion projecting radially inward from the inner circumferential surface of the edge of the opening, and the pressure release valve comprises: a base member fixed to the case and having an air hole connecting the internal space of the case with the external space of the case; a valve member that moves toward and away from the base member to open and close the air hole; and a biasing member that biases the valve member in the direction in which the valve member abuts against the base member, wherein the base member has an insertion portion inserted into the opening, and the insertion portion has: a retaining portion that engages with the edge portion to prevent the insertion portion from coming out of the opening in the axial direction of the base member; a first stopper portion that restricts the base member from rotating in a first direction around the axis; and a second stopper portion that restricts the base member from rotating in a second direction opposite to the first direction, and the retaining portion has a retaining surface facing in the axial direction, a pressure release valve mounting structure, characterized in that the first stopper portion has a first stopper surface facing the first direction, the second stopper portion has a resilient piece extending circumferentially of the insertion portion and flexible in the axial direction, and a second stopper surface facing the second direction, the retaining surface abutting against a back surface of the flange portion when the retaining portion rotates in the first direction, the first stopper surface abutting against one end surface of the flange portion when the first stopper portion rotates in the first direction, and when the second stopper portion rotates in the first direction, the resilient piece bends in the axial direction, causing the second stopper surface to move from one end side of the flange portion over the flange portion to the other end side of the flange portion and abut against the other end surface of the flange portion.

5. The pressure release valve described in claim 1, characterized in that the base member has a valve seat, the valve member has a shaft portion that prevents it from coming off the base member, a seal portion that moves toward and away from the valve seat to open and close the vent hole, and a first engagement portion that is provided radially outward of the shaft portion, and the seal portion contacts the valve seat to close the vent hole, covering the valve seat and the seal portion, and has a second engagement portion that rotates in a third direction to engage with the first engagement portion.

6. A pressure release valve as described in claim 5, characterized in that the cap has a through hole penetrating the cap in the plate thickness direction, the second engagement portion is formed on a first hole edge of the through hole, and the second hole edge of the through hole, which is located on the side of the first hole edge in a fourth direction opposite to the third direction, abuts against the first engagement portion, thereby restricting rotation of the cap in the third direction.

7. A pressure release valve as described in claim 6, characterized in that the first engaging portion has a stopper portion provided at the end in the third direction and abutting against the second engaging portion.

8. The pressure release valve as described in claim 6, characterized in that the first engagement portion moves in the fourth direction inside the through hole relative to the cap as the cap rotates in the third direction, and engages with the second engagement portion.

9. A pressure release valve as described in claim 5, characterized in that the valve member has a biasing portion provided between the first engagement portion and the sealing portion in the radial direction and biasing the cap in a direction away from the base member.

10. A pressure release valve as described in claim 1, further comprising: a sealing member formed in an annular shape and abutting against the surface of the case around the opening to seal; a cover member having an engaging portion that engages with the base member and surrounds the sealing member; and an accommodating groove that accommodates the sealing member, wherein the base member has a flange portion that functions as a valve seat on which the valve member can be seated and that protrudes radially outward from the insertion portion, and the cover member forms at least a portion of the accommodating groove.

11. The pressure release valve according to claim 10, wherein the cover member is sandwiched between the surface of the case and the flange portion when the pressure release valve is attached to the case.

12. A pressure release valve as claimed in claim 10 or 11, characterized in that a gap is provided between the cover member and the flange portion to allow water to flow therethrough.

13. A pressure release valve as described in claim 12, characterized in that the locking portion is an elastic claw extending in a direction away from the surface of the case, and the cover member has a through-hole portion that penetrates along the locking portion and forms part of the flow path.

14. A pressure release valve as claimed in claim 10 or 11, characterized in that the flange portion has a surrounding portion whose outer periphery is formed in a polygonal shape and which surrounds the sealing member.

Images