Pressure relief valve

Abstract

Provided is a pressure release valve capable of improving the assembly workability. This pressure release valve 10 includes: a base member which is fixed to a member to be attached and has a valve seat and a vent hole inside the valve seat; a valve body 30 which has a shaft part 34, is slidable relative to the base member to be brought into contact with and separated from the valve seat to open and close the vent hole; a spring member which is externally mounted on the shaft part 34 and biases the valve body 30 toward the valve seat; and a spring pressing member 50 having a spring support part for supporting one end of the spring member. This pressure release valve includes a snap fit coupling structure between the shaft part 34 and the spring pressing member 50, the snap fit coupling structure being for snap-fit coupling the spring pressing member 50 to the shaft part 34.

Description

pressure relief valve

[0001] The present invention relates to a pressure relief valve that is attached to a workpiece to relieve pressure within the workpiece.

[0002] For example, hybrid vehicles and electric vehicles use electricity storage devices such as batteries and capacitors. In the case of batteries such as lithium-ion batteries, the pressure in such electricity storage devices can increase due to gas generated by a chemical reaction in the electrolyte. In this case, it is necessary to release the pressure by discharging the gas from inside the electricity storage device to the outside of the electricity storage device.

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

[0004] The pressure regulating part has a leg part with a valve seat part and a bearing part provided inside the leg part, and the cover part has an umbrella-shaped part and a shaft part that protrudes from the center of the back side of the umbrella-shaped part and is inserted into the bearing part. A stopper such as a nut is screwed onto the tip of the shaft part. Then, a spring is placed on the outer periphery of the shaft part, and one end of the spring is supported by the bearing part. Then, by screwing the stopper onto the tip of the shaft part, the other end of the spring is supported by the stopper and the spring is held in a compressed state.

[0005] Japanese Patent Application Laid-Open No. 2020-21897

[0006] In the case of the pressure regulating valve described in Patent Document 1, when assembling the pressure regulating valve, a stopper such as a nut must be screwed onto the tip of the shaft, which requires a screwing operation to rotate the stopper relative to the shaft, and the assembly workability of the pressure regulating valve cannot be said to be good.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a pressure relief valve that can improve assembly workability.

[0008] In order to achieve the above object, the present invention provides a pressure release valve to be attached to a workpiece, comprising: a base member fixed to the workpiece and having a valve seat and a vent hole formed therein; a valve body having a shaft and slidable relative to the base member and moving toward and away from the valve seat to open and close the vent hole; a spring member attached to the shaft and urging the valve body toward the valve seat; and a spring holder member having a spring support portion that supports one end of the spring member, wherein a snap-fit ​​connection structure is provided between the shaft and the spring holder member for snap-fitting the spring holder member to the shaft.

[0009] According to the pressure release valve of the present invention, the snap-fit ​​connection structure provided between the shaft portion and the spring holding member snap-fits the spring holding member to the shaft portion, so that the spring holding member can be easily attached to the shaft portion, improving the ease of assembly of the pressure release valve.

[0010] 10 is an exploded perspective view of an embodiment of a pressure release valve according to the present invention. FIG. 11 is a perspective view of the pressure release valve. FIG. 12 is a perspective view of the pressure release valve as viewed from a direction different from that of FIG. 2. FIG. 13 is a bottom view of the pressure release valve. FIG. 14 is an enlarged perspective view of a base member constituting the pressure release valve. FIG. 15 is an enlarged perspective view of the base member constituting the pressure release valve as viewed from a direction different from that of FIG. 5. FIG. 16 is an enlarged perspective view of a valve body constituting the pressure release valve as viewed from a direction different from that of FIG. 1. FIG. 17 is an enlarged perspective view of a spring presser member constituting the pressure release valve. FIG. 18 is an enlarged perspective view of the spring presser member constituting the pressure release valve as viewed from a direction different from that of FIG. 8. FIG. 19 is a bottom view of the spring presser member constituting the pressure release valve. FIG. 19 is a cross-sectional view taken along the line B-B of FIG. 10. FIG. 11 is a perspective view of the pressure release valve in a state before the spring presser member is attached to the shaft portion. FIG. 12 is a cross-sectional view taken along the line A-A of FIG. 4. FIG. 13 is a cross-sectional view of the state when the valve body is separated from the valve seat to the maximum extent from the state of FIG. 14 and the vent hole is opened. FIG. 14 is an exploded perspective view of another embodiment of a pressure release valve according to the present invention. Fig. 18 is a perspective view of the pressure release valve. Fig. 18 is a cross-sectional view taken along the line of arrows D-D in Fig. 17. Fig. 18 is a cross-sectional view taken along the line of arrows E-E in Fig. 17. Fig. 18 shows yet another embodiment of the pressure release valve according to the present invention, and is an enlarged perspective view of the essential parts in a state before a spring presser member is attached to the shaft portion. Fig. 19 is a perspective view of the pressure release valve in a state where a spring presser member is attached to the shaft portion.

[0011] (One Embodiment of Pressure Relief Valve) Hereinafter, one embodiment of a pressure relief valve according to the present invention will be described with reference to the drawings.

[0012] As shown in Figures 14 and 15, this pressure release valve 10 (hereinafter simply referred to as the "release valve 10") is attached to an attachment hole 3 of an attachment member 1 that houses, for example, an electrical storage device, etc., and is designed to release (reduce) the pressure within the attachment member 1 by venting the gas within the attachment member 1 when the pressure within the attachment member 1 rises.

[0013] Examples of the power storage device housed in the attachment base 1 include batteries (lithium ion batteries, etc.), condensers, and capacitors used in hybrid vehicles including plug-in hybrid vehicles, electric vehicles, etc., but other devices, parts, etc. may also be used. The attachment hole 3 formed in the attachment base 1 is a circular hole.

[0014] As shown in Figure 14, the internal space of the workpiece 1 (meaning the lower space in Figure 14, with the wall of the workpiece 1 as the boundary) is referred to as internal space R1, and the external space of the workpiece 1 (meaning the upper space in Figure 14, with the wall of the workpiece 1 as the boundary) is referred to as external space R2.

[0015] As shown in Figures 1 to 3, 14, and 15, the release valve 10 in this embodiment is mainly composed of a base member 20 that is fixed to the workpiece 1 and has a valve seat 23 and a vent hole 24 provided inside the valve seat 23, a valve body 30 that has a shaft 34 and is slidable relative to the base member 20, and that moves toward and away from the valve seat 23 to open and close the vent hole 24, a sealing member 29 that is arranged on the back side of the valve body 30 and ensures sealing with the surface of the workpiece 1 (the mounting surface of the release valve 10), a spring member 70 (a coil spring in this embodiment) that is fitted around the shaft 34 and urges the valve body 30 toward the valve seat 23, and a spring presser member 50 (hereinafter also simply referred to as the "presser member 50") that has a spring support portion 52 that supports one end of the spring member 70.

[0016] In addition, a snap-fit ​​connection structure is provided between the shaft portion 34 and the pressing member 50, which snap-fits the pressing member 50 to the shaft portion 34. Furthermore, the snap-fit ​​connection structure in this embodiment is such that the pressing member 50 is snap-fitted to the shaft portion 34 by rotating the pressing member 50 relative to the shaft portion 34.

[0017] In the following description, the "back side" and "rear side" of each component such as the base component 20, valve body 30, and spring pressing component 50 refer to the side closest to the component 1, unless otherwise specified, and the "front side" and "front surface side" refer to the opposite side of the "back side" and "rear side" (the side away from the component 1).

[0018] 5 and 6, the base member 20 will be described in detail. The base member 20 of this embodiment has a substantially cylindrical main body tubular portion 21 and a flange portion 22 that extends from the outer periphery of the base end of the main body tubular portion 21 to form a substantially diamond shape.

[0019] The outer peripheral edge of the main body tubular portion 21 on the surface side of the flange portion 22 forms the valve seat 23. The inner space of the main body tubular portion 21, radially inward of the valve seat 23, forms an air vent 24 that connects the internal space R1 and the external space R2 of the workpiece 1 to each other.

[0020] An annular protrusion 22a is provided on the surface side of the flange portion 22, radially outward of the valve seat 23, so as to surround the valve seat 23 and the vent hole 24. In addition, bosses 22b, 22b for attachment to the attached member 1 are formed near both longitudinal ends of the flange portion 22. As shown in Figure 6, an outer peripheral wall 25 extends from the periphery of the back side of the flange portion 22, and an inner peripheral wall 26 extends inside this outer peripheral wall 25. A seal member 29 is disposed between these peripheral walls 25, 26.

[0021] 5, 6, 14, and 15, the base member 20 is provided with a plate-shaped guide piece 27 that extends radially inward of the main body cylindrical portion 21, along the valve axis direction (the direction along the axis of the pressure release valve 10 and the valve body 30; the same applies to the valve axis direction of other members) and toward the valve body opening direction (the direction in which the valve body 30 moves away from the valve seat 23 to open the air vent 24).

[0022] In this embodiment, a plurality of guide pieces 27 (eight in this embodiment) are arranged at equal intervals radially from the axial center (radial center) of the base member 20 or the tubular main body portion 21. As shown in Figures 3 and 5, a restricting portion 27b that restricts the axial movement of the presser member 50 is provided on the inner edge of a given guide piece 27, midway along the valve axis. The outer edge 27a of the guide piece 27 provided with the restricting portion 27b is slidably inserted into a recess 41 (see Figure 7) of the valve element 30, thereby guiding the valve element 30 to slide relative to the base member 20.

[0023] The other ends of the guide pieces 27 in the extension direction are connected to each other by a spring support part 28 having a substantially circular ring shape with a circular hole 28a in the center. As shown in Figures 14 and 15, the other end of the spring member 70 in the extension direction is supported on the back side of the spring support part 28, on the periphery of the circular hole 28a.

[0024] 2, 7, 14, 15, etc., the valve element 30 will be described in detail. The valve element 30 of this embodiment has a valve body 31 and a seal portion 32 made of an elastic material such as rubber or an elastic elastomer and attached to the valve body 31. The valve element as a whole has a generally hat-like shape with a closed ceiling side and a flange-like protruding base end side.

[0025] The seal portion 32 has a substantially annular shape, and is provided with an elastically deformable seal lip 32a that abuts against the valve seat 23 of the base member 20 from the radially inner inner peripheral edge portion on the back side thereof. In addition, an annular portion 32b that is disposed on the outer periphery of the annular protrusion 22a of the base member 20 protrudes from the radially outer outer peripheral edge portion on the back side of the seal portion 32.

[0026] The valve body 31 also has a ceiling portion 33 arranged opposite the vent port 24, a shaft portion 34 protruding from the back side of the ceiling portion 33, and a peripheral wall portion 35 arranged outside the shaft portion 34 and extending in the valve axis direction, and is approximately cylindrical with an open side opposite the ceiling portion 33.

[0027] Describing the valve body 31 in detail, the ceiling portion 33 is a generally circular plate-like member disposed opposite the vent hole 24. The shaft portion 34 is made up of a plurality of (four in this example) ribs 36 that extend radially at equal intervals from the axial center of the valve body 31, and has a generally cross-shaped columnar cross section perpendicular to the axial direction, protruding a predetermined length from the radial center of the back side of the ceiling portion 33.

[0028] In this embodiment, the shaft portion 34 is inserted radially inside the spring member 70, so that the spring member 70 is attached to the shaft portion 34 in a state where it stands upright on the outside (radially outside) of the shaft portion 34 in line with the axis of the shaft portion 34.

[0029] A notch 37a is formed in each of the ribs 36 that make up the shaft 34 at one axial end (the tip in the extending direction) of the shaft 34. A protrusion 37 that fits into a fitting recess 59a (see FIG. 9) of the pressing member 50 is provided at the axial tip of each rib 36 of the shaft 34 via the notch 37a.

[0030] In this embodiment, the protrusions 37 are generally rectangular with a uniform height and a uniform thickness that is slightly thinner than the thickness of each rib 36. Adjacent protrusions 37 are arranged perpendicular to each other. As a result, the four protrusions 37 formed on each rib 36 form a generally cross shape when viewed in the axial direction of the shaft portion 34, as shown in Figure 4.

[0031] The peripheral wall portion 35 is disposed radially outward of the shaft portion 34 and has a generally cylindrical shape extending a predetermined length, with a plurality of (four in this example) bulging portions 40 provided on its outer periphery at equal circumferential intervals and extending along the axial direction. Furthermore, as shown in Figure 7, a guide groove-like recess 41 extending along the axial direction of the peripheral wall portion 35 is formed on the radially inner side of the peripheral wall portion 35 at a position corresponding to the bulging portion 40.

[0032] The outer edge 27a of the guide piece 27 provided with the restricting portion 27b is slidably inserted into this recess 41, and the sliding movement of the valve body 30 relative to the base member 20 is guided along the valve axis direction.

[0033] Next, the spring presser member 50 will be described in detail with reference to Figures 8 to 11. The spring presser member 50 of this embodiment has a generally cylindrical tubular portion 51 and an annular spring support portion 52 that extends from the outer periphery of one axial end (base end) of the tubular portion 51 and that abuts against and supports one end of the spring member 70 in the extending direction.

[0034] 8 , at the other axial end (tip) of the cylindrical portion 51, a plurality of (four in this example) generally fan-shaped ceiling walls 55 are provided at equal intervals in the circumferential direction from the radially inner side. The cylindrical portion 51 and the plurality of ceiling walls 55 form an insertion hole 53 at the other axial end of the cylindrical portion 51. This insertion hole 53 is formed by a large-diameter circular hole formed in the radial center of the pressing member 50, and a plurality of (four in this example) notched groove-like grooves 53 a, each narrower than the diameter of the circular hole, are provided at equal intervals in the circumferential direction on the outer periphery of the circular hole.

[0035] 8, 9, and 11, a protrusion 57 extending along the axial direction of the cylindrical portion 51 is provided on one circumferential end of each ceiling wall 55, on the inner peripheral surface of the cylindrical portion 51. The protrusion 57 has a generally triangular shaped axial cross section (cross section perpendicular to the axial direction) of the circumferential end of the ceiling wall 55.

[0036] Furthermore, the engaged portion 59 having a flat surface is provided on the back side (one axial end side of the cylindrical portion 51) of each ceiling wall 55. The engaged portion 59 is adapted to engage with the protrusion 37 of the shaft portion 34 by inserting the protrusion 37 of the shaft portion 34 into the insertion hole 53 and then extending the protrusion 37 from the insertion hole 53 so that the protrusion 37 is positioned so as not to overlap (do not overlap) with the engaged portion 59 in the axial direction or so as not to overlap the engaged portion 59 at all (see FIG. 13 ).

[0037] As described above, a snap-fit ​​connection structure is provided between the shaft portion 34 and the pressing member 50 to connect the pressing member 50 to the shaft portion 34 by snap-fit ​​connection.

[0038] The snap-fit ​​connection structure in this embodiment is composed of a protrusion 37 provided on the shaft portion 34 of the valve body 30, the pressing member 50 itself biased by a spring member 70, a tubular portion 51 provided on the pressing member 50 and into which one end of the shaft portion 34 is inserted, an insertion hole 53 formed at the other axial end (tip) of the tubular portion 51 and through which the shaft portion 34 and the protrusion 37 are inserted, and an engaged portion 59 formed at the other axial end of the tubular portion 51 at the edge (side edge) of the insertion hole 53, with which the protrusion 37 engages when the pressing member 50 is rotated in a predetermined direction and by a predetermined angle relative to the shaft portion 34.

[0039] The snap-fit ​​connection means that when specific components are connected to each other, they are mechanically connected by utilizing the elasticity of the specified components.

[0040] Furthermore, a rotation restricting portion 61 is provided on the outer surface of each protrusion 57 facing the engaged portion 59. That is, when the protrusion 37 of the shaft 34 is inserted into the insertion hole 53 and then extended and retracted from the insertion hole 53 so that the protrusion 37 does not axially overlap or nearly does not overlap the engaged portion 59, and the pressing member 50 is rotated in a predetermined direction by a predetermined angle relative to the shaft 34, the protrusion 37 corresponding to the rotation restricting portion 61 comes into contact, restricting further rotation of the pressing member 50 (see FIG. 13 ).

[0041] Furthermore, a rectangular recessed mating portion 59a that is open upward (toward the mating portion 59) and to the side (toward the radially inner side of the spring presser member) is formed in each of the engaged portions 59 at a position close to the protrusion 57. The circumferential width of each of the mating recesses 59a is sized to fit the width of the protrusion 37 of the shaft portion 34, and one circumferential end is formed to a length that reaches the rotation restricting portion 61 of the protrusion 57.

[0042] Then, when the protrusion 37 is inserted and removed from the insertion hole 53, and the protrusion 37 is positioned so that it does not overlap or almost does not overlap the engaged portion 59 in the axial direction, and the pressing member 50 is rotated in a predetermined direction and by a predetermined angle relative to the shaft portion 34, the protrusion 37 corresponding to the engaging recess 59a engages (see Figure 13).

[0043] Furthermore, the outer surface of the protrusion 57 opposite to the engaged portion 59 forms a guide portion 62. When the pressing member 50 is pressed against the shaft portion 34 to insert or remove the protrusion 37 inserted into the insertion hole 53 from the insertion hole 53, this guide portion 62 comes close to or slides against one outer surface of the protrusion 37, thereby serving as an insertion guide for the protrusion 37.

[0044] Furthermore, a plurality of (four) protrusions 65 are provided at equal intervals in the circumferential direction on the outer periphery of the spring support portion 52 at locations that circumferentially coincide with the four insertion holes 53. When the pressing member 50 is mounted on the shaft portion 34 in a manner that restricts rotation and prevents it from coming off, these protrusions 65 are positioned to align with the restricting portions 27b provided on the inner edge of the guide piece 27 (see FIG. 3), and the plurality of protrusions 65 can abut against the corresponding restricting portions 27b.

[0045] Furthermore, in this release valve 10, with the protrusion 37 of the shaft portion 34 engaged with the engaged portion 59 of the pressing member 50, a clearance CL is formed that allows the pressing member 50 to be pushed axially against the urging force of the spring member 70 relative to the shaft portion 34. Here, as shown in Fig. 14, the clearance CL is formed between the other axial end face (upper end face) of the cylindrical portion 51 of the pressing member 50 and the end face 34a of the shaft portion 34 that is located on the other axial end side of the notch 37a.

[0046] 12 and 13, the presser member 50 can be attached (assembled) to the shaft 34, for example, as follows. For ease of explanation, parts other than the part centered on the shaft 34 of the valve body 30 (such as the spring member 70 and parts of the valve body 30 other than the shaft 34) are omitted from Figures 12 and 13.

[0047] First, the spring member 70 is disposed radially outward of the shaft portion 34 of the valve body 30, and the other end of the spring member 70 in the extending direction is supported by the spring support portion 28 of the base member 20. Then, the cylindrical portion 51 of the pressing member 50 is inserted into one end of the spring member 70 in the extending direction, and the one end of the spring member 70 in the extending direction is supported by the front side of the spring support portion 52.

[0048] In the above state, as shown in Fig. 12 , the protrusions 37 of the shaft 34 are aligned (positioned) with the corresponding grooves 53a of the insertion holes 53 of the pressing member 50. Thereafter, as shown by arrow F1 in Fig. 12 , the pressing member 50 is pressed onto the shaft 34. Here, the protrusions 37 are guided by the guide portions 62 of the ridges 57, while the pressing member 50 is pressed onto the shaft 34, and the spring members 70 are compressed against the biasing force of the spring members 70, causing the protrusions 37 of the shaft 34 to be inserted into and removed from the rear peripheral edges of the grooves 53a of the insertion holes 53.

[0049] At this time, the spring member 70 biases the pressing member 50 in a direction that moves the pressing member 50 away from the ceiling portion 33 of the valve body 30. In other words, the pressing member 50 is provided with an elastic force by the spring member 70.

[0050] Then, each protrusion 37 is inserted and removed from each groove 53a of the insertion hole 53 (the protrusion 37 is inserted and removed from the opening periphery of the groove 53a on the back surface side of the ceiling wall 55), and with the protrusion 37 positioned so that it does not axially overlap or almost does not overlap with the engaged portion 59, the presser member 50 is rotated a predetermined angle in the direction indicated by arrow F2 in Figure 12 relative to the shaft portion 34. Here, the protrusion 37 inserted and removed from the groove 53a is directed toward the rotation restriction portion 61 of a predetermined protrusion portion 57, and the presser member 50 is rotated relative to the shaft portion 34.

[0051] Then, the pressing member 50 rotates with each protrusion 37 leaving a gap between it and the engaged portion 59 or sliding against the engaged portion 59, and when each protrusion 37 abuts against the rotation regulating portion 61, further rotation of the pressing member 50 is restricted and the circumferential positions of the protrusion 37 and the mating recess 59a are aligned.

[0052] At this time, the presser member 50 is biased by the spring member 70 in a direction away from the ceiling portion 33 of the valve body 30, and the elastic force of the spring member 70 is applied to the presser member 50, so that each protrusion 37 of the shaft portion 34 fits into the corresponding fitting recess 59a with a click, i.e., the elastic force applied to the presser member 50 is utilized to snap-fit ​​the presser member 50 onto the shaft portion 34. As a result, the presser member 50 is attached to one end of the shaft portion 34 in a state where rotation is restricted and where it is prevented from coming off.

[0053] As described above, in the snap fit connection of this embodiment, the spring force (elastic force) of the spring member 70 is applied to the pressing member 50, and the shaft portion 34 and the pressing member 50 are mechanically connected to each other by utilizing the elasticity indirectly applied to the pressing member 50.

[0054] As described above, both ends of the spring member 70 are supported by the spring support portions 28, 52 of the base member 20 and the pressing member 50, and the spring member 70 is held in a compressed state radially outside the shaft portion 34 of the valve body 30 so that it cannot come loose.As a result, the spring force of the spring member 70 urges the valve body 30 toward the valve seat 23, causing the seal lip 32a of the valve body 30 to abut against the valve seat 23, and maintaining the air vent 24 in a closed state.

[0055] (Modifications) The shapes, structures, layouts, etc. of the base member, valve body, seal member, spring retainer member, snap-fit ​​joint, etc. that constitute the pressure release valve of the present invention are not limited to the above-described embodiments.

[0056] For example, the base member may have a shape in which a circular plate-shaped flange portion projects from the outer periphery of the cylindrical portion, or the inner periphery of the cylindrical portion may have an inclined surface without any steps.

[0057] Furthermore, although the shaft portion 34 in this embodiment is cylindrical with a generally cross-shaped cross section, the shaft portion may be cylindrical, elliptical, or rectangular such as a triangular or square prism, or may be cylindrical, elliptical, triangular, or square.

[0058] Furthermore, in this embodiment, the four protrusions 37 form a generally cross shape, but for example, a pair of protrusions may be provided at radially opposing locations, or three, five or more protrusions may be provided at equal intervals around the circumferential direction of the shaft. In this case, it is preferable that the insertion holes formed in the spring presser member, the engaged portion, and the mating recesses formed in the engaged portion are adapted to the number of protrusions.

[0059] In addition, in this embodiment, the shaft portion 34 and the protrusion 37 have the same shape (approximately cross-shaped) when viewed in the axial direction, but they may have different shapes.

[0060] The snap-fit ​​connection structure in this embodiment is composed of a protrusion 37 provided on the shaft portion 34, a tubular portion 51 provided on the pressing member 50, an insertion hole 53 formed in the tubular portion 51, and an engaged portion 59 with which the protrusion 37 engages.By rotating the pressing member 50 relative to the shaft portion 34, the pressing member 50 is snap-fit ​​connected to the shaft portion 34, and this snap-fit ​​connection structure utilizes the elasticity imparted to the pressing member 50 by the spring member 70 to connect the shaft portion 34 and the pressing member 50.

[0061] However, the snap-fit ​​connection structure may be such that the spring holding member is snap-fit ​​connected to the shaft portion without rotating the spring holding member relative to the shaft portion, for example, by moving the spring holding member in the axial direction relative to the shaft portion, and the specific structure may be, for example, a configuration consisting of an elastic engaging portion formed on one of the shaft portion or the spring holding member so as to be flexible with or without a slit, and an engaged portion formed on the other of the shaft portion or the spring holding member with which the elastic engaging portion engages, and any configuration is sufficient as long as it allows for a snap-fit ​​connection in which the shaft portion and the spring holding member are mechanically connected by utilizing elasticity.

[0062] In addition, an inclined surface, a guide surface, a cam surface, or the like may be provided on the periphery of the insertion hole provided in the spring pressing member to make it easier for the protrusion inserted through the insertion hole to move onto the engaged portion.

[0063] Furthermore, although the fitting recess 59a in this embodiment has a rectangular recess shape, and the protrusion 37 of the shaft 34 has a rectangular protrusion shape that fits into the fitting recess 59a, the fitting recess may have, for example, a concave shape with a curved surface such as an arc or hemisphere, or a V-groove or U-groove shape, etc. In this case, it is preferable that the protrusion of the shaft have a shape that fits into the fitting recess, such as a curved protrusion shape, a triangular protrusion shape, or a protrusion shape that protrudes with a certain width and has a curved tip.

[0064] Furthermore, in this embodiment, the spring member 70 is arranged (exterior-wrapped) radially outside the shaft portion 34, but, for example, the shaft portion may be cylindrical and the spring member may be arranged radially inside this cylindrical shaft portion.

[0065] (Operation and Effect) In this release valve 10, the spring member 70 and the spring pressing member 50 can be assembled to the shaft portion 34 in the manner described above in (Assembly process of shaft portion and pressing member).

[0066] That is, the spring member 70 is placed radially outside the shaft portion 34, one end of which is supported by the spring support portion 52 of the pressing member 50, and the other end is supported by the spring support portion 28 of the base member 20. After that, each protrusion 37 of the shaft portion 34 is inserted into each insertion hole 53 of the pressing member 50, and the pressing member 50 is rotated in a predetermined direction and by a predetermined angle relative to the shaft portion 34. As shown in Figures 12 and 13, the shaft portion 34 and the pressing member 50 are snap-fit ​​connected by the snap-fit ​​connection structure, and the pressing member 50 can be attached to the shaft portion 34.

[0067] Therefore, according to this pressure release valve 10, the snap-fit ​​connection structure provided between the shaft portion 34 and the pressure member 50 snap-fits the pressure member 50 to the shaft portion 34, so that the pressure member 50 can be easily attached to the shaft portion 34, improving the assembly workability of the pressure release valve 10.

[0068] In this embodiment, the snap-fit ​​connection structure is such that the pressing member 50 is snap-fit ​​connected to the shaft portion 34 by rotating the pressing member 50 relative to the shaft portion 34 .

[0069] According to the above-described embodiment, the pressing member 50 can be attached to the shaft portion 34 by the simple operation of simply rotating the pressing member 50 relative to the shaft portion 34, which further improves the ease of assembly of the pressure release valve 10. In addition, compared to an embodiment in which the pressing member 50 is moved axially relative to the shaft portion 34, the shaft portion 34 and the pressing member 50 are less bulky in the valve axis direction, making it possible to make the pressure release valve 10 more compact in the valve axis direction.

[0070] Furthermore, in this embodiment, the snap-fit ​​connection structure is composed of a protrusion 37 provided on the shaft portion 34, a tubular portion 51 provided on the pressing member 50, an insertion hole 53 formed in the tubular portion 51 through which the shaft portion 34 and the protrusion 37 are inserted, and an engaged portion 59 formed on the edge of the insertion hole 53 with which the protrusion 37 engages when the pressing member 50 is rotated relative to the shaft portion 34.

[0071] According to the above aspect, since the snap-fit ​​connection structure is composed of the above-mentioned parts, the snap-fit ​​connection structure can be reliably and easily provided on the release valve 10, and the snap-fit ​​connection structure can reliably attach the pressing member 50 to the shaft portion 34.

[0072] Furthermore, in this release valve 10, when the protrusion 37 of the shaft portion 34 is engaged with the engaged portion 59 of the pressing member 50, a clearance CL is formed that allows the pressing member 50 to be pushed axially against the shaft portion 34 against the biasing force of the spring member 70.

[0073] That is, when the protrusion 37 is engaged with the engaged portion 59, as shown in FIG. 14 , a clearance CL is formed that allows the pressing member 50 to be pushed axially against the shaft portion 34 against the biasing force of the spring member 70. Therefore, when the pressing member 50 is rotated relative to the shaft portion 34 while being pushed against the biasing force of the spring member 70, the clearance CL allows the protrusion 37 to move axially so as not to overlap with the engaged portion 59 in the axial direction (overstroke to prevent overlap), thereby reliably separating the protrusion 34 axially from the engaged portion 59. This reduces the rotational resistance of the pressing member 50 relative to the shaft portion 34, making it easier to attach the pressing member 50 to the shaft portion 34.

[0074] Furthermore, in this embodiment, a rotation restriction portion 61 is provided on the inner circumference of the tubular portion 51, which abuts against the protrusion 37 and restricts the rotation of the pressing member 50 when the pressing member 50 is rotated relative to the shaft portion 34 (see Figures 12 and 13).

[0075] According to the above aspect, when the pressing member 50 is rotated relative to the shaft portion 34 with the protrusion 37 inserted and removed from the insertion hole 53 in order to attach the pressing member 50 to the shaft portion 34, the rotation regulating portion 61 abuts against the protrusion 37, thereby regulating the rotation of the pressing member 50, thereby regulating excessive rotation of the pressing member 50 and making it easier to engage the protrusion 37 with the engaged portion 59.

[0076] In this embodiment, the engaged portion 59 has a fitting recess 59 a into which the protrusion 37 fits when the spring member 70 is rotated relative to the shaft portion 34 .

[0077] According to the above aspect, when the pressing member 50 is rotated relative to the shaft portion 34 with the protrusion 37 inserted and removed from the insertion hole 53 in order to attach the pressing member 50 to the shaft portion 34, the protrusion 37 engages with the engaging recess 59a, thereby reliably restricting the rotation of the pressing member 50 relative to the shaft portion 34, and the spring force of the spring member 70 urges the protrusion 37 in the direction of entering the engaging recess 59a, thereby reliably preventing the pressing member 50 from coming off the shaft portion 34.

[0078] 14 shows a case where the pressure in the internal space R1 of the workpiece 1 is below a predetermined value. In this case, the biasing force of the spring member 70 causes the seal lip 32a of the seal portion 32 of the valve body 30 to abut against the valve seat 23 of the base member 20, closing the vent hole 24.

[0079] From this state, if gas is generated inside the case due to the power storage device, for example, when the power storage device supplies power to the drive source or electrical components, or due to the external or internal environment of the case in which the power storage device is housed (for example, when a power storage device such as a lithium-ion battery supplies power by driving a motor or the like, gas is generated by a chemical reaction in the electrolyte), the device will operate as follows.

[0080] That is, when the pressure in the internal space R1 of the workpiece 1 increases and exceeds the biasing force of the spring member 70, the valve body 30 slides against the biasing force while being slidably guided by the guide piece 27 in a direction away from the valve seat 23, and the seal lip 32a moves away from the valve seat 23. Then, as shown in Figure 15, the vent hole 24 of the base member 20 opens, and the internal space R1 of the workpiece 1 and the external space R2 communicate with each other through this vent hole 24.

[0081] As a result, the gas in the internal space R1 of the workpiece 1 flows into the main body tube portion 21 of the base member 20, passes through the gap between adjacent guide pieces 27, 27 in the circumferential direction, and is exhausted through the ventilation hole 24 to the external space R2 of the workpiece 1 (see arrow L in Figure 15), thereby releasing (reducing) the pressure within the workpiece 1.

[0082] 16 to 19 show other embodiments of the pressure release valve according to the present invention. Note that parts that are essentially the same as those in the above embodiment are given the same reference numerals and their description will be omitted.

[0083] The pressure release valve 10A of this embodiment (hereinafter simply referred to as the "release valve 10A") differs from the previous embodiment mainly in the shapes of the shaft 42 and the spring retainer member 50A. Also, the guide piece 27 provided on the base member 20A constituting the release valve 10A is shorter in length than the guide piece 27 of the release valve 10 of the previous embodiment.

[0084] 18 and 19, a cover 90 is attached to the valve body 30A to cover the ceiling portion 33 and the peripheral wall portion 35. A circular recess 42a of a predetermined depth is formed on the axial base end (other end) side of the shaft portion 42 that constitutes the valve body 30A, and a breather valve 80 in the shape of a circular plate that allows a predetermined gas (e.g., gas, air, etc.) to pass through is placed in the recess 42a.

[0085] As shown in Figure 16, the shaft portion 42 protruding from the center of the back side of the ceiling portion 33 of the valve body 30 is tubular with an internal space V1 (see Figures 18 and 19). More specifically, the shaft portion 42 has a first tubular portion 43 having a substantially cylindrical shape and a second tubular portion 44 that is axially connected to the first tubular portion 43, has a smaller diameter than the first tubular portion 43, and has a through hole 44a in the radial center. A flat stepped portion 45 is formed between one end (tip end) of the first tubular portion 43 and the other end (base end) of the second tubular portion 44.

[0086] Furthermore, a plurality of (four in this example) protrusions 46 are provided at equal circumferential intervals from the outer periphery of the axial tip of the second cylindrical portion 44. Furthermore, a plurality of (four in this example) first holes 47 that communicate with the internal space V1 of the shaft portion 42 are formed in the axially intermediate portion of the shaft portion 34 (here, the stepped portion 45 and the first cylindrical portion 43) at positions that align radially with the protrusions 46. Furthermore, a protrusion 46a that is narrower than the circumferential width of the protrusion 46 protrudes from the center in the width direction of the back side of each protrusion 46 (the side facing the base end of the shaft portion 42) at a position that aligns with the first hole 47.

[0087] 16 , the spring presser member 50A (hereinafter also simply referred to as "presser member 50A") has a bottom 51a located in the axial direction of the cylindrical portion 51, and multiple (four in this example) second holes 66 communicating with the internal space V2 of the cylindrical portion 51 are formed at positions aligned with the engaged portion 59 (not shown). Also, a through hole 51b is formed in the radial center of the bottom 51a of the cylindrical portion 51. Furthermore, the fitting recess 59a formed in the engaged portion 59 is formed with a shape and dimensions that fit the protrusion 46a of the shaft portion 34.

[0088] Furthermore, in this release valve 10A, when the protrusion 46 of the shaft 42 is engaged with the engaged portion 59 of the pressing member 50A (here, the protrusion 46a), a clearance CL is formed that allows the pressing member 50A to be pushed axially against the shaft 42 against the biasing force of the spring member 70, as shown in Figures 18 and 19.

[0089] Here, a clearance CL is formed between the surface (upper surface) of the bottom 51a of the tubular portion 51 of the pressing member 50A and the tip surface (lower surface) of the second tubular portion 44 of the shaft portion 42, and a clearance CL is also formed between the other axial end surface (upper end surface) of the tubular portion 51 of the pressing member 50A and the stepped portion 45 of the shaft portion 42.

[0090] Then, a spring member 70 is positioned radially outside the shaft portion 42, and each protrusion 46 of the shaft portion 42 is inserted and removed from each insertion hole 53 of the pressing member 50A. By rotating the pressing member 50A relative to the shaft portion 42, the pressing member 50A is snap-fit ​​connected to the shaft portion 42 using a snap-fit ​​connection structure, and the pressing member 50A can be attached to the shaft portion 42.

[0091] Furthermore, when the pressing member 50A is rotated relative to the shaft portion 42 while being pushed in against the spring force of the spring member 70, the above-mentioned clearance CL allows the protrusion 46 to move axially so that it does not overlap with the engaged portion 59 in the axial direction, thereby reliably separating the protrusion 46 from the engaged portion 59 in the axial direction, thereby reducing the rotational resistance of the pressing member 50A relative to the shaft portion 42 and making it easier to attach the pressing member 50A to the shaft portion 42.

[0092] Furthermore, in this embodiment, the shaft portion 42 is cylindrical, and a breather valve 80 can be placed on the base end side of the shaft portion 42. A first hole 47 that communicates with the internal space V1 of the shaft portion 42 is formed in the axial middle portion of the shaft portion 42 at a position that is radially aligned with the protrusion 46, and a second hole 66 that communicates with the internal space V2 of the cylindrical portion 51 is formed in the cylindrical portion 51 of the pressing member 50A at a position that is radially aligned with the engaged portion 59.

[0093] According to the above aspect, it is possible to form a gas flow passage by utilizing the first hole 47 and the second hole 66, which allows gas to flow into the internal space V1 of the shaft portion 42 on which the breather valve 80 is mounted. That is, as shown in Fig. 19, the first hole 47 and the second hole 66 can connect the internal space V1 of the shaft portion 42 and the internal space V2 of the pressing member 50A to each other, thereby forming a gas flow passage.

[0094] As shown in Figure 18, the internal spaces V1, V2 of the shaft portion 42 and the pressing member 50A are connected to each other via the through holes 44a, 51b, and these through holes 44a, 51b can also form a flow passage for circulating gas into the internal space V1 of the shaft portion 42.

[0095] 20A and 20B show a further embodiment of the pressure relief valve according to the present invention. Note that parts that are substantially the same as those in the previous embodiment are given the same reference numerals and their description will be omitted.

[0096] In this embodiment, a pair of protrusions 37B, 37B protrude from the axial tip of a shaft 34B provided on the valve body at locations facing each other in the radial direction. The base member is provided with a cylindrical tube portion 21a, into which the shaft 34B is inserted.

[0097] Furthermore, spring presser member 50B (hereinafter simply referred to as "presser member 50B") is a thin, generally circular plate with a circular outer periphery and a keyhole-shaped insertion hole 53 formed in the radial center, and has no cylindrical portion. A pair of engaged portions 59, 59 extending generally fan-shaped along the circumferential direction are provided on the radial inner periphery of presser member 50B, at the side edges of insertion hole 53. A fitting recess 59a into which protrusion 37B fits is formed in the circumferential center of each engaged portion 59.

[0098] Then, the spring member 70 is disposed radially outward of the shaft portion 34B, the protrusions 37B of the shaft portion 34B are inserted into and removed from the insertion holes 53 of the pressing member 50B, and the pressing member 50B is rotated relative to the shaft portion 34B, whereby the pressing member 50B is snap-fit ​​connected to the shaft portion 34B by the snap-fit ​​connection structure, and the pressing member 50B can be attached to the shaft portion 34B. The pressing member 50B of this embodiment is in the shape of a substantially circular plate without a cylindrical portion, and therefore is not bulky in the axial direction, allowing for compactness.

[0099] It should be noted that the present invention is not limited to the above-described embodiment, and various modified embodiments are possible within the scope of the gist of the present invention, and such embodiments are also included in the scope of the present invention.

[0100] 1...Attached member, 10, 10A...Pressure release valve, 20, 20A...Base member, 23...Valve seat, 24...Ventilation port, 30...Valve body, 34, 34B, 42...Shaft portion, 37, 37B, 46...Protrusion, 47...First hole, 50, 50A, 50B...Spring pressing member, 51...Cylindrical portion, 52...Spring support portion, 53...Insertion hole, 59...Engaged portion, 59a...Fitting recess, 61...Rotation restriction portion, 66...Second hole, 70...Spring member, 80...Breather valve.

Claims

1. A pressure release valve to be attached to a workpiece, comprising: a base member fixed to the workpiece and having a valve seat and a vent hole on the inside thereof; a valve body having a shaft portion and slidable relative to the base member so as to approach and separate from the valve seat to open and close the vent hole; a spring member attached to the shaft portion and urging the valve body toward the valve seat; and a spring holder member having a spring support portion that supports one end of the spring member, wherein a snap-fit ​​connection structure is provided between the shaft portion and the spring holder member to snap-fit ​​connect the spring holder member to the shaft portion.

2. A pressure release valve as claimed in claim 1, wherein the snap-fit ​​connection structure is such that the spring pressing member is snap-fit ​​connected to the shaft portion by rotating the spring pressing member relative to the shaft portion.

3. A pressure release valve as described in claim 2, wherein the snap-fit ​​connection structure is composed of a protrusion provided on the shaft portion, a cylindrical portion provided on the spring presser member, an insertion hole formed in the cylindrical portion for inserting the shaft portion and the protrusion, and an engaged portion formed on the edge of the insertion hole with which the protrusion engages when the spring presser member is rotated relative to the shaft portion.

4. A pressure release valve as claimed in claim 3, wherein when the protrusion is engaged with the engaged portion, a clearance is formed that allows the spring pressing member to be pushed axially against the shaft portion against the biasing force of the spring member.

5. A pressure release valve as described in claim 3 or 4, wherein the inner circumference of the cylindrical portion is provided with a rotation restricting portion that abuts against the protrusion to restrict the rotation of the spring retaining member when the spring retaining member is rotated relative to the shaft portion.

6. A pressure release valve as set forth in claim 3 or 4, wherein said engaged portion has a fitting recess into which said protrusion fits when said spring member is rotated relative to said shaft portion.

7. A pressure release valve as claimed in claim 3 or 4, wherein the shaft portion is cylindrical and a breather valve can be mounted on the base end side of the shaft portion, a first hole communicating with the internal space of the shaft portion is formed in the axial middle portion of the shaft portion at a position radially aligned with the protrusion, and a second hole communicating with the internal space of the cylindrical portion is formed in the cylindrical portion of the spring retainer member at a position radially aligned with the engaged portion.

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