JP7765626B2 - Pressure release valve for power storage devices - Google Patents

Description

The present invention relates to a pressure relief valve for an electricity storage device that is attached to a case that houses the electricity storage device and releases pressure within the case.

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

For example, Patent Document 1 below 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.

The pressure regulating unit has a base that is attached to the opening of the housing. This base is cylindrical and has multiple flexible legs formed through multiple axially extending slits. Each leg has a locking protrusion protruding from the outer periphery at the tip. When the base is inserted into the opening of the housing, the locking protrusions are pressed against the inner periphery of the opening, causing the legs to bend and deform as they are inserted. When the locking protrusions come out the back side of the opening, the legs elastically return to their original position and the locking protrusions lock onto the periphery of the back side of the opening. As a result, the base is fixed to the opening, and the entire pressure regulating valve is attached to the opening of the housing.

Japanese Patent Application Laid-Open No. 2020-21897

As mentioned above, the pressure regulating valve in Patent Document 1 is configured to be attached to the opening of the housing using multiple flexible legs provided on the base, and the base is not fixed to the housing with bolts, nuts, etc., making it relatively easy to attach the pressure regulating valve to the opening of the housing. However, the fixing force of the base to the opening of the housing is relatively weak, making it easy for the base to come off from the opening.

Therefore, the object of the present invention is to provide a pressure relief valve for an electrical storage device that is easy to attach to a case and is difficult to detach from the case.

To achieve the above object, the present invention provides a pressure release valve for an electricity storage device that is attached to a case that houses an electricity storage device, and that includes a fixing member that is inserted into and fixed to a case opening formed in the case, and a valve unit that is slidably inserted inside the fixing member. The valve unit includes a vent hole that connects the internal space of the case with the external space, a valve seat provided on the periphery of the vent hole, an engaged portion that engages with the fixing member at a predetermined position, a valve body that opens and closes the vent hole, and biasing means that biases the valve body toward the valve seat. The fixing member is provided with a retaining portion that engages with the case, a temporary engagement portion that is provided inside the fixing member and engages with the engaged portion at a predetermined insertion position when the valve unit is inserted into the fixing member, and a final engagement portion that engages with the engaged portion at an insertion position deeper than the temporary engagement portion, and the retaining portion is configured to bend inward in a temporary holding state in which the engaged portion is engaged with the temporary engagement portion, and to have its diameter restricted by the valve unit in a final fixed state in which the engaged portion is engaged with the final engagement portion.

According to this invention, when the fixing member and valve unit are inserted into the case opening in a temporary retaining state in which the engaged portion is engaged with the temporary engaging portion of the fixing member, the retaining portion of the fixing member can bend inward, allowing the valve unit to be easily inserted into the case opening together with the fixing member. In this state, when the valve unit is inserted further into the fixing member and the engaged portion engages with the permanent engaging portion of the fixing member, the valve unit is positioned inside the retaining portion of the fixing member, preventing the retaining portion of the fixing member from bending inward and restricting its diameter reduction, allowing the valve unit to be firmly secured to the case via the fixing member. This results in a release valve that is easy to attach to the case and is not likely to come off from the case.

1 is an exploded perspective view showing one embodiment of a pressure release valve for an electricity storage device according to the present invention. FIG. 2 is a perspective view of the pressure release valve for the electricity storage device. FIG. 2 is an enlarged perspective view of a lower member constituting the pressure release valve for the electricity storage device. FIG. 2 is an enlarged perspective view of a valve seat forming member that constitutes the pressure release valve for the electricity storage device. 3 is an enlarged perspective view showing an upper member that constitutes the pressure release valve for the electricity storage device. FIG. 3 is a bottom view of the upper member that constitutes the pressure release valve for the electricity storage device. FIG. FIG. 2 is an enlarged perspective view of a valve body that constitutes the pressure release valve for the electricity storage device. FIG. 2 is an enlarged perspective view of a cap that constitutes the pressure release valve for the electricity storage device. FIG. FIG. 2 is an enlarged perspective view of a sealing member that constitutes the pressure release valve for the electricity storage device. FIG. 2 is an enlarged perspective view of a cover member that constitutes the pressure release valve for the electricity storage device. 4 is a cross-sectional view illustrating a first assembly step of the pressure release valve for the electricity storage device. FIG. 10 is a cross-sectional view illustrating a second assembly step of the pressure release valve for the electricity storage device. FIG. 10A to 10C are cross-sectional explanatory views illustrating a first step of attaching the pressure release valve for the electricity storage device to the case. 10 is a cross-sectional view illustrating a second step of attaching the pressure release valve for the electricity storage device to the case. FIG. 10 is a cross-sectional view illustrating a third step in the process of attaching the pressure release valve for the electricity storage device to the case. FIG. 16 is a cross-sectional explanatory view showing a state in which the valve body separates from the valve seat and the vent hole opens from the state shown in FIG. 15. FIG. FIG. 10 is an exploded perspective view showing another embodiment of a pressure release valve for an electricity storage device according to the present invention. FIG. 2 is a perspective view of the pressure release valve for the electricity storage device. FIG. 2 is an enlarged perspective view of a base member that constitutes the pressure release valve for the electricity storage device. FIG. 2 is an enlarged perspective view of a cover member that constitutes the pressure release valve for the electricity storage device. 3 is an enlarged perspective view of a pushing member that constitutes the pressure release valve for the electricity storage device. FIG. FIG. 2 is an enlarged perspective view of a cap member that constitutes the pressure release valve for the electricity storage device. 4 is a cross-sectional view illustrating a first assembly step of the pressure release valve for the electricity storage device. FIG. 10 is a cross-sectional view illustrating a second assembly step of the pressure release valve for the electricity storage device. FIG. 10 is a cross-sectional view illustrating a third assembly step of the pressure release valve for the electricity storage device. FIG. 10A to 10C are cross-sectional explanatory views showing a process of attaching the pressure release valve for the electricity storage device to the case. 19 is a cross-sectional explanatory view taken along the line AA of FIG. 18, showing the pressure release valve for an electricity storage device attached to the case. 19 is an enlarged cross-sectional explanatory view taken along the line BB of FIG. 18, showing the pressure release valve for the electricity storage device attached to the case. 19 is an enlarged cross-sectional explanatory view taken along the line DD in FIG. 18, showing the pressure release valve for the electricity storage device attached to the case. 28 is an explanatory cross-sectional view showing a state in which the valve disc separates from the valve seat and the vent hole opens from the state shown in FIG. 27. FIG. 19 is a perspective view showing a state in which a plate-like piece provided on the cover member is opened from the state shown in FIG. 18. FIG. FIG. 10 is a perspective view showing still another embodiment of a pressure release valve for an electricity storage device according to the present invention.

(One embodiment of a pressure release valve for an electricity storage device)
Hereinafter, one embodiment of a pressure release valve for an electricity storage device according to the present invention will be described with reference to the drawings.

As shown in Figures 15 and 16, this pressure release valve 10 for an electricity storage device (hereinafter simply referred to as "release valve 10") is attached to a case 1 that houses an electricity storage device (not shown), and is intended to release (reduce) the pressure inside the case when the pressure increases.

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

As shown in FIG. 1, the case 1 has a case opening 3. More specifically, the case 1 in this embodiment has a recess 2 formed in a generally circular recess. A generally circular recess deeper than the recess 2 is provided at the bottom of the recess 2, with a circular hole formed in the center of the recess and a cylindrical portion 3a protruding from the rear periphery of the circular hole. The cylindrical portion 3a and the inner periphery of the circular hole form the case opening 3. The bottom of the recess, which is deeper than the recess 2, forms the front periphery 4 of the case opening 3. As shown in FIGS. 13 to 16, the internal space of the case 1 forms the case internal space R1, and the external space of the case 1 forms the case external space R2.

As shown in Figures 1 and 13, the release valve 10 in this embodiment has a fixed member that is inserted into and fixed in the case opening 3, and a valve unit 15 that is slidably inserted inside the fixed member. In this embodiment, the fixed member forms a cylindrical sealing member 20. The valve unit 15 is inserted inside the sealing member 20 and is fixed to the case 1 via the sealing member 20.

The valve unit 15 also has a vent hole 52 that connects the case internal space R1 and the case external space R2, a valve seat 53 provided on its periphery, an engaged portion that engages with the fixed member at a predetermined position, a valve body 70 that opens and closes the vent hole 52, and a biasing means that biases the valve body 70 toward the valve seat 53.

Furthermore, in this embodiment, the "engaged portion" in this invention refers to the base member side engaging portion 45 and pressing portion 41a, which will be described later, as shown in Figure 14. These engage with the temporary engaging portion 25 and the inner surface of the main body portion 21, which will be described later, respectively, thereby holding the valve unit 15 in a temporary held state relative to the fixing member. Furthermore, the base member side engaging portion 45 and pressing portion 41a engage with the main engaging portion 26 and pressing protrusion 28, which will be described later, respectively, thereby holding the valve unit 15 in a final fixed state relative to the fixing member.

In this embodiment, the temporary engagement portion 25 and the inner surface of the main body portion 21 form the "temporary engagement portion" described below in this invention. The full engagement portion 26 and the pressing protrusion 28 form the "full engagement portion" described below in this invention.

In this embodiment, the valve unit 15 has a base member with an engaged portion, and the valve body 70 is slidable relative to the base member. The base member also has a base member-side engaging portion 45 that engages with the seal member 20.

Furthermore, as shown in Figure 11, in this embodiment, the first assembly 15A is formed by assembling four parts: the upper member 60, the valve body 70, the cap 80, and the coil spring 90. Also as shown in Figure 11, the second assembly 15B is formed by assembling two parts: the lower member 40 and the valve seat forming member 50. Note that the biasing means in this embodiment is the coil spring 90, which is made by winding a wire of a specified diameter at a specified pitch.

Also, as shown in Figure 12, a cover member 30 is attached to the sealing member 20.

In this embodiment, the "base member" of the present invention is composed of a lower member 40, a valve seat forming member 50 attached to the lower member 40 and provided with a valve seat 53, and an upper member 60 assembled to the lower member 40. A cap 80 is attached to and integrated with the valve body 70.

In the following description, the terms "front side" and "surface side" refer to the side facing the case 1, and the terms "rear side" and "rear side" refer to the opposite side. This also applies to other components (base member, seal member, valve member, cap, etc.) described below. In the following description, the insertion direction F of the release valve 10 into the case opening 3 (the insertion direction of the release valve 10 into the case opening 3) as shown in FIG. 13 is also simply referred to as the "insertion direction F." The insertion direction of the first assembly 15A into the second assembly 15B (the insertion direction of the first assembly 15A into the second assembly 15B) as shown in FIG. 11 and the insertion direction of the valve unit 15 into the seal member 20 (the insertion direction of the valve unit 15 into the seal member 20) as shown in FIG. 12 are also referred to as the "insertion direction F."

First, referring to Figures 3 and 11, we will explain the lower member 40 that constitutes the base member.

The lower member 40 has a tubular portion 41 that is approximately cylindrical. A circularly rounded pressing portion 41a is provided on the outer periphery of the axial base end (the end on the insertion direction F side) of the tubular portion 41. An annular flange portion 42 extends from the outer periphery of the axial tip end (the end opposite the insertion direction F) of the tubular portion 41. Furthermore, multiple (four in this example) engagement pieces 43, each with an engagement hole 43a, extend upright at equal intervals from the axial tip surface of the tubular portion 41. A guide groove 43b is formed on the inner surface of the tip of each engagement piece 43 in the upright direction. When inserting the engaging piece 62 of the upper member 60 into the tubular portion 41 of the lower member 40 to assemble the lower member 40 and the upper member 60, this guide groove 43b guides the engaging claw 63 (see Figure 5) protruding from the outer surface of the engaging piece 62, making it easier to engage with the engaging hole 43a.

Furthermore, an annular protrusion 44 protrudes inward from the inner periphery of the cylindrical portion 41 on the axial base end side. A base member side engaging portion 45 also protrudes from the outer periphery of the cylindrical portion 41 at a predetermined axial position (here, a position slightly toward the axial base end). A tapered surface 45a is formed on the outer surface of the base end of this base member side engaging portion 45.

Next, with reference to Figures 4 and 11, we will explain the valve seat forming member 50 that is attached to the lower member 40.

The valve seat forming member 50 is formed from an elastic material such as rubber or an elastic elastomer, and has a generally cylindrical tubular portion 51. The internal space of the tubular portion 51 forms a vent hole 52. As shown in FIG. 16 , the internal space R1 of the case 1 communicates with the external space R2 of the case 1 via the vent hole 52. A valve seat 53 is provided on the axial tip surface (the end surface opposite the insertion direction F) of the tubular portion 51, on the outer peripheral edge of the vent hole 52. Furthermore, a tapered surface 51a is formed on the outer periphery of the axial base end (the end on the insertion direction F side) of the tubular portion 51.

An annular groove-shaped engagement groove 54 is formed on the outer periphery of the axial tip end of the tubular portion 51, into which the annular protrusion 44 of the lower member 40 engages. As shown in Figure 11, the tubular portion 51 is positioned on the inner periphery of the base end of the lower member 40, and the annular protrusion 44 of the lower member 40 is engaged with the engagement groove 54, thereby attaching the valve seat forming member 50 to the lower member 40. As a result, the vent hole 52 and valve seat 53 are provided in the lower member 40.

Next, with reference to Figures 5 and 11, we will explain the upper member 60 that is assembled to the lower member 40.

The upper member 60 has a substantially circular annular base 61. A plurality of engaging pieces 62 are evenly spaced apart and hang down from the base end surface (the end surface facing the insertion direction F) of the annular base 61. Here, four engaging pieces 62 are provided, corresponding to the engaging pieces 43 of the lower member 40. When the upper member 60 is assembled to the lower member 40, each engaging piece 62 is positioned inside the corresponding engaging piece 43 of the lower member 40. Each engaging piece 62 is also formed with a flexibly deformable engaging claw 63 via a substantially U-shaped slit 63a.

As shown in Figure 12, an engagement piece 62 is positioned inside the engagement piece 43 of the lower member 40, and its engagement claw 63 engages with the inner circumference of the engagement hole 43a of the engagement piece 43 of the lower member 40, thereby assembling the upper member 60 to the lower member 40.

An annular ceiling portion 64 is disposed at the radial center of the annular base portion 61, protruding further than the annular base portion 61. The annular base portion 61 and the ceiling portion 64 are connected to each other by a plurality of ribs 65 that extend radially from the axis of the upper member 60. Openings 66 are formed between adjacent ribs 65, 65, connecting the internal and external spaces of the base member. A roughly cylindrical tube portion 67 hangs down from the rear peripheral edge of the ceiling portion 64.

Next, with reference to Figures 6 and 11, we will explain the valve body 70 that is slidably housed within the base member.

This valve body 70 has a flange portion 72 that contacts and separates from the valve seat 53, and a shaft portion 71 that protrudes from the radial center of the front side of the flange portion 72. The shaft portion 71 is generally cylindrical, with a closed ceiling surface 71a at its axial tip (the end opposite the insertion direction F). The flange portion 72 can also be said to have an annular shape that extends from the outer periphery of the axial base end (the end on the insertion direction F side) of the shaft portion 71. As shown in Figure 11, the shaft portion 71 is arranged coaxially with the tubular portion 67 of the upper member 60, and is slidably inserted and supported within the tubular portion 67.

Furthermore, the flange portion 72 of the valve body 70 is positioned opposite the ceiling portion 64 and ribs 65 of the upper member 60. This flange portion 72 has a circular outer periphery and its outer diameter is larger than the inner diameter of the tubular portion 51 of the valve seat forming member 50, so that it moves toward and away from the valve seat 53 to open and close the vent port 52. Furthermore, the outer diameter of the flange portion 72 is sized to approximately fit the inner diameter of the multiple engagement pieces 62 of the upper member 60 (see Figure 13), allowing the valve body 70 to slide up and down within the upper member 60 while being prevented from tilting.

A ring-shaped recess 72a recessed to a predetermined depth is formed in the inner diameter portion on the front side of the flange portion 72, and one end (axial base end) of the coil spring 90 abuts and is supported against the bottom surface of the ring-shaped recess 72a. Furthermore, a ring-shaped seal projection 73 protrudes from the outer periphery on the back side of the flange portion 72. This seal projection 73 moves toward and away from the valve seat 53 of the valve seat forming member 50 to open and close the vent port 52 (see Figures 15 and 16).

With regard to the valve disc 70 described above, the relationship with the coil spring 90, which serves as a biasing means, will now be explained. As shown in Figure 11, this coil spring 90 is disposed on the outer periphery of the tubular portion 67 of the upper member 60, into which the shaft portion 71 of the valve disc 70 is inserted. One end of the coil spring 90 is supported by abutting against the bottom surface of the annular recess 72a of the flange portion 72 of the valve disc 70, and the other end (the axial tip) is supported by abutting against the rear peripheral edge of the tubular portion 67 of the ceiling portion 64 of the upper member 60. As a result, the coil spring 90 is housed and held in a compressed state within the base member, biasing the valve disc 70 toward the valve seat 53.

Returning to the explanation of the valve body 70, a protrusion 75 protrudes from the radial center of the ceiling surface 71a of the shaft portion 71, and a strip-shaped retaining piece 75a is attached to the tip of the protrusion 75. As shown in Figure 11, the protrusion 75 and retaining piece 75a are inserted into the shaft insertion hole 84a of the cap 80, and the retaining piece 75a engages with the outer peripheral edge of the shaft insertion hole 84a when the valve body 70 is rotated a predetermined angle.

Next, with reference to Figures 7, 8, 11, etc., we will explain the cap 80, which is fixed to and integrated with the valve body 70.

The cap 80 of this embodiment has a generally circular plate-shaped ceiling portion 81, a peripheral wall 83 that extends diagonally outward from the outer periphery of the ceiling portion 81, and a seal flange portion 85 that extends annularly from the outer periphery of the base end (the end on the insertion direction F) of the peripheral wall 83. As shown in Figure 15, the cap 80 has a larger diameter than the outer periphery of the lower member 40 and the upper member 60 so that it can cover the entire base member. The seal flange portion 85 can open and close multiple openings 66 formed in the lower member 40 by coming into and out of contact with the flange portion 32 of the cover member 30 that constitutes the seal member 20 (see Figures 15 and 16).

A circular recess 84 of a predetermined depth is formed in the radial center of the front side of the ceiling portion 81. A keyhole-shaped shaft insertion hole 84a is formed in the bottom of this recess 84. As shown in Figure 8, a pair of retaining projections 84b, 84b protrude from the bottom of the recess 84, on the outer periphery of the shaft insertion hole 84a.

The protrusion 75 and retaining piece 75a of the valve body 70 are then inserted into the shaft insertion hole 84a, and the cap 80 is then rotated 90 degrees to engage the retaining piece 75a with the outer periphery of the shaft insertion hole 84a, thereby preventing the cap 80 from coming off the valve body 70 and integrating the valve body 70 and cap 80. In this state, one end of the retaining piece 75a fits between the pair of retaining protrusions 84b, 84b, preventing the cap 80 from rotating relative to the valve body 70.

As a result of the cap 80 being integrated with the valve body 70 in this manner, as the valve body 70 slides relative to the base member, the cap 80 also moves toward or away from the front side of the upper member 60 that constitutes the base member, and its seal flange portion 85 moves toward or away from the flange portion 32 of the cover member 30.

Next, the sealing member 20 will be described with reference to Figures 9, 12 to 15, etc.

The sealing member 20 is formed from an elastic material such as rubber or an elastic elastomer, and has a substantially cylindrical main body 21. The tubular portion 41 of the lower member 40 is inserted into the main body 21.

A pair of annular protrusions 22, 23 are provided in parallel on the outer periphery of the main body 21 at the axial tip (the end opposite the insertion direction F). The annular protrusion 22 protrudes from the outer periphery of the axial tip of the main body 21, while the annular protrusion 23 is positioned closer to the axial base end (the end on the insertion direction F side) of the main body 21 than the annular protrusion 22 and has a larger diameter than the annular protrusion 22. As shown in Figure 14, the annular protrusion 23 abuts against the front peripheral edge 4 of the case opening 3 of the case 1.

Furthermore, an annular groove-shaped mounting groove 24 is formed on the outer periphery of the main body 21, between the two annular protrusions 22, 23. The cover member 30 is attached to the seal member 20 via this mounting groove 24.

In relation to the above-mentioned mounting groove 24, the cover member 30 will be explained with reference to Figures 10, 12, etc.

This cover member 30 consists of a generally cylindrical tubular portion 31, a thin-walled, annular flange portion 32 that extends from the axial tip end (the end opposite the insertion direction F) of the tubular portion 31, and a mounting protrusion 33 that protrudes from the inner periphery of the axial base end (the end on the insertion direction F side) of the tubular portion 31 and is inserted into the mounting groove 24 of the seal member 20. The axial tip end of the main body 21 of the seal member 20 can be inserted into the tubular portion 31. Furthermore, when the release valve 10 is fixed to the case opening 3, the flange portion 32 is positioned opposite the front peripheral edge 4 of the case opening 3 with a predetermined gap between them (see Figure 14).

12, by inserting the mounting protrusion 33 of the cover member 30 into the mounting groove 24 of the seal member 20, the mounting protrusion 33 is clamped between the pair of annular protrusions 22, 23, and the cover member 30 is attached to the seal member 20. As a result, the outer periphery of the axial tip end of the seal member 20 is covered by the cover member 30. Note that the seal flange portion 85 of the cap 80 described above comes into contact with and separates from the surface side of the flange portion 32 (see Figures 15 and 16), opening and closing the opening 31a at the axial tip end of the cover member 30.

Let's return to the explanation of the sealing member 20.

On the inside of the fixed member, which is a sealing member, there is a temporary engagement portion that engages with the engaged portion at a predetermined insertion position when the valve unit 15 is inserted into the fixed member, and a full engagement portion that engages with the engaged portion at an insertion position deeper than the temporary engagement portion.

In this embodiment, the inner circumference of the sealing member 20 is provided with a temporary engagement portion 25 that engages with the base member side engagement portion 45 of the base member at a predetermined insertion position when the valve unit 15 is inserted into the sealing member 20, and a full engagement portion 26 that engages with the base member side engagement portion 45 of the base member at an insertion position deeper than the temporary engagement portion 25.

More specifically, as shown in Figures 12 and 14, a hollowed-out portion 21a is provided on the inner periphery of the main body portion 21 of the seal member 20, on the axial tip side. The hollowed-out portion 21a is formed by hollowing out the inner periphery of the main body portion 21. A temporary engagement portion 25 in the form of an annular protrusion projects radially inward from the axial tip of the inner periphery of the main body portion 21 through the hollowed-out portion 21a.

13 and 14, the base member-side engaging portion 45 on the base member engages with the rear peripheral edge of this temporary engaging portion 25, thereby temporarily holding the valve unit 15 to the seal member 20. This temporary engaging portion 25 is positioned at the same axial height as the annular protrusion 22. In other words, the annular protrusion 22 and the temporary engaging portion 25 are provided on the outer and inner peripheries, respectively, of the axial tip of the main body portion 21.

Furthermore, as shown in Figure 14, the recessed portion 21a ensures clearance between the tapered surface 45a of the base member side engaging portion 45 and the inner circumference of the main body portion 21 when the base member side engaging portion 45 is engaged with the temporary engaging portion 25, making it easier to push the valve unit 15 into the main body portion 21 of the sealing member 20.

Furthermore, a tapered surface 25a is formed on the inner circumference of the main body portion 21, from a position closer to the axial base end than the temporary engagement portion 25, such that the amount of protrusion inward of the main body portion 21 gradually increases toward the axial base end of the main body portion 21.

A main engagement portion 26, which is an annular groove of a predetermined depth, is formed on the inner periphery of the main body portion 21 at a midpoint in the axial direction, in this case adjacent to the apex of the tapered surface 25a (the portion that protrudes most inwardly into the main body portion). As shown in Figure 15, the base member-side engagement portion 45 on the base member side is inserted into this main engagement portion 26, and this base member-side engagement portion 45 engages with the inner circumferential surface of the axial tip of the main engagement portion 26, thereby finally fixing the valve unit 15 to the seal member 20.

Furthermore, the seal member 20 is provided with a retaining portion 27 that engages with the case 1. In addition, when the main engagement portion 26 of the seal member 20 is engaged with the base member side engagement portion 45 of the base member in the main fixed state, the outer peripheral surface of the seal member 20 engages with the case 1 (in this embodiment, as shown in Figure 15, an engagement protrusion 29 provided on the outer peripheral surface of the base end of the retaining portion 27 engages with the rear peripheral edge of the case opening 3).

The anti-slip portion 27 provided on the fixed member, which is a sealing member, is configured to bend inward in a temporary holding state in which the engaged portion is engaged with the temporary engaging portion, and to be regulated in diameter reduction by the valve unit 15 in a final fixed state in which the engaged portion is engaged with the final engaging portion.

In this embodiment, this anti-slip portion 27 is able to bend inward in a temporary holding state in which the temporary engagement portion 25 of the sealing member 20 is engaged with the base member side engagement portion 45 of the base member (see Figure 14), and in a permanently fixed state in which the base member side engagement portion 45 of the base member is engaged with the permanent engagement portion 26 of the sealing member 20, the base member is positioned inside the anti-slip portion 27, so that the base member restricts the reduction in diameter of the anti-slip portion 27 and it is configured to engage with the rear peripheral edge of the case opening 3 (see Figure 15).

More specifically, the anti-slip portion 27 is flexibly deformable and is provided at a position on the main body 21 of the sealing member 20 closer to the axial base end than the main engagement portion 26 (a position closer to the insertion direction F relative to the case opening 3 than the main engagement portion 26).

A pressing protrusion 28 having an annular projection protrudes from the inner peripheral surface of the retaining portion 27, at the axially most proximal end. This pressing protrusion 28 constitutes the "protrusion" of the present invention. As shown in FIG. 14 , the inner diameter of this pressing protrusion 28 is smaller than the outer diameter of the tubular portion 41 of the lower member 40. Therefore, when the valve unit 15 is further pressed into the seal member 20 from the temporarily held state in which the valve unit 15 is temporarily held in the seal member 20 as shown in FIG. 14 , the pressing protrusion 28 is pressed by the pressing portion 41 a on the outer periphery of the base end of the tubular portion 41 of the lower member 40, allowing the retaining portion 27 to bend and deform outward from the seal member 20.

Furthermore, a tapered surface 28a is formed on the outer surface of the pressing protrusion 28, gradually increasing the amount of protrusion toward the insertion direction F. By forming this tapered surface 28a, the pressing protrusion 28 is more easily pressed when pressed by the cylindrical portion 41 of the lower member 40.

Furthermore, an annular projection-shaped engagement protrusion 29 protrudes from the outer peripheral surface of the retaining portion 27, at the axially most proximal end. That is, in this embodiment, the retaining portion 27 has a pressing protrusion 28 and an engagement protrusion 29 protruding from the inner and outer peripheral surfaces, respectively, of its axially proximal end (the most extreme end in the insertion direction F relative to the case opening 3). As shown in FIG. 15 , when the retaining portion 27 is pressed by the pressing protrusion 28 and flexes and deforms outwardly of the seal member 20, the engagement protrusion 29 engages with the rear peripheral edge of the case opening 3 (the rear end surface of the tubular portion 3a). Furthermore, the engagement protrusion 29, together with the annular protrusion 23, clamps the case opening 3 of the case 1 (here, the portion from the front side of the case opening 3 to the proximal end of the tubular portion 3a).

The outer surface of the engaging protrusion 29 is formed with a tapered surface 29a that gradually reduces the amount of protrusion toward the insertion direction F. This tapered surface 29a makes it easier to insert the main body 21 of the seal member 20 into the case opening 3. As shown in FIG. 13, the outer diameter of the engaging protrusion 29 (the outer diameter of the most protruding top) is larger than the inner diameter of the case opening 3 of the case 1. Therefore, as shown by arrow F in FIG. 13, when the valve unit 15 is inserted into the case opening 3, the top of the engaging protrusion 29 and the tapered surface 29a are pressed against the inner periphery of the case opening 3, causing the retaining portion 27 to bend and deform inwardly toward the seal member 20.

The sealing member 20 allows the valve unit 15 to be temporarily held or permanently fixed as follows.

That is, as shown by arrow F in Figure 12, when the valve unit 15 is pushed in the insertion direction F toward the seal member 20, the cylindrical portion 41 of the lower member 40 is inserted into the main body 21 of the seal member 20. Then, the tapered surface 45a of the base member side engaging portion 45 of the lower member 40 is pressed against the temporary engaging portion 25 of the seal member 20, causing the cylindrical portion 41 of the lower member 40 to deform slightly inward.

When the base member side engaging portion 45 moves over the temporary engaging portion 25, as shown in Figures 13 and 14, the base member side engaging portion 45 engages with the rear peripheral edge of the temporary engaging portion 25, and the pressing portion 41a engages with the inner periphery of the main body portion 21, thereby temporarily holding the valve unit 15 at a relatively shallow insertion position relative to the seal member 20. In this temporary holding state, the tubular portion 41 of the lower member 40 is not positioned inside the retaining portion 27, so the retaining portion 27 can flex and deform inward of the seal member 20.

In addition, it can also be said that the anti-slip portion 27 of the sealing member 20 extends further toward the insertion direction F than the base end of the tubular portion 41 of the lower member 40 when in a temporary holding state in which the temporary engagement portion 25 is engaged with the base member side engagement portion 45.

When the valve unit 15 is further pushed in the insertion direction F toward the seal member 20 from the above-described temporary holding state, the base member side engaging portion 45 disengages from the temporary engaging portion 25 and moves a predetermined distance within the recessed portion 21a. After that, the base member side engaging portion 45 slides along the tapered surface 25a within the main body portion 21. When the base member side engaging portion 45 is inserted into the main engaging portion 26, the base member side engaging portion 45 engages with the inner peripheral surface at the axial tip of the main engaging portion 26. Furthermore, as described below, the pressing portion 41a engages with the pressing protrusion 28, thereby finally fixing the valve unit 15 to the seal member 20 at an insertion position deeper than the above-described temporary holding state (see Figure 15).

At the same time, the tapered surface 28a of the pressing protrusion 28 of the retaining portion 27 is pressed against the pressing portion 41a of the tubular portion 41 of the lower member 40, causing the retaining portion 27 to flex outward from the seal member 20, and the engaging protrusion 29 on the outer periphery of the base end of the retaining portion 27 engages with the rear peripheral edge of the case opening 3 (the rear peripheral edge of the tubular portion 3a of the case opening 3). In other words, it can be said that the pressing portion 41a engages with the pressing protrusion 28. As a result, the valve unit 15 is fixed to the case opening 3 via the seal member 20. In the fully fixed state described above, the tubular portion 41 of the lower member 40 is positioned inside the retaining portion 27, which prevents the retaining portion 27 from flexing inward from the seal member 20, thereby restricting its diameter reduction.

(Modification)
In the embodiment described above, the case 1 is configured with the case opening 3 at the bottom of a plurality of recesses, but it may also be configured without recesses and with the case opening being provided directly in a wall such as the ceiling wall of the case 1. The shape of the case opening may be rectangular, square, elliptical, or the like, as long as it is a shape that allows the release valve to be attached.

Furthermore, the shapes and structures of the sealing member, cover member, lower member, valve seat forming member, upper member, valve body, cap, etc. that make up the pressure release valve are not limited to the above embodiments.

For example, the main body of the sealing member, the tubular portion of the cover member, the tubular portion of the lower member, and the tubular portion of the valve seat forming member are cylindrical, but these portions may also be elliptical or rectangular. Furthermore, the flange portion of the valve disc has a circular outer periphery corresponding to the shape of the tubular portion of the valve seat forming member and upper member, but it may also be elliptical or rectangular, for example, as long as it is shaped so that it can approach and separate from the valve seat of the valve seat forming member to open and close the vent.

Furthermore, in this embodiment, the seal member 20 and cover member 30, and the lower member 40 and valve seat forming member 50 are each separate bodies, but the seal member and cover member, and the lower member and valve seat forming member may each be integrally formed by so-called two-shot molding, in which, for example, the cover member and lower member are molded in a specified mold, and then the seal member and valve seat forming member are molded in the same mold while holding them in place.

In addition, in this embodiment, the structure for engaging the upper member and the lower member is such that an engaging piece 43 with an engaging hole 43a formed therein is provided on the lower member 40 side, and an engaging claw 63 that engages with the engaging hole 43a is provided on the upper member 60 side.However, for example, an engaging claw or engaging leg may be provided on the lower member side, and an engaging hole into which they engage may be provided on the upper member side; the engagement structure between the upper member and the lower member is not particularly limited.

Furthermore, in this embodiment, a cylindrical portion 67 is provided on the upper member 60 side, and an axial portion 71 is provided on the flange portion 72 side of the valve body 70 (see Figure 11), but the opposite may be true, with a cylindrical portion provided on the flange portion side of the valve body, and an axial portion inserted into the cylindrical portion and supported by sliding, provided on the upper member side.

In this embodiment, the retaining portion 27 of the seal member 20 has a continuous, annular cylindrical wall shape. However, the retaining portion may also have, for example, (1) a structure consisting of multiple flexible pieces arranged circumferentially of the seal member via multiple axially extending slits, (2) a shape in which the continuous cylindrical wall or multiple flexible pieces described above gradually narrows while forming a curved or tapered surface toward the axial base end of the seal member, or (3) a bulged portion is provided midway along the axial direction of the continuous cylindrical wall or multiple flexible pieces. In other words, the retaining portion may have a structure that can engage with the case (a structure that can engage with the rear peripheral edge of the case opening) when the base member-side engaging portion engages with the main engaging portion in the final fixed state, and the base member is positioned inside the retaining portion in the final fixed state, allowing the base member to restrict the diameter reduction of the retaining portion.

In addition, in this embodiment, pressing protrusions 28 and engaging protrusions 29 are provided on the inner and outer peripheral surfaces of retaining portion 27, but one or both of these protrusions may be absent. If pressing protrusions 28 are not provided on the inner peripheral surface of retaining portion 27, it is preferable to have a structure in which the inner peripheral surface of the retaining portion can be expanded from the inside by the outer peripheral surface of the valve unit when the main engaging portion is engaged with the base member side engaging portion to achieve the main fixed state (for example, the dimensions of the base end inner peripheral of the retaining portion are made smaller than the dimensions of the base end outer peripheral of the valve unit).

On the other hand, even if an engagement protrusion 29 is not provided on the outer peripheral surface of the retaining portion 27, it is sufficient that the retaining portion can engage with the case when the base member side engagement portion engages with this engagement portion to achieve the final fixed state (for example, if a pressing protrusion 28 is provided on the inner peripheral surface of the retaining portion 27, the retaining portion 27 will be pushed open from the inside when the valve unit or seal member is final fixed, and its outer peripheral surface will be able to engage with the rear peripheral edge of the case opening 3).

In addition, the base member in this embodiment is a case-shaped valve case that accommodates the valve body in a slidable manner within the internal space of the lower member and upper member, but the base member may have any shape or structure as long as it has an air vent and a valve seat, is provided with an engaging portion on its outer periphery, and is capable of supporting the valve body in a slidable manner.

Furthermore, while the upper member 60 in this embodiment has multiple openings 66 that are opened and closed by caps 80, it is also possible to configure the upper member without openings, without providing caps. In this case, however, it is preferable to form slots or the like in the peripheral wall of the base member that can communicate with the vent holes, allowing gas to flow through the case. In other words, any shape or structure that allows communication between the internal and external spaces of the case when the valve disc separates from the valve seat and opens the vent holes will suffice.

In addition, in this embodiment, the base member side engaging portion 45 and pressing portion 41a, which form the "engaged portion," engage with the temporary engaging portion 25, which form the "temporary engaging portion," and the inner surface of the main body portion 21, respectively, thereby holding the valve unit 15 in a temporary holding state relative to the fixed member, and the main engaging portion 26 and pressing protrusion 28, which form the "main engaging portion," respectively, thereby holding the valve unit 15 in a main fixed state relative to the fixed member.

In other words, the base member side engaging portion 45 and pressing portion 41a, which constitute the "engaged portion" in this embodiment, are used for both engagement with the temporary engaging portion and engagement with the final engaging portion, and serve both as temporary engagement and final engagement, but the "engaged portion" may have different shapes or structures or be located in different positions for engagement with the temporary engaging portion and engagement with the final engaging portion (it may also have separate, independent shapes, structures, or layouts that are not a dual-purpose structure).

(Action and effect)
Next, the operation and effect of the release valve 10 according to the present invention having the above-described structure will be described.

First, we will explain the assembly process of the release valve 10.

As shown in Figure 11, the axial tip of the coil spring 90 is placed on the outer periphery of the tubular portion 67 of the upper member 60, and the axial tip of the coil spring 90 is supported against the rear peripheral edge of the ceiling portion 64. The shaft portion 71 of the valve body 70 is inserted through the rear opening of the tubular portion 67 of the upper member 60, and the axial base end of the coil spring 90 is supported against the bottom surface of the annular recess 72a of the valve body 70. In this state, the cap 80 is placed on the front side of the upper member 60, and the protrusion 75 and retaining piece 75a of the valve body 70 are aligned with the shaft insertion hole 84a (see Figure 8), and then the protrusion 75 and retaining piece 75a are inserted and removed from the shaft insertion hole 84a.

Then, the cap 80 is rotated 90 degrees to engage the retaining piece 75a with the front peripheral edge of the shaft insertion hole 84a, and one end of the retaining piece 75a is fitted between the pair of retaining projections 84b, 84b (see Figure 8). This allows the cap 80 to be attached to the valve body 70 in a state where the cap 80 is prevented from coming off and its rotation is restricted relative to the valve body 70. As a result, the first assembly 15A is assembled, consisting of four parts: the upper member 60, the valve body 70, the cap 80, and the coil spring 90.

In the above state, the coil spring 90 is compressed and interposed between the upper member 60 and the valve body 70, so that the flange portion 72 of the valve body 70 is biased in a direction away from the ceiling portion 64 of the upper member 60.

11, the valve seat forming member 50 can be attached to the lower member 40 by inserting the cylindrical portion 51 of the valve seat forming member 50 into the inner periphery of the base end of the lower member 40 and engaging the annular protrusion 44 of the lower member 40 with the engagement groove 54 of the valve seat forming member 50. As a result, a second assembly 15B consisting of two parts, the lower member 40 and the valve seat forming member 50, is assembled.

Then, after aligning each engaging piece 43 of the lower member 40 constituting the second assembly 15B with the corresponding engaging piece 62 of the upper member 60 constituting the first assembly 15A, the first assembly 15A is pushed into the second assembly 15B as shown by arrow F in Figure 11.

Then, as shown in Figure 12, multiple engagement pieces 62 of the upper member 60 are inserted into the tubular portion 41 of the lower member 40, and the engagement claws 63 engage with the engagement holes 43a of the corresponding engagement pieces 43 on the lower member 40, thereby assembling the first assembly 15A and the second assembly 15B to each other and assembling the valve unit 15.

In this state, the flange portion 72 of the valve body 70, biased by the coil spring 90, is biased toward the valve seat 53 of the valve seat forming member 50, and the sealing protrusion 73 on the back side of the flange portion 72 of the valve body 70 abuts against the valve seat 53, blocking the air vent 52 (see Figure 12).

Also, as shown in Figure 12, the cover member 30 can be attached to the seal member 20 by inserting the mounting protrusion 33 of the cover member 30 into the mounting groove 24 of the seal member 20 and clamping it between a pair of annular protrusions 22, 23.

As shown by arrow F in Figure 12, when the valve unit 15 is pushed in the insertion direction F, the cylindrical portion 41 of the lower member 40 is inserted into the main body portion 21 of the seal member 20. Then, as shown in Figure 13, the base member side engaging portion 45 of the lower member 40 engages with the rear peripheral edge of the temporary engaging portion 25 of the seal member 20, and the pressing portion 41a engages with the inner periphery of the main body portion 21, temporarily holding the valve unit 15 in a relatively shallow insertion position relative to the seal member 20.

As a result, the release valve 10 is formed, consisting of the valve unit 15 and the seal member 20. In this temporarily held state, the retaining portion 27 is able to bend and deform inward of the seal member 20. In this embodiment, the release valve 10 is transported with the valve unit 15 temporarily held by the seal member 20.

Then, the release valve 10 is aligned with the case opening 3 and inserted from the front side of the case opening 3, as shown by arrow F in Figure 13. This presses the engagement protrusion 29 of the seal member 20 against the inner periphery of the case opening 3, causing the retaining portion 27 to bend and deform inward toward the seal member 20. The release valve 10 is then pushed into the case opening 3 until the annular protrusion 22 of the seal member 20 abuts against the front peripheral edge 4 of the case opening 3. When the engagement protrusion 29 of the seal member 20 leaves the back opening of the cylindrical portion 3a of the case opening 3, the retaining portion 27 of the seal member 20 elastically returns to its original position.

14, the engaging protrusion 29 of the retaining portion 27 is then positioned with a slight gap relative to the rear end surface of the cylindrical portion 3a of the case opening 3, temporarily fixing the seal member 20 to the case opening 3, and ultimately temporarily fixing the release valve 10 to the case opening 3. Even in this state, the retaining portion 27 is still able to flex and deform inward of the seal member 20.

Then, as shown by arrow F in Figure 14, the valve unit 15 is pushed into the seal member 20 that is temporarily fixed to the case opening 3. In this case, the valve unit 15 is pushed in until the flange portion 42 of the lower member 40 abuts against the annular protrusion 22 of the main body portion 21 of the seal member 20 and the temporary engagement portion 25. Then, the base member side engagement portion 45 of the lower member 40 disengages from the temporary engagement portion 25 of the seal member 20, and the base member side engagement portion 45 is inserted into the main engagement portion 26 of the seal member 20.

15, the base member engaging portion 45 engages with the inner peripheral surface of the axial tip of the main engaging portion 26, and the pressing protrusion 28 is pressed against the tubular portion 41 of the lower member 40, causing the retaining portion 27 to flex and deform outward from the seal member 20, and the engaging protrusion 29 engages with the rear peripheral edge of the tubular portion 3a of the case opening 3. In other words, the retaining portion 27 is pressed outward via the pressing protrusion 28, and the engaging protrusion 29 provided on the outer periphery of the retaining portion 27 is pressed firmly against the rear peripheral edge of the tubular portion 3a of the case opening 3, so that the engaging protrusion 29 engages with the rear peripheral edge of the tubular portion 3a of the case opening 3 without any gaps.

As a result, the valve unit 15 is fully fixed to the seal member 20 at an insertion position deeper than the temporary holding state of the valve unit 15 shown in Figure 14, and the base end portion of the tubular portion 3a is clamped from the front side of the case opening 3 between the annular protrusion 22 of the seal member 20 and the engaging protrusion 29 of the anti-slip portion 27.As shown in Figure 15, the valve unit 15 is fully fixed to the case opening 3 via the seal member 20, and the entire release valve 10 can be attached to the case 1.

In this final fixed state, the cylindrical portion 41 of the lower member 40 is positioned inside the anti-slip portion 27, which prevents the anti-slip portion 27 from bending and deforming inward toward the sealing member 20, restricting its reduction in diameter and keeping the engaging protrusion 29 of the anti-slip portion 27 engaged with the rear peripheral edge of the cylindrical portion 3a of the case opening 3, thereby allowing the valve unit 15 to remain in a final fixed state relative to the case 1 via the sealing member 20.

In this release valve 10, when the valve unit 15 and seal member 20 are inserted into the case opening 3 of the case 1 in a temporary holding state in which the temporary engagement portion 25 of the seal member 20 is engaged with the base member side engagement portion 45 of the base member of the valve unit 15, as shown in Figure 13, the anti-slip portion 27 of the seal member 20 can bend inward of the seal member 20, so that the seal member 20 can be easily inserted into the case opening 3 together with the valve unit 15 (see Figure 14).

In this state, as shown by arrow F in Figure 14, if the valve unit 15 is inserted further and the base member-side engagement portion 45 of the base member engages with the main engagement portion 26 of the seal member 20, the base member will be positioned inside the retaining portion 27 (here, the tubular portion 41 of the lower member 40 that constitutes the base member is positioned inside the retaining portion 27).The base member prevents the retaining portion 27 of the seal member 20 from bending inward into the seal member 20, restricting its diameter reduction, allowing the valve unit 15 to be firmly fixed to the case opening 3 via the seal member 20.As a result, a release valve 10 can be obtained that is easy to attach to the case 1 and difficult to remove from the case 1.

15, the coil spring 90 held in a compressed state within the base member biases the valve body 70 toward the valve seat forming member 50, causing the seal protrusion 73 on the back side of the flange portion 72 of the valve body 70 to abut against the valve seat 53, blocking the vent hole 52. Furthermore, the cap 80 integrated with the valve body 70 is biased toward the cover member 30 via the coil spring 90, causing the seal flange portion 85 to abut against the front side of the flange portion 32 of the cover member 30, blocking the multiple openings 66 in the upper member 60.

When gas is generated inside the case due to the power storage device supplying 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, etc., gas is generated due to a chemical reaction in the electrolyte), the system operates as follows.

In other words, when the pressure in the internal space R1 of the case 1 increases and exceeds the biasing force of the coil spring 90, which serves as the biasing means, the valve body 70 slides in a direction away from the valve seat forming member 50 against the biasing force of the biasing means, and its flange portion 72 moves away from the valve seat 53.

16, the vent hole 52 in the valve seat forming member 50 opens, and the cap 80 integrated with the valve body 70 moves away from the front side of the cover member 30 in conjunction with the valve body 70, opening the multiple openings 66 in the upper member 60. As a result, the internal space R1 and external space R2 of the case 1 are connected via the vent hole 52 in the valve seat forming member 50 and the multiple openings 66 in the upper member 60.

As a result, as shown by arrow L in Figure 16, gas in the internal space R1 of the case 1 passes through the case opening 3, the ventilation hole 52 in the valve seat forming member 50, and the opening 66 in the upper member 60 and is exhausted to the external space R2 of the case 1, thereby releasing (reducing) the pressure within the case 1.

In addition, in this embodiment, a protrusion (pressure protrusion 28) is provided on the inner surface of the sealing member 20, and this pressure protrusion 28 is configured to be pressed against the base member in a fixed state in which the base member side engagement portion 45 of the base member engages with the main engagement portion 26 of the sealing member 20, thereby expanding the diameter of the anti-slip portion 27.

According to this aspect, in the fixed state in which the base member side engaging portion 45 of the base member engages with the main engaging portion 26 of the sealing member 20, the base member presses against the anti-slip portion 27, causing it to expand in diameter, thereby more firmly fixing the sealing member 20 to the case opening 3.

Furthermore, in this embodiment, the valve body 70 has a flange portion 72 that moves toward and away from the valve seat 53, and the base member has a lower member 40 on which the valve seat 53 is provided and an upper member 60 that is assembled to the lower member 40, with a cylindrical portion 67 formed on the upper member 60 side, and a shaft portion 71 that is inserted into the cylindrical portion 67 and supported for sliding movement formed on the flange portion 72, and the biasing means consists of a coil spring 90, one end of which is supported by the flange portion 72 of the valve body 70 and the other end of which is supported by the upper member 60.

According to the above-described embodiment, the lower member 40 and the upper member 60 can be assembled while maintaining the coil spring 90, which serves as the biasing means, in a compressed state, thereby improving the ease of assembly of the valve unit 15. Specifically, by utilizing the shaft portion 71 of the valve body 70 and the tubular portion 67 that supports it, the coil spring 90 can be maintained in a position aligned with their axes (straight, not tilted), and the lower member 40 and the upper member 60 can be assembled while compressing the coil spring 90. This improves the ease of assembly of the valve unit 15. (If the coil spring 90's position cannot be maintained, the elastic force of the coil spring 90 will affect assembly, making it difficult to assemble.) Similar effects can also be achieved when a tubular portion is formed on the flange side and a shank that is inserted into the tubular portion and slidably supported is formed on the upper side.

(Another embodiment of the pressure release valve for an electricity storage device)
17 to 31 show other embodiments of the pressure release valve for an electricity storage device 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.

As shown in Figure 17, this pressure release valve 10A for an electricity storage device (hereinafter also referred to simply as "release valve 10A") has a fixed member 16 and a valve unit 17 that is slidably inserted inside the fixed member 16.

In addition, the fixing member 16 in this embodiment has a grommet 90A having an insertion portion 92 into the case opening 3, and a sealing member that is softer than the grommet 90A and is attached to the outer periphery of the grommet 90A to seal the outer peripheral edge of the case opening 3.A retaining portion 110 is formed on the insertion portion 92, and the valve unit 17 is inserted inside the insertion portion 92.

More specifically, the fixing member 16 in this embodiment is composed of a grommet 90A having the above-mentioned insertion portion 92 and anti-slip portion 110, a first sealing member 20A attached to the base end side of the grommet 90A and constituting the above-mentioned sealing member, and a cover member 120 attached to the tip end side of the grommet 90A.

On the other hand, the valve unit 17 has a vent hole 132 that connects the case internal space R1 and the case external space R2, a valve seat (first seal portion 86 described later) provided on its periphery, an engaged portion that engages with the fixed member at a predetermined position, a valve body 60A that opens and closes the vent hole 132, and a biasing means that biases the valve body 60A toward the valve seat.

More specifically, the valve unit 17 in this embodiment is composed of a pushing member 130 that can be pushed into the grommet 90A and restricts the deflection deformation of the retaining portion 110 toward the base member, the valve body 60A, and a cap member 140 that supports one end 5a of the coil spring 5 and pushes the pushing member 130 through the second seal member 80A.

The pushing member 130 also consists of a pushing member main body 130A and a second sealing member 80A attached to the pushing member main body 130A.

Furthermore, in this embodiment, the pushing member 130 constituting the valve unit 17 is inserted inside the insertion portion 91 of the grommet 90A so as to be able to slide from a temporary holding position in the temporary holding state to a permanent fixing position in the permanent fixing state, and the pushing member 130 has a first seal portion 86A which forms a valve seat against which the valve body 60A contacts and separates, and a second seal portion 87 which slides against the inner circumference of the insertion portion 92.

In addition, the "engaged portion" in the present invention has different shapes, structures, and layouts for temporary holding of the valve unit 17 relative to the fixed member 16 and for permanent fixing of the valve unit 17 relative to the fixed member 16.

That is, in this embodiment, the "engaged portion" for temporary retention refers to the engaging claw 145 and the base end of the peripheral wall 131, as shown in Figure 26, which are described below, and these engage with the temporary engagement surface 103 and receiving portion 113, respectively, to hold the valve unit 17 in a temporary retention state relative to the fixing member 16. Note that in this embodiment, the temporary engagement surface 103 and receiving portion 113 form the "temporary engagement portion" of the present invention, which will be described below.

On the other hand, in this embodiment, the "engaged portion" for this fixation refers to the engaging claw 145 (see Figure 27), the engaging claw 134 (see Figure 28), and the protrusion 135 (see Figure 29).

Then, as shown in Figure 27, the engagement claw 145 engages with the main engagement surface 107, which will be described later; as shown in Figure 28, the engagement claw 134 engages with the engagement protrusion 114, which will be described later; and, as shown in Figure 29, the tip of the extension direction of the protrusion 135 abuts and engages with the lower end surface of the positioning groove 115, which will be described later (note that the abutment of the protrusion 135 with the positioning groove 115 also serves to regulate the pushing of the valve unit 17 into the fixing member 16), thereby maintaining the valve unit 17 in a main fixed state relative to the fixing member 16.

In other words, in this embodiment, the main engagement surface 107, the engagement protrusion 114, and the positioning groove 115 form the "main engagement portion" described later in this invention.

23, the pushing member 130 is formed by assembling the two parts, the pushing member main body 130A and the second seal member 80A, and the assembly 17A is formed by assembling the two parts, the grommet 90A and the first seal member 20A. Furthermore, as shown in FIG. 19, the pushing member 130 and the assembly 17A are assembled to form the assembly 18A.

First, we will explain grommet 90A with reference to Figures 19 and 23, etc.

More specifically, the grommet 90A has a generally cylindrical insertion portion 91 that is inserted into the case opening 3, a generally annular bottom plate 93 that extends radially outward from the outer peripheral surface of the insertion portion 91 near the tip, a generally annular ceiling plate 94 that is also disposed opposite the bottom plate 93 at a predetermined distance, and multiple connecting pieces 95 that connect the two plates 93, 94 to each other. The insertion portion 91 also has a protrusion 91a that protrudes a predetermined height from the inner peripheral edge of the bottom plate 93 toward the ceiling plate 94.

Each connecting piece 95 is plate-shaped and extends radially across each plate portion 93, 94, with all connecting pieces 95 extending in the same direction. The opening 97 is provided between adjacent connecting pieces 95, 95 in the circumferential direction and the bottom plate portion 93 and ceiling plate portion 94. This opening 97 radially connects the internal and external spaces of the grommet 90A.

Furthermore, a first plate-like piece 98 extending in the same direction as each connecting piece 95 is provided between each of the connecting pieces 95 located at two radially opposing positions on both plate portions 93, 94. Furthermore, the first plate-like piece 98 and the connecting pieces 95, 95 located on both sides thereof are connected to each other by a second plate-like piece 99 located closer to the ceiling plate portion 94 and extending across each piece 95, 98, and these portions as a whole form a roughly lattice shape.

In addition, a third plate-like piece 100 protrudes from the outer surface of each of a pair of connecting pieces 95, 95, which are arranged perpendicular to the pair of first plate-like pieces 98, 98, perpendicular to the extension direction of the connecting pieces 95. Furthermore, a fourth plate-like piece 101 protrudes from both sides of the base end of each third plate-like piece 100.

In addition, the locking claws 128 of the cover member 120 are designed to engage with the base end surfaces (back surfaces of the base ends) of the first plate-shaped piece 98 and the third plate-shaped piece 100 (see Figure 26).

In addition, notches 102 are formed on the inner peripheral edge of the ceiling plate portion 94 at the locations where the first plate piece 98 and the second plate piece 99 are provided, and at the locations where the third plate piece 100 and the fourth plate piece 101 are provided, allowing the engagement piece 144 of the cap member 140 to be inserted. Here, four notches 102 are formed at equal intervals around the circumference.

In addition, a temporary engagement surface 103 is provided on the back surface of the ceiling plate portion 94, at the inner peripheral edge of the notch 102, with which the engagement claw 145 of the cap member 140 engages, temporarily holding the cap member 140 in a protruding state from the surface of the ceiling plate portion 94 of the grommet 90A (see Figure 25).

Positioning protrusions 104, which are inserted into positioning holes 123a (see Figure 20) of the cover member 120, protrude from the surface of the outer peripheral edge of the ceiling plate portion 94 at positions corresponding to the notches 102. Furthermore, guide grooves 105, which guide the guide ribs 121a of the cover member 120, are formed between adjacent positioning protrusions 104, 104 in the circumferential direction on the outer peripheral edge of the ceiling plate portion 94.

In addition, a permanent engagement protrusion 106 protrudes from the inner surface of the second plate-shaped piece 99 at a position spaced from the temporary engagement surface 103, and from the inner surface of the connecting piece 95 from which the third plate-shaped piece 100 protrudes at the same height as the second plate-shaped piece 99.

The back surface of each main engagement protrusion 106 forms a main engagement surface 107. As shown in Figure 27, the engagement claws 145 of the cap member 140 engage with the main engagement surface 107, thereby main engaging the cap member 140 with the grommet 90A such that the surface of the ceiling plate 141 of the cap member 140 is flush with the surface of the ceiling wall 123 of the cover member 120 (the cap member 140 does not protrude from the ceiling surface of the grommet 90A or the cover member 120).

A pair of parallel slits 109, 109 are formed at the axial base end of the insertion portion 91, and a flexible retaining portion 110 is formed through the pair of slits 109, 109. In this embodiment, four retaining portions 110 are formed at equal intervals around the circumference of the insertion portion 91.

An engagement portion 111 protrudes from the outer periphery of the tip of each retaining portion 110 in the extension direction, engaging with the rear peripheral edge of the case opening 3. The outer surfaces of the base and tip of the engagement portion 111 are tapered, with the apex as the boundary. Furthermore, a raised portion 112 is provided on the inner periphery of the tip of the retaining portion 110, protruding radially inward from the insertion portion 91.

When the cap member 140 is temporarily held in the grommet 90A and the pusher member 130 is not pushed in by the cap member 140, the peripheral wall 131 of the pusher member body 130A is not positioned inside the raised portion 112 (see Figure 26), and the raised portion 112 and the peripheral wall 131 are radially spaced apart. Therefore, each retaining portion 110 can bend and deform radially inward of the insertion portion 91, allowing the insertion portion 91 to be inserted from the front side to the back side of the case opening 3 (see Figure 26).

27, when the cap member 140 is fully engaged with the grommet 90A, the cap member 140 pushes the pusher member 130 in, positioning the peripheral wall 131 of the pusher member body 130A inside the raised portion 112, which moves close to the peripheral wall 131. This prevents each retaining portion 110 from bending radially inward from the insertion portion 91, preventing the insertion portion 91 from being pulled out of the case opening 3 and holding the grommet 90A in the case opening 3.

In addition, a plurality of receiving portions 113, which form protrusions and extend a predetermined length in the circumferential direction, are provided on the inner peripheral surface of the insertion portion 91, closer to the base end than the bottom plate portion 93, at a predetermined height. When the cap member 140 is temporarily held in the grommet 90A, these receiving portions 113 receive the base end of the peripheral wall 131 of the pushing member main body 130A (see Figure 24), and prevent the peripheral wall 131 of the pushing member main body 130A from being positioned inside the raised portion 112 of the retaining portion 110.

Furthermore, multiple engagement protrusions 114 protrude from the inner surface of the insertion portion 91 closer to the base end than the bottom plate portion 93, at a position closer to the base end (tip in the extension direction) of the insertion portion 91 than the receiving portion 113.

Then, when the cap member 140 is fully engaged with the grommet 90A and the pushing member 130 is pushed in through the second seal member 80A, and the peripheral wall 131 of the pushing member main body 130A is positioned inside the raised portion 112 of the retaining portion 110 (see Figure 27), the predetermined engaging claws 134 (see Figure 21) provided on the pushing member main body 130A can engage with each engaging protrusion 114, holding the pushing member 130 in that position.

In addition, multiple positioning grooves 115, each having a concave groove shape and extending along the axial direction, are formed at predetermined positions on the inner peripheral surface of the insertion portion 91, closer to the base end than the bottom plate portion 93. A predetermined ridge 135 (see Figure 22) on the pushing member 130 is inserted into each positioning groove 115, serving as a pushing guide when the pushing member 130 is pushed into the grommet 90A and restricting the rotation of the pushing member 130 relative to the grommet 90A. Furthermore, the ridge 135 abuts against the lower end surface, restricting the pushing of the pushing member 130 into the grommet 90A (see Figure 29).

Next, with reference to Figures 17 and 23, we will explain the first sealing member 20A that is attached to the base end side of the grommet 90A.

The first seal member 20A in this embodiment has a generally circular plate-shaped main body 21. From the outer periphery of this main body 21, annular thin-walled seal flanges 22A and 24A extend diagonally outward and are spaced apart from each other. One seal flange 22A elastically abuts against the front peripheral edge of the case opening 3 (see Figure 27), and the other seal flange 24A elastically abuts against the back surface of the bottom plate 93 of the grommet 90A (see Figure 23).

In addition, multiple annular sealing protrusions 29A protrude from the back and front surfaces of the main body 21.

As shown in Figure 23, by placing the first sealing member 20A on the outer periphery of the tip of the insertion portion 91 of the grommet 90A, the inner peripheral edge of the main body portion 21 abuts against the outer periphery of the tip of the insertion portion 91, and the pair of sealing protrusions 29A, 29A on the surface side of the main body portion 21 abuts against the back surface of the bottom plate portion 93 of the grommet 90A, thereby attaching the first sealing member 20A to the grommet 90A.

In addition, when the insertion portion 91 of the grommet 90A is inserted from the front side of the case opening 3, and each engagement portion 111 on the outer periphery of the flexible piece engages with the rear peripheral edge of the case opening 3, as shown in Figure 27, when the release valve 10A is attached to the case opening 3, the seal flange portion 22A of the first seal member 20A abuts against the front peripheral edge of the case opening 3, and a pair of seal protrusions 29A, 29A on the rear side of the main body portion 21 abut.

Next, with reference to Figures 20 and 25, etc., we will explain the cover member 120 that is attached to the tip side of the grommet 90A.

In this embodiment, the cover member 120 has a generally cylindrical peripheral wall 121 and a ceiling wall 123 that protrudes in the shape of an annular flange from the inner periphery of the tip of the peripheral wall 121. The peripheral wall 121 is positioned outside the surface opening of the opening 97 of the grommet 90A, and the ceiling wall 123 is positioned on the front side of the ceiling plate portion 94 of the grommet 90A.

In addition, multiple positioning holes 123a are formed at equal intervals around the periphery of the outer peripheral edge of the ceiling wall 123. A positioning protrusion 104 (see Figure 19) provided on the grommet 90A is inserted into each positioning hole 123a, restricting the rotation of the cover member 120 relative to the grommet 90A.

Furthermore, multiple guide ribs 121a are provided at equal intervals around the inner periphery of the peripheral wall 121, extending along the axial direction of the peripheral wall 121. Each guide rib 121a is inserted into a guide groove 105 provided in the grommet 90A to guide the cover member 120 when it is assembled to the grommet 90A and to regulate the rotation of the cover member 120 relative to the grommet 90A.

Furthermore, the base end of the peripheral wall 121 is formed with a plurality of approximately L-shaped slits 124 consisting of grooves extending in the circumferential direction and grooves extending in the axial direction, and a plurality of long, deformable plate-like pieces 125 are provided via each slit 124. As shown in Figure 31, each plate-like piece 125 has a thin, hinge-like fixed end 126 that can open and close a roughly elongated hole-shaped opening 127.

Furthermore, multiple locking claws 128 protrude from the inner periphery of the base end of the peripheral wall 121. As shown in Figure 26, these locking claws 128 are designed to lock onto the base end surfaces of the first plate piece 98 and the third plate piece 100 of the grommet 90A.

When the cover member 120 is attached to the grommet 90A, a gap 129 is formed between the base end of the peripheral wall 121 of the cover member 120 and the bottom plate portion 93 of the grommet 90A (see Figures 27 and 28), and the gap 129 is connected to the opening 97.

Next, with reference to Figures 21 and 23, etc., we will explain the pushing member 130, which can be pushed into the grommet 90A and regulates the deflection deformation of the retaining portion 110 toward the base member.

The pushing member body 130A constituting the pushing member 130 has a generally cylindrical peripheral wall 131. The inner peripheral opening of this peripheral wall 131 forms an air vent 132 that connects the case internal space R1 and the case external space R2.

A pair of parallel slits 133a, 133a are formed in the peripheral wall 131 from the axial base edge toward the axial tip, and a flexible piece 133 is formed through the pair of slits 133a, 133a. Multiple flexible pieces 133 are formed at predetermined intervals around the peripheral wall 131.

Furthermore, an engagement claw 134 protrudes from the outer periphery of the tip end in the extension direction of each flexible piece 133. When the pushing member 130 is pushed through the second seal member 80A and the peripheral wall 131 of the pushing member 130 is positioned inside the raised portion 112 of the retaining portion 110, each engagement claw 134 can engage with the engagement protrusion 114 provided on the grommet 90A, thereby holding the pushing member 130 in the above position.

Furthermore, multiple ridges 135 extend axially at equal circumferential intervals on the outer periphery of the peripheral wall 131. Each ridge 135 is inserted into a predetermined positioning groove 115 provided in the grommet 90A to guide the pushing member 130 into the grommet 90A, restrict the rotation of the pushing member 130 relative to the grommet 90A, and, by abutting against the lower end surface of the positioning groove 115, restrict the pushing member 130 from being pushed into the grommet 90A (see Figure 29).

The peripheral wall 131 also has a mounting protrusion 136 at its tip for mounting the second seal member 80A. A roughly cross-shaped cap receiving portion 137 is provided on the inner periphery of the base end of the peripheral wall 131. As shown in Figure 21, the cap receiving portion 137 has a valve body receiving portion 138 formed on its upper surface for receiving the bottom of the valve body 60A.

Next, with reference to Figures 17 and 23, etc., we will explain the second sealing member 80A that is attached to the pushing member main body 130A.

In this embodiment, the second seal member 80A has a generally cylindrical tubular portion 81A, with an attachment groove 85A formed on its inner periphery. As shown in Figure 23, the attachment protrusion 136 of the pushing member 130 is inserted into this attachment groove 85A, thereby attaching the second seal member 80A to the outer periphery of the tip of the pushing member main body 130A.

A first seal portion 86, which is an annular protrusion and serves as a valve seat, protrudes from the inner peripheral edge of the axial tip of the cylindrical portion 81A. The second seal surface 65A provided on the valve body 60A comes into contact with and separates from this first seal portion 86, thereby opening and closing the vent port 132 (see Figures 27 and 30).

Furthermore, a second seal portion 87 in the form of an annular protrusion protrudes from the outer periphery of the base end of the cylindrical portion 81A. As shown in Figures 27 and 28, this second seal portion 87 elastically abuts against the inner circumferential surface of the insertion portion 91 of the grommet 90A, sealing the gap between the insertion portion 91 and the second seal member 80A.

Next, with reference to Figures 22 and 24, we will explain the cap member 140, which supports one end 5a of the coil spring 5 and pushes the pushing member 130 through the second sealing member 80A.

The cap member 140 in this embodiment has a ceiling plate 141 having an approximately circular plate shape, a peripheral wall 142 extending vertically from the outer peripheral edge of the ceiling plate 141 by a predetermined length, and a tubular portion 143 having an approximately cylindrical shape protruding from the center of the back surface of the ceiling plate 141.

25, one end of the coil spring 5 is inserted inside the cylindrical portion 143, and one end 5a of the coil spring 5 is supported at the center of the back surface of the ceiling plate 141. Also, as shown in Figures 27 and 30, the cylindrical portion 143 is arranged on the inner periphery of the cylindrical portion 61A of the valve body 60A, and guides the sliding movement of the valve body 60A as it slides up and down relative to the cap member 140.

Furthermore, multiple (four in this example) engagement pieces 144 extend from the leading end of the peripheral wall 142 at equal intervals in the circumferential direction. Each engagement piece 144 extends from the leading end of the peripheral wall in a direction away from the ceiling plate 141 and is folded back via a curved bend 144a in a direction approaching the ceiling plate 141, forming a roughly U-shape overall.

Furthermore, an engagement claw 145 protrudes from the outer periphery of the tip of each engagement piece 144. As shown in Figure 25, the engagement claw 145 engages with the temporary engagement surface 103 of the grommet 90A, thereby temporarily holding the cap member 140 to the grommet 90A. On the other hand, as shown in Figure 27, the engagement claw 145 engages with the main engagement surface 107 of the main engagement protrusion 106 of the grommet 90A, thereby finally engaging the cap member 140 to the grommet 90A.

Furthermore, as shown in Figure 24, multiple long pressure plates 146 are vertically attached to the back surface of the ceiling plate 141 at a location slightly offset radially inward from the outer peripheral edge of the ceiling plate 141.

Each pressing plate 146 presses the outer peripheral edge portion of the axial tip side of the tubular portion 81A of the second sealing member 80A, and when the cap member 140 is pressed into the grommet 90A, it indirectly presses the pushing member 130 via the second sealing member 80A.

In addition, plate-shaped ribs 147, 148 protrude from the outer surface of each pressure plate 146 at the center of its width, perpendicular to the pressure plate 146.

The rib 147 is provided between a predetermined engagement piece 144 and a pressure plate 146 at a position corresponding to the engagement piece 144, and at the tip side of the rib 147, a receiving portion 147a is formed to receive the protrusion 91a of the insertion portion 91 of the grommet 90A (see Figures 24 and 27).

In addition, as shown in Figure 22, a receiving portion 148a is formed at the tip of the rib 148, which is located between circumferentially adjacent engagement pieces 144, 144, to receive the protrusion 91a of the insertion portion 91 of the grommet 90A.

Next, we will explain the valve body 60A with reference to Figures 17 and 24, etc.

The valve body 60A in this embodiment has a tubular portion 61A having an approximately cylindrical shape, a flange portion 62A having an approximately circular plate shape that protrudes from the outer periphery of the tubular portion 61A near the tip end, and a spring support portion 63A having an approximately hat shape that is provided on the inner periphery of the base end of the tubular portion 61A.

The cylindrical portion 61A is disposed on the outer periphery of the cylindrical portion 143 of the pusher member main body 130A and guides the up-down sliding movement of the valve body 60A (see Figures 27 and 30). The spring support portion 63A is inserted into the inner periphery of the other end of the coil spring 5 and abuts against the other end 5b of the coil spring 5 to support the other end of the coil spring 5 (see Figure 27).

Furthermore, an annular protrusion protrudes from the back surface of the outer peripheral edge of the flange portion 62A, and the back surface of the annular protrusion forms a second sealing surface 65A that abuts against the peripheral edge of the ventilation opening 132 (approaching and separating from the first sealing portion 86).

As shown in Figure 27, the second sealing surface 65A is positioned closer to the external space R2 of the case 1 than the first sealing surface 28A, which consists of the back surface of the sealing flange portion 22A and the back surfaces of the pair of sealing protrusions 29A, 29A.

Furthermore, as shown in Figure 28, when the second sealing surface 65A is at its maximum distance from the first sealing portion 86, the second sealing surface 65A is configured to be positioned closer to the case external space R2 than the inner edge portion 97a of the opening 97 provided in the grommet 90A, which is closest to the case internal space R1.

(Action and effect)
Next, the function and effect of the release valve 10A having the above-described structure will be described.

First, we will explain the assembly process of the release valve 10A.

First, the second seal member 80A is attached to the outer periphery of the tip of the pushing member body 130A by inserting the mounting protrusion 136 of the pushing member body 130A into the mounting groove 85A of the second seal member 80A, thereby assembling the pushing member 130 (see Figure 23). Next, the first seal member 20A is attached to the grommet 90A by placing it on the outer periphery of the tip of the insertion portion 91 of the grommet 90A, thereby assembling the assembly 17A (see Figure 23).

Next, the pushing member 130 and assembly 17A are assembled. That is, the protrusions 135 of the pushing member body 130A are aligned with the corresponding positioning grooves 115 of the grommet 90A, and the pushing member 130 is pushed into the grommet 90A. The protrusions 135 inserted into the positioning grooves 115 guide the pushing member 130 as it is pushed in.

Then, the base end of the peripheral wall 131 of the pushing member main body 130A is received by the receiving portion 113 of the grommet 90A, restricting further pushing of the pushing member 130 and restricting rotation of the pushing member 130 relative to the grommet 90A, thereby assembling the assembly 18A (see Figure 24).

When the assembly 18A is assembled, the base end of the peripheral wall 131 of the pushing member main body 130A is retracted toward the tip of the insertion portion 91 of the grommet 90A rather than the base end of the insertion portion 91, and since the peripheral wall 131 of the pushing member main body 130A is not positioned inside the raised portion 112 of the anti-slip portion 110, each anti-slip portion 110 can be flexibly deformed inward toward the insertion portion 91.

Next, the valve body 60A is inserted through the upper opening of the grommet 90A, and the outer peripheral edge of the flange portion 62A of the valve body 60A is abutted against the first seal portion 86 of the second seal member 80A to support the valve body 60A. The other end of the coil spring 5 is then supported by the spring support portion 63A of the valve body 60A.

The corresponding engagement pieces 144 of the cap member 140 are then aligned with the respective notches 102 of the grommet 90A, and the cap member 140 is pressed into the grommet 90A. One end of the coil spring 5 is then inserted and supported within the cylindrical portion 143 of the cap member 140, the engagement claws 145 of each engagement piece 144 engage with the provisional engagement surface 103 of the grommet 90A, and the base end of the peripheral wall 131 engages (is received by) the receiving portion 113, temporarily holding the cap member 140 in place on the grommet 90A (see Figure 25).

Then, align the positioning protrusions 104 of the grommet 90A with the corresponding positioning holes 123a of the cover member 120, and press the cover member 120 into the grommet 90A. The guide ribs 121a inserted into the guide grooves 105 guide the cover member 120 as it is pressed into the grommet 90A.

Then, each locking claw 128 of the cover member 120 locks onto the base end surface of the first plate piece 98 and the third plate piece 100 of the grommet 90A, and each positioning protrusion 104 of the grommet 90A is inserted into the corresponding positioning hole 123a of the cover member 120, thereby attaching the cover member 120 to the grommet 90A in a state where rotation is restricted (see Figure 26).

In the above state, the cap member 140 is temporarily held in the grommet 90A, the pushing member 130 is not being pushed by the cap member 140, and the peripheral wall 131 of the pushing member 130 is not positioned inside the raised portion 112, so each anti-slip portion 110 can be flexibly deformed radially inward of the insertion portion 91.

Then, as shown in the insertion direction F in Figure 26, the release valve 10A is inserted from the front side of the case opening 3. As a result, the tapered outer surface of the base of the engagement portion 111 of the grommet 90A is pressed against the inner periphery of the case opening 3, causing the retaining portion 110 to bend and deform inward toward the insertion portion 91.

Then, the release valve 10 is pushed into the case opening 3 until the seal flange portion 22A of the first seal member 20A and the pair of seal protrusions 29A, 29A abut against the front peripheral edge of the case opening 3. When the top of the engagement portion 111 escapes through the back opening of the case opening 3, the retaining portion 110 elastically returns to its original position, and the outer surface of the tapered tip of the engagement portion 111 engages with the back peripheral edge of the case opening 3, temporarily fixing the release valve 10A to the case opening 3.

From the above state, the cap member 140 is pushed into the grommet 90A in the insertion direction F. This causes the multiple pressure plates 146 of the cap member 140 to press against the second seal member 80A, causing the push-in member 130 to be pushed in through the second seal member 80A.

Then, when the pushing member 130 is pushed in until the tip of the protrusion 135 abuts against the lower end surface of the positioning groove 115, the base end of the peripheral wall 131 of the pushing member body 130A is positioned inside the raised portion 112 of the retaining portion 110 of the grommet 90A, and the engagement claw 134 of the flexible piece 133 of the pushing member 130 engages with the engagement protrusion 114 of the grommet 90A (see Figure 28). At the same time, the engagement claw 145 of the cap member 140 engages with the main engagement surface 107 of the main engagement protrusion 106 (see Figure 27). Furthermore, the tip of the protrusion 135 abuts against and engages with the lower end surface of the positioning groove 115 (see Figure 29).

As a result, the cap member 140 fully engages with the grommet 90A, and the release valve 10A can be fully fixed to the case opening 3, as shown in Figure 27.

27, the peripheral wall 131 of the push-in member 130 is located inside the raised portion 112 of the retaining portion 110 of the grommet 90A, preventing each retaining portion 110 from bending and deforming inwardly of the insertion portion 91. As a result, the grommet 90A is held in place against the case opening 3, and the release valve 10A can be maintained in a fixed state at the case opening 3.

24 and 27, the cap member 140 has a generally U-shaped engagement piece 144, and a receiving portion 147a is formed between the base end 144b of the engagement piece 144 and the pressure plate 146 to receive the protrusion 91a of the insertion portion 91 of the grommet 90A. When the valve unit 17 is fully fixed to the fixing member 16 and the protrusion 91a is received in the receiving portion 147a, the base end 144b of the engagement piece 144 is positioned slightly spaced from the outer periphery of the protrusion 91a of the cylindrical wall portion 91.

Therefore, when the valve unit 17 is temporarily held relative to the fixed member 16, the protrusion 91a is easily received within the receiving portion 147a. Furthermore, if a force acts in a direction that moves the valve unit 17 away from the fixed member 16 while the valve unit 17 is permanently fixed to the fixed member 16, the engaging piece 144 bends and deforms inwardly of the cover member, and its base end 144b abuts against the protrusion 91a, making it difficult for the protrusion 91a to come out of the receiving portion 147a.

In other words, it becomes easier to temporarily hold the valve unit 17 in the fixing member 16, and once the valve unit 17 is permanently fixed to the fixing member 16, it becomes more difficult for the valve unit 17 to come off the fixing member 16.

Furthermore, as shown in Figure 26, when the valve unit 17 is temporarily held in the fixed member 16, the second seal portion 87 provided on the second seal member 80A abuts against the inner circumference of the insertion portion 91 of the grommet 90A, thereby improving the sealing performance in the temporarily held state.

Furthermore, in the state shown in Figure 27, the coil spring 5 held in a compressed state between the cap member 140 and the valve body 60A biases the second seal surface 65A of the valve body 60A toward the first seal portion 86 provided on the second seal member 80A, causing the second seal surface 65A to abut against the first seal portion 86 and closing the air vent 132.

When the pressure in the internal space R1 of the case 1 rises and exceeds the spring force of the coil spring 5, the valve body 60A slides against the spring force in a direction away from the first seal portion 86, and the second seal surface 65A moves away from the first seal portion 86.

30, the ventilation hole 132 provided in the push-in member 130 opens, and the case internal space R1 and the case external space R2 communicate with each other through this ventilation hole 132. In this embodiment, the case internal space R1 and the housing internal space R3 communicate with each other through the ventilation hole 132, and the housing internal space R3 and the case external space R2 communicate with each other through the opening 97, the gap 129, etc.

Therefore, gas and other vapors in the case internal space R1 flow into the housing internal space R3 through the ventilation opening 132, pass through the gap between the engaging pieces 144 of the cap member 140, pass over the inner edge 97a of the opening 97 of the grommet 90A (the tip of the protruding portion 91a of the insertion portion 91), pass through the opening 97, and then are exhausted from the gap 129 into the case external space R2 (see the arrow in Figure 30). As a result, the pressure inside the case can be released.

In this embodiment, the cover member 120 has a structure including a peripheral wall 121 and a plate-like piece 125 formed on the peripheral wall 121 so as to be able to flex and deform through a slit 124. Therefore, for example, if a large amount of gas is generated in the case internal space R1 and the pressure in the case internal space R1 rises suddenly, the plate-like piece 125 flexes and deforms, as shown in Figure 31, and the gas can be quickly discharged from its opening portion 127.

In this release valve 10A, when the fixing member 16 and valve unit 17 are inserted into the case opening 3 in a temporary holding state in which the temporary engagement surface 103 and receiving portion 113, which are temporary engagement portions, are engaged with the engaging claw 145 and the base end of the peripheral wall 131, which are engaged portions for temporarily holding the valve unit, the anti-slip portion 110 can bend toward the inside of the fixing member, so that the valve unit 17 can be easily inserted into the case opening 3 together with the fixing member 16.

In this state, if the valve unit 17 is inserted further into the fixing member 16 and the main engagement surface 107, engagement protrusion 114, and positioning groove 115 engage with the engagement claw 145, engagement claw 134, and protrusion 135, which are the engaged portions for main fixing of the valve unit (see Figures 27-29), the valve unit 17 will be positioned inside the retaining portion 110, which will no longer bend toward the inside of the fixing member and will restrict its diameter reduction, allowing the valve unit 17 to be firmly fixed to the case 1 via the fixing member 16. As a result, a release valve 10A can be obtained that is easy to attach to the case 1 and will not easily come off from the case 1.

In addition, the fixing member 16 in this embodiment has a grommet 90A having an insertion portion 92 into the case opening 3, and a sealing member (first sealing member 20A) that is softer than the grommet 90A and is attached to the outer periphery of the grommet 90A to seal the outer peripheral edge of the case opening 3.A retaining portion 110 is formed on the insertion portion 92, and the valve unit 17 is inserted inside the insertion portion 92.

In the above-described embodiment, the retaining portion 110 is formed on the insertion portion 91 of the grommet 90A, which is harder than the first seal member 20A. This makes it easier to determine whether the retaining portion 110 has flexed or deformed, compared to when the retaining portion is provided on a soft seal member, and makes it clear that the release valve 10A has been fully secured to the case opening 3. Furthermore, the retaining force of the retaining portion 110 against the case opening 3 can be improved compared to when the retaining portion is provided on a seal member.

Furthermore, in this embodiment, the pushing member 130 constituting the valve unit 17 is inserted inside the insertion portion 92 of the grommet 90A so as to be able to slide from a temporary holding position in the temporary holding state to a permanent fixing position in the permanent fixing state, and the pushing member 130 has a first seal portion 86A which forms a valve seat against which the valve body 60A contacts and separates, and a second seal portion 87 which slides against the inner circumference of the insertion portion 92.

According to the above aspect, the second seal portion 87 slides against the inner circumference of the insertion portion 92 from the temporary holding state to the final fixed state of the pushing member 130, thereby maintaining the sealing ability between the fixing member 16 and the valve unit 17 (particularly, the sealing ability between the inner circumference of the insertion portion 91 of the grommet 90A and the outer circumference of the peripheral wall 131 of the pushing member main body 130A), thereby making it difficult for foreign matter such as water or debris to enter the valve unit 17.

(Still another embodiment of the pressure release valve for an electricity storage device)
32 shows yet another embodiment of the pressure release valve for an electricity storage device according to the present invention. Note that parts that are essentially the same as those in the previous embodiment are given the same reference numerals and their description will be omitted.

As shown in Figure 32, the pressure release valve 10B for an electricity storage device of this embodiment (hereinafter also simply referred to as "release valve 10B") differs from the embodiment shown in Figures 17 to 31 in the shape of the cover member 120B.

In other words, in this embodiment, the cover member 120B has openings 122 formed between the tip of the peripheral wall 121 and the ceiling wall 123, and multiple openings 122 are formed in the circumferential direction of the peripheral wall 121 and the ceiling wall 123. Furthermore, each opening 122 is connected to the internal space of the cover member 120B.

In this embodiment, for example, if a large amount of gas is generated in the case internal space R1 and the pressure in the case internal space R1 rises suddenly, the gas can be quickly discharged through the multiple openings 122.

The present invention is not limited to the above-described embodiments, 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.

1 Case 3 Case opening 10, 10A, 10B Pressure release valve for power storage device (Release valve)
15, 17 Valve unit 16 Fixing member 18 Push-in member 20 Sealing member 25 Provisional engagement portion 26 Full engagement portion 27 Anti-slip portion 28 Pressing protrusion 40 Lower member 45 Base member side engagement portion 50 Valve seat forming member 52, 132 Vent 53 Valve seat 60 Upper member 67 Cylinder portion 70 Valve body 71 Shaft portion 72 Flange portion 80 Cap 80A Second sealing member 86 First sealing portion 87 Second sealing portion 90 Coil spring 90A Grommet 91 Insertion portion 110 Anti-slip portion

Claims (6)

A pressure release valve for an electricity storage device, which is attached to a case that houses the electricity storage device,
a fixing member that is inserted into and fixed to a case opening formed in the case;
a valve unit slidably inserted into the fixing member,
the valve unit includes a vent hole that connects the internal space and the external space of the case, a valve seat provided on the periphery of the vent hole, an engaged portion that engages with the fixed member at a predetermined position, a valve body that opens and closes the vent hole, and biasing means that biases the valve body toward the valve seat;
The fixing member includes:
a retaining portion that engages with the case;
a temporary engagement portion that is provided inside the fixing member and that engages with the engaged portion at a predetermined insertion position when the valve unit is inserted into the fixing member, and a full engagement portion that engages with the engaged portion at an insertion position deeper than the temporary engagement portion,
A pressure release valve for an electricity storage device, characterized in that the anti-slip portion is configured to bend inward in a temporary holding state in which the engaged portion is engaged with the temporary engaging portion, and to be configured so that the reduction in diameter is regulated by the valve unit in a final fixed state in which the engaged portion is engaged with the final engaging portion. The fixing member is
a grommet having an insertion portion into the case opening;
a sealing member that is softer than the grommet and is attached to the outer periphery of the grommet to seal the front peripheral edge of the case opening,
The pressure release valve for an electricity storage device according to claim 1 , wherein the retaining portion is formed in the insertion portion, and the valve unit is inserted into the insertion portion. a push-in member constituting the valve unit is inserted inside the insertion portion of the grommet so as to be slidable from a temporary holding position in the temporary holding state to a final fixing position in the final fixing state;
3. The pressure release valve for an electric storage device according to claim 2, wherein the pushing member has a first seal portion that forms the valve seat against which the valve body comes into contact and a second seal portion that comes into sliding contact with the inner periphery of the insertion portion. the fixing member is a cylindrical sealing member that is inserted into and fixed to a case opening formed in the case,
The valve unit is inserted into the inside of the seal member and fixed to the case via the seal member,
The valve unit includes:
a base member having the vent hole and the valve seat, and further having the engaged portion that engages with the seal member, the valve body being slidable relative to the base member;
an inner peripheral surface of the seal member is provided with the temporary engagement portion that engages with the engaged portion at a predetermined insertion position when the valve unit is inserted into the seal member, and the full engagement portion that engages with the engaged portion at an insertion position deeper than the temporary engagement portion,
The sealing member is provided with a retaining portion that engages with the case,
2. A pressure release valve for an electricity storage device as described in claim 1, wherein the anti-slip portion is configured to bend inward in a temporary holding state in which the engaged portion is engaged with the temporary engaging portion, and to be regulated in diameter reduction by the base member in a final fixed state in which the engaged portion is engaged with the final engaging portion. A protrusion is provided on the inner circumferential surface of the seal member,
5. The pressure release valve for an electricity storage device according to claim 4, wherein the protrusion is pressed against the base member in a fully fixed state in which the engaged portion is engaged with the fully engaging portion, thereby expanding the diameter of the retaining portion. The valve body has a flange portion that comes into contact with and separates from the valve seat,
the base member has a lower member provided with the valve seat and an upper member assembled to the lower member,
a cylindrical portion is formed on one of the flange portion and the upper member,
a shaft portion that is inserted into and slidably supported by the cylindrical portion is formed on the other of the flange portion and the upper member,
6. A pressure release valve for an electrical storage device according to claim 4 or 5, wherein the biasing means comprises a coil spring, is arranged on the outer periphery of the cylindrical portion, has one end supported by the flange portion of the valve body, and the other end supported by the upper member.