Gas exhaust device for power storage device

Abstract

To provide a gas discharge device for a power storage device capable of reliably removing a cap member from a base member when gas pressure rises while maintaining sealing performance between the base member and the cap member.SOLUTION: A gas discharge device 10 for a power storage device includes a base member 20, a cap member 50, and a seal member 70. The cap member 50 includes a lid portion 51, an elastic piece 59, and a claw portion 61. When the gas pressure is equal to or higher than a predetermined value, the elastic piece 59 is flexurally deformed outward and detached from the base member 20, and an engaged portion 33 and a seal member mounting portion 31 are provided on the outer periphery of the base member, and a restricting wall 35 is provided on the outer periphery of the sealing member 70 to restrict its expansion outside the seal member mounting portion 31.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gas discharge device for an electricity storage device, which discharges gas when the gas pressure at a gas discharge port of the electricity storage device is equal to or higher than a predetermined value. [Background technology]

[0002] For example, hybrid cars and electric cars use electricity storage devices such as batteries and capacitors. For example, when the electricity storage device is a battery such as a lithium-ion battery, gas may be generated due to a chemical reaction of the electrolyte. In this case, it is necessary to exhaust the gas from inside the electricity storage device to the outside of the electricity storage device.

[0003] For example, Patent Document 1 listed below describes a sealed lead-acid battery having a cylindrical liquid filling port protruding upward from an inner lid of the battery, a cap-shaped cap valve having a ceiling plate and a peripheral wall hanging down from the peripheral edge thereof and removably attached to the tip of the liquid filling port, and locking members are provided on the outer periphery of the upper part of the liquid filling port and on the inner periphery of the opening of the cap valve, making it difficult for the cap valve to come off.

[0004] Specifically, a protrusion (locking member) is provided on the outer periphery of the upper part of the inlet, the outer surface of which is tapered, and the lower end surface of which is a horizontal locking surface. A protrusion (locking member) is also provided on the inner periphery of the lower end of the peripheral wall of the cap valve, the outer surface of which is tapered, and the upper end surface of which is a horizontal locking surface. By placing the cap valve on the outer periphery of the upper part of the inlet, the locking surface of the protrusion on the inlet side and the locking surface of the protrusion on the cap valve side are locked together, and the cap valve is attached to the inlet. When the gas pressure in the lead-acid battery reaches or exceeds a predetermined value, the cap valve is removed from the inlet, and the gas in the lead-acid battery is discharged. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-315799 Summary of the Invention [Problem to be solved by the invention]

[0006] In the case of the sealed lead-acid battery of Patent Document 1, a locking member is provided on the outer periphery of the upper part of the liquid inlet and on the inner periphery of the opening of the cap valve, and the horizontal locking surfaces of both locking members are configured to lock with each other, making it difficult for the cap valve to come off from the liquid inlet. Therefore, even if the internal pressure of the storage battery increases, the cap valve is difficult to come off from the liquid inlet, making it difficult to discharge gas inside the storage battery. This is an inconvenience.

[0007] Therefore, an object of the present invention is to provide a gas exhaust device for an electricity storage device that can reliably remove the cap member from the base member when the gas pressure at the gas exhaust port of the electricity storage device increases while maintaining the sealing property between the base member and the cap member. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides a gas exhaust device for an electricity storage device that exhausts gas when a gas pressure at a gas exhaust port of the electricity storage device is equal to or higher than a predetermined value, the gas exhaust device comprising: a base member that is fixed to the gas exhaust port and has a passage therein that communicates with the gas exhaust port; a cap member that is removably attached to the base member so as to block an outlet of the passage in the base member; and a seal member that is disposed between the base member and the cap member and seals a gap between the base member and the cap member, the cap member having a lid portion that is disposed opposite the outlet of the passage in the base member and a claw portion that engages with the base member, and is configured such that when the gas pressure at the gas exhaust port is equal to or higher than a predetermined value, the engagement of the claw portion with the base member is released by the pressure received by the lid portion and the cap member is removed from the base member, the base member being provided with a seal member attachment portion to which the seal member is attached, and a restricting wall that is disposed on the outer periphery of the seal member and restricts the expansion of the seal member. Effect of the Invention

[0009] According to the present invention, when the gas pressure at the gas exhaust port of the electricity storage device reaches or exceeds a predetermined value, the lid portion of the cap member is pushed by the gas pressure, and the engagement of the claw portion with the base member is released by the pressure received by the lid portion, and the cap member is removed from the base member. At this time, the gas pressure also acts on the seal member and the seal member tries to expand, but the expansion is restricted by the restricting wall of the base member, and the seal member maintains the seal between the base member and the cap member, so that the gas pressure acts firmly on the lid portion of the cap member and the cap member can be reliably removed from the base member. Therefore, the seal between the base member and the cap member can be maintained, and when the gas pressure at the gas exhaust port rises, the cap member can be reliably removed from the base member, and gas can be discharged from the electricity storage device. [Brief description of the drawings]

[0010] [Figure 1] 1 is an exploded perspective view showing one embodiment of a gas discharge apparatus for an electricity storage device according to the present invention. [Diagram 2] 2 is a perspective view showing a state in which the components of the gas discharge apparatus for the electricity storage device are assembled. FIG. [Diagram 3] 4 is a front view of a base member constituting the gas discharge device for the electricity storage device. FIG. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] 13 is a bottom view of the base member with the seal member attached thereto. FIG. [Figure 7] 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 8] FIG. 3 is a cross-sectional view taken along the line BB of FIG. 2. [Figure 9] 9 is an explanatory cross-sectional view of the state in which the cap member is detached from the base member in the state shown in FIG. 8. FIG. [Figure 10] FIG. 2 is a perspective view illustrating a location where the gas discharge device for an electricity storage device according to the present invention is used. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (One embodiment of a gas discharge device for an electricity storage device) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, one embodiment of a gas discharge apparatus for an electricity storage device according to the present invention will be described with reference to the drawings.

[0012] As shown in FIG. 10, this gas discharge device 10 for an electricity storage device (hereinafter also simply referred to as "discharge device 10") is for discharging gas G when the gas pressure at the gas discharge port 6 (see FIGS. 7 to 9) of the electricity storage device 1 is equal to or higher than a predetermined value.

[0013] In this embodiment, a plurality of electricity storage devices 1 are arranged in a case 2. Here, two electricity storage devices 1 are arranged in each of the left and right regions in the case 2. A connector 3 communicating with the internal space of each electricity storage device 1 is attached to each of the electricity storage devices 1. A pair of electricity storage devices 1, 1 arranged in each of the left and right regions in the case 2 are connected to a common gas exhaust tube 4 via the connectors 3, 3.

[0014] The gas exhaust tubes 4 extend outward from the case 2 via tube holding members 5 made of rubber, sponge, or the like. That is, the gas exhaust tubes 4 extend outward from the case 2 from both the left and right side walls thereof.

[0015] 7 to 9, a gas exhaust port 6 is provided at the tip of each gas exhaust tube 4 in the extending direction. In this embodiment, the gas exhaust port 6 is arranged so that its opening faces downward. Also, a mounting member 7 having a mounting hole 7a is arranged at a position facing the gas exhaust port 6, and a discharge device 10 is attached to the mounting hole 7a of the mounting member 7 (see FIGS. 7 to 9).

[0016] Examples of the electricity storage device 1 include batteries (lithium ion batteries, etc.), condensers, and the like 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. In addition, the shape and structure of the case, and the shapes and number of electricity storage devices arranged in the case, etc. are not particularly limited.

[0017] As shown in Figures 1 and 2 and 7 to 9, the exhaust device 10 in this embodiment includes a base member 20 that is fixed to the gas exhaust port 6 and has a passage 21 therein that communicates with the gas exhaust port 6, a cap member 50 that is removably attached to the base member 20 so as to block the outlet 21b of the passage 21 in the base member 20, and a sealing member 70 that is disposed between the base member 20 and the cap member 50 to seal the gap between the base member 20 and the cap member 50.

[0018] Furthermore, the discharge device 10 has a seal washer 8 that is attached to the base member 20 and seals the gap between the mounting hole 7 a of the mounted member 7 and the base member 20 .

[0019] The above-mentioned seal member 70 and seal washer 8 are annular and made of a porous material such as sponge, or an elastic material such as rubber or elastic elastomer. The seal member 70 can be deformed by being compressed by being pressed from the axial direction by an external force, gas pressure, etc., to reduce its thickness, by being pressed from the radially inward direction to expand, or by being pressed from the radially outward direction to reduce its diameter. The seal member 70 has a smaller diameter than the seal washer 8.

[0020] Next, the detailed structure of the base member 20 will be described with reference to FIG. 1 and FIGS.

[0021] As shown in Figs. 7 to 9, the base member 20 of this embodiment has a passage 21 formed therein and is generally cylindrical as a whole. An annular flange portion 23 extends from the outer periphery of the base member 20 at a midpoint in the axial direction. As shown in Figs. 7 to 9, when the base member 20 is attached to the attachment hole 7a of the attached member 7, the flange portion 23 holds the seal washer 8 between the attached member 7. In addition, the base member 20 has a base end side (one end side) in the extension direction of the base member 20 via the flange portion 23 forming a connection portion 25, and a tip end side (the other end side) in the extension direction of the base member 20 forming an insertion portion 27.

[0022] In the following description, the tip side of the base member 20 means the end side where the cap member 50 is arranged, and the base side of the base member 20 means the end side opposite the tip side where the gas exhaust port 6 is arranged.

[0023] Moreover, by inserting the connection part 25 into the gas exhaust port 6 of the gas exhaust tube 4, the base member 20 is connected and fixed to the gas exhaust port 6. As shown in Figs. 7 and 8, the insertion direction of the base member 20 into the gas exhaust port 6 at this time is designated as "F1". An annular protruding stopper part 25a is provided on the outer periphery on the tip side of the connection part 25 to prevent excessive insertion into the gas exhaust port 6, and furthermore, a plurality of annular protrusions 25b having tapered surfaces are provided on the outer periphery on the base side of the stopper part 25a (see Figs. 3 and 4).

[0024] On the other hand, the insertion portion 27 is inserted into the mounting hole 7a of the mounted member 7 and is projected from an opening on the back side of the mounting hole 7a (the side opposite to the front side which is the opposing surface of the flange portion 23).

[0025] In addition, a base end opening on the connection portion 25 side of the passage 21 formed inside the base member 20 serves as an inlet 21a for gas G attempting to flow into the passage 21 via the gas exhaust tube 4. Furthermore, a tip opening on the insertion portion 27 side of the passage 21 serves as an outlet 21b for gas G flowing out of the passage 21.

[0026] 7 to 9, a seal pressing portion 29 having an annular projection is provided on the outer periphery slightly toward the base end side from the tip of the insertion portion 27. The seal pressing portion 29 abuts against one end face of the seal member 70 in the thickness direction, and serves to restrict the axial movement of the seal member 70 relative to the base member 20.

[0027] 8, the base member 20 is provided with a seal member mounting portion 31 to which the seal member 70 is mounted, a restricting wall 35 that is disposed on the outer periphery of the seal member 70 and restricts the seal member 70 from expanding, and an engaged portion 33 with which the claw portion 61 of the cap member 50 engages. The restricting wall 35 is disposed on the outer periphery of the seal member 70, outside the seal member mounting portion 31.

[0028] In this embodiment, the portion of the insertion portion 27 that is axially closer to the tip end than the seal pressing portion 29 forms the seal member mounting portion 31, and the seal member 70 is mounted on the outer periphery of this seal member mounting portion 31. The outer diameter of the seal member mounting portion 31 is sized to approximately match the inner diameter of the seal member 70.

[0029] Also, the engaged portion 33, which engages with the claw portion 61 of the cap member 50, is provided on the front surface side (the surface on the insertion direction F1 side of the base member 20) of the annular protrusion-shaped seal pressing portion 29, at its outer circumferential edge. In this embodiment, the engaged portions 33 are provided at locations facing each other in the radial direction of the seal pressing portion 29 (see FIG. 5). Also, as shown in the partial enlarged view of FIG. 8 and FIG. 9, the engaged portion 33 has a horizontal surface 33a (a surface perpendicular to the axis of the base member 20) that is a flat horizontal surface, and a curved surface 33b that is located radially outward from the horizontal surface 33a and has a curved surface.

[0030] Furthermore, the restricting wall 35, which is disposed outside the seal member mounting portion 31 and on the outer periphery of the seal member 70 and restricts the seal member 70 from expanding, has the following configuration.

[0031] As shown in Fig. 1 and Fig. 5, in this embodiment, a pair of regulating walls 35, 35 are arranged to sandwich the pair of engaged parts 33, 33 and extend in a curved shape along the circumferential direction of the seal pressing part 29. Also, as shown in Fig. 3 and Fig. 7, each regulating wall 35 extends toward the tip of the base member 20 in the extension direction, is provided with a length that reaches a position slightly forward of the tip, and overlaps (wraps) with a predetermined length in the axial direction of the seal member mounting part 31. In other words, it can be said that the tip of the seal member mounting part 31 in the extension direction protrudes from the tip of the regulating wall 35. Also, the axial length (extending length) of each regulating wall 35 is a length that can cover the entire area in the thickness direction of the seal member 70 (see Fig. 7).

[0032] 5 and 6, when the base member 20 is viewed from the axial direction (when viewed from the extending direction of the base member 20), each of the restricting walls 35 is an arc-shaped wall formed with an inner diameter larger than the outer diameter of the seal member 70. The seal member 70 is disposed between the pair of restricting walls 35 and the seal member mounting portion 31 disposed radially inside thereof (see FIGS. 6 and 7). That is, the pair of restricting walls 35 are disposed on the outer periphery of the seal member 70 mounted on the outer periphery of the seal member mounting portion 31, and the pair of restricting walls 35 restrict the seal member 70 from expanding radially outward.

[0033] The structure of the regulating wall 35 can also be described as follows. That is, as shown in Fig. 5, a pair of notches 39, 39 are formed at two radially opposing positions of an annular wall arranged concentrically on the outer periphery of the seal member mounting portion 31, and the annular wall is separated via the pair of notches 39, 39 to provide a pair of regulating walls 35, 35. The engaged portion 33 is arranged at a position aligned with the notches 39.

[0034] 1 and 3, a pair of ribs 37, 37 in the form of thin plates arranged in parallel to each other extend from the circumferential edge portions (portions matching with the engaged portions 33) of the pair of restricting walls 35, 35 on the front surface (the surface on the side of the base member 20 in the insertion direction F1) along the extension direction of the base member 20. One end of each of the ribs 37 in the extension direction is connected to the rear side of the flange portion 23.

[0035] A notch 40 is formed between the pair of ribs 37, 37. As shown in Fig. 3, this notch 40 is aligned with a notch 39 formed between the pair of regulating walls 35, 35 in the circumferential direction of the base member 20, so that the base member 20 has the notches 39, 40 continuously provided along its axial direction. These notches 39, 40 are also disposed opposite each other in the radial direction of the base member 20.

[0036] Thus, in this embodiment, the outer periphery of the base member 20 is provided with cutout portions 39, 40 formed by cutting out a portion of the outer periphery, and these cutout portions 39, 40 are adapted to receive the elastic pieces 59 of the cap member 50 when the cap member 50 is attached to the base member 20, as shown in FIG. 2.

[0037] 1, 3, and 5, a pair of flexibly deformable fixing pieces 41, 41 extend obliquely outward from the outer periphery of the pair of regulating walls 35, 35 at the center in the circumferential direction toward the flange portion 23. As shown in FIG. 5, the pair of fixing pieces 41, 41 are arranged perpendicular to the pair of engaged portions 33, 33 and the pair of cutout portions 39, 39. A tapered engagement surface 41a is formed on the outer surface of the tip of each fixing piece 41 in the extending direction. As shown in FIG. 7, the engagement surface 41a of each fixing piece 41 engages with the rear peripheral edge of the mounting hole 7a of the mounting member 7, so that the base member 20 is fixed to the mounting hole 7a via the pair of fixing pieces 41, 41, and the entire discharge device 10 is attached to the mounting member 7.

[0038] 8, the base member 20 is provided with a protrusion 43 formed at a position facing the guide surface 58 of the cap member 50, which serves as a guide when the cap member 50 is attached and holds the seal member 70 in place. Furthermore, this protrusion 43 protrudes outward from the base member 20 and is located inside the cap member 50, so as to restrict radial movement of the cap member 50.

[0039] In this embodiment, the protrusions 43 are provided on the outer periphery of the most distal end of the sealing member mounting portion 31, protruding from a position that aligns with the cutout portions 39, 40 and the engaged portion 33, and consist of a pair of protrusions arranged at two radially opposing positions on the base member 20 (see Figures 3 and 5).

[0040] As shown in the partially enlarged view of Figure 8 and Figure 9, each protrusion 43 has an apex 43a that protrudes most radially outward from the outer surface of the seal member mounting portion 31, a tapered surface 43b that is formed on the outer surface of the tip side of the base member 20 and has an inclined surface shape that gradually reduces the amount of protrusion from the apex 43a toward the tip of the base member, and an engagement surface 43c that is formed on the outer surface opposite to the tapered surface 43b (the base end side of the base member 20) and has an inclined surface shape that gradually reduces the amount of protrusion from the apex 43a toward the base end of the base member.

[0041] 8, when the cap member 50 is attached to the base member 20, each protrusion 43 is disposed within the peripheral wall 53 of the cap member 50 and disposed to face the inner peripheral surface of the peripheral wall 53, with the engagement surface 43c engaging with the inner peripheral edge portion of the other end in the thickness direction of the seal member 70. As a result, one end face in the thickness direction of the seal member 70 is abutted against and supported by the seal pressing portion 29, and the other end face in the thickness direction is engaged and supported by the engagement surface 43c of the protrusion 43, so that the seal member 70 is held in place so as not to move axially relative to the base member 20.

[0042] Furthermore, when the cap member 50 is attached to the base member 20, the protrusion 43 is disposed within the peripheral wall 53 of the cap member 50, so that even if the cap member 50 attempts to move radially relative to the base member 20, the radial movement is restricted. In this embodiment, as shown in the partially enlarged view of FIG. 8, when the cap member 50 is attached to the base member 20 via the elastic piece 59 and the claw portion 61, a predetermined gap CL is generated between the top portion 43a of the protrusion 43 and the inner peripheral surface of the peripheral wall 53 of the cap member 50, so that the protrusion 43 is restricted from abutting against the inner peripheral surface of the peripheral wall 53 of the cap member 50.

[0043] Incidentally, the engaging surface 43c has an inclined surface shape, which makes it possible to accommodate variations in the thickness of the sealing member 70. In addition, the tapered surface 43b makes it difficult for the protrusion 43 to abut against the peripheral wall 53 (see FIG. 8) of the cap member 50 when the sealing member 70 is attached to the base member 20.

[0044] Next, the detailed structure of the cap member 50 that is detachably attached to the base member 20 will be described with reference to FIG. 1 and FIGS.

[0045] The cap member 50 of this embodiment has a lid portion 51 disposed opposite the outlet 21b of the passage 21 of the base member 20, and a claw portion 61 that engages with the base member 20, and is configured so that when the gas pressure at the gas exhaust port 6 is equal to or greater than a predetermined value, the engagement of the claw portion 61 with the base member 20 is released by the pressure received by the lid portion 51, causing the cap member 50 to come off from the base member 20. The cap member 50 also has a flexibly deformable elastic piece 59 extending from the outer periphery of the lid portion 51, and the claw portion 61 protrudes from the inner periphery of the elastic piece 59.

[0046] In addition, the cap member 50 is attached to the base member 20 by pushing it toward the outlet 21b of the passage 21 of the base member 20 and engaging the claw portion 61 of the elastic piece 59 with the engaged portion 33 of the base member 20, and the pushing direction of the cap member 50 into the base member 20 at this time is designated as "F2" (see Figures 7 and 8).

[0047] 1, the lid portion 51 of the cap member 50 in this embodiment has a substantially circular plate shape and serves as a portion for receiving the gas G flowing out from the outlet 21b of the passage 21 of the base member 20. (It can also be said that this is a portion on which the pressure of the gas G at the gas outlet 6 acts.)

[0048] A peripheral wall 53 having a substantially cylindrical wall shape is erected from the outer peripheral edge of the lid portion 51. The peripheral wall 53 is composed of a base portion 55 provided on the base end side in the erecting direction (the end close to the lid portion 51) and a pressing wall portion 57 protruding in the axial direction of the peripheral wall 53 from the inner peripheral edge of a tip surface 55a in the erecting direction of the base portion 55 and having an outer diameter smaller than that of the base portion 55. The pressing wall portion 57 presses the seal member 70 in the axial direction when the cap member 50 is attached to the base member 20 (see Figs. 7 and 8). The inner diameters of the base portion 55 and the pressing wall portion 57 are the same.

[0049] 7, the outer diameter of the base 55 is sized to almost match the outer diameter of the restriction wall 35 of the base member 20 (here, the outer diameter of the base 55 is slightly smaller than the outer diameter of the restriction wall 35). Therefore, in a state where the cap member 50 is attached to the base member 20, the tip surface 55a of the base 55 and the tip surface of the restriction wall 35 of the base member 20 are disposed opposite to each other.

[0050] The outer diameter of the pressing wall portion 57 is smaller than the inner diameter of the restricting wall 35, and the inner diameter of the pressing wall portion 57 is larger than the outer diameter of the seal member mounting portion 31 (see FIG. 7). Therefore, when the cap member 50 is mounted on the base member 20, the pressing wall portion 57 enters the gap between the seal member mounting portion 31 of the base member 20 and the pair of restricting walls 35, 35, and presses the seal member 70 arranged in the gap from the axial direction, compressing and deforming the seal member 70 (see FIGS. 7 and 8). As a result, the seal member 70 is deformed so as to expand radially outward.

[0051] A pair of elastic pieces 59, 59 extend from the outer peripheral edge of the base 55, which is located radially opposite to the base 55 constituting the peripheral wall 53. Each elastic piece 59 has a base end (fixed end) connected to the outer peripheral edge of the tip surface 55a of the base 55, extends beyond the tip of the pressing wall 57 of the peripheral wall 53, and is a strip-shaped piece having a length (length that can be wrapped) that overlaps the engaged portion 33 when attached to the base member 20, and the tip of the extending direction is a free end, which can be flexibly deformed inward or outward of the cap member 50. The pair of elastic pieces 59, 59 extend parallel to each other and parallel to the axial direction of the peripheral wall 53 of the cap member 50. Furthermore, the width of the elastic piece 59 along the circumferential direction is narrower than the notches 39, 40 of the base member 20, so that the elastic piece 59 can enter into the notches 39, 40 when the cap member 50 is attached to the base member 20.

[0052] Furthermore, a claw portion 61 is provided protruding from the inner circumference of the tip of the elastic piece 59 in the extension direction. As shown in the partial enlarged view of FIG. 8 and FIG. 9, the claw portion 61 has a top portion 63 that protrudes most from the inner circumference of the elastic piece 59, a tapered surface 65 formed on the outer surface on the side of the pushing direction F2 of the cap member 50 into the base member 20 (the side away from the lid portion 51) and having an inclined surface shape that gradually reduces the amount of protrusion from the top portion 63 toward the tip end side in the extension direction of the elastic piece 59, and an engagement surface 67 formed on the outer surface on the opposite side to the tapered surface 65 (the opposite side to the pushing direction F2 of the cap member 50) and having an inclined surface shape that gradually reduces the amount of protrusion from the top portion 63 toward the base end side in the extension direction of the elastic piece 59. The claw portion 61 is formed over the entire range in the circumferential direction (width direction) of the elastic piece 59 (see FIG. 1).

[0053] Then, in order to attach the cap member 50 to the base member 20, the cap member 50 is pushed into the base member 20. Then, the tapered surface 65 of the claw portion 61 is pressed against the tip surface side of the seal pressing portion 29 of the base member 20 opposite to the engaged portion 33, and the elastic piece 59 is pushed and spread out, and is bent and deformed outward of the cap member 50 (it can also be said that it is deformed in a direction away from the outer periphery of the base member 20). After that, when the top portion 63 of the claw portion 61 climbs over the engaged portion 33 of the base member 20, the elastic piece 59 elastically returns to its original state and is bent and deformed inward of the cap member 50 (it can also be said that it is deformed in a direction approaching the outer periphery of the base member 20), and the engagement surface 67 of the claw portion 61 engages with the horizontal surface 33a and the curved surface 33b of the engaged portion 33 (see the partially enlarged view of FIG. 8). As a result, the cap member 50 is attached to the base member 20 via the pair of elastic pieces 59, 59 and the claw portions 61, 61. In this state, as shown in the partially enlarged view of FIG. 8, the engaged portion 33 of the base member 20 and the claw portion 61 of the cap member 50 are arranged diagonally.

[0054] In this embodiment, the claw portion 61 is provided with an inclined engaging surface 67, and the claw portion 61 is engaged with the engaged portion 33 of the base member 20, including the curved surface 33b, so that the engaging force of the cap member 50 with respect to the base member 20 is lower than when the engaging surface of the claw portion and the engaged portion are both horizontal surfaces and engage with each other. Therefore, when the gas pressure at the gas exhaust port 6 reaches a predetermined value or more, and the gas G flowing into the passage 21 from the inlet 21a of the base member 20 and flowing out from the outlet 21b also reaches a predetermined value or more, the pair of elastic pieces 59, 59 are each deflected outward via the lid portion 51 of the cap member 50 pressed by the gas G (see the two-dot chain line in the partially enlarged view of FIG. 8), and the engagement of the claw portion 61 with the engaged portion 33 of the base member 20 is released, and the cap member 50 is removed from the base member 20.

[0055] As described above, in this embodiment, when the top 63 of the claw portion 61 overcomes the engaged portion 33 and elastically returns to its original state, the elastic piece 59 does not completely return to a state in which it is not bent outwardly from the cap member 50 (see Figure 9), but rather the claw portion 61 engages with the engaged portion 33 while maintaining a state in which it is slightly bent outwardly from the cap member 50.

[0056] Furthermore, as shown in the partially enlarged view of Figure 8, the inclination angle θ of the engagement surface 67 of the claw portion 61 with respect to the pushing direction F2 of the cap member 50 into the base member 20 (here, the direction along the axial direction of the peripheral wall 53 of the cap member 50) is preferably 60 to 85°, and more preferably 75 to 80°.

[0057] (Modification) In the above-described embodiment, the shapes, structures, layouts, etc. of the electricity storage device, the case, the gas exhaust tube, the tube holding member, the gas exhaust port, etc. are not limited to the above-described aspects. For example, in this embodiment, two electricity storage devices 1 are used as one set, but three or more electricity storage devices may be used as one set via connectors or tubes. In addition, the gas exhaust port 6 is an opening facing downward, but may be an opening facing sideways.

[0058] Furthermore, the shapes and structures of the base member, cap member, seal member, seal washer, and the like that constitute the gas discharge device for an electricity storage device are not limited to the above-mentioned embodiments.

[0059] For example, the base member 20 has a connection part 25 and an insertion part 27 and is generally cylindrical in shape, but may be generally rectangular or elliptical in shape, as long as it is fixed to the gas exhaust port and has a passage therein that communicates with the gas exhaust port. In addition, the base member 20 in this embodiment is configured so that its connection part 25 is inserted into and fixed to the gas exhaust port 6 of the gas exhaust tube 4, but a tube may be inserted into the base member and the base member may be fixed to the gas exhaust port.

[0060] In addition, in the base member 20 of this embodiment, the engaged portions 33, the restricting walls 35, and the fixed pieces 41 are all provided in pairs, but the number of each of these may be one, or three or more.

[0061] Furthermore, in this embodiment, an engaged portion 33 is provided on a portion of the surface side of the annular protrusion-shaped seal pressing portion 29 (at a position aligned with the cutout portion 39); however, for example, a recess into which the claw portion can fit may be provided on the outer peripheral surface of the base member, and the inner surface of this recess may serve as the engaged portion.

[0062] In addition, the base member 20 in this embodiment has a pair of arc-shaped regulating walls 35, 35, but the regulating walls may, for example, be a continuous annular frame-shaped wall (circular, angular, elliptical, etc.) with no separated parts, or may be a plurality of narrow walls (a plurality of separated walls) arranged at a predetermined interval along the outer periphery of the sealing member, and may have any shape or structure that is arranged around the outer periphery of the sealing member and can regulate its expansion.

[0063] Furthermore, the base member 20 in this embodiment has a pair of anchor-shaped fixing pieces 41, 41, but, for example, an engaging protrusion may be provided on the outer periphery of the base member and this engaging protrusion may be engaged with a mounting hole in the workpiece, and the mounting structure of the base member relative to the mounting hole is not particularly limited.

[0064] In addition, in this embodiment, the cap member 50 has a lid portion 51 that is approximately circular plate-shaped to correspond to the approximately cylindrical insertion portion 27 of the base member 20. However, for example, the lid portion may be approximately rectangular or elliptical, etc., as long as it is capable of covering the outlet of the passage in the base member and receiving the gas flowing out from the outlet.

[0065] In addition, in this embodiment, a pair of elastic pieces 59, 59 are provided corresponding to a pair of engaged portions 33, 33 of the base member 20, but the number of these elastic pieces may be one or three or more as long as the cap member can be attached to the base member.

[0066] In this embodiment, the claw portion 61 is protruded from the inner periphery of the tip portion of the elastic piece 59, but the claw portion may be provided midway in the extending direction of the elastic piece as long as it is capable of engaging with the engaged portion.

[0067] Furthermore, in this embodiment, the elastic piece 59 is in an outwardly deflected state and its claw portion 61 engages with the engaged portion 33 (see the enlarged partial view of Figure 8), but the claw portion may also engage with the engaged portion when the elastic piece is not in an outwardly deflected state.

[0068] In addition, in this embodiment, the cap member 50 is configured so that, when the gas pressure is equal to or greater than a predetermined value, the elastic piece 59 bends outward and deforms to detach from the base member 20. To achieve this, the inclination angle of the engagement surface 67 of the claw portion 61 on the cap member 50 side is set to the angle described in paragraph 0055 above, and a horizontal surface 33a and a curved surface 33b are provided on the engaged portion 33 on the base member 20 side. However, the structure for detaching the cap member from the base member when the gas pressure is equal to or greater than a predetermined value is not limited to the above-described form.

[0069] For example, (1) the engaging surface of the claw portion of the cap member is a curved surface, while the engaged portion of the base member is a horizontal surface only, or a combination of a horizontal surface and a curved surface, or a combination of a horizontal surface and an inclined surface; (2) the engaging surface of the claw portion of the cap member is an inclined surface, while the engaged portion of the base member is a horizontal surface only, or a combination of a horizontal surface and an inclined surface; (3) the engaging surface of the claw portion of the cap member is a horizontal surface, while the engaged portion of the base member is a combination of a horizontal surface and an inclined surface, or a combination of a horizontal surface and an inclined surface; (4) the engaged portion of the base member is an inclined surface and the inclination angle is adjusted; (5) a combination of the above (1) to (4); or (6) the thickness, width, length, etc. of the claw portion is appropriately set to adjust the engagement allowance (engagement area) with respect to the base member.

[0070] Additionally, although both the seal member 70 and the seal washer 8 are circular, they may be rectangular or elliptical, and may be modified as appropriate depending on the shape and structure of the base member.

[0071] Furthermore, the lid portion 51 of the cap member 50 has the function of receiving the pressure of the gas G, but this lid portion may also have a pressure regulating function that does not allow moisture to pass through but allows a predetermined flow rate of gas or other vapor to pass through.

[0072] (Action and effect) Next, the effects of the discharge device 10 according to the present invention having the above-mentioned configuration will be described.

[0073] First, the assembly process of the discharge device 10 will be described.

[0074] That is, the seal member 70 is inserted into the gap between the seal member mounting portion 31 of the base member 20 and the pair of regulating walls 35, 35, and the seal member 70 is pushed in until it abuts against the seal pressing portion 29. Then, one end face in the thickness direction of the seal member 70 abuts against and is supported by the seal pressing portion 29, and the other end face in the thickness direction is engaged and supported by the engaging surface 43c of the protrusion 43, so that the seal member 70 can be held in place relative to the base member 20 so as not to move in the axial direction.

[0075] With the seal member 70 attached to the base member 20 as described above, as shown in FIG. After aligning the pair of elastic pieces 59, 59 of the cap member 50 with the cutout portions 39, 40 on one side of the radial direction of the base member 20 and the cutout portions 39, 40 on the other side of the radial direction, the cap member 50 is pressed against the base member 20 in the direction shown by F2 in Fig. 8. Then, the tapered surface 65 of the claw portion 61 is pressed against the tip surface side of the seal pressing portion 29, and the elastic pieces 59 are pushed apart and deformed outwardly.

[0076] Thereafter, when the claw portion 61 overcomes the engaged portion 33, the elastic piece 59 elastically returns to its original state and enters the cutout portions 39, 40 of the base member 20, and the engaging surface 67 of the claw portion 61 engages with the horizontal surface 33a and the curved surface 33b of the engaged portion 33 (see the partially enlarged view of FIG. 8), and the cap member 50 can be attached to the base member 20 with the seal member 70 interposed between the base member 20 and the cap member 50, as shown in FIG. 8. At this time, since the tip surface 55a of the base portion 55 of the cap member 50 and the tip surface of the regulating wall 35 of the base member 20 are arranged to face each other (see FIG. 7), even if the cap member 50 is excessively pressed against the base member 20, both tip surfaces come into contact with each other and function as a push-in stopper, and the seal member 70 can be prevented from being compressed more than necessary and becoming worn out. 7, the outer diameter of the base 55 is sized to approximately match the outer diameter of the restriction wall 35 of the base member 20 (here, the outer diameter of the base 55 is slightly smaller than the outer diameter of the restriction wall 35). Therefore, when the cap member 50 is attached to the base member 20, the tip surface 55a of the base 55 rests on the base member 20.

[0077] Thereafter, the seal washer 8 is placed on the back side of the flange portion 23 of the base member 20, and the insertion portion 27 of the base member 20 is inserted from the front opening of the mounting hole 7a of the attached member 7. Then, the pair of fixing pieces 41, 41 are pressed by the inner circumference of the mounting hole 7a and are deformed inwardly, and when the engagement surface 41a of the fixing piece 41 comes out of the back opening of the mounting hole 7a, the pair of fixing pieces 41, 41 elastically return to their original state and the engagement surfaces 41a, 41a engage with the back periphery of the mounting hole 7a, and the discharge device 10 can be attached to the mounting hole 7a (see FIG. 7). In this state, the seal washer 8 is sandwiched between the flange portion 23 of the base member 20 and the front periphery of the mounting hole 7a of the attached member 7, ensuring watertightness.

[0078] When gas G is generated in the electricity storage device 1 due to the supply of power from the electricity storage device 1 to the driving source or electrical components, or due to the external or internal environment of the electricity storage device 1 (for example, when an electricity storage device such as a lithium ion battery supplies power by driving a motor or the like, gas is generated by a chemical reaction in the electrolyte), the gas G flows through the connector 3 and gas exhaust tube 4 and reaches the gas exhaust port 6, and when the gas pressure at this gas exhaust port 6 reaches or exceeds a predetermined value, the cap member 50 is detached from the base member 20.

[0079] That is, the gas G flows into the passage 21 from the inlet 21a of the base member 20, flows through the passage 21, and flows out from the outlet 21b, pressing the lid portion 51 of the cap member 50. When the gas pressure at the gas exhaust port 6 reaches a predetermined value or more, the pressure of the gas G (see FIG. 8) acting on the lid portion 51 of the cap member 50 also reaches a predetermined value or more. Then, the lid portion 51 of the cap member 50 is pressed by the gas G, so that the curved surface 33b of the engaged portion 33 presses the engagement surface 67 of the claw portion 61, and the elastic piece 59 is bent and deformed outward of the cap member 50 via the claw portion 61, as shown by the two-dot chain line in the partially enlarged view of FIG. 8. As a result, the engagement surface 67 of the claw portion 61 is disengaged from the horizontal surface 33a and the curved surface 33b of the engaged portion 33, and the engagement between the engaged portion 33 and the claw portion 61 is released, so that the cap member 50 is detached from the base member 20, as shown in FIG. 9. The pair of elastic pieces 59, 59 of the cap member 50 that has been removed from the base member 20 elastically return to their original position so as to be parallel to the axial direction of the peripheral wall 53 of the cap member 50.

[0080] As described above, in this exhaust device 10, when the gas pressure at the gas exhaust port 6 of the electricity storage device 1 reaches or exceeds a predetermined value, the lid portion 51 of the cap member 50 is pushed by the gas pressure, causing the elastic piece 59 to bend and deform outward, and the claw portion 61 to disengage from the engaged portion 33 of the base member 20, thereby removing the cap member 50 from the base member 20.

[0081] At this time, the gas pressure also acts on the seal member 70, which tries to expand in the radial direction (see the horizontal arrow in FIG. 7), but the expansion is restricted by the pair of restricting walls 35, 35 of the base member 20, so that the gas pressure acts firmly on the lid portion 51 of the cap member 50 while the seal between the base member 20 and the cap member 50 is maintained by the seal member 70. That is, the restricting wall 35 maintains the seal between the base member 20 and the cap member 50, so that the gas G does not escape (is not exhausted) from the gas exhaust port 6 through the seal member 70, and the gas pressure of the gas G reliably acts on the lid portion 51 of the cap member 50. As a result, the cap member 50 can be reliably removed from the base member 20. Note that, since the seal member mounting portion 31 of the base member 20 is located inside the seal member 70, even if the seal member 70 tries to reduce its diameter in the radial direction when gas pressure acts on the seal member 70, the reduction in diameter is restricted.

[0082] In this way, with this exhaust device 10, the sealing performance between the base member 20 and the cap member 50 can be maintained, and when the gas pressure at the gas exhaust port 6 increases, the cap member 50 can be reliably removed from the base member 20, thereby enabling the gas G to be exhausted from the electricity storage device 1.

[0083] Also, in this embodiment, as shown in the partially enlarged view of Figure 8, the cap member 50 has an elastic piece 59 extending from the lid portion 51, and a claw portion 61 is formed on the elastic piece 59, and the claw portion 61 is configured to engage with the base member 20 when the elastic piece 59 is bent and deformed outward.

[0084] According to the above embodiment, the elastic restoring force of the elastic piece 59 can be utilized to firmly engage the claw portion 61 with the base member 20, thereby enabling the cap member 50 to be attached to the base member 20 in a stable position (here, the cap member 50 can be attached to the base member 20 in a position in which the axis of the base member 20 and the axis of the peripheral wall 53 of the cap member 50 are aligned), and the cap member 50 can be more reliably removed from the base member 20 with a predetermined gas pressure.

[0085] Furthermore, in this embodiment, as shown in FIGS. 7 and 8, the cap member 50 has a pressing wall portion 57 that presses the seal member 70 in the axial direction when the cap member 50 is attached to the base member 20.

[0086] According to the above aspect, when the cap member 50 is attached to the base member 20, the sealing member 70 is pressed in the axial direction by the pressing wall portion 57, so that the sealing member 70 is held in the axial direction of the base member 20, making it possible to easily remove the cap member 50 from the base member 20 at a predetermined gas pressure (since the sealing member 70 is not configured to slide against the cap member 50 in the radial direction, the cap member 50 can easily be removed from the base member 20).

[0087] Furthermore, when the cap member 50 is attached to the base member 20, the seal member 70 is pressed by the pressing wall portion 57 of the cap member 50, and the seal member 70 is compressed, thereby improving the sealing performance between the base member 20 and the seal member 70.

[0088] Furthermore, when the cap member 50 is attached to the base member 20, the seal member 70 is pressed by the pressing wall portion 57 of the cap member 50, so that rattling of the seal member 70 relative to the base member 20 can be suppressed.

[0089] In this embodiment, as shown in FIG. 8, the base member 20 is provided with a protrusion 43 that protrudes outward and is located inside the cap member 50 to restrict radial movement of the cap member 50 and to hold the seal member 70 in place.

[0090] Also, in this embodiment, as shown in FIG. 8, the cap member 50 has a guide surface 58 that is positioned on the outer periphery of the base member 20 when the cap member 50 is attached to the base member 20, and the base member 20 is provided with an engaged portion 33 with which the claw portion 61 engages, and a protrusion 43 that is formed in a position opposite the guide surface 58 of the cap member 50, serves as a guide when the cap member 50 is attached, and holds the sealing member 70 in place to prevent it from coming loose.

[0091] According to the above embodiment, the protrusion 43 holds the seal member 70 in the axial direction of the base member 20, thereby preventing the seal member 70 from falling off from the base member 20. As a result, when gas pressure acts on the seal member 70, the seal member 70 is prevented from coming off the base member 20, the sealing performance between the base member 20 and the cap member 50 is reliably maintained, and the gas pressure can be reliably applied to the lid portion 51 of the cap member 50.

[0092] Furthermore, when the cap member 50 is attached to the base member 20, the guide surface 58 of the cap member 50 is guided by the protrusion 43 of the base member 20, making it easier to attach the cap member 50 to the base member 20 and allowing the cap member 50 to be attached to the base member 20 in a stable posture. This suppresses variation in the engagement allowance (engagement area) of the claw portion 61 with the base member 20 and allows the cap member 50 to be more reliably removed from the base member 20 with a specified gas pressure.

[0093] Furthermore, in this embodiment, as shown in the partially enlarged view of FIG. 8, when the cap member 50 is attached to the base member 20, a predetermined gap CL is generated between the protrusion 43 and the guide surface 58 of the cap member 50. Therefore, as described above, the protrusion 43 and the guide surface 58 can be used to further improve the guiding performance when the cap member 50 is attached to the base member 20. In addition, by providing a predetermined gap CL between the protrusion 43 and the guide surface 58 of the cap member 50 when the cap member 50 is attached to the base member 20, when the gas pressure at the gas exhaust port 6 becomes equal to or greater than a predetermined value and the cap member 60 is about to be removed from the base member 20, no frictional resistance acts between the guide surface 58 of the cap member 50 and the protrusion 43 of the base member 20, and the cap member 50 can be smoothly removed from the base member 20.

[0094] Furthermore, in this embodiment, the base member 20 has cutout portions 39, 40 formed by cutting out a portion of its outer periphery, into which the elastic piece 59 fits, and a protrusion 43 is provided at a position aligned with the cutout portions 39, 40 (see Figure 3).

[0095] According to the above embodiment, when the cap member 50 is attached to the base member 20, as shown in Fig. 2, the elastic pieces 59 of the cap member 50 enter the notches 39, 40 of the base member 20, so that the radial outward protrusion of the elastic pieces 59 is suppressed, and the gas discharge device 10 can be made compact in the radial direction. Furthermore, when the cap member 50 is attached to the base member 20, the elastic pieces 59 of the cap member 50 enter the notches 39, 40 of the base member 20, so that the cap member 50 can be attached in a state in which its rotation is restricted relative to the base member 20. Furthermore, since the notches 39, 40 are provided in the base member 20, the seal member 70 can be easily attached to the seal member attachment portion 31 of the base member 20 by utilizing the notches 39, 40. Furthermore, since the protrusions 43,43 are provided at positions of the base member 20 that match the cutouts 39,40, there are no undercut portions when the protrusions 43,43 are removed from the mold, making it easier to form the protrusions 43,43.

[0096] In addition, in this embodiment, when the cap member 50 is attached to the base member 20, the engaged portion 33 of the base member 20 and the claw portion 61 of the cap member 50 are arranged diagonally, as shown in the partially enlarged view of Figure 8, and from that viewpoint as well, the discharge device 10 can be made compact in the radial direction.

[0097] Furthermore, in this embodiment, a pair of ribs 37, 37 are provided on the outer periphery of the base member 20, and the elastic piece 59 and the claw portion 61 of the cap member 50 are arranged between them. Therefore, even if an external force acts from outside the base member 20, the external force is less likely to act on the elastic piece 59 and the claw portion 61, and the attachment state between the base member 20 and the cap member 50 can be firmly maintained.

[0098] It should be noted that the present invention is not limited to the above-described embodiment, and various modified embodiments are possible within the scope of the gist of the present invention, and such embodiments are also included in the scope of the present invention. [Explanation of symbols]

[0099] 1. Energy storage devices 6 Gas exhaust port 8 Seal Washer 10 Gas exhaust device for power storage device (exhaust device) 20 Base material Aisle 21 21b Exit 33 Engaged part 35 Regulatory barriers 39,40 Notch 41 Fixed piece 43 Protrusion 50 Cap member 51 Lid 53 Peripheral wall 57 Pressing wall 59 Elastic piece 61 Claw part 70 Sealing material

Claims

1. A gas exhaust device for an electricity storage device, which exhausts gas when a gas pressure at a gas exhaust port of the electricity storage device is equal to or higher than a predetermined value, a base member fixed to the gas exhaust port and having a passage therein communicating with the gas exhaust port; a cap member detachably attached to the base member so as to close an outlet of the passage of the base member; a seal member disposed between the base member and the cap member to seal a gap between the base member and the cap member; the cap member has a lid portion disposed opposite the outlet of the passage of the base member and a claw portion engaging with the base member, and is configured to be disengaged from the base member by the pressure received by the lid portion when the gas pressure at the gas exhaust port is equal to or greater than a predetermined value, A gas exhaust device for an electricity storage device, characterized in that the base member is provided with a seal member mounting portion into which the seal member is mounted, and a regulating wall arranged on the outer periphery of the seal member and regulating the expansion of the seal member.

2. The gas exhaust device for an electricity storage device as described in claim 1, wherein the cap member has an elastic piece extending from the lid portion, the claw portion is formed on the elastic piece, and when the elastic piece is bent and deformed outward, the claw portion is configured to engage with the base member.

3. 3 . The gas discharge apparatus for an electricity storage device according to claim 1 , wherein the cap member has a pressing wall portion that presses the seal member in an axial direction when the cap member is attached to the base member.

4. the cap member has a guide surface that is disposed on an outer periphery of the base member when the cap member is attached to the base member, A gas exhaust device for an electricity storage device as described in any one of claims 1 to 3, wherein the base member is provided with an engaged portion with which the claw portion engages, and a protrusion formed in a position opposite to a guide surface of the cap member, which serves as a guide when the cap member is attached and holds the sealing member in place to prevent it from coming loose.

5. The cap member has an elastic piece extending from the lid portion, and the claw portion is formed on the elastic piece. The base member has a cutout portion formed by cutting out a part of its outer periphery and into which the elastic piece fits, The gas discharge device for an electricity storage device according to claim 4 , wherein the protrusion is provided at a position aligned with the notch.

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