JP2014059973A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device that easily positions a seal member at a location where the seal member provides sealing performance.SOLUTION: A secondary battery 10 includes a case main body 13, a lid 14, an electrode assembly 20, a positive electrode terminal 41, and a negative electrode terminal. Each of the positive electrode terminal 41 and the negative electrode terminal has: a base 43; and an electrode pole 44 that is erected from the base 43 and that protrudes from inside the case main body 13 through an insertion hole 14b formed in the lid 14 to the outside. An O-ring 56 is sandwiched between an inner surface 14a of the lid 14 nearer the case main body 13 and a seating surface 43a of the base 43 facing the inner surface 14a so as to seal the insertion hole 14b. At a base thereof, each electrode pole 44 has a tapered portion T that becomes wider toward the base 43 in cross-section shape along an axis L.

Description

  The present invention includes a base, an electrode terminal that is erected from the base and protrudes from the inside of the case body through the insertion hole to the outside, and is electrically connected to the electrode assembly, and a lid The present invention relates to a power storage device having an inner surface on the case main body side and an annular seal member sandwiched between a base seating surface facing the inner surface.

  A vehicle such as an EV (Electric Vehicle) or a PHV (Plug in Hybrid Vehicle) is equipped with a secondary battery as a power storage device that stores power supplied to the traveling motor. As a secondary battery, there is a battery configured by housing an electrode assembly in a case. The case includes a case main body and a lid welded to the case main body. An electrode terminal is electrically connected to the electrode assembly accommodated in the case body, and the electrode terminal penetrates the insertion hole of the lid and protrudes from the inside of the case body to the outside. An insulation distance is secured between the inner peripheral surface of the insertion hole and the outer peripheral surface of the electrode terminal facing the inner peripheral surface. The secondary battery is provided with a gap seal structure (see, for example, Patent Document 1).

  As shown in FIG. 10, the battery 80 of Patent Document 1 is configured by accommodating a winding electrode body 84 inside an outer can 83 formed by welding lids 82 to both ends of a cylindrical body 81. . An electrode terminal mechanism 85 is attached to the lid 82, and the take-up electrode body 84 and the electrode terminal mechanism 85 are connected.

  The electrode terminal mechanism 85 includes a positive electrode lead terminal 86 made of a screw member that is attached through the lid 82 of the outer can 83, and a base end portion of the positive electrode lead terminal 86 includes a flange 86a. A resin insulating member 87 is attached to the gap between the inner peripheral surface of the through hole 82 a and the outer peripheral surface of the positive electrode lead-out terminal 86, and the insulating member 87 seals between the lid 82 and the positive electrode lead-out terminal 86. As well as ensuring electrical insulation. A washer 88 is fitted to the positive electrode lead-out terminal 86 from the outside of the outer can 83, and a first nut 89a and a second nut 89b are screwed together. And the sealing performance of the through-hole 82a is improved by fastening the 1st nut 89a and pinching the insulation member 87 with the collar part 86a and the washer 88 of the positive electrode derivation | leading-out terminal 86. FIG.

  However, in Patent Document 1, in order to ensure the sealing performance of the through hole 82a, the insulating member 87 having a complicated shape must be in close contact with the periphery of the through hole 82a while being caulked. It was complicated, and the mounting was troublesome, and the formation of the seal structure was troublesome. Therefore, Patent Document 2 discloses an O-ring having a simple structure as a sealing member.

  As shown in FIG. 11, in the sealed battery 90 of Patent Document 2, the lid body 91 includes a terminal lead hole 91a, and the positive terminal 92 attached to the terminal lead hole 91a includes an inner member 93 and an outer member 94. Prepare. The seal member compression portions 93a and 94a of the inner member 93 and the outer member 94 are respectively provided with annular grooves 93b and 94b, and O-ring seal members 95 and 96 are attached to the annular grooves 93b and 94b, respectively. The inner member 93 and the outer member 94 are welded, so that the seal members 95 and 96 are sandwiched between the seal member compression portions 93a and 94a and the lid body 91 in a compressed state.

JP 2000-149915 A JP 2009-134985 A

  By the way, in Patent Document 2, the seal member 95 is not accurately mounted in the annular groove 93b, and a part of the circumferential direction rides on the inner side of the annular groove 93b and is displaced with respect to the terminal lead hole 91a. 93 and the outer member 94 may be welded. In this case, the seal member 95 is broken or the seal member 95 does not adhere to the lid body 91 and the seal member compression portion 93a, and the sealing performance is deteriorated.

  An object of the present invention is to provide a power storage device in which a sealing member can be easily positioned at a position where the sealing performance can be exhibited.

  In order to solve the above-described problems, the invention according to claim 1 includes a case main body having an opening, a lid that closes the opening and has an insertion hole through which an electrode terminal is inserted, and the case main body. An electrode assembly housed in the case body, a base portion having a cross-sectional area larger than the area of the insertion hole, and a base portion standing from the base portion and passing through the insertion hole. The electrode terminal having a pole portion projecting from the inside to the outside, electrically connected to the electrode assembly, the inner surface of the lid on the case body side, and the seating surface of the base portion facing the inner surface An annular seal member sandwiched between and at least a base portion connected to at least the base portion of the pole column portion in a cross-sectional shape along the axis of the pole column portion. Tapered portion that spreads toward the base Having at least a portion around said axis, said sealing member is summarized in that arranged on the radially outer side at the position of the tapered portion.

  According to this, since the sealing member is sandwiched between the inner surface of the lid and the seating surface of the base portion, when the sealing member is first mounted on the pole column portion, a part of the inner peripheral edge of the sealing member comes into contact with the tapered portion and rides up. Suppose that the seal member is arranged at a position not surrounding the insertion hole from the outer peripheral side. In this case, when the pole member is passed through the insertion hole and the electrode terminal is assembled to the lid, when the seal member is pushed by the inner surface of the lid, the seal member moves along the tapered portion. Then, the portion riding on the taper portion is guided by the taper portion in the radial direction of the pole column portion in a direction away from the pole column portion, and the portion on the opposite side in the radial direction is the radial direction of the pole column portion. Is drawn toward the pole portion. As a result, the sealing member can be disposed at a position surrounding the pole column portion on the radially outer side of the tapered portion by the tapered portion. And since the pole column part is penetrated by the penetration hole, the circumference | surroundings of the penetration hole can be enclosed by the sealing member surrounding the pole column part. Therefore, even when the seal member rides on the taper portion and is displaced with respect to the insertion hole, the seal member can be easily positioned at a position where the sealing performance can be exhibited when the electrode terminal is assembled to the lid.

  And a terminal insulating member inserted between an inner surface of the insertion hole and a side surface of the pole column portion facing the inner surface, and the terminal insulating member is the seal as viewed from an axial direction of the pole column portion. It may overlap at least a part of the member.

  According to this, the terminal insulating member is provided to insulate between the lid and the electrode terminal, and prevents the sealing member from coming out from between the inner surface of the insertion hole and the side surface of the pole column portion. Can do. In particular, even when the internal pressure in the power storage device rises and the seal member is pushed by the internal pressure, it is possible to prevent the seal member from coming out from between the inner surface of the insertion hole and the side surface of the pole column portion.

The seal member is an O-ring.
According to this, a sealing member can be arrange | positioned in the position which can seal an insertion hole with a taper part. Therefore, even if an O-ring having a simple configuration is used as the seal member, the insertion hole can be reliably sealed.

Further, the tapered portion may have a tapered shape in which the cross-sectional shape extends linearly toward the base portion.
According to this, when a seal member moves along a taper part, a seal member can be moved smoothly.

  The cover includes an insulating cover that insulates between the inner surface of the case body side of the lid and the seating surface of the base portion facing the inner surface, and the insulating cover includes an insertion portion for the pole column portion, and the pole In the radial direction of the column part, the seal member may be arranged inside the insertion part.

  According to this, when the sealing member is mounted on the pole column portion, even if the sealing member rides on the taper portion, the outer peripheral edge of the sealing member contacts the inner peripheral edge of the insulating cover, and the sealing member becomes the pole column portion. It is possible to prevent the position from being greatly displaced in the radial direction.

  The power storage device is a secondary battery.

  According to the present invention, the sealing member can be easily positioned at a position where the sealing performance can be exhibited.

The disassembled perspective view which shows the secondary battery of embodiment. The perspective view which shows the external appearance of the secondary battery of embodiment. The perspective view which shows the state which integrated the lid | cover with the electrode assembly. The top view which shows a positive electrode electrically-conductive member, a positive electrode terminal, and an insulation cover. FIG. 5 is a cross-sectional view taken along line 5a-5a in FIG. 3 showing an insulating structure of the positive electrode terminal. FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 3 showing an insulating structure of the positive electrode terminal. Sectional drawing which shows the state by which the O-ring was inclined and arrange | positioned. The top view which shows the state by which the O-ring was inclined and arrange | positioned. Sectional drawing which shows the state which pushed down O-ring with the cover and has arrange | positioned in the predetermined position. The figure which shows the background art of patent document 1. FIG. The figure which shows the background art of patent document 2. FIG.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIGS. 1 to 3, in a secondary battery 10 as a power storage device, an electrode assembly 20 is accommodated in a metal case 12. The case 12 includes a rectangular parallelepiped case main body 13 having an opening 13 d and a rectangular flat plate-shaped lid 14 that closes the opening 13 d of the case main body 13. The case body 13 and the lid 14 are both made of metal (for example, stainless steel or aluminum), and the case body 13 and the lid 14 are joined by laser welding. The case body 13 includes a rectangular bottom plate 13a, a short side wall 13b erected from a pair of opposed short side edges of the bottom plate 13a, and a long side wall 13c erected from a pair of long side edges of the bottom plate 13a. With. In addition, the secondary battery 10 of the present embodiment is a prismatic battery whose outer shape is rectangular. Further, the secondary battery 10 of the present embodiment is a lithium ion battery.

  As shown in FIG. 6, the electrode assembly 20 includes a positive electrode 21 and a negative electrode 22, and a laminated body having a layer shape with a separator 23 interposed between the positive electrode 21 and the negative electrode 22. Has been. The positive electrode 21 includes a rectangular metal foil for positive electrode (aluminum foil in the present embodiment) 21a and electrode active material layers 21b on both surfaces of the metal foil for positive electrode 21a. The negative electrode 22 has a rectangular negative electrode metal foil (copper foil in this embodiment) 22a and negative electrode active material layers 22b on both surfaces of the negative electrode metal foil 22a.

  As shown in FIG. 1, a positive electrode current collecting tab 31 having a protruding shape is provided on a part of one side of the positive electrode 21. The positive electrode current collecting tab 31 is disposed at the same position in each positive electrode 21 constituting the electrode assembly 20 and has the same shape. A protruding negative electrode current collecting tab 32 is provided on a part of the negative electrode 22 in one side direction. The negative electrode current collecting tab 32 is disposed at the same position in each negative electrode 22 constituting the electrode assembly 20 and has the same shape.

  The positive electrode current collecting tabs 31 are laminated so that the respective positive electrode current collecting tabs 31 are arranged in a line along the lamination direction. Similarly, the negative electrode current collecting tabs 32 are stacked such that the respective negative electrode current collecting tabs 32 are arranged in a row along the stacking direction so as not to overlap the positive electrode current collecting tabs 31. The plurality of positive electrode current collecting tabs 31 are collected in a range from one end to the other end of the electrode assembly 20 in the stacking direction. Similarly, the plurality of negative electrode current collecting tabs 32 are collected in a range from one end to the other end in the stacking direction of the electrode assembly 20.

  The electrode assembly 20 includes a positive electrode tab group 45 formed by collecting positive electrode current collecting tabs 31. The positive electrode tab group 45 is welded to the positive electrode conductive member 33. The electrode assembly 20 includes a negative electrode tab group 46 formed by collecting the negative electrode current collecting tabs 32. The negative electrode tab group 46 is welded to the negative electrode conductive member 37.

  The positive electrode conductive member 33 and the negative electrode conductive member 37 have a terminal connection portion 34 having a square plate shape. The positive electrode conductive member 33 and the negative electrode conductive member 37 have a rising portion 35 rising from the terminal connection portion 34 and a tab weld portion 36 extending from the rising portion 35 in a direction away from the terminal connection portion 34. The welded portion 36 has a rectangular plate shape. Then, the tab welded portion 36 of the positive electrode conductive member 33 is welded to the positive electrode tab group 45 of the electrode assembly 20, and the tab welded portion 36 of the negative electrode conductive member 37 is welded to the negative electrode tab group 46 of the electrode assembly 20. Yes.

  A positive electrode terminal 41 as an electrode terminal is welded to the terminal connection portion 34 of the positive electrode conductive member 33, and a negative electrode terminal 42 as an electrode terminal is welded to the terminal connection portion 34 of the negative electrode conductive member 37. Each of the positive electrode terminal 41 and the negative electrode terminal 42 has a base portion 43 having a square plate shape. A cylindrical pole column 44 is erected from the center of the base 43, and the lid-side seating surface 43 a of the base 43 has a pole when the positive electrode terminal 41 and the negative electrode terminal 42 are viewed from the tip end side of the pole column 44. The column portion 44 is surrounded. The pole portion 44 includes a male screw 44a on its outer peripheral surface and a female screw 44b on its inner peripheral surface.

  As shown in FIGS. 5 and 6, the pole column portion 44 includes a tapered portion T at the root portion connected to the base portion 43. In the taper portion T, the diameter of the pole column portion 44 is gradually increased toward the base portion 43 along the axis L of the pole column portion 44. The tapered portion T has a tapered shape in which a cross-sectional shape along the axis L extends linearly toward the base portion 43. Further, when a straight line passing through the inner surface 14a on the case body 13 side in the lid 14 is indicated by an imaginary line M, the taper portion T expands from the imaginary line M and is positioned in the case body 13. In the cross-sectional shape along the axis L of the polar column portion 44, the surface of the tapered portion T is formed in a shape that is inclined linearly from the polar column portion 44 toward the base portion 43. Further, when a position where the virtual line N passing through the surface of the taper portion T reaches the seating surface 43a of the base portion 43 is a point P, this point P is the inner peripheral surface of the insertion hole 14b along the thickness direction of the lid 14. It is located on the reference line R that passes.

  As shown in FIG. 1, a resin insulating cover 50 is attached to the base 43. The insulating cover 50 includes a lid-side insulating plate 51 that is sandwiched between the seating surface 43a of the base portion 43 and the inner surface 14a of the lid 14, and the lid-side insulating plate 51 allows the lid 14, the positive terminal 41, and the negative terminal. 42 is electrically insulated. The lid-side insulating plate 51 has an insertion portion 51a through which the pole column portion 44 is inserted in the thickness direction, and the inner peripheral edge of the lid-side insulating plate 51 has an arc shape. The lid-side insulating plate 51 has a cut-out communication portion 51b that opens the insertion portion 51a to one side of the lid-side insulation plate 51, and the lid-side insulation plate 51 is formed by the insertion portion 51a and the communication portion 51b. It is U-shaped in plan view.

  Of the edges of the lid-side insulating plate 51, the case-side insulating plate 52 extends in a direction away from the lid 14 from the opposite edge of the communicating portion 51 b with the insertion portion 51 a interposed therebetween. The case body 13 is electrically insulated from the positive terminal 41 and the negative terminal 42. The case-side insulating plate 52 has a rectangular plate shape and extends perpendicular to the lid-side insulating plate 51. The extension length of the case-side insulating plate 52 from the lid-side insulating plate 51 is set to be longer than the thickness of the base portion 43. In the case-side insulating plate 52, the assembly-side insulating plate 53 extends in the same direction as the lid-side insulating plate 51 from the tip on the side away from the lid 14. The positive electrode terminal 41 and the negative electrode terminal 42 are electrically insulated. The case side insulating plate 52 has a rectangular plate shape. The distance between the facing surfaces of the lid-side insulating plate 51 and the assembly-side insulating plate 53 is set slightly longer than the thickness of the base portion 43.

  The insulating cover 50 having the above configuration is attached to the positive terminal 41 and the negative terminal 42 from the short side wall 13b side of the case body 13. The pole column portion 44 is inserted into the insertion portion 51 a of the lid side insulating plate 51, and the lid side insulating plate 51 surrounds almost the entire circumference of the tapered portion T of the pole column portion 44. The lid-side insulating plate 51 is supported on the seating surface 43 a of the base 43.

  As shown in FIGS. 4 and 5, an O-ring 56 as a seal member is provided on the seating surface 43 a of the base portion 43 so as to surround the tapered portion T of the pole column portion 44. The O-ring 56 has an annular shape made of a rubber material having a circular cross section. Of the thickness along the radial direction, the O-ring 56 has a half on the outer peripheral edge side located outside the reference line R, and the inner peripheral edge on the base 43 side contacts the tapered portion T over the entire circumference. The ring 56 is disposed outside in the radial direction at the position of the tapered portion T. The O-ring 56 is disposed in the insertion portion 51 a of the lid-side insulating plate 51 in the radial direction of the pole column portion 44, and the O-ring 56 is substantially surrounded by the lid-side insulating plate 51. In other words, the O-ring 56 is surrounded by the inner peripheral edge of the lid-side insulating plate 51 except for the portion facing the communication portion 51b.

  In a state where the O-ring 56 surrounds the pole column 44 concentrically and the base 43 side of the inner periphery contacts the tapered portion T, the lid 14 side and the pole column 44 of the inner periphery of the O-ring 56 are in contact. There is a gap Ka between the outer peripheral surface of each of them. Further, in a state where the O-ring 56 is concentrically surrounded with the pole column portion 44 as the center, a gap Kb exists between the outer peripheral edge of the O-ring 56 and the inner peripheral edge of the lid-side insulating plate 51, and this gap Kb Is set narrower than the gap Ka between the pole column portion 44 and the pole column portion 44.

  As shown in FIGS. 5 and 6, the pole portion 44 inserted through the insertion portion 51 a of the lid-side insulating plate 51 protrudes from the inside of the case main body 13 through the insertion hole 14 b provided in the lid 14. (Exposed). The base 43 of the positive terminal 41 and the negative terminal 42 is disposed in the case body 13. Further, the cross-sectional area of the base portion 43 that is orthogonal to the axis L of the pole portion 44 and along the seating surface 43a is set to be larger than the area of the insertion hole 14b. For this reason, the base 43 cannot be removed from the insertion hole 14 b inside the case body 13.

  The inner peripheral surface as the inner surface of the insertion hole 14 b and the outer peripheral surface as the side surface of the pole post 44 are insulated by the terminal insulating member 19. The terminal insulating member 19 includes a cylindrical ring 19a and a flange portion 19b extending outward from one end edge of the ring 19a. The ring 19 a is interposed between the inner peripheral surface of the insertion hole 14 b and the outer peripheral surface of the pole column portion 44. The terminal insulating member 19 has the outer peripheral edge side of the ring 19 a overlapping the inner peripheral edge side of the O-ring 56 over the entire circumference when viewed from the axial direction of the pole post 44. Further, the tip of the ring 19 a on the side away from the flange portion 19 b is in contact with the O-ring 56.

  In the flange portion 19b, the surface on which the ring 19a extends is a locking surface 19c that is locked to the outside of the insertion hole 14b on the outer surface 14c of the lid 14. The extending length of the ring 19 a from the locking surface 19 c is set to be the same as the thickness of the lid 14. Therefore, the tip of the ring 19a is located on the same plane as the inner surface 14a of the lid 14, and covers the O-ring 56 from the lid 14 side.

  A nut 55 is screwed into the pole post 44. A flange portion 19b of the terminal insulating member 19 is interposed between the nut 55 and the outer surface 14c of the lid 14, and the nut 55 and the lid 14 are insulated by the flange portion 19b. Further, the flange portion 19 b, the lid 14, and the lid-side insulating plate 51 are sandwiched between the nut 55 and the base portion 43, and the pole column portion 44 is fastened to the lid 14. In this fastened state, the O-ring 56 is compressed between the inner surface 14a of the lid 14 and the seating surface 43a of the base 43, is in close contact with the inner surface 14a of the lid 14 and the seating surface 43a of the base 43, and is inserted into the insertion hole 14b. The insertion hole 14b is sealed around the periphery.

Next, the effect | action of the secondary battery 10 is demonstrated with a manufacturing method.
First, in the positive electrode conductive member 33 and the negative electrode conductive member 37, the base portions 43 of the positive electrode terminal 41 and the negative electrode terminal 42 are welded to the terminal connection portions 34, and the positive electrode conductive member 33 and the positive electrode terminal 41 are integrated and electrically connected. At the same time, the negative electrode conductive member 37 and the negative electrode terminal 42 are integrated and electrically connected. Next, the tab weld portion 36 of the positive electrode conductive member 33 is welded to the positive electrode tab group 45 of the electrode assembly 20, and the tab weld portion 36 of the negative electrode conductive member 37 is welded to the negative electrode tab group 46 of the electrode assembly 20. .

  As shown in FIG. 7, the insulating cover 50 is attached to the positive terminal 41, and the lid-side insulating plate 51 is supported on the seating surface 43 a of the base 43, and the assembly-side insulating plate 53 is disposed below the base 43. The insulating cover 50 is pushed in until the case-side insulating plate 52 comes into contact with the opposing base portion 43. Although not shown, the insulating cover 50 is also attached to the negative terminal 42.

Next, an O-ring 56 is externally mounted on each pole column portion 44.
As shown in FIGS. 7 and 8, it is assumed that the O-ring 56 has a part of the inner peripheral edge in the circumferential direction riding on the tapered portion T. In this case, the O-ring 56 is partly in contact with the tapered portion T in the circumferential direction, and the opposite side in the radial direction is separated from the tapered portion T with respect to the contact portion. The state is inclined with respect to the axis L.

  Next, the ring 19 a of the terminal insulating member 19 is inserted into the insertion hole 14 b of the lid 14, and the flange portion 19 b is locked to the outer surface 14 c of the lid 14. Then, with the O-ring 56 tilted, the lid 14 is assembled while the pole column portion 44 is inserted into the ring 19a in the insertion hole 14b. At this time, the ring 19 a exists between the inner peripheral surface of the insertion hole 14 b and the outer peripheral surface of the pole column portion 44 by the ring 19 a, and the O ring 56 is connected to the inner peripheral surface of the insertion hole 14 b and the pole column portion 44. Biting between the outer peripheral surface is prevented.

  When the lid 14 is assembled, the inner surface 14 a of the lid 14 comes into contact with the O-ring 56, and the O-ring 56 is pushed toward the base portion 43. Then, the O-ring 56 is moved to the base 43 side along the tapered portion T. At this time, since the taper portion T expands toward the base portion 43, the O-ring 56 extends along the taper portion T, so that the side that is in contact with the taper portion T extends along the radial direction of the pole column portion 44. While being guided in a direction away from the portion 44, the portion on the opposite side in the radial direction is drawn toward the polar column portion 44 along the radial direction of the polar column portion 44. As a result, as shown in FIG. 9, the O-ring 56 is disposed concentrically around the pole column portion 44 and is disposed inside the lid-side insulating plate 51.

  Then, when the lid 14 is supported by the O-ring 56, the nut 55 is screwed onto the male screw 44 a of the pole post 44. Then, the inner surface 14 a of the lid 14 comes into contact with the lid-side insulating plate 51, and the O-ring 56 is crushed toward the base 43 by the lid 14. At this time, the thickness of the lid-side insulating plate 51 prevents the O-ring 56 from being excessively crushed by the lid 14. As a result, the O-ring 56 is positioned at a position in close contact with the inner surface 14a of the lid 14 and the seating surface 43a of the base portion 43 and surrounding the periphery of the insertion hole 14b.

  Further, as the nut 55 is screwed, the flange portion 19 b is pushed toward the lid 14, the ring 19 a is pushed toward the terminal insulating member 19, and the ring 19 a overlaps the O ring 56 from the lid 14 side. Thereafter, the electrode assembly 20 is accommodated in the case main body 13, and the lid 14 is welded to the case main body 13 to form the case 12. As a result, the secondary battery 10 is manufactured.

According to the above embodiment, the following effects can be obtained.
(1) The positive electrode terminal 41 and the negative electrode terminal 42 are formed from a base portion 43 and a polar column portion 44, and the polar column portion 44 is a taper portion that extends toward the base portion 43 in a cross-sectional shape at the root portion connected to the base portion 43. T. Therefore, when the O-ring 56 is mounted on the pole portion 44, the positive terminal 41 and the negative terminal 42 are assembled to the lid 14 even if the O-ring 56 rides on the tapered portion T and is displaced with respect to the insertion hole 14b. At this time, when the O-ring 56 is pushed by the lid 14, the O-ring 56 can be moved to a position surrounding the pole column 44 concentrically by the tapered portion T. For this reason, by providing the tapered portion T, the O-ring 56 can be disposed at a position where the O-ring 56 can be enclosed and sealed around the insertion hole 14 b and can be performed simultaneously with the assembly of the lid 14.

  (2) If the O-ring 56 is pushed by the lid 14 and disposed around the tapered portion T, then the inner periphery of the O-ring 56 contacts the tapered portion T, and the O-ring 56 moves in the radial direction. Can be regulated.

  (3) A ring 19 a of the terminal insulating member 19 that insulates between the pole column portion 44 and the lid 14 is inserted between the inner peripheral surface of the insertion hole 14 b and the outer periphery surface of the pole column portion 44. The ring 19 a of the terminal insulating member 19 overlaps the O-ring 56 when viewed from the axial direction of the pole column portion 44. For this reason, for example, even if the internal pressure of the case 12 increases and the internal pressure acts on the O-ring 56, the terminal insulating member 19 can prevent the O-ring 56 from being lifted to the lid 14 side. Can be prevented from slipping out of the case 12 from between the inner peripheral surface and the outer peripheral surface of the pole post 44.

  (4) By providing the tapered part T in the pole column part 44 of the positive electrode terminal 41 and the negative electrode terminal 42, the O-ring 56 can be easily arranged at a position where the insertion hole 14b can be sealed. Therefore, even if the rubber O-ring 56 having a simple configuration is employed as the seal member, the insertion hole 14b can be reliably sealed.

  (5) The taper portion T has a taper shape that extends linearly toward the base portion 43 in its cross-sectional shape. For this reason, when the O-ring 56 is pushed by the lid 14, the O-ring 56 can be moved smoothly.

  (6) The insulating cover 50 is attached to the base portion 43 of the positive electrode terminal 41 and the negative electrode terminal 42, and the pole column portion 44 is inserted into the insertion portion 51 a of the lid-side insulating plate 51. When the O-ring 56 is externally mounted on the pole column portion 44, the O-ring 56 is disposed inside the lid-side insulating plate 51 in the radial direction of the pole column portion 44. When the O-ring 56 is arranged concentrically with respect to the pole column 44 on the radially outer side of the pole column 44, the gap Ka between the inner peripheral edge of the O-ring 56 and the pole column 44 is outside the O-ring 56. It is larger than the gap Kb between the peripheral edge and the inner peripheral edge of the lid-side insulating plate 51. For this reason, even if the O-ring 56 is displaced in the radial direction, the outer peripheral edge of the O-ring 56 comes into contact with the inner peripheral edge of the lid-side insulating plate 51 and moves until the inner peripheral edge of the O-ring 56 comes into contact with the pole column portion 44. This can be prevented, and the O-ring 56 can be brought into contact with the tapered portion T. Therefore, when the O-ring 56 is pushed by the lid 14, the amount by which the O-ring 56 is moved can be reduced.

  (7) The lid-side insulating plate 51 of the insulating cover 50 is interposed between the lid 14 and the base portion 43 when the nut 55 is screwed into the male screw 44 a of the pole post 44. For this reason, the lid-side insulating plate 51 functions as a spacer between the lid 14 and the base 43, and the nut 55 can be prevented from excessively screwing. Therefore, the O-ring 56 can be prevented from being excessively crushed by interposing the lid-side insulating plate 51.

  (8) A taper portion T is formed at the root portion of the pole column portion 44, and the O-ring 56 is positioned concentrically around the pole column portion 44 on the outer side in the radial direction of the pole column portion 44 by the taper portion T. It can arrange | position in the position which surrounds the circumference | surroundings of the insertion hole 14b. For this reason, when the O-ring 56 is crushed by the lid 14, it is possible to prevent the inner peripheral edge of the insertion hole 14 b from hitting the O-ring 56. Further, in order to assemble the positive terminal 41 and the negative terminal 42 to the lid 14 with the terminal insulating member 19 inserted in the insertion hole 14b of the lid 14, the O-ring 56 is inserted into the insertion hole 14b by the ring 19a of the terminal insulating member 19. It is possible to prevent biting between the inner peripheral surface and the outer peripheral surface of the pole post 44.

  (9) Since the pole portion 44 has the taper portion T at the base portion, the positive electrode terminal 41 and the negative electrode terminal 42 are assembled to the lid 14 even when the O-ring 56 is displaced from the insertion hole 14b. The O-ring 56 can be positioned at a position surrounding the insertion hole 14b. Therefore, there is no need to manually correct the position of the O-ring 56, and the assembling property and productivity of the secondary battery 10 can be improved.

In addition, you may change the said embodiment as follows.
○ The insulating cover 50 may be omitted.
In the embodiment, in the cross-sectional shape along the axis L, the tapered portion T is linearly inclined toward the base 43, but the tapered portion T is a cross-sectional shape along the axis L of the polar column portion 44. However, the taper portion T does not have to be inclined linearly, and the tapered portion T is curved in an arc shape bulging outward or conversely concave inward. May be.

In the embodiment, the seal member is embodied as the O-ring 56 having a circular cross section, but the cross-sectional shape is not limited to the circular shape, and may be an O-ring having another cross-sectional shape.
In the embodiment, the O-ring 56 is embodied as a seal member, but may be changed to a resin gasket or the like.

  In the embodiment, the ring 19 a of the terminal insulating member 19 overlaps the O-ring 56 when viewed from the axial direction of the pole column portion 44, but the ring 19 a may not overlap the O-ring 56.

  In the embodiment, the terminal insulating member 19 is formed in a cylindrical shape, and the ring 19a is inserted over the entire circumference between the inner peripheral surface of the insertion hole 14b and the outer peripheral surface of the pole column portion 44. The member 19 may be inserted only in a part in the circumferential direction between the inner peripheral surface of the insertion hole 14 b and the outer peripheral surface of the pole column portion 44. The terminal insulating member 19 may overlap only a part in the circumferential direction of the O-ring 56 when viewed from the axial direction of the pole post 44. Further, the ring 19 a of the terminal insulating member 19 may overlap the entire O-ring 56 when viewed from the axial direction of the pole column portion 44.

In the embodiment, the tapered portion T is formed over the entire circumference of the polar column portion 44, but may be formed only in a part of the circumferential direction of the polar column portion 44.
The pole column portion 44 may be formed in a conical shape over the entire axial direction, and the entire pole column portion 44 may be a tapered portion T.

The number of the positive electrode 21 and the negative electrode 22 which comprise the electrode assembly 20 may be changed suitably.
○ The shape of the case 12 may be cylindrical or elliptical.

  The present invention may be embodied as a nickel hydride secondary battery as an electricity storage device or an electric double layer capacitor.

  L ... axis, T ... taper part, 10 ... secondary battery as a power storage device, 13 ... case main body, 13d ... opening, 14 ... lid, 14a ... inner surface, 14b ... insertion hole, 19 ... terminal insulating member, 20 ... Electrode assembly 41: Positive terminal as electrode terminal, 42: Negative terminal as electrode terminal, 43: Base, 43a ... Seat surface, 44 ... Polar column part, 50 ... Insulation cover, 51a ... Insertion part, 56 ... Seal O-ring as a member.

In order to solve the above problems, the invention according to any one of claims 1 to 3 includes a case main body having an opening, a lid having an insertion hole for closing the opening and through which an electrode terminal is inserted, and the case. An electrode assembly housed in the body, a base portion disposed in the case body and having a cross-sectional area larger than the area of the insertion hole, and a case erected from the base portion and passing through the insertion hole A pole post projecting from the inside of the main body to the outside; the electrode terminal electrically connected to the electrode assembly; an inner surface of the lid on the case main body side; and the base portion facing the inner surface. A cross-section along the axis of the pole column at a root portion connected to at least the base of the pole column. A tape that extends in the shape toward the base. Has a section in at least a part around said axis, said sealing member that is located radially outwardly at the position of the tapered portion.

The invention according to claim 1 includes a terminal insulating member that is inserted between an inner surface of the insertion hole and a side surface of the pole column portion that faces the inner surface, and the terminal insulating member is provided on the pole column portion. The gist is that the seal member overlaps at least a part of the seal member when viewed from the axial direction.

The gist of the invention described in claim 2 is that the seal member is an O-ring.
According to this, a sealing member can be arrange | positioned in the position which can seal an insertion hole with a taper part. Therefore, even if an O-ring having a simple configuration is used as the seal member, the insertion hole can be reliably sealed.
The invention according to claim 3 includes an insulating cover that insulates between the inner surface of the lid on the case main body side and the seating surface of the base portion facing the inner surface, and the insulating cover includes the pole column portion. And the sealing member is arranged inside the insertion portion in the radial direction of the pole portion.
According to this, when the sealing member is mounted on the pole column portion, even if the sealing member rides on the taper portion, the outer peripheral edge of the sealing member contacts the inner peripheral edge of the insulating cover, and the sealing member becomes the pole column portion. It is possible to prevent the position from being greatly displaced in the radial direction.

Claims (6)

A case body having an opening;
A lid that closes the opening and has an insertion hole through which the electrode terminal is inserted;
An electrode assembly housed in the case body;
A base portion disposed in the case body and having a cross-sectional area larger than the area of the insertion hole, and a pole column portion standing from the base portion and projecting from the inside of the case body to the outside through the insertion hole And the electrode terminal electrically connected to the electrode assembly,
An electrical storage device having an inner surface of the lid on the case body side and an annular seal member sandwiched between a seating surface of the base portion facing the inner surface,
At least a part of the base portion connected to at least the base portion of the polar column portion has a taper portion extending toward the base portion in a cross-sectional shape along the axis line of the polar column portion, at least around the axis line,
The power storage device, wherein the seal member is disposed on a radially outer side at the position of the tapered portion.   A terminal insulating member inserted between an inner surface of the insertion hole and a side surface of the pole column portion facing the inner surface, and the terminal insulating member of the seal member as viewed from the axial direction of the pole column portion; The power storage device according to claim 1, wherein the power storage device overlaps at least a part thereof.   The power storage device according to claim 1, wherein the seal member is an O-ring.   The power storage device according to any one of claims 1 to 3, wherein the tapered portion has a tapered shape in which the cross-sectional shape extends linearly toward the base portion.   The cover includes an insulating cover that insulates between the inner surface of the case body side of the lid and the seating surface of the base portion facing the inner surface, and the insulating cover includes an insertion portion for the pole column portion, and the pole 5. The power storage device according to claim 1, wherein the seal member is disposed inside the insertion portion in a radial direction of the column portion.   The power storage device according to any one of claims 1 to 5, wherein the power storage device is a secondary battery.