JP2018186053A - Power storage device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device capable of reducing weight and cost of an external terminal.SOLUTION: A power storage device (1) according to the present invention includes an exterior body (30) accommodating a power storage element (4) and an external terminal (50) exposed to the outside of the exterior body (30), and the external terminal (50) has a hollow terminal main body (52) having a peripheral wall (54) protruding outward from the surface of the exterior body (30) and an end wall (58) blocking the tip end opening of the peripheral wall (54). The external terminal (50) may include a resin layer (70) covering at least a part of the inner surface of the terminal main body (52).SELECTED DRAWING: Figure 9

Description

  The present invention relates to a power storage device including an exterior body and an external terminal.

  In an engine room of an engine automobile, a power storage device having a relatively low voltage (for example, 12V) is usually mounted. As disclosed in Patent Document 1, lead storage batteries are mainly used as this type of power storage device. The lead acid battery has a pair of frustoconical external terminals (so-called pole terminals) protruding from the upper surface of the exterior body. A ring-shaped fitting portion provided at the tip of the connection member on the vehicle body side is fitted and tightened on the outside of each external terminal, whereby the power storage device is connected to the electric system on the vehicle body side.

  In recent years, a battery other than a lead storage battery, such as a lithium ion battery, may be used as the above-described in-vehicle power storage device instead of a lead storage battery. In lead-acid batteries, the use of lead, which is a hazardous substance, is exceptionally permitted as a material for parts, and therefore, lead external terminals manufactured by casting are generally used. On the other hand, in batteries other than lead acid batteries, the use of lead external terminals is restricted.

  Examples of materials other than lead used as the material of the external terminal include copper, brass, aluminum, and aluminum alloys. When manufacturing external terminals using these metal materials, casting is not performed because the melting point is higher than that of lead. Usually, the surface is formed by rolling or cutting after being formed by cold forging using a mold. Is processed.

JP 2017-033662 A

  By the way, metal materials such as copper, brass, aluminum, and aluminum alloy described above are more expensive than lead. Moreover, when manufacturing an external terminal by the forging and surface processing mentioned above, a manufacturing cost tends to become high compared with the case where a lead-made external terminal is manufactured by casting. Furthermore, since the conventional external terminal is usually a solid columnar shape or a truncated cone shape, the weight tends to increase. Therefore, there is room for improvement in lightening the power storage device and reducing the cost.

  However, no effective proposal has been made to date for reducing the weight of the external terminal and reducing the cost of the power storage device including the external terminal made of a material other than lead.

  In view of the above, an object of the present invention is to provide a power storage device capable of reducing the weight and cost of an external terminal.

  One embodiment of the present invention includes an exterior body that houses a power storage element, and an external terminal that is exposed to the outside of the exterior body. The external terminal protrudes outward from the surface of the exterior body, and the circumferential wall Provided is a power storage device including a hollow terminal body having an end wall that closes a tip opening.

  In this power storage device, since the terminal body of the external terminal is hollow, the weight of the external terminal can be reduced as compared with the case where a solid terminal body is used. In addition, since the terminal body composed of the peripheral wall and the end wall can be formed by drawing a single plate material, the manufacturing cost is reduced compared to the case of manufacturing a solid terminal body by forging or casting. be able to. Furthermore, since the displacement of the front-end | tip part of the surrounding wall of a terminal main body is controlled by the end wall provided in the front-end | tip of a terminal main body, a deformation | transformation of the surrounding wall when external force is applied can be suppressed. In addition, since the end opening of the peripheral wall of the terminal body is closed by the end wall, the airtightness of the power storage device can be ensured.

  In the above power storage device, it is preferable that the external terminal includes a resin layer that covers at least a part of the inner surface of the terminal body.

  In this case, the peripheral wall and end wall of the terminal body can be reinforced by the resin layer covering the inner surface of the terminal body. Further, the terminal body can be thinned by the reinforcement by the resin layer, thereby further reducing the weight of the external terminal. If the entire internal space of the terminal body is filled with molten resin and solidified, and if a pre-molded resin molded product is attached to the inside of the terminal body, a gap is formed between the inner surface of the terminal body and the resin part. Is likely to occur. On the other hand, the resin layer covering the inner surface of the terminal body as described above is easily formed in a state where the resin layer overlaps the inner surface of the terminal body without any gap by, for example, insert molding. Therefore, the external force applied to the terminal body can be reliably received by the resin layer, so that effective reinforcement can be achieved.

  In the above power storage device, when at least a part of the exterior body is made of a resin member, the resin layer may be a part of the resin member.

  In this case, for example, by molding the resin layer integrally with at least a part of the exterior body by insert molding, dedicated parts for reinforcing the terminal body from the inside can be omitted, thereby reducing the number of parts and the number of assembly steps. Can be planned.

  In the above power storage device, the peripheral wall may include a non-exposed portion sandwiched between the resin layer and a portion other than the resin layer of the resin member, and a through hole is provided in the non-exposed portion. May be.

  In the case where the external terminal in this power storage device, at least a part of the exterior body, and the resin layer are integrally formed by insert molding, when injecting resin into the mold, via the through hole in the peripheral wall of the external terminal, The resin can flow between the inside and the outside of the peripheral wall. Therefore, the resin can be smoothly supplied to the entire inside and outside of the peripheral wall inside the mold, thereby enabling high-precision insert molding. Moreover, since the resin-made connection part which connects an exterior body and a resin layer is shape | molded in the through-hole of the surrounding wall of an external terminal, the displacement to the circumferential direction of a surrounding wall is controlled by this connection part. As a result, it is possible to achieve a detent function that restricts relative rotation of the external terminal with respect to the exterior body.

  In the above power storage device, a resin beam portion that connects between a plurality of locations in the resin layer may be provided inside the terminal body. In this case, the terminal body can be more effectively reinforced by supporting the plurality of portions of the resin layer from the side opposite to the terminal body by the resin beam portion.

  In the above power storage device, the external terminal may include a protrusion provided on the inner surface of the peripheral wall, and the protrusion may be covered with the resin layer. In this case, the relative displacement of the external terminal with respect to the exterior body can be restricted by restricting the circumferential displacement of the protrusion provided on the inner side of the peripheral wall of the external terminal by the resin layer integral with the exterior body.

  In the above power storage device, the external terminal may include a protrusion that protrudes radially outward from the peripheral wall, and the protrusion has the exterior body so that the entire surface thereof is covered with the material of the exterior body. It may be embedded in. In this case, the circumferential and axial displacements of the protrusions provided on the external terminal are restricted by the exterior body, so that the relative rotation of the external terminal with respect to the exterior body can be restricted, and the external terminal can be removed from the exterior body. The stop is fulfilled.

  In the above power storage device, the external terminal may further include a connection part integrally formed with the terminal body, and the power storage element and the terminal body are electrically connected via the connection part. Also good. In this case, the number of parts of the connecting member such as a bus bar can be reduced by providing the connecting portion integrally with the external terminal. Moreover, the process of fixing the terminal body to the connecting member such as a bus bar can be omitted when manufacturing the power storage device.

  In the above power storage device, at least a part of the connection portion may be embedded in the exterior body. In this case, the connection part of the external terminal is embedded in the exterior body, whereby occurrence of a short circuit due to contact between the connection part and another conductive member can be suppressed.

  Another aspect of the present invention provides a method for manufacturing a power storage device, in which an external terminal exposed outside the exterior body of the power storage device is formed by drawing a single metal plate with a press die.

  According to this method for manufacturing a power storage device, an external terminal having a hollow terminal body can be easily formed by drawing. Therefore, when manufacturing an external terminal using a metal material having a higher melting point than lead, such as copper, brass, aluminum, and aluminum alloy, compared to manufacturing a solid external terminal by casting or forging, The weight of the external terminal can be reduced and the manufacturing cost can be reduced.

  In the manufacturing method of the power storage device, the external terminal formed by the drawing process is inserted into an insert mold, and a resin is injected around the external terminal inserted into the insert mold. You may make it shape | mold the said exterior body which consists of the said resin within the said insert molding die. In this case, the resin-made exterior body can be easily integrated with the external terminal made of one metal plate by insert molding.

  In the power storage device manufacturing method, when the exterior body is molded in the insert molding die, a resin layer covering at least a part of the inner surface of the external terminal is molded integrally with the exterior body. Also good. In this case, in the insert molding die, the exterior body is molded with the resin filled outside the external terminal, and the resin layer is molded with the resin filled inside the external terminal, so that the external terminal, the exterior body, In addition, the resin layer can be easily integrated. In addition, it is possible to reduce the thickness of the metal plate that constitutes the external terminal while reinforcing the inner surface of the external terminal with the resin layer, thereby further reducing the weight of the external terminal.

  According to the present invention, since the terminal body of the external terminal is hollow, the weight of the external terminal can be reduced as compared with the case where a solid terminal body is used. Further, since the terminal body can be formed by drawing a single plate material, the manufacturing cost can be reduced as compared with the case where the solid terminal body is manufactured by forging or casting.

The perspective view which shows the electrical storage apparatus which concerns on one Embodiment of this invention. The disassembled perspective view of the electrical storage apparatus shown in FIG. The perspective view which looked at the external terminal from the upper part. The perspective view which looked at the external terminal from the downward direction. The perspective view which looked at the external terminal and its peripheral part from the upper part. The perspective view which looked at the external terminal and its peripheral part from the downward direction. The top view of an external terminal and its peripheral part. The side view of an external terminal and its peripheral part. AA line sectional view of Drawing 7 which looked at an external terminal and its peripheral part from the side. The BB sectional drawing of FIG. 8 which looked at the lower end part and peripheral part of the external terminal from the downward direction. The CC sectional view taken on the line of FIG. Sectional drawing which shows an example of the process of insert molding which integrates an external terminal and a cover body. Sectional drawing similar to FIG. 9 which looked at the external terminal and its peripheral part in the electrical storage apparatus which concerns on a modification from the side. The DD sectional view taken on the line of FIG. 13 which looked at the inside of the terminal main body of the external terminal shown in FIG.

  Hereinafter, a power storage device according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, terms indicating specific directions and positions (for example, terms including “up”, “down”, “lateral”, “side”, “end”) are used as necessary. The use of the term is for facilitating the understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meaning of the term. That is, these terms indicate directions in the posture of the power storage device shown in the attached drawings, and do not necessarily coincide with directions in an actual use state. Further, the following description is merely illustrative in nature and is not intended to limit the present invention, its application, or its use.

[overall structure]
As shown in FIGS. 1 and 2, an assembled battery (battery module) 1 as a power storage device according to this embodiment includes a single battery (battery cell) 4 (see FIG. 2) and a single battery 4 as power storage elements. And an exterior body 20 to be accommodated. Although the use of the assembled battery 1 is not limited, For example, you may mount in moving bodies, such as a motor vehicle. In this case, for example, the assembled battery 1 can be used as a relatively low voltage (for example, 12V) auxiliary battery mounted on a vehicle such as a gasoline vehicle or a diesel vehicle.

  The single battery 4 shown in FIG. 2 is a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery, for example. The single battery 4 is a so-called square battery. For example, a plurality of unit cells 4 are stacked in the horizontal direction. These unit cells 4 are held in a stacked state using, for example, a metal restraint band 6. However, the stacking direction of the unit cells 4 is not particularly limited. For example, a plurality of unit cells 4 may be stacked in the vertical direction.

  Each unit cell 4 has, for example, positive and negative terminals (not shown) arranged on the upper surface thereof. A terminal of each unit cell 4 is electrically connected to a terminal of another unit cell 4 via a bus bar (not shown). In this way, the module main body 2 is composed of a plurality of unit cells 4 stacked and electrically connected to each other.

  An electrical component unit 8 including an electrical component such as a circuit breaker is attached to one side surface in the stacking direction of the unit cells 4 in the module body 2. On the upper surface of the module main body 2, the end of the first bus bar 10 electrically connected to the positive terminals of some of the single cells 4 constituting the module main body 2 and another single cell constituting the module main body 2. An end portion of the second bus bar 14 electrically connected to the negative electrode terminal 4 is disposed. The first bus bar 10 and the second bus bar 14 are made of, for example, aluminum, aluminum alloy, copper, or brass.

  The first bus bar 10 is connected to the positive electrode terminal of the unit cell 4 via, for example, the electric component of the electric component unit 8. The second bus bar 14 is connected to the negative terminal of the unit cell 4 via, for example, a shunt resistor (not shown). However, the 1st bus bar 10 and the 2nd bus bar 14 may be directly connected to the terminal of unit cell 4 without passing through an electric part.

  On the upper surface of the module body 2, the end of the first bus bar 10 is disposed at one end of the unit cell 4 in the stacking direction, and the end of the second bus bar 14 is disposed at the other end of the unit cell 4 in the stacking direction. Has been. Note that a monitoring unit 18 having a control board (not shown) is disposed between the end of the first bus bar 10 and the end of the second bus bar 14 on the upper surface of the module body 2.

  The exterior body 20 includes a box-shaped case main body 22 having an upper surface opened, and a lid body 30 that closes the upper surface opening of the case main body 22. The case main body 22 and the lid 30 are resin members. However, the material of the case body 22 and the lid 30 may be an insulating material other than resin.

  A rib-like engagement portion 24 extending in the circumferential direction is provided in the vicinity of the upper edge of the case body 22. The lid body 30 has an upper surface portion 32 that faces the upper surface of the module body 2 and a peripheral wall portion 34 that extends downward from the peripheral edge portion of the upper surface portion 32. For example, a pair of handle portions 36 are provided on the upper surface portion 32 of the lid 30. The lid 30 is attached to the case body 22 with the peripheral wall portion 34 fitted to the outside of the upper edge of the case body 22 (see FIG. 1). In this attached state, the inner peripheral surface of the peripheral wall portion 34 of the lid 30 is engaged with the engaging portion 24 of the case body 22.

  However, the configuration for attaching the lid 30 to the case body 22 is not particularly limited. For example, the lid 30 is attached to the case body 22 by fastening, bonding, or welding using screws. Also good.

  The lid 30 is provided with a positive external terminal 50A and a negative external terminal 50B. Each external terminal 50 </ b> A, 50 </ b> B protrudes upward from the upper surface portion 32 of the lid 30, and is thereby exposed to the outside of the exterior body 20.

[External terminal]
Hereinafter, the configuration of the external terminal 50 (50A, 50B) will be described. The positive external terminal 50A and the negative external terminal 50B have the same configuration.

  As shown in FIGS. 3 and 4, the external terminal 50 includes a hollow terminal body 52 and a connection portion 68 that is integrally connected to the terminal body 52. The terminal body 52 and the connection portion 68 are integrally formed. The material of the terminal body 52 and the connection portion 68 is, for example, aluminum or an aluminum alloy, but may be other metals or conductive materials other than metals.

  The terminal main body 52 includes a peripheral wall 54 that extends in the axial direction, and an end wall 58 that closes the tip opening of the peripheral wall 54. The end wall 58 has a circular shape, for example, and the peripheral wall 54 has, for example, a circular cross section. The peripheral wall 54 includes a main peripheral wall portion 55 that extends downward from the peripheral portion of the end wall 58, a flange portion 56 that extends radially outward from the lower end of the main peripheral wall portion 55, and a lower peripheral wall that extends downward from the peripheral portion of the flange portion 56. Part 57.

  As shown in FIG. 5, the main peripheral wall portion 55 is disposed so as to protrude upward from the upper surface portion 32 of the lid body 30. Accordingly, the main peripheral wall portion 55 and the end wall 58 are disposed so as to be exposed to the outside of the exterior body 20. The main peripheral wall portion 55 and the end wall 58 constitute a so-called pole terminal having a truncated cone-shaped contour that is gradually reduced in diameter toward the distal end side in the axial direction.

  However, the contour of the pole terminal composed of the main peripheral wall portion 55 and the end wall 58 may be a columnar shape having a constant diameter over the entire length in the axial direction, and gradually increases in diameter toward the distal end side in the axial direction. An inverted frustoconical shape may be used.

  When the assembled battery 1 is mounted on an automobile, a connection member (not shown) generally called “battery terminal” is fitted to the outside of the main peripheral wall portion 55. The assembled battery 1 is connected to an electric system on the vehicle body side via the connection member.

  As shown in FIGS. 3 and 4, the lower peripheral wall portion 57 is a ring-shaped portion having a larger diameter than the main peripheral wall portion 55. A through hole 66 is provided in the lower peripheral wall portion 57. A plurality of through holes 66 are provided at intervals in the circumferential direction.

  The terminal main body 52 further includes a flange-shaped protrusion 60 that protrudes radially outward from the lower end of the peripheral wall 54, that is, the lower end of the lower peripheral wall 57. The protrusion 60 is continuously provided over a predetermined circumferential region in the peripheral wall 54. On the outer periphery of the protrusion 60, a plurality of teeth 62 are provided at intervals in the circumferential direction. A tooth gap 64 is formed between adjacent tooth portions 62.

  The connection portion 68 of the external terminal 50 is provided so as to extend in a band plate shape from the lower end portion of the peripheral wall 54 toward the radially outer side. The proximal end portion of the connecting portion 68 is connected to the remaining circumferential region except for the circumferential region where the protrusion 60 is formed on the circumferential wall 54. The distal end portion of the connecting portion 68 is joined to the end portion of the first bus bar 10 or the second bus bar 14 (see FIG. 2) by, for example, fixing with a bolt and a nut, or welding.

  Thereby, the terminal main body 52 of the positive external terminal 50A is electrically connected to the positive terminal of the unit cell 4 via the connection portion 68 and the first bus bar 10, and the terminal main body 52 of the negative external terminal 50B is connected to The unit 68 and the second bus bar 14 are electrically connected to the negative terminal of the unit cell 4.

  The connecting portion 68 may be provided so as to extend linearly from the proximal end portion to the distal end portion, and a bent portion or a curved portion is provided between the proximal end portion and the distal end portion of the connecting portion 68. May be.

  The material of the connecting portion 68 in the positive external terminal 50A is preferably the same type of metal as that of the first bus bar 10, and the material of the connecting portion 68 of the negative external terminal 50B is the same type of metal as that of the second bus bar 14. It is preferable that Thereby, joining of the connection part 68 with respect to the 1st bus bar 10 and the 2nd bus bar 14 by welding can be performed favorably.

  The thickness of the terminal body 52 is preferably, for example, 1.0 mm or more and 3.0 mm or less. When the terminal body 52 has a thickness of 1.0 mm or more, the terminal body 52 has good rigidity and strength, and when the terminal body 52 has a thickness of 3.0 mm or less, the external terminal 50 is lightweight. Is effectively realized. The thickness of the connection portion 68 may be the same as or different from that of the terminal body 52.

  The configuration of the external terminal 50 and its peripheral part will be further described with reference to FIGS.

  As shown in FIGS. 5 to 9, the external terminal 50 is integrated with the lid body 30 by, for example, insert molding. On the upper surface portion 32 of the lid body 30, a first covering portion 42 that covers the lower peripheral wall portion 57 of the terminal body 52, a second covering portion 44 that covers the protruding portion 60 of the terminal body 52, and a connection portion of the external terminal 50. A third covering portion 46 covering 68 is provided.

  In particular, as shown in FIGS. 5 and 9, the first covering portion 42 is provided so as to protrude upward from the upper surface portion 32 of the lid body 30 (outside the exterior body 20). The first covering portion 42 is an annular portion that extends in the circumferential direction over the entire circumference along the outer peripheral surface of the lower peripheral wall portion 57 of the terminal body 52. Accordingly, the lower peripheral wall portion 57 is a non-exposed portion that is covered from the outside in the radial direction by the portion including the first covering portion 42 in the lid body 30.

  The upper end portion of the first covering portion 42 covers a corner portion between the lower peripheral wall portion 57 and the flange portion 56 of the terminal body 52. As a result, only the radially inner portion of the flange portion 56 is exposed.

  In particular, as shown in FIGS. 6 and 9, the second covering portion 44 is provided so as to protrude downward from the upper surface portion 32 of the lid body 30 (inside the exterior body 20). The second covering portion 44 is an annular portion that extends in the circumferential direction along the lower end portion of the peripheral wall 54 of the terminal body 52.

  The protrusion 60 provided on the lower end portion of the peripheral wall 54 of the terminal body 52 is covered from the upper side and the lower side in the axial direction and from the outer side and the inner side in the radial direction by the portion including the second covering portion 44 in the lid body 30. It has been broken. That is, the protrusion 60 is embedded in the lid 30 so that the entire surface is covered with the material of the lid 30. Thereby, the relative movement of the terminal body 52 with respect to the lid body 30 is restricted in the axial direction and the radial direction. Particularly, the relative displacement in the axial direction is restricted, so that the external terminal 50 is prevented from coming off from the lid 30.

  As shown in FIG. 10, the second covering portion 44 is provided with a tooth portion 45 fitted into the tooth groove 64 in the protruding portion 60 of the terminal body 52. The resin material constituting the tooth portion 45 of the second covering portion 44 is filled in the entire tooth groove 64 of the protruding portion 60. The tooth portions 45 of the second covering portion 44 are provided so as to correspond to all the tooth spaces 64 in the protruding portion 60. In this manner, the tooth portion 45 of the lid 30 is engaged with the tooth groove 64 of the terminal body 52, so that the relative rotation of the external terminal 50 with respect to the lid 30 is restricted.

  In particular, as shown in FIGS. 5, 6, 9, and 10, the third covering portion 46 is provided so as to protrude downward from the upper surface portion 32 of the lid body 30 (inside the exterior body 20). The third covering portion 46 is a band plate-like portion extending along the connection portion 68 of the external terminal 50. The 3rd coating | coated part 46 does not need to be provided over the full length of the connection part 68, and it is preferable that the junction part with the 1st bus bar 10 or the 2nd bus bar 14 in the connection part 68 is exposed.

  The connection portion 68 of the external terminal 50 is disposed in parallel to the upper surface portion 32 of the lid 30 and is covered at least from the lower side by the third covering portion 46. More specifically, the connecting portion 68 is embedded in the lid body 30 in the longitudinal direction portion where the third covering portion 46 is provided. Thereby, the connection part 68 is the upper part and the lower part (the outer side and the inner side of the exterior body 20) of the thickness direction and the short side direction (the width direction) by the part including the third covering part 46 in the lid body 30. Covered from both sides.

  Since the connection part 68 covered with the 3rd coating | coated part 46 is controlled in contact with a surrounding conductive member, generation | occurrence | production of a short circuit can be suppressed. Further, the relative movement of the connecting portion 68 with respect to the lid body 30 is restricted in the thickness direction and the short side direction of the connecting portion 68, so that the external terminal 50 can be prevented from coming off from the lid body 30 and the lid body 30. The external terminal 50 is prevented from being rotated.

  In particular, as shown in FIGS. 9 and 11, the external terminal 50 further includes a resin layer 70 that covers the inner surface of the terminal body 52. The resin layer 70 is integrally formed with the lid body 30. That is, the resin layer 70 is a part of the lid 30.

  The resin layer 70 includes a first layer portion 72 that covers the inner peripheral surface of the peripheral wall 54 of the terminal body 52, and a second layer portion 74 that covers the lower surface of the end wall 58 of the terminal body 52.

  The first layer portion 72 is provided over the entire circumference of the peripheral wall 54. The first layer portion 72 is provided over the entire length in the axial direction from the upper end portion to the lower end portion of the peripheral wall 54. A lower end portion of the first layer portion 72 is integrally connected to the second covering portion 44.

  The lower end portion of the first layer portion 72 is disposed along the inner peripheral surface of the lower peripheral wall portion 57 of the peripheral wall 54. Accordingly, the lower peripheral wall portion 57 is sandwiched between a portion (a portion including the first covering portion 42) other than the resin layer 70 in the lid body 30 and the first layer portion 72 of the resin layer 70.

  The through hole 66 of the lower peripheral wall portion 57 is filled with the resin material of the lid body 30. Thereby, a resin-made connecting portion 80 that penetrates the lower peripheral wall portion 57 and extends in the radial direction is formed for each through-hole 66. The connecting portion 80 connects the resin portion that covers the lower peripheral wall portion 57 of the lid 30 from the outside to the first layer portion 72 of the resin layer 70 that covers the lower peripheral wall portion 57 from the inside.

  Since the resin layer 70 is supported by the lid body 30 via the plurality of connecting portions 80, it is possible to improve the support strength of the resin layer 70 by the lid body 30. In addition, since the displacement of the terminal body 52 in the circumferential direction is restricted by the connecting portion 80, the relative rotation of the external terminal 50 with respect to the lid body 30 is restricted.

  The second layer portion 74 is provided over the entire end wall 58. The peripheral edge portion of the second layer portion 74 is integrally connected to the upper end portion of the first layer portion 72.

  Inside the terminal main body 52, a first beam portion 76 and a second beam portion 78 made of resin are provided to connect a plurality of locations in the resin layer 70. The first beam portion 76 and the second beam portion 78 are formed so as to leave a space inside the terminal body 52. The first beam portion 76 and the second beam portion 78 are integrally formed with the resin layer 70. That is, the first beam portion 76 and the second beam portion 78 together with the resin layer 70 constitute a part of the lid body 30.

  As shown in FIG. 11, the first beam portion 76 is provided so as to extend in a radial direction from a predetermined circumferential direction portion in the first layer portion 72 of the resin layer 70 to a circumferential direction portion opposed thereto. Similarly, the second beam portion 78 extends in the radial direction so as to connect two other circumferential portions of the first layer portion 72.

  The first beam portion 76 and the second beam portion 78 are arranged so as to intersect when viewed in the axial direction. More specifically, the first beam portion 76 and the second beam portion 78 intersect at a right angle. The first beam portion 76 and the second beam portion 78 are disposed so as to pass through the center of the main peripheral wall portion 55 of the terminal body 52 when viewed from the axial direction.

  As shown in FIG. 9, the first beam portion 76 and the second beam portion 78 are provided over the entire length of the resin layer 70 in the axial direction. Thereby, the internal space of the terminal body 52 is partitioned into a plurality of spaces by the first beam portion 76 and the second beam portion 78. The upper ends of the first beam portion 76 and the second beam portion 78 are connected to the second layer portion 74 in the resin layer 70.

  The resin layer 70 is supported from the side opposite to the terminal body 52 by the first beam portion 76 and the second beam portion 78 provided as described above. In addition, the first beam portion 76 and the second beam portion 78 reinforce the terminal body 52 from the inside through the resin layer 70.

[Production method]
Regarding the manufacture of the assembled battery 1, an example of a method of forming the external terminal 50 and integrating it with the lid 30 will be described.

  The external terminal 50 is first formed into the shape shown in FIGS. 3 and 4 by pressing one metal plate. Here, the terminal main body 52 of the external terminal 50 is formed by drawing one metal plate using a press die. Thereby, a hollow pole terminal having a frustoconical contour can be formed.

  Subsequently, the external terminal 50 molded as described above is integrated with the lid 30 by insert molding. As the insert molding die, for example, a first die 201 and a second die 202 as shown in FIGS. 12A and 12B are used.

  12A and 12B, only a part of the molds 201 and 202, specifically, a part for molding the peripheral part of one external terminal 50 in the lid 30 is illustrated. ing.

  First, as shown in FIG. 12A, the external terminal 50 molded as described above is set in the first mold 201 with the second mold 202 opened. Thereafter, as shown in FIG. 12B, the second mold 202 is closed, whereby the external terminals 50 are inserted into the molds 201 and 202. At this time, a first space S1 is formed between the first mold 201 and the external terminal 50, and a second space S2 is formed between the second mold 202 and the external terminal 50.

  Subsequently, molten resin is injected into the first space S1 and the second space S2 around the external terminal 50. At this time, the resin injection may be performed only in one of the first space S1 or the second space S2, or may be performed in both.

  Since the first space S1 and the second space S2 communicate with each other through a through hole 66 provided in the terminal body 52 of the external terminal 50, the resin between the first space S1 and the second space S2 The flow is possible. Thereby, resin is smoothly supplied over the whole 1st space S1 and 2nd space S2.

  Thereafter, the resin is cooled and solidified, whereby the lid body 30 made of the resin is formed. Further, the resin layer 70, the first beam portion 76, the second beam portion 78, and the connecting portion 80 described above are integrally formed with the lid body 30.

  Finally, the member which integrated the cover body 30 and the external terminal 50 is obtained by releasing.

[Function and effect]
According to the above manufacturing method, the external terminal 50 having the hollow terminal body 52 can be easily formed by drawing. Therefore, when manufacturing the external terminal 50 using a metal material having a melting point higher than that of lead, such as copper, brass, aluminum, and an aluminum alloy, compared to manufacturing a solid external terminal by casting or forging. Thus, the weight of the external terminal 50 can be reduced and the manufacturing cost can be reduced.

  In addition, the resin lid 30 can be easily integrated with the external terminal 50 made of one metal plate by insert molding. In particular, in the insert molding dies 201 and 202, the lid body 30 is molded by the resin filled in the first space S1 outside the external terminal 50, and the resin filled in the second space S2 inside the external terminal 50. Thus, the resin layer 70, the first beam portion 76, and the second beam portion 78 are formed, and the connecting portion 80 is formed by the resin filled in the through hole 66 of the terminal body 52, so that the external terminal 50, the lid body are formed. 30, the resin layer 70, the first beam portion 76, the second beam portion 78, and the connecting portion 80 can be easily integrated.

  Further, if the entire interior space of the terminal body 52 is filled and solidified during insert molding, and if a pre-molded resin molded product is attached to the inside of the terminal body 52, the terminal body 52 A gap is likely to occur between the inner surface of the resin and the resin portion.

  On the other hand, in this embodiment, since the layered resin is filled along the inner surface of the terminal body 52 in the insert molding dies 201 and 202, the resin layer 70 is placed on the inner surface of the terminal body 52. Easy to form with no gaps.

  Therefore, in the assembled battery 1 manufactured as described above, when an external force is applied to the terminal body 52, the load applied to the terminal body 52 is reliably received by the resin layer 70 inside the terminal body 52. The inner surface of the terminal body 52 can be effectively reinforced by the resin layer 70. In addition, the resin layer 70 is supported from the side opposite to the terminal body 52 by the first beam portion 76 and the second beam portion 78 (see FIGS. 6 and 9 to 11) described above, and thus the terminal The main body 52 is reinforced more effectively.

  In addition, since the resin layer 70 is integrally formed with the lid 30 by insert molding, a dedicated part for reinforcing the terminal body 52 from the inside can be omitted, thereby reducing the number of parts and the number of assembly steps. it can.

  Furthermore, in the assembled battery 1 manufactured as described above, since the terminal body 52 is hollow, the weight of the external terminal 50 can be reduced compared to the case where a solid pole terminal is used. Moreover, since the terminal body 52 can be thinned by reinforcement by the resin layer 70, the first beam portion 76, and the second beam portion 78, the external terminal 50 can be further reduced in weight.

  Further, in the hollow terminal main body 52, the front end opening of the peripheral wall 54 is closed by the end wall 58, so that the airtightness of the assembled battery 1 can be ensured. Further, the displacement of the distal end portion of the peripheral wall 54 is regulated by the end wall 58, so that the peripheral wall 54 when an external force is applied, for example, when a connecting member fitted to the outside of the main peripheral wall portion 55 is tightened. Can be suppressed.

  Furthermore, since the external terminal 50 is integrally provided with a connection portion 68 used for connection to the terminal of the unit cell 4, the number of parts of the connection member such as a bus bar can be reduced. Further, when the assembled battery 1 is manufactured, the step of fixing the terminal body 52 to the connection member such as a bus bar can be omitted.

  The configuration of the external terminal 50 described above is merely an example, and various changes can be made to the configuration of the external terminal in the present invention.

[Modification]
A configuration of the external terminal 150 according to the modification will be described with reference to FIGS. 13 and 14. In the description of the modified example shown in FIGS. 13 and 14, the description of the same components as those of the previously described embodiment is omitted, and the same reference numerals as those in the above embodiment are given in FIGS. Yes.

  The external terminal 150 according to the modified example is provided with a protruding portion 160 shown in FIGS. 13 and 14 in addition to the protruding portion 60 (see FIGS. 3, 4, and 10) in the above-described embodiment. In the modification, the same protrusion 60 as in the embodiment may be omitted. The protrusion 160 is provided on the inner peripheral surface of the peripheral wall 54 of the terminal body 52.

  More specifically, as shown in FIG. 13, a protrusion 160 is provided on the inner peripheral surface of the upper end portion of the peripheral wall 54. That is, the protrusion 160 is provided so as to protrude inward from the corner portion between the main peripheral wall portion 55 and the end wall 58. However, the protrusion 160 may be provided in another part of the peripheral wall 54 in the axial direction.

  Moreover, as shown in FIG. 14, the protrusion part 160 is provided with two or more in the circumferential direction at intervals. A groove 162 is formed between each protrusion 160 adjacent in the circumferential direction. The entire surface of the protrusion 160 is covered with the resin layer 70. The resin layer 70 is formed with an engaging portion 140 that is engaged with the protruding portion 160. A plurality of engaging portions 140 are provided corresponding to the protruding portions 160 at intervals in the circumferential direction. Each engaging portion 140 is made of a resin material filled in the groove portion 162 of the terminal body 52.

  In the external terminal 150 configured as described above, the circumferential displacement of the protrusion 160 provided on the terminal main body 52 is regulated by the engaging portion 140 of the resin layer 70 engaged with the protrusion 160. Yes. The resin layer 70 is integral with the lid body 30. Therefore, the relative rotation of the external terminal 150 with respect to the lid 30 can be effectively restricted.

  While the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments.

  For example, in the above-described embodiment, the example in which the resin layer 70 of the external terminal 50 is provided on the entire inner surface of the terminal body 52 has been described. However, in the present invention, the resin layer is partially formed on the inner surface of the terminal body. It may be provided.

  Further, in the above-described embodiment, the example in which the two beam portions 76 and 78 are provided in the X shape when viewed from the axial direction inside the terminal main body 52 has been described. However, the shape, size, and thickness of the beam portion are described. Various changes can be made to the number, the number, and the arrangement, and the beam portion can be omitted.

  Furthermore, the inner surface of the terminal body 52 is not limited to a smooth surface, and may be an uneven surface. In this case, the resin layer 70 is preferably provided so as to bite into the recesses on the inner surface of the terminal body 52, thereby effectively suppressing the displacement of the resin layer 70 with respect to the inner surface of the terminal body 52.

  9 shows an example in which the terminal main body 52 and the connection portion 68 of the external terminal 50 have a uniform thickness throughout, but the terminal main body 52 and the connection portion 68 may have different thicknesses. The thicknesses of the terminal main body 52 and the connecting portion 68 may be different depending on the part.

  Furthermore, in the above-described embodiment, the example in which the cross-sectional shape of the terminal body is circular has been described. However, in the present invention, the cross-sectional shape of the terminal body is not particularly limited.

  In the above-described embodiment, the example in which the external terminal 50 is provided in the lid 30 has been described. However, in the present invention, the external terminal may be provided in a portion other than the lid in the exterior body.

  Furthermore, the power storage element constituting the power storage device according to the present invention is not limited to the prismatic battery as in the above-described embodiment, and may be, for example, a cylindrical battery or a laminate (pouch-type) battery. Also good.

  In the above-described embodiment, the power storage device according to the present invention has been described by way of example of a power storage device having a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery as a power storage element. The power storage elements to be configured may be various power storage elements including secondary batteries other than non-aqueous electrolyte secondary batteries, primary batteries, and capacitors.

  Furthermore, in the exterior body of the power storage device according to the present invention, a power storage element having a container individually may be accommodated together with the container, or an electrode or an electrolyte may be directly accommodated.

1 battery pack (power storage device)
4 Single battery (storage element)
DESCRIPTION OF SYMBOLS 20 Exterior body 30 Cover body 50 (50A, 50B) External terminal 52 Terminal main body 54 Peripheral wall 58 End wall 60 Projection part 62 Tooth part 66 Through-hole 68 Connection part 70 Resin layer 76 1st beam part 78 2nd beam part 80 Connection part 150 External terminal 160 Projection

Claims (12)

An exterior body that houses the storage element;
An external terminal exposed outside the exterior body,
The said external terminal is an electrical storage apparatus provided with the hollow terminal main body which has the surrounding wall which protruded outside from the surface of the said exterior body, and the end wall which block | closes the front-end | tip opening of this surrounding wall.   The power storage device according to claim 1, wherein the external terminal includes a resin layer that covers at least a part of an inner surface of the terminal body. At least a part of the exterior body is made of a resin member,
The power storage device according to claim 2, wherein the resin layer is a part of the resin member. The peripheral wall includes a non-exposed portion sandwiched between the resin layer and a portion of the resin member other than the resin layer,
The power storage device according to claim 3, wherein a through hole is provided in the non-exposed portion.   The power storage device according to any one of claims 2 to 4, wherein a resin beam portion that connects a plurality of locations in the resin layer is provided inside the terminal body. The external terminal includes a protrusion provided on the inner surface of the peripheral wall,
The power storage device according to claim 2, wherein the protrusion is covered with the resin layer. The external terminal includes a protrusion protruding radially outward from the peripheral wall,
The power storage device according to claim 1, wherein the protrusion is embedded in the exterior body so that the entire surface thereof is covered with the material of the exterior body. The external terminal further includes a connection part formed integrally with the terminal body,
The power storage device according to any one of claims 1 to 7, wherein the power storage element and the terminal body are electrically connected via the connection portion.   The power storage device according to claim 8, wherein at least a part of the connection portion is embedded in the exterior body.   A method of manufacturing a power storage device, wherein an external terminal exposed outside the exterior body of the power storage device is formed by drawing a single metal plate with a press die. Insert the external terminal molded by the drawing into an insert molding die,
Injecting resin around the external terminals inserted into the insert mold,
The manufacturing method of the electrical storage apparatus of Claim 10 which shape | molds the said exterior body which consists of the said resin within the said insert molding metal mold | die.   12. The method for manufacturing a power storage device according to claim 11, wherein when molding the exterior body in the insert molding die, a resin layer covering at least a part of the inner surface of the external terminal is molded integrally with the exterior body. .

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