JP2017220344A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack which can suppress slippage between components constituting a housing and is also capable of easily adjusting a compression amount of a seal member arranged between the components.SOLUTION: A battery pack 1 according to one embodiment is configured such that a plurality of battery modules 3 are housed in a housing 2. The battery pack 1 comprises: a body part 4 and a lid part 5 which constitute the housing 2; a bolt 6 which couples the body part 4 to the lid part 5; a washer 7 into which the bolt 6 is inserted; and a seal member 8 arranged between the body part 4 and the lid part 5. The body part 4 and the lid part 5 are coupled to each other via the bolt 6 with the washer 7 interposed therebetween. The seal member 8 is compressed by the body part 4 and the lid part 5 in accordance with a clearance between the body part 4 and lid part 5 which is defined by the washer 7.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a battery pack.

  Conventionally, a battery pack in which a plurality of battery modules are housed in a casing is known (see, for example, Patent Document 1). The casing of the battery pack described in Patent Document 1 has a main body portion that opens on one side and a lid portion that closes the opening of the main body, and is assembled by fastening the lid portion to the main body portion with, for example, a bolt or the like. Yes.

JP 2014-76887 A

  In the battery pack as described above, the fastening surfaces of the main body part and the lid part of the casing are painted surfaces, and the weight of the casing is large, so that the main body part and the lid part are brought into direct contact with each other and the bolt is fastened. In such a case, when an impact or the like is applied to the housing, there is a possibility that slip occurs between the main body portion and the lid portion. When such slipping occurs, there may arise a problem that, for example, a bolt that fastens the main body and the lid is damaged or broken. Moreover, in order to improve the airtightness of a housing | casing, although a sealing member may be provided between a main-body part and a cover part, in this case, it is necessary to adjust the compression amount of a sealing member to an appropriate range. It is difficult to perform such adjustment only by adjusting the strength of bolt tightening.

  Then, an object of this invention is to provide the battery pack which can adjust the compression amount of the sealing member provided between the said members while being able to suppress the slip between the members which comprise a housing | casing.

  A battery pack according to an aspect of the present invention is a battery pack in which one or more battery modules are accommodated in a housing, and includes a first member, a second member, a first member, and a second member constituting the housing. A bolt for fastening the member; an annular member into which the bolt is inserted; and a seal member disposed between the first member and the second member. The first member and the second member are annular members. The seal member is compressed by the first member and the second member in accordance with the separation distance between the first member and the second member defined by the annular member. .

  In this battery pack, the first member and the second member constituting the housing are bolted via the annular member, so that the sliding of the second member with respect to the first member is suppressed. Furthermore, the compression amount of the seal member (that is, the thickness of the seal member before compression and the thickness of the seal member after compression is determined according to the separation distance between the first member and the second member defined by the annular member. Difference) is adjusted. Therefore, according to the said battery pack, while being able to suppress the slip between the members (1st member and 2nd member) which comprise a housing | casing, the compression amount of the sealing member provided between the said members can be adjusted easily.

  The first member is a box-shaped main body provided with an opening, the second member is a plate-like lid fixed to the main body so as to close the opening, and the second member includes: At least one battery module may be attached.

  In general, since the battery module is heavy, when the battery module is attached to the lid portion, the lid portion easily slides with respect to the main body portion due to an impact on the battery pack or the like. In the above configuration, since the annular member is interposed between the main body portion and the lid portion, even when the battery module is attached to the lid portion, the sliding of the lid portion with respect to the main body portion can be suppressed. Further, since the battery module can be attached to both the main body portion and the lid portion, it is possible to improve the storage property of the battery module in the housing and the workability in the assembly work of the housing.

  The annular member has a first surface facing the first member and a second surface facing the second member, and one of the first surface and the second surface is one of the first member and the second member. A protrusion that protrudes toward the other of the first member and the second member may be provided on the other of the first surface and the second surface.

  In the above configuration, the position of the annular member with respect to one member is fixed by fixing one surface (one of the first surface and the second surface) of the annular member to one member (one of the first member and the second member). Misalignment is prevented. Further, the protrusion provided on the other surface of the annular member (the other of the first surface and the second surface) suppresses the displacement of the annular member with respect to the other member (the other of the first member and the second member). . Therefore, it is possible to effectively suppress slipping between members (first member and second member) constituting the housing.

  The annular member has a first surface that faces the first member and a second surface that faces the second member, and the first surface is provided with a protrusion that protrudes toward the first member. And the 2nd surface may be provided with the projection part which protrudes toward the 2nd member.

  In the said structure, the position shift of the annular member with respect to a 1st member and a 2nd member is suppressed by the projection part provided in both surfaces (1st surface and 2nd surface) of the annular member. Therefore, it is possible to effectively suppress slipping between members (first member and second member) constituting the housing.

  The appropriate range of the thickness of the bolt of the seal member in the compressed state in the axial direction is a range between the thickness in the axial direction of the portion excluding the protrusion from the annular member and the thickness in the axial direction of the annular member. It may be adjusted to include.

  When the projecting portion is provided on the annular member, the projecting portion may or may not completely bite into the first member or the second member depending on factors such as the fastening force of the bolt at the time of assembly. Therefore, when the annular member is provided with a protrusion, the separation distance between the first member and the second member can vary between the thickness of the portion excluding the protrusion from the annular member and the thickness of the annular member. In the above configuration, since the appropriate range of the thickness of the seal member after compression is adjusted to include the above fluctuation range, the thickness of the seal member after compression can always be within the appropriate range. Thereby, the assembly | attachment error of the housing | casing of whether a projection part bites into a housing | casing is permitted, and the airtightness of a housing | casing can be ensured.

  The resistance to deformation of the housing, the projected area of the projection when the annular member is viewed from the axial direction of the bolt, and the fastening force of the bolt may be adjusted so that the projection bites into the housing.

  In the configuration described above, the protrusion provided on the annular member bites into the housing (first member or second member), so that the surface (first surface or second surface) on which the protrusion is provided on the annular member and the The positional deviation between the member (the first member or the second member) facing the surface is more reliably suppressed. Thereby, the slip between the members (1st member and 2nd member) which comprise a housing | casing can be suppressed much more effectively.

  The annular member may be integrated with the seal member.

  According to the above configuration, the number of parts can be reduced, and the sealing member and the annular member can be easily arranged between the first member and the second member.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to suppress the slip between the members which comprise a housing | casing, the battery pack which can adjust easily the compression amount of the sealing member provided between the said members can be provided.

It is a disassembled perspective view which shows the battery pack of 1st Embodiment. It is sectional drawing along the II-II line of FIG. It is the (a) perspective view and (b) sectional view showing the washer in the battery pack of a 1st embodiment. It is an expanded sectional view which shows the fastening part of the main-body part and lid part in the battery pack of 1st Embodiment. It is an expanded sectional view which shows the fastening part of the main-body part and lid part in the battery pack of 2nd Embodiment. It is the (a) perspective view and (b) sectional view which show the washer in the battery pack of a 2nd embodiment. It is a disassembled perspective view which shows the battery pack of 3rd Embodiment. It is an expanded sectional view which shows the fastening part of the main-body part and lid part in the battery pack of 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the dimensional ratios in the drawings do not necessarily match the battery pack described.

[First Embodiment]
The battery pack 1 of 1st Embodiment is demonstrated with reference to FIGS. 1-4. FIG. 1 is an exploded perspective view showing the battery pack 1. As shown in FIG. 1, the battery pack 1 includes one or more (seven as an example in the present embodiment) battery modules 3 housed in a housing 2. The battery pack 1 is configured as a vehicle battery, for example. The battery module 3 includes, for example, an array body in which a plurality of battery cells are arrayed and a restraining member that applies a restraining load to the array body in the array direction of the battery cells. The battery cell is a secondary battery such as a lithium ion battery.

  The housing | casing 2 has the substantially rectangular parallelepiped external shape as a whole. The housing | casing 2 is formed with metal materials, such as iron (SS400), for example. The housing 2 includes a box-shaped main body portion 4 (first member) having an opening A and a plate-shaped lid portion 5 (second member). The lid 5 is fastened to the main body 4 with bolts 6 so as to close the opening A of the main body 4. The main body 4 and the lid 5 are fastened with bolts 6 to form the housing 2.

  The main body 4 includes a base plate 41 and four side plates 42 erected on the peripheral edge of the base plate 41. The base plate 41 and the side plate 42 are each a rectangular flat plate member, and are joined together and integrated by, for example, welding. Three battery modules 3 are attached to the inner surface of the base plate 41 constituting the inner surface of the housing 2. Eight bolt holes 44 into which the bolts 6 are screwed are provided in the end face 43 having a rectangular frame shape formed by the end portions on the opening A side of the four side plates 42. In this example, the bolt holes 44 are provided at a total of eight positions including four corners (corner portions) of the end face 43 and four intermediate positions between adjacent corner portions.

  The lid 5 is made of a rectangular flat plate member having the same shape as the base plate 41. The lid 5 has an inner surface 51 that faces the base plate 41 and an outer surface 52 that is located on the opposite side of the inner surface 51. Four battery modules 3 are attached to the inner surface 51. The lid portion 5 is provided with eight insertion holes 53 having a circular cross section that penetrate from the inner surface 51 to the outer surface 52 so as to correspond to the positions of the eight bolt holes 44 provided on the end surface 43 of the main body portion 4. Yes. The insertion hole 53 is a so-called fool hole. That is, the hole diameter of the insertion hole 53 is slightly larger than the shaft diameter of the bolt 6.

  A washer 7 is interposed between the end surface 43 of the main body 4 and the inner surface 51 of the lid 5 as an annular member through which the bolt 6 is inserted. The washer 7 has a function of suppressing the relative movement (sliding) of the lid 5 with respect to the main body 4 in the direction orthogonal to the axial direction X of the bolt 6 and also plays a role of adjusting the amount of compression of the seal member 8 described later. . 3A is a perspective view showing the washer 7, and FIG. 3B is a cross-sectional view taken along the line bb of FIG. 3A. The washer 7 is formed in an annular shape, and has a surface 71 (second surface) that faces the lid portion 5 and a surface 72 (first surface) that faces the main body portion 4. The washer 7 is provided with an insertion hole 73 having a circular cross section penetrating from the surface 71 to the surface 72. Similar to the hole diameter of the insertion hole 53, the hole diameter of the insertion hole 73 is slightly larger than the shaft diameter of the bolt 6.

  On the surface 71 of the washer 7, a plurality of (in this example, twelve) projecting portions 74 projecting toward the lid portion 5 are provided. In this example, the plurality of protrusions 74 are arranged at equal intervals along the peripheral edge of the surface 71. Each protrusion 74 has a slope shape that is an upward gradient at an inclination angle θ1 in the clockwise direction when the washer 7 is viewed from the surface 71 side. The thickness in the direction orthogonal to the surfaces 71 and 72 of the washer 7 (that is, the axial direction X of the bolt 6) (hereinafter, the “thickness in the axial direction X of the bolt 6” is simply referred to as “thickness”). , The sum (d + d1) of the thickness d of the portion excluding the protrusion 74 from the washer 7 and the maximum thickness d1 of the protrusion 74.

  The surface 72 of the washer 7 is fixed to the end surface 43 of the main body 4 by welding or the like so that the central axis of the bolt hole 44 and the central axis of the insertion hole 73 coincide.

  As shown in FIGS. 1 and 2, the main body 4 and the lid 5 are fastened by bolts 6 with a washer 7 interposed therebetween. Specifically, the main body 4 and the lid 5 are configured such that the bolt 6 passes through the insertion hole 53 of the lid 5 and the insertion hole 73 of the washer 7 and is screwed into the bolt hole 44 of the main body 4. It is fastened through a washer 7.

FIG. 4 is an enlarged cross-sectional view showing a fastening portion between the main body 4 and the lid 5 in the battery pack 1. As shown in FIG. 4, in this example, in a state where the main body 4 and the lid 5 are fastened by the bolt 6 via the washer 7, the protrusion 74 provided on the surface 71 of the washer 7 5 bites into. Such a state includes the resistance to deformation of the lid 5 (housing 2), the projected area of the plurality of protrusions 74 when the washer 7 is viewed from the axial direction X of the bolt 6, and the fastening force of the bolt 6 (fastening). (Axial force) is adjusted so as to satisfy the following formula (1). In addition, the proof stress with respect to a deformation | transformation of the cover part 5 is adjusted by changing the material of the cover part 5, etc.
σb [MPa] <F / S1 cos θ1 (1)

  In the above formula (1), σb is a yield strength against the depression (deformation) of the lid 5. That is, σb is a limit pressure that can be withstood without a part of the lid 5 being depressed when pressure is applied to a part of the lid 5. F is a fastening force of the bolt 6 (that is, a force for sandwiching the washer 7 by the main body portion 4 and the lid portion 5 along the axial direction X of the bolt 6). S1 is the sum of the surface areas of the inclined surfaces 74a of the plurality of protrusions 74. Therefore, S1 cos θ1 indicates the projected area of the plurality of protrusions 74 when the washer 7 is viewed from the axial direction X of the bolt 6. Further, F / S1 cos θ1 is applied per unit projected area with respect to a portion of the lid portion 5 that contacts the inclined surfaces 74a of the plurality of projection portions 74 in a state where the plurality of projection portions 74 have bitten into the lid portion 5. Indicates the fastening force. Here, at the time of fastening with the bolt 6, the projected area of the portion where the inclined surfaces 74a of the plurality of protrusions 74 and the lid 5 are in contact with each other gradually changes from 0 to S1 cos θ1. The fastening force (pressure) applied per unit projected area to the portion of the lid 5 that contacts the inclined surfaces 74 a of the plurality of protrusions 74 is in a state where the entirety of the plurality of protrusions 74 bites into the lid 5. The smallest value (F / S1 cos θ1) is obtained. Therefore, when the proof stress σb against the depression of the lid portion 5 satisfies the above formula (1), the entire plurality of protrusions 74 bite into the lid portion 5 as shown in FIG.

  The seal member 8 is formed of, for example, EPDM (ethylene / propylene / diene rubber) or the like, and has a rectangular ring shape (see FIG. 1). The seal member 8 is disposed between the end surface 43 of the main body portion 4 and the inner surface 51 of the lid portion 5. The seal member 8 is compressed between the end surface 43 and the inner surface 51 in a state where it is compressed from both sides by the main body portion 4 and the lid portion 5 according to the separation distance between the end surface 43 and the inner surface 51 defined by the washer 7. Seal. Thereby, the airtightness and watertightness of the housing | casing 2 are improved. In this example, the seal member 8 is disposed outside the plurality of bolt holes 44 and the plurality of washers 7 between the end face 43 and the inner surface 51, but the seal member 8 is provided with the plurality of bolt holes 44. And it may be arranged inside a plurality of washers 7. Further, the seal member 8 may be disposed on both the outer side and the inner side of the plurality of bolt holes 44 and the plurality of washers 7.

  In FIG. 4, the alternate long and short dash line indicates the outline of the seal member 8 in a state before compression. As shown in FIG. 4, the thickness h of the seal member 8 before compression is greater than the distance between the end surface 43 and the inner surface 51 after bolt fastening. Then, the lid 5 is fastened to the main body 4 by the bolt 6, so that the seal member 8 is compressed to a thickness h <b> 1 (<h). In this example, since the entire protrusion 74 is in a state of being bitten into the lid 5, the separation distance between the end surface 43 and the inner surface 51 matches the thickness d of the portion excluding the protrusion 74 from the washer 7. Therefore, the relationship “h1 = d” is established.

Here, a case where the protrusion 74 does not bite into the lid 5 is also conceivable, such as when the relationship of the above formula (1) is not established. When the protrusion 74 does not bite into the lid 5, the distance between the end face 43 and the inner surface 51 is the thickness (d + d1) of the entire washer 7 including the protrusion 74. That is, the distance between the end face 43 and the inner surface 51 is from d to (d + d1), depending on whether or not the protrusion 74 bites into the lid 5 (or the extent to which the protrusion 74 bites into the lid 5). Can vary in range. That is, the thickness h1 of the compressed seal member 8 can vary within the range indicated by the following formula (2). Further, in order to effectively seal between the end surface 43 and the inner surface 51 by the seal member 8, the seal member 8 needs to be compressed with an appropriate compression amount. In other words, the thickness h1 of the compressed seal member 8 needs to be within a predetermined proper range.
d ≦ h1 ≦ d + d1 (2)

  Therefore, an appropriate range of the thickness h1 of the seal member 8 after compression is a range between the thickness d of the portion excluding the protrusion 74 from the washer 7 and the total thickness (d + d1) of the washer 7 [d, d + d1] is preferably adjusted. Such adjustment of the appropriate range may be performed, for example, by adjusting the initial compression amount or the like of the seal member 8, or the thickness d of the portion excluding the protrusion 74 of the washer 7 and the protrusion 74. It may be performed by adjusting the maximum thickness d1 or the like.

  Then, the effect of the battery pack 1 is demonstrated. Since the main body 4 and the lid 5 are normally painted, the end surface 43 of the main body 4 and the inner surface 51 of the lid 5 are painted surfaces and are easy to slide. Further, as described above, the insertion hole 53 of the lid portion 5 is a so-called fool hole, and the hole diameter of the insertion hole 53 is slightly larger than the shaft diameter of the bolt 6. Accordingly, if a configuration is adopted in which the end face 43 and the inner surface 51 are brought into direct contact with each other and the bolt is fastened without providing the washer 7 in the battery pack 1, the bolt 6 is loosened when an impact is applied to the battery pack 1. An event in which the lid 5 slides with respect to the main body 4 may occur. When such an event occurs, the lid 5 slides sideways, so that a force is applied in the direction orthogonal to the axial direction X with respect to the axial portion of the bolt 6, and the bolt 6 is damaged or broken. There is a risk of it.

  On the other hand, in the battery pack 1, the main body 4 and the lid 5 constituting the housing 2 are bolted via the washer 7, so that the main body 4 in the direction orthogonal to the axial direction X of the bolt 6 can be obtained. The sliding of the lid 5 is suppressed. Furthermore, the compression of the seal member 8 is performed according to the separation distance between the main body 4 and the lid 5 defined by the washer 7 (in this example, the thickness d of the portion excluding the protrusion 74 from the washer 7). The amount (that is, the difference between the thickness h of the seal member 8 before compression and the thickness h1 of the compressed seal member 8) is adjusted. Therefore, according to the battery pack 1, the slip between the members (the main body 4 and the lid 5) constituting the housing 2 can be suppressed, and the compression amount (h-h1) of the seal member 8 provided between the members. Can be adjusted easily.

  In general, since the weight of the battery module 3 is large, when the battery module 3 is attached to the lid 5, the lid 5 is easily slipped with respect to the main body 4 due to an impact on the battery pack 1 or the like. . In the above configuration, the washer 7 is interposed between the main body 4 and the lid 5, so that the sliding of the lid 5 with respect to the main body 4 can be suppressed even when the battery module 3 is attached to the lid 5. . In addition, since the battery module 3 can be attached to both the main body 4 and the lid 5, the storage property of the battery module 3 in the housing 2 and the workability in the assembly work of the housing 2 are improved. Can be achieved.

  In addition, since the surface 72 of the washer 7 is fixed to the end surface 43 of the main body 4, the washer 7 is prevented from being displaced with respect to the main body 4. Further, the protrusion 74 provided on the surface 71 of the washer 7 suppresses the displacement of the washer 7 with respect to the lid 5. In particular, in this embodiment, the yield strength (σb) against deformation of the lid 5 (housing 2), the projected area (S1 cos θ1) of the plurality of protrusions 74 when the washer 7 is viewed from the axial direction X of the bolt 6, and the bolt The fastening force (F) 6 is adjusted so that the protrusion 74 bites into the lid 5. That is, it is adjusted so that the relationship of the above formula (1) is established. As a result, as shown in FIG. 4, the protrusion 74 bites into the lid portion 5, so that the displacement of the washer 7 with respect to the lid portion 5 is more reliably suppressed. As described above, as a result of preventing or suppressing the displacement of the main body 4 and the lid 5 with respect to the washer 7, the slip between the members (the main body 4 and the lid 5) constituting the housing 2 is effectively suppressed. it can.

  Further, the appropriate range of the thickness h1 of the compressed seal member 8 is adjusted to include the above range [d, d + d1]. Thereby, the thickness h1 of the compressed seal member 8 can always be within the appropriate range regardless of whether or not the protrusion 74 bites into the lid 5. As a result, an assembling error of the housing 2 such as whether or not the protrusion 74 bites into the lid 5 is allowed, and the airtightness of the housing 2 can be ensured.

[Second Embodiment]
With reference to FIG.5 and FIG.6, battery pack 1A of 2nd Embodiment is demonstrated. In the battery pack 1A, a washer 7A having projections 74 and 75 provided on both surfaces (surface 71 and surface 72) is used instead of the washer 7 provided with the projection 74 only on one surface (surface 71). The battery pack 1 is different from the battery pack 1 in other configurations. FIG. 5 is an enlarged cross-sectional view showing a fastening portion between the main body 4 and the lid 5 in the battery pack 1A. 6A is a perspective view showing the washer 7A, and FIG. 6B is a cross-sectional view taken along line bb of FIG. 6A.

  As shown in FIG. 6, a plurality of (in this example, twelve) protrusions 74 are provided on the surface 71 of the washer 7 </ b> A that faces the lid 5, similarly to the washer 7. Further, in the washer 7 </ b> A, a plurality of (in this example, twelve) projecting portions 75 projecting toward the main body portion 4 are provided on the surface 72 facing the main body portion 4. In this example, the plurality of protrusions 75 have the same shape and arrangement as the plurality of protrusions 74. That is, the plurality of protrusions 75 are arranged at equal intervals along the peripheral edge of the surface 72. Each projecting portion 75 has a slope shape with an upward slope at an inclination angle θ2 in the clockwise direction when the washer 7A is viewed from the surface 72 side. The thickness of the washer 7A is represented by the sum (d + d1 + d2) of the thickness d of the portion excluding the protrusions 74 and 75 from the washer 7A, the maximum thickness d1 of the protrusion 74, and the maximum thickness d2 of the protrusion 75. The

As shown in FIG. 5, in this example, in a state where the main body 4 and the lid 5 are fastened by the bolt 6 via the washer 7A, the protrusion 74 provided on the surface 71 of the washer 7A has the lid 5 The protrusion 75 provided on the surface 72 of the washer 7 </ b> A bites into the main body 4. Specifically, the state in which the protrusion 74 bites into the lid 5 is a plurality of protrusions when the washer 7A is viewed from the strength (σb) against deformation of the lid 5 (housing 2) and the axial direction X of the bolt 6. This is realized by adjusting the projected area (S1 cos θ1) of the portion 74 and the fastening force (F) of the bolt 6 so as to satisfy the above formula (1). Similarly, the state in which the protruding portion 75 bites into the main body portion 4 is a plurality of protruding portions 75 when the washer 7A is viewed from the strength (σb) against deformation of the main body portion 4 (housing 2) and the axial direction X of the bolt 6. The projected area (S2 cos θ2) and the fastening force (F) of the bolt 6 are adjusted so as to satisfy the following expression (3).
σb [MPa] <F / S2 cos θ2 (3)

  In the above formula (3), σb is a yield strength against the depression (deformation) of the main body 4. In the present embodiment, since the main body 4 and the lid 5 are formed of the same member, the strength of the main body 4 against the depression is the same as the strength of the lid 5 against the depression. S2 is the sum of the surface areas of the slopes 75a of the plurality of protrusions 75. Therefore, S2 cos θ2 indicates the projected area of the plurality of protrusions 75 when the washer 7A is viewed from the axial direction X of the bolt 6. Further, F / S2 cos θ2 is applied per unit projected area with respect to a portion of the main body portion 4 that contacts the inclined surfaces 75a of the plurality of protrusion portions 75 in a state where the entire plurality of protrusion portions 75 bite into the main body portion 4. Indicates the fastening force. Here, at the time of fastening with the bolt 6, the projected area of the portion where the inclined surface 75a of the plurality of projecting portions 75 and the main body portion 4 are in contact with each other gradually changes from 0 to S2 cos θ2. The fastening force (pressure) applied per unit projected area to the portion of the main body 4 that contacts the inclined surfaces 75 a of the plurality of protrusions 75 is in a state where the whole of the plurality of protrusions 75 bites into the main body 4. The smallest value (F / S2 cos θ2) is obtained. Therefore, when the proof stress σb against the depression of the main body 4 satisfies the above formula (3), the whole of the plurality of protrusions 75 bites into the main body 4 as shown in FIG.

  As shown in FIG. 5, the lid 5 is fastened to the main body 4 by the bolt 6, so that the seal member 8 is compressed to a thickness h <b> 2 (<h). In this example, since the entire protrusion 74 digs into the lid 5 and the entire protrusion 75 digs into the main body 4, the distance between the end face 43 and the inner surface 51 is from the washer 7 </ b> A to the protrusion. This corresponds to the thickness d of the portion excluding 74 and 75, and the relationship of “h2 = d” is established.

Here, when the relationship of the said Formula (1) or the said Formula (3) is not materialized, the case where the projection part 74 does not bite into the cover part 5, or the case where the projection part 75 does not bite into the main-body part 4 is also considered. . When the protrusions 74 and 75 do not bite into the lid part 5 and the main body part 4, the distance between the end face 43 and the inner surface 51 is the thickness (d + d1 + d2) of the entire washer 7A including the protrusions 74 and 75. That is, depending on whether or not the protrusions 74 and 75 bite into the lid part 5 and the main body part 4 (or the extent to which the projection parts 74 and 75 bite into the lid part 5 and the main body part 4), The separation distance of can vary in a range from d to (d + d1 + d2). That is, the thickness h2 of the compressed seal member 8 can vary within the range indicated by the following formula (4).
d ≦ h2 ≦ d + d1 + d2 (4)

  Therefore, an appropriate range of the thickness h2 of the seal member 8 after compression is a range between the thickness d of the portion excluding the protrusions 74 and 75 from the washer 7A and the total thickness (d + d1 + d2) of the washer 7A [ d, d + d1 + d2] is preferably adjusted. Such adjustment of the appropriate range may be performed, for example, by adjusting the initial compression amount or the like of the seal member 8, or the thickness d of the portion excluding the protrusions 74 and 75 of the washer 7A, the protrusion The maximum thickness d1 of 74, the maximum thickness d2 of the protrusion 75, and the like may be adjusted.

  In the battery pack 1 </ b> A described above, similarly to the battery pack 1, it is possible to suppress slipping between members (the main body portion 4 and the lid portion 5) constituting the housing 2 and compression of the seal member 8 provided between the members. The amount (h-h2) can be easily adjusted.

  Specifically, the protrusion 74 provided on the surface 71 of the washer 7A suppresses displacement of the washer 7A with respect to the lid 5, and the protrusion 75 provided on the surface 72 of the washer 7A causes the main body portion. 4 is prevented from shifting the position of the washer 7A. In particular, in this embodiment, the yield strength (σb) against deformation of the housing 2, the projected areas (S1 cos θ1 and S2 cos θ2) of the plurality of protrusions 74 and 75 when the washer 7A is viewed from the axial direction X of the bolt 6, and the bolt 6 The fastening force (F) is adjusted so that the protrusions 74 and 75 bite into the lid 5 and the main body 4. That is, adjustment is made so that the relationship of the above formulas (1) and (3) is established. As a result, as shown in FIG. 5, the protrusion 74 bites into the lid 5 and the projection 75 bites into the main body 4, so that the position shift of the washer 7 </ b> A with respect to the lid 5 and the main body 4 is more reliably performed. It is suppressed. As described above, as a result of suppressing the displacement of the main body portion 4 and the lid portion 5 with respect to the washer 7A, slipping between members (the main body portion 4 and the lid portion 5) constituting the housing 2 can be effectively suppressed.

  Further, the appropriate range of the thickness h2 of the compressed seal member 8 is adjusted so as to include the above range [d, d + d1 + d2]. Thereby, the thickness h2 of the compressed seal member 8 can always be within the appropriate range regardless of whether or not the protrusions 74 and 75 bite into the lid portion 5 and the main body portion 4. As a result, an assembling error of the housing 2 such as whether or not the protrusions 74 and 75 bite into the lid portion 5 and the main body portion 4 is allowed, and the airtightness of the housing 2 can be ensured.

[Third Embodiment]
With reference to FIG.7 and FIG.8, the battery pack 1B of 3rd Embodiment is demonstrated. The battery pack 1B is different from the battery pack 1A in that a seal member 9 integrated with a washer 7A is used instead of the seal member 8, and the other configuration is the same as that of the battery pack 1A. FIG. 7 is an exploded perspective view showing the battery pack 1B. FIG. 8 is an enlarged cross-sectional view showing a fastening portion between the main body 4 and the lid 5 in the battery pack 1B. However, in FIG. 7, the seal member 9 in a state before compression is illustrated.

  As shown in FIG. 7, the seal member 9 is formed of the same material as the seal member 8 and is provided in a rectangular ring shape along the end surface 43. The thickness h of the seal member 9 before compression is larger than the thickness (d + d1 + d2) of the washer 7A. Eight insertion holes 9 a are provided at four intermediate positions between the four corners (corner portions) of the seal member 9 and the adjacent corner portions so as to correspond to the eight bolt holes 44 provided in the end surface 43. Yes. The diameter of each insertion hole 9a is sized to match the outer shape of the washer 7A, and the washer 7A is disposed inside each insertion hole 9a. The washer 7A is disposed in the insertion hole 9a, for example, by bonding the side surface of the washer 7A to the inner wall of the insertion hole 9a. In this example, the washer 7A is disposed in the insertion hole 9a so that the surface 72 of the washer 7A is located on the same plane as the surface of the seal member 9 on the main body 4 side.

  In the battery pack 1B, the lid 5 is bolted to the main body 4 in a state where the seal member 9 in which the washer 7A is incorporated in each insertion hole 9a is sandwiched between the main body 4 and the lid 5 as described above. It is concluded with. As a result, as shown in FIG. 8, the seal member 9 is compressed by the main body portion 4 and the lid portion 5. In this example, the seal member 9 is compressed to a thickness h3 (<h). Similarly to the battery pack 1A described above, the protrusion 74 provided on the surface 71 of the washer 7A bites into the lid 5, and the protrusion 75 provided on the surface 72 of the washer 7A bites into the main body 4. Yes. Therefore, the separation distance between the end surface 43 and the inner surface 51 is equal to the thickness d of the portion excluding the protrusions 74 and 75 from the washer 7A, and the relationship of “h3 = d” is established.

  The conditions for the protrusion 74 provided on the surface 71 of the washer 7A to bite into the lid 5 and the protrusion 75 provided to the surface 72 of the washer 7A to bite into the main body 4 are as described above. That is, the relationship of the expressions (1) and (3) is established. Regardless of whether or not the protrusions 74 and 75 bite into the lid portion 5 and the main body portion 4, the conditions for keeping the thickness of the compressed seal member 9 within an appropriate range are the battery pack 1 </ b> A described above. Similarly, the appropriate range of the thickness h3 of the seal member 9 is adjusted to include the range [d, d + d1 + d2].

  In the battery pack 1B described above, similarly to the battery packs 1 and 1A, the sliding between the members (the main body 4 and the lid 5) constituting the housing 2 can be suppressed, and the seal member 9 provided between the members. The amount of compression (h-h3) can be easily adjusted. Further, in the battery pack 1B, a plurality of (eight in this example) washers 7A are integrated with the seal member 9 to reduce the number of parts and to seal between the main body 4 and the lid 5. The member 9 and the washer 7A can be easily arranged.

  In addition, this invention is not limited to embodiment mentioned above.

  For example, the direction of the washer 7 in the battery pack 1 may be switched. Specifically, the surface 72 of the washer 7 may be opposed to the inner surface 51 of the lid portion 5, and the surface 71 of the washer 7 may be opposed to the end surface 43 of the main body portion 4. And while fixing the surface 72 to the inner surface 51 of the cover part 5, it is good also as a structure which the protrusion part 74 provided in the surface 71 bites into the main-body part 4. FIG.

  Further, in the battery pack 1B, as the washer integrated with the seal member 9, the washer 7 may be used instead of the washer 7A.

  Further, the shape and the number of the protrusions 74 and 75 are not limited to the example of the above embodiment. However, the protrusions 74 and 75 are tapered toward the housing 2 (the body portion 4 or the lid portion 5) as in the above embodiment (in the above embodiment, as an example, a right triangle shape in a side view). By doing so, there is an advantage that the protrusions 74 and 75 can easily bite into the housing 2.

  Moreover, in each embodiment, the annular member arrange | positioned between the main-body part 4 and the cover part 5 is not restricted to a washer, An annular member other than washers, such as a metal collar, may be used. Further, the shape of the annular member is not limited to an annular shape, and may be, for example, a rectangular shape. In the above embodiment, an example is shown in which the surface of the washer on which the protrusion is not provided is fixed to the housing (main body or lid) by welding or the like. However, the surface on which the protrusion is not provided is shown. Instead of fixing to the body, a non-slip process may be applied to the surface. For example, if the surface on which the protrusion is not provided is a washer coated with a material having a high coefficient of friction, the position shift of the washer with respect to the housing can be suppressed even if the surface is not fixed to the housing. As a result, it is possible to suppress slipping between the main body part and the lid part across the washer. Further, a washer that is anti-slip processed on both sides and is not provided with a protrusion on either side may be used as the annular member. Even in such a case, the position shift of the washer with respect to the housing can be suppressed, and the slip between the main body portion and the lid portion sandwiching the washer can be suppressed.

  DESCRIPTION OF SYMBOLS 1,1A, 1B ... Battery pack, 2 ... Case, 3 ... Battery module, 4 ... Body part (first member), 5 ... Lid part (second member), 6 ... Bolt, 7,7A ... Washer (annular) Member), 8, 9 ... seal member, 44 ... bolt hole, 53 ... insertion hole, 71 ... surface (first surface), 72 ... surface (second surface), 73 ... insertion hole, 74 ... projection, X ... Axial direction.

Claims (7)

A battery pack containing one or more battery modules in a housing,
A first member and a second member constituting the housing;
A bolt for fastening the first member and the second member;
An annular member through which the bolt is inserted;
A seal member disposed between the first member and the second member;
With
The first member and the second member are fastened by the bolt in a state of sandwiching the annular member,
The seal member is compressed by the first member and the second member according to a separation distance between the first member and the second member defined by the annular member.
Battery pack. The first member is a box-shaped main body provided with an opening,
The second member is a plate-like lid portion fixed to the main body portion so as to close the opening,
At least one of the battery modules is attached to the second member.
The battery pack according to claim 1. The annular member has a first surface facing the first member, and a second surface facing the second member;
One of the first surface and the second surface is fixed to one of the first member and the second member;
The other of the first surface and the second surface is provided with a protrusion that protrudes toward the other of the first member and the second member.
The battery pack according to claim 1 or 2. The annular member has a first surface facing the first member, and a second surface facing the second member;
The first surface is provided with a protrusion that protrudes toward the first member,
The second surface is provided with a protrusion that protrudes toward the second member.
The battery pack according to claim 1 or 2. An appropriate range of the thickness of the seal member in the axial direction of the bolt in the compressed state is the thickness in the axial direction of the portion excluding the protrusion from the annular member and the thickness in the axial direction of the annular member. Adjusted to include the range between,
The battery pack according to claim 3 or 4. The resistance to deformation of the housing, the projected area of the projection when the annular member is viewed from the axial direction of the bolt, and the fastening force of the bolt are adjusted so that the projection bites into the housing. ing,
The battery pack according to any one of claims 3 to 5. The annular member is integrated with the seal member;
The battery pack according to any one of claims 1 to 6.

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