JP5037740B1 - Battery case and battery pack including the same - Google Patents

Abstract

In a battery case in which a battery unit composed of a plurality of batteries is housed, a configuration capable of regulating the movement of the battery in the battery case without affecting the output performance of the battery pack is compact and low-cost. Realized by simple configuration.
A battery case (2) includes a cylindrical side wall (22). The side wall portion (22) is a battery unit (3) in which a plurality of columnar batteries (11) are stacked so that the axes are parallel to each other, with the axis parallel to the bottom surface (21). A stowable storage space (24) is formed. On the inner surface of the side wall (22) facing the axial end of the battery (11) in the side wall (22), the protruding end is at the position corresponding to the axial end of the battery (11). 11) A plurality of ribs (23) (protruding portions) protruding inward of the storage space (24) so as to be located on a plane orthogonal to the axis of 11) are integrated with the inner surface of the side wall portion (22). Form.
[Selection] Figure 6

Description

  The present invention relates to a battery case for storing a plurality of batteries electrically connected to each other, and a battery pack configured by storing batteries in the battery case.

  Conventionally, a configuration in which a battery pack is formed by housing a plurality of batteries electrically connected to each other in a battery case is known. As such a configuration, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2006-134800, a plurality of batteries and spacers arranged between the batteries are provided in a plastic main body case (battery case). The stowed configuration is known. In this configuration, in order to electrically connect a plurality of batteries to each other, lead plates are attached to the end faces of the plurality of batteries.

  Here, in the case of the plastic main body case as described above, since a so-called draft angle is required when molding with a molding die, generally, the case side surface is positioned on the outer side toward the case opening side. It is inclined with respect to the normal on the bottom of the case. Therefore, a gap becomes larger between the main body case and the battery toward the case opening side.

  In the configuration of the above-described Japanese Patent Application Laid-Open No. 2006-134800, the gap is filled with a gap plate integrally formed with a spacer disposed between the batteries, thereby restricting the movement of the battery in the main body case. I have to.

JP 2006-134800 A

  Incidentally, in the case of the configuration as described in JP-A-2006-134800 described above, in order to ensure the strength of the gap plate, the gap plate needs to have a certain thickness. When the wall thickness is increased, the entire battery pack is enlarged accordingly.

  In the case of the configuration described in Japanese Patent Application Laid-Open No. 2006-134800, the gap plate is integrally formed with the spacer arranged between the batteries. Therefore, the arrangement of the gap plate is a lead that connects the batteries. Limited by the arrangement and shape of the plate. That is, since it is necessary to connect the axial direction edge part of a some battery with a lead plate, it is necessary to provide a clearance plate in a spacer so that the lead plate may be avoided. If so, the shape of the gap plate becomes complicated, and it is difficult to make the shape of the gap plate an optimum shape for restricting the movement of the battery. In other words, when the gap plate is optimally shaped to restrict the movement of the battery, on the contrary, the shape of the lead plate is limited, so the shape of the lead plate is made suitable for current distribution. There is a possibility that it cannot be formed.

  Furthermore, in the case of the configuration as described in Patent Document 1 described above, if the battery is to be stacked in three or more stages, the separator and the gap plate cannot be configured by a single molded part, and thus it is necessary to configure the battery by a plurality of parts. If it does so, the manufacturing cost of a molded article will increase.

  Therefore, in the present invention, in the battery case in which the battery unit composed of a plurality of columnar batteries is housed, a configuration that can regulate the movement of the battery in the battery case without affecting the output performance of the battery pack. It is intended to be realized by a compact and low-cost configuration.

  A battery case according to an embodiment of the present invention includes a side wall portion formed in a cylindrical shape extending in a cylinder axis direction, and the side wall portion includes a plurality of columnar batteries extending in an axial direction and the axes are parallel to each other. A battery unit configured by electrically connecting the batteries to each other in a stacked state to form a storage space capable of storing the battery in a state where both end portions in the axial direction of the battery face the side wall portion. In addition, a protruding end is orthogonal to the axis of the battery at a position corresponding to the end of the battery in the axial direction on the inner surface of the side wall facing the end in the axial direction of the battery. A plurality of projecting portions projecting inward of the storage space are integrally formed on the inner surface of the side wall portion so as to be positioned on a plane to be out of both ends of the side wall portion in the cylinder axis direction, At least one end has an opening. The side wall portion is inclined so that the inner surface is gradually located outward from the other end portion toward the one end portion, and compared to the plane, the side wall portion is The inclination of the inner surface is large (first configuration).

  With the above configuration, the battery unit housed in the battery case is restricted from moving in the battery case by the protruding portion integrally formed on the inner surface of the side wall portion of the battery case. Moreover, the plurality of batteries are arranged so that the end portions in the axial direction are at the same position in the axial direction by forming the protruding portions so that the protruding end portions are located on a plane orthogonal to the axis of the battery. In this case, the gap between the end face of each battery of the battery unit and the protruding end of the protruding portion becomes uniform. Therefore, in this case, it is possible to prevent variation in the amount of movement of each battery within the battery case. In general, the end of each battery in the battery unit in the axial direction is electrically connected by a connecting member. Therefore, by applying the above-described configuration in such a configuration, the connection is made due to variations in the amount of movement of each battery. The material can be prevented from being damaged.

  Moreover, in the above-described configuration, since the protruding portion is provided on the inner surface of the side wall portion of the battery case, the shape and arrangement of the connecting member that electrically connects the end portions in the axial direction of the battery can be freely designed. Furthermore, since the protruding portion is integrally formed on the inner surface of the side wall portion of the battery case, a configuration that restricts the movement of the battery can be realized with a low-cost and compact configuration.

  Therefore, with the above-described configuration, a battery case that can regulate the movement of the battery without affecting the output performance of the battery pack can be realized with a low-cost and compact configuration.

  Moreover, by making the side wall portion inclined as described above, it is possible to form the side wall portion by a molding die having a draft angle while forming only the protruding portion by a special method. Therefore, since it is not necessary to form the whole battery case by a special method, the battery case can be easily formed.

  In the first configuration, the projecting portion is provided such that the plane on which the projecting end portion is located is parallel to the end portion of the battery unit in the axial direction (second configuration). . Thereby, since the space | interval of the edge part of the axial direction of the battery in a battery unit and a some protrusion part becomes uniform, a movement of a battery unit can be more reliably controlled by this protrusion part. That is, with the above-described configuration, variation in movement of the end in the battery axis direction in the battery unit can be suppressed, so that the battery unit can be prevented from being damaged due to variation in movement of the battery in the battery unit.

  In the first or second configuration, the protrusion has a difference between a distance between the protrusion end and a part of the side wall facing the protrusion and a length in the axial direction of the battery. It is provided in the inner surface of the said side wall part so that it may become below the regulation value which can control a movement (3rd structure).

  Thereby, the movement of the battery can be more reliably regulated by the protrusion provided on the inner surface of the side wall.

  In any one of the first to third configurations, the protrusions are provided on the inner surfaces of the opposing side wall portions at positions facing each other (fourth configuration). Thereby, the battery unit accommodated in the battery case is restricted from moving in the axial direction of the battery by the protruding portions provided at positions facing each other. Therefore, the movement of the battery within the battery case can be more reliably regulated by the above-described configuration.

  In the fourth configuration, the projecting portion is configured such that the plane on which the projecting end portion is located is parallel to the plane on which the projecting end portion of the projecting portion provided at a position facing the projecting portion is located. Are provided on the inner surface of the side wall (fifth configuration).

  By doing so, the distance between each battery of the battery unit arranged in the battery case and the protruding end of the protruding portion becomes uniform at both ends of the battery in the axial direction of the battery. Variation in battery movement can be suppressed.

  In any one of the first to fifth configurations, an opening is formed in at least one end of both end portions of the side wall portion in the tube axis direction, and the protruding portion is , Formed on the inner surface of the side wall portion in a rib shape extending in the cylinder axis direction (sixth configuration).

  With such a configuration, the protruding portion provided in a rib shape on the inner surface of the side wall portion of the battery case also functions as a reinforcing rib of the side wall portion, so that the strength of the battery case can be improved.

  In any one of the first to sixth configurations, the side wall portion has a closing plate portion that covers the other end portion of both ends of the side wall in the cylinder axis direction, It is integrally formed with the side wall (seventh configuration). Thereby, the battery case which has a side wall part and an obstruction board part can be formed easily. Therefore, the battery unit housed in the battery case can be covered more extensively by the side wall portion and the closing plate portion.

  A battery pack according to an embodiment of the present invention is configured by housing a battery unit in the battery case according to any one of the first to seventh configurations (eighth configuration). Thereby, the battery pack which can regulate the movement of the battery in the battery case without affecting the output performance can be realized with a low cost and a compact configuration.

  In the eighth configuration, the battery unit further includes a connection member for electrically connecting the ends of the batteries, and an insulating sheet provided to cover the connection member and the ends of the battery. (Ninth configuration). Thereby, while being able to protect a connection member with an insulating sheet, the short circuit of this connection member can be prevented. Moreover, the impact applied to the battery unit in the battery case can be reduced by the insulating sheet.

  According to the battery case of one embodiment of the present invention, on the inner surface of the side wall portion, the protruding end portion is located on a plane perpendicular to the battery axis at a position corresponding to the axial end portion of the battery. As described above, a plurality of protrusions were formed integrally with the inner surface. Thereby, the movement of the battery within the battery case can be restricted by the protruding portion. In addition, since the protruding portion is formed in the battery case, the shape and arrangement of the connection member of the battery unit are not restricted, and thus the output performance of the battery pack is not affected. Moreover, since the said protrusion part is integrally formed by the side wall part, the battery pack which can control the movement of the battery in a battery case can be comprised with a low-cost and compact structure.

FIG. 1 is a perspective view illustrating a schematic configuration of the battery pack according to the first embodiment. FIG. 2 is a perspective view showing a schematic configuration of the battery case. FIG. 3 is a perspective view showing a schematic configuration of the battery unit. FIG. 4 is an exploded perspective view of the battery unit. FIG. 5 is a diagram illustrating a schematic configuration of a battery and a separator. 6 is a cross-sectional view taken along line VI-VI in FIG. FIG. 7 is a diagram schematically showing a state of rib forming when the rib of the battery case is formed using an inclined pin. FIG. 8 is a diagram schematically illustrating a state in which the molded battery case is released when the ribs of the battery case are formed using inclined pins. FIG. 9 is a diagram showing a schematic configuration of a forming die, a core, and an inner slide core used when forming a rib of the battery case. FIG. 10 is a diagram schematically showing a state of rib forming when the rib of the battery case is formed using the inner slide core. FIG. 11 is a diagram schematically illustrating a state in which the forming die is moved after the battery case is formed when the rib of the battery case is formed using the inner slide core. FIG. 12 is a diagram schematically illustrating how the battery case is released from the mold when the rib of the battery case is formed using the inner slide core. FIG. 13 is a perspective view illustrating a schematic configuration of a battery case of the battery pack according to the second embodiment. FIG. 14 is a diagram illustrating a positional relationship between the rib and the battery when the battery pack is viewed from the side. FIG. 15 is a diagram illustrating a schematic shape of a rib of a battery case according to another embodiment. FIG. 16 is a diagram showing a schematic shape of a rib of a battery case according to another embodiment. FIG. 17 is a diagram illustrating a schematic shape of a protruding portion of a battery case according to another embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
(overall structure)
FIG. 1 is a diagram showing a schematic configuration of a battery pack 1 according to Embodiment 1 of the present invention. The battery pack 1 accommodates a battery unit 3 configured by electrically connecting a plurality of substantially cylindrical batteries 11 extending in the axial direction in a box-shaped battery case 2 having an open surface. Consists of. The battery pack 1 is used, for example, as a power source for an electric tool, a power source for an electric bicycle, a power source for a portable device, or the like.

  The battery case 2 is a member made of a flame retardant resin material such as a flame retardant polycarbonate resin, and is molded using a molding die as described later. Further, the battery case 2 is formed in a box shape with one surface of a rectangular parallelepiped open, and is configured to be able to accommodate the battery unit 3 therein. The detailed configuration of the battery case 2 will be described later.

  The battery unit 3 is accommodated in the battery case 2 as shown in FIG. As shown in FIGS. 3 and 4, the battery unit 3 is configured to electrically connect a separator 31 for storing a plurality of batteries 11 and ends of the batteries 11 stored in the separator 31. Tabs 32 to 36 (connection members) and insulating sheets 37 that cover both end surfaces of the battery 11 from above the tabs 32 to 36 are provided.

  The separator 31 is made of a flame retardant resin material such as a flame retardant polycarbonate resin, and has a plurality of holes 31 a that can accommodate a plurality of substantially cylindrical batteries 11 as shown in FIGS. 4 and 5. ing. That is, the separator 31 is formed with a plurality of hole portions 31 a so as to extend in the same direction, and each hole portion 31 a is formed to have substantially the same length as the length of the battery 11 in the longitudinal direction. . Each hole 31a is formed to have a diameter substantially equal to the diameter of the battery 11. Thereby, in each hole part 31a, each battery 11 can be hold | maintained so that the mutual axis line L may become parallel.

  As shown in FIG. 4, in this embodiment, the separator 31 is provided with three vertical holes 31 a arranged in the horizontal direction. Thereby, the plurality of batteries 11 can be stacked in three stages while being arranged in the horizontal direction so that the axis lines L are parallel to each other (see FIG. 5). In addition, in the present embodiment, in the separator 31, the hole portions 31 a of the upper and lower adjacent steps are formed at positions shifted in the lateral direction. Thereby, many hole parts 31a can be provided as densely as possible, and the separator 31 as a whole can be miniaturized.

  In addition, the hole 31a provided in the separator 31 may not be three steps as in the present embodiment, but may be one step, two steps, four steps or more. Moreover, you may provide the hole part 31a of the step adjacent to the upper and lower sides so that it may be located in a line up and down instead of the position shifted in the horizontal direction.

  Further, in the present embodiment, the separator 31 is provided with a hole 31 a that can store the battery 11, and is configured to cover the entire side surface of the battery 11 with the separator 31. You may make it the shape which covers only a part of side surface. That is, the separator may be configured to cover only a part of the side surface of the battery 11 in the circumferential direction, or may be configured to cover only a part of the side surface of the battery 11 in the axial direction. .

  The tabs 32 to 36 are attached to the end portions of the batteries 11 by resistance welding so as to electrically connect the batteries 11 housed in the separator 31 to each other. Specifically, for example, as shown in FIG. 4, tabs 32 to 34 are attached to one end side of the battery 11, while tabs 35 and 36 are attached to the other end side of the battery 11. Each of the tabs 32 to 34 includes a tab main body 32a to 36a for electrically connecting the plurality of batteries 11 to each other, and a protrusion 32b that protrudes from the tab main body 32a to 36a and is connected to a lead wire (not shown). ~ 36b. These protrusions 32b to 36b protrude from the separator 31 with the tabs 32 to 36 being attached to the end of the battery 11 (see FIGS. 1 and 3). Thus, even when the tabs 32 to 36 are attached to the end portions of the battery 11 accommodated in the separator 31 and accommodated in the battery case 2 (FIG. 1), the protruding portions 32b to 36b of the tabs 32 to 36 are separated from each other. Since it protrudes more than 31, the lead-out wiring can be easily attached to the protrusions 32b to 36b.

  The tabs 32 to 36 are not limited to the shape shown in FIG. 4 as long as the plurality of batteries 11 can be electrically connected to each other, and may have any shape.

  The insulating sheet 37 is made of, for example, flame retardant fiber paper. As shown in FIG. 4, the insulating sheet 37 is attached on the tabs 32 to 36 so as to cover both ends of the plurality of batteries 11. The insulating sheet 37 is attached to the separator 31 so as to cover both open ends of the separator 31. The insulating sheet 37 is fixed to the separator 31, the battery 11, and the tabs 32-36 with an adhesive. Thereby, the battery unit 3 as shown in FIG. 3 is comprised.

(Battery case configuration)
As described above, the battery case 2 is made of a resin member molded by a molding die, and is formed in a shape in which one surface of a rectangular parallelepiped is opened. That is, as shown in FIG. 2, the battery case 2 includes a bottom surface portion 21 (blocking plate portion) that is substantially rectangular in plan view, and a side wall portion 22 that is integrally formed on the outer peripheral side of the bottom surface portion 21. ing. The side wall portion 22 is formed in a rectangular tube shape extending in the cylinder axis direction, and the bottom surface portion 21 is provided at an end portion of the side wall portion 22 in the cylinder axis direction. The side wall portion 22 includes a pair of long side wall portions 22 a provided on the long side of the substantially rectangular bottom surface portion 21 and a pair of short side wall portions 22 b provided on the short side of the bottom surface portion 21. And have.

  As a result, a storage space 24 is formed in the battery case 2 in which the above-described battery unit 3 can be stored in a state in which both end portions in the axial direction of the battery 11 face the side wall portion 22. Further, in the battery case 2, a case opening 2 a (opening) is formed at one end of both end portions of the side wall 22 in the cylinder axis direction by the side wall 22.

  The side wall portion 22 of the battery case 2 is provided with a so-called draft so that the battery case 2 can be smoothly removed from the mold when the battery case 2 is molded with the mold. That is, the long side wall portion 22a and the short side wall portion 22b are inclined with respect to the bottom surface portion 21 such that the long side wall portion 22a and the short side wall portion 22b are tilted outward from the battery case 2 rather than at a right angle. is doing. That is, the inner surfaces of the long side wall portion 22 a and the short side wall portion 22 b are gradually located outward from the other end portion of the side wall portion 22 toward one end portion. The inclination angle (draft angle) of the long side wall portion 22 a and the short side wall portion 22 b is, for example, an angle of about 1 degree with respect to the normal of the bottom surface portion 21. The draft angle of the battery case 2 may be an angle other than 1 degree as long as the battery case 2 can be smoothly removed from the mold.

  On the inner surface of the long side wall portion 22a of the battery case 2, it extends in the depth direction of the battery case 2 (the direction from the case opening 2a side to the bottom surface portion 21 side of the battery case 2, the vertical direction in FIG. 2). A plurality of ribs 23 (projections) are provided. That is, these ribs 23 are formed to extend in the cylinder axis direction of the side wall portion 22. These ribs 23 are directed from the bottom surface portion 21 side to the case opening 2a side so that the protruding end portion is positioned on the plane A that is orthogonal to the axis L of the battery 11 on the long side wall portion 22a. (See FIG. 6). As shown in FIG. 6, the plane A is a plane parallel to the end of the battery unit 3 in the axial direction of the battery 11. Thereby, since the edge part of the battery unit 3 can be supported uniformly by the rib 23, the battery 11 in this battery unit 3 can be supported uniformly. Therefore, even if an impact, vibration, or the like is applied to the battery pack 1, it is possible to prevent the battery unit 3 from moving relative to the battery unit 3 and damaging the battery unit 3.

  The thickness of the rib 23 is preferably ½ or less of the thickness of the long side wall 22 a of the battery case 2. Moreover, the length of the rib 23 may be a length that protrudes from the long side wall portion 22a, or the length from the bottom surface portion 21 side to the case opening 2a side in the long side wall portion 22a. The length may be shorter than that.

  Moreover, as shown in FIG. 2, these ribs 23 are provided at opposing positions on the pair of long side wall portions 22a. Therefore, the battery unit 3 housed in the battery case 2 is sandwiched between the ribs 23 formed on the pair of long side wall portions 22 a of the battery case 2. As a result, the battery unit 3 is restricted from moving toward the long side wall 22 a in the battery case 2 by the ribs 23 provided in the battery case 2. In the present embodiment, the ribs 23 are provided at opposing positions on the pair of long side wall portions 22a. However, the rib 23 is not limited to this, and if the movement of the battery 11 in the axial direction can be restricted, the ribs 23 are provided. May not be provided at positions facing each other.

  As shown in FIGS. 2 and 6, each rib 23 has a protruding end located on the inner side of the battery case 2 extending perpendicularly to the case opening 2 a side of the battery case 2 with respect to the bottom surface portion 21. In addition, it is formed on the long side wall portion 22a. That is, the rib 23 is formed such that the protruding end portion on the inner side of the battery case 2 has a draft angle of zero. Here, the long side wall portion 22a is inclined such that the inner surface is gradually located outward from the bottom surface portion 21 side toward the case opening 2a side. That is, the inner surface of the long side wall portion 22 a is inclined with respect to the normal of the bottom surface portion 21.

  With the above-described configuration, each rib 23 protrudes from the long side wall 22a toward the opening side of the battery case 2 with respect to the long side wall 22a having a draft. Moreover, as shown in FIG. 6, the ribs 23 formed on the pair of long side wall portions 22 a are parallel to each other in the plane A where the protruding end portions are located. Therefore, the distance between the battery unit 3 housed in the battery case 2 and the protruding end portion of the rib 23 formed on the long side wall portion 22a of the battery case 2 is the depth direction of the battery case 2. Becomes uniform. Therefore, the distance between the end in the axial direction of the battery 11 constituting the battery unit 3 and the protruding end of the rib 23 is also uniform in the depth direction of the battery case 2. In FIG. 6, the configuration of the battery unit 3 is shown in a simplified manner, and the ribs 23 are shown larger than the actual size.

  In addition, each rib 23 has a long side so that a difference between the distance between the protruding ends and the length in the axial direction of the battery 11 is equal to or less than a specified value that can restrict the movement of the battery 11 by each rib 23. It is provided on the inner surface of the side wall portion 22a. Here, the specified value is a gap that prevents the battery 11 in the battery case 2 from moving and damaging the battery unit 3 when vibration or impact is applied to the battery pack 1. Further, if the specified value is a value that can be absorbed by the deflection of the side wall portion 22 of the battery case 2, it is less than zero, that is, a value at which the battery unit 3 is press-fitted into the rib 23 of the battery case 2. There may be.

  Specifically, the specified value is a component (insulating in this embodiment) that is disposed at the end of the battery unit 3 in the axial direction of the battery 11 in the gap between the battery unit 3 and the rib 23 that is obtained as described later. It is a value obtained by adding the thicknesses of the sheet 37 and the tabs 32 to 36). In addition, since the thickness of these insulating sheets 37 and tabs 32 to 36 is sufficiently small with respect to the length of the battery 11 in the axial direction, it is not necessary to consider the tolerance of these thicknesses.

  The gap between the battery unit 3 and the rib 23 is defined as follows.

  First, the case where the dimension between the protruding ends of the ribs 23 in the battery case 2 is larger than the length in the battery axis direction in the battery unit 3 will be described.

  The length of the battery unit 3 in the battery axis direction is P, the dimensional tolerance of the length P is a%, and the distance between the protruding ends of the ribs 23 provided on the long side wall 22a of the battery case 2 When the dimensional tolerance is b%, the gap Y between the battery unit 3 and the battery 11 has the following relationship with respect to P, a, and b.

  P × | a−b | ≦ Y ≦ P × (a + b)

  Next, considering the case where the protruding end portion of the rib 23 has a draft angle θ and the battery unit 3 is constituted by a plurality of stages of batteries 11, the battery unit 3 at the height H of the central axis of the battery 11 is considered. A gap Z caused by the draft angle θ is expressed by the following equation.

  Z = 2 × H × tan θ

  By adding this Z to the above-mentioned Y, the gap between the battery unit 3 and the rib 23 at the height H of the central axis of the battery 11 can be obtained.

Here, when there is no draft at the protruding end of the rib 23 of the battery case 2, the maximum value of the gap between the battery unit 3 and the rib 23 at the height H of the central axis of the battery 11 is Z = 0 and Y Is the maximum when
Y = P × (a + b)
It becomes. On the other hand, when the rib 23 of the battery case 2 has a draft, the minimum value of the gap between the battery unit 3 and the rib 23 at the height H of the central axis of the battery 11 is Y = 0.
Z = 2 × H × tan θ
It becomes.

  For example, P = 65 mm, a = b = 0.5%, batteries having a diameter of 18.3 mm are stacked in two stages in the vertical direction, and the thickness of the separator is 1 mm and H = 29.45 mm. Further, the draft angle of the protruding end portion of the rib 23 is set to, for example, 0.5 degrees. In such a condition, the above-mentioned Y and Z are 0 ≦ Y ≦ 0.62 mm and Z = 0.51 mm.

Therefore, in the above-mentioned conditions, when there is no draft at the protruding end of the rib 23, the gap between the battery unit 3 and the rib 23 at the height H of the axis of the battery 11 is
0 ≦ Y ≦ 0.62mm
It becomes. On the other hand, when the projecting end of the rib 23 has a draft of 0.5 degrees under the above-described conditions, the gap between the battery unit 3 and the rib 23 at the height H of the axis of the battery 11 is
0.62 ≦ Y + Z ≦ 1.13mm
It becomes.

  It should be noted that the tolerance of H and θ need not be considered because the influence on Z is as small as about 0.01 mm.

  In the range of 0.62 ≦ Y + Z ≦ 1.13 mm, the battery unit 3 moves in the battery case 2, so that the battery unit 3 may be damaged. Therefore, considering the safety side, the gap between the battery unit 3 and the rib 23 is preferably 0.5 mm or less under the above-described conditions. As described above, when there is no draft at the protruding end of the rib 23, the gap between the battery unit 3 and the rib 23 is 0.62 mm. By making the interval between the projecting ends of the ribs 23 shorter than P, the gap between the battery unit 3 and the ribs 23 can be made 0.5 mm or less.

  Next, the case where the dimension between the protruding ends of the ribs 23 in the battery case 2 is smaller than the length in the battery axial direction in the battery unit 3 will be described. In this case, the gap between the battery unit 3 and the rib 23 is preferably within a range in which the battery case 2 can be elastically deformed. However, as described below, by expanding the inside of the battery case 2 with heat, the gap is reduced. Any range that can accommodate the battery unit 3 in the battery case 2 is acceptable.

  When the linear expansion coefficient α of the material constituting the battery case 2, the room temperature T 1, the heating temperature T 2, and the length of the battery unit 3 in the battery axial direction is P, the specified value d is expressed by the following equation.

  d = α × (T2−T1) × P

For example, consider a case in which a battery with an axial length of 65 mm is used and the battery case 2 is made of polycarbonate resin. When the linear expansion coefficient of the polycarbonate resin is α = 6.6 × 10 ⁻⁵ and the battery case 2 is raised from 30 ° C. to 100 ° C., d = 0.3 mm.

  Therefore, when the dimension between the projecting ends of the ribs 23 in the battery case 2 is smaller than the length in the battery axial direction of the battery unit 3, the ribs 23 are not easily deformed in the battery case 2 at both longitudinal ends. It is preferable that the difference between the distance between the projecting end portions and the length of the battery unit 2 in the battery axis direction is 0.3 mm or less.

  By the way, since the long side wall portion 22a of the battery case 2 which is a molded product tends to warp the central portion in the longitudinal direction, the protruding ends of the ribs 23 provided on the pair of long side wall portions 22a. The interval between the portions is smaller on the central side in the longitudinal direction than on the side in the longitudinal direction of the long side wall portion 22a. On the other hand, the central portion in the longitudinal direction of the long side wall portion 22a of the battery case 2 can be easily pushed and expanded in the direction to return the warp as described above. Therefore, the difference between the distance between the protruding end portions of the rib 23 and the length in the battery axial direction in the battery unit 2 is 0.3 mm which is the above-described calculation result (calculation result at both ends in the longitudinal direction in which no warpage occurs). If it is below, there is no problem.

  From the above, if the difference between the distance between the projecting ends of the ribs 23 and the length of the battery unit 2 in the battery axial direction is within the above range (0.3 mm or less), the elastic deformation of the battery case 2 alone Even when the battery unit 3 cannot be stored in the battery case 2, the battery unit 3 can be stored in the battery case 2 by increasing the temperature of the battery case 2 and causing the battery case 2 to expand.

  In the present embodiment, since the ribs 23 are provided at positions where the pair of long side wall portions 22a face each other, the difference between the distance between the protruding ends of the ribs 23 and the length in the axial direction of the battery 11 is determined. Used. When the ribs 23 are not provided at positions facing each other, the difference between the distance between the protruding end portion of the rib 23 and the inner surface of the long side wall portion 22a facing the rib 23 and the length in the axial direction of the battery 11 may be used. . That is, in the battery case 2, the distance between the portions facing the axial end of the battery 11 may be used.

  Thereby, when the battery unit 3 has a configuration in which a plurality of batteries 11 are stacked in multiple stages, the battery unit 3 is housed in the battery case 2 and the axial end of the battery 11 and the protruding end of the rib 23 are The interval is uniform in the battery stacking direction of the battery unit 3. Therefore, even when vibration or impact is applied to the battery pack 1, the batteries 11 of the battery unit 3 can be evenly supported by the ribs 23 of the battery case 2. 36 can be prevented from being damaged.

  With the above-described configuration, the difference between the protruding end portions of the ribs 23 and the length of the battery unit 3 in the battery axial direction is not more than a predetermined value that can regulate the movement of the battery unit 3 by the ribs 23. Become. That is, the ribs 23 are set so that the difference between the distance between the protruding end portions and the length of the battery unit 3 in the battery axial direction is equal to or less than a predetermined value by which the movement of the battery unit 3 can be regulated by the ribs 23. Further, it may be provided on the inner surface of the long side wall portion 22a. Thereby, in a state where the battery unit 3 in which the plurality of batteries 11 are stacked in multiple stages is housed in the battery case 2, the distance between the battery unit 3 and the rib 23 is uniform in the battery stacking direction of the battery unit 3. Therefore, even when vibration or impact is applied to the battery pack 1, the entire battery unit 3 can be evenly supported by the ribs 23 of the battery case 2, so that the battery 11 is relatively displaced in the battery unit 3 and the tabs. It is possible to prevent 32 to 36 from being damaged.

  Here, the predetermined value is a gap that prevents the battery unit 3 in the battery case 2 from moving and being damaged when vibration or impact is applied to the battery pack 1. If the predetermined value is a value that can be absorbed by the deflection of the side wall portion 22 of the battery case 2, the predetermined value is not more than zero, that is, a value at which the battery unit 3 is press-fitted into the rib 23 of the battery case 2. There may be.

  The predetermined value is equal to the gap between the battery unit 3 and the rib 23 when the above-mentioned specified value is obtained. Therefore, the predetermined value is defined in the same manner as the above-described concept when the gap between the battery unit 3 and the rib 23 is obtained.

  Note that the difference between the distance between the protruding ends of the ribs 23 and the length of the battery unit 3 in the battery axial direction is also determined when the ribs 23 are not provided at positions facing each other. What is necessary is just to use the space | interval with the part which opposes.

  Each rib 23 is provided so that a part of the rib 23 is positioned at the center of the end of each battery 11 in the battery unit 3 in the axial direction in a state where the battery unit 3 is housed in the battery case 2. ing. That is, the plurality of ribs 23 are formed on the long side wall 22a of the battery case 2 so that any one of the ribs 23 is located on the center of the end in the axial direction of the battery 11 of the battery unit 3. ing. Thereby, the displacement of each battery 11 of the battery unit 3 in the battery case 2 can be more reliably regulated by the rib 23.

  It is not necessary to provide the rib 23 so that any one of the ribs 23 is positioned at the center of the end of the battery 11 in the axial direction, and a portion where the rib 23 is not provided is sufficient to prevent damage due to vibration or impact. There may be. In addition, the protruding end portion of each rib 23 may be provided with an R portion, a chamfered portion, or the like in consideration of the formability of the battery case 2 and the assembly workability of the battery unit 3 with respect to the battery case 2.

  As described above, the ribs 23 are provided on the battery case 2 to restrict the movement of the battery unit 3 in the battery case 2, so that the shapes of the tabs 32 to 36 of the battery unit 3 can be freely set. In addition to the design, the separator 31 of the battery unit 3 can have a simple configuration. Therefore, with the above-described configuration, the manufacturing cost of the separator 31 and the tabs 32 to 36 of the battery unit 3 can be reduced, and the overall size of the battery pack 1 can be prevented from being increased. In addition, with the above-described configuration, the tabs 32 to 36 can be designed to have a shape suitable for the current distribution, so that it is possible to prevent the output performance of the battery pack 1 from being affected.

  In this embodiment, the draft angle of the protruding end portion of the rib 23 is set to zero. This zero draft angle means that the molded product is smoothly released from the molding die when molded with the molding die. It means that the gradient is smaller than the gradient required for. That is, the draft angle zero means a gradient that cannot be released unless undercut processing is performed, and is not necessarily zero. Although details will be described later, as in the present embodiment, by forming only the rib 23 with zero draft, the rib that can suppress the movement of the battery unit 3 while efficiently securing the moldability of the battery case 2 can be efficiently obtained. Can be molded.

  In addition, the protruding end portion of the rib 23 extends in a direction perpendicular to the bottom surface portion 21 when the battery unit 3 is displaced by the displacement of the battery 11 when vibration or impact is applied to the battery pack 1. It also includes a tilt that allows the battery 11 to be displaced so as not to be damaged.

  Furthermore, the protruding end portions of the ribs 23 are substantially parallel. When the battery unit 3 is disposed between the ribs 23, the battery unit 3 remains in the battery case 2 even if vibration or impact is applied to the battery pack 1. Means a positional relationship that does not move toward the long side wall portion 22a. Therefore, when the battery pack 1 is subjected to an impact, the protruding end portions of the ribs 23 may not be completely parallel to each other as long as the battery unit 3 does not move within the battery case 2. It may be slightly inclined with respect to the vertical line.

  Similarly, the uniform distance between the battery unit 3 and the protruding end of the rib 23 means that the battery unit 3 is damaged by the displacement of the battery 11 in the battery unit 3 when vibration or impact is applied to the battery pack 1. Including variations in intervals that are not affected.

(Battery case manufacturing method)
Next, the manufacturing method of the battery case 2 is demonstrated using FIG.7 and FIG.8. In addition, since the manufacturing method of the battery case 2 whole is the same as the normal method which performs resin molding using a mold, the following mainly describes the molding method of the rib 23 portion. 7 and 8, a portion protruding from the bottom surface portion 21 toward the opposite side of the long side wall portion 22a is a portion formed by a direct gate and is removed after the battery case 2 is formed.

  7 and 8, in order to compare the manufacturing method of the side wall portion 22 having the draft and the rib 23, the cross section of the long side wall portion 22 a where the rib 23 is not provided and the rib 23 are provided. The cross section of the portion is shown in one figure. That is, in FIGS. 7 and 8, the cross section of the upper part and the cross section of the lower part across the center line (one-dot chain line) are 90 degrees with respect to the bottom surface part 21 of the battery case 2 as viewed from the surface normal direction. Sections at different positions are shown.

  As described above, since the draft angle of the rib 23 formed in the battery case 2 is zero, the rib 23 is formed by using, for example, the inclined pin 43 as shown in FIGS. That is, when the battery case 2 is molded between the pair of molding dies 41 and 42 by, for example, injection molding, the protruding end portion of the rib 23 that makes the draft angle zero is molded by the inclined pin 43.

  The inclined pin 43 is slidable in a direction perpendicular to the clamping direction on one end side of the sliding portion 44 configured to be slidable in the clamping direction of the pair of molding dies 41, 42 with respect to the molding die 42. It is connected. The inclined pin 43 is configured to be rotatable around one end side connected to the slide portion 44. Moreover, the inclined pin 43 is coupled to the slide portion 44 so as to be inclined with respect to the moving direction (mold clamping direction) of the slide portion 44.

  In addition, the inclined pin 43 is formed so that the other end side opposite to the one end side connected to the slide portion 44 increases in cross-sectional area toward the tip. That is, the inclined pin 43 that is inclined with respect to the mold clamping direction has a cross-sectional area toward the tip on the other end side so that the protruding end portion of the rib 23 of the battery case 2 is formed by the side surface on the other end side. Is getting bigger.

  As in this embodiment, the portion formed with zero draft is only the rib 23 of the side wall portion 22, and the other portion of the side wall portion 22 is molded with a draft, thereby forming the battery case 2. The rib capable of suppressing the movement of the battery unit 3 can be efficiently formed while securing the property.

  In the present embodiment, the shape of the inclined pin 43 is such that the other end side opposite to the one end side connected to the slide portion 44 has a cross-sectional area that increases toward the tip. However, the shape is not limited to this, and any other shape may be used as long as it functions as an inclined pin.

  In addition to the one end side of the inclined pin 43 described above, one end side of a projecting pin 45 for projecting the battery case 2 from the molding die 42 is connected to the slide portion 44.

  As shown in FIG. 8, after the battery case 2 is formed by the pair of forming dies 41, 42, the slide portion 44 is slid in the direction approaching the forming die 42 (indicated by the white arrow in the figure), and the protruding pin 45 is moved. The battery case 2 is released from the mold 42 by the inclined pins 43. At this time, the protrusion pin 45 protrudes the battery case 2 straight by the sliding movement of the slide portion 44. On the other hand, the inclined pin 43 moves in an oblique direction with respect to the moving direction of the slide portion 44. Note that one end side of the inclined pin 43 slidably coupled to the slide portion 44 slides in a direction perpendicular to the slide direction of the slide portion 44 with respect to the slide portion 44.

  Thereby, the other end side of the inclined pin 43 is separated from the rib 23 of the battery case 2 toward the inner side of the battery case 2, so that the rib 23 can be smoothly released even when the draft is zero. it can.

  The rib 23 having no draft angle may be formed using an inner slide core in addition to the method using the inclined pin 43 as described above. Hereinafter, a method for forming the rib 23 with no draft angle using the inner slide core will be described with reference to FIGS.

  9 to 12, in order to compare the manufacturing method of the side wall portion 22 having the draft and the rib 23, the cross section of the long side wall portion 22 a where the rib 23 is not provided and the rib 23 are provided. The cross section of the portion is shown in one figure. That is, in FIGS. 9 to 12, the cross section of the upper part and the cross section of the lower part across the center line (one-dot chain line) are 90 degrees with respect to the bottom surface part 21 of the battery case 2 as viewed from the surface normal direction. Sections at different positions are shown.

  In the molding method using the inner slide core, as shown in FIG. 10, the outer side of the battery case 2 is molded by the molding dies 51 and 52, while the inner side of the battery case 2 is part of the molding die 52, the core. 53 and the inner slide core 54 are used for molding.

  The mold 51 is a fixed mold and has a recess that forms the outer surface of the battery case 2.

  The molding die 52 is a movable die and has a hole portion in which a core 53 and a slide core 54 for molding the inside of the battery case 2 can be placed. In addition, the mold 52 has a protrusion 52 a for molding the inner surface of the side wall portion 22 in a region where the side wall portion 22 of the battery case 2 is to be formed in the peripheral portion of the hole portion. The protrusion 52 a has a draft angle on the surface facing the mold 51, while the hole-side surface of the mold 52 extends in the movement direction of the mold 52 and is perpendicular to the bottom surface 21 of the battery case 2. Is formed. Further, the molding die 52 is formed with a through hole penetrating the protruding portion 52a in the protruding direction. In this through hole, the protruding pin 57 is arranged so as to be movable in the protruding direction of the protruding portion 52.

  The core 53 is configured to mold a part of the inner surface of the bottom surface portion 21 in the battery case 2. The core 53 is in contact with an inner slide core 54 elastically supported by the molding die 52 by a compression spring 55 and a slide surface that comes into contact with the surface of the projection 52a of the molding die 52 on the hole side. And a tapered surface 53a.

  The core 53 moves together with the movable mold 52, and the moving speed is higher than that of the mold 52 in the latter half of the mold clamping. For example, the core 53 has a rod shape that operates like a so-called seesaw in which when the movable mold 52 approaches the fixed mold 51, one end is pushed by the fixed mold 51 and the other end is raised. The other end of the member is connected. As a result, the core 53 approaches the stationary mold 51 at a higher moving speed than the movable mold 52 in the latter half of the mold clamping. The rod-shaped member is provided with a biasing member that biases the core 53 downward in FIG. Here, in this embodiment, the moving mechanism of the core 53 is configured to use a mechanism such as a seesaw. However, the moving mechanism is not limited to this, and can move faster than the movable mold 52 in the latter half of the mold clamping. Any configuration may be used as long as it has such a configuration.

  The inner slide core 54 is configured to mold the protruding end portion of the rib 23 of the battery case 2. The inner slide core 54 is connected to a movable mold 52 via a compression spring 55. As a result, the inner slide core 54 is urged in a direction away from the mold 52 by the compression spring 55 as shown in FIGS. 9, 11, and 12.

  Each of the core 53 and the inner slide core 54 is formed in a tapered shape at a portion in contact with each other. Specifically, the core 53 is such that the thickness dimension in the width direction (the left-right direction in FIGS. 9 to 12) decreases toward the fixed-side mold 51 in a state where the molds 51 and 52 are clamped. A tapered surface 53a is provided. On the other hand, the inner slide core 54 is tapered such that the thickness dimension in the width direction (the left-right direction in FIGS. 9 to 12) increases toward the fixed-side mold 51 in a state where the molds 51 and 52 are clamped. It has a surface 54a. Thereby, when the core 53 is moved to the fixed mold 51 side, the taper surface 53a of the core 53 comes into contact with the taper surface 54a of the inner slide core 54, and the inner slide core 54 is compressed by a compression spring. 55 is moved in the direction in which it is compressed (the right direction in FIGS. 9 to 12).

  In the above configuration, as shown in FIG. 9, when the movable mold 52 is brought closer to the fixed mold 51, the core 53 is moved to the movable mold 52 in the latter half of the mold clamping as described above. Approach faster. At this time, the taper surface 53a of the core 53 and the taper surface 54a of the inner slide core 54 come into contact with each other, and the inner slide core 54 moves in the direction in which the compression spring 55 is compressed (right direction in FIG. 9) by the core 53. To do. When the mold clamping is completed, the movable side mold 52 and the core 53 are also stopped, and as shown in FIG. 10, the taper surface 53a of the core 53 and the taper surface 54a of the inner slide core 54 are all over them. In contact. In addition, the code | symbol 56 in FIGS. 9-12 is a holding member.

  In the state of FIG. 10, the battery case 2 is molded by filling the resin formed in the space formed by the molds 51 and 52, the core 53 and the inner slide core 54. After the battery case 2 is molded, the movable mold 52 is moved away from the mold 51 as shown in FIG. Since the core 53 is urged by the urging member as described above, the core 53 moves faster than the molding die 52, and the taper surface 53 a of the core 53 is against the taper surface 54 a of the inner slide core 54. Move the slide. As a result, the inner slide core 54 is not pressed from the core 53, and moves in a direction away from the movable mold 52 by the elastic restoring force of the compression spring 55. Thereafter, as shown in FIG. 12, the battery case 2 is released from the mold 52 by the protruding pin 57.

  9 to 12, as in FIGS. 7 and 8, the portion protruding from the bottom surface portion 21 toward the opposite side of the long side wall portion 22 a is a portion formed by a direct gate, It is removed after the battery case 2 is molded.

(Effect of Embodiment 1)
As described above, in this embodiment, among the side wall portions 22 of the battery case 2 that accommodates the battery unit 3, the long side wall portion 22a is provided with a plurality of ribs 23 with a draft angle of the protruding end portion of zero. Thereby, even when an impact is applied to the battery pack 1, the displacement of the battery unit 3 in the battery case 2 can be evenly regulated by the ribs 23. Therefore, even in the battery unit 3 in which the batteries 11 are stacked in a plurality of stages, the difference in displacement between the battery 11 in the lowermost stage and the battery 11 in the uppermost stage can be reduced. Therefore, it is possible to prevent the tabs 32 to 36 connected to the ends of the battery 11 from being damaged when vibration or impact is applied to the battery pack 1.

  Further, the ribs 23 are provided on the pair of long side wall portions 22 a of the battery case 2 so as to face each other. Thereby, the movement of the battery unit 3 accommodated in the battery case 2 can be more reliably regulated by the rib 23.

  Further, at least one rib 23 among the plurality of ribs 23 is an end portion of the battery 11 of the battery unit 3 as viewed from the side of the battery case 2 in a state where the battery unit 3 is accommodated in the battery case 2. It is provided so that it may be located on the center of. Thereby, even when the battery unit 3 moves in the battery case 2, each battery 11 of the battery unit 3 can be more reliably supported by the ribs 23, and the movement of each battery 11 is more reliably regulated. be able to.

  Moreover, since the plurality of ribs 23 are integrally formed with the long side wall portion 22a of the battery case 2, a configuration that can more reliably restrict the movement of the battery 11 can be realized at low cost.

  Further, by providing the rib 23 on the battery case 2, it is not necessary to provide a movement restricting structure for the battery 11 on the battery unit 3 side as in the prior art, so that the battery unit 3 can be reduced in size and the tabs 32-36. The degree of freedom of design can be improved. Thereby, the manufacturing cost of the tabs 32 to 36 can be reduced, and the performance deterioration of the battery pack 1 due to the restriction of the shape of the tabs 32 to 36 can be prevented.

  Furthermore, the rib 23 is provided on the long side wall portion 22a of the battery case 2 so as to extend from the bottom surface portion 21 to the case opening 2a side of the battery case 2, whereby the strength of the battery case 2 can be improved. That is, the rib 23 provided on the long side wall portion 22a of the battery case 2 also functions as a reinforcing rib for the long side wall portion 22a.

[Embodiment 2]
In FIG. 13, schematic structure of the battery case 61 which concerns on Embodiment 2 of this invention is shown. This embodiment is different from the configuration of the first embodiment described above in that ribs 64 are provided on the long side wall 63a of the battery case 61 so as to correspond to the respective batteries 11 of the battery unit 3. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

  Specifically, as shown in FIGS. 13 and 14, the long-side side wall 63 a of the battery case 61 corresponds to the batteries 11 stacked in a plurality of stages (for example, three stages) in the first embodiment. A plurality of ribs 64 (projections) shorter than the ribs 23 are provided. That is, in the long side wall portion 63 a of the battery case 61, the case opening of the battery case 61 from the bottom surface portion 62 to a portion where the end portion of each battery 11 is located in a state where the battery unit 3 is disposed in the battery case 61. A plurality of ribs 64 extending to the 61a side are formed.

  In this embodiment, the rib 64 has a length of about 1/3 of the length from the bottom surface portion 62 side of the long side side wall portion 63a to the case opening portion 61a side of the battery case 61. Are arranged in three stages. Further, in this embodiment, the ribs 64 are provided at different positions in the vertical direction in the steps adjacent to each other in the vertical direction. Further, the ribs 64 are formed on the pair of long side wall portions 63a of the battery case 61 at positions facing each other, as in the first embodiment.

  Also in this embodiment, as shown in FIG. 14, the rib 64 is provided so as to be positioned at the center of the end of each battery 11 when viewed from the side of the battery case 61. Thereby, even when the battery pack 60 is subjected to vibration or impact, the movement of each battery 11 can be more reliably regulated by the rib 64 provided in the battery case 61.

  In addition, the rib 64 of this embodiment can also be formed by using an inclined pin or an inner slide core as in the first embodiment.

  13 and 14, reference numeral 63 indicates a side wall, reference numeral 63 b indicates a short side wall, and reference numeral 65 indicates a storage space.

(Effect of Embodiment 2)
As described above, in this embodiment, the plurality of ribs 63 are provided on the long side wall portion 22 a of the battery case 2 so as to correspond to each battery 11 of the battery unit 3. Thereby, the movement of each battery 11 can be regulated more reliably. Therefore, damage to the tabs 32 to 36 of the battery unit 3 can be prevented more reliably.

(Other embodiments)
While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented without departing from the spirit of the invention.

  In each of the above embodiments, the ribs 23 are positioned on the long side wall portions 22a and 63a of the battery cases 2 and 61 so as to be positioned at the centers of the batteries 11 of the battery unit 3 when viewed from the side of the battery cases 2 and 61. , 64 are formed. However, the present invention is not limited to this, and the rib may be provided at any position as long as the movement of the battery unit 3 in the battery cases 2 and 61 can be restricted. That is, if a rib for restricting the movement of the battery pack 3 is provided to such an extent that the battery unit 3 is not damaged when vibration or impact is applied to the battery pack 1, all the batteries 11 of the battery unit 3 are supported. It is not necessary to provide a rib. However, even in this case, when the battery unit 3 moves in the battery cases 2 and 61, the base portions of the protruding portions 32b to 36b of the tabs 32 to 36 are easily damaged, and therefore the battery 11 around the protruding portions 32b to 36b. It is preferable to provide a rib so as to restrict the movement.

  In each of the embodiments described above, the ribs 23 and 64 extending in the depth direction of the battery case 2 and 61 (perpendicular to the bottom surface portion) are provided on the long side wall portions 22a and 63a of the battery case 2 and 61. Forming. However, the shape of the rib is not limited to this, and the shape of the rib may be any shape as long as the protruding end portion is located on the plane A perpendicular to the axis L of the battery 11. Moreover, even if it is a protrusion part which has shapes other than a rib, if the protrusion edge part protrudes inward of the battery cases 2 and 61 so that it may be located on the plane A orthogonal to the axis line L of the battery 11, Good.

  Specifically, as shown in FIG. 15, a plurality of ribs 74 extending in parallel to the bottom surface portion 72 may be formed on the inner surface of the long side wall portion 73 a in the side wall portion 73 of the battery case 71. . In this case, each rib 74 is provided on the long side wall portion 73 a so as to pass through the central portion of the end portion in the axial direction of the battery 11 when viewed from the axial direction of the battery 11.

  These ribs 74 are preferably provided at positions facing the pair of long side wall portions 73a so as to pass through the central portions of the end portions in the axial direction of all the batteries 11. It may pass through other parts of the part, or may not be formed corresponding to the end of the battery 11 in the axial direction. Moreover, you may provide the rib 74 only in the long side wall part 73a of one side among a pair of long side wall parts 73a. In other words, the rib 74 may be provided in any manner as long as the movement of the battery 11 in the axial direction can be restricted. FIG. 15 is a view showing a cross section of the battery case 71 when the battery case 71 is cut in the longitudinal direction at the center portion in the width direction of the short side wall portion 73b.

  In addition, as shown in FIG. 16, the inner surface of the long side wall 83 a of the side wall 83 of the battery case 81 extends across the axial ends of the plurality of batteries 11 when viewed from the axial direction of the battery 11. The ribs 84 and 85 may be formed in a polygonal shape such as a square or a hexagon. Specifically, in the example of FIG. 16, the long side wall 83 a has a rhomboid rib 84 and the end of the battery 11 that does not overlap the rib 84 when viewed from the axial direction of the battery 11. Hexagonal ribs 85 are formed. In addition, in the example of FIG. 16, these ribs 84 and 85 are doubled on the outer side and the inner side, respectively. Thereby, all the batteries 11 in the battery unit 3 can be supported in a more stable state by the ribs 84 and 85.

  These ribs 84 and 85 are preferably provided at positions where the pair of long side wall portions 83a are opposed to each other, as in the configuration shown in FIG. 15, but are provided only on one long side wall portion 83a. Also good. Moreover, in FIG. 16, although the shape is changed with the rib 84 and the rib 85, all the shapes of a rib may be the same, and all shapes may be different. Further, the shape of the rib may be any shape as long as the movement of the battery 11 in the axial direction can be restricted by supporting the end of the battery 11 in the axial direction. FIG. 16 is also a view showing a cross section of the battery case 81 when the battery case 81 is cut in the longitudinal direction at the center portion in the width direction of the short side wall portion 83b, as in FIG.

  Furthermore, as shown in FIG. 17, in the side wall portion 93 of the battery case 91, the inner surface of the long side wall portion 93 a has the same circular shape as the axial end portions of the plurality of batteries 11 when viewed from the axial direction of the battery 11. A protruding portion 94 that bulges out and has the same diameter as the axial end portion may be formed. The protruding portion 94 is formed in a flat shape on the protruding end side. Thereby, since each battery 11 can be supported by each protrusion part 94, the movement of the axial direction of this battery 11 can be more reliably controlled by the protrusion part 94.

  As in the configuration shown in FIGS. 15 and 16, the protruding portion 94 is preferably provided at a position where the pair of long side wall portions 93 a are opposed to each other, but is provided only on one long side wall portion 93 a. Also good. Further, the protrusion 94 may have a shape other than a circle as long as the movement of the battery 11 in the axial direction can be restricted by supporting the end of the battery 11 in the axial direction. The outer shape may be smaller than the end of the battery 11 in the axial direction when viewed from the axial direction. FIG. 17 is also a view showing a cross section of the battery case 91 when the battery case 91 is cut in the longitudinal direction at the center portion in the width direction of the short side wall portion 93b, as in FIGS.

  15 to 17 described above, the ribs 74, 84, 85 and the protruding portion 94 are formed so that the protruding end portions are located on the plane A perpendicular to the axis L of the battery 11. Yes. That is, the ribs 74, 84, 85 and the protruding portion 94 may have any shape as long as the protruding end portion is located on the plane A orthogonal to the axis L of the battery 11. The plane A is preferably parallel to the end of the battery unit 3 in the battery axis direction.

  In each said embodiment, although the battery 11 is made into the column-shaped battery, it is not restricted to this, The other columnar battery may be sufficient.

  In each of the above-described embodiments, the inclined pins and the inner slide core are used to form the ribs 23 and 64 having the protruding end portions with zero draft angle. However, the present invention is not limited to this, and the ribs 23 and 64 can be formed. Any other method may be used as long as it is a simple method.

  In each said embodiment, the ribs 23 and 64 are provided in the position which mutually faces on the long side wall part 22a, 63a of the battery case 2,61. However, this is not restrictive, and the ribs 23 and 64 may be provided at different positions on the long side wall portions 22a and 63a as long as the battery 11 can be supported in the longitudinal direction. The same applies to the configurations shown in FIGS. 15 to 17 described above.

  In each said embodiment, the figure of the state which has arrange | positioned the battery unit 3 in the battery cases 2 and 61 is shown. However, a lid may be attached to the battery cases 2 and 61 so as to cover the openings 2a and 61a, or the other battery case may be aligned with the openings 2a and 61a. May cover the openings 2a and 61a. Moreover, you may arrange | position the battery cases 2 and 61 so that the bottom face parts 21 and 62 may be located upwards.

  In each of the above-described embodiments, the bottom surface portions 21 and 62 and the side wall portions 22 and 63 are integrally formed in the battery cases 2 and 61. However, only the side wall portions 22 and 63 are integrally formed to form the bottom surface portions 21 and 62. May be a separate member. That is, it may be a battery case in which openings are formed at both ends of the side wall portions 22 and 63 in the cylinder axis direction. The shape of the side walls 22 and 63 of the battery cases 2 and 61 may be any shape as long as the battery unit 3 can be housed inside.

  The battery case according to the present invention can be used as a battery case constituting a battery pack by accommodating a plurality of columnar batteries.

Claims (9)

A side wall portion formed in a cylindrical shape extending in the cylinder axis direction,
The side wall portion includes a battery unit configured by electrically connecting the batteries to each other in a state in which a plurality of columnar batteries extending in the axial direction are stacked so that the axes are parallel to each other. A storage space that can be stored in a state in which both end portions in the axial direction face the side wall portion,
On the inner surface of the side wall portion facing the axial end portion of the battery among the side wall portions, a protruding end portion is on a plane perpendicular to the axial line of the battery at a position corresponding to the axial end portion of the battery. A plurality of projecting portions projecting inward of the storage space are integrally formed on the inner surface of the side wall portion,
An opening is formed in at least one end of both end portions of the side wall portion in the tube axis direction,
The side wall portion is inclined such that the inner surface is gradually located outward from the other end portion toward the one end portion, and the inclination of the inner surface with respect to the cylindrical axis as compared with the flat surface. The battery case is big. The battery case according to claim 1,
The projecting portion is a battery case in which the flat surface on which the projecting end portion is located is provided so as to be parallel to the end portion of the battery unit in the axial direction. The battery case according to claim 1 or 2,
In the protrusion, the difference between the distance between the protrusion end and a part of the side wall facing the protrusion and the length in the axial direction of the battery is equal to or less than a specified value that can regulate the movement of the battery. Thus, the battery case provided in the inner surface of the said side wall part. The battery case according to any one of claims 1 to 3,
The protruding portion is a battery case provided on the inner surface of the opposing side wall portion at a position facing each other. The battery case according to claim 4,
The projecting portion has an inner surface of the side wall portion such that the plane on which the projecting end portion is located is parallel to a plane on which the projecting end portion of the projecting portion provided at a position facing the projecting portion is located. A battery case provided above. The battery case according to any one of claims 1 to 5,
An opening is formed in at least one end of both end portions of the side wall portion in the tube axis direction,
The projecting portion is a battery case formed on the inner surface of the side wall portion in a rib shape extending in the cylindrical axis direction. The battery case according to any one of claims 1 to 6,
Of the both end portions of the side wall portion in the cylinder axis direction, it has a closing plate portion that covers the other end portion,
The closing plate part is a battery case integrally formed with the side wall part.   The battery pack comprised by accommodating a battery unit in the battery case as described in any one of Claim 1 to 7. The battery pack according to claim 8, wherein
The battery unit is
A connection member for electrically connecting the ends of the batteries;
A battery pack, further comprising: an insulating sheet provided to cover the connection member and an end of the battery.

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