JP5673385B2 - Assembled battery - Google Patents

Description

  The present invention relates to a battery case for a unit cell suitable for manufacturing a battery pack.

  As a technology for connecting a plurality of unit cells to form a module (assembled battery), a plurality of unit cells, a battery partition wall disposed between the stacked unit cells, and a pair of end plates for sandwiching them There is known a secondary battery module including a fastening member protruding from an end plate and a fastening rod inserted through the fastening member to fasten a pair of end plates (Patent Document 1).

JP 2006-156392 A

  In contrast to the conventional structure in which an assembled battery is held only by a pair of end plates and a fastening (connecting) rod, the present inventor has provided a connecting member provided with a connecting rod through-hole on the side surface of each unit cell. Is studying a new structure.

  However, the through hole and the end plate are both concentric, and the inner diameter of the through hole is larger than the inner diameter of the connecting rod by the clearance when the connecting rod is inserted, so backlash is likely to occur due to vibration and impact. . Furthermore, rattling increases under a long-term vibration environment, the through-holes wear and the load is easily applied to the connecting rod.

  The present invention has been made in view of the above, and an object of the present invention is to suppress the occurrence of rattling due to vibration and impact even when the assembled battery is placed in a vibration environment for a long period of time.

In the battery case according to the present invention, the battery case has a rectangular parallelepiped shape having a pair of narrow short side surfaces and a pair of wide long side surfaces, and connecting members at both upper and lower ends of the pair of short side surfaces. With
The connecting member includes a through hole penetrating in the width direction of the short side surface, and the through hole has a tapered shape with respect to the width direction.

  In addition, a unit cell can be configured by including the power generation element housed in the battery case and the output terminal of the power generation element above the battery case, and a plurality of the unit cells can be formed. An assembled battery can be comprised by arrange | positioning and connecting.

  The assembled battery configured by using the present invention can suppress the occurrence and increase of rattling due to vibration and impact even in a vibration environment for a long period of time.

The assembled battery of 1st Embodiment, (a) is sectional drawing of a connection member, (b) is a figure explaining insertion of a connection rod. 1A is a perspective view of a unit cell, and FIG. 1B is a front view of the unit cell. The perspective view of the assembled battery of 1st Embodiment The figure explaining insertion of the ferrule of the assembled battery of 2nd Embodiment The assembled battery of 3rd Embodiment, (a) is a figure explaining attachment of a buffer member, (b) is a figure which shows the assembled battery after attachment of a buffer member The assembled battery of 4th Embodiment, (a) is a figure explaining attachment of a buffer member, (b) is a figure which shows the assembled battery after attachment of a buffer member A battery case that houses a single cell described in each embodiment

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, about the component which exhibits the same or the same kind of function, description may be abbreviate | omitted using the same code | symbol. Each embodiment is only an example and does not give a limited interpretation on the present invention. First, the whole assembled battery of 1st Embodiment is demonstrated.

(First embodiment)
FIG. 3 is a perspective view of the assembled battery according to the first embodiment. The assembled battery 20 includes a plurality of unit cells 10, a pair of end plates 11, a connecting rod 12, a nut 13, and a spacer 14 having convex portions at both ends.

  FIG. 2 is a diagram showing a unit cell of the assembled battery of FIG. FIG. 2A is a perspective view of the unit cell, and FIG. 2B is a front view of the unit cell. As shown in FIG. 2A, the cell 10 includes a power generation element housed in the battery case 1, the positive electrode terminal 2 and the negative electrode terminal 3 are provided at both ends of the upper surface of the cell 10, and a safety valve 6 is provided at the center. Is provided.

  FIG. 7A is a perspective view of the battery case 1, and FIG. 7B is a front view of the battery case 1. As shown in this figure, the battery case 1 has a rectangular parallelepiped shape having a pair of narrow short side surfaces and a pair of wide long side surfaces. A positive electrode, a negative electrode, an electrolyte, and the like are placed inside the battery case 1. The power generation element provided can be accommodated. And the connection members 4 and 5 comprised by resin etc. are provided in each of this pair of short side surfaces. In addition, this battery case is used for the single cell demonstrated by each following embodiment.

  Fig.1 (a) is sectional drawing which shows the state which arranged the cell in parallel, and has shown the internal structure of the connection member. FIG.1 (b) is a figure explaining the insertion direction of a connection rod, and the arrow of a broken line has shown the direction where a connection rod is inserted.

  As shown in FIG. 1A, the connecting member 4 includes through holes 41 and 42 and a window frame portion 44 penetrating in the width direction of the short side surface, and is connected to the through holes in a state where a plurality of single cells are juxtaposed. The assembled battery can be configured by inserting the rod 12 and holding both ends with a fastener such as a nut. Although not shown in FIG. 1A, a connecting member 5 is also provided on the opposite side of the short side surface of the battery case. The connecting member 5 is made of a member having the same diameter and the same size as the connecting member 4.

  As shown in FIG. 2, the battery case 1 exemplified in the present embodiment is composed of upper and lower connecting members attached to one short side surface as a single body, and window frame portions 44, 54 leading to the center portion thereof. Respectively. The window frame portions 44 and 54 play a role of promoting heat dissipation from the short side surface of the unit cell 10. Further, the connecting members 4 and 5 are provided with a spacer 14 for forming a gap between adjacent unit cells. Concave portions 43 and 53 for attaching the spacer 14 are provided on both sides of the window frame portion. When the connecting member is configured integrally with the upper and lower sides, there is an advantage that the manufacturing process can be simplified by reducing the number of injection ports when forming by injection molding, and there is also an advantage that the recesses 43 and 53 can be provided. However, the upper and lower connecting members may be configured separately. If it is configured as a separate body, the exposed portion of the battery case becomes larger, so that it has the effect of promoting heat dissipation more than when a window frame is provided.

  In the present embodiment, the through holes 41 and 42 are processed into a tapered shape (tapered shape) from the diameter R1 to the diameter R2 (R1> R2), and the directions of the taper are reversed in the vertical direction. The connecting rod 12 is inserted from the through hole having the larger diameter. The through hole having the larger diameter serves to secure a clearance for inserting the connecting rod. The binding force of each connecting member can be improved by making the through-hole having the smaller diameter small to substantially the same thickness as the connecting rod. Furthermore, the direction of a taper can be disperse | distributed by making the direction of a taper mutually reverse in up and down, right and left.

  As shown in FIG. 2B, a gap 7 is formed by the connecting member 4 or the connecting member 5 and the curved surface portion of the short side surface. Even when the connecting members 4 and 5 are subjected to a pressing force in the peeling direction with respect to the battery case 1 by forming the gap 7, the connection member 4, 5 and the battery case 1 are less likely to be directly subjected to the load. Moreover, when providing the buffer member which consists of an elastic body between the connection members 4 and 5 so that it may mention later, it can utilize also as a gap | interval for installation.

  As shown in FIG. 2A, the widths of the connecting members 4 and 5 are configured to be larger than the width of the short side surface of the battery case in consideration of the width of the spacer 14. As illustrated in the embodiment, a buffer member that also functions as a spacer may be provided between adjacent connecting members with the same width as the short side surface of the battery case.

  The material of the battery case 1 is made of a metal such as aluminum or a synthetic resin, for example. The material of the connecting members 4 and 5 is a member that is mechanically softer than a connecting rod such as a resin, and is manufactured by injection molding, for example. In this way, even when the diameter R2 of the through hole on the outlet side of the connecting rod, that is, the smaller diameter through hole is slightly smaller than the thickness of the connecting rod, the diameter of the through hole is pushed when the connecting rod is inserted. It is widened, the assembling work is easy, and the binding force can be improved.

  The connecting members 4 and 5 may be attached to the battery case 1 with an adhesive, or may be formed integrally with the metal battery case 1 by injection molding. For example, a resin connecting member may be joined to an aluminum battery case using the following method. First, in an aqueous electrolyte solution containing a triazine thiol derivative, a battery case (aluminum) is used as an anode, a platinum plate, a titanium plate, or a carbon plate is used as a cathode, and a voltage is applied between the anode and the cathode. An anodized film is formed on the surface of the case (electrodeposition process). Thereafter, the battery case is washed with water at a temperature of 40 ° C. to 60 ° C. for 5 seconds to 120 seconds (cleaning step). Thereby, the aluminum member excellent in bondability with the resin material is formed in the battery case. And a resin connection member can be joined to a battery case made of aluminum by directly forming a connection member into the aluminum member by injection molding.

  The assembled method of the assembled battery 20 is as follows. First, the cells 10 are arranged in parallel so that the connecting members 4 and the connecting members 5 are alternately adjacent to each other. At this time, the protrusions of the spacers 14 are fitted into the recesses of the connecting members 4 and 5, respectively, and the spacers 14 are arranged between the unit cells 10. Next, they are clamped by a pair of end plates 11, and the connecting rods 12 are inserted into the connecting members 4, 5 and the through holes 41, 42, 51, 52 of the end plate 11 from the larger diameter. Next, both ends of the connecting rod 12 are tightened with nuts 13 to connect the unit cells 10. Thereby, the assembled battery 20 can be obtained.

  The end plate 11 is useful for increasing the mechanical strength. However, if the strength satisfies the required specifications, the end plate 11 may be changed to a simpler fixing tool such as just tightening with a nut. By doing so, the assembled battery can be reduced in weight.

  When an assembled battery is configured by a single battery configured using the battery case described in the present embodiment, even when the assembled battery is placed in a vibration environment for a long period of time, it is difficult for rattling to occur and between the connecting members. It is possible to maintain the assembled state while suppressing the looseness.

(Second Embodiment)
The assembled battery according to the first embodiment has a gap between the through hole of the connecting member and the connecting rod. By filling the gap, the vibration resistance can be further improved.

  FIG. 4 is a diagram illustrating a state in which a ring-shaped member called “ferrule” is inserted into the assembled battery according to the second embodiment. The arrow indicates the ferrule insertion direction. A ferrule is a metal ring-shaped member used for fluid sealing or the like of a pipe joint. The ferrule is deformed by tightening a connecting rod to increase a fastening force by acting like a rust. In the present embodiment, as shown in FIG. 4, before inserting the connecting rod into the through holes 41, 42, 51, 52, the ferrule 15 is inserted in advance from the side with the smaller diameter of each through hole. By tightening the nut on the connecting rod, it is deformed to increase the fastening force.

  According to the second embodiment, the ferrule 15 can enhance the adhesion between the connecting rod and the through hole, and can suppress vibrations caused by the gap between the connecting rod and the through hole, thereby improving the vibration resistance. As other means for filling the gap between the through hole and the connecting rod, for example, a “seal material” such as a seal tape may be used instead of the “ferrule”.

(Third embodiment)
In the assembled battery exemplified in the first and second embodiments, the width of each connecting member may be equal to the width of the short side surface of the battery case, and a buffer member may be provided between adjacent connecting members. FIG. 5 is a diagram illustrating an example of the assembled battery according to the third embodiment. Fig.5 (a) is a figure explaining a mode that a buffer member is attached, FIG.5 (b) is a figure which shows the assembled battery after the attachment of a buffer member. In FIG. 5, other cells, end plates, connecting rods and the like are omitted. An arrow shows the direction in which the fitting convex part of a buffer member is inserted. As shown in FIGS. 5A and 5B, the buffer member 16 is made of an elastic member such as rubber and has a fitting convex portion 17. The buffer member 16 is disposed so as to be sandwiched between the upper and lower ends of the connecting members 4 and 5. At this time, the fitting convex portion 17 is fitted into the gap 7 formed by the short side surface of the battery case 1 and the connecting member 4 or the connecting member 5 to prevent the buffer member 16 itself from rotating.

  Since the buffer member 16 is formed of an elastic member, when the assembled battery receives a mechanical shock, the shock applied to each unit cell is reduced. In particular, compared to the case where the connecting members are in direct contact with each other, even when the assembled battery receives stress due to external impact, the stress is not directly transmitted through the connecting member, so that the damage and peeling of the connecting member can be suppressed. .

  In the assembled battery of the third embodiment, the buffer member 16 can buffer vibrations and shocks between the unit cells 10 to suppress loosening between the unit cells 10. Moreover, the distance between each single battery 10 can be adjusted by using the buffer member 16 as a spacer. Moreover, it is possible to reduce the standard score of the component parts (ASSY) of the battery case of each expensive unit cell, which is advantageous in terms of cost.

(Fourth embodiment)
FIG. 6 is a diagram illustrating another example of the assembled battery according to the fourth embodiment. Fig.6 (a) is a figure explaining a mode that a buffer member is attached, FIG.6 (b) is a figure which shows the assembled battery after the attachment of a buffer member. In FIG. 6, other cells, end plates, connecting rods and the like are omitted. An arrow shows the direction in which the fitting convex part of a buffer member is inserted. As shown in FIGS. 6A and 6B, the unit cell 91 is provided with connecting members 92 and 93 made of resin or the like on each of a pair of short side surfaces. The configuration of the unit cell 91 other than the connecting members 92 and 93 is basically the same as that of the unit cell 10 of the first embodiment. The connecting member 92 has a configuration similar to that of the connecting member 4, and further has grooves 94 at both upper and lower ends. The connecting member 93 has the same configuration as that of the connecting member 5 and is further provided with grooves 94 at both upper and lower ends. The buffer member 95 is made of an elastic member such as rubber and has a fitting convex portion 96. The buffer member 95 is disposed so as to be sandwiched between the upper and lower ends of the connecting members 92 and 93. At this time, the fitting convex portions 96 are respectively fitted in the grooves 94 of the connecting member 92 or the connecting member 93 to prevent the buffer member 95 itself from rotating. The buffer member 95 reduces the impact on each unit cell when the assembled battery receives a mechanical impact.

  In the assembled battery of the fourth embodiment, the buffer member 95 can buffer vibrations and shocks between the unit cells 91 to suppress loosening between the unit cells 91. Moreover, the distance between each cell 91 can be adjusted by using the buffer member 95 as a spacer. Moreover, it is possible to reduce the standard score of the component parts (ASSY) of the battery case of each expensive unit cell, which is advantageous in terms of cost.

DESCRIPTION OF SYMBOLS 1 Battery case 2, 3 Output terminal 4, 5 Connecting member 6 Safety valve 7 Space | gap 10 Cell 11 End plate 12 Connecting rod 13 Nut 14 Spacer 15 Ferrule 16 Buffer member 20 Battery assembly 41, 42, 51, 52 Through-hole 43, 53 recess

Claims (2)

A battery group in which a plurality of cells including a battery case, a power generation element housed in the battery case, and an output terminal of the power generation element are juxtaposed, a fixture for sandwiching the battery group, and a connection An assembled battery including a rod,
The output terminal is provided above the battery case,
The battery case has a rectangular parallelepiped shape having a pair of narrow short side surfaces and a pair of wide long side surfaces, and includes connecting members at both upper and lower ends of the pair of short side surfaces,
The connecting member includes a through-hole penetrating in the width direction of the short side surface,
The through hole is tapered with respect to the width direction,
The connecting rod is inserted through the through hole to connect the unit cell group and the fixture,
The assembled battery in which the smaller diameter of the tapered through hole is the same as the thickness of the connecting rod or smaller than the thickness of the connecting rod . The assembled battery according to claim 1, wherein the tapered shape of the through hole is opposite in the upper and lower end portions of the connecting member.

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