JP2001006642A - Assembled battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an assembled battery for use in an electric vehicle, etc., capable of high reliability connection of a battery with a connector using an inexpensive means free of strain generation, etc., even if the battery length involves dispersion. SOLUTION: An assembled battery is configured with a casing having a pair of supporting plates 2 and 3, a plurality of batteries 1 with both ends of each held pinchedly by the supporting plates 2 and 3, a connector 4 to connect the batteries in series electrically, and a resilient piece 5 installed between the casing and the connector 4. Thereby a high reliability connection of battery with connector can be established using an inexpensive means free of strain generation, etc., even if the battery length involves dispersion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery pack used for electric vehicles and the like.

[0002]

2. Description of the Related Art In recent years, air pollution due to exhaust gas from automobiles and the like has become a worldwide problem, and the development of electric vehicles using electricity as a power source for automobiles has been progressing and suitable for use in such electric vehicles. There is a demand for the development of secondary batteries. This type of secondary battery is a battery module formed by electrically and mechanically connecting a plurality of cells in a line in series,
It is known that a large number of battery modules are arranged in parallel and held in a holder case, and these battery modules are electrically connected in series so that high-voltage power can be taken out.

Conventionally, an assembled battery is disclosed in Japanese Patent Application Laid-Open No. 10-270006.
Japanese Unexamined Patent Publication (Kokai) No. H10-264, pp. 157-334 is known. The assembled battery structure is shown in FIGS. FIG. 5 is a perspective view of a battery module 109 in which six conventionally used cells are connected in series, and FIG. 6 is a cross-sectional view thereof. As shown in FIGS. 5 and 6, the individual cells 107 are connected in series via a metal connection ring 150 using spot welding.

Further, a square nut 111 is connected to the positive electrode end of the battery module 109 via the connection ring 150 by spot welding to the unit cell 107 at the positive electrode end. Further, a hexagon nut 112 is attached to the negative electrode end of the battery module 109 by spot welding through the connection ring 150 using the unit cell 10 at the negative electrode end.
7 is connected. In addition, resin-made insulating rings 113a and 113b for preventing a short circuit between a positive electrode and a negative electrode in the same single cell are interposed in the connection portion.

Next, the above-described battery module 109 is
The structure of the battery packs arranged in parallel will be described with reference to FIGS. In the figure, 118 is the case body, 119 is the first end plate, 120 is the second end plate, 12
1 is a cooling fin plate, 122 is a vibration-proof rubber sheet, and the case main body 118 is a resin-integrated molded product formed in the shape of a rectangular parallelepiped box whose upper and lower surfaces are open. The battery module 109 is located at the same corresponding position on both end walls 123 and the partition wall 125 of the case body 118 and the fin plate 121.
Through holes 123a, 125a, 121a for inserting
Are provided in a total of 21 rows of 3 rows in the horizontal direction and 7 rows in the vertical direction. The insertion holes 123a, 125a, and 121a are provided at equal vertical and horizontal pitches, and are formed to have a diameter larger than the outer diameter of the battery module 109. This insertion hole 123
The battery module 109 is inserted through the battery packs a, 125a, and 121a to form a battery pack.

[0006] A first end plate 119 is fixed to one end of the case main body 118, and a second end plate 120 is fixed to the other end. As shown in FIG. 12, the first end plate 119 is formed of a resin plate, and a pass bar 128 is embedded and fixed in the resin plate by insert molding. The pass bar 128 is electrically and mechanically connected to the square nut 111 at the positive electrode end or the hexagon nut at the negative electrode end of the battery module 109 by fastening the bolt 134. Second
Similarly to the first end plate 119, the end plate 120 is formed of a resin plate, and a pass bar 128 is embedded and fixed in the resin plate by insert molding. The pass bar 128 is fixed to the battery module 109 by fastening bolts 134. Square nut 11 at positive electrode end
It is electrically and mechanically coupled to a hexagon nut at one or the minus electrode end. As described above, the 21 battery modules 109 arranged in parallel with the assembled battery include the pass bar 128 of the first end plate 119 and the second end plate 120.
Are electrically connected in series by the pass bar 128.

[0007]

However, in the above-described conventional configuration, if there is a variation in the length of the unit cells, that is, a variation in the length of the battery module, when each electrode end of the battery module and the pass bar are fastened by bolts. ,
Stress is generated in the battery module in the length direction or the bending direction, and the distortion of the battery module due to the stress reduces the reliability of spot welding connecting the connection ring to the unit cell or the electrode end. Also, in order to prevent the battery module from being distorted, if the strength of the pass bar is reduced and the length variation is absorbed by the deformation of the pass bar, the thickness of the pass bar must be reduced. There is a problem that not only a large amount of power loss occurs when a current flows, but also a large amount of heat is generated, which may impair safety.

As means for solving such a problem, a flat knitted wire using a metal flat knitted body for the conductive portion of the connection body,
JP-A-6-140020 and JP-A-9-1067
Japanese Patent Application Publication No. 99-9999 discloses a structure in which a metal pipe or a metal plate is crimped and integrated at both ends of a terminal main portion in which thin metal strips are laminated. However, in any case, there is a problem in that the connecting body is composed of a plurality of parts and the cost increases.

The present invention solves the above-mentioned conventional problems, and it is possible to connect a highly reliable battery to a connecting body by inexpensive means without distortion or the like even if the length of the battery varies. It is an object of the present invention to provide an assembled battery. Further, the above battery may be a battery module in which a plurality of unit cells are connected in series as in the conventional example.

[0010]

In order to achieve this object, an assembled battery according to the present invention comprises: a housing having a pair of plate-shaped support plates; a plurality of batteries having both ends sandwiched between the support plates; A connection body fixed to the battery outside the housing and electrically connecting the plurality of batteries in series; and an elastic body provided between the housing and the connection body.

With this configuration, it is possible to obtain an assembled battery that can be connected to a highly reliable battery and a connector by inexpensive means without distortion or the like even if the length of the battery varies.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION
A housing having a pair of plate-shaped support plates, a plurality of batteries having both ends sandwiched by the support plates, and affixed to the batteries outside the housing to electrically connect the plurality of batteries in series A connection body, which is provided with an elastic body between the housing and the connection body, does not cause distortion of the battery even if the length of the battery varies, and a highly reliable battery with inexpensive means. This has the effect of enabling connection of the connecting body.

According to a second aspect of the present invention, the elastic body is located at a substantially intermediate portion between the two batteries connected by the connecting body, and the deformation of the elastic body is minimized. This has the effect that stable battery connection is possible.

According to a third aspect of the present invention, the battery is formed by electrically and mechanically connecting a plurality of cells in series, and connects a plurality of cells having length variations. However, since the battery can be connected with high reliability without distortion or the like due to the elastic body, the operation of adjusting the length during welding can be eliminated.

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG.

(Embodiment 1) FIG. 1 is a perspective view of an assembled battery according to the present invention, FIG. 2 is a perspective view of a pair of supports serving as a housing, and FIG.
FIG. 4 is a configuration explanatory view of the battery pack, and FIG. 4 is a partial cross-sectional view of the battery pack. In the figure, 1 is a unit cell, 2 is a first support, 3 is a second support, and the first support and the second support are fitting portions 2a having irregularities as shown in FIG. 3a is fitted to form a housing. Further, fitting holes 2b and 3b for fitting to the outer diameter of the unit cell 1 are provided on the inner wall surfaces of the first support and the second support 3, respectively.
The individual pieces are held at both ends in a two-row bale stack as shown in FIG. At this time, the positive and negative electrodes of the unit cell 1 are fitted and held in reverse to the adjacent unit cells as shown in FIG. Reference numeral 4 denotes a connector for electrically connecting the cells in series, and has projections at several places for projection welding with the cells 1. The connection body 4 is projection-welded from the outside of the supports 2 and 3 with one end to the positive electrode side of the unit cell 1 and the other end to the negative electrode side of the adjacent unit cell 1. The outer shape of one end 4a (positive electrode side) of the connection body 4 is square and the outer shape of the other end 4b (negative electrode side) is circular, and is arranged outside the fitting holes 2b, 3b of the supports 2, 3. Holes 2c, 2d, 3c, and 3d. In addition, one end 4 a of the connection body 4 has a hole that fits into the protrusion on the positive electrode side of the unit cell 1. With these external shapes and fitting holes, erroneous battery connection cannot be performed, so that a high-quality assembled battery is possible. An elastic body 5 made of a rubber sheet or the like is fixed to the connection body 4. As shown in FIG. 4, when the connection body 4 is welded to the unit cell 1, the elastic body 5 It is as if sandwiched between the connecting member 4 and the 2e portion or 3e portion of the support 2 or the second support 3.
In this state, the elastic body 5 is compressed by a predetermined amount in the thickness direction. At this time, the restoring force F of the elastic body 5 is applied to the supports 2 and 3 in the direction of the arrow. Since the supports 2 and 3 are held by the restoring force F, the fitting portions 2a and 3a are in a fixed state without using any fastening parts.

Here, the length of the cell 1 varies, and FIG.
Assuming that a short cell like 1a in the figure is built in,
The thickness t of the elastic body 5 ′ between the connecting body 4 and the support 2 is smaller than the thickness T of the other elastic body 5, and the connecting body 4 is attached in a slightly inclined state as shown in the figure. Strictly speaking, the restoring force of the elastic body 5 ′ is applied to the cell 1 a larger than the other elastic bodies 5, but the force is not large enough to give a strain to the cell 1. Also, although the welding surface of the connection body 5 'unit cell 1a is not strictly parallel, the difference falls within the welding margin of projection welding, so that there is no problem in welding. In addition, since the elastic body 5 is located almost in the middle of the two cells connected by the connecting body 4, as can be seen from FIG. 4, the difference in thickness (T− t) is cell 1
And the length of the cell 1a is smaller than that of the cell 1a, and the increase in the restoring force of the elastic body 5 'is also minimized.

As described above, the short unit cell 1a is
The support members 2 and 3 and the connecting member 5 are not deformed even if they are incorporated in a housing made of three. Further, since no distortion is given to the cell, the cell 1 and the connection body 4 are securely connected.

A cover 14 made of resin or the like as an insulator is fixed to the outside of each of the supports 2 and 3 by a mounting screw 15 to prevent a short circuit or the like due to contact of foreign matter between the connectors 4.

In the assembled battery of the present invention configured as described above, a plurality of the assembled batteries are stacked on the surface of the cover 14 to which the cover 14 is not fixed, as one unit. Then, the plurality of assembled batteries are electrically connected in series via the output portions 6 and 7 to output high-voltage power and are mounted on an electric vehicle or the like.

In the above description, the elastic member 5 is a rubber sheet, but the elastic member 5 may be a spring material such as a leaf spring.

In this embodiment, the unit cell 1 is sandwiched between the first support 2 and the second support 3 which are formed into a housing. It can be understood that a similar effect can be obtained by replacing the cell 1 with a battery module in which the cells are electrically and mechanically connected in series.

[0023]

As described above, according to the present invention, even if the length of the battery varies, the battery can be connected to the connecting member with high reliability by inexpensive means without distortion of the battery.

Further, when the elastic body is located substantially in the middle of the two batteries connected by the connecting body, stable battery connection is possible by minimizing deformation of the elastic body.

Also, in connection of a battery module in which a plurality of unit cells having a variation in length are connected, a highly reliable connection can be made without any distortion or the like in the battery module due to the elastic body. The work of length adjustment can be abolished.

[Brief description of the drawings]

FIG. 1 is a perspective view of an assembled battery according to Embodiment 1 of the present invention.

FIG. 2 is a perspective view of a support in the first embodiment.

FIG. 3 is a configuration explanatory view of a battery pack according to the first embodiment.

FIG. 4 is a partial cross-sectional view of the battery pack according to the first embodiment.

FIG. 5 is a perspective view of a battery module in a conventional assembled battery.

FIG. 6 is a cross-sectional view of a battery module in a conventional assembled battery.

FIG. 7 is an exploded perspective view of a conventional assembled battery.

FIG. 8 is a sectional view of a conventional assembled battery.

FIG. 9 is a sectional view of a main part of a conventional assembled battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Single cell 2 1st support 3 2nd support 4 Connection body 5 Elastic body

Claims (3)

[Claims] 1. A housing having a pair of plate-shaped support plates, a plurality of batteries sandwiched between both ends by the support plate, and a plurality of batteries fixed to the unit cells outside the housing. An assembled battery comprising: a connecting body that is connected in series; and an elastic body between the housing and the connecting body. 2. The battery pack according to claim 1, wherein the elastic body is located at an intermediate portion between the two batteries connected by the connecting body. 3. The battery pack according to claim 1, wherein the plurality of cells are electrically and mechanically connected in series.