JP2006134800A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable radiation of the heat of batteries, by improving heat conduction from the batteries to the side wall, and to improve impact resistance strength by closing the gap between the end face of the batteries and the sidewall. <P>SOLUTION: The battery pack has a plurality of batteries 2 arranged in parallel in the body case 1A having side walls 11 along the periphery of a bottom plate 10, and, by housing the end face of the batteries 2 facing the sidewall 11, closes the opening part of the body case 1A by a lid case 1B. The battery pack has a spacer 3 made of plastic between the batteries 2. This spacer 3 has a clearance plate 6, arranged between the end face of the batteries 2 and the sidewall 11 molded integrally with a spacer body 3A arranged between the batteries 2. In the battery pack, the spacer body 3A is arranged between the batteries 2, and the clearance plate 6 molded integrally with the spacer body 3A is arranged between the end face of the batteries 2 and the sidewall 11 of the body case 1A, thereby, the heat of the batteries 2 are conducted to the sidewall 11 through the clearance plate 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a battery pack in which a plurality of batteries are housed in a case.

  As shown in FIG. 1, in a battery pack in which a plurality of batteries 22 are stored in a case 21, the case 21 is formed of plastic, and the batteries 22 are stored in the case 21. This battery pack radiates heat from the battery 22 to the outside through the case 21. The heat dissipation of the battery can be increased by widening the contact surface between the battery and the case. This is because the heat of the battery is conducted to the case at the contact surface between the battery and the case, and the heat of the case is radiated to the outside. If the battery does not directly contact the case, an air layer is formed between the battery and the case. According to this structure, since the heat of the battery is conducted to the case through the air, it cannot be efficiently conducted to the case. For this reason, in order to effectively dissipate the heat of the battery, it is important to bring the battery into direct contact with the case.

  In addition, a battery pack in which a battery is placed in a case and there is a gap between the battery and the case also has a drawback in that the impact strength is reduced. This is because the battery moves within the case when subjected to an impact. For this reason, it is important to store the battery so that there is no gap in the case.

  The plastic case has excellent physical properties as a case of a battery pack because it has excellent insulating properties and impact resistance. However, as shown in FIG. 1, a battery pack in which the case 21 is formed in a shape having a side wall 24 around the bottom plate 23 and the battery 22 is accommodated inside the side wall 24 is manufactured from the manufacturing process by the battery 22 and the side wall 24. It is extremely difficult to eliminate any gaps between them. This is because a draft angle is provided in order to smoothly release the case molded from plastic from the mold. The draft angle is formed so that the inner side of the side wall 24 is tapered toward the opening so that the side wall 24 can be easily released from the mold. The side wall formed in this shape widens the distance between the end surface of the battery and the inner surface of the side wall toward the opening of the side wall. For this reason, a gap is formed between the end surface of the battery and the inner surface of the side wall. This gap deteriorates the heat conduction from the battery to the side wall and reduces the impact resistance of the battery pack.

  This problem can be solved by inserting a spacer that closes the gap between the end face and the side wall of the battery. However, since the battery in which the spacer is inserted here needs to insert a dedicated spacer at a specific position, the manufacturing process becomes complicated. Further, the spacer put in here needs to be fixed at a fixed position by bonding or the like so as not to be displaced during use, and there is a further disadvantage that it takes time and effort.

The present invention has been developed for the purpose of solving such drawbacks. An important object of the present invention is to provide a battery pack that can improve heat conduction from the battery to the side wall and effectively radiate the heat of the battery from the case.
Another important object of the present invention is to provide a battery pack that can improve the impact strength by closing the gap between the end face and the side wall of the battery.
Still another object of the present invention is to provide a battery pack in which a spacer or a lead plate for closing a gap so as not to be displaced can be disposed at an accurate position between the end face and the side wall of the battery.

  The battery pack according to claim 1 of the present invention includes a plurality of batteries 2 in a posture parallel to the bottom plate 10 in a plastic main body case 1A integrally formed along the periphery of the bottom plate 10 and provided with a side wall 11. Are arranged in parallel, the end surface of the battery 2 is stored facing the side wall 11, and the opening of the main body case 1A is closed by the lid case 1B. In the battery pack, a plastic spacer 3 is disposed between the batteries 2. In the spacer 3, a gap plate 6 disposed between the end face of the battery 2 and the side wall 11 is formed integrally with a spacer body 3 </ b> A disposed between the batteries 2. In the battery pack, a spacer body 3A is disposed between the batteries 2, and a gap plate 6 formed integrally with the spacer body 3A is disposed between the end face of the battery 2 and the side wall 11 of the body case 1A. The heat of the battery 2 is conducted to the side wall 11 through the gap plate 6.

  The battery pack of the present invention can be disposed between the batteries 2 in which a plurality of batteries 2 are stacked in a plurality of stages in the main body case 1A and the spacer bodies 3A are stacked in a plurality of stages.

  In the battery pack of the present invention, the batteries 2 arranged adjacent to each other are connected by a metal lead plate 4 disposed between the end face of the battery 2 and the side wall 11. The gap plate 6 of the spacer 3 can be disposed on the surface. Furthermore, the battery pack according to the present invention includes a plurality of batteries 2 stacked in a plurality of stages in the main body case 1A, and a circuit board is disposed outside one of the main body case 1A and the lid case 1B. The lead plate 4 can be connected to the circuit board.

  In the battery pack of the present invention, the battery 2 can be a cylindrical battery, and the spacer body 3A can have a curved surface along the surface of the cylindrical battery.

  Furthermore, the battery pack according to claim 6 of the present invention includes a battery body 1A having a side wall 11 around the bottom plate 10 and a plurality of batteries 2 arranged in parallel in a posture parallel to the bottom plate 10. 2 is disposed opposite to the side wall 11, and a lead plate 4 is disposed on the end surface of the battery 2. The lead plate 4 is connected to the end surface of the battery 2 to connect adjacent batteries 2, and The opening of the case 1A is closed with a lid case 1B. The lead plate 4 is an elastic metal plate and is bent into a shape in which an elastic convex portion 7 protruding toward the side wall 11 is provided. In the battery pack, the lead plate 4 is disposed between the end face of the battery 2 and the side wall 11 of the main body case 1 </ b> A to conduct the heat of the battery 2 to the side wall 11.

  The battery pack of the present invention has the advantage that heat conduction from the battery to the side wall is good and the heat of the battery can be effectively dissipated from the case. In the battery pack according to the first aspect of the present invention, the gap plate disposed between the battery end surface and the side wall is integrally formed in the spacer body disposed between the batteries. The heat of the battery can be conducted to the side wall via the gap plate disposed between the side wall and the heat of the battery can be effectively radiated from the case. In the battery pack according to claim 6, since the lead plate connecting the end faces of the adjacent batteries is bent and provided with the elastic convex portion, the elasticity of the lead plate disposed between the battery end face and the side wall is provided. The protrusion is brought into elastic contact with the side wall, and the heat of the battery is conducted to the side wall via the lead plate, so that the heat of the battery can be effectively radiated from the case.

  Further, in the battery pack of the present invention, the spacer convex plate or the elastic convex portion of the lead plate is disposed between the end surface of the battery and the side wall of the main body case. The impact strength of the battery pack can be improved by closing the gap between the battery and the side wall. In particular, the battery pack of the present invention can very easily close the gap formed between the end face of the battery and the inner surface of the side wall without complicating the manufacturing process, unlike the conventional battery pack in which a dedicated spacer is inserted. There are features. In addition, the battery pack of the present invention has an elastic projection provided on the gap plate and the lead plate integrally formed on the spacer body between the end face and the side wall of the battery to close the gap. Another advantage is that the spacer and lead plate to be plugged can be placed in the correct position so as not to be displaced.

  Embodiments of the present invention will be described below with reference to the drawings. However, the example shown below illustrates the battery pack for embodying the technical idea of the present invention, and the present invention does not specify the battery pack as follows.

  Further, in this specification, in order to facilitate understanding of the scope of claims, numbers corresponding to the members shown in the examples are indicated in the “claims” and “means for solving problems” sections. It is added to the members. However, the members shown in the claims are not limited to the members in the embodiments.

  The battery pack shown in FIGS. 2 to 6 includes a plastic main body case 1A, a plurality of batteries 2 accommodated in the main body case 1A, a spacer 3 disposed between the batteries 2, and a main body case. And a plastic lid case 1B that closes the opening of 1A.

  The main body case 1 </ b> A is provided by integrally molding the side wall 11 along the periphery of the bottom plate 10. The main body case 1A shown in the figure has a rectangular box shape with the bottom plate 10 as a rectangle, and is provided with side walls 11 on the four surrounding sides and opens upward in the figure. The side wall 11 of the rectangular main body case 1A includes a long side wall 11A provided along both side edges and a short side wall 11B provided along both ends. The long side wall 11A and the short side wall 11B are perpendicular to each other at the corners. It is linked to. The battery 2 is housed in the case 1 with its end face opposed to the inside of the long side wall 11A, that is, side by side in a posture parallel to the short side wall 11B. Therefore, the distance between the long side walls 11A on both sides is substantially equal to the entire length of the battery 2 having the lead plates 4 connected to both ends. The interval between the short side walls 11B is adjusted by the number of batteries 2 housed inside. In the illustrated battery pack, the seven batteries 2 are arranged side by side and arranged on the same plane, so that the interval between the short side walls 11B is set to a length that can accommodate the seven batteries 2. In the main body case 1A, the bottom plate 10 and the side wall 11 are integrally formed. The main body case 1A, which is integrally molded as a whole, has a draft angle on the inner surface of the side wall 11 so that it can be easily released from the mold.

  The battery pack shown in the figure is housed by stacking batteries 2 in a case 1 in two upper and lower stages. Therefore, the height of the side wall 11 is formed such that the lid case 1B is connected to the opening so that the battery 2 stacked inside can be accommodated. In the illustrated battery pack, a lower peripheral wall 12 is integrally formed on the periphery of the lid case 1B. The lid case 1B connects the lower end edge of the peripheral wall 12 to the upper end edge of the side wall 11 provided in the main body case 1A, and closes the opening of the main body case 1A. Therefore, the peripheral wall 12 and the side wall 11 are shape | molded in the same shape in planar shape. The peripheral wall 12 and the side wall 11 are connected by ultrasonic welding, connected by adhesion, or connected by a locking structure.

  The battery 2 is stored in the case 1 in a posture parallel to the bottom plate 10, arranged side by side in parallel, and in a posture where the end surface faces the inner surface of the side wall 11. The battery pack shown in the figure has seven batteries 2 arranged in parallel in the same plane and accommodated in a case 1. Further, seven batteries 2 are arranged in two upper and lower stages, and 14 batteries 2 are accommodated as a whole.

  In the illustrated battery pack, the battery 2 is a cylindrical battery. When the cylindrical batteries are arranged on the same plane, a valley is formed between the batteries 2. In the illustrated battery pack, the upper battery 2 is placed in the valley between the lower batteries 2, and the lower battery 2 is placed in the valley between the upper batteries 2, and the batteries 2 are stacked in a so-called stacked state. Thus, the gap formed between the adjacent batteries 2 is narrowed. With this structure, it is possible to reduce a useless space in the case 1 and to reduce the outer shape of the battery pack. Further, the spacer 3 inserted in the gap between the batteries 2 can be thinned to reduce the temperature difference between the batteries 2. In addition, the upper and lower batteries 2 are arranged in the valley to prevent positional deviation from each other. However, the battery pack of the present invention can be stacked by placing the upper battery above the lower battery without stacking the batteries as shown in the figure. In the illustrated battery pack, the batteries 2 are stacked in two stages and stored in the case 1. However, the batteries can be stored in the case in a single stage or stacked in three or more stages.

  The battery 2 is a lithium ion secondary battery. However, other rechargeable secondary batteries other than lithium ion secondary batteries, such as nickel metal hydride batteries and nickel cadmium batteries, can be used as the batteries. A lithium ion secondary battery has a high voltage, and can be used safely by detecting the voltage of each battery to control charging and discharging. In order to realize this, the battery pack in which the battery 2 is a lithium ion secondary battery incorporates a circuit board (not shown) on which a voltage detection circuit for detecting each battery voltage is mounted. In the illustrated battery pack, the circuit board is disposed outside the bottom plate 10 of the main body case 1A. The circuit board disposed here connects the lead plate 4 connected to the end face of the battery 2 to detect each battery voltage.

  In the illustrated battery pack, two batteries 2 arranged on the upper and lower sides are connected in parallel, and the batteries 2 arranged horizontally are connected in series. That is, two sets of upper and lower batteries 2 connecting seven batteries 2 in series are connected in parallel to each other. In order to connect the batteries 2 in this state, the other two batteries 2 except for the two batteries 2 disposed above and below the two ends are connected by the lead plate 4. The batteries 2 at both ends are connected to each other by two lead plates 4. The lead plate 4 is connected to the end face of the battery 2 by resistance spot welding or laser welding. The lead plate 4 is formed by cutting a metal plate into an outer shape that creates a gap between the lead plate 4 and the adjacent lead plate 4. The gap is set to, for example, 1 mm to 10 mm so that the adjacent lead plate 4 can be prevented from coming into contact and short-circuited, and the gap plate 6 of the spacer 3 described later can be disposed here.

  Connection terminals 5 are provided on all the lead plates 4 in order to connect the electrodes of all the batteries 2, that is, the end faces to the circuit board. The lead plate 4 shown in the figure has a connection terminal 5 protruding downward. The connection terminal 5 penetrates through the bottom plate 10 of the main body case 1 </ b> A and is connected to a circuit board disposed outside the bottom plate 10. In the battery pack, the circuit board can be disposed outside the lid case. This battery pack is connected to the circuit board by passing the connection terminal of the lead plate through the lid case.

  The circuit board includes a voltage detection circuit that detects the voltage of each battery 2, and this voltage detection circuit detects each battery voltage via the lead plate 4. The voltage detection circuit detects the battery voltage and controls charging / discharging of the battery pack. For example, when the battery pack is being discharged, if any battery voltage drops to the minimum voltage, the discharge current is cut off. Further, when any battery voltage rises to the maximum voltage while charging the battery pack, the charging current is cut off.

  The spacer 3 is manufactured by integrally molding the whole with plastic. The spacer 3 is manufactured by molding polypropylene. However, the spacer 3 can be manufactured by molding a plastic other than polypropylene, for example, a plastic such as polyethylene, vinyl chloride, nylon, urethane, EVA or the like. The spacer 3 is disposed between the batteries 2, and is disposed between the spacer body 3 </ b> A sandwiched between the batteries 2 and the end surface of the battery 2 and the side wall 11. The gap plate 6 that closes the gap is integrally formed.

  The battery pack shown in the figure has cylindrical batteries stacked in two layers and stored in the case 1 in a stacked state. In this battery pack, a spacer body 3 </ b> A is disposed between the stacked batteries 2. Although not shown, the battery pack may be stacked in three or more stages and stored in a case. In this battery pack, a spacer body is disposed between batteries stacked in a plurality of stages. The spacer main body 3A disposed between the cylindrical batteries is formed into a curved surface along the surface of the cylindrical battery. As shown in FIG. 6, the spacer body 3 </ b> A is preferably formed in a shape that closes a gap formed between adjacent batteries 2. According to this structure, the adjacent batteries 2 are in contact with the spacer body 3A over a wide area. For this reason, the temperature difference between the adjacent batteries 2 is reduced, and the battery 2 can be effectively cooled via the spacer 3.

  The spacer 3 is provided by integrally forming a gap plate 6 on both side edges of the spacer body 3A so as to be orthogonal to the spacer body 3A. The gap plate 6 is disposed in a gap between the end surface of the battery 2 and the inner surface of the side wall 11 to close the gap between the battery 2 and the side wall 11. Since the lead plate 4 is also connected to the end face of the battery, the gap plate 6 is provided on the same surface as the lead plate 4 in a portion where the lead plate 4 is not provided. In the illustrated battery pack, the outer shape of the lead plate 4 connecting the four batteries 2 is a parallelogram, and a gap with a constant interval is provided between the lead plates 4. The gap plate 6 is formed to have a width slightly narrower than the width of the gap so as to be disposed in the gap. Since the gap plate 6 closes the gap between the end surface of the battery 2 and the inner surface of the side wall 11, the gap plate 6 is formed to have a thickness equal to the gap between the end surface of the battery 2 and the inner surface of the side wall 11. The gap between the side wall 11 of the case 1 and the end face of the battery 2 becomes wider toward the opening due to the draft angle. The gap plate 6 is formed thicker toward the opening of the side wall 11 and thicker upward in FIGS. 1 and 2, and the gap between the end face of the battery 2 and the inner surface of the side wall 11 is in an ideal state. Can be closed. However, even if the thickness of the gap plate is the same, the gap between the end face of the battery and the inner surface of the side wall can be substantially closed.

  The structure in which the gap plate 6 is disposed in the gap between the lead plates 4, in other words, the structure in which the lead plate 4 is disposed between the gap plates 6 is between the end face of the battery 2 and the inner surface of the side wall 11. And a lead plate 4 are disposed. In this battery pack, both the gap plate 6 and the lead plate 4 block the gap between the end face of the battery 2 and the inner surface of the side wall 11, or the gap plate 6 closes the gap and the lead plate 4 narrows the gap. For this reason, since this pack battery conducts the heat of the battery 2 to the side wall 11 by both the gap plate 6 and the lead plate 4, the battery 2 can be cooled more efficiently.

  Further, FIG. 7 shows a lead plate 4 that efficiently conducts the heat of the battery 2 to the side wall 11. The lead plate 4 is made of an elastic metal plate that is elastically deformed, such as iron, iron alloy, or nickel plate plated on the surface. The lead plate 4 is bent into a shape in which an elastic convex portion 7 protruding toward the inner surface of the side wall 11 is provided. When the lead plate 4 is disposed between the end face of the battery 2 and the side wall 11, the elastic convex portion 7 comes into contact with the inner surface of the side wall 11 while being elastically pressed. Even if the gap between the end surface of the battery 2 and the inner surface of the side wall 11 is somewhat wide, the elastic convex portion 7 is elastically pressed and brought into contact with the inner surface of the side wall 11. For this reason, the end surface of the battery 2 reliably contacts the inner surface of the side wall 11 via the lead plate 4, and the heat of the battery 2 is effectively conducted to the side wall 11 via the lead plate 4. Therefore, the battery 2 is efficiently cooled by the side wall 11.

  Further, although not shown, a battery pack in which a gap is provided between the lead plates 4 of FIG. 7 and a gap plate is disposed in the gap can conduct the heat of the battery to the side wall by both the gap plate and the lead plate. In addition, this battery pack has a feature that the battery can be efficiently cooled while the adjacent lead plates are insulated by the gap plate. The battery 2 connected by the lead plate 4 of FIG. 7 is manufactured by being housed in a case in the same manner as the battery pack shown in FIGS. Further, the battery 2 connected by the lead plate 4 of FIG. 7 can be housed in a case by providing a spacer 3 between the batteries 2.

  Further, although not shown in the figure, the battery pack of the present invention has a silicon plate in the gap between the end face and the side wall of the battery in a state where the spacer gap plate and the elastic convex portion of the lead plate are disposed between the end face and the side wall of the battery. It is also possible to fill with a filler such as urethane resin. A battery pack filled with a filler such as silicon or urethane resin can be further improved in heat conduction from the battery to the side wall by thermally bonding the end face and the side wall of the battery with the filler. It has a feature that can dissipate heat more effectively. Furthermore, this battery pack has the advantage that the impact resistance strength can be further improved by the filler and that this portion can be made waterproof.

  Furthermore, in this battery pack, the inner surface of the case can be textured in order to improve the adhesion between the case and a filler such as silicon or urethane resin. The case having a textured inner surface improves the adhesion of the filler applied to the rough surface and can effectively prevent the filler from peeling off after application. In addition, when molding the case with a transparent resin, the surface of the case is embossed so that the transparency appears only in the part where the filler is applied, so the application state of the filler can be easily confirmed from the outside. There is also.

  Since the above battery pack has the circuit board fixed to the outside of the main body case 1A and the lid case 1B, the battery pack is completed by putting it in an outer case (not shown). Moreover, it can also be used as a pack battery for apparatus incorporation, without putting in an outer case.

It is a schematic sectional drawing which shows the state which accommodates a battery in the case of the conventional battery pack. 1 is an exploded perspective view of a battery pack according to an embodiment of the present invention. It is a perspective view which shows the battery assembly incorporated in the battery pack shown in FIG. FIG. 4 is a plan view, a front view, and both side views of the battery assembly shown in FIG. 3. It is a cross-sectional view of a battery pack according to an embodiment of the present invention. It is a longitudinal cross-sectional view of the pack battery concerning one Example of this invention. It is a perspective view of the battery assembly built in the battery pack concerning the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Case 1A ... Main body case 1B ... Lid case 2 ... Battery 3 ... Spacer 3A ... Spacer main body 4 ... Lead plate 5 ... Connection terminal 6 ... Gap plate 7 ... Elastic convex part 10 ... Bottom plate 11 ... Side wall 11A ... Long side wall 11B ... Short side wall 12 ... peripheral wall 21 ... case 22 ... battery 23 ... bottom plate 24 ... side wall

Claims (6)

Place a plurality of batteries (2) in a posture parallel to the bottom plate (10) in a plastic body case (1A) integrally formed along the periphery of the bottom plate (10) and provided with side walls (11). A battery pack in which the end face of the battery (2) is stored facing the side wall (11), and the opening of the main body case (1A) is closed with a lid case (1B),
A plastic spacer (3) is disposed between the battery (2), and this spacer (3) is a gap plate (between the end face of the battery (2) and the side wall (11) ( 6) is integrally formed in the spacer body (3A) disposed between the batteries (2), and the spacer body (3A) is disposed between the batteries (2). A gap plate (6) molded integrally with the battery (2) is disposed between the end face of the battery (2) and the side wall (11) of the main body case (1A), and the heat of the battery (2) is transferred to the gap plate ( A battery pack which conducts to the side wall (11) through 6).   A plurality of batteries (2) are stacked and stored in the main body case (1A), and the spacer body (3A) is disposed between the batteries (2) stacked in multiple stages. Item 4. A battery pack according to item 1.   The adjacent battery (2) is connected by a metal lead plate (4) disposed between the end face of the battery (2) and the side wall (11). The battery pack according to claim 1, wherein a gap plate (6) of a spacer (3) is disposed between 4).   A plurality of batteries (2) are housed in multiple layers in the main body case (1A), and a circuit board is arranged outside either the main body case (1A) or the lid case (1B). The battery pack according to claim 3, wherein a lead plate (4) is connected to the circuit board.   The battery pack according to claim 1, wherein the battery (2) is a cylindrical battery, and the spacer body (3A) has a curved surface along the surface of the cylindrical battery. In a plastic body case (1A) provided with a side wall (11) around the bottom plate (10), a plurality of batteries (2) are arranged in parallel in a posture parallel to the bottom plate (10). The end face of the battery is stored facing the side wall (11), and the lead plate (4) is disposed on the end face of the battery (2), and the lead plate (4) is connected to the end face of the battery (2). The battery (2) adjacent to each other is connected, and the opening of the main body case (1A) is closed by the lid case (1B),
The lead plate (4) is an elastic metal plate and is bent into a shape in which the lead plate (4) is provided with an elastic convex portion (7) protruding toward the side wall (11). A battery pack disposed between the end face of 2) and the side wall (11) of the main body case (1A) so as to conduct heat of the battery (2) to the side wall (11).

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