JP5646297B2 - Pack battery - Google Patents

Description

  The present invention relates to a battery pack in which a plurality of prismatic cells are arranged and connected by a lead plate.

Square lithium ion secondary batteries and polymer batteries have been developed for portable electronic devices. A prismatic battery has a flat electrode body housed in a flat rectangular outer can or a laminate sheet, and a currently developed battery is set to be thin.
A pack battery in which a plurality of such prismatic cells are arranged and housed in a case together with a circuit board in which a protection circuit is incorporated has also been developed for a battery of a personal computer.

For example, in the battery pack disclosed in Patent Document 1, a battery cell group in which a plurality of prismatic battery cells are arranged is provided to realize a thin and high-capacity battery pack.
In this battery pack, the circuit board is arranged along the side of the unit cell group, and a lead plate is arranged between the terminals of each unit cell and between the unit cell and the circuit board.
In addition, an insulating plate is interposed between the unit cell and the lead plate so that these lead plates do not come into contact with parts having different potentials in the unit cell.

Generally, in such a battery pack, a holder member is provided to hold the unit cells in a fixed positional relationship in a state where a plurality of unit cells are arranged.
In the battery pack disclosed in Patent Document 1, a frame-shaped holder member is provided along the outer periphery of the unit cell group, the lead plate is also disposed along the outer periphery of the unit cell, and the lead plate is used as the holder member. Can be attached to.

In addition, a convex negative electrode terminal is provided on one end surface of the unit cell, but since the peripheral region of the negative electrode terminal on the one end surface is positive, the lead plate connected to the negative electrode terminal is A holder member is interposed so as not to contact the peripheral area of the one end face.
It is preferable to arrange the holder and the lead plate in such a form in order to keep the thickness of the battery pack thin, and the thickness can be made as thin as the thickness of the unit cell, and there is little dead space generated when it is mounted on the device. Become.

JP 2009-43462 A

In a battery pack including a unit cell group in which a plurality of unit cells are arranged as described above, it is conceivable that adjacent unit cells are connected in series and output at a high voltage. In that case, since the potentials of the outer cans of adjacent unit cells are different, it is necessary to prevent the outer cans from contacting each other. In addition, it is necessary to prevent a thermal chain from occurring between adjacent unit cells.
Therefore, in a battery pack in which a plurality of prismatic cells connected in series with each other are arranged, a holder member for holding the position of the unit cells is disposed by combining the above-described techniques, and between the unit cells. By appropriately disposing an insulating plate and further appropriately disposing an insulating plate between the lead plate connected to the terminal and the unit cell, it is possible to hold the unit cell, insulate the outer can of the unit cell, Although it is considered possible to prevent the insulation and insulation between the unit cell and the lead plate, the number of parts constituting the battery pack increases, and it takes time to assemble the battery pack.

  In view of the above problems, the present invention provides a battery pack in which a plurality of prismatic battery cells are arranged, and the number of components constituting the battery pack while maintaining the holding function and the insulating function of the battery cell and the lead plate as described above. The purpose is to simplify the manufacturing process.

In order to achieve the above object, a battery pack according to the present invention includes a unit cell group in which a plurality of rectangular unit cells each having a terminal on one end surface are arranged on a plane, and the plurality of arranged unit cells. and one or more of the holder member for holding at a predetermined interval, and a one or more lead plates for connecting a plurality of unit cells to each other, each of the unit cells, the terminal polarity opposite region of the periphery of the terminal at one end face One of the holder members has an insertion portion that is disposed adjacent to each other in the unit cell group and is inserted in a gap between the series connected unit cells, and extends along the gap, and Bending from the extension direction end of the insertion part, extending along one end face of one of the adjacently arranged unit cells, and providing an end face covering part covering the peripheral region of the terminal on the one end face, one plate, before the surface of the end surface covering portion is a part Disposed along the surface of the insertion device, it was decided to connect to the other unit cell in which the terminal provided on one end surface arranged adjacent unit cells.

Alternatively, the battery pack according to the present invention includes a unit cell group in which three or more rectangular unit cells each having a terminal on one end surface are arranged on a plane and connected in series, and the arranged unit cells are arranged at a predetermined interval. in a first holder and a second holder member for holding, each of the unit cells include those having the terminal opposite polarity region of the periphery of the terminal at one end face, the first holder member, In the unit cell group, an insertion part that is inserted in a gap between the unit cells that are adjacently arranged in the same direction and extends along the gap, and bent from one end part in the extension direction of the insertion part, It extends along one end surface of the unit cell and has an L -shape comprising an end surface covering portion covering the peripheral region of the terminal on the one end surface, and the second holder members are opposite to each other in the unit cell group. Inserted in the gap between adjacent cells An insertion portion that extends along the gap, and bends from one end portion in the extension direction of the insertion portion, extends along one end surface of one unit cell, and is a peripheral region of the terminal on the one end surface. And an end face covering the peripheral area of the terminal on the one end face by bending from the other end part in the extension direction of the insertion part and extending along one end face of the other unit cell a Z-shape having a covering portion, along the surface of the end surface covering portion for covering an end face of each of the unit cell disposed the lead plates and the lead plate is configured to be connected to the terminal of the end face .

According to the battery pack of the present invention, the holder member is inserted in the gap between the cells that are arranged adjacently and connected in series, and extends along the gap, and the extension direction of the insertion part An end surface covering portion that is bent from the end portion and extends along one end surface of one of the adjacently disposed unit cells and covers the peripheral region of the terminal on the one end surface is provided.
Here, the insertion part secures a gap between the adjacently arranged unit cells and secures the positional relationship between them. As a result, the unit cells are insulated and the thermal chain is suppressed.

One of the lead plates is connected to a terminal provided on one end surface of the unit cell, but is disposed along the surface of the end surface covering portion. The surrounding area on one end face of the unit cell is insulated by the end face covering portion.
In this way, with one holder member, it is possible to realize the positional relationship maintenance between the adjacently arranged unit cells, insulation and prevention of thermal chain, and insulation between the lead plate and one end surface of the unit cell.

In the above battery pack, it is preferable that one of the holder members is an L-shaped member including an insertion portion and an end surface covering portion in order to simplify the holder member.
Here, if one part of the lead plate is bent from the surface of the end face covering portion and disposed along the surface of the insertion portion and connected to the other unit cell arranged adjacently, this lead plate In a state in which the holder member is sandwiched between the plate and the unit cells, the unit cells arranged adjacent to each other can be connected in series.

When the terminal provided on one end surface of the unit cell is a convex terminal, a hole into which the convex terminal is inserted is formed in the end surface covering portion, and one of the lead plates and the convex terminal are provided. If it connects via the said hole, since a convex terminal and a hole will fit, a holder member can be aligned and fixed with respect to a unit cell by it.
In the holder member, if the insertion portion and the end surface covering portion are integrally formed of the same material, the holder member can be easily manufactured by injection molding.

If a rib for sandwiching a part of the lead plate is formed on the surface of the end surface covering portion, the lead plate is held at a predetermined position on the battery holder, and the displacement of the lead plate can be prevented.
In the above battery pack, when the unit cell group is the first unit cell group and the second unit cell group having the same configuration as the first unit cell group is stacked on the first unit cell group, the first unit cell group The impact resistance of the battery pack can be improved by inserting a belt-like spacer between the insertion part of the holder member provided in the battery and the insertion part of the holder member provided in the second unit cell group. .

The spacer has a portion extending along the insertion portion of the holder member provided in the first unit cell group and the insertion portion of the holder member provided in the second unit cell group, and the portion is the first unit cell group. In order to improve the impact resistance of the battery pack, it is preferable to provide the battery unit so as not to be sandwiched between the unit cell constituting the battery unit and the unit cell constituting the second unit cell group.
Further, in a battery pack in which three or more unit cells are arranged on a plane and connected in series with each other, the battery pack can be obtained by combining the L-shaped holder member and the Z-shaped holder member as described above. In addition to reducing the number of components, the effect of simplifying the manufacturing process is enhanced.

2 is an exploded perspective view showing a configuration of a battery pack according to Embodiment 1. FIG. 3 is a perspective view showing a state in which a battery pack main body 1 is housed in a lower case 2. FIG. In the battery pack main body 1, the lead plates 41 to 46 and the holder members 31 to 33 are arranged with respect to the unit cell group 20. It is a figure which shows formation in which the holder member 31 and the lead plate 42 are mounted | worn with the unit cell 21. It is the perspective view of the holder member 31, and its partial enlarged view. 4 is an exploded perspective view showing a configuration of a battery pack according to Embodiment 2. FIG. It is a figure which shows the position where a spacer is arrange | positioned with respect to a unit cell group. It is a figure which shows a mode that an impact test is performed with respect to the unit cell group 120,220 laminated | stacked. It is a figure which shows the battery pack main body using the spacer concerning a comparative example. It is the perspective view and top view which show the battery 70 with a lead concerning a reference example.

[Embodiment 1]
FIG. 1 is an exploded perspective view showing the configuration of the battery pack according to the first embodiment. For the sake of explanation, the direction indicated by the arrow X is defined as the forward direction, and the direction indicated by the arrow Y is defined as the horizontal direction.
This battery pack is used as a power source for a portable personal computer. A rectangular battery pack body 1 that is long in the lateral direction is housed in a lower case 2 and an upper case 3, and is placed on the upper surface of the upper case 3. The label 4 is attached and configured.

The lower case 2 has a space for housing the battery pack body 1 including the unit cell group 20 therein, and the upper case 3 covers the opening.
The lower case 2 and the upper case 3 are entirely formed of plastic which is an insulating material such as PC (polycarbonate).
The label 4 is bonded to the upper surface of the upper case 3 through an adhesive layer or an adhesive layer.

(Configuration of the battery pack body 1)
FIG. 2 is a perspective view showing a state in which the battery pack body 1 is housed in the lower case 2.
As shown in FIGS. 1 and 2, the battery pack body 1 includes a unit cell group 20 in which rectangular unit cells 21 to 24 having a flat rectangular parallelepiped shape are arranged, and unit cells constituting the unit cell group 20 are spaced apart from each other. Are constituted by holder members 31 to 33, lead plates 41 to 46 connected to each unit cell, circuit board 50, and the like.

Each of the four unit cells 21 to 24 is a square (rectangular) secondary battery in which the thickness in the Z direction is thinner than the lateral width in the Y direction, and is connected in series.
And the four unit cells 21-24 are arranged in the horizontal direction (Y direction) along the XY plane in the state which faced the side parts 21a-24a.
Here, each of the unit cells 21 to 24 is a lithium ion battery in which an outer can serves as a positive electrode terminal. However, the type of the unit cell is not particularly limited, and may be a lithium polymer battery, a nickel-hydrogen battery, or a nickel-cadmium battery.

Each unit cell 21-24 has the convex negative electrode terminal 25 in the upper surfaces 21b-24b, and the bottom surfaces 21c-24c are positive electrode terminals.
Each of the unit cells 21 to 24 is arranged with the top surfaces 21b to 24b and the bottom surfaces 21c to 24c facing in the front-rear direction. Here, with respect to the orientation of each of the unit cells 21 to 24, only the unit cell 24 has the upper surface 24b facing forward and the bottom surface 24c facing backward, and the unit cells 21 to 23 facing the upper surface 21b to 23b rearward and the bottom surface 21c to 23c. Is facing forward.

The circuit board 50 is attached in front of the unit cell group 20, and a protection circuit for preventing overcharge and overdischarge of the unit cell group 20 is mounted on the circuit board 50.
An external connector 51 is provided on the front side of the circuit board 50. The external connector 51 is exposed to the outside from the notches 2a and 3a provided in the cases 2 and 3.
Lead plates 41 to 45 are connected to the terminals 52 to 57 of the circuit board 50 as described below. The thermistor 58 is connected to the circuit board 50 so that the temperature of the unit cell 23 can be measured.

(Battery holder and lead plate)
FIG. 3 is a diagram showing a configuration in which the battery holder (holder members 31 to 33) and the lead plates 41 to 46 are arranged with respect to the unit cell group 20 in the battery pack body 1.
As shown in the drawing, the battery holder is composed of a plurality of holder members 31 to 33.
Each of the holder members 31 to 33 is an integrally formed member made of plastic which is an insulating material, and is interposed between adjacent unit cells in the unit cell group 20 and extends in the front-rear direction. 31a to 33a and end face covering portions 31b to 33b and 33c which are bent from the end portions of the insertion portions 31a to 33a and extend along the upper surface having the negative electrode terminal in the unit cell.

That is, the holder member 31 includes an insertion portion 31a extending in the front-rear direction between the side portion 21a of the unit cell 21 and the side portion 22a of the unit cell 22, and a unit cell from the rear end of the insertion portion 31a. 21 is an L-shaped member that extends along an upper surface 21b (an end surface from which the negative electrode terminal 25 protrudes) of an upper surface 21 and includes an end surface covering portion 31b that covers a region around the negative electrode terminal 25 on the upper surface 21.
Similarly, the holder member 32 includes an insertion portion 32a extending in the front-rear direction between the side portion 22a of the unit cell 22 and the side portion 23a of the unit cell 23, and the unit cell 22 from the rear end of the insertion portion 32a. This is an L-shaped member that extends along the upper surface (the end surface from which the negative electrode terminal 25 protrudes) and includes an end surface covering portion 32 b that covers the peripheral region of the negative electrode terminal 25 on the upper surface 21.

  The holder member 33 includes an insertion part 33a extending in the front-rear direction between the side part 23c of the unit cell 23 and the side part 24c of the unit cell 24, and a rear end of the insertion part 33a. It extends along the upper surface 23b (the end surface from which the negative electrode terminal 25 protrudes), and the upper surface 24b (the negative electrode terminal 25 protrudes from the front end of the end surface covering portion 33b covering the upper surface and the insertion portion 33a). The Z-shaped member is formed of an end surface covering portion 33c that extends along the upper surface 24b and covers the peripheral region of the negative electrode terminal 25 on the upper surface 24b.

Insulating plates 35 and 36 are attached to the upper and lower portions of the insertion portions 31a to 33a in the holder members 31 to 33, respectively. An adhesive insulating sheet 37 is interposed between the unit cell group 20 (unit cells 21 to 24) and the bottom surface of the lower case 2.
The unit cell group 20 is fixed to the lower case 2 by the insulating sheet 37.
Next, the lead plates 41 to 45 will be described.

The lead plate 41 connects the bottom surface 21 c (positive electrode terminal) of the unit cell 21 and the breaker 61. The breaker 61 is connected to the terminal 52 of the circuit board 50 via the lead plate 46 and the polyswitch 62. The lead plate 41 is also connected to the terminal 53 of the circuit board 50.
The lead plate 42 includes a vertical lead portion 42a extending in the front-rear direction between the insertion portion 31a of the holder member 31 and the side portion 22a of the unit cell 22, and a bent portion from the rear end of the vertical lead portion 42a. A lateral lead portion 42b extending laterally along the surface of the end surface covering portion 31b of the member 31, and a lateral lead portion bending from the front end of the longitudinal lead portion 42a and extending laterally along the bottom surface 22c of the unit cell 22 This is a Z-shaped member consisting of 42c. The lateral lead part 42b is connected to the negative electrode terminal 25 of the unit cell 21, and the lateral lead part 42c is connected to the bottom surface 22c (positive electrode terminal) of the unit cell 22, whereby the unit cell 21 and the unit cell 22 are connected in series. ing.

Regarding the connection between the negative electrode terminal 25 of the unit cell 21 and the lateral lead portion 42 b, a hole 310 is opened at a position corresponding to the negative electrode terminal 25 in the end surface covering portion 31 b of the holder member 31, and the negative electrode terminal is passed through the hole 310. 25 and the lateral lead 42b are welded (see FIG. 4).
The lead plate 43 includes a vertical lead portion 43a extending in the front-rear direction between the insertion portion 32a of the holder member 32 and the side portion 23a of the unit cell 23, and a holder member bent from the front end of the vertical lead portion 43a. A horizontal lead portion 43b extending in the horizontal direction along the surface of the end face covering portion 32b, and a horizontal lead portion 43c bent from the front end of the vertical lead portion 43a and extended in the horizontal direction along the bottom surface 23c of the unit cell 23. A Z-shaped member consisting of The lateral lead portion 43b is connected to the negative electrode terminal 25 of the unit cell 22, and the lateral lead portion 43c is connected to the bottom surface 23c (positive electrode terminal) of the unit cell 23, whereby the unit cell 23 and the unit cell 23 are connected in series. ing.

Regarding the connection between the negative electrode terminal 25 of the unit cell 22 and the lateral lead portion 43b, a hole 320 is opened in the end surface covering portion 32b of the holder member 32, and the negative electrode terminal 25 and the lateral lead portion 43b are connected through the hole 320. It is welded.
The lead plate 44 has a vertical lead portion 44a extending in the front-rear direction along the side portion 24a of the unit cell 24, and is bent from the rear end of the vertical lead portion 44a in the lateral direction along the bottom surface 24c of the unit cell 24. It is an L-shaped member comprising a lateral lead portion 44b that extends, the longitudinal lead portion 44a being connected to the terminal 57 of the circuit board 50, and the lateral lead portion 44b being the negative terminal 25 of the unit cell 23 and the unit cell 24. The unit cell 23 and the unit cell 24 are connected in series by being connected to the bottom surface 24c (positive electrode terminal) and the terminal 55 of the circuit board 50.

Also in the connection between the negative electrode terminal 25 of the unit cell 23 and the lateral lead portion 44b, a hole 330 is opened in the end surface covering portion 33b of the holder member 33, and the negative electrode terminal 25 and the lateral lead portion 44b are connected via the hole 330. It is welded.
The lead plate 45 extends in the lateral direction along the surface of the end surface covering portion 33 c and is connected to the negative terminal 25 of the unit cell 24 and the terminal 56 of the circuit board 50.

Regarding the connection between the negative electrode terminal 25 of the unit cell 24 and the lead plate 45, a hole 331 is opened in the end surface covering portion 33 c of the holder member 33, and the negative electrode terminal 25 and the lead plate 45 are welded and joined through the hole 331. ing.
The lead plates 41 to 45 and the terminals are joined by resistance spot welding, laser welding, soldering, or the like.

A thermal fuse is incorporated in the lateral lead portions 42b, 43b, 44b and the lead plate 45 of each of the lead plates 42 to 44.
With such lead plates 41 to 45, the four unit cells 21 to 24 in the unit cell group 20 are connected in series so that power is output between the terminals 52 and 57 of the circuit board 50 from both ends thereof. It has become. An intermediate voltage is input to the terminals 54, 55, and 57 of the circuit board 50.

(Details of holder members 31-33)
As shown in FIG. 4, the side part 21a of the unit cell 21 is covered with the insertion part 31a of the holder member 31, and the vertical lead part 42a of the lead plate 42 is mounted on the insertion part 31a.
Further, the upper surface 21b of the unit cell 21 is covered by the end surface covering portion 31b of the holder member 31, and the lateral lead portion 42b of the lead plate 42 is mounted on the end surface covering portion 31b.

Further, the lateral lead portion 42 c of the lead plate 42 is joined to the upper surface 22 c of the unit cell 22.
FIG. 5 is a perspective view of the holder member 31 and a partially enlarged view thereof.
Ribs 311 and 312 are provided along both edges of the insertion part 31 a of the holder member 31, and the vertical lead part 42 a of the lead plate 42 is sandwiched between the ribs 311 and 312. In addition, ribs 313 and 314 are provided along both edges of the end surface covering portion 31b of the holder member 31, and the lateral lead portions 42b of the lead plate 42 are sandwiched by the ribs 313 and 314. ing.

Further, a projection 315 is provided on the end surface covering portion 31 b of the holder member 31, and a hole 420 opened in the lateral lead portion 42 b of the lead plate 42 is fitted into the projection 315.
With such a mechanism, the lead plate 42 mounted on the holder member 31 can be firmly fixed.

  Although not shown, the holder member 32 and the lead plate 43 have the same configuration as the holder member 31 and the lead plate 42 described above, and are provided by ribs provided on the insertion portion 32a and the end surface covering portion 32b of the holder member 32. Further, the vertical lead portion 43a and the horizontal lead portion 43b of the lead plate 43 are sandwiched, and further, a hole provided in the horizontal lead portion 43b of the lead plate 43 is filled in the protrusion provided on the end surface covering portion 32b of the holder member 32. The lead plate 43 is firmly fixed on the holder member 32 by being stuck.

Further, the lateral lead portion 44 b of the lead plate 44 is also clamped by the rib provided on the end surface covering portion 33 b of the holder member 33 and fixed on the end surface covering portion 33 b, and the lead plate 45 is also the end surface covering portion of the holder member 33. It is clamped by the rib provided in 33c and is fixed on the end surface covering portion 33b.
Thus, each lead plate 42-45 is fixed on the surface of each holder member 31-33, and thereby each lead plate 42-45 and each holder member 31-33 become difficult to mutually shift. Yes.

(Method of manufacturing a battery pack)
When assembling the battery pack 1, the holder members 31 to 33 and the lead plates 41 to 46 are attached to the unit cells 21 to 24 constituting the unit cell group 20, and the unit cells 21 to 24 are attached. Arrange. Further, the lead plates 41 to 45 are connected to the terminals of the unit cells 21 to 24.

Specifically, as shown in FIG. 4A, the holder member 31 and the lead plate 42 are attached to the unit cell 21, and the lateral lead portion 42 b and the negative electrode terminal 25 are connected.
Here, since the holder member 31 includes the insertion portion 31a and the end surface covering portion 31b, when the holder member 31 is mounted, the insertion portion 31a and the end surface covering portion 31b are simultaneously mounted.

FIG. 4B shows a state where the holder member 31 and the lead plate 42 are attached to the unit cell 21.
Similarly, the holder member 32 and the lead plate 43 are attached to the unit cell 22.
A holder member 33 is attached to the unit cell 23 and the unit cell 24. Then, the horizontal lead portion 44 b of the lead plate 44 and the negative electrode terminal 25 of the unit cell 23 are connected, and the horizontal lead portion 44 b and the bottom surface 24 c of the unit cell 24 are connected. Further, the negative electrode terminal 25 of the unit cell 24 and the lead plate 45 are also connected.

As described above, if a unit cell with a holder member and a lead plate is prepared, the battery pack body 1 can be easily assembled by combining and connecting them.
That is, the unit cell 21 with the holder member 31 and the lead plates 42 and 46, the unit cell 22 with the holder member 32 and the lead plate 43, and the unit cells 23 and 24 with the holder member 33 and the lead plates 44 and 45 are produced, respectively. These are arranged to form the unit cell group 20, the connection between the lateral lead portion 42 c of the lead plate 42 and the bottom surface 22 c of the unit cell 22, and the lateral lead portion 43 c of the lead plate 43 and the unit cell 23. Connection to the bottom surface 23c is performed.

And the circuit board 50 is arrange | positioned along the front side of the unit cell group 20, and the pack battery main body 1 is completed by connecting the lead plates 41-46 and the terminals 52-57 of the circuit board 50. FIG.
An insulating sheet 37 is attached to the lower surface of the unit cell group 20 on the battery pack body 1, and this is attached to the bottom surface of the lower case 2. Then, the battery pack is completed by covering the upper case 3.

(Effect by holder members 31-33)
The effect of using the holder members 31 to 33 will be described by taking the holder member 31 typically attached to the unit cells 21 and 22 as an example.
First, the role of the insertion part 31a of the holder member 31 will be described. In the unit cells 21 and 22 adjacent to each other, the side parts 21a and 22a are electrically connected to the bottom surfaces (positive terminals) 21c and 22c and have the same potential. Since the adjacent unit cells are connected in series, it is necessary to insulate the side portions 21 a and 22 a from each other, but the insertion portion 31 a of the holder member 31 is the side portion 21 a of the unit cell 21. Between the unit cell 22 and the side part 22a of the unit cell 22 to ensure insulation between the two while ensuring a certain distance between them, and to suppress heat transfer between the unit cell 21 and the unit cell 22 It also serves to prevent heat chains.

The insertion portion 31a is also interposed between the side portion 21a of the unit cell 21 and the vertical lead portion 42a of the lead plate 42 to insulate between the two while ensuring a gap therebetween. .
Next, the role of the end surface covering portion 31b of the holder member 31 will be described. Since the peripheral region of the negative electrode terminal 25 on the upper surface 21b of the unit cell 21 is electrically connected to the positive electrode terminal, it is connected to the negative electrode terminal 25 of the unit cell 21. It is necessary to insulate from the lead plate 42, but the end surface covering portion 31 b of the holder member 31 includes the lateral lead portion 42 b of the lead plate 42 connected to the negative electrode terminal 25 of the unit cell 21, and the upper surface 21 b of the unit cell 21. Is interposed between the two to insulate them.

As described above, the single holder member 31 provides insulation between the adjacent unit cells 21 and 22 and prevention of heat chain, and also provides insulation between the lead plate 42 and the unit cell 21.
The holder member 31 is sandwiched and fixed between the lead plate 42 connected to the negative electrode terminal 25 of the unit cell 21 and the bottom surface 22c of the unit cell 22, and the side part 21a and the top surface 21b of the unit cell 21. Since the holder member 31 is not easily displaced with respect to the unit cell 21, the function as the holder member can be maintained for a long time.

Further, since the negative electrode terminal 25 provided on the upper surface 21 b of the unit cell 21 is fitted and fitted in the hole 310 formed in the end surface covering portion 31 b of the holder member 31, the unit cell 21 of the holder member 31. Is easy to align and secure.
In addition, since the lead plate 42 is sandwiched between the ribs 311 and 312 and the ribs 313 and 314 of the holder member 31 and the hole 420 of the lead plate 42 is fitted in the protrusion 315 of the holder member 31, It is difficult for positional deviation between the lead plate 42 and the holder member 31 to occur, and the function of the holder member 31 can be stably maintained.

  Moreover, since the holder member 31 has the insertion part 31a and the end surface coating | coated part 31b, if this holder member 31 is used also in the process of assembling the battery pack main body 1, FIG. ), The insertion portion 31a and the end surface covering portion 31b can be attached to the unit cell 21 at the same time. Therefore, a manufacturing process can be easily implemented compared with the case where separate members corresponding to the insertion portion 31a and the end surface covering portion 31b are attached.

The effects as described above are similarly achieved in the holder member 32 and the holder member 33.
Further, as described in the manufacturing process of the above embodiment, the holder member 31 and the lead plates 42 and 46 are attached to the unit cell 21, the holder member 32 and the lead plate 43 are attached to the unit cell 22, and the unit cell 23, The battery pack main body 1 can be easily assembled by attaching the holder member 33 and the lead plates 44 and 45 to 24 and combining them.

As described above, in the battery pack of this embodiment, the L-shaped holder members 31 and 32 and the Z-shaped holder member 33 are used in combination, thereby reducing the number of parts constituting the battery pack. Also, the effect of simplifying the manufacturing process can be enhanced.
Similarly, in a battery pack comprising a unit cell group in which three or more unit cells are generally arranged on a plane and connected in series with each other, by using a combination of an L-shaped holder member and a Z-shaped holder member In addition to the effect of reducing the number of parts constituting the battery pack, the effect of simplifying the manufacturing process is enhanced.

In addition, in this embodiment, it has the convex negative electrode terminal 25 in the upper surfaces 21b-24b of each unit cell 21-24, and the circumference | surroundings of the negative electrode terminal 25 in the upper surfaces 21b-24b were positive polarity, The same can be applied to the case where the upper surface of the unit cell has a convex positive electrode terminal and the periphery of the positive electrode terminal on the upper surface is negative.
[Embodiment 2]
In the present embodiment, in the battery pack body, two unit cell groups having the same configuration as the unit cell group 20 of the first embodiment are stacked. And the band-shaped spacer is inserted between the insertion part of the holder member with which the lower unit cell group is provided, and the insertion part of the holder member with which the upper unit cell group is provided. As will be described, the insertion part of the holder member provided in the lower unit cell group, the band-shaped spacer, and the insertion part of the holder member provided in the upper unit cell group serve as a support column. Impact resistance can be improved.

FIG. 6 is a diagram showing the configuration of the battery pack according to the second embodiment, and shows a state in which the battery pack main body 1 is housed in the lower case 102.
In the first embodiment, the four unit cells 21 to 24 are arranged in the horizontal direction (Y direction) to form the unit cell group 20. However, in the battery pack body 101 in the present embodiment, the unit cell group 101 has four units. A unit cell group 120 in which the unit cells 121 to 124 are arranged in the horizontal direction and a unit cell group 220 in which the four unit cells 221 to 224 are arranged in the horizontal direction are stacked in two upper and lower stages. Yes. That is, the lower unit cell group 120 has four unit cells 121 to 124 arranged in the horizontal direction, and the upper unit cell group 220 has four unit cells 221 to 224 arranged in the horizontal direction. .

The form in which the four unit cells 121 to 124 are arranged in the lower unit cell group 120 is the same as the form in which the unit cells 21 to 24 in the first embodiment are arranged. The interposition portions 131a to 133a of the holder members 131 to 133 are interposed between .about.124. And these four unit cells 121-124 are connected in series.
Further, in the upper unit cell group 220, the form in which the four unit cells 221 to 224 are arranged is the same as the form in which the unit cells 21 to 24 are arranged, and the adjacent unit cells 221 to 224 are adjacent to each other. Between them, the insertion portions 231a to 233a of the holder member are interposed, and the four unit cells 221 to 224 are connected in series.

Note that the unit cells stacked in the vertical direction (that is, the unit cell 121 and the unit cell 221, the unit cell 122 and the unit cell 222, the unit cell 123 and the unit cell 223, and the unit cell 124 and the unit cell 224) are lead plates. Are connected to each other in parallel, and are also connected to the circuit board 150.
Spacers 401 to 403 and 411 to 418 are interposed between the upper surface of the lower unit cell group 120 and the lower surface of the upper unit cell group 220.

FIG. 7 is a diagram illustrating a position where the spacer is disposed with respect to the unit cell group.
As shown in FIGS. 7A and 7B, the spacers 401 to 403 are disposed on the insertion portions 131 a to 133 a interposed between the adjacent unit cells 121 to 124.
The spacers 411 to 414 are arranged along the front ends of the unit cells 121 to 124, and the spacers 415 to 418 are arranged along the rear ends of the unit cells 121 to 124.

  Although the upper unit cell group 220 is not shown in FIG. 7, the upper unit cell group 220 is also arranged at the same position. That is, the spacers 401 to 403 are disposed under the insertion portions 231 a to 233 a interposed between the adjacent unit cells 221 to 224, and the spacers 411 to 414 extend along the front ends of the unit cells 221 to 224. The spacers 415 to 418 are disposed on the side surfaces 121d to 124d along the rear ends of the unit cells 221 to 224, respectively.

These spacers 401 to 403 and 411 to 418 are band-shaped members made of an insulating material, and are attached to the lower unit cell group 120 with a double-sided tape. The upper surfaces of the spacers 401 to 403 and 411 to 418 are also attached to the upper unit cell group 220 with double-sided tape.
Examples of the material of the spacers 401 to 403 and 411 to 418 include insulating paper (Nomex, DuPont) made of an aramid polymer. The thickness of the spacer is, for example, 0.51 mm, and the thickness of the double-sided tape is, for example, 0.4 mm.

FIGS. 8A and 8B are diagrams illustrating a state in which an impact test is performed on the unit cell groups 120 and 220 stacked via the spacers 401 to 403 and 411 to 418, and FIG. The cross section of the unit cell group 120, 220 cut in the lateral direction, (b) shows the cross section of the unit cell group 120, 220 cut in the front-rear direction at the unit cells 123, 223.
FIG. 9 is a diagram showing a battery pack body using a spacer according to a comparative example. Spacers 501 to 504 are provided between the upper surface of the lower unit cell group 120 and the lower surface of the upper unit cell group 220. It is inserted.

The spacers 501 to 504 according to this comparative example are also formed of insulating plates, but are frame-like members stacked on the outer peripheral portions of the side surfaces 121d to 124d of the respective unit cells 121 to 124.
An impact test was performed on an example in which the unit cell groups 120 and 220 were stacked using the spacers 401 to 403 and 411 to 418 and a comparative example in which the unit cell groups 120 and 220 were stacked using the spacers 501 to 504. It was.

In the impact test method, the stacked unit cell groups 120 and 220 are placed on a table, a round bar (Φ16 mm) is placed on the unit cell group 220, and a certain height with respect to the round bar is set. The weight was dropped and impact F was applied, and whether or not the unit cell groups 120 and 220 were damaged was observed.
As a result, in the comparative example, the side pieces of the unit cells 121 to 124 and 221 to 224 (regions A1 to A5 surrounded by a broken line in FIG. 9A) are deformed, and particularly the regions A1 at both ends. , A5 was easily deformed, but in the examples, the cells 121 to 124 and 221 to 224 were not deformed.

The reason will be described with reference to FIGS. 8A and 8B according to the embodiment and FIG. 9B according to the comparative example.
In the battery pack body 101 according to the example, as shown in FIGS. 8A and 8B, the insertion portions 231a to 233a, the spacers 401 to 403, and the insertion portions 131a to 133a penetrate vertically. Since it exists like a support | pillar, even if a compressive force is applied to the battery pack main body 101 from the upper and lower sides, the unit cells 121 to 124 and 221 to 224 do not have much force.

That is, the spacers 401 to 403 extend along the insertion portions 131a to 133a of the holder members 131 to 133 and the insertion portions 231a to 233a of the holder members 231 to 233, and are interposed between the insertion portions 131a to 133a. It is interposed between the insertion portions 231a to 233a.
On the other hand, a spacer is not interposed between the unit cells stacked vertically below the round bar. In other words, the spacers 401 to 403 extending along the insertion portions 131 a to 133 a and the insertion portions 231 a to 233 a are the unit cells 121 to 124 that constitute the unit cell group 120 and the unit cells that constitute the unit cell group 220. It is not sandwiched between the batteries 221 to 224.

Therefore, for example, when an impact force F is applied to the round bar from above, it is transmitted to the base mainly via the insertion portions 231a to 233a, the spacers 401 to 403, and the insertion portions 131a to 133a. The impact force is not applied to ˜124 and 221˜224.
Further, just below the round bar, there is a gap between the unit cells stacked one above the other, so that when a pressing force is applied to the unit cells, as shown by a broken line L in FIG. The unit cell can be bent.

Therefore, in the embodiment, even if a compressive force or an impact force is applied, the unit cells 121 to 124 and 221 to 224 are hardly deformed.
On the other hand, in the battery pack body of the comparative example, as shown in FIG. 9B, the side portions of the unit cells 221 to 224 and the side portions of the unit cells 121 to 124 that are stacked one above the other directly below the round bar. The spacers 501 to 504 are interposed therebetween.

Therefore, when a compressive force is applied to the battery pack body or an impact force F is applied to the round bar, the side portions of the unit cells 221 to 224, the spacers 501 to 504, and the side portions of the unit cells 121 to 124 are moved. Since it is transmitted to the stand via, a force compressed from above and below is applied to the side portions of the unit cells 121 to 124 and 221 to 224.
[Reference example]
FIG. 10A is a perspective view showing a leaded battery 70 according to a reference example, and FIG. 10B is a top view thereof.

It is composed of a rectangular unit cell 71 and a lead plate 75 attached to the unit cell 71.
The lead plate 75 is an L-shaped member having a vertical lead portion 75 a extending along the side portion 71 a of the unit cell 71 and a horizontal lead portion 75 b extending along the upper surface 71 b of the unit cell 71.
A clad plate 72 is attached as a positive electrode terminal to the upper surface 71 b of the unit cell 71, and the lateral lead portion 75 b is welded to the clad plate 72.

The lateral lead portion 75b of the lead plate 75 has a tip portion 751 that is narrow, and the width W2 of the tip portion 751 is set to be equal to the width W1 of the clad plate 72.
The leading end portion 751 of the lead plate 75 is joined with being aligned with the clad plate 72.
Thus, by setting the width W2 of the tip portion 751 of the lead plate 75 and the width W1 of the clad plate 72 to be equal, when the lead plate 75 is joined to the unit cell 71, the lead plate 75 The tip portion 751 and the clad plate 72 on the unit cell 71 can be easily aligned. Therefore, a joining process can be performed easily.

  The present invention is suitable for a battery pack for portable electronic devices, particularly a battery pack in which a plurality of prismatic cells are arranged and connected in series.

DESCRIPTION OF SYMBOLS 1 Pack battery main body 2 Lower case 3 Upper case 20 Unit cell group 21-24 Unit cell 21a-24a Side part 21b-24b Upper surface 21c-24c Bottom surface 25 Negative electrode terminal 31-33 Holder member 31a-33a Insertion part 31b-33b End surface covering portion 41 to 46 Lead plate 42a, 43, 44a Vertical lead portion 42b, 43b, 44b, 42c Horizontal lead portion 50 Circuit board 51 External connector 311, 312 Rib 313, 314 Rib

Claims (8)

A unit cell group in which a plurality of rectangular unit cells each having a terminal on one end surface are arranged on a plane; one or more holder members that hold the plurality of arranged unit cells at a predetermined interval; and a least one lead plate connecting the unit cells to each other,
Before Kimoto Each cell has a corresponding pin and opposite polarity region of the periphery of the terminal at one end face,
One of the holder members is
An insertion portion that is arranged adjacent to each other in the unit cell group and is inserted in a gap between the unit cells connected in series, and extends along the gap;
An end surface covering portion that is bent from the end portion in the extending direction of the insertion portion and extends along one end surface of one of the adjacent unit cells to cover the peripheral region of the terminal on the one end surface. And
One of the lead plates is
A part thereof is disposed along the surface of the insertion part from the surface of the end face covering part,
A battery pack, characterized in that the battery pack is connected to the other unit cell arranged adjacent to a terminal provided on one end surface of the unit cell. One of the holder members is
The battery pack according to claim 1, wherein the battery pack is an L-shaped member including the insertion portion and the end surface covering portion. The terminal provided on one end surface of the unit cell is a convex terminal,
The end surface covering portion is provided with a hole into which the convex terminal is inserted,
One said convex terminal, the battery pack according to claim 1, wherein it is connected via the hole of the lead plate. In the holder member,
A battery pack according to claim 1 to 3 wherein the end surface covering portion and the insertion member is characterized by being integrally molded of the same material. The battery pack according to any one of claims 1 to 4 , wherein a rib for sandwiching a part of the lead plate is formed on a surface of the end face covering portion. A first unit cell group in which a plurality of rectangular unit cells having terminals on one end face are arranged on a plane; one or more holder members that hold the plurality of arranged unit cells at a predetermined interval; and One or more lead plates for connecting a plurality of unit cells,
Each of the unit cells has a region of opposite polarity to the terminal around the terminal on one end surface,
One of the holder members is
An insertion part that is arranged adjacent to each other and connected in series in the first unit cell group and extends along the gap;
An end surface covering portion that is bent from the end portion in the extending direction of the insertion portion and extends along one end surface of one of the adjacent unit cells to cover the peripheral region of the terminal on the one end surface. And
One of the lead plates is
A part of the end surface covering portion is disposed along the surface,
Connected to a terminal provided on one end surface of the unit cell;
The first second unit cell group having the same structure as the unit cell group, stacked on the first unit cell group,
Wherein the insertion device of the first unit cell group comprises the holder member, between the insertion device of the holder member in which the second unit cell group comprising, characterized in that the strip-shaped spacers are interposed It packs battery. The spacer is
It has a portion which extends along the insertion device of the insertion device and the second unit cell set comprises a holder member of the holder member to which the first unit cell group is provided,
The portion, said a unit cell constituting the first unit cell group, pack of claim 6, wherein the provided without being held between the unit cells constituting the second battery cell groups battery. A unit cell group in which three or more rectangular unit cells having terminals on one end face are arranged on a plane and connected in series, a first holder member and a second holder for holding the arranged unit cells at a predetermined interval A holder member,
Before Kimoto Each cell has a corresponding pin and opposite polarity region of the periphery of the terminal at one end face,
Said first holder member,
An insertion portion that is inserted in a gap between the unit cells adjacently arranged in the same direction in the unit cell group and extends along the gap;
It is bent from one end part in the extension direction of the insertion part, extends along one end face of one unit cell, and is formed in an L shape including an end face covering part that covers the peripheral region of the terminal on the one end face. Yes,
Said second holder member,
An insertion part that is inserted in a gap between the unit cells arranged adjacent to each other in opposite directions in the unit cell group, and extends along the gap;
Bending from one end of the insertion portion in the extending direction, extending along one end surface of one unit cell, and covering the peripheral area of the terminal on the one end surface; A Z -shape having an end surface covering portion that is bent from the other end portion in the extending direction, extends along one end surface of the other unit cell, and covers the peripheral region of the terminal on the one end surface,
A battery pack, wherein a lead plate is disposed along a surface of an end surface covering portion that covers one end surface of each of the unit cells , and the lead plate is connected to a terminal on the one end surface.

Images