CN203859171U - Battery pack - Google Patents

Abstract

The utility model provides a battery pack. The battery pack includes a battery stack and a battery pack box for accommodating the battery stack. The battery stack has a stacked body obtained by stacking a plurality of battery cells, and a stacked body sandwiched from both ends along the stacking direction. A pair of end plates; the battery pack box has a lower box that is fixedly connected with the end plates to support the two ends of the battery stack, and an upper box that covers the battery stack supported by the lower box from above. Between the battery stack and the upper box, anti-vibration rubber is respectively provided. A reinforcement member for tightening the hoop with the upper box body. With this structure, the bending deformation of the battery stack can be suppressed without increasing the rigidity of the battery pack case itself, and the vibration resistance performance of the battery stack can be improved.

Description

Battery

technical field

The utility model relates to a battery pack, in particular to a battery pack containing a battery stack including a plurality of battery cells in a box body.

Background technique

In the prior art, it is known that a stacked body obtained by stacking a plurality of battery cells is clamped and accommodated in a battery pack case having a lower case body and an upper case body by a pair of end plates from the stacking direction. in the battery pack. This kind of battery pack fixes the two ends of the battery stack on the lower box body by fixing the above-mentioned pair of end plates on the lower box body. Thus, in this structure, the cell stack is only supported by the end plates at both ends.

However, if the number of battery cells included in the battery stack is large, the amount of deflection of the battery stack is large and the natural frequency of vibration is low, so the battery stack tends to bend downward and easily resonate. In the prior art, in order to solve this problem, for example, by fixedly connecting all the battery cells contained in the battery stack to the lower case, or using fixing members for all the battery cells, the amount of deflection of the battery stack can be reduced and the battery life can be improved. The natural vibration frequency of the battery stack. However, the adoption of these methods brings problems of increased manufacturing cost and weight of the battery pack due to increased number of components and increased assembly man-hours.

In addition, in order to solve the above-mentioned problems, it is also conceivable, for example, to provide anti-vibration rubber between the battery stack and the lower case. However, in the case of such a structure, if the battery pack case does not have a sufficiently high rigidity, the reaction force exerted by the rubber on the battery pack case may cause the battery pack case to expand and deform, and the battery pack as a whole may be damaged. Bend downward. However, if the rigidity of the battery pack case is greatly increased, the manufacturing cost of the battery pack will be greatly increased, and the weight of the battery pack will be increased.

Utility model content

In order to solve the above technical problems, the purpose of this utility model is to provide a battery pack that can suppress the bending deformation of the battery pack and improve the anti-vibration performance of the battery pack without increasing the rigidity of the battery pack case itself.

As a technical solution to solve the above technical problems, the utility model provides a battery pack. The battery pack includes a battery stack and a battery pack case for accommodating the battery stack, the battery stack has a stacked body obtained by stacking a plurality of battery cells, and the stack is sandwiched from both ends along the stacking direction. A pair of end plates of the layer; the battery box has a lower case fixedly connected to the end plates to support both ends of the battery stack, and covers the battery supported by the lower case from above The upper box body of the stack is characterized in that: between the battery stack and the lower box body, between the battery stack and the upper box body, anti-vibration rubber is respectively arranged, and the battery pack box On the outer surface of the body, there is provided a reinforcing member extending in a direction perpendicular to the length direction of the battery pack case and tightening the lower case and the upper case.

The advantage of the battery pack of the present invention with the above structure is that, since anti-vibration rubbers are respectively provided between the battery stack and the lower box body, and between the battery stack and the upper box body, the bending deformation of the battery stack can be reduced. amount (deflection), and increase the natural vibration frequency of the battery stack to enhance the vibration resistance of the battery stack. In addition, since the reinforcing member for tightening the lower case and the upper case is provided, the expansion deformation of the battery pack case can be prevented without increasing the rigidity of the battery pack case itself, and the bending deformation of the entire battery pack can be suppressed. .

In the above-mentioned battery pack of the present invention, preferably, the anti-vibration rubber disposed between the battery stack and the lower case body, and the anti-vibration rubber disposed between the battery stack and the upper case body The position of the anti-vibration rubber in the length direction of the battery stack corresponds to the position. With this structure, the mechanical structure of the battery stack can be stabilized by providing anti-vibration rubber on the upper side and the lower side of the same position in the longitudinal direction of the battery stack, so that the bending deformation of the battery stack can be effectively suppressed, and the stability of the battery stack can be improved. Anti-vibration performance.

In the above-mentioned battery pack of the present invention, preferably, the reinforcing member corresponds to the position of the anti-vibration rubber in the length direction of the battery pack case. With this structure, by correspondingly arranging reinforcing members and anti-vibration rubber at the same position in the longitudinal direction of the battery pack case, the overall mechanical structure of the battery pack can be stabilized, thereby preventing the expansion of the battery pack case more effectively. Deformation, suppress the bending deformation of the battery pack as a whole, and improve the vibration resistance of the battery pack as a whole.

Description of drawings

FIG. 1 is a perspective perspective view showing a battery pack according to an embodiment.

Fig. 2 is a sectional view of plane A-A in Fig. 1 .

Fig. 3 is a perspective view showing only the connection structure of members for fixing the battery cell stack.

FIG. 4 is a schematic diagram showing a mechanical model of a battery stack.

FIG. 5 is a schematic diagram showing a mechanical model of the battery pack.

Detailed ways

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. However, this invention is not limited to description of following embodiment.

1 is a perspective perspective view showing a battery pack 1 according to this embodiment; FIG. 2 is a cross-sectional view taken along the A-A plane of FIG. 1; and FIG. The battery pack 1 is, for example, a battery device installed in a fuel cell hybrid vehicle, an electric vehicle, or the like. The battery pack 1 includes a battery stack 2 and a battery pack case 3 that accommodates the battery stack 2 .

As shown in FIG. 1 , the battery stack 2 includes a plurality of battery cells 4 , a plurality of battery racks 5 , a pair of end plates 6 , and an upper binding member 7 and a lower binding member 8 . The battery stack 2 is configured such that battery cells 4 and battery frames 5 are alternately stacked, and these stacked battery cells 4 and battery frames 5 (hereinafter also referred to as stacked body 9 ) are composed of a The end plates 6 disposed at both ends are sandwiched along the stacking direction (Y direction in FIG. 1 ). The plurality of battery cells 4 are electrically connected to each other by bus bars (not shown).

Specifically, the battery holder 5 is made of an electrically insulating resin material. A pair of end plates 6 are arranged at the front end and the rear end of the laminated body 9 parallel to the battery frame 5 and the battery cells 4 . In this state, on the top surface of the laminated body 9 along the stacking direction from the end plate 6 at the front end to the end plate 6 at the rear end, two upper side restraining members 7 at a predetermined interval, and the upper side binding member 7 on the laminated body On the bottom surface of 9, two lower binding members 8 extending from the end plate 6 at the front end to the end plate 6 at the rear end along the stacking direction sandwich the stacked body 9 from the vertical direction. And, as shown in FIG. 3, by fastening and connecting the front and rear ends of the upper side binding member 7 and the lower side binding member 8 corresponding up and down with the connecting member 31 and the connecting member 32 respectively, each battery rack of the laminated body 9 5 and the battery cells 4 are fastened vertically by the upper binding member 7 and the lower binding member 8 .

The battery case 3 has a lower case 10 and an upper case 11 . In FIG. 1 , in order to clearly show the components of the battery stack 2 , the upper case 11 is transparently shown. The lower case 10 is formed in a rectangular plate shape. The longitudinal direction of the lower case 10 is consistent with the stacking direction of the battery cells 4 . Legs 12 are mounted on the bottoms of both ends in the longitudinal direction of the lower box body 10 . The lower box body 10 is fixedly connected to the vehicle floor (not shown) through the legs 12 at both ends. Therefore, a gap whose height is the height of the leg 12 is formed between the bottom surface of the lower box body 10 and the surface of the vehicle floor.

A pair of end plates 6 of the battery stack 2 are respectively fixedly connected to the upper surface of the lower case body 10 by fastening members 13, and the fixed connection positions of the pair of end plates 6 are set such that the length of the lower case body 10 The center in the side direction coincides with the center in the stacking direction of the cell stack 2 . By fixing the pair of end plates 6 on the upper surface of the lower case body 10 in this way, the pair of end plates 6 supported by the lower case body 10 can maintain the laminated body 9 in a state suspended above the lower case body 10 .

On the other hand, the upper box body 11 has a rectangular top wall 14, side wall portions 15 extending downward from both side edges of the top wall 14, and flanges 16 respectively extending outward from the lower ends of the two side wall portions 15. . The battery stack 2 supported by the lower case 10 can be covered by the upper case 11 from above by joining the two flanges 16 to the edge portions on both sides of the lower case 10 respectively by means of welding or the like.

However, in this structure, since the amount of deflection δ _S (=5×w _S ×L _S ³ /(384×E _S ×I _S )) representing the degree of downward bending of the cell stack 2 is three times the length L _S The natural vibration frequency k _S (=48×E _S ×I _S /L _S ³ ) of the battery stack 2 is inversely proportional to the cube of the length L _S (here, w _S , L _S , E _S , I _S represents the weight, length, Young's modulus, and moment of inertia of the battery stack 2, respectively), so when the number of battery cells 4 is large (that is, the length L _S in the stacking direction of the battery stack 2 is long), , the deflection δ _S is larger and the natural vibration frequency k _S is lower. Therefore, if the stack 9 is supported only by the end plates 6 at both ends, the battery stack 2 is prone to bending deformation and resonance when the number of battery cells 4 is large.

In the prior art, in order to solve this problem, for example, all the battery cells 4 are fixedly connected to the lower box body 10, or all the battery cells 4 are fixed by fixing members, so as to suppress the bending deformation and resonance of the battery stack 2 . However, adopting these methods leads to an increase in the manufacturing cost and weight of the battery pack 1 due to an increase in the number of parts and assembly man-hours.

In this regard, in the battery pack 1 of the present embodiment, as shown in FIG. Anti-vibration rubber18. Furthermore, the anti-vibration rubber 17 and the anti-vibration rubber 18 correspond to the positions of the battery stack 2 in the stacking direction (longitudinal direction), and are located in the middle of the battery stack 2 in the longitudinal direction. Specifically, as shown in FIG. 2 , the anti-vibration rubber 17 is provided between the lower binding member 8 and the lower case 10 ; and the anti-vibration rubber 18 is provided between the upper binding member 7 and the upper case 11 .

In this way, by setting the anti-vibration rubber 17 and the anti-vibration rubber 18 at the middle part of the stacking direction of the battery stack 2, the middle part of the stacking direction of the battery stack 2 suspended on the lower case 10 is covered by the anti-vibration rubber 17 and the anti-vibration rubber 18. The vibrating rubber 18 is supported between the lower box body 10 and the upper box body 11 of the battery pack box body 3 . The load model of the battery stack 2 of this structure is shown in Figure 4, since the fulcrum of the battery stack 2 is changed from the original two (the end plate 6 at the front end and the end plate 6 at the rear end) to three (the anti-vibration rubber 17 is added and the fulcrum formed by the anti-vibration rubber 18), therefore, the battery stack 2 can be divided into two parts in the stacking direction, and the length and weight of each part are the length L _S and weight w _S of the battery stack 2 Calculate the deflection δ _S and natural vibration frequency k _S of each part by half of each. That is, the deflection amount δ _S (=5×(w _S /2)×(L _S /2) ³ /(384×E _S ×I _S )) of each portion is reduced to 1/16 of the original. The natural vibration frequency k _S (=48×E _S ×I _S /(L _S /2) ³ ) of each part increases to 8 times of the original. It can be seen that by arranging the anti-vibration rubber 17 and the anti-vibration rubber 18 in the middle of the stacking direction of the battery stack 2, the deflection δ _S of the battery stack 2 is greatly reduced, and the natural vibration frequency k _S of the battery stack 2 is greatly reduced. The rise, therefore, can effectively prevent bending deformation and resonance of the battery stack 2 .

However, in the above-mentioned structure, since the anti-vibration rubber 17 arranged between the battery stack 2 and the lower case body 10 and the anti-vibration rubber 18 arranged between the battery stack 2 and the upper case body 11 are opposite to the lower case body 10 and the lower case body 10 respectively The upper box body 11 exerts a reaction force, so the battery pack box body 3 may expand and deform, causing the anti-vibration rubbers 17, 18 to loosen or even fall off.

In addition, since the battery stack 2 and the lower box body 10, and between the battery stack 2 and the upper box body 11 are connected by anti-vibration rubber 17 and anti-vibration rubber 18, the battery stack 2 and the battery pack box body 3 are connected. into one. In this case, the deflection δ _P of the battery pack 1 as a whole is: δ _P =c1×w _P ×L _P ³ / _EP ×I _P ; the natural vibration frequency k _P is: k _P =c2×EP _× I _P /L _P ³ , where c1 and c2 are coefficients, w _P , L _P , _EP , and _IP are the weight, length, Young's modulus, and section moment of inertia of the battery box body 3, respectively, and _EP × _IP represents the rigidity of the battery box body 3 . It can be seen that, for the battery pack 1 as a whole, when the length _LP of the battery pack case 3 is long, if the rigidity ( _EP × I _P ) is not sufficiently high, the amount of deflection δ _P is still large. , The natural vibration frequency _kP is still low. However, if the rigidity ( _EP × _IP ) is greatly increased, the manufacturing cost and weight of the battery pack case 3 will be greatly increased.

In the battery pack 1 of the present embodiment, in order to solve this technical problem, on the outer surface of the battery pack case body 3, a set extending along the direction perpendicular to the length direction of the battery pack case body 3, facing the lower case body 10 and The upper box body 11 is provided with a reinforcing member 19 for tightening.

Specifically, as shown in FIG. 1 , the reinforcing member 19 is provided at a middle portion in the longitudinal direction of the battery pack case 3 . Since the center of the longitudinal direction of the battery pack box body 3 coincides with the center of the stacking direction of the battery stack 2, the reinforcing member 19 is connected to the anti-vibration rubber 17 arranged between the battery stack 2 and the lower box body 10, and the The position of the anti-vibration rubber 18 between the battery stack 2 and the upper case body 11 in the length direction of the battery pack case body 3 is corresponding.

As shown in FIG. 2 , the reinforcing member 19 includes a bottom member 20 , a top member 21 , and a pair of side members 22 . The bottom member 20, the top member 21, and the side members 22 are made of channel steel. The bottom surface member 20 is disposed in the middle of the longitudinal direction (Y direction in FIG. 1 ) of the bottom surface of the lower case 10 along the direction perpendicular to the longitudinal direction of the battery pack case 3 (the X direction in FIG. 1 ) (vibration-proof rubber 17), and the length is the same as the bottom width of the lower box body 10. The top surface member 21 is disposed in the middle of the longitudinal direction (Y direction in FIG. 1 ) of the top wall 14 of the upper case 11 along the direction perpendicular to the longitudinal direction of the battery pack case 3 (the X direction in FIG. 1 ). (just above the anti-vibration rubber 18), and its two ends protrude from both sides of the top wall 14 and are aligned with the two ends of the bottom surface member 20. In addition, a pair of side members 22 are arranged between the ends of the top member 21 and the end of the bottom member 20 along the Z direction of FIG. flange 16).

Then, by fixing the upper end of the side member 22 with the end of the top surface member 21 with such as fastening members such as bolts and nuts; As shown in FIG. 2 , the bottom member 20 , the top member 21 , and a pair of side members 22 are connected to form a square frame-shaped reinforcement member 19 that is tightly hooped around the battery box body 3 .

By setting the reinforcing member 19, the battery pack case 3 is fastened by the reinforcing member 19 in the height direction (Z) and the width direction (X), thus effectively preventing the vibration-proof rubber 17 from being damaged due to the expansion and deformation of the battery pack case 3. , 18 loose, fall off the situation occurs.

On the other hand, the deflection amount δ _P (=c1×w _P ×L _P ³ / _EP × _IP ) and the natural vibration frequency k _P (=c2×E _P ×I _P /L In the calculation of _P ³ ), since the battery stack 2 is only supported by the lower box body 10 before the reinforcing member 19 is installed, the cross-sectional moment of inertia _IP is the distance from the center of the battery stack 2 to the center of the thickness of the bottom plate of the lower box body 10 to calculate. After the reinforcement member 19 is installed, the overall load model of the battery pack 1 is shown in Figure 5. The battery stack 2 is jointly supported by the lower box body 10 and the upper box body 11, so the cross-sectional moment of inertia _IP is defined as the load from the bottom surface member 20 to the top box body. The distance to surface member 21 is calculated. Therefore, after the reinforcing member 19 is installed, the value of the section moment of inertia _IP increases greatly, so that the value of the deflection δ _P that is inversely proportional to the value of the section moment of inertia _IP decreases _; The value of the natural vibration frequency _kP increases in proportion to the value. Therefore, without increasing the rigidity (E _P × _IP ) of the battery pack case 3 itself, the purpose of reducing the amount of deflection δ _P and increasing the natural frequency k _P can also be achieved.

To sum up, with the above structure of this embodiment, it is possible to suppress the bending deformation of the battery pack 1 and improve the vibration resistance of the battery pack 1 without greatly increasing the manufacturing cost, weight, and assembly man-hours of the battery pack 1. .

In the above-mentioned embodiment, the example in which the reinforcing member 19 is provided in the middle of the battery pack box body 3; the anti-vibration rubber 17, 18 is provided in the middle of the battery stack 2 has been described, but the utility model is not limited thereto. Reinforcement members 19 and anti-vibration rubbers 17 and 18 may also be provided at other locations. In addition, reinforcement members 19 may also be provided at multiple locations of the battery pack case body 3 ; anti-vibration rubbers 17 and 18 may be provided at multiple locations of the battery stack 2 .

In addition, the structure of the reinforcement member 19 is not limited, as long as it is a structure that can apply a fastening force to the battery pack case 3 in the height direction of the battery pack case 3 .

Claims (3)

1. A battery pack, comprising a battery stack and a battery pack case for accommodating the battery stack, the battery stack has a stacked body obtained by stacking a plurality of battery cells, and clamps from both ends along the stacking direction A pair of end plates holding the laminated body; the battery pack box has a lower box that is fixedly connected to the end plates to support both ends of the battery stack, and covers and is supported by the lower box from above. The upper case of the battery stack is characterized in that: Between the battery stack and the lower box body, between the battery stack and the upper box body, anti-vibration rubber is respectively arranged, On the outer surface of the battery pack case, a reinforcing member extending in a direction perpendicular to the length direction of the battery pack case and tightening the lower case and the upper case is provided. 2. The battery pack according to claim 1, characterized in that: The anti-vibration rubber arranged between the battery stack and the lower box body, and the anti-vibration rubber arranged between the battery stack and the upper box body are arranged in the length direction of the battery stack corresponding to the position above. 3. The battery pack according to claim 2, characterized in that: The reinforcing member corresponds to the position of the anti-vibration rubber in the length direction of the battery pack case.