Battery pack

Abstract

To improve mounting efficiency of a battery in a battery pack having a weight for adjusting vehicle weight.SOLUTION: A battery pack mounted on a vehicle includes a battery module and a weight. The weight includes a plurality of members facing the battery module. The plurality of members are arranged to constrain movement of each other.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a battery pack installed in a vehicle. [Background technology]

[0002] Patent Document 1 discloses a battery pack that can adjust the weight without increasing the size of the entire battery pack. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-191735 Summary of the Invention [Problem to be solved by the invention]

[0004] In order for vehicles (especially industrial work vehicles) to continue operating for long periods of time, the batteries installed on board are required to have a certain level of battery capacity. Weight adjustment weights may also be required to ensure traction and prevent the vehicle from tipping over due to the weight of the load scooped up by the forks. In particular, when lightweight batteries such as lithium-ion batteries are used as on-board batteries, a method of installing weight adjustment components is often used. However, installing weights to adjust the vehicle weight poses the problem of the weight taking up space for the battery, reducing battery installation efficiency.

[0005] One object of the present disclosure is to provide a technology for improving the battery mounting efficiency in a battery pack that includes a weight for adjusting the vehicle weight. [Means for solving the problem]

[0006] The first aspect relates to a battery pack mounted on a vehicle. The battery pack includes a battery module and a weight. The weight includes a plurality of members that face the battery module. The members are arranged to restrict movement of one another. [Effects of the Invention]

[0007] According to the first aspect, the multiple members included in the weight are arranged so as to constrain one another. This allows the weight itself to exert resistance against external impacts on the battery pack. This allows the thickness of the battery case used to protect the battery to be reduced. A thinner battery case means more space within the battery case. This contributes to improving the battery mounting efficiency of the battery pack. Furthermore, a thinner battery case leads to reduced material and processing costs for the battery case itself. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of a vehicle equipped with a battery pack. [Figure 2] FIG. 2 is a perspective view of the battery pack. [Figure 3] FIG. 2 is an XY plan view for explaining the configuration of the weight. [Figure 4] FIG. [Figure 5] FIG. 10 is an XY plan view showing a first modified example of the battery pack. [Figure 6] FIG. 10 is a schematic diagram showing a second modified example of the battery pack. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0010] 1.Basic configuration FIG. 1 is a schematic diagram of a vehicle 10 equipped with a battery pack 1. The power source of the vehicle 10 is electricity supplied from the battery pack 1. There are no particular limitations on the type of vehicle 10, but as described in this embodiment, an electric industrial work vehicle (a loading vehicle such as a forklift, a towing vehicle, etc.) is particularly suitable. In order for the vehicle 10 to continue working for a long period of time, the battery pack 1 is required to have a certain level of battery capacity. Furthermore, the vehicle 10 may require a member (weight) for adjusting its weight to ensure tractive force and to prevent it from tipping over due to the weight of a load scooped up by the forks. In particular, when a lightweight battery such as a lithium-ion battery is used as the on-board battery, a method of installing a member for adjusting the weight is often used.

[0011] Here, the X direction in the attached drawings indicates the direction in which the vehicle 10 moves forward, the Z direction indicates the upward direction of the vehicle 10, and the Y direction indicates the right direction as seen by the occupant of the vehicle 10, i.e., the direction into the paper in Figure 1.

[0012] FIG. 2 is a perspective view of the battery pack 1. The battery pack 1 includes a battery module 20 configured by stacking a plurality of battery cells, and a weight 40. The battery cells are rechargeable secondary batteries, such as lithium-ion secondary batteries. The battery module 20 is typically disposed within a battery case 30 (shown by the dashed line in FIG. 1). In this embodiment, the weight 40 is disposed between the battery module 20 and the battery case 30. A typical example of the material for the weight 40 and the battery case 30 is a metal such as steel.

[0013] FIG. 3 is an XY plan view illustrating the configuration of the weight 40. The weight 40 includes multiple members facing the battery module 20. The multiple members are arranged to constrain one another. In the example of FIG. 3, the weight 40 includes multiple members: a first member 41, a second member 42, a third member 43, and a fourth member 44. The first member 41 has a cutout portion 41A. The cutout portion 41A includes cutout surfaces 41a and 41b. The cutout surfaces 41a and 41b are adjacent to each other and form a substantially right angle. The second member 42 is engaged with the cutout portion 41A. At this time, a first end portion 42a of the second member 42 is arranged to contact the cutout surfaces 41a and 41b of the first member 41.

[0014] Consider a case where forces (impacts) F1 and F2 are applied to the battery pack 1 inward. Resistance to force F1 is generated when the notched surface 41a and the first end 42a of the second member 42 press against each other. Resistance to force F2 is generated when the notched surface 41b and the first end 42a of the second member 42 press against each other. In other words, the first member 41 and the second member 42 that constitute weight 40 are arranged so as to constrain each other, and weight 40 itself exerts resistance to the forces F1 and F2 that act inward toward the battery pack 1.

[0015] In the example of FIG. 3, the second member 42 and the third member 43 are further constrained to each other. The configuration of the third member 43 is similar to that of the first member 41. That is, the third member 43 has a notch portion 43A. The notch portion 43A includes notch surfaces 43a and 43b. The notch surfaces 43a and 43b are adjacent to each other and form a substantially right angle. The second member 42 is engaged with the notch portion 41A of the first member 41 as well as the notch portion 43A of the third member 43. At this time, the second end portion 42b of the second member 42 is positioned so as to contact the notch surfaces 43a and 43b of the third member 43.

[0016] In this case, the second member 42 is constrained by the notch 41A of the first member 41 as well as the notch 43A of the third member 43. Therefore, the resistance to force F2 is greater than when the second member 42 is engaged only with the first member 41. Furthermore, a resistance to force F3 is also generated as the notch surface 43a and the second end 42b of the second member 42 press against each other.

[0017] The first member 41 and the third member 43 may further include notches 41B and 43B. In the case of FIG. 3, the first member 41 includes notch 41B in addition to notch 41A, and the third member 43 includes notch 43B in addition to notch 43A. The fourth member 44 is disposed to engage with notches 41B and 43B. That is, the first end 44a of the fourth member 44 contacts notch surfaces 41c and 41d, and the second end 44b of the fourth member 44 contacts notch surfaces 43c and 43d, respectively. Therefore, the fourth member 44 is restrained by both the first member 41 and the third member 43 against force F4. With this configuration, the weight 40 itself can exert resistance to any of forces F1 to F4 applied externally to the battery pack 1.

[0018] <Effects> As described above, the multiple members included in weight 40 are arranged to constrain one another, so that weight 40 itself exerts resistance to external impacts on battery pack 1.

[0019] As a comparative example, consider a case where none of the multiple members included in weight 40 have a notch, as shown in Figure 4. In this case, weight 40 itself exerts resistance to forces F1 and F3, but weight 40 does not exert resistance to forces F2 and F4 because second member 42 and fourth member 44 are not constrained by other members. In this configuration, in order to increase resistance to external impacts, it is necessary to take measures such as increasing the thickness of battery case 30 or using a special high-strength material for battery case 30.

[0020] On the other hand, in the battery pack 1 according to the present embodiment, the weight 40 itself has resistance to impact, so less strength is required of the battery case 30. As a result, the thickness of the battery case 30 in the battery pack 1 can be made thinner than in the comparative example. A thinner battery case 30 means that the space (internal dimensions) in which the battery module 20 can be mounted in the battery case 30 increases. This contributes to improving the battery mounting efficiency of the battery pack 1. Furthermore, a thinner battery case 30 leads to reduced material and processing costs for the battery case 30.

[0021] 2. Variations <First Modification> FIG. 5 is an XY plan view showing a first modified example of the battery pack 1. In FIG. 5, a gap G is provided in a portion between the weight 40 and the battery module 20. Specifically, the gap G is provided between the battery module 20 and the first member 41 and between the battery module 20 and the third member 43. When an impact is applied to the first member 41 or the third member 43, the gap G prevents the impact from being directly transmitted to the battery module 20. In other words, since the first member 41 and the third member 43 have room to deform, they can absorb large impact energy through deformation. The size of the gap G is determined by calculating the expected amount of deflection based on the expected magnitude of the impact and the material and dimensions of the weight 40.

[0022] It is preferable that the gap G be disposed along the side direction of the vehicle 10 (along the X direction). In the case of an industrial vehicle such as a forklift, various devices and equipment are mounted in the front-to-rear direction of the vehicle 10, which act as barriers to absorb impacts. On the other hand, there are generally few barriers along the side direction of the vehicle 10 to make it easier for workers to get on and off. For this reason, a mechanism including the gap G is particularly effective as a defense against impacts applied to the side of the vehicle 10.

[0023] <Second Modification> FIG. 6 is a schematic diagram showing a second modified example of the battery pack 1. In FIG. 6, the weight 40 and the battery module 20 are fastened together. Specifically, the fourth member 44 and the battery module 20 are fastened together. To stably install the battery module 20, it is desirable to fasten the battery module 20 and the weight 40 together. For example, as shown in FIG. 6, the two are mechanically fastened together via a fastener 50 (here, an L-shaped bracket). Alternatively, the weight 40 itself may be fastened directly to the battery module 20 without using a separate fastener 50. Here, fastening the battery module 20 and the weight 40 together means that an impact applied to the fastened portion is transmitted to the battery module 20 via the fastener 50. Therefore, for the same reason as in the first modified example described above, it is desirable to install the fastener 50 in a direction opposite to the longitudinal direction of the vehicle 10, which is equipped with many energy absorbing elements.

[0024] <Other> The first and second modified examples may be applied in combination. In this case, for the reasons described above, it is preferable that the gap G be disposed along the side surface of the vehicle body of the vehicle 10, and the fastener 50 be installed in a direction opposite to the longitudinal direction of the vehicle 10.

[0025] The shape of weight 40 is not limited to the shapes described above. For example, there are no particular limitations on the thickness or height of the multiple members included in weight 40. Furthermore, the bottom surface portion of weight 40 and the side surface portion intersecting with the bottom surface portion may be formed integrally or separately. [Explanation of symbols]

[0026] 1: Battery pack 10: Vehicle 20: Battery module 30: Battery case 40: Weight 41: First member 41A: Notch 41B: Notch 42: Second member 43: Third member 43A: Notch 43B: Notch 44: Fourth member 50: Fastener G: air gap

Claims

1. A battery pack to be mounted on a vehicle, A battery module; Weight and Equipped with The weight is a plurality of members facing the battery module; The plurality of members include: positioned to restrict each other's movement Battery pack.

2. 2. The battery pack according to claim 1, the plurality of members includes a first member and a second member, the first member includes a notch; The second member is disposed so as to fit into the notch of the first member. Battery pack.

3. 2. The battery pack according to claim 1, A gap is provided at least partially between the weight and the battery module. Battery pack.

4. 2. The battery pack according to claim 1, The weight and the battery module are fastened together. Battery pack.

5. 5. The battery pack according to claim 1, a gap is provided between the weight and the battery module in a direction along the side surface of the vehicle; The weight and the battery module are fastened in opposing directions in the front-rear direction of the vehicle. Battery pack.

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