Battery pack

Abstract

The invention provides a battery pack which is provided with a counterweight for adjusting the weight of a vehicle and improves the carrying efficiency of a battery. A battery pack mounted on a vehicle includes a battery module and a counterweight. The counterweight includes a plurality of members opposed to the battery module. The plurality of members are arranged so as to constrain the movement of each other.

Description

Technical Field

[0001] This disclosure relates to a battery pack mounted in a vehicle. Background Technology

[0002] Patent document 1 discloses a battery pack whose weight can be adjusted without increasing the overall size of the battery pack.

[0003] Existing technical documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2017-191735

[0005] For vehicles (especially industrial vehicles) to operate continuously for extended periods, a certain battery capacity is required for the onboard battery. Furthermore, to ensure traction and prevent tipping caused by the weight of goods lifted by the forks, counterweights are sometimes needed for weight adjustment. This is particularly true when using lightweight batteries such as lithium-ion batteries, often employing weight adjustment components. However, this method of using counterweights for vehicle weight adjustment presents a challenge: the counterweights compress the battery mounting space, leading to reduced battery mounting efficiency. Summary of the Invention

[0006] One object of this disclosure is to provide a technique for improving battery loading efficiency in a battery pack having a counterweight for adjusting the weight of a vehicle.

[0007] The first point concerns the battery pack mounted in the vehicle.

[0008] The battery pack includes battery modules and counterweights.

[0009] The counterweight consists of several components that are positioned opposite the battery module.

[0010] Multiple components are configured to constrain each other's movement.

[0011] According to the first viewpoint, the counterweight consists of multiple components configured in a mutually constraining manner.

[0012] Therefore, the counterweights themselves act as a drag force against external impacts on the battery pack. This allows for a reduction in the thickness of the battery casing used to protect the batteries. A thinner battery casing means more internal space, which helps improve the battery pack's battery carrying capacity. Furthermore, a thinner battery casing leads to reductions in material and manufacturing costs. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a vehicle equipped with a battery pack.

[0014] Figure 2 It is a 3D view of the battery pack.

[0015] Figure 3 This is an XY top view used to illustrate the structure of the counterweight.

[0016] Figure 4 This is a diagram representing a comparative example.

[0017] Figure 5 This is an XY top view showing the first modified example of the battery pack.

[0018] Figure 6 This is a schematic diagram showing a second modified example of the battery pack.

[0019] The annotations in the attached figures are explained as follows:

[0020] 1: Battery pack, 10: Vehicle, 20: Battery module, 30: Battery casing, 40: Counterweight, 41: First component, 41A: Cutout, 41B: Cutout, 42: Second component, 43: Third component, 43A: Cutout, 43B: Cutout, 44: Fourth component, 50: Fastener, G: Gap. Detailed Implementation

[0021] The embodiments of this disclosure will be described with reference to the accompanying drawings.

[0022] 1. Basic Structure

[0023] Figure 1 This is a schematic diagram of a vehicle 10 equipped with a battery pack 1. The power source for the vehicle 10 is electricity supplied from the battery pack 1. The type of vehicle 10 is not particularly limited, but as explained in this embodiment, an electric industrial work vehicle (loading and unloading vehicle such as a forklift, tractor, etc.) is particularly preferred. To enable the vehicle 10 to operate continuously for extended periods, the battery pack 1 requires a certain battery capacity. Furthermore, to ensure traction and prevent tipping caused by the weight of goods lifted by the forks, a weight adjustment component (counterweight) is sometimes needed in the vehicle 10. Especially when using lightweight batteries such as lithium-ion batteries as the vehicle's battery, the method of equipping the vehicle with a weight adjustment component is frequently employed.

[0024] In the attached diagram, the X direction represents the direction in which vehicle 10 moves forward, the Z direction represents the upward direction of vehicle 10, and the Y direction represents the rightward direction as observed from the passenger in vehicle 10. Figure 1 The middle indicates the inside of the paper.

[0025] Figure 2 This is a perspective view of battery pack 1. Battery pack 1 includes a battery module 20 composed of multiple stacked battery cells and a counterweight 40. The battery cells are rechargeable secondary batteries, such as lithium-ion secondary batteries. Battery module 20 is typically disposed within battery housing 30 (in... Figure 1(Diagram shown in dashed lines). In this embodiment, the counterweight 40 is disposed between the battery module 20 and the battery casing 30. Typical materials for the counterweight 40 and the battery casing 30 include metals such as steel.

[0026] Figure 3 This is an XY top view used to illustrate the structure of the counterweight 40. The counterweight 40 includes multiple components opposite to the battery module 20. These components are configured in a mutually constrained manner. Figure 3 In this example, the counterweight 40 includes a first component 41, a second component 42, a third component 43, and a fourth component 44 as multiple components. The first component 41 has a cutout portion 41A. The cutout portion 41A includes cut surfaces 41a and 41b. The cut surfaces 41a and 41b are adjacent to each other, and the angle they form is approximately a right angle. The second component 42 is fitted into the cutout portion 41A. At this time, the first end 42a of the second component 42 is arranged in contact with the cut surfaces 41a and 41b of the first component 41.

[0027] Consider the case where forces (impacts) F1 and F2 are applied to the battery pack 1 toward the inside of the battery pack 1. For force F1, resistance is generated by the mutual compression between the cut surface 41a and the first end 42a of the second component 42. Similarly, for force F2, resistance is generated by the mutual compression between the cut surface 41b and the first end 42a of the second component 42. That is, the first component 41 and the second component 42 constituting the counterweight 40 are arranged in a mutually constrained manner, thereby the counterweight 40 itself exerts resistance relative to the forces F1 and F2 toward the inside of the battery pack 1.

[0028] exist Figure 3 In the example, the second component 42 and the third component 43 are further constrained to each other. The structure of the third component 43 is the same as that of the first component 41. That is, the third component 43 has a cut portion 43A. The cut portion 43A includes cut surfaces 43a and 43b. The cut surfaces 43a and 43b are adjacent to each other, and the angle they form is approximately a right angle. The second component 42 not only engages with the cut portion 41A of the first component 41, but also engages with the cut portion 43A of the third component 43.

[0029] At this time, the second end 42b of the second component 42 is configured to contact the cut surfaces 43a and 43b of the third component 43.

[0030] In this case, the second component 42 is constrained not only by the cutout 41A of the first component 41, but also by the cutout 43A of the third component 43. Therefore, the resistance to force F2 is greater than when the second component 42 is only engaged with the first component 41. In addition, for force F3, resistance is also generated by the mutual compression between the cutout surface 43a and the second end 42b of the second component 42.

[0031] The first component 41 and the third component 43 may also have further cutouts 41B and 43B. Figure 3 In this configuration, the first component 41 has a cutout portion 41B in addition to the cutout portion 41A, and the third component 43 has a cutout portion 43B in addition to the cutout portion 43A. The fourth component 44 is configured to fit into the cutout portions 41B and 43B. That is, the first end portion 44a of the fourth component 44 contacts the cutout surfaces 41c and 41d, and the second end portion 44b of the fourth component 44 contacts the cutout surfaces 43c and 43d. Therefore, the fourth component 44 is constrained by both the first component 41 and the third component 43 relative to the force F4. With this structure, the counterweight 40 itself can provide resistance to any of the forces F1 to F4 applied externally to the battery pack 1.

[0032] <Effect>

[0033] As described above, the multiple components of the counterweight 40 are arranged in a mutually constraining manner. Thus, the counterweight 40 itself acts as a drag force against external impacts on the battery pack 1.

[0034] As a comparative example, such as Figure 4 As shown, consider the case where none of the components included in the counterweight 40 have cutouts. In this case, the counterweight 40 itself provides resistance to forces F1 and F3, but relative to forces F2 and F4, the second component 42 and the fourth component 44 are not constrained by other components, therefore the counterweight 40 does not provide resistance. In such a structure, to increase resistance to external impacts, it is necessary to increase the thickness of the battery casing 30, and to use special high-strength materials for the battery casing 30, etc.

[0035] On the other hand, in the battery pack 1 of this embodiment, since the counterweight 40 itself has resistance to impact, the required strength of the battery casing 30 is relatively small. As a result, the battery pack 1 can have a thinner battery casing 30 compared to the comparative example. A thinner battery casing 30 means an increase in the space (internal dimensions) for the battery module 20 that can house the battery casing 30. This helps to improve the battery carrying efficiency of the battery pack 1. In addition, the thinner battery casing 30 leads to a reduction in material costs and processing costs.

[0036] 2. Variations

[0037] <First Variation>

[0038] Figure 5 This is an XY top view showing a first modified example of battery pack 1. Figure 5In this design, a gap G is provided between the counterweight 40 and the battery module 20. Specifically, gaps G are provided between the battery module 20 and the first component 41, and between the battery module 20 and the third component 43. The gap G prevents the direct transmission of impact to the battery module 20 when impacts are applied to the first component 41 or the third component 43. That is, since the first component 41 and the third component 43 have room for deformation, they can absorb a large amount of impact energy through deformation. The size of the gap G is determined by calculating the assumed deflection based on the assumed magnitude of the impact, the material of the counterweight 40, and its dimensions.

[0039] The clearance G is preferably configured along the side direction (along the X direction) of the vehicle 10. In the case of industrial vehicles such as forklifts, various machines and equipment are mounted in the front-rear direction of the vehicle 10, which act as a collision barrier to absorb impacts. On the other hand, the side direction of the vehicle 10 usually lacks a protective barrier structure for the convenience of operators to enter and exit. Therefore, a mechanism with clearance G is particularly effective as a defense against impacts applied to the side of the vehicle 10.

[0040] <Second Variation>

[0041] Figure 6 This is a schematic diagram showing a second modified example of battery pack 1. Figure 6 In this configuration, the counterweight 40 is fastened to the battery module 20. Specifically, the fourth component 44 is fastened to the battery module 20. For stable mounting of the battery module 20, it is preferable to fasten the battery module 20 to the counterweight 40. For example, both are... Figure 6 As shown, the counterweight 40 is mechanically fastened via fastener 50 (in this case, an L-shaped bracket). Alternatively, the counterweight 40 can be directly fastened to the battery module 20 without using fastener 50. Here, fastening the battery module 20 to the counterweight 40 means that impacts applied to the fastened portion are transmitted to the battery module 20 via fastener 50. Therefore, for the same reasons as in the first variation described above, it is preferable that the fastener 50 is positioned in the direction corresponding to the longitudinal direction of the vehicle 10 equipped with a large number of energy-absorbing structures.

[0042] <Other>

[0043] The first and second modifications can also be used in combination. In this case, based on the reasons stated above, it is preferable that the gap G is arranged along the side of the vehicle body 10, and the fastener 50 is preferably provided in a direction corresponding to the front-rear direction of the vehicle 10.

[0044] The shape of the counterweight 40 is not limited to the shape described herein. For example, the thickness and height of the multiple components included in the counterweight 40 are not particularly limited. In addition, the bottom portion and the side portion intersecting with the bottom portion of the counterweight 40 can be formed integrally or separately.

Claims

1. A battery pack, mounted in a vehicle, wherein, The battery pack includes battery modules and counterweights. The counterweight includes a plurality of components opposite the battery module, the plurality of components being configured in a manner that constrains the movement of each other.

2. The battery pack according to claim 1, wherein, The plurality of components includes a first component and a second component. The first component has a cutout. The second component is configured to engage with the cutout portion of the first component.

3. The battery pack according to claim 1, wherein, At least a portion of the space between the counterweight and the battery module is provided with a gap.

4. The battery pack according to claim 1, wherein, The counterweight is fastened to the battery module.

5. The battery pack according to any one of claims 1 to 4, wherein, A gap is provided between the counterweight and the battery module, along the side of the vehicle. The counterweight is fastened to the battery module in a direction corresponding to the longitudinal direction of the vehicle.

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