TECHNICAL FIELD

The present invention relates to a support device for a vehicle battery pack mounted on an electric vehicle such as a full electric car and a hybrid electric car.

BACKGROUND ART

From a viewpoint of reducing environmental burdens, development of electric vehicles, such as full electric cars using a motor as a power source for propulsion in place of an internal combustion engine which used as an engine and hybrid electric cars using both an internal combustion engine and a motor, has been progressing. In such electric vehicles, a battery for driving the motor is mounted. Supplied with electricity from the battery, the motor generates power to move the vehicle.

In recent years, also in the field of commercial vehicles such as trucks, development of electric vehicles has been being promoted. For example, Patent Document 1 discloses a battery box holding structure for a commercial vehicle which provides improved collision safety.

CITATION LIST

Patent Document

[Patent Document 1] Japanese Patent Laid-Open No. 2016-113063

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

However, commercial vehicles, which are configured to carry cargo and large in size, have a great vehicle weight as compared with passenger cars. In the field of commercial vehicles having a great vehicle weight as compared with passenger cars, in order to put an electric vehicle with a sufficient travel range into practical use, increasing the battery on-board capacity of the electric vehicle is an important issue. Further, regarding the commercial vehicles which are likely to experience external force applied from a road surface and causing vibration, etc. during traveling, as compared with passenger cars, not only an increase in battery on-board capacity but also keeping reliability of batteries is required.

The present invention has been made in view of the above problem. An object of the present invention is to provide a support device for a vehicle battery pack configured to provide an increased battery on-board capacity for an electric vehicle, which can reduce the influence of external force, applied to the vehicle during traveling, upon the vehicle battery pack, thereby improving the reliability thereof.

Arrangement for Solving the Problem

(1) The vehicle battery pack support device according to the embodiment is intended for a vehicle battery pack comprising a first battery accommodating portion arranged in a first space between two side rails constituting a ladder frame of a vehicle, a second battery accommodating portion greater in vehicle-widthwise dimension than the first battery accommodating portion and connected to the first battery accommodating portion to be located in a second space vehicle-heightwise below the first space, and batteries held in the first and second battery accommodating portions. The support device comprises a frame-side bracket provided at a vehicle-widthwise outer surface of a web of a side rail of the ladder frame to project vehicle-widthwise outward, and a connecting member elastically connecting the second battery accommodating portion to the frame-side bracket to suspend the vehicle battery pack to the ladder frame.

The vehicle battery pack support device according to the embodiment enables the vehicle battery pack, configured to provide an increased battery on-board capacity, to be suspended to the ladder frame, elastically, by virtue of the connecting member. Thus, if, during traveling, an external force which may cause vibration, etc. in the ladder frame is applied from a road surface via wheels, the connecting member absorbs the external force, thereby reducing transmission of the external force to the vehicle battery pack. Since the influence of external force on the battery pack is reduced in this manner, the battery pack mounted on the vehicle has improved reliability. The vehicle battery pack support device according to the embodiment can thus reduce the influence of external force, applied to the vehicle during traveling, upon the battery pack configured to provide an increased battery on-board capacity for the vehicle, thereby improving the reliability thereof.

(2) The vehicle battery pack support device described in paragraph (1) above may further comprise a battery-side bracket provided at a vehicle-widthwise outer surface of the second battery accommodating portion to project vehicle-widthwise outward. The battery-side bracket helps firm and reliable attachment of the connecting member to the second battery accommodating portion, leading to improved reliability of the battery pack mounted on the vehicle.

(3) In the vehicle battery pack support device described in paragraph (2) above, the battery-side bracket may be provided in a manner avoiding a weld included in a housing composed of the first and second battery accommodating portions. When the support device is provided avoiding a weld which is relatively low in stiffness, the influence of external force transmitted via the battery-side bracket is reduced, leading to improved strength reliability of the battery housing. Accordingly, the battery pack is mounted with a decrease in reliability suppressed.

(4) In the vehicle battery pack support device described in paragraph (3) above, the battery-side bracket may be provided at a location away from a vehicle-longitudinal end of the housing. In this case, the influence of external force transmitted via the battery-side bracket is reduced, leading to improved strength reliability of the battery housing. Accordingly, the battery pack is mounted with a decrease in reliability suppressed.

(5) In the vehicle battery pack support device described in any of paragraphs (1) to (4) above, the frame-side bracket may be connected to the web of the side rail with an adjustment plate interposed between them for regulating the amount of projection from the side rail. In this case, the amount of projection of the frame-side bracket from the side rail can be regulated. Thus, if the vehicle-widthwise dimension of the second battery accommodating portion is changed, the connecting member can be arranged at an appropriate position by regulating the amount of projection of the frame-side bracket from the side rail, without the need to change the vehicle-widthwise dimensions of the frame-side and battery-side brackets. This eliminates the need to prepare a variety of frame-side and battery-side brackets different in size according to battery packs different in size, thus allowing standardization of components, leading to a reduction in cost related to supporting the battery pack.

