BACKGROUND

1. Field

The present disclosure relates to vehicle battery cooling devices and battery modules.

2. Description of the Related Art

A battery module for supplying power to a motor as a driving source is mounted on a hybrid vehicle or an electric vehicle. The battery module includes a battery pack comprised of a plurality of unit batteries. Thermal runaway (abnormal temperature increase) may occur in the unit battery provided in the battery pack due, for example, to a short circuit.

A battery device (battery module) designed to inject an incombustible cooling medium from a predetermined valve to a location exposed to the combustion gas generated from the unit battery accommodated in the case is known as a technology to cool the unit battery in which thermal runaway occurs (see, for example, patent literature 1).[Patent literature 1] JP2009-238654

In the battery device according to patent literature 1, the device may not be sufficiently cooled even when the cooling medium is injected into the interior of the case, if the unit battery in which thermal runaway occurs is remote from the valve that injects the cooling medium. It is conceivable to detect the position of the unit battery in which thermal runaway occurs and change the position or direction in which the cooling medium is injected. In this case, however, the setup may become complicated.

SUMMARY

The disclosure addresses the above-described issue, and a general purpose thereof is to provide a vehicle battery cooling device capable of cooling the entirety of the battery pack uniformly by means of a simple setup, when thermal runaway occurs in the unit battery in the battery pack.

An embodiment of the present disclosure relates to a vehicle battery cooling device adapted to cool a battery pack including a plurality of unit batteries. The vehicle battery cooling device includes: a case that contains a cooling fluid for cooling the battery pack; a pipe which runs inside the case and in which a cooling medium for cooling the cooling fluid is caused to flow; and a control valve that is provided in the pipe and discharges the cooling medium in the case in accordance with a temperature of the battery pack.

