Supercharging device for a vehicle and method for controlling the same

摘要

A supercharging device for a vehicle engine for use in a construction machine which has good acceleration performance, which is small in size but provides high output and which provides good engine braking performance and a method for controlling the device. In a vehicle engine equipped with a mechanical supercharger adapted to be driven by the output of the engine through mechanical means, the supercharging device comprises a differential planetary gear device (10) connected to the engine (1) and having a differential limiting means (L) for distributing the power of the engine to the mechanical supercharger (40) and to vehicle running and the mechanical supercharger (40) adapted to be driven via the differential planetary gear device (10). In a case where the vehicle starts from a stop position, when the vehicle still remains in the stopped state, the whole output of the engine (1) is accelerated by the differential planetary gear device (10) and outputted to the mechanical supercharger (40) so as to keep it rotating by applying a brake (36) on a driving force transmission system (20) of the vehicle and the brake (36) is released when a command for start is given, and the engine output is distributed to the mechanical supercharger (40) and to vehicle running by means of the differential planetary gear device (10), whereby the vehicle is started and then accelerated. Disclosed is a supercharging device for a vehicle engine, for use in construction machines, etc., that has high acceleration performance, that is compactly made but provides high output, and that provides good engine braking efficiency, and a method for controlling such a supercharging device. A vehicle engine of the present invention, on which is mounted a mechanical supercharger that is driven by mechanical means using an output of the engine, comprises: a differential planetary gear device (10), which is connected to the vehicle engine (1) and which has differential limiting means (L) for distributing power that is produced by the vehicle engine for driving a mechanical supercharger (40) and for driving; and the mechanical supercharger (40), which is to be driven by the differential planetary gear device (10). When a vehicle is at a halt and when the vehicle is to move, a brake (36) is applied to a power transmission system (200 of the vehicle to increase total power output by the engine (1) by using the differential planetary gear device (10); the power output is directed to the mechanical supercharger (40) to rotate the mechanical supercharger (40); the brake (36) is released upon receipt of a start command; the engine power output is distributed by the differential planetary gear device (10) for driving the mechanical supercharger (40) and