Patent ID: 6929296
Filing Date: 2005-08-16
Classification: B60R

Abstract:
1. A motor vehicle bumper system installed in a motor vehicle and using flow rate of oil circulating through an oil tank of the motor vehicle to control pressure and an accumulator to absorb energy upon receiving a bump, comprising: a. a bumper unit, said bumper unit comprising a bumper, and parallel hydraulic cylinders controlled to move said bumper between an extended position and a retracted position; b. a pressure-setup pipe unit connected between said hydraulic cylinders, and an oil tank of the motor vehicle, said pressure-set up pipe unit comprising an upper oil chamber connecting pipe connected between an upper oil chamber of said hydraulic cylinders for guiding the oil into said hydraulic cylinders to retract said bumper, a lower oil chamber connecting pipe connected between a lower oil chamber of said hydraulic cylinders for guiding the oil into said hydraulic cylinders to extend out said bumper, a direction control valve adapted to control the connection of said upper oil chamber connecting pipe and said lower oil chamber connecting pipe to a pump and the oil tank of the motor vehicle, a branch pipe extended from said lower oil chamber connecting pipe to the oil tank of the motor vehicle, a decompression valve installed in said branch pipe; and c. a pressure-relief pipe unit, said pressure-relief pipe unit comprising the accumulator, a hydraulic oil pressure sensor, a pipe having one end connected to said lower oil chamber connecting pipe and an opposite end connected to said hydraulic oil pressure sensor through said accumulator, and a relief valve installed in the pipe between said lower oil chamber connecting pipe and said accumulator; and d. wherein when a control switch means is switched on, said decompression valve and said relief valve are closed, a direction control valve is in action, and said pump is started to pump the oil to said hydraulic cylinders to extend out said bumper, and then said decompression valve and said relief valve are opened after said bumper has been extended out; when said control switch means is switched off, said decompression valve and said relief valve are closed, said direction control valve is reversed, enabling said hydraulic cylinders to retract said bumper.