Patent ID: 8998342
Filing Date: 2015-04-07
Classification: B60P

Abstract:
1. A conveyance vehicle comprising: an automotive vehicle body; a loading platform provided on said vehicle body for loading objects to be transported such that a front side is rotationally movable in upward and downward directions by using a rear side thereof as a fulcrum; a hoist cylinder to extend and contract between said loading platform and said vehicle body and to rotationally move said loading platform upward by extending the hoist cylinder; a hydraulic power source to supply pressurized oil to operate said hoist cylinder; a tank to supply oil to said hydraulic power source; a control valve device provided between said hydraulic power source and said hoist cylinder to control the supply and discharge of the pressurized oil to said hoist cylinder, where said control valve device has a plurality of switching positions including a neutral position to stop movement of said hoist cylinder, a raising position where said hoist cylinder is extended by the pressurized oil to rotationally move said loading platform upward, a lowering position where said hoist cylinder is contracted by the pressurized oil to rotationally move said loading platform downward, and a floating position where said hoist cylinder is contracted by discharging the pressurized oil by the weight of said loading platform to allow said loading platform to free fall; and a flow control valve provided between said control valve device and said tank to control a flow rate of the pressurized oil discharged from said hoist cylinder when said control valve device is at said floating position, wherein a first throttle is provided at said floating position of said control valve device, and a second throttle provided at said flow control valve is connected in series to said first throttle to control the flow rate of the pressurized oil when the pressurized oil flowing out through said floating position of said control valve device exceeds a predetermined pressure.