JP2012136170A5 - - Google Patents

Claims (2)

In a loading platform lifting device that supports loading and unloading work on a loading platform of a vehicle,
A guide rail attached to the lower part of the vehicle;
A slider that can travel along this guide rail;
An arm connected to the slider;
A receiving platform connected to the arm;
A lift cylinder that drives the arm to raise and lower the load receiving table;
A hydraulic pump;
A lift cylinder control valve for controlling the flow of pressure oil from the hydraulic pump to the lift cylinder;
A main relief valve that regulates the maximum value of pressure oil in the discharge line of the hydraulic pump;
A sub-relief valve that regulates the maximum value of pressure oil in the discharge pipe to a value lower than the relief pressure of the main relief valve;
A load receiving table elevating device comprising: a switching valve for communicating or blocking the flow of pressure oil to the sub relief valve. The load receiving table lifting device according to claim 1,
A slide cylinder for moving the slider along the guide rail;
A storage sensor for detecting that the slider is in a storage position;
A slide cylinder control valve that controls the flow of pressure oil from the hydraulic pump to the slide cylinder;
A control device for controlling the lift cylinder control valve, the slide cylinder control valve and the switching valve;
At the time of storing operation of the consignment table, the control device
When it is detected that the slider has reached the storage position based on a signal from the storage sensor, the switching valve is opened, and the maximum pressure of the lift cylinder circuit is increased from the relief pressure of the main relief valve to the sub-relief valve. The load receiving platform lifting device is characterized in that the slide cylinder is stopped and the lift cylinder is driven to raise the load receiving platform to a retracted posture.