On the principle of hydraulic lifting platform, using the foot switch control, when stepping on hydraulic pump, hydraulic platform, depressed when, what is under the control of the hydraulic cylinder pressure?
There is a very commonly used in oil overflow valve, its role is: regardless of the flow of oil, only to a certain pressure to open (internal spring, spring elastic adjustable), also have the effect of pressure.
Connected up button, hydraulic motor, discharge solenoid valve closed at this time, so the hydraulic oil cylinder filling to make uniform rise lifts, downward, control solenoid valve to open, due to the effect of gravity of the lifting platform, discharge of the hydraulic oil in the hydraulic cylinder, lifting table drop!
The hydraulic pump is always on standby when the hydraulic platform is working, and the oil pressure returns to the tank through the overflow valve. Pedal switch is a reverse valve:
When stepping down, the oil line to the left of the cylinder is connected, and the oil cylinder on the right side of the cylinder is returned to the oil and the platform rises. When lifting the foot, the oil line to the right of the oil cylinder is connected, and the oil cylinder on the left side of the cylinder is returned to the oil port and the platform drops. The commutator valve can be divided into several, such as: stop, positive, negative or positive. The above is the simplest of all, which can actually be used to implement sequential actions of multiple hydraulic cylinders through sequential valves, or more complex actions.
