What are the steps of structural design of hydraulic system of dump truck?

The lifting method is not the same, the algorithm is not the same, generally according to the principle of moment balance, pay attention to check the lifting to the maximum angle when the goods are not unloaded.

The hydraulic oil is formed by the vane pump to form a cracked pressure, through the oil filter, explosion-proof electromagnetic reversing valve, throttle valve, hydraulic control check valve, balance valve into the lower end of the cylinder, so that the piston of the cylinder moves upward, lifting the weight, the upper end of the cylinder oil return through the explosion-proof electromagnetic spine change hail closed valve back to the oil tank, its rated pressure is adjusted through the relief valve.

The piston of the cylinder moves downward (i.e., the weight is lowered). The hydraulic oil enters the upper end of the hydraulic cylinder through the explosion-proof electromagnetic reversing valve, and the oil return at the lower end of the hydraulic cylinder returns to the oil tank through the balance valve, the hydraulic check valve, the throttle valve, and the explosion-proof electromagnetic reversing valve.

In order to make the heavy object descend smoothly and brake safely and reliably, a balance valve is set on the oil return road to balance the circuit and maintain the pressure, so that the descending speed is not changed by the heavy object, and the flow rate is adjusted by the throttle flow valve to control the lifting speed.

1. Lifting state.

When lifting the body, we need to turn the pneumatic valve to the left to the lifting position, connect the system air pressure and the pneumatic valve lifting channel, and the system air pressure flows through the pneumatic valve through the limit valve from the lifting interface into the inside of the hungry lead call lifting valve.

Act on the cylinder piston, promote the piston to move to the left, and drive the valve core to move to the left, connect the oil pump interface with the lifting cylinder interface, and the high-pressure oil enters the oil cylinder and jacks up the oil cylinder; If the lifting pressure is too high, the bypass relief valve will be opened to prevent the continuous rise of pressure and damage to the gear pump and pipeline;

2. Descending state.

When we need to lower the body, we need to turn the pneumatic control valve to the right to the descending position, connect the system air pressure and the pneumatic control valve descending channel, the system air pressure enters the lifting valve from the descending interface through the pneumatic control valve, acts on the piston, pushes the piston to move to the right, and drives the valve core to move to the right, connects the lifting cylinder interface with the oil return interface, and the high-pressure oil in the oil cylinder flows back to the oil tank and is filtered by the oil return filter;

3. Stop-in state.

Whether we are lifting or descending, we can stop the movement of the cylinder at any time. As soon as we turn the pneumatic valve to the intermediate stop position, the compressed air acting on the piston in the lift valve is discharged from the exhaust port of the pneumatic valve.

Then the valve core returns to the middle position under the action of spring elasticity, cuts off the connection between the oil cylinder interface and other interfaces, and the high-pressure oil in the oil cylinder stops flowing in or out, and the oil cylinder piston is in a stationary state, the said middle stop state;

The automatic dumping box of the dump truck is realized by a special lifting mechanism. At present, on large-tonnage dump trucks, hydraulic lifting and tilting mechanisms are widely used. It is mainly composed of lifting cylinder, control valve, lifting control valve, limit valve and lifting oil pump.

The lifting of the tilting mechanism is completed by the lifting of the lifting cylinder. The work of the lifting dumping cylinder is controlled by the control valve, and the control valve is operated by the driver, in order to limit the maximum inclination angle of the cargo box, and make the cargo box be stable in a certain inclined position according to the need, a limit valve is set in the hydraulic system. On some dump trucks with hydraulic steering power assist device, because the tilting mechanism is only used in the case of stopping, the steering oil pump and the dumping oil pump are also used to pump oil for the hydraulic system of the tilting mechanism together, so as to obtain more working oil flow.

When lifting, cut off the passage between the steering oil pump and the steering afterburner, so that the oil output by the steering oil pump is also used for the tilting cylinder through the afterburner valve.

Simple, the oil pump provides power, the oil pipe is connected to both ends of the oil cylinder, when working, one oil pipe feeds oil, pushes the cylinder piston to one side to move, and the other oil pipe returns the oil, when reverse, the direction of the hydraulic oil flow of the two oil pipes is opposite, the oil inlet pipe becomes the oil return pipe, and the direction is reversed with a solenoid valve.

There is a transfer case next to the gearbox that drives an oil pump, and the oil pump is transmitted to the oil cylinder through the oil pipe, and there is an operating valve to control it

This question has been answered many times, simply put, it is that the power take-off is engaged, so that the gear pump rotates to provide hydraulic oil output; The manual control valve controls the air circuit so that the pneumatic control reversing valve is from the middle stop station to the lifting station, and the hydraulic oil is entered into the lower cavity of the cylinder to realize the lifting and unloading, and the goods are unloaded after reaching the limit height, and the gas path of the limit valve is opened, so that the reversing valve returns to the middle stop station; The manual control valve is moved to the lowering station, and the hydraulic oil in the lower chamber of the cylinder returns to the oil tank through the reversing valve, so that the cylinder is lowered, and there are two forms: fast descent and slow descent.

1.When lifting the body, we need to turn the pneumatic valve to the left to the lifting position, connect the system air pressure and the pneumatic valve lifting channel, and the system air pressure flows through the pneumatic valve through the limit valve from the lifting interface into the inside of the lifting valve. Acting on the cylinder piston, pushing the piston to the left, and driving the valve core to move to the left, will.

2.Descending state When it is time to lower the body, we need to turn the air control valve to the right to the descending position, connect the system air pressure and the Exciting air control valve down channel, and the system air bench lead pressure enters through the air control valve from the descending interface.

3.Stopped state: Regardless of whether it is being lifted.