The hydraulic system of the working device consists of a system oil tank, a working oil pump, a multi-way directional control valve (distribution valve), a lift cylinder, a side-tilt cylinder, oil pipe joints, etc. During the operation of the bucket, the working oil pump draws oil from the oil tank and then changes the direction of the oil flow through the multi-way directional control valve to control the movement direction of the lift cylinder and the side-tilt cylinder, thus meeting the requirements of various operation actions.
When the lifting control lever and the side-tilt control lever in the driver's cab are both in the middle position, the lift slide valve and the side-tilt slide valve of the multi-way control valve are in the closed position. The oil from the working oil pump directly returns to the oil tank through the multi-way valve. This is the non-working state.
When the lifting control lever is moved to the lifting (lowering) position, the soft shaft controls the lift slide valve to move to the right (left) to the working position. The oil pump's oil pushes open the one-way valve and enters the small cavity (large cavity) of the lifting cylinder through the inlet of the multi-way valve, thereby pushing the piston rod to move back and forth and achieving the lifting or lowering of the bucket. Finally, the hydraulic oil flows from the large cavity (small cavity) of the lifting cylinder through the multi-way valve back to the oil tank.
When the lifting control lever is in the floating position, the lift slide valve is at the leftmost end of the control valve. At this time, the inlet and outlet of the oil passage are connected, so the large and small cavities of the lifting cylinder are connected and are in a low-pressure state. The cylinder is in a free-floating state due to the weight of the working device and the ground force.
Similarly: When the side-tilt control lever is moved to the left (right) tilt position, the side-tilt slide valve moves to the left (right). The hydraulic oil pushes open the one-way valve and enters the large cavity (small cavity) of the side-tilt cylinder through the inlet of the multi-way valve, pushing the piston rod to extend and retract, thereby achieving the left (right) tilt of the bucket. Finally, the hydraulic oil flows from the small cavity (large cavity) of the side-tilt cylinder through the multi-way valve back to the oil tank.
The lift of the bucket is achieved by the extension and retraction of the lifting cylinder. The process is very clear. By the repeated extension and retraction of the side-tilt cylinder, the successful movement process of the bucket to side-tilt clockwise or counterclockwise in the vertical plane around the longitudinal axis of the wheel pusher can be achieved.Bulldozer
