1.Preventing hydraulic shock when the hydraulic piston is suddenly braked, decelerated or stopped at the middle position of the stroke.
Set small safety valves with quick response and high sensitivity at the inlet and outlet of the hydraulic cylinder; use pressure control valves with good dynamic characteristics (such as small dynamic adjustment); reduce driving energy, that is, when the required driving force is reached , Reduce the working pressure of the system as much as possible; in the system with back pressure valve, properly increase the working pressure of the back pressure valve; in the hydraulic control circuit of the vertical power head or vertical hydraulic machine drag plate, the rapid drop, Balance valve or back pressure valve should be installed; two-speed conversion is adopted; bladder-shaped corrugated accumulator is installed near the hydraulic shock; rubber hose is used to absorb the energy of hydraulic shock; prevent and eliminate the air.
2. Prevent the hydraulic shock caused by the piston of the hydraulic cylinder when it stops or reverses at the stroke end.
In this case, the general prevention method is to provide a buffer device in the hydraulic cylinder to increase the oil return resistance when the piston has not reached the end point, so as to slow down the movement speed of the piston.
The so-called hydraulic shock is when the machine suddenly starts, stops, shifts or changes direction, due to the inertia of the flowing liquid and moving parts, so that the system has a very high pressure instantaneously. Hydraulic shock not only affects the performance stability and working reliability of the hydraulic system, but also causes vibration and noise and loose connections, and even ruptures the pipeline and damages the hydraulic components and measuring instruments. In high-pressure, large-flow systems, it The consequences are more serious. Therefore, it is important to prevent hydraulic shock.
3. The method to prevent the hydraulic shock generated when the directional valve is quickly closed, or when the inlet and return ports are opened.
(1) Under the premise of ensuring the working cycle of the directional valve, the speed of closing or opening the inlet and return ports of the directional valve should be slowed as much as possible. The method is: use dampers at both ends of the directional valve, and use a one-way throttle valve to adjust the moving speed of the directional valve; the directional circuit of the electromagnetic directional valve, if the hydraulic shock occurs due to the fast directional speed, it can be replaced Use an electromagnetic directional valve with a damper device; appropriately reduce the control pressure of the directional valve; prevent leakage of oil chambers at both ends of the directional valve.
(2) When the directional valve is not completely closed, the flow rate of the liquid is reduced. The method is to improve the structure of the control side of the inlet and return ports of the directional valve. The structure of the control sides of the inlet and return ports of each valve has a variety of forms such as right-angled, tapered and axial triangular grooves. When the right-angled control side is used, the hydraulic impact is large; when the tapered control side is used, such as the system If the moving cone angle is large, the hydraulic impact is more than iron ore; if the triangular groove is used to control the side, the braking process is smoother; the effect of pre-braking with the pilot valve is better.
Reasonably choose the brake cone angle and the length of the brake cone. If the brake cone angle is small and the length of the brake cone is long, the hydraulic impact is small.
Correctly select the reversing function of the three-position reversing valve, reasonably determine the opening amount of the reversing valve in the middle position.
(3) For directional valves (such as surface grinders and cylindrical grinders) that require fast jump action, the fast jump action cannot be offside, that is, the structure and size should be matched to ensure that the directional valve is in the middle position after fast jump.
(4) Properly increase the diameter of the pipeline, shorten the pipeline from the directional valve to the hydraulic cylinder, and reduce the bending of the pipeline.
Post time: Dec-24-2024