The normal operation of the cylinder needs to meet many conditions, if one factor causes an exception, it can cause some problems. For example, if the pressure continues to drop during the required pressure holding time, the cylinder cannot maintain the pressure. So, what's the reason for this problem?
After analysis research, we think that the pressure problem is mainly caused by the leakage of the hydraulic cylinder control valve. So, to minimize this problem is to minimize leakage. However, since leakage is difficult to completely avoid, if there are special requirements that pressure be maintained maintained for a long period of time, some measures should be taken to achieve this goal. The cause of this problem has already been mentioned, so we can minimize the possibility of a leak by reducing the number of leaks. Then, in the design, the number of control valves connections on the closed oil line of the hydraulic cylinder should be minimized.
Another effective method is to replenish oil. The so-called filling oil refers to the continuous compensation of the hydraulic cylinder when the pressure is maintained for a long time. There are two specific methods:
One method USES a pump to replenish oil. The main advantage of this method is that the pressure of the hydraulic cylinder can be kept stable for a long time. Under normal circumstances, we can use the variable pump oil supply system, so that the two pumps in the operation of the oil supply system. When maintaining pressure, the large-flow pump is discharged through the solenoid overflow valve, the small-flow oil pump, namely the pressure-maintaining pump, provides pressure oil separately to compensate for the system leakage, thus achieving the purpose of maintaining pressure.
In another method, the accumulator is used to replenish the oil to maintain the pressure. The main advantage of this method is that, even if the pressure is maintained for a long period of time, it can significantly save power without causing too many accidents. The specific method is to connect the high pressure oil in the accumulator with the hydraulic cylinder to play a compensation role.
