The prerequisite for the normal operation of the hydraulic cylinder is that the air inside it is evacuated. Therefore, generally after the hydraulic press is installed, the hydraulic device of the hydraulic system should be inspected and tested. During this process, special attention should be paid to check the exhaust and oil discharge of the hydraulic cylinder.

After inspection, if the equipment parts are found to be normal and there is no oil leakage, the air in the hydraulic cylinder needs to be exhausted. This is because if the air enters and is not discharged in time, the oil in the hydraulic cylinder will mix with the air, which may cause the piston of the device to be unstable, such as shaking or crawling.

If this problem is solved, the air in the hydraulic cylinder must be discharged in advance. Of course, this requires ventilation. Usually, the ventilator of the hydraulic machine is located on the top of the hydraulic circuit of the machine. However, if it is a forging equipment, it needs to be installed vertically.

In this case, the mixing of air may cause the machine to run at abnormal speed, and even the sealing parts may burn due to the high temperature stroke of the insulation device. Therefore, for safety reasons, in forging machines, the hydraulic cylinder exhaust device is usually arranged in the cylinder barrel under the piston.

After the exhaust device is installed, it needs to be adjusted appropriately to achieve the required exhaust effect. The adjustment steps of the hydraulic cylinder exhaust device of the hydraulic press are as follows:

1. Reduce the working pressure to an appropriate range first, and then start the hydraulic cylinder.

2. During the reciprocating stroke of the piston, check whether the vibration and crawling of the machine are serious.

3. When the pistons alternate, the gauze should be sealed at the exhaust port, and the exhaust valve should be opened at the same time to complete the exhaust.