Technical Article

Cylinder exhaust problem

After the cylinder is running, if there is a creeping phenomenon, it needs to be exhausted. Generally, the cylinder has an exhaust port or exhaust valve. If it is an exhaust port, when one end enters the oil, observe the vicinity of the oil return pipe at the other end to see if there is any plugging, and perform corresponding operations. If the cylinder is equipped with an exhaust valve, you can loosen the oil pipe joint, and then let the cylinder do a few more movements to exhaust.

If there are neither of these on the cylinder, the exhaust operation can also be performed. The specific operation is: first move the piston rod to one direction, pause for some time, then let it move to the other direction, and then pause for some time. Repeatedly, you can exhaust the air in the cylinder.

The air remaining in the hydraulic cylinder sometimes cannot be discharged by itself, causing the hydraulic device to often vibrate, tremble and crawl during work, and accompanied by noise, which affects the normal operation of the machine. It should be pointed out that not all hydraulic cylinders need to be equipped with exhaust devices. For hydraulic cylinder accessories that are not demanding, special exhaust devices are often not provided. Instead, the oil openings are arranged at the highest point at both ends of the cylinder, which can make The air in the cylinder is discharged with the flow of oil; for large hydraulic cylinders that require high speed stability, exhaust devices, such as exhaust plugs, exhaust valves, etc., must be installed.

When the hydraulic system stops working for a long time, the oil in the system flows due to its own weight and other reasons. At this time, it is easy for air to enter the system. If there is air in the hydraulic cylinder or the oil is mixed with air, the movement of the hydraulic cylinder will be unstable. Therefore, the air in the system should be discharged before the hydraulic system starts to work. For this reason, an exhaust device can be installed at the highest part (often where air collects) at both ends of the cylinder. There are two types of exhaust devices. One is to open an exhaust hole at the highest part of the hydraulic cylinder and connect the exhaust valve with a pipe for exhaust; the other is to place an exhaust plug at the highest part of the cylinder. Both exhaust devices are opened when the cylinder is exhausted, and closed after exhausting.