Hydraulic press brake adopts a full steel welded structure, providing sufficient strength and rigidity, stability, and reliability. It is suitable for industries related to large steel structures, iron towers, street lamp poles, high lamp poles, automobile beams, and car cargo boxes. Hydraulic press brakes generally do not experience faults, but occasional malfunctions cannot be ruled out. How to repair the downward slide of the hydraulic cylinder? What should be done if the hydraulic cylinder is leaking? Let's find out below.
Causes of the fault:
1. Dirty or damaged counterbalance valve and actuating valve.
2. Insufficient counterbalance.
3. Damage or wear of seals.
4. Damage to the inner wall of the cylinder.
5. If the slide block slowly descends from any position and the descent is less than 0.50mm in 5 minutes, it is considered normal. This phenomenon is mainly caused by the characteristics of the hydraulic oil.
Solution:
1. Clean the counterbalance valve and actuating valve. If they are damaged, replace them.
2. Adjust the counterbalance valve pressure according to the standard.
3. Replace the seals and inspect the reasons for seal damage or wear.
4. Generally caused by oil contamination, replace the cylinder barrel and sealing ring.
5. No action required.
Second, what to do if the hydraulic cylinder is leaking oil
The hydraulic cylinder of the press brake consists of a piston, sleeve, piston rod, screw, and other components. Generally, oil leakage from the cylinder is caused by aging or deformation of the sealing ring on the outer surface of the piston and the inner surface of the sleeve. The direct solution is to replace the sealing ring. Most domestic press brake manufacturers use sealing rings from Taiwan or Japan, so the service life of the sealing ring is relatively long. If the press brake cylinder is leaking oil, when replacing the sealing ring, be sure to choose high-quality and durable sealing rings. This will ensure that the replaced cylinder does not leak oil for a long time.
Steps to replace the sealing ring: The steps may vary depending on the design of each press brake. Commonly, there is a worm gear and worm square on the cylinder, which contains a worm wheel and a screw rod connecting the cylinder piston. First, remove this part, and then remove the screw rod. It is necessary to have auxiliary equipment such as a hoist or forklift to assist in this process, as it is difficult and dangerous to do it manually. When lifting the screw rod, it must be done slowly to avoid damaging the piston due to excessive force. After removing it, you will find many sealing rings on the outer surface of the piston. They are generally divided into dust seals, O-rings, sealing rings, gaskets, etc., with the sealing ring being the most important. Other seals generally do not need to be replaced unless they are severely damaged.
After replacing the sealing ring, external force assistance is also required when reinstalling the cylinder. Once everything is installed, the most important step is to adjust the cylinder stroke and angles on both sides (this generally requires professional adjustment). During the adjustment, the bending machine pressure should be set to around 5-10MPA, then conduct several tests with thin plates, repeatedly adjusting the cylinder stroke. Generally, the right side cylinder serves as the reference point (depending on the actual situation), adjust the other side cylinder until the angles are the same. Then adjust the pressure to normal and conduct tests with thicker plates. This will complete the process!
