Why does the oil pipe of the four-column hydraulic machine vibrate and make noise?
The hydraulic pipelines of four-column hydraulic machines often vibrate violently, especially when several pipelines are arranged together. Vibration may result in noise, oil leakage and damage to pipe joints. The reasons are as follows:
① The vibration frequency of vibration sources such as oil pumps and motors matches the vibration frequency of piping, causing resonance. To prevent vibration resonance, the ratio of the two vibration frequencies should be outside the range of 1/3 to 3.
② The vibration of the oil column in the pipe can be prevented and mitigated by changing the length of the pipe to change the natural vibration frequency of the oil column, and connecting damping (throttle) in series in the pipe.
③ Pipe wall vibration: Try to avoid narrow places and sharp bends, and use elbows as much as possible. When elbows are needed, the bending radius should be as large as possible.
④ Use pipe clamps and elastic brackets to prevent vibration.
⑤ The joints at the oil confluence must be considered, otherwise vibration and noise will occur due to eddy current cavitation.
⑥Air has entered the tube, causing vibration and noise.
⑦ If the remote control oil path is too long, there may be bubbles in the pipe. The compressed oil in the pipe will vibrate and resonate with the relief valve and pilot valve spring, causing noise. Therefore, when the length of the system remote control pipe is > lm, a throttling element (damping) must be added near the remote control port to solve the problem.
⑧ When the four-column hydraulic press has improper piping or unreliable fixing, if the two pump outlets are very close to each other and a tee joint is used to connect the overflow oil, vortex flow will occur and cause pipeline noise. There is usually a noise near the oil pump outlet. Vortex, this kind of vortex that changes direction rapidly and has a confluence of swirling liquid flows, will produce a partial vacuum, cause cavitation, and produce vibration and noise. The solution is to use it at places where the pressure changes sharply such as the pump outlet and valve outlet. Combined piping. Don't get too close, but lengthen the distance appropriately to avoid the above noise.