Customer reversed internal and external leakage of the hydraulic directional control valve, causing vibration, AAK new design solved it all at once

Stephen is from Hi-Force hydraulic equipment manufacturing company in the UK. In the second half of last year, he was promoted to the purchasing manager of Kuala Lumpur Branch due to his excellent work. Within a week of taking office, he met with complaints. A batch of their hydraulic cylinders were noisy and vibrated seriously during operation. The after-sales engineer failed to solve the problem within 3 days. The user was not satisfied. Stephen was a little worried.

Stephen browsed an article of AAK on Google: "change the design of the hydraulic directional control valve, the vibration disappeared, and AAK eliminated the Canadian factory at zero cost", and left a message: how to solve the noise and vibration of the hydraulic cylinder? After reading this message, I roughly judged that either the hydraulic directional control valve used had problems or the original design had hidden dangers. We asked Stephen to provide the hydraulic system schematic diagram and design drawings, and AAK engineer judges that the working principle of the hydraulic cylinder is reasonable, only by checking on site can we find out the source of the vibration, and then no news from Stephen. 2 weeks later, Stephen emailed that according to the last case that AAK solved the vibration of the hydraulic cylinder, they also added a triangular throttling groove to the hydraulic direction control valve, but after installation, the hydraulic cylinder still vibrated. Their engineers said that AAK solution was a lie. I was speechless and didn't want to explain anything, so I ignored him.

3 days later, Stephen emailed us again, and sent a video of the hydraulic cylinder working and asked our help to check. AAK engineers found that the hydraulic cylinder will emit rhythmic noise and vibration whenever the load drops in the actual work, and preliminarily judged that there is a problem with the hydraulic direction control valve. AAK technical team discussed again according to the drawings, the working principle diagram of the hydraulic cylinder and the working video of the hydraulic cylinder, and confirmed that the problem lies in the hydraulic direction control valve. I told him that AAK could redesign the hydraulic directional control valve and asked him to send us samples of the original hydraulic directional control valve. Stephen may have no choice but promised.

5 days later, we received the sample of the original hydraulic directional control valve, which confirmed the judgment of our engineers that the internal leakage and external leakage of the original hydraulic directional control valve was reversed. 1 week later, AAK sent the newly designed external leakage type hydraulic directional control valve. Stephen informed by email that the noise and vibration problems of the hydraulic cylinder had been solved after using AAK external leakage hydraulic directional control valve. In the past 4 weeks, their engineers, from suspicion, disdain to admiration, wanted to know how AAK engineers found and solved problems, and sent out new hydraulic directional control valves in only 1 week.

When the load of the hydraulic cylinder moves downward, the pressure at the oil inlet of the hydraulic directional control valve is pushed higher due to the action of the needle valve. At this time, the control oil inlet is still the original set pressure. Under the action of the oil inlet pressure, the hydraulic directional control valve will be closed. When the oil inlet pressure drops, the hydraulic directional control valve will be opened again. The repetition of this process leads to the vibration and noise of the hydraulic cylinder. That is, the reason for the problem lies in the selection of hydraulic directional control valve. It is only necessary to change the internal leakage hydraulic directional control valve into the external leakage hydraulic directional control valve. Just a while ago, a Canadian customer also ordered the same type of external leakage hydraulic directional control valve, and we have existing samples, so they were sent out soon. Their engineers have to sigh that AAK has too many customer cases, which is true and can really solve the problem.

Stephen also privately informed us that his boss was very satisfied with his attitude and spirit to solve the problem this time, and his colleagues in Kuala Lumpur Branch admired him.

AAK hydraulic directional control valve, no noise, no vibration, you can also have a small try!

AAK HYDRAULIC VALVES (252) 2022-06-09