Hydraulic directional control valve vibration, AAK 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!

https://www.aakindustry.com/info-detai , l/hydraulic-directional-control-valve-
aak252

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