AAK hydraulic pressure control valve with 4 precision requirements

Hannelore came from Demag hydraulic company in Germany and started to work in
Shanghai branch at the beginning of the previous year. I don't have much
contact with the Shanghai office. Frankly speaking, I'm not very good at
dealing with these offices with Chinese people. These people are unprofessional
and backseat drivers, they also need kickbacks. I hate kickbacks in business.
In August last year, Hannelore asked whether AAK was willing to cooperate with
them to develop a high-precision hydraulic pressure control valve, and attached
the drawings and working condition requirements. After several rounds of email
communication, I learned that they were in big trouble with this hydraulic
pressure control valve, which made him irritable.

They have a hydraulic injection molding machine to be promoted at the
exhibition in October. This high-precision hydraulic injection molding machine
has very high requirements for the accuracy of its core components. The
accuracy requirements for the hydraulic pressure control valve used have been
strictly refined in 4 aspects. The boss asked Hannelore to find a manufacturer
of hydraulic pressure control valves with high quality. After a round of
inquiry, only two factories were willing to try samples, and the others said
that the accuracy requirement was unbearable. Two months later, the samples
from the two hydraulic pressure control valve manufacturers were tested.
Unfortunately, there was still a deviation in the accuracy, but both
manufacturer was unwilling to try again. In other words, his busy more than two
months were in vain, and the boss was already very unhappy.

After analyzing the drawing of the hydraulic pressure control valve, AAK
engineers found that the 4 accuracy requirements are more than twice that of
the standard hydraulic pressure control valves. At the same time, the diameter
of the blind hole in the valve body is only 5mm, but the depth needs to be 50mm
long, it is very thin and extremely deep. During the processing process, the
tool cannot pass through the hole completely, and the inner hole is easy to
cause radial deformation, and the axial taper requirement is 1:45, and the
ovality cannot be greater than 0.01mm, this accuracy is too difficult to
control. No wonder all of those manufacturers have surrendered. After 3 days of
study and research, AAK technical team informed that the samples of hydraulic
pressure control valve could be sent after 40 days. Hannelore emailed me the
bank slip of the development fee the next day, and stressed that AAK must find
a way to deal with it, otherwise he was very afraid of the boss's outbreak.

Two weeks after the sample was sent, his email came. AAK hydraulic pressure
control valve passed the accuracy test, and the test result on the machine was
good. Their team was confident that it would sell well at the exhibition. After
the exhibition ended in October, Hannelore placed the order for 1,000 hydraulic
pressure control valves. Hannelore privately informed that the equipment had
sold well, and the boss's cold look at him turned into a happy face. After 4
months of anxiety, he could finally relax.

The reason why we did what our peers all surrendered is that there are 3
points:

1. The production process of hydraulic pressure control valve is set up with
ingenious tricks, including drilling, reaming, coarse reaming, fine reaming,
hole cutting, and calibration, changing the speed, adjusting the accuracy
coefficient, eliminating the bell mouth of blind hole and strictly control the
surface roughness.

2.Use the Swiss high-precision machine tool and the bladed reamer to cut the
hole, and the roughness of the blind hole reaches Ra value of 0.2-0.4 μm. The
ovality circle error is 0.01-0.02mm, the taper error is 0.01-0.025mm, and the
dimensional accuracy of the hole can be controlled within 1μm.

3.Before machining, the accuracy of each axis of the machine tool is tested,
including positioning accuracy, repeated positioning accuracy and reverse
positioning accuracy. After obtaining the test data, the accuracy is
compensated. Most hydraulic valve manufacturers ignore this small detail.

AAK hydraulic pressure control valve, benchmarking the accuracy of
international first-line brands, you can also have a small try!

https://www.aakindustry.com/info-detai , l/hydraulic-pressure-control-valves-
aak281

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