The accuracy of valve hole IT7 ~ 4 is difficult to be matched by peers

When back from the Spring Festival, we received a reorder for 120 hydraulic threaded cartridge valves from Echerle company. Dean has been engaged in hydraulic parts purchasing in Echerle company for many years, and has been doing very well. The boss also trusts him. At the beginning of last year, the company developed a new hydraulic power unit, which has high requirements for the accuracy of the hydraulic threaded cartridge valve to be used. Because of the high accuracy requirement, the original hydraulic threaded cartridge valve manufacturer said that he was not able to achieve it. Dean used a new hydraulic threaded cartridge valve manufacturer finally. After their hydraulic power unit equipment has been sold for just less than 3 months, the customer complained about insufficient power supply. Their engineers believe that the hydraulic threaded cartridge valve was stuck and caused the problem. However, the hydraulic threaded cartridge valve manufacturer believes that it is caused by the uncleanness of hydraulic oil, but the engineer detected that the hydraulic oil is normal.

The boss was not satisfied with such a hydraulic threaded cartridge valve manufacturer and asked dean to find a new hydraulic valve manufacturer and replenish goods as soon as possible. Dean left a message on AAK website and asked, what are the reasons for the stuck of the hydraulic threaded cartridge valve? We estimated that he had encountered the complaint about the stuck of hydraulic threaded cartridge valve. After communication, we learned that he was cheated by the new hydraulic valve manufacturer.

According to the hydraulic threaded cartridge valve drawings sent by him, the accuracy requirements are high, especially the dimensional accuracy requirement of the valve hole is IT7 ~ 4. Among the hydraulic valve manufacturers in Ningbo, there may be no more than 3 factories that are able to meet it. We suggested Dean send the abnormal hydraulic threaded cartridge valve to us. After receiving and disassembling the sample, it was found that the cylindricity and coaxiality of the valve hole of the hydraulic threaded cartridge valve had errors, that is, the accuracy was not enough, the pressure in the matching gap between the valve hole and the valve spool is not balanced, resulting in the limited flexibility and easy stagnation of the valve spool in the valve body.

Dean asked whether we can produce hydraulic threaded cartridge valves meeting valve hole accuracy requirements of IT7 ~ 4? We told Dean that for the hydraulic threaded cartridge valve, the valve hole accuracy is the key point and also the difficulty of quality control process. It directly affects the working performance, service life and stability of the hydraulic threaded cartridge valve. General hydraulic valve manufacturers surrender to this accuracy. AAK has a precision honing machine imported from the United States, which guarantees the finishing of the valve hole of the hydraulic thread cartridge valve, and has the special machine operated by a specially assigned person. After honing, the dimensional accuracy of the valve hole of the hydraulic threaded cartridge valve is IT7 ~ 4, and the surface roughness can reach Ra0.32 ~ 0.04 microns.