Change the design of hydraulic directional control valve, the vibration disappears, and AAK eliminated Canadian factory at zero cost Hunter is an old purchaser of EAGLE PRO company in Canada. It has been several years since he purchased hydraulic directional control valves from AAK. In the second half of last year, Hunter emailed that he would become the general manager of Hangzhou branch in a month and visit AAK. Hunter has been engaged in procurement for 5 or 6 years. This promotion must be due to outstanding contributions. Some time ago, their company developed a batch of hydraulic cylinders, which vibrated greatly during commissioning. Their engineer thought that there was a problem with the hydraulic directional control valve, but the hydraulic directional control valve was normal when tested separately. The engineer was confused, and the boss was also very anxious. He asked hunter to consult the manufacturer of hydraulic directional control valves. This hydraulic directional control valve is produced by a local factory in Canada. After on-site analysis, the engineer of the original factory thinks that the vibration is caused by the sharp change of oil port pressure during the reversing of the hydraulic directional control valve. It can be solved by changing the hydraulic manifold design. The engineer's scheme is to connect two small adjustable one-way throttle valves in series on the control oil circuit at both ends of the hydraulic direction control valve. After 20 days, according to the plan of the original hydraulic directional control valve manufacturer, there was no vibration. The boss was very happy and let Hunter be promoted. Knowing that the installation of two throttle valves has increased their cost by 20%, I wonder if there is any other scheme. After getting their hydraulic direction control valve drawings, hydraulic manifold drawings and the hydraulic schematic diagram of the system, AAK engineers began to analyze. Three days later, AAK's scheme came out. The shoulder of the hydraulic directional control valve spool table was redesigned and a triangular throttling groove was added to avoid the sharp change of oil port pressure during reversing. This new design does not change the production cost of the hydraulic directional control valve, that is, it solves the vibration at zero cost. Hunter was a little incredible and asked AAK to immediately sample the new hydraulic direction control valve. One month later, the hydraulic directional control valve of AAK sample was sent out. After commissioning, there is no vibration, but the cost is zero. Hunter's boss happily saved 20% of the cost and asked hunter to always send inquiry for any hydraulic directional control valves to AAK at the first time. The design of hydraulic directional control valve runs through the whole process of design, manufacturing, use and maintenance. A good hydraulic directional control valve design cannot be separated from manufacturing.