外文翻译-混凝土运输车中液压泵压力的影响.docVIP

附 录 （英文文献和中文翻译） Investigation on Pressure Impact in Concrete Pumping Hydraulic System Abstract：The pressure impact in hydraulic systems of such concrete pumping machinery as trailer concrete pump，transported concrete pump，and truck mounted concrete pump，is a key factor affecting their reliability and usage life．Based on the pressure forming principle of the oil in a hydrostatic closed pressure chamber，the mechanism of producing pressure impact is analyzed synthetically，and the theory that oil flow matches requirement， and pump displacement control harmonizes valve shifting time control，to mitigate pressure impact，is put forward．The quantitative controlling parameters about shifting time and displacement control are introduced to realize accurate control．The experiment investigations of pressure impact property and its control are carried through on an experimental system which is able to simulate concrete pumping condition．The basic law that pressure impact and controlling parameters vary with working condition respectively．The feasibility and validity of the technology proposed in this paper to control pressure impact are confirmed. Keywords: Pressure impact；Hydraulic system； Concrete pumping machinery． 1 Introduction During working process of such concrete machinery as trailer concrete pump，transported concrete pump，and truck mounted concrete pump，two oil cylinders drive two concrete delivery cylinders respectively，and quickly switch direction with the possible highest frequency of more than 30 times per minute，which generates serious hydraulic impact．It is an important factor resulting in bad performance and low use reliability of the machine， and vibration，noise and overheating etc．so it’s a key of improving concrete pumping machinery’s reliability to gain a mastery of pressure impact property in concrete pumping hydraulic system and its controlling technology．Such technological measures as follows were taken to reduce pressure impact：(1)installation o