| Shield tunnelling machine (hereinafter refer to as shield) is a kind of engineering machine that used for underground excavation, which concerns of machine, electricity, hydraulic, transducer, information etc. Power transmitting and controlling of shield have characteristics of big power transmission, changeable load, complicated movement, high control precision and reliability requirement, small installation space and bad environment. Inherent characteristic of electro-hydraulic control system can meet these kinds of demands of shield. The electro-hydraulic control technology that developed rapidly in recent years utilizes the advantages of electronic technology in the signal measuring, amplifying, dealing with and transmitting, and it also utilizes the advantages of hydraulic in the power conversing, amplifying and carrying out, which become the irreplaceable way of power transmitting and controlling for shield. In this paper, electro-hydraulic control systems of thrust device and cutting wheel drive system are designed and simulated, finally they are verified by the engineering construction.Such research contents of this paper were performed:1, According to the tunnelling requirements of shield, speed and pressure of thrust hydraulic cylinders were real-time controlled by applying electro-hydraulic proportional control technology, and proportional pressure and flow compound control strategy was also put forward. It points out the thrust hydraulic cylinder should adopt zone control, and zoning principle of thrust hydraulic cylinder was also supplied.2, Aim at the situation of heat difficult to dispel in the field construction of shield, thrust hydraulic system adopted control technology of load-sensitivity and integrated technology of cartridge valve. The technology reduced heat generation in the hydraulic system and improved system efficiency. Simulation of hydraulic cylinder retraction proved that application of cartridge valve integrated technology can reduce pressure loss.3 , Test platform of thrust valve blocks was designed using three-dimensional parameter design software Pro-Engineer of USA PTC Company. It increased direct viewing, it was also convenient to test the flow passage's interfere and facilitate to arrange the components of the platform. Design efficiency was improved using its function of delivering the two-dimensional figure.4, Models of thrust hydraulics system and its loads were set up using the software— AMESim of France Imagine Company, which was based on the hydraulic pressure/ mechanical system modeling, simulation and analysis of dynamic engineering systems. Simulation analysis was also carried out. The results showed that thrust hydraulics system could control pressure, reduce the speed fluctuation caused by pressure and increase the system control precision by adopting proportional pressure and flow compound control.
|
PDF Full Text Request