Research On Electro-hydraulic Control And Condition Monitoring System For Wet Spraying Machine

As a kind of construction machinery capable of the transporting and laying of concrete, the wet shot concrete machine (hereinafter referred to as Wet Spraying Machine) has become an indispensable engineering equipment in modern architecture construction. Some new ideas have been put forward for it on its performance, operation mode, and operating repairs to make the Wet Spraying Machine work efficiency and reliability of casting.With respect to pump type concrete Wet Spraying Machine in this paper. Its electro-hydraulic control system has been upgraded by making use of computer control and sensor inspection technologies. Make it capable of operation status monitoring, fault detection and alarm, and we can find fault in after protecting with integrated operations and intelligent control functions. This paper finished the following work:Firstly, basic structure and pumping characteristics of concrete Wet Spraying Machine are lucubrated. The theoretical basis for the design of electro-hydraulic control system has been provided.Secondly, the electric control system diagram has been designed based on the working theory and control requirements of Wet Spraying Machine. According to the actual requirements, the Siemens S7-200 PLC was chose to be as the core of the whole control system after comparing with relay control system, computer control system and distributed control system. The Siemens S7-200 PLC program editor STEP7-Micro/Windows NT was used for the control system to realize the automatic control and the manual control for Wet Spraying Machine.Thirdly, the overall design for Wet Spraying Machine of condition monitoring system has been finished. It was combined with the EM231 special function block and 4～20mA output selection standards of temperature, pressure transmitter for hydraulic system to control the temperature and pressure respectively, which reduced the complexity and induced the responsibility.The whole automatic system has the advantage of simple configuration, high automation, precise control, and stable work. It is also easy to use and to be maintained.