Development of the mathematical model a single stage pulse hydraulic drive

Abstract

The hydraulic drive is used in most structures of construction and road equipment. Hydrostatic volumetric drive allows the working bodies of construction machines to perceive heavy loads with a high rate of energy transfer. This gives of advantages not available on electric machines. The control of the hydraulic drive can be proportional and discrete. Proportional control is more precise control in comparison with discrete, however, more energy consuming. The discrete switching mode of the hydraulic drive can be performed using a high-speed valve, which is widely used for pilot valves because of their advantages in terms of simplicity of digital control, low power losses and insensitivity to contamination. However, to control such hydraulic valves, it is necessary to clearly understand and represent the principal features of the operation of a pulsed hydraulic system, to know the optimal values of the control system settings and transient parameters, to understand the relationships between the input control signals and the outgoing kinematic parameters. In this study, we developed a mathematical model that allows us to investigate the dynamics of high-velocity fluid flow switching valve for controlling the hydraulic power consumer. Mathematical modeling is proposed to be carried out over a typical cell of a hydraulic system consisting of a linear hydraulic cylinder, which is a consumer of hydraulic energy and a high-speed control spool valve. The actuating spool valve consists of a body inside which the valve moves, driven by a solenoid, at the input contacts of which a variable magnetic flux is generated, forming a variable magnetic force. Inside the body of the high-speed valve, the return spring of the spool is also installed, which is used to balance it. For the input of the valve control electric solenoid is energized variable frequency. By adjusting the fill factor of the control signal by pulse-width modulation, it is possible to change the magnitude of the spool force, thereby performing its programmatic movement. Thus will be regulated distributor spool slits overlap, thereby passing a continuous flow and fluid pressure through a distributor.