Static loading of the power hydraulic drive of the manipulator links of the timber transport machine in critical mode

Abstract

The safe and effective modes of operation of handling equipment of the manipulator type for the forest complex assume a mandatory horizontal position of the frame of the mobile technological machine. In unfavorable production conditions, a forest transport machine may find itself in a critical situation associated with the rotation of the manipulator's support frame relative to the horizon. Correction of this situation can be provided through the use of outriggers. This paper presents the results of a theoretical study of static loads that are characteristic of hydraulic cylinders of outriggers and other elements of the hydraulic manipulator of a forest transport machine with its various configurations. Technologies for loading, moving and unloading forest cargoes can be carried out using special equipment, subject to certain rules. The safe and effective operation modes of manipulator handling equipment assume a mandatory horizontal position of the support-turntable. In unfavorable production conditions, the wood transport machine may find itself in a critical situation related to the rotation of the support and turning frame of the manipulator relative to the horizon. Correction of such position can be insured by use of outriggers. This paper presents the theoretical study results of the static loads, which are characteristic for the hydraulic cylinder of outrigger and other elements of the hydraulic manipulator of a timber transport machine in its various configurations. Balance equations in generalized coordinates are used to describe the equilibrium conditions of the mechanical system under study, which includes a basic vehicle, outriggers, a boom, a handle with a telescopic extension, a grip device and hydraulic drives that ensure their functioning. The rotation angle of support-turning frame in vertical plane, the boom rotation angle, the handle rotation angle and extension of the telescopic part are selected as generalized coordinates. Analytical expressions are obtained for forces on rods of hydraulic cylinders and the working fluid pressure values in piston cavities of hydraulic cylinders in equilibrium state at different position of manipulator links. Calculations based on the obtained formulas can be used in designing technological modes of operation of timber transport machines for carrying out loading and unloading operations of cargoes with the possibility of bringing the support-turntable into a horizontal position.