Optimization of hydraulic parameters of the lifting mechanism of the manipulator of the truck

The article discusses the possible improvements in the design of a fluid driven lifting gear of a backhoe boom mounted on a forward. The authors have solved the problem of optimizing the position of a hydraulic cylinder of the boom with account of the inertia force and the compliance factor of the hydraulic drive. The calculations were made using the program (certificate No. 2008613437 RF). Parameters of a hydraulic actuator of the manipulator LV-184А-06, mounted on a car of KAMAZ-type were used as the input data. We found that when the hydraulic cylinder takes the optimal position there is a decrease in instantaneous peak pressure in the system from 34 MPa to 20 MPa, and the use of additional damper decreases the decay time of the oscillations that affect the performance of a hydraulic manipulator. For each cavity of the damper according to the calculated pressure we determined forces affecting the plunger, the plunger velocity and its new position taking into account the supply and drain of fluid from the hydraulic pump during boom lifting and lowering movements. Computer experiments were conducted using the developed software (certificate No. 2009610503 RF). Theoretical time dependences of the pressure of the working fluid in the cavities of the rod and piston of the hydraulic cylinder are obtained. Dual dependence parameters are studied, thus allowing us to determine the effect of a combination of different acting on the hydraulic system factors on the damping effectiveness. The conducted two-factor optimization led to the conclusion that the optimum value of the diameter of damper throttling channels is 3.5 to 4.5 mm. It is established that optimization of the hydraulic cylinders position of the lifting mechanism of the manipulator of the car and the parameters of the proposed additional damper reduces the pressure surges of the working fluid in the piston cavity of the hydraulic cylinder by approximately 47 %, in the cavity of the rod by 25% and the duration of transients when lifting by 45%