Определение оптимальной силы и скорости копания грунта одноковшового гидравлического экскаватора с ковшом сферической формы

Abstract

Introduction. The paper describes the scope and purpose of single-bucket hydraulic excavators. The method of digging a single-bucket excavator with a bucket of spherical shape, which allows to increase productivity, is considered. The urgency of increasing the productivity of these machines is formulated. The purpose of the work: to determine the optimal strength and speed of digging the soil of a single-bucket hydraulic excavator with a spherical bucket. Research methodology. To confirm the effectiveness of the proposed bucket design, a diagram of the forces acting on it during digging is presented. The rheological model of the process of digging with a bucket of spherical shape is considered. A mathematical model in the form of a system of second-order differential equations has been compiled on the basis of the force scheme and the rheological model. Research results. A mathematical model has been identified that makes it possible to calculate the dependence of the speed and optimal force when digging the soil with a spherical bucket of a single-bucket hydraulic excavator, depending on the design parameters of the bucket and the parameters of the soil. The dependence for determining the friction force of the soil inside the bucket arising during digging is given. The dependencies for determining the weight of the soil in the bucket and the bucket itself are described. The dependence for calculating the lateral pressure of the soil using a stabilometer is given. The dependences of the calculation of the friction force of the external soil on the bucket and the friction force of the external soil on the soil in front of the bucket edge are presented. A dependence for determining the normal force from the external soil to the compacted soil in front of the bucket edge is proposed. The concept of a "compacted core of the soil" in front of the bucket edge is given and the dependence for determining its depth is given, however, a more precise definition of the latter requires additional research. A dependence is proposed for determining the mass of soil located in front of the bucket edge. The conditions for the possibility of digging the soil are accepted, in which the digging speed is greater than zero, and the digging force is minimal. An algorithm is described that allows you to select the minimum force for the digging process based on the dependencies given in the work. A block diagram of the algorithm for selecting the minimum force for the process of digging with a spherical bucket is given. The selection of the minimum digging force will confirm the effectiveness of a single-bucket hydraulic excavator with a spherical bucket.