Determination of the energy required to expose the surface of the knife and the bottom of the bulldozer blade to the ground at the beginning of the pass
Authors: Nikolayev V. A. 
Published: September 2022

Introduction. The use of a complex of continuous units in the construction of roads will increase labour productivity, improve the quality of road construction. Therefore, the purpose of the design is to create a complex of units for the continuous construction of roads, mainly in automatic mode. In the first stage, a combination of theoretical calculations of the parameters of the continuous technology tools and design developments is the right way to achieve this goal. To remove stones, bushes, trees from the right-of-way of the future road, it is advisable to use units with bulldozer equipment. Although the theoretical foundations of soil development are considered in great detail, but based on them it is difficult to identify and compare the partial energy costs of the impact on the soil of the elements of technical means. Therefore, a detailed analysis of the interaction with the soil of the elements of various technical means, in particular, bulldozer equipment, is necessary. Before considering the primary pseudo-shift of the soil, it is necessary to calculate the effective forces and energy costs necessary for the impact of the surface of the knife and the lower part of the bulldozer blade on the ground.

The method of research. If the depth of the knife is small, the surface of the knife transports the soil upwards, carrying out: secondary displacement of the soil after the primary pseudo-shift; raising the soil to a height; overcoming the force of inertia of the developed soil; acceleration of the soil; overcoming the force of friction of the soil on the surface. A method for determining the energy costs required for the impact of the surface of the knife and the lower part of the bulldozer blade to the ground at the beginning of the passage, taking into account these components, has been developed.

Results. On the basis of the developed methodology, energy costs have been determined: for the displacement of the soil after the primary shift, raising the soil to a height, overcoming the inertial force of the developed soil, accelerating the soil, overcoming the friction force of the soil on the surface. The total energy costs, power, traction force are revealed, based on the initial conditions. The results of calculations of the energy costs required to move the surface of the knife and the lower part of the blade, during the cutting of the soil with different depths of the knife, are obtained. The parameter dependencies on the depth of the knife of the bulldozer equipment are constructed.

Conclusion. Analysing the drawings, it can be seen that the P-point of application of the concentrated normal reaction of the knife and the lower part of the blade, passing through O mass center of the displaced soil, with an increase in the depth of the bulldozer knife, shifts down, passing to the knife blade. So, when the knife is buried by more than 200 mm, P point of application of the concentrated normal reaction of the knife and the lower part of the blade is located outside the blade of the knife. During the operation of the bulldozer, this may not happen if the knife is deepened gradually. As the bulldozer knife is deepened, the total volumetric energy required to move the surface of the knife and the lower part of the blade at the beginning of the passage increases in the ground.