Determination of Attack Angle and Tilt Angle of a Cutting Pick

Abstract

Mechanical excavators play an important role in mining and construction. An excavation machine cuts rocks using its cutterhead which is normally composed of a large number of cutting picks. These picks are installed on a drum with certain attack angles, tilt angles and skew angles. These angles, especially attack and tilt angles, will affect the forces acting on individual picks and the cutterhead. To ensure the reliability and productivity of the excavation machine, these angles have to be kept in their optimal values. However, in manufacturing, these three types of angles cannot be set simultaneously. They have to be respectively set one after another. As a result, the angle which is set previously will be changed by the angles which are determined after it. Understanding the relationship between the values of the final angle and the designed angle is important for optimizing drum and pick design. This paper develops a formula for quantitatively analyzing this relationship, with the research scope limited to attack angle and tilt angle only as the first stage of the study.