Burnishing Process Using Spherical 5-DOF Hybrid-Type Parallel Mechanism with Force Control

Abstract

This paper proposes a novel diamond tip burnishing process to improve the integrity of various free-curved surfaces using a spherical 5-Degree-Of-Freedom (5-DOF), hybrid parallelmechanism. The developed parallel mechanism, which has high rigidity and a large workspace, is composed of a spherical 3-DOF parallel mechanism and anXYstage, and is equipped with a burnishing tool on its output link. Using a threedimensional force control system, the parallel mechanism can adjust the thrust force in the burnishing process. The surface roughness and profile of the stainless steel (AISI 316) workpiece, burnished by the proposed method, were evaluated. The surface integrity depended on the values of cross-feed and thrust force, which were controlled by the hybrid parallel mechanism. In addition, the surface roughness improved as cross-feed decreased and thrust force increased. The preliminary surface roughness ofRa= 2.5 µm was improved toRa= 0.25 µm in the burnishing process of the free curved surface, and homogeneous surface integrity was obtained. The results thus suggest that the proposed burnishing method can achieve a highquality surface finish, even on a free curved surface.

Burnishing characteristics of sliding burnishing process with active rotary tool targeting stainless steel

“…These investigations applied the cylindrical burnishing tool to a workpiece with an axisymmetric shape that was rotated by a machine tool like a lathe. The authors have developed a newly sliding burnishing method that used a spherical diamond burnishing tool and can be applied to both flat and curved surfaces (Okada et al, 2014) (Okada et al, 2017a). In this burnishing method, the burnishing tool was actively rotated at high speeds and the rotation axis of the burnishing tool was inclined from the normal direction of the target surface to achieve a high sliding speed.…”

A New Welding Robot for Intersected Weld of Pipes Used in Large Pressure Vessels

“…Other researchers have developed a welding robot, which installed on the top of the cylinder, implementing the welding process with the rotation around its axis [4][5][6]. A synthesized mechanism was chosen as the parallel module of a five degree of freedom hybrid machine tool [7][8][9][10]. However, for large intersecting line components, due to their large weight, movement needs greater power, and the cost of tooling is also higher, resulting in more complex and high cost of control system.…”

Application of roller burnishing technologies to improve the wear resistance of submerged pump parts made of powder alloys

“…It should be noted that today the overwhelming majority of published works related to the study of SPD processes were performed for monolithic parts obtained by casting, forging, and other methods [34]. SPD technologies for the parts produced from Fe-Cu alloys using powder metallurgy remain practically unexplored.…”