Regular Article

Decomposition analysis and peak stagger design for Crank-triangular linkage-elbow mechanism of mechanical servo presses

¹ School of Material and Energy Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
² Mechatronic Engineering Department, Shunde Polytechnic Institute, E. Desheng Rd., Shunde 528333, PR China

^* e-mail: ys1944@139.com

Received: 15 February 2020
Accepted: 25 August 2021

Abstract

High mechanical advantage as well as low and steady slide speed within the working stroke S_n are the fundamental requirements for the working mechanism of servo-mechanical press. Currently, the Crank-Triangular Linkage-Elbow (CTLE) mechanism has attracted more and more attention from researchers and manufacturers of servo presses. This paper presents a new analysis and design method of CTLE. The mechanism is decomposed into two sub-units: crank and triangular-linkage elbow, followed by the kinematic and force analysis of each sub-unit. The influences of each structural parameter on the working performance are obtained and can be used as the basis for preliminary design. Through the offset design, the mechanical advantage peaks of the two units, MA_1max and MA_2max, do not occur at the same time: MA_1max is located near S_n, while MA_2max is just at BDC (Bottom Dead Center). Because the mechanical advantage of the whole mechanism is the product of the two subunits, the designed mechanism can obtain high and steady mechanical advantage together with low and steady slide speed within S_n. After preliminary design, the scheme can be further modified by numerical simulation and optimization. Hence the design efficiency can be improved.