The Interaction of the Punch Toroidal Surface with the Eyelet During Grommeting Textile Materials

Introduction. For the effective use of equipment for setting metal fi ttings in light industry products, in particular in footwear, leather goods, textiles, corsetry, and curtain products, the regularities of changing the strain force acting on metal grommets during their interaction with the punch toroidal surface should be taken into account.Problems Statement. For solving many practical problems, it is necessary to calculate the parameters of the strain force acting on metal accessories (in particular grommets) from the working surface of the tool. Knowing the force parameters allows us to calculate the strength of the punch, to predict its wear resistance, and to determine the necessary kinematic and energy characteristics of the equipment.Purpose. Establishing the regularities of changes in the strain force acting on metal fi ttings during their interaction with the toroidal surface of the punch, given the conditions of contact interaction and the physical and mechanical properties of the fi ttings material.Materials and Methods. Theoretical and experimental methods of research based on the classical laws of mechanics and the simulation of the process of deformation with the use of information technologies have been employed. Microsoft Excel has been used to create the computation program. The analytical calculations and the experiment have been made for a 08 kp steel eyelet.Results. The dependence of the total strain force acting on the eyelet on the punch step has been analytically established; the process of grommet deformation by the toroidal surface of the punch has been experimentally studied. The strain forces are most signifi cantly aff ected by: the grommet thickness, the radius of the punch toroidal part, the radius of the point of transition of the punch conical surface into the toroidal one. Conclusions. The shape of the working surfaces and the geometric parameters of the punch have a decisive influence on the process pressure values. The resulting dependencies can be used for developing new press equipment for grommeting light industry products, as well as for selecting the operating conditions of the existing equipment. This improves the quality of process operations, reduces the energy consumption of equipment, and increases the labor productivity.