The synthesis of cam-gear mechanism for discrete transportation of cardboard blanks by its side bleeds through units of the die-cutting equipment

The article shows the functioning specifics of the die-cutting equipment components which are connected to the cyclic displacement of the pressure plate of the press, technological tools in the striping station and the blank separation section. It has been marked that discrete displacement of carriers with fixed cardboard blanks is provided by a cam-gear mechanism. The article reveals the essence of the proposed method and the scheme of the device for cardboard blanks transportation in the die-cutting equipment by its side bleeds that makes possible the implementation of relatively insignificant movement of the massive pressure plate of the press. Providing the rational alternation of standing and movement phases of carriers through the technological units is the condition for the effective execution of the cut-outs die-cutting operation. Four phases of the cyclic functioning of the cam-gear mechanism have been highlighted: acceleration of the gear sector, its movement with constant angular velocity, deceleration and movement of the gear sector in the opposite direction. The method of the cam-gear mechanism synthesis has been developed. The article provides the research of the duration of the standing phase of the cam-gear mechanism depending on the ratio of the pitch radiuses of the gear and the sector. It has been recommended at the beginning of the synthesis of the mechanism to set the angle of uniform rotation of the gear sector for providing the duration of the standing phase of grippers in technological units of the equipment. During the duration of the standing of grippers with cardboard blanks, technological operations are performed in all units. It is necessary to take into account the restrictions that are put on the functionality of the cam mechanism. For deceleration of the gear sector, sinusoid law of periodic movement is recommended to use with the aim to minimize inertial loads. It has been stated that smooth deceleration of the gear sector can be provided by the matching of the value of its angular velocity at the end of the previous phase and the beginning of the next one. The recommendations for the smooth acceleration of the gear sector and providing of the conditions of joining the angular velocity at the boundary of adjacent phases have been received. The analytical dependencies have been derived for the justification of the geometric and kinematic parameters of the mechanism components provided the consideration of phases duration. The value of the relative angular velocity of the gear that drives the conveyors of carriers has been received for the specific value of the duration of standing.

Keywords: die-cutting equipment, discrete displacement, cardboard blank, side bleeds, cam-gear mechanism, gear sector, acceleration, deceleration, phase duration.

doi: 10.32403/0554-4866-2021-2-82-11-20