Modernization of Harvester Head Delimbing Knife

Abstract

In recent decade, the development of the logging industry in the world is defined by a significant increase in the diversity of logging vehicle fleet. The demand for modern high-capacity equipment, which allows increasing of forest processing efficiency, forces scientists and forest vehicles manufacturers to develop new equipment and regularly improve its existing models. Design development of multifunctional harvesting equipment working bodies
(harvesters and processors) is of particular interest. The purpose of the proposed delimbing knife modernization is impact reduction from dissipative forces and energy intensity of the process by forehanded moving the knife to the position of cutting limbs off and removing the knife from the tree trunk in their absence. This is achieved due to the fact that delimbing knife movement from angular (nonoperative) position to operative position parallel to tree trunk feed direction occurs after the knife body undergoes an external load from displacement of a pusher located in front of the knife. The pusher is shifted beyond the area of delimbing knife cutting edge under the load from cutting limbs and returned to its original position immediately after cutting. As a result of using the proposed delimbing knife operation method, the knife is moved quickly and in a well-timed manner to operative or nono-perative position. Special attention in realization of the new technical solution was paid to strength and reliability of construction operating under high loads, reducing the sensitivity of the delimbing knife to dirt accumulation and constant impacts. Implementation of the proposed delimbing knife operation for tree trunk pruning will allow to decrease the influence from dissipative forces and energy capacity of the process, and to increase the quality of tree processing at this stage of the technological process.