DEVELOPMENT AND RESEARCH OF A SHOE-TYPE OPENER WITH ADJUSTABLE STIFFNESS OF THE ELASTIC TINE

In the design of grain seeders and sowing systems, the shoe-type openers are used for separate application of mineral fertilizers into the soil and for sowing. Structurally, they can be designed in the form of a cultivator working organ with spring suspension of the S-shaped tine and with fixed attachment of the tine to the seeder frame. This article presents the proposed design of a shoe-type opener in the form of a cultivator working organ on an S-shaped elastic tine equipped with a device for adjusting its stiffness. The purpose of the study is to determine the movement and the resulting stresses of a S-shaped elastic tine in the basic design and with the device developed to change its stiffness. The results of the study on the stiffness of the S-shaped elastic opener tine depending on the adjustment parameters of the adjustment device, which was made in the form of computer modeling of the opener-soil interaction process, are also presented. As a result of the tests carried out, it is found that the device for adjusting the stiffness of the S-shaped elastic opener tine is capable of increasing its stiffness by 1.3...3.4 times compared to the basic tine, i.e. the increase in stiffness from 22.6 N/mm for the basic tine up to 29.6 N/mm when the spike of the tine stiffness adjustment device is aligned with the last adjustment groove and up to 77.5 N/mm when the spike of the tine stiffness adjustment device is aligned with the first adjustment groove.