Wear Resistant Design And Experimental Research Of Trip Mechanism Of Knotter

Aiming at existing knotter that cuts the rope tripping mechanism work, the spherical roller and cam serious impact mutually, based on this impact of stress concentration and serious abrasion, a line contact type space cam mechanism is designed, which is based on the sine acceleration of a cutter arm, to reduce the original tripping mechanism of roller and cam contact stress, and eliminate the impact roller and cam.According to the theory of Achard wear model to derive the tripping mechanism wear calculation model,In order to carry out relevant research about knotter abrasion,To improve the before and after the improvement of trip mechanism wear simulation calculation, The main research work is as follows:(1) Tripping mechanism wear model: In this paper, according to the Achard wear model, reduce the knot trip mechanism of wear simulation model, with the aid of MATLAB software to wear simulation of trip mechanism, to improve the knot trip mechanism impact, serious problems such as providing theoretical basis for abrasion.(2) The line contact spatial CAM mechanism design: according to the requirements of oscillating sine acceleration, the both satisfaction of the CAM and roller motion in the form of line contact, references existing trip mechanism of CAM base circle radius and lift, the tripping mechanism of CAM contour surface equation is established, using MATLAB to calculate the three-dimensional curved surface of CAM contour coordinates, import it into P/ROE curved surface of CAM 3 d model is established in the software. By calculating and comparing the original trip mechanism pressure Angle and the improved trip mechanism pressure Angle, the results show that the improved trip mechanism at the beginning of the lift and lift the end of the pressure Angle by 30%,reduce the 20 degree than before improvement.(3)Tripping mechanism contact stress calculation and analysis:Through the contact mechanics model of trip mechanism analysis, it is concluded that the contact force of CAM mechanism. Then establishs simplified model of the CAM mechanism before andafter improvement, the import trip mechanism of contact stress analysis in ANSYS, the stress analysis results provides necessary data for wear MATLAB simulation calculation.(4) Based on MATLAB trip mechanism of the wear calculation: Reling on the CAM wear model, at the beginning of the CAM into the lift in the interval of every 5degrees for discrete points, in the MATLAB software simulation calculation of the discrete point of wear, contrast improvement in front of the CAM and the improved CAM wear, the results show that the improved than before improvement of CAM wear of the CAM wear is reduced by 60%.(5) Tripping mechanism of wear test and analysis: Adoptting aluminum alloy CAM, will improve the former trip mechanism and improved trip mechanism that is installed on the knot machine fatigue test bench for trip mechanism wear test, the results show that: when a cord pulling force of 120 N, the spindle speed is 60 RPM, 250 after the knot was reduced by 43%, the improved CAM wear tie 600 times after the improved CAM wear is reduced by 56%, to 1300 times tied after the improved CAM wear volume was reduced by 46%,and to 2000 times tied after the improved CAM wear volume was reduced by 37%. The improved trip mechanism as the surface with a roller CAM contact area increases, the impact is reduced, its wear is obviously improved, the improved tripping mechanism was verified the correctness and effectiveness of design.