Operating Member of Shock Machines Based on the Non-axial Slider-crank Mechanism with a Disjointed Slider

Abstract

To perform various technological operations to process and destruct materials, power pulses of high amplitude and very short duration are necessary. Special devices, which can be hydraulic, pneumatic, electromagnetic or mechanical pulse generators, generate such shock pulses. Mechanical generators of power pulses can be based on the various mechanisms, many of which are among the mechanisms of a variable structure.The Machinery Researching Institute of National Academy of Sciences of Kyrgyz Republic has offered to use the crank-slider mechanism of a variable structure with a disjointed slider in the shock machines. The operation aspect of this mechanism is that at the beginning of the working course a lead (drive dog) and a hammer block, which form the slider, make a joint movement, are separated when the lead movement slows down, and then upon the shock of the hammer block to the tool and the mechanism being under idle operation these two parts again make a joint movement.The shortcoming of this mechanism is that its coefficient of the changing average speed of the slider is equal to unit. But as to the shock machine, it is desirable for this coefficient to be higher than one. In this case the average speed of the slider at the working course will be higher than when idling, and the hammer block can have the higher speed. Also it should be noted that when idling there are more favorable conditions to fix the hammer block, which has made a rebound after the shock to the tool, with a lead at great values of the coefficient of the changing average speed of the slider.The coefficient of the changing average speed of the slider can be increased through the crank support shift in direction, perpendicular to the trajectories of the slider movement, by converting an axial mechanism into the non-axial one. Based on the specified values of frequency and energy of blow and also conditions for ensuring the working capacity and compactness of the shock machine, the paper makes synthesis of key parameters of the operating member of the non-axial slider-crank mechanism with the disjointed slider.