Crank shaft finish machining process

Abstract

The invention discloses a crank shaft finish machining process, which comprises the following steps of: clamping: making the axial line of a main journal of the crank shaft overlapped with a first coordinate axis; setting a tool: rotating the crank shaft to a preset position and setting coordinates of a third coordinate axis to be 0; adjusting positions of a sliding plate on the first coordinate axis and a second coordinate axis, so that the working belt face of a sanding belt and a crank neck of the crank shaft on the first coordinate axis are aligned and in surface contact, and setting parameters of the second coordinate axis to be 0; and grinding: starting a sanding belt mechanism according to a function relation of the coordinates of a surface contact point between the sanding belt and the crank neck on the third coordinate axis and the second coordinate axis, and starting a numerical control system to do interpolation motion on the second coordinate axis and the third coordinate axis according to the function relation. By the crank shaft finish machining process, the precision and the efficiency of crank neck finish machining can be improved.

Description

technical field [0001] The invention relates to a crankshaft finishing process, in particular to a process for finishing the crankshaft neck by using an abrasive belt. high. Background technique [0002] At present, there are mainly three methods for the finishing of the crankshaft neck. [0003] The first type of crankshaft processing technology is to adjust the crankshaft neck to the coaxial line with the machine tool spindle, and at the same time to counterweight the spindle at both ends of the machine tool. After the counterweight is completed, the crankshaft neck is rotated around the axis of the spindle. At this time The crankshaft neck makes a rotary motion, and then the grinding head of the grinding machine can be used to complete the grinding of the crankshaft neck. Although the grinding process of this processing method is simple, its disadvantages are very obvious. Due to the eccentric rotation of the workpiece, the moment of inertia is very large, which require...

AI Technical Summary

Problems solved by technology

Although the grinding process of this processing method is simple, the disadvantages are very obvious. Due to the eccentric rotation of the workpiece, the moment of inertia is very large, which requires the machine tool spindle and tail shaft assembly to have sufficient rigidity, the processing equipment is extremely large, and the processing cost is high.

Another disadvantage is that there are several turns on the crankshaft, corresponding to several turn necks, and the eccentricity needs to be adjusted once for each turn neck to be processed. At the same time, a suitable counterweight must be carried out, which is very cumbersome and the overall processing efficiency is extremely low.

The third disadvantage is that due to the eccentric rotation of the workpiece, its operation is not stable, and vibration will inevitably occur. Not only the surface roughness is large (generally only up to 0.4μm), but the machining accuracy of the workpiece is poor, which cannot meet the requirements of precision engine crankshaft processing.

However, because the basic motion form of the neck in this polishing machine is that its projection in the horizontal plane is a harmonic motion, and the motion curve is a sinusoidal curve, the force of the neck in contact with the belt wheel is equal to each generatrix in the circumferential direction of the neck. It is not the same, and the critical point difference between the peak and trough of the corresponding sinusoidal curve is the largest, which makes it difficult to grind the entire neck evenly. Although the surface roughness basically meets the requirements, the roundness error is too large

[0006] Although the abrasive belt mechanism was first used in the finishing of turning necks, the above-mentioned third grinding method is currently used by similar equipment, and its improvement is limited by its own working principle, and there is little room for improvement.

Images