A Machining Method for the Unloading Groove of the Crankshaft Neck of a Medium and High Speed

Abstract

The invention relates to a machining method of an unloading groove of a turning neck of a medium and high speed crankshaft. The crankshaft is clamped to a turn-milling machining center. A milling cutter body composed of a vibration-preventing milling cutter rod, a milling cutter disc and an arc blade is installed on a cutter frame. The crankshaft rotates around the center of the main shaft neck. The milling cutter body rotates along with the turning neck of the crankshaft in a servo manner. The arc blade rotates at a high speed to carry out cutting. Cutting starts from the oblique cone sectionof the concave type lug-shaped unloading groove to the arc section to carry out profiling finish milling machining, and the margin of 1 mm is left. After the crankshaft completes rotating of one circle, the cutter is pressed once, and the number of profiling cutter pressing takes the standard that the roughness of the unloading groove obtained after profiling finish milling machining reaches Ra3.2. In the machining process, the milling cutter body carries out milling machining in a servo manner, vibration and deformation of workpieces are reduced, and the error generated by eccentric distanceadjusting of the workpieces and the rotating angle is reduced. The unloading groove machined by the adoption of the method is high in size precision, the allowance reaches 0.2 mm, the roughness obtained after turn-milling machining is over Ra3.2, the roughness obtained after polishing can reach Ra0.63, and the quality is stable and reliable.

Description

technical field [0001] The invention relates to a processing method for a crank neck unloading groove of a medium-high speed crankshaft. Background technique [0002] This is the first development of a certain medium and high-speed crankshaft, and the unloading groove on the crankshaft neck (see figure 1 ) is the shape in which the arc segment 9 is connected to the conical surface, the concave crank arm is deep, and the roughness requirement is high. The shape and roughness of the unloading groove after processing will directly affect the fatigue strength and life of the crankshaft. Since the center of the neck is deviated from the center of the main journal, the unloading groove of the neck cannot be turned by ordinary lathe. The traditional method of processing the crankshaft unloading groove is turning on the CNC crankshaft lathe. The turning of the crankshaft lathe needs to manually adjust the eccentricity through the tooling, and the turning of the multiple neck unload...

AI Technical Summary

Problems solved by technology

In addition, due to the centrifugal force, the cutting speed is low, and the overhang of the turning tool bar is too long, and the rigidity of the tool bar is also poor, so that the cutting amount and machining feed rate are low, so the traditional method of machining unloading grooves is more efficient. Very low, the processing quality is not high, and the amount of manual grinding and polishing in the later stage is also relatively large

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