A design method for full-fiber multi-throw crankshaft forgings

Abstract

The invention discloses an all-fiber multi-turning crankshaft forging piece design method. Under the condition that the step shaft blank dimension is not changed, a different-thickness crankshaft method is used for designing a crankshaft forging piece, in particular, on the basis that the relative position of a crankshaft forging piece connecting rod neck is not changed, the increasing direction of the crankshaft thickness is on the main shaft neck side, the crank throw left and right crank arm thickness ratio parameter scope is given out for the first time, according to the horizontal upsetting direction clamping projection areas of workblanks in different stages, a crank arm thickness allocation value is obtained, the crankshaft forging piece design is improved, synchronization mold filling of crank arms of single crank throws is achieved, axial flowing is restrained, the middle wrong throw die extra bending stress is reduced, and the service life of a die is prolonged. According tothe all-fiber multi-turning crankshaft forging piece design method, under the condition that the cost is not increased, the crankshaft forging quality can be effectively improved.

Description

technical field [0001] The invention relates to a design method of an all-fiber multi-turn crankshaft forging. Background technique [0002] The crankshaft fatigue performance of high power density diesel engine directly affects the reliability of engine operation. The shape of crankshaft streamline distribution directly affects its reliability. Such as figure 1 As shown, each crank throw of the multi-throw crankshaft is distributed symmetrically around the axial direction, and from the field of precision plastic forming, it belongs to forgings with complex shapes in space. [0003] The crankshaft streamlines prepared by the upsetting-extrusion composite forming of each crankshaft of the crankshaft are continuously distributed along its shape, which can greatly improve its fatigue resistance, and is the preferred forming process for high-performance crankshafts. This process adopts the turn-by-turn forming method (as shown in Figure 2). The upsetting in the horizontal dir...

AI Technical Summary

Problems solved by technology

[0004] When forming each turn, due to the difference in the contact area between the thrust die and the blank in the axial direction, there is a certain difference in the metal flow law during horizontal upsetting forming, resulting in inconsistent order of complete filling in the crank arm area. The mold is filled earlier on the side with a larger contact area, so that the middle bending mold bears a certain bending stress, which is prone to bending fracture. In addition, the inconsistent filling sequence can cause abnormal axial flow, which makes the shape and position accuracy of the crankshaft poor. And other issues

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