Blank-making rolling method for conical hub of automotive transmission

Abstract

The invention discloses a blank-making rolling method for a conical hub of an automotive transmission using circular steel as a blank material. The method comprises the steps of cutting, heating, upsetting, punching a blind hole and pre-forming, punching a wad and pressing an end face, performing ring rolling forming, shaping, normalizing, performing impeller blasting, and the like, wherein the key point is that the section of the cavity formed by the mould used in the step of pre-forming and punching a blind hole is approximately the same as a circular inner cavity with different inner and outer diameters corresponding to the blank of the conical hub of the automotive transmission; when the step of performing ring rolling forming is finished, the section of the cavity formed by a rollingwheel and a rolling shaft is completely the same as the circular inner cavity with different inner and outer diameters corresponding to the blank of the conical hub of the automotive transmission, and the outer ring of the rolling wheel and the outer ring of a top wheel are respectively engaged with the outer ring of the blank; and simultaneously, a step of pre-ring rolling is carried out on a part with large deformation difference in the step of performing ring rolling forming. By applying ring rolling process to the blank of the conical hub of the transmission, which is the blank of asymmetric ring, the subsequent machining amount is reduced to the greatest extent, the material consumption is reduced, and the service life of the finished product is prolonged.

Description

Technical field [0001] The invention belongs to the technical field of automobile transmissions, and in particular, is a rolling blank method for the cone hub of automobile transmissions. Background technique [0002] my country's automobile transmission cone hub blanks have been made by traditional forging and pressing methods by blanking, heating, piercing, pressing, and punching and skinning. Because the cone hub blank has a large pressing surface area, the flat part is thinner, and it has a higher and thinner corrugated ring. The external dimensions of each part are required to be accurate. The forging pressure during closed pressing is very large, and a large tonnage pressure must be used. The machine can be pressed into shape, so the configuration and use equipment is large, and the equipment energy consumption is high. Due to the large diameter of the inner hole of the cone hub, the weight of the connecting skin removed by the punching after forging and forming is large, ...

AI Technical Summary

Problems solved by technology

Since the cone hub blank has a large pressing plane area, a thin plane part, and a taller and thinner corrugated ring, the external dimensions of each part are required to be accurate, and the forging pressure during closed pressing is very large, so a large tonnage of pressure must be used. The machine can be pressed and formed, so the configuration and use of equipment is large, and the energy consumption of the equipment is high

Due to the large diameter of the inner hole of the cone hub, the weight of the skin removed by punching after forging is large, and the material consumption is high.

[0003] The rolling and expanding processing method adopted by the rolling blank method of the synchronous sliding sleeve of the automobile transmission is limited to the manufacture of symmetrical circular ring blanks similar to the synchronous sliding sleeve blanks. The synchronous sliding sleeve rolling billet method performs double-piece symmetrical pressing according to double pieces, so when the billet is made in the billet making process, it cannot be pressed to meet the preformed size of the cone hub blank part when the ring rolling machine is rolling. When the billet is made, the blank is pressed into a straight ring. Since the width ratio and thickness ratio of each part of the finished cone hub blank are very different, the deformation of each part is poor when the straight ring blank is rolled (deformation difference = rolling The difference between the outer diameter and the inner diameter at the corresponding position before expansion - the difference between the outer diameter and the inner diameter at the corresponding position after rolling) is very different, when the difference between the inner and outer diameters is large (that is, the blank is very thick) When it has been pressed to meet the size and shape requirements of the finished product, the part with a small difference between the inner and outer diameters (that is, the blank is very thin) cannot meet the shape requirements of the finished product at all.

Moreover, because the thick and narrow part of the cone hub cannot be preformed in advance during the double-piece rolling, it is difficult to squeeze the blank metal into the rolling wheel due to the influence of poor fluidity and large deformation resistance during rolling. The deep and narrow grooves in the cavity form a blank that meets the requirements of the finished product's external dimensions

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