Method and equipment for producing directional vertical taper pipe in motorcycle through cold extrusion

Abstract

A cold extrusion technology for machining the vertical conic stearing tube of motorcycle includes reducing hoop, hole enlargnig and plumply shaping to obtain the target product with conic internal hole, cylindrical upper segment, and stepped cylindrical lower segment. The extrusion apparatus for reducing hoop and enlarging hole is composed of lower and upper demoulding buffer cylinders and shaping cylinder. The extrusion apparatus for plumply shaping consists of demoulding cylinder and extruding cylinder.

Description

(1) Technical field [0001] The invention relates to a production method and a device for a tapered riser, in particular to a method and a device for producing a motorcycle direction tapered riser by cold extrusion. (2) Technical background [0002] Such as figure 1 As shown, the tapered standpipe in the direction of motorcycle is a diameter from large to small, and the appearance shape is successively from the largest diameter straight section (AB section), the conical section (BC section), the smaller diameter straight section (CD section), A steel pipe with a smooth transition of four parts including the straight line segment with the smallest diameter (DE segment). The existing motorcycle direction tapered riser is made of straight steel pipes. The traditional processing method is: firstly heat the steel pipe to raise the temperature, then forge the steel pipe into a cone shape, and then process it after cooling , that is, use a lathe to rough the entire outer surface o...

AI Technical Summary

Problems solved by technology

[0005] 3. Single selection of materials: Still taking the production of the above-mentioned tapered riser as an example, the diameter of the selected steel pipe should not be too large, because it is too wasteful of material, nor too small, because the production and processing cannot meet the technical requirements of the product, generally only Steel pipes with a diameter of 35.5 mm and a thickness of 5.5 mm can be selected, so its material selection is single

[0006] 4. The riser is rough: due to the heating and forging of the steel pipe, the tapered riser produces an oxide shell from the inside to the outside, and is bent and deformed, with low coaxiality and uneven wall thickness

The resulting oxide shell is unfavorable to cutting, and the turning tool wears a lot

Although the outer surface has been processed with a lathe, the smoothness is still difficult to meet the product requirements, and the inner hole is irregular, there are many oxide shells, and the wall thickness is uneven.

[0007] 5. Heavy workload: the outer surface of the tapered riser must be fully processed, and the amount of machining is large

[0008] 6. High scrap rate: Generally, the tapered riser produced by traditional methods has a scrap rate as high as 3% to 4%.

[0009] Based on the above-mentioned deficiencies, relevant technical personnel have attempted to change the processing method of producing motorcycle direction tapered risers, and have carried out research for many years by cold extrusion. After the 15th printing of the second edition of the book titled "Stamping Manual" by the Industry Press in June 2002, especially seeing "avoid taper" in the basic requirements for cold extrusion parts on page 403 of the book After the description, the research work was stopped. Therefore, there has been no breakthrough in the method of producing motorcycle direction tapered risers by cold extrusion. When it is tapered, a harmful horizontal component force will be generated, which will bring difficulties to extrusion. For this part, the allowance should be increased, and it can be obtained by cutting after extrusion.”

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