Method for manufacturing a camshaft

Abstract

A method of manufacturing a camshaft for an engine having cylinder head bolts, includes providing a tube, placing at least one separately produced cam in a position on the tube along an axis of the tube, fastening the cam to the tube and pressing at least one external indentation into the tube at a part of the circumference of the tube. The indentation is pressed transversely toward the tube axis into inner and outer surfaces of a wall thickness of the tube at an axial location along the tube axis and does not encircle the tube. The indentation is also disposed along the tube and beside the cam with no part of the indentation being covered by the cam and the indentation being sufficiently deep to allow access to the cylinder head bolts of the engine.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This is a divisional of application Ser. No. 10 / 093,592, filed Mar. 8, 2002, which claimed priority on Swiss application no. 2179 / 01 filed Nov. 27, 2001, which claim is repeated here.FIELD AND BACKGROUND OF THE INVENTION [0002] The present invention relates to a method for manufacturing camshafts. [0003] Camshafts for the control of internal combustion engines for motor vehicles are today installed in ever more compact configurations. For example, for reasons of saving space, camshafts are disposed pairwise in such proximity that direct access to the cylinder head bolts is no longer possible. In order to dismount the cylinder head or to tighten up cylinder head bolts, such camshafts must in these cases be first dismounted, which is not service-friendly and entails additional costs. In the case of solidly built-up camshafts one solution proposes to mill or grind a transversely disposed groove-shaped indentation in the proximity of the cy...

AI Technical Summary

Benefits of technology

The present invention solves the problem of disadvantages in prior art camshafts by developing a camshaft as a tube and applying convexities or indentations to its walls. These indentations allow for access to the cylinder head bolts without losing the benefits of built-up camshafts. The invention uses a production method that ensures the camshaft can be precisely assembled from the tube, cams, and other components. The camshaft is held in a bottom die for generating the indentation, which allows for precise encompassing holding of the tube. The invention also allows for a projection of the original outer diameter in the proximity of the pressed-in indentation, with the projection being maximized stamped out so far that it does not interfere with the remaining adjacent part of the engine aggregate during rotation of the shaft. The invention provides a cost-effective and efficient solution for generating built-up camshafts.

Problems solved by technology

In the production process a further intermediate process step between the generation of the indentation in the shaft and the mounting of the parts is undesirable.

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