Camshaft and method for producing the camshaft

Patent metadata

Field	Value
Publication number	US-10036455-B2
Application number	US-201214124882-A
Country	US
Kind code	B2
Filing date	Mar 20, 2012
Priority date	Jun 8, 2011
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

A camshaft contains a support tube, on which components including at least one cam are arranged at predetermined locations. The support tube extends at least partially through a hole in the components, and wherein a press fit is produced between the support tube and the components by hydroforming. Accordingly, at least one locally formed material formation is provided between the support tube and the hole. Via the material formation, the component is retained at the location in a desired orientation relative to the support tube in such a way that the support tube having the mounted components can be fed for hydroforming.

First claim

The invention claimed is:

1. A camshaft, comprising:
components including at least one cam and each having a hole formed therein;
the components being placed on a support tube in a state as forged;
the support tube defining predetermined seat positions and supporting said components including said at least one cam at said predetermined seat positions, said support tube at least partially extending through said hole in each of said components and an interference fit between said support tube and said components is formed by means of internal pressure forming, said hole of each of said components having a greater diameter than an outer diameter of said support tube;
a plurality of locally formed material moldings disposed between said support tube and said hole of each of said components, through said plurality of locally formed material moldings said components are held in said predetermined seat positions in a desired orientation relative to said support tube such that said support tube with said components can be fed to the internal pressure forming, with said components assuming a definite position, said plurality of locally formed material moldings formed on at least one outer surface of said support tube at said predetermined seat positions of said support tube and extending in a longitudinal direction of said support tube;
said plurality of locally formed material moldings embodied in an elongated manner extending in the longitudinal direction of said support tube with a length of each of said material moldings having one of the width of a component of said components or the width of a predetermined seat position of said predetermined seat positions;
said support tube at each of said predetermined seat positions having exactly three of said plurality of locally formed material moldings, which are evenly distributed over a circumference of said support tube in an angle division of 120° to each other, and are introduced in said outer surface of said support tube;
said plurality of locally formed material moldings having a cross-sectional shape consisting of a trapezium; and
said plurality of locally formed material moldings having a height of 0.5 mm and are made by knurling.

2. A method for producing a camshaft having a support tube, on which at least one component including at least one cam, is disposed in a predetermined seat position, which comprises the steps of:
providing the support tube and the at least one component, a hole being formed in the at least one component for disposing the at least one component on the support tube, the at least one component being disposed on the support tube in a state as forged;
forming exactly three locally formed material moldings on an outer surface of the support tube at the predetermined seat position through a knurling method, the three locally formed material moldings embodied in an elongated manner extending in a longitudinal direction of the support tube with a length of each of said material moldings having one of the width of the at least one component or the width of the predetermined seat position, and said three locally formed material moldings having a height of approximately 0.5 mm and a cross-sectional shape consisting of a trapezium, the three locally formed material moldings being evenly distributed over a circumference of the support tube in an angle division of 120° to each other, and are introduced in the outer surface of said support tube;
rotationally fixed prepositioning the at least one component in the predetermined seat position by forming at least a non-positive connection of the at least one component with the support tube in a region of a material molding of said three locally formed material moldings with the at least one component assuming a definite position on the support tube, wherein the support tube at least partially extends through the hole in the at least one component, wherein the material molding is introduced in the hole; and
creating an interference fit assembly between the support tube and the at least one component by means of internal pressure forming subject to forming a required connection strength between the at least one component and the support tube.

3. The method according to claim 2 , wherein the internal pressure forming further creates at least one bearing position on the support tube through plastic forming.

4. The method according to claim 2 , wherein, following the creation of the interference fit assembly, the at least one component is finish-worked through a cutting process method.

5. A method for producing a camshaft having a support tube, on which at least one component including at least one cam, is disposed in a predetermined seat position, which comprises the steps of:
providing the support tube and the at least one component, a hole being formed in the at least one component for disposing the at least one component on the support tube;
disposing the at least one component on the support tube in a state as forged;
forming exactly three locally formed material moldings on an outer surface of the support tube at the predetermined seat position, the three locally formed material moldings embodied in an elongated manner extending in a longitudinal direction of the support tube with a length of each of said material moldings having one of the width of the at least one component or the width of the predetermined seat position, and said three locally formed material moldings having a height of approximately 0.5 mm and a cross-sectional shape consisting of a trapezium, the three locally formed material moldings being evenly distributed over a circumference of the support tube in an angle division of 120° to each other, and are introduced in the outer surface of said support tube;
rotationally fixed prepositioning the at least one component in the predetermined seat position by forming at least a non-positive connection of the at least one component with the support tube in a region of a material molding of said three locally formed material moldings; and
creating an interference fit assembly between the support tube and the at least one component by means of internal pressure forming subject to forming a required connection strength between the at least one component and the support tube.

6. The method according to claim 5 , wherein the support tube at least partially extends through the hole in the at least one component, and the material molding is introduced in the hole.

7. The method according to claim 5 , which further comprises introducing the material molding in at least one of the outer surface of the support tube or in the hole through a knurling method.

8. The method according to claim 5 , wherein the internal pressure forming further creates at least one bearing position on the support tube through plastic forming.

9. The method according to claim 5 , wherein the interference fit assembly is created through a cutting process method that is finish-worked.

Assignees

• Paul Daniel
• Reichelt Robert
• Thyssenkrupp Presta Tecct Ag

Inventors

• Paul Daniel
• Reichelt Robert

Classifications

• F16D1/072

  involving plastic deformation (plastic welding F16D1/068) · CPC title

• Y10T29/49293

  Camshaft making · CPC title

• F16H25/14 Primary

  with reciprocation perpendicular to the axis of rotation (crank or eccentric gearings without swinging connecting-rod F16H21/36) · CPC title

• B21D53/845 Primary

  Making camshafts · CPC title

• Y10T74/2101

  Cams · CPC title