Partial Cam Geometry for Formed Camshafts With Lower Tool Wear
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing camshaft designs for internal combustion engines face inefficiencies in production and stability, with prior art methods requiring complex machining and grinding processes that result in reduced tool lifespan and suboptimal material usage.
Innovation Solution
A cam design featuring at least two partial cams arranged along a longitudinal axis with a variable undercut profile and contour, produced using forming technology, which reduces contact stresses and allows for higher material filling with lower pressing forces, enabling enhanced stability and adjustable valve control behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If complex machining and grinding processes are used to produce cams, then manufacturing precision can be achieved, but tool lifespan is reduced and production efficiency decreases
Solution Approach 1:
The invention changes the fundamental production parameter from subtractive machining to additive forming. By using hot pressing forming technology with specially designed cavity contours, the cam is directly formed with the required geometry including variable undercuts, eliminating the need for subsequent machining and grinding operations. This parameter change resolves the contradiction by achieving both high precision and high productivity.
Solution Approach 2:
The forming tool cavity is designed in advance with the precise contour that will create the cam's geometry including variable undercuts. This preliminary action of pre-configuring the forming cavity eliminates the need for post-forming machining operations, thereby improving both manufacturing precision and production efficiency simultaneously.
2Ease of manufacture
If conventional forming technology is used with constant undercut contours, then production is simplified, but cam stability and tool lifespan are reduced
Solution Approach 1:
The invention applies asymmetry by designing variable undercut contours that are not constant around the cam perimeter. The undercut depth and shape vary at different angular positions, optimizing the cam's structural stability and stress distribution. This asymmetric design resolves the contradiction by maintaining manufacturing simplicity through forming technology while significantly improving cam stability and tool lifespan.
Solution Approach 2:
The forming process creates locally optimized undercut contours at different positions around the cam. Each region's undercut geometry is specifically tailored to local stress requirements, with deeper undercuts in high-stress areas and shallower ones elsewhere. This local quality approach resolves the contradiction by maintaining ease of manufacture while enhancing overall cam reliability.
3Manufacturing precision
If higher pressing forces are used in hot pressing, then material filling improves, but tool wear and energy consumption increase
Solution Approach 1:
The forming tool cavity employs optimized curved surfaces and smooth transitions that facilitate material flow during hot pressing. The contoured cavity design guides the material to fill all regions uniformly without requiring excessive pressing force. This curvature optimization resolves the contradiction by achieving complete material filling with reduced energy input and minimized tool wear.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The camshaft design achieves improved stability, reduced tool wear, and increased material efficiency, along with customizable valve operation through variable tread contours, enhancing the production process and engine performance.
Implementation Method 1
If the cam is created using forming technology, contact or bending stresses in the forming tool are also reduced
Implementation Method 2
For the production of a multiple cam, it is known, for example, to produce a blank by hot pressing
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a cam with two partial cams (1, 2, 3) arranged axially along a longitudinal axis (L) one behind the other and an intermediate relief groove (10, 20). The partial cams (1, 2, 3) have radially outward running surfaces (1', 2', 3') with variable running surface contours. The relief groove (10, 20) has a profile (10', 20') with a variable contour (10"). The running surface contours of the partial cams (1, 2, 3) differ from one another. The contour (10") is determined by the running surface contour that has a smaller radial distance to the longitudinal axis (L) than the other running surface contour.