Camshaft Adjustment Device Using Single Tappet Unit
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Solution Overview
Problem
Existing camshaft adjustment devices for internal combustion engines are structurally complex, require significant installation space, and are costly due to the need for multiple tappets and complex groove engagement mechanisms, leading to potential errors and high component expenditure.
Innovation Solution
A tappet unit with a constant outer diameter and bi- or tri-stable actuator moves an armature unit along the movement direction to actuate control grooves of different penetration depths, allowing for reliable axial adjustment of the camshaft with a single axial installation site, using a single-piece cylindrical body and electromagnetic actuation with permanent magnets for stable positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple tappets with different diameters are used to engage control grooves at different penetration depths, then the camshaft can be adjusted to multiple axial positions, but the device becomes structurally complex and requires large installation space
Solution Approach 1:
The patent combines multiple tappet functions into a single tappet unit with a constant outer diameter. This single tappet can engage with control grooves at different penetration depths (first and second depths) to achieve multiple camshaft adjustment positions, eliminating the need for separate inner and outer tappets with different diameters.
Solution Approach 2:
The single tappet unit is designed to perform multiple functions: it can engage with control grooves at different penetration depths and interact with different control grooves (first, second, and third control grooves) to achieve various camshaft positions. This multi-functional design replaces the need for multiple specialized tappets.
2Adaptability or versatility
If multiple tappets and complex groove engagement mechanisms are used, then various cam tracks can be associated switchably to the combustion engine, but the component expenditure and assembly costs increase
Solution Approach 1:
The patent merges multiple tappets into a single integrated tappet unit that can achieve various camshaft positions through different engagement configurations with the control grooves. This reduces the number of components that need to be manufactured and assembled.
Solution Approach 2:
The single tappet unit is designed with universal functionality to engage with different control grooves at different penetration depths, enabling switchable cam track association without requiring multiple specialized components for each function.
3Reliability
If inner and outer tappets are used to realize two penetration depths, then the desired axial movement behavior can be achieved, but the device becomes costly and potentially prone to error
Solution Approach 1:
The patent combines the functions of inner and outer tappets into a single tappet unit with constant outer diameter. This unified structure eliminates the potential for errors in coordinating the movement of multiple tappets while maintaining reliable control over axial movement through different penetration depths.
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
This solution simplifies the structural realization, reduces component complexity, and enhances operating reliability by enabling compact, reliable camshaft adjustment with reduced assembly costs and increased flexibility in application.
Implementation Method 1
a bi- or tri-stable actuator, which moves an armature unit along the movement direction
Implementation Method 2
electromagnetic actuation with permanent magnets for stable positions
Data Source
AI summary
A device for adjusting the camshaft of an internal combustion engine, having a lift profile element (12) which is provided on an axially movable mounted camshaft for conjoint rotation therewith and which provides a control groove, and having a control unit for generating a predetermined axial movement of the camshaft, wherein the control unit has a tappet unit (17) which is movable radially with respect to the camshaft along a movement direction and which is designed for controllable engagement into the lift profile element, and wherein the lift profile element forms a first control groove (16) which is designed to interact with the tappet unit at a first penetration depth so as to describe a first axial movement of the camshaft, and the lift profile element forms a second control groove (18, 22) which is designed to interact with the tappet unit at a second penetration depth, which differs from the first penetration depth, so as to describe a second axial movement, which differs from the first axial movement, of the camshaft.