Axially Displaceable Cam Elements for Cylinder Deactivation
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Solution Overview
Problem
Existing motor vehicle valve train adjustment devices lack an efficient mechanism for cylinder deactivation, which affects engine performance and fuel efficiency during partial engine operation.
Innovation Solution
A motor vehicle valve train adjustment device with at least one camshaft featuring axially displaceable cam elements, including a cam track with zero lift for deactivation and multiple valve lifts, along with a control and regulation unit to manage cam element operation, allowing for efficient cylinder deactivation by switching between different valve lifts and zero lift configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a cam element has only a single cam track for valve actuation, then the structure is simple, but cylinder deactivation cannot be achieved
Solution Approach 1:
The cam element is divided into multiple independent cam tracks (first cam track with first valve lift, second cam track with second valve lift, third cam track with zero lift). Each cam track can be independently selected through axial displacement, enabling cylinder deactivation while maintaining a modular structure that balances complexity and functionality.
2Adaptability or versatility
If multiple valve lifts are provided for different operating modes, then operating flexibility is improved, but the cam element design becomes more complex
Solution Approach 1:
The cam element incorporates axial displacement capability to dynamically switch between different cam tracks (first, second, and third cam tracks with different valve lifts). This dynamic reconfiguration allows the same cam element to adapt to different operating modes (cylinder deactivation vs. full operation) without requiring multiple separate cam elements, thereby achieving operating flexibility while controlling design complexity.
3Loss of energy
If zero lift cam track is added for cylinder deactivation, then fuel efficiency during partial operation is improved, but the cam element structure becomes more complex
Solution Approach 1:
The cam element is designed with multi-functionality, incorporating three cam tracks that serve different purposes: the first cam track provides normal valve actuation, the second cam track provides alternative valve actuation with different lift characteristics, and the third cam track provides zero lift for cylinder deactivation. This universal design allows a single cam element to handle multiple operating conditions, improving fuel efficiency during partial operation while avoiding the need for separate deactivation mechanisms.
Data Source
Figure 1
AI summary
The invention relates to a motor vehicle valve train adjustment device comprising at least one camshaft (10, 11) which comprises at least two axially displaceably arranged cam elements (12, 13, 14, 15, 16, 17, 18, 19), at least one cam element (13, 14, 17, 18) of the at least two cam elements (12, 13, 14, 15, 16, 17, 18, 19) having a cam track (20, 21, 22, 23, 24, 25, 26, 27) with valve lift and having a cam track (28, 29, 30, 31, 32, 33, 34, 35) with zero lift for cylinder deactivation. The at least one other cam element (12, 15, 16, 19) of the at least two cam elements (12, 13, 14, 15, 16, 17, 18, 19) has a cam track (36, 37, 38, 39, 40, 41, 42, 43) with a first valve lift and has a cam track (44, 45, 46, 47, 48, 49, 50, 51) with a second valve lift.