Leaf Spring Valve Train Reduces Engine Brake Assembly Space
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Solution Overview
Problem
Existing valve trains for internal combustion engines are inefficient in terms of cost and installation space, particularly due to the use of helical springs which complicate manufacturing and assembly, and require more space compared to leaf springs.
Innovation Solution
The valve train employs leaf springs instead of helical springs to pre-tension the engine brake rocker shaft against the camshaft, allowing for a more cost-effective and space-efficient design, with the leaf springs being manufactured as stamped or bent parts and integrated into a single spring body for simultaneous mounting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If helical springs are used to pre-tension the engine brake rocker shaft, then the valve train can maintain reliable contact between the rocker shaft and camshaft, but the manufacturing complexity and installation space requirements increase
Solution Approach 1:
The patent replaces complex helical springs with simple leaf springs that can be manufactured as stamped or bent parts. These leaf springs are designed as single-use, non-adjustable components that are replaced as a unit, eliminating the need for complex assembly and adjustment procedures while maintaining sufficient reliability for the application.
Solution Approach 2:
The patent changes the spring type from helical to leaf spring, fundamentally altering the mechanical parameter of spring configuration. This parameter change enables manufacturing as stamped or bent metal parts rather than requiring complex coiling processes, thereby reducing manufacturing complexity while maintaining the pre-tensioning function.
2Force
If helical springs are used for pre-tensioning, then adequate spring force can be maintained, but the installation space required increases
Solution Approach 1:
The patent transitions from three-dimensional helical spring geometry to a two-dimensional leaf spring configuration. This dimensional change allows the spring element to achieve the required pre-tensioning force with significantly reduced installation space, as the leaf spring can be positioned flat against the rocker shaft rather than requiring radial space for coiling.
3Reliability
If multiple separate spring elements are used for each engine brake rocker shaft, then individual pre-tensioning can be optimized, but the number of parts and assembly complexity increase
Solution Approach 1:
The patent combines multiple separate spring elements into a single integrated spring body with multiple arms. Each arm provides pre-tensioning for its corresponding rocker shaft while the entire assembly is manufactured as one piece and installed as a single unit, thereby maintaining individual optimization capability while dramatically improving assembly efficiency.
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 reduces production and installation costs while minimizing space requirements, enabling a more efficient engine braking operation and overall cost-effective manufacturing of the valve train.
Implementation Method 1
the spring element is formed as a leaf spring... by means of which the engine brake rocker shaft is pre-tensioned against the camshaft
Data Source
AI summary
A valve train for an internal combustion engine includes an outlet valve, an engine brake rocker shaft that is pivotable around a pivot axis, where the outlet valve is operable by pivoting the engine brake rocker shaft during an engine braking operation of the internal combustion engine, a camshaft which has a cam via which the engine brake rocker shaft is pivotable around the pivot axis, and a spring element via which the engine brake rocker shaft is tensioned against the camshaft. The spring element is a leaf spring.