Variable Lift Valve Train Lever Bar Timing Adjustment

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Solution Overview

Problem

Internal combustion engines face limitations in variability of valve timing and lift, which are crucial for improving performance and efficiency, especially with rising fuel costs, as existing solutions are either complex or limited in their ability to adjust independently of engine RPM.

Innovation Solution

A variable lift valve train system comprising a spring-loaded valve connected to a lever bar, which is attached to a stroke limiter and influenced by an overhead cam, allowing independent adjustment of valve timing and lift through a mechanical connection that includes a stroke limiter cam, enabling operation independent of engine RPM.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional valve train mechanisms are used, then the structure is simple, but the valve timing and lift cannot be adjusted independently of engine RPM

Engineering Contradiction:

Improvevalve timing and lift adjustment capabilityVSAvoidvalve train mechanism complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The valve train is segmented into functionally independent components: a cam for controlling valve lift and a separate mechanism (lever bar with stroke limiter) for controlling valve timing. This segmentation allows independent adjustment of lift and timing without requiring a completely complex new mechanism, as each function has its own control element.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention introduces dynamic adjustability to the valve train by allowing the lever bar to pivot at an adjustable angle relative to the stroke limiter. This dynamic geometric relationship enables the timing of valve opening and closing to be varied independently of engine speed, while the cam profile continues to control lift independently.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If existing variable timing mechanisms are implemented, then valve timing can be adjusted, but the number of components increases significantly

Engineering Contradiction:

Improvevalve timing variabilityVSAvoidnumber of components

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The lever bar serves multiple functions: it transmits motion from the cam to the valve, provides the timing control through its pivot angle adjustment, and works in conjunction with the stroke limiter to define the valve event timing. This multi-functionality reduces the need for separate dedicated timing control components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention merges the timing control function into the existing valve actuation mechanism by using the lever bar's pivot point and angle. Instead of adding a completely separate timing control system, the timing variability is achieved by modifying the geometric relationship within the existing components, effectively combining lift and timing control in a integrated manner.

Inventive Principle:

Principle #5Merging (Combining)

3Productivity

If conventional valve trains are used, then the mechanism is straightforward, but performance and efficiency improvements are limited

Engineering Contradiction:

Improveengine performance and efficiencyVSAvoidvalve train mechanism

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The invention enables performance improvement by allowing continuous variation of critical valve train parameters (timing and lift) through geometric adjustments. The lever bar pivot angle and stroke limiter positioning can be changed to optimize valve timing for different operating conditions, directly impacting engine performance and efficiency without requiring complex electronic control systems.

Inventive Principle:

Principle #35Parameter changes

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 system effectively varies the timing and lift of the valve stem using fewer components, enhancing engine performance and efficiency by allowing independent adjustment of valve operation, thus overcoming traditional limitations related to engine RPM dependence.

Implementation Method 1

A variable lift valve train (100) includes a spring-loaded valve (112)

Methodology Applied

Scientific EffectSpring: Spring

Implementation Method 2

The lever bar (101) is further defined with a second lever end (113) that rests atop of the spring-loaded valve (112)

Methodology Applied

Scientific EffectLever: Lever

Implementation Method 3

The lever bar (101) is positioned under a first cam (119). The angle of the first cam (119) adjusts the angular orientation of the lever bar (101)

Methodology Applied

Scientific EffectCam: Cam

Data Source

PatentUS9732639B1Variable lift valve train

Publication Date: 2017.08.15 DIKE ANTHONY

AI summary

The variable lift valve train includes a spring-loaded valve that is in mechanical connection with a lever bar. The lever bar is attached to a stroke limiter. The lever bar extends across the spring-loaded valve and the stroke limiter. The lever bar is positioned under a first cam. The angle of the first cam adjusts the angular orientation of the lever bar with respect to the stroke limiter as well as the spring-loaded valve. The stroke limiter is biased via a stroke spring. Moreover, the stroke limiter extends downwardly, and optionally engages against a stroke limiter cam. The stroke limiter cam is optionally able to influence the stroke limiter, and is a secondary influence when compared to the angular orientation of the lever bar. In use, the variable lift valve train is able to adjust the timing and lift of the spring-loaded valve of the engine.