Integrated Swing Shaft Variable Valve Timing Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing engine variable valve timing systems face challenges in achieving optimal valve timing and reducing variation between cylinders due to complex link mechanisms and assembly errors, leading to suboptimal performance and inefficiency.

Innovation Solution

A variable valve timing system featuring a swing shaft with an integrated eccentric and main shaft portion, coupled via universal joints, and an actuator-controlled link mechanism with a stopper for precise angle adjustment, reducing backlash and assembly errors across cylinders.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a complex link mechanism and actuator are used to adjust valve timing, then valve timing adjustment capability is improved, but device complexity and assembly errors increase

Engineering Contradiction:
Improvevalve timing adjustment capabilityVSAvoidlink mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the exhaust swing arm and intake swing arm into a single integrated swing shaft structure. The exhaust swing arm is supported by a main shaft portion, while the intake swing arm is supported by an eccentric shaft portion that is integrated into the main shaft portion. This merging eliminates the need for separate link mechanisms for each valve train, reducing device complexity while maintaining valve timing adjustment capability through the unified swing shaft rotation.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If multiple separate swing shafts are used for each cylinder, then individual cylinder adjustment is improved, but variation between cylinders increases

Engineering Contradiction:
Improveindividual cylinder adjustmentVSAvoidvalve timing consistency between cylinders
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent creates a universal swing shaft structure that serves multiple cylinders simultaneously. The integrated swing shaft with main shaft portion and eccentric shaft portion provides a common rotation axis for both exhaust and intake swing arms across cylinders. By coupling swing shafts between adjacent cylinders, the system ensures identical rotation angles and timing for all cylinders, eliminating variation while maintaining the ability to adjust valve timing for the entire engine through a single actuator.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If separate link mechanisms are used for each cylinder, then individual timing control is improved, but assembly errors and timing variation increase

Engineering Contradiction:
Improveindividual timing controlVSAvoidtiming consistency
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent merges the timing control function into a single actuator that rotates the unified swing shaft. The exhaust swing arm and intake swing arm are both driven by the rotation of the integrated swing shaft, ensuring synchronized and consistent timing across all cylinders. This eliminates assembly errors associated with multiple separate link mechanisms while maintaining individual timing control through the eccentric shaft portion design.

Inventive Principle:
Principle #5Merging (Combining)

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 configuration enhances support rigidity, eliminates assembly errors, and allows for synchronized valve timing across cylinders, reducing variation and optimizing engine performance by controlling valve timing through a single actuator and link mechanism.

Implementation Method 1

the swing shaft has an eccentric shaft portion which supports the intake swing arm and which is provided in a main shaft portion supporting the exhaust swing arm

Methodology Applied
Scientific EffectEccentric mechanism: Eccentric

Data Source

PatentEP3061929B1Variable valve timing mechanism and engine with variable valve timing mechanism
Publication Date: 2019.12.11 YANMAR CO LTD
  • EP3061929B1 patent drawingFigure 1
  • EP3061929B1 patent drawingFigure 2
  • EP3061929B1 patent drawingFigure 3(A)~3(D)

AI summary

An engine (100) is provided with variable valve timing mechanisms (5) each comprising: an exhaust swing arm (53) swinging in response to the rotation of a camshaft (15); an intake swing arm (53) swinging in response to the rotation of the camshaft (15); and a swing shaft (51) for supporting in a swingable manner the exhaust swing arm (52) and the intake swing arm (53). In the engine (100), adjacent swing shafts (51) are connected to each other and the engine is provided with: a link mechanism (6) connected to one of the swing shafts (51); and an actuator (7) for moving the link mechanism (6). As a result of this configuration, the actuator (7) can control the pivot angle of all of the swing shafts (51) through the link mechanism (6).