Continuously Variable Valve Lift via Adjustable Swing Arm

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Solution Overview

Problem

Existing engine valve systems have a fixed valve movement, which cannot adjust valve lift and duration according to operational conditions, making it difficult to balance power and economy in varying load conditions.

Innovation Solution

A continuously variable valve lift system with a driving swing arm, camshaft, and adjusting swing arm, allowing for adjustable valve lift and duration through a simple structure that includes a torsion spring and rolling friction contact with the camshaft, enabling the engine to adapt to different load conditions by changing the contact position between the roller rocker arm and the driving arc surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed valve driving mechanism is used, then the engine structure is simple, but the valve lift and duration cannot be adjusted according to operational conditions

Engineering Contradiction:
Improvevalve lift adjustment capabilityVSAvoidvalve driving mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a dynamically adjustable valve lift mechanism where the swing arm can change its effective lever arm length continuously. The driving arc surface contacts different positions on the swing arm based on operational conditions, enabling the valve lift to be adjusted from zero to a maximum value dynamically, transforming a static mechanism into a dynamic one that adapts to varying engine loads.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the geometric parameter of the valve lift mechanism by utilizing a curved driving arc surface. As the camshaft rotates, the contact point moves along the arc, changing the effective radius and thus the valve lift parameter continuously. This allows the system to achieve variable valve lift without complex additional components by simply changing the contact position parameter.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If existing variable valve lift systems are used, then valve lift can be adjusted, but the structure becomes complex and difficult to manufacture

Engineering Contradiction:
Improvevalve lift adjustment capabilityVSAvoidmanufacturing difficulty
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent segments the valve driving function into two independent components: a fixed camshaft that provides the driving force and a movable swing arm that provides the adjustment capability. This segmentation allows each component to be manufactured separately using standard machining processes, avoiding the need to manufacture complex integrated assemblies, thereby improving ease of manufacture while maintaining variable valve lift functionality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a swing arm as an intermediary component between the camshaft and the valve. This intermediary element simplifies the overall structure by decoupling the camshaft design from the valve lift adjustment mechanism. The swing arm acts as a mechanical mediator that translates camshaft rotation into variable valve lift through its swinging motion, making the system easier to manufacture and assemble.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If a fixed valve movement is used, then the engine design is simple, but it cannot reconcile the demands of power in high load and economy in low load

Engineering Contradiction:
Improveoperational condition adaptabilityVSAvoidvalve driving mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent creates a dynamic valve control system where the valve lift and duration can be continuously adjusted based on engine operational conditions. The swing arm's ability to pivot and change its effective lever arm length allows the system to optimize valve timing and lift for both high-load power delivery and low-load fuel economy, transforming a static system into an adaptive one.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent designs a universal valve driving mechanism that can handle multiple operational requirements with a single system. The swing arm mechanism serves multiple functions: it provides variable valve lift, adjustable valve duration, and adapts to different engine loads, replacing the need for multiple specialized mechanisms and simplifying the overall engine design while improving operational flexibility.

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

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 allows for continuous adjustment of valve lift and duration, enabling the engine to optimize power and economy by increasing valve lift in high load areas and reducing it in low load areas, thus improving fuel efficiency and combustion optimization.

Implementation Method 1

a torsion spring, one end of the torsion spring is adapted to be fixed to a casing of an engine, and the other end of the torsion spring is fixed to the driving swing arm

Methodology Applied
Scientific EffectTorsion spring: Torsion Spring

Implementation Method 2

The driving swing arm is provided with a driving arc surface. The driving arc surface contacts with the roller rocker arm to drive the valve to move in a reciprocating manner

Methodology Applied
Scientific EffectRolling friction: Friction

Data Source

PatentEP3392476B1Continuously variable valve lift system and automobile
Publication Date: 2021.03.31 GUANGZHOU AUTOMOBILE GROUP CO LTD
  • EP3392476B1 patent drawingFigure 1
  • EP3392476B1 patent drawingFigure 2
  • EP3392476B1 patent drawingFigure 3

AI summary

Disclosed are a continuously variable valve lift system and an automobile comprising same. The continuously variable valve lift system comprises a driving swing arm (20), a camshaft (50) and a valve mechanism (60), wherein the valve mechanism (60) comprises a roller rocker arm (61) and a valve (62) which is connected to the roller rocker arm (61), the driving swing arm (20) comprises a driving surface (21), and the driving surface (21) makes contact with the roller rocker arm (61) so as to drive the valve (62) to perform reciprocating motion. The continuously variable valve lift system further comprises a control shaft (10) and an adjustment swing arm (30), wherein the driving swing arm (20) is sleeved on the control shaft (10) and can swing around the control shaft (10), a fixed part (11) is provided on the control shaft (10), the fixed part (11) is fixed on the control shaft (10), the adjustment swing arm (30) is connected on the fixed part (11) and can swing relative to the fixed part (11), the adjustment swing arm (30) is provided between the camshaft (50) and the driving swing arm (20), and two sides of the adjustment swing arm (30) respectively make contact with the camshaft (50) and the driving swing arm (20).