Axial Vane Actuators for Compact Variable Valve Timing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional internal combustion engines with cam phase change mechanisms face challenges in controlling the independent variable ranges of intake valve opening and closing timings, leading to a large valve train size and inadequate control over combustion efficiency.

Innovation Solution

The implementation of a cam phase change mechanism with two vane-type hydraulic actuators arranged axially on the intake camshaft, allowing for differential control of opening and closing timings of intake valves using the same supplied oil pressure, enabling independent control of valve timings and reducing the valve train size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If two camshafts are arranged laterally to control intake valves, then the opening and closing timings can be varied, but the valve train becomes large-sized

Engineering Contradiction:

Improvevalve timing control capabilityVSAvoidvalve train size

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent transitions from a lateral arrangement of two camshafts to an axial arrangement of cam phase change mechanisms on a single camshaft. This dimensional change allows the same valve timing control functionality to be achieved within a compact axial space, reducing the overall valve train size while maintaining the capability to independently control opening and closing timings of intake valves

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Device complexity

If a single cam phase change mechanism is used to control both opening and closing timings, then the structure is simplified, but it cannot properly control both timings with different variable ranges

Engineering Contradiction:

Improvecam phase change mechanism structureVSAvoidindependent valve timing control range

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent divides the cam phase change mechanism into two separate vane-type hydraulic actuators arranged axially on the same camshaft. Each actuator is responsible for controlling one specific timing (opening or closing), allowing independent adjustment of each timing parameter. This segmentation enables the system to handle different variable ranges for opening and closing timings while maintaining a relatively simple integrated structure

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent assigns different characteristics to the two actuators - they produce different variable-phase torques at the same supplied oil pressure. This local differentiation in actuator properties allows each actuator to be optimized for its specific control function, with one actuator providing larger torque for closing timing control and the other for opening timing control, thereby achieving proper independent control of both timings

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS8205587B2Internal combustion engine with variable valve gear

Publication Date: 2012.06.26 MITSUBISHI MOTORS CORP

AI summary

In an engine with a cam phase change mechanism which is disposed on one end portion of an intake camshaft and variably changes a phase of a drive cam of an intake valve relative to a crankshaft, the cam phase change mechanism is configured so that two vane-type hydraulic actuators of which variable-phase torques produced at the same supplied oil pressure are different are arranged axially relative to the intake camshaft.