Valve Train Device Axial Cam Piece Guide

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Solution Overview

Problem

Conventional valve train devices with axially displaceable cam pieces are complex, prone to errors, and costly due to the need for multiple shifting gates and actuators, leading to high assembly work and acoustic abnormalities at higher engine speeds.

Innovation Solution

A valve train device featuring a double cam piece with axially independent link tracks, where each link track is used for distinct directions of cam piece displacement, reducing mechanical loads on adjustment pins and eliminating common track sections to enhance durability and reduce noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional valve train devices use multiple shifting gates and actuators for each cylinder, then the valve timing control is achieved, but the device complexity and assembly work increase considerably

Engineering Contradiction:
Improvevalve timing controlVSAvoidnumber of shifting gates and actuators
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges multiple cam pieces into a single double cam piece that controls multiple cylinders simultaneously. This single cam piece integrates the functions of what would traditionally require separate cam pieces, shifting gates, and actuators for each cylinder, thereby reducing device complexity while maintaining valve timing control capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The double cam piece is designed to perform multiple functions: it controls valve timing for multiple cylinders simultaneously and enables both activation and deactivation operations through its integrated design with two cam tracks. This multi-functional approach eliminates the need for separate actuators for each cylinder

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

2Device complexity

If conventional valve train devices use common track sections in cam tracks, then the structure is simplified, but acoustic abnormalities occur at higher engine speeds

Engineering Contradiction:
Improvecam track structureVSAvoidacoustic abnormalities
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent segments the cam track into two completely separate and independent cam tracks without any common track sections. Each cam track is dedicated to a specific function (activation or deactivation), which eliminates the interference and acoustic abnormalities that occur when multiple operations share common track sections, especially at higher engine speeds

Inventive Principle:
Principle #1Segmentation

3Volume of moving object

If conventional valve train devices use shared cam tracks for forward and reverse displacement, then the structure is compact, but mechanical loads on adjusting pins increase

Engineering Contradiction:
Improvecam piece structureVSAvoidmechanical loads on adjusting pins
Core Design Contradiction:
Volume of moving objectVSStress or pressure

Solution Approach 1:

The patent divides the cam piece structure into two independently guided cam tracks, where each track handles a specific displacement direction. This segmentation allows each adjusting pin to operate in its dedicated track without bearing the combined mechanical loads that would result from sharing a common track, thereby reducing stress and improving durability

Inventive Principle:
Principle #1Segmentation

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 solution allows for reliable and efficient valve lift switching at higher speeds with reduced mechanical stress and noise, increasing the durability of the valve train device and lowering production costs by using narrower adjustment pins and more compact cam pieces.

Implementation Method 1

the first cam track is for axially displacing the cam piece in a forward direction and a second cam track for axially displacing the cam piece in a reverse direction opposite to the forward direction

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3292280B1Valve train device
Publication Date: 2021.03.10 VOLKSWAGEN AG
  • EP3292280B1 patent drawingFigure 1~3
  • EP3292280B1 patent drawingFigure 4

AI summary

The invention relates to a valve train device comprising: a camshaft with an axially movably arranged cam piece (10) having at least two cams (12, 14) that allow, in the event of a rotation of the camshaft, phase-shifted cam strokes and that are associated with different cylinders; and a slotted guide (20) for the axial movement of the cam piece (10), said slotted guide having a first slotted guide track (22) for the axial movement of the cam piece in a forward direction (V) and a second slotted guide track (24) for the axial movement of the cam piece in a reverse direction (R) counter to the forward direction. The first slotted guide track (22) and the second slotted guide track (24) have a common track section (25).