Variable Stroke Tamper Bar Sections for Paving Compaction

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Solution Overview

Problem

Existing road finishers struggle to maintain consistent compaction performance across varying paving thickness and speed, leading to undesirable variations in pavement thickness and width, which affect the final quality of the surface layer.

Innovation Solution

The road finisher allows for variable stroke and frequency adjustments of tamper bar sections across the paving width, enabling remote control of compaction performance to match local paving conditions, ensuring a consistent and high-quality surface layer despite changes in thickness and speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the stroke and frequency of the tamper device are kept constant, then the device complexity is reduced, but the manufacturing precision of the pavement thickness deteriorates due to variations in compaction performance

Engineering Contradiction:
Improvetamper device control systemVSAvoidpavement thickness uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The tamper device is divided into multiple tamper bar sections (at least three sections across the paving width), each with independently adjustable stroke and/or frequency. This segmentation allows different sections to be optimized for local conditions while maintaining overall system simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different tamper bar sections are assigned different strokes and/or frequencies according to local paving conditions. For example, sections paving over thicker material or slower speeds receive higher stroke values, while sections with thinner material or higher speeds receive lower stroke values, ensuring uniform compaction quality across the entire paving width.

Inventive Principle:
Principle #3Local quality

2Power

If the stroke of the tamper device is increased to improve compaction performance, then the compaction power is improved, but the angle of attack of the screed changes undesirably affecting pavement thickness

Engineering Contradiction:
Improvecompaction powerVSAvoidpavement thickness
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The stroke of each tamper bar section is individually adjusted according to local conditions. Sections requiring higher compaction power receive increased stroke, while other sections maintain lower strokes to preserve the screed's angle of attack and pavement thickness, allowing differentiated compaction without uniform adverse effects.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The stroke and frequency of tamper bar sections are made dynamically adjustable during operation, allowing real-time optimization of compaction power while maintaining stable screed positioning and consistent pavement thickness through coordinated control.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the paving speed is varied to increase productivity, then the productivity is improved, but the compaction performance deteriorates due to constant stroke and frequency

Engineering Contradiction:
Improvepaving speedVSAvoidcompaction performance
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The stroke and frequency of tamper bar sections are dynamically adjusted in response to variations in paving speed. When paving speed increases, the stroke and/or frequency of affected sections is increased to maintain compaction performance, allowing high productivity without sacrificing compaction quality.

Inventive Principle:
Principle #15Dynamics

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 solution ensures a consistently high-quality surface layer by dynamically adjusting tamper bar strokes and frequencies to match local paving conditions, maintaining a constant angle of attack and compaction performance across the paving width, thereby improving the final quality of the paved surface.

Implementation Method 1

The lifting drive (22) has at least two couplings (16) which transmit the stroke and the frequency of the lifting drive

Methodology Applied
Scientific EffectMechanical coupling through eccentrics: Mechanical Force

Implementation Method 2

The rotary drive (18), from whose rotation via the couplings (16) (at least one of which has a degree of freedom) the strokes of the tamper bar section are derived

Methodology Applied
Scientific EffectEccentric conversion: Eccentric

Data Source

PatentEP2366832B1Method and paver for producing a compacted paved surface
Publication Date: 2015.09.23 JOSEPH VOEGELE AG
  • EP2366832B1 patent drawingFigure 1~2
  • EP2366832B1 patent drawingFigure 3~5

AI summary

In a method for laying a surface layer using a paver F comprising a screed B, wherein the screed, equipped with a tamper T and a smoothing blade 12, at least compacts and smooths the surface of the surface layer, the stroke h and/or the frequency f of the tamper T are remotely varied to lay a surface layer 3 with varying layer thickness D and/or layer speed V across the paving width b and transversely to the direction of travel R within the paving width b. In a paver suitable for carrying out the method, the paver or the screed B has an adjustment device E for remotely and locally varying at least the stroke h of the tamper T within the paving width b.