Asynchronous Tamping Unit Control for Ballast Wear Reduction

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Solution Overview

Problem

Existing tamping methods face challenges in efficiently tamping adjacent sleepers, especially in encrusted ballast, leading to increased wear on both the ballast and tamping units, and suboptimal penetration due to simultaneous lowering of tamping units.

Innovation Solution

Implementing a time-delayed lowering mechanism for adjacent tamping units, where one drive is actuated earlier than the other by 100 to 300 milliseconds, allowing the leading inner tamping pick to penetrate the ballast first and facilitate easier penetration for the following pick.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If two tamping units are lowered simultaneously to tamp adjacent sleepers, then the tamping process is efficient and both sleepers are tamped at the same time, but the ballast displacement is doubled causing increased wear on ballast and tamping units, and penetration becomes difficult in encrusted ballast

Engineering Contradiction:
Improvetamping efficiencyVSAvoidballast wear and tamping unit wear
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The first tamping unit is lowered and begins tamping before the second tamping unit is lowered. This preliminary action allows the first unit to start displacing ballast and creating a path, reducing the resistance for the second unit and minimizing overall ballast displacement and wear.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The lowering of the two tamping units is made dynamic rather than simultaneous. The control system adjusts the timing of each unit's lowering independently, creating a time-delayed sequence that adapts to the ballast conditions and reduces harmful displacement effects.

Inventive Principle:
Principle #15Dynamics

2Productivity

If two tamping units are lowered simultaneously, then both inner tamping picks penetrate the ballast at the same time, but this causes excessive ballast displacement and makes penetration difficult in encrusted ballast

Engineering Contradiction:
Improvetamping speedVSAvoidpenetration ease
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The first inner tamping pick penetrates the ballast before the second inner tamping pick. This preliminary penetration creates a path through the encrusted ballast, reducing resistance for the second pick and making overall penetration easier while maintaining efficient tamping speed.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If both tamping units are lowered together, then the tamping process is simplified, but the vibration of the following tamping pick is reduced making penetration harder

Engineering Contradiction:
Improvecontrol simplicityVSAvoidpenetration capability
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The first tamping unit is lowered and generates vibration in the ballast before the second unit is lowered. This preliminary vibration loosens the ballast structure, and when the second unit is lowered, it benefits from this pre-loosened state, enhancing its penetration capability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses dynamic timing control where the second tamping unit is lowered after a delay following the first unit. This dynamic approach ensures the second unit penetrates into already-vibrated ballast, maximizing penetration effectiveness while the control system manages the timing automatically.

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 approach significantly reduces ballast displacement, eases penetration, and minimizes wear on both the ballast and tamping units by allowing the leading tine to initiate ballast movement, making it easier for the subsequent tine to follow.

Implementation Method 1

the vibration of the leading inner tamping tine causes the surrounding gravel to flow, thus facilitating the penetration of the second inner tamping tine, which follows behind

Methodology Applied
Scientific EffectVibration: Vibration

Data Source

PatentEP2912226B1Method for tamping a railway track by means of asynchronously actuated tamping aggregates
Publication Date: 2018.03.21 PLASSER & THEURER EXPORT VON BAHNBAUMASCHINEN GMBH
  • EP2912226B1 patent drawingFigure 1~4

AI summary

For tamping two adjacent sleepers (9) of a track (3), the joint lowering of two adjoining tamping units (2) takes place with a time delay. As a result, the immersion in particular of immediately adjacent inner tamping tines (20) plunging into a common sleeper crib (18) is facilitated.