Road Paver Leveling Cylinder Control for Precise Screed Height

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Solution Overview

Problem

Modern road pavers face challenges in maintaining precise layer thickness and efficiency due to limitations in controlling the screed's angle of attack and material distribution, often requiring manual intervention and indirect measurement methods.

Innovation Solution

A road paver with a height-adjustable chassis and an electronic control system that automatically adjusts the leveling cylinder's towing point height using sensors and a hydraulic control system, allowing for precise control of the screed's angle of attack and material distribution without operator intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the chassis height is manually adjusted to change layer thickness, then material distribution capacity is improved, but layer thickness precision deteriorates due to manual intervention errors

Engineering Contradiction:
Improvematerial distribution capacityVSAvoidlayer thickness precision
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent replaces manual mechanical adjustment of the leveling cylinder with an electronic control system that uses sensors to detect chassis height position and automatically actuates the leveling cylinder to maintain the correct towing point height, thereby eliminating manual intervention errors while preserving material distribution capacity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a feedback control system where sensors continuously monitor the actual towing point height, compare it with the target height, and automatically adjust the leveling cylinder position to correct any deviations, ensuring precise layer thickness control while maintaining optimal material distribution

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If sensors are added to automatically monitor towing point height, then layer thickness precision is improved, but device complexity increases

Engineering Contradiction:
Improvelayer thickness precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements a self-service control system where the electronic control unit automatically processes sensor signals and actuates the leveling cylinder without operator intervention, reducing the need for complex manual control interfaces and minimizing system complexity while maintaining high precision

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent uses an electronic control unit as an intermediary that simplifies the connection between sensors and the leveling cylinder actuator, processing sensor signals and generating appropriate control commands, thereby reducing overall system complexity while enabling precise automatic control

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the towing point height is not automatically corrected, then device complexity is reduced, but productivity deteriorates due to incorrect layer thickness requiring rework

Engineering Contradiction:
Improvecontrol system complexityVSAvoidpaving efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent applies preliminary action by automatically correcting the towing point height before the paving process begins or during idle periods, ensuring the system is properly calibrated before production starts, thereby preventing incorrect layer thickness without requiring complex real-time intervention during paving operations

Inventive Principle:
Principle #10Preliminary action

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 ensures consistent layer thickness and efficient material distribution by automatically correcting the towing point height, preventing incorrect layer installation and reducing operational complexity and costs.

Implementation Method 1

The control system comprises a receiving unit, an evaluation unit, and a command unit. The receiving unit is configured and interconnected to detect a current actual towing point height.

Methodology Applied
Scientific EffectSensor measurement:

Implementation Method 2

a correction signal sent by the command unit causing a hydraulic control to adjust at least one of the leveling cylinders

Methodology Applied
Scientific EffectHydraulic control: Hydraulic Press

Data Source

PatentEP3498914B1Adjustment of the levelling cylinder in a road finisher
Publication Date: 2024.05.15 JOSEPH VOEGELE AG
  • EP3498914B1 patent drawingFigure 1
  • EP3498914B1 patent drawingFigure 2
  • EP3498914B1 patent drawingFigure 3

AI summary

A road paver (1) comprising a running gear (19), a chassis (3) height-adjustable relative to the running gear (19), an electronic control system (36), and a screed (7) attached to drawbars (9), wherein the drawbars (9) are each articulated to a drawbar point (15) on the chassis (3), and the drawbar points (15) are each adjustable relative to the chassis (3) by means of a leveling cylinder (11). Height adjustment of the chassis (3) can cause a deviation of the actual drawbar point height (N) from a target drawbar point height.To correct this deviation, the control system (36) includes a receiving unit (37) configured to detect a current actual drawbar height (N), an evaluation unit (39) configured to calculate a deviation of the actual drawbar height (N) from a target drawbar height caused by a height adjustment of the chassis (3) relative to the running gear (19), and a command unit (41) configured to automatically correct the deviation at least partially by sending a correction signal (47) from the command unit (41) to cause a hydraulic control (49) to adjust at least one of the leveling cylinders (11).