Two-Way Excavator Hydraulic Control Segmentation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing two-way excavators face challenges in efficiently converting rail axles for road travel while maintaining compliance with axle load regulations, requiring complex hydraulic control systems that complicate operation and retrofitting.

Innovation Solution

A road-rail excavator with a separate hydraulic control system for rail axles during road travel, utilizing a simple structure with check valves and pressure control via ball valves to convert rail axles into additional wheeled axles, allowing independent control and adjustment of contact pressure for road travel without affecting rail travel operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a complex hydraulic control system is used to control rail axles during road travel, then the excavator can comply with axle load regulations, but the system complexity and difficulty of operation increase

Engineering Contradiction:
Improveaxle load complianceVSAvoidhydraulic control system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The hydraulic control system is segmented into two independent parts: the existing rail travel hydraulic control and the new road travel hydraulic control. Each controls specific hydraulic cylinders for its intended function, avoiding the need for a single complex unified system. The road travel control independently manages the conversion of rail axles to wheeled axles without interfering with rail travel operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The road travel control functionality is extracted as a separate, independent hydraulic control system rather than being integrated into the existing rail travel control. This extraction allows the road travel function to be added without complicating the original rail travel control system, enabling simple retrofitting while maintaining operational simplicity.

Inventive Principle:
Principle #2Taking out (Extraction)

2Adaptability or versatility

If the hydraulic control system is modified to accommodate road travel with additional axles, then axle load distribution is improved, but the ease of manufacture and retrofitting deteriorates

Engineering Contradiction:
Improveweight distributionVSAvoidretrofitting complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The control system is divided into independent segments (rail travel control and road travel control) that can be manufactured and installed separately. The road travel control is designed as a standalone unit that interfaces with existing hydraulic cylinders through simple connections, facilitating easy retrofitting without requiring complete system redesign.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The road travel hydraulic control is designed to work with the existing hydraulic cylinders used for rail travel, making these cylinders multi-functional. The same cylinders that pivot rail axles for rail travel are also used to convert them into wheeled axles for road travel, eliminating the need for separate actuators and simplifying retrofitting.

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

3Adaptability or versatility

If a unified hydraulic control system is used for both rail and road travel, then system integration is achieved, but the ease of operation and maintenance deteriorates

Engineering Contradiction:
Improvedual-mode operationVSAvoidcontrol operation simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The hydraulic control system is segmented into functionally independent units: rail travel control and road travel control. Each unit operates autonomously and can be activated only when needed, simplifying the operator's decision-making process. The system automatically switches between modes based on which control unit is engaged, reducing operational complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The road travel control function is extracted as a separate, independently operable system that does not interfere with the rail travel control. This extraction allows each control system to be optimized for its specific function, maintaining simplicity while achieving dual-mode capability.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Enables easy retrofitting and operation, using proven components to maintain normal two-way operation while allowing the rail axle to function as an additional wheeled axle during road travel, ensuring compliance with axle load regulations and providing adjustable contact pressure for efficient road travel.

Implementation Method 1

the rail axles being pivotable by hydraulic cylinders into an operating position for rail travel

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP2141290B1Two-way excavator
Publication Date: 2020.07.29 LEIBHERR HYDRAULIKBAGGER GMBH
  • EP2141290B1 patent drawingFigure 1a~1b
  • EP2141290B1 patent drawingFigure 2
  • EP2141290B1 patent drawingFigure 3

AI summary

The excavator has two wheel axles with wheels for road travel and two rail axles with rail wheels for rail travel. The rail axles are tiltable by hydraulic cylinders (1, 2) in an operating position for rail travel. The cylinders are controlled during rail travel over a rail travel hydraulic control (3). A rail axle for road travel is retrofitted to provide another axle during road travel. A road travel-hydraulic control (4) controls a hydraulic cylinder of the retrofitted axle and is independent of the hydraulic control (3), where the hydraulic control (4) is in the form of a retrofit kit.