Excavator Engine Speed Control for Low-Load Energy Saving

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Solution Overview

Problem

Existing excavator technologies do not effectively reduce energy consumption during low-load operations.

Innovation Solution

The excavator includes a power engine with a rotation speed reduction mechanism that adjusts engine speed before starting low-load operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the power engine operates at high rotation speed continuously, then the excavator can respond quickly to high-load operations, but energy consumption increases during low-load operations

Engineering Contradiction:
Improveresponse speedVSAvoidenergy consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The power engine's rotation speed is made dynamically adjustable based on operational needs. The control unit varies the rotation speed between high and low states according to whether high-load or low-load operations are detected, allowing the system to adapt its performance characteristics to match actual work requirements rather than maintaining a fixed high-speed state

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rotation speed parameter of the power engine is changed based on detected operation types. When low-load operations are detected, the control unit reduces the rotation speed parameter to a lower value, thereby reducing energy consumption while maintaining sufficient performance for the actual work being performed

Inventive Principle:
Principle #35Parameter changes

2Power

If the power engine maintains high rotation speed, then sufficient power is available for high-load operations, but wasteful energy consumption occurs during low-load operations

Engineering Contradiction:
Improveavailable powerVSAvoidwasteful energy consumption
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The control unit detects operation types in advance and adjusts the power engine's rotation speed accordingly before actual operations commence. By identifying whether upcoming operations will be high-load or low-load, the system can pre-adjust the engine speed to appropriate levels, avoiding unnecessary energy consumption while ensuring sufficient power availability when needed

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control unit continuously monitors operation types and uses this feedback information to adjust the power engine's rotation speed. This closed-loop control ensures that the engine operates at the minimum necessary speed to perform the detected operation type, thereby eliminating wasteful energy consumption during low-load operations while maintaining sufficient power for high-load operations

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4159929B1excavator
Publication Date: 2025.11.12 SUMITOMO CONSTRUCTION MACHINERY
  • EP4159929B1 patent drawingFigure 1
  • EP4159929B1 patent drawingFigure 2
  • EP4159929B1 patent drawingFigure 3

AI summary

An excavator (100) includes a lower traveling body (1); an upper turning body (3) turnably mounted to the lower traveling body (1); an attachment (AT) that is attached to the upper turning body (3); and a power engine that is mounted to the upper turning body (3). The excavator (100) is configured such that, before a low-load operation by the attachment (AT) is started, a rotation speed of the power engine is reduced.