Lawn Mower Control Unit Adapting Speed and Flap Angle

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Solution Overview

Problem

The existing rotary lawn mowers face inefficiencies in maintaining consistent cutting quality due to varying lawn conditions, requiring manual adjustment by operators, which affects work efficiency and evenness of grass cutting.

Innovation Solution

A lawn mower equipped with a cutter blade, a drive source, a grass clippings container, a flap with adjustable angle, an actuator, and a control unit that adjusts the rotation speed and flap angle based on detected weight changes in the clippings container to adapt to different lawn conditions, ensuring efficient cutting and storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If manual adjustment by operator is used to maintain cutting quality, then cutting evenness is improved, but work efficiency deteriorates

Engineering Contradiction:
Improvecutting evennessVSAvoidwork efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The lawn mower system performs self-adjustment of cutting parameters through the control unit that automatically modifies rotation speed and flap angle based on weight detection feedback, eliminating the need for manual operator intervention and maintaining cutting quality autonomously

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses weight detection of grass clippings in the container as feedback to automatically adjust cutting parameters, creating a closed-loop control system that maintains optimal cutting performance without manual intervention

Inventive Principle:
Principle #23Feedback

2Productivity

If automatic adjustment based on weight detection is implemented, then work efficiency is improved, but device complexity increases

Engineering Contradiction:
Improvework efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system replaces manual mechanical adjustment with automated electronic control based on weight detection, using sensors and control units to substitute human operator actions with automatic detection and adjustment mechanisms

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

Solution Approach 2:

The control unit automatically adjusts operational parameters (rotation speed and flap angle) based on detected weight changes, dynamically modifying system parameters to optimize performance without manual intervention

Inventive Principle:
Principle #35Parameter changes

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 enables stable and efficient lawn mowing operations regardless of lawn conditions, eliminating uneven cutting and improving work efficiency by automatically adjusting the cutting parameters, and enhancing the storage capacity of grass clippings in the container.

Implementation Method 1

a grass clippings container weight detection unit configured to detect weight of the grass clippings container

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP3210450B1Lawn mower
Publication Date: 2019.01.23 HONDA MOTOR CO LTD
  • EP3210450B1 patent drawingFigure 1
  • EP3210450B1 patent drawingFigure 2
  • EP3210450B1 patent drawingFigure 3

AI summary

A lawn mower (10) includes a drive source (15) for driving a cutter blade (14), flaps (52), a grass clippings container (22), a grass clippings container weight detection unit (113), a travel distance detection unit (131), and a control unit (117). The control unit (117) determines a change amount (Wa) of weight (Wr) of the grass clippings container (22) detected by the grass clippings container weight detection unit (113) over the elapsed time period from the time when detection of travel distance (Lr) of the lawn mower (10) is started by the travel distance detection unit (131) to the time when travel of predetermined distance (Ls) is completed, and implements control in a manner that the rotation speed (Ner) of the drive source (15) and the flap angle (θr) of the flaps (52) are adjusted in accordance with the change amount (Wa) of the weight (Wr).