Acceleration Lever Stopper for Intermediate Engine Speed Control

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Solution Overview

Problem

Conventional construction machines require operators to carefully position the acceleration lever at an intermediate-speed position to balance engine output and fuel consumption, which is difficult and time-consuming.

Innovation Solution

A construction machine with a lever mechanism that includes an acceleration lever movable between low-speed, intermediate-speed, and high-speed positions, featuring intermediate- and high-speed stoppers to easily position the lever at the intermediate-speed setting, reducing operator effort and enhancing operability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the acceleration lever is manually positioned at an intermediate-speed position to balance engine output and fuel consumption, then fuel consumption is improved, but the ease of operation deteriorates due to the difficulty and time required for careful positioning

Engineering Contradiction:
Improvefuel consumptionVSAvoidease of operation
Core Design Contradiction:
Use of energy by moving objectVSEase of operation

Solution Approach 1:

The acceleration lever's movement range is segmented into multiple discrete positions (low-speed, intermediate-speed, high-speed) with stoppers at each position. This segmentation allows the lever to be easily positioned at the intermediate-speed position without requiring careful manual adjustment, thus improving ease of operation while maintaining fuel consumption benefits.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Stoppers are introduced as intermediary elements between the acceleration lever and the operator. These stoppers automatically position the lever at predetermined speeds, acting as a mediator that eliminates the need for careful manual positioning while achieving the desired intermediate-speed setting for optimal fuel consumption.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the acceleration lever is freely movable to allow easy positioning, then the ease of operation is improved, but the reliability deteriorates due to the risk of accidental movement to high-speed positions

Engineering Contradiction:
Improveease of operationVSAvoidreliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

Stoppers are positioned in advance at specific locations along the acceleration lever's path to prevent accidental movement to high-speed positions. These stoppers create preliminary resistance that counteracts unintended lever movement, thereby improving reliability while maintaining ease of operation through defined positioning points.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The stoppers provide beforehand cushioning by physically blocking the acceleration lever from moving beyond predetermined positions. This prior cushioning prevents accidental transitions to high-speed positions, ensuring reliable operation while allowing easy positioning at the intended intermediate-speed setting.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP2811079B1Construction machine
Publication Date: 2022.04.13 KOBELCO CONSTR MASCH CO LTD
  • EP2811079B1 patent drawingFigure 1
  • EP2811079B1 patent drawingFigure 2
  • EP2811079B1 patent drawingFigure 3

AI summary

Provided is a construction machine with an acceleration lever to be easily positioned at an intermediate-speed position. The construction machine includes an acceleration lever (30) movable in front and rear directions of an upper slewing body between a low-speed position and a high-speed position, an engine-speed operation member (39) to change engine speed in accordance with the moving amount of the acceleration lever (30) in front and rear directions, and an intermediate-speed stopper (40) to stop the acceleration lever (30) at an intermediate-speed position between the low-speed and high-speed positions. The intermediate-speed stopper (40) stops the acceleration lever (30) at the intermediate-speed position by restraining the acceleration lever (30) from movement. The intermediate-speed stopper (40) releases the restraint as the acceleration lever (30) moves from the intermediate-speed position to a release position in a direction different from front and rear directions.