Auto Idle Assembly for Riding Lawn Mower Throttle Control

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Solution Overview

Problem

Riding lawn care vehicles often experience sudden lunges due to full throttle engagement when the brake is released, leading to operator discomfort, potential damage, and inefficiencies in fuel economy, noise, and emissions.

Innovation Solution

An auto idle assembly is integrated into the vehicle, which automatically shifts the engine to an idle setting based on predefined criteria, such as brake position and vehicle state, using a combination of mechanical and electronic control systems to manage throttle position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the throttle remains at full speed setting when the brake is applied, then the vehicle can quickly accelerate when the brake is released, but this causes sudden lunges forward that startle the driver, spill cargo, and cause excessive wear or damage to system components

Engineering Contradiction:
Improvevehicle acceleration responseVSAvoidsudden lunge forward
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary action by automatically reducing the throttle to an idle setting when the brake is detected to be applied. This preemptive throttle reduction prevents the harmful sudden lunge from occurring in the first place, while still allowing quick acceleration when needed by maintaining the throttle system's readiness to respond.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from brake position sensors to automatically adjust throttle position. When the brake sensor detects brake application, the system feeds this information back to the throttle control mechanism, which automatically reduces throttle. This closed-loop feedback system continuously monitors and adjusts to prevent harmful lunges while maintaining operational responsiveness.

Inventive Principle:
Principle #23Feedback

2Ease of operation

If the throttle is set to full speed continuously, then the vehicle is ready for immediate movement, but this results in poor fuel economy, increased noise, and higher emissions when the vehicle is stationary or braking

Engineering Contradiction:
Improvevehicle readiness for movementVSAvoidfuel economy
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The system implements dynamic throttle control that automatically adjusts between full speed and idle settings based on real-time operating conditions. Rather than maintaining a static full-throttle position, the throttle dynamically responds to brake application and vehicle state, optimizing fuel economy during stationary/braking phases while maintaining operational readiness when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the throttle parameter (position/opening degree) based on detected operating conditions. When braking or stationary, the throttle parameter is automatically changed from full open to idle position, reducing fuel consumption, noise, and emissions. This parameter adjustment maintains vehicle readiness while improving efficiency during non-movement phases.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If a manual throttle control system is used, then the system is simple in structure, but it requires constant operator attention and manual adjustment to prevent sudden lunges and optimize fuel efficiency

Engineering Contradiction:
Improvecontrol system structureVSAvoidthrottle position adjustment
Core Design Contradiction:
Device complexityVSExtent of automation

Solution Approach 1:

The system implements self-service by automatically monitoring brake position and autonomously adjusting throttle settings without requiring operator intervention. The control system serves itself by detecting when the brake is applied and automatically reducing throttle to prevent lunges and optimize fuel economy, eliminating the need for constant manual attention while maintaining simple overall system architecture.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2966968B1Riding lawn care vehicle auto idle system
Publication Date: 2021.01.06 HUSQVARNA AB
  • EP2966968B1 patent drawingFigure 1
  • EP2966968B1 patent drawingFigure 2
  • EP2966968B1 patent drawingFigure 3

AI summary

A riding lawn care vehicle may include a mobility assembly configured to support the riding lawn care vehicle during movement over ground, a working assembly configured to perform a working function, an engine operably coupled to the mobility assembly and the working assembly, a drive control system, and an auto idle assembly. The engine may be configured to selectively provide power to the mobility assembly and the working assembly. The drive control system may be configured to control delivery of the power from the engine to the mobility assembly. The auto idle assembly may be configured to automatically provide inputs to the drive control system to shift to an idle mode responsive to detection of predetermined criteria.