Automatic Throttle for Hydrostatic Tractor Pedals

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Solution Overview

Problem

Tractor applications often require frequent or continuous changes in engine speed, which is inefficient with existing systems that rely on manual hand throttle or hand accelerator lever operation in twin pedal hydrostatic transmissions.

Innovation Solution

An automatic throttle system using Bowden cables and bell cranks connects the twin foot pedals to the engine throttle, allowing for automatic engine speed adjustments without manual intervention, with customizable throttle response for forward and reverse pedals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual hand throttle or hand accelerator lever is used to control engine speed, then the operator can adjust engine speed, but frequent or continuous manual adjustments are required which increases operator workload and reduces efficiency

Engineering Contradiction:
Improveoperator workloadVSAvoidoperational efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The system enables self-service operation where the engine speed automatically adjusts itself based on pedal position signals. The electronic controller continuously monitors the position of forward and reverse pedals and automatically commands the throttle actuator to adjust engine speed, eliminating the need for manual hand throttle operations and reducing operator workload while maintaining optimal engine speed for various operating conditions

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the manual mechanical hand throttle control system with an electronic control system. Instead of mechanically linking the hand throttle lever to the throttle body, the invention uses electronic sensors to detect pedal position and an electronic controller to command an electric throttle actuator, substituting mechanical manual control with an automated electronic control system that improves operational efficiency

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

2Extent of automation

If electronic controller with pedal position sensing is used for automatic throttle control, then engine speed adjustments are automated, but system complexity and cost increase

Engineering Contradiction:
Improveautomatic throttle controlVSAvoidcontrol system complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The electronic controller serves multiple functions: it monitors the position of both forward and reverse pedals, determines which pedal is depressed, calculates the desired engine speed based on pedal position, and commands the throttle actuator accordingly. This multi-functional approach consolidates what could be separate control circuits into a single integrated controller, reducing overall system complexity while achieving comprehensive automatic throttle control

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

Solution Approach 2:

The system uses parameter changes in the form of voltage signals representing pedal position to control engine speed. Instead of complex mechanical linkages or hydraulic systems, the invention translates physical pedal position into electrical signals that the controller processes to adjust throttle opening, using simple parameter changes (voltage levels) to achieve sophisticated automatic control with minimal hardware complexity

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If separate control circuits are used for forward and reverse pedals, then each pedal can be precisely controlled, but circuit complexity and cost increase

Engineering Contradiction:
Improvepedal position detectionVSAvoidcontrol circuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the control logic for forward and reverse pedals into a single electronic controller with unified processing. Instead of using separate independent control circuits for each pedal, the invention combines both pedal position sensing and control logic into one integrated controller that handles both pedals through a single microprocessor or control unit, reducing circuit complexity while maintaining precise detection and control of each pedal's position

Inventive Principle:
Principle #5Merging (Combining)

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

Eliminates the need for frequent hand throttle adjustments, providing efficient and operator-friendly engine speed control, reducing operator workload and enhancing operational efficiency in applications like front end loader operations and road transport.

Implementation Method 1

A first Bowden cable 114 connecting booth of the twin foot pedals to engine throttle 116. When either of the twin foot pedals is depressed by the operator, the pedal pulls and tensions internal cable 119, and move the engine throttle

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

The automatic throttle includes a plurality of bell cranks 120, 122 and 124 mounted independently to the same cross shaft 126. First and second bell cranks 120 and 122 are connected by first and second linkages or rods 128 and 130 to forward and reverse pedals 104 and 106 respectively

Methodology Applied
Scientific EffectLever: Lever

Data Source

PatentEP3613622B1Automatic throttle
Publication Date: 2022.03.09 DEERE & CO
  • EP3613622B1 patent drawingFigure 1
  • EP3613622B1 patent drawingFigure 2
  • EP3613622B1 patent drawingFigure 3

AI summary

An automatic throttle for a hydrostatic transmission having a forward pedal and a reverse pedal. Each pedal actuates a swash plate on a hydraulic pump for forward and reverse travel. A first bell crank and a second bell crank are connected to the forward pedal and the reverse pedal respectively. Each bell crank may pull a Bowden cable connected to an engine throttle to increase engine speed when either of the pedals is depressed.