Industrial Vehicle Torque Control for Eco-Mode Performance

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Solution Overview

Problem

Industrial vehicles, such as forklift trucks, face challenges in improving fuel efficiency while maintaining performance due to torque restrictions in Eco-mode, as they often require higher torque for heavy loads and specific operations, leading to potential failures in loading and speed limitations.

Innovation Solution

An industrial vehicle system that includes an accelerator sensor, loading unit, and control units to dynamically release and resume torque restrictions based on predetermined conditions, such as accelerator opening, vehicle speed, and lifting operations, allowing for adaptive torque control in Eco-mode to balance fuel efficiency and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If torque restriction is applied in Eco-mode to improve fuel efficiency, then fuel consumption is reduced, but vehicle performance deteriorates due to insufficient torque for heavy loads and maximum speed achievement

Engineering Contradiction:
Improvefuel efficiencyVSAvoidvehicle performance
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The torque restriction control is made dynamic by continuously monitoring accelerator opening degree, vehicle speed, and loading unit position. The control system adjusts torque restriction levels based on real-time operating conditions, transitioning between restricted and unrestricted states as needed to maintain both fuel efficiency and performance

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the torque restriction parameter based on detected operating conditions. When accelerator opening exceeds threshold, vehicle speed exceeds threshold, or loading unit is in lifting operation, the torque restriction parameter is adjusted to provide full power, otherwise it maintains restricted torque for fuel efficiency

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If torque restriction is continuously applied in Eco-mode, then fuel efficiency is improved, but loading operation reliability deteriorates due to insufficient torque for lifting operations

Engineering Contradiction:
Improvefuel efficiencyVSAvoidloading operation reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The control system uses feedback from the loading unit position sensor to detect lifting operations. When the loading unit is detected to be in a lifting operation state, the system provides feedback to the torque control unit to release torque restriction, ensuring reliable loading operation while maintaining fuel efficiency during non-lifting operations

Inventive Principle:
Principle #23Feedback

3Use of energy by moving object

If torque restriction is applied to maintain fuel efficiency, then energy consumption is reduced, but vehicle speed capability deteriorates due to insufficient torque for achieving maximum speed

Engineering Contradiction:
Improvefuel consumptionVSAvoidmaximum vehicle speed
Core Design Contradiction:
Use of energy by moving objectVSSpeed

Solution Approach 1:

The torque restriction control dynamically responds to vehicle speed conditions. When vehicle speed exceeds a predetermined threshold, the system automatically releases torque restriction to enable achievement of maximum vehicle speed, while maintaining restricted torque at lower speeds to optimize fuel consumption

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2862834B1Industrial vehicle
Publication Date: 2017.12.27 TOYOTA INDUSTRIES CORP
  • EP2862834B1 patent drawingFigure 1
  • EP2862834B1 patent drawingFigure 2A~3

AI summary

An industrial vehicle (10) includes an accelerator (29), an accelerator opening sensor (30) which detects an opening of the accelerator (29), a loading unit (11), an engine (19) and a torque restriction releasing unit (32). When the torque restriction releasing unit (32) is set in an Eco-mode in which torque of the engine (19) is restricted, if the opening of the accelerator (29) detected by the accelerator opening sensor (30) is a first predetermined value (XA) or greater and at least one of conditions that a speed of the vehicle is a second predetermined value (YA) or greater and that the loading unit (11) is in a lifting operation, is satisfied and such conditions of the accelerator (29) and the vehicle speed and/or lifting operation are continued for a predetermined period of time, the torque restriction releasing unit (32) releases the torque restriction.