Motor-Generator Torque Switching During Work Machine Startup

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Solution Overview

Problem

Existing working machines do not efficiently perform assisting or electricity generating actions during starting operations, neglecting the behavior of the machine at the time of starting.

Innovation Solution

A working machine with a starting action determining unit that sets torque for the motor/generator based on the operation member's change, distinguishing between starting and non-starting actions, and using first and second torque settings based on engine rotation speed relationships.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a work machine is equipped with both a work implement and a cargo body, then work efficiency is improved, but the machine becomes top-heavy and unstable

Engineering Contradiction:
Improvework efficiencyVSAvoidmachine stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The cargo body is designed to be movable relative to the carriage frame, allowing it to be positioned in different locations (front, rear, or removed entirely) depending on the working conditions. This dynamic reconfiguration enables the machine to maintain stability by adjusting the cargo body position to achieve proper weight distribution during different operational phases.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The cargo body is separated from the main carriage frame as an independent movable component rather than a fixed integral part. This segmentation allows the cargo body to be independently positioned, moved, or removed to optimize the machine's weight distribution and stability characteristics for different working scenarios.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If the cargo body is fixed to the carriage frame, then structural simplicity is maintained, but the machine cannot adapt to different working conditions

Engineering Contradiction:
Improvestructural simplicityVSAvoidadaptability to working conditions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The cargo body is designed with movable mounting mechanisms that allow it to be repositioned along the carriage frame or removed entirely. This dynamic capability provides adaptability to different working conditions while maintaining relatively simple structural implementation through standardized mounting and dismounting interfaces.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The movable cargo body design enables the machine to perform multiple functions by adjusting the cargo body position or removing it. The same basic structure can accommodate different working conditions, making the machine versatile without requiring entirely different configurations for each application.

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

3Stability of the object's composition

If the cargo body is moved frequently to optimize weight distribution, then machine stability is improved, but operation time is lost

Engineering Contradiction:
Improveweight distributionVSAvoidoperation time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The cargo body is designed with quick-adjustment mechanisms that allow for rapid repositioning or removal without requiring time-consuming disassembly operations. The movable mounting system enables operators to quickly adapt the weight distribution configuration during different phases of work, minimizing time loss while maintaining optimal stability.

Inventive Principle:
Principle #15Dynamics

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

Enables efficient performance of assisting or electricity generating actions during starting operations, optimizing machine behavior and efficiency.

Implementation Method 1

a motor/generator configured to perform a first action in which the motor/generator functions as a motor using electricity

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

a second action in which the motor/generator functions as a generator using power from the engine

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 3

a battery configured to store electricity generated by the second action by the motor/generator

Methodology Applied
Scientific EffectElectrical energy storage: Battery (electricity)

Data Source

PatentEP3992374B1Work machine
Publication Date: 2026.03.25 KUBOTA CORP
  • EP3992374B1 patent drawingFigure 1
  • EP3992374B1 patent drawingFigure 2
  • EP3992374B1 patent drawingFigure 3

AI summary

An assisting action or an electricity generating action can be efficiently performed when a starting action for a working machine (1) is performed. A working machine (1) comprises: a machine body (2); an engine (60) provided on the machine body (2); a motor/generator (63) to perform an assisting action in which the motor/generator (63) functions as a motor to assist the engine (60) in driving and an electricity generating action in which the motor/generator (63) functions as a generator to generate electricity using power from the engine (60); a battery (66) to store electricity generated by the motor/generator (63); an operation member (58) for operation of the machine body (2); a starting action determining unit (70e) to determine, upon operation of the operation member (58), whether the operation corresponds to a starting action for the machine body (1); a first setting unit (70f) to set, if the starting action determining unit (70e) determines that the operation of the operation member (58) corresponds to the starting action, a torque of the motor/generator (63) for the assisting action or the electricity generating action to a first torque; and a second setting unit (70g) to set, if the starting action determining unit (70e) determines that the operation of the operation member (58) does not correspond to the starting action, the torque for the assisting action or the electricity generating action to a second torque differing from the first torque set by the first setting unit (70f).