Hybrid Construction Machine Engine Load Management During Warming

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Solution Overview

Problem

Existing hybrid construction machines face engine stall issues when simultaneously warming up power storage units and hydraulic oil, as the engine load becomes excessively large due to the generator motor's power generation operation for both tasks.

Innovation Solution

A hybrid construction machine with a control unit that calculates warming-up time charging power for the power storage unit and adjusts hydraulic pump horsepower by subtracting this power from the preset pump horsepower, allowing simultaneous warming while managing engine load.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the generator motor performs power generation operation to warm up the power storage unit, then the power storage unit temperature is raised, but the engine load becomes excessively large causing engine stall

Engineering Contradiction:
Improvepower storage unit temperatureVSAvoidengine load
Core Design Contradiction:
TemperatureVSPower

Solution Approach 1:

The patent applies dynamics by making the hydraulic pump capacity variable rather than fixed. The control unit dynamically adjusts the hydraulic pump capacity based on real-time conditions (power storage temperature, engine load, hydraulic oil temperature) to optimize the balance between warming up the power storage unit and preventing engine stall. This dynamic adjustment allows the system to adapt to changing conditions during the warming-up process.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of hydraulic pump capacity from a fixed value to a variable parameter that can be adjusted in real-time. By modifying this parameter based on the operating conditions, the system can control the engine load during power generation operation to prevent stall while maintaining effective warming-up of the power storage unit.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If hydraulic load is applied simultaneously with power storage unit warming up, then hydraulic oil temperature is raised, but the engine load becomes excessively large

Engineering Contradiction:
Improvehydraulic oil temperatureVSAvoidengine load
Core Design Contradiction:
TemperatureVSPower

Solution Approach 1:

The patent uses dynamic control of the hydraulic pump capacity to manage the simultaneous warming-up of both power storage unit and hydraulic oil. The control unit continuously monitors the total engine load and adjusts the hydraulic pump capacity accordingly, allowing hydraulic oil warming when engine capacity permits while preventing overload conditions that would cause engine stall.

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

This configuration enables efficient and simultaneous warming of both power storage units and hydraulic oil without causing engine stalls, improving overall warming efficiency and reliability.

Implementation Method 1

a generator motor 2 that is driven by the engine 1; a power storage unit 4 that is charged by power generation operation of the generator motor 2

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the generator motor forcedly charges and discharges the power storage unit and raises the temperature of the power storage unit with internal heating

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

actuating a hydraulic load (a relief valve) to increase a pump load (=an engine load)... raise the temperature of hydraulic oil

Methodology Applied
Scientific EffectViscous heating: Viscous Heating

Data Source

PatentEP3061873B1Hybrid construction machine
Publication Date: 2018.09.05 KOBELCO CONSTR MASCH CO LTD
  • EP3061873B1 patent drawingFigure 1
  • EP3061873B1 patent drawingFigure 2
  • EP3061873B1 patent drawingFigure 3

AI summary

A first warming-up control unit calculates warming-up time charging power from a power storage SOC and power storage temperature and causes a generator motor (2) to perform power generation operation thereby charging a power storage unit (4) on the basis of the calculated warming-up time charging power. A second warming-up control unit applies, during the power generation operation, a hydraulic load to a hydraulic pump (5) by a hydraulic load unit (10, 11) and performs horsepower control of the hydraulic pump (5) using a value obtained by subtracting the warming-up time charging power from preset warming-up time pump horsepower.