Hybrid Vehicle Catalyst Heating Control via Preliminary Battery Charging

Solution Overview

Problem

In hybrid vehicles, starting the internal combustion engine to warm up the purifying catalyst at system startup worsens fuel efficiency and emission quality, especially when a large capacity battery is charged from an external power supply during shutdown.

Innovation Solution

Implementing a control method that prioritizes motor travel based on the accumulated charge ratio, delaying engine startup until the catalyst is warmed up appropriately, using a hybrid vehicle configuration with a battery unit, charger, and control modules to manage power distribution and engine operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the internal combustion engine is started up at system startup to warm up the purifying catalyst, then the catalyst reaches operating temperature faster, but fuel efficiency deteriorates

Engineering Contradiction:

Improvecatalyst temperatureVSAvoidfuel efficiency

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary charging of the battery from an external power supply during system shutdown before vehicle operation begins. This preliminary action stores sufficient electrical energy to power the catalyst heater during initial vehicle operation, eliminating the need for immediate engine startup and enabling delayed engine operation while maintaining catalyst warm-up capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an external power supply as an intermediary energy source between the battery and the catalyst heater. This intermediary allows the system to decouple the catalyst warm-up function from the internal combustion engine, using electrical energy instead of mechanical energy for heating, thereby resolving the contradiction between catalyst temperature rise and fuel consumption

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If the internal combustion engine is started up at system startup to warm up the purifying catalyst, then the exhaust emission quality improves, but fuel consumption increases

Engineering Contradiction:

Improveexhaust emission qualityVSAvoidfuel consumption

Core Design Contradiction:

Object-generated harmful factorsVSLoss of energy

Solution Approach 1:

The system performs preliminary charging of the battery from an external power supply during system shutdown before vehicle operation begins. This preliminary action stores sufficient electrical energy to power the catalyst heater during initial vehicle operation, eliminating the need for immediate engine startup and enabling delayed engine operation while maintaining catalyst warm-up capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an external power supply as an intermediary energy source between the battery and the catalyst heater. This intermediary allows the system to decouple the catalyst warm-up function from the internal combustion engine, using electrical energy instead of mechanical energy for heating, thereby resolving the contradiction between catalyst temperature rise and fuel consumption

Inventive Principle:

Principle #24Intermediary (Mediator)

3Duration of action of moving object

If the battery capacity is increased to extend motor travel range, then the motor travel capability is improved, but the fuel efficiency worsens when the engine is started at system startup

Engineering Contradiction:

Improvemotor travel rangeVSAvoidfuel efficiency

Core Design Contradiction:

Duration of action of moving objectVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary charging of the battery from an external power supply during system shutdown before vehicle operation begins. This preliminary action stores sufficient electrical energy to power the catalyst heater during initial vehicle operation, eliminating the need for immediate engine startup and enabling delayed engine operation while maintaining catalyst warm-up capability

Inventive Principle:

Principle #10Preliminary action

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

Enhances fuel efficiency by optimizing engine startup timing for catalyst warming, reducing emission impact during hybrid travel, and ensuring the catalyst is warmed before switching to hybrid travel mode.

Implementation Method 1

a catalytic conversion unit (134) including a purifying catalyst for purifying exhaust

Methodology Applied

Scientific EffectCatalytic conversion: Catalysis

Implementation Method 2

a catalyst heater for heating a purifying catalyst which purifies the engine exhaust

Methodology Applied

Scientific EffectHeating: Heating

Data Source

PatentUS8751081B2Hybrid vehicle and control method thereof

Publication Date: 2014.06.10 TOYOTA JIDOSHA KK

AI summary

A hybrid vehicle that runs in an electric running priority mode after the engine reaches a driving condition appropriate for heating the catalyst (S130-S150) if the system has been started up and the following conditions are met: the vehicle is running in an electric running priority mode in which electric power is used preferentially to drive the vehicle; the temperature (Tc) at which the catalyst becomes activated to purify the engine exhaust falls below a threshold value (Tref); and a battery storage rate (SOC) falls below a threshold value (Scd) which reaches a threshold value (Shv). Then the system switches to a hybrid running priority mode after running on electric power for the length of time necessary to heat the catalyst.