Hybrid Engine Start via Transmission Inertia Torque

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Solution Overview

Problem

Current engine starting methods in hybrid vehicles are inefficient, leading to long starting times, unsmooth transitions, increased fuel consumption, and pollutant emissions, as well as frequent start motor wear, which reduces its lifespan.

Innovation Solution

A method and system that detect the vehicle's speed and utilize inertia torque generated by the transmission to start the engine when the speed is greater than or equal to a predetermined level, avoiding frequent start motor activation and optimizing power output during mode switching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the engine is started by a start motor mounted on the flywheel side, then the engine can be started, but the starting time is long and the starting process is unsmooth

Engineering Contradiction:

Improvestarting speedVSAvoidstarting time

Core Design Contradiction:

SpeedVSLoss of time

Solution Approach 1:

Instead of using the start motor to drive the engine from stationary state, the invention reverses the approach by using the transmission system to generate inertia torque that drives the engine crankshaft. The transmission leverages the vehicle's motion inertia to rotate the engine, fundamentally inverting the traditional starting direction and mechanism.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The transmission system acts as an intermediary between the vehicle's motion and the engine starting process. By engaging the transmission gears, the vehicle's kinetic energy is transmitted through the transmission components to generate the necessary torque for engine starting, eliminating the need for direct motor-driven starting.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the start motor is used frequently when operation mode is switched, then the engine can be restarted, but the life of the start motor is greatly reduced

Engineering Contradiction:

Improvemode switching capabilityVSAvoidstart motor life

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system uses the vehicle's own motion energy to start the engine, eliminating dependence on the start motor. The transmission system automatically generates the necessary inertia torque during mode transitions, making the starting process self-sufficient and reducing wear on the start motor.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The invention enables periodic engine starting based on operation mode transitions without continuously relying on the start motor. By utilizing the transmission's inertia torque during each mode switch, the system creates a rhythmic, sustainable starting mechanism that preserves motor life.

Inventive Principle:

Principle #19Periodic action

3Power

If the start motor is used for engine starting, then the engine can be started, but fuel consumption increases and pollutant emission increases

Engineering Contradiction:

Improvestarting powerVSAvoidfuel consumption

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The invention converts the vehicle's motion energy, which would otherwise be wasted during mode transitions, into useful starting torque for the engine. By capturing and utilizing the kinetic energy already present in the moving vehicle, the system eliminates the need for additional fuel consumption during the starting process.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system recovers the kinetic energy that would be lost during operation mode transitions. Instead of dissipating this energy, the transmission system captures it and converts it into the torque needed for engine starting, effectively recycling energy that would otherwise be wasted.

Inventive Principle:

Principle #34Discarding and recovering

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 approach enhances the smoothness of power output during mode switching, extends the life of the start motor, reduces fuel consumption, and minimizes pollutant emissions, thereby saving energy and protecting the environment.

Implementation Method 1

outputting an inertia torque generated by a transmission of the hybrid vehicle to a crankshaft of the engine to start the engine when the speed is larger than or equal to a predetermined speed

Methodology Applied

Scientific EffectInertia: Inertia

Data Source

PatentUS9889841B2Method and system for starting engine of hybrid vehicle

Publication Date: 2018.02.13 BYD CO LTD

AI summary

A method for starting an engine of a hybrid vehicle is provided. The method includes: detecting a speed of the hybrid vehicle when receiving an instruction to start the engine; and outputting an inertia torque generated by a transmission of the hybrid vehicle to a crankshaft of the engine to start the engine when the speed is larger than or equal to a predetermined speed. Further, a system for starting an engine of a hybrid vehicle and a hybrid vehicle including the system are provided.