Idling-Stop Engine Starter Relay Control for Resistor Protection

Solution Overview

Problem

Conventional engine starting devices for idle reduction vehicles face the risk of resistor burnout due to prolonged high current flow when the bypass relay fails to close, and power shutdown of electronic parts due to voltage drops during engine restart.

Innovation Solution

The engine starting device interrupts current supply to the control means when the engine is first started by the driver, ensuring the bypass relay remains closed and the resistor is short-circuited, and supplies current to the control means when restarting after idle reduction, allowing the bypass relay to open and prevent voltage drops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the bypass relay is kept open to suppress voltage drop during engine restart, then the electronic parts are protected from power shutdown, but the resistor may burn out due to prolonged high current flow

Engineering Contradiction:

Improveprotection of electronic partsVSAvoidresistor burnout

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The bypass relay contact state is dynamically changed based on engine operation mode: normally closed state for first start to protect resistor, and open state for restart to protect electronic parts. The control means switches the relay contact between closed and open positions according to whether it is a first start or restart condition, making the system adaptive to different operational requirements.

Inventive Principle:

Principle #15Dynamics

2Object-affected harmful factors

If the bypass relay is kept closed to protect the resistor from burnout, then the resistor is protected, but voltage drop occurs during engine restart causing power shutdown of electronic parts

Engineering Contradiction:

Improveresistor protectionVSAvoidprotection of electronic parts

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The bypass relay contact state is dynamically changed based on engine operation mode: normally closed state for first start to protect resistor, and open state for restart to protect electronic parts. The control means switches the relay contact between closed and open positions according to whether it is a first start or restart condition, making the system adaptive to different operational requirements.

Inventive Principle:

Principle #15Dynamics

3Ease of operation

If current is supplied to the control means during first start, then the bypass relay can be controlled, but the resistor may burn out if the relay fails to close

Engineering Contradiction:

Improvecontrol of bypass relayVSAvoidresistor burnout

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The control means is configured to interrupt current supply to the bypass relay coil during first start operation beforehand. This preliminary action ensures that even if the relay contact fails to close properly, no high current will flow through the resistor causing burnout. The current interruption is implemented as a preventive measure before the potential hazard can occur.

Inventive Principle:

Principle #10Preliminary action

4Object-affected harmful factors

If current is interrupted to the control means during first start, then the resistor is protected from burnout, but the bypass relay cannot be controlled to open state for restart

Engineering Contradiction:

Improveresistor protectionVSAvoidcontrol of bypass relay

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The control means is configured to interrupt current supply to the bypass relay coil during first start operation beforehand. This preliminary action ensures that even if the relay contact fails to close properly, no high current will flow through the resistor causing burnout. The current interruption is implemented as a preventive measure before the potential hazard can occur.

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

This approach prevents both resistor burnout and power shutdown of electronic parts by controlling the bypass relay's state based on the engine's operational mode, ensuring reliable engine starting and reduced component failure.

Implementation Method 1

a bypass relay (24) arranged in parallel to the resistor (23) and having a normally close contact (26) which is opened by energization

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a resistor (23) arranged in series between the starter motor (21) and the battery (22)

Methodology Applied

Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentEP2818691B1Engine startup device of idling-stop vehicle

Publication Date: 2018.12.19 NISSAN MOTOR CO LTD

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AI summary

A current is supplied to a driving relay 27 that drives a bypass relay 24 when restarting an engine after idle reduction, and the current supply to the driving relay 27 is interrupted when the engine is started for the first time based on operation of a driver.