Starter Control Device Pinion Gear Synchronization

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Solution Overview

Problem

Conventional starters face challenges in synchronizing the rotation speeds of the pinion gear and ring gear, leading to unwanted noise and premature wear, especially when engine rotation speed detection is unreliable or variable.

Innovation Solution

A starter system with a second gear and a motor that can be controlled independently of the actuator, allowing for restricted rotation mode to synchronize the pinion and ring gear speeds, and an engagement mode to ensure proper engagement without rotation, optimizing engine cranking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the pinion gear is rotated before engagement when engine rotation speed is high, then the engine can be restarted more quickly, but the difference between pinion gear rotation speed and ring gear rotation speed increases causing noise and wear

Engineering Contradiction:

Improvetime lag between restart request and engine crankingVSAvoidnoise and gear wear

Core Design Contradiction:

Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The control device changes the operational parameters of the starter motor based on engine rotation speed. When engine rotation speed is high, the system restricts the rotation mode to prevent excessive speed difference. When engine rotation speed is low, the system permits rotation mode to enable faster restart. This dynamic parameter adjustment resolves the contradiction by adapting the operation mode to the current operational conditions.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the rotation mode is permitted when synchronization is difficult to achieve, then engine restart is faster, but the pinion gear and ring gear experience greater speed difference leading to collision noise

Engineering Contradiction:

Improveengine restart speedVSAvoidcollision noise between gears

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The control device continuously monitors engine rotation speed and provides feedback to determine whether to permit or restrict the rotation mode. This feedback mechanism ensures that the rotation mode is only permitted when synchronization can be achieved, preventing collision noise while maintaining fast restart capability when conditions are appropriate.

Inventive Principle:

Principle #23Feedback

3Speed

If the actuator and motor are driven in rotation mode, then the pinion gear rotates before engagement, but synchronization between ring gear and pinion gear rotation speeds becomes difficult

Engineering Contradiction:

Improvepinion gear rotation speedVSAvoidsynchronization reliability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The system dynamically switches between rotation mode and engagement mode based on real-time engine rotation speed conditions. This dynamic adaptation ensures that the rotation mode is only activated when synchronization can be reliably achieved, maintaining both speed performance and synchronization reliability.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8695553B2Control device and control method for starter, and vehicle

Publication Date: 2014.04.15 TOYOTA JIDOSHA KK

AI summary

A starter can independently drive an actuator for moving a pinion gear to a position where the pinion gear is engaged with a ring gear and a motor for rotating the pinion gear. When synchronization between the ring gear and the pinion gear is restricted, a rotation mode in which the pinion gear is rotated before the actuator is driven is restricted.