Pre-engaged Pinion Starter Auto-Start Timing

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Solution Overview

Problem

Current starter motor systems in vehicles with engine auto-stop functions face delays and gear noise issues due to the time required for pinion gear engagement and potential gear tooth damage during rapid engine restarts, especially when engine speed is low.

Innovation Solution

A pre-engaged piston starter system that calculates a pinion pre-engagement engine speed based on flywheel teeth and estimated engaging time, allowing for controlled solenoid activation to engage the pinion gear at a reduced engine speed, minimizing delay and preventing gear tooth butting, with a solenoid energized when engine speed drops below a calibrated threshold.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the solenoid device is used to pre-engage the pinion gear to reduce start time and noise, then the engagement time is reduced and noise is decreased, but the solenoid device continuously consumes power during the pre-engagement

Engineering Contradiction:

Improveengagement timeVSAvoidsolenoid power consumption

Core Design Contradiction:

Loss of timeVSUse of energy by moving object

Solution Approach 1:

The pinion gear is pre-engaged with the flywheel before the starter motor is activated. The solenoid is energized in advance to position the pinion gear in mesh with the flywheel teeth, ensuring that when the starter motor engages, the gear connection is already established, thereby reducing overall engagement time and noise while allowing the solenoid to be de-energized after pre-engagement is complete

Inventive Principle:

Principle #10Preliminary action

2Productivity

If the starter pinion is forced into engagement with the flywheel gear during low engine speed period, then the engine can be restarted, but gear tooth butting occurs resulting in gear noise and damage

Engineering Contradiction:

Improveengine restart capabilityVSAvoidgear noise and damage

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system calculates a predetermined pinion engagement time based on the current engine speed and flywheel tooth configuration. The solenoid is energized at a calculated moment before the starter motor engages, allowing the pinion gear to smoothly engage with the flywheel teeth at the optimal moment, preventing tooth butting and reducing noise while enabling reliable engine restart

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The controller continuously monitors engine speed and uses this feedback to determine the optimal timing for pinion gear engagement. Based on the real-time engine speed and pre-calculated engagement parameters, the controller activates the solenoid at the precise moment when gear engagement will occur without causing tooth butting, thereby preventing noise and damage while maintaining restart capability

Inventive Principle:

Principle #23Feedback

3Reliability

If a time delay of 40 ms to 50 ms is incurred before the starter motor pinion gear engages the flywheel gear, then the gear engagement can be completed, but this delay is objectionable to the vehicle operator

Engineering Contradiction:

Improvegear engagement completionVSAvoidengagement delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The pinion gear engagement is initiated in advance before the starter motor is activated. The solenoid is energized at a calculated time based on engine speed and flywheel tooth configuration, allowing the pinion to engage with the flywheel teeth before the starter motor engages, thereby eliminating the 40-50ms delay and reducing overall engagement time while ensuring reliable gear meshing

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the pinion engagement timing based on real-time engine speed conditions. The controller calculates the optimal engagement moment using current engine speed and pre-determined parameters, allowing the pinion gear to engage at the precise moment that minimizes delay while ensuring proper gear meshing, thereby adapting the engagement timing to current operating conditions

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 solution reduces the auto-start time by 20-30 msec, prevents gear noise and damage, and ensures smooth and quiet engagement, improving the overall engine restart process.

Implementation Method 1

A solenoid is energized to shift the pinion gear to an engaged position between the flywheel and the starter gear

Methodology Applied

Scientific EffectSolenoid: Solenoid

Data Source

PatentUS11236718B1Control of pre-engaged pinion starter

Publication Date: 2022.02.01 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A pre-engaged piston starter system of an automobile vehicle includes an engine having a flywheel to start the engine connected to the engine by an engine shaft. A starter motor provides rotational energy to a starter gear. A pinion gear transfers rotational energy of the starter gear to the flywheel. A solenoid is energized to shift the pinion gear to an engaged position between the flywheel and the starter gear. An auto-stop mode is entered when an engine speed is decreased below a calibrated threshold speed defining approximately 250 rpm. A calculated pinion pre-engagement engine speed allows engagement of the pinion gear when the engine speed is below the calibrated threshold speed.