Starter Pinion Meshing via Toe-In Actuator and Controlled Force

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Solution Overview

Problem

Existing start-stop systems for internal combustion engines face delays and comfort disadvantages due to the need for the drive shaft or crankshaft to come to a complete standstill before restarting, which can be mitigated by early engagement of the starter pinion in the ring gear, but existing methods often result in unwanted collisions and wear.

Innovation Solution

A method involving a toe-in force to advance the starter pinion towards the ring gear until it touches, followed by a targeted meshing force to engage it gently, ensuring zero crossing alignment for reduced wear and quicker restarts, with pre-calculated timing to minimize collisions and optimize engagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the starter pinion is engaged after the drive shaft has come to a complete standstill, then the meshing process is simple and reliable, but the restart time is delayed and comfort is reduced

Engineering Contradiction:
Improvemeshing reliabilityVSAvoidrestart time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The control unit determines a target point P (specific speed value) and a time period TP in advance before the drive shaft reaches complete standstill. The starter pinion engagement is timed to occur at this predetermined moment during the coasting phase, enabling early engagement that reduces restart time while maintaining meshing reliability through precise pre-calculated timing.

Inventive Principle:
Principle #10Preliminary action

2Loss of time

If the starter pinion is engaged early during coasting to reduce restart time, then comfort is improved, but unwanted collisions and wear increase

Engineering Contradiction:
Improverestart timeVSAvoidwear and collisions
Core Design Contradiction:
Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The method monitors the actual speed of the drive shaft and compares it with the target speed (zero crossing point). The engagement timing is dynamically adjusted based on the actual coasting behavior and speed profile. By changing the engagement parameter from fixed (after standstill) to variable (at predetermined speed point during coasting), the system achieves early engagement without excessive collisions, as the engagement occurs when relative speed differences are minimized.

Inventive Principle:
Principle #35Parameter changes

3Loss of time

If the starter pinion is engaged at various positive speeds during coasting, then restart time is further reduced, but vibrations and noise increase

Engineering Contradiction:
Improverestart timeVSAvoidvibrations and noise
Core Design Contradiction:
Loss of timeVSObject-generated harmful factors

Solution Approach 1:

The method utilizes the natural coasting deceleration of the drive shaft and converts the kinetic energy into a beneficial timing mechanism. By engaging the starter pinion at the predetermined zero crossing point during natural coasting, the system transforms what would otherwise be wasted deceleration time into an opportunity for optimized engagement timing. This approach converts the harmful effect of coasting (uncontrolled deceleration) into a benefit (natural speed reduction to optimal engagement point), minimizing vibrations and noise while achieving early engagement.

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

Data Source

PatentEP2798197B1Method for meshing a starter pinion of a starting device into a ring gear of an internal combustion engine
Publication Date: 2021.04.07 SEG AUTOMOTIVE GERMANY GMBH
  • EP2798197B1 patent drawingFigure 1a~3
  • EP2798197B1 patent drawingFigure 4
  • EP2798197B1 patent drawingFigure 5

AI summary

The invention relates to a method for meshing a starter pinion (19) of a starting device (16) into a ring gear (13) of an internal combustion engine (10). The internal combustion engine (10) has a driveshaft (22), and the starting device (16) has a starter motor (25), said driveshaft (22) having a variable rotational speed (n). The internal combustion engine (10) is switched off in a method step (S1), and the starter pinion (19), which is not being rotationally driven by the starter motor (25), is then advanced in the direction of the ring gear (13) by a toe-in actuator (28) by means of a toe-in force (FV) in a method step (S2) until the starter pinion contacts the ring gear. A meshing force (FE) is then exerted onto the starter pinion (19) in a controlled manner in an additional method step (S3) in order to mesh the starter pinion (19) into a tooth gap (34) of the ring gear (13).