Actuation Unit Auxiliary Device Prevents Unintended Locking

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Solution Overview

Problem

Existing actuation units for vehicle transmission control members, such as park-lock devices, automatically lock the vehicle in parked condition during power supply interruptions due to spring disengagement, leading to unnecessary locking.

Innovation Solution

An actuation unit with an auxiliary actuation device that shifts the coupling member into a disengagement position only under controlled conditions, using electronic control or user intervention, to prevent automatic movement to a predefined angular position, ensuring safe mode activation only in genuine emergencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a spring is used to automatically disengage transmission members during power interruption, then the system provides automatic safety locking, but it causes unnecessary locking during non-critical power fluctuations

Engineering Contradiction:
Improvesafety locking functionVSAvoidunintended activation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The control unit performs preliminary checks (vehicle speed verification, operational state assessment) before activating the safe mode. This preliminary action distinguishes between critical emergencies requiring safety locking and non-critical situations where locking would be unnecessary, thereby resolving the contradiction between reliable safety locking and preventing unintended activation.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the control member automatically moves to predefined angular position during power failure, then emergency safety is ensured, but normal operation is disrupted by false emergencies

Engineering Contradiction:
Improveemergency safetyVSAvoidoperation continuity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The control unit continuously monitors system parameters (power supply status, vehicle speed, operational state) and uses this feedback to intelligently determine whether to activate the safe mode. This feedback mechanism ensures that automatic movement to the predefined angular position occurs only when genuinely necessary, maintaining both emergency safety and operation continuity.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If the transmission members are kept engaged by elastic force, then the system maintains operational connection, but it cannot provide automatic emergency disengagement

Engineering Contradiction:
Improveoperational connectionVSAvoidemergency disengagement
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The control unit acts as an intermediary between the elastic engagement mechanism and the transmission members. It monitors the engagement state and can actively control disengagement through the auxiliary actuation device, thereby maintaining operational connection during normal operation while enabling reliable emergency disengagement when safety conditions are met.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Prevents unintended activation of the safe mode by requiring preliminary checks, such as vehicle speed verification, ensuring the control member moves to a predefined position only when necessary, thus avoiding unnecessary locking during power fluctuations.

Implementation Method 1

first elastic means interposed between the first transmission member and the second transmission member to cause a relative rotation of the second transmission member with respect to the first transmission member when the coupling member is in the disengagement position

Methodology Applied
Scientific EffectElastic action: Elasticity

Implementation Method 2

second elastic means arranged to maintain the coupling member in the engagement position

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP3279523B1Actuation unit for controlling the angular position of a control member, particularly for a vehicle transmission
Publication Date: 2020.09.30 DANA GRAZIANO SRL
  • EP3279523B1 patent drawingFigure 1
  • EP3279523B1 patent drawingFigure 2
  • EP3279523B1 patent drawingFigure 3

AI summary

The actuation unit (10) comprises a primary motor (18) and a transmission mechanism (22, 24, 26, 28, 36, 38) for transmitting to a control member (12) the motion generated by the primary motor (18). The transmission mechanism (22, 24, 26, 28, 36, 38) comprises: a first rotary transmission member (24) connected to a drive shaft (20) of the primary motor (18); a second rotary transmission member (26) arranged to be drivingly connected for rotation with the control member (12); a coupling member (28) selectively shiftable between an engagement position, in which it connects the first and second transmission members (24, 26) for rotation with each other, and a disengagement position, in which it disconnects the first and second transmission members (24, 26) from each other; first elastic means (42) interposed between the first and second transmission members (24, 26) to cause rotation of the second transmission member (26) relative to the first transmission member (24) when the coupling member (28) is in the disengagement position; second elastic means (36) tending to elastically urge the coupling member (28) towards the engagement position, so that the coupling member (28) is normally kept in the engagement position; and an auxiliary actuation device (38) arranged to control shifting of the coupling member (28) from the engagement position and the disengagement position, acting against the second elastic means (36).