Parking Lock Actuating Lever Emergency Decoupling Mechanism

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Solution Overview

Problem

Existing parking lock systems in motor vehicle transmissions face issues such as actuator failure leading to unsafe parking, complex emergency actuation, high operational forces, and limited locking/unlocking frequency, particularly in 'park-by-wire' systems.

Innovation Solution

A parking lock system with an actuating lever that can be prestressed into a locking position, allowing for emergency locking and release through a decoupling mechanism, utilizing an emergency lever and potentially an electromagnetic actuator to ensure safe operation even in actuator failure scenarios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a 'park-by-wire' system with actuator is used to automate parking lock operation, then ease of operation is improved, but reliability deteriorates due to actuator failure risk

Engineering Contradiction:
Improveautomated parking lock operationVSAvoidparking lock engagement reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

A mechanically actuated emergency lever serves as an intermediary backup system. When the primary actuator fails, the emergency lever can directly manipulate the actuating lever through a separate mechanical path, bypassing the failed actuator and ensuring the parking lock can still be engaged or disengaged.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The emergency lever is pre-configured with direct mechanical connection to the actuating lever. This beforehand preparation ensures that if actuator failure occurs, the backup mechanical path is already in place and can be immediately activated without requiring complex diagnostic or setup procedures.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If an emergency actuation mechanism is added to handle actuator failure, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveparking lock system reliabilityVSAvoidactuation mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The emergency lever serves multiple functions: it can engage the parking lock when the actuator fails, it can disengage the parking lock if locked inadvertently, and it provides a mechanical backup path that simplifies the overall control architecture by reducing dependence on the primary actuator system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The emergency lever is designed to be manually operable by the driver without requiring external tools or complex activation procedures. The lever directly manipulates the actuating lever through pre-configured mechanical linkages, allowing the system to self-rescue from actuator failure without external intervention.

Inventive Principle:
Principle #25Self-service

3Reliability

If the actuating lever is prestressed into the locking angle position, then reliability of emergency locking is improved, but force requirements increase

Engineering Contradiction:
Improveemergency locking reliabilityVSAvoidactuating force requirement
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The actuating lever is prestressed into the locking angle position before emergency operation is needed. This preliminary positioning ensures that when the emergency lever is activated, the actuating lever is already close to the final locking position, requiring minimal additional force to complete the engagement and overcoming the prestress in the correct direction.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The prestress spring acts as a counterweight force that, when properly directed, assists rather than opposes the emergency locking action. By pre-positioning the actuating lever against the prestress, the emergency lever utilizes the spring's stored energy to help complete the locking motion, reducing the net force required from the driver.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

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

Enables reliable emergency locking and release of the parking lock system, ensuring vehicle safety and adaptability across different transmission variants with reduced complexity and operational forces.

Implementation Method 1

the actuating lever is prestressed in the direction of the locking angle position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2927540B1Parking lock system for a motor vehicle transmission and motor vehicle transmission using the same
Publication Date: 2018.10.03 MAGNA PT BV & CO KG
  • EP2927540B1 patent drawingFigure 1
  • EP2927540B1 patent drawingFigure 2~3
  • EP2927540B1 patent drawingFigure 4~6

AI summary

Parking lock system (40) for a motor vehicle transmission (16), comprising a housing (34), a locking mechanism (42) configured to lock a shaft (34) relative to the housing (34) in a locking position (S) and to release the shaft (32) in a release position (F), an actuating mechanism (60) for actuating the locking mechanism (42), wherein the actuating mechanism (60) has an actuating lever (62) pivotable about an actuating axis (64) fixed to the housing between a locking angle position (SW) and a release angle position (FW), which is positively coupled to the locking mechanism (42).The actuating lever (62) is biased in the direction of the locking angle position (SW), wherein an actuator element (72) is movable by means of an actuator in an actuating direction between a holding position, in which the actuator element holds the actuating lever (62) in the release angle position (FW), and an actuating position (B), and wherein the actuator element (72) is movable in a coupling direction (80) between a coupling position (K), in which the actuator element (72) is coupled to the actuating lever (62), and a decoupling position (E), in which the actuator element (72) is decoupled from the actuating lever (62), the coupling direction (80) being transverse to the actuating direction (74). (Figure 1).