Vehicle Park Lock Manual Unlocking Eccentric Slide Mechanism

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Solution Overview

Problem

Existing unlocking devices for vehicle parking locks often require power and are not easily accessible for manual emergency unlocking, especially when a vehicle needs to be towed after a defect, and they can cause disturbing vibrations and noises due to multiple transmission elements.

Innovation Solution

An unlocking device comprising an eccentric device, a slide unit, and an actuating device that uses a single cable pull to manually unlock the parking lock without power, featuring a compression spring for easy re-engagement and a damping element for noise reduction, allowing the device to be installed below the gear selector lever for easy access and minimal noise transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a parking lock is controlled via cable from the gear selector lever with electric motor actuation, then the parking lock can be reliably engaged and disengaged, but the unlocking device requires power and is not accessible for manual emergency unlocking

Engineering Contradiction:
Improveparking lock engagementVSAvoidmanual emergency unlocking
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The unlocking device is segmented into distinct functional components: an actuating device with cam mechanism for manual operation, a slide unit for linear motion, and a cable pull transmission element. This segmentation allows the manual actuating mechanism to be separated from the electric motor system, enabling independent manual operation for emergency unlocking while maintaining the reliability of the overall parking lock system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cam mechanism in the actuating device is designed to directly translate rotational motion into linear motion of the slide unit without requiring external power assistance. The geometric shape of the cam profile itself provides the mechanical advantage needed to move the cable pull and disengage the parking lock, making the system self-sufficient for manual emergency operation.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If multiple transmission elements are used to actuate the parking lock, then the parking lock can be controlled from the gear selector lever, but disturbing vibrations and noises are generated

Engineering Contradiction:
Improveparking lock controlVSAvoidvibrations and noises
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The harmful vibrations and noises are extracted from the main control path by isolating the manual actuating device from the electric motor system. The cam mechanism and slide unit form a separate mechanical transmission path that directly actuates the cable pull without involving the complex multi-element transmission system, thereby eliminating the source of vibrations and noises while maintaining control functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of transmitting force from the gear selector lever through multiple transmission elements to the parking lock, the invention inverts the approach by having the actuating device on the gear selector lever directly convert rotational motion into linear cable pull motion through the cam mechanism. This inversion simplifies the transmission path and eliminates the intermediate elements that generate vibrations and noises.

Inventive Principle:
Principle #13The other way round (Inversion)

3Ease of operation

If the eccentric device is moved from first position to second position to unlock the parking lock, then manual unlocking without power is enabled, but the slide unit must be translated which may cause wear and tear

Engineering Contradiction:
Improvemanual unlockingVSAvoidwear and tear on components
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

A compression spring is pre-installed in the unlocking device to cushion the translation motion of the slide unit. The spring absorbs impact forces and reduces mechanical shocks during the movement from locked to unlocked position, thereby minimizing wear and tear on the cam mechanism, slide unit, and cable pull while enabling reliable manual unlocking operation.

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

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 the vehicle to be unlocked manually and without power, reducing noise and vibration disturbances, facilitating safe towing and emergency situations while maintaining modularity and ease of operation.

Implementation Method 1

the unlocking device can have a compression spring which is relaxed in the first position of the eccentric device and which is arranged to be tensioned in response to actuation by at least one component of the eccentric device

Methodology Applied
Scientific EffectElastic potential energy storage and release: Spring

Implementation Method 2

featuring a compression spring for easy re-engagement and a damping element for noise reduction

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP3545216B1Unlocking device for unlocking a park lock of a vehicle and method for operating an unlocking device
Publication Date: 2020.09.02 ZF FRIEDRICHSHAFEN AG
  • EP3545216B1 patent drawingFigure 1
  • EP3545216B1 patent drawingFigure 2
  • EP3545216B1 patent drawingFigure 3

AI summary

The present approach relates to an unlocking device (105) for unlocking a park lock (110) of a vehicle (100). The unlocking device (105) comprises at least an eccentric apparatus (115), a slide unit (120) and an actuation apparatus (125). The eccentric apparatus (115) is designed, in a first position in which the eccentric apparatus is accommodated at least partly in the slide unit (120), to hold the slide unit (120) in a locking position in which the park lock (110) is locked or engaged and, in a second position, to enable the transfer of the slide unit (120) into an unlocking position in which the park lock (110) is unlocked or disengaged. The slide unit (120) is or can be coupled to the park lock (110) via cable pull transmission element (155) and is designed, in the locking position, to position the transmission element (155) in a park locking position in order to lock the park lock (110) and, in the unlocking position, to position the transmission element (155) in a park unlocking position in order to unlock the park lock (110). The actuation apparatus (125) is designed to move the eccentric apparatus (115) from the first position into the second position in response to actuation.