Selector Lever Reset Device for Vehicle Gearbox

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In electronically controllable vehicle transmissions, the lack of mechanical coupling between the selector lever and the transmission can lead to discrepancies between the selector lever position and the actual transmission position, causing incorrect driver information and stability issues, especially in shift-by-wire systems.

Innovation Solution

A selector lever reset device with a lever guide mechanism featuring a sliding element and a locking slide, where the selector lever is mechanically coupled to move between rest and actuating positions, utilizing a latching contour and element for secure positioning, and a pretensioning device to return the lever to the rest position with minimal force, ensuring accurate alignment with the transmission position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a locking mechanism is used to fix the selector lever in a predefined lever position, then the stability of the selector lever position is improved, but the actuator force required to reset the selector lever increases

Engineering Contradiction:
Improvestability of selector lever positionVSAvoidactuator force required to reset selector lever
Core Design Contradiction:
Stability of the object's compositionVSForce

Solution Approach 1:

The locking mechanism uses a locking slide that can be actively displaced between a locking position and a release position. In the locking position, the latching element engages with the latching contour to provide stable positioning. When resetting is needed, the locking slide is actively moved to the release position, allowing the latching element to disengage. This dynamic switching between locked and unlocked states enables stable positioning during normal operation while allowing easy resetting when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A pretensioning device, specifically a spring element, is pre-loaded to exert a pretensioning force on the selector lever in the direction of the rest position. This preliminary action means that when the locking mechanism is released, the selector lever is already under tension and will automatically return to its rest position without requiring additional actuator force. The spring element stores potential energy that is released to move the lever back, significantly reducing the force needed for resetting.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If shift-by-wire system is used to replace mechanical transmission actuation, then the complexity of mechanical coupling is reduced, but the alignment accuracy between selector lever position and transmission position deteriorates

Engineering Contradiction:
Improvemechanical coupling complexityVSAvoidalignment accuracy between selector lever and transmission
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent implements a shift-by-wire system where the mechanical coupling between the selector lever and transmission is replaced by an electrical interface. The selector lever position is detected by sensors, and this information is transmitted electronically to control the transmission gear changes. This eliminates the need for direct mechanical linkage, reducing mechanical complexity while maintaining precise control through electronic feedback and actuation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system incorporates sensors to detect the selector lever position and transmits this information electronically to the transmission control system. This feedback mechanism ensures that the transmission responds accurately to the driver's selector lever input, maintaining alignment accuracy between the lever position and actual transmission gear position despite the absence of mechanical coupling. The electronic feedback loop allows for precise control and correction of any position discrepancies.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3120049B1Selector lever reset device for a vehicle gearbox, and method and device for operating such a selector lever reset device
Publication Date: 2019.06.12 ZF FRIEDRICHSHAFEN AG
  • EP3120049B1 patent drawingFigure 1
  • EP3120049B1 patent drawingFigure 2a~2b
  • EP3120049B1 patent drawingFigure 2c~2d

AI summary

The invention relates to a selector lever reset device (100) for a vehicle gearbox. The selector lever reset device (100) comprises a selector lever (105) for selecting a gearbox setting of the vehicle gearbox and a lever guide apparatus (110) which has at least one slide element (115) and a locking slide (120). The slide element (115) is movably arranged in the lever guide apparatus (110) along a slide axis (125) and has a latch contour (145). The selector lever (105) is or can be mechanically coupled to the slide element (115) in order to be moved along the slide axis (125) between a rest position (130) and an actuating position (135). The locking slide (120) is movably arranged in the lever guide apparatus (110) along a slide axis (140) deviating from the slide axis (125) at least between a rest position and a release position and has at least one latching element (150). The latching element (150) latches in place with the latching contour (145) when the selector lever (105) is in the actuating position (135) and the locking slide (120) is in the latching position. In the reverse, the latching element (150) releases the latching contour (145) when the locking slide (120) is in the release position.