Gear Shift Cable Dampening Structure Using Composite Materials

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Solution Overview

Problem

Existing gear shift cable solutions either lose the desired shift feeling due to the use of soft materials or transmit vibrations due to stiff materials, and are often bulky, difficult to manufacture, and expensive.

Innovation Solution

A shift cable design featuring a stiff, low-density material separated from the socket by a thin flexible material, which maintains the desired shift feeling while reducing vibration transfer through a combination of the stiff material's direct response and the flexible material's dampening effect, along with a thin air layer for additional vibration isolation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If soft material is used in the antivibration member, then vibration dampening is improved, but shift feeling is lost

Engineering Contradiction:

Improvevibration dampeningVSAvoidshift feeling

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The patent employs a composite antivibration member comprising a soft material layer (for vibration dampening) and a stiff material layer (for maintaining shift feeling). This composite structure allows the soft material to absorb vibrations while the stiff material preserves the direct mechanical response needed for accurate shift feedback, thereby resolving the contradiction between vibration dampening and shift feeling.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The antivibration member is designed with different material properties in different regions: the outer layer uses soft material optimized for vibration absorption, while the inner layer or core uses stiff material optimized for mechanical response. This local differentiation allows each region to perform its specific function, achieving both vibration dampening and preserved shift feeling simultaneously.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If stiff material is used in the antivibration member, then shift feeling is maintained, but vibration transfer occurs

Engineering Contradiction:

Improveshift feelingVSAvoidvibration transfer

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

Inventive Principle:

Principle #40Composite materials

3Object-affected harmful factors

If mass damper is added to the shift cable, then vibration dampening is improved, but vehicle weight increases

Engineering Contradiction:

Improvevibration dampeningVSAvoidvehicle weight

Core Design Contradiction:

Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The patent changes the material parameters of the existing antivibration member by using composite materials with optimized density and damping properties. Instead of adding mass, the solution modifies the material composition to achieve high vibration dampening efficiency with low density, thereby eliminating the need for additional mass dampers and avoiding weight increase.

Inventive Principle:

Principle #35Parameter changes

4Object-affected harmful factors

If traditional antivibration solutions are used, then vibration dampening is achieved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvevibration dampeningVSAvoidstructure complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the antivibration function directly into the existing socket structure by integrating the composite antivibration member as part of the socket assembly. This integration eliminates the need for separate antivibration components and simplifies the overall structure, reducing both device complexity and manufacturing steps while maintaining effective vibration dampening.

Inventive Principle:

Principle #5Merging (Combining)

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

The solution provides a lightweight, efficient vibration dampening system that maintains accurate and responsive shifting while minimizing noise and vibration transfer, offering a more pleasant driving experience without the drawbacks of traditional mass dampers.

Implementation Method 1

The shift tuning structure is provided between the cable conduit and the socket in order to provide a vibration dampening between the inner cable and the socket

Methodology Applied

Scientific EffectVibration dampening: Damping

Implementation Method 2

The flexible material is thinner than the stiff, low-density material

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP2733390B1Dampening structure for gear shift cables

Publication Date: 2020.05.13 VOLVO CAR CORP

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AI summary

The object of the present invention is to provide an inventive shift cable (3) for transmitting of operation commands to a transmission (1), wherein the shift cable (3) comprising a cable conduit (10), an inner cable (11), a socket (12) and a shift tuning structure (13). The socket (12) is adapted to attach the shift cable (3) to a housing. The shift tuning structure (13) is provided between the cable conduit (10) and the socket (12) in order to provide a vibration dampening between the inner cable (11) and the socket (12) and to provide a desired shift feeling when the inner cable (11) is transmitting an operation command. The shift tuning structure (13) comprises a stiff, low-density material (14) which is separated from the socket (12) in axial and radial direction through a flexible material (15), which is thinner than the stiff, low-density material (14).