Adjustable Telescopic Fork with Electric Motor for Ride Height Control

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Solution Overview

Problem

Existing motorcycle suspension systems fail to maintain consistent riding characteristics and stability as the fuel tank level decreases during riding, affecting the motorcycle's handling and stability due to changes in caster angle and trail.

Innovation Solution

An adjustable telescopic fork with a pair of parallel fork tube assemblies, featuring an inner and outer tube configuration with a coil spring and an externally operable electric motor and transmission unit, allowing for real-time adjustment of ride height to compensate for fuel tank depletion, while also enabling switching between on-road and off-road settings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the fuel tank level decreases during riding, then the weight of the motorcycle decreases, but the sag and ride height change, affecting handling and stability

Engineering Contradiction:
Improvefuel tank levelVSAvoidhandling and stability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent implements a dynamic suspension system where the coil spring pre-load can be adjusted in real-time based on fuel tank level. The system transitions from a static suspension configuration to a dynamic one that automatically adapts to changing weight conditions, maintaining consistent sag and ride height throughout the fuel consumption cycle.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates a fuel level sensor that continuously monitors the fuel tank level and provides feedback to the control unit. Based on this feedback, the control unit automatically adjusts the coil spring pre-load via the electric motor, creating a closed-loop control system that maintains optimal suspension characteristics despite changing fuel weight.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If the caster angle and trail are allowed to change with fuel level, then the motorcycle adapts to weight changes, but the riding characteristics and stability are compromised

Engineering Contradiction:
Improveweight adaptationVSAvoidriding characteristics
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent creates a dynamically adjustable suspension system that maintains constant geometric parameters (caster angle and trail) by compensating for weight changes through real-time adjustment of coil spring pre-load, rather than allowing these parameters to vary with fuel level.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the physical parameter of coil spring pre-load to compensate for changes in motorcycle weight. By adjusting the pre-load force applied by the coil spring, the system maintains the desired suspension sag and ride height, thereby keeping caster angle and trail constant despite fuel level variations.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If an adjustable fork system is implemented, then riding characteristics can be maintained, but the device complexity increases

Engineering Contradiction:
Improveriding characteristicsVSAvoidfork system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical adjustment mechanisms with an electric motor-driven system. Instead of using manual cable-operated adjusters or complex mechanical linkages, the system uses an electric motor controlled by a microprocessor to adjust the coil spring pre-load, simplifying the mechanical structure while enabling automated control.

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

Solution Approach 2:

The suspension system becomes self-adjusting through automated control. The fuel level sensor and control unit work together to automatically adjust the coil spring pre-load without requiring manual intervention from the rider, making the system self-regulating in response to changing fuel weight.

Inventive Principle:
Principle #25Self-service

4Ease of operation

If hydraulic or pneumatic systems are used for suspension adjustment, then ride height can be changed, but friction, wear, and thermal effects are introduced

Engineering Contradiction:
Improveride height adjustmentVSAvoidfriction, wear, and thermal effects
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes the harmful elements (hydraulic fluid or pneumatic gas) from the suspension adjustment system. By eliminating these fluid-based systems, the invention avoids the associated friction, wear, and thermal effects while maintaining the core function of ride height adjustment through a cleaner mechanical-electrical system.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent substitutes hydraulic or pneumatic adjustment mechanisms with an electric motor-driven mechanical adjustment system. This replacement eliminates the need for hydraulic fluid circulation or pneumatic pressure changes, thereby removing the sources of friction, wear, and thermal effects inherent in fluid-based systems.

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

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 maintains consistent riding characteristics and stability by adjusting sag and travel characteristics in real-time, enhancing handling and comfort across varying fuel levels without additional friction, wear, or thermal effects, and allows seamless transitions between on-road and off-road settings.

Implementation Method 1

a coil spring arranged inside the fork tube assembly between a support element of the inner tube and a support element of the outer tube

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

an externally operable electric motor having a drive shaft

Methodology Applied
Scientific EffectElectric motor: Linear Motor

Implementation Method 3

a transmission unit for converting a rotational motion of the drive shaft into a translational movement of the moveably mounted support element

Methodology Applied
Scientific EffectMechanical conversion: Mechanical Advantage

Data Source

PatentEP2773553B1Adjustable telescopic fork for a motorcycle with built in electric motor , externally adjustable fork tube assembly, suspension system and motorcycle comprising the same
Publication Date: 2022.03.02 TRACTIVE SUSPENSION
  • EP2773553B1 patent drawingFigure 1A
  • EP2773553B1 patent drawingFigure 1B
  • EP2773553B1 patent drawingFigure 2

AI summary

The present invention is related to an adjustable telescopic fork suitable for changing the ride height of a motorcycle while riding. It is further related to an externally adjustable fork tube assembly (10) for use in a telescopic fork and to a motorcycle comprising the same. According to the invention, the telescopic fork is adjustable by means of an electric motor (103) which alters the pre-tension of the coil spring (102) of the telescopic fork. This allows the fork to be adjusted to compensate for a change in sag during riding as a result of a depleting fuel tank, and/or to switch between different riding characteristics depending on the preference of the motorcyclist or the condition of the road surface.