Motorcycle Fork Electrovalve Positioning for Real-Time Damping

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Solution Overview

Problem

The existing fork assemblies with electrovalves face challenges such as increased production costs due to the need for redesigning the entire fork, larger dimensions of the cartridge and piston, and pressurization issues, which affect performance and make it difficult to adjust oil flow while the motorcycle is moving.

Innovation Solution

The electrovalve is positioned in the working chamber outside the cartridge, allowing for automatic adjustment of oil flow using an electronic control circuit and sensors, while maintaining standard dimensions and reducing the need for re-designing the fork.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If the electrovalve is integrated inside the cartridge, then automatic oil flow adjustment is achieved, but the cartridge and piston dimensions increase and production costs rise

Engineering Contradiction:
Improveautomatic oil flow adjustmentVSAvoidcartridge dimension
Core Design Contradiction:
Extent of automationVSVolume of stationary object

Solution Approach 1:

The system is divided into two functional segments: the cartridge assembly (without electrovalve) and the working chamber assembly (containing electrovalve). This segmentation allows the cartridge to maintain its original compact dimensions while the electrovalve is housed in the separate working chamber, eliminating the need to increase cartridge size.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrovalve is relocated from the radial dimension (inside the cartridge) to the axial dimension (in the working chamber outside the cartridge). This dimensional relocation allows automatic control functionality to be added without increasing the radial dimensions of the cartridge and piston components.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Extent of automation

If the electrovalve is integrated inside the cartridge, then automatic oil flow adjustment is achieved, but production costs increase due to redesign

Engineering Contradiction:
Improveautomatic oil flow adjustmentVSAvoidproduction cost
Core Design Contradiction:
Extent of automationVSEase of manufacture

Solution Approach 1:

By segmenting the fork assembly into cartridge and working chamber portions, the invention allows manufacturers to produce the cartridge using existing tooling and processes, while only the working chamber requires modification to accommodate the electrovalve. This reduces overall production costs compared to complete redesign.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The working chamber is designed to serve multiple functions: it houses the electrovalve for automatic control, contains the spring mechanism, and provides the necessary hydraulic pathways. This multi-functionality reduces the need for additional components and simplifies manufacturing.

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

3Extent of automation

If the electrovalve is integrated inside the cartridge, then automatic oil flow adjustment is achieved, but pressurization issues affect performance

Engineering Contradiction:
Improveautomatic oil flow adjustmentVSAvoidfork performance
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The electrovalve is extracted from the pressurized cartridge environment and placed in the working chamber where pressure conditions are more favorable. This extraction eliminates the risk of electrovalve malfunction due to high pressure, improving system reliability and performance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The working chamber acts as an intermediary space that mediates between the electrovalve and the high-pressure cartridge environment. It provides a transition zone where the electrovalve can operate in more favorable pressure conditions while still controlling oil flow to the cartridge.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If manual adjustment of oil flow is used, then the fork structure remains simple, but adjustment cannot be made while the motorcycle is moving

Engineering Contradiction:
Improveadjustment capabilityVSAvoidfork structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The manual mechanical adjustment system is replaced with an electronic control system comprising sensors, control unit, and electrovalve. This substitution enables dynamic adjustment during motorcycle operation while the mechanical fork structure itself remains relatively simple and unchanged.

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

Solution Approach 2:

The fork assembly incorporates sensors that automatically detect riding conditions and trigger appropriate oil flow adjustments without requiring manual intervention. The system serves itself by continuously monitoring and adapting to changing conditions, eliminating the need for rider action.

Inventive Principle:
Principle #25Self-service

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

This solution enables real-time adjustment of oil flow during motorcycle operation without manual intervention, reducing production costs and maintaining performance by integrating the electrovalve within the existing fork structure.

Implementation Method 1

said electrovalve (8) is situated in said working chamber (C2) and is mechanically joined to said tubular rod (5) in such manner that said electrovalve (8) automatically adjusts the oil flow inside said axial conduit (50) by means of an electronic control circuit

Methodology Applied
Scientific EffectElectrovalve control: Valve

Implementation Method 2

A spring (M1) is disposed inside the internal pipe (2) in the working chamber (C2) around a spring guide (61) and is interposed between the closing bush (30) of the cartridge (3) and a metal ring (7) fixed to the spring guide (61)

Methodology Applied
Scientific EffectSpring compression: Spring

Implementation Method 3

A piston (4) is slidably mounted inside the cartridge (3) and slides inside the chamber (C1). The two pistons (4,41) divide the chamber (C1) of the cartridge (3) into three chambers (C1a, C1b, C1c)

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Gradient

Implementation Method 4

The piston (4) is provided with holes or blades (40) adapted to make the oil pass through the piston (4) during its movement in the chamber (C1)

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Data Source

PatentEP2917095B1Fork assembly with electrovalve
Publication Date: 2016.12.14 VRM SPA
  • EP2917095B1 patent drawingFigure 1
  • EP2917095B1 patent drawingFigure 2
  • EP2917095B1 patent drawingFigure 3

AI summary

A fork assembly (300; 400) comprising an external pipe (1) closed on top with a first plug (10), an internal pipe (2) slidably housed inside said external pipe (1), and a cartridge (3) disposed inside said internal pipe (2) and closed with a closing bush (30); said fork (300, 400) also comprising an electrovalve (8) disposed in intermediate position between the closing bush (30) of the cartridge (3) and the first plug (10) of the external pipe (1).