Front Fork Axial Adjuster Mechanism for Independent Damping Control

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Solution Overview

Problem

The existing front fork designs for straddle-riding vehicles are complex and difficult to assemble due to the need for multiple adjuster nuts and components, which increase the number of parts and costs, while also limiting the ability to adjust damping force characteristics effectively.

Innovation Solution

The design features first and second axially movable adjusters on the cap, with non-overlapping contact portions to allow independent movement of adjustment rods, eliminating the need for additional nuts and simplifying the structure by enabling independent axial movement of the first and second adjustment rods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple adjuster nuts and components are used to adjust damping force characteristics, then the ability to adjust damping force characteristics is improved, but the device complexity and number of components increases

Engineering Contradiction:
Improvedamping force characteristics adjustmentVSAvoidnumber of components
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the valve adjustment function and spring adjustment function into a single integrated adjuster mechanism. The adjuster simultaneously controls both the needle valve degree of opening and the spring force by rotating a single adjustment portion, eliminating the need for separate adjuster nuts for each function. This merging reduces the number of components while maintaining full adjustability of damping force characteristics.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single adjuster mechanism performs multiple functions: it adjusts both the valve degree of opening and the spring force, and it can operate in multiple modes (locking mechanism engaged or disengaged). The adjustment portion serves as a universal interface for controlling different aspects of the damping system, reducing the need for multiple specialized components.

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

2Adaptability or versatility

If multiple adjuster nuts and components are used to adjust damping force characteristics, then the ability to adjust damping force characteristics is improved, but the ease of manufacture and assembly deteriorates

Engineering Contradiction:
Improvedamping force characteristics adjustmentVSAvoidassembly difficulty
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

By merging the valve adjustment and spring adjustment into a single integrated mechanism, the patent reduces the number of parts that need to be manufactured and assembled. The single adjuster assembly can be manufactured as one unit or pre-assembled module, simplifying the manufacturing process and reducing assembly steps compared to multiple separate adjuster nuts and components.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If adjuster nuts are prevented from rotating by insertion holes, then the adjustment stability is improved, but the device complexity increases

Engineering Contradiction:
Improveadjustment stabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates the anti-rotation function directly into the adjustment portion design rather than using separate adjuster nuts with insertion holes. The adjustment portion itself is designed to engage with the adjuster mechanism in a way that prevents rotation while maintaining simplicity. This merging of functions reduces structural complexity while ensuring adjustment stability.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3287660B1Front fork
Publication Date: 2020.05.06 KYB MOTORCYCLE SUSPENSION CO LTD
  • EP3287660B1 patent drawingFigure 1
  • EP3287660B1 patent drawingFigure 2
  • EP3287660B1 patent drawingFigure 3~4

AI summary

Provided is a front fork which has a small number of components with simple structure and is easy to assemble. In order to achieve the above object, in a front fork F according to the means for solving the problem of the present invention, first and second adjusters 5, 6 are mounted on a cap 4 so as to be axially movable, and a contact portion 52 of the first adjuster 5 in contact with a first adjustment rod 7 and a contact portion 62 of the second adjuster 6 in contact with a second adjustment rod 8 are displaced in an axial direction of a vehicle body tube 2 so as not to interfere with each other. Therefore, even when each of the first and second adjusters 5, 6 moves in the axial direction with respect to the cap 4, the corresponding first and second adjustment rods 7, 8 can be moved independently without being interfered with each other.