Hydraulic Shock Absorber Air Bubble Expulsion

Solution Overview

Problem

Hydraulic shock absorbers in motorcycles face issues with air bubbles collecting in the oil chamber, leading to slackness in damping action, and existing solutions require additional components like check valves that increase space and manufacturing costs.

Innovation Solution

A hydraulic shock absorber design that includes a ring-shaped flow passage and inner/outer side flow passages to pressurize and expel air bubbles from the oil chamber into an air chamber, eliminating the need for check valves and reducing space and manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a check valve (O-ring) is installed to expel air bubbles from the ring-shaped oil chamber, then air bubble removal is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improvedamping action consistencyVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the air bubble removal function from a separate check valve component and integrates it into the existing partition wall structure. The partition wall is designed with an inclined surface that acts as a one-way valve seat, allowing air bubbles to be expelled during compression while preventing oil leakage during extension, thereby eliminating the need for a separate check valve component.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the air bubble expulsion function with the partition wall structure. The partition wall serves dual purposes: separating the oil reservoir chamber from the hydraulic oil chamber and simultaneously functioning as a one-way valve through its inclined surface design. This integration reduces component count while maintaining air bubble removal capability.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If a check valve (O-ring) is installed to expel air bubbles from the ring-shaped oil chamber, then air bubble removal is improved, but space requirements increase

Engineering Contradiction:

Improvedamping action consistencyVSAvoidspace requirements

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The invention merges the air bubble expulsion function with the partition wall structure. The partition wall serves dual purposes: separating the oil reservoir chamber from the hydraulic oil chamber and simultaneously functioning as a one-way valve through its inclined surface design. This integration reduces component count while maintaining air bubble removal capability.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If a check valve (O-ring) is installed to expel air bubbles from the ring-shaped oil chamber, then air bubble removal is improved, but manufacturing cost increases

Engineering Contradiction:

Improvedamping action consistencyVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The invention merges the air bubble expulsion function with the partition wall structure. The partition wall serves dual purposes: separating the oil reservoir chamber from the hydraulic oil chamber and simultaneously functioning as a one-way valve through its inclined surface design. This integration reduces component count while maintaining air bubble removal capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The partition wall is designed to perform multiple functions: chamber separation and one-way valve operation. The inclined surface of the partition wall creates a self-sealing mechanism that allows air bubble expulsion during compression while preventing oil leakage during extension, eliminating the need for separate check valve components and reducing manufacturing complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 design effectively prevents slackness in the damping action by continuously expelling air bubbles, maintaining consistent damping performance while reducing space requirements and manufacturing costs.

Implementation Method 1

hydraulic oil of an amount corresponding to the volume of the piston rod that has entered into the hydraulic oil chamber during the stroke flows out from the hydraulic oil chamber and into the ring-shaped oil chamber, and when the front fork is extended

Methodology Applied

Scientific EffectHydraulic pressure: Pressure Increase

Implementation Method 2

a collection of air bubbles present in the ring-shaped oil chamber is pushed out into the oil reservoir chamber during an external operation

Methodology Applied

Scientific EffectFluid compression: Compression

Data Source

PatentEP2783967B1Hydraulic shock absorber

Publication Date: 2017.07.12 SHOWA CORP

Figure 1
Figure 2
Figure 3

AI summary

A hydraulic shock absorber (10) provides, a ring-shaped flow passage (B) formed continuously along a circumferential direction between an outer circumference of a partition wall member (19) and an inner circumference of an inner tube (12), in a range from an abutting surface (19D) to a screw coupling starting portion of a thread section (12E) of the inner tube (12); an outer side flow passage (A) which is formed to a ring-shaped oil chamber (17) side from a dividing member (20) positioned on an open end surface side of the inner tube (12) and which connects a ring-shaped oil chamber (17) and the ring-shaped flow passage (B), an inner side flow passage (C) which is formed in the partition wall member (19) and which connects the ring-shaped flow passage (B) and an oil reservoir chamber (22).