Hydraulic Shock Absorber Bypass Closure Mechanism

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Solution Overview

Problem

Conventional hydraulic shock absorbers face challenges in achieving a large damping force during maximum expansion without increasing costs, particularly due to the need for a push rod to reduce the sectional area of the bypass passage and lack of consideration for complete closure of the bypass passage.

Innovation Solution

A hydraulic shock absorber design featuring a piston rod with a bypass passage that includes a first and second hole, where the second hole is closed by a block ring during maximum expansion, and an adjustable needle to regulate the bypass passage opening, allowing for enhanced damping force generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a push rod is used to reduce the sectional area of the bypass passage, then the damping force in maximum expansion is increased, but the manufacturing cost increases

Engineering Contradiction:
Improvedamping forceVSAvoidmanufacturing cost
Core Design Contradiction:
ForceVSEase of manufacture

Solution Approach 1:

The invention extracts the function of reducing bypass passage area from the push rod and transfers it to the block ring. The block ring is a simple annular component that can be easily manufactured and installed, eliminating the need for the complex push rod mechanism while achieving the same damping force enhancement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The block ring is a simple, inexpensive component compared to the push rod. It achieves the same functional effect (reducing bypass area) but can be manufactured much more cheaply as a simple annular ring that fits into the bypass passage.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Force

If the bypass passage is not completely closed, then the structure is simpler, but the damping force in maximum expansion is insufficient

Engineering Contradiction:
Improvedamping forceVSAvoidbypass passage closure mechanism
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The block ring is positioned and held in place by the rebound spring, which automatically pushes the block ring against the bypass passage opening during compression. This self-actuating mechanism eliminates the need for complex control systems or additional actuating components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The rebound spring acts as an intermediary that transfers the mechanical energy from the shock absorption process to position and hold the block ring in the correct position. The spring provides the necessary force to ensure the block ring seals the bypass passage without requiring complex control mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 achieves complete closure of the bypass passage during maximum expansion, resulting in increased damping force without the need for a push rod, thereby improving the shock absorber's performance while maintaining cost-effectiveness.

Implementation Method 1

a rebound spring supported at one end thereof by an end member mounted to a lower opening portion of the damper cylinder and adapted to be compressively deformed in the case of maximum expansion of the piston rod

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

when the hydraulic shock absorber is expanded, the surface of the block ring comes into abutment against the axial side surface to close the opening of the second hole

Methodology Applied
Scientific EffectMechanical closure: Mechanical Force

Implementation Method 3

a piston provided on the piston rod so as to slide on the inner circumferential surface of the damper cylinder and partition the inside space of the damper cylinder into a rod-side oil chamber and a piston-side oil chamber, the piston having a damping force generating device

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Data Source

PatentEP2233777B1Hydraulic shock absorber
Publication Date: 2011.03.09 HONDA MOTOR CO LTD
  • EP2233777B1 patent drawingFigure 1
  • EP2233777B1 patent drawingFigure 2
  • EP2233777B1 patent drawingFigure 3

AI summary

To provide a hydraulic shock absorber which can exhibit a large damping force in the case of maximum expansion. In a hydraulic shock absorber 10, a piston holder 41 has an axial side surface 41e formed with an opening of an inclined hole 48b exposed to a rod-side oil chamber 43B, and a block ring 71 capable of closing the opening of the inclined hole 48b is provided around a piston rod body 22 at a position between the axial side surface 41e of the piston holder 41 and the upper end of a rebound spring 32.