Shock Absorber Valve Seat Structure for Stable Damping Force
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Solution Overview
Problem
Conventional shock absorbers experience variations in damping force due to changes in the contact width between the leaf valve and the seat portion, leading to inconsistencies in pressure-receiving area and valve-opening points.
Innovation Solution
A shock absorber design featuring a piston with annular protrusion portions that ensure the valve member abuts only the second protrusion portion, maintaining a consistent contact area and reducing variations in damping force by controlling hydraulic fluid flow through specific passages and chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the leaf valve is seated on the entire surface of the seat portion in the width direction, then the contact width between the seat portion and the leaf valve varies when the step of the seat portion is small, but this configuration is simple in structure
Solution Approach 1:
The seat portion is segmented into multiple protrusion portions (first protrusion portion and second protrusion portion) with different heights. The valve member contacts only the second protrusion portion, dividing the contact area into controlled segments that prevent unwanted contact width variation while maintaining structural simplicity.
Solution Approach 2:
Different portions of the seat portion are given different local qualities through varying heights. The second protrusion portion extends further in the direction away from the piston than the first protrusion portion, creating a localized contact area that ensures consistent valve opening characteristics regardless of small step variations.
2Manufacturing precision
If the contact width between the seat portion and the valve member varies, then the pressure-receiving area of the valve member becomes variable, but maintaining a fixed contact width requires precise manufacturing
Solution Approach 1:
The seat portion is pre-configured with protrusion portions of different heights before valve assembly. This preliminary structural arrangement ensures that the valve member automatically contacts only the second protrusion portion, pre-determining the contact width and pressure-receiving area to prevent variations during operation.
Solution Approach 2:
The second protrusion portion acts as an intermediary element between the valve member and the piston. By extending further than the first protrusion portion, it mediates the contact interaction, ensuring consistent valve opening characteristics while reducing sensitivity to manufacturing tolerances of the overall seat portion.
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 configuration stabilizes the damping force by minimizing contact area variations and maintaining consistent valve operation, thereby reducing fluctuations in the shock absorber's performance.
Implementation Method 1
a shock absorber that generates a variable damping force by controlling a flow of hydraulic fluid caused in reaction to a stroke of a piston rod
Data Source
AI summary
One aspect of the present invention is configured in such a manner that a main valve (a valve member) is in abutment with only a ridge portion (a second protrusion portion) on the inner peripheral side of a seat portion (a first seat portion) in a state of being mounted on a piston. This configuration can reduce the radial contact width between the main valve and the seat portion, and contribute to preventing or reducing variations in the valve-opening point and the damping force by managing the radial dimension of the ridge portion on the inner peripheral side of the seat portion to allow the contact diameter between the main valve and the seat portion to be kept constant.