Hydraulic Shock Absorber Piston Valve for Damping Force Control
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Solution Overview
Problem
Existing hydraulic shock absorbers experience sharp changes in damping force characteristics, making it difficult to set damping forces easily and potentially leading to noise and degradation of ride quality.
Innovation Solution
The shock absorber design includes a piston assembly with a disk valve and sub-seat portions that form sub-valve chambers, allowing for controlled flow path adjustments through the use of a pressing member and initial deflection of the disk valve, reducing sharp changes in damping force and enabling easier setting of damping force characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a disk valve is used to control fluid flow in the passage, then damping force characteristics can be adjusted, but sharp changes in damping force occur making it difficult to set damping forces easily
Solution Approach 1:
The invention divides the single valve chamber into two separate chambers: a first valve chamber and a second valve chamber. Each chamber has its own disk valve (first disk valve and second disk valve) that can be independently adjusted. This segmentation allows the damping force characteristics to be tuned separately in different piston speed regions, eliminating the sharp changes that occur when using a single disk valve and making it easier to set the desired damping force characteristics.
2Reliability
If the disk valve deflects to open in the intermediate piston speed region, then damping force characteristics are maintained, but sharp changes in damping force still occur
Solution Approach 1:
The invention segments the valve control into two independent chambers. The first valve chamber handles low piston speed regions while the second valve chamber handles intermediate and high piston speed regions. This segmentation allows each chamber to be optimized for its specific operating range, preventing the sharp transitions that occur when a single disk valve operates across all speed ranges.
Solution Approach 2:
Each valve chamber is designed with specific local characteristics tailored to its operating range. The first disk valve and first valve chamber are optimized for low speed operation, while the second disk valve and second valve chamber are optimized for intermediate and high speed operation. This local optimization ensures smooth damping force transitions across the entire piston speed range.
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 design effectively suppresses sharp changes in damping force, improves ride quality, and simplifies the manufacturing process by allowing for more stable and easily adjustable damping force characteristics across different piston speed regions.
Implementation Method 1
the disk valve deflects to open according to the piston speed, thereby generating a damping force of valve characteristics
Implementation Method 2
The damping force generating mechanism generates a damping force by controlling, through the orifice and the disk valve, the flow of hydraulic fluid
Implementation Method 3
a pressing member that presses the disk valve toward the main seat portion at the inner peripheral side of the main seat portion
Data Source
AI summary
A hydraulic shock absorber has a cylinder having a hydraulic fluid sealed therein and a piston connected with a piston rod and slidably provided in the cylinder. The piston is provided with a circular main seat portion to form a main valve chamber communicating with an extension passage. Arcuate sub-seat portions are provided in concentric relation to the main seat portion to form sub-valve chambers. A disk valve is seated on the main and sub-seat portions to form clearances between them that always communicate between the main and sub-valve chambers. The disk valve opens upon receiving the pressure in the main and sub-valve chambers. The clearances restrict the flow of hydraulic fluid flowing out through the sub-valve chambers at the beginning of opening of the disk valve to prevent a sharp change in damping force. The concentric arrangement of the main and sub-seat portions facilitates the setting of an initial deflection for the disk valve.