Sub-Piston Damper Orifice Control Across Stroke Speeds
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Solution Overview
Problem
Existing dampers fail to efficiently adjust damping force across varying stroke speeds, particularly experiencing a sharp increase in damping force at high speeds, necessitating improved adjustability.
Innovation Solution
Incorporation of a sub-piston with a second damping force generator featuring an annular groove, disk valve, and support structure to adjust damping force through static and variable orifice areas, allowing for controlled damping force adjustment from lower to higher speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a speed detection valve disk is used to close the fluid path at high speeds, then damping force increases, but the damping force increases sharply causing instability
Solution Approach 1:
The patent replaces the dynamic closure mechanism (speed detection valve disk closing the fluid path) with a static geometric configuration (annular groove and disk valve creating a fixed orifice area). This static design allows damping force to be adjusted smoothly across different speed ranges without the sharp increases caused by dynamic closure, thereby maintaining stability while still providing speed-dependent damping control.
Solution Approach 2:
The patent changes the parameter control approach from dynamic closure (binary open/closed state) to static geometric parameters (orifice area defined by annular groove and disk valve). By using the orifice area as the controlling parameter instead of valve disk position, the system achieves smooth damping force adjustment without sharp transitions, resolving the stability issue.
2Force
If the fluid path is closed by the speed detection valve disk, then damping force increases at high speed, but adjustability of damping force is reduced
Solution Approach 1:
The patent maintains dynamic adaptability through the disk valve's ability to deflect under fluid pressure, which dynamically adjusts the orifice area based on stroke speed. This dynamic deflection provides continuous damping force adjustment across speed ranges without the binary closure limitation, preserving versatility while achieving high-speed damping control.
Solution Approach 2:
The patent replaces the mechanical closure system (valve disk making contact to close the path) with a fluid-pressure-driven deflection system. The disk valve deflects according to fluid pressure, which varies with stroke speed, providing automatic and continuous damping adjustment without mechanical contact closure, thereby maintaining adjustability.
3Force
If valve disks are pressed onto the valve main body to close fluid paths, then damping force is generated, but the structure becomes complex
Solution Approach 1:
The patent extracts the essential damping function from the complex valve disk closure mechanism and implements it through a simpler orifice-based system. The annular groove and disk valve create a flow restriction without requiring multiple valve disks, retainers, and compression springs, thereby reducing structural complexity while maintaining damping force generation.
Solution Approach 2:
The patent uses fluid dynamics (hydraulic principle) to generate damping force through the orifice created by the annular groove and disk valve, replacing the mechanical valve disk closure system. This hydraulic approach simplifies the structure by eliminating the need for multiple mechanical components while still achieving pressure-dependent damping control.
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
Enables smooth and adjustable damping force adjustment across a wide range of stroke speeds, reducing sharp increases and enhancing damping force control.
Implementation Method 1
If the fluid pressure on the valve disks exceeds a bending load of the valve disks, the valve disks deflect elastically to open the compression fluid paths
Implementation Method 2
the valve disks deflect elastically to open the compression fluid paths provided in the valve main body
Implementation Method 3
An orifice of the sub-piston is defined by an outer diameter of the disk valve and an outer diameter of the groove
Implementation Method 4
the flow comes to a limit and the fluid pressure decreases
Data Source
AI summary
A damper includes a main piston and a sub-piston. The main piston includes a main piston main body and a first damping force generator. The sub-piston includes a sub-piston main body and a second damping force generator. The second damping force generator includes a groove in a main surface of the sub-piston main body, a disk valve to cover the groove, and a port in the groove extending through the sub-piston main body. The disk valve does not make contact with the sub-piston main body. The sub-piston includes an orifice defined by an outer diameter of the disk valve and an outer diameter of the groove to adjust a damping force when a stroke speed is in a lower-speed range, and the disk valve has a stiffness to adjust the damping force when the stroke speed is in a higher-speed range.