Shock Absorber Piston With Circumferential Choke Passage
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Solution Overview
Problem
Conventional shock absorbers face limitations in setting high damping force characteristics at low speeds due to the restricted length of the choke passage, which cannot be extended beyond the piston's axial length, leading to insufficient damping force during low-speed extension and contraction.
Innovation Solution
The shock absorber design incorporates a partition member with a disk shape that includes a choke passage extending along the circumferential direction, allowing for increased passage length without increasing the axial length of the piston, thereby enhancing the freedom in designing the choke passage length and enabling sufficient damping force at low speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the passage length of the choke passage is increased to increase damping force, then the damping force at low speed is improved, but the axial length of the piston must be increased which limits the design
Solution Approach 1:
The choke passage extends radially through the piston wall rather than axially through the piston body. This allows the passage length to be determined by the radial thickness of the piston wall, enabling independent optimization of damping force without being constrained by the axial length of the piston
Solution Approach 2:
The piston structure is designed with different functional zones: the radial choke passage provides localized flow resistance for damping force control, while the axial length of the piston is independently optimized for stroke length. This local differentiation of functions allows simultaneous optimization of both damping force and stroke length
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 increases the damping force during low-speed operations and allows for easier setting of damping force characteristics, eliminating the need for orifices with difficult-to-set damping force characteristics.
Implementation Method 1
the shock absorber exerts a damping force depending on a pressure loss when the hydraulic fluid passes only through the choke passage
Implementation Method 2
the hydraulic fluid flows back and forth between the extension side chamber and the compression side chamber through the choke passage
Implementation Method 3
an extension side leaf valve having an annular shape that is stacked on a compression side chamber side end of the piston, has an inner periphery fixed to the piston rod and an outer periphery allowed to bend, and opens and closes the extension side port
Data Source
AI summary
A shock absorber according to the present invention includes: a cylinder, a rod movably inserted into the cylinder, and a partition member having a disk shape and inserted into the cylinder to partition an inside of the cylinder into two working chambers, in which the partition member includes a plurality of ports that communicates the working chambers with each other, and a choke passage having a portion communicating the working chambers with each other and passing through an inner peripheral side or an outer peripheral side of each port along a circumferential direction.