Motorcycle Shock Absorber Inlet Port Design for High-Speed Damping
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Solution Overview
Problem
Hydraulic shock absorbers for motorcycles fail to maintain their original damping characteristics when oil flows at high speeds, leading to increased passage resistance and improper damping force generation.
Innovation Solution
The shock absorber design features a damping force generator with an inlet port opening cross-sectional area larger than the downstream passage area, which suppresses passage resistance and ensures consistent damping performance even at high oil flow speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the passage through which oil flows is narrowed to generate damping force at low flow speeds, then damping force is generated effectively at low speeds, but passage resistance increases excessively at high flow speeds causing loss of damping characteristics
Solution Approach 1:
The passage is divided into two distinct sections: a first passage with a smaller cross-sectional area for generating damping force at low flow speeds, and a second passage with a larger cross-sectional area for reducing passage resistance at high flow speeds. The oil flow path is segmented to flow through the first passage initially, and when a specific flow rate is exceeded, it flows through the second passage instead, thus resolving the contradiction between needing narrow passages for damping force and wide passages for low resistance.
2Object-affected harmful factors
If the valve opening area is increased to reduce passage resistance at high flow speeds, then damping characteristics are maintained, but damping force generation capability decreases at low flow speeds
Solution Approach 1:
The system dynamically switches between two passage configurations based on flow rate conditions. At low flow speeds, the valve closes the second passage and oil flows through the narrower first passage to generate sufficient damping force. When flow rate exceeds a threshold, the valve opens to allow oil to flow through the wider second passage, reducing passage resistance. This dynamic adaptation resolves the contradiction between maintaining damping force at low speeds and reducing resistance at high speeds.
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 allows the shock absorber to reliably exhibit its original damping characteristics by preventing excessive resistance and ensuring proper damping force generation across varying flow speeds.
Implementation Method 1
the valve elastically deforms according to the pressure of the oil in a direction of being separated from the surface of the piston body
Implementation Method 2
The passage of the oil is narrowed by the gap between the valve and the piston body, and the damping force is generated as a result
Data Source
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AI summary
A damping force generator (40) includes: a valve body (66) having a compression-side inlet port (66c) into which the oil pushed by the piston (12) flows; and a compression-side damping valve (65) provided so as to block a port outlet and elastically deformed according to pressure of the oil flowing into the compression-side inlet port (66c) to thereby exhibit damping force. An opening cross-sectional area (A1) of a port inlet opening (79A) is larger than a passage cross-sectional area (A0) of the compression-side inlet port (66c).