Parallel-Passage Shock Absorber for High-Speed Damping Control
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Solution Overview
Problem
Conventional shock absorbers experience excessive damping force in the high speed range due to the sub valve being deflected by a valve stopper, leading to a bottleneck in flow passage area and impaired ride quality.
Innovation Solution
A shock absorber design with parallel main and sub passages, featuring a main damping force generation element with a main valve and a sub damping force generation element with a sub valve having a lower opening pressure, allowing independent control of damping force characteristics and avoiding bottleneck issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sub valve is pressed by a valve stopper to regulate deflection amount, then the sub valve is protected from excessive load, but the flow passage area becomes a bottleneck and excessive damping force is generated in high speed range
Solution Approach 1:
The shock absorber is divided into two independent parallel passages: a main passage with a main valve and a sub passage with a sub valve. This segmentation allows each valve to operate independently, preventing the sub valve from becoming a bottleneck that generates excessive damping force in high speed ranges while still providing protection through the main valve.
Solution Approach 2:
The main valve acts as an intermediary that handles high speed flow conditions, while the sub valve handles low speed conditions. This mediator relationship allows the system to bypass the bottleneck effect by routing high speed flow through the main passage, preventing excessive damping force generation.
2Adaptability or versatility
If the sub valve and leaf valves are disposed in series, then the damping force characteristic becomes speed dependent, but the sub valve deflection is regulated by valve stopper causing excessive damping force in high speed range
Solution Approach 1:
The series arrangement is changed to a parallel arrangement where the main passage and sub passage operate independently. This allows the damping force characteristic to remain speed-dependent through valve selection while avoiding the excessive damping force problem caused by series arrangement with valve stopper regulation.
Solution Approach 2:
The system dynamically selects which passage to use based on flow conditions: the sub passage is used for low speed conditions while the main passage handles high speed conditions. This dynamic switching prevents the valve stopper from creating a bottleneck during high speed operation.
3Productivity
If the entire flow rate passes through the sub valve, then the sub valve must handle all flow conditions, but this causes the valve stopper to create a bottleneck in high speed range
Solution Approach 1:
The flow path is segmented into two parallel passages that can handle flow independently. The main passage is designed to handle high speed flow conditions while the sub passage handles low speed conditions, eliminating the bottleneck effect of forcing all flow through a single sub valve.
Solution Approach 2:
The system dynamically routes flow based on speed conditions: at low speeds, flow passes through the sub passage; at high speeds, flow is routed through the main passage. This dynamic flow routing allows the system to maintain productivity while avoiding excessive damping force generation.
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
Improves ride quality by preventing excessive damping force override in high speed ranges, ensuring optimal damping force characteristics across varying speeds.
Implementation Method 1
a sub valve that opens and closes the sub passage and has a lower valve opening pressure than that of the main valve
Implementation Method 2
the end portion on the free end side of the sub valve is deflected, the gap formed on the outer circumference of the free end becomes wide
Implementation Method 3
a main valve that opens and closes the main passage
Implementation Method 4
used to suppress vibrations of the vehicle body by generating damping force with resistance given to a flow of a liquid generated when the shock absorber extends and contracts
Implementation Method 5
resistance given to a flow of a liquid generated when the shock absorber extends and contracts
Implementation Method 6
a main passage and a sub passage that communicate in parallel two working chambers provided in the shock absorber main body
Data Source
AI summary
A shock absorber includes: a shock absorber main body that has an outer tube and a rod movably inserted into the outer tube and can extend and contract; a main passage and a sub passage that communicate in parallel two working chambers provided in the shock absorber main body; a main damping force generation element provided in the main passage; and a sub damping force generation element provided in the sub passage. The main damping force generation element has only a main valve that opens and closes the main passage. The sub damping force generation element has an orifice provided in series with the sub passage, and a sub valve that opens and closes the sub passage and has a valve opening pressure lower than that of the main valve.