Shock Absorber Valve Layout for Stable Damping Under Pressure Differences
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Solution Overview
Problem
Conventional damping valve systems face issues where the solenoid valve can inadvertently close due to increased pressure differences, leading to incorrect damping force characteristics during normal operation, and the adjustment range of damping force is limited when the solenoid valve is used for both pressure control and passage opening/closing.
Innovation Solution
A valve device with a solenoid valve that controls the first passage and a passive valve in the second passage, allowing independent adjustment of damping force characteristics during normal operation and failure scenarios, using a solenoid valve to control the pressure of the back pressure chamber and a passive valve to maintain consistent damping force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the solenoid valve is used to control both pressure and passage opening/closing, then the device complexity is reduced, but the reliability deteriorates due to inadvertent closure from pressure differences
Solution Approach 1:
The solenoid valve is divided into two independent valve bodies: a pressure control valve body that controls the pressure control valve passage, and an opening/closing valve body that controls the first and second passages. This segmentation allows each valve body to perform its specific function independently, preventing the reliability issue where pressure differences cause inadvertent closure of the opening/closing function while maintaining the simplified structure benefit of using a single solenoid coil.
2Adaptability or versatility
If the passive valve is positioned upstream of the pressure control valve, then the adjustment range of damping force is improved, but the device complexity increases due to additional passages and components
Solution Approach 1:
The passive valve is extracted from the traditional upstream position and relocated to the downstream side of the solenoid valve in the second passage. This extraction simplifies the passage configuration by eliminating the need for complex upstream routing while maintaining the ability to provide a backup damping force path. The passive valve connects the second passage to the piston rod side chamber, providing a direct backup path without requiring additional complex passages.
3Reliability
If the solenoid valve closes due to increased pressure difference, then the passive valve can provide backup damping force, but the damping force characteristics become incorrect during normal operation
Solution Approach 1:
The pressure control valve passage acts as an intermediary element between the first passage and the second passage. It includes a pressure control valve hole that communicates between these passages and a throttle hole that provides flow resistance. This intermediary structure allows the system to maintain precise damping force characteristics by controlling the pressure balance, while still providing a backup path through the passive valve when the solenoid valve closes, whether intentionally or due to pressure differences.
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
Prevents failure states during normal operation and allows for free setting of passive valve characteristics, ensuring consistent damping force adjustment regardless of solenoid valve activation, thereby maintaining stable damping force characteristics.
Implementation Method 1
a solenoid that applies to the solenoid valve valve body a thrust in a direction opposite to a direction of the force of the spring
Implementation Method 2
a spring that pushes up the solenoid valve valve body in a direction in which the pressure control valve valve body and the pressure control valve valve seat are away from each other
Data Source
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AI summary
Provided is a valve device and a shock absorber that can prevent them from being in a failure state at the normal time and can freely set a passive valve even when both pressure control and passage opening/closing are performed by a solenoid valve. For this reason, the valve device includes a first passage (P3) and a second passage (P4) connected downstream of the pressure introducing passage, a solenoid valve (4) that opens the first passage (P3) to control the upstream pressure and closes the second passage (P4) when energized, and that closes the first passage (P3) and opens the second passage (P4) when not energized, and a passive valve (5) provided downstream of the solenoid valve (4) in the second passage (P4).