Shock Absorber Yoke Flow Path for Wider Damping Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing damping force adjustment valves in shock absorbers, when installed inside the piston rod, narrow the annular gap between the housing part and the cylinder, leading to increased pressure loss and a limited damping force adjustment range, which restricts the minimum damping force and causes the damping force to rise in the full soft mode.
Innovation Solution
A shock absorber design that includes a damping force adjustment valve with a solenoid-driven spool and a tubular yoke with through-holes and grooves on the perimeter, which enlarges the flow channel area in the annular gap between the cylinder and the yoke, minimizing resistance and allowing for wider damping force adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the damping force adjustment valve is installed inside the piston rod, then the damping force can be adjusted, but the annular gap between the housing part and the cylinder becomes extremely narrow
Solution Approach 1:
The invention introduces through-holes opening from the side surface of the housing part, creating an additional dimensional pathway for hydraulic oil flow. This bypasses the constrained annular gap and provides an alternative flow route that does not depend on the narrow radial clearance between the housing part and cylinder.
Solution Approach 2:
The flow passage is segmented into multiple independent pathways: the annular gap pathway and the through-hole pathway. This segmentation allows the system to utilize both flow routes simultaneously, with the through-holes providing additional capacity that compensates for the limited annular gap area.
2Device complexity
If the annular gap is narrowed to house the damping force adjustment valve, then the valve can be integrated in the piston rod, but the pressure loss in the annular gap increases
Solution Approach 1:
The through-holes act as intermediary flow passages that connect the extension side chamber and compression side chamber independently of the annular gap. Hydraulic oil can flow through these intermediary pathways, bypassing the high-resistance annular gap region and reducing overall pressure loss.
Solution Approach 2:
The invention utilizes hydraulic pathways through the through-holes to create an alternative flow route. By designing the through-holes with appropriate dimensions and orientations, the system optimizes hydraulic flow characteristics to minimize pressure losses while maintaining compact integration.
3Device complexity
If the annular gap flow channel area is reduced, then the damping force adjustment valve can be housed inside the piston rod, but the minimum damping force is determined by the annular gap resistance and cannot be adjusted
Solution Approach 1:
The through-holes provide an additional dimensional flow pathway that is independent of the annular gap dimensions. This allows the damping force adjustment valve to control flow through the through-holes while the annular gap provides a parallel pathway, ensuring that the minimum damping force is determined by the combined resistance of both pathways rather than being limited by the annular gap alone.
Solution Approach 2:
The damping force adjustment valve dynamically controls the flow resistance in the through-hole pathway, while the annular gap provides a relatively constant parallel pathway. This dynamic control mechanism allows for continuous adjustment of the total flow resistance, expanding the damping force adjustment range even when the annular gap area is reduced.
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 widens the damping force adjustment range and lowers the damping force in the full soft mode, improving ride quality by reducing resistance and allowing for more precise control of damping forces.
Implementation Method 1
a solenoid that drives the spool in opposition to the biasing force of the spool spring
Implementation Method 2
the flow channel resistance imparted to the flow of the hydraulic oil passing through the passage can be varied
Implementation Method 3
the flow channel area of the annular gap becomes narrower than the flow channel area of the damping force adjustment valve when the valve is fully open, and the pressure loss in the annular gap may be greater than the pressure loss in the damping force adjustment valve
Data Source
AI summary
A shock absorber is provided with a cylinder, a piston inserted into the cylinder and demarcating an interior of the cylinder into an extension side chamber and a compression side chamber, a piston rod joined to the piston, a damping passage, provided in the piston rod, that communicates with the extension side chamber and the compression side chamber, and a damping force adjustment valve provided in the damping passage. The damping force adjustment valve includes a damping force adjustment unit and a solenoid that drives the damping force adjustment unit to adjust a flow channel resistance. The piston rod includes a yoke into which the damping force adjustment valve is inserted, and a piston holding member mounted on the yoke. The yoke includes a through-hole opening from a side of the yoke and leading to the interior, and a groove provided on a perimeter of the yoke, extending from an anti-piston end, and leading to the through-hole.