Shock Absorber Spool Valve for Faster Damping Response
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Solution Overview
Problem
Existing electrically controlled valves in shock absorbers are slow to react to control signals, leading to inadequate dynamic adjustment of damping characteristics, and are often larger and more expensive due to the need for strong actuators to manage needle movement under high fluid pressures.
Innovation Solution
A valve design featuring a spool movable between open and restricting positions, with radial ports and a pressure compensation chamber, allowing for quick fluid flow adjustments and reduced actuator power requirements, utilizing a stepper motor for precise control and minimizing machining complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a needle valve is used to control fluid flow, then the valve can be compact in size, but the actuator becomes slow and requires high power to overcome fluid pressure forces on the needle
Solution Approach 1:
The patent replaces the traditional needle valve mechanical control system with a spool valve system. The spool valve uses a different mechanical principle where the spool moves axially within a valve body, creating annular flow passages. This substitution allows for faster actuator response because the spool has lower friction and inertia compared to a needle, while maintaining compact valve dimensions.
Solution Approach 2:
The patent changes the control parameter from needle displacement (radial movement) to spool displacement (axial movement). This parameter change enables the use of a stepper motor actuator that can quickly and precisely control the spool position, thereby improving response speed while keeping the valve compact.
2Volume of moving object
If a needle valve is used to control fluid flow, then the valve can be compact, but a stronger actuator is required to move the needle under high fluid pressures
Solution Approach 1:
The patent substitutes the needle valve mechanism with a spool valve mechanism. The spool valve design reduces the effective area on which fluid pressure acts, thereby reducing the force required to move the spool. This allows the use of a lower power actuator (stepper motor) while maintaining compact valve size.
Solution Approach 2:
The spool valve divides the fluid flow control into multiple annular passages along the axial direction. This segmentation allows the control force to be distributed over a longer distance, reducing the instantaneous force requirement on the actuator while maintaining compact overall valve dimensions.
3Quantity of substance
If fluid pressure acts on the needle in a needle valve, then flow control is achieved, but the actuator speed decreases due to increased forces on the needle
Solution Approach 1:
The patent replaces the needle valve system with a spool valve system that maintains effective fluid flow control through annular passages. The spool valve design reduces mechanical friction and inertia, allowing the actuator to respond faster to control signals while maintaining precise flow control capability.
Solution Approach 2:
The spool valve design incorporates dynamic characteristics that allow for faster response. The spool can move quickly between positions due to reduced friction and lighter effective mass, enabling the valve to adapt damping characteristics rapidly in response to control signals while maintaining fluid flow control.
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
The valve design enhances reaction speed and reduces size and cost by maintaining constant fluid pressure within the spool, allowing for faster and more efficient adaptation of damping characteristics while minimizing turbulence and flow resistance.
Implementation Method 1
The spool is configured to throttle the secondary fluid flow at the fluid inlets of the piston holder by gradually blocking the fluid inlets of the secondary fluid channel with an outer surface of the spool upon movement of the spool from the open position towards the restricting position
Implementation Method 2
maintaining constant fluid pressure within the spool, allowing for faster and more efficient adaptation of damping characteristics
Implementation Method 3
The valve further comprises an electrically controlled actuator configured to move the spool between its open and restricting positions
Implementation Method 4
The piston comprises a primary fluid channel fluidly connecting the second and third chambers to allow for a primary fluid flow between the second and third chambers
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
An electrically controlled valve (1) for a shock absorber (2). The valve comprises a piston (7) providing a primary fluid channel (10) for damping fluid. A piston holder (5) is provided with an internal secondary fluid channel (11) for damping fluid. Fluid flow (23) through the secondary fluid channel is controlled by a spool (12) movable within the piston holder (5) by means of an electrically controlled actuator (13). Fluid flow (23) through the secondary fluid channel (11) is controlled by restriction at the inlet of the secondary fluid channel (11), said inlet comprising one or more radial holes through the piston holder.