Piston Slide Valve with Permanent Magnet for Fail-Safe Stroke
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Solution Overview
Problem
Electromagnetically actuated piston slide valves in vehicle shock absorbers face challenges with high basic current requirements for maintaining the fail-safe position, susceptibility to external interference, and limited fail-safe stroke due to stiff springs, which can lead to unintended switching between damping characteristics.
Innovation Solution
Incorporating a permanent magnet that counteracts the force of the second prestressing device, allowing for a lower basic electrical current supply and increased fail-safe stroke, while enhancing robustness against external influences by supporting the valve's position with magnetic force during energization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a stiff fail-safe spring is used to ensure a large fail-safe stroke, then the fail-safe stroke is increased, but the base current requirement increases and the valve becomes more susceptible to unintended switching
Solution Approach 1:
The patent replaces part of the mechanical spring system with a magnetic field system. A permanent magnet is introduced to provide a magnetic force that counteracts the fail-safe spring force, reducing the mechanical preload required. This substitution allows for a larger fail-safe stroke without proportionally increasing the base current requirement, as the magnetic field assists in balancing the spring force during normal operation.
Solution Approach 2:
The patent changes the magnetic properties of the system by introducing a permanent magnet with specific magnetic moment. This alters the force balance in the system, allowing the fail-safe spring to be softer while still achieving the required fail-safe stroke. The magnetic field provides additional force to maintain valve position, enabling parameter optimization for both stroke and current consumption.
2Stability of the object's composition
If a stiff fail-safe spring is used to maintain valve position, then position stability is improved, but external vibrations can cause unintended switching and energy consumption increases
Solution Approach 1:
The patent replaces part of the mechanical positioning system with a magnetic field system. The permanent magnet creates a magnetic field that provides continuous force to maintain valve position, reducing reliance on high spring stiffness. This magnetic support makes the system more compliant to external vibrations while maintaining position stability, as the magnetic field can dynamically adjust to force variations.
3Reliability
If a stiff fail-safe spring is used to ensure fail-safe position, then the fail-safe function is reliable, but the control resolution and energy efficiency deteriorate
Solution Approach 1:
The patent substitutes mechanical spring force with magnetic field force to maintain the fail-safe position. The permanent magnet provides continuous magnetic force that counteracts the spring force, allowing the spring to be softer and the base current to be lower. This reduces energy consumption while maintaining fail-safe reliability, as the magnetic field provides stable positional support without requiring high continuous electrical power.
4Stability of the object's composition
If high base current is applied to maintain fully open position against stiff spring, then the valve remains stable in open position, but the system becomes more complex and energy-intensive
Solution Approach 1:
The patent introduces a permanent magnet to create a magnetic field that assists in maintaining valve position. This magnetic field system replaces part of the high-current electromagnetic actuation system, allowing for lower base current operation. The permanent magnet is integrated into the existing valve structure, minimizing additional complexity while providing continuous positional support that reduces the electrical power required for stability.
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 solution reduces energy consumption, allows for a harder fail-safe adjustment, and increases the control range with better resolution, ensuring stability and moderate damping characteristics even under system failures or external disruptions.
Implementation Method 1
a permanent magnet (14), which acts on at least one of the first magnetic armature (11) and the second magnetic armature (12) such that a magnetic force counteracts the force of the second preloading device (10)
Implementation Method 2
By generating an electromagnetic field through energizing a coil, the piston can be axially displaced against the force of the first preloading device
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
An electromagnetically actuated piston spool valve (1") comprises a piston spool assembly with a piston (5) that is axially displaceable to control the free cross-sectional area of a fluid passage (6) of the valve (1"). The piston spool assembly includes a first magnetic armature (11) connected to the piston (5) and a second magnetic armature (12) that is axially displaceable relative to the piston (5). The piston (5) is axially displaceable by generating an electromagnetic field by energizing a coil (8) against the force of a first preload spring (9). A second preload spring (10) is supported against the first magnetic armature (11) and the second magnetic armature (12), so that, when the coil (8) is not energized, the piston (5) assumes a predetermined position by axial displacement due to the force of the second preload spring (10) against the force of the first preload spring (9).A permanent magnet (14) is provided which preferably generates an attractive force between the first and second magnetic armature (11, 12) which counteracts the force of the second preload spring (10).