Solenoid Actuated Shock Absorber Preload Control
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Solution Overview
Problem
Existing shock absorber systems lack efficient control over rebound damping forces, as they rely on fixed preload forces that cannot be effectively adjusted to vary damping characteristics without complex and costly control systems.
Innovation Solution
A shock absorber system with a piston valve spring seat connected to a moveable solenoid actuator, utilizing two co-axial springs to adjust preload force and rebound damping, where the position of the spring seat is influenced by the solenoid's plunger, allowing for variable damping force control through electromechanical action.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed preload force is used in the piston valve, then the shock absorber structure is simple, but the rebound damping force cannot be effectively adjusted
Solution Approach 1:
The patent applies the Dynamics principle by making the previously fixed spring seat movable through solenoid actuation. The spring seat is now connected to a solenoid plunger that can adjust its position, thereby dynamically changing the preload force on the valve discs. This allows the rebound damping force to be adjusted between different levels (e.g., soft and hard modes) while maintaining a relatively simple overall structure without requiring complex control systems.
2Adaptability or versatility
If a solenoid actuator is used to adjust preload force, then damping control is achieved, but energy consumption increases
Solution Approach 1:
The patent applies the Periodic action principle by using a bi-stable solenoid that operates in discrete states rather than continuous control. The solenoid has two stable positions (de-energised and energised) corresponding to different damping modes. This allows the system to switch between damping levels with low energy consumption, as the solenoid only consumes significant power during state transitions, not while maintaining a state.
Solution Approach 2:
The patent extracts the energy-intensive continuous control function and replaces it with a bi-stable solenoid that maintains its state without continuous power input. The solenoid is designed to have two stable positions, allowing it to hold the spring seat in either the de-energised or energised position without requiring continuous electrical power, thereby reducing overall energy consumption while maintaining damping control capability.
3Adaptability or versatility
If the spring seat is made movable to adjust preload, then damping variability is improved, but device complexity increases
Solution Approach 1:
The patent applies the Merging principle by combining the spring seat adjustment mechanism with the existing solenoid actuator. The spring seat is directly connected to the solenoid plunger, merging the damping adjustment function with the actuation system. This integration allows the preload force to be adjusted through the same actuator that controls valve operation, reducing overall device complexity while achieving damping variability.
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
Enables low-cost, low-energy control of damping forces by modifying preload force, achieving high latching force with low current draw and reducing the need for expensive controls, applicable to various damper platforms.
Implementation Method 1
a solenoid actuator to vary the preload force in a piston valve. The force generated by the solenoid acts directly on the soft-magnetic spring seat
Implementation Method 2
A bi-stable solenoid is disposed in the housing and is interconnected with the resilient disc of the valve. The bi-stable solenoid's armature is moveable between a first stable position for applying a first biasing force against the resilient disc
Data Source
Figure 1
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AI summary
In shock absorber system 10, solenoid 18 varies the damping force by changing the position of spring seat 24, and the effective preload force, at the same time. In the normal, de-energized condition (with no current), damping forces are generated by the piston valve 30 including piston 20. The actuated valve spring 16 is relaxed and set in such a way that it applies only a minimum preload force to the rebound-side disc stack 28. The motion of the plunger 14, pin 32 and movable spring seat 24 assembly changes the spring force by varying the distance between the movable spring seat 24 and the stationary spring seat 22. In the energized state, applying current to coil 12 generates a pulling force on the plunger 14 in the direction of the core element 34 to attract plunger 14 towards the core 34 and across the initial gap 36 until it is in a direct contact with the core's surface 38. Maintaining plunger 14 at this position requires applying a continuous constant holding current to coil 12 so that the position of the plunger is preserved (and the high preload force at the same time). When current is no longer applied to the coil 12, then the pulling force is no longer generated, and the plunger assembly returns back to the original (soft) position due to the reverse action of the valve spring 16.