Stepped Bore Damper Assembly for Variable Damping Control
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Solution Overview
Problem
Conventional dampers lack the ability to accurately control damping characteristics, particularly in small-scale applications like furniture, where manufacturing tolerances can affect performance, leading to inconsistent energy absorption and potential 'bounce' issues during impact.
Innovation Solution
A piston and cylinder type damper with a stepped bore conduit and an elongate pin element that partly occludes it, featuring multiple seals to control fluid flow between chambers, allowing for adjustable damping resistance by varying the annular gap size based on piston position, enabling tailored damping stages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional damper with uniform bore is used, then the structure is simple, but the damping characteristics cannot be precisely controlled and manufacturing tolerances affect performance consistency
Solution Approach 1:
The conduit is divided into multiple sections with different bore diameters (first section with larger diameter, second section with smaller diameter), allowing different damping characteristics in different stroke portions. This segmentation enables precise control of fluid flow at different stages of piston movement, resolving the contradiction between manufacturing precision and device complexity.
Solution Approach 2:
Different sections of the conduit have different bore diameters tailored to specific functional requirements. The first section has a larger diameter for initial fluid passage, while the second section has a smaller diameter for restricted flow and higher damping. This local differentiation of properties allows precise damping control without excessive overall complexity.
2Ease of manufacture
If manufacturing tolerances are relaxed, then the device is easier to manufacture, but damping performance becomes inconsistent and bounce issues occur
Solution Approach 1:
The damper incorporates a resilient element that dynamically adjusts the sealing engagement between the piston assembly and cylinder wall. This dynamic adjustment compensates for manufacturing tolerances in real-time, maintaining reliable sealing and consistent damping performance across different manufactured units without requiring extremely tight tolerances.
Solution Approach 2:
The stepped bore design changes the critical flow parameters at different stroke positions. By creating distinct flow regimes in different sections, the system becomes less sensitive to small dimensional variations, improving manufacturing tolerance robustness while maintaining reliable damping performance.
3Use of energy by moving object
If a single damping stage is used, then the device structure is simpler, but the energy absorption capability is insufficient for varying impact conditions
Solution Approach 1:
The damping process is segmented into two distinct stages corresponding to the two bore sections. The first stage handles initial fluid displacement with larger flow capacity, while the second stage provides restricted flow for higher damping forces. This segmentation enables multi-stage energy absorption without requiring multiple separate dampers, balancing energy absorption capability with structural simplicity.
Solution Approach 2:
Multiple damping stages are merged into a single integrated conduit structure with varying bore diameters. The different damping characteristics are combined in one continuous flow path, allowing the damper to handle varying impact conditions effectively while avoiding the complexity of multiple separate damping mechanisms.
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 design allows for precise control of damping forces, ensuring effective energy absorption without bounce, by transitioning from low to high resistive force stages as the piston moves through different bore diameters, enhancing reliability and accuracy in small-scale applications.
Implementation Method 1
a piston and cylinder type damper with a piston assembly mounted for reciprocal movement in a cylinder containing damping fluid... allowing passage of damping fluid between the chambers... providing a damped resistive force
Implementation Method 2
A compression spring 18 is arranged in one of these chambers, mounted between the closed end 12' of the cylinder 12 and the piston assembly 10. The spring 18 acts to press the piston assembly 10 into its engagement with the piston rod 11, hence biasing the piston rod towards its extended position.
Data Source
Figure 1~4
AI summary
A damper assembly comprises a piston and cylinder type damper with a piston assembly (10) mounted for reciprocal movement in a cylinder (12) containing damping fluid. The piston assembly divides the interior of the cylinder into two chambers and provides a means of communication in the form of channels (12a, 12b, 17, 20) for passage of damping fluid between the chambers. The channels are arranged to allow passage of more or less damping fluid, depending on the position of the piston assembly with respect to the cylinder along its path of reciprocation.