Multistage Jounce Bumper with Hydraulic Tuning
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Solution Overview
Problem
Conventional jounce bumper systems in automotive suspension fail to effectively absorb high jounce forces and energies, leading to a rough ride and discomfort due to abrupt energy transfer as the energy absorbed exceeds the system's capacity, resulting in a hard mechanical stop and load management issues.
Innovation Solution
A multistage jounce bumper integrating a jounce bumper cushion with a hydraulic jounce bumper, where the hydraulic response is tunable via hydraulic fluid flow, providing a seamless transition from the cushion to the hydraulic bumper to absorb additional energy and manage jounce forces through three distinct stages: initial cushion compression, hydraulic absorption, and a hard stop engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional jounce bumper cushion is used, then the structure is simple and easy to manufacture, but the energy absorption capacity is insufficient leading to rough ride
Solution Approach 1:
The jounce bumper system is divided into three distinct stages: a first stage cushion element for initial contact, a second stage hydraulic element for intermediate energy absorption, and a third stage cushion element for final energy absorption. This segmentation allows each element to be optimized for its specific function while collectively providing enhanced energy absorption capacity.
Solution Approach 2:
The patent combines multiple different types of cushion elements (first stage cushion, hydraulic element, third stage cushion) into a single integrated jounce bumper system. This merging of different energy absorption mechanisms creates a multistage system that can handle a broader range of energy levels than any single element could provide alone.
2Ease of operation
If a conventional jounce bumper cushion is used, then the device complexity is low, but the ride quality is poor due to abrupt energy transfer
Solution Approach 1:
The first stage cushion element is positioned to engage first during jounce motion, providing preliminary cushioning before the more rigid hydraulic element is activated. This staged approach prevents abrupt energy transfer by gradually transitioning from soft to firm resistance, improving ride comfort.
Solution Approach 2:
The jounce bumper system transitions dynamically between different stages as jounce force increases. The system adapts its stiffness characteristics by engaging different elements in sequence, providing a progressive response that maintains ride comfort across varying load conditions.
3Reliability
If the jounce bumper cushion compression exceeds its capacity, then a hard mechanical stop is engaged, but this causes load management issues and ride disruption
Solution Approach 1:
The hydraulic element and third stage cushion element are pre-positioned to engage before a hard mechanical stop would occur. This preliminary action ensures that energy absorption is progressively managed through multiple stages, preventing the abrupt load transfer that would otherwise cause ride disruption.
Solution Approach 2:
The system changes its mechanical parameters (stiffness, damping characteristics) as it transitions between stages. By adjusting these parameters progressively rather than abruptly, the system maintains reliable jounce force management while avoiding the harmful effects of sudden hard stops.
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 multistage system enhances energy absorption and ride quality by managing jounce forces more effectively, reducing ride disruption and improving load control by absorbing increased jounce energy and forces beyond conventional systems, with graphs showing improved performance in static and dynamic load tests.
Implementation Method 1
a hydraulic jounce bumper, where the hydraulic response is tunable via hydraulic fluid flow, providing a seamless transition from the cushion to the hydraulic bumper to absorb additional energy
Implementation Method 2
An optional skin 50 of a compliant material (i.e., having energy absorbing or damping properties) may, or may not, overlay an interior of resilient elastomeric material 52
Data Source
AI summary
A multistage jounce bumper, including a jounce bumper cushion integrated with a hydraulic jounce bumper, wherein provided are the damping characteristic of the hydraulic jounce bumper and the damping/spring characteristics of a jounce bumper cushion. The hydraulic jounce bumper hydraulic response is tunable via adjustment of hydraulic flow with respect to a communicating hydraulic fluid reservoir. When maximum jounce is approached, jounce force and energy are exchanged, at a first stage, with the jounce bumper cushion, then at a predetermined compression, jounce force and energy are exchanged, at a second stage, with the hydraulic jounce bumper. Thereafter, a mechanical abutment is provided as a third stage of jounce management.