Height-Adjustable Spring Arrangement Maintaining Constant Preload
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Solution Overview
Problem
Conventional height-adjustable spring arrangements for motor vehicles often result in reduced spring preload when the driving position is lowered, leading to potential damage and poor performance due to insufficient spring force, as well as acoustically perceptible noises.
Innovation Solution
A height-adjustable spring arrangement featuring a suspension spring clamped between first and second limiting cylinders and a guide cylinder, where the guide piston rod is displaced to adjust the spring preload and maintain constant negative spring deflection, using fluid displacement to control the height adjustment and prevent spring detachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the vehicle's ride height is lowered to adjust the driving position, then the height adjustment range is improved, but the spring preload becomes insufficient and the negative spring travel becomes too large
Solution Approach 1:
The spring arrangement is divided into functionally independent components: the suspension spring for force generation, the first limiting cylinder for controlling negative spring travel, and the second limiting cylinder for controlling positive spring travel. This segmentation allows each component to independently maintain its designated function regardless of height adjustments, ensuring the spring preload remains sufficient even when the ride height is lowered.
Solution Approach 2:
The invention changes the control parameters of spring travel by introducing limiting cylinders that mechanically constrain the spring's movement. The first limiting cylinder restricts the negative spring travel to a predetermined maximum value, while the second limiting cylinder restricts the positive spring travel. These parameter changes ensure that the spring operates within safe limits regardless of the vehicle's ride height, preventing insufficient preload conditions.
2Adaptability or versatility
If the negative spring travel is increased when lowering the vehicle, then the height adjustment capability is improved, but the spring can detach from the spring bearing causing damage and noise
Solution Approach 1:
The first limiting cylinder is pre-configured to restrict the negative spring travel to a predetermined maximum value before the spring can detach from the spring bearing. This preliminary action prevents the harmful detachment event by establishing a mechanical barrier that stops the spring's rebound motion in advance, eliminating the risk of damage and noise associated with spring detachment.
3Adaptability or versatility
If the spring preload is reduced during height adjustment, then the height adjustment range is improved, but the spring force becomes insufficient leading to poor handling characteristics
Solution Approach 1:
The invention introduces a dynamic height adjustment mechanism using the second limiting cylinder that can modify the positive spring travel according to different driving conditions. This allows the spring arrangement to adapt its characteristics dynamically: in normal conditions, the full positive travel is available for comfort, while in sport mode, the positive travel is reduced to increase the spring's effective preload and stiffness, thereby maintaining sufficient spring force across different operating conditions without compromising the height adjustment capability.
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
Maintains constant spring preload and negative spring deflection during height adjustments, preventing damage and noise issues, while allowing for continuous and precise adjustment of the vehicle's driving position.
Implementation Method 1
a suspension spring (40), which is pre-tensioned between a first limiting cylinder (10; 20; 30) and a guide cylinder housing (31)
Implementation Method 2
The guide piston rod (33) is displaceable by means of the first and second limiting cylinders (10; 20; 30)
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a height-adjustable spring arrangement (1) for a vehicle, having a bearing spring (40), a first delimitation cylinder with a first delimitation cylinder pot (11) and a first delimitation piston (12), a second delimitation cylinder with a second delimitation cylinder pot (21) and a second delimitation piston, and a guide cylinder, which has a guide cylinder pot (31), a guide piston displaceably mounted in the guide cylinder pot (31) and a guide piston rod (33), which is fixed on the guide piston and extends out of the guide cylinder pot (31) along a longitudinal axis (L) of the bearing spring (40) and through the bearing spring (40), wherein the guide piston rod (33) can be displaced by means of the first and second delimitation cylinder and thereby a spring preload acting on the bearing spring (40) and a negative spring path (NF) of the bearing spring (40) remain constant.