The Effects of the Number and Position of Comfort Channels in Cylinders on Comfort and Road Handling Performance in Twin-Tube Telescopic Dampers

The damper is a component found between the chassis and the wheels of vehicles that absorbs impacts and vibrations from the road surface. Its primary function is to improve the comfort of the vehicle during driving and to ensure the stability of the vehicle by minimizing any shocks and vibrations that may occur, responding to road conditions. In conventional dampers, there are many parameters that affect damper performance. Key parameters can be listed as damper valve type, subcomponents used in the valves, the type and amount of oil, and whether the product is gas-filled or not. In valve groups, there are an infinite number of combinations that can be considered. By changing the sequence and parameters of the shims and discs, an infinite number of combinations and damping forces can be achieved. In twin-tube rear dampers, which consist of a body tube and cylinder components, there is generally no comfort channel in the cylinder parts. Comfort channels are special channels or passageways located around the piston of the damper. These channels allow the fluid inside the damper to flow in a way that creates resistance against the piston movement. Comfort channels are an important design feature that improves passenger comfort and vehicle stability by more effectively absorbing the vibrations and shocks during driving in commercial vehicles and twin-tube passive dampers. In this study, the effects of different quantities, sizes, and locations of comfort channels on damping force and road handling performance were examined on the same damper. As a result of the study, increasing the quantity and depth of the comfort channels was shown to reduce road vibrations more effectively and improve driving comfort. However, since a high depth of the channels and a large number of comfort channels increase the variation in the transition zone, they cannot reduce the shock effect at high speeds. From a performance perspective, maintaining a smaller difference in the transition zones helps to improve road handling by ensuring vehicle stability. This improvement arises from the dampers’ ability to absorb high-speed shocks more effectively. Similarly, the length of the comfort channel should be determined according to the design position of the vehicle and the total stroke values. Otherwise, although the comfort channel length contributes significantly to damping vibrations, it could have a negative impact on safety.