As can be seen from the graphic, the spring characteristic represents the force progression of the gas spring over the stroke, from the extended to the inserted state and back. In the process, the spring characteristic value represents the force ratio F2/F1. When designing a pneumatic spring, the force F1 is the most important criterion in addition to the dimensions. The force F1 is measured 5 mm before the end of the extension movement, thus defining the value of the spring force. The force FR resulting from the friction is created between the force lines in the insertion and extension direction. The extension speed is divided into two types of damping: With the standard gas spring, the extension speed is controlled via a pneumatic and hydraulic range. When installing the gas spring with piston rod facing down, the piston first moves through the gas-filled part (pneumatic area), then through the oil-filled part of the pressure pipe (hydraulic area). The piston rod is braked by the oil.
If desired, the damping can also occur dynamically. For this purpose, a longitudinal groove is provided in the pipe, which allows for a positionally-independent damping of the gas spring.
Gas springs with hydraulic damping can be designed as special versions according to the following principles:
extension-damped gas spring
insertion-damped gas spring
insertion and extension-damped gas spring
Gas spring without damping