During the working process of hydraulic cylinder, especially at the end of the stroke, the piston moves at a high speed. If there is no buffer device, a large impact force will be generated, causing damage to the hydraulic cylinder and related equipment. Therefore, the design of the buffer device is crucial.
Its design principle is mainly based on the conversion and consumption of energy. When the hydraulic cylinder approaches the end of the stroke, the buffer device starts to work. Common buffering methods include throttling buffering and gap buffering. Throttling buffering is to set a throttle valve or throttle hole on the oil circuit of the hydraulic cylinder to limit the return oil flow, thereby reducing the movement speed of the piston. For example, when the piston moves toward the cylinder head, the buffer plunger enters the buffer chamber of the cylinder head, and the oil in the chamber can only flow out through the throttle valve or throttle hole. As the return oil resistance increases, the piston speed gradually decreases. Gap buffering uses the small gap between the piston and the cylinder barrel. When approaching the end of the stroke, the oil is forced to squeeze out of the gap to generate a damping force to slow down the piston movement. This method has a relatively simple structure, but the buffering effect is relatively weak. It is often used for some small hydraulic cylinders or those with low buffering requirements.
In terms of performance verification, theoretical calculations must be performed first. According to the working parameters of the hydraulic cylinder, such as piston diameter, stroke, movement speed, working pressure, etc., the theoretical buffer force, buffer stroke and buffer time under different buffer structures and parameters are calculated. By comparing with the design requirements, the feasibility of the buffer device is preliminarily evaluated. Then a simulation experiment is carried out, using hydraulic simulation software to simulate the working process of the hydraulic cylinder, inputting the actual system parameters and buffer device parameters, and observing the curve changes of the piston movement speed, buffer force, etc. The simulation experiment can optimize and adjust the buffer device before actual manufacturing to reduce costs and development cycles.
Finally, actual test verification. After the hydraulic cylinder is actually installed on the equipment, professional testing instruments such as pressure sensors, displacement sensors and speed sensors are used to measure various data of the hydraulic cylinder during operation. Compare the actual test data with the theoretical calculation and simulation test results to evaluate whether the buffer device achieves the expected buffering effect, such as whether it effectively reduces the impact and whether it meets the smooth stop requirements of the equipment. If deviations are found, the causes are further analyzed and the buffer device is improved to ensure that it can work reliably and efficiently under actual working conditions and protect the safe and stable operation of the hydraulic cylinder and the entire hydraulic system.
