Abstract: A new buffer with controllable percussive force,of which the concussion spring is connected to the piston of the cavity,is discussed.When collision occurs,the spring will move in a limited way while compressing to absorb forces,which prolongs the time of collision,reduces the percussion force and thus improve the ability of force absorption.The study shows that the percussion force on the buffer can be controlled by changing the area of discharge orifice on the end of the cavity.The principle of this buffer can be used to realize the control over the percussion force within a default.

Key words: buffer, percussion force, controllable, area of discharge orifice