Design Of Boring-burnishing Compound Tool For Small Cylinder Hole And Investigation Of Quality Of Machined Surface

As a basic element of pneumatic technology,cylinder has become miniaturization,integration and preciseness with the development of pneumatic technology.When the cylinder is working,the piston undergo a linear reciprocating motion in the cylinder.For increasing the durability of cylinder,low surface roughness,high surface hardness and high fatigue strength is important for the inner surface of cylinder.In order to make the inner surface of cylinder have better surface quality,it is necessary to use surface strengthening techniques to improve the surface quality of inner surface of cylinder.As well known,two common surface strengthening techniques are shot peening and burnishing.Because the diameter of the small cylinder hole is too small,it is difficult for shot peening to take effect.But burnishing can improve surface quality of inner surface of small cylinder effectively and spent lower cost.As a result,burnishing is a better choice to improve surface quality of inner surface of small cylinder.As a independent process,burnishing will prolong production time and increase the cost.So the process which combines boring and burnishing for the production of small cylinder is necessary.In this paper,a new boring-burnishing compound tool for small cylinder hole has been described.The new boring-burnishing compound tool which has been designed could improve the machining efficiency and the quality of the inner surface of small cylinder.At the same time,the influences of process parameters such as burnishing depth,processing speed and feed rate on the surface roughness,surface hardness,residual stress and microstructure of the inner surface of small cylinder have been investigated.In addition,the 3D finite element analysis model of boring-burnishing process has been established,and the effects of process parameters such as circle radius of roller,burnishing depth,processing speed and feed rate on burnishing force,residual stress and equivalent strain have been studied by using the 3D finite element analysis model.