Research On The Cast Iron Ring Groove Surface Quality Of Al-Si Alloy Piston

With the increasing engine strengthened degree and more strict requirements of emission,the piston quality manage and control and focus are becoming toward to refinement.Small quality big problem is becoming the piston failure highlight mode and the important part of the piston manufacturers’ quality cost in the"Three-guarantees" claim,etc.How to improve the product quality and guarantee the current pistons’ design performance are the effective approach and real demands of realizing piston performance with high efficient and low cost conveniently.On the matter of how to assure the product quality efficiently and strengthen the manufacturing process control,research has been conducted in overseas and domestic and which is becoming more and more detailed.The piston insert austenite casting iron ring groove’s structure and quality are the key related part of actualizing piston function,and which is affecting the engine power release and gas emission.And they are the key point and difficulty in the piston manufacturing process.Based on the current status of the overseas and domestic piston manufacturing process control technique development,the article research and discuss on the piston austenite casting iron ring groove’s manufacturing process control depending on some certain of theory calculation and analysis and the factory’s actual production.And lots of tests and demonstration work have been carried out so that the piston austenite casting iron ring groove surface quality improved effectively.The article researched several aspects of casting iron ring groove process characteristic analysis,automatic anti-error precaution in the machining,harmful burrs prevention,casting iron ring carrier bonding inspection.Firstly,Brief introduction of the piston austenite casting iron ring groove structure.Analysis of the surface quality related characteristics one by one.According to each characteristic dimensions tolerance requirements and current equipment assurance capability,analyze and recognize the quality control difficulties and risk point,and which are the theoretical basis for the article research’s necessity.At the meanwhile,clarified and analyzed the casting iron ring groove machining equipment precision requirements,the machining process equipment and its machine connection precision,and casting iron ring groove surface quality inspection requirements,and which are the basic assurance elements for the piston casting iron ring groove machining.Secondly,For the common piston register chips problem in the machining,the article designed one set of air tightness proof devices and application procedure.Through adding air tightness anti-error proof system,it effectively prevents the positioning datum from unstable problem,and assures the ring groove surface quality’s characteristics such as groove side runout and angle,etc.that are stable and not out of tolerance.It reduced the operator’s labor intensity and improved the current equipments’ machining capabilities.Thirdly,According to the recently years of quality exclaim from OEM and end users,the burrs raised at the down side of the casting iron ring groove is the striking problem caused quality accidents such as engine leakage,blow-by result in engine fuel with lower efficiency,burn engine oil,etc.The raised burrs are easy to strip off during the engine running,and the detached particles could cause irreversible harm to other sensitive parts of the engine such as crankshaft,connecting rod,cylinder liner wall,etc.The article combines the theory and practice to optimize the process flow according to the burrs raising reason,and which means control raised burrs at the ring land within the allowed range effectively.Fourthly,Adoption of piston top positioning method effectively avoids the unstable detection problem due to the piston panel structure.The article designed not only a simple structure and easy operation of detection machine rotating mechanism,a displacement adjusting mechanism and probe adjusting mechanism,but also one kind of detection bonding rate inspection sample marking which is applicable into transmission detection method,and both of which ensure the piston strength required by engine effectively.