Research For Connecting Process Of Assembled Camshaft

The cam shaft is a key component of engine valve mechanism, the cam shaft is a slender shaft, a plurality of cam, shaft, gear shaft, disc signal in the body, installed in the valve chamber of the cylinder head, engine, crankshaft sprocket through the chain or gear driven camshaft timing gear rotation and the camshaft t iming gear and the cam shaft is rigidly connected, the cam shaft will rotate together, open the control valve and the closing action, when the engine is running, the exhaust valve need to alternately open and close, high pressure pump, fuel injection press ure of the accumulator alternately, the cam to withstand cyclic impact load, cam surface and plane the tappet(or roller arm) between the contact stress is large, relative sliding speed is also very high, cam and tappet(or roller arm) oil lubrication between the friction pair by a shaft neck overflow, lubricating environment Some poor, therefore, is the main failure form of the camshaft cam surface pitting, scuffing, cam phase angle changes(only assembled camshaft will appear) and rapid wear, if the failu re form of cam, will to open and close the valve of arrhythmia, will appear in the exhaust gas shortage, a series of net the problem, affecting the normal work of the engine, therefore, the camshaft should have enough strength and toughness, between the ca m and the shaft body has enough connecting strength, the cam surfaces have good impact resistance and wear resistance.Should the requirements of energy-saving and environmental protection, at the same time the engine in the pursuit of high speed and high torque must be lightweight, miniaturization, put forward higher requirements on the cam shaft material, weight, strength, wear resistance, tensile strength, torsional strength and other performance indicators, the camshaft manufacturing cost in traditiona l manufacturing process and high production low efficiency, high energy consumption, the development speed of the labor intensity of workers has disadvantages can not catch up with the cam shaft design, especially in recent years, VVL(variable valve lift) technology, the thickness of the cam narrows, complex degree increase, the overall structure of the camshaft almost redefines the traditional process has been unable to meet the the assembled camshaft, the change is an inevitable trend, the assembled camshaft adopting innovative ideas. The main contents of this paper are as follows:1) a comprehensive comparison of traditional type cam shaft and assembled camshaft mechanical properties and manufacturing process, objectively expounds the advantages and disadvantages of the camshaft in the form of two respectively and the problems in production and risk; in the manufacturing process of the paper, the current domestic and foreign engine camshaft form and structure analysis of knowledge;2) the performance co mparison of the traditional camshaft, the assembly cam shaft, the production process, the common problems and solutions in practical production;3) calculation and selection of the hot pressing process parameters of the cam shaft of CA3 GA engine;4) single connection test and future technology outlook.