| The technics of assembled camshaft is a new manufacture technology, which can make shaft, cam and wheelneck apart and then remake a new one. Through material select apart, Shaft can gain higher strenghth and cam can pick materials which have such properties as ankylosis resistance, dot friction resistance, wear resistance. Compared with the traditional camshaft manufacture technology, The assembled camshaft technology combines design of camshaft and choices of materials with analysis of performance rightly.Which possesses important meaning for reducing automotive cost, lightening weight and enhancing performance of engine. And has wide development outlook. The bonding technology of shaft and cam is the key of assembled camshaft. This paper studied a novel jointing technology—internal high-pressure expanding camshaft. It's characteristic is that the shaft adopts hollow steel tube, high-pressure liquid is loaded inside of shaft, The shaft will take place plastic deformation, Subsequently. The contact pressure will be produced in contact areas between cam and shaft. This pressure makes cam elastic deformation. The tight expanding of cam and shaft will be achieved through different value of springback after uninstall. Compared with other joint technics, The internal high-pressure expanding assembled camshaft possesses many advantages including higher productivity, even and stable expanding pressure and higher expanding quality. Aimimg at problems of the internal high-pressure expanding assembled camshaft, This paper simulated process of internal high-pressure expanding assembled camshaft with ANSYS, Following are the main achievements: 1. On the basis of plane strain hypothesis, Analyzed three phases of the internal high-pressure expanding assembled camshaft with elastic-plastic theory, and educed the expression of remnant contact press after expanding. The three phases are the elastic-plastic deformation phase, Shaft and cam deformation contemporarily phase and springback phase after unloading. The conclusion has been drawn remnant contact press after expanding increased linearly with the increasing of the loading pressure. 2. Established the numerical emulate model of the 20#shaft, the 45#cam, Shaft inner radius is 9.8mm, Wall thickness is 2.2mm, Cam inner radius is 12.025mm, The clearance is 0.025mm, Loading pressure is 320MPa. By software ANSYS. Analyzed the distribution of stress, strain, deformation quantity and the remnant contact press and so on. Then analyzed the expanding devastating retortion and come to the conclusion that the max expanding intension is 430.11N·m ,as far as 40～50N·m of the retortion of the 488 engine camshaft at practice work. So the Internal high-pressure expanding technology can meet the practice work. 3. Established a series of different parameters model of internal high-pressure expanding assembled camshaft with CAE software ANSYS,Analyzed the effect of different material combination and loading pressure on expanding intensity,Drew the conclusion that the expanding effect better if cam intensity smaller and softer, Intensity difference between shaft and cam greater under the condition that ensure intensity need. At the same time, The remnant contact pressure and expanding intensity increased with the increasing of loading pressure on the premise of absent plastic deformation. 4. Through a number of numerical simulation of different parameters of 20# and 45# camshaft expanding process,And analyzed the rule of shaft thickness, clearance between shaft and cam,breadth of cam and round radius effect on expanding intensity under same loading pressure. Under the same condition,... |
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