“…(2) To perform further research on the torsional test, considering that the thin wall of the tube may lead to improper clamping, it is necessary to separate the cam and then complete the assembly. Figure 5 Assembled camshaft 34 : ( a ) simulation model, ( b ) coupling setting of cam, tube, and centroid point and ( c ) torsional state. …”
Section: Key Technology Of Finite Element Analysis Processmentioning
confidence: 99%
“… Assembled camshaft 34 : ( a ) simulation model, ( b ) coupling setting of cam, tube, and centroid point and ( c ) torsional state. …”
Section: Key Technology Of Finite Element Analysis Processmentioning
The assembled camshaft is a novel manufacturing product which connects the cam and the mandrel by tube hydroforming (THF) technology after they are processed separately. However, in the process of THF, the structure of the cam-bores has a crucial influence on the connection strength of the assembled camshafts. Therefore, three kinds of cam-bores with circular structure, isometric-trilateral profile and logarithmic spiral profile are selected for hydroforming with a hollow mandrel (tube) in this study. The finite-element-analysis is carried out by ABAQUS software, the variations of (residual) contact pressure and contact area under different structures are obtained, and the torsional angle variations after assembly are measured. Further, the connection strength of the assembled camshaft under three structures is discussed. The results show that the evaluation of connection strength of the assembled camshaft is affected by many factors, including contact pressure, maximum residual contact pressure, axial and circular residual contact pressure, contact area and its rate, residual contact area percentage and torsional angle. Through the comprehensive analysis of various factors, the torsional angle of the camshaft with circular structure is the largest, i.e. poor connection strength. By contrast, the torsional strength of the camshaft with isometric-trilateral profile is the largest, namely, the best connection strength.
“…(2) To perform further research on the torsional test, considering that the thin wall of the tube may lead to improper clamping, it is necessary to separate the cam and then complete the assembly. Figure 5 Assembled camshaft 34 : ( a ) simulation model, ( b ) coupling setting of cam, tube, and centroid point and ( c ) torsional state. …”
Section: Key Technology Of Finite Element Analysis Processmentioning
confidence: 99%
“… Assembled camshaft 34 : ( a ) simulation model, ( b ) coupling setting of cam, tube, and centroid point and ( c ) torsional state. …”
Section: Key Technology Of Finite Element Analysis Processmentioning
The assembled camshaft is a novel manufacturing product which connects the cam and the mandrel by tube hydroforming (THF) technology after they are processed separately. However, in the process of THF, the structure of the cam-bores has a crucial influence on the connection strength of the assembled camshafts. Therefore, three kinds of cam-bores with circular structure, isometric-trilateral profile and logarithmic spiral profile are selected for hydroforming with a hollow mandrel (tube) in this study. The finite-element-analysis is carried out by ABAQUS software, the variations of (residual) contact pressure and contact area under different structures are obtained, and the torsional angle variations after assembly are measured. Further, the connection strength of the assembled camshaft under three structures is discussed. The results show that the evaluation of connection strength of the assembled camshaft is affected by many factors, including contact pressure, maximum residual contact pressure, axial and circular residual contact pressure, contact area and its rate, residual contact area percentage and torsional angle. Through the comprehensive analysis of various factors, the torsional angle of the camshaft with circular structure is the largest, i.e. poor connection strength. By contrast, the torsional strength of the camshaft with isometric-trilateral profile is the largest, namely, the best connection strength.
“…Also, Mori et al [12] proposed the idea of using pulsing pressure to improve formability in the free bulge hydroforming process of steel tube. In the following years, Loh-Mousavi et al [13,14] used this method for forming T shape and square parts and Ma et al [15] used in the manufacture of assembled camshafts.…”
The use of tube hydroforming process to produce integrated parts is growing in various industries. In this research, the hydroforming process has been used to convert the circular cross-section of the tube into a square one. In this process, due to the high hydrostatic pressure of the fluid, the friction in the contact area between the tube and the die surface increases significantly. High friction prevents the metal flowing of the tube material on the die surface and therefore it becomes very difficult to completely form the tube inside the die and obtain sharp corners. In this research, in order to improve the tube formability, applying ultrasonic vibrations to the hydroforming die has been used, which causes a temporary gap to be created in the contact surface of the tube and the die, and therefore the amount of friction is reduced and the tube material can slide more easily. By developing a 3D finite element model, the ultrasonic tube hydroforming process was evaluated. Modal analysis was used to evaluate the different shape modes of the die. The effects of ultrasonic vibrations on the deformation process have been evaluated using two variables: corner radius of square die and average wall thickness. An ultrasonic hydroforming setup was designed to form the annealed copper tube and was stimulated using selected resonance frequencies. The results of the finite element model were validated with the deformed tube in the experimental test. After confirming the results, the numerical model was used to evaluate the process parameters.
“…Also, Mori et al [12] proposed the idea of using pulsing pressure to improve formability in the free bulge hydroforming process of steel tube. In the following years, Loh-Mousavi et al [13,14] used this method for forming T shape and square parts and Ma et al [15] used in the manufacture of assembled camshafts.…”
The use of tube hydroforming process to produce integrated parts is growing in various industries. In this research, the hydroforming process has been used to convert the circular cross-section of the tube into a square one. In this process, due to the high hydrostatic pressure of the fluid, the friction in the contact area between the tube and the die surface increases significantly. High friction prevents the metal flowing of the tube material on the die surface and therefore it becomes very difficult to completely form the tube inside the die and obtain sharp corners. In this research, in order to improve the tube formability, applying ultrasonic vibrations to the hydroforming die has been used, which causes a temporary gap to be created in the contact surface of the tube and the die, and therefore the amount of friction is reduced and the tube material can slide more easily. By developing a 3D finite element model, the ultrasonic tube hydroforming process was evaluated. Modal analysis was used to evaluate the different shape modes of the die. The effects of ultrasonic vibrations on the deformation process have been evaluated using two variables: corner radius of square die and average wall thickness. An ultrasonic hydroforming setup was designed to form the annealed copper tube and was stimulated using selected resonance frequencies. The results of the finite element model were validated with the deformed tube in the experimental test. After confirming the results, the numerical model was used to evaluate the process parameters.
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