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Yang J.,Lanzhou Jiaotong University | Zhang W.,Lanzhou Jiaotong University | Jiang F.,Lanzhou LS Heavy Machinery Technology Co.
Sichuan Daxue Xuebao (Gongcheng Kexue Ban)/Journal of Sichuan University (Engineering Science Edition) | Year: 2014

On the issues of that the traditional determination method of clamping force has a large error in calculation and failed to guide the construction design of clamping device effectively, the actual application condition of forging manipulator was analyzed and the difference between the theoretical analysis and the practical application was determined to work out a jaw's mechanical model based on the forging manipulator's clamping analysis in workpiece's allowable downward deflection condition. The jaw clamping force in both vertical and horizontal conditions was analyzed with the mechanical model and the clamping force formula of jaw in any rotation angle was established to work out the jaw's minimum stable clamping force to the workpiece when the forging manipulator meets the workpiece's downward deflection condition. With the example of the 300 kN forging manipulator's structure parameters, the jaw clamping force of clamping device was worked out based on the research results, a virtual prototype of the forging manipulator's claw beam in ADAMS environment was built, and the motion simulation was processed. The analysis result showed the validity of clamping force calculation theory.

Yang J.,Lanzhou Jiaotong University | He Q.-G.,Lanzhou LS Heavy Machinery Technology Co. | Tong X.-X.,Lanzhou Jiaotong University
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2013

A buffer device, consisting of the combined unit of hydraulic cylinder and accumulator, was designed for alleviating the impact on the damping bar banging system of an oscillating bar forging manipulator. In order to determine the buffering stiffness and damping coefficient in the vertical lifting and dropping movement of the hanging system, theoretical dynamic analysis was carried out based on the simplified physical model of the equipment construction and the equation of movement derived by using Largrange method. Taking the 50 kN forging manipulator as an example, the influences of buffering stiffness and damping on the movement parameters, such as hanging bar's swing angle, workpiece centroid position, swing angle of clamping bar, etc. were analysed through sloving the dynamic equation by Metlab. Then, the effects of buffering stiffness and damping on the vertical lifting and dropping movement were clatified. The procedure of determining the buffer device' stiffness and damping was provided. This will give a theoretical base for designing the hydraulic cylinder and accumulator of buffer device.

Liu Y.,Lanzhou Jiaotong University | Yang J.,Lanzhou Jiaotong University | Chen C.,Lanzhou Jiaotong University | He Q.,Lanzhou LS Heavy Machinery Technology Co. | Jiang F.,Lanzhou LS Heavy Machinery Technology Co.
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2012

Based on the importance and difficulties of the calculation of the chucking power of the heavy-duty forging manipulator, it is pointed out that the jaw's surface is different from the ordinary automatic hand's clamp face. A thread of the calculation of chucking power has been worked out basing on the simplification of the action between gripping mechanism's jaw and forging's contact surface to the action between jaw's crowned tooth and forging's extrusion groove. On the basis of the working condition, the operating conditions of the jaw have been separated into the clamping and the gripping condition. After peculiarity and effect of two conditions was discussed, a mechanical model of workpiece under the gripping condition has been formed and the chucking power of the jaw on both horizontal and vertical position are studied. With the gripping force corrected by the amplification factor, the output force of the claw-beam gripping hydro-cylinder can be set to actualize?the concave-convex mechanism between the jaw and the workpiece under the clamping condition to make sure the maximum gripping moment can be reached under the gripping condition. Considering the construction peculiarity of the jaw and working piece's contact surface, the idea and principle of jaw's crowned tooth design has been worked out. The example calculation and the virtual prototype simulation prove that the calculation method is effective. © 2012 Journal of Mechanical Engineering.

Liu Y.,Lanzhou Jiaotong University | Yang J.,Lanzhou Jiaotong University | Ma X.,Lanzhou LS Heavy Machinery Technology Co. | Hu Z.,Lanzhou Jiaotong University
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2014

Aiming at the pushing high-speed forging hydraulic press, the frictional resisting torque and friction radius of supporting spherical hinge in the working cylinder is analyzed, the supporting spherical hinge's side thrust to the working cylinder's plunger with single and double spherical hinges structures is studied and influencing factor of hydraulic press' structure parameter to the plunger's side thrust is determined. By synthesizing the structure influences of working cylinder, supporting spherical hinges and movable beam, the conditions the forging eccentricity should meet when the movable beam is in rotating self-locked condition and the internal relations between hydraulic press' structure parameter and movable beam's self-locked condition can be determined. Base on the structure parameter of domestic pushing high-speed forging hydraulic press and some import devices, the forging eccentricity that meets the movable beam's self-locked conditions is calculated and the working conditions of movable beam in eccentric forging and the effect of working cylinder's supporting spherical hinge in the hydraulic press' operation is analyzed. By simulated analysis, the movable beam's rotating self-locked condition in eccentric forging is further verified to provide theoretical basis to the research of large scale double column free forging hydraulic press and the optimization design of medium and small scale hydraulic press. © 2014 Journal of Mechanical Engineering.

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