Translated Abstract
The rapid development of automotive, aerospace in manufacturing brings higher
requirements the demand and performance of thread shaft. However, the current widely used
radial-infeed rolling process have some disadvantages, such as large forming force and low
production efficiency, and rolling equipment also exists some defects, such as complex
structure, bulky and huge. Therefore, systematic on the rolling plastic deformation
mechanism and servo drive device of axial-infeed thread rolling are conducted in this paper.
The effects of process system parameters (rolling die number N and its heads number Z) on
the size of rolling die and the stability of rolling process were analyzed; the relationship
between rolling die reduction T and workpiece rotation angle θ during rolling forming
process of M24 thread shaft are studied. Under the same conditions, the relationship between
rolling pressure and time is consistent with the relationship between reduction and rotation
angle, which is proved by finite element simulation analysis. The position requirements of
the rolling dies before thread rolling is analyzed. Then the calculation formula and
adjustment method of initial phase of die for multi die thread rolling are deduced. Finally,
the feasibity of the above research is cerified by the finite element simulation results of 9
three die rolling forming conditions.
Based on the FORGE finite element software platform, the numerical analysis of axial feed
thread rolling process is carried out. The plastic deformation mechanism and flow behavior
of the no deformation region, small deformation region and large deformation region of the
thread shaft are studied. The effect of the main process parameters, such as the initial
diameter of the blank, the condition of the friction and the speed of the blank, on the tooth
rolling process, the tooth quality , the rolling pressure and the stress of the die are obtained.
An axial-infeed thread rolling equipment which is dreiven by AC servo motor and its
computer control system are developed. The power is 18.5kW, and the processing range is
M10~M42. The equipment consists of three subsystems: the servo power system that
realizes the active rotation of the billet, the rolling system for forming the thread shafts and
the self-feed system that ensures the axial motion of the rolling device. The rolling dies are
divided into two groups reasonably, so that they can be changed quickly and conveniently .
M10~M20 rolling die installation center is 26mm, and the die shaft diameter is 20mm.
M24~M42 rolling die installation center is 67mm, and the die shaft diameter is 40mm.
The rolling forming process experiment is carried out on the equipment, and the threaded
shafts with qualified teeth are manufactured. In the process of rolling, the rolling die and
workpiece have stable mesh transmission. The size accuracy, microstructure and
microhardness of threaded shaft are analyzed, and the microstructure and properties of
turning and rolling are compared. Then the forming experiment of red copper, 35 and 45
carbon steel at different billet diameters and speeds are carried out. The greater the yield
strength and hardness of the material, the lower the plastic deformation depth of the billet
surface, and the lighter the tooth ＂crown ear＂ shape is.
Translated Keyword
[Axial-infeed, Plastic deformation mechanism, Rolling die, Rolling forming process, Thread shaft]
Corresponding authors email
