Study On Warm Extrusion Of Machining Deep Hole In Sheet

Sheet metal deep hole processing is a kind of green special processing method different from the traditional hole processing methods.The traditional machining method is commonly to remove part metal to form the pore,so the depth of hole is equal to the thickness of plate.In this paper,using the metal’s thermoplasticity to make hole processing of sheet metal.By rotating between the no edge drill and the sheet metal to produce friction heat to soften its pore forming zone material and reduce its deformation resistance.And then run through the hole.Depending on the thickness of the plate and the diameter of the driller,the depth of the hole is about3-4 times the thickness of the plate.By using the metal’s thermoplasticity,the machining process won’t produce cuttings.During the machining process,it also need not add coolant.It makes full use of the material.Meanwhile,the hole area of workpiece can get reasonable streamline distribution and good mechanical properties.In this paper,the forming process of deep hole in sheet is made theoretical analysis,simulation analysis and experimental verification.And outside the scope of the conventional forming temperature(below recrystallization temperature)of the sheet deep hole machining,the study of pore forming is carried on.Specific to do the following work:From Rayleigh Ritz method of energy theorem,we can get deflection function of four edges clamped elastic thin plate and conclude that the elastic limit of deep hole machining plate and plate thickness.According to the classical friction theory and the shear friction theory,it establishes the theory model of spherical cone drilling tools’ friction heat source in the process of thin plate’s deep hole machining,and obtains a mathematical formula of heat-absorbing of the thin plate.Under different processing parameters,the simulation analysis is carried out on the pore-forming.The whole process of sheet metal’s deep hole processing is studied.Using the upperlimit method it establishes the mechanics model of extrusion stage and using the integral method establishes the mechanical model of bulging stage.The paper obtains suitable processing parameters of warm extrusion processing that provides more reliable theoretical basis for the actual production and processing.