Analysis of the basic methods of spinning of CNC spinning machine

CNC Spinning Machine Spinning Technology is an advanced process that combines the characteristics of forging, extrusion, drawing, bending, ring rolling, cross rolling and rolling, with no cutting, and can process metal blanks, flat blanks or The preform is tightly pressed on the core of the numerical control spinning machine, and the core rod and the blank are rotated by the main shaft, and the spinning wheel presses the material from the side of the blank onto the rotating core mold, so that the material is continuous point by point. Plastic deformation, thereby obtaining hollow body parts of various busbar shapes.

According to the change of the thickness of the blank during the spinning process, the spinning process is generally divided into two types: ordinary spinning and strong spinning.

Ordinary spinning is referred to as general rotation. According to the traditional view, the thickness of the blank remains basically unchanged during the general rotation process. The forming mainly depends on the circumferential shrinkage of the blank and the elongation deformation along the radial direction. The important feature is that the blank can be clearly seen during the molding process. The change in the diameter.

The basic methods of ordinary spinning are: deep drawing spinning (drawing), reducing diameter spinning (shrinking) and expanding diameter spinning (expanding).

Deep drawing spinning refers to the spinning forming method during the drawing of the blank. It is the most important and widely used forming method in ordinary spinning. The bending plastic deformation of the blank is its main deformation mode. Deep drawing spinning can be divided into simple drawing spinning and multi-pass drawing spinning.

Reduced diameter spinning refers to a molding method in which a rotary body (or a friction block) is used to radially rotate a rotary body hollow member or a tubular blank to reduce its diameter. During the reduction and spinning process, the blank is appropriately clamped in a proper mandrel, and the part to be formed is exposed from the outside. When the spindle drives the blank to rotate, the rotary wheel is manually operated or automatically controlled. The shape trajectory is reciprocated, and a lateral feed of a certain size is given each time the direction is changed, and the outer circumference of the blank is gradually reduced in diameter to obtain a part having a throat shape or a closed sphere. In order to avoid wrinkles and rupture of the workpiece, the process should be divided into several passes or processes according to the ratio of the diameter before and after the reduction, that is, the revolving of the revolver should be repeated multiple times, and each time a certain feed is given. Quantity, sometimes need to replace the core mold several times and carry out intermediate heat treatment. Depending on the material and the size of the workpiece, it is sometimes necessary to squash under heating. If possible, by supporting the edge of the container to reduce the tendency of production wrinkles, the feed can be increased and the production cycle can be reduced.

Expanding diameter spinning is a spinning forming method in which a hollow rotating body container or a tubular blank is increased in diameter (middle or end) by a spinning tool. The limitation of this method is mainly the material properties of the workpiece, such as tensile strength. Strength, yield limit, elongation, reduction of area, etc. According to the degree of expansion of the workpiece, it is often divided into several passes. The principle of determining the number of passes is that the material does not cause excessive strain (stress) during the expansion process, that is, the stress during the molding process cannot exceed the tensile strength of the material, which may cause cracking. If the material has a large work hardening tendency, the number of passes should be small, and the diameter of each pass should be as large as possible. Otherwise, due to the hardening, the intermediate heat treatment needs to be performed earlier, otherwise it will not be possible.