Inspection and Research on the Effect of NC Machining of Pipeline

As long as the core rod protrudes from the core rod fillet radius, the anti-wrinkle effect of the core rod can be achieved, and the anti-wrinkle block can be matched to prevent the occurrence of the unstable wrinkle defect. In this paper, the formula of the core rod extension is derived by the mandrel geometry. When the amount of protrusion of the mandrel exceeds the maximum value, the mandrel will interfere with the pipe, causing protrusions on the outside of the pipe, causing excessive wall thickness reduction, and severe cracking at the protrusion. Since the mandrel fillet radius r only completes the transition, it is only necessary to take a smaller value. For the core thickness k, it should not be too thin or too thick. If it is too thin, the mechanical connection strength cannot be guaranteed. If it is too thick, the gap between the core point A and the inner diameter of the pipe is too large to support.

Experimental study on the forming effect of the mandrel. The effect of the mandrel on the numerical control elbow is studied experimentally. The experimental equipment is a self-designed custom microcomputer PLC controlled hydraulic pipe bending machine W27YPC63NC (as shown). The device has the same forming principle and mold structure as CNC bending. The experiment focused on the influence of the amount of mandrel protrusion and the number of cores on wrinkling, wall thickness reduction and cross-section distortion, and studied the influence of different materials on the protrusion of the mandrel. The principle and method of selecting the reasonable core stick extension and the number of effective cores. The tube forming process is stable and the surface quality is good. The use of other lubricants such as MoS2, the core mold damage is extremely serious, the pipe can not be bent properly. Therefore, stainless steel special stretching oil S980B is selected as the lubricant. The indicators for measuring the quality of the formed pipe are the corrugated corrugation height, the roundness of the pipe section and the wall thickness.

The influence of the amount of mandrel protrusion on the wrinkling and wall thickness reduction is based on the theoretical derivation formula of the mandrel extension amount, and the range of the mandrel protrusion amount is determined. Other conditions are stable forming conditions and the mandrel protrusion amount is selected within the range, and no unstable wrinkles and cracks occur in the pipe, wherein 6 mm and 123 mm are the lower limit value and the upper limit value of the mandrel protrusion amount, respectively. When the mandrel protrudes <6mm, the tube has the possibility of compression instability, which causes great damage to the mold and bending process. More than 123mm, the pipe has a goose head and even cracked. Since the mandrel is >6mm, its effect on the instability and wrinkling can be exerted. Therefore, the influence of the amount of mandrel protrusion on the wall thickness reduction is emphasized.

The effect of the amount of mandrel protrusion on the section distortion experiment found that if the mandrel protrusion amount is too small, the pipe member will not be strongly supported, which will increase the possibility of flattening. Therefore, this paper studies the influence of the amount of mandrel protrusion on the cross-section distortion of the pipe. It shows the trend of the ellipticity of the formed pipe with the amount of protrusion of the mandrel. The roundness of the pipe at the rear end of the curved section is good, and the pipe is not supported by the core, thereby increasing the possibility of flattening. It can be seen that the ellipticity at the end of each pipe member is negative, that is, the long axis is smaller than the short axis, and the length of the long and short axes is smaller than the original diameter. This is because the tube member is most obviously supported by the core at the end, and is also assisted by the pressure block, thereby causing the short axis elongation and the long axis shortening of the tube at the cut point of the bending portion.

Conclusion 1) Excessive value of the core rod extension will increase the wall thickness and even cause the tube to crack. As long as it is not less than the minimum value of 6mm, the amount of protrusion will have less influence on the unstable wrinkling; The characteristics of process tube cross-section distortion obtained the selection strategy of reasonable mandrel extension. 2) The core is the main factor affecting the distortion of the section. Considering the pipe diameter, bending radius and bending angle, it is only necessary to carry out effective arc length support for the dangerous section of the pipe bending, which can effectively control the distortion degree of the pipe section. 3) Through the method of segmented core-pulling, the problem that the resistance of the mandrel to the pipe is too large during the bending process of the small bending radius, causing the sliding of the pipe and the clamp, thereby avoiding the possible instability of the inside of the pipe. wrinkle.

(Finish)

Shoes Printer

Shoes Printer is a kind of machine used on shoes, also can be used on T-shirt, pants, clothing, hat, silk, shopping bag, hoodies and so on. We adopt digital programming, precision infrared scanning, multi - position sensor and high precision parts, to ensure that the printer performance is more stable and more precise positioning!

We can design and open new mould for you upon your request. Also accept OEM services.

Shoes Printer,Digital Shoes Printer,Custom Shoes Printer,Offset Shoes Printer

Shenzhen Refinecolor Technology Co., LTD. , https://www.rfcprinter.com