1. Proposal of the problem Usually, bottle caps of mineral water, cola and other beverage bottles or edible oils and other household liquids are bottled, and most of them are special threads. Its particularity is manifested in the closing, segmentation, segmentation, closing, short-end and short-tail, and sometimes even several features. The closing end is a professional common name, also known as thread spiral end closing or rat tail, which means a piece of thread. When the pitch is constant, the beginning part is shallow and deep, gradually becomes "thick", and the ending part is deep. And shallow, gradually become "fine." Common closing ends are often completed in 1/3 week to 1 week. The closing of the "quick" completion in 1/3 week or even 1/10 weeks is called short-end and short-tail. The common thread has the infeed slot and the undercut, and often only sees the middle part of the thread, not the head and tail. The amount of such plastic bottles with special threads is self-evident, and even the hundreds of mold factories and mold processing self-employed households in the hometown of China's molds, Huangyan, specialize in producing such plastic bottle molds. One of the technical difficulties in such mold processing is the processing of special threads. Many manufacturers have tried manual, electrical machining, milling (including CNC milling), casting and other processing methods, the results are not satisfactory. Then, if a special CNC lathe with a unit price of 100,000 yuan can be developed, it can be used as a general CNC lathe and can process these special threads. The market prospect and social benefits are obviously optimistic. To this end, we conducted the following research. 2, CNC lathe turning general thread processing In order to find a breakthrough, we should first understand and analyze the process of turning the general thread on a CNC lathe: As shown in Figure 1, each car is divided into three sections, the AB section is the acceleration section or the assisting section, the tool tip is accelerated from the standstill to the turning speed; the BC section is the constant speed section, which is also the turning thread segment, and the speed should be when the spindle rotates one. When the circle is used, the tool tip just advances evenly with a pitch (lead); the DC segment is the deceleration section, and the tool tip is reduced from the turning speed to the rest. In other words, the real processing is only the BC segment, and the AB segment and the CD segment are only essential as the run-up and deceleration segments. figure 1 Next page EV Charge Station,Charging station,Electric vehicle charging station,EV charging point,EV charging Yangzhou Beyond Solar Energy Co.,Ltd. , https://www.ckbsolar.com
At present, in high-end CNC equipment, a single-function CNC lathe or vertical machining center with a price of 700,000 yuan and 800,000 yuan cannot directly process such special threads. Only the turning center with dynamic turret and complex tooling or CNC rotation The vertical machining center of the shaft has the possibility of solving it, but to solve it in the end, it is quite difficult for CNC programming alone, and only advanced programmers with strong mathematical skills and experience can complete it. Therefore, it is not good for SMEs. 