Research Of On-line Measurement Technology For Spiral Curved Surface End Cross-section Shape

With the development of up-to-date science and technology, complex spiral curved surface is applied more and more widely, the manufacture technology of which has been developed rapidly from the bypast form milling to enveloping milling, and from the milling with finger cutter to the the plate milling and the whirlwind milling. This has made its manchining agility and processing efficiency enhance greatly. The non-instance center enveloping technology is adopted in the high efficiency NC screw rod milling machine. With the interpolations movement of the each NC axel, the relative meshing motion between cutting tool knife-edge and spiral curved surface is realized, then the whole spiral curved surface part is formed by enveloping milling point by point. Accordingly the new requirement to the on-line measurement technology for end cross-section shape of spiral curved surface has been put forward. Spiral curved surface on-line measurement technology is still the blank in our country, which directly influences the accuracy of manufacturing and working efficiency for spiral curved surface. Under this condition, spiral machinery manufacture level has been restricted in our country, so the realization of spiral curved surface on-line measurement technology will have important value and meaning.According to the characteristic of the screw rod envelope milling processing and based on the screw rod NC milling machine, on-line measurement technology for the spiral curved surface end cross-section shape is putforward, then the screw rod coincided with the requirement of working accuracy can be made by program compensating.This paper has mainly studied following several aspects content.(1) The geometry characteristic of spiral curved surface is analyzed, and on-line measurement programme is putforward in this paper.(2) Grounded on coordinate measuring technology of CMM, in this paper, two-coordinate on-line measurement principle for spiral curved surface and probe radius compensating method are researched.(3) According to the geometry characteristic and processing method of spiral curved surface, error model is set up and standard of compensating is cofirmed at the same time.(4) In the foundation of spiral curved surface end cross-section shape digitization reconstruction, 3D space reconstruction model is established.Using computer technology, the probe radius compensation procedure, the error compensation procedure and the data processing programme are compiled. Under this condition, the spiral curved surface on-line measurement technology based on two coordinates is successfully realized, and the screw rod machining precision is also guaranteed. The NC procedure revision, the control to the milling machine, the cutting tool compensating can be realized in this foundation. So the NC screw rod milling machine will be developed in the direction of the high accuracy, high efficiency, high flexible, and the high integration.