The Study of Tacking Patterns in Milling Machines with Impact Effect

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676.15.051.44

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Abstract

It is known that during grinding of fibrous semi-finished products in cutting mills, the impact contact along the length of the cutting edges of the blades in the rotor and stator through the compressed layer of  fibers hanging over them produces a stronger chopping and cutting action on the mass at minimum energy consumption. The paper studied the known version – with  rectangular blades and an author one – with radial blades. The study focused on: - common and special features of the versions, as well as on the force action at  simulta-neous contact of cutting edges; - geometry of patterns of these versions; - testing these versions on simultaneity of contact of cutting edges along their entire length. Among common features we found geometric and dynamic characteristics, as well as the fact that circumferential velocity vectors and effort vectors at points of the cutting edges of individual rotor blades are normal with respect to the radii drawn from the center of the disk to these points, .i.e. perpendicular. Among special features we found geometric and dynamic characteristics of the versions. Simultaneity of the contact along the entire length of the cutting edges of single rectangular and radial blades was tested during their passage in unequally distant points of circumferential arcs, limited by the generatrices contacting with each other. The results showed that the time of the passage of circumferential arcs in unequally distant points of the cutting edges for: - rectangular blades is not the same at different rotation angles of these points, due to which the contact along the length of the cutting edges is not simultaneous; - radial blades is the same at equal rotation angles of these points, due to which the contact along the length of the cutting edges is simultaneous. Consclusions: - for blades with rectangular grinding surface, simultaneous contact along the length of their cutting edges is impossible; - for rotor blades with trapezoidal grinding surface, the contact along the length of the cutting edges is simultaneous; - trapezoidal grinding surface of blades creates prerequisites for impact action on the fiber;  -the information provided is well founded using mathematical framework;  - increasing share of the fibrillation effect as the cutting edges are getting blunt (curved) is of interest for further research.

Authors

V.I. Kovalev, Candidate of Engineering, Associate Professor; V.A. Kozhukhov, Senior Lecturer; Yu.D. Alashkevich, Doctor of Engineering, Professor

Affiliation

Siberian State Technological University

Keywords

simultaneous and radial contact, edge, cutting, impact.

References

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