Non-resonant three-dimensional elliptical diamond fly-cutting optical free curved surface method and special device

Abstract

The invention discloses a non-resonant three-dimensional elliptical diamond fly-cutting optical free curved surface method and a special device, belonging to the field of cutting technology of free curved surface of hard-processing materials. In the invention, a non-resonant driving mode is used to enable a diamond cutter to generate medium-high frequency or ultrahigh frequency three-dimensional elliptical movement in order to form high-speed or ultrahigh-speed diamond fly-cutting main movement; a cutter edge motion track is projected as reciprocating rectilinear movement on an x-z plane and is respectively projected as elliptical movement on an x-y plane and a y-z plane; the optical free curved surface is created on the basis of the combination of the movements of three-dimensional elliptical diamond fly cutting, X-axis feeding, Z-axis reciprocating feeding, worepiece rotary feeding, and the like. The invention also discloses a diamond cutter three-dimensional elliptical movement track generating device which are directly driven by four piezoelectric stacks, the three-dimensional elliptical movement parameters can be independently controlled, which is beneficial to the obtaining of optimal cutting performance, and the follow-up control of the three-dimensional elliptical movement avoids distortion in a real cutting process.

Description

technical field [0001] The invention belongs to the technical field of ultra-precision cutting processing and cutting processing of complex optical parts of difficult-to-machine materials, and in particular relates to a non-resonant three-dimensional elliptical diamond fly-cut optical free-form surface method and a special device. Background technique [0002] Optical freeform surface refers to an optical surface without rotational symmetry (Garrard 2005), which has many advantages such as improving the performance of the optical system and reducing the size of the optical system, and has a wide range of application requirements in many industrial fields. [0003] Diamond flying cutting is an important type of optical free-form surface processing method (Brinksmeier 2008). Its essence is single-blade circumferential milling. In each revolution, the blade only participates in cutting for a part of the time, so compared with continuous cutting, the cutting heat is reduced. cau...

AI Technical Summary

Problems solved by technology

The shortcomings of the existing diamond flying cutting method are: ①. Not suitable for optical free-form surfaces with small local curvature radii; ②. The improvement of cutting speed is very limited; ③. For ferrous materials such as hardened steel and brittle materials such as silicon carbide material, diamond tools have poor machinability

The main disadvantages of resonance-driven EVC are: ①. For a non-linear tool holder, the two transverse bending vibrations and longitudinal vibrations are often coupled, which is prone to crosstalk

②. The elliptical motion parameters (such as frequency) of the blade cannot be adjusted, and it is difficult to adapt to the different requirements of different processing materials for the blade motion parameters

However, in order to obtain the best cutting performance, there are still some deficiencies in this non-resonant driving method that need to be further resolved, mainly including: ①. Whether the piezoelectric actuators are arranged in parallel or perpendicular to each other, these two types of structures can only To achieve two-dimensional EVC in the plane, the orientation of the ellipse plane is difficult to adjust

②.The existing non-resonant two-dimensional EVC is all open-loop control, and the elliptical motion trajectory during actual cutting will inevitably be distorted

But the disadvantages still lie in: the existing resonant three-dimensional EVC, blade elliptical motion trajectory parameters (such as elliptical motion frequency) are still difficult to adjust, lack of adaptability to different materials

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