Air bag polishing system for large-caliber special-shaped off-axis aspheric mirror and working method thereof

Abstract

According to the air bag polishing system of the large-caliber special-shaped off-axis aspheric mirror and the working method of the air bag polishing system, a mirror grinding machine serves as a carrier, the polishing system is composed of a numerical control system, an air bag polishing device and a balance weight structure, the air bag polishing device is composed of a flexible air bag and a double-swing-head structure and hung at the front end of a balance weight rod through a balance weight floating structure, the air bag polishing device always floats on a polished mirror surface underfixed pressure and is driven by a numerical control guide rail to linearly feed in the X direction and the Y direction; the air bag polishing device is composed of a polishing servo motor, a hollow spindle, an air bag clamping head, a square shaft sleeve, an upper bearing seat and a lower bearing seat; the double-swing-head structure is composed of an L-shaped support, a C-shaped support, a C-axisservo motor, a precision planetary speed reducer, an A-axis servo motor and a precision planetary speed reducer; and the polishing servo motor drives the hollow spindle to rotate through a synchronous belt wheel so as to drive the flexible air bag to rotate. The problem that the aperture size of the polished mirror surface is limited and the precision is not high in a horizontal structure and a gantry structure of other polishing system structures can be effectively solved.

Description

technical field [0001] The invention relates to a polishing system, in particular to an airbag polishing system suitable for large-caliber special-shaped off-axis aspheric mirrors. The invention also relates to the method of operation of such a polishing system. Background technique [0002] At present, large-aperture special-shaped off-axis aspheric mirrors are widely used in the field of space optics and astronomy. Special-shaped off-axis aspheric mirrors have the advantages of reducing the overall weight of the optical system, avoiding light shading, avoiding mutual interference between the mirror body and the mechanical structure, and facilitating installation and adjustment. Its shape is generally a rounded rectangle, a stadium shape, a quasi-octagonal shape (called a special shape) as shown in Figure 1. How to develop high-quality large-aperture special-shaped off-axis aspheric optical elements is of great significance to the development of space optics and astronomic...

AI Technical Summary

Problems solved by technology

[0004] Disadvantages: ①The convergence efficiency of grinding and polishing is low; ②The grinding and polishing of small grinding discs is very easy to cause medium and high frequency errors on the optical mirror; ③There is an edge effect; ④The small grinding disc is always perpendicular to the contact area of ​​the optical mirror during the polishing process, and the linear velocity of the center point of the contact area is zero, and the farther away from the contact center, the greater the linear velocity and the greater the grinding removal amount. It is necessary to introduce revolution motion to improve the shape of the removal model, and the structure of the polishing head is complex

[0006] Disadvantages: The removal efficiency of magnetorheological polishing is low. Before the application of magnetorheological polishing technology, the mirror surface to be polished needs to be pre-polished by other polishing methods. The surface accuracy must basically meet the requirements before using magnetorheological polishing technology.

[0008] Disadvantages: ①The material removal efficiency is low, the mirror surface needs to be pre-polished by other polishing methods before polishing, and the surface shape accuracy must basically meet the requirements before using the ion beam polishing method

②The equipment is expensive and the operating cost is high

[0015] Disadvantages: Although the IRP series airbag polishing equipment has excellent performance, the price is very expensive and the technology is strictly confidential

[0017] Disadvantages: Although the precision of the trial-produced experimental prototype can meet the requirements of ultra-precision polishing, due to structural limitations, the equipment is only suitable for small and medium-caliber optical components

[0018] Disadvantages: It is oriented to the polishing of free-form surface molds, and is not suitable for ultra-precision polishing of large-diameter off-axis aspheric optical components

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