CN103212722B - A kind of processing method of fery's prism - Google Patents

Abstract

The invention discloses a method for processing a Ferry prism, which comprises the following steps: (1) processing the initial structure cylinder of the curved surface prism Ferry prism, the diameter of which is equal to the diameter of the first curved surface of the Ferry prism, and the two end faces are both A plane perpendicular to the axis of the cylinder, the length of the cylinder is equal to the maximum length of the workpiece on the optical axis of the first curved surface of the Ferry prism plus the amount of cutting removal; (2) cutting an elliptical plane on the cylinder, Obtain the wedge-shaped cylindrical structure of the Ferry prism, and the wedge-shaped cylindrical structure contains the Ferry prism to be processed in space; (3) process the first curved surface on the circular end face of the cylinder; (4) process the second curved surface on the elliptical plane surfaces. The invention has the advantages of simple process, low cost and easy control of the angle precision of the optical axis, and is suitable for single-piece processing or small-batch processing.

Description

A kind of processing method of Ferry prism

technical field

The invention belongs to the technical field of optical device manufacturing, and relates to a processing method for a curved prism, in particular to a single-piece processing method for a Ferry prism.

Background technique

In order to make the spectrograph obtain a "pure" spectrum, Ferry proposed to replace the flat prism with a curved prism in 1910. The results showed that this improvement has many advantages that the flat prism cannot match. After more than 100 years of development, the Ferry prism has the characteristics of small absorption loss, large astigmatism, compact structure, large field of view, and light weight. , aerospace and other fields have broad application prospects. In view of the many uses of curved prisms, Ferry prisms, some domestic institutions have carried out a lot of research work on the processing of curved prisms.

For example, Chinese invention patent application CN102139376A discloses a free-form surface prism processing method. First, the sides of each prism are initialized to a plane to ensure that each side is adjusted according to the reference plane. The axis machine tool or machining center is clamped and milled at one time, and the angle between the optical axes of each curved surface is guaranteed by the rotation accuracy of the machine tool's rotary axis. Such a processing method needs to specially make a tool holder for fixing the diamond tool, and transform the machine tool equipment to establish a free-form prism ultra-precision machining system. This technique is too costly for single-piece processing or small-batch processing of curved prism Ferry prisms.

As a kind of curved prism, the Ferry prism is usually composed of two curved surfaces with a certain angle between the optical axes. Its structure is different from the prism structure with all planes and the double-sided lens structure with only one optical axis. . The optical axis angle parameter of the Ferry prism is a very important parameter in its structural parameters. If the optical axis angle is not processed correctly, it will not only seriously affect the imaging quality of the optical system, but also make the installation and adjustment of the system very difficult. The processing of Ferry prisms in the prior art requires precision multi-axis machine tools to ensure the accuracy of each structural parameter of the Ferry prism. Therefore, it is necessary to invent a low-cost method suitable for single-piece processing or small-batch processing that does not rely on precision multi-axis machine tools, can be directly processed on ordinary single-axis machine tools, and can ensure the accuracy of the included angle of the optical axis of the Ferry prism.

Contents of the invention

The purpose of the invention is to provide a low-cost processing method suitable for single-piece processing or small-batch processing, without using high-precision multi-axis numerical control processing equipment, which can be processed in a general optical processing center to ensure the accuracy of the optical axis of the Ferry prism .

In order to achieve the above-mentioned purpose of the invention, the technical solution adopted in the present invention is: a kind of processing method of Ferry prism, comprises the steps:

(1) processing the initial structure of the curved prism Ferry prism, the initial structure is a cylinder, the diameter of the cylinder is equal to the diameter of the first curved surface of the Ferry prism and both end faces are perpendicular to the axis of the cylinder The plane of the cylinder, the length of the cylinder is equal to the maximum length of the workpiece on the optical axis of the first surface of the Ferry prism plus the cutting removal amount;

(2) take an end face of the initial structure cylinder as the datum plane, cut an elliptical plane equal to the included angle of the two mirror surfaces of the Ferry prism with the included angle between the said datum plane on the cylinder, obtain the Ferry prism A wedge-shaped cylindrical structure, which spatially contains the Ferry prism to be processed;

(3) Fix the wedge-shaped cylindrical structure processed in step (2) on the rotary table of the optical machining center, adjust the position of the workpiece so that the axis of the cylinder is coaxial with the axis of the rotary table, and process the first round end surface of the cylinder. A curved surface, the optical axis of the first curved surface of the processed Ferry prism coincides with the axis of the cylinder;

(4) Fix the workpiece processed in step (3) on the rotary table of the optical machining center, adjust the position of the workpiece so that the elliptical plane is parallel to the table surface of the rotary table and the rotation axis of the workpiece coincides with the optical axis of the second curved surface to be processed , machining a second curved surface on the elliptical plane.

Further technical scheme, during processing, in step (1), the length of the initial structure cylinder is equal to the sum of the maximum distance and the minimum distance from the elliptical end surface of the wedge-shaped cylinder structure to the round end surface on the axis line direction of the wedge-shaped cylinder structure of the Ferry prism. For the upper cutting removal amount, the initial structure cylinder is cut into two parts according to the angle between the two curved surface optical axes of the Ferry prism, and the cutting parts respectively form elliptical planes to obtain the wedge-shaped cylindrical structure described in the two steps (2), respectively Processed into a Ferry prism.

Preferred technical scheme, the initial structure of the Ferry prism of the present invention has the following characteristics: the initial structure is a cylinder, and the diameter of the cylinder is equal to the diameter of the first curved surface of the Ferry prism, and both end faces are aligned with the axis of the cylinder. A circular planar cylinder whose line is perpendicular, the length of the cylinder meets the requirements of two identical Ferry prism wedge-shaped cylinder structures that can be obtained after cutting. The length of the initial structural cylinder is equal to the sum of the maximum distance and the minimum distance from the elliptical end surface of the wedge-shaped cylindrical structure to the circular end surface of the wedge-shaped cylindrical structure of the Ferry prism in the direction of the axis line of the cylinder, because the actual initial structure is affected by the material removal amount of the cutting gap during cutting The length of the cylinder plus the projection length of the width of the cutting gap in the axial direction of the cylinder. The advantage of this design is that the material is saved to the greatest extent, and two wedge-shaped cylindrical structures with equal wedge angles can be obtained by one cutting, so that the two Ferry prisms obtained after processing have good stability in the angle error of the optical axis.

Due to the use of the above-mentioned technical solutions, the present invention has the following advantages compared with the prior art:

1. The invention realizes the processing of the Ferry prism by cutting to form an elliptical plane, without using high-precision multi-axis numerical control processing equipment, which is easy to realize, and is especially suitable for single-piece or small-batch processing requirements.

2. In the present invention, the included angle between the cylinder end face and the elliptical plane is equal to the included angle of the two curved surface optical axes of the Ferry prism. Therefore, the two curved surface optical axes of the Ferry prism can be realized by controlling the cutting of the elliptical plane. Precise machining of included angles.

3. The present invention can combine and process two Ferry prisms with one initial structure, which saves materials, and the error stability of the optical axis angle of the two Ferry prisms obtained after processing is good.

Description of drawings

Fig. 1 is the initial structure schematic diagram of the curved prism Ferry prism processed in the embodiment of the present invention;

Fig. 2 is a schematic diagram of the structure of a Ferry prism wedge-shaped cylinder cut on the initial structure cylinder in Embodiment 1 of the present invention;

Fig. 3 is the Ferry prism schematic diagram of processing the first curved surface in the embodiment of the present invention;

Fig. 4 is the sketch map of the Ferry prism processing the second curved surface on the ellipse end surface in the first embodiment of the present invention;

5 is a schematic diagram of the structure of two identical wedge-shaped cylinders obtained by cutting a cylinder to obtain a Ferry prism in Embodiment 1 of the present invention.

Among them: 1. Circular end face; 2. Oval plane; 3. Cylinder axis; 4. The first curved surface; 5. Workpiece rotation axis; 6. The second curved surface; 7. The first wedge-shaped cylinder Structure; 8. The second wedge-shaped cylindrical structure.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing and embodiment:

Embodiment one: a kind of processing method of curved prism Ferry prism, comprises the following steps:

(1) According to the initial structure of the curved prism Ferry prism that needs to be processed, calculate the initial structure, as shown in Figure 1, process the initial structure into a cylinder whose diameter is equal to the diameter of the first curved surface of the Ferry prism and Both end faces are circular planes perpendicular to the axis of the cylinder; the initial structure of the curved prism Ferry prism is processed, the initial structure is a cylinder, and the length of the cylinder is slightly longer than the first curved surface of the Ferry prism. The maximum length of the upward workpiece;

(2) Process the wedge-shaped cylindrical structure of the curved surface prism Ferry prism, as shown in Figure 2. Taking one of the circular end faces 1 of the initial structure cylinder as the reference plane, a wedge angle θ equal to the reference plane is cut on the cylinder. The elliptical plane 2 of the included angle of the optical axes of the two mirror surfaces of the inner prism, this step is an important technical means to realize the present invention to accurately control the included angle of the optical axes of the Ferry prism;

(3) Fix the wedge-shaped cylinder processed in step (2) on the rotary table of the optical machining center, as shown in Figure 3, adjust the position of the workpiece so that the axis line 3 of the cylinder is coaxial with the axis line of the rotary table. The first curved surface 4 is processed on the circular end surface, and the optical axis of the first curved surface of the processed Ferry prism coincides with the axis of the cylinder;

(4) As shown in Figure 4, fix the Ferry prism processed in step (3) on the rotary table of the optical processing center, adjust the position of the workpiece so that the elliptical plane 2 is parallel to the table surface of the rotary table and the axis of rotation of the workpiece is 5 Coinciding with the optical axis of the second curved surface to be processed, a second curved surface 6 is processed on the elliptical end face of the Ferry prism. The present invention realizes the conversion of the optical axis angle β to the control wedge angle θ through the technical means of step (3) and step (4).

The preferred embodiment of the initial structure mentioned in the implementation process is: the initial structure of the Ferry prism is designed to have the following characteristics: the initial structure is a cylinder, and the diameter of the cylinder is equal to the aperture of the first curved surface of the Ferry prism, see Fig. As shown in 5, the two end faces are circular plane cylinders perpendicular to the axis of the cylinder, and the length of the cylinder meets the requirements of the cutting process in the step (2) described in claim 1, so that two identical Ferry cylinders can be obtained. Prism wedge-shaped cylindrical structure requires that the length of the initial structural cylinder is equal to the sum of the maximum distance and the minimum distance from the elliptical end face of the wedge-shaped cylindrical structure to the circular end face of the wedge-shaped cylindrical structure in the direction of the axis line of the Ferry prism wedge-shaped cylindrical structure. The removal amount affects the projected length of the actual initial structural cylinder length plus the width of the cutting gap in the axial direction of the cylinder. The advantage of this technical means is that the material is saved to the greatest extent, and the first wedge-shaped cylindrical structure 7 and the second wedge-shaped cylindrical structure 8 with two equal wedge angles can be obtained in one cutting, and the two Ferry prisms obtained after processing like this Optical axis angle error stability is good.

The processing method of the curved surface prism Ferry prism of the present invention does not need to use high-precision multi-axis machine tools and does not need to modify existing equipment. It only needs to make a wedge-shaped cylindrical structure according to the structural parameters of the Ferry prism, through the technical means of the present invention. Realize the transformation from the control of the included angle of the optical axis to the control of the wedge angle of the wedge-shaped cylindrical structure. Therefore, the present invention has the characteristics of simple processing technology, low cost, easy control of the precision of the included angle of the optical axis, and is suitable for single-piece processing or small-batch processing.

Claims (2)

1. a processing method for fery's prism, is characterized in that, comprises the steps:

(1) initial configuration of processing curve prism fery's prism, described initial configuration is cylinder, the equal diameters of described cylinder diameter and fery's prism first curved surface and two end faces are all the planes vertical with cylinder axial line, cylindrical length equal fery's prism first curved surface optical axis axially maximum length of workpiece size add cutting removal amount;

(2) with the cylindrical end face of initial configuration for datum level, angle on cylinder between machining one and described datum level equals the elliptic plane of fery's prism two minute surface optical axis included angle, obtain the wedge shape column structure of fery's prism, described wedge shape column structure spatially contains fery's prism to be processed;

(3) the wedge shape column structure after step (2) being processed is fixed on optical manufacturing central rotation platform, the adjustment location of workpiece makes its cylinder axial line coaxial with turntable axial line, cylinder circular end face processes first curved surface, and fery's prism first curved surface optical axis of processing overlaps with cylinder axial line;

(4) workpiece after step (3) being processed is fixed on optical manufacturing central rotation platform, the adjustment location of workpiece makes its elliptic plane parallel with turntable table top and the rotating shaft of workpiece and to be processed second curved surface optical axis coincidence, and elliptic plane processes second curved surface.

2. the processing method of fery's prism according to claim 1, is characterized in that: wherein in step (1) cylindrical length equal fery's prism first curved surface optical axis axially maximum length of workpiece size add cut removal amount replace with oval end face that initial configuration cylinder length equals wedge shape column structure on fery's prism wedge shape column structure cylinder direction of axis line to nose circle face ultimate range and minimum range with add cutting removal amount; Initial configuration cylinder is cut into two parts by the angle of fery's prism two curved surface optical axises, and cutting part forms elliptic plane respectively, obtains the wedge shape column structure described in two steps (2), is processed into fery's prism respectively.