Ultra-precision turning equipment for oblique off-axis ellipsoidal mirrors

Abstract

This invention provides an ultra-precision turning apparatus for oblique off-axis ellipsoidal mirrors, comprising a base, an ellipsoidal mirror, and a cutting tool. The base has a first side and a second side arranged opposite to each other. The first side is used to connect to the spindle of a turning machine tool. The ellipsoidal mirror has an ellipsoidal surface to be machined, and the ellipsoidal mirror is detachably connected to the second side so that the rotation center axis of the ellipsoidal mirror coincides with the rotation center axis of the spindle. The cutting tool includes a tool holder and a cutting head connected to the end of the tool holder. The ultra-precision turning apparatus provided by this invention can be installed in conjunction with a turning machine tool to achieve ultra-precision turning of oblique off-axis ellipsoidal mirrors. Compared with the traditional polishing method for preparing oblique off-axis ellipsoidal mirrors, it is more efficient, lower in cost, and also has the advantages of high machining accuracy, simple installation, and avoidance of machining interference.

Description

Technical Field

[0001] This invention relates to the field of ultra-precision machining technology, and more specifically, to an ultra-precision turning apparatus for an oblique off-axis ellipsoidal mirror. Background Technology

[0002] An ellipsoid is a three-dimensional surface formed by rotating an ellipse around one of its major and minor axes. Due to its excellent optical properties, it is used in lasers and optical imaging. The ellipsoidal mirror machining methods disclosed in relevant literature typically employ milling, but the surface accuracy and roughness are relatively low, failing to meet the requirements of reflective optical systems. Especially for ellipsoidal mirrors formed by rotating an ellipse around its major axis, with some parts extending beyond the vertex of the minor axis, the curvature changes significantly and the sag is large. Therefore, rotary turning poses multiple interference risks when machining these surfaces. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] The technical problem to be solved by the present invention is that when the ellipsoidal surface of the existing ellipsoidal mirror is machined by rotary turning, there are multiple interference risks.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] An ultra-precision turning apparatus for an off-axis ellipsoidal mirror is provided, comprising a base, an ellipsoidal mirror, and a cutting tool. The base has a first side and a second side arranged opposite to each other. The first side is used to connect to the spindle of a turning machine tool. The ellipsoidal mirror has an ellipsoidal surface to be machined. The ellipsoidal mirror is detachably connected to the second side so that the rotation center axis of the ellipsoidal mirror coincides with the rotation center axis of the spindle. The cutting tool includes a tool shank and a cutting head connected to the end of the tool shank. The angle α between the axis of the tool shank and the tangent plane of the cutting head satisfies: greater than the first critical angle between the center line of the arc cutting edge of the cutting head and the rotation center axis of the ellipsoidal mirror when the outermost edge of the arc cutting edge of the cutting head enters the ellipsoidal surface; and less than the second critical angle between the center line of the arc cutting edge of the cutting head and the rotation center axis of the ellipsoidal mirror when the outermost edge of the arc cutting edge of the cutting head cuts out of the ellipsoidal surface.

[0008] Preferably, the first critical included angle β min =π / 2-(φ-θ / 2), where θ is the arc wrap angle of the cutter head, and φ is the angle between the tangent and the axis of rotation of the ellipsoid.

[0009] Preferably, the second critical included angle β max=π-(φ+θ / 2), where θ is the arc wrap angle of the cutter head, and φ is the angle between the tangent and the axis of rotation of the ellipsoid.

[0010] Preferably, the length of the cutting tool is greater than the Z-axis height between the point where the cutting head enters the ellipsoidal mirror and the point where the cutting head exits the ellipsoidal mirror.

[0011] Preferably, the ultra-precision turning device further includes a fastener, the base is provided with a first through hole, the ellipsoidal mirror is provided with a threaded hole corresponding to the first through hole, and the fastener passes through the first through hole and is threadedly connected to the threaded hole.

[0012] Preferably, the ellipsoidal mirror has a groove, and the base has a boss, with the groove and the boss engaging and connecting.

[0013] Preferably, the ellipsoidal mirror has a boss, and the base has a groove, which is connected to the boss.

[0014] Preferably, the base is further provided with a counterweight, which is disposed on the base opposite to the ellipsoidal mirror.

[0015] Preferably, the material of the cutting head is diamond.

[0016] Preferably, the ellipsoid is a part of a complete ellipsoid, which is formed by rotating an elliptic curve around the line containing its two foci.

[0017] (III) Beneficial Effects

[0018] The above-described technical solution of the present invention has at least the following advantages:

[0019] 1. The ultra-precision turning device provided by the present invention can be installed in conjunction with a turning machine tool to realize ultra-precision turning of oblique off-axis ellipsoidal mirrors. Compared with the traditional polishing method for preparing oblique off-axis ellipsoidal mirrors, it is more efficient and less expensive.

[0020] 2. By precisely connecting the base and the ellipsoidal mirror, the present invention can precisely install and fix the ellipsoidal mirror on the base. Then, by defining the positional relationship between the cutting tool and the ellipsoidal mirror, the ellipsoidal mirror can be precisely machined, avoiding machining interference. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is an exploded view of the structure of the ultra-precision turning device for the oblique off-axis ellipsoidal mirror provided in an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the structure of the cutting tool provided in an embodiment of the present invention.

[0024] Figure 3 This is a cross-sectional view of the ultra-precision turning apparatus for an oblique off-axis ellipsoidal mirror provided in an embodiment of the present invention.

[0025] The labels for the attached figures are as follows:

[0026] 10. Ellipsoid mirror; 20. Base; 30. Counterweight; 40. Cutting tool; 11. Ellipsoid surface; 12. Threaded hole; 13. Groove; 301. First side surface; 302. Boss; 303. First through hole; 304. Second side surface; 401. Tool holder; 402. Tool head. Detailed Implementation

[0027] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0028] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be located directly on or indirectly on the other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to the other component.

[0029] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate that the device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or the number of technical features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. The specific implementation of this invention will be described in more detail below with reference to specific embodiments:

[0031] like Figure 1 , Figure 2 and Figure 3As shown, this embodiment of the invention provides an ultra-precision turning device for an off-axis ellipsoidal mirror, including a base 20, an ellipsoidal mirror 10, and a cutting tool 40. The base 20 has a first side 301 and a second side 304 arranged opposite to each other. The first side 301 is used to connect to the spindle of a turning machine tool. Specifically, the first side 301 is adsorbed onto the spindle of the turning machine tool by a vacuum chuck. The ellipsoidal mirror 10 has an ellipsoidal surface 11 to be machined. The ellipsoidal mirror 10 is detachably connected to the second side 304 so that the rotation center axis of the ellipsoidal mirror 10 coincides with the rotation center axis of the spindle. The cutting tool 40 includes a tool holder 401 and a cutting head 402 connected to the end of the tool holder 401. The angle α between the axis of the tool holder 401 and the tangent surface of the cutting head 402 satisfies: greater than the first critical angle β between the center line of the arc cutting edge of the cutting head 402 and the rotation center axis of the ellipsoidal mirror 10 when the outermost edge of the arc cutting edge of the cutting head 402 enters the ellipsoidal surface. min ; and the second critical angle β between the center line of the arc-shaped cutting edge of the cutter head 402 and the rotation center axis of the ellipsoidal mirror 10 when the outermost edge of the arc-shaped cutting edge of the cutter head 402 cuts out the ellipsoidal surface 11. max Specifically, the base 20 is cylindrical in shape, and the rotation center axis of the base 20 is aligned with the rotation center axis of the spindle by adjusting the runout of the outer circle of the cylinder using a dial indicator. Furthermore, the first side surface 301 is ground to ensure its flatness and is mounted on the spindle of the turning machine tool by vacuum adsorption. The outer circle is machined by an ultra-precision machine tool to ensure coaxiality during installation.

[0032] In one embodiment, such as Figure 3 As shown, Figure 3 In the diagram: a is the length of the major axis of the ellipse, b is the length of the minor axis of the ellipse, and the first critical angle β is... min =π / 2-(φ-θ / 2), where π is 180°, θ is the arc wrap angle of the 402 cutter head, and φ is the angle between the tangent and the rotation axis of the ellipsoid mirror.

[0033] In one embodiment, the second critical angle β max =π-(φ+θ / 2), where π is 180°, θ is the arc wrap angle of the cutter head, and φ is the angle between the tangent and the axis of rotation of the ellipsoid.

[0034] In one embodiment, the length L of the tool 40 (the length from the cutting point to the end of the tool holder) is greater than the Z-axis height H between the entry point of the tool head 402 into the ellipsoid 10 and the exit point of the tool head 402 from the ellipsoid 10.

[0035] In one embodiment, the ultra-precision turning apparatus also includes a fastener, a first through hole 303 on the base 20, and a threaded hole 12 corresponding to the first through hole 303 on the ellipsoid mirror 10. The fastener passes through the first through hole 303 and is threadedly connected to the threaded hole.

[0036] In one embodiment, the ellipsoidal mirror 10 has a groove 13, and the base 20 has a boss 302, with the groove 13 and the boss 302 engaging. Specifically, the position on the base 20 for mounting the ellipsoidal mirror 10 has a certain slope, and this slope and the position of the boss 302 together ensure that the axis of the ellipsoidal mirror 10 coincides with the axis of rotation of the base 20. The engagement of the groove 13 and the boss 302 enables rapid positioning and installation of the ellipsoidal mirror 10 on the base 20.

[0037] In one embodiment, the ellipsoidal mirror 10 is provided with a boss, and the base 20 is provided with a groove, which is connected to the boss.

[0038] In one embodiment, a counterweight 30 is also provided on the base 20, and the counterweight 30 is disposed opposite to the ellipsoidal mirror 10 on the base 20. The counterweight 30 is used to balance the weight of the ellipsoidal mirror 10 so that the rotation of the base 20 is smooth.

[0039] In one embodiment, the cutting tip 402 is made of diamond. Diamond has high hardness, making it suitable for use as a cutting tip.

[0040] In one embodiment, the ellipsoid 11 is a portion of a complete ellipsoid, which is formed by rotating an elliptic curve around the line containing its two foci. The ellipsoidal mirror 10 has surface distributions on both sides of the vertex of the minor axis of the complete ellipsoid.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-precision turning apparatus for an oblique off-axis ellipsoidal mirror, characterized in that, include: The base has a first side and a second side disposed opposite to each other, the first side being used for connection with the spindle of a turning machine tool; An ellipsoidal mirror has an ellipsoidal surface to be processed. The ellipsoidal mirror is detachably connected to the second side surface so that the rotation center axis of the ellipsoidal mirror coincides with the rotation center axis of the main shaft. A cutting tool includes a shank and a cutting head connected to the end of the shank. The angle α between the axis of the shank and the tangential surface of the cutting head satisfies: greater than the first critical angle between the center line of the arc-shaped cutting edge of the cutting head and the central axis of rotation of the ellipsoid when the outermost edge of the arc-shaped cutting edge enters the ellipsoid; and less than the second critical angle between the center line of the arc-shaped cutting edge of the cutting head and the central axis of rotation of the ellipsoid when the outermost edge of the arc-shaped cutting edge cuts out of the ellipsoid. The first critical angle β min =π / 2 - (φ - θ / 2), the second critical included angle β max =π - (φ + θ / 2), where π is 180°, θ is the arc wrap angle of the cutter head, and φ is the angle between the tangent and the rotation axis of the ellipsoid.

2. The ultra-precision turning apparatus for an oblique off-axis ellipsoidal mirror as described in claim 1, characterized in that, The length of the cutting tool is greater than the Z-axis height between the point where the cutting head enters the ellipsoid and the point where the cutting head exits the ellipsoid.

3. The ultra-precision turning apparatus for an oblique off-axis ellipsoidal mirror as described in claim 1, characterized in that, The ultra-precision turning device also includes fasteners. The base is provided with a first through hole, and the ellipsoidal mirror is provided with a threaded hole corresponding to the first through hole. The fastener passes through the first through hole and is threadedly connected to the threaded hole.

4. The ultra-precision turning apparatus for an oblique off-axis ellipsoidal mirror as described in claim 1, characterized in that, The ellipsoidal mirror has a groove, and the base has a boss. The groove and the boss are connected in a mating manner.

5. The ultra-precision turning apparatus for an oblique off-axis ellipsoidal mirror as described in claim 1, characterized in that, The ellipsoidal mirror has a boss, and the base has a groove, which is connected to the boss.

6. The ultra-precision turning apparatus for an oblique off-axis ellipsoidal mirror as described in claim 1, characterized in that, The base is also provided with a counterweight, which is disposed on the base opposite to the ellipsoidal mirror.

7. The ultra-precision turning apparatus for an oblique off-axis ellipsoidal mirror as described in claim 1, characterized in that, The material of the cutting head is diamond.

8. The ultra-precision turning apparatus for an oblique off-axis ellipsoidal mirror as described in claim 1, characterized in that, The ellipsoid is a part of a complete ellipsoid, which is formed by rotating an elliptic curve around the line containing its two foci.

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