Ultra-precision five-axis lathe y-axis perpendicularity error detection test piece and detection method thereof

Abstract

The application discloses a kind of ultra-precision five-axis lathe Y-axis perpendicularity error detection test pieces and its detection method, wherein detection test piece includes pedestal and is located at the center of the upper surface of the pedestal Cylinder, the pedestal is regular polygon, the upper end surface of the cylinder is provided with a conical hole and twelve circular machining point positions, the central axis of the cylinder is coaxial with the central axis of the pedestal, the central axis of the conical hole is coaxial with the central axis of the pedestal, the central axis of the twelve circular machining point positions is coaxial with the central axis of the pedestal.The detection test piece configuration is simple and can correctly reflect the perpendicularity error of ultra-precision five-axis lathe Y-axis, compared with the existing laser interferometer and other technologies for directly measuring lathe, the detection method is simple, the detection precision is high, and the influence of perpendicularity error on workpiece machining under lathe machining state can be more truly reflected.

Description

Technical Field

[0001] This invention relates to the field of ultra-precision CNC lathe technology, specifically to a test piece for detecting the Y-axis perpendicularity error of an ultra-precision five-axis lathe and its detection method. Background Technology

[0002] Ultra-precision lathes are mainly used in the manufacturing of high-precision components such as key aerospace equipment, marine crankshafts, and optical lens assemblies. Machining errors on ultra-precision lathes directly affect the machining accuracy of parts. Error analysis of the lathe can determine the causes of these errors, which is crucial for improving part machining accuracy. Perpendicularity error is an important component of lathe geometric error terms. It is usually considered as translational axis rotation angle error and is introduced into part machining. Changes in the translational axis machining stroke affect the machining process.

[0003] Existing methods for detecting perpendicularity errors mainly involve using instruments such as laser interferometers to directly inspect the lathe. However, this inspection is conducted in a non-cutting state and cannot accurately reflect the machining accuracy. Furthermore, the accuracy of the inspection depends heavily on the precision of the instrument. Existing instruments are ill-suited for detecting sub-micron level perpendicularity errors. Therefore, instrument-based inspection methods are insufficient for detecting errors in ultra-precision lathes.

[0004] For methods of detecting lathe geometric errors by machining test pieces, existing standard test pieces include the NAS979 test piece developed by NASA in the 1970s and the "S"-shaped test piece developed by Chengdu Aircraft Industry (Group) Co., Ltd. in China. Due to the shape and machining characteristics of these test pieces, they are primarily designed for precision testing of milling machines and are not well-suited for detecting perpendicularity errors in lathes. Furthermore, the accuracy of the tests performed using the NAS979 and S-shaped test pieces does not reach the level of ultra-precision testing. Therefore, existing test pieces are not suitable for detecting perpendicularity errors in ultra-precision five-axis lathes. Summary of the Invention

[0005] The purpose of this invention is to provide a test piece and a testing method for detecting the Y-axis perpendicularity error of an ultra-precision five-axis lathe in order to better detect the Y-axis perpendicularity error. The test piece has a simple configuration and can accurately reflect the Y-axis perpendicularity error of the ultra-precision five-axis lathe. The testing method is simple and has high accuracy, which can more realistically reflect the impact of perpendicularity error on workpiece processing under lathe machining conditions.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides a test piece for detecting the Y-axis perpendicularity error of an ultra-precision five-axis lathe, comprising a base and a cylinder disposed at the center of the upper surface of the base. The base is a regular polygon, and the upper end face of the cylinder is provided with a conical hole and twelve circular machining points. The central axis of the cylinder is coaxial with the central axis of the base, the central axis of the conical hole is coaxial with the central axis of the base, and the central axes of the twelve circular machining points are coaxial with the central axis of the base.

[0008] In the above scheme, a regular polygonal base and a cylinder are set up, and twelve circular machining points are formed on the end face of the cylinder. Due to the existence of Y-axis perpendicularity error, when the Y-axis height changes, the workpiece will shift in the X direction, which will lead to an error in the machining radius. Therefore, the influence of Y-axis perpendicularity error on the machining accuracy of the lathe can be examined by testing the machining circle of the test piece. The test piece has a simple configuration and can accurately reflect the Y-axis perpendicularity error of the ultra-precision five-axis lathe. Compared with existing technologies such as laser interferometers that directly measure the lathe, the detection method is simple, the detection accuracy is high, and it can more realistically reflect the influence of perpendicularity error on workpiece machining under lathe machining conditions.

[0009] In some embodiments, the diameters of the twelve circular processing points are distributed between 50 and 120 mm.

[0010] In some embodiments, the twelve circular processing points are divided into three groups of four circles each, with the diameter difference between adjacent circles in each group being 0.1-2 mm.

[0011] In some embodiments, the thickness of the base is 10-30 mm.

[0012] In some embodiments, the side length of the base is 60-80 mm.

[0013] In some embodiments, the height of the cylinder is 50-70 mm.

[0014] In some embodiments, the diameter of the cylinder is 100-120 mm.

[0015] In some embodiments, the diameter of the conical hole is 1 mm and the depth is 1 mm.

[0016] In some embodiments, the base is hexagonal.

[0017] Secondly, the present invention provides a method for detecting the Y-axis perpendicularity error of a test piece using an ultra-precision five-axis lathe as described in the first aspect, comprising the following steps:

[0018] Step 1: Based on the motion characteristics of the lathe's translational axis, analyze the impact of the Y-axis perpendicularity error on machining according to the geometric definition of the translational axis perpendicularity error;

[0019] Step 2: Establish the machining radius formula under the influence of Y-axis perpendicularity error, expressed as follows:

[0020]

[0021] Where re represents the actual machining radius, S xy drx represents the perpendicularity error of the Y-axis relative to the X-axis, dry represents the tool setting error in the X-direction, y0 represents the tool setting error in the Y-direction, and x represents the initial height of the C-axis relative to the bed. m Represents the X-axis control coordinate of the lathe, y m Indicates the Y-axis control coordinate of the lathe;

[0022] Step 3: Transform and simplify the machining radius formula

[0023] -2·x m ·y m ·S xy -2·x m ·drx-2·y m ·dry=(2*ri+dr)*dr

[0024] Where, x m y m S xyy drx and dry are defined the same as in step two, and ri represents the theoretical machining radius, the value of which is equal to dr represents the difference between the actual machining radius and the theoretical machining radius;

[0025] Step 4: Establish the calculation matrix for perpendicularity error and machining radius, represented as follows:

[0026]

[0027] Where, x mn The lathe X-axis control coordinate for machining the nth circle, y mn For the lathe Y-axis control coordinate when machining the nth circle, ri n Let n be the theoretical machining radius of the nth circle. This is the difference between the actual machining radius and the theoretical machining radius of the nth circle.

[0028] Step 5: Mount the workpiece on the C-axis of the lathe, with one side of the regular polygonal base parallel to the X-axis, and complete the tool setting. Set the X and Y axes of the lathe to zero.

[0029] Step 6: Set the Y-axis to zero, move the X-axis to the specific coordinates of the first machined circle in the first group, fix the X and Y axis coordinates, rotate the C-axis to complete the machining of the first circle, and use this as the reference circle;

[0030] Step 7: Move the X and Y axes to other specific machining coordinates in the first group, feed the Z axis and rotate the C axis, and machine the last three circles in the group in sequence;

[0031] Step 8: Repeat steps 6 and 7 to process the two sets of circles.

[0032] Step 9: Measure the distance between each machining circle in each group to calculate the actual machining radius of the three circles, and calculate the perpendicularity error S of the lathe's Y-axis along the X-axis. xy The tool setting errors drx and dry exist in this machining process.

[0033] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0034] 1. This invention can detect the Y-axis perpendicularity error of an ultra-precision five-axis lathe. Compared with existing technologies such as laser interferometers that directly measure lathes, this invention can more realistically reflect the impact of perpendicularity error on workpiece processing under lathe processing conditions by processing the workpiece.

[0035] 2. Compared with existing NAS979 test specimens and "S"-shaped inspection test specimens, this invention is more suitable for lathe inspection;

[0036] 3. The present invention has a simple structure, is easy to promote and apply, and the measurement results are intuitive and reliable;

[0037] 4. The surface characteristics of this invention are simple and can be flexibly combined with the processing of other workpieces, exhibiting excellent scalability;

[0038] 5. This invention optimizes the calculation by using the distance between the two circles as a measurement factor, which can achieve higher accuracy results with lower measuring instrument accuracy.

[0039] 6. This invention can detect the Y-axis perpendicularity error of an ultra-precision five-axis lathe, as well as the tool setting error during the machining process, for subsequent analysis. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0041] Figure 1 This is a three-dimensional structural view of the test specimen in this invention;

[0042] Figure 2 This is a front view of the test specimen in this invention;

[0043] Figure 3 This is a schematic diagram of the processing points and processing circle of the present invention;

[0044] Figure 4 This is a structural schematic diagram of a certain ultra-precision five-axis lathe;

[0045] Figure 5 This is a schematic diagram illustrating the effect of the Y-axis perpendicularity error on the machining radius in this invention;

[0046] Figure 6 This is a machining error curve diagram of the circular machining radius of the present invention;

[0047] Figure 7 This is a graph showing the verticality error of the present invention.

[0048] The attached diagram shows the markings and corresponding component names:

[0049] 1-Base, 2-Cylinder, 3-Circular machining point, 4-Lathe, 41-Bed, 42-X-axis, 43-Y-axis, 44-Z-axis, 45-C-axis, 46-B-axis, 47-Tool. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0052] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary and secondary relationship of the indicated technical features.

[0053] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0054] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0055] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0056] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces), unless otherwise explicitly specified.

[0057] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0058] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0059] Example 1

[0060] Please refer to Figures 1-3 This application provides a test piece for detecting the Y-axis perpendicularity error of an ultra-precision five-axis lathe, comprising a base 1 and a cylinder 2 located at the center of the upper surface of the base 1. The base 1 is hexagonal, and the upper end face of the cylinder 2 is provided with a conical hole and twelve circular machining points 3. The central axis of the cylinder 2 is coaxial with the central axis of the base 1, the central axis of the conical hole is coaxial with the central axis of the base 1, and the central axis of the twelve circular machining points 3 is coaxial with the central axis of the base 1.

[0061] By setting up a regular polygonal base and a cylinder, and forming twelve circular machining points on the end face of the cylinder, due to the existence of Y-axis perpendicularity error, when the Y-axis height changes, the workpiece will shift in the X direction, which will lead to an error in the machining radius. Therefore, the influence of Y-axis perpendicularity error on lathe machining accuracy can be examined by inspecting the machining circle of the test piece. The test piece has a simple configuration and can accurately reflect the Y-axis perpendicularity error of an ultra-precision five-axis lathe. Compared with existing technologies such as laser interferometers that directly measure lathes, the detection method is simple, the detection accuracy is high, and it can more realistically reflect the influence of perpendicularity error on workpiece machining under lathe machining conditions.

[0062] According to some embodiments of this application, the diameters of the twelve circular processing points 3 are distributed between 50-120 mm.

[0063] According to some embodiments of this application, the twelve circular processing points are divided into three groups of four circles each, with the diameter difference between adjacent circles in each group being 0.1-2 mm.

[0064] According to some embodiments of this application, the thickness of the base 1 is 10-30 mm.

[0065] According to some embodiments of this application, the side length of the base 1 is 60-80mm. Since the base 1 is a regular polygon with a plate-like structure of a certain thickness, the side length here refers to the side length of the regular polygon formed by the projection of the base.

[0066] According to some embodiments of this application, the height of the cylinder 2 is 50-70mm.

[0067] According to some embodiments of this application, the diameter of the cylinder 2 is 100-120 mm.

[0068] According to some embodiments of this application, the conical hole has an opening diameter of 1 mm and a depth of 1 mm, and the top surface of the conical hole coincides with the upper end surface of the cylinder 2. The conical hole is located at the center of the upper end surface of the cylinder 2 and is located inside the twelve circular machining points 3.

[0069] Example 2

[0070] Please refer to Figures 4-7 This application provides a method for detecting the Y-axis perpendicularity error of an ultra-precision five-axis lathe, using the ultra-precision five-axis lathe Y-axis perpendicularity error detection test piece described in Example 1. In this test piece, the hexagonal base 1 has a thickness of 10mm, and the cylinder 2 has a height of 60mm. Each side of the hexagonal base 1 is 80mm long, the cylinder 2 has a diameter of 120mm, the conical hole has an opening diameter of 1mm and a depth of 1mm, and the top surface of the conical hole coincides with the upper end face of the cylinder. The specific coordinates of the twelve circular machining points 3 are shown in the table below:

[0071]

[0072] Specifically, the method for detecting the Y-axis perpendicularity error of this ultra-precision five-axis lathe includes the following steps:

[0073] Step 1: Based on the motion characteristics of the lathe's translational axes, analyze the impact of Y-axis perpendicularity error on machining according to the geometric definition of translational axis perpendicularity error. Figure 4 Taking the lathe shown as an example, the lathe 4 includes a bed 41, an X-axis 42, a Y-axis 43, a Z-axis 44, a C-axis 45, a B-axis 46, and a cutting tool 47. Due to the existence of Y-axis perpendicularity error, when the Y-axis height changes, the workpiece shifts in the X-direction, leading to an error in the machining radius. Therefore, the impact of Y-axis perpendicularity error on lathe machining accuracy can be examined by inspecting the machined circle of the test piece. The effect of Y-axis perpendicularity error along the X-axis on the Y-axis is that the actual tool tip movement axis is not parallel to the Y-axis axis, changing the direction of Y-axis movement and causing it to shift along the X-axis. Figure 5 The figure shows the effect of Y-axis perpendicularity error on the position of the tool tip.

[0074] Step 2: Establish the machining radius formula under the influence of Y-axis perpendicularity error, expressed as follows:

[0075]

[0076] Where re represents the actual machining radius, S xy drx represents the perpendicularity error of the Y-axis relative to the X-axis, dry represents the tool setting error in the X-direction, y0 represents the tool setting error in the Y-direction, and x represents the initial height of the C-axis relative to the bed. m Represents the X-axis control coordinate of the lathe, y m This represents the Y-axis control coordinate of the lathe.

[0077] Step 3: Transform and simplify the machining radius formula

[0078] -2·xm ·y m ·S xy -2·x m ·drx-2·y m ·dry=(2*ri+dr)*dr

[0079] Where, x m y m S xy drx and dry are defined the same as in step two, and ri represents the theoretical machining radius, the value of which is equal to dr represents the difference between the actual machining radius and the theoretical machining radius.

[0080] Step 4: Establish the calculation matrix for perpendicularity error and machining radius, represented as follows:

[0081]

[0082] Where, x mn The lathe X-axis control coordinate for machining the nth circle, y mn For the lathe Y-axis control coordinate when machining the nth circle, ri n Let n be the theoretical machining radius of the nth circle. This is the difference between the actual machining radius and the theoretical machining radius of the nth circle.

[0083] Step 5: Install the workpiece on the C-axis of the lathe, with one side of the hexagonal base parallel to the X-axis, and complete the tool setting. Set the X and Y axes of the lathe to zero.

[0084] Step 6: Set the Y-axis to zero, move the X-axis to the specific coordinates of the first machining circle in the first group, fix the X and Y axis coordinates, rotate the C-axis to complete the machining of the first circle, and use this as the reference circle.

[0085] Step 7: Move the X and Y axes to other specific machining coordinates in the first group, feed the Z axis and rotate the C axis, and machine the last three circles in the group in sequence.

[0086] Step 8: Repeat steps 6 and 7 to process the two sets of circles.

[0087] Step 9: Measure the distance between each machining circle in each group using an optical microscope to calculate the actual machining radius of the three circles. Based on the optical microscope results, substitute the results into the perpendicularity error model to calculate the perpendicularity error S of the lathe's Y-axis along the X-axis. xy The tool setting errors drx and dry in this machining process were compared and verified.

[0088] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for detecting the perpendicularity error of the Y-axis of an ultra-precision five-axis lathe, characterized in that, Errors are analyzed and calculated by processing test pieces. The test pieces include a base and a cylinder located at the center of its upper surface. The base is a regular polygon. The upper end face of the cylinder has a conical hole and twelve circular processing points. The twelve circular processing points are divided into three groups of four circles each. The central axis of the cylinder, the central axis of the conical hole, and the central axis of the twelve circular processing points are all coaxial with the central axis of the base. The method specifically includes the following steps: Step 1: Based on the motion characteristics of the lathe's translational axis, analyze the impact of the Y-axis perpendicularity error on machining according to the geometric definition of the translational axis perpendicularity error; Step 2: Establish the machining radius formula under the influence of Y-axis perpendicularity error, expressed as follows: ； Where re represents the actual machining radius, S xy drx represents the perpendicularity error of the Y-axis relative to the X-axis, dry represents the tool setting error in the X-direction, y0 represents the tool setting error in the Y-direction, and x represents the initial height of the C-axis relative to the bed. m Represents the X-axis control coordinate of the lathe, y m Indicates the Y-axis control coordinate of the lathe; Step 3: Transform and simplify the machining radius formula ； Where, x m y m S xy drx and dry are defined the same as in step two, and ri represents the theoretical machining radius, the value of which is equal to dr represents the difference between the actual machining radius and the theoretical machining radius; Step 4: Establish the calculation matrix for perpendicularity error and machining radius, represented as follows: ； Where, x mn The lathe X-axis control coordinate for machining the nth circle, y mn This refers to the Y-axis control coordinate of the lathe when machining the nth circle. Let n be the theoretical machining radius of the nth circle. This is the difference between the actual machining radius and the theoretical machining radius of the nth circle. Step 5: Install the test piece on the C-axis of the lathe, with one side of the regular polygonal base parallel to the X-axis, and complete the tool setting. Set the X and Y axes of the lathe to zero. Step 6: Set the Y-axis to zero, move the X-axis to the specific coordinates of the first machined circle in the first group, fix the X and Y axis coordinates, rotate the C-axis to complete the machining of the first circle, and use this as the reference circle; Step 7: Move the X and Y axes to other specific machining coordinates in the first group, feed the Z axis and rotate the C axis, and machine the last three circles in the group in sequence; Step 8: Repeat steps 6 and 7 to process the two sets of circles. Step 9: Measure the distance between each machining circle in each group to calculate the actual machining radius of the three circles, and calculate the perpendicularity error S of the lathe's Y-axis along the X-axis. xy The tool setting errors drx and dry exist in this machining process.

2. The method for detecting the Y-axis perpendicularity error of an ultra-precision five-axis lathe according to claim 1, characterized in that, The diameters of the twelve circular machining points are distributed between 50 and 120 mm.

3. The method for detecting the Y-axis perpendicularity error of an ultra-precision five-axis lathe according to claim 2, characterized in that, The diameter difference between adjacent circles in each group of processing points is 0.1-2mm.

4. The method for detecting the Y-axis perpendicularity error of an ultra-precision five-axis lathe according to claim 1, characterized in that, The thickness of the base is 10-30mm.

5. The method for detecting the Y-axis perpendicularity error of an ultra-precision five-axis lathe according to claim 4, characterized in that, The base has a side length of 60-80mm.

6. The method for detecting the Y-axis perpendicularity error of an ultra-precision five-axis lathe according to claim 1, characterized in that, The height of the cylinder is 50-70mm.

7. The method for detecting the Y-axis perpendicularity error of an ultra-precision five-axis lathe according to claim 6, characterized in that, The diameter of the cylinder is 100-120mm.

8. The method for detecting the Y-axis perpendicularity error of an ultra-precision five-axis lathe according to claim 1, characterized in that, The conical hole has an opening diameter of 1 mm and a depth of 1 mm.

9. The method for detecting the Y-axis perpendicularity error of an ultra-precision five-axis lathe according to claim 1, characterized in that, The base is in the shape of a regular hexagon.

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