Precision control method for high-precision hole series of web

Abstract

The invention provides a precision control method for a web high-precision hole system, and the method comprises the steps: building a theoretical precision hole machining coordinate system under a part machining coordinate system; self-adaptive compensation is conducted on the current state of the part through the measuring function of a machine tool measuring head, and an actual precision hole machining coordinate system is obtained; a precision hole is manufactured under the precision hole actual machining coordinate system; according to the method, the part with the precision hole with the requirement for the mutual position degree can be machined by automatically converting the coordinate system in an unmanned mode in any numerical control machine tool with the measuring head function, self-adaptive precision compensation is achieved, and the influence of deformation of a web of the part on the hole position of the precision hole is reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of numerical control machining, and specifically relates to a method for controlling the accuracy of a high-precision hole system of a web. Background Art

[0002] The processing of the web precision hole system has always been a hot spot and difficulty in mechanical processing. Its structural feature is that multiple precision holes of different sizes that are coordinated with each other are distributed on the reinforcement ribs or bosses of the web of the part. In the field of aerospace, the parts are subject to weight requirements, and the thickness of the web is usually not more than 3mm. Due to the small size and poor rigidity of the web of the product, deformation is easy to occur during processing. When the deformation is large, it will affect the position of the web precision hole system, and even cause the position to exceed the tolerance and the product to be unqualified.

[0003] In traditional processing, in order to eliminate the influence of deformation caused by the machining process on the position of precision holes, precision hole processing is often used as a separate process. After completing the processing of other parts, the part posture is manually adjusted on the boring machine to make the flatness of the web within a certain range, and then the hole is bored to ensure the position of the hole. This processing method is completely dependent on the skill level of the operator, resulting in the quality of the part being linked to the skill level of the operator, which poses a greater quality risk.

[0004] At the same time, this method requires operators to constantly manually debug to reduce the impact of the deformation of the web of the part on the position of the precision hole, resulting in long machine time, long part processing cycle and low efficiency. As the development and production tasks of various types of military and civilian aircraft projects in the aviation manufacturing industry become increasingly heavy, the existing precision hole processing methods are becoming a bottleneck restricting the rapid batch development of models. Summary of the invention

[0005] Purpose of the invention: Since traditional processing methods are completely dependent on the skill level of operators, the quality of parts is linked to the skill level of operators, and there is a great quality risk. Therefore, this application proposes an automated precision control method for high-precision hole systems of webs, which is of great significance for improving product quality, shortening processing cycles, and enhancing the level of automation in parts processing.

[0006] The present application provides a method for controlling the accuracy of a high-precision hole system of a web, the method comprising:

[0007] Under the part processing coordinate system, establish the theoretical precision hole processing coordinate system;

[0008] Use the measuring function of the machine tool probe to adaptively compensate the current state of the part and obtain the actual machining coordinate system of the precision hole;

[0009] Make precision holes in the actual machining coordinate system of the precision holes.

[0010] Preferably, establishing a theoretical precision hole processing coordinate system under the part processing coordinate system includes:

[0011] The inner shape of the part is known, and the web and two precision holes have been machined to the coordinate system datum.

[0012] The X-axis is established using two precision holes, one of the precision holes is set as the origin of the part, and any point on the web surface of the part is set as the XY plane of the theoretical precision hole processing coordinate system to establish the theoretical precision hole processing coordinate system.

[0013] Preferably, the method of establishing the X-axis by using two precision holes, setting one of the precision holes as the origin of the part, and setting any point on the web surface of the part as the XY plane of the theoretical precision hole machining coordinate system, after establishing the theoretical precision hole machining coordinate system, further comprises:

[0014] Verify the origin of the coordinate system. In the theoretical precision hole processing coordinate system established above, measure the coordinates (X, Y) of the center of the reference precision hole made by the upper station, and calculate the position deviation (X0, Y0) between the measured value and the theoretical value. When the deviation value is within the tolerance range, it is considered that there is no problem with the origin of the coordinate system.

[0015] Preferably, the method of using the measuring function of the machine tool probe to adaptively compensate the current state of the part to obtain the actual machining coordinate system of the precision hole includes:

[0016] The deformation value of the lower web of the part is measured, and the deformation value is automatically compensated to the theoretical precision hole processing coordinate system. The compensated theoretical precision hole processing coordinate system becomes the actual precision hole processing coordinate system.

[0017] Preferably, when the deformation value of the lower web of the measuring part is measured, the deformation value is automatically compensated to the theoretical precision hole processing coordinate system, and the compensated theoretical precision hole processing coordinate system becomes the actual precision hole processing coordinate system, including:

[0018] Select any point within φ50 of the part endpoint in the direction of maximum deformation as Z1, select any point within φ50 of the part endpoint in the direction of minimum deformation as Z2, and any point within φ50 of the part's geometric center as Z3. Use the probe to measure the Z values ​​of these three points and record them in the R variable.

[0019] Use the actual Z values ​​of the three points measured in the previous step to fit a plane, and calculate the angle between the plane and the XY plane of the theoretical precision hole machining coordinate system;

[0020] By rotating the Z axis of the theoretical precision hole machining coordinate system, the angle is compensated to the theoretical precision hole machining coordinate system, and the actual machining coordinate system of the precision hole is established.

[0021] Preferably, the step of making the precision hole in the actual precision hole processing coordinate system includes:

[0022] Center drill: use φ2.1 alloy center drill to drill the φ10H8 precision hole;

[0023] Use a φ9*60 alloy drill bit to make a φ10H8 precision hole;

[0024] Use φ9.8*80 flat bottom reamer to expand the φ10H8 precision hole;

[0025] Use a reamer on the weaving machine to make a φ10H8 precision hole, and use a φ10*60PVC machine reamer to make a φ10H8 precision hole;

[0026] Use a machine reamer to make a φ28H8 precision hole, and use a φ28*60PVC machine reamer to make a φ28H8 precision hole;

[0027] Use a machine reamer to make a φ15H8 precision hole, and use a φ15*60PVC machine reamer to make a φ15H8 precision hole.

[0028] Preferably, the method further comprises:

[0029] Taking the origin of the actual machining coordinate system of the precision hole as the starting point, the precision hole machining of each size starts from the nearest hole and proceeds from near to far.

[0030] Preferably, the method is applied to a numerical control device having a probe function.

[0031] Beneficial technical effects of this application:

[0032] The present application enables parts with precision holes that have mutual position requirements to be processed in any CNC machine tool with a probe function by automatically converting the coordinate system in an unmanned manner, thereby achieving adaptive precision compensation and reducing the impact of part web deformation on the position of the precision holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is the top view converted from the part processing coordinate system to the theoretical precision hole processing coordinate system;

[0034] Figure 2 It is a cross-sectional view of the schematic diagram of the precision hole position in the theoretical precision hole machining coordinate system;

[0035] Figure 3 It is a cross-sectional view showing the schematic diagram of the positions of the theoretical precision hole machining coordinate system and the actual precision hole machining coordinate system;

[0036] Figure 4 It is a top view of the precision hole processing of the part;

[0037] Among them: 1-part processing coordinate system, 2-precision hole theoretical processing coordinate system, 3-part, 4-probe, 5-22H8 precision hole, 6-φ16H8 precision hole, 7-reference plane, 8-φ10H8 precision hole, 9-φ10H8 precision hole, 10-φ10H8 precision hole, 11-φ28H8 precision hole, 12-φ28H8 precision hole, 13-φ15H8 precision hole, 14-φ15H8 precision hole, 15-precision hole actual processing coordinate system, 16-point Z1, 17-point Z2, 18-point Z3. DETAILED DESCRIPTION

[0038] The present invention provides a method for controlling the accuracy of a high-precision hole system of a web. As is known, the high-precision hole system is a group of precision holes of different sizes and uneven distribution to meet certain assembly or transmission requirements, and these precision holes have strict position requirements on each other. High-precision hole systems are commonly found on the webs of various large mechanical structural parts.

[0039] Through the present invention, precision hole parts with strict position requirements can be automatically processed in an unmanned manner in any CNC machine tool with a probe function, the coordinate system can be automatically converted, and automatic precision compensation can be achieved, thereby eliminating the influence of deformation on the position of the precision hole. In addition, a process scheme and cutting parameters are provided to ensure the hole diameter requirements.

[0040] In the embodiments of the present application, the present invention is composed of the following contents:

[0041] See also Figure 1-Figure 4 The present application provides a method for controlling the precision of a high-precision hole system of a web, and the method consists of three parts.

[0042] The first step is to automatically establish the theoretical accuracy hole processing coordinate system under the part processing coordinate system.

[0043] 1) The inner shape of the part is known, and the web and two precision holes have been machined. Use the two precision holes to establish the X-axis, set one of the precision holes as the origin of the part, and set any point on the web surface of the part as the XY plane of the theoretical precision hole machining coordinate system to establish the theoretical precision hole machining coordinate system;

[0044] 2) Check the origin of the coordinate system. In the theoretical precision hole processing coordinate system established above, measure the coordinates (X, Y) of the center of the reference precision hole prepared by the upper station, and calculate the position deviation (X0, Y0) between the measured value and the theoretical value. When the deviation value is within the tolerance range, it is considered that there is no problem with the origin of the coordinate system.

[0045] The second step is to use the measurement function of the machine tool probe to adaptively compensate the current state of the part to establish the actual precision hole processing coordinate system. By measuring the deformation value of the lower web of the part, the deformation value is automatically compensated to the theoretical precision hole processing coordinate system. The compensated theoretical precision hole processing coordinate system becomes the actual precision hole processing coordinate system.

[0046] 1) Select any point within φ50 of the part endpoint in the direction of maximum deformation as Z1, select any point within φ50 of the part endpoint in the direction of minimum deformation as Z2, and any point within φ50 of the part's geometric center as Z3. Use the probe to measure the Z values ​​of these three points and record them in the R variable.

[0047] 2) Use the actual Z values ​​of the three points measured in the previous step to fit a plane, and calculate the angle between the plane and the XY plane of the theoretical precision hole machining coordinate system;

[0048] 3) By rotating the Z axis of the theoretical precision hole processing coordinate system, the angle is compensated to the theoretical precision hole processing coordinate system to establish the precision hole processing coordinate system.

[0049] The third step is to make other precision holes in the actual processing coordinate system of the precision hole.

[0050] 1) Center drill: use φ2.1 alloy center drill to drill φ10H8 precision hole, the specific parameters are S=2000r / min, F=200mm / min, AP=0.5mm;

[0051] 2) Drill the initial hole of φ10H8 precision hole with φ9*60 alloy drill bit, the specific parameters are S=2000r / min, F=200mm / min, AP=3mm;

[0052] 3) Use φ9.8*80 flat bottom reamer to reamer φ10H8 precision hole, with a margin of 0.1mm, and specific parameters S=2000r / min, F=200mm / min, AP=3mm;

[0053] 4) Use a reamer on the weaving machine to make a φ10H8 precision hole, and use a φ10*60PVC machine reamer to make a φ10H8 precision hole. The specific parameters are S=6000r / min, F=200mm / min;

[0054] 5) Use a machine reamer to make a φ28H8 precision hole. Use a φ28*60PVC machine reamer to make a φ28H8 precision hole. The allowance is 0.2mm. The specific parameters are S=6000r / min, F=200mm / min;

[0055] 6) Use a machine reamer to make a φ15H8 precision hole. Use a φ15*60PVC machine reamer to make a φ15H8 precision hole with a margin of 0.1mm. The specific parameters are S=6000r / min, F=200mm / min.

[0056] It should be noted that each reaming program takes the origin of the actual machining coordinate system of the precision hole as the starting point. The precision hole machining of each size starts from the nearest hole and proceeds from near to far, avoiding repeated machining paths to produce precision holes on the belly plate, so as to reduce repeated positioning errors of the machine tool.

[0057] The present application enables parts with precision holes that have mutual position requirements to be processed in any CNC machine tool with a probe function by automatically converting the coordinate system in an unmanned manner, thereby achieving adaptive precision compensation and reducing the influence of part web deformation on the position of the precision hole. The minimum path principle is adopted in the hole making process, which reduces the repeated positioning error of the machine tool and further ensures the position accuracy of the hole. At the same time, a parameter for reaming holes on the machine is provided to ensure that the aperture size of the precision hole of the part meets the design requirements.

[0058] In other embodiments of the present application, the invention scheme is further described by taking the processing of partition parts by an automated production line composed of several CNC machine tools as an example. The CNC machine tools in the automated production line are five-axis CNC machining centers, the product entry and exit method is the automatic exchange of pallets, and the pallets are automatically positioned and clamped on the workbench using a zero-point positioning system or other similar methods; the parts are connected to the pallets through tooling or directly; and the measurement method in the machine tool is probe measurement.

[0059] The first step is to automatically establish the theoretical precision hole processing coordinate system 2 under the part processing coordinate system 1, such as Figure 1 , Figure 2 , Figure 3 and Figure 4 shown.

[0060] 1) Establish a theoretical precision hole coordinate system. Probe 4 measures the centers of 22H8 precision hole 5 and φ16H8 precision hole 6 respectively. The line connecting the two centers is set as the X-axis of the theoretical precision hole processing coordinate system 2. The direction of φ16H8 precision hole 6 pointing to 22H8 precision hole 5 is the positive direction of the X-axis. Probe 4 measures the center of 22H8 precision hole 5 and sets it as the origin of the theoretical precision hole processing coordinate system 2. Probe 4 measures the midpoint Z value of the line connecting the two centers of 22H8 precision hole 5 and φ16H8 precision hole 6 on the web of part 3 as the Z0 surface of the theoretical precision hole processing coordinate system 2.

[0061] 2) Check the origin of the coordinate system. In the theoretical precision hole processing coordinate system 2, use the probe 4 to measure the coordinates (0, 0) of the center of the φ22H8 precision hole 5 on the part 3. Calculate the position deviation (0.01, 0.005) between the measured value and the theoretical value. The deviation values ​​of X and Y are within 0.02mm. There is no problem with the origin of the theoretical precision hole processing coordinate system 2.

[0062] The second step is to adaptively compensate the theoretical precision hole machining coordinate system 2. Under the theoretical precision hole machining coordinate system 2, the part web deformation error is automatically compensated to the theoretical precision hole machining coordinate system, and the compensated theoretical precision hole machining coordinate system 2 becomes the precision hole machining coordinate system 15.

[0063] 1) The actual Z value of point Z116 measured by probe 4, which is a point within φ50 of the part endpoint in the direction of maximum part deformation; the actual Z value of point Z217 measured by probe 4, which is a point within φ50 of the part endpoint in the direction of minimum part deformation; the actual Z value of point Z318 measured by probe 4, which is a point within φ50 of the part geometric center;

[0064] 2) Using the measured Z values ​​of point Z116, point Z217, and point Z318 in step 1), a plane is fitted, and the angle θ between the plane and the XY plane in the theoretical precision hole machining coordinate system 2 is calculated;

[0065] 3) By rotating the Z axis of the theoretical precision hole processing coordinate system 2, the angle θ is compensated to the theoretical precision hole processing coordinate system 2, and the precision hole processing coordinate system 15 is established.

[0066] Among them, the following table 1 is a comparison of the precision hole position of the parts in the theoretical precision hole machining coordinate system 2 and the theoretical precision hole machining coordinate system 2:

[0067] Table 1 Effect of adaptive compensation on hole position

[0068]

[0069] The design of this partition part family requires a hole position accuracy of 0.1. When the adaptive compensation coordinate system is not used, the parts are affected by the deformation of the web, the hole position accuracy is not high, and some precision holes are out of tolerance. After using the adaptive compensation coordinate system, the hole position accuracy is significantly improved.

[0070] The third step is to make other precision holes under the actual processing coordinate system 15 of the precision hole.

[0071] 1) Center drill: Use φ2.1*30 alloy center drill to drill φ10H8 precision hole 8, φ10H8 precision hole 9, and φ10H8 precision hole 10. The specific parameters are S=2000r / min, F=200mm / min, AP=0.5mm;

[0072] 2) φ10 precision hole initial hole made by alloy drill: use φ9*60 alloy drill to make φ10H8 precision hole 8, φ10H8 precision hole 9, φ10H8 precision hole 10 initial hole, specific parameters S=2000r / min, F=200mm / min, AP=3mm;

[0073] 3) Expanding φ10H8 precision hole: call φ9.8*80 flat bottom hole expansion drill to expand φ10H8 precision hole 8, φ10H8 precision hole 9, φ10H8 precision hole 10, the allowance is 0.1mm on one side, the specific parameters are S=2000r / min, F=200mm / min, AP=3mm;

[0074] 4) Machine reamer to make φ10H8 precision hole: call φ10*60 machine PVC machine reamer to make φ10H8 precision hole 8, φ10H8 precision hole 9, φ10H8 precision hole 10, specific parameters S = 6000r / min, F = 200mm / min;

[0075] 5) Machine reamer to make φ28H8 precision hole: call φ28*60PVC machine reamer to make φ28H8 precision hole 11, φ28H8 precision hole 12, specific parameters S = 6000r / min, F = 200mm / min, single side allowance 0.2mm;

[0076] 6) The program for making φ15H8 precision holes with a machine reamer is to use a φ15*60PVC machine reamer to make φ15H8 precision holes 13 and φ15H8 precision holes 14, with a margin of 0.1mm. The specific parameters are S=6000r / min, F=200mm / min.

[0077] Among them, taking the origin 15 of the actual processing coordinate system of the precision hole as the starting point, the precision hole processing of each size starts from the nearest hole, from near to far, avoiding repeated processing paths, and making the precision holes on the web. The specific order is: 9→8→10→11→12→13→14.

Claims

1. A method for controlling the accuracy of a high-precision hole system of a web, characterized in that: The method comprises: Under the part processing coordinate system, establish the theoretical precision hole processing coordinate system; Use the measuring function of the machine tool probe to adaptively compensate the current state of the part and obtain the actual machining coordinate system of the precision hole; Make precision holes in the actual machining coordinate system of the precision holes.

2. The method according to claim 1, characterized in that The method of establishing a theoretical precision hole processing coordinate system under the part processing coordinate system includes: The inner shape of the part is known, and the web and two precision holes have been machined to the coordinate system datum. The X-axis is established using two precision holes, one of the precision holes is set as the origin of the part, and any point on the web surface of the part is set as the XY plane of the theoretical precision hole processing coordinate system to establish the theoretical precision hole processing coordinate system.

3. The method according to claim 2, characterized in that The X-axis is established by using two precision holes, one of the precision holes is set as the origin of the part, and any point on the web surface of the part is set as the XY plane of the theoretical precision hole processing coordinate system. After the theoretical precision hole processing coordinate system is established, the method further includes: Verify the origin of the coordinate system. In the theoretical precision hole processing coordinate system established above, measure the coordinates (X, Y) of the center of the reference precision hole made by the upper station, and calculate the position deviation (X0, Y0) between the measured value and the theoretical value. When the deviation value is within the tolerance range, it is considered that there is no problem with the origin of the coordinate system.

4. The method according to claim 1, characterized in that: The method of using the measuring function of the machine tool probe to adaptively compensate the current state of the part to obtain the actual machining coordinate system of the precision hole includes: The deformation value of the lower web of the part is measured, and the deformation value is automatically compensated to the theoretical precision hole processing coordinate system. The compensated theoretical precision hole processing coordinate system becomes the actual precision hole processing coordinate system.

5. The method according to claim 4, characterized in that When measuring the deformation value of the lower web of the part, the deformation value is automatically compensated to the theoretical precision hole processing coordinate system, and the compensated theoretical precision hole processing coordinate system becomes the actual precision hole processing coordinate system, including: Select any point within φ50 of the part endpoint in the direction of maximum deformation as Z1, select any point within φ50 of the part endpoint in the direction of minimum deformation as Z2, and any point within φ50 of the part's geometric center as Z3. Use the probe to measure the Z values ​​of these three points and record them in the R variable. Use the actual Z values ​​of the three points measured in the previous step to fit a plane, and calculate the angle between the plane and the XY plane of the theoretical precision hole machining coordinate system; By rotating the Z axis of the theoretical precision hole machining coordinate system, the angle is compensated to the theoretical precision hole machining coordinate system, and the actual machining coordinate system of the precision hole is established.

6. The method according to claim 1, characterized in that The method of making a precision hole in an actual precision hole processing coordinate system includes: Center drill: use φ2.1 alloy center drill to drill the φ10H8 precision hole; Use a φ9*60 alloy drill bit to make a φ10H8 precision hole; Use φ9.8*80 flat bottom reamer to expand the φ10H8 precision hole; Use a reamer on the weaving machine to make a φ10H8 precision hole, and use a φ10*60PVC machine reamer to make a φ10H8 precision hole; Use a machine reamer to make a φ28H8 precision hole, and use a φ28*60PVC machine reamer to make a φ28H8 precision hole; Use a machine reamer to make a φ15H8 precision hole, and use a φ15*60PVC machine reamer to make a φ15H8 precision hole.

7. The method according to claim 6, characterized in that The method further comprises: Taking the origin of the actual machining coordinate system of the precision hole as the starting point, the precision hole machining of each size starts from the nearest hole and proceeds from near to far.

8. The method according to claim 1, characterized in that The method is applied to a numerical control device, and the numerical control device has a probe function.

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