A milling clamping device for thin-walled structural parts and a control method for machining deformation

Abstract

The present invention belongs to the field of mechanical processing technology, and discloses a milling clamping device for thin-walled structural parts and a control method for processing deformation, comprising: a first support block 1, a second support block 2, a base plate 3, a profiling positioning block 4, a rhombus pin 5, a cylindrical pin 6, a sliding support plate 7, a side pull screw 8, a fastening screw 9, a clamping pressure plate 10, a locking nut 11, and a fixed stud bolt 12; the first support block 1 and the second support block 2 are fixed on a workbench by universal bolts and T-nuts; the two ends of the base plate 3 are respectively fixed on the first support block 1 and the second support block 2, and the end of the base plate 3 is provided with a double T-guide groove, the profiling positioning block 4 is fixed on the base plate 3 by the rhombus pin 5 and the positioning pin 6, and is locked by the fastening screw 9, so as to solve the problems of unreliable clamping and clamping deformation of such thin-walled structural parts in current processing.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing, and in particular relates to a milling clamping device for thin-walled structural parts and a method for controlling processing deformation. Background Art

[0002] With the rapid development of my country's aviation industry, especially in the key manufacturing technology of advanced aircraft engines, the requirements for reducing engine weight, improving engine kinetic energy, and ensuring engine safety and reliability are becoming higher and higher. Thin-walled parts have been increasingly widely used in various industrial sectors due to their light weight and compact structure, but the processing of thin-walled parts is more difficult. The reason is that thin-walled parts have poor rigidity and weak strength, and are very easy to deform during processing, making it difficult to ensure the processing quality of parts. Small aircraft engine thin-walled long suspension is a type of thin-walled part, which is very easy to deform during processing and cause dimensional deviation.

[0003] This type of thin-walled structural parts has serious deformation at the rear end during processing, and the clamping is not secure, which leads to severe vibration during processing, large deformation, and irregular deviation of parts. The scrap rate of parts processing is high. The traditional viscose fixing method also has the problem of uncertain deformation, but it is relatively small, but it will also cause quality fluctuations in parts, and the viscose removal process takes a long time and has low processing efficiency. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a milling clamping device for thin-walled structural parts and a method for controlling machining deformation, so as to solve the problems of unreliable clamping and clamping deformation of such thin-walled structural parts during machining.

[0005] The technical solution of the present invention:

[0006] Technical solution 1:

[0007] A milling clamping device for thin-walled structural parts, the device comprising: a first support block 1, a second support block 2, a base plate 3, a contoured positioning block 4, a rhombus pin 5, a cylindrical pin 6, a sliding support plate 7, a side pull screw 8, a fastening screw 9, a clamping plate 10, a locking nut 11, and a fixing stud bolt 12;

[0008] The first support block 1 and the second support block 2 are fixed on the workbench by universal bolts and T-nuts; the two ends of the bottom plate 3 are respectively fixed on the first support block 1 and the second support block 2, and the end of the bottom plate 3 is provided with a double T-shaped guide groove, and the contour positioning block 4 is fixed on the bottom plate 3 by a diamond pin 5 and a positioning pin 6, and is locked by a fastening screw 9;

[0009] The sliding support plate 7 has a T-shaped guide rail that matches the double T-shaped guide rail groove of the bottom plate 3; wherein the sliding support plate 7 can freely slide a short distance at the end of the bottom plate 3;

[0010] The T-shaped guide rail of the sliding support plate 7 is in flat sliding cooperation with the bottom plate 3 and is locked with a locking bolt 14 .

[0011] The characteristics and further improvements of the technical solution 1 of the present invention are:

[0012] (1) The contour positioning block 4 is matched according to the shape of the part.

[0013] (2) The T-shaped guide rail of the sliding support plate 7 is a rectangular T-shaped guide rail, and the connecting surface of the T-shaped guide rail is a square positioning surface, and is in flat sliding cooperation with the bottom plate 3.

[0014] Technical solution 2:

[0015] A method for controlling machining deformation of thin-walled structural parts is implemented by using the milling clamping device described in the first technical solution, and the method comprises:

[0016] Step 1: Roughly process the various surface dimensions of thin-walled structural parts, and reserve 1mm margin for positioning planes and positioning holes;

[0017] Step 2: Finish the positioning plane of the thin-walled structural part. The flatness of the front positioning plane is guaranteed to be within 0.02mm, and the overall height difference between the rear positioning plane and the front positioning plane is less than 0.1mm;

[0018] Step 3: Finishing the positioning reference holes of thin-walled structural parts;

[0019] Step 4: Finishing the threaded holes of thin-walled structural parts;

[0020] Step 5, placing the thin-walled structural component in the thin-walled structural component milling clamping device for rough positioning;

[0021] Step 6: Remove the thin-walled structural part, use the on-site CMM to measure the four lateral positioning holes of the thin-walled structural part in a free state, and record the marked measurement data and the spatial offset direction of the hole position;

[0022] Step 7: input the measurement data with the spatial offset direction into the user parameters of the CNC control system according to the direction; re-place the thin-walled structural part into the thin-walled structural part milling clamping device, and re-install it with the lever dial indicator;

[0023] Step 8. Perform mathematical fitting on the spatial offset data of the four high-precision locating holes on the side in the free state measured by CMM, the design theoretical data of the four high-precision locating holes on the side of the thin-walled structural parts, and the actual data of the four high-precision locating holes on the side of the machine in the clamped state of the thin-walled structural parts, and transfer the actual data after fitting to the high-precision five-axis CNC control drive system to drive the mechanical coordinate axis to complete the precision boring process;

[0024] Step 9. In this state, the hole system and threaded hole system in the lateral thin-walled rib plate are processed based on the 4 high-precision positioning holes on the side of the thin-walled structural part.

[0025] The characteristics and further improvements of the second technical solution of the present invention are:

[0026] (1) In step 3, when the thin-walled structural part is a thin-walled long suspension, the four φ15 mm positioning holes are completed by spiral milling to remove the excess and fine boring, ensuring that their position accuracy is within 0.03 mm and that the flatness of the 4.5 mm thick positioning plane is less than 0.02 mm.

[0027] (2) In step 4, when the thin-walled structural part is a thin-walled long suspension, the 4 M5 threaded bottom holes suspended under the 2.5mm to 3mm thin-walled rib plate and the 4 M6 threaded bottom holes on the side of the rear end face are drilled to remove the excess, and the threaded bottom holes are bored to the tolerance with a fine boring tool to complete the threaded bottom hole processing and then the thread tapping is performed.

[0028] (3) In step five, when the thin-walled structural part is a thin-walled long hanging part, the front end positioning surface is close to the fixture positioning surface, and the positioning gap is less than 0.02 mm; the rear end is fixed by lateral tightening of the sliding support plate, and the deformation of the part is observed with a lever dial indicator, and the dial reading is controlled at 0.03 mm.

[0029] (4) In step eight, the spatial offset data of the four high-precision positioning holes in the lateral direction measured by the CMM in the free state, the design theoretical data of the four high-precision positioning holes in the lateral direction of the thin-walled structural part, and the actual data of the four high-precision positioning holes in the lateral direction of the thin-walled structural part in the clamped state are mathematically fitted, specifically:

[0030] Xsimulation = Xmachine - Xc + Xprinciple

[0031] Ysimulation=Ymachine-Yc+Yprinciple

[0032] Among them, X-machine and Y-machine represent the data measured by CMM, Xc and Yc represent the actual measured data of thin-walled structural parts in the clamping state, and Xtheory and Ytheory represent the theoretical data of thin-walled structural parts.

[0033] The embodiment of the present invention provides a control method for the processing deformation of a thin-walled long suspension of a small aircraft engine, which adopts a rough positioning method of lateral tensioning through rough positioning by profiling and adding a sliding auxiliary reinforcing support plate. And by developing an online deformation measurement method and a reverse automatic compensation method, the deformation of thin-walled long suspension parts is eliminated, so that the processing state is closer to the theoretical state, and the processing accuracy and processing efficiency are improved. During the processing, the method of the present invention changes direction to eliminate the processing size fluctuation caused by inconsistent deformation of parts, and ensures that the processing state is close to the theoretical state specified in the part design. Thereby ensuring the qualified rate of parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of the use state of the milling clamping device for thin-walled structural parts provided by an embodiment of the present invention;

[0035] Figure 2 A three-dimensional schematic diagram of a milling clamping device for thin-walled structural parts provided by an embodiment of the present invention;

[0036] In the figure, 1-support block, 2-support block, 3-base plate, 4-contact positioning block, 5-diamond pin, 6-cylindrical pin, 7-sliding support plate, 8-side pull screw, 9-fastening screw, 10-clamping pressure plate, 11-locking nut, 12-fixing stud bolt, 14-sliding support plate fixing bolt. DETAILED DESCRIPTION

[0037] The milling clamping device for thin-walled structural parts of the present invention will be described below in conjunction with specific embodiments.

[0038] like Figure 1 As shown, the thin-walled structural part milling clamping device includes a first support block 1, a second support block 2, a base plate 3, a contoured positioning block 4, a diamond pin 5, a cylindrical pin 6, a sliding support plate 7, a side pull screw 8, a fastening screw 9, a clamping pressure plate 10, a locking nut 11, a fixing stud bolt 12, and a sliding support plate fixing bolt 14.

[0039] The first support block 1 is a 60*60 square, and the second support block 2 is a 60*140 rectangular, which are fixed on the workbench by universal bolts and T-nuts; the end of the bottom plate 3 is provided with a double T-shaped guide groove, and the contour positioning block 4 is replaced according to the shape of the positioning surface of the part, fixed to the bottom plate 3 by the diamond pin 5 and the positioning pin 6, and locked by the fastening screw 9. The sliding support plate 7 is provided with a T-shaped guide rail matching the double T-shaped guide groove of the bottom plate 3; wherein the sliding support plate 7 can slide freely for a short distance at the end of the bottom plate 3;

[0040] The sliding support plate 7 is a rectangular T-shaped guide rail, and the square positioning surface of the T-shaped guide rail connecting surface is in sliding cooperation with the plane of the bottom plate 3 and is locked with the sliding support plate locking bolt 14 .

[0041] The first support block 1, the second support block 2, and the bottom plate 3 are pressed against the workbench by bolts and corresponding T-nuts.

[0042] Select the contour positioning block 4 according to the shape and size of the positioning surface of the part 13. Use the diamond pin 5 and the cylindrical pin 6 to position on the bottom plate 3 and lock it with the fastening screw 9.

[0043] The part 13 is placed flat in the profiling positioning block 4, and the diamond pin 5 and the cylindrical pin 6 are used for rough positioning, so as to ensure that the gap between the positioning surface of the part 13 and the contact plane of the profiling positioning block 4 is not greater than 0.02 mm. The clamping plate 10 is compressed with the locking nut 11 to fix the part.

[0044] Slide the sliding support plate 7 according to the length of the part 13, so that it is close to the rear end surface of the part 13, and hold it with your hand to keep the position unchanged, and lock the sliding support plate fixing bolts 14 to fix the position of the sliding support plate 7.

[0045] After the sliding support plate 7 is fixed, the part 13 is fastened to the sliding support plate 7 by using the side pull screws 8 .

[0046] The contour positioning block can be quickly replaced according to the positioning surface shape of the processed part, fixed in place with two positioning pins and locked with two fastening screws. The sliding support plate can be adjusted according to the length or size tolerance of the part, so that the support plate fits tightly with the side of the part. This increases the rigidity of thin-walled structural parts and ensures accurate and reliable positioning of parts. This device can be quickly adjusted and installed according to slight changes in the shape or length of the part, which is simple and convenient. It also increases the overall rigidity of thin-walled parts and ensures the processing accuracy of parts.

[0047] The present invention uses the above structure to quickly clamp thin-walled structural parts, ensuring that the parts remain in the correct position during processing, and at the same time, increasing the rigidity of the thin-walled structural parts to avoid irregular deformation during the processing of the parts and causing the parts to be scrapped. At the same time, the rapid replacement structure can also ensure that it has a universal type of similar parts, reducing the design and manufacturing costs of the fixture.

[0048] Example

[0049] The embodiment of the present invention also provides a method for controlling the processing deformation of a thin-walled long suspension of a small aircraft engine. The method for controlling the processing deformation of a thin-walled long suspension of a small aircraft engine adopts a rough positioning method of lateral tensioning by rough positioning through profiling and adding a slidable auxiliary reinforcement support plate. The deformation of thin-walled long suspension parts is eliminated by developing an online deformation measurement method and a reverse automatic compensation method, so that the processing state is closer to the theoretical state.

[0050] The specific steps of the control method for processing deformation of thin-walled long suspension of small aircraft engines are as follows:

[0051] Step 1: Roughly process the various surface dimensions of thin-walled long hanging parts. The rough machine and inspection dimensions are directly processed to the design drawing requirements at one time, and a 1mm margin is reserved for the positioning plane and positioning hole;

[0052] Step 2: Finely process the thin-walled long hanging positioning plane. The flatness of the front positioning plane is guaranteed to be within 0.02mm, and the overall height difference between the rear positioning plane and the front positioning plane is less than 0.1mm;

[0053] Step 3: Finish the thin-walled long hanging positioning reference holes. Among them, the 4 φ15 positioning holes are completed by spiral milling to remove the excess and fine boring, ensuring that their position accuracy is within 0.03mm, and at the same time ensuring that the flatness of the 4.5mm thick positioning plane is less than 0.02mm;

[0054] Step 4: Finish the thin-walled long hanging threaded holes. Among them, the 4 M5 threaded bottom holes suspended under the 2.5-3mm thin-walled ribs and the 4 M6 threaded bottom holes on the side of the rear end face are drilled to remove the excess, and the threaded bottom holes are bored to the tolerance with a fine boring tool to complete the threaded bottom hole processing and then the thread tapping is performed;

[0055] Step 5. Place the thin-walled long suspension in a specially designed profiling fixture for rough positioning. The front end positioning surface is close to the fixture positioning surface, and the positioning gap is less than 0.02mm. The rear end is fixed by lateral tightening with a sliding auxiliary support plate, and the deformation of the part is observed with a lever dial indicator, and the dial reading is controlled at 0.03mm. Use the drilling-milling-finishing boring sequence to rough-machine 4 high-precision positioning holes on both sides and the internal threaded bottom hole;

[0056] Step 6: Remove the thin-walled long hanging, use the on-site CMM to measure the four lateral positioning holes of the thin-walled long hanging in a free state, and record the marked measurement data and the spatial offset direction of the hole positions;

[0057] Step 7: Input the measurement data with the spatial offset direction into the user parameters of the CNC control system according to the direction. Re-place the thin-walled long suspension into the profiling fixture and re-install it with the lever dial indicator;

[0058] Step 8. Use the human-machine interaction mode of the high-precision five-axis CNC control system to develop user cycle commands for automatic measurement and automatic compensation. Perform mathematical fitting on the spatial offset data of the four high-precision locating holes on the side in the free state measured by the CMM, the theoretical design data of the four high-precision locating holes on the side of the thin-walled long hanging, and the actual data of the four high-precision locating holes on the side of the machine in the thin-walled long hanging clamping state. Automatically transfer the actual data after fitting to the high-precision five-axis CNC control drive system to drive the mechanical coordinate axis to complete the precision boring process;

[0059] Mathematical fitting calculation formula: Xsimulated = Xmachine-Xc+Xmechanical (with direction)

[0060] Ysimulation = Ymachine-Yc+Yprinciple (with direction)

[0061] Step 9: In this state, the hole system and threaded hole system in the lateral thin-walled rib plate are processed based on the 4 high-precision positioning holes on the side of the thin-walled long suspension. Among them, the M5 threaded hole system is processed by a drill-thread milling cutter.

[0062] In step five, the thin-walled long suspension is placed in a specially designed profiling fixture for rough positioning. The front end positioning surface is close to the fixture positioning surface, and the positioning gap is less than 0.02mm. The rear end is fixed by lateral tightening of the sliding auxiliary support plate, and the deformation of the part is observed with a lever dial indicator, and the dial reading is controlled at 0.03mm. The four high-precision positioning holes and the internal thread bottom hole on both sides are roughly processed in the sequence of drilling-milling-fine boring.

[0063] In the step eight, the human-computer interaction mode of the high-precision five-axis CNC control system is used to develop user cycle commands for automatic measurement and automatic compensation. The spatial offset data of the four high-precision positioning holes on the side in the free state measured by the CMM, the theoretical design data of the four high-precision positioning holes on the side of the thin-walled long hanging, and the actual data of the four high-precision positioning holes on the side of the machine in the thin-walled long hanging clamping state are mathematically fitted. The actual data after fitting is automatically transferred to the high-precision five-axis CNC control drive system to drive the mechanical coordinate axis to complete the precision boring process;

[0064] The present invention can achieve the purpose of processing thin-walled long suspensions by arranging a reasonable process route, selecting suitable processing equipment and reasonable processing parameters, and designing and manufacturing special clamps; during the processing, the principle of unification of the positioning datum and the design datum is guaranteed, and a lateral tightening mechanism with a slidable auxiliary support is added to ensure the stability of the clamping of the rear end of the thin-walled long suspension suspended in the air, increase the overall rigidity of the thin-walled long suspension, effectively avoid the cumulative error caused by inconsistent datums, and reduce the processing deformation. At the same time, automatic measurement and automatic compensation user cycle functions are developed to eliminate the deformation of the thin-walled long suspension, so that the processing state approaches the theoretical state. Through the processing method of the present invention, the qualified rate of parts of the thin-walled long suspension of small aircraft engines reaches 100%, and the processing efficiency is increased by 4 times. It is universal and instructive for the processing of thin-walled high-precision space hole system parts.

Claims

1. A method for controlling the machining deformation of thin-walled structural parts, which is implemented by a thin-walled structural part milling clamping device, characterized in that: The thin-walled structural component milling clamping device comprises: a first support block (1), a second support block (2), a base plate (3), a contoured positioning block (4), a rhombus pin (5), a cylindrical pin (6), a sliding support plate (7), a side pull screw (8), a fastening screw (9), a clamping plate (10), a locking nut (11), and a fixing stud bolt (12); The first support block (1) and the second support block (2) are fixed on the workbench by universal bolts and T-nuts; the two ends of the base plate (3) are respectively fixed on the first support block (1) and the second support block (2); the end of the base plate (3) is provided with a double T-guide groove; the contour positioning block (4) is fixed on the base plate (3) by a diamond pin (5) and a cylindrical pin (6), and is locked by a fastening screw (9); The sliding support plate (7) has a T-shaped guide rail that matches the double T-shaped guide rail groove of the bottom plate (3); wherein the sliding support plate (7) can freely slide a short distance at the end of the bottom plate (3); The T-shaped guide rail of the sliding support plate (7) is in flat sliding cooperation with the bottom plate (3) and is locked with a locking bolt (14); the contoured positioning block (4) is matched according to the shape of the parts; the T-shaped guide rail of the sliding support plate (7) is a rectangular T-shaped guide rail, the connecting surface of the T-shaped guide rail is a square positioning surface, and is in flat sliding cooperation with the bottom plate (3); The control method comprises: Step 1: Roughly process the various surface dimensions of thin-walled structural parts, and reserve 1mm margin for positioning planes and positioning holes; Step 2: Finish the positioning plane of the thin-walled structural part. The flatness of the front positioning plane is guaranteed to be within 0.02mm, and the overall height difference between the rear positioning plane and the front positioning plane is less than 0.1mm; Step 3: Finishing the positioning reference holes of thin-walled structural parts; Step 4: Finishing the threaded holes of thin-walled structural parts; Step 5, placing the thin-walled structural component in the thin-walled structural component milling clamping device for rough positioning; Step 6: Remove the thin-walled structural part, use the on-site CMM to measure the four lateral positioning holes of the thin-walled structural part in a free state, and record the marked measurement data and the spatial offset direction of the hole positions; Step 7: input the measurement data with the spatial offset direction into the user parameters of the CNC control system according to the direction; re-place the thin-walled structural part into the thin-walled structural part milling clamping device, and re-install it with the lever dial indicator; Step 8. Perform mathematical fitting on the spatial offset data of the four high-precision locating holes on the side in the free state measured by CMM, the design theoretical data of the four high-precision locating holes on the side of the thin-walled structural parts, and the actual data of the four high-precision locating holes on the side of the machine in the clamped state of the thin-walled structural parts, and transfer the actual data after fitting to the high-precision five-axis CNC control drive system to drive the mechanical coordinate axis to complete the precision boring process; Step 9. In this state, the hole system and threaded hole system in the lateral thin-walled rib plate are processed based on the 4 high-precision positioning holes on the side of the thin-walled structural part.

2. A method for controlling machining deformation of thin-walled structural parts according to claim 1, characterized in that: In step three, when the thin-walled structural part is a thin-walled long suspension, the four φ15mm positioning holes are completed by spiral milling to remove the excess and fine boring, ensuring that their position accuracy is within 0.03mm and that the flatness of the 4.5mm thick positioning plane is less than 0.02mm.

3. The method for controlling machining deformation of thin-walled structural parts according to claim 1, characterized in that: In step 4, when the thin-walled structural part is a thin-walled long suspension, 4 M5 threaded bottom holes suspended under the 2.5mm~3mm thin-walled rib and 4 M6 threaded bottom holes on the side of the rear end face are drilled to remove the excess, and the threaded bottom holes are bored to the tolerance with a fine boring tool to complete the threaded bottom hole processing and then thread tapping is performed.

4. The method for controlling machining deformation of thin-walled structural parts according to claim 1, characterized in that: In step five, when the thin-walled structural part is a thin-walled long hanging part, the front end positioning surface is close to the fixture positioning surface, and the positioning gap is less than 0.02mm; the rear end is fixed by lateral tightening of the sliding support plate, and the deformation of the part is observed with a lever dial indicator, and the dial reading is controlled at 0.03mm.

5. The method for controlling machining deformation of thin-walled structural parts according to claim 1, characterized in that: In step eight, the spatial offset data of the four high-precision locating holes in the free state measured by the CMM, the design theoretical data of the four high-precision locating holes in the lateral direction of the thin-walled structural part, and the actual data of the four high-precision locating holes in the lateral direction of the machine in the clamped state of the thin-walled structural part are mathematically fitted, specifically: Xsimulation = Xmachine - Xc + Xprinciple Ysimulated = Ymachine - Yc + Yprincipal Among them, X-machine and Y-machine represent the data measured by CMM, Xc and Yc represent the data actually measured under the clamping state of thin-walled structural parts, and Xtheory and Ytheory represent the theoretical data of thin-walled structural parts.

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