A method for machining large titanium alloy sidewall deep cavity structure parts

Abstract

This invention belongs to the field of aerospace manufacturing technology and discloses a method for processing large titanium alloy sidewall deep cavity structure parts. Based on the structural characteristics of the product parts and the existing equipment models and performance, this method provides a manufacturing method for processing and anti-deformation control of large-size, high-precision TC18 material titanium alloy forging inner annular deep cavity structure parts.

Description

Technical Field

[0001] This invention belongs to the field of aerospace manufacturing technology, and in particular relates to a method for processing large titanium alloy sidewall deep cavity structure parts. Background Technology

[0002] The titanium alloy turntable transition component is a key load-bearing part connecting the dome to the aircraft fuselage. It features a side-wall annular deep cavity structure and is the largest TC18 titanium alloy forging in China to date, exhibiting extremely high manufacturing precision. The machining technology for large titanium alloy side-wall deep cavity structure parts provides a processing and deformation prevention control method for manufacturing such large-sized, high-precision titanium alloy inner annular deep cavity structure parts. Summary of the Invention

[0003] The technical problem solved by this invention: This invention provides a method for processing large titanium alloy sidewall deep cavity structure parts, and provides a manufacturing method for processing and anti-deformation control of large-size, high-precision TC18 material titanium alloy forging inner annular deep cavity structure parts.

[0004] The technical solution of this invention:

[0005] A method for machining large titanium alloy sidewall deep cavity structure parts, the machining method comprising:

[0006] 1) Inspect the shape and dimensions of the parts, requiring a flatness of no more than 0.5mm;

[0007] 2) Mill the upper and lower surfaces and reference edges of the part;

[0008] 3) Roughly machine the inner and outer shapes of the parts, the inner and outer ring grooves, and the mounting surfaces of the legs, leaving a 3mm allowance;

[0009] 4) The parts have been left to stand naturally for more than 48 hours;

[0010] 5) Grind the edges of the parts to remove burrs;

[0011] 6) Measure the deformation of the part;

[0012] 7) Mill the upper and lower surfaces of the part, and mill the reference holes;

[0013] 8) Leave a 1mm allowance for the inner and outer shapes of semi-finished parts, inner and outer ring grooves, and support leg assembly surfaces;

[0014] 9) Grind the edges of the parts to remove burrs;

[0015] 10) Measure the deformation of the part;

[0016] 11) Stress-relief annealing to eliminate stress in parts;

[0017] 12) Measure the deformation of the part;

[0018] 13) Mill the upper and lower surfaces of the part, and mill the reference holes;

[0019] 14) Finish the inner and outer shapes of the parts, as well as the inner and outer annular grooves;

[0020] 15) Semi-finished support leg assembly surfaces, leave a allowance of 0.5mm;

[0021] 16) The parts should be left to stand naturally for more than 48 hours;

[0022] 17) Machining precision holes on mating surfaces and CNC boring reference holes;

[0023] 18) Finish the mating surfaces of the support legs of the parts, and create precision holes on the mating surfaces of the support legs;

[0024] 19) Fitter: Grinding the edges of parts and removing burrs;

[0025] 20) Part measurement.

[0026] Furthermore, in 7), the design principles for milling datum holes are: ① Datum coincidence principle: newly added process datums should coincide with design datums and assembly datums; ② Datum same principle: all surface machining uses the same precision datum; ③ Mutual datum principle: the method of repeatedly machining datums using mutual datums is adopted.

[0027] Furthermore, prior to 1), the method further includes:

[0028] Based on the part design model and the spindle dimensions of the machining equipment, a mathematical analysis model is established to verify the feasibility of the collision interference problem from a theoretical perspective; specifically including:

[0029] 1) Construct a 1:1 digital dynamic model of the machine tool based on the parameters of the processing equipment, and use CATIA software to perform dynamic simulation of the programmed toolpath to verify the correctness and feasibility of the machining toolpath;

[0030] 2) Construct a 1:1 digital simulation model of the machine tool based on the parameters of the processing equipment, and use VERICUT simulation software to simulate the G-code generated by the programmed tool path;

[0031] 3) Arrange for simulated parts to undergo trial processing to verify the safety and reliability of the processing equipment and processing code in the actual processing process.

[0032] Furthermore, in the method, the cutting tool is selected with a tool holder that has anti-vibration function; during processing, the principle of "separating long and short tools" is adopted. First, the shorter tool is used to process the upper part of the groove cavity, then the longer tool is used to process the middle part of the groove cavity, and finally the long tool is used to process the bottom of the groove cavity. The three types of tools use three different processing parameters to ensure the processing quality of the parts.

[0033] Furthermore, in 2) and 13), the tool specifications used for the reference surface are mandrel-type disc milling cutters, with cutter heads of Φ80 and Φ63, and inserts of R8 and R6.

[0034] Furthermore, 3) the tool specifications used for roughing and intermediate machining are: anti-vibration milling cutter bar or carbide cutter bar, with cutter head specifications of Φ32 or Φ25 indexable milling cutter head, and insert specifications of R1.8 or R0.2 inserts.

[0035] Furthermore, 3) the fast feed short cutter used for medium and rough machining has a specification of Φ32R1.8H100, a cutting depth of 1mm, a cutting width of 22mm, a cutting speed of 800~1000mm / min, a spindle speed of 650r / min, and a number of tool teeth of 5;

[0036] The rapid feed tool specification is Φ32R1.8H140, the cutting depth is 0.7mm, the cutting width is 14mm, the cutting speed is 500~800mm / min, the spindle speed is 450r / min, and the number of tool teeth is 5;

[0037] The rapid feed long cutter has a specification of Φ32R1.8H200, a cutting depth of 0.5mm, a cutting width of 6mm, a cutting speed of 200~400mm / min, a spindle speed of 320r / min, and 5 teeth.

[0038] Furthermore, in 8) and 14), the tool specifications used for semi-finishing and finishing are anti-vibration milling cutter bars or carbide cutter bars, the cutter head specifications are Φ32 and Φ25 indexable milling cutter heads, and the insert specifications are R3 inserts.

[0039] Furthermore, in 8) and 14), the square shoulder end mill used for semi-finishing and finishing is Φ25R3H100, with a cutting depth of 1mm, a cutting width of 6mm, a cutting speed of 500~700mm / min, a spindle speed of 500r / min, and 3 teeth.

[0040] The square shoulder milling cutter has a specification of Φ25R3H140, a cutting depth of 0.5mm, a cutting width of 6mm, a cutting speed of 300~300mm / min, a spindle speed of 400r / min, and a cutter tooth count of 3;

[0041] The square shoulder end mill has a specification of Φ25R3H200, a cutting depth of 0.5mm, a cutting width of 6mm, a cutting speed of 150~300mm / min, a spindle speed of 300r / min, and 3 teeth.

[0042] This invention provides a method for machining large titanium alloy sidewall deep cavity structure parts, providing a manufacturing method for machining and anti-deformation control of large-size, high-precision TC18 material titanium alloy forgings with inner annular deep cavity structure parts. Attached Figure Description

[0043] Figure 1 This is a process diagram of machining steps for a large titanium alloy sidewall deep cavity structure part;

[0044] Figure 2 This is a schematic diagram illustrating the design principles of the positioning ear piece in the manufacturing process. Detailed Implementation

[0045] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0046] This invention provides a method for machining large titanium alloy sidewall deep cavity structure parts.

[0047] 1. Solutions to spindle collision during machining of inner annular grooves: Based on the design model and spindle dimensions of the machining equipment, relevant data are extracted to establish a mathematical analysis model, and the feasibility of the "collision interference" problem is verified from a theoretical perspective; a 1:1 digital dynamic model of the machine tool is constructed based on the parameters of the machining equipment, and combined with the mathematical analysis data, the programmed toolpath is dynamically simulated using CATIA software to verify the correctness and feasibility of the machining toolpath; a 1:1 digital simulation model of the machine tool is constructed based on the parameters of the machining equipment, and the G-code generated by the programmed toolpath is simulated using VERICUT simulation software; a simulated dummy is arranged for trial machining to verify the safety and reliability of the machine tool model and machining code in the actual machining process.

[0048] 2. Measures to ensure high precision requirements of parts: For parts with high manufacturing precision requirements, a semi-finishing step is set when designing the process plan for the part. The specific plan is as follows: ① Before finishing the front side and the inner and outer cavities of the ring, leave a 1mm allowance between the inner and outer walls of the planes A and B and C on the turntable and the transition part that are in contact with the beam; ② Allow natural aging for more than 48 hours to fully release the deformation of the part; ③ Then remove the 1mm allowance to ensure the flatness and angle control requirements between the planes.

[0049] 3. Part Deformation Control Measures: The flatness of the supplied blanks must be guaranteed to be 0.5mm, and the external dimensions must be controlled within positive tolerance limits. Part machining is divided into "rough machining" and "semi-finishing" steps to fully release part deformation generated during machining. After the "rough machining" and "heat treatment" processes, additional part condition inspection requirements are added, using a coordinate measuring machine (CMM) for measurement and data recording. After organizing and analyzing the measurement data, the cutting allowance for subsequent processes is rationally arranged to minimize or even eliminate part deformation during the cutting process.

[0050] 4. Part Machining Scheme: 1) To address the issue of excessive tool overhang in the inner and outer cavities of the annular part, tool holders with anti-vibration capabilities will be prioritized. The machining process will follow the principle of "separating long and short tools," first using shorter tools for the upper part of the cavity, then longer tools for the middle part, and finally the long tool for the bottom. Three different machining parameters will be used for each tool type to ensure the part's machining quality. 2) For tools with excessive overhang, tool holders with anti-vibration capabilities will be used. Based on the part's structure, rough machining will use a Φ32 rapid feed end mill, and finish machining will use Φ32 and Φ25 square shoulder end mills. The machining process is detailed below. Figure 1 .

[0051] Specifically, this invention provides a method for machining large titanium alloy sidewall deep cavity structure parts, providing a manufacturing method for machining and preventing deformation of large-size, high-precision TC18 material titanium alloy forgings with inner annular deep cavity structure parts. The specific steps are as follows:

[0052] Step 1: Solutions to Spindle Collision During Inner Circular Groove Machining

[0053] Based on the part design model and the spindle dimensions of the machining equipment, relevant data are extracted to establish a mathematical analysis model, and the feasibility of the "collision interference" problem is verified from a theoretical perspective.

[0054] 1) Construct a 1:1 digital dynamic model of the machine tool based on the parameters of the processing equipment, and use CATIA software to perform dynamic simulation of the programmed toolpath to verify the correctness and feasibility of the machining toolpath;

[0055] 2) Construct a 1:1 digital simulation model of the machine tool based on the parameters of the processing equipment, and use VERICUT simulation software to simulate the G-code generated by the programmed tool path;

[0056] 3) Arrange for simulated parts to undergo trial processing to verify the safety and reliability of the processing equipment and processing code in the actual processing process.

[0057] Step 2: Ensuring high precision requirements for parts and measures to prevent deformation

[0058] 1) For parts with high manufacturing precision requirements, the process design for this part is divided into "rough machining - semi-finishing" steps to fully release the deformation of the part during the machining process. The specific plan is as follows: ① Before the finishing of the front and the inner and outer grooves of the ring, rough machining is performed on the assembly mating surfaces of the turntable transition part (part), leaving a 1mm allowance; ② Natural aging is performed for more than 48 hours to fully release the deformation of the part; ③ The 1mm allowance is then removed to ensure the flatness and angle control requirements between planes.

[0059] 2) After the "rough machining" and "heat treatment" processes, additional part condition inspection requirements are added, using a coordinate measuring machine for measurement and data recording. After organizing and analyzing the measurement data, the cutting allowance for subsequent processes is rationally arranged to minimize or even eliminate part deformation during the cutting process.

[0060] 3) Design principles for positioning lugs in process machining: ① Principle of datum coincidence. Newly added process datums should coincide with design datums and assembly datums to avoid introducing new positioning errors due to datum misalignment; ② Principle of identical datums. All surface machining uses the same precision datum; ③ Principle of mutual datums. To obtain higher positional accuracy, a method of repeatedly machining datums using mutual datums is adopted.

[0061] Step 3: Selection of Machining Tools

[0062] 1) To address the issue of excessive tool overhang in the inner and outer cavities of machined parts, tool holders with anti-vibration functions should be prioritized. During machining, a "long and short tool separation" principle is adopted: first, a shorter tool is used to machine the upper part of the cavity; second, a longer tool is used to machine the middle part; and finally, a long tool is used to machine the bottom of the cavity. Three different machining parameters are used for each type of tool to ensure the machining quality of the parts.

[0063] 2) For tools with longer overhangs, use tool holders with anti-vibration function. The specific tool types for machining the parts are shown in the table below, depending on the part structure.

[0064]

[0065] Step 4: Selecting Processing Parameters

[0066]

[0067]

[0068] Step 5: The final processing flow chart is shown below. Figure 1 .

[0069] 1) Raw inspection: Inspect the shape and dimensions of the parts, and require that the flatness of the raw blank is no more than 0.5mm;

[0070] 2) CNC milling: Milling the upper and lower surfaces and reference edges of the blank;

[0071] 3) CNC milling: rough machining of the inner and outer shapes of the parts, the inner and outer ring grooves, and the mounting surfaces of the legs, leaving a 3mm allowance;

[0072] 4) Natural aging: The parts are left to stand naturally for more than 48 hours;

[0073] 5) Fitter: Grinding the edges of parts and removing burrs;

[0074] 6) Deformation Measurement: Measuring the amount of deformation of parts.

[0075] 7) CNC milling: Milling the upper and lower surfaces of the part, and milling the reference holes;

[0076] 8) CNC milling: Semi-finish machining of the inner and outer shapes of the parts, the inner and outer ring grooves, and the mounting surfaces of the legs, leaving a 1mm allowance;

[0077] 9) Fitter: Grinding the edges of parts and removing burrs;

[0078] 10) Deformation Measurement: Measure the amount of deformation of a part;

[0079] 11) Heat treatment: stress-relieving annealing to eliminate stress in parts.

[0080] 12) Deformation measurement: Measuring the amount of deformation of a part;

[0081] 13) CNC milling: Milling the upper and lower surfaces of the part, and milling the reference holes;

[0082] 14) CNC milling: finish machining of the inner and outer shapes of parts, and inner and outer annular grooves.

[0083] 15) CNC milling: Semi-finish machining of the support leg assembly surface, leaving a allowance of 0.5mm;

[0084] 16) Natural aging: The parts are left to stand naturally for more than 48 hours;

[0085] 17) CNC milling: machining precision holes on mating surfaces, CNC boring of reference holes.

[0086] 18) CNC milling: finish machining the mating surfaces of the support legs of the parts, and making precision holes on the mating surfaces of the support legs;

[0087] 19) Fitter: Grinding the edges of parts and removing burrs;

[0088] 20) Part measurement.

[0089] 7) Design principles for milling datum holes: ① Datum coincidence principle: newly added process datums should coincide with design datums and assembly datums; ② Datum same principle: all surface machining uses the same precision datum; ③ Mutual datum principle: the method of repeatedly machining datums using mutual datums is adopted.

[0090] Before performing the aforementioned step, the method further includes:

[0091] Based on the part design model and the spindle dimensions of the machining equipment, a mathematical analysis model is established to verify the feasibility of the "collision interference" problem from a theoretical perspective; specifically including:

[0092] 1) Construct a 1:1 digital dynamic model of the machine tool based on the parameters of the processing equipment, and use CATIA software to perform dynamic simulation of the programmed toolpath to verify the correctness and feasibility of the machining toolpath;

[0093] 2) Construct a 1:1 digital simulation model of the machine tool based on the parameters of the processing equipment, and use VERICUT simulation software to simulate the G-code generated by the programmed tool path;

[0094] 3) Arrange for simulated parts to undergo trial processing to verify the safety and reliability of the processing equipment and processing code in the actual processing process.

[0095] In the aforementioned process, a tool holder with anti-vibration function is selected as the cutting tool; during machining, the principle of "separating long and short tools" is adopted. First, the shorter tool is used to machine the upper part of the groove cavity, then the longer tool is used to machine the middle part of the groove cavity, and finally the long tool is used to machine the bottom of the groove cavity. The three types of tools use three different machining parameters to ensure the machining quality of the parts.

[0096] 2) The tool specifications used for the reference surface in 13) are as follows: the first row in the table above;

[0097] 3) The specifications of the tools used for roughing are as follows: the second row in the table above, from bottom to top, consists of short tools, medium-length tools, and long tools;

[0098] 3) The tool parameters used for roughing and intermediate machining are shown in the first three rows of the table below;

[0099] 8)14) The tool specifications used for semi-finishing and finishing are shown in the third row of the table above;

[0100] 8)14) The tool parameters used for semi-finishing and finishing are shown in rows four to six of the table below;

[0101] 17) 18) The hole-making parameters are shown in the last two rows of the table below;

[0102] The machining parameters for the cutting tool are shown in the table below:

[0103]

[0104]

[0105] This invention provides a method for machining large titanium alloy sidewall deep cavity structure parts. Based on the structural characteristics of the product parts and the existing equipment models and performance, this method provides a manufacturing approach for machining and preventing deformation of large-size, high-precision TC18 titanium alloy forgings with inner annular deep cavity structures.

Claims

1. A method for machining large titanium alloy sidewall deep cavity structure parts, characterized in that, The processing method includes: 1) Inspect the shape and dimensions of the parts, requiring a flatness of no more than 0.5mm; 2) Mill the upper and lower surfaces and reference edges of the part; 3) Roughly machine the inner and outer shapes of the parts, the inner and outer ring grooves, and the mounting surfaces of the legs, leaving a 3mm allowance; 4) The parts have been left to stand naturally for more than 48 hours; 5) Grind the edges of the parts to remove burrs; 6) Measure the deformation of the part; 7) Mill the upper and lower surfaces of the part, and mill the reference holes; 8) Leave a 1mm allowance for the inner and outer shapes of semi-finished parts, inner and outer ring grooves, and support leg assembly surfaces; 9) Grind the edges of the parts to remove burrs; 10) Measure the deformation of the part; 11) Stress-relief annealing to eliminate stress in parts; 12) Measure the deformation of the part; 13) Mill the upper and lower surfaces of the part, and mill the reference holes; 14) Finish the inner and outer shapes of the parts, as well as the inner and outer annular grooves; 15) Semi-finished support leg assembly surfaces, leave a allowance of 0.5mm; 16) The parts should be left to stand naturally for more than 48 hours; 17) Machining precision holes on mating surfaces and CNC boring reference holes; 18) Finish the mating surfaces of the support legs of the parts, and create precision holes on the mating surfaces of the support legs; 19) Fitter: Grinding the edges of parts and removing burrs; 20) Part measurement.

2. The method for machining a large titanium alloy sidewall deep cavity structure part according to claim 1, characterized in that, 7) Design principles for milling reference holes: ① The principle of reference coincidence: newly added process references should coincide with design references and assembly references; ② The principle of using the same datum: all surface processing uses the same precision datum; ③ The principle of mutual reference is to use each other as a reference and repeatedly process the reference.

3. The method for machining a large titanium alloy sidewall deep cavity structure part according to claim 1, characterized in that, Prior to 1), the method further includes: Based on the part design model and the spindle dimensions of the machining equipment, a mathematical analysis model is established to verify the feasibility of the collision interference problem from a theoretical perspective; specifically including: 1) Construct a 1:1 digital dynamic model of the machine tool based on the parameters of the processing equipment, and use CATIA software to perform dynamic simulation of the programmed toolpath to verify the correctness and feasibility of the machining toolpath; 2) Construct a 1:1 digital simulation model of the machine tool based on the parameters of the processing equipment, and use VERICUT simulation software to simulate the G-code generated by the programmed tool path; 3) Arrange for simulated parts to undergo trial processing to verify the safety and reliability of the processing equipment and processing code in the actual processing process.

4. The method for machining a large titanium alloy sidewall deep cavity structure part according to claim 1, characterized in that, In the method described above, a tool holder with anti-vibration function is selected as the cutting tool. During machining, a principle of separating long and short tools is adopted. First, the shorter tool is used to machine the upper part of the groove cavity, then the longer tool is used to machine the middle part of the groove cavity, and finally the long tool is used to machine the bottom of the groove cavity. Three machining parameters are used for the three types of tools to ensure the machining quality of the parts.

5. The method for machining a large titanium alloy sidewall deep cavity structure part according to claim 1, characterized in that, The cutting tools used for the reference surfaces in 2) and 13) are mandrel-type disc milling cutters with Φ80 and Φ63 cutter heads and R8 and R6 inserts.

6. The method for machining a large titanium alloy sidewall deep cavity structure part according to claim 1, characterized in that, 3) The tool specifications used for medium and rough machining are: anti-vibration milling cutter bar or carbide cutter bar, with cutter head specifications of Φ32 or Φ25 indexable milling cutter head, and insert specifications of R1.8 or R0.2 inserts.

7. The method for machining a large titanium alloy sidewall deep cavity structure part according to claim 1, characterized in that, 3) The fast feed short cutter used for medium and rough machining has a specification of Φ32R1.8H100, a cutting depth of 1mm, a cutting width of 22mm, a cutting speed of 800~1000mm / min, a spindle speed of 650r / min, and a cutter tooth count of 5; The rapid feed tool specification is Φ32R1.8H140, the cutting depth is 0.7mm, the cutting width is 14mm, the cutting speed is 500~800mm / min, the spindle speed is 450r / min, and the number of tool teeth is 5; The rapid feed long cutter has a specification of Φ32R1.8H200, a cutting depth of 0.5mm, a cutting width of 6mm, a cutting speed of 200~400mm / min, a spindle speed of 320r / min, and 5 teeth.

8. A method for machining large titanium alloy sidewall deep cavity structure parts according to claim 1, characterized in that, In 8) and 14), the tool specifications used for semi-finishing and finishing are anti-vibration milling cutter bars or carbide cutter bars, the cutter head specifications are Φ32 and Φ25 indexable milling cutter heads, and the insert specifications are R3 inserts.

9. A method for machining large titanium alloy sidewall deep cavity structure parts according to claim 1, characterized in that, In 8) and 14), the square shoulder end mill used for semi-finishing and finishing is Φ25R3H100, with a cutting depth of 1mm, a cutting width of 6mm, a cutting speed of 500~700mm / min, a spindle speed of 500r / min, and 3 teeth. The square shoulder milling cutter has a specification of Φ25R3H140, a cutting depth of 0.5mm, a cutting width of 6mm, a cutting speed of 300~300mm / min, a spindle speed of 400r / min, and 3 teeth. The square shoulder end mill has a specification of Φ25R3H200, a cutting depth of 0.5mm, a cutting width of 6mm, a cutting speed of 150~300mm / min, a spindle speed of 300r / min, and 3 teeth.

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