Precision machining tooling and machining method for two-part thin-walled cylindrical complex components

Abstract

The present invention relates to a precision machining tool and machining method for a two-part, thin-walled, cylindrical complex component, comprising: 1. rough machining, including machining the outer arc portion of the two-part component, the B end face perpendicular to its axial direction and the bottom face parallel to the B end face, the C surface of the two-part component in contact with each other, the inner cavity notch, and each circular surface of the inner cavity, wherein a first auxiliary device is used to clamp and secure the component during machining of each circular surface of the inner cavity; 2. stress relief annealing to heat treat the component; 3. semi-finishing machining, including machining the B end face perpendicular to its axial direction and the bottom face parallel to the B end face, the C surface of the two-part component in contact with each other, and each circular surface of the inner cavity, wherein a first auxiliary device is used to clamp and secure the component during machining of each circular surface of the inner cavity; 4. stress relief annealing and high-low temperature stabilization treatment to heat treat the component; 5. finishing machining, including grinding the C surface of the two-part component using a grinding plate and securing the component using a second auxiliary device. The present invention improves machining efficiency and machining accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of component processing, and in particular relates to a two-part thin-walled cylindrical complex component precision processing tool and a processing method. Background Art

[0002] When installing a high-precision gyroscope on the equipment, a two-part thin-walled cylindrical complex component is used. The component is made by combining two structural parts. Figure 1 As shown in the figure, the inner hole accuracy requirements of the two components are consistent and the hole accuracy is very high. It is required that the inner hole accuracy remains unchanged after the two components are disassembled and reassembled.

[0003] The traditional processing method of this component is to complete it by processing separately and then combining them. The process flow is: A1 rough processing - B1 heat treatment - A2 semi-finishing processing - B2 heat treatment - A3 semi-finishing processing - B3 heat treatment - A4 finishing processing

[0004] Traditionally, the process involves four rounds of machining, with heat treatment performed between each round to relieve stress. This four-step process of stock removal is primarily due to the thin-walled structure and incomplete internal cavity of this component, which generates significant machining stress. After the clamp is released, the component deforms and releases, making it difficult to maintain component accuracy.

[0005] A1 rough machining: The process includes machining the outer arc surface of split parts 1 and 2, the B end surface perpendicular to their axial direction and the bottom surface parallel to the B end surface, the C end surface where the two split parts are in contact, the inner cavity notch and the circular surfaces of the inner cavity.

[0006] A1-1. Milling and boring: First, process the B surface and the parallel bottom surface of the split parts 1 and 2 respectively, leaving a 1mm margin each. Process the outer arc surface and the inner cavity notch of the two components respectively to meet the requirements. Process the C surface of the two components respectively, leaving a 1mm margin each.

[0007] A1-2, Lathe processing: Then use the caran to fix the two pieces on the lathe to process the inner hole, leaving a 1mm margin on each side of the inner hole;

[0008] B1 heat treatment: stress relief annealing.

[0009] A2 semi-finishing: The process includes machining the B end face and the bottom face parallel to it, the C end face and the inner cavity circles of split parts 1 and 2.

[0010] A2-1. Milling and boring: First, machine the B surface and the parallel bottom surface of split parts 1 and 2 respectively, leaving a 0.5mm allowance for each, and machine the C surface of the two parts respectively, leaving a 0.5mm allowance for each;

[0011] A2-2, Lathe processing: Use a carabiner to fix the two pieces on the lathe to process the inner hole, leaving a 1mm margin on each side of the inner hole;

[0012] B3 heat treatment: stress relief annealing.

[0013] A3 semi-finishing: The process includes machining the B end face and the parallel bottom face, C end face and inner cavity circles of split parts 1 and 2:

[0014] A3-1. Milling and boring: First, machine the B surface and the parallel bottom surface of split parts 1 and 2 respectively, leaving a 0.2mm allowance for each, and machine the C surface of the two parts respectively, leaving a 0.1mm allowance, and machine the screw holes and countersunk holes on the C surface of the two parts to meet the requirements;

[0015] A3-2. Clamping: The clamper uses screws to fasten the two parts through the countersunk holes and screw holes.

[0016] A3-3, turning: Then process the inner hole on the lathe, leaving a 0.3mm margin on each side of the inner hole;

[0017] B3 heat treatment: stress relief annealing.

[0018] A4 finishing: The process includes machining the B end face and the bottom face parallel to it, the C end face and the inner cavity circle of split parts 1 and 2:

[0019] A4-1. Bench processing: Grind the C surfaces of the two parts separately to meet the requirements; then fix the two parts with screws and positioning pins;

[0020] A4-2, Grinding: Grind the B surface and the parallel bottom surface of the two pieces to meet the requirements;

[0021] A4-3. Boring: Then finish bore the inner hole to meet the requirements.

[0022] Milling, boring and turning equipment are used in each round of processing, and vises, screw clamps and other clamping tools are used to clamp the components.

[0023] Traditional processing methods have the following problems:

[0024] 1. Since the structural parts are thin-walled, the inner wall structure is not a complete hole, there are two large openings in the middle, and the material is a casting (titanium alloy ZTC4). The stress generated during processing is large, the component deformation is large, and the accuracy is difficult to guarantee. In order to reduce the deformation of the component, the entire production process is divided into 4 rounds and the processing allowance is removed in batches, resulting in a very long entire processing cycle.

[0025] 2. The accuracy can meet the requirements just after processing on the equipment, but the components will be deformed after loosening the clamping, resulting in poor accuracy;

[0026] 3. Since the requirements cannot be met in one processing, repeated trimming is required, which leads to a long processing cycle and easy scrapping of components.

[0027] 4. The processing level of the operator is very high. Summary of the Invention

[0028] Aiming at the deficiencies of the existing technology, the present invention proposes a two-part thin-walled cylindrical complex component precision machining tool and machining method that can improve production efficiency, improve machining accuracy, and reduce machining technical difficulty.

[0029] One of the above-mentioned purposes of the present invention is achieved by the following technical solutions:

[0030] A two-part, thin-walled, cylindrical, complex component precision machining tool comprises a first auxiliary device and a second auxiliary device; the first auxiliary device is used to achieve alignment and snap-fit ​​internal fixation of the two parts of the component during rough turning and semi-finishing turning of the component; the second auxiliary device is used to achieve fixation of a single part of the component with its contact surface with the other part exposed during finishing of the component;

[0031] The first auxiliary device includes a device body, a ball stud, a pressure plate, an arc-shaped hard baffle, an arc-shaped soft baffle, a soft filling block, and an end pressure plate; the device body is a cylinder provided with an inner hole, the shape of the inner hole of which is consistent with the outer surface shape of the thin-walled cylindrical complex component, and an axial limit platform for limiting the component is provided at one end of the inner hole; two mounting through holes are vertically provided at the inner cavity notches of the device body corresponding to the two outer bosses of the component, and the mounting through holes are composed of a stud connecting threaded hole located on the outside and a pressure plate mounting hole located on the inside; the inner ball head of the ball stud cooperates with the ball socket on the pressure plate to form a ball joint clamping assembly; a ball joint clamping assembly is installed in each mounting through hole on the device body, and a clamping contact is formed with the outer side surface of the outer boss of the component through the pressure plate; The arc-shaped soft baffle and the arc-shaped hard baffle are stacked inside and outside to form an arc-shaped baffle assembly; a group of arc-shaped baffle assemblies are respectively arranged on both sides between the embedding grooves of the two bosses of the component in the inner hole of the device body, and radial tightening screws are installed on the device body at positions corresponding to the arc-shaped baffle assemblies on both sides, and the arc-shaped baffle assembly is pressed against the outer surface of the component by the screws; the shapes of the two soft filling blocks are consistent with the shapes of the inner grooves of the outer bosses on both sides of the component, and the two soft filling blocks are respectively embedded in the inner grooves on both sides of the component; the end face pressure plate is an annular pressure cover, the aperture of its inner hole is larger than the inner aperture of the component and smaller than the outer diameter of the component, and it is coaxially fixed to the end of the device body away from its axial limit platform by screws to achieve axial fixation of the component.

[0032] The second auxiliary device includes a device body, a ball stud and a pressure plate. The device body is a frame structure. The length of the frame inner cavity matches the axial size of the component single-piece, and the width of the frame inner cavity matches the distance between the outer side surfaces of the two side bosses of the component single-piece. Positioning bosses corresponding to the upper end surfaces of the two bosses on the component are arranged near the two sides along the long side direction in the upper part of the frame inner cavity; mounting holes are vertically arranged on the four side edges of the frame and on the two positioning bosses, and symmetrical handrails are arranged on both sides of the upper end of the frame; the inner ball head of the ball stud cooperates with the ball socket on the pressure plate to form a ball joint clamping assembly, and a ball joint clamping assembly is installed in each mounting hole. Through the ball joint clamping assembly, the component is fixed in the frame with the contact surface of the single-piece exposed downward.

[0033] The second object of the present invention is achieved by the following technical solutions:

[0034] A processing method using the above-mentioned two-part thin-walled cylindrical complex component precision processing tooling comprises the following steps:

[0035] Step 1: Rough machining: This includes machining the outer arc portion of split component 1 and split component 2, the end face B perpendicular to the axial direction thereof and the bottom face parallel to the end face B, the contact surface C of the two split components, the inner cavity notch, and the inner cavity circular surfaces. The machining of the inner cavity circular surfaces is performed using the first auxiliary device mentioned above to clamp and fix the components.

[0036] Step 2: heat treating the component by stress relief annealing;

[0037] Step 3, semi-finishing: including machining the B end faces perpendicular to the axial direction and the bottom faces parallel to the B end faces of the split parts 1 and 2, the C surfaces of the two split parts in contact with each other, and the circular surfaces of the inner cavity. The first auxiliary device mentioned above is used to clamp and fix the components during machining of the circular surfaces of the inner cavity.

[0038] Step 4: Heat-treat the component by stress relief annealing and high and low temperature stabilization treatment;

[0039] Step 5, finishing, including grinding the C surface of the split part 1 and the split part 2, using a grinding plate, and fixing the components using the above-mentioned second auxiliary device.

[0040] Furthermore, step 1 includes:

[0041] 1-1. Milling and boring processing: First, process the C surface of split parts 1 and 2 separately, leaving a 1mm allowance, and process the B surface and the parallel bottom surface of split parts 1 and 2 separately, leaving a 0.4mm allowance respectively. Process the outer arc surface of the two parts to meet the requirements, process the inner cavity groove to meet the requirements, process the screw holes and countersunk holes connecting the two parts on the C surface to meet the requirements, and finally process the C surface of the two parts separately, leaving a 0.1mm allowance respectively;

[0042] 1-2: Bench processing: Process the threaded holes on the split component 1 to meet the requirements, and tap the threads with an M6 tap; use screws to fix the two components according to the component assembly position shown in the figure: use hexagon socket screws M6×15 screws to fix the two components through the screw fastening holes in the figure, and finally tighten them with a uniform torque wrench, using a torque of 9N.m;

[0043] 1-3: Grinding: Grind the B surface of the component and the lower surface parallel to it, removing 0.1mm each, ensuring that the parallelism of the two surfaces is no more than 0.02mm;

[0044] 1-4 Turning: Use a faceplate clamp on the lathe to process the inner holes of the component combination, leaving a 1mm margin on each side of the inner hole; processing parameters: spindle speed: 100r / min; lateral feed rate: F=0.3mm / r; longitudinal cutting depth 0.3mm.

[0045] Moreover, step 2 is specifically as follows: heating the furnace to 700° C., keeping the temperature for 2 hours, and then cooling the furnace.

[0046] Furthermore, step 3 includes:

[0047] 3.1. Grinding: Grind the C surface of split part 1 and split part 2 separately: the removal amount is 0.05, and the flatness after grinding is not greater than 0.006mm; processing parameters: Grind the C surface on a zero-level grinding plate, using W20 boron carbide grinding material.

[0048] 3.2、Fix the two components with screws according to the assembly position of the components in the drawing: Use the hexagon socket screw M6×15 screw to fix the two components through the position of the screw fastening hole in the drawing. When tightening, use a uniform torque wrench to fix it. The torque is 9N.m. Taper pin hole and install the taper pin;

[0049] 3.3, Grinding: Grind the component combination B surface and the bottom surface parallel to it, remove 0.2mm each, and ensure that the parallelism of the two surfaces is not greater than 0.008mm; Surface grinding machine processing parameters: Use Silicon carbide grinding wheel, grit size 46, grinding wheel linear speed 35m / s; vertical feed 0.003mm, lateral feed 10mm / time, longitudinal feed 18m / min;

[0050] 3.4. Turning: Use a faceplate clamp on the lathe to process the inner holes of the component combination, leaving a 0.3mm margin on each side of the inner hole; processing parameters: spindle speed: 150r / min; lateral feed rate: F = 0.2mm / r; longitudinal cutting depth 0.2mm; the turning tool is a carbide forming tool.

[0051] Moreover, step 4 is specifically as follows: stress relief annealing: heating to 675°C with the furnace, keeping warm for 2 hours, and then cooling with the furnace; high and low temperature stabilization treatment: high temperature: heating to 100°C in 30 minutes, keeping warm for 2 hours, and air cooling to room temperature; low temperature: cooling to -75°C in 30 minutes, keeping warm for 2 hours, and leaving the box to room temperature; the treatment is carried out in the order of hot and cold, and a total of 6 hot and cold cycles are performed.

[0052] Moreover, in step 5, the precision of the grinding plate is zero level, and a cross groove with a width of 2×2 is processed on the plane of the grinding plate.

[0053] The advantages and positive effects of the present invention are:

[0054] 1. The present invention shortens the processing cycle of component finishing. By designing special auxiliary devices for grinding and turning, the accuracy of the parts grinding and turning processes is improved. At the same time, the temperature of heat treatment is increased, so that the processing stress of the parts is removed more thoroughly. The deformation of the parts in subsequent processing is easier to control. Therefore, the original four-round processing can be improved to three-round processing, shortening the overall precision processing cycle of the parts.

[0055] 2. The present invention reduces the processing deformation of components and improves the accuracy and reliability of components: by adjusting the annealing temperature of parts, the processing stress of parts is removed more thoroughly, and by increasing high and low temperature stabilization treatment, the processing stability of parts is increased and the processing deformation is smaller; special auxiliary devices are used during grinding and turning, so that the grinding accuracy of the flatness of the joint surface of the two parts can be easily met, while improving the grinding efficiency; special devices are used during turning to enhance the rigidity of thin-walled parts, reduce the vibration of parts during processing, and easily ensure the accuracy of parts during fine machining, thereby improving the accuracy and reliability of parts.

[0056] The present invention can be used in the processing and forming technology of thin-walled incomplete and complex structural parts in the aerospace, aviation, shipbuilding, precision instruments and other industries, and has a very broad promotion and application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 This is a structural diagram of a two-part thin-walled cylindrical complex component according to the present invention, 1a is a split diagram, and 1b is a combined diagram;

[0058] Figure 2 This is a process flow chart of the precision machining method of a two-part thin-walled cylindrical complex component of the present invention;

[0059] Figure 3 It is a structural schematic diagram of the main part of the first auxiliary device of the present invention;

[0060] Figure 4 This is a schematic diagram of the appearance of the present invention in which two separate components are placed in the first auxiliary device;

[0061] Figure 5 yes Figure 4 Schematic diagram after installing the end pressure plate;

[0062] Figure 6 is a cross-sectional schematic diagram of the two-part component of the present invention placed in the first auxiliary device;

[0063] Figure 7 Schematic diagram of the structure of the grinding plate used in the present invention;

[0064] Figure 8 8a is a schematic structural diagram of a second auxiliary device of the present invention, 8b is a stereoscopic view from a front angle, 8c is a partial cross-sectional view at position A, 8d is a partial cross-sectional view at position B, and 8e is a partial cross-sectional view at position C;

[0065] Figure 9 This is a reference diagram of the present invention using the second auxiliary device for grinding and finishing. DETAILED DESCRIPTION

[0066] The structure of the present invention will be further described below with reference to the accompanying drawings and through examples. It should be noted that the present examples are descriptive rather than restrictive.

[0067] A precision machining method for two-part thin-walled cylindrical complex components, see Figures 1-9 The invention point is: it includes the following processing steps in sequence:

[0068] J1, rough machining;

[0069] R1, heat treatment;

[0070] J2, semi-finishing;

[0071] R2, heat treatment;

[0072] J3. Finishing.

[0073] See the processing flow Figure 2 The specific processing steps are as follows:

[0074] J1. Rough machining: The process includes machining the outer arc parts of split parts 1 and 2, the B end face perpendicular to their axial direction and the bottom face parallel to the B end face, the C surface where the two split parts are fastened together, the inner cavity notch and the circular surfaces of the inner cavity.

[0075] J1-1. Milling and boring: First, process the C surface of split parts 1 and 2 separately, leaving a 1mm allowance, process the B surface and the parallel bottom surface of split parts 1 and 2 separately, leaving a 0.4mm allowance, process the outer arc surface of the two parts to meet the requirements, process the inner cavity groove to meet the requirements, process the screw holes and countersunk holes connecting the two parts on the C surface to meet the requirements, and finally process the C surface of the two parts separately, leaving a 0.1mm allowance;

[0076] Step 1-1: Process the C surface with a 1mm machining allowance, using a vertical machining center. Processing parameters: diameter Milling cutter, cutting depth a p＝ 0.5mm, feed speed F=150mm / min, speed 1000r / min;

[0077] Step 1-2: Use C surface as the reference to process B surface and the bottom surface parallel to B surface, leaving 1mm machining allowance, using vertical machining center for processing, machining parameters: diameter Milling cutter, cutting depth a p＝ 0.5mm, feed speed F=150mm / min, speed 1000r / min;

[0078] Step 1-3: Process the arc surface to meet the size requirements in the figure. Use vertical machining center for processing. Processing parameters: ball cutter Depth of cut a p＝ 0.05mm, feed speed F=100mm / min, speed 800r / min;

[0079] Step 1-4: Process the grooves in the inner cavity to meet the size requirements in the figure. Use a vertical machining center for processing. Processing parameters: diameter Milling cutter, cutting depth a p＝ 0.5mm, feed speed F=120mm / min, speed 1000r / min;

[0080] Step 1-5: Process the C surface with a 0.1mm margin; use a vertical machining center to process. Milling cutter, processing parameters: diameter Depth of cut a p＝ 0.2mm, feed speed F=100mm / min, speed 1000r / min;

[0081] Step 1-6: Use vertical machining center to process the bottom holes of each screw hole on the C surface of split part 1 to meet the requirements. Processing parameters: drill bit Depth of cut a p＝ 0.3mm, feed speed F = 30mm / min, speed 800r / min; process the through holes on the C surface of the split part 2 to the size shown in the figure, processing parameters: drill bit Depth of cut ap＝ 0.3mm, feed speed F = 30mm / min, speed 800r / min; milling cutter Depth of cut a p＝ 0.3mm, feed speed F=20mm / min, speed 600r / min;

[0082] J1-2: Bench processing: Process the threaded holes on the split part 1 to meet the requirements, and tap the threads with an M6 tap; use screws to fix the two components according to the component combination position in the drawing: use hexagon socket screws M6×15 screws to fix the two parts through the position of the screw fastening holes in the figure, and finally use a unified torque wrench to fix it when tightening, and the torque is 9N.m.

[0083] J1-3: Grinding: Grind the B surface of the component and the lower surface parallel to it, removing 0.1mm each, and ensure that the parallelism of the two surfaces is not greater than 0.02mm.

[0084] Use surface grinder for processing, surface grinder processing parameters: use Silicon carbide grinding wheel, grit size 60, grinding wheel linear speed 35m / s; vertical feed 0.005mm, lateral feed 10mm / time, longitudinal feed 18m / min;

[0085] J1-4 lathe: Then use the faceplate clamping on the lathe to process the component combination inner hole, leaving a 1mm margin on each side of the inner hole; ( The machining rotation diameter is greater than )

[0086] Processing parameters: spindle speed: 100r / min; transverse feed: F = 0.3mm / r; longitudinal cutting depth 0.3mm;

[0087] The first auxiliary device is used during lathe clamping, see Figure 3-Figure 6 shown.

[0088] The structure of the first auxiliary device is as follows: a ball joint clamping mechanism consisting of a ball stud 2 and a pressure plate 3 is respectively installed on the left and right sides of the device body 1. The round ball of the ball stud and the inner spherical surface of the pressure plate have high requirements for the fit, requiring the ball pair contact rate of the two parts to be no less than 70%, and the axial clearance between the ball head and the concave ball cannot be greater than 0.003mm; an arc baffle assembly is respectively installed in front and behind the inner cavity of the device body. The arc baffle assembly consists of an arc hard baffle 8 and an arc soft baffle 9. The two pieces are glued together. The arc hard baffle plays a supporting role. The material is aluminum plate. The arc soft baffle is a non-metallic material polyurethane (hardness 40A). The material is relatively soft and elastic, and grooves are processed on its surface to enhance the release of its deformation; the arc surface clamping screw is screwed into the screw hole 1.3 on the device body, and there are 9 arc surfaces in total.

[0089] Instructions for use of the first auxiliary device:

[0090] 1. Unscrew the arc-shaped compression screw 10 (indicated by the line position in the figure) outward about 2mm; make the arc-shaped hard baffle assembly close to the inner wall of the device body;

[0091] 2. Unscrew each ball stud 3mm outward;

[0092] 3. Place the two-part component 5 into the inner cavity 1.2 of the device, then place the end pressure plate 7 on the top of the component assembly, and tighten it with the end fastening screw 6. Use a torque screwdriver when tightening, and use a torque of 5Nm.

[0093] 4. Place two soft fillers 4 into the inner cavity gaps 1.1 on the left and right sides of the component combination respectively. The plasticine needs to be well fitted to all sides of the gap. The second soft filler is plasticine.

[0094] 5. Then screw in the fastening screws on both sides of the arc surface. Use a torque screwdriver and a torque of 0.2Nm to make the soft arc hard baffle close to the arc surface of the component combination without deforming the component combination. The use of soft materials can absorb the vibration of the component during processing and ensure that the component accuracy meets the requirements.

[0095] 6. Screw in the ball studs on the left and right sides of the device and tighten them with a torque screwdriver, using a torque of 0.1Nm. Using a torque screwdriver of 0.1Nm is to prevent the component from being deformed during tightening.

[0096] 7. Then install the entire device as a whole on the spindle of the lathe, clamp the end face and extension of the A side of the device, find the inner hole of the component, and then process the inner hole of the component combination to meet the requirements.

[0097] J1 process analysis description:

[0098] When machining the inner hole after the components are assembled, large deformation will occur. As a result, the original process needs to gradually remove the machining amount in multiple times. The clamping device designed for turning can strengthen the disadvantage of the thin wall of the component combination, suppress the deformation and extension of the component during processing, and after the two components are combined, the B surface and the bottom surface parallel to it are flattened, which also makes a good benchmark for turning and can reduce the deformation of clamping. After turning, the component combination is disassembled, and the deformation of the C surface of the two components is significantly reduced. The deformation of the inner hole is not more than 0.03, and the deformation of the C surface is not more than 0.03mm. Therefore, leaving 0.1mm on the end face can ensure the subsequent processing allowance; the previous large allowance on the C surface was because when turning the inner hole, the component deformation was large, which could reach 0.2mm, causing the C surface to distort. More allowance is needed to ensure the subsequent processing, otherwise the component will be scrapped;

[0099] R1: Heat treatment; stress relief annealing.

[0100] Heat the furnace to 700°C, keep warm for 2 hours, and then cool the furnace.

[0101] The original heat treatment temperature was 650℃. The deformation of the component was still large in the subsequent processing. In order to more thoroughly eliminate the internal stress of the component processing, the heat treatment temperature was increased to 700℃. This temperature is lower than the melting temperature of the casting, 950℃. Raising the temperature to this temperature will not reduce the strength of the component, and the effect of removing the internal stress after heat treatment will be better.

[0102] J2: Semi-finishing

[0103] J2-1. Grinding process: Grind the C surface of split part 1 and split part 2 separately: the removal amount is 0.05, and the flatness after grinding is not greater than 0.006mm; processing parameters: Grind the C surface on a zero-level grinding plate, using W20 boron carbide grinding material.

[0104] J2-2、Fix the two components with screws according to the assembly position of the components in the drawing: Use hexagon socket screws M6×15 to fix the two components through the screw fastening holes in the drawing. Use a uniform torque wrench to tighten the screws, and use a torque of 9N.m. Taper pin hole and install the taper pin.

[0105] J2-3. Grinding: Grind the component combination B surface and the bottom surface parallel to it, removing 0.2mm each, and ensure that the parallelism of the two surfaces is not greater than 0.008mm.

[0106] Use surface grinder for processing, surface grinder processing parameters: use Silicon carbide grinding wheel, grit size 46, grinding wheel linear speed 35m / s; vertical feed 0.003mm, lateral feed 10mm / time, longitudinal feed 18m / min;

[0107] J2-4, Turning: Use the faceplate clamping to process the inner hole of the component assembly on the lathe, leaving a 0.3mm margin on each side of the inner hole; ( The machining rotation diameter is greater than ), a clamping workpiece positioning device is used during turning.

[0108] Processing parameters: spindle speed: 150r / min; transverse feed rate: F=0.2mm / r; longitudinal cutting depth 0.2mm; turning tool is a carbide forming tool.

[0109] J2 process optimization analysis description:

[0110] Optimizations over the original process: The C surfaces of components 1 and 2 are ground with a removal of 0.05mm. The remaining allowance is now 0.05mm each, significantly less than the traditional process, which used a 0.5mm allowance each. The reason: The addition of flat grinding on the B surface of the component assembly provides a high-precision benchmark for semi-finishing turning, reducing deformation during clamping. Furthermore, a clamping workpiece positioning device is used during turning, significantly reducing deformation of the machined components. With the improved process, the C surface of both components is minimal, and the inner hole is essentially a full circle during component assembly machining. The removal of the inner hole is uniform and minimal, resulting in minimal deformation of the component. Therefore, the two original semi-finishing processes have been combined into one.

[0111] R2: Heat treatment; stress relief annealing + high and low temperature stabilization treatment.

[0112] Stress relief annealing: Heat to 675°C in the furnace, hold for 2 hours, then cool in the furnace. High and low temperature stabilization: High temperature: Heat to 100°C in 30 minutes, hold for 2 hours, then remove from the furnace and air cool to room temperature. Low temperature: Cool to -75°C in 30 minutes, hold for 2 hours, then remove from the oven and allow to return to room temperature. This treatment is performed in a sequence of hot and cold, for a total of 6 hot and cold cycles.

[0113] The original heat treatment temperature was 625°C, now 675°C, which provides better stress relief without reducing component strength. Adding a high-low temperature stabilization cycle after stress relief annealing, through the cross-temperature impact of high and low temperatures, improves component stability and makes it easier to ensure precision during finishing.

[0114] J3. Grinding: Process the C surface of split parts 1 and 2, and the flatness of the C surface of the two parts is required to be no more than 0.003mm.

[0115] Place split parts 1 and 2 on the workbench. A grinding plate, the second auxiliary device used for grinding, is also placed on the workbench. In addition, grinding sand (borax W20), white kerosene, non-woven fabric, medical cotton, gasoline and a brush are also required.

[0116] Grinding plate 11 see Figure 7 As shown, the precision of the grinding plate is zero level, and a cross groove with a width of 2×2 is processed on the plane of the grinding plate. The function of the groove is to facilitate the removal of abrasives during grinding and prevent the grinding component from having inconsistent removal amounts at the periphery and center, which affects the overall flatness accuracy of the component.

[0117] Secondary auxiliary device for grinding, see Figure 8As shown. The device body 12 is a frame, which has a frame structure. The length of the frame's inner cavity matches the axial dimension of the component's single split body, and the width of the frame's inner cavity matches the distance between the outer side surfaces of the two side bosses of the component's single split body. Positioning bosses 12.1 corresponding to the upper end surfaces of the two bosses on the component are provided near the two sides along the long side of the upper portion of the frame's inner cavity. Mounting holes are vertically provided on the four side edges of the frame and on the two positioning bosses. Symmetrical handrails 13 are provided on both sides of the upper end of the frame. The inner ball head of the ball stud cooperates with the ball socket on the pressure plate to form a ball joint clamping assembly. A ball joint clamping assembly is installed in each mounting hole. Through the ball joint clamping assembly, the component is fixed in the frame with the contact surface of the single split body exposed downward.

[0118] There are 4 ball joint clamping assemblies installed on the front and back sides of the frame. The ball joint clamping assembly (see the cross-sectional view at A) is a clamping mechanism composed of a ball stud and a pressure plate. The round ball of the ball stud and the inner spherical surface of the pressure plate have high requirements for the fit. The ball pair contact rate of the two pieces is required to be no less than 70%, and the axial clearance between the ball head and the concave ball cannot be greater than 0.003mm; There are 2 ball joint clamping assemblies installed on the left and right sides of the frame. The ball joint clamping assembly (see the cross-sectional view at B) is a clamping mechanism composed of a ball stud and a pressure plate. The round ball of the ball stud and the inner spherical surface of the pressure plate have high requirements for the fit. The ball pair contact rate of the two pieces is required to be no less than 70%, and the axial clearance between the ball head and the concave ball cannot be greater than 0.003mm. The inner spherical surface of the ball and the pressure plate have high requirements for fit, requiring the ball pair contact rate of the two pieces to be no less than 70%, and the axial clearance between the ball head and the concave ball cannot be greater than 0.003mm; three ball joint clamping assemblies are installed on both sides of the upper part of the frame. The ball joint clamping assembly (see the cross-sectional view at C) is a clamping mechanism composed of a ball stud and a pressure plate. The ball of the ball stud and the inner spherical surface of the pressure plate have high requirements for fit, requiring the ball joint contact rate of the two pieces to be no less than 70%, and the axial clearance between the ball head and the concave ball cannot be greater than 0.003mm. Explanation of the use of ball joints for ball screws and pressure plates: Since the flatness of each surface of the outer shape of split parts 1 and split parts 2 cannot reach the ideal 0mm, the actual flatness of each surface can reach 0.2mm; if only screws are used for direct tightening, the contact position is the screw head, and the contact area is small. Moreover, after the screws are tightened with normal force, large local deformation will occur, resulting in increased deformation of the component clamping, affecting the processing accuracy. Therefore, a ball joint structure is adopted. The pressure plate presses the side of the component. The end face of the pressure plate is large, and the contact area with the component is large. Because of the ball joint pair, when the center line of the screw hole is not perpendicular to the side of the component, the ball joint plays a role. It not only ensures the complete structure of the end face of the pressure plate and the side of the component, but also applies the clamping force perpendicularly to the side of the component through the ball joint pair to ensure that the side of the component is compressed and compacted. When the screw is screwed in, the pressure plate and the ball screw can rotate slightly, so that the end face of the pressure plate can reliably contact the component surface. The external thread of the ball screw adopts a fine thread pitch of 0.75, and the screw hole on the device is also M6×0.75, which strengthens the self-locking function of the thread and prevents loosening after the screw is tightened.

[0119] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will understand that various replacements, changes and modifications are possible without departing from the spirit of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A two-part thin-walled cylindrical complex component precision machining tool, characterized by: The invention comprises a first auxiliary device and a second auxiliary device; the first auxiliary device is used to realize the alignment and snap-fit ​​internal fixation of the two parts of the component during rough turning and semi-finishing turning of the component; the second auxiliary device is used to realize the fixation of a single part of the component in a manner in which the contact surface between the single part and the other part is exposed during finishing of the component; The first auxiliary device includes a device body, a ball stud, a pressure plate, an arc-shaped hard baffle, an arc-shaped soft baffle, a soft filling block, and an end pressure plate; the device body is a cylinder provided with an inner hole, the shape of the inner hole of which is consistent with the outer surface shape of the thin-walled cylindrical complex component, and an axial limit platform for limiting the component is provided at one end of the inner hole; two mounting through holes are vertically provided at the inner cavity notches of the device body corresponding to the two outer bosses of the component, and the mounting through holes are composed of a stud connecting threaded hole located on the outside and a pressure plate mounting hole located on the inside; the inner ball head of the ball stud cooperates with the ball socket on the pressure plate to form a ball joint clamping assembly; a ball joint clamping assembly is installed in each mounting through hole on the device body, and a clamping contact is formed with the outer side surface of the outer boss of the component through the pressure plate; The arc-shaped soft baffle and the arc-shaped hard baffle are stacked inside and outside to form an arc-shaped baffle assembly; a group of arc-shaped baffle assemblies are respectively arranged on both sides between the embedding grooves of the two bosses of the component in the inner hole of the device body, and radial tightening screws are installed on the device body at positions corresponding to the arc-shaped baffle assemblies on both sides, and the arc-shaped baffle assembly is pressed against the outer surface of the component by the screws; the shapes of the two soft filling blocks are consistent with the shapes of the inner grooves of the outer bosses on both sides of the component, and the two soft filling blocks are respectively embedded in the inner grooves on both sides of the component; the end face pressure plate is an annular pressure cover, the aperture of its inner hole is larger than the inner aperture of the component and smaller than the outer diameter of the component, and it is coaxially fixed to the end of the device body away from its axial limit platform by screws to achieve axial fixation of the component; The second auxiliary device includes a device body, a ball stud and a pressure plate. The device body is a frame structure. The length of the frame inner cavity matches the axial size of the component single-piece, and the width of the frame inner cavity matches the distance between the outer side surfaces of the two side bosses of the component single-piece. Positioning bosses corresponding to the upper end surfaces of the two bosses on the component are arranged near the two sides along the long side direction in the upper part of the frame inner cavity; mounting holes are vertically arranged on the four side edges of the frame and on the two positioning bosses, and symmetrical handrails are arranged on both sides of the upper end of the frame; the inner ball head of the ball stud cooperates with the ball socket on the pressure plate to form a ball joint clamping assembly, and a ball joint clamping assembly is installed in each mounting hole. Through the ball joint clamping assembly, the component is fixed in the frame with the contact surface of the single-piece exposed downward.

2. A processing method using the two-part thin-walled cylindrical complex component precision processing tooling according to claim 1, characterized in that: The steps include: Step 1: Perform rough machining: This includes machining the outer arc portion of split component 1 and split component 2, the B end face perpendicular to the axial direction thereof and the bottom face parallel to the B end face, the C surface where the two split components meet, the inner cavity notch, and the various circular surfaces of the inner cavity. The first auxiliary device is used to clamp and fix the components during machining of the various circular surfaces of the inner cavity. Step 2: heat treating the component by stress relief annealing; Step 3, semi-finishing: including machining the B end faces perpendicular to the axial direction and the bottom faces parallel to the B end faces of the split parts 1 and 2, the C surfaces of the two split parts in contact with each other, and the circular surfaces of the inner cavity. The first auxiliary device mentioned above is used to clamp and fix the components during machining of the circular surfaces of the inner cavity. Step 4: Heat-treat the component by stress relief annealing and high and low temperature stabilization treatment; Step 5, finishing, including grinding the C surface of split part 1 and split part 2, using a grinding plate, and using a second auxiliary device to fix the components.

3. The processing method according to claim 2 using the two-part thin-walled cylindrical complex component precision processing tooling according to claim 1 is characterized in that: Step 1 includes: 1-1. Milling and boring processing: First, process the C surface of split parts 1 and 2 separately, leaving a 1mm allowance, and process the B surface and the parallel bottom surface of split parts 1 and 2 separately, leaving a 0.4mm allowance respectively. Process the outer arc surface of the two parts to meet the requirements, process the inner cavity groove to meet the requirements, process the screw holes and countersunk holes connecting the two parts on the C surface to meet the requirements, and finally process the C surface of the two parts separately, leaving a 0.1mm allowance respectively; 1-2: Bench processing: Process the threaded holes on the split component 1 to meet the requirements, and tap the threads with an M6 tap; use screws to fix the two components according to the component assembly position shown in the figure: use hexagon socket screws M6×15 screws to fix the two components through the screw fastening holes in the figure, and finally tighten them with a uniform torque wrench, using a torque of 9N.m; 1-3: Grinding: Grind the B surface of the component and the lower surface parallel to it, removing 0.1mm each, ensuring that the parallelism of the two surfaces is no more than 0.02mm; 1-4 Turning: Use a faceplate clamp on the lathe to process the inner holes of the component combination, leaving a 1mm margin on each side of the inner hole; processing parameters: spindle speed: 100r / min; lateral feed rate: F=0.3mm / r; longitudinal cutting depth 0.3mm.

4. The processing method according to claim 2 using the two-part thin-walled cylindrical complex component precision processing tooling according to claim 1 is characterized in that: Step 2 is specifically as follows: heating the furnace to 700°C, keeping the temperature for 2 hours, and then cooling the furnace.

5. The processing method according to claim 2 using the two-part thin-walled cylindrical complex component precision processing tooling according to claim 1 is characterized in that: Step 3 includes: 3.

1. Grinding: Grind the C surface of component 1 and component 2 separately: the removal amount is 0.05, and the flatness after grinding is not greater than 0.006mm; processing parameters: Grind the C surface on a zero-level grinding plate, using W20 boron carbide grinding material; 3.2、Fix the two components with screws according to the assembly position of the components in the drawing: Use the hexagon socket screw M6×15 screw to fix the two components through the position of the screw fastening hole in the drawing. When tightening, use a uniform torque wrench to fix it. The torque is 9N.m. Taper pin hole and install the taper pin; 3.3, Grinding: Grind the component combination B surface and the bottom surface parallel to it, remove 0.2mm each, and ensure that the parallelism of the two surfaces is not greater than 0.008mm; Surface grinding machine processing parameters: Use Silicon carbide grinding wheel, grit size 46, grinding wheel linear speed 35m / s; vertical feed 0.003mm, lateral feed 10mm / time, longitudinal feed 18m / min; 3.

4. Turning: Use a faceplate clamp on the lathe to process the inner holes of the component combination, leaving a 0.3mm margin on each side of the inner hole; processing parameters: spindle speed: 150r / min; lateral feed rate: F = 0.2mm / r; longitudinal cutting depth 0.2mm; the turning tool is a carbide forming tool.

6. The processing method according to claim 2 using the two-part thin-walled cylindrical complex component precision processing tooling according to claim 1 is characterized in that: Step 4 is specifically as follows: stress relief annealing: heating to 675°C in the furnace, keeping warm for 2 hours, and then cooling in the furnace; high and low temperature stabilization treatment: high temperature: heating to 100°C in 30 minutes, keeping warm for 2 hours, and air cooling to room temperature; low temperature: cooling to -75°C in 30 minutes, keeping warm for 2 hours, and then taking out of the box and placing it at room temperature; the treatment is carried out in the order of hot and cold, and a total of 6 hot and cold cycles are performed.

7. The processing method according to claim 2 using the two-part thin-walled cylindrical complex component precision processing tooling according to claim 1, characterized in that: In step 5, the precision of the grinding plate is zero level, and a cross groove with a width of 2×2 is processed on the plane of the grinding plate.

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