A grinding process for tenon of aircraft engine turbine blades

Abstract

The present invention discloses a grinding process for the tenon of an aero-engine turbine blade, and belongs to the technical field of aero-engine turbine blade processing. The process comprises the following steps: step one, casting a rectangular parallelepiped alloy body; step two, installing and fixing a universal fixture on the workbench of a grinder; step three, positioning and clamping the blade to be processed on the blade fixture; step four, locking and fixing the blade fixture to the universal fixture through a connecting component A; step five, grinding the upper surface and the upper half end of the tenon; step six, turning the blade fixture and the blade to be processed together by 180°, and locking and fixing the blade fixture to the universal fixture again; step seven, grinding the lower surface and the lower half end of the tenon. Since the speed of positioning the relative position of the blade fixture and the universal fixture is relatively fast, the positioning and clamping efficiency of the blade to be processed can be significantly improved, thereby achieving the purpose of improving the grinding efficiency of the tenon.

Description

Technical Field

[0001] The invention relates to a grinding process for a tenon of an aero-engine turbine blade, and belongs to the technical field of aero-engine turbine blade processing. Background Art

[0002] The turbine blades of aircraft engines are the main source of power for aircraft. They are located in the hot end of aircraft engines and need to withstand the high-temperature gas scouring and temperature changes during the engine start-stop cycle, as well as the centrifugal force at high speeds. This requires the turbine blades to have sufficient high-temperature tensile strength, endurance strength, creep strength, long-term structural stability, and good impact resistance.

[0003] The turbine blades are rotating blades, which are connected to the disc parts through tenons. The blade tenons are high-precision machining parts with strict contour requirements and small tolerances. They are machined by slow-feed grinding. The working environment and use function of the turbine blades determine that the material used is high-temperature alloy castings. Figure 1 As shown in Figure 1, the turbine blade is mainly composed of three parts: the tenon, the blade body and the blade crown. Figure 2 As shown, the cross-section of the blade body is an irregular "banana shape", which cannot be used as a positioning reference to achieve precise processing of the tenon and blade crown.

[0004] To this end, a Chinese patent document with publication number CN105538096A discloses a blade tenon grinding fixture for quickly positioning and clamping the blade to be processed, so as to meet the purpose of meeting the technical requirements of the dimensional tolerance and form and position tolerance after the blade tenon is ground. The blade to be processed is cast with a square box at its blade basin and blade back for auxiliary positioning during clamping. The blade tenon grinding fixture greatly simplifies the operation of rapid loading and unloading of the blade to be processed. The specific process is as follows: 1. Loosen the nut and adjust the bolt to make it horizontal; 2. Rotate the pressing plate and the pressing block around the cylindrical pin to a vertical state; 3. Squeeze the blade after the square box is cast to the correct position of the fixture, and automatically position and clamp the front and back and left and right sides of the square box through the positioning pin; 4. Reverse the operation according to step 2 and step 1 in sequence, and finally complete the positioning and clamping of the upper and lower sides of the square box. After one end of the blade tenon is ground, remove the square box and the blade on it and rotate it 180°, and install it on the grinder in the same way to grind the other end face of the tenon.

[0005] However, after one end of the blade tenon is ground, it is necessary to remove the lower box and the upper blade and rotate it 180°, and then re-position and clamp the front and back, left and right, top and bottom of the other box according to steps 1 to 4 above, which greatly reduces the efficiency of the fixture in positioning and clamping the blade, and reduces the grinding efficiency of the blade tenon. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a grinding process for a tenon of an aircraft engine turbine blade.

[0007] The present invention is achieved through the following technical solutions: A grinding process for a tenon of an aero-engine turbine blade comprises the following steps: Step 1: pouring alloy into the blade body section of the blade to be processed to form a rectangular alloy body; Step 2: Install and fix the universal fixture on the working table of the grinder; Step 3: Use the rectangular alloy body to position and clamp the blade to be processed onto the blade fixture; Step 4: Lock and fix the blade clamp to the universal clamp through the connecting component A; Step 5: Grind the upper surface and upper end of the tenon of the blade to be processed; Step 6: Remove the connection component A, turn the blade fixture and the blade to be processed 180 degrees, and then re-lock the blade fixture to the universal fixture through the connection component A; Step 7: Grind the lower surface and lower end of the tenon of the blade to be processed, and the tenon grinding process is completed.

[0008] The alloy poured in the step 1 is a tin-beryllium alloy, wherein Sn:Bi of the tin-beryllium alloy is 43:57, and the pouring temperature is 152° C. to 165° C. After the tin-beryllium alloy is poured, water is passed through the alloy to condense the alloy for 2 min to 3 min. After the tin-beryllium alloy is completely solidified, excess burrs and protrusions around the rectangular alloy body are removed.

[0009] The rectangular alloy body is provided with mutually perpendicular reference planes C, D and G. Reference plane C is an end surface of the rectangular alloy body close to the tenon. When the reference plane D is the bottom surface, the tenon is in a horizontal state. A notch A is formed in the middle of a reference plane D on the rectangular parallelepiped alloy body, and a notch B is formed in the middle of a side surface opposite to the reference plane G on the rectangular parallelepiped alloy body.

[0010] The universal clamp includes a base and a threaded bushing. A positioning plate is integrally formed on one side of the base. The bottom surface of the positioning plate is coplanar with the bottom surface of the base, and the top surface of the positioning plate is located above the top surface of the base. A T-shaped hole is provided on the base along the thickness direction, and the threaded bushing is arranged in the T-shaped hole.

[0011] A positioning boss A is provided on one side of the positioning plate close to the base above the base, and a threaded hole A is provided at the bottom of the base close to the threaded bushing. A set screw A is connected to the inner thread of the threaded hole A, and the set screw A contacts the threaded bushing.

[0012] The method for installing and fixing the universal clamp on the workbench of the grinder in step 2 is: place the base on the workbench of the grinder, and align it with a dial indicator to ensure that the runout of the base along the X-axis and Y-axis on the horizontal plane is less than 0.005mm, and then fix the base on the workbench.

[0013] The connecting component A is a bolt.

[0014] The blade clamp includes a clamp body and a blade pressing assembly, a concave cavity is provided on the clamp body, and a dividing block is integrally formed on the bottom surface of the concave cavity, a through hole A and a threaded hole C are provided on the dividing block, two rectangular positioning plates are provided in the concave cavity, and the dividing block is located between the two rectangular positioning plates, two positioning bosses B are provided on one side of the clamp body, a positioning plate A is provided on the first side of the rectangular positioning plate on the clamp body, two eccentric pins are rotatably provided on the second side of the rectangular positioning plate, and an eccentric pin is provided on the third side of the rectangular positioning plate, the first side, the second side and the third side are three sides adjacent to each other in a clockwise direction, and the first side is a side of the rectangular positioning plate away from the positioning boss B, the blade pressing assembly is located on the upper side of the dividing block and the two rectangular positioning plates, and the blade pressing assembly is connected to the dividing block and the clamp body through the connecting assembly B.

[0015] The blade pressing assembly includes a connecting block and two pressing blocks, each of which is provided with a through hole B. The two pressing blocks are rotatably connected to the two ends of the connecting block in a one-to-one correspondence, and both ends of the connecting block are provided with limit screws to limit the pressing blocks; The two pressing blocks are located one by one directly above the two rectangular positioning plates, and the connecting block is connected to the separating block and the fixture body through a connecting component B.

[0016] The connecting block comprises a connecting block body, a U-shaped notch is provided in the middle of the connecting block body, connecting shafts are provided at both ends of the connecting block body, and a threaded hole B is coaxially provided on the connecting shaft.

[0017] The connection assembly B includes a stud, a washer and a nut. The lower end of the stud is threadedly connected to the threaded hole C on the partition block. The washer is sleeved on the stud. The nut is threadedly connected to the stud, and the washer is located between the nut and the connection block.

[0018] The method of positioning the blade to be processed on the blade fixture by using the rectangular alloy body in step 3 comprises the following steps: Step A, placing two blades to be processed on two rectangular positioning plates respectively, and making the reference surface D on the rectangular alloy body keep in contact with the rectangular positioning plate, and making the reference surface C on the rectangular alloy body keep in contact with the positioning plate A; Step B, rotating three eccentric pins located on the second side and the third side of the rectangular positioning plate to lock the rectangular parallelepiped alloy body; Step C, fitting the two pressing blocks onto the two ends of the connecting block one by one, and screwing limiting screws into the two ends of the connecting block to limit the pressing blocks; Step D: insert the stud into the U-shaped notch on the connecting block, and then tighten the nut to press and fix the rectangular alloy bodies on the two blades to be processed through the two pressing blocks, thereby achieving positioning and clamping of the blades to be processed.

[0019] The method for locking and fixing the blade clamp to the universal clamp through the connecting component A in the step four is: place the blade clamp on the universal clamp, and keep the bottom surface of the clamp body in contact with the top surface of the base, keep the positioning boss B on the clamp body in contact with the positioning boss A on the positioning plate, then pass one end of the connecting component A through the through hole A and connect it to the threaded bushing, and tighten the connecting component A to lock the blade clamp to the universal clamp.

[0020] In step five and step seven, the tenon is ground with four knives. The grinding speed is 32m / s, the pressure of the coolant is 0.95MPa, the grinding depths of the first, second, third and fourth knives are ≤1.5mm, ≤0.3mm, ≤0.1mm and ≤0.06mm respectively, the feed speeds are 125mm / min, 130mm / min, 140mm / min and 150mm / min respectively, and the residual margins are 1.0mm, 0.3mm, 0.06mm and 0mm respectively.

[0021] The beneficial effects of the present invention are: 1. After grinding the upper surface and upper end of the tenon of the blade to be processed, remove the connection component A, then flip the blade fixture and the blade to be processed together, quickly locate the relative position of the blade fixture and the universal fixture again, and then re-lock and fix the blade fixture to the universal fixture through the connection component A. Since the speed of locating the relative position of the blade fixture and the universal fixture is much faster than the speed of re-locating the six faces of the rectangular alloy body, the present invention can significantly improve the positioning and clamping efficiency of the universal fixture and the blade fixture for the blade to be processed, thereby achieving the purpose of improving the grinding efficiency of the tenon.

[0022] 2. A U-shaped notch is provided in the middle of the connecting block body, so that the stud can be quickly inserted into the U-shaped notch without removing the washer and nut from the stud, thereby improving the efficiency of the blade fixture in assembling and disassembling the blade to be processed.

[0023] 3. When tightening the nut on the stud, the nut quickly presses and fixes the rectangular alloy bodies on the two blades to be processed through the washer, the connecting block and the two pressing blocks, thereby realizing the rapid clamping and fixing of the two blades to be processed to the blade fixture, improving the positioning and clamping efficiency of the blades to be processed and the grinding efficiency of the tenon. Conversely, after loosening the nut on the stud, the two pressing blocks can quickly loosen the two blades to be processed, improving the efficiency of removing the blades to be processed from the blade fixture.

[0024] 4. The blade fixture can position and clamp two blades to be processed at one time, which is convenient for grinding the tenons of the two blades to be processed at the same time in steps 5 and 7, further improving the grinding efficiency of the tenons of the blades to be processed.

[0025] 5. The blade clamp is connected to the universal clamp through the connecting component A, and the connecting component A is a bolt. That is to say, the blade clamp and the universal clamp can be quickly assembled and disassembled through a bolt, which helps to improve the grinding efficiency of the tenon. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of a blade to be processed according to the present invention; Figure 2 for Figure 1 Section view along AA; Figure 3 This is a front view of the present invention after a rectangular parallelepiped alloy body is cast on the blade to be processed; Figure 4 for Figure 3 Bottom view of Figure 5 It is a front view of the connection assembly A of the present invention after being assembled with the universal clamp; Figure 6 for Figure 5 A top view of Figure 7 It is a structural schematic diagram of the connection component A of the present invention; Figure 8 It is a structural schematic diagram of the blade clamp of the present invention; Fig. 9 for Figure 8 Step section view along BB; Fig.10 is a top view of the clamp body of the present invention; Fig.11 for Fig.10 Step section view along DD; Fig.12 It is a left side view of the clamp body of the present invention; Fig.13 It is a front view of the eccentric pin of the present invention; Fig.14 for Fig.13 Left view of Fig.15 A front view of a compact of the present invention; Fig.16 for Fig.15 Left view of Fig.17 It is a front view of the connection block of the present invention; Fig.18 for Fig.17 Sectional view along CC; Fig.19 It is a front view of the blade clamp of the present invention after being assembled with the universal clamp; Fig. 20 for Fig.19 A top view of Fig.21 It is a schematic diagram of the positions of the upper surface, upper half end, lower surface and lower half end of the tenon of the present invention; Fig. 22 This is a metallographic image of the grinding surface of the tenon magnified 500 times.

[0027] In the figure: 1-blade to be processed, 10-tenon, 11-blade body, 12-blade crown, 13-rectangular alloy body, 130-slot A, 131-slot B, 2-universal fixture, 20-base, 200-threaded hole A, 21-threaded bushing, 22-positioning plate, 220-positioning boss A, 3-blade fixture, 30-fixture body, 300-recess, 301-positioning boss B, 30 2-partition block, 303-through hole A, 304-threaded hole C, 31-eccentric pin, 32-pressure block, 320-through hole B, 33-limit screw, 34-positioning plate A, 35-connecting block, 350-connecting block body, 351-connecting shaft, 352-U-shaped notch, 353-threaded hole B, 36-nut, 37-stud, 38-washer, 39-rectangular positioning plate, 4-connecting component A. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0029] like Figures 1 to 22 As shown, the present invention provides a grinding process for the tenon of an aircraft engine turbine blade, comprising the following steps: Step 1: pouring alloy into the blade body 11 of the blade 1 to be processed to form a rectangular parallelepiped alloy body 13.

[0030] like Figure 3 and Figure 4As shown, specifically, according to the shape characteristics of the blade 1 to be processed, and the position characteristics and allowances of the tenon 10 and the blade crown 12 that need to be processed, six key positioning points are taken on the blade 1 to be processed to position it, wherein positioning point A1, positioning point A2 and positioning point B4 are the positioning points of the tenon 10; positioning point A3 is the positioning point of the blade body 11; positioning point B5 and positioning point C6 are the positioning points of the blade crown 12. The method for selecting the six key positioning points can refer to the prior art with publication number CN117450967A and patent name A Six-Point Positioning Detection Method for Turbine Blades, which will not be repeated here. After positioning the blade 1 to be processed, clamp the N and H points on the blade 1 to be processed to fix it. At this time, the tenon 10 is in a horizontal state, which is the state of the blade 1 to be processed when the tenon 10 is ground.

[0031] A cavity for forming the alloy is provided in the middle of the mold for pouring the alloy, and the blade body 11 of the blade 1 to be processed is located in the cavity.

[0032] After the alloy is poured to form a rectangular alloy body 13, the relative positions of the six key positioning points need to be measured, specifically: when the reference plane G is used as the bottom surface and the measurement reference, the position accuracy of the positioning points B4 and B5 are both less than 0.06mm; when the reference plane D is used as the bottom surface and the measurement reference, the position accuracy of the positioning points A1, A2 and A3 are all less than 0.06mm; the relative position accuracy of the positioning points A1 and A2 is less than 0.05mm; the relative position accuracy of the positioning points B4 and B5 is less than 0.08mm; the distance L±0.05mm from the measurement reference plane C to the positioning point C6 on the blade crown 12 meets the requirements. This ensures that after the reference is converted into a rectangular alloy body 13 through six-point positioning, the reference of the blade 1 to be processed is unified and correct.

[0033] The rectangular alloy body 13 is formed by casting alloy to achieve the reference conversion of the blade 1 to be processed, which is convenient for grinding the tenon 10 and other post-processing, solves the problem of difficult positioning during processing of the turbine blade 1 to be processed, and improves the reference consistency.

[0034] Step 2: Install and fix the universal fixture 2 onto the workbench of the grinder.

[0035] Step three: using the rectangular alloy body 13 for positioning, the blade 1 to be processed is positioned and clamped on the blade fixture 3.

[0036] Step 4: Lock and fix the blade clamp 3 to the universal clamp 2 through the connecting component A4.

[0037] Step 5: Grind the upper surface and upper end of the tenon 10 of the blade 1 to be processed.

[0038] Step 6: Remove the connection component A4, and flip the blade fixture 3 and the blade 1 to be processed by 180 degrees, and then re-lock and fix the blade fixture 3 to the universal fixture 2 through the connection component A4.

[0039] Step 7: Grind the lower surface and the lower end of the tenon 10 of the blade 1 to be processed, and the grinding process of the tenon 10 is completed.

[0040] After the upper surface and the upper end of the tenon 10 of the blade 1 to be processed are ground, the connection component A4 is removed, and then the blade fixture 3 and the blade 1 to be processed are turned 180 degrees together, and the relative position of the blade fixture 3 and the universal fixture 2 is quickly positioned again, and then the blade fixture 3 is re-locked and fixed to the universal fixture 2 through the connection component A4. Since the speed of positioning the relative position of the blade fixture 3 and the universal fixture 2 is much faster than the speed of re-positioning the six faces of the rectangular alloy body 13, the present invention can significantly improve the positioning and clamping efficiency of the universal fixture 2 and the blade fixture 3 on the blade 1 to be processed, thereby achieving the purpose of improving the grinding efficiency of the tenon 10.

[0041] The alloy poured in step 1 is a tin-beryllium alloy, wherein Sn:Bi of the tin-beryllium alloy is 43:57, and the pouring temperature is 152° C. to 165° C. After the tin-beryllium alloy is poured, water is passed through it for condensation for 2 min to 3 min. After the tin-beryllium alloy is completely solidified, the excess burrs and protrusions around the rectangular alloy body 13 are removed.

[0042] The rectangular alloy body 13 is provided with mutually perpendicular reference planes C, D and G. The reference plane C is an end surface of the rectangular alloy body 13 close to the tenon 10. When the reference plane D is the bottom surface, the tenon 10 is in a horizontal state. A notch A130 is provided in the middle of the reference surface D on the rectangular parallelepiped alloy body 13, and a notch B131 is provided in the middle of the side surface opposite to the reference surface G. When the blade 1 to be processed is positioned and clamped on the blade fixture 3, the reference surface D on the rectangular parallelepiped alloy body 13 is closely attached to the upper surface of the rectangular positioning plate 39. Therefore, by providing the notch A130 in the middle of the reference surface D, the contact area between the reference surface D and the top surface of the rectangular positioning plate 39 can be reduced to improve the positioning accuracy.

[0043] The universal clamp 2 includes a base 20 and a threaded bushing 21. A positioning plate 22 is integrally formed on one side of the base 20. The bottom surface of the positioning plate 22 is coplanar with the bottom surface of the base 20, and the top surface of the positioning plate 22 is located above the top surface of the base 20. A T-shaped hole is provided on the base 20 along the thickness direction, and the threaded bushing 21 is arranged in the T-shaped hole.

[0044] A positioning boss A220 is provided on the side of the positioning plate 22 close to the base 20 above the base 20, and a threaded hole A200 is provided on the bottom of the base 20 close to the threaded bushing 21. A set screw A (not shown) is connected to the inner thread of the threaded hole A200, and the set screw A contacts the threaded bushing 21. The positioning boss A220 is used to cooperate with the positioning boss B301 to position the relative position of the blade clamp 3 and the universal clamp 2; the positioning boss B301 and the positioning boss A220 are used to position the relative position of the blade clamp 3 and the universal clamp 2 in close contact, which can reduce the contact area between the positioning plate 22 and the clamp body 30 and improve the positioning accuracy. The threaded bushing 21 is stopped and prevented from loosening by the set screw A.

[0045] The method for installing and fixing the universal clamp 2 on the workbench of the grinder in step 2 is: place the base 20 on the workbench of the grinder, and align it with a dial indicator to ensure that the runout of the base 20 along the X-axis and Y-axis on the horizontal plane is less than 0.005mm, and then fix the base 20 on the workbench.

[0046] The connecting component A4 is a bolt.

[0047] The blade clamp 3 comprises a clamp body 30 and a blade pressing assembly. A concave cavity 300 is provided on the clamp body 30, and a partition block 302 is integrally formed on the bottom surface of the concave cavity 300. The partition block 302 is provided with a through hole A303 and a threaded hole C304. Two rectangular positioning plates 39 are provided in the concave cavity 300, and the partition block 302 is located between the two rectangular positioning plates 39. Two positioning bosses B301 are provided on one side of the clamp body 30. A first side of the rectangular positioning plate 39 is provided on the clamp body 30. There is a positioning plate A34, two eccentric pins 31 are rotatably provided on the second side of the rectangular positioning plate 39, and an eccentric pin 31 is provided on the third side of the rectangular positioning plate 39. The first side, the second side and the third side are three sides adjacent to each other in the clockwise direction, and the first side is a side of the rectangular positioning plate 39 away from the positioning boss B301. The blade clamping assembly is located on the upper side of the partition block 302 and the two rectangular positioning plates 39, and the blade clamping assembly is connected to the partition block 302 and the clamp body 30 through the connecting assembly B.

[0048] The blade pressing assembly includes a connecting block 35 and two pressing blocks 32. The pressing blocks 32 are provided with through holes B320. The two pressing blocks 32 are rotatably connected to the two ends of the connecting block 35 in a one-to-one correspondence. Both ends of the connecting block 35 are provided with limit screws 33 to limit the pressing blocks 32. The two pressing blocks 32 are located directly above the two rectangular positioning plates 39 in a one-to-one correspondence, and the connecting block 35 is connected to the partition block 302 and the fixture body 30 through a connecting assembly B.

[0049] The connecting block 35 includes a connecting block body 350, a U-shaped notch 352 is provided in the middle of the connecting block body 350, connecting shafts 351 are provided at both ends of the connecting block body 350, and a threaded hole B353 is coaxially provided on the connecting shaft 351. The U-shaped notch 352 is provided in the middle of the connecting block body 350, so that the stud 37 can be quickly inserted into the U-shaped notch 352 without removing the washer 38 and the nut 36 from the stud 37, thereby improving the efficiency of the blade fixture 3 in assembling and disassembling the blade 1 to be processed.

[0050] The connection assembly B includes a stud 37, a washer 38 and a nut 36. The lower end of the stud 37 is threadedly connected to the threaded hole C304 on the partition block 302, the washer 38 is sleeved on the stud 37, the nut 36 is threadedly connected to the stud 37, and the washer 38 is located between the nut 36 and the connection block 35. When in use, the lower end of the stud 37 is threadedly connected to the threaded hole C304, and the bottom of the clamp body 30 is also threadedly connected with a set screw B to stop and prevent the stud 37 from loosening.

[0051] The method of positioning the blade 1 to be processed on the blade fixture 3 by using the rectangular alloy body 13 in step 3 comprises the following steps: Step A: Place two blades 1 to be processed on two rectangular positioning plates 39 respectively, and keep the reference surface D on the rectangular alloy body 13 in contact with the rectangular positioning plate 39, and keep the reference surface C on the rectangular alloy body 13 in contact with the positioning plate A34.

[0052] Step B: Rotate the three eccentric pins 31 located on the second and third sides of the rectangular positioning plate 39 to lock the rectangular alloy body 13. One end of the rectangular alloy body 13 close to the tenon 10 (i.e., the reference surface C) is positioned by the rectangular positioning plate 39, and the other end is positioned by the eccentric pin 31 located on the third side of the rectangular positioning plate 39; one side surface of the rectangular alloy body 13 (i.e., the opposite side of the reference surface G) is positioned by the two eccentric pins 31 located on the second side of the rectangular positioning plate 39, and the other side (i.e., the reference surface G) is positioned by the side wall of the partition block 302 or the side wall of the concave cavity 300; the bottom surface of the rectangular alloy body 13 (i.e., the reference surface D) is positioned by the rectangular positioning plate 39, and the top surface is positioned and pressed and fixed by the pressing block 32, so as to realize the positioning and clamping of the blade 1 to be processed.

[0053] Step C: Put two pressing blocks 32 onto the two ends of the connecting block 35 in a one-to-one correspondence, and screw the limiting screws 33 into the two ends of the connecting block 35 to limit the pressing blocks 32 .

[0054] Step D, insert the stud 37 into the U-shaped notch 352 on the connecting block 35, and then tighten the nut 36 to press and fix the two rectangular alloy bodies 13 on the two blades 1 to be processed through the two pressing blocks 32, thereby achieving the positioning and clamping of the blades 1 to be processed. When tightening the nut 36 on the stud 37, the nut 36 quickly presses and fixes the rectangular alloy bodies 13 on the two blades 1 to be processed through the washer 38, the connecting block 35 and the two pressing blocks 32, thereby achieving the rapid clamping and fixing of the two blades 1 to be processed to the blade fixture 3, improving the positioning and clamping efficiency of the blades 1 to be processed and the grinding efficiency of the tenon 10. Conversely, after loosening the nut 36 on the stud 37, the two pressing blocks 32 can quickly loosen the two blades 1 to be processed, thereby improving the efficiency of removing the blades 1 to be processed from the blade fixture 3.

[0055] Specifically, the blade fixture 3 can position and clamp two blades 1 to be processed at one time, which is convenient for grinding the tenons 10 of the two blades 1 to be processed simultaneously in step five and step seven, further improving the grinding efficiency of the tenons 10 of the blades 1 to be processed.

[0056] The method of locking and fixing the blade clamp 3 to the universal clamp 2 through the connecting component A4 in step 4 is as follows: placing the blade clamp 3 on the universal clamp 2, and keeping the bottom surface of the clamp body 30 in contact with the top surface of the base 20, keeping the positioning boss B301 on the clamp body 30 in contact with the positioning boss A220 on the positioning plate 22, and then passing one end of the connecting component A4 through the through hole A303 and connecting it to the threaded bushing 21, and tightening the connecting component A4 to lock and fix the blade clamp 3 on the universal clamp 2. The blade clamp 3 is connected to the universal clamp 2 through the connecting component A4, and the connecting component A4 is a bolt, that is, the blade clamp 3 and the universal clamp 2 can be quickly assembled and disassembled by a bolt, which helps to improve the grinding efficiency of the tenon 10.

[0057] In step five and step seven, the tenon 10 is ground with four cutters. The grinding speed is 32 m / s, the pressure of the coolant is 0.95 MPa, the grinding depths of the first cutter, the second cutter, the third cutter and the fourth cutter are ≤1.5 mm, ≤0.3 mm, ≤0.1 mm and ≤0.06 mm respectively, the feed speeds are 125 mm / min, 130 mm / min, 140 mm / min and 150 mm / min respectively, and the residual margins are 1.0 mm, 0.3 mm, 0.06 mm and 0 mm respectively.

[0058] Since the tenon 10 has a very high precision requirement, each grinding feed must be strictly controlled. In steps 5 and 7, the tenon 10 is ground with four cuts. The program for CNC machining of the slow-feed grinder is compiled. The process parameters are shown in the following table: Parameter Name Number of Knives Cutting depth Cutting speed Feed speed Coolant pressure Remaining amount First cut (rough grinding) ≤1.5mm 32m / s 125mm / min 0.95MPa 1.0mm Second knife (fine grinding) ≤0.3mm 32m / s 130mm / min 0.95MPa 0.3mm The third knife (fine grinding) ≤0.1mm 32m / s 140mm / min 0.95MPa 0.06mm Fourth knife (fine grinding) ≤0.06mm 35m / s 150mm / min 0.95MPa 0 After completing step five or step seven, it is necessary to measure the dimensions of the tenon 10 and check whether the grinding surface of the tenon teeth of the tenon 10 is overheated or has surface cracks. Fig. 22 As shown, through the metallographic image of the grinding surface at the transverse tenon of the blade body, it can be seen that there are no cracks on the grinding surface of the tenon and no heat phenomenon in the structure.

Claims

1. A grinding process for a tenon of an aircraft engine turbine blade, characterized in that: The following steps are involved: Step 1: pouring alloy into the blade body (11) section of the blade (1) to be processed to form a rectangular parallelepiped alloy body (13); Step 2: Install and fix the universal fixture (2) on the working table of the grinding machine; Step 3: Using the rectangular alloy body (13) for positioning, the blade to be processed (1) is positioned and clamped on the blade fixture (3); Step 4: Lock and fix the blade clamp (3) to the universal clamp (2) through the connecting component A (4); Step 5: Grinding the upper surface and upper end of the tenon (10) of the blade (1) to be processed; Step 6: Remove the connecting component A (4), flip the blade fixture (3) and the blade to be processed (1) together by 180 degrees, and then re-lock the blade fixture (3) onto the universal fixture (2) through the connecting component A (4); Step 7: Grind the lower surface and the lower end of the tenon (10) of the blade (1) to be processed, and the grinding process of the tenon (10) is completed.

2. The aero-engine turbine blade tenon grinding process according to claim 1, characterized in that: The alloy poured in step 1 is a tin-beryllium alloy, wherein Sn:Bi of the tin-beryllium alloy is 43:57, and the pouring temperature is 152° C. to 165° C. After the tin-beryllium alloy is poured, water is passed through it for condensation for 2 min to 3 min. After the tin-beryllium alloy is completely solidified, excess burrs and protrusions around the rectangular alloy body (13) are removed.

3. The aero-engine turbine blade tenon grinding process according to claim 1, characterized in that: The rectangular alloy body (13) is provided with a reference plane C, a reference plane D and a reference plane G which are perpendicular to each other, the reference plane C being an end surface of the rectangular alloy body (13) close to the tenon (10), and when the reference plane D is used as the bottom surface, the tenon (10) is in a horizontal state; The rectangular alloy body (13) has a notch A (130) in the middle of a reference plane D, and a notch B (131) in the middle of a side surface opposite to the reference plane G.

4. The aero-engine turbine blade tenon grinding process according to claim 1, characterized in that: The universal clamp (2) comprises a base (20) and a threaded bushing (21); a positioning plate (22) is integrally formed on one side of the base (20); the bottom surface of the positioning plate (22) is coplanar with the bottom surface of the base (20), and the top surface of the positioning plate (22) is located above the top surface of the base (20); a T-shaped hole is provided on the base (20) along the thickness direction, and the threaded bushing (21) is disposed in the T-shaped hole.

5. The aero-engine turbine blade tenon grinding process according to claim 4, characterized in that: A positioning boss A (220) is provided on one side of the positioning plate (22) close to the base (20) above the base (20), and a threaded hole A (200) is provided at the bottom of the base (20) close to the threaded bushing (21). A set screw A is connected to the inner thread of the threaded hole A (200), and the set screw A is in contact with the threaded bushing (21).

6. The aero-engine turbine blade tenon grinding process according to claim 4, characterized in that: The method for fixing the universal fixture (2) to the workbench of the grinding machine in step 2 is as follows: placing the base (20) on the workbench of the grinding machine and aligning it with a dial indicator to ensure that the runout of the base (20) along the X-axis and the Y-axis on the horizontal plane is less than 0.005 mm, and then fixing the base (20) on the workbench.

7. The aero-engine turbine blade tenon grinding process according to claim 1, characterized in that: The connecting assembly A (4) is a bolt.

8. The aero-engine turbine blade tenon grinding process according to claim 5, characterized in that: The blade clamp (3) comprises a clamp body (30) and a blade pressing assembly, the clamp body (30) being provided with a concave cavity (300), and a separator block (302) being integrally formed on the bottom surface of the concave cavity (300), the separator block (302) being provided with a through hole A (303) and a threaded hole C (304), two rectangular positioning plates (39) being provided in the concave cavity (300), and the separator block (302) being located between the two rectangular positioning plates (39), two positioning bosses B (301) being provided on one side of the clamp body (30), and the clamp body (30) being provided with a plurality of positioning bosses B (301) on the rectangular positioning plates (39). ), a positioning plate A (34) is provided on the first side of the rectangular positioning plate (39), two eccentric pins (31) are rotatably provided on the second side of the rectangular positioning plate (39), and an eccentric pin (31) is provided on the third side of the rectangular positioning plate (39), the first side, the second side and the third side are three sides adjacent to each other in a clockwise direction, and the first side is a side of the rectangular positioning plate (39) away from the positioning boss B (301), the blade clamping assembly is located on the upper side of the partition block (302) and the two rectangular positioning plates (39), and the blade clamping assembly is connected to the partition block (302) and the clamp body (30) via a connecting assembly B.

9. The aero-engine turbine blade tenon grinding process according to claim 8, characterized in that: The blade pressing assembly comprises a connecting block (35) and two pressing blocks (32), wherein the pressing blocks (32) are provided with through holes B (320), the two pressing blocks (32) are rotatably connected to the two ends of the connecting block (35) in a one-to-one correspondence, and both ends of the connecting block (35) are provided with limit screws (33) to limit the pressing blocks (32); The two pressing blocks (32) are located directly above the two rectangular positioning plates (39) in a one-to-one correspondence, and the connecting block (35) is connected to the partition block (302) and the clamp body (30) via a connecting assembly B.

10. The aircraft engine turbine blade tenon grinding process according to claim 9, characterized in that: The connection block (35) comprises a connection block body (350), a U-shaped notch (352) is provided in the middle of the connection block body (350), connection shafts (351) are provided at both ends of the connection block body (350), and a threaded hole B (353) is coaxially provided on the connection shaft (351).

11. The aero-engine turbine blade tenon grinding process according to claim 10, characterized in that: The connection assembly B comprises a stud (37), a washer (38) and a nut (36); the lower end of the stud (37) is threadedly connected to a threaded hole C (304) on the partition block (302); the washer (38) is sleeved on the stud (37); the nut (36) is threadedly connected to the stud (37); and the washer (38) is located between the nut (36) and the connection block (35).

12. The aircraft engine turbine blade tenon grinding process according to claim 11, characterized in that: The method of positioning the blade to be processed (1) on the blade fixture (3) by using the rectangular alloy body (13) for positioning in step 3 comprises the following steps: Step A, placing two blades to be processed (1) on two rectangular positioning plates (39) respectively, and making the reference surface D on the rectangular alloy body (13) keep in contact with the rectangular positioning plate (39), and making the reference surface C on the rectangular alloy body (13) keep in contact with the positioning plate A (34); Step B, rotating three eccentric pins (31) located on the second side and the third side of the rectangular positioning plate (39) to lock the rectangular parallelepiped alloy body (13); Step C, fitting the two pressing blocks (32) onto the two ends of the connecting block (35) in a one-to-one correspondence, and screwing limiting screws (33) into the two ends of the connecting block (35) to limit the pressing blocks (32); Step D: insert the stud (37) into the U-shaped notch (352) on the connecting block (35), and then tighten the nut (36) to press and fix the two rectangular alloy bodies (13) on the two blades (1) to be processed via the two pressing blocks (32), thereby achieving positioning and clamping of the blades (1) to be processed.

13. The aircraft engine turbine blade tenon grinding process according to claim 8, characterized in that: The method for locking and fixing the blade clamp (3) to the universal clamp (2) by means of the connecting component A (4) in step 4 is as follows: placing the blade clamp (3) on the universal clamp (2), and making the bottom surface of the clamp body (30) keep in contact with the top surface of the base (20), and making the positioning boss B (301) on the clamp body (30) keep in contact with the positioning boss A (220) on the positioning plate (22), and then passing one end of the connecting component A (4) through the through hole A (303) and connecting it to the threaded bushing (21), and tightening the connecting component A (4) to lock and fix the blade clamp (3) on the universal clamp (2).

14. The aircraft engine turbine blade tenon grinding process according to claim 1, characterized in that: In both step 5 and step 7, the tenon (10) is ground with four cutters, the grinding speed is 32 m / s, the pressure of the coolant is 0.95 MPa, the grinding depths of the first cutter, the second cutter, the third cutter and the fourth cutter are ≤1.5 mm, ≤0.3 mm, ≤0.1 mm and ≤0.06 mm, respectively, the feed speeds are 125 mm / min, 130 mm / min, 140 mm / min and 150 mm / min, respectively, and the residual margins are 1.0 mm, 0.3 mm, 0.06 mm and 0 mm, respectively.

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