A processing method of precision casting blade with pre-twisted angle

Abstract

The application relates to a processing method of a precision-cast moving vane with a pre-torsion angle, and relates to the technical field of vane processing. The application is used for solving the problems of the existing precision-cast moving vane blank reference point setting and the limited angle of a grinding machine, the difficulty in simultaneously processing the middle body of a middle-long vane and the reference surfaces of a surrounding band respectively on a back radial direction and an air outlet side, the tolerance accumulation caused by the sequence processing of vane reference surfaces, and the poor product precision and quality problems. The application comprises blank reference point selection and vane processing. The vane processing comprises processing the back radial reference surface and the air outlet side reference surface of the middle body, the back radial reference surface and the air outlet side reference surface of the surrounding band, processing the vane root profile, processing the inner profile line of the surrounding band, processing the back profile line of the surrounding band, and processing the inner radial direction of the middle body. The application is used for processing the precision-cast moving vane with the pre-torsion angle.

Description

Technical Field

[0001] This invention relates to the field of blade processing technology, and specifically to a processing method for precision-cast moving blades with pre-twist angle. Background Technology

[0002] When designing the blank drawing, the six reference points for precision-cast moving blades are generally selected as follows: two reference points are selected from the groove on the back of the middle body, one point is selected on the back arc side near the air passage of the shroud as three radial positioning points, one point is selected on the air inlet side of the air passage with equal height section, one point is selected at the inner arc conical surface, and one point is selected on the air inlet side of the blade root, for a total of six reference points. During machining, the reference points are used for positioning and machining the blade root tooth shape. Then, the blade root tooth shape is used for positioning and machining other parts. The disadvantage of this machining method is that the reference is converted to the tooth shape. The stability and consistency of clamping and inspection based on the tooth shape are poor. It is difficult to guarantee the shroud accuracy of blades with a blade height of 350mm or more. Summary of the Invention

[0003] To address the problem of poor product precision caused by the accumulation of tolerances due to the limited setting of reference points for existing precision-cast moving blade blanks and the restricted rotation angle of grinding machines, which makes it difficult to simultaneously process the reference surfaces of the intermediate body of the medium-length blade and the surrounding belt on the back radial and exhaust sides respectively, resulting in the sequential processing of the blade reference surfaces, this invention proposes a processing method for precision-cast moving blades with a pre-twist angle.

[0004] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0005] A method for machining a precision-cast moving blade with a pre-twist angle includes the following steps:

[0006] Step 1: Selection of blank reference points: Select the first reference point on the inner arc of the air passage near the side of the shroud, select the second reference point on the height air intake edge, select the third reference point in the radial weight removal groove inside the intermediate body, select the fourth reference point on the cone surface on the inner arc side, and select the fifth and sixth reference points on the air intake side of the intermediate body. At the same time, the second reference point is the point of tangency between the plane parallel to the plane containing the fifth and sixth reference points and the air intake edge of the air passage.

[0007] Step 2, Blade Machining: After selecting the blank reference point, the blade is ground on a grinding machine. The blade machining process includes the following steps:

[0008] Step 1: Machining the radial back, vent side, and circumferential reference surface of the intermediate body;

[0009] Step 2: Process the leaf root teeth;

[0010] Step 3: Process the inner molding lines of the enclosure;

[0011] Step 4: Process the backing line of the belt;

[0012] Step 5: Machining the radial direction within the intermediate body.

[0013] Furthermore, in step one, the blank is first clamped onto a six-point positioning fixture, and positioned at the blank's reference points. During clamping, the second reference point is positioned using a positioning plate, while the first, third, fourth, fifth, and sixth reference points are all positioned using spherical positioning pins. After clamping, the reference surfaces of the intermediate body's back radial direction, the vent side, and the surrounding belt's back radial direction and vent side are machined. The machining process includes the following steps:

[0014] Step 1: The blade length is arranged along the Z-axis of the machine tool, with the blade root facing the inside of the machine tool and the air outlet side of the blade root facing upwards. The grinding wheel moves along the X-axis of the machine tool to machine the air outlet side of the blade root.

[0015] Step 2: Keep the A axis of the worktable stationary and rotate the B axis of the worktable 180° so that the air outlet side of the shroud faces upward and the shroud faces the inside of the machine tool to machine the reference surface of the air outlet side of the shroud. At this time, the air outlet side of the shroud is parallel to the air outlet side of the blade root. The grinding wheel moves along the X axis and the shroud is machined with a 1mm allowance reserved at the part with the smallest allowance on the air outlet side of the shroud.

[0016] Step 3: Rotate the B axis of the worktable 90° and the A axis 70°, turn the back radial surface of the intermediate body to the horizontal, place the blade length along the X axis, and move the grinding wheel along the X axis to process the back radial surface of the intermediate body and process the back radial reference surface of the surrounding belt with a 1mm allowance at the minimum back radial allowance part. This step processes the back radial surface of the intermediate body and the back radial reference surface of the surrounding belt at the same time.

[0017] Furthermore, in the first process, the processing parameters for step one include:

[0018] Roughing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 40mm / min, the depth of cut per cut is 0.10mm, and a 0.5mm machining allowance is reserved for finishing;

[0019] Finishing: Grinding wheel linear speed VC is 30m / min, feed rate F is 40mm / min, depth of cut per pass is 0.05mm, number of passes is 6; depth of cut per pass is 0.03mm, number of passes is 6; depth of cut per pass is 0.01mm, number of passes is 2.

[0020] The machining parameters for step two include: grinding wheel linear speed VC is 26m / min, feed rate F is 40mm / min, and the depth of cut per cut is 0.10mm;

[0021] The processing parameters for step three include:

[0022] Roughing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 40mm / min, and the depth of cut per cut is 0.10mm. The process continues until the machining allowance of the surrounding band is 1mm. The intermediate body back radial section is then machined using the above parameters until a machining allowance of 0.5mm is reserved for finishing.

[0023] First finishing: Only the back radial direction of the intermediate body is machined, the grinding wheel linear speed VC is 30m / min, the feed rate F is 40mm / min, the depth of cut per tool is 0.05mm, and the number of cuts is 6; the depth of cut per tool is 0.03mm, and the number of cuts is 6.

[0024] Second finishing: The grinding wheel linear speed VC is 30m / min, the feed speed F is 40mm / min, and the back radial direction of the intermediate body and the back radial direction of the surrounding belt are machined at the same time. The depth of cut of each tool is 0.01mm, and the number of cuts is 2.

[0025] Furthermore, in the second process, the workpiece is first clamped onto the blade root tooth fixture. The fixture is positioned with reference surfaces of the back radial direction of the intermediate body, the air outlet side of the intermediate body and the back radial direction of the surrounding belt, and the air outlet side of the surrounding belt, which were processed in the first process. The length direction is positioned with the fourth reference point. The clamping plates are placed on the air inlet side of the intermediate body and the air inlet side of the surrounding belt to clamp the workpiece. After clamping is completed, the blade root tooth is processed.

[0026] Furthermore, in the second step, the processing parameters include:

[0027] Roughing: Grinding wheel linear speed VC is 26m / min, feed rate F is 70-80mm / min, depth of cut per cut is 0.1mm, and number of cuts is 3.

[0028] Finishing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 40mm / min, the depth of cut per cut is 0.03-0.05mm, and the number of cuts is 8.

[0029] Furthermore, in the third step, the workpiece is first clamped onto the inner radial fixture of the grinding belt. The fixture is positioned by the blade root back tooth shape processed in the second step, the blade root exhaust side processed in the first step, the back radial reference surface of the belt, and the exhaust side reference surface of the belt. The blade is clamped so that the intersection edge line of the inner radial working surface of the blade belt and the inner radial non-working surface of the belt is parallel to the X-axis of the machine tool. After clamping, the inner profile of the belt is processed. The processing uses a full-profile diamond roller grinding wheel to grind the grinding wheel. The grinding wheel moves along the X-axis in a straight line to process the inner profile of the belt.

[0030] Furthermore, in step three, the processing parameters include:

[0031] Roughing: Grinding wheel linear speed VC is 26m / min, feed rate F is 70-80mm / min, and the depth of cut per pass is 0.1-0.2mm;

[0032] Finishing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 40mm / min, and the depth of cut per cut is 0.03-0.05mm.

[0033] Furthermore, in step four, the workpiece is first clamped onto the grinding belt back profile fixture. The fixture is positioned by the blade root internal tooth profile processed in step two, the blade root exhaust side processed in step one, and the inner profile of the belt processed in step three. The blade is clamped so that the intersection edge line of the working surface and the non-working surface of the blade back radial surface is parallel to the X-axis of the machine tool. After clamping, the back profile of the belt is processed. The processing uses a full profile roller grinding wheel, and the grinding wheel moves along the X-axis in a straight line to process the outer profile of the belt.

[0034] Furthermore, in step five, the workpiece is first clamped onto the radial fixture inside the grinding intermediate. The fixture is positioned by the blade root back tooth shape processed in step two, the blade root outlet side processed in step one, and the surrounding belt back shape line processed in step four. The blade is clamped so that the radial surface inside the blade intermediate is horizontal, the blade length is placed along the Z-axis, and the blade root faces the inside of the machine tool. After clamping, the radial surface inside the intermediate is processed. The processing uses a flat roller grinding wheel, and the grinding wheel moves along the X-axis in a straight line to process the radial surface inside the intermediate.

[0035] Furthermore, in both steps four and five, the processing parameters include:

[0036] Roughing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 70-80mm / min, the depth of cut per pass is 0.1-0.2mm, and a 0.5mm machining allowance is reserved for finishing;

[0037] Finishing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 40mm / min, and the depth of cut per cut is 0.03-0.05mm.

[0038] The beneficial effects of this invention compared to the prior art are:

[0039] This invention provides a method for machining precision-cast moving blades with pre-twist angle. During machining, six reference points are selected as reference points for the blank. The intermediate body back radial direction, the exhaust side and the reference surface of the shroud, the blade root tooth shape, the inner profile of the shroud, the back profile of the shroud and the intermediate body inner radial direction are machined in sequence to complete the entire blade machining process. The machining process adopts a six-point positioning fixture with integrated clamping and measuring. After the blade is machined, the relative dimensions of the machined surface and the measuring block are directly measured on the fixture to ensure the stability of the measurement and improve the machining accuracy and consistency of precision-cast moving blades with pre-twist angle. Attached Figure Description

[0040] Figure 1 This is a blank drawing of the precision-cast moving blade with pre-twist angle in this invention;

[0041] Figure 2 yes Figure 1 GG view in the middle;

[0042] Figure 3 yes Figure 1 HH direction view in the middle;

[0043] Figure 4 yes Figure 1 JJ in the view;

[0044] Figure 5 This is a clamping diagram of process one in this invention;

[0045] Figure 6 yes Figure 5 The left view;

[0046] Figure 7 yes Figure 5 CC view in the middle;

[0047] Figure 8 yes Figure 5 BB view in the middle;

[0048] Figure 9 yes Figure 5 AA direction view in the middle;

[0049] Figure 10 yes Figure 5 EE to view;

[0050] Figure 11 yes Figure 5 DD direction view in the middle;

[0051] Figure 12 This is a clamping diagram of step two in this invention;

[0052] Figure 13 yes Figure 12 The left view;

[0053] Figure 14 yes Figure 13 OO view in the middle;

[0054] Figure 15 yes Figure 13 FF view in the middle;

[0055] Figure 16 This is the clamping diagram for process three in this invention;

[0056] Figure 17 yes Figure 16 The left view;

[0057] Figure 18 yes Figure 17 RR direction view in;

[0058] Figure 19 yes Figure 17 SS-direction view in the middle;

[0059] Figure 20 This is the clamping diagram for step four in this invention;

[0060] Figure 21 yes Figure 20 The left view;

[0061] Figure 22 yes Figure 20 VV-direction view in the middle;

[0062] Figure 23 yes Figure 20 UU-direction view in the middle;

[0063] Figure 24 This is a clamping diagram of the comprehensive measuring tool in this invention;

[0064] Figure 25 yes Figure 24 The left view;

[0065] Figure 26 yes Figure 25 PP view in the middle;

[0066] Figure 27 This is a schematic diagram of the clamping process during the inspection on the comprehensive measuring tool in step three of this invention;

[0067] Figure 28 This is a schematic diagram of the clamping process in step four of this invention when the instrument is used for testing. Detailed Implementation

[0068] To make the technical problems solved, the technical solutions, and the beneficial effects of the present invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0069] Specific implementation method one: Combining Figures 1 to 28 This embodiment describes a method for machining a precision-cast moving blade with a pre-twist angle, comprising the following steps:

[0070] Step 1: Selection of reference points for the blank: Select the first reference point D1 on the inner arc of the air passage near the side of the shroud, select the second reference point D2 on the height air intake edge, select the third reference point D3 in the radial weight removal groove inside the intermediate body, select the fourth reference point D4 on the cone surface on the inner arc side, and select the fifth reference point D5 and the sixth reference point D6 on the air intake side of the intermediate body. At the same time, the second reference point D2 is the point of tangency between the plane parallel to the plane containing the fifth reference point D5 and the sixth reference point D6 and the air intake edge of the air passage.

[0071] Step 2, Blade Machining: After selecting the blank reference point, the blade is ground on a grinding machine. The blade machining process includes the following steps:

[0072] Step 1: Machining the radial back, vent side, and circumferential reference surface of the intermediate body;

[0073] Step 2: Process the leaf root teeth;

[0074] Step 3: Process the inner molding lines of the enclosure;

[0075] Step 4: Process the backing line of the belt;

[0076] Step 5: Machining the radial direction within the intermediate body.

[0077] Specific Implementation Method Two: Combining Figures 1 to 28 This embodiment describes a process where, in step one, the blank is first clamped onto a six-point positioning fixture. The blank is positioned at its reference points. During clamping, the second reference point D2 is positioned using a positioning plate, while the first reference point D1, third reference point D3, fourth reference point D4, fifth reference point D5, and sixth reference point D6 are all positioned using spherical positioning pins. After clamping, the reference surfaces of the intermediate body's back radial direction, the vent side, and the surrounding belt's back radial direction and vent side are machined. The machining process includes the following steps:

[0078] Step 1: The blade length is arranged along the Z-axis of the machine tool, with the blade root facing the inside of the machine tool and the air outlet side of the blade root facing upwards. The grinding wheel moves along the X-axis of the machine tool to machine the air outlet side of the blade root.

[0079] Step 2: Keep the A axis of the worktable stationary and rotate the B axis of the worktable 180° so that the air outlet side of the shroud faces upward and the shroud faces the inside of the machine tool to machine the reference surface of the air outlet side of the shroud. At this time, the air outlet side of the shroud is parallel to the air outlet side of the blade root. The grinding wheel moves along the X axis and the shroud is machined with a 1mm allowance reserved at the part with the smallest allowance on the air outlet side of the shroud.

[0080] Step 3: Rotate the B axis of the worktable 90° and the A axis 70°, turn the back radial surface of the intermediate body to the horizontal, place the blade length along the X axis, and move the grinding wheel along the X axis to process the back radial surface of the intermediate body and process the back radial reference surface of the surrounding belt with a 1mm allowance at the minimum back radial allowance part. This step processes the back radial surface of the intermediate body and the back radial reference surface of the surrounding belt at the same time.

[0081] The undisclosed technical features in this embodiment are the same as those in Specific Embodiment 1.

[0082] The tolerance for the height difference between the reference plane of the air outlet side of the circumference belt in step two and the air outlet side of the blade root is ±0.02, and the tolerance for the height difference between the reference plane of the back radial direction of the intermediate body and the back radial direction of the circumference belt in step three is ±0.02.

[0083] In the six-point positioning fixture, the base plate 1 is horizontally positioned. The first positioning plate 2, the second positioning plate 3, the first positioning seat 4, the locking seat 7, the second positioning seat 8, the third positioning seat 12, and the measuring block 11 are all fixed to the upper surface of the base plate 1 by screws 9 and positioning pins 10. The locking seat 7 and the second positioning seat 8 are positioned opposite each other. Spherical positioning pins 5 are fixed to the positioning seats, and locking screws 6 are installed on the locking seat 7 to clamp the blade. The second reference point D2 is positioned by the first positioning plate 2. The first reference point D1, the third reference point D3, the fifth reference point D5, and the sixth reference point D6 are all positioned by R4 spherical positioning pins 5. The first positioning plate 2 of the second reference point D2 on the air intake side of the air passage is provided with a clamping foot structure to prevent the blade from rotating when the back arc side pressure plate is applied (see Figures CC and EE). The back arc pressure plate of the air passage is shown in view BB. The pressure plate 17 is applied to the air seal end face on the air outlet side of the intermediate body. To ensure the dimensional accuracy of the machined parts, a measuring block 11 is designed on the fixture, as shown in Figure DD. After the blade is machined, the relative dimensions between the machined surface and the measuring block 11 can be directly checked on the fixture. This avoids the clamping error caused by the six-point positioning clamping when the blade is measured on the machine tool and the dimensions are not up to standard, and the blade is put back on the machine tool for supplementary machining.

[0084] Spherical positioning pin design 5 The mating pins are embedded in each positioning seat. The other parts are connected to the base plate 1 using screws 9 and locating pins 10.

[0085] Specific implementation method three: Combining Figures 1 to 28 This embodiment describes a process where the processing parameters for step one include:

[0086] Roughing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 40mm / min, the depth of cut per cut is 0.10mm, and a 0.5mm machining allowance is reserved for finishing;

[0087] Finishing: Grinding wheel linear speed VC is 30m / min, feed rate F is 40mm / min, depth of cut per pass is 0.05mm, number of passes is 6; depth of cut per pass is 0.03mm, number of passes is 6; depth of cut per pass is 0.01mm, number of passes is 2.

[0088] The machining parameters for step two include: grinding wheel linear speed VC is 26m / min, feed rate F is 40mm / min, and the depth of cut per cut is 0.10mm;

[0089] The processing parameters for step three include:

[0090] Roughing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 40mm / min, and the depth of cut per cut is 0.10mm. The process continues until the machining allowance of the surrounding band is 1mm. The intermediate body back radial section is then machined using the above parameters until a machining allowance of 0.5mm is reserved for finishing.

[0091] First finishing: Only the back radial direction of the intermediate body is machined, the grinding wheel linear speed VC is 30m / min, the feed rate F is 40mm / min, the depth of cut per tool is 0.05mm, and the number of cuts is 6; the depth of cut per tool is 0.03mm, and the number of cuts is 6.

[0092] Second finishing: The grinding wheel linear speed VC is 30m / min, the feed speed F is 40mm / min, and the back radial direction of the intermediate body and the back radial direction of the surrounding belt are machined at the same time. The depth of cut of each tool is 0.01mm, and the number of cuts is 2.

[0093] The undisclosed technical features in this embodiment are the same as those in Specific Embodiment Two.

[0094] Specific implementation method four: Combination Figures 1 to 28 This embodiment describes a second step where the workpiece is first clamped onto the blade root tooth fixture. The fixture is positioned using the radial back surface of the intermediate body, the air outlet side of the intermediate body, the radial back surface of the shroud, and the air outlet side reference surface of the shroud, all machined in step one. The length direction is positioned using the fourth reference point D4. Clamping plates are placed on the air inlet side of the intermediate body and the air inlet side of the shroud. After clamping, the blade root tooth profile is machined. Undisclosed technical features in this embodiment are the same as in specific embodiment one.

[0095] During clamping, the first blade root positioning seat 13 and the first shroud positioning seat 14 in the blade root tooth profile fixture are positioned opposite each other. To ensure clamping stability, a toothed structure is designed on the first blade root positioning seat 13, with the toothed portion reduced by 1mm according to the blade root tooth normal in the product drawing. The F-surface profile of the first blade root positioning seat 13 is measured to be 0.02mm using the outlet side positioning surface as a reference. The straightness of the machined blade root tooth profile is then checked using the F-surface of the first blade root positioning seat 13.

[0096] Spherical positioning pin design 5 The mating pin is embedded in the conical positioning seat 15. The pin hole is used for mounting. All other parts are connected using bolts and locating pins.

[0097] In the second process, during processing, the dial indicator runout along the X and Y directions of the fixture blade root positioning surface must be ≤0.02 before processing can proceed.

[0098] Specific Implementation Method Five: Combining Figures 1 to 28 This embodiment describes a process where the processing parameters for step two include:

[0099] Roughing: Grinding wheel linear speed VC is 26m / min, feed rate F is 70-80mm / min, depth of cut per cut is 0.1mm, and number of cuts is 3.

[0100] Finishing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 40mm / min, the depth of cut per cut is 0.03-0.05mm, and the number of cuts is 8.

[0101] The undisclosed technical features in this embodiment are the same as those in Specific Embodiment Four.

[0102] Specific Implementation Method Six: Combination Figures 1 to 28 This embodiment describes a third step where the workpiece is first clamped onto the inner radial fixture of the grinding belt. The fixture is positioned using the blade root back tooth shape machined in step two, the blade root exhaust side machined in step one, the back radial reference surface of the grinding belt, and the exhaust side reference surface of the grinding belt. The blade is clamped so that the intersection line of the inner radial working surface and the inner radial non-working surface of the blade is parallel to the X-axis of the machine tool. After clamping, the inner profile of the grinding belt is machined using a full-profile diamond roller grinding wheel, with the grinding wheel moving along a straight line along the X-axis to machine the inner profile of the grinding belt. Any undisclosed technical features in this embodiment are the same as in specific embodiment one.

[0103] During clamping, the second blade root positioning seat 16 and the second belt positioning seat 17 in the inner radial clamp of the grinding belt are set opposite to each other. To ensure clamping stability, a first toothed block 18 structure is designed on the second blade root positioning seat 16. The toothed part is designed according to the theoretical contour of the blade root tooth in the product drawing.

[0104] To ensure measurement accuracy, a back positioning block 23 and an inner template 24 are designed on the upper circumference of the comprehensive measuring tool, at the back reference surface and the air outlet reference surface. The back positioning block is designed according to the theoretical position of the reference surface, and the measuring surface of the template is designed according to the maximum solid size of the product. The back positioning block does not leak light, and the light leakage gap of the inner template is ≤0.1 mm when it is qualified.

[0105] Specific implementation method seven: Combination Figures 1 to 28 This embodiment describes a process where, in step three, the processing parameters include:

[0106] Rough machining: The linear velocity VC of the grinding wheel is 26 m / min, the feed rate F is 70 - 80 mm / min, and the depth of cut per tool is 0.1 - 0.2 mm;

[0107] Finishing machining: The linear velocity VC of the grinding wheel is 26 m / min, the feed rate F is 40 mm / min, and the depth of cut per tool is 0.03 - 0.05 mm.

[0108] The technical features not disclosed in this embodiment are the same as those in the sixth specific embodiment.

[0109] Specific embodiment eight: Combining Figures 1 to 28 To illustrate this embodiment, in process four of this embodiment, first, the workpiece is clamped onto the grinding belt back profile line fixture. The fixture is positioned by the root inner tooth profile machined in process two, the root outlet side machined in process one, and the belt inner profile machined in process three. Clamp the blade so that the intersection edge line of the working surface and the non - working surface of the blade back radial surface is parallel to the X - axis of the machine tool. After clamping, the processing of the belt back profile line is carried out. During the processing, a full - profile roller grinding wheel is used, and the grinding wheel feeds along a straight line parallel to the X - axis to process the outer profile line of the belt. The technical features not disclosed in this embodiment are the same as those in the first specific embodiment.

[0110] During clamping, the third root positioning seat 19, the belt outlet side positioning seat 21, and the belt inner radial positioning seat 22 in the grinding belt inner radial fixture are arranged opposite to each other. To ensure the clamping stability, a second tooth - shaped block 20 structure is designed on the third root positioning seat 19, and the tooth - shaped part is designed according to the theoretical profile of the root tooth profile in the product drawing.

[0111] To ensure the measurement accuracy, a back template 25 is designed at the inner back radial working surface during the comprehensive measuring tool inspection. It is used in conjunction with the inner template 24 in process three. The inner template, the back template, and the measuring surface of the back template are designed according to the maximum entity of the product. It is qualified when the light leakage gap and △X + △Y ≤ 0.2.

[0112] Specific embodiment nine: Combining Figures 1 to 28 To illustrate this embodiment, in process five of this embodiment, first, the workpiece is clamped onto the grinding middle - body inner radial fixture. The fixture is positioned by the root back tooth profile machined in process two, the root outlet side machined in process one, and the belt back profile machined in process four. Clamp the blade so that the inner radial surface of the blade middle - body is horizontal, the blade length is placed along the Z - axis, and the root faces the inside of the machine tool. After clamping, the processing of the middle - body inner radial is carried out. During the processing, a flat roller grinding wheel is used, and the grinding wheel feeds along a straight line parallel to the X - axis to process the inner radial surface of the middle - body. The technical features not disclosed in this embodiment are the same as those in the first specific embodiment.

[0113] Specific embodiment ten: Combining Figures 1 to 28 To illustrate this embodiment, in processes four and five of this embodiment, the processing parameters both include:

[0114] Roughing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 70-80mm / min, the depth of cut per pass is 0.1-0.2mm, and a 0.5mm machining allowance is reserved for finishing;

[0115] Finishing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 40mm / min, and the depth of cut per cut is 0.03-0.05mm.

[0116] The undisclosed technical features in this embodiment are the same as those in specific embodiments eight or nine.

[0117] In this embodiment, the blades are ground and assembled simultaneously to ensure that the gap between the intermediate parts meets the design requirements.

[0118] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for machining precision-cast moving blades with pre-twist angle, characterized in that: The method includes the following steps: Step 1: Selection of reference points for the blank: Select the first reference point (D1) on the inner arc of the air passage near the side of the shroud, select the second reference point (D2) on the height air intake edge, select the third reference point (D3) in the radial weight removal groove inside the intermediate body, select the fourth reference point (D4) on the cone surface on the inner arc side, and select the fifth reference point (D5) and the sixth reference point (D6) on the air intake side of the intermediate body. At the same time, the second reference point (D2) is the point of tangency between the plane parallel to the plane containing the fifth reference point (D5) and the sixth reference point (D6) and the air intake edge of the air passage. Step 2, Blade Machining: After selecting the blank reference point, the blade is ground on a grinding machine. The blade machining process includes the following steps: Step 1: Machining the radial back, vent side, and circumferential reference surface of the intermediate body; Step 2: Process the leaf root teeth; Step 3: Process the inner molding lines of the enclosure; Step 4: Process the backing line of the belt; Step 5: Machining the radial direction within the intermediate body; In the second process, the workpiece is first clamped onto the blade root tooth fixture. The fixture is positioned with reference surfaces of the back radial direction of the intermediate body, the air outlet side of the intermediate body and the back radial direction of the surrounding belt, and the air outlet side of the surrounding belt, which are processed in the first process. The length direction is positioned with the fourth reference point (D4). The clamping plates are placed on the air inlet side of the intermediate body and the air inlet side of the surrounding belt. After clamping is completed, the blade root tooth is processed. In the second process, the processing parameters include: Roughing: Grinding wheel linear speed VC is 26m / min, feed rate F is 70-80mm / min, depth of cut per cut is 0.1mm, and number of cuts is 3. Finishing: Grinding wheel linear speed VC is 26m / min, feed rate F is 40mm / min, depth of cut per cut is 0.03-0.05mm, and number of cuts is 8. In the third process, the workpiece is first clamped onto the inner radial fixture of the grinding belt. The fixture is positioned by the blade root back tooth shape processed in the second process, the blade root exhaust side processed in the first process, the back radial reference surface of the belt, and the exhaust side reference surface of the belt. The blade is clamped so that the intersection edge line of the inner radial working surface of the blade belt and the inner radial non-working surface of the belt is parallel to the X-axis of the machine tool. After clamping, the inner profile of the belt is processed. The processing uses a full profile diamond roller grinding wheel to grind the grinding wheel. The grinding wheel moves along the X-axis in a straight line to process the inner profile of the belt. In the third process, the processing parameters include: Roughing: Grinding wheel linear speed VC is 26m / min, feed rate F is 70-80mm / min, and the depth of cut per pass is 0.1-0.2mm; Finishing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 40mm / min, and the depth of cut per cut is 0.03-0.05mm.

2. The machining method for a precision-cast moving blade with pre-twist angle according to claim 1, characterized in that: In the first process, the blank is first clamped onto a six-point positioning fixture and positioned at the reference point. During clamping, the second reference point (D2) is positioned using a positioning plate, while the first reference point (D1), third reference point (D3), fourth reference point (D4), fifth reference point (D5), and sixth reference point (D6) are all positioned using spherical positioning pins. After clamping, the reference surfaces of the intermediate body's back radial direction, the vent side, and the surrounding belt's back radial direction and vent side are machined. The machining process includes the following steps: Step 1: The blade length is arranged along the Z-axis of the machine tool, with the blade root facing the inside of the machine tool and the air outlet side of the blade root facing upwards. The grinding wheel moves along the X-axis of the machine tool to machine the air outlet side of the blade root. Step 2: Keep the A axis of the worktable stationary and rotate the B axis of the worktable 180° so that the air outlet side of the shroud faces upward and the shroud faces the inside of the machine tool to machine the reference surface of the air outlet side of the shroud. At this time, the air outlet side of the shroud is parallel to the air outlet side of the blade root. The grinding wheel moves along the X axis and the shroud is machined with a 1mm allowance reserved at the part with the smallest allowance on the air outlet side of the shroud. Step 3: Rotate the B axis of the worktable 90° and the A axis 70°, turn the back radial surface of the intermediate body to the horizontal, place the blade length along the X axis, and move the grinding wheel along the X axis to process the back radial surface of the intermediate body and process the back radial reference surface of the surrounding belt with a 1mm allowance at the minimum back radial allowance part. This step processes the back radial surface of the intermediate body and the back radial reference surface of the surrounding belt at the same time.

3. The machining method for a precision-cast moving blade with pre-twist angle according to claim 2, characterized in that: In the first process, the processing parameters for step one include: Roughing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 40mm / min, the depth of cut per cut is 0.10mm, and a 0.5mm machining allowance is reserved for finishing; Finishing: Grinding wheel linear speed VC is 30m / min, feed rate F is 40mm / min, depth of cut per pass is 0.05mm, number of passes is 6; depth of cut per pass is 0.03mm, number of passes is 6; depth of cut per pass is 0.01mm, number of passes is 2. The machining parameters for step two include: grinding wheel linear speed VC is 26m / min, feed rate F is 40mm / min, and the depth of cut per cut is 0.10mm; The processing parameters for step three include: Roughing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 40mm / min, and the depth of cut per cut is 0.10mm. The process continues until the machining allowance of the surrounding band is 1mm. The intermediate body back radial section is then machined using the above parameters until a machining allowance of 0.5mm is reserved for finishing. First finishing: Only the back radial direction of the intermediate body is machined, the grinding wheel linear speed VC is 30m / min, the feed rate F is 40mm / min, the depth of cut per tool is 0.05mm, and the number of cuts is 6; the depth of cut per tool is 0.03mm, and the number of cuts is 6. Second finishing: The grinding wheel linear speed VC is 30m / min, the feed speed F is 40mm / min, and the back radial direction of the intermediate body and the back radial direction of the surrounding belt are machined at the same time. The depth of cut of each tool is 0.01mm, and the number of cuts is 2.

4. The machining method for a precision-cast moving blade with pre-twist angle according to claim 1, characterized in that: In step four, the workpiece is first clamped onto the grinding belt back profile fixture. The fixture is positioned by the blade root internal tooth profile processed in step two, the blade root exhaust side processed in step one, and the inner profile of the belt processed in step three. The blade is clamped so that the intersection edge line of the working surface and the non-working surface of the blade back radial surface is parallel to the X-axis of the machine tool. After clamping, the back profile of the belt is processed. The processing uses a full profile roller grinding wheel, and the grinding wheel moves along the X-axis in a straight line to process the outer profile of the belt.

5. The machining method for a precision-cast moving blade with pre-twist angle according to claim 1, characterized in that: In step five, the workpiece is first clamped onto the radial fixture inside the grinding intermediate. The fixture is positioned by the blade root back tooth shape processed in step two, the blade root outlet side processed in step one, and the surrounding belt back shape line processed in step four. The blade is clamped so that the radial surface inside the blade intermediate is horizontal, the blade length is placed along the Z-axis, and the blade root faces the inside of the machine tool. After clamping, the radial surface inside the intermediate is processed. The processing uses a flat roller grinding wheel, and the grinding wheel moves along the X-axis in a straight line to process the radial surface inside the intermediate.

6. A method for machining a precision-cast moving blade with a pre-twist angle according to claim 4 or 5, characterized in that: In both steps four and five, the processing parameters include: Roughing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 70-80mm / min, the depth of cut per pass is 0.1-0.2mm, and a 0.5mm machining allowance is reserved for finishing; Finishing: The grinding wheel linear speed VC is 26m / min, the feed rate F is 40mm / min, and the depth of cut per cut is 0.03-0.05mm.

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