A turbine stator blade machining clamp and a grinding machining method thereof

Abstract

This invention provides a fixture for machining turbine stator blades and a grinding method thereof. The fixture uses two types of tooling to clamp and fix the blades, followed by two corresponding roller grinding processes to complete the grinding process. This method reduces the number of steps, increases processing efficiency, reduces cost, and achieves high machining accuracy. It includes a first clamping fixture and a second clamping fixture, which clamp and fix the blades, respectively, before machining the exhaust side mounting edge and back radial surface, and the intake side mounting edge and inner radial surface. The first clamping fixture includes a first base, on which a support clamping mechanism, a side clamping mechanism, and a downward side clamping mechanism are respectively provided.

Description

Technical Field

[0001] This invention relates to the technical field of turbine stator blade machining methods, specifically to a fixture for machining turbine stator blades and its grinding method. Background Technology

[0002] With the rapid development of gas turbine manufacturing technology, the materials and processes for turbine blades are constantly being updated, and the corresponding blade processing technology is also changing, shifting from primarily cutting to primarily grinding. For example... Figure 1 The image shows a turbine stator blade for a gas turbine. The blade material is K452, a nickel-based precipitation-hardening equiaxed crystal casting high-temperature alloy, which is a typical difficult-to-machine material. Currently, during the machining process of this blade, it is necessary to machine the exhaust side mounting edge a and back radial surface b, and the intake side mounting edge c and inner radial surface d. This is generally achieved through triaxial high-intensity grinding. At the same time, each process can only machine one part (i.e., grind one part), which results in the blade needing to be clamped multiple times. This process is complicated, has low machining efficiency, high cost, and low machining accuracy. Summary of the Invention

[0003] To address the problems of existing blade grinding processes requiring multiple clamping and fitting operations, resulting in complex procedures, low processing efficiency, high costs, and low machining accuracy, this invention provides a fixture for turbine stator blade machining and its grinding method. By designing two tooling fixtures to clamp and fix the blade, and then combining them with two corresponding roller grinding processes, the grinding process can be completed. This method reduces the number of steps, increases processing efficiency, reduces costs, and achieves high machining accuracy.

[0004] The technical solution is as follows: a fixture for machining turbine stator blades, characterized in that: it includes a first clamping fixture and a second clamping fixture, the blade is clamped and fixed by the first clamping fixture and then its outlet side mounting edge and back radial surface are machined, the blade is clamped and fixed by the second clamping fixture and then its inlet side mounting edge and inner radial surface are machined.

[0005] The first clamping fixture includes a first base, on which a support clamping mechanism, a side clamping mechanism, and a downward side clamping mechanism are respectively provided. The support clamping mechanism includes three parts, two of which are used to clamp the lower flange of the small edge plate of the blade, and the other is used to clamp one side of the lower flange of the large edge plate of the blade. The side clamping mechanism is used to press against the inner radial surfaces of both sides of the blade, both sides of the blade body, and the outer side of one side of the lower flange of the large edge plate. The downward side clamping mechanism is used to clamp the other side of the lower flange of the large edge plate of the blade.

[0006] A further feature is that: the support and pressing mechanism includes a support seat and a lower pressing seat that cooperate with each other; the support seat includes a fixed column connected to the first base; the top of the fixed column is provided with a support shaft; the lower pressing seat includes a fixed block connected to the first base; the upper end of the fixed block is provided with a lower pressing plate that is hingedly connected via a connecting shaft; the middle part of the lower pressing plate is provided with a waist-shaped through groove; and the lower pressing screw passes through the through groove and is threadedly connected to the fixed block.

[0007] The side pressing mechanism includes a side pressing block connected to the first base. The side pressing block has an insertable, movably connected ejector block on one side near the blade. The other side of the side pressing block has a fixing plate. The fixing block has a threaded adjusting screw. The adjusting screw extends into the side pressing block and connects with a slot on the ejector block.

[0008] The downward pressing mechanism includes a positioning block connected to the first base. The top of the positioning block is provided with a sliding groove, and a pressure plate is provided on the sliding groove. The pressure plate is provided with a waist-shaped groove. The lower end of the connecting rod passes through the waist-shaped groove and is connected to the bottom wall of the sliding groove. A push block is inserted into the middle of the positioning block near the blade. A fixing plate is provided on the other side of the positioning block. A threaded ejector rod is provided on the fixing plate. The ejector rod extends into the positioning block and is connected to the slot on the push block.

[0009] Support blocks are provided on both sides of the first base corresponding to the bottom of the blade body, and a stop block is provided on the first base corresponding to the outer side of the blade body. The support blocks and the stop blocks are respectively fitted with tightening balls.

[0010] The second clamping mechanism includes a second base. On one side of the second base are two support seats corresponding to the bottom of the blade small edge plate. The middle part of the two support seats is provided with a through groove. The through groove is provided with a first clamping block and a second clamping block that cooperate with each other. The outside of the two support seats is provided with a fixing plate. The upper and lower ends of the fixing plate are provided with a first screw and a second screw that are threadedly connected. The first screw and the second screw extend into the inside of the support seat and are respectively connected to the slots of the first clamping block and the second clamping block. The second base has a support strip on the other side corresponding to the bottom of the blade's large edge plate. A third clamping block and a fourth clamping block are provided on the support strip near the blade. Fixing plates are provided on the upper and lower sides of the other side of the support strip. A third screw and a fourth screw are threadedly connected to the two fixing plates. The third screw and the fourth screw extend into the support strip and connect with the slots of the third clamping block and the fourth clamping block, respectively. It also includes a side stop block corresponding to the back radial surface of the blade. An upper top block and a lower top block are provided on the side stop block near the blade. A connecting piece is provided on the other side of the side stop block. A threaded screw is provided on the connecting piece. The screw extends into the side stop block and connects with the slot of the lower top block. A lower pressure plate is also provided on the side stop block and is movably connected via the screw.

[0011] The second base is provided with clamping plates connected by support rods, corresponding to the lower flanges of the large and small flanges of the blade. The clamping plates have a through groove in the middle, and the clamping screw passes through the through groove and connects to the second base. The second base is also provided with inverted T-shaped blocks at both ends of the blade body. The upper end of the T-shaped blocks is provided with a strip plate that clamps the blade body by bolts. The second base is also provided with side blocks corresponding to the blade body.

[0012] The present invention also provides a method for grinding turbine stator blades, characterized by the following steps: S1, clamping the blade on the first clamping fixture and machining the exhaust side mounting edge and back radial surface of the blade; S2, clamping the blade on the second clamping fixture and machining the intake side mounting edge and inner radial surface of the blade.

[0013] In S1, a five-axis high-power creep grinder is used. The rollers and grinding wheels are selected to process the air outlet side mounting edge and back radial surface of the blade. During grinding, the linear speed of the grinding wheel is 10~25M / S, the feed rate is 200~350mm / min, and the depth of cut is 0.3~1.5mm. The diamond roller dressing method is set to dress and grind simultaneously, and the dressing speed is 0.2~0.8um / rad.

[0014] In S2, a five-axis high-power creep grinder is used to process the air intake side mounting edge and inner radial surface of the blade using rollers and grinding wheels. During grinding, the linear speed of the grinding wheel is 10~25M / S, the feed rate is 200~350mm / min, and the depth of cut is 0.3~1.5mm. The diamond roller dressing mode is set to simultaneous dressing and grinding, with a dressing speed of 0.2~0.8um / rad.

[0015] With the above structure, by setting the first clamping fixture and the second clamping fixture, the blade is clamped and fixed by the first clamping fixture and then its exhaust side mounting edge and back radial surface are machined, and the blade is clamped and fixed by the second clamping fixture and then its intake side mounting edge and inner radial surface are machined. The grinding process of the blade can be completed in two processes, with fewer processes, higher processing efficiency, lower cost and higher processing accuracy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the turbine stator blade structure;

[0017] Figure 2 This is a schematic diagram of the turbine stator blade structure from another direction.

[0018] Figure 3 This is a schematic diagram of the structure of the first clamping fixture and the turbine stator blade of the present invention;

[0019] Figure 4 This is a schematic diagram of the first clamping fixture and the turbine stator blade from another direction of the present invention;

[0020] Figure 5 This is a schematic diagram of the structure of the first clamping fixture of the present invention;

[0021] Figure 6 This is a schematic diagram of the ejector block and adjusting screw of the present invention;

[0022] Figure 7 This is a schematic diagram of the structure of the second clamping fixture and the turbine stator blade of the present invention;

[0023] Figure 8 This is a schematic diagram of the structure of the second clamping fixture of the present invention;

[0024] Figure 9 This is a schematic diagram of the structure of the first clamping block and the second clamping block of the present invention;

[0025] Figure 10 This is a schematic diagram of the outer ring air outlet side step processing (roller and grinding wheel combination) part of the present invention;

[0026] Figure 11 This is a schematic diagram of another part of the outer ring air outlet side step processing (roller and grinding wheel combination) of the present invention;

[0027] Figure 12 This is a schematic diagram of the structure of another annular air outlet side step processing (roller and grinding wheel combination) part of the present invention;

[0028] Figure 13 This is a schematic diagram of the structure of the inner ring air outlet side step processing (roller and grinding wheel combination) part of the present invention;

[0029] Figure 14 This is a schematic diagram of the outer ring intake side step processing (roller and grinding wheel combination) part of the present invention;

[0030] Figure 15 This is a schematic diagram of the inner ring intake side step machining (roller and grinding wheel combination) part of the present invention;

[0031] Figure 16 This is a schematic diagram of another part of the inner ring air outlet side step processing (roller and grinding wheel combination) of the present invention. Detailed Implementation

[0032] A fixture for machining turbine stator blades includes a first clamping fixture and a second clamping fixture. The first clamping fixture holds the blade in place for machining its outlet-side mounting edge and back radial surface. The second clamping fixture holds the blade in place for machining its inlet-side mounting edge and inner radial surface. Specifically, as shown... Figures 3 to 5 As shown, the first clamping fixture includes a first base 1, on which a support and clamping mechanism 3, a side clamping mechanism 4, and a downward clamping mechanism 5 are respectively provided. The support and clamping mechanism 3 includes three parts, two of which are used to clamp the lower flange of the small flange of the blade 2, and the other is used to clamp one side of the lower flange of the large flange of the blade 2. The side clamping mechanism 4 is used to press against the inner radial surfaces of both sides of the blade 2, both sides of the blade body, and the outer side of one side of the lower flange of the large flange. The downward clamping mechanism 5 is used to clamp the other side of the lower flange of the large flange of the blade 2.

[0033] Preferably, the support and clamping mechanism 3 includes a support base 31 and a lower pressure base 32 that cooperate with each other. The support base 31 includes a fixed column connected to the first base 1, and a support shaft is provided at the top of the fixed column. The lower pressure base 32 includes a fixed block 321 connected to the first base 1. The upper end of the fixed block 321 is provided with a hinged lower pressure plate 322 connected by a connecting shaft. The middle part of the lower pressure plate 322 is provided with a waist-shaped through groove, and the lower pressure screw 323 passes through the through groove and is threadedly connected to the fixed block 321. The support base 31 provides support, and the lower pressure plate 322 is pressed down by tightening the lower pressure screw 323. When it cooperates with the support base 31, the flange of the blade 2 can be clamped and fixed.

[0034] Preferably, the side clamping mechanism 4 includes a side clamping block 41 connected to the first base 1, such as... Figure 6As shown, a push-out block 42, which is inserted and movably connected, is provided on the side pressure block 41 near the blade 2. A fixing plate 43 is provided on the other side of the side pressure block 43. An adjusting screw 44 is threadedly connected to the fixing block 43. The adjusting screw 44 extends into the side pressure block 41 and connects with the slot on the push-out block 42. By rotating the adjusting screw 44, the push-out block 42 can be pushed to extend and retract, pressing the blade 2 tightly.

[0035] Preferably, the downward pressing mechanism 5 includes a positioning block 51 connected to the first base 1. The top of the positioning block 51 is provided with a sliding groove, and a pressure plate 52 is slidably connected to the sliding groove. The pressure plate 52 is provided with a waist-shaped groove. The lower end of the connecting rod 53 passes through the waist-shaped groove and is connected to the bottom wall of the sliding groove. A push block is movably connected to the middle of the positioning block 51 near the blade 2. The structure of the push block is the same as described above. Figure 5 The structure is similar, that is, a fixing plate is provided on the other side of the positioning block 51, and a threaded ejector rod is provided on the fixing plate. The ejector rod extends into the positioning block 51 and connects with the slot on the push block. The lower flange of the large edge plate of the blade 2 is pressed by the downward pressing side pressing mechanism 5.

[0036] Preferably, support blocks 6 are provided on both sides of the first base 2 corresponding to the bottom of the blade body of the blade 2, and a stop block 7 is provided on the first base 2 corresponding to the outer side of the blade body of the blade 2. The support blocks 6 and the stop block 7 are respectively fitted with tightening balls. The support blocks 6 support the blade body of the blade 2, and the stop block 7 limits the blade body, further ensuring the stability of the blade clamping.

[0037] like Figures 7 to 9As shown, the second clamping mechanism includes a second base 8. Two support seats 9 are provided on one side of the second base 8, corresponding to the bottom of the small flange of the blade 2. Each of the two support seats 9 has a through groove in its middle. Inside each through groove are a first clamping block 91 and a second clamping block 92 that cooperate with each other. A fixing plate 93 is provided on the outside of each of the two support seats 9. The upper and lower ends of the fixing plate 93 are respectively provided with a first screw 94 and a second screw 95 that are threaded together. The first screw 94 and the second screw 95 extend into the support seat 9 and are respectively connected to the slots of the first clamping block 91 and the second clamping block 92. By rotating the first screw 94 and the second screw 95, the first clamping block 91 and the second clamping block 92 are moved, thereby adjusting the relative distance between the first clamping block 91 and the second clamping block 92 to clamp the lower flange position of the small flange of the blade 2. On the other side of the second base 8, there is a support strip 10 corresponding to the bottom of the large edge plate of the blade 2. The support strip 10 has limiting grooves on both sides corresponding to the large edge plate of the blade 2. On the support strip 10, near the blade 2, there are mutually cooperating third clamping blocks 101 and fourth clamping blocks 102. This structure is similar to the structure of the first clamping block 91 and the second clamping block 92 mentioned above. Specifically, the other side of the support strip 10 has upper and lower fixing plates respectively. The two fixing plates are respectively provided with threaded third screws and fourth screws. The third screws and fourth screws extend into the support strip and connect with the slots of the third clamping blocks 101 and fourth clamping blocks 102. By adjusting the third screws and fourth screws, the third clamping blocks 101 and fourth clamping blocks 102 are driven to clamp the lower flange position of the large edge plate of the blade. It also includes a side stop block 11 corresponding to the back radial surface of the blade 2. The side stop block 11 has an upper top block 111 and a lower top block 112 on the side near the blade 2. The other side of the side stop block 11 has a connecting piece with a threaded screw. The screw extends into the side stop block 11 and connects with the slot of the lower top block 112. The side stop block 11 also has a lower pressure plate 113 that is movably connected by the screw. The upper top block 111 and the lower top block 112 on the side stop block 11 are used to press against the back radial surface of the blade 2.

[0038] The second base 8 has clamping plates 12 connected by support rods to the lower flanges of the large and small flanges of blade 2, respectively. A through groove is provided in the middle of each clamping plate 12, through which a clamping screw passes and connects to the second base 8. The clamping plates 12 can press down on the flanges of the blade. The second base 8 also has inverted T-shaped blocks 13 at both ends of the blade body of blade 2. A strip plate for pressing down on the blade body of blade 2 is bolted to the upper end of each T-shaped block 13. The strip plate presses down on the blade body of blade 2. The second base 8 also has side stops 14 corresponding to the blade body of blade 2.

[0039] A method for grinding turbine stator blades includes the following steps: S1, clamping the blade on the first clamping fixture and machining the exhaust side mounting edge and back radial surface of the blade; S2, clamping the blade on the second clamping fixture and machining the intake side mounting edge and inner radial surface of the blade.

[0040] In S1, a five-axis high-power creep grinder is used. The rollers and grinding wheels are selected to process the air outlet side mounting edge and back radial surface of the blade. During grinding, the linear speed of the grinding wheel is 10~25M / S, the feed rate is 200~350mm / min, and the depth of cut is 0.3~1.5mm. The diamond roller dressing method is set to dress and grind simultaneously, and the dressing speed is 0.2~0.8um / rad.

[0041] In S2, a five-axis high-power creep grinder is used to process the air intake side mounting edge and inner radial surface of the blade using rollers and grinding wheels. During grinding, the linear speed of the grinding wheel is 10~25M / S, the feed rate is 200~350mm / min, and the depth of cut is 0.3~1.5mm. The diamond roller dressing mode is set to simultaneous dressing and grinding, with a dressing speed of 0.2~0.8um / rad.

[0042] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A fixture for machining turbine stator blades, characterized in that: It includes a first clamping fixture and a second clamping fixture. The blade is clamped and fixed by the first clamping fixture and then its outlet side mounting edge and back radial surface are machined. The blade is clamped and fixed by the second clamping fixture and then its inlet side mounting edge and inner radial surface are machined. The first clamping fixture includes a first base, on which a support clamping mechanism, a side clamping mechanism, and a downward side clamping mechanism are respectively provided. The support clamping mechanism includes three parts, two of which are used to clamp the lower flange of the small edge plate of the blade, and the other is used to clamp one side of the lower flange of the large edge plate of the blade. The side clamping mechanism is used to press against the inner radial surfaces of both sides of the blade, both sides of the blade body, and the outer side of one side of the lower flange of the large edge plate. The downward side clamping mechanism is used to clamp the other side of the lower flange of the large edge plate of the blade. The second clamping fixture includes a second base. On one side of the second base, there are two support seats corresponding to the bottom of the blade small edge plate. The middle part of the two support seats is provided with a first through groove. The first through groove is provided with a first clamping block and a second clamping block that cooperate with each other. The outside of the two support seats is provided with a second fixing plate. The upper and lower ends of the second fixing plate are respectively provided with a first screw and a second screw that are threaded together. The first screw and the second screw extend into the inside of the support seat and are respectively connected to the slots of the first clamping block and the second clamping block. The second base has a support strip on the other side corresponding to the bottom of the blade's large edge plate. A third clamping block and a fourth clamping block are provided on the support strip near the blade. A third fixing plate is provided on the upper and lower sides of the other side of the support strip. A third screw and a fourth screw are threadedly connected to the two third fixing plates. The third screw and the fourth screw extend into the support strip and connect with the slots of the third clamping block and the fourth clamping block, respectively. It also includes a side stop block corresponding to the back radial surface of the blade. An upper top block and a lower top block are provided on the side stop block near the blade. A connecting piece is provided on the other side of the side stop block. A threaded screw is provided on the connecting piece. The screw extends into the side stop block and connects with the slot of the lower top block. A lower pressure plate is also provided on the side stop block via a screw.

2. The fixture for machining turbine stator blades according to claim 1, characterized in that: The support and pressing mechanism includes a support base and a pressing base that cooperate with each other. The support base includes a fixed column connected to the first base. The top of the fixed column is provided with a support shaft. The pressing base includes a fixed block connected to the first base. The upper end of the fixed block is provided with a pressing plate that is hingedly connected via a connecting shaft. The middle part of the pressing plate is provided with a waist-shaped through groove. The pressing screw passes through the waist-shaped through groove and is threadedly connected to the fixed block.

3. The fixture for machining turbine stator blades according to claim 2, characterized in that: The side-pressing mechanism includes a side-pressing block connected to the first base. The side-pressing block has an insertable, movably connected ejector block on one side near the blade. The other side of the side-pressing block has a first fixing plate. The first fixing plate has a threaded adjusting screw. The adjusting screw extends into the side-pressing block and connects with a slot on the ejector block.

4. The fixture for machining turbine stator blades according to claim 3, characterized in that: The downward pressing mechanism includes a positioning block connected to the first base. The top of the positioning block is provided with a sliding groove, and a pressure plate is provided on the sliding groove. The pressure plate is provided with a waist-shaped groove. The lower end of the connecting rod passes through the waist-shaped groove and is connected to the bottom wall of the sliding groove. A push block is inserted into the middle of the positioning block near the blade. A fixing plate is provided on the other side of the positioning block. A threaded ejector rod is provided on the fixing plate. The ejector rod extends into the positioning block and is connected to the slot on the push block.

5. A fixture for machining turbine stator blades according to claim 4, characterized in that: Support blocks are provided on both sides of the first base corresponding to the bottom of the blade body, and a stop block is provided on the first base corresponding to the outer side of the blade body. The support blocks and the stop blocks are respectively fitted with tightening balls.

6. A fixture for machining turbine stator blades according to claim 1, characterized in that: The second base is provided with clamping plates connected by support rods, corresponding to the lower flanges of the large and small flanges of the blade. The clamping plates are provided with a second through groove in the middle, and the clamping screw passes through the second through groove and is connected to the second base. The second base is also provided with inverted T-shaped blocks at both ends of the blade body. The upper end of the T-shaped blocks is provided with a strip plate that clamps the blade body by bolts. The second base is also provided with side blocks corresponding to the blade body.

7. A method for grinding turbine stator blades, characterized in that: Includes the following steps: It uses a first clamping fixture and a second clamping fixture of a turbine stator blade machining fixture according to any one of claims 1-6, S1, clamping the blade on the first clamping fixture and machining the exhaust side mounting edge and back radial surface of the blade; S2, clamping the blade on the second clamping fixture and machining the intake side mounting edge and inner radial surface of the blade.

8. The grinding method for turbine stator blades according to claim 7, characterized in that: In S1, a five-axis high-power creep grinder is used. The rollers and grinding wheels are selected to process the air outlet side mounting edge and back radial surface of the blade. During grinding, the linear speed of the grinding wheel is 10~25m / s, the feed rate is 200~350mm / min, and the depth of cut is 0.3~1.5mm. The diamond roller dressing method is set to dress and grind simultaneously, and the dressing speed is 0.2~0.8um / rad.

9. The method for grinding turbine stator blades according to claim 7, characterized in that: In S2, a five-axis high-power creep grinder is used to process the air intake side mounting edge and inner radial surface of the blades using rollers and grinding wheels. During grinding, the linear speed of the grinding wheel is 10~25m / s, the feed rate is 200~350mm / min, and the depth of cut is 0.3~1.5mm. The diamond roller dressing method is set to dress and grind simultaneously, with a dressing speed of 0.2~0.8um / rad.

Images