Nozzle ring blade patch polishing detection method

Abstract

The invention relates to the field of precision casting, and particularly discloses a nozzle ring blade patching polishing detection method, which comprises the following steps of: preparing a trailing edge detection sample plate and a chord length detection sample plate according to the design size of a blade, aligning the trailing edge detection sample plate with an exhaust edge of the blade and inserting, and observing whether the trailing edge detection sample plate is completely inserted into the exhaust edge of the blade; appropriate polishing is carried out according to the clearance between the inner wall of the trailing edge detection sample plate and the blade exhaust edge, the chord length detection sample plate is attached to the back side of the blade, and the normal distance between the chord length detection sample plate on the back side of the blade and the end face of the trailing edge detection sample plate is measured; the trailing edge detection sample plate and the chord length detection sample plate are prepared according to the theoretical model contour of the blade and are attached to the blade, whether the blade exhaust edge patch is polished in place or not is judged according to the distance between the trailing edge detection sample plate and the chord length detection sample plate, operation is easy and convenient, the polishing amount can be repeatedly corrected in the polishing process, production efficiency is improved, and production cost is reduced. The accuracy of polishing amount is easy to control, and the rejection rate is reduced.

Description

Technical Field

[0001] The present invention relates to the field of precision casting, and specifically to a method for grinding and detecting the subsidy of nozzle ring blades. Background Art

[0002] The nozzle ring (as Figure 1 shown) is one of the important components used to adjust the gas flow direction of a gas turbine. The nozzle ring has high overall precision, as well as the installation precision and casting precision of the blades. The existing nozzle ring blades are fixed to the inner and outer fixing rings and are formed by one-time integral casting. In the casting process, in order to obtain a nozzle ring with high precision, it is necessary to rely on highly difficult casting techniques and use special equipment for processing.

[0003] The cross-sections of the blades of the nozzle ring are relatively small, with the thinnest part being only 0.6 mm, usually located at the exhaust edge of the blade. Due to factors such as solidification shrinkage and the poor fluidity of the molten metal during cooling, defects such as misruns, deformations, porosities, and cracks are extremely likely to occur during the casting solidification process, which makes the casting very difficult.

[0004] Usually, we add a subsidy to the exhaust edge of the nozzle ring blades on the wax mold model of the casting. By thickening the thickness of the exhaust edge, the functions of increasing the thickness of the filling cavity, compensating for solidification shrinkage, improving the solidification sequence, and reducing stress concentration are achieved, thereby solving the above-mentioned defects. Then, the subsidy on the exhaust edge is ground off during the post-casting treatment process to obtain a casting that meets the structure.

[0005] During the casting process of the nozzle ring casting, adding a process subsidy to the exhaust edge part of the nozzle ring blades and solving defects such as misruns, deformations, porosities, and cracks by increasing the thickness of the exhaust edge is a commonly used process method in the casting process. However, during the post-processing grinding and removal process, it is very difficult to measure the grinding amount. Among them, the thickness dimension of the exhaust edge of the blade and the chord length dimension of the blade are particularly important. Too much or too little grinding amount will result in unqualified thickness dimensions of the exhaust edge of the blade and chord length dimensions of the blade, and even a too large grinding amount at one time will cause the casting to be scrapped. How to detect the amount of grinding during the grinding process becomes crucial, and how to measure it has become an urgent problem to be solved.

[0006] Currently, for measuring the thickness of the exhaust edge of the nozzle ring blades, a coordinate measuring machine and blue light scanning are usually used to measure and check the profile accuracy and related blade profile dimensions. For measuring the chord length of the nozzle ring blades, a coordinate measuring machine and blue light scanning are usually used to measure and check the blade profile cross-section. However, during the grinding process of the exhaust edge subsidy, it is necessary to repeatedly calibrate the grinding amount. Otherwise, the thickness of the exhaust edge and the chord length value of the blade profile after grinding cannot be guaranteed. The traditional measurement methods are particularly cumbersome and lack pertinence to this process, which not only affects the production efficiency but also makes it difficult to grasp the accuracy of the grinding amount.

[0007] In view of the above problems, the present application proposes a method for detecting the grinding of the nozzle ring blade subsidy. Summary of the Invention

[0008] In view of the existing problems, the present invention provides a method for detecting the grinding of the nozzle ring blade subsidy, which can effectively solve the problems raised in the background technology.

[0009] To solve the above problems, the present invention adopts the following technical solutions:

[0010] A method for detecting the grinding of the nozzle ring blade subsidy includes the following steps:

[0011] S1. Detection preparation: Prepare a trailing edge detection template and a chord length detection template according to the blade design dimensions. The trailing edge detection template fits the profile of the blade exhaust side, and the chord length detection template fits from the back side of the blade to the profile of the blade intake side.

[0012] S2. Grinding detection of the exhaust side: After appropriately grinding the blade exhaust side, insert the trailing edge detection template into the blade exhaust side. Observe whether the trailing edge detection template is completely inserted into the blade exhaust side. If it is not completely inserted, perform appropriate grinding again according to the gap between the inner wall of the trailing edge detection template and the blade exhaust side until the trailing edge detection template is completely inserted into the blade exhaust side and the inner wall of the trailing edge detection template fits the blade exhaust side without shaking.

[0013] S3. Blade chord length detection: After the grinding of the blade exhaust side is completed, fit the chord length detection template to the back side of the blade, and measure the normal distance between the chord length detection sample on the back side of the blade and the end face of the trailing edge detection template. When the normal distance is 20 mm, the subsidy grinding is qualified. If the normal distance is greater than 20 mm, the blade chord length is too large, and the blade exhaust side subsidy needs to be ground again.

[0014] As a further scheme of the present invention: In the step S1, both the trailing edge detection template and the chord length detection template are prepared by 3D printing of photosensitive resin or metal processing.

[0015] As a further scheme of the present invention: In the step S1, on the side close to the outer ring of the nozzle ring of both the trailing edge detection template and the chord length detection template, there is a positioning structure that fits the outer ring of the nozzle ring.

[0016] As a further scheme of the present invention: In the step S1, the cross-section of the trailing edge detection template is a U-shaped structure, which can wrap the trailing edge of the blade exhaust side, and the end face of the trailing edge detection template is 3-5 mm away from the trailing edge of the blade exhaust side.

[0017] As a further scheme of the present invention: In the step S1, one end of the chord length detection template is provided with a bending structure, and the bending structure fits the blade intake side and extends to one side of the front of the blade.

[0018] As a further solution of the present invention: the distance between the trailing edge detection template and the chord length detection template and the inner ring of the nozzle ring in the step S1 is 4-6 mm.

[0019] As a further solution of the present invention: the profile tolerance between the trailing edge detection template and the chord length detection template and the blade fitting surface in the step S1 is -0.01 mm to -0.04 mm.

[0020] As a further solution of the present invention: if the trailing edge detection template does not fit the blade exhaust edge and can shake after being completely inserted into the blade exhaust edge in the step S2, it means that the grinding amount is excessive and difficult to repair, and it shall be scrapped.

[0021] As a further solution of the present invention: the tolerance of the normal distance in the step S3 is ±0.01 mm.

[0022] As a further solution of the present invention: if the normal distance in the step S3 is less than 20 mm, it means that the trailing edge of the blade exhaust edge is ground excessively and difficult to repair, and it shall be scrapped.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: in the present invention, the trailing edge detection template and the chord length detection template are prepared according to the theoretical model profile of the blade, and whether the subsidy grinding of the blade exhaust edge is in place is judged by the fitting of the trailing edge detection template and the chord length detection template with the blade and the distance between the two. The operation is simple and convenient, and the grinding amount can be repeatedly calibrated during the grinding process, which can better integrate into the subsidy grinding work, improve the production efficiency, easily control the accuracy of the grinding amount, and reduce the scrap rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural diagram of the existing nozzle ring;

[0025] Figure 2 is a schematic structural diagram of the trailing edge detection template in the present invention;

[0026] Figure 3 is a schematic structural diagram of the chord length detection template in the present invention;

[0027] Figure 4 is a schematic diagram of the detection after the subsidy grinding of the blade exhaust edge in the nozzle ring of the present invention;

[0028] Figure 5 is another perspective schematic diagram of the present invention Figure 4 ;

[0029] Figure 6 is another Figure 4 schematic diagram of the present invention;

[0030] Figure 7 is anotherFigure 6 Schematic diagram of A-A section.

[0031] In the figure: 1. Blade; 11. Blade exhaust edge; 12. Blade inlet edge; 13. Blade back side; 2. Outer ring of nozzle ring; 3. Inner ring of nozzle ring; 4. Trailing edge detection template; 5. Chord length detection template; 51. Bending structure; 6. Positioning structure. Specific implementation mode

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Combined with Figures 2 to 7 This embodiment is described. This embodiment provides a method for detecting and grinding the nozzle ring blade subsidy, which includes the following steps:

[0034] S1. Detection preparation: Prepare the trailing edge detection template 4 and the chord length detection template 5 according to the design dimensions of the blade 1. The trailing edge detection template 4 fits the contour of the blade exhaust edge 11, and the chord length detection template 5 fits the contour from the blade back side 13 to the blade inlet edge 12. Specifically, both the trailing edge detection template 4 and the chord length detection template 5 are prepared by 3D printing of photosensitive resin or metal processing. When metal processing, investment casting can be used for preparation;

[0035] S2. Exhaust edge grinding detection: After appropriately grinding the blade exhaust edge 11, insert the trailing edge detection template 4 into the blade exhaust edge 11. Observe whether the trailing edge detection template 4 is completely inserted into the blade exhaust edge 11. If it is not completely inserted, perform appropriate grinding again according to the gap between the inner wall of the trailing edge detection template 4 and the blade exhaust edge 11 until the trailing edge detection template 4 is completely inserted into the blade exhaust edge 11 and the inner wall of the trailing edge detection template 4 fits the blade exhaust edge 11 without shaking. If the trailing edge detection template 4 is completely inserted into the blade exhaust edge 11 but does not fit and the trailing edge detection template 4 can shake, it means that the grinding is excessive and difficult to repair, and it should be scrapped;

[0036] S3. Blade 1 chord length detection: After the grinding of the blade exhaust edge 11 is completed, the chord length detection template 5 is fitted to the back side 13 of the blade, and the normal distance between the chord length detection sample on the back side 13 of the blade and the end face of the trailing edge detection template 4 is measured. When the normal distance is 20 mm, the supplementary grinding is qualified. If the normal distance is greater than 20 mm, the chord length of blade 1 is too large, and the blade exhaust edge 11 needs to be ground again with a supplementary material. The tolerance of the normal distance is ±0.01 mm. If the normal distance is less than 20 mm, it means that the trailing edge of the blade exhaust edge 11 is over-ground and difficult to repair, and it will be scrapped.

[0037] Furthermore, on the side of the trailing edge detection template 4 and the chord length detection template 5 close to the outer ring 2 of the nozzle ring, a positioning structure 6 that fits the outer ring of the nozzle ring is provided. The positioning structure 6 is formed by folding up the side edges of the two detection templates. The height of the positioning structure 6 is 2 - 3 mm, and the positioning structure 6 can position the lateral positions of the trailing edge detection template 4 and the chord length detection template 5. And the cross-section of the trailing edge detection template 4 is a U-shaped structure, which can wrap the trailing edge 11 of the blade exhaust edge, and the end face of the trailing edge detection template 4 is 3 - 5 mm away from the trailing edge 11 of the blade exhaust edge. One end of the chord length detection template 5 is provided with a bending structure 51, and the bending structure 51 is attached to the blade inlet edge 12 and extends to the front side of the blade 1. During detection, the bending structure 51 of the chord length detection template 5 hooks the blade inlet edge 12 for positioning. The distance between the trailing edge detection template 4 and the chord length detection template 5 and the inner ring 3 of the nozzle ring is 4 - 6 mm, which is convenient for inserting to measure the fitting degree between the trailing edge detection template 4 and the chord length detection template 5 and the contour of the blade 1. To ensure the detection accuracy, the contour tolerance of the fitting surface between the trailing edge detection template 4 and the chord length detection template 5 and the blade 1 is -0.01 mm to -0.04 mm.

[0038] It should be noted that in order to avoid excessive grinding, when grinding the supplementary material each time, the single grinding amount should not be too much. Grinding operations need to be carried out based on the results of each detection. And in this example, the position where the supplementary material is set is the trailing edge part of the blade exhaust edge 11, and the trailing edge detection template 4 is also used to detect the trailing edge part of the blade exhaust edge 11.

[0039] The working principle of the present invention is: The trailing edge detection template 4 and the chord length detection template 5 are prepared according to the theoretical model contour of the blade 1, and it is judged whether the supplementary grinding of the blade exhaust edge 11 is in place based on the fitting of the trailing edge detection template 4 and the chord length detection template 5 to the blade 1 and the distance between the two. The operation is simple and convenient. The grinding amount can be repeatedly calibrated during the grinding process, which can better integrate into the supplementary grinding work, improve production efficiency, easily control the accuracy of the grinding amount, and reduce the rejection rate.

[0040] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0041] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A nozzle ring blade patch grinding detection method, characterized in that: The steps include: S1. Test preparation: Prepare the trailing edge test sample and the chord length test sample according to the blade design size. The trailing edge test sample fits the contour of the blade exhaust edge, and the chord length test sample fits the contour from the back side of the blade to the inlet side of the blade; S2. Grinding and testing of the exhaust edge: After properly grinding the exhaust edge of the blade, align the trailing edge detection template with the exhaust edge of the blade and insert it to observe whether the trailing edge detection template is fully inserted into the exhaust edge of the blade. If not, grind it again properly according to the gap between the inner wall of the trailing edge detection template and the exhaust edge of the blade until the trailing edge detection template is fully inserted into the exhaust edge of the blade and the inner wall of the trailing edge detection template fits the exhaust edge of the blade without shaking; S3. Blade chord length detection: After the exhaust edge of the blade is polished, fit the chord length detection template to the back of the blade, and measure the normal distance between the chord length detection sample on the back of the blade and the end face of the trailing edge detection template. When the normal distance is 20mm, the subsidy is polished qualified. If the normal distance is greater than 20mm, the blade chord length is too large and the exhaust edge of the blade needs to be polished again.

2. A nozzle ring blade patch grinding detection method according to claim 1, characterized in that: In step S1, the trailing edge detection sample and the chord length detection sample are both prepared by photosensitive resin 3D printing or metal processing.

3. A nozzle ring blade patch grinding detection method according to claim 1, characterized in that: In the step S1, one side of the trailing edge detection template and the chord length detection template close to the outer ring of the nozzle ring is provided with a positioning structure that fits with the outer ring of the nozzle ring.

4. A nozzle ring blade patch grinding detection method according to claim 1, characterized in that: In step S1, the cross-section of the trailing edge detection template is a U-shaped structure, which can wrap the trailing edge of the blade exhaust side, and the end face of the trailing edge detection template is 3 to 5 mm away from the trailing edge of the blade exhaust side.

5. A nozzle ring blade patch grinding and detection method according to claim 1, characterized in that: In step S1, a bending structure is provided at one end of the chord length detection template, and the bending structure is attached to the air inlet edge of the blade and extends to a front side of the blade.

6. A nozzle ring blade patch grinding and detection method according to claim 1, characterized in that: In step S1, the distance between the trailing edge detection sample and the chord length detection sample and the inner ring of the nozzle ring is 4-6 mm.

7. A nozzle ring blade patch grinding and inspection method according to claim 1, characterized in that: In step S1, the contour tolerance between the trailing edge detection sample and the chord length detection sample and the blade fitting surface is -0.01mm to -0.04mm.

8. A nozzle ring blade patch grinding and inspection method according to claim 1, characterized in that: In step S2, if the trailing edge detection template is fully inserted into the exhaust edge of the blade and does not fit the exhaust edge of the blade and the trailing edge detection template can shake, it means that it has been over-polished and is difficult to repair, so it is scrapped.

9. A nozzle ring blade patch grinding and inspection method according to claim 1, characterized in that: The tolerance of the normal distance in step S3 is ±0.01 mm.

10. A nozzle ring blade patch grinding detection method according to claim 1 or 9, characterized in that: If the normal distance in step S3 is less than 20 mm, it means that the trailing edge of the exhaust side of the blade is over-polished and difficult to repair, so it is scrapped.

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