A detection tool and manufacturing method for a long blade of a turbine final stage

Abstract

The application discloses a kind of detection tool and manufacturing method of turbine last stage long blade, it is related to blade detection field, and its technical solution points are in including annular part, multiple detection zones distributed around annular part circumference are arranged on the annular part, multiple blade root grooves that are evenly indexed around annular part axis circumference are opened in each detection zone;All blade root grooves in the same detection zone are used to install the blade of the same model;The blade root grooves of different detection zones are used to install the blade of different models respectively.The application can meet the detection needs of multiple moving blades, can realize the single blade tenon tooth profile line detection of moving blade, the cooperation detection of blade tenon tooth surface and blade root groove surface, the cooperation and circumferential gap detection between multiple blades, blade crown tooth shape end surface cooperation detection and the like, and detection function is rich.

Description

Technical Field

[0001] This invention relates to the field of blade inspection, and more specifically, to an inspection fixture and manufacturing method for long turbine last-stage blades. Background Technology

[0002] Turbine blades, as a key core component of gas turbines, operate in high-temperature, high-pressure, and high-speed environments. Their complex structure and extremely precise dimensional requirements necessitate top-tier design, development, and manufacturing technologies. Blade machining is one of the most technically challenging, complex, and risky parts of gas turbine manufacturing, directly impacting the turbine's safety and service life.

[0003] Due to the numerous specialized processes and parameters involved in machining moving blades, each batch of moving blades requires trial machining using test pieces. Once all indicators pass inspection, the machining parameters are solidified before mass production begins, thereby improving yield and reducing costs. This is especially true for long turbine last-stage blades, which, due to their large aspect ratio and toothed crowns, are prone to torsional deformation at the blade tip during machining due to limited clamping positions and the combined effects of cutting forces. This makes it extremely difficult to guarantee the profile of the toothed end face of the blade crown. Therefore, dimensional inspection of key mating surfaces after machining long turbine last-stage blades is particularly important.

[0004] Currently, the mainstream method still uses coordinate measuring machines (CMMs) to perform multi-point scanning or profile scanning on various surfaces of long blades and compares the results with the theoretical design model to verify whether the machining dimensions are within the design profile range. However, this method can only be used to inspect and judge single parts and cannot meet the requirements for assembly inspection of long blade tenons and wheel disc root grooves, measurement of circumferential clearance of multiple blades mounted on the wheel disc, and inspection of the mutual fit of long blade crown tooth end faces. Furthermore, measuring each blade using a CMM requires positioning, measurement, and data report analysis, which is time-consuming.

[0005] For the inspection of the tenon profile of long blades, a single blade root groove can currently be broached from a single metal test block to achieve fit inspection. However, due to the extremely large cutting force during broaching, the clamping fixture of the metal test block is extremely complex, and the test block cannot be centered, making it impossible to precisely index and machine multiple blade root grooves. Generally, only a single blade root groove can be machined, which cannot meet the requirements for circumferential fit and clearance inspection of multiple blades.

[0006] For the reasons mentioned above, providing a blade inspection fixture capable of performing various inspections, such as single blade tenon profile inspection, blade tenon surface and blade root groove surface fit inspection, fit and circumferential clearance inspection between multiple blades, and blade crown tooth end face fit inspection, has become an urgent problem to be solved in the field of blade inspection. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a testing fixture and manufacturing method for long turbine last-stage blades. This method involves setting multiple testing zones on a ring-shaped component, with multiple blade root grooves corresponding to different blade models within each zone. This satisfies the testing needs of various moving blades, enabling a single fixture to test multiple moving blades, significantly improving the utilization rate of the testing fixture. The blade root grooves designed in each testing zone can perform tests such as the profile of a single blade tenon tooth, the fit between the blade tenon tooth surface and the blade root groove surface, the fit and circumferential clearance between multiple blades, and the fit of the blade crown tooth end face.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a testing fixture for a turbine last-stage long blade, comprising an annular component, wherein multiple testing zones are arranged around the circumference of the annular component, and each testing zone has multiple blade root grooves evenly indexed around the axis of the annular component; all blade root grooves in the same testing zone are used to install blades of the same type; and blade root grooves in different testing zones are used to install blades of different types.

[0009] The present invention is further configured such that: when the blade root groove penetrates both end faces of the annular component, and when the length of the blade root groove in the axial direction of the annular component is greater than the axial width of the blade root of the blade to be installed, a width limiting notch is provided in the detection area where the blade root groove is located, which penetrates the detection area radially along the annular component. The width limiting notch is located at one end of the blade root groove, and in the axial direction of the annular component, the distance from the other end of the blade root groove to the width limiting notch is equal to the axial width of the blade root of the blade to be installed.

[0010] The invention is further configured to include a baffle, wherein each detection zone is fixed with a baffle for blocking one end of all leaf root grooves in the detection zone, the baffle is parallel to the end face of the annular component, and the baffle is detachably connected to the annular component.

[0011] The invention is further configured to include bolts, wherein each baffle is fixed to the annular member by bolts.

[0012] The invention is further configured such that: the annular component is divided into multiple layers along its axial direction, and the multiple layers are integrally formed; each layer has the same inner diameter, and the outer diameters of different layers decrease sequentially along the axial direction of the annular component; an arc-shaped groove can be provided in each detection area; the arc-shaped groove is collinear with the axis of the annular component, and each arc-shaped groove penetrates the annular component in a direction parallel to the axis of the annular component, and penetrates multiple arc surfaces on the outer side of the annular component radially; the minimum radius of the arc-shaped groove is equal to the outer diameter of any layer, and the blade root groove is opened on the arc-shaped wall surface of the arc-shaped groove; in the detection area where no arc-shaped groove is provided, the blade root groove is opened on the outer arc surface of the layer with the largest outer diameter.

[0013] The present invention is further configured such that: in each detection zone, the outer ring surface of the annular layer where the blade root groove is located is a radially aligned surface, and the end face of the annular layer where the blade root groove is located near the side with the smallest outer diameter of the annular part is an axially aligned surface; a radial notch is provided on the radially aligned surface, which penetrates the layer with the largest outer diameter of the annular part radially along the annular part; an axial notch is provided on the axially aligned surface, which penetrates the inner wall of the annular part radially along the annular part.

[0014] The present invention is further configured such that: a clearance groove is provided on the two surfaces of the two adjacent layers of the annular part that are in contact with each other, and the clearance groove is provided at the edge of the layer with the smaller outer diameter of the two layers of the annular part.

[0015] The present invention is further configured such that at least three leaf root grooves are formed on the arc-shaped wall surface of each arc-shaped groove.

[0016] The present invention also provides a method for manufacturing a testing fixture for a turbine last-stage long blade, which is used to process the above-mentioned testing fixture for a turbine last-stage long blade. The annular part is made of metal and is manufactured by cutting.

[0017] The invention is further configured such that the leaf root groove is formed by broaching.

[0018] In summary, compared with the prior art, the present invention has the following advantages: Each detection zone in the present invention can realize the detection of one type of moving blade, so the tooling can meet the detection needs of multiple moving blades, achieving the purpose of detecting multiple moving blades with one tooling, and greatly improving the utilization rate of the detection tooling. The blade root groove designed in each detection zone can realize the detection of the profile of a single blade tenon tooth and the fit detection of the blade tenon tooth surface and the blade root groove surface; at the same time, the present invention can also realize the fit and circumferential clearance detection between multiple blades, the fit detection of the blade crown tooth end face, etc., with rich detection functions. The annular part in the present invention can be completed by one positioning and clamping, which improves the machining accuracy of the detection tooling and reduces the manufacturing cost. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of Example 1;

[0020] Figure 2 A view showing the radial notch in Example 1;

[0021] Figure 3 for Figure 2 Sectional view of AA;

[0022] Figure 4 for Figure 2 BB section view;

[0023] Figure 5 for Figure 2 CC section view;

[0024] Figure 6 This is a schematic diagram of the overall structure of Example 2;

[0025] Figure 7 This is a view illustrating the multi-layered structure in Example 2.

[0026] In the figure: 1. Ring-shaped part; 11. Arc groove; 12. Blade root groove; 13. Width limiting notch; 14. Radial tool setting face; 15. Axial tool setting face; 16. Radial notch; 17. Axial notch; 18. Clearance groove; 2. Baffle; 3. Bolt; 4. Blade. Detailed Implementation

[0027] The technical solution of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the invention.

[0028] It should be noted that the terms "center", "upper", "lower", "horizontal", "left", "right", "front", "rear", "lateral", "longitudinal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0029] Example 1

[0030] like Figure 1-5 The diagram shows the basic structure of a testing fixture for a turbine last-stage long blade according to Embodiment 1 of the present invention. It includes an annular component 1, on which multiple testing zones are arranged circumferentially around the annular component 1. Each testing zone has multiple blade root grooves 12 evenly spaced around the axis of the annular component 1. All blade root grooves 12 within the same testing zone are used to install blades of the same type 4. Blade root grooves 12 in different testing zones are used to install blades of different types 4. The blade root grooves 12 match the shape of the blade root and are used for detecting the tenon tooth profile of a single blade 4. In this embodiment, two testing zones are provided.

[0031] In this embodiment, each detection zone can detect one type of moving blade 4. Therefore, this fixture can meet the detection needs of multiple moving blades 4, achieving the purpose of detecting multiple moving blades 4 with one fixture, greatly improving the utilization rate of the detection fixture. The blade root groove 12 designed in each detection zone can realize the detection of the profile of the tenon tooth of a single moving blade 4, and the detection of the fit between the tenon tooth surface of the blade 4 and the surface of the blade root groove 12; at the same time, this embodiment can also realize the detection of the fit and circumferential clearance between multiple blades 4, and the detection of the fit of the blade crown tooth end face, etc., with rich detection functions. The annular part 1 in this embodiment can be completed by one positioning and clamping, which improves the machining accuracy of the detection fixture and reduces the manufacturing cost.

[0032] Specifically, when the blade root groove 12 penetrates both end faces of the annular component 1, and when the length of the blade root groove 12 in the axial direction of the annular component 1 is greater than the axial width of the blade root of the blade 4 to be installed, a width-limiting notch 13 is provided in the detection area where the blade root groove 12 is located, which penetrates the detection area radially along the annular component 1. The width-limiting notch 13 is located at one end of the blade root groove 12, and in the axial direction of the annular component 1, the distance from the other end of the blade root groove 12 to the width-limiting notch 13 is equal to the axial width of the blade root of the blade 4 to be installed. In this embodiment, the blade root groove 12 is located at the middle position in the circumferential direction of the arc groove 11.

[0033] This embodiment also includes a baffle 2. Each detection zone is fixed with a baffle 2 for blocking one end of all leaf root grooves 12 in the detection zone. The baffle 2 is parallel to the end face of the annular component 1, and the baffle 2 is detachably connected to the annular component 1.

[0034] This embodiment also includes bolts 3, and each baffle 2 is fixed to the annular part 1 by bolts 3.

[0035] Specifically, the annular component 1 is divided into multiple layers along its axial direction, and the multiple layers are integrally formed. Each layer has the same inner diameter, and the outer diameters of different layers decrease sequentially along the axial direction of the annular component 1. An arc-shaped groove 11 can be set in each detection area. The arc-shaped groove 11 is collinear with the axis of the annular component 1, and each arc-shaped groove 11 penetrates the annular component 1 in a direction parallel to the axis of the annular component 1, and penetrates multiple arc surfaces on the outer side of the annular component 1 radially. The minimum radius of the arc-shaped groove 11 is equal to the outer diameter of any layer, and the blade root groove 12 is formed on the arc-shaped wall surface of the arc-shaped groove 11. In the detection area where no arc-shaped groove 11 is set, the blade root groove 12 is formed on the outer arc surface of the layer with the largest outer diameter. The setting of the arc-shaped groove 11 allows the annular component 1 to simulate the radial position where the blade 4 is actually installed, making the test closer to the actual application environment and improving the accuracy of the test results. In this embodiment, the annular component 1 is divided into two layers, and one arc-shaped groove 11 is set.

[0036] Specifically, in each inspection zone, the outer annular surface of the annular layer containing the blade root groove 12 is the radial tool-setting surface 14, and the end face of the annular layer containing the blade root groove 12 near the minimum outer diameter of the annular component 1 is the axial tool-setting surface 15. The radial tool-setting surface 14 and the axial tool-setting surface 15 are used to provide tool-setting references for the broaching machining of the blade root groove 12. A radial notch 16 is provided on the radial tool-setting surface 14, which penetrates the maximum outer diameter layer of the annular component 1 radially; an axial notch 17 is provided on the axial tool-setting surface 15, which penetrates the inner wall of the annular component 1 radially. The radial notch 16 and the axial notch 17 can reduce the area that needs to be finished and improve machining efficiency.

[0037] Specifically, clearance grooves 18 are provided on the two mating surfaces of adjacent layers of the annular component 1. The clearance grooves 18 are located at the edge of the layer with the smaller outer diameter of the two layers of the annular component 1. This provides a channel for chip removal during turning of the annular component 1, improves the cooling effect of the coolant, and protects the cutting tool.

[0038] Specifically, at least three blade root grooves 12 are formed on the arc-shaped wall surface of each arc-shaped groove 11. In this embodiment, three blade root grooves 12 are formed on the arc-shaped wall surface of each arc-shaped groove 11.

[0039] This embodiment also provides a method for manufacturing a testing fixture for a turbine last-stage long blade. Specifically, the annular component 1 is made of metal and is manufactured by machining. The blade root groove 12 is specifically manufactured by broaching.

[0040] In this embodiment, the processing method of the ring-shaped part 1 is as follows:

[0041] S1. Turn out the annular contour of the annular part 1. Specifically, first turn out a single-layer annular workpiece; then turn out a multi-layer structure along the axial direction of this annular workpiece, with the outer diameter of different layers decreasing sequentially along the axial direction of the annular workpiece.

[0042] S2. Milling the arc-shaped groove 11. Specifically, firstly, the clearance groove 18 is machined by turning or milling, and the radial notch 16 and the axial notch 17 are milled out; then, the end face of each layer of the annular workpiece near the smallest outer diameter and the outer ring surface of each layer are machined by turning to produce the radial tool setting surface 14 and the axial tool setting surface 15; finally, the arc-shaped groove 11 is milled out with the radial tool setting surface 14 and the axial tool setting surface 15 as the reference.

[0043] S3. Mill the width-limiting notch 13 according to actual needs and mill the threaded hole to accommodate the bolt 3. The order of S2 and S3 can be interchanged.

[0044] S4. Broaching the blade root groove 12. Specifically, the inner ring surface of the annular workpiece is used for centering, and the radial tool setting surface 14 and the axial tool setting surface 15 are used as references to broach the blade root groove 12.

[0045] In summary, each detection zone in this embodiment can detect one type of moving blade 4. Therefore, this fixture can meet the detection needs of multiple moving blades 4, achieving the purpose of detecting multiple moving blades 4 with one fixture, greatly improving the utilization rate of the detection fixture. The blade root groove 12 designed in each detection zone can realize the detection of the profile of the tenon tooth of a single moving blade 4, and the detection of the fit between the tenon tooth surface of the blade 4 and the surface of the blade root groove 12; at the same time, this embodiment can also realize the detection of the fit and circumferential clearance between multiple blades 4, and the detection of the fit of the blade crown tooth end face, etc., with rich detection functions. The annular part 1 in this embodiment can be processed by one positioning and clamping, which improves the processing accuracy of the detection fixture and reduces the manufacturing cost.

[0046] Example 2

[0047] like Figure 6-7 As shown, the difference between this embodiment and embodiment 1 is that all detection areas are evenly distributed around the axis of the annular component 1. In this embodiment, four detection areas are set, the annular component 1 is divided into four layers, and three arc-shaped grooves 11 are set. The minimum radius of the three arc-shaped grooves 11 is equal to the minimum radius of the three layers of the annular component 1, respectively.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A detection tool for a long last blade of a turbine, characterized in that: The device includes an annular component (1), on which multiple detection zones are arranged around the circumference of the annular component (1). Each detection zone has multiple blade root grooves (12) evenly spaced around the axis of the annular component (1). All blade root grooves (12) in the same detection zone are used to install blades (4) of the same type. Blade root grooves (12) in different detection zones are used to install blades (4) of different types. When the blade root groove (12) penetrates both end faces of the annular component (1), and the length of the blade root groove (12) in the axial direction of the annular component (1) is greater than the axial width of the blade root of the blade (4) to be installed, a width-limiting notch (13) is set in the detection zone where the blade root groove (12) is located, which penetrates the detection zone radially along the annular component (1). The width-limiting notch (13) is located at one end of the blade root groove (12). In the axial direction of the annular component (1), the blade root groove (12) 12) The distance from the other end to the width-limiting notch (13) is equal to the axial width of the blade root of the blade (4) to be installed; the annular part (1) is divided into multiple layers along its axial direction, and the multiple layers are integrally formed; the inner diameter of each layer is the same, and the outer diameter of different layers decreases sequentially along the axial direction of the annular part (1); an arc groove (11) is provided in each detection area; the arc groove (11) is collinear with the axis of the annular part (1), and each arc groove (11) penetrates the annular part (1) in a direction parallel to the axis of the annular part (1), and penetrates multiple arc surfaces on the outer side of the annular part (1) radially; the minimum radius of the arc groove (11) is equal to the outer diameter of any layer, and the blade root groove (12) is opened on the arc wall of the arc groove (11); in the detection area where no arc groove (11) is provided, the blade root groove (12) is opened on the outer arc surface of the layer with the largest outer diameter; In each detection zone, the outer ring surface of the annular layer where the leaf root groove (12) is located is the radial cutting surface (14), and the end face of the annular layer where the leaf root groove (12) is located near the minimum outer diameter of the annular part (1) is the axial cutting surface (15). A radial notch (16) is provided on the radial cutting surface (14), which penetrates the outer diameter of the annular part (1) radially. An axial notch (17) is provided on the axial cutting surface (15), which penetrates the inner wall of the annular part (1) radially.

2. A detection tool for a long last blade of a turbine according to claim 1, characterized in that: It also includes a baffle (2), each detection zone is fixed with a baffle (2) for blocking one end of all leaf root grooves (12) in the detection zone, the baffle (2) is parallel to the end face of the annular part (1), and the baffle (2) is detachably connected to the annular part (1).

3. A detection tool for a long last blade of a turbine according to claim 2, characterized in that: It also includes bolts (3), each baffle (2) being fixed to the annular part (1) by bolts (3).

4. The inspection fixture for a long turbine last-stage blade according to claim 1, characterized in that: The two adjacent layers of the annular part (1) are provided with clearance grooves (18), which are located at the edge of the layer with the smaller outer diameter of the two layers of the annular part (1).

5. The inspection fixture for a long turbine last-stage blade according to claim 1 or 4, characterized in that: At least three leaf root grooves (12) are provided on the arc-shaped wall of each arc groove (11).

6. A method for manufacturing a testing fixture for long turbine last-stage blades, characterized in that: The inspection fixture for processing the turbine last-stage long blades as described in any one of claims 1-5, wherein the annular part (1) is made of metal and is manufactured by cutting.

7. The method for manufacturing a testing fixture for a long turbine last-stage blade according to claim 6, characterized in that: The leaf root groove (12) is made by broaching.

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