A double-web turbine disk structure and a mold centering method thereof

Abstract

The application provides a double-web turbine disc structure and a mold casting centering method thereof, and the ceramic core is accurately positioned through a clamping structure and multiple positioning references, so that the performance of the blank of the double-web turbine disc in the mold casting process is ensured, and local defects caused by special processes such as welding are avoided. The whole casting mode of the mold casting is adopted, so that the technical problem that the main forming process of the double-web disc in the prior art adopts separate forging, resulting in large defects, and the design and use effect of the internal precise structure of the disc body are poor are solved, the mechanical properties of the whole turbine disc are ensured to be uniform, and the technical effect of greatly improving the production efficiency is achieved.

Description

Technical Field

[0001] This invention relates to the field of aero-engine turbines, and in particular to a double-spoke turbine disk structure and its investment casting centering method. Background Technology

[0002] In axial-flow turbomachinery, the turbine disk is a key component of the engine. US Patent Application No. 5961287A, published on October 5, 1999, describes a novel double-spoke turbine disk, distinct from previous single-spoke designs. This turbine disk consists of two axially aligned spokes, one in front and one behind, forming a central disk cavity. Compared to traditional single-spoke turbine disks, this structure offers higher load-bearing capacity, lower thermal and mechanical inertia, and lighter weight, effectively reducing the weight of engine turbine components.

[0003] In existing publicly available patents (CN202111310661.0, CN202011106872.8, CN202011114296.1), the main forming process of the double-spoke turbine disk is as follows: two separate half-disc structures are manufactured by forging, then the disk surface and some important structures, such as internal flow channels and cooling pipes, are machined, and finally the two half-discs are welded together and then machined as a whole. However, this method has the following drawbacks: the two half-discs welded together are usually quite thick. To ensure that all contact parts can be welded together, the required welding energy is often large, generating extremely high process temperatures, which damage the microstructure. Not only is the performance of the weld lower than that of the raw material, but it also affects the performance of the original base material. The high welding temperature can easily cause deformation of the parts, especially inside the disk. Once welded together, the inside of the disk cannot be precisely machined, which inevitably affects the design and use effect of the precision structure inside the disk. The half-turbine disk manufactured by precision machining is limited by processing equipment and processes, making it difficult to realize some complex or irregularly shaped local cooling structures. Summary of the Invention

[0004] In view of this, the present invention provides a centering method for investment casting of a double-spoke turbine disk, in order to solve the technical problems in the prior art where the main forming process of the double-spoke disk is carried out by separate forging, resulting in large defects and poor design and use effect of the precision structure inside the disk.

[0005] The technical solution of the present invention is as follows: a centering method for investment casting of a double-spoke turbine disk structure, comprising: fixing a ceramic core by clamping an outer end cylinder and an inner end rib, wherein the outer end cylinder passes through the outer edge of the double-spoke turbine disk structure, and the inner end rib passes through the cold air inlet hole at the center of the double-spoke turbine disk structure; fixing the clamping structure of the ceramic core by the clamping mechanism of the double-spoke turbine disk structure according to the axial positioning reference, radial positioning reference and circumferential positioning reference respectively, thereby completing the centering process of the ceramic core.

[0006] Furthermore, after the ceramic core is centered, the outer end cylinder of the circumferential positioning datum and the radial positioning datum are used as references to check the dimensional tolerances of the outer end cylinder of the circumferential positioning datum, the core body and the inner end rib, so that the profile and position deviations are less than or equal to 0.02.

[0007] Furthermore, after completing the centering process of the ceramic core, the investment casting centering method further includes: performing investment casting based on the ceramic core after centering to obtain a casting model; using the casting model for casting, and performing cooling treatment after casting to obtain a blank structure of the double-spoke turbine disk structure; inspecting the casting quality of the blank structure, performing solution treatment on the qualified blank structure, and performing external structural design through machining to obtain the double-spoke turbine disk structure.

[0008] The present invention also provides a double-spoke turbine disk structure, which is formed by a centering casting method for investment casting of a double-spoke turbine disk structure. The double-spoke turbine disk structure includes: tenons, located on the edge of the double-spoke turbine disk, evenly distributed along the circumferential direction of the double-spoke turbine disk, and a discrete hole connected to the bottom of each tenon, the discrete holes extending along the radial direction of the double-spoke turbine disk; and spoke structure, including a first spoke and a second spoke, which are respectively connected to the root of the tenon, and reinforcing ribs evenly distributed between the first spoke and the second spoke to form a disk core structure, with cold air inlets between each reinforcing rib, and the first spoke, the second spoke, and the reinforcing ribs forming an internal cavity structure.

[0009] Furthermore, the double-spoke turbine disk is fixed by a ceramic core, which includes: an outer cylinder located at the outer edge of the core body and evenly distributed along the circumference of the ceramic core, with the outer cylinder corresponding to the discrete holes; a core body connected at one end to the outer cylinder, with its thickness increasing along the outer cylinder towards the axis of the ceramic core, and a transition rounded between the outer cylinder and the core body; a positioning structure connected to the core body via inner ribs, with the inner ribs evenly distributed along the circumference of the ceramic core, and the root of the inner ribs having a first rounded and a second rounded; and a clamping structure connected to the positioning structure to form a stepped structure, wherein the connection between the clamping structure and the positioning structure has a third rounded.

[0010] Furthermore, the diameter of the outer cylinder is greater than or equal to 1 mm.

[0011] Furthermore, the thickness of the inner end rib is greater than or equal to 1 mm.

[0012] Furthermore, the end face diameter of the clamping structure is greater than or equal to 5mm, and the length is greater than or equal to 5mm.

[0013] Compared with the prior art, the beneficial effects achieved by at least one of the above-mentioned technical solutions adopted in the embodiments of this specification include at least the following: This invention provides a centering method for investment casting of a double-spoke turbine disk structure. A ceramic core is fixed by clamping an outer cylinder and an inner rib. The outer cylinder passes through the outer edge of the double-spoke turbine disk structure, and the inner rib passes through the cold air inlet hole at the center of the double-spoke turbine disk structure. The clamping structure of the ceramic core is fixed by the clamping mechanism of the double-spoke turbine disk structure according to the axial positioning reference, radial positioning reference, and circumferential positioning reference, respectively, thereby completing the centering process of the ceramic core. By accurately positioning the ceramic core, the performance of the blank in the investment casting process of the double-spoke turbine disk is ensured, local defects caused by special processes such as welding are avoided, the overall mechanical properties of the turbine disk are ensured to be uniform, and the technical effect of greatly improving production efficiency is achieved. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the centering of a double-spoke turbine disk in investment casting according to an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the double-spoke turbine disk structure according to an embodiment of the present invention;

[0017] Figure 3 This is a schematic diagram of the ceramic core structure according to an embodiment of the present invention;

[0018] Figure 4 This is a partially enlarged schematic diagram of the ceramic core according to an embodiment of the present invention.

[0019] The attached figures are labeled as follows: 1. Double-spoke turbine disk structure; 101. Tenon; 102. Discrete hole; 103. Internal cavity structure; 104. Reinforcing rib; 105. Disk center hole; 106. Cold air inlet; 107. Pressing end face; 108. First spoke; 109. Second spoke; 2. Ceramic core; 201. Outer cylinder; 202. Core body; 203. Inner rib; 204. Positioning structure; 205. Clamping structure; 206. Transition rounding; 207. First rounding; 208. Second rounding; 209. Third rounding; 210. Axial positioning reference; 211. Radial positioning reference. Detailed Implementation

[0020] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0021] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] In this embodiment of the invention, a method for centering a double-spoke turbine disk structure in investment casting is provided, such as... Figure 1 As shown, the method includes: fixing the ceramic core 2 by clamping the outer end cylinder 201 and the inner end rib 203, wherein the outer end cylinder 201 passes through the outer edge of the double-spoke turbine disk structure 1, and the inner end rib 203 passes through the cold air inlet 106 at the center of the double-spoke turbine disk structure 1; fixing the clamping structure 205 of the ceramic core 2 by the clamping mechanism of the double-spoke turbine disk structure 1 according to the axial positioning reference 210, the radial positioning reference 211 and the circumferential positioning reference 211, respectively, to complete the centering process of the ceramic core 2.

[0023] This invention provides a centering method for investment casting of a double-spoke turbine disk structure. A ceramic core is fixed by clamping an outer cylinder and an inner rib. The outer cylinder passes through the outer edge of the double-spoke turbine disk structure, and the inner rib passes through the cold air inlet at the center of the disk. The clamping structure of the ceramic core is fixed according to axial, radial, and circumferential positioning references, with the outer cylinder secured by the clamping mechanism of the double-spoke turbine disk structure, thus completing the centering process of the ceramic core. Precise positioning of the ceramic core ensures the performance of the blank during investment casting of the double-spoke turbine disk, avoids local defects caused by special processes such as welding, ensures uniform mechanical properties of the overall turbine disk, and significantly improves production efficiency.

[0024] like Figure 1 and Figure 2 As shown, the investment casting centering method for a double-spoke turbine disk structure provided in the first embodiment of the present invention specifically includes: fixing the ceramic core 2 by clamping the outer end cylinder 201 and the inner end rib 203, wherein the outer end cylinder 201 passes through the outer edge of the double-spoke turbine disk structure 1, and the inner end rib 203 passes through the cold air inlet hole 106 at the center of the double-spoke turbine disk structure 1; fixing the clamping structure 205 of the outer end cylinder 201, which holds the ceramic core 2 according to the axial positioning reference 210, the radial positioning reference 211 and the circumferential positioning reference respectively, through the clamping mechanism of the double-spoke turbine disk structure 1 to complete the centering process of the ceramic core 2.

[0025] Furthermore, after the ceramic core 2 is formed, the outer end cylinder 201 of the circumferential positioning reference and the radial positioning reference 211 are used as references to check the dimensional tolerances of the outer end cylinder 201 of the circumferential positioning reference, the core body 202, and the inner end rib 203, so that the surface profile and position deviation are less than or equal to 0.02.

[0026] Specifically, for turbine disks with a central hole, equiaxed crystal investment casting is used to produce turbine disk blanks. The main steps include: centering, wax injection, demolding, slurry application, dewaxing, casting, heat preservation, core removal, and inspection. The inspected and qualified turbine disk blanks are then precision machined to achieve the external design structures such as tenons and the central hole. The turbine disk centering process involves fixing a ceramic core based on the double-spoke turbine disk structure within an external casting mold. Figure 1 and Figure 2As shown, during the casting of the turbine disk blank, the outer edge of the turbine disk lacks a tenon and slot structure. To ensure the precise positioning of the ceramic core 2, a two-end clamping method is adopted: the outer end cylinder 201 of the ceramic core 2 passes through the outer edge of the double-spoke turbine disk structure 1, and the inner end rib 203 passes through the cold air inlet 106 at the center of the disk; the clamping structure 205 is fixed by other clamping mechanisms on the double-spoke turbine disk structure 1, where 210 is the axial positioning reference, 211 is the radial positioning reference, and the outer end cylinder 201 is the circumferential positioning reference. After the ceramic core is formed, the dimensional tolerances of the outer end cylinder 201, the core body 202, the inner end rib 203, and other parts of the ceramic core 2 must be checked using the outer end cylinder 201 and the radial positioning reference 211 as references to ensure that the profile and positional deviations do not exceed 0.02. By using two-end clamping and multiple positioning references to precisely position the ceramic core 2, the casting quality and performance of the turbine disk blank are guaranteed.

[0027] Furthermore, after completing the centering process of the ceramic core 2, the process includes: performing investment casting based on the ceramic core 2 after centering to obtain a casting model; casting using the casting model, followed by cooling after casting to obtain a blank structure of the double-spoke turbine disk structure 1; inspecting the casting quality of the blank structure, performing solution treatment on the qualified blank structure, and performing external structural design through machining to obtain the double-spoke turbine disk structure 1.

[0028] Specifically, after completing the centering process of ceramic core 2, the double-spoke turbine disk structure is cast according to the investment casting steps: centering, wax injection, demolding, slurry application, dewaxing, casting, heat preservation, core removal, and inspection. Preferably, after casting, the high-temperature turbine disk blank is cooled by heat preservation and natural cooling.

[0029] Preferably, non-destructive testing methods such as X-ray and fluorescence are used to inspect the casting quality of the blank;

[0030] Preferably, the qualified blanks need to undergo solution heat treatment to eliminate the thermal stress during the casting process before they can be machined.

[0031] The preferred, preferably machined double-spoke turbine disk structure 1 requires solution-aging heat treatment to ensure stable part structure and improve performance.

[0032] Furthermore, the inspected and qualified blank structure undergoes solution treatment, and the external structure, such as the tenon and groove and the center hole, is designed and machined through machining to obtain the double-spoke turbine disk structure 1. By adopting an integral casting method, the defects of localized degradation of mechanical properties, especially in key parts of the tenon teeth, caused by special processes such as welding are avoided, ensuring the uniformity of the mechanical properties of the overall turbine disk and guaranteeing the accuracy of the internal structural design and machining of the double-spoke turbine disk structure 1.

[0033] In addition, such as Figure 2 As shown, this embodiment of the invention also provides a double-spoke turbine disk structure 1. The double-spoke turbine disk structure 1 is formed by centering and casting using a centering method for investment casting of a double-spoke turbine disk structure provided in this embodiment of the invention. The double-spoke turbine disk structure 1 includes: tenons 101, located on the edge of the double-spoke turbine disk structure 1, evenly distributed along the circumferential direction of the double-spoke turbine disk structure 1, and a discrete hole 102 connected to the bottom of each tenon 101, the discrete hole 102 extending along the radial direction of the double-spoke turbine disk structure 1; and a spoke structure, including a first spoke 108 and a second spoke 109, the first spoke 108 and the second spoke 109 respectively connected to the root of the tenon 101, and a uniformly distributed reinforcing rib 104 between the first spoke 108 and the second spoke 109 to form a disk core structure, with a cold air inlet 106 between each reinforcing rib 104. The first spoke 108, the second spoke 109 and the reinforcing rib 104 form an internal cavity structure 103.

[0034] Specifically, the double-spoke turbine disk structure 1 is as follows: Figure 2 As shown, the double-spoke turbine disk structure 1 is centered and cast using a casting centering method for a double-spoke turbine disk structure provided in this embodiment of the invention. The tenon 101 is used to assemble turbine blades, and the discrete holes 102 correspond one-to-one with the tenon 101. The cold air inlet 106 is located between two adjacent reinforcing ribs 104. The internal cavity structure 103 has a double-spoke structure on both sides, including a first spoke 108 and a second spoke 109. The reinforcing ribs 104 pass through the disk center structure, which has a disk center hole 105 connecting the first spoke 108 and the second spoke 109. The structure located on one side of the second spoke 109 is a pressing end face 107. When the turbine disk is pressed at the end face, the reinforcing ribs 104 can ensure the rigidity of the turbine disk and prevent the left and right spokes of the turbine disk from being crushed.

[0035] Preferably, the diameter of the discrete hole 102 is smaller than the minimum width of the tenon groove 101.

[0036] Furthermore, the double-spoke turbine disk structure 1 is fixed by a ceramic core 2, such as... Figure 3 and Figure 4As shown, the ceramic core 2 includes: an outer cylinder 201, which is located on the outer edge of the core body 202 and is evenly distributed along the circumferential direction of the ceramic core 2; the outer cylinders 201 are correspondingly arranged with discrete holes 102; and a core body 202, one end of which is connected to the outer cylinder 201, and the thickness of the core body 202 increases along the outer cylinder 201 towards the axial direction of the ceramic core 2; the outer cylinder 201 and the core body 202 have a transition rounded shape. 206; Positioning structure 204, the positioning structure 204 is connected to the core body 202 through inner end ribs 203, the inner end ribs 203 are evenly spaced along the circumference of the ceramic core 2, and the root of the inner end ribs 203 has a first rounded 207 and a second rounded 208; Clamping structure 205, the clamping structure 205 is connected to the positioning structure 204 to form a stepped structure, wherein the connection between the clamping structure 205 and the positioning structure 204 has a third rounded 209.

[0037] Preferably, the diameter of the outer end cylinder 201 is greater than or equal to 1 mm.

[0038] Preferably, the thickness of the inner end rib 203 is greater than or equal to 1 mm.

[0039] Preferably, the end face diameter of the clamping structure 205 is greater than or equal to 5 mm, and the length is greater than or equal to 5 mm.

[0040] Specifically, the double-spoke turbine disk structure 1 is positioned by a ceramic core 2, such as... Figure 3 and Figure 4 As shown, in the ceramic core 2 structure, the outer cylindrical section 201 forms discrete holes 102 for the internal cooling air passages of the turbine blades at the disk rim; the core body 202 forms the internal cavity structure 103 of the turbine disk and also serves as an auxiliary positioning structure for the ceramic core 2; the inner rib 203 forms the cooling air inlet 106 at the center of the turbine disk; and the positioning structure 204 is a positioning structure for the ceramic core 2 to mate with the central hole of the turbine disk. Through precise positioning between the double-spoke turbine disk structure 1 and the clamping structure 205, and then auxiliary positioning by the core body 202, the dimensional accuracy of the internal structure of the turbine disk can be ensured. Figure 4 In the enlarged view of the ceramic core 2, the transition rounded end 206 is the rounding between the outer cylinder 201 and the core body 202 to avoid local stress concentration in the turbine disk caused by sharp corners, and also to avoid local casting deficiencies during the casting process. Simultaneously, adding rounding at the location forming the discrete orifice 102 can prevent flow separation at the inlet and significantly improve the flow rate of the cooling air entering the blades. The first rounded end 207 and the second rounded end 208 are the root roundings of the inner end rib 203, used to avoid local stress concentration in the turbine disk and local casting deficiencies during the casting process. Furthermore, a third rounded end 209 is present at the connection between the clamping structure 205 and the positioning structure 204.

[0041] Preferably, the dimensions of the transition rounding 206 and the first rounding 207 are not less than R1.

[0042] The embodiments of the present invention achieve the following technical effects:

[0043] 1. The integral casting method avoids the defects caused by welding and other special processes, such as localized degradation of mechanical properties, especially in critical areas like the tenon teeth, ensuring uniform mechanical properties of the entire turbine disk. Integral investment casting allows for the simultaneous preparation of multiple turbine disk blanks, significantly improving production efficiency and avoiding the numerous processes and long production cycles associated with traditional welding methods, while also reducing production costs.

[0044] 2. The adoption of a double-spoke design can greatly reduce the overall weight of the turbine disk and improve engine performance;

[0045] 3. By precisely positioning the ceramic core, the performance of the blank of the double-spoke turbine disk during the investment casting process is ensured, thereby further improving the performance of the double-spoke turbine disk.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the embodiments of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A centering method for investment casting of a double-spoke turbine disk structure, characterized in that, include: The ceramic core (2) is fixed by clamping the outer end cylinder (201) and the inner end rib (203). The outer end cylinder (201) passes through the outer edge of the double-spoke turbine disk structure (1), and the inner end rib (203) passes through the cold air inlet (106) at the center of the double-spoke turbine disk structure (1). The clamping structure (205) of the ceramic core (2) is fixed by the clamping mechanism of the double-spoke turbine disk structure (1) according to the outer cylinder (201) of the axial positioning reference (210), the radial positioning reference (211) and the circumferential positioning reference, respectively, so as to complete the centering process of the ceramic core (2); After the ceramic core (2) is centered, the outer end cylinder (201) of the circumferential positioning reference and the radial positioning reference (211) are used as references to check the dimensional tolerances of the outer end cylinder (201) of the circumferential positioning reference, the core body (202), and the inner end rib (203), so that the surface profile and position deviation are less than or equal to 0.

02.

2. The centering method for investment casting of a double-spoke turbine disk structure according to claim 1, characterized in that, After completing the centering process of the ceramic core (2), the following steps are included: Based on the ceramic core (2) after centering treatment, investment casting is performed to obtain the casting model; Casting is performed using the casting model, and cooling is performed after casting to obtain the blank structure of the double-spoke turbine disk structure (1). The casting quality of the blank structure is inspected, the blank structure that passes the inspection is subjected to solution treatment, and the external structure is designed through machining to obtain a double-spoke turbine disk structure (1).

3. A double-spoke turbine disk structure, characterized in that, The double-spoke turbine disk structure (1) is formed by centering and casting using the investment casting centering method for a double-spoke turbine disk structure as described in any one of claims 1 to 2. The double-spoke turbine disk structure (1) includes: The tenon (101) is located on the edge of the double-spoke turbine disk structure (1) and is evenly distributed along the circumferential direction of the double-spoke turbine disk structure (1). Each tenon (101) has a corresponding discrete hole (102) at the bottom of the groove. The discrete hole (102) extends along the radial direction of the double-spoke turbine disk structure (1). The spoke structure includes a first spoke (108) and a second spoke (109). The first spoke (108) and the second spoke (109) are respectively connected to the root of the tenon (101). The first spoke (108) and the second spoke (109) are provided with evenly spaced reinforcing ribs (104) to form a disc core structure. Cold air inlet holes (106) are provided between each reinforcing rib (104). The first spoke (108), the second spoke (109) and the reinforcing ribs (104) form an internal cavity structure (103). The double-spoke turbine disk structure (1) is fixed by a ceramic core (2), which includes: The outer end cylinder (201) is located on the outer edge of the core body (202) and is evenly distributed along the circumferential spacing of the ceramic core (2). The outer end cylinder (201) is correspondingly set with the discrete hole (102). The core body (202) is connected at one end to the outer cylinder (201), and the thickness increases along the outer cylinder (201) towards the axial direction of the ceramic core (2). There is a transition rounded (206) between the outer cylinder (201) and the core body (202). The positioning structure (204) is connected to the core body (202) through the inner end rib (203). The inner end rib (203) is evenly spaced along the circumferential direction of the ceramic core (2). The root of the inner end rib (203) has a first rounded (207) and a second rounded (208). The clamping structure (205) and the positioning structure (204) are connected to form a stepped structure, wherein the connection between the clamping structure (205) and the positioning structure (204) has a third rounded edge (209).

4. The double-spoke turbine disk structure according to claim 3, characterized in that, The diameter of the outer end cylinder (201) is greater than or equal to 1 mm.

5. The double-spoke turbine disk structure according to claim 3, characterized in that, The thickness of the inner end rib (203) is greater than or equal to 1 mm.

6. The double-spoke turbine disk structure according to claim 3, characterized in that, The end face diameter of the clamping structure (205) is greater than or equal to 5 mm, and the length is greater than or equal to 5 mm.

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