Disc tool for filling strip forming, turbine outer ring preparation method and forming mold

Abstract

The invention provides a disc tool for filling strip forming, a turbine outer ring forming mold and a turbine outer ring preparation method, and the preparation method comprises the following steps that a turbine outer ring is divided into a ring plate, a mounting rib plate and a supporting piece, the ring plate and the mounting rib plate are arranged as laying parts, and the supporting piece is arranged as a winding forming part; preparing a paving part by using a paving forming process, preparing a winding forming part by using a winding forming process, and respectively carrying out primary low-temperature curing treatment; and splicing the prepared laying part and the prepared winding forming part, and obtaining the turbine outer ring subjected to integral compression molding by using an integral compression molding process. The disc tool for filling strip forming comprises a first disc piece, a second disc piece and a rotating shaft so that winding forming of the whole supporting piece can be achieved. According to the method and the tool, the turbine outer ring can be efficiently prepared, and the prepared turbine outer ring has good internal compactness and overall strength performance.

Description

Technical Field

[0001] The invention relates to the field of gas turbine engines, and in particular to the field of turbine outer ring preparation. Background Art

[0002] Ceramic matrix composites (CMC) are a type of composite materials with ceramic as the matrix and various fibers as the composite. They usually have excellent properties such as high temperature resistance, high strength and modulus, low density and strong corrosion resistance. They have broad application prospects in aerospace hot end structural components.

[0003] The turbine shroud is the main stationary part of the gas turbine engine turbine. It is placed on the casing corresponding to the turbine rotating blades. It is subjected to high temperature and high pressure service environment and is required to be able to expand freely and be wear-resistant to adapt to the expansion of the casing and the appropriate collision and wear of the turbine rotating blades.

[0004] At present, the outer ring components are mainly made of high-temperature alloy materials, which significantly affects the upper limit of the outer ring component's operating temperature. Using ceramic matrix composites (CMC) instead of high-temperature alloy materials to prepare the outer ring components can give full play to the excellent high-temperature mechanical properties of CMC, significantly improve the upper limit of the outer ring component's operating temperature and the overall efficiency of the engine, and reduce pollution emissions.

[0005] Affected by the preparation and molding process, the CMC outer ring components currently prepared are prone to internal preparation defects such as delamination and holes, which seriously affect the overall quality and strength performance; in addition, the current preparation cycle of CMC outer ring components is long, and the preparation method is not conducive to mass production, which will significantly restrict its engineering application. Summary of the invention

[0006] An object of the present invention is to provide a disc tool for forming filler strips, which tool can efficiently prepare filler pieces.

[0007] Another object of the present invention is to provide a method for preparing a turbine outer ring, which can efficiently prepare a turbine outer ring with good densified internal quality and overall strength performance.

[0008] Another object of the present invention is to provide a turbine outer ring forming die for realizing the integral combined compression molding of the turbine outer ring.

[0009] To achieve the above-mentioned purpose, a disc tool for forming a filling strip comprises a first disc member, a second disc member and a rotating shaft, wherein the first disc member and the second disc member are arranged opposite to each other; the rotating shaft is rotatably matched with the first disc member and the second disc member to drive the first disc member and the second disc member to rotate; wherein the first disc member and the second disc member respectively comprise a first extrusion surface and a second extrusion surface facing each other, and the first disc member and / or the second disc member are further provided with a supporting portion, including a supporting surface; a fiber winding space is defined between the first extrusion surface, the second extrusion surface and the supporting surface; the fibers are extruded by the first extrusion surface, the second extrusion surface and the supporting surface to form an annular filling strip.

[0010] In one or more embodiments, the supporting portion is a first boss and a second boss on the first disk member and the second disk member that are opposite to each other and mesh with each other, and radial outer side surfaces of the first boss and the second boss are used to provide the supporting surface.

[0011] In one or more embodiments, the supporting portion is a convex ring disposed on the first disk member and / or the second disk member, and a radially outer annular surface of the convex ring is used to provide the supporting surface.

[0012] In one or more embodiments, the first disk member and the second disk member further include a first vertical surface and a second vertical surface arranged opposite to each other, respectively, and the first vertical surface and the second vertical surface are respectively arranged radially outside the first extrusion surface and the second extrusion surface, for defining an entry space for the fiber to enter the winding space.

[0013] In one or more embodiments, the first extrusion surface and the second extrusion surface are arc surfaces, inclined surfaces, or plane surfaces.

[0014] In one or more embodiments, the first disk member and the second disk member are provided with a non-circular central through hole, and the rotation axis has a non-circular cross-section having the same shape as the through hole.

[0015] In one or more embodiments, the first disk member and the second disk member are configured to be axially movable and circumferentially rotatable relative to the rotation axis.

[0016] To achieve the above-mentioned purpose, the method for preparing a turbine outer ring includes the following steps: S1. dividing the turbine outer ring into a draping part and a winding forming part; S2. independently preparing the draping part using a draping forming process, preparing the winding forming part using a winding forming process, and performing initial low-temperature curing treatment on each of them; S3. combining the draping part and the winding forming part prepared in step S2, and using a compression molding process to obtain a compression-molded turbine outer ring.

[0017] In one or more embodiments, in step S1, the turbine outer ring is divided into a ring plate, a mounting rib plate and a filling strip, the ring plate and the mounting rib plate are divided into a covering part, and the filling strip is divided into a winding forming part.

[0018] In one or more embodiments, the covering portion is divided into an L-shaped covering portion, a U-shaped covering portion, and a flat covering portion, and are prepared independently.

[0019] In one or more embodiments, preparing the winding forming part includes the following steps: using the above-mentioned filling bar forming disc tooling to prepare an annular filling bar; cutting the annular filling bar into single-piece filling bars, and the single-piece filling bar is the winding forming part.

[0020] In one or more embodiments, in step S2, the first and second disks are operated in a first temperature environment when winding the fibers, and the first and second disks are heated after the winding and extrusion actions are completed, and the filling strips are initially low-temperature cured and then cut.

[0021] In one or more embodiments, the fibers pass through a pre-impregnated slurry pool before entering the winding space, and then enter the winding space after being soaked with the required slurry.

[0022] In one or more embodiments, the method further includes step S4. A prepreg melt infiltration process is used to perform secondary low-temperature curing, high-temperature carburization and siliconization treatment on the compression-molded turbine outer ring to obtain the turbine outer ring.

[0023] A turbine outer ring forming mold for achieving the above-mentioned purpose is used for the compression molding process in the above-mentioned turbine outer ring preparation method. The mold includes a base, a pair of upper outer mold blocks and an upper middle mold block. The base includes an annular paving surface; a pair of upper outer mold blocks are located on both sides of the annular paving surface, including an L-shaped paving surface; the upper middle mold block is located between the pair of upper outer mold blocks, including a U-shaped paving surface.

[0024] In one or more embodiments, the base, the upper outer mold block and the upper middle mold block respectively include base through holes, upper outer mold block through holes and upper middle mold block through holes, and the mold also includes a plurality of connecting parts for connecting two of the base through holes, the upper outer mold block through holes and the upper middle mold block through holes.

[0025] The above-mentioned method for preparing the turbine outer ring is based on the unidirectional tape laying and prepreg melt infiltration densification process. The CMC outer ring is divided into regions, and then the materials and filling strips in each divided region are simultaneously laid and initially low-temperature cured. Subsequently, the above-mentioned regional materials and filling strips are combined and molded using the designed turbine outer ring molding mold, thereby significantly improving the preparation and molding efficiency and speed of large-scale CMC outer ring components, and efficiently completing the preparation and molding of the entire CMC outer ring.

[0026] The CMC outer ring component prepared based on the above method has good compaction effect in each area during the compression molding process, especially in the triangular transition area between the ring plate and the mounting rib plate, that is, the support part position, ensuring that it has good densified internal quality and overall strength performance.

[0027] The support piece obtained based on the above-mentioned disc tooling for forming filling strips can be used to mass-produce annular filling strips, which can then be cut into multiple single-piece filling strips as needed, thereby significantly improving the production efficiency of the filling strips. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0029] Figures 1A-1C It is a schematic diagram of the structure of a single-sided disc;

[0030] Figure 2A-2C is a schematic diagram of the first plate and the second plate in a docking state;

[0031] Figure 3A-3B It is a schematic diagram of the structure of a disc tooling for forming a filler strip;

[0032] Figure 4A-4B is a schematic diagram of fiber winding;

[0033] Figure 5 It is a schematic diagram of the extrusion molding of the annular filling strip;

[0034] Figure 6 It is a schematic diagram of cutting the annular filling strip;

[0035] Figure 7A-7B This is a schematic diagram of the structure of the CMC outer ring forming base;

[0036] Figures 8A-8B It is a schematic diagram of the structure of the upper outer mold block for CMC outer ring molding;

[0037] Figures 9A-9B It is a schematic diagram of the structure of the upper and middle mold blocks for CMC outer ring molding;

[0038] Figures 10A-10CIt is a schematic diagram of the laying of different components of the CMC outer ring on each mold block;

[0039] Figures 11A-11B It is a schematic diagram of the molding process of different components of the CMC outer ring;

[0040] Figures 12A-12B This is a schematic diagram of the different components of the CMC outer ring in the completed mold state;

[0041] Fig.13 This is a schematic diagram of the structure of the prepared CMC turbine outer ring;

[0042] Fig.14 is a flow chart of a method for preparing a turbine outer ring;

[0043] Fig.15 It is a flow chart of a specific embodiment of the method for preparing a turbine outer ring. DETAILED DESCRIPTION

[0044] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0045] It should be noted that these and other subsequent drawings are only examples and are not drawn to scale, and should not be used to limit the actual scope of protection required by the present invention.

[0046] Reference for disc tooling for filling strip forming Figures 1A to 3B As shown, it comprises a first disk member 1a and a second disk member 1b, which are arranged opposite to each other. A rotating shaft 2 is rotatably matched with the first disk member 1a and the second disk member 1b to drive the first disk member 1a and the second disk member 1b to rotate.

[0047] The first plate 1a and the second plate 1b respectively include a first extrusion surface and a second extrusion surface facing each other, and the first plate 1a and / or the second plate 1b are also provided with a support portion to provide a support surface. The first extrusion surface, the second extrusion surface and the support surface define a fiber winding space P, such as Figure 2C As shown. It is used to provide a support surface for the winding space. The fiber FI is extruded by the first extrusion surface, the second extrusion surface and the support surface to form an annular filling strip 32.

[0048] The term "fiber" refers to both individual fibers and fiber bundles.

[0049] The disc tooling is made of a material with a small coefficient of thermal expansion in a lower temperature range, such as Invar steel.

[0050] In some specific embodiments, the supporting portion is a first boss 12a and a second boss 12b on the first disk member and the second disk member that are opposite to each other and mesh with each other, and the radial outer side surfaces of the first boss 12a and the second boss 12b are used to provide a supporting surface.

[0051] The first disc member 1a and the second disc member 1b further include a first vertical surface 131a and a second vertical surface 131b which are arranged opposite to each other. The first vertical surface 131a and the second vertical surface 131b are respectively arranged radially outside the first extrusion surface and the second extrusion surface, defining an entry space F for the fiber to enter the winding space P.

[0052] Figures 1A to 1C A schematic structural diagram of a specific embodiment of the first disk member 1a or the second disk member 1b is shown. The first disk member 1a or the second disk member 1b is in the shape of a single-sided disk 1, including a central hole 11 for mounting the rotating shaft 2 and a circle of engaging bosses 12 equidistantly distributed in the circumferential direction on the outer edge. The engaging boss 12 includes an outer annular surface 121 located radially outward, and the outer annular surface 121 provides a support surface for supporting fiber winding. The radial flange 13 is arranged at the outermost side of the single-sided disk 1, the vertical surface 131 is arranged relatively radially outward, and the arc surface 132 is arranged relatively radially inward. The arc surface 132 intersects tangentially with the outer annular surface 121. The arc surface 132 serves as an extrusion surface for extruding fibers.

[0053] In some embodiments, the center hole 11 is generally a non-circular hole, which cooperates with the rotating shaft having the same non-circular cross-section, so that the first disk member 1a and the second disk member 1b are configured to be axially movable and circumferentially rotatable relative to the rotating shaft 2.

[0054] Specifically, when the fibers (bundles) are wound, the first disk 1a and the second disk 1b are in a relatively open state. When a sufficient number of fibers (bundles) are wound into the winding space P, the first disk 1a and the second disk 1b will move relative to each other, and the wound fibers (bundles) are squeezed by the support surface, the first extrusion surface and the second extrusion surface to be compacted and shaped. Therefore, this process requires that the first disk and / or the second disk can not only rotate synchronously with the rotating shaft 2, but also can generate relative movement relative to the axial direction of the rotating shaft 2 to achieve the extrusion action after the winding is completed.

[0055] Continue to refer to FIG. 2A to FIG. 3BAs shown, the first disk member 1a and the second disk member 1b are in a spliced ​​state, the rotating shaft 2 is matched with the center hole 11, and the matching section of the rotating shaft usually has a non-circular cross section. The first disk member 1a and the second disk member 1b, which have the same structure as the disk 1, are installed on the rotating shaft 2 through the center hole 11 in a facing manner, so that the rotating shaft 2 can drive the first disk member 1a and the second disk member 1b to rotate synchronously. Moreover, in the axial direction along the rotating shaft 2, one of the first disk member 1a and the second disk member 1b is fixed relative to the rotating shaft 2, and the other can slide axially.

[0056] In the installed state, the engaging bosses 12 on the respective disk surfaces of the first disk member 1a and the second disk member 1b engage with each other. Figure 2C As shown, the first outer annular surface 121a of the first disc 1a and the second outer annular surface 121b of the second disc 1b form a complete annular surface in the meshing overlap area, and the annular surface is the support surface of the winding space P to support the placement and winding of the fiber. A given gap width is left between the first vertical surface 131a of the first disc 1a and the second vertical surface 131b of the second disc 1b to provide an entry space F for fiber winding.

[0057] In other embodiments, the support portion includes but is not limited to bosses that mesh with each other, and may also be a convex ring (not shown in the figure) provided on the first disk member or the second disk member, and the radial outer annular surface of the convex ring is used to provide a support surface.

[0058] Figure 4A and Figure 4B FIG. 2 is a schematic diagram of fiber bundle winding. In this state, the rotating shaft 2 drives the disks 1a and 1b to rotate, so that the fiber bundle FI with pulp is wound from the entry space between the first vertical surface 131a of the first disk 1a and the second vertical surface 131b of the second disk 1b to the complete annular surface formed by the alternation of the first outer annular surface 121a and the second outer annular surface 121b, as shown in FIG. Figure 4B The fiber bundles shown are wound and piled up to form an annular strip 31 .

[0059] Figure 5The schematic diagram shows that the annular strip 31 formed by winding and stacking the fiber bundles is extruded into an annular filling strip 32. After the winding is completed, the first disk 1a and the second disk 1b move toward each other along the axial direction of the rotating shaft 2 under the action of external force, that is, they are extruded in the direction Pu. The first vertical surface 131a and the second vertical surface 131b, the first arc surface 132a and the second arc surface 132b, the first outer annular surface 121a and the second outer annular surface 121b are extruded synchronously together. Among them, the first arc surface 132 and the second arc surface 132b directly extrude and shape the annular strip 31, so that it is formed into an approximately triangular annular filling strip 32. The radius of gyration and the cross-sectional shape of the approximately triangular annular filling strip 32 are the same as those of the triangular filling area of ​​the CMC outer ring, that is, the shape and size of the above-mentioned extrusion surface must be the same as those of the above-mentioned triangular filling area.

[0060] After the extrusion molding is completed, in order to prevent the triangular annular filling strip 32 from becoming loose when it is removed from the tooling, the annular filling strip 32 may be heated in advance to complete the preliminary curing molding.

[0061] When removing, firstly, the first plate 1a and the second plate 1b are axially separated from each other, and then the filling strip 32 is removed from the tooling.

[0062] Figure 6 Schematic diagram of cutting the triangular filling strip 32. In this process, the entire triangular filling strip 32 is cut at the same rotation angle as the single CMC outer ring component to form a single filling strip 321 for standby use. When cutting, it is preferred to leave appropriate circumferential margins at both ends as needed.

[0063] In the above embodiment, the first extrusion surface and the second extrusion surface are provided by the first arc surface 132 and the second arc surface 132 b . In addition, the first extrusion surface and the second extrusion surface may also be inclined surfaces or planes, depending on the required shape of the annular filling strip 32 .

[0064] The above-mentioned tooling enables the single filling strip 321 to be first obtained as a whole and then cut as needed, which effectively improves the efficiency of production and manufacturing.

[0065] The present application also introduces a method for preparing a turbine outer ring, which comprises the following steps: S1. dividing the turbine outer ring into a draping part and a winding forming part.

[0066] This step divides the CMC turbine outer ring into regions according to its structural characteristics and manufactures them separately according to the characteristics. For example, the turbine outer ring is divided into a ring plate 81, a mounting rib plate 82 and a filling strip, such as Fig. 12B and Fig.13 As shown, the single-piece filling strip 321 is used as a filling strip between the ring plate 81 and the mounting rib plate 82. The ring plate 81 and the mounting rib plate 82 are divided into a covering part, and the filling strip is divided into a winding forming part.

[0067] Then, step S2 is performed to prepare the draping part by using the draping molding process and the winding molding part by using the winding molding process. The two processes can be performed simultaneously, and the initial low-temperature curing treatment is performed separately.

[0068] The draping process generally refers to the process of laying multiple layers of fibers and shaping them into various shapes from the initial flat state under the shaping of a certain shape of mold. The winding process generally refers to the process of continuously and stably covering the fiber yarn bundle on the surface of the core mold according to the designed linear arrangement rules through winding tension, and finally heating and curing to obtain the winding part.

[0069] The filling strip is used as a winding forming part and is prepared and formed by the above-mentioned filling strip forming disc tooling. Specifically, the annular filling strip 32 is first prepared using the above-mentioned filling strip forming disc tooling, and then the annular filling strip is cut into single-piece filling strips 321 as required. The single-piece filling strip 321 is the winding forming part required for a single turbine outer ring, thereby pre-preparing a triangular monomer filling strip 321 that is reinforced with unidirectional continuous fibers and has good density and internal quality.

[0070] Before entering the winding space, the wound fiber (bundle) first passes through the pre-impregnated slurry pool, and then enters the winding space after being soaked with the required slurry. The above slurry will fill the pores between the (bundle) fibers, so that the low-temperature cured annular filling strip forms a dense shape.

[0071] When the fibers (bundles) are wound, the first disk 1a and the second disk 1b operate at room temperature. After the winding and extrusion actions are completed, the first disk and the second disk begin to heat up. After the temperature reaches the temperature required by the initial low-temperature curing process, the initial low-temperature curing of the filling strips begins. After the initial low-temperature curing is completed, the first disk and the second disk cool down and move away from each other, and then the annular filling strips that have completed the initial low-temperature curing are removed, and then the cutting operation is performed.

[0072] The paving part and the winding forming part in step S2 can be carried out in parallel, effectively improving the production efficiency. The paving parts of each ring plate 81 and the mounting rib plate 82 can also be carried out in parallel and independently, so as to produce the prefabricated parts of the ring plate 81 and the mounting rib plate 82 in parallel, thereby realizing batch production.

[0073] Fig. 12B The classification of the covering parts is shown, including an L-shaped covering part 71, a U-shaped covering part 72 and a flat covering part 73. The flat covering part corresponds to the outer side of the ring plate 81, and the L-shaped covering part and the U-shaped covering part are combined into a mounting rib plate 82. The three can be prepared independently.

[0074] After the manufacture of each component is completed, step S3 is performed to assemble the draping part and the winding forming part prepared in step S2, and obtain the turbine outer ring by using a compression molding process. The compression molding process is to place a preform on a mold and solidify the preform in a high pressure and high temperature environment to obtain a composite material component as a whole.

[0075] In some embodiments, the method also includes step S4, using a prepreg melt infiltration process to perform secondary low-temperature curing on the turbine outer ring in a compression molded state to form the outer ring as a whole; then the compression mold is removed, and high-temperature carburization and siliconization treatment are performed to finally complete the densification molding of the CMC outer ring to obtain the turbine outer ring.

[0076] The integral compression molding process uses a dedicated turbine outer ring molding die.

[0077] Turbine outer ring forming die Figures 7A to 11B As shown, the mold includes a base 4, a pair of upper outer mold blocks 5 and an upper middle mold block 6. The base 4 includes an annular paving surface 41, a pair of upper outer mold blocks 5 are located on both sides of the annular paving surface 41, including an L-shaped paving surface 51, and the upper middle mold block 6 is located between the pair of upper outer mold blocks 5, including a U-shaped paving surface 61. The base 4, the upper outer mold block 5 and the upper middle mold block 6 respectively include a base through hole 43, an upper outer mold block through hole 53 and an upper middle mold block through hole 63, and the mold also includes a plurality of connectors 8 for connecting two of the base through holes, the upper outer mold block through holes and the upper middle mold block through holes. For example, in one embodiment, the connector 8 includes a tightening bolt 801 and a tightening nut 802.

[0078] Please refer to the attached drawings for details. Fig. 7A and Figure 7B The schematic diagram of the structure of the base 4 for integral compression molding of the CMC outer ring is shown in FIG. The base 4 for compression molding is in the shape of a thick flat plate. The annular paving surface 41 is arranged in the center of the upper side of the base, and is used to pave the material of the annular surface area of ​​the CMC outer ring, that is, to match the straight paving part of the turbine outer ring. Grooves 42 are arranged on the sides of the base to provide space for installing and tightening bolts and nuts. The through holes 43 of each base are used for bolts to pass through and apply preload between different mold blocks.

[0079] Fig. 8A and Figure 8B It is a schematic structural diagram of the upper outer mold block 5 used for integral compression molding of the CMC outer ring.

[0080] The L-shaped paving surface 51 is used to pave the outer area of ​​the CMC outer ring, that is, to match the outer ring of the turbine.

[0081] The L-shaped covering part. The mounting rib plate 52 is provided with a plurality of upper outer mold block through holes 53.

[0082] 53 is provided for bolts to pass through and apply pre-tightening force between different mold blocks.

[0083] Fig.9A and Fig. 9B It is a structural schematic diagram of the upper middle mold block 6 for integral compression molding of the CMC outer ring. The U-shaped paving surface 61 is used to pave the material of the upper middle area of ​​the CMC outer ring, that is, it is adapted to the U-shaped paving part of the turbine outer ring; 62 is a plurality of groove features distributed in the central circumferential direction, and a part of the upper middle mold block through holes 63 are provided on the side of the grooves. The upper middle mold block through holes 63 are for bolts to pass through and apply preload between different mold blocks.

[0084] FIG. 10A to FIG. 10C This is a schematic diagram of how the materials in different divided areas of the CMC outer ring are laid out on their corresponding mold blocks.

[0085] On the laying surface provided by each mold block, the prepreg unidirectional tape is laid according to the number of layers, laying sequence and area required by the design. The number of layers determines the total thickness. The upper outer mold block 5 cooperates with the L-shaped laying part 71, the U-shaped laying surface 61 of the upper middle mold block 6 cooperates with the U-shaped laying part 72, and the annular laying surface 4 cooperates with the straight laying part 73. After the laying is completed, the preliminary shaping of the material in the above-mentioned divided area is completed by molding the outer surface or using vacuum bag pressing and other methods combined with initial low-temperature curing.

[0086] Since the geometric shapes of the materials in the above-mentioned divided areas are relatively simple, the forming operation using prepreg unidirectional tape laying is simple, and the initial pressing and shaping and low-temperature curing are also easy, so fast and efficient preparation and forming can be achieved.

[0087] In addition, the material laying and forming operations in the above-mentioned divided areas can be carried out simultaneously and in parallel, including the preparation and forming of the single-piece filling strip 321, which will significantly shorten the laying and forming preparation cycle of the CMC outer ring, thereby significantly improving the preparation and forming efficiency and speed of large-scale CMC outer ring components.

[0088] Fig.11A and Fig. 11B A schematic diagram of the CMC outer ring integral molding process using the designed CMC outer ring integral molding die is given. Fig. 12A and Fig. 12B The structural and cross-sectional schematic diagrams of the mold-closing completion state are given.

[0089] The specific process of integral compression molding is introduced below.

[0090] First, the annular paving surface 41 is paved with a straight paving portion 73; then, two single-piece filling strips 321 are placed on the upper surface of the straight paving portion 73 in the correct position; then, the upper middle mold block 6 with the U-shaped paving portion 72 is placed on the upper surface of the straight paving portion 73 in the correct position; then, two groups of upper middle mold blocks 5a and 5b with L-shaped paving portions 71a and 71b are placed on the upper surface of the straight paving portion 73, i.e., on both sides of the U-shaped paving portion 72, in the correct position; finally, multiple groups of tightening bolts 801 are used to pass through the base through holes 43, the upper outer mold block through holes 53 and the upper middle mold block through holes 63, and the tightening nuts 802 are used to complete the compaction and shaping of the materials in each divided area between adjacent mold blocks.

[0091] Specifically, the two upper outer mold blocks 5 are clamped with the central upper middle mold block 6 along the axial direction of the outer ring rotation, and the two upper outer mold blocks 5 and the upper middle mold block 6 are clamped with the base 4 along the radial direction of the outer ring rotation, thus completing the compression of the materials in each divided area of ​​the CMC outer ring along the out-of-plane normal direction. At the same time, the triangular single-piece filling strip 321 provides a solid support between the materials in the adjacent areas, which is also conducive to improving the compactness and density of the CMC outer ring as a whole, especially in the triangular transition area between the ring surface and the rib plate.

[0092] By using the above-mentioned integral compression molding die and scheme, the overall compression molding of the CMC outer ring component is completed, and then the molding and densification of the CMC outer ring component is completed through secondary low-temperature curing, high-temperature carbonization and siliconization densification based on the prepreg infiltration process. Finally, the post-work such as burr cutting and surface processing, and preparation of abradable EBC coating are carried out. On the basis of good compaction in the early stage, the CMC outer ring prepared by the above method will have good internal densification molding quality, significantly reduce the probability of initial preparation defects such as holes and delamination, and greatly improve the overall strength performance of the CMC outer ring component.

[0093] Fig.13 Schematic diagram of the structure of the prepared CMC outer ring, wherein 81 is the ring plate and 82 is the mounting rib plate.

[0094] The above method is based on the specific scheme of regional division, pre-preparation and molding of each area, winding molding of triangular filling strips, and overall combined compression molding. The method uses ceramic-based composite materials to replace high-temperature alloy materials to prepare gas turbine engine turbine outer ring components, which overcomes the shortcomings of high-temperature alloy materials with low upper temperature limit, high material density and poor chemical stability. The CMC outer ring prepared by the designed preparation and molding scheme has good internal density quality and overall strength performance, especially in the triangular transition zone between the ring surface and the rib plate. In addition, the above method and mold can efficiently complete the overall compression molding of the materials and triangular filling strips in the above-mentioned different divided areas, significantly improving the preparation and molding efficiency and speed of large-scale CMC outer ring components, which is conducive to engineering applications.

[0095] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A disc tool for forming a filling strip, characterized in that: include: The first plate and the second plate are arranged opposite to each other; A rotating shaft, rotatably matched with the first disk member and the second disk member, and used for driving the first disk member and the second disk member to rotate; Wherein, the first plate member and the second plate member respectively comprise a first extrusion surface and a second extrusion surface facing each other, and the first plate member and / or the second plate member further comprises a support portion, including a support surface; A fiber winding space is defined between the first extrusion surface, the second extrusion surface and the support surface; the fibers are extruded by the first extrusion surface, the second extrusion surface and the support surface to form an annular filling strip.

2. The disc tool for forming a filling strip according to claim 1, characterized in that: The supporting portion is a first boss and a second boss on the first disk member and the second disk member that are opposite to each other and mesh with each other, and the radial outer side surfaces of the first boss and the second boss are used to provide the supporting surface.

3. The disc tool for forming a filling strip according to claim 1, characterized in that: The supporting portion is a convex ring arranged on the first disk member and / or the second disk member, and the radial outer ring surface of the convex ring is used to provide the supporting surface.

4. The disc tool for forming a filling strip according to claim 1, characterized in that: The first disc member and the second disc member further include a first vertical surface and a second vertical surface disposed opposite to each other, respectively. The first vertical surface and the second vertical surface are respectively disposed radially outside the first extrusion surface and the second extrusion surface to define an entry space for the fiber to enter the winding space.

5. The disc tool for forming a filling strip according to claim 1, characterized in that: The first extrusion surface and the second extrusion surface are arc surfaces, inclined surfaces or plane surfaces.

6. The disc tool for forming a filling strip according to claim 1, characterized in that: The first disk member and the second disk member are provided with a non-circular central through hole, and the rotation shaft has a non-circular cross section having the same shape as the through hole.

7. The disc tool for forming a filling strip according to claim 6, characterized in that: The first disk member and the second disk member are arranged to be axially movable and circumferentially rotatable relative to the rotation axis.

8. A method for preparing a turbine outer ring, characterized in that: The steps include: S1. The turbine outer ring is divided into a cladding portion and a winding forming portion; S2. independently preparing the covering part by a draping molding process, preparing the winding molding part by a winding molding process, and performing a primary low-temperature curing treatment respectively; S3. Assemble the draping part and the winding forming part prepared in step S2, and use a compression molding process to obtain a compression molded turbine outer ring.

9. The method for preparing a turbine outer ring according to claim 8, characterized in that: In step S1, the turbine outer ring is divided into a ring plate, a mounting rib plate and a filling strip, the ring plate and the mounting rib plate are divided into a covering part, and the filling strip is divided into a winding forming part.

10. The method for preparing a turbine outer ring according to claim 9, characterized in that: The covering portion is divided into an L-shaped covering portion, a U-shaped covering portion and a straight covering portion, and are prepared independently.

11. The method for preparing a turbine outer ring according to claim 8, characterized in that: The preparation of the winding forming part comprises the following steps: preparing an annular filling strip using the filling strip forming disc tooling as described in any one of claims 1 to 7; cutting the annular filling strip into individual filling strips, wherein the individual filling strips are the winding forming part.

12. The method for preparing a turbine outer ring according to claim 11, characterized in that: In step S2, the first and second discs are operated in a first temperature environment when winding the fibers, and the first and second discs are heated after the winding and extrusion actions are completed, and the filling strips are initially cured at low temperature before being cut.

13. The method for preparing a turbine outer ring according to claim 12, characterized in that: Before the fibers enter the winding space, they first pass through a pre-impregnated slurry pool, and then enter the winding space after being soaked with the required slurry.

14. The method for preparing a turbine outer ring according to claim 8, characterized in that: The method also includes step S4. The prepreg melt infiltration process is used to perform secondary low-temperature curing, high-temperature carbonization and siliconization treatment on the compression-molded turbine outer ring to obtain the turbine outer ring.

15. A turbine outer ring forming mold, used for carrying out the compression molding process in the method for preparing a turbine outer ring according to any one of claims 8 to 14, the mold comprising: A base including an annular paving surface; A pair of upper outer mold blocks, located on both sides of the annular paving surface, including an L-shaped paving surface; as well as The upper middle mold block is located between the pair of upper outer mold blocks and includes a U-shaped paving surface.

16. The turbine outer ring forming die according to claim 15, characterized in that: The base, the upper outer mold block and the upper middle mold block respectively include base through holes, upper outer mold block through holes and upper middle mold block through holes. The mold also includes multiple connecting parts for connecting two of the base through holes, the upper outer mold block through holes and the upper middle mold block through holes.

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