Reverse-flow type flame tube shaping mold and method for manufacturing reverse-flow type flame tube

Abstract

The invention provides a backflow type flame tube shaping mold which comprises an inner mold and an outer mold, the inner mold and the outer mold are both combined molds and are of an annular structure, a first shaping face is formed on the inner side of the outer mold, and a second shaping face is formed on the outer side of the inner mold. And after the inner mold is coaxially assembled to the inner side of the outer mold, a forming space of the backflow type flame tube is formed between the first shaping surface and the second shaping surface. When the backflow type flame tube is manufactured, all the components of the inner mold and the outer mold are connected in a matched mode through inverted conical surfaces, vertical pressing force can be deflected into pressing force loads in the normal direction of the molded surface of the backflow type flame tube, and pressing forming of a fiber prefabricated body is facilitated; in the pressing process, the molded surface of the outer mold is kept unchanged, and the inner mold expands outwards to press the fiber preform in a fluffy state, so that the fiber preform is prevented from shrinking to generate wrinkles; efficient and high-precision forming of the backflow type flame tube can be achieved, and the forming quality of the backflow type flame tube and the demolding efficiency of the formed flame tube are improved.

Description

Technical Field

[0001] The invention relates to a flame tube shaping mold, in particular to a ceramic-based composite material reflow type flame tube shaping mold and a method for manufacturing the reflow type flame tube. Background Art

[0002] The combustion chamber of an aircraft engine is mainly composed of an air intake device, a nozzle, a flame tube, an outer casing, an ignition device, etc. The flame tube is located in the center of the combustion chamber and is in the shape of a long cylinder. It includes an inner tube and an outer tube. The inner and outer tubes are located between the flame tube cavity, which provides a stable space for the gas flame and ensures the smooth progress of the combustion process. Figure 1 As shown in the figure, due to its small axial size, it is mainly used in small aviation gas turbine engines. Its inner and outer cylinders have bending features on the meridian section, forming a "J" shape. When using ceramic-based composite materials to prepare flame tubes, in order to ensure the surface accuracy of the flame tube, it is necessary to design shaping molds on both the inner and outer surfaces of the flame tube, and place the flame tube body between the inner and outer molds to clamp and shape it.

[0003] Ceramic matrix composites are a type of continuous fiber reinforced composite material. During molding and preparation, it is required to be pressed along the normal direction of the part surface to increase the fiber volume fraction and improve the mechanical properties of the part. If the pressing force is too large along the tangential component, it may cause the internal fibers to be delaminated and dislocated, affecting the mechanical properties of the part. In addition, after the part is molded and solidified, the bonding force between the part and the mold is relatively strong. Therefore, during the demolding process, the mold is required to be ejected in the normal direction as much as possible. If the demolding force along the tangential direction is too large, it may cause demolding difficulties.

[0004] In the existing ceramic-based composite cylindrical component preparation technology, in order to facilitate demolding, the inner mold generally adopts an integral structure and the outer mold adopts a block structure. With such a mold design, when the cylindrical ceramic composite component is shaped and compacted, the inner mold remains stationary and the outer mold is compacted inward, which causes the cylindrical blank to undergo a radius contraction process when it changes from a fluffy state to a compacted state, which can easily cause excess material and produce internal fiber wrinkles, affecting material properties. For ceramic-based composite cylindrical components with bending features, it is difficult to demold the mold on the inside of the bending angle after compaction, and no good solution has been disclosed.

[0005] The Chinese patent with publication number CN114484505A discloses a ceramic-based composite full-ring flame tube, a shaping mold and a preparation method thereof, which uses an inner and outer double-layer mold to shape the full-ring flame tube, wherein the inner mold is a full ring and the outer mold is a block. The shaping mold used in the patent compresses the fiber preform from the outside to the inside, which easily causes wrinkles inside the fiber, affecting the mechanical properties of the flame tube, and is not suitable for the preparation of cylindrical components with bending features, and does not provide an effective solution for demoulding the bent rotating body. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a reflow flame tube shaping mold and a method for making a reflow flame tube. The inner mold and the outer mold designed in blocks cooperate with each other, which can effectively solve the surface positioning problem of the ceramic-based composite material reflow combustion chamber flame tube with bending features during the preparation process, facilitate the compaction and molding of the fiber preform, avoid wrinkles in the fibers, and facilitate the demolding of the reflow flame tube with bending features after molding, thereby improving the demolding efficiency.

[0007] To achieve the above purpose, the technical solution proposed by the present invention is:

[0008] In the first aspect, the present invention provides a reflow flame tube shaping mold, including an inner mold and an outer mold, wherein the inner mold and the outer mold are both combined molds, the inner side of the outer mold is formed with a first shaping surface matching the outer profile of the reflow flame tube, the outer side of the inner mold is formed with a second shaping surface matching the inner profile of the reflow flame tube, the inner mold is coaxially assembled on the inner side of the outer mold, and a molding space for the reflow flame tube is formed between the first shaping surface and the second shaping surface.

[0009] Optionally, the outer mold includes an outer mold outer retaining ring, an outer mold outer ring, an outer mold inner ring, and an outer mold inner retaining ring, which are coaxially arranged in sequence from outside to inside, and the inner side surface of the outer mold outer retaining ring and the outer side surface of the outer mold outer ring, the lower part of the inner side surface of the outer mold outer ring and the lower part of the outer side surface of the outer mold inner ring, and the inner side surface of the outer mold inner ring and the lower part of the outer side surface of the outer mold inner retaining ring are all connected through an inverted cone surface, the upper part of the outer side surface of the outer mold inner ring and the upper part of the inner side surface of the outer membrane outer ring jointly form the first shaping surface, which is used for shaping the outer surface of the reflow flame tube, and the upper part of the outer mold inner retaining ring radially extends outward to have a first positioning ring plate that cooperates with the top of the outer mold inner ring for positioning.

[0010] Optionally, the outer mold outer clamping ring and the outer mold inner clamping ring are integral annular structures; the outer mold outer ring and the outer mold inner ring are both annular structures composed of at least two fan-shaped ring structures.

[0011] Optionally, the inner mold includes an inner mold outer ring, an inner mold clamping ring, and an inner mold inner ring, which are coaxially arranged in sequence from outside to inside, and the inner side surface of the inner mold outer ring and the lower part of the outer side surface of the inner mold clamping ring, as well as the lower part of the inner side surface of the inner mold clamping ring and the outer side surface of the inner mold inner ring are all connected by inverted cone surfaces, and the outer side surface of the inner mold outer ring and the inner side surface of the inner mold inner ring jointly form the second shaping surface for shaping the inner surface of the flame tube, and a second positioning ring plate is radially extended outward from the upper part of the inner mold clamping ring to cooperate with the top of the inner mold outer ring for positioning, and a third positioning ring plate is radially extended inward from the middle part of the inner mold clamping ring to cooperate with the top of the inner mold inner ring for positioning.

[0012] Optionally, the inner mold clamping ring is an integral circular ring structure; the inner mold outer ring and the inner mold inner ring are both circular ring structures composed of at least two fan-shaped ring structures, preferably four; and gaps are provided between the fan-shaped ring structures constituting the inner mold outer ring or the inner mold inner ring.

[0013] Optionally, the axial height of the outer ring of the outer mold is 1 to 1.8 times, preferably 1.2 to 1.4 times, of the outer ring of the reflow flame tube; the axial height of the inner ring of the outer mold is 1 to 1.8 times, preferably 1.2 to 1.4 times, of the inner ring of the reflow flame tube.

[0014] Optionally, the axial height of the outer ring of the inner mold is 1 to 1.6 times, preferably 1.1 to 1.4 times, of the outer ring of the reflow flame tube; the axial height of the inner ring of the inner mold is 1 to 1.6 times, preferably 1.1 to 1.4 times, of the inner ring of the reflow flame tube.

[0015] Optionally, the angle between any one of the inverted cone surfaces and the axis of the shaping mold is 1° to 15°, preferably 3° to 5°.

[0016] Optionally, the first positioning ring plate and the second positioning ring plate are both provided with a plurality of threaded through holes, and the outer mold inner clamping ring and the inner mold clamping ring can be removed by screwing in bolts during demoulding.

[0017] Optionally, at least two lugs are provided on the outer clamping ring of the outer mold, and each of the lugs is provided with a lifting hole, and the lifting hole is preferably a threaded through hole.

[0018] In a second aspect, a method for manufacturing a reflow flame tube using the reflow flame tube shaping mold of the present invention comprises the following steps:

[0019] Assembling the outer mold to form a first shaping surface;

[0020] Laying the ceramic-based composite fiber on the first shaping surface of the outer mold;

[0021] Assembling the inner mold inside the outer mold so that the second shaping surface formed by the inner mold contacts and matches with the upper surface of the ceramic-based composite fiber;

[0022] The assembled shaping mold and the ceramic-based composite fiber in the shaping mold are placed on a press to be pressed so that the outer mold is flush with the top of the inner mold; at the same time, the shaping mold and the ceramic-based composite fiber are heated, and after the heating is completed, they are taken out and cooled to solidify the ceramic-based composite fiber;

[0023] The inner mold and the outer mold are demoulded to obtain a fiber blank of the reflow flame tube, and then the fiber blank is densified and machined to obtain the reflow flame tube.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) In the reflow flame tube shaping mold provided by the present invention, both the outer mold and the inner mold adopt a block assembly design, which is convenient for demolding the reflow flame tube with bending features after molding. The multiple parts that make up the outer mold and the inner mold adopt an inverted cone surface matching design. The outer clamping ring of the outer mold provides a restraining force, and the clamping force is applied by the inner clamping ring of the outer mold and the inner mold clamping ring. The vertical clamping force is deflected into a clamping force load along the normal direction of the reflow flame tube profile through the inverted cone surface, which is convenient for the compression molding of the fiber preform; the cooperation between the inverted cone surfaces of different parts can also transmit the handling load, which is convenient for the overall handling and transfer of the mold after assembly, and realizes hoisting.

[0026] 2) The flame tube shaping mold provided by the present invention maintains an outer mold surface unchanged during the pressing process, while the inner mold expands outward to press the fiber preform in a fluffy state, and the annular flame tube as a whole is subjected to a tensile force from the inside to the outside, which can prevent the fiber preform from shrinking and producing wrinkles. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of a reflow flame tube; Figure (a) is a three-dimensional schematic diagram; Figure (b) is a partial cross-sectional view;

[0028] Figure 2 It is a schematic diagram of the cross-sectional structure of the reflow type flame tube shaping mold;

[0029] Figure 3 Schematic diagram of the three-dimensional structure of the outer mold;

[0030] Figure 4 Schematic diagram of the cross-sectional structure of the outer mold;

[0031] Figure 5 It is a schematic diagram of the structure of the outer clamping ring of the outer mold;

[0032] Figure 6 It is a schematic diagram of the three-dimensional structure of the clamping ring inside the outer mold;

[0033] Figure 7 It is a schematic diagram of the cross-sectional structure of the outer mold inner clamping ring;

[0034] Figure 8 This is a schematic diagram of the structure of the outer ring of the 1 / 2 outer mold;

[0035] Fig. 9 This is a schematic diagram of the structure of the inner ring of the 1 / 4 outer mold;

[0036] Fig.10 It is a structural schematic diagram of the inner mold;

[0037] Fig.11 Schematic diagram of the cross-sectional structure of the inner mold;

[0038] Fig.12This is a schematic diagram of the structure of the 1 / 4 inner mold outer ring;

[0039] Fig.13 This is a schematic diagram of the structure of the inner circle of the 1 / 4 inner mold;

[0040] Fig.14 Schematic diagram of the three-dimensional structure of the inner mold clamp ring;

[0041] Fig.15 It is a schematic diagram of the cross-sectional structure of the inner mold clamping ring;

[0042] In the figure: 1-reflow flame tube, 11-flame tube outer surface, 12-flame tube inner surface,

[0043] 2-outer mold, 21-outer mold outer snap ring, 22-outer mold inner snap ring, 23-outer mold outer ring, 24-outer mold inner ring, 25-first shaping surface, 211-lifting ear, 212-first threaded through hole, 213-inner side of outer mold outer snap ring, 221-second threaded through hole, 222-lower part of outer side of inner snap ring of outer mold, 223-first positioning ring plate, 224-upper end face of inner snap ring of outer mold, 231-outer side of outer mold outer ring, 232-shaping surface I, 233-lower part of inner side of outer mold outer ring, 241-inner side of outer mold inner ring, 242-lower part of outer side of outer mold inner ring, 243-shaping surface II,

[0044] 3-inner mold, 31-inner mold outer ring, 32-inner mold inner ring, 33-inner mold retaining ring, 34-second molding surface, 311-molding surface III, 312-inner side surface of inner mold outer ring, 321-molding surface IV, 322-outer side surface of inner mold inner ring, 331-lower part of outer side surface of inner mold retaining ring, 332-lower part of inner side surface of inner mold retaining ring, 333-second positioning ring plate, 334-third threaded through hole, 335-third positioning ring plate, 336-top surface of inner mold retaining ring. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by terms such as “upper”, “lower”, “top”, “bottom”, “inside” and “outside” are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0047] Embodiment 1;

[0048] like Figure 1-Figure 15 A reflow flame tube shaping mold comprises an inner mold 3 and an outer mold 2. The inner mold 3 and the outer mold 2 are both combined molds as a whole, and are an annular structure. A first shaping surface 25 matching the outer profile 11 of the reflow flame tube is formed on the inner side of the outer mold 2, and a second shaping surface 34 matching the inner profile 12 of the reflow flame tube is formed on the outer side of the inner mold 3. After the inner mold 3 is coaxially assembled to the inner side of the outer mold 2, a shaping space of the reflow flame tube is formed between the first shaping surface 25 and the second shaping surface 34, and the shaping space is used for geometric adaptation and geometric shape shaping with the reflow flame tube 1.

[0049] The outer mold 2 includes an outer mold outer retaining ring 21, an outer mold outer ring 23, an outer mold inner ring 24, and an outer mold inner retaining ring 22, which are coaxially arranged from the outside to the inside. The inner side surface 213 of the outer mold outer retaining ring and the outer side surface 231 of the outer mold outer ring, the lower part of the inner side surface of the outer mold outer ring 23 and the lower part of the outer side surface 242 of the outer mold inner ring, and the inner side surface 241 of the outer mold inner ring and the lower part of the outer side surface 222 of the outer mold inner retaining ring are all connected by inverted cone surfaces. After the outer mold outer retaining ring 21, the outer mold outer ring 23, the outer mold inner ring 24, and the outer mold inner retaining ring 22 are assembled together to form the outer mold 2, a first shaping surface 25 can be formed at the upper part of the outer side surface of the outer mold inner ring 24 and the upper part of the inner side surface of the outer membrane outer ring 23. The first shaping surface 25 is compatible with the outer shaping surface 11 of the flame tube.

[0050] In this embodiment, the outer mold outer clamping ring 21 is an integral circular ring structure, and the inner side surface 213 of the outer mold outer clamping ring is an inverted cone, and the angle between the inverted cone and the axis of the outer mold 2 is 1°~15°; two lugs 211 are provided on the outer mold outer clamping ring 21, and the lugs 211 are evenly distributed along the circumference of the outer mold outer clamping ring 211. Each lug 211 is provided with a lifting hole, and the lifting hole adopts a first threaded through hole 212. The first threaded through hole 212 can be screwed into the carrying handle to realize the transportation of the entire mold. Since the various components of the outer mold 2 are connected by inverted cone surfaces, the outer mold outer clamping ring 21 can hold other components and prevent them from falling.

[0051] In this embodiment, the outer mold outer ring 23 is a combined annular structure, which is composed of two fan-shaped structures. The two fan-shaped structures are evenly distributed along the circumferential direction of the outer mold outer ring 23. The outer mold outer ring 23 is a rotating body, and its rotation axis is the axis of the outer mold 2. The rotated basic figure is an L-shape with a chamfer, and the sharp corner of the L-shape faces outward. The upper part of the inner side surface of the outer mold outer ring (that is, the inner part of the L-shape, including the inclined surface segment and the curved surface segment) is a molding surface I232 that constitutes the first molding surface 25. The curvature of surface I232 is designed to be consistent with the outer ring part of the outer profile surface 11 of the flame tube to be formed, and is used to shape the flame tube 1. The lower part 233 of the inner side surface of the outer ring of the outer mold (i.e., the rightmost part of the L-shape) is an inverted cone surface, and the outer side surface 231 of the outer ring of the outer mold is also an inverted cone surface. The outer side surface 231 of the outer ring of the outer mold is connected with the inner side surface 213 of the outer retaining ring of the outer mold through an inverted cone surface. The two inverted cone surfaces that are matched with each other have the same angle relative to the axis of the outer mold 2, both of which are 1° to 15°.

[0052] In this embodiment, the outer mold inner ring 24 is composed of four fan-shaped structures evenly divided along the circumferential direction. The four fan-shaped structures are spliced ​​and assembled into a complete circular ring structure. The outer mold inner ring 24 is a rotating body, and its rotation axis is the axis of the outer mold 2. The rotated basic figure is also an L-shape with a chamfer, and the sharp corner of the L-shape faces inward, but its height is lower than the outer mold outer ring 23. The upper part of the outer side surface of the outer mold inner ring 24 (that is, the inner part of the L-shape, including the inclined surface segment and the curved surface segment) is a shaping surface II243 constituting the first shaping surface, and the shaping surface II2 The curvature of 43 is designed to be consistent with the inner ring part of the flame tube outer profile 11 to be formed, and the shaping surface II 243 and the shaping surface I 232 constitute the first shaping surface 25, which is used for shaping the flame tube outer profile 11. The inner side surface 241 of the outer mold inner ring is an inverted cone, and the lower part 242 of the outer side surface of the outer mold inner ring is an inverted cone. The lower part 242 of the outer side surface of the outer mold inner ring is connected with the lower part 233 of the inner side surface of the outer mold outer ring through the inverted cone. The two inverted cones connected with each other have the same angle with respect to the axis of the outer mold 2, which is 1° to 15°.

[0053] In this embodiment, the outer mold inner retaining ring 22 is an integral annular structure, and the lower part 222 of the outer side surface of the outer mold inner retaining ring is an inverted cone, which is connected to the inner side surface 241 of the outer mold inner ring through the inverted cone. The upper part of the outer mold inner retaining ring 22 is provided with a first positioning ring plate 223 extending radially outward, and the bottom surface of the first positioning ring plate 223 is used to cooperate with the top surface of the outer mold inner ring 24 to position and constrain it; a plurality of second threaded through holes 221 are distributed along the annular direction on the first positioning ring plate 223, and the axis of the second threaded through hole 221 is parallel to the axis of the outer mold 2. When demolding, the outer mold inner retaining ring 22 can be removed from the inner side of the outer mold inner ring 24 by screwing bolts into the second threaded through holes 221, which is convenient for demolding; the inner side surface of the outer mold inner retaining ring 22 is preferably a cylindrical surface, which is convenient for transferring the load of the press when making the flame tube; the upper end surface 224 of the outer mold inner retaining ring is a plane, which is convenient for bearing the downward pressure load of the press during the molding process.

[0054] In this embodiment, the contact surfaces between the outer mold outer clamping ring 21, the outer mold outer ring 23, the outer mold inner ring 24, and the outer mold inner clamping ring 22 are all connected by inverted conical surfaces, and the inverted conical surfaces tend to expand from bottom to top, which is convenient for the assembly of the outer mold 2 and the transmission of the restraining force between the outer mold outer clamping ring 21 and the outer mold inner clamping ring 22 when the shaping mold is lifted as a whole or when the press presses the outer mold inner clamping ring 22. The axial height of the outer mold outer ring 23 is 1 to 1.8 times that of the outer ring part of the reflow flame tube 1, and the axial height of the outer mold inner ring 24 is 1 to 1.8 times that of the inner ring part of the reflow flame tube.

[0055] The inner mold 3 includes an inner mold outer ring 31, an inner mold retaining ring 33, and an inner mold inner ring 32, which are coaxially arranged from the outside to the inside. The lower part of the outer side surface 331 of the inner mold retaining ring and the inner side surface 312 of the inner mold outer ring, and the lower part of the inner side surface 332 of the inner mold retaining ring and the outer side surface 322 of the inner mold inner ring are connected by inverted cone surfaces. The outer side surface of the inner mold outer ring (i.e., shaping surface III 311) and the inner side surface of the inner mold inner ring (i.e., shaping surface IV 321) jointly form a second shaping surface 34 for shaping the inner profile 12 of the reflow flame tube. A second positioning ring plate 333 is radially extended outward from the upper part of the outer side surface of the inner mold retaining ring 33 to cooperate with the top of the inner mold outer ring 31 for positioning. A third positioning ring plate 334 is radially extended inward from the middle part of the inner side surface of the inner mold retaining ring 33 to cooperate with the top of the inner mold inner ring 32 for positioning.

[0056] In this embodiment, the inner mold outer ring 31 is composed of four fan-shaped ring structures evenly divided along the circumferential direction. The four fan-shaped ring structures are spliced ​​and assembled into a complete circular ring structure. Gaps are arranged between the four fan-shaped ring structures to facilitate the smooth placement of the inner mold 3 into the outer mold 2 with the fiber laid when the fiber preform is in a fluffy state; the inner side surface 312 of the inner mold outer ring is an inverted cone surface, and the outer side surface of the inner mold outer ring forms a shaping surface III311, which is compatible with the outer ring part of the inner profile 12 of the flame tube.

[0057] In this embodiment, the inner mold inner ring 32 is also composed of four fan-shaped structures evenly divided along the circumferential direction. The four fan-shaped structures are assembled into a complete circular ring structure, but the height of the inner mold inner ring 32 is smaller than that of the inner mold outer ring 31. There are gaps between the four fan-shaped structures, so that the fiber preform can be smoothly placed in the outer mold with the fiber laid in a fluffy state; the outer side surface 322 of the inner mold inner ring is an inverted cone surface, and the inner side surface of the inner mold inner ring forms a shaping surface IV321, which is compatible with the inner ring part of the flame tube inner profile 12. The shaping surface IV321 and the shaping surface III311 form a second shaping surface 34, which is compatible with the flame tube inner profile 12. The gap between the inner mold outer ring 31 and the inner mold inner ring 32 is to facilitate the assembly of the inner mold, but it cannot affect the molding quality of the reflow flame tube. The smaller the gap, the better.

[0058] In this embodiment, the inner mold clamping ring 33 is an integral annular structure, the lower part 331 of the outer side surface of the inner mold clamping ring is an inverted cone surface, and is connected with the inner side surface 312 of the inner mold outer ring through an inverted cone surface, the upper part of the outer side surface of the inner mold clamping ring is radially extended outward with a second positioning ring plate 333, the bottom surface of the second positioning ring plate 333 is matched with the top surface of the inner mold outer ring 31 for positioning, the lower part 332 of the inner side surface of the inner mold clamping ring is an inverted cone surface, and is connected with the outer side surface 322 of the inner mold inner ring through an inverted cone surface, and the middle part of the inner side surface of the inner mold clamping ring 33 is radially extended inward with a third positioning ring plate 335, which is connected with the inner mold inner ring The top surface of the ring 32 is positioned in cooperation, and the two groups of inverted cone surfaces connected to each other have the same angle relative to the axis of the inner mold 3, both of which are 1° to 15°; a plurality of third threaded through holes 334 are distributed along the annular direction on the second positioning ring plate 333, and the number of the third threaded through holes 334 is consistent with the number of blocks of the inner mold outer ring 31. When demolding, the inner mold clamping ring 33 can be removed from between the inner mold outer ring 31 and the inner mold inner ring 32 by screwing bolts into the third threaded through holes 334; the top surface 336 of the inner mold clamping ring is a plane, which is convenient for bearing the downward pressure load of the press during the molding process. The angles of different groups of inverted cone surfaces can be different.

[0059] In this embodiment, the contact surfaces between the inner mold clamp ring 33, the inner mold inner ring 32, and the inner mold outer ring 31 are all connected by inverted conical surfaces, and the inverted conical surfaces tend to expand from bottom to top, which is convenient for the assembly of the mold, the transmission of the restraining force when the shaping mold is lifted as a whole, and the transmission of the pressing force to the inner mold outer ring 31 and the inner mold inner ring 32 when the press presses the inner mold clamp ring 33, so that the pressing force on the fiber preform is normal, not tangential, to avoid wrinkles and dislocation of the fibers inside the manufactured reflow flame tube, which affects the performance of the flame tube, so that the demolding is also done as much as possible from the normal direction, not the tangential direction, to overcome the influence of the bonding force between the flame tube material and the mold on the performance of the flame tube as much as possible. The axial height of the inner mold outer ring is 1 to 1.6 times that of the outer ring part of the reflow flame tube; the axial height of the inner mold inner ring is 1 to 1.6 times that of the inner ring part of the reflow flame tube. When the ceramic-based composite fiber is placed in the shaping mold and compacted to a designed thickness, the tops of the inner mold 3 and the outer mold 2 are flush.

[0060] Both the inner mold 3 and the outer mold 2 are made of metal materials. The metal materials used must have good thermal conductivity and deformation resistance, be able to perform hot pressing and curing on the reflow flame tube, achieve near-net size molding, and reduce the processing volume of subsequent preparation steps of the flame tube.

[0061] Embodiment 2;

[0062] like Figure 1-Figure 15 As an improvement of Example 1, the axial height of the outer ring 23 of the outer mold is 1.2 to 1.4 times that of the outer ring of the reflow flame tube 1, and the axial height of the inner ring 24 of the outer mold is 1.2 to 1.4 times that of the inner ring of the reflow flame tube 1; the axial height of the outer ring 31 of the inner mold is 1.1 to 1.4 times that of the outer ring of the reflow flame tube 1; the axial height of the inner ring 32 of the inner mold is 1.1 to 1.4 times that of the inner ring of the reflow flame tube 1. The angles of the two inverted cone surfaces of each group of mutually matched connections relative to the axis of the shaping mold are the same, both of which are 3° to 5°.

[0063] Embodiment 3;

[0064] like Figure 1-Figure 15 The method for manufacturing a reflow flame tube using the reflow flame tube shaping mold in Embodiment 1 or Embodiment 2 of the present invention comprises the following steps:

[0065] Assembling the outer mold 2 to form a first molding surface 25;

[0066] Laying the ceramic-based composite fiber required for making the reflow flame tube 1 on the first shaping surface 25 of the outer mold 2;

[0067] Assemble the inner mold 3 inside the outer mold 2 so that the second shaping surface 34 formed by the inner mold 3 contacts and matches with the upper surface of the ceramic-based composite fiber;

[0068] The assembled shaping mold and the ceramic-based composite fiber in the shaping mold are placed on a press to be pressed, so that the outer mold is flush with the top of the inner mold, and the internal ceramic-based composite fiber can reach the designed thickness; at the same time, the shaping mold and the ceramic-based composite fiber are placed in a heating device for heating; after the heating is completed, the mold is taken out and cooled to solidify the ceramic-based composite fiber;

[0069] The inner mold 3 and the outer mold 2 are demoulded to obtain a fiber blank of the reflow flame tube 1 , and then the fiber blank is densified and machined to obtain the reflow flame tube 1 .

[0070] Specifically, when assembling the finalizing mold,

[0071] After the outer mold outer clamping ring 21 is placed, the outer mold outer ring 23 and the outer mold inner ring 24 are assembled in sequence in the outer mold outer clamping ring 21, and then the outer mold inner clamping ring 22 is assembled to the inner side of the outer mold inner ring 24, and a first molding surface 25 is formed in the upper area between the outer mold outer ring 23 and the outer mold inner ring 24;

[0072] After laying the ceramic-based composite fiber on the first shaping surface 25 of the outer mold 2, the inner mold outer ring 31 and the inner mold inner ring 32 are assembled on the inner side of the outer mold 2 and above the ceramic-based composite fiber, and then the inner mold clamping ring 33 is embedded between the inner mold outer ring 31 and the inner mold inner ring 32 to form a second shaping surface 34 in contact with the upper surface of the ceramic-based composite fiber.

[0073] Specifically, when the inner mold 3 and the outer mold 2 are demoulded,

[0074] First, screw a bolt into the third threaded through hole 334 on the third positioning ring plate 335, lift up the inner mold clamping ring 33 by the counter pressure force and then remove it, then remove the inner mold inner ring 32 and the inner mold outer ring 31 composed of the segmented fan ring structure along the normal direction of the reflow flame tube, and thus the demoulding of the inner mold 3 is completed;

[0075] Screw a bolt into the second threaded through hole 221 on the first positioning ring plate 223, lift up the outer mold inner retaining ring 22 through the reverse pressure force and then remove it, then remove the outer mold inner ring 24 of the segmented fan-shaped ring structure along the normal direction of the reflow flame tube, and then remove the outer mold outer retaining ring 21 and the outer mold outer ring 23 to complete the demolding of the outer mold 2.

[0076] During the demolding process, since the inner mold retaining ring 33 and the outer mold inner retaining ring 22 are removed first, the inner mold inner ring 32, the inner mold outer ring 31, and the outer mold inner ring 24 can all be demolded from the normal direction of the reflow flame tube rather than the tangential direction. In this way, the adverse effects of the adhesion between the ceramic-based composite fiber and the shaping mold on the quality and performance of the reflow flame tube can be overcome as much as possible.

[0077] In the method and process of making a reflow flame tube, matters not covered are prior art.

Claims

1. A reflow flame tube shaping mold, comprising an inner mold and an outer mold, characterized in that: The inner mold and the outer mold are both combined molds. The inner side of the outer mold is formed with a first molding surface that matches the outer surface of the reflow flame tube, and the outer side of the inner mold is formed with a second molding surface that matches the inner surface of the reflow flame tube. The inner mold is coaxially assembled on the inner side of the outer mold to form a molding space for the reflow flame tube between the first molding surface and the second molding surface.

2. The reflow flame tube shaping mold according to claim 1, characterized in that: The outer mold includes an outer mold outer clamping ring, an outer mold outer ring, an outer mold inner ring, and an outer mold inner clamping ring. The inner side surface of the outer mold outer clamping ring and the outer side surface of the outer mold outer ring, the lower part of the inner side surface of the outer mold outer ring and the lower part of the outer side surface of the outer mold inner ring, and the inner side surface of the outer mold inner ring and the lower part of the outer side surface of the outer mold inner clamping ring are all connected through inverted cone surfaces. The upper part of the outer side surface of the outer mold inner ring and the upper part of the inner side surface of the outer membrane outer ring jointly form the first shaping surface. The upper part of the outer mold inner clamping ring radially extends outward to have a first positioning ring plate that cooperates with the top of the outer mold inner ring for positioning.

3. The reflow flame tube shaping mold according to claim 2, characterized in that: The outer mold outer clamping ring and the outer mold inner clamping ring are integral annular structures; the outer mold outer ring and the outer mold inner ring are both annular structures composed of at least two fan-shaped ring structures, and the first positioning ring plate is provided with a plurality of threaded through holes.

4. The reflow flame tube shaping mold according to claim 2, characterized in that: The angle between any one of the inverted cone surfaces and the axis of the shaping mold is 1° to 15°, the axial height of the outer ring of the outer mold is 1 to 1.8 times that of the outer ring of the reflow flame tube, and the axial height of the inner ring of the outer mold is 1 to 1.8 times that of the inner ring of the reflow flame tube.

5. The reflow flame tube shaping mold according to claim 2, characterized in that: At least two lugs are arranged on the outer clamping ring of the outer mold, and each lug is provided with a hoisting hole.

6. The reflow flame tube shaping mold according to claim 1, characterized in that: The inner mold comprises an inner mold outer ring, an inner mold clamping ring, and an inner mold inner ring. The inner side surface of the inner mold outer ring and the lower part of the outer side surface of the inner mold clamping ring, and the lower part of the inner side surface of the inner mold clamping ring and the outer side surface of the inner mold inner ring are all connected by inverted cone surfaces. The outer side surface of the inner mold outer ring and the inner side surface of the inner mold inner ring jointly form the second shaping surface. A second positioning ring plate extends radially outward from the upper part of the inner mold clamping ring to cooperate with the top of the inner mold outer ring for positioning. A third positioning ring plate extends radially inward from the middle part of the inner mold clamping ring to cooperate with the top of the inner mold inner ring for positioning.

7. The reflow flame tube shaping mold according to claim 6, characterized in that: The inner mold clamping ring is an integral circular ring structure; the inner mold outer ring and the inner mold inner ring are both circular ring structures composed of at least two fan-shaped ring structures, and gaps are provided between the fan-shaped ring structures constituting the inner mold outer ring or the inner mold inner ring.

8. The reflow flame tube shaping mold according to claim 6, characterized in that: The angle between any one of the inverted cone surfaces and the axis of the shaping mold is 1° to 15°, the axial height of the outer ring of the inner mold is 1 to 1.6 times that of the outer ring of the reflow flame tube; the axial height of the inner ring of the inner mold is 1 to 1.6 times that of the inner ring of the reflow flame tube.

9. The reflow flame tube shaping mold according to claim 6, characterized in that: The second positioning ring plate is provided with a plurality of threaded through holes.

10. A method for manufacturing a reflow flame tube using the reflow flame tube shaping mold according to any one of claims 1 to 9, comprising the following steps: Assembling the outer mold to form a first shaping surface; Laying the ceramic-based composite fiber on the first shaping surface; Assembling the inner mold inside the outer mold so that the second shaping surface formed by the inner mold contacts and matches with the upper surface of the ceramic-based composite fiber; The assembled shaping mold and the ceramic-based composite fiber in the shaping mold are placed on a press to be pressed so that the outer mold is flush with the top of the inner mold; the shaping mold and the ceramic-based composite fiber are heated at the same time; after the heating is completed, the shaping mold is taken out and cooled to solidify the ceramic-based composite fiber; The inner mold and the outer mold are demoulded to obtain a fiber blank of the reflow flame tube, and then the fiber blank is densified and machined to obtain the reflow flame tube.

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