Forming tool for aircraft s-shaped inlet and its design and use method

Abstract

The application discloses a forming tool for an S-shaped air inlet of an airplane and a design and use method thereof. The forming tool comprises a core mold and a laying support frame. The core mold is a multi-section structure and is hollow in sections. Each section of the core mold comprises a plurality of detachable core mold split bodies, and each core mold split body can be taken out from an inner cavity of the S-shaped air inlet product. The laying support frame is used for supporting the assembled core mold to lay and support the composite material of the S-shaped air inlet product and form. The core mold is hollow and is divided into multiple blocks, which not only reduces the weight of the mold, but also provides operation space for the internal disassembly of the mold, facilitates taking out the core mold in blocks during demolding, solves the demolding problem after the S-shaped air inlet product is formed, is suitable for processing technology and composite material product forming with special requirements on temperature and pressure, and guarantees the forming quality of the S-shaped air inlet product, and has good practical value.

Description

TECHNICAL FIELD

[0001] The present application relates to a forming tool for an aircraft S-shaped inlet duct and its design and use method. BACKGROUND

[0002] The inlet duct, as the inlet and passage of the air required by the jet engine, not only provides a certain flow of air for the aircraft engine, but also ensures the normal work of the compressor and combustion chamber. The turbine jet engine has strict restrictions on the non-uniformity of the flow field. In flight, the inlet duct needs to achieve the function of reducing the speed and increasing the pressure of the high-speed airflow, and convert the kinetic energy of the airflow into pressure energy. With the increase of flight speed, the pressure increasing effect of the inlet duct is more and more important, and the pressure increasing effect in supersonic flight can greatly exceed the compressor, so the inlet duct of the supersonic aircraft plays an important role in improving the flight performance.

[0003] In order to achieve the function of reducing the speed and increasing the pressure, the aircraft S-shaped inlet duct is designed to be S-shaped, as shown in Figures 1 to 3 The structural feature is that there is a special-shaped twisted structure, that is, the shapes of each cross section of the inlet duct are different. The traditional S-shaped inlet duct is manufactured by metal blocks, which are combined by welding or mechanical connection. Due to the large weight of metal materials, it cannot adapt to the lightweight design concept, and in order to adapt to the structure of the inlet duct, the metal blocks are cut and cut, and after the assembly by welding or mechanical connection, the connection is easy to be damaged or broken under high-frequency vibration and load, which cannot meet the needs of the further development of supersonic aircraft. With the development of aerospace technology, composite materials with small specific gravity, large specific strength and specific modulus, and many other advantages have gradually become the best choice in the field of aerospace, and are also the preferred material for manufacturing S-shaped inlet duct.

[0004] Generally, in order to ensure the smoothness and accuracy of the inner surface of the composite part, a metal positive mold is usually used for forming manufacturing. However, based on the structural characteristics of the aircraft S-shaped inlet, using ordinary metal positive mold forming has the problem that the part cannot be demolded. In view of this problem, the current effective solution is to use hot gas expansion metal as a positive mold core for laying and manufacturing. For example, the aircraft engine inlet and its integrated forming process disclosed in Chinese patent application CN115111060A uses a hot gas expansion metal pipe as a core mold after heating and inflation to maintain the required dimensional accuracy, and then the composite material is laid on the outer surface for co-curing forming. Through the thermal expansion and contraction characteristics of the hot gas expansion metal combined with the inflation pressure, the positive mold forming and demolding are realized. This forming method can improve the degree of automation of production and has the advantage of high efficiency of part forming. However, using hot gas expansion metal as a core mold requires strict control of its expansion temperature and inflation pressure to meet the dimensional accuracy of the inlet. This process requires appropriate heating and cooling, and the precision control is difficult. It is easy to cause errors in the size of the core mold due to improper temperature control or poor pressure sealing, resulting in unqualified inlet parts. In addition, using hot gas expansion metal as a positive mold core is not suitable for processing techniques that have special requirements for temperature and pressure, such as hot press molding. It also has limitations on the application scenarios and the types of composite materials that require special temperature or pressure treatment.

[0005] Therefore, how to design the S-shaped inlet forming tooling to solve the demolding problem after part forming while adapting to the processing techniques that have special requirements for temperature and pressure and the forming of composite parts is still a problem to be solved. SUMMARY

[0006] In view of the above problems, the present application provides a forming tooling for an aircraft S-shaped inlet and its design and use method. According to the numerical model theory of the inner surface of the aircraft S-shaped inlet, a core mold is designed. The core mold is a hollow structure and is divided into multiple blocks. This not only reduces the weight of the mold, but also provides operating space for the internal disassembly of the mold, making it easy to remove the core mold in blocks during demolding, and solving the demolding problem after the S-shaped inlet part is formed. The specific technical solutions are as follows:

[0007] Firstly, the present application provides a forming tooling for an aircraft S-shaped inlet, which comprises a core mold and a laying support frame. The core mold is a detachable multi-section structure, and each section is hollow. Each core mold section comprises a plurality of detachable core mold sub-molds, and each core mold sub-mold can be removed from the inner cavity of the S-shaped inlet part. The laying support frame is used to support the assembled core mold for composite material laying and forming of the S-shaped inlet part.

[0008] Secondly, the present application provides a design method for the forming tooling of an aircraft S-shaped inlet, comprising the following steps:

[0009] 1) The overall design of the core mold: according to the numerical model theory of the aircraft S-shaped inlet, the hollow overall structure of the core mold is designed, and the material and wall thickness of the core mold are determined;

[0010] 2) Axial parting design: according to the actual bending condition and cross-sectional diameter of the overall structure of the core mold, the core mold is divided into several small sections from the length direction;

[0011] 3) Annular parting design: according to the diameter size of the hollow cavity in each section of the core mold, each section of the core mold is divided into several modules in the annular direction, forming several core mold parting bodies; the annular cross-sectional size of the core mold parting body is smaller than the cavity size of the core mold, so that it can be easily taken out from the inside of the S-shaped inlet part during demolding;

[0012] 4) Axial connection design: a connecting part is designed at the end of the axial section of the core mold parting body, which is integrally formed with the core mold parting body and is folded inward into the core cavity, and a bolt through hole is provided on the connecting part, so that the axial core mold parting bodies are connected by bolt locking;

[0013] 5) Annular connection design: a positioning ring connection structure is designed on the connecting part of the core mold parting body, and the core mold parting bodies are connected in the annular direction through the positioning ring connection structure;

[0014] 6) Laying frame design: connecting shafts are designed at both ends of the overall structure of the core mold, and the assembled core mold is erected on the laying support frame through the connecting shafts, so as to prepare for the laying and molding of the composite material of the S-shaped inlet part.

[0015] In the foregoing design method of the aircraft S-shaped inlet forming tool, in step 1), the core mold is made of hot work die steel, and the wall thickness is 10-20 mm.

[0016] In the foregoing design method of the aircraft S-shaped inlet forming tool, in step 2), the core mold is divided into several small sections from the length direction, and the bending degree of each section of the core mold is not more than 15 degrees.

[0017] In the foregoing design method of the aircraft S-shaped inlet forming tool, in step 5), the positioning ring connection structure includes a positioning connecting ring, a plurality of positioning teeth are provided at the outer edge of the positioning connecting ring, a positioning recess is provided at the inner edge of one of the connecting parts of the two adjacent core mold parting bodies, and a plurality of bolt through holes are provided on the bottom surface of the positioning recess and the corresponding part of the positioning connecting ring, so that the core mold parting body and the positioning connecting ring are connected by bolts; a positioning notch matching the positioning teeth at the outer edge of the positioning connecting ring is provided at the inner edge of the other connecting part of the two adjacent core mold parting bodies, and each core mold parting body of each section of the core mold is ring-shapedly clamped by the positioning teeth and the positioning notch.

[0018] The connecting part of each core mold segment body at the axial end is provided with a positioning recess at one end and a positioning notch at the other end.

[0019] The positioning notch on each core mold segment body is at least one.

[0020] In step 6), the connecting shaft comprises a connecting shaft seat and a connecting shaft body, which are welded together; the outer end of the core mold segment body at the two ends of the core mold is provided with a connecting shaft mounting part, which is integrally formed with the core mold segment body and is folded outward from the cavity of the core mold; the connecting shaft seat is matched with the connecting shaft mounting part, and bolt through holes are arranged on the connecting shaft mounting part and the connecting shaft seat in correspondence, and the connecting shaft is mounted on the core mold through bolts.

[0021] In step 6), the laying support frame is a "N" type frame structure, and connecting shaft body mounting positions are arranged on the two side support columns for matching connection with the connecting shaft body, so as to mount the assembled core mold on the laying support frame.

[0022] Further, the application provides a use method of the forming tool of the S-shaped inlet duct, comprising the following steps:

[0023] S1: annular assembly of molds: according to the position designed by the annular segmenting, the core mold segment bodies of each segment are annularly combined, and are assembled by using a positioning ring joint structure to obtain core mold segments;

[0024] S2: axial assembly of molds: according to the position designed by the axial segmenting, the core mold segments are axially combined, and are assembled by using a bolt locking connection to obtain a core mold whole structure;

[0025] S3: erection: the connecting shaft is mounted at the two ends of the assembled core mold whole structure, and is erected on the laying support frame for laying;

[0026] S4: laying and curing: the composite material used for preparing the S-shaped inlet duct part is laid on the erected core mold according to the laying requirement, and is cured according to the curing requirement of the composite material to form;

[0027] S5: disassembly and demolding: after the S-shaped inlet duct part is completely cured and formed, the core mold is disassembled from the end part, and the core mold segment bodies are taken out from the S-shaped inlet duct part one by one.

[0028] The application has the following beneficial effects:

[0029] 1) The present application designs a metal core mold according to the numerical simulation theory of the inner surface of an airplane S-shaped air inlet, the metal core mold is a hollow structure and is divided into multiple blocks, which not only reduces the weight of the mold, but also provides operating space for the internal disassembly of the mold, facilitates the block-by-block removal of the core mold during demolding, solves the demolding problem of the S-shaped air inlet after forming, and can adapt to the processing technology with special requirements for temperature and pressure and the forming of composite parts.

[0030] 2) The present application designs the position of the core mold segmentation and the number of core mold blocks according to the length and twist degree of the S-shaped air inlet, which can well ensure the surface precision of the assembled mold and the forming quality of the S-shaped air inlet part.

[0031] 3) The core mold design of the present application uses a positioning ring with a positioning boss to realize the positioning and locking of the ring-shaped blocks, and only uses screws to assemble at the segmented connection, which is simple to assemble and convenient to disassemble and demold.

[0032] 4) The S-shaped air inlet core mold of the present application is directly laid on the laying frame through the connecting shaft after assembly, which is simple to operate and avoids turning over the mold during laying operation, further ensures the surface position and precision of the assembled mold, ensures the forming quality and size precision of the part, and has good practical value. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a schematic diagram of the side surface structure of the S-shaped air inlet of the present application;

[0034] Figure 2 It is a schematic diagram of the front end of the S-shaped air inlet of the present application;

[0035] Figure 3 It is a schematic diagram of the rear end of the S-shaped air inlet of the present application;

[0036] Figure 4 It is a schematic diagram of the forming tool structure of the airplane S-shaped air inlet of the present application;

[0037] Figure 5 It is a schematic diagram of the axial connection section of the core mold of the airplane S-shaped air inlet forming tool of the present application;

[0038] Figure 6 It is a schematic diagram of the ring connection section of the core mold of the airplane S-shaped air inlet forming tool of the present application;

[0039] Figure 7 It is a schematic diagram of the core mold of the airplane S-shaped air inlet forming tool of the present application;

[0040] Figure 8 It is a schematic diagram of the positioning ring connection structure of the airplane S-shaped air inlet forming tool of the present application.

[0041] In the figure: 1, core mold; 101, core mold parting body; 2, paving support frame; 3, S-shaped air inlet; 4, connecting part; 5, bolt through hole; 6, bolt; 7, positioning ring structure; 701, positioning connecting ring; 7011, positioning convex tooth; 702, positioning concave table; 703, positioning gap; 8, connecting shaft; 801, connecting shaft seat; 802, connecting shaft body; 9, connecting shaft mounting part; 10, connecting shaft body mounting position. DETAILED DESCRIPTION

[0042] The technical solutions of the present application will be described clearly and completely below in combination with embodiments. Obviously, the described embodiments are only the preferred embodiments of the present application, not all the embodiments, and are not intended to limit the present application in other forms. Any skilled person in the art can make changes or modifications or equivalent changes by using the disclosed technical content. However, any simple modification, equivalent change and modification made to the above embodiments without departing from the technical solution content of the present application, and according to the technical essence of the present application, still belongs to the protection scope of the technical solution of the present application.

[0043] Embodiment 1

[0044] This embodiment is a forming tool for an aircraft S-shaped air inlet and a design method thereof, as shown in the figure, the forming tool for the S-shaped air inlet includes a core mold 1 and a paving support frame 2; the core mold 1 is made of hot work die steel P20, the core mold has a detachable multi-section structure, and the section is hollow; each section of the core mold includes a plurality of detachable core mold parting bodies 101, and each core mold parting body 101 can be taken out from the inner cavity of the S-shaped air inlet part 3; the paving support frame 2 is used to support the assembled core mold 1 to perform S-shaped air inlet part 3 composite material paving and forming. Figures 4 to 8 The design method of the S-shaped air inlet forming tool includes the following steps:

[0045] 1) Core mold overall design: according to the theoretical inner surface design of the aircraft S-shaped air inlet part 3, the hollow core mold 1 overall structure is designed, and the wall thickness of the core mold 1 is determined to be 10-20mm;

[0046] 2) Axial parting design: according to the actual bending condition and cross-sectional diameter size of the core mold 1 overall structure, the core mold 1 is divided into several small sections from the length direction; the bending degree of each section of the core mold 1 is not more than 15 degrees;

[0047] 3) Ring parting design: according to the diameter size of the hollow cavity of each section of the core mold 1 axial parting, each section of the core mold 1 is divided into several modules in the ring direction to form several core mold parting bodies 101; the ring cross-sectional size of the core mold parting body 101 is smaller than the cavity size of the core mold 1, so that it can be easily taken out from the inside of the S-shaped air inlet part 3 during demolding;

[0048] ​

[0049] 4) Axial connection design: the connection part 4 is designed at the end of the axial section of the core mold parting body 101, which is integrally formed with the core mold parting body 101 and is folded inward into the cavity of the core mold 1, and bolt through holes 5 are provided on the connection part 4, and each core mold parting body 101 is connected by bolts 6 in the axial direction;

[0050] 5) Ring connection design: the connection part 4 of the core mold parting body 101 is designed with a positioning ring structure 7, and each core mold parting body 101 is connected in the ring direction through the positioning ring structure 7. The positioning ring structure 7 includes a positioning connection ring 701, and a plurality of positioning protrusions 7011 are provided at the outer edge of the positioning connection ring 701; the inner edge of one of the connection parts 4 of two adjacent core mold parting bodies 101 is provided with a positioning recess 702 for accommodating the positioning connection ring 701, and a plurality of bolt through holes 5 are provided on the bottom surface of the positioning recess 702 and the corresponding part of the positioning connection ring 701, and the core mold parting body 101 and the positioning connection ring 701 are connected by bolts 6; the inner edge of the other connection part 4 of the two adjacent core mold parting bodies 101 is provided with a positioning gap 703 matched with the positioning protrusions 7011 at the outer edge of the positioning connection ring 701, and each core mold parting body 101 of each core mold 1 is ring-coupled by the positioning protrusions 7011 and the positioning gap 703. In order to facilitate assembly and disassembly, in this embodiment, the connection part 4 at the axial end of each core mold parting body 101 is provided with a positioning recess 702 at one end and a positioning gap 703 at the other end; the connection parts 4 at the same axial end of each core mold parting body 101 of each core mold parting body 101 are of the same type. In order to make the core mold parting body 101 ring-coupled and positioned, at least one positioning gap 703 is provided on each core mold parting body 101.

[0051] 6) Laying frame design: connection shafts 8 are designed at both ends of the overall structure of the core mold 1, and the assembled core mold 1 is erected on the laying support frame 2 through the connection shafts 8, so as to be prepared for the composite material laying and molding of the S-shaped air inlet passage product 3. The connection shaft 8 includes a connection shaft seat 801 and a connection shaft body 802, which are welded together; the outer end of the core mold parting body 101 at both ends of the core mold 1 is provided with a connection shaft mounting part 9, which is integrally formed with the core mold parting body 101 and is folded outward from the cavity of the core mold 1; the connection shaft seat 801 matches the connection shaft mounting part 9, and bolt through holes 5 are provided on the connection shaft mounting part 9 and the connection shaft seat 801, and the connection shaft 8 is mounted on the core mold 1 through bolts 6. The laying support frame 2 is a "N" type frame structure, and connection shaft body mounting positions 10 are provided on the two side support columns for matching connection with the connection shaft body 802, so as to mount the assembled core mold 1 on the laying support frame 2 for laying and molding.

[0052] Example 2

[0053] This embodiment is designed according to the tool design method of embodiment 1 to design a forming tool for an S-shaped air inlet of a certain type of aircraft, and the S-shaped air inlet part is formed by using the forming tool. The specific process is as follows:

[0054] According to the hollow core mold overall structure designed in the theoretical inner surface of the S-shaped air inlet part of the aircraft of this type, the wall thickness is determined to be 15 mm; according to the actual bending condition and the diameter size of the cross section of the core mold overall structure, it is divided into four sections from the length direction, as shown in Figure 4 , the bending degree of each section of the core mold 1 is not more than 10 degrees; according to the diameter size of the hollow cavity of each section of the axial parting, each section of the core mold is divided into several modules in the ring direction to form several core mold parting bodies. For example, as shown in Figure 6 , the first section of the core mold at the front end is divided into 5 blocks, and the cross-sectional size of each block is smaller than the cavity size of the core mold, so that it can be easily taken out from the inside of the S-shaped air inlet part during demolding.

[0055] Axially, the connecting part is designed at the segmented section of the core mold parting body, the connecting part is integrally formed with the core mold parting body and is folded inward into the core mold cavity, and the bolt through hole is provided on the connecting part to axially lock and connect each core mold parting body by bolts; in the ring direction, the positioning ring joint structure is designed on the connecting part on the section of the core mold parting body, and each core mold parting body is connected in the ring direction through the positioning ring joint structure. In this embodiment, the connecting part at the axial end of each core mold parting body is: one end is provided with a positioning recess, and the other end is provided with a positioning notch; the connecting part types of the same axial end of each core mold parting body of each section of the parting are consistent, and at least one positioning notch is provided on each core mold parting body.

[0056] The use method of the forming tool of the S-shaped air inlet described in this embodiment includes the following steps:

[0057] S1: ring direction assembly: according to the position of the ring direction parting design, the core mold parting bodies of each section are combined in the ring direction, and the positioning ring joint structure is used for assembly to obtain the core mold section;

[0058] S2: axial assembly: according to the position of the axial parting design, the core mold sections of each section are combined axially, and the bolt locking connection is used to obtain the core mold overall structure;

[0059] S3: erection: install the connecting shaft to the two ends of the assembled core mold overall structure, and then erect it on the laying support frame 2 for laying;

[0060] S4: laying and curing: lay the composite material used to prepare the S-shaped air inlet part on the erected core mold 1 according to the laying requirements, and then perform curing forming according to the curing requirements of the composite material;

[0061] S5: Splitting demolding: after the S-shaped air inlet part is completely cured and formed, the core mold is split from the end, and the core mold is taken out from the S-shaped air inlet part piece by piece.

[0062] It will be obvious to a person skilled in the art that the application is not limited to the details of the above-described exemplary embodiments, but that the application can be implemented in other concrete forms without departing from the spirit or essential characteristics of the application. The embodiments should therefore be considered in all respects as illustrative and not restrictive, the scope of the application being defined by the appended claims rather than by the above description, and it is therefore intended that all changes and modifications that come within the meaning and range of equivalency of the claims are to be embraced by the application. Any reference signs in the claims should not be construed as limiting the claims to the figures in which the reference signs are used.

[0063] Furthermore, it should be understood that although the present specification describes exemplary embodiments, not every exemplary embodiment contains all features. The specification is written with a certain degree of apparent separability of features, but it should be understood that the feature combinations can be formed in other ways, and that the skilled person should consider the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by the skilled person.

Claims

1. A method for designing a forming tool for an aircraft S-duct, characterized in that: The forming tool includes a core mold (1) and a laying support frame (2); the core mold (1) is a multi-section structure which can be disassembled, and the section is hollow; each section of the core mold includes a plurality of disassembled core mold sub-molds (101), and each core mold sub-mold (101) can be taken out from the inner cavity of the S-shaped air inlet part (3); the laying support frame (2) is used for supporting the assembled core mold (1) to perform the composite material laying and forming of the S-shaped air inlet part (3); and the forming tool design method includes the following steps: 1) Core mold overall design: according to the theoretical inner surface design of the numerical model of the aircraft S-shaped air inlet part (3), the hollow core mold (1) overall structure is designed, and the material and wall thickness of the core mold (1) are determined; the core mold (1) is hot work die steel, and the wall thickness is 10-20 mm; 2) Axial sectioning design: according to the actual bending condition and cross-sectional diameter size of the core mold (1) overall structure, the core mold (1) is divided into a plurality of small sections from the length direction, and the bending degree of each section of the core mold (1) is not more than 15 degrees; 3) Ring sectioning design: according to the diameter size of the hollow cavity of each section of the core mold (1) in the axial sectioning, each section of the core mold (1) is divided into a plurality of modules in the ring direction to form a plurality of core mold sub-molds (101); the ring cross-sectional dimension of the core mold sub-mold (101) is smaller than the cavity dimension of the core mold (1), so that it can be smoothly taken out from the inside of the S-shaped air inlet part (3) during demolding; 4) Axial connection design: a connecting part (4) is designed at the end of the axial section of the core mold sub-mold (101) which contacts with the section, the connecting part (4) is integrally formed with the core mold sub-mold (101) and is folded inward into the cavity of the core mold (1), a bolt through hole (5) is arranged on the connecting part (4), and the core mold sub-molds (101) are axially connected through bolts (6); 5) Ring connection design: a positioning ring connection structure (7) is designed on the connecting part (4) of the core mold sub-mold (101), and the core mold sub-molds (101) are connected in the ring direction through the positioning ring connection structure (7); the positioning ring connection structure (7) includes a positioning connecting ring (701), and a plurality of positioning protrusions (7011) are arranged at the outer edge of the positioning connecting ring (701); one of the connecting parts (4) of the two adjacent core mold sub-molds (101) is provided with a positioning recess (702) for accommodating the positioning connecting ring (701), a plurality of bolt through holes (5) are arranged on the bottom surface of the positioning recess (702) and the corresponding part of the positioning connecting ring (701), and the core mold sub-mold (101) and the positioning connecting ring (701) are connected through the bolts (6); the other connecting part (4) of the two adjacent core mold sub-molds (101) is provided with a positioning gap (703) matched with the positioning protrusions (7011) at the outer edge of the positioning connecting ring (701), and each core mold sub-mold (101) of each section of the core mold (1) is ring-shapedly clamped through the clamping of the positioning protrusions (7011) and the positioning gap (703). 6) The design of the laying frame: the connecting shaft (8) is designed at both ends of the overall structure of the core mold (1), and the assembled core mold (1) is erected on the laying support frame (2) through the connecting shaft (8) to prepare for the composite material laying and molding of the S-shaped air inlet passage product (3).

2. The method of designing a tooling for an aircraft S-duct according to claim 1, characterized in that: The connecting part (4) at the axial end of each core mold split body (101) is provided with a positioning recess (702) at one end and a positioning notch (703) at the other end; the connecting parts (4) at the same axial end of each core mold split body (101) of each split mold are of the same type.

3. The method of designing a tooling for an aircraft S-duct according to claim 1, wherein: The positioning notch (703) on each core mold split body (101) is at least one.

4. The method of designing a tooling for an aircraft S-duct according to claim 1, wherein: In step 6), the connecting shaft (8) includes a connecting shaft seat (801) and a connecting shaft body (802), which are welded together; The outer end of the core mold split body (101) at both ends of the core mold (1) is provided with a connecting shaft mounting part (9), which is integrally formed with the core mold split body (101) and is folded outward to the cavity of the core mold (1); The connecting shaft seat (801) matches the connecting shaft mounting part (9), and the connecting shaft mounting part (9) and the connecting shaft seat (801) are provided with bolt through holes (5) corresponding thereto, and the connecting shaft (8) is installed on the core mold (1) through the bolt (6).

5. The method of designing a tooling for an aircraft S-duct according to claim 1, wherein: In step 6), the laying support frame (2) is a "N" type frame structure, and the connecting shaft body mounting position (10) is provided on the both side support columns for matching connection with the connecting shaft body (802), so as to install the assembled core mold (1) on the laying support frame (2).

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