Structure part boss and variable thickness area pre-pressing tool and forming method

Abstract

The invention relates to the technical field of composite material bearing structural part forming, in particular to a structural part boss and variable thickness area pre-pressing tool and a forming method. The invention provides a structural part boss and variable thickness area pre-pressing tool which comprises a tool body and a plurality of pre-pressing parts, the multiple pre-pressing parts are arranged in the circumferential direction of the tool body at intervals, each pre-pressing part comprises an installation part and a pre-pressing part, the installation parts are connected with the tool body, and the pre-pressing parts are connected with the tool body. And the pre-pressing piece is connected with the mounting piece in a sliding manner. According to the technical scheme, the accuracy of the boundary dimension is guaranteed, the butt joint strength requirement of the boss and the variable thickness area is improved, and the problem that the boundary dimension and the internal quality of the carbon fiber special-shaped structure are difficult to guarantee through machining is solved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of composite material load-bearing structural component forming, and in particular to a structural component boss and variable thickness area pre-pressing tooling and a forming method. Background Art

[0002] Resin-based structural composite materials have the characteristics of high strength, high modulus, corrosion resistance and fatigue resistance. They are currently widely used in structural composite materials for aerospace. In order to adapt to the development and production of different types of products, a variety of product structures have emerged. In order to meet the assembly requirements of large and small ends, a certain type of product is designed with a variable thickness area and a special-shaped internal boss structure, and the molding process adopts a layup-autoclave process. The small end of the product has multiple bosses, and the large end frame has multiple variable thickness areas. The thickness of the boss and variable thickness area is relatively large, while the size of the boss is small. It is difficult to control the layup process together with the product, and it is impossible to accurately control the external dimensions after layup.

[0003] Therefore, how to ensure the external dimension requirements of the boss and variable thickness area is an urgent problem to be solved. Summary of the invention

[0004] The present disclosure aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] To this end, the present disclosure provides a pre-stressing tool for a structural part boss and a variable thickness area in a first aspect of the present disclosure, comprising a tool body and a plurality of pre-stressing parts, wherein the plurality of pre-stressing parts are arranged at intervals along the circumference of the tool body, wherein the pre-stressing part comprises a mounting part and a pre-stressing part, wherein the mounting part is connected to the tool body, and the pre-stressing part is slidably connected to the mounting part.

[0006] In a feasible implementation manner, a driving member is further included, wherein the driving member is connected to the pre-pressing member, and the driving member is used to apply a force to the pre-pressing member to compact the structural member to be formed.

[0007] In a feasible implementation manner, the tool body is configured in a circular ring shape, and the compacting direction of the pre-pressed part is toward the center of the tool body.

[0008] In a feasible embodiment, the pre-pressed part includes an adjusting part, a first pre-pressed part, a second pre-pressed part and a positioning pre-pressed part, the adjusting part is connected to the mounting part, the first pre-pressed part, the second pre-pressed part and the positioning pre-pressed part are connected to the adjusting part, and the adjusting part is used to adjust the pressing surface of one of the first pre-pressed part, the second pre-pressed part and the positioning pre-pressed part toward the structural part to be formed.

[0009] In a feasible implementation manner, a positioning member is further included, the pre-pressing portion is slidably connected to the tool body, and the positioning member is used to fix the relative position of the pre-pressing portion on the tool body.

[0010] In a feasible implementation manner, the pre-pressing member includes an adjusting rod and a pressing head, the adjusting rod is movably connected to the mounting member, and the pressing head is detachably connected to the adjusting rod.

[0011] In a second aspect of the present disclosure, a method for forming a boss and a variable thickness area in a housing is provided, which is applied to the above-mentioned pre-pressing tooling for the boss and the variable thickness area of ​​the structural part, comprising:

[0012] Laying the boss processing surface, alternately laying the boss processing surface, and staggering the layout direction of each layer, and pre-pressing the small end processing surface respectively through the pre-pressing piece;

[0013] The variable thickness area and the boss are laid, the bosses are laid alternately and gradually, the variable thickness area is laid alternately, and the layout direction of each layer of the variable thickness area is staggered. The variable thickness area and the boss are laid, and after being laid to half of the preset size, they are put into the oven for pre-pressing. After being taken out of the oven, the variable thickness area and the boss are pre-pressed twice by the pre-pressing block; after the second pre-pressing, the laying is completed to the preset size and then pre-pressed in the oven. After being taken out of the oven, they are pre-pressed three times by the pre-pressing block;

[0014] Curing and molding: vacuum hot pressing is performed on the structural parts after three pre-pressing.

[0015] In a feasible implementation manner, the layers are staggered in the order of 0 degrees, 90 degrees, +45 degrees, and -45 degrees, and every 4 layers are pre-pressed once by the pre-pressing member.

[0016] In a feasible implementation manner, the order of alternating and decreasing plies of the bosses is 0 degrees, 90 degrees; the order of staggered plies of the variable thickness areas is 0 degrees, 90 degrees, +45 degrees, -45.

[0017] In a feasible implementation, in the curing and molding step, the vacuum pressure of the vacuum hot pressing is less than or equal to -0.09 MPa, the hot pressing pressure is 0.3 MPa, the curing temperature is 200°C, and the post-processing temperature is 240°C.

[0018] The above description is only an overview of the technical solution provided by the present disclosure. In order to more clearly understand the technical means of the present disclosure, it can be implemented according to the contents of the specification. In order to make the above and other features and effects of the present disclosure more obvious and easy to understand, the implementation method of the present disclosure is specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the exemplary embodiments below. The accompanying drawings are only for the purpose of illustrating exemplary embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0022] Figure 1 This is one of the structural schematic diagrams of the pre-pressing part and the tooling body disclosed in the present invention;

[0023] Figure 2 This is the second structural schematic diagram of the pre-pressing part and the tooling body disclosed in the present invention;

[0024] Figure 3 This is the third structural schematic diagram of the pre-pressing part and the tooling body disclosed in the present invention;

[0025] Figure 4 is a schematic diagram of the structure of the boss disclosed in the present invention;

[0026] Figure 5 It is a schematic diagram of the front view structure of the variable thickness area disclosed in the present invention;

[0027] Figure 6 This is one of the structural schematic diagrams of the variable thickness area pre-pressing portion disclosed in the present invention;

[0028] Figure 7 This is the second structural schematic diagram of the variable thickness area pre-pressing part disclosed in the present invention;.

[0029] in, Figures 1 to 7 The corresponding relationship between the reference numerals and the component names is as follows:

[0030] 100-variable thickness area; 200-boss;

[0031] 1- tooling body; 2- pre-pressing part; 21- mounting piece; 22- pre-pressing piece; 221- first pre-pressing piece; 222- second pre-pressing piece; 223- positioning pre-pressing piece; 224- adjusting rod; 225- pressing head. DETAILED DESCRIPTION

[0032] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0034] At present, in order to meet the assembly requirements of large and small ends, a certain model of product is designed with a variable thickness area and a special-shaped internal boss structure, and the molding process adopts the lamination-autoclave process; the small end of the product has multiple bosses, and the large end frame has multiple variable thickness areas. The thickness of the boss and the variable thickness area is large, while the size of the boss is small. It is difficult to control the lamination process together with the product, and it is impossible to accurately control the external dimensions after lamination. Therefore, how to ensure the external dimension requirements of the boss and variable thickness area is an urgent problem to be solved.

[0035] Based on this, the embodiment of the present disclosure provides a tool, including a tool body and a plurality of pre-pressing parts, the plurality of pre-pressing parts are arranged at intervals along the circumference of the tool body, wherein the pre-pressing part includes a mounting part and a pre-pressing part, the mounting part is connected to the tool body, and the pre-pressing part is slidably connected to the mounting part. By implementing the technical solution of the present disclosure, the accuracy of the external dimensions is ensured, the strength requirements for the connection between the boss and the variable thickness area are improved, and the problem that it is difficult to ensure the external dimensions and internal quality of the carbon fiber special-shaped structure by mechanical processing is solved.

[0036] The following is a detailed description of the structural member boss and variable thickness area pre-pressing tooling and forming method through a specific embodiment:

[0037] Reference Figures 1 to 7 As shown, in the first aspect of the present disclosure, a pre-stressing tool for a structural part boss and a variable thickness area is provided, comprising a tool body 1 and a plurality of pre-stressing parts 2, wherein the plurality of pre-stressing parts 2 are arranged at intervals along the circumference of the tool body 1, wherein the pre-stressing part 2 comprises a mounting member 21 and a pre-stressing member 22, wherein the mounting member 21 is connected to the tool body 1, and the pre-stressing member 22 is slidably connected to the mounting member 21.

[0038] The tooling body 1 disclosed in the present invention is used as an installation and connection part that cooperates with the convex membrane of the structural part. A plurality of pre-pressing parts 2 are arranged on it, and the plurality of pre-pressing parts 2 are arranged at intervals in the circumference of the tooling body 1. The setting position and spacing distance are adjusted according to the boss setting of the structural part to be processed in order to adapt to the shape. The pre-pressing part 2 includes a mounting part 21 and a pre-pressing part 22. The mounting part 21 is connected to the tooling body 1, and the pre-pressing part 22 is slidably connected to the mounting part 21. The pre-pressing part 22 pre-presses the boss and the variable thickness area during the plying at each stage, which can better ensure the accuracy of the outer dimensions and improve the process method of the strength of the butt joint between the large and small ends, and solves the problem that mechanical processing is difficult to ensure the outer dimensions and internal quality of the carbon fiber special-shaped structure. Specifically, the pre-pressing part 22 can be set as a pressing block, a pressing plate, etc., and its structural form and setting quantity are selected according to the adaptability of the structural part form. The compaction force can be achieved by manual compaction, or a driving element can be set for CNC automatic compaction. For example, the boss pre-pressing parts are arranged in three groups, the first group is provided with 12 pieces for pre-pressing boss shape positioning, the second group is provided with 12 pieces for pre-pressing during the ply laying process, and the third group is provided with eight pieces for pre-pressing smaller bosses at various locations after the ply laying process is completed; and the variable thickness area pre-pressing blocks are arranged in two groups, each group is provided with four pieces, which are pre-pressed during the ply laying process and after the ply laying process, respectively. Furthermore, the tooling body 1 can be a separate body with boss-specific pre-pressing parts and variable thickness area-specific pre-pressing parts arranged on opposite sides, or the end pressure head of the pre-pressing part can be replaced to adjust whether it pre-presses the boss or the variable thickness area; or, the tooling body 1 is arranged as a variable thickness area tooling body and a boss tooling body, and boss pre-pressing parts and variable thickness area pre-pressing parts are arranged correspondingly, and the variable thickness area tooling body and the boss tooling body are connected by a connector.

[0039] In some embodiments, a driving member is further included, which is connected to the pre-pressing member 22 and is used to apply a force to the pre-pressing member 22 to compact the structural member to be formed.

[0040] In this embodiment, the driving member is used to apply the force of the pre-pressing member 22 to compact the structure to be formed, so as to replace manual compaction, so as to improve the operation efficiency and avoid manual compaction contacting the body of the structure to be processed. Specifically, the driving member can be a driving motor, a telescopic cylinder, a telescopic oil cylinder, etc. The present disclosure specifically uses a driving motor to ensure a fine compaction strength.

[0041] In some embodiments, the tool body 1 is set in a circular ring shape, and the compaction direction of the pre-pressed piece 22 is toward the center of the tool body 1. In this embodiment, the tool body 1 is set in a circular ring shape to better adapt the tool body 1 to be set in a circular ring shape, and the compaction direction of the pre-pressed piece 22 is toward the center of the tool body 1.

[0042] In some embodiments, the pre-pressed part 22 includes an adjusting part, a first pre-pressed part 221, a second pre-pressed part 222 and a positioning pre-pressed part 223, the adjusting part is connected to the mounting part 21, the first pre-pressed part 221, the second pre-pressed part 222 and the positioning pre-pressed part 223 are connected to the adjusting part, and the adjusting part is used to adjust the pressing surface of one of the first pre-pressed part 221, the second pre-pressed part 222 and the positioning pre-pressed part 223 to face the structural part to be formed.

[0043] In this embodiment, the first pre-pressed part 221, the second pre-pressed part 222 and the positioning pre-pressed part 223 are connected to the adjusting part, and the adjusting part is used to adjust the pressing surface of one of the first pre-pressed part 221, the second pre-pressed part 222 and the positioning pre-pressed part 223 to face the structural part to be formed, so that the first pre-pressed part 221, the second pre-pressed part 222 and the positioning pre-pressed part 223 do not need to be manually replaced, and the shapes of the three groups of pre-pressed parts are adaptively selected according to the process flow. Specifically, the adjusting part can use a turntable, an electric bearing, etc., and the first pre-pressed part 221, the second pre-pressed part 222 and the positioning pre-pressed part 223 are evenly distributed along the circumference of the adjusting part, and the pressing surface is aligned by rotating the adjusting part. It can be understood that a certain amount of rotation space is required when adjusting the first pre-pressed part 221, the second pre-pressed part 222 and the positioning pre-pressed part 223.

[0044] In some embodiments, a positioning member is further included, and the pre-pressing portion 2 is slidably connected to the tool body 1 , and the positioning member is used to fix the relative position of the pre-pressing portion 2 on the tool body 1 .

[0045] In this embodiment, the entire pre-pressing part 2 is slidably connected to the tool body 1, for example, the mounting member 21 is slidably connected to the tool body 1, so that the pre-pressing part 2 can adjust its position to adapt to various shapes and types of structural parts pre-pressing bosses and thickening areas. The fixing member can be fixed by a clamping method for the tool body 1, or it can be fixed by bolts.

[0046] In some embodiments, the pre-pressing member 22 includes an adjusting rod 224 and a pressing head 225, wherein the adjusting rod 224 is movably connected to the mounting member 21, and the pressing head 225 is detachably connected to the adjusting rod 224. In this embodiment, the pressing head 225 is detachably connected to the adjusting rod 224 to facilitate replacement of the pressing head.

[0047] In a second aspect of the present disclosure, a method for forming a boss and a variable thickness area in a housing is provided, which is applied to the above-mentioned pre-pressing tooling for the boss and the variable thickness area of ​​the structural part, comprising:

[0048] The boss processing surface is layered, and the boss processing surface is alternately layered, and the layout direction of each layer is staggered, and the small end processing surface is pre-pressed by the pre-pressing member 22;

[0049] The variable thickness area and boss are laid, the boss is laid alternately and decreasingly, the variable thickness area is laid alternately, and the layout direction of each layer in the variable thickness area is staggered. The variable thickness area and boss are laid, and after laying to half of the preset size, they are put into the oven for pre-pressing. After coming out of the oven, the variable thickness area and boss are pre-pressed twice by the pre-pressing block; after the second pre-pressing, the laying is completed to the preset size and then pre-pressed in the oven. After coming out of the oven, they are pre-pressed three times by the pre-pressing block;

[0050] Curing and molding: vacuum hot pressing is performed on the structural parts after three pre-pressing.

[0051] In some embodiments, the order of staggered arrangement of the plies is 0 degree, 90 degree, +45 degree, and −45 degree, and every four plies are pre-pressed once by the pre-pressing member 22 .

[0052] In some embodiments, the order of alternating and decreasing plies of the bosses is 0 degrees, 90 degrees; the order of staggered arrangement of plies in the variable thickness areas is 0 degrees, 90 degrees, +45 degrees, -45.

[0053] In some embodiments, in the curing molding step, the vacuum pressure of vacuum hot pressing is less than or equal to -0.09 MPa, the hot pressing pressure is 0.3 MPa, the curing temperature is 200°C, and the post-processing temperature is 240°C.

[0054] The present invention discloses a method for forming a boss and a variable thickness area inside a shell. According to the structural characteristics and stress characteristics of the product, a forming mold is provided to cooperate with the structural boss and variable thickness area pre-pressing tooling provided in the first aspect of the present invention. The mold body adopts a punch positioning cylinder, a steel split-flap punch and a die. The punch positioning cylinder serves as an internal support and a rotating clamp for laying layers, thereby avoiding structural instability and deformation of the mold due to external pressure during the forming process. The split-flap punch is a laying surface and is installed on the punch positioning cylinder; the die serves to ensure the outer dimensions and the pre-pressing of the mold.

[0055] Specifically, due to the large thickness of the boss and the variable thickness area, and the small size of the boss, it is difficult to control the layering process together with the product, and the external dimensions after layering cannot be accurately controlled. Therefore, the above-mentioned position area is layered in the punch, and after the reinforcement ribs and end frame in the shell are layered, the whole is then covered in the skin. In order to ensure the overall continuity of the fiber, the present invention can be formed by a unidirectional cloth layering method, and at the same time play a role in supporting the connection between cabin sections; during the molding process, due to the thick size of the boss, it is necessary to perform multiple oven pre-pressing to ensure the density of the middle layer. First, the male and female molds are combined in the oven for pre-pressing, and then the boss and variable thickness area pre-pressing tooling are assembled with the mold for pre-pressing after coming out of the oven. In order to ensure the pressure transmission effect during the pre-pressing process, it is necessary to mechanically pressurize the pre-pressing block 21 immediately after leaving the oven to ensure that the pressure is transmitted in place.

[0056] The carbon fiber process skin is obtained by curing the concave mold layer, and the rear cover plate, large end filling ring, front cover plate, and small end filling ring molds are assembled and molded, and the product is cured by vacuum-assisted autoclave pressurization. During curing, after the carbon fiber composite shell is laid, in order to ensure that the product's external dimensions meet the design requirements, it is necessary to use a carbon fiber process skin with good rigidity, and at the same time to ensure that the vacuum pressure is transmitted to the product; after the assembly, a semi-vacuum operation is performed, in which the vacuum pressure is below -0.092MPa. This pressure range can effectively remove the air and volatiles between the prepreg layers, so that the prepreg can fit tightly.

[0057] After the product is cured, it is taken out of the oven, the vacuum coating material on the mold surface is removed, and finally the outer dimensional process skin, large and small end molds, and the internal punch blocks are removed to obtain a carbon fiber composite cabin section with a variable thickness area and a special-shaped boss. The shell end frame end face, inner circle, boss and other parts are all left with margins, which are guaranteed through processing, process pin control and process connection holes are punched, and the skin opening is performed at the same time, followed by ultrasonic and three-dimensional scanning inspections.

[0058] For example, a structural compartment contains 4 variable thickness areas and 12 bosses at the large and small end frames. The skin thickness is 1 mm; there are 4 annular ribs distributed on the inner profile of the shell, one at each of the large and small end frames, with a rib width of 20 mm and a thickness of 2 mm. There are 2 ribs in the middle of the shell, with a rib width of 20 mm, and a gradual thickness change near quadrants I and III, with a change process of 2 mm → 1.17 mm → 1.5 mm. There are six longitudinal ribs distributed on the inner profile of the shell, one at each of quadrants I and III, with the lower end surface penetrating to the lower end frame and the upper end surface ending at the opening position, with a width of 30 mm and a thickness of 1.16 mm. There are two ribs in quadrants II and IV, with a width of 20 mm and a height of 2 mm, which penetrate the end surface from top to bottom. The thickness of the bosses is 12 mm and 13.8 mm respectively, and the variable thickness area transitions from 5.33 mm to 0 mm. The material selected is T700 carbon fiber and BMI resin system, the prepreg thickness is 0.1 mm, the 3K carbon cloth is 0.2 mm, and the curing temperature is 200°C.

[0059] Among them, the boss processing surface is laid with a thickness of 2 mm, and the laying sequence is [0 / 90 / +45 / -45]5, the unit is angle °, which represents the direction of carbon fiber in the prepreg, and 5 represents that the above laying sequence is repeated 5 times; after simulation analysis, this laying sequence can ensure the mechanical strength of the structure under load, and at the same time can reduce the deformation of the structure after curing, and pre-press once every 4 layers, and then use the pre-pressing part 21 to pre-press the boss processing surface respectively, and then a 3K carbon cloth is laid as the bottom layer, and the pre-pressing is completed. The 2 mm layers of the circumferential ribs, longitudinal ribs, and end frames need to be folded toward the variable thickness area and the boss, and the laying sequence is [0 / 90 / +45 / -45]5, and 4 layers are pre-pressed once. Vacuum pre-pressing can remove air and ensure the initial bonding of each layer of prepreg, which is conducive to subsequent curing and molding, and avoids defects such as delamination; it can make the distribution of fibers in the prepreg more uniform, reduce porosity, and improve the mechanical properties of the material, such as interlaminar shear strength;

[0060] The variable thickness area and boss are laid, the boss is laid alternately at 0° / 90° and the variable thickness area is laid alternately at [0 / 90 / +45 / -45]. After laying half the thickness, the material is put into the oven for pre-pressing. After coming out of the oven, the pre-pressing piece 21 is used to pre-press the variable thickness area and boss respectively. After the layer is completely laid, the pre-pressing piece 21 is used again for compaction. After pre-pressing, the missing parts of the boss and variable thickness area are repaired.

[0061] After the pre-pressing and repairing of the boss and variable thickness area is completed, the skin is laid with 1.5 mm layers in the order of [90 / 0 / 90 / 45 / -45 / 90 / 0 / 90 / 0 / 90 / -45 / 45 / 90 / 0 / 90], 4 layers are pre-pressed once, and the last 4 layers are pre-pressed in the oven; subsequently, the large and small end frames are laid, at which time the boss and variable thickness area are completely covered in the layer structure. After all the layers are completed, the concave mold and the convex mold are closed, and finally vacuumed, and then sent to the autoclave for mold closing and pre-pressing. For the final curing, the carbon fiber process skin replaces the concave mold for dimensional curing. The vacuum is not greater than -0.09MPa, the autoclave pressure is 0.3MPa, the curing temperature is 200℃, and the post-processing temperature is 240℃ ，According to the standard requirements of the composite autoclave molding process, the autoclave pressure is guaranteed to be below 1MPa, and the specific curing temperature and pressure are determined by the physical properties of the resin and carbon fiber filaments in the prepreg. If the temperature is too high, the resin will cure too quickly, resulting in greater internal stress, causing defects such as cracks and deformation in the product, and high temperature may damage the carbon fiber; if the temperature is too low, the resin will not cure completely, and the product will become soft and lack strength. Insufficient pressure will lead to loose fit between layers, more porosity, and poorer mechanical properties of the product; excessive pressure will cause excessive loss of resin, affecting the strength and rigidity of the product, and may damage the mold. After the curing is completed, demolding is carried out to remove the coating materials in turn, and the mold is disassembled to obtain an integrated carbon fiber composite cabin section with special-shaped bosses and variable thickness areas. Machining dimensions and shell openings

[0062] In the present disclosure, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance; the term "plurality" refers to two or more, unless otherwise expressly defined. The terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to the specific circumstances.

[0063] In the description of the present disclosure, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "left", "right", "front", "back", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, should not be understood as a limitation on the present disclosure.

[0064] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0065] The above are only preferred embodiments of the present disclosure and are not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A pre-pressing tool for bosses and variable thickness areas of structural parts, characterized in that: It comprises a tool body and a plurality of pre-pressing parts, wherein the plurality of pre-pressing parts are arranged at intervals along the circumference of the tool body, wherein: The pre-pressing part comprises a mounting part and a pre-pressing part, wherein the mounting part is connected to the tooling body, and the pre-pressing part is slidably connected to the mounting part.

2. The structural component boss and variable thickness area pre-pressing tooling according to claim 1, characterized in that: It also includes a driving member, which is connected to the pre-pressing member and is used to apply a force for the pre-pressing member to compact the structural member to be formed.

3. The structural component boss and variable thickness area pre-pressing tooling according to claim 1, characterized in that: The tool body is arranged in a circular ring shape, and the compacting direction of the pre-pressing member is toward the center of the tool body.

4. The structural component boss and variable thickness area pre-pressing tooling according to claim 1, characterized in that: The pre-pressed part includes an adjusting part, a first pre-pressed part, a second pre-pressed part and a positioning pre-pressed part, the adjusting part is connected to the mounting part, the first pre-pressed part, the second pre-pressed part and the positioning pre-pressed part are connected to the adjusting part, and the adjusting part is used to adjust the pressing surface of one of the first pre-pressed part, the second pre-pressed part and the positioning pre-pressed part to face the structural part to be formed.

5. The structural component boss and variable thickness area pre-pressing tooling according to claim 1, characterized in that: It also includes a positioning piece, the pre-pressing part is slidably connected to the tool body, and the positioning piece is used to fix the relative position of the pre-pressing part on the tool body.

6. The structural component boss and variable thickness area pre-pressing tooling according to claim 1, characterized in that: The pre-pressing member comprises an adjusting rod and a pressing head, wherein the adjusting rod is movably connected to the mounting member, and the pressing head is detachably connected to the adjusting rod.

7. A method for forming a boss and a variable thickness area in a shell, applied to the pre-pressing tool for boss and variable thickness area of ​​a structural part according to any one of claims 1 to 6, characterized in that: include: Laying the boss processing surface, alternately laying the boss processing surface, and staggering the layout direction of each layer, and pre-pressing the small end processing surface respectively through the pre-pressing piece; The variable thickness area and the boss are laid, the bosses are laid alternately and gradually, the variable thickness area is laid alternately, and the layout direction of each layer of the variable thickness area is staggered. The variable thickness area and the boss are laid, and after being laid to half of the preset size, they are put into the oven for pre-pressing. After being taken out of the oven, the variable thickness area and the boss are pre-pressed twice by the pre-pressing block; after the second pre-pressing, the laying is completed to the preset size and then pre-pressed in the oven. After being taken out of the oven, they are pre-pressed three times by the pre-pressing block; Curing and molding: vacuum hot pressing is performed on the structural parts after three pre-pressing.

8. The structural component boss and variable thickness area pre-pressing tooling according to claim 1, characterized in that: The staggered arrangement order of the plies is 0 degrees, 90 degrees, +45 degrees, and -45 degrees, and every 4 layers are pre-pressed once by the pre-pressing member.

9. The structural component boss and variable thickness area pre-pressing tooling according to claim 1, characterized in that: The order of alternating and decreasing plies of the bosses is 0 degrees, 90 degrees; the order of staggered arrangement of plies of the variable thickness areas is 0 degrees, 90 degrees, +45 degrees, -45.

10. The structural component boss and variable thickness area pre-pressing tooling according to claim 1, characterized in that: In the curing and molding step, the vacuum pressure of the vacuum hot pressing is less than or equal to -0.09 MPa, the hot pressing pressure is 0.3 MPa, the curing temperature is 200°C, and the post-processing temperature is 240°C.

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