A device and method for preparing a composite tubular joint preform

Abstract

The application belongs to the technical field of resin-based carbon fiber composite material manufacturing, and discloses a composite material tubular joint prefabricated body preparation device and method. The device comprises a bottom plate, a quadrilateral groove and a columnar groove are arranged on the bottom plate; a fixed support column is matched with the quadrilateral groove, and the fixed support column is provided with a threaded hole; an interface positioning pin connects the end of the composite material tubular joint to the fixed support column; a rotating support block is matched with the columnar groove and is connected to the end of the composite material tubular joint through the interface positioning pin. The device solves the technical problems of the existing product and the difficulty in layer positioning. The device can realize accurate positioning of the product and the layer position, ensure the layer position precision, and adapt to the pasting operation of different layer structure characteristics.

Description

Technical Field

[0001] This invention application belongs to the field of resin-based carbon fiber composite material manufacturing technology, specifically relating to a device and method for preparing composite material tubular joint preforms. Background Technology

[0002] Joints are connecting structures in aircraft structures, providing load transfer paths between various components. With the large-scale and in-depth application of composite materials in aircraft structures, composite material joints, due to their advantages such as lightweight and excellent fatigue performance, have become a development direction for aircraft structural optimization. Tubular composite material joints are used in parts such as aircraft landing gear, and consist of a mandrel and a composite material structure. The composite material is the main load-bearing structure during the aircraft's service life. The mandrel has metal bushings with assembly holes at both ends, providing interfaces for connecting other parts.

[0003] The fabrication process of the tubular composite material joint is as follows: a mandrel is prepared according to the product's numerical model; reinforcing material layups are applied to the surface of the mandrel to prepare a preform; the preform is then assembled with the mold; resin is injected into the mold to fully impregnate the preform; finally, it is cured and demolded to obtain the product. In actual operation, the reinforcing material layup structure is complex, involving circumferential layups, wound filaments, and layups unfolded along different splicing directions. During layup positioning, the mandrel must be accurately positioned to determine the specific placement of the reinforcing layer using methods such as laser projection. During layup, the mandrel's posture needs continuous adjustment to ensure that all parts of the product are operable. Summary of the Invention

[0004] This invention application addresses the technical problem of difficult positioning of existing products and layups by proposing a device and method for preparing prefabricated tubular joints of composite materials. This method can achieve accurate positioning of products and layups, ensure the accuracy of layup positions, adapt to laying operations with different layup structure characteristics, and allow for continuous adjustment of product angles to ensure sufficient operating space for all parts of the product during the laying process.

[0005] To achieve the aforementioned objectives, the technical solution adopted in this application is as follows:

[0006] A composite material tubular joint preform preparation apparatus, comprising:

[0007] A base plate, wherein a quadrilateral groove and a columnar groove are provided on the base plate;

[0008] A fixed support column is adapted to the quadrilateral groove, and the fixed support column has a threaded hole;

[0009] An interface positioning pin connects the end of the composite material tubular joint to the fixed support column;

[0010] A rotating support block, adapted to the columnar groove, is connected to the end of the composite material tubular joint via the interface positioning pin.

[0011] As a further aspect of the present invention: the interface positioning pin has a threaded positioning pin, an interface core mold and an opening module connected in sequence, the interface core mold is adapted to the assembly holes at both ends of the composite material tubular joint, and the threaded positioning pin is adapted to the threaded hole on the fixed support column.

[0012] As a further aspect of the present invention: the axis of the threaded locating pin coincides with the axis of the interface core mold.

[0013] As a further aspect of the present invention: the opening module is provided with an opening hole.

[0014] As a further aspect of the present invention: the rotating support block comprises a block body, a rotating positioning pin is provided at the bottom of the block body, which is adapted to the columnar groove of the base plate; a support block threaded hole is provided in the middle of the block body, which is adapted to the interface positioning pin.

[0015] As a further embodiment of the present invention: the fixed support column, the interface positioning pin, the rotating support block, the quadrilateral groove, and the columnar groove are respectively provided in 2, 3, 1, 3, and 1 units.

[0016] As a further aspect of the present invention, a rolling bearing is fitted between the rotary positioning pin and the columnar groove.

[0017] As a further embodiment of the present invention: the fixed support column may also adopt a split structure, including:

[0018] Upper support column and lower support column: The upper support column and the lower support column have a quadrilateral cross section at one end, which is adapted to the quadrilateral groove on the base plate, and the other end is equipped with a positioning boss.

[0019] Middle support column: The middle support column has a threaded hole that is adapted to the threaded positioning pin on the interface positioning pin. The middle support column also has two positioning grooves that are adapted to the positioning bosses on the upper support block and the lower support block.

[0020] As a further aspect of the present invention: the central support column is also equipped with a positioning pin, the axis of which coincides with the central axis of the central support column.

[0021] A method for preparing a composite material tubular joint preform, comprising the following steps using the aforementioned preparation apparatus:

[0022] (a) Prepare a core mold with assembly holes based on the three-dimensional digital model of the composite tubular joint product;

[0023] (b) Connect the two fixed support columns to the quadrilateral groove on the base plate;

[0024] (c) Connect the assembly hole on the product core mold to the interface core mold on the interface positioning pin;

[0025] (d) Connect the threaded locating pin on the interface locating pin to the threaded hole on the fixed support column;

[0026] (e) Apply reinforcing material to the upper surface of the product core mold in the horizontal direction, and then rotate the core mold, fixed support column and interface positioning pin as a whole in the vertical direction by 180°. The fixed support column is connected to the quadrilateral groove on the base plate. Apply reinforcing material to the other side of the product core mold.

[0027] (f) Remove the interface positioning pin at one end of the fixed support column and the product core mold, and connect the threaded positioning pin on the other end of the interface positioning pin with the threaded hole on the rotating support block.

[0028] (g) The rolling bearing is fitted into the columnar groove of the base plate, and the rotating positioning pin on the rotating support block is connected to the columnar groove on the base plate.

[0029] (h) Rotate the core mold around the rotating positioning pin as the axis, and lay reinforcing material on the core mold;

[0030] (i) Repeat steps (b) to (h) until the composite tubular joint preform is completed.

[0031] Preparing a composite tubular joint preform using the apparatus of the preferred embodiment includes the following steps:

[0032] (a) Prepare a core mold with assembly holes based on the three-dimensional digital model of the composite tubular joint product.

[0033] (b) Match the assembly hole on the product core mold with the interface core mold on the interface positioning pin, and then match the threaded positioning pin on the interface positioning pin with the threaded hole on the middle support column of the fixed support column.

[0034] (c) Connect the lower support column of the fixed support column to the quadrilateral groove on the base plate, mate the positioning boss on the lower support column with the positioning groove on the middle support column, and then mate the positioning boss of the upper support column with another positioning groove on the middle support column.

[0035] (d) Lay reinforcing material on the upper surface of the core mold in the horizontal direction, then rotate the product core mold, fixed support column and interface positioning pin as a whole in the vertical direction by 180° and connect them with the quadrilateral groove on the base plate, and continue to lay reinforcing material on the other side of the product core mold.

[0036] (e) Remove the upper and lower support columns, insert the rolling bearing into the columnar groove of the base plate, and connect the positioning pin on the middle support column with the columnar groove on the base plate.

[0037] (f) Rotate the product core mold around the locating pin as the axis and lay reinforcing material on the product core mold.

[0038] (i) Repeat steps (b) to (f) until the composite tubular joint preform is completed.

[0039] Compared with the prior art, the beneficial effects of this application are:

[0040] 1. It can adjust the product posture during the laying process. The product can be fixed horizontally by fixing the support column, and the product can be kept vertical by rotating the support block. Adjusting the product posture can adapt to the operational needs of different products and layup structures.

[0041] 2. The product can be rotated continuously in a vertical position, providing a larger installation space and reducing the difficulty of operation.

[0042] 3. By utilizing the assembly holes of the connector products themselves, precise positioning of the products can be achieved in a lateral orientation, which can effectively ensure the accuracy of the layup position and the product shape.

[0043] 4. In actual operation, the device can be used flexibly according to the product and the layup structure. For reinforcing layers with high positioning accuracy requirements, the layup position can be accurately positioned using laser projection in a lateral orientation. For layups where the splicing surface is parallel to the base plate, the fixed support column can be flipped, and the reinforcing material can be laid on both sides in a lateral orientation. For circumferential layups or wound filaments, the layup boundary can be positioned in a lateral orientation and then adjusted to a vertical orientation. The preform is then prepared during continuous rotation of the product core mold.

[0044] The present application will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0045] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0046] In the attached diagram:

[0047] Figure 1 This is a schematic diagram of the apparatus for preparing the composite tubular joint preform of this application;

[0048] Figure 2 This is an exploded structural diagram of the composite material tubular joint preform preparation device of this application;

[0049] Figure 3This is a schematic diagram of an interface positioning pin according to this application;

[0050] Figure 4 This is a schematic diagram of another interface positioning pin in this application;

[0051] Figure 5 This is a schematic diagram of the fixed support column structure of this application.

[0052] The following are the annotations in the attached diagram: 1-Base plate, 2-Quadrilateral groove, 3-Columnar groove, 4-Interface positioning pin, 5-Interface core mold, 6-Mold opening hole, 7-Mold opening module, 8-Threaded positioning pin, 9-Tube connector, 10-Assembly hole, 12-Fixed support column, 13-Threaded hole, 14-Rotating support block, 15-Rotating positioning pin, 16-Support block threaded hole, 17-Upper support column, 18-Lower support column, 19-Middle support column, 20-Positioning boss, 21-Positioning pin, 22-Positioning groove. Detailed Implementation

[0053] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0054] Example 1:

[0055] The composite tubular joint, 650 mm long, consists of a mandrel and a composite material structure. The mandrel has a composite material support in the middle section, with one end extending into two branches, each connected to a metal bushing. The other end of the support has composite lugs and is also connected to a metal bushing. The composite material structure covers the outside of the mandrel, and the layup consists of the following structural forms:

[0056] Circular lay-up: A reinforcing fabric is wound around the surface of a tubular mandrel several times.

[0057] Lay-up splicing: The reinforcing material fabric does not overlap on the surface of the core mold and is spliced ​​along a specific surface or line.

[0058] Winded fiber bundle: Reinforcing material fibers are wound around the surface of the mandrel at a specific angle and in a specific line shape.

[0059] Prepare the preform on the mandrel. Place the mandrel horizontally on the worktable and determine the layup positions. Lay the reinforcing material fabric on the upper surface of the mandrel. Rotate the reinforcing material and the mandrel at a certain angle and continue to lay the reinforcing material fabric on the upper surface. Prepare the filament bundle by pulling the filament bundle along the length of the product while continuously rotating the mandrel. Repeat the above steps until the preform is completed.

[0060] The tubular joint preform prepared using the above method has several drawbacks. Due to the need for continuous rotation and adjustment of the mandrel's posture during operation, precise positioning of the mandrel is impossible, and positioning aids such as laser projection cannot be used. Therefore, the layup position deviation is approximately 1 mm, failing to meet the design acceptance technical requirements (±0.5 mm). During filament winding, the mandrel cannot rotate along a fixed axis, and the rotation is synchronized with the filament winding, making operation difficult. Consequently, the winding angle of the filament cannot be guaranteed, and filament slippage occurs. During circumferential layup, the operation space is limited to the area above the mandrel, resulting in poor shaping and numerous wrinkles and looseness in the layup.

[0061] Example 2:

[0062] For the tubular joint in Example 1, a preform preparation device is designed, comprising the following parts:

[0063] Base plate 1: Rectangular flat plate structure with quadrilateral groove 2 and columnar groove 3.

[0064] Two fixed support columns: The fixed support column 12 cooperates with the quadrilateral groove 2 on the base plate 1. One of the fixed support columns 12 has two threaded holes 13 in the middle, and the other fixed support column 12 has one threaded hole 13 on the top.

[0065] Interface locating pin 4: Includes interface core mold 5, opening module 7 with opening hole 6, and threaded locating pin 8. One end of interface core mold 5 is connected to the opening module 7, and the other end is connected to the threaded locating pin 8. The axis of threaded locating pin 8 coincides with the axis of interface core mold 5. Interface core mold 5 mates with assembly holes 10 located at both ends of composite material tubular joint 8. Threaded locating pin 8 connects to threaded holes 13 on fixed support column 12.

[0066] A rotating support block 14 comprises a block body, a rotating positioning pin 15 located at the bottom of the block body, and a support block threaded hole 16 located in the middle of the block body. The rotating positioning pin 15 engages with a columnar groove 3 on the base plate 1, and a rolling bearing is embedded between the rotating positioning pin 15 and the columnar groove 3. The support block threaded hole 16 engages with a threaded positioning pin 8 on the interface positioning pin 4.

[0067] Using the above-mentioned composite material tubular joint preform preparation apparatus, a composite material tubular joint preform is prepared, comprising the following steps:

[0068] (a) Prepare a core mold with assembly holes based on the three-dimensional digital model of the composite tubular joint product.

[0069] (b) Connect the two fixed support columns 12 to the quadrilateral groove 2 on the base plate 1.

[0070] (c) Connect the assembly hole 10 on the product core mold to the interface core mold 5 on the interface positioning pin 4.

[0071] (d) Connect the threaded locating pin 8 on the interface locating pin 4 to the threaded hole 13 on the fixed support column 12.

[0072] (e) With the assistance of laser projection, determine the layup splicing position, lay the reinforcing material on the upper surface of the product core mold in the horizontal direction, and then rotate the core mold, fixed support column 12 and interface positioning pin 4 as a whole in the vertical direction by 180°. The fixed support column 12 is connected to the quadrilateral groove 2 on the base plate 1, and the reinforcing material is laid on the other side of the product core mold.

[0073] (f) Remove the interface positioning pin 4 at one end of the fixed support column 12 and the product core mold, and connect the threaded positioning pin 8 on the other end of the interface positioning pin 4 with the support block threaded hole 16 on the rotating support block 14.

[0074] (g) The rolling bearing is inserted into the columnar groove 3 of the base plate, and the rotating positioning pin 15 on the rotating support block 14 is connected to the columnar groove 3 on the base plate 1.

[0075] (h) Rotate the mandrel around the locating pin 15 to wind the reinforcing fiber onto the mandrel at the specified angle and in the specified pattern. Position one end of the circumferential layup on the surface of the mandrel, and rotate the mandrel around the locating pin 15 to complete the laying of the circumferential layup.

[0076] (i) Repeat steps (b) to (h) until the composite tubular joint preform is completed.

[0077] The composite tubular joint preform prepared according to the method of this embodiment defines the position of the mandrel by fixing support columns and interface positioning pins, which can ensure accurate positioning of the ply positions. During the splicing and laying process, the positioning of the ply above the mandrel is completed first, and then the fixing support columns are flipped to position the ply below the mandrel. When laying circumferential ply and winding the fiber bundle, the rotation axis of the mandrel is fixed by rotating support blocks, which can realize continuous rotation of the mandrel, reduce the difficulty of operation, and significantly increase the operating space. Therefore, the reinforcing fibers are flat and free from defects such as wrinkles, bridging, and looseness.

[0078] Example 3:

[0079] For the tubular joint in Example 1, a preform preparation device was designed. Based on the scheme of Example 2, the structure of the fixed support column 12 was further adjusted, specifically including the following parts:

[0080] Upper support column 17 and lower support column 18: One end of the upper support column 17 and the lower support column 18 has a quadrilateral cross section, which matches the quadrilateral groove 2 on the base plate 1, and the other end has a positioning boss 20.

[0081] The middle support column 19 has a threaded hole that mates with the threaded locating pin 8 on the interface locating pin 4. The middle support column 19 also has a locating pin 21, the axis of which aligns with the central axis of the middle support column 19. The middle support column 19 also has two locating grooves 22, which mate and connect with the locating bosses 20 on the upper support block 17 and the lower support block 18.

[0082] The preparation of composite tubular joint preforms using the apparatus described above includes the following steps:

[0083] (a) Prepare a core mold with assembly holes based on the three-dimensional digital model of the composite tubular joint product.

[0084] (b) Connect the assembly hole 10 on the product core mold to the interface core mold 5 on the interface positioning pin 4, and then connect the threaded positioning pin 8 on the interface positioning pin 5 to the threaded hole on the middle support column 19 of the fixed support column 12.

[0085] (c) Connect the lower support column 18 in the fixed support column 12 to the quadrilateral groove 2 on the base plate, mate the positioning boss 20 on the lower support column 18 with the positioning groove 22 on the middle support column 19, and then mate the positioning boss of the upper support column 17 with another positioning groove on the middle support column.

[0086] (d) Lay reinforcing material on the upper surface of the core mold in the horizontal direction, and then rotate the product core mold, fixed support column 12, and interface positioning pin 4 as a whole in the vertical direction by 180° and connect them with the quadrilateral groove 2 on the base plate 1. Continue to lay reinforcing material on the other side of the product core mold.

[0087] (e) Remove the upper support column 17 and the lower support column 18, insert the rolling bearing into the columnar groove 3 of the base plate, and connect the positioning pin 21 on the middle support column 19 with the columnar groove 3 on the base plate 1.

[0088] (f) Rotate the product core mold 23 around the positioning pin 21 as the axis, and lay reinforcing material on the product core mold 23.

[0089] (i) Repeat steps (b) to (f) until the composite tubular joint preform is completed.

[0090] The composite tubular joint preform prepared according to the method of this embodiment has accurate ply positioning, low difficulty in plying operation, significantly increased operating space, and smooth reinforcing fibers without defects such as wrinkles, bridging, or looseness. Compared with Embodiment 2, Embodiment 3 combines the function of the rotating support block with the fixed support column. When adjusting the product posture during the plying process, it is not necessary to remove the interface positioning pin, making the operation simpler. At the same time, the device structure is further simplified, and the cost is further reduced.

[0091] Thus, the objective of this invention has been achieved.

[0092] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for preparing a preform of a composite tubular joint, characterized in that, include: A base plate, wherein a quadrilateral groove and a columnar groove are provided on the base plate; A fixed support column is adapted to the quadrilateral groove, and the fixed support column has a threaded hole; An interface positioning pin connects the end of the composite material tubular joint to the fixed support column; A rotating support block, which is adapted to the columnar groove, is connected to the end of the composite material tubular joint through the interface positioning pin; The interface positioning pin has a threaded positioning pin, an interface core mold and a starting module connected in sequence. The interface core mold is adapted to the assembly holes at both ends of the composite material tubular joint, and the threaded positioning pin is adapted to the threaded hole on the fixed support column. The rotating support block includes a block body, a rotating positioning pin is provided at the bottom of the block body, which is adapted to the columnar groove of the base plate; a support block threaded hole is provided in the middle of the block body, which is adapted to the interface positioning pin; A rolling bearing is fitted between the rotary positioning pin and the columnar groove.

2. The composite material tubular joint preform preparation device according to claim 1, characterized in that, The axis of the threaded locating pin coincides with the axis of the interface core mold.

3. The composite material tubular joint preform preparation device according to claim 2, characterized in that, The opening module is provided with an opening hole.

4. The composite material tubular joint preform preparation device according to claim 1, characterized in that, The fixed support column, interface positioning pin, rotating support block, quadrilateral groove, and columnar groove are respectively provided in 2, 3, 1, 3, and 1 units.

5. The apparatus for preparing a composite material tubular joint preform according to claim 1 or 4, characterized in that, The fixed support column adopts a split structure, including: Upper support column and lower support column: The upper support column and the lower support column have a quadrilateral cross section at one end, which is adapted to the quadrilateral groove on the base plate, and the other end is equipped with a positioning boss. Middle support column: The middle support column has a threaded hole that is adapted to the threaded positioning pin on the interface positioning pin. The middle support column also has two positioning grooves that are adapted to the positioning bosses on the upper support column and the lower support column.

6. The apparatus for preparing a composite material tubular joint preform according to claim 5, characterized in that, The central support column also has a positioning pin, the axis of which coincides with the central axis of the central support column.

7. A method for preparing a composite material tubular joint preform, comprising preparing the composite material tubular joint preform using the preparation apparatus according to any one of claims 1 to 6, characterized in that, Includes the following steps: (a) Prepare a core mold with assembly holes based on the three-dimensional digital model of the composite tubular joint product; (b) Connect the two fixed support columns to the quadrilateral groove on the base plate; (c) Connect the assembly hole on the product core mold to the interface core mold on the interface positioning pin; (d) Connect the threaded locating pin on the interface locating pin to the threaded hole on the fixed support column; (e) Apply reinforcing material to the upper surface of the product core mold in the horizontal direction, and then rotate the core mold, fixed support column, and interface positioning pin as a whole in the vertical direction by 180°. The fixed support column is connected to the quadrilateral groove on the base plate. Apply reinforcing material to the other side of the product core mold. (f) Remove the interface positioning pin at one end of the fixed support column and the product core mold, and connect the threaded positioning pin on the other end of the interface positioning pin with the threaded hole of the support block on the rotating support block. (g) The rolling bearing is fitted into the columnar groove of the base plate, and the rotating positioning pin on the rotating support block is connected to the columnar groove on the base plate. (h) Rotate the core mold around the rotating positioning pin as the axis, and lay reinforcing material on the core mold; (i) Repeat steps (b) to (h) until the composite tubular joint preform is completed.

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