A method and device for manufacturing a special-shaped multi-layer three-dimensional fabric with a negative curvature profile

Abstract

This invention relates to a method and apparatus for preparing multi-layered three-dimensional fabrics with negative curvature surfaces. The method includes the following steps: (1) fixing and installing a lower negative curvature mold, and setting a horizontally movable, mirror-symmetrical positive curvature mold on the lower negative curvature mold; (2) preparing a layer of fiber preform on the positive curvature mold; (3) horizontally moving the positive curvature mold out; (4) applying an external load to the negative curvature surface portion through the upper negative curvature mold, so that the positive curvature portion of the positive curvature preform completely fits with the negative curvature portions of the upper and lower negative curvature molds, thus completing the preparation of a single-layer negative curvature fabric; (5) repeating steps 2-4 until the preparation of a multi-layered negative curvature fabric is completed. This invention solves the problems of complex operation, long preparation time, and high production cost associated with the original positive-negative curvature conversion process, achieving the requirements for preparing multi-layered, multi-density, and high-precision fabrics, reducing production costs, shortening the preparation cycle, and improving competitiveness.

Description

Technical Field

[0001] This invention belongs to the field of composite materials, specifically relating to a method and apparatus for preparing irregularly shaped multilayer three-dimensional fabrics with negative curvature surfaces. Background Technology

[0002] Currently, irregularly shaped multilayer three-dimensional fabrics are increasingly widely used in thermal insulation and wave-transparent composite materials. However, the current irregularly shaped multilayer three-dimensional fabrics are prepared according to their application requirements, based on a positive curvature profile. In the later composite process of the preform, the positive curvature preform is then converted into a negative curvature preform. This process results in high production costs, long preparation cycles, and difficulty in ensuring the required surface accuracy of the fabric. Summary of the Invention

[0003] The purpose of this invention is to provide a method and apparatus for preparing irregularly shaped multilayer three-dimensional fabrics with negative curvature surfaces, which solves the problems of high production cost and long preparation cycle of negative curvature surface preforms and ensures their high surface accuracy requirements.

[0004] The technical solution to achieve the objective of this invention is: a method for preparing irregularly shaped multilayer three-dimensional fabrics with negative curvature surfaces, comprising the following steps:

[0005] Step (1): Fix and install a lower negative curvature mold with the same shape as the negative curvature profile of the fabric. Set a horizontally movable positive curvature mold on the lower negative curvature mold. The positive curvature mold and the lower negative curvature mold are fixedly set in a mirror symmetrical manner.

[0006] Step (2): Prepare a layer of fiber preform on a positive curvature mold;

[0007] Step (3): While ensuring that the preform does not deform, move the positive curvature mold horizontally out;

[0008] Step (4): By setting an upper negative curvature mold above the positive curvature mold with a curvature matching that of the lower negative curvature mold, an external load is applied to the negative curvature surface of the preform, so that the positive curvature part of the positive curvature preform is completely attached to the negative curvature parts of the upper and lower negative curvature molds, so that the positive curvature part of the positive curvature preform is completely converted to negative curvature, and the preparation of the single-layer negative curvature fabric is completed;

[0009] Step (5): Repeat steps 2-4 until the negative curvature multilayer fabric is prepared.

[0010] Furthermore, in step (1), the positive curvature mold and the lower negative curvature mold are set up in a mirror symmetrical manner by calibrating with a laser level.

[0011] Furthermore, in step (2), a fiber preform is prepared on a positive curvature mold by needle punching, stitching 2.5D, or three-dimensional methods.

[0012] Furthermore, when the prepared three-dimensional fabric needs to withstand shear force, the fiber preform prepared in step (2) is reinforced in the Z direction and then pressed together.

[0013] Furthermore, in step (2), the bulk density of each layer is 0.3-0.9 g / cm³. 3 .

[0014] Furthermore, the shape of the three-dimensional fabric can be cylindrical, flat, conical, frustum, or curved.

[0015] Furthermore, in step (2), the fiber preform uses one or more of the following: quartz fiber, carbon fiber, silicon carbide fiber, alumina fiber, or silicon nitride fiber.

[0016] Furthermore, in step (4), multiple pressing is used, and the pressure distance between the upper and lower negative curvature molds gradually decreases in each pressing until the upper and lower negative curvature molds are completely bonded to the preform.

[0017] An apparatus for preparing irregularly shaped multilayer three-dimensional fabrics with negative curvature surfaces includes a hydraulic cylinder (1), an outer frame, a negative pressure component suspension beam, a negative pressure component support frame, an upper negative curvature mold, a negative pressure component slider rail, a positive curvature pressing mold, a positive curvature mold, a forming component slider rail, a lower negative curvature mold, and a support component support seat.

[0018] The hydraulic cylinder is bolted to the outer frame. The hydraulic cylinder's hydraulic rod drives the negative pressure component's suspension beam to move up and down along the negative pressure component's slider rail. The negative pressure component's suspension beam acts on the upper negative curvature mold through the negative pressure component's support frame. The negative pressure component's slider rail is fixed to the inner wall of the outer frame. The lower negative curvature mold is installed directly below the upper negative curvature mold and is mounted on the support component's support seat. The support component's support seat is welded to the bottom of the outer frame. The upper negative curvature mold is bolted to one end of the forming component's slider rail, and the positive curvature mold is bolted to the forming component's slider rail, thus allowing the positive curvature mold to move horizontally on the forming component's slider rail.

[0019] Furthermore, the positive curvature mold and the negative curvature mold are integrally formed or segmented formed, and the design principle of equal perimeter is adopted, so that the positive and negative curvature lengths are equal on the same height section.

[0020] Furthermore, the negative curvature mold and the working platform, as well as the negative curvature mold and the positive curvature mold, are fixed in a relatively fixed manner by means of bolt fixing, slot fixing, or magnetic fixing.

[0021] Furthermore, the upper negative curvature mold is made of stainless steel or high alloy steel;

[0022] The positive curvature mold is made of rubber or nylon.

[0023] Furthermore, the negative curvature portion of the negative curvature mold has strong air permeability, and is preferably honeycomb-shaped, strip-shaped, or dot-shaped.

[0024] Furthermore, the upper negative curvature mold, positive curvature mold, and lower negative curvature mold can be interchanged, and the curvature is set according to the curvature of the negative curvature surface of the fabric.

[0025] Multiple sets of upper negative curvature molds, positive curvature molds, and lower negative curvature molds are set up, and the number of sets is determined according to the number of negative curvature surfaces of the fabric.

[0026] Compared with the prior art, the significant advantages of this invention are:

[0027] (1) The present invention proposes a method for forming irregular multi-layer three-dimensional fabrics, which can realize the arbitrary combination of preforms with different processes to meet different usage requirements.

[0028] (2) The present invention proposes a method for forming a three-dimensional fabric with a multi-layer structure, which can achieve high-precision preparation of the preform in the thickness direction.

[0029] (3) The present invention proposes a method for forming a three-dimensional fabric with a multi-layer structure, which can achieve the preform without displacement during the preparation process, complete the positive and negative curvature surface conversion, and ensure the high precision surface requirements of the fabric.

[0030] (4) The present invention proposes a method for forming irregular multi-layer three-dimensional fabrics, which has low production cost and short preparation cycle, thereby improving the company's product competitiveness. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the preparation apparatus of the present invention.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1-Hydraulic cylinder, 2-Outer frame, 3-Negative pressure component suspension beam, 4-Negative pressure component support frame, 5-Upper negative curvature mold, 6-Negative pressure component slider rail, 7-Positive curvature mold, 8-Forming component slider rail, 9-Lower negative curvature mold, 10-Support component support seat. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings.

[0035] A three-dimensional fabric with an irregular multi-layer structure, comprising the following steps:

[0036] Step 1: Place the negative curvature mold on the work platform and fix it on the work platform to ensure that the negative curvature mold does not move during the work process;

[0037] Step 2: Place the positive curvature mold on the negative curvature mold, ensuring that the positive and negative curvature positions of the two molds are completely mirror-symmetrical and fixed, and ensuring that there is no displacement between the two molds;

[0038] Step 3: Prepare a preform on a positive curvature mold using existing technology. The preform is made of fiber and has a multi-layer structure. The preparation process of each layer is different to ensure that the volume density of each layer meets the requirements.

[0039] Step 4: After the single-layer preform is prepared, use a positive curvature pressing mold to press the curvature to ensure that the surface accuracy of each layer meets the process requirements.

[0040] Step 5: After all the positive curvature preforms are completed, loosen and remove the fixing bolts connecting the positive and negative curvature molds, remove the positive curvature mold, and ensure that the curvature of the positive curvature preform is mirror-symmetrical to the curvature of the negative curvature mold.

[0041] Step 6: Place a negative curvature device directly above the positive curvature preform, with the negative curvature portion of the negative curvature device being a perfect mirror image of the positive curvature portion of the positive curvature preform;

[0042] Step 7: Apply an external load to the negative curvature tooling as a whole, press the positive curvature part of the positive curvature preform into place, so that the positive curvature part of the positive curvature preform is completely in contact with the negative curvature part of the upper and lower negative curvature devices, so that the positive curvature part of the positive curvature preform is completely converted to negative curvature, ensuring that its surface accuracy meets the design requirements.

[0043] like Figure 1 As shown, a three-dimensional fabric forming device with an irregular multi-layer structure is provided. The device includes:

[0044] 1. Hydraulic cylinder; 2. Outer frame; 3. Negative pressure component suspension beam; 4. Negative pressure component support frame; 5. Negative curvature mold; 6. Negative pressure component slider rail; 7. Positive curvature mold; 8. Forming component slider rail; 9. Negative curvature mold; 10. Support component support seat. Hydraulic cylinder 1 is bolted to outer frame 2. The hydraulic cylinder rod pushes downward against negative pressure component suspension beam 3. Both ends of negative pressure component suspension beam 3 are connected to negative pressure component slider rail 6 and fixed to negative pressure component support frame 4 by bolts. Negative curvature mold 5 is welded to negative pressure component support frame 4, so the up and down movement of negative pressure mold 5 can be controlled by controlling the extension and retraction of hydraulic cylinder 1. Negative curvature mold 9 is installed directly below negative curvature mold 5 and is installed on support component support seat 10, which is welded to the bottom of outer frame 2. Negative curvature mold 9 is bolted to one end of forming component slider rail 8. Similarly, positive curvature mold 7 is bolted to forming component slider rail 8, so that positive curvature mold 7 can slide left and right on forming component slider rail 8.

[0045] The positive curvature mold and the negative curvature mold are integrally formed or segmented formed. They adopt the principle of equal perimeter design, and the positive and negative curvature lengths are equal on the same height section, so as to ensure that the positive and negative curvature parts are completely mirror-symmetrical after the positive curvature mold and the negative curvature mold are assembled.

[0046] The connection method between the negative curvature mold and the working platform, and between the negative curvature mold and the positive curvature mold, is not fixed, including but not limited to bolt fixing, and can also be fixed by slot or magnetic fixing.

[0047] The positive curvature mold is designed with multiple sets of molds for different layer areas according to the requirements of fabric layering and shape, so as to meet the requirements of different shape areas.

[0048] The positive and negative curvature mold materials are made of machinable metals, such as stainless steel and aluminum alloy.

[0049] The negative curvature part of the negative curvature mold has strong air permeability, such as honeycomb, strip, dot, etc.

[0050] The positive and negative curvature positions of the positive and negative curvature molds can be calibrated using a laser level to ensure that the positive and negative curvature positions of the two molds are completely mirror-symmetrical.

[0051] When the preform is switched between positive and negative curvature, the distance between the two negative curvature devices is adjusted, and the switch is repeated multiple times until the two negative curvature devices are fully attached to the preform.

[0052] The preform structure can be one or more of the following: needle punching, 2.5D, stitching, and triaxial. If the preform has special requirements for shear performance, the stitching process can be used to reinforce the preform in the Z direction.

[0053] The bulk density of each unit layer of the prefabricated body is 0.3-0.9 g / cm³. 3 .

[0054] The irregularly shaped multi-layered three-dimensional fabric can have any number of negative curvature surface features.

[0055] The three-dimensional fabric can be cylindrical, flat, conical, frustum-shaped, or curved.

[0056] The material of the three-dimensional fabric is one or more of the following: quartz fiber, carbon fiber, silicon carbide fiber, alumina fiber, or silicon nitride fiber.

[0057] The negative pressure component 5 is made of stainless steel or high alloy steel.

[0058] The positive curvature mold 7 is made of a soft material, generally rubber or nylon.

[0059] The negative curvature mold 5, positive curvature mold 7, and negative curvature mold 9 can all be replaced with different curvatures to meet the preparation requirements of different fabrics.

Claims

1. An apparatus for preparing irregularly shaped multilayer three-dimensional fabrics with negative curvature surfaces, characterized in that, It includes a hydraulic cylinder (1), an outer frame (2), a negative pressure component suspension beam (3), a negative pressure component support frame (4), an upper negative curvature mold (5), a negative pressure component slider rail (6), a positive curvature pressing mold, a positive curvature mold (7), a forming component slider rail (8), a lower negative curvature mold (9), and a support component support seat (10). The hydraulic cylinder (1) is bolted to the outer frame (2). The hydraulic cylinder hydraulic rod drives the negative pressure component suspension beam (3) to move up and down along the negative pressure component slider rail (6). The negative pressure component suspension beam (3) acts on the upper negative curvature mold (5) through the negative pressure component support frame (4). The negative pressure component slider rail (6) is fixed to the inner wall of the outer frame (2). The lower negative curvature mold (9) is installed directly below the upper negative curvature mold (5) and is installed on the support component support seat (10). The support component support seat (10) is welded to the bottom of the outer frame (2). The upper negative curvature mold (5) is connected to one end of the forming component slider rail (8) by bolts, and the positive curvature mold (7) is connected to the forming component slider rail (8) by bolts, so that the positive curvature mold (7) can move horizontally on the forming component slider rail (8).

2. The apparatus according to claim 1, characterized in that, The positive curvature mold and the negative curvature mold are formed in one piece or in sections, and adopt the principle of equal perimeter design, so that the positive and negative curvature lengths are equal on the same height section.

3. The apparatus according to claim 2, characterized in that, The connection between the negative curvature mold and the positive curvature mold is fixed by bolts, slots, or magnets.

4. The apparatus according to claim 3, characterized in that, The upper negative curvature mold (5) is made of high alloy steel; The positive curvature mold (7) is made of rubber or nylon.

5. The apparatus according to claim 4, characterized in that, The negative curvature part of the negative curvature mold has strong air permeability and is honeycomb-shaped, strip-shaped, or dot-shaped.

6. The apparatus according to claim 5, characterized in that, The upper negative curvature mold (5), the positive curvature mold (7) and the lower negative curvature mold (9) can be replaced and set according to the curvature of the negative curvature surface of the fabric. Multiple sets of upper negative curvature mold (5), positive curvature mold (7) and lower negative curvature mold (9) are set up, and the number of sets is determined according to the number of negative curvature surfaces of the fabric.

7. A method for preparing an irregularly shaped multi-layered three-dimensional fabric with a negative curvature profile using the apparatus of any one of claims 1-6, characterized in that, Includes the following steps: Step (1): Fix and install a lower negative curvature mold with the same shape as the negative curvature profile of the fabric. Set a horizontally movable positive curvature mold on the lower negative curvature mold. The positive curvature mold and the lower negative curvature mold are fixedly set in a mirror symmetrical manner. Step (2): Prepare a layer of fiber preform on a positive curvature mold; Step (3): While ensuring that the fiber preform does not deform, move the positive curvature mold horizontally out; Step (4): By setting an upper negative curvature mold above the positive curvature mold with a curvature matching that of the lower negative curvature mold, an external load is applied to the negative curvature profile of the fiber preform, so that the positive curvature part of the fiber preform is completely attached to the negative curvature parts of the upper and lower negative curvature molds, so that the positive curvature part of the fiber preform is completely converted to negative curvature, and the preparation of the single-layer negative curvature fabric is completed. Step (5): Repeat steps (2)-(4) until the negative curvature multilayer fabric is prepared.

8. The method according to claim 7, characterized in that, In step (1), the positive curvature mold and the lower negative curvature mold are set up in a mirror symmetrical manner by calibrating with a laser level.

9. The method according to claim 8, characterized in that, In step (2), fiber preforms are prepared on a positive curvature mold by needle punching, stitching 2.5D, or three-dimensional methods.

10. The method according to claim 9, characterized in that, When the prepared three-dimensional fabric needs to withstand shear force, the fiber preform prepared in step (2) is reinforced in the Z direction and then pressed.

11. The method according to claim 10, characterized in that, Step (2) The bulk density of each layer of the fiber preform is 0.3-0.9 g / cm³. 3 .

12. The method according to claim 11, characterized in that, The shapes of three-dimensional fabrics can be cylindrical, flat, conical, frustum, or curved.

13. The method according to claim 12, characterized in that, In step (2), the fiber preform uses one or more of the following: quartz fiber, carbon fiber, silicon carbide fiber, alumina fiber, or silicon nitride fiber.

14. The method according to claim 13, characterized in that, In step (4), multiple pressing is used, and the pressure distance between the upper and lower negative curvature molds gradually decreases with each pressing until the upper and lower negative curvature molds are completely bonded to the preform.

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