Integrated forming process for glass fiber reinforced plastic outer skin and foam sandwich structure

Abstract

The invention provides a glass fiber reinforced plastic outer skin and foam sandwich structure integrated forming process which comprises the following steps: firstly, taking a foaming mold as a carrier, and fixing a prototype skeleton in the foaming mold; the inner end faces of all the longitudinal partition plates are evenly coated with glue, the foaming mold is closed, and the two prototype skeletons are fixed to the outer wall of the barrel; after the glue solution is completely cured, opening the mold, so that the skeleton of the prototype is formed on the outer surface of the cylinder body according to the outline determined by the foaming mold; a skin is built on the outer side of the principle prototype framework, the skin is spliced at the position of the cross beam, and meanwhile, the skin is fixed at the position corresponding to each longitudinal partition plate in a riveting mode; the foaming mold is used for locking the skeleton of the prototype with the skin again, then foam is poured into all foaming cavities one by one, and standing is conducted after pouring is completed; and after the foam is completely cured, demolding. In the forming process, the skin and the foam layer structure are integrally formed, a machine tool does not need to be occupied, the process is simple, and operability is high.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material molding, and in particular relates to an integrated molding process of a glass fiber reinforced plastic outer skin and a foam sandwich structure. Background Art

[0002] Under special working conditions, underground pipelines, insulated pipelines and other cylindrical products have strict environmental requirements. Such products are required to have high strength, good insulation, excellent shockproof and soundproof properties. Therefore, a sandwich structure needs to be set on the outside of the cylinder of such products. Polyurethane foam has the characteristics of good insulation, light weight, high specific strength, sound insulation, shockproof, etc., and has been applied to such cylinders. In the prior art, the molding process of such sandwich structures generally requires spraying a foam layer with a sufficient thickness margin on the product, and then machining the desired size through a machine tool. Finally, glass fiber cloth and resin are used on the foam surface through a vacuum infusion process to form a glass fiber reinforced plastic layer. In this solution, the outer contour of the foam layer needs to be guaranteed by machining. Since such products are generally large in size and the processing equipment is limited, there are still many problems in mass production, such as a long and time-consuming process route, more machine tool resources are occupied, and the airtightness is uncontrollable during the vacuum infusion process, etc., resulting in high production costs and a relatively low yield. Summary of the invention

[0003] In view of this, the present invention aims to overcome the defects in the prior art and proposes an integrated molding process of a fiberglass outer skin and a foam sandwich structure.

[0004] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0005] A process for integrating a fiberglass outer skin and a foam sandwich structure, comprising the following steps:

[0006] S1. Using the foaming mold as a carrier, a set of principle prototype skeletons are fixed on the inner side of each foaming mold; the principle prototype skeleton includes a plurality of longitudinal partitions arranged at intervals along the axial direction of the cylinder, so that a foaming cavity is formed between two adjacent longitudinal partitions, and each longitudinal partition is connected into a whole by a cross beam arranged at intervals along the circumferential direction of the cylinder;

[0007] S2. Apply glue evenly on the inner end faces of all longitudinal partitions, then close the foaming mold, and use the foaming mold to lock the two principle prototype frames, so that each longitudinal partition is bonded and fixed to the cylinder, and the two principle prototype frames are integrally covered on the outer wall of the cylinder;

[0008] S3, after the glue is completely solidified, the mold is opened, and the prototype skeleton is formed on the outer surface of the cylinder according to the outer contour determined by the foaming mold;

[0009] S4. Build the skin on the outside of the prototype frame and splice the skin at the crossbeam. At the same time, the skin is riveted and fixed at the corresponding position of each longitudinal partition.

[0010] S5. Use the foaming mold to lock and build the prototype skeleton with the skin again, and then pour foam into each foaming cavity one by one. After the last foaming cavity is poured, let it stand;

[0011] S6. After the foam is completely solidified, demoulding is performed.

[0012] Furthermore, an L-shaped auxiliary connection part is provided on the inner end surface of the longitudinal partition. The cross-section of the L-shaped auxiliary connection part facing the cylinder side is wider than that in the thickness direction of the longitudinal partition. At the same time, the L-shaped auxiliary connection part also plays a role in supporting the longitudinal partition. After the end surface of the L-shaped auxiliary connection part facing the cylinder side is coated with glue, it can be better bonded and fixed to the cylinder.

[0013] Furthermore, two oblique beams are provided between the cross beams within each foaming cavity, and the two oblique beams are arranged in an "X" shape.

[0014] Furthermore, the thickness of the skin is 1-2 mm.

[0015] Furthermore, the skin is made of fiberglass reinforced plastics.

[0016] Furthermore, the fibers of the skin are continuous in the length direction of the cylinder.

[0017] Further, in step S5, after the foam is poured into the last foaming cavity, it is left to stand for 24 hours.

[0018] Furthermore, each skin is bonded and fixed to the corresponding crossbeam.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] In the molding process provided by the present invention, the skin and the foam layer structure are integrally molded, a foam cavity is formed in the prototype skeleton, and each foam cavity is cast independently, which can ensure the molding quality of the foam sandwich, not only meet the structural strength of the product, but also meet the use conditions of the product in various practical environments. Compared with the prior art, the polyurethane foam is first molded on the outer surface of the cylinder, and then the foam shape is processed, and finally the glass fiber outer skin is vacuum-infused. In the present invention, the outer contour of the sandwich structure is directly guaranteed by the foaming mold, without occupying the machine tool, the process is simple, and the operability is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0022] Figure 1 This is a schematic diagram of the invention's prototype skeleton being formed on the outer surface of the cylinder;

[0023] Figure 2 This is a schematic diagram of the invention creating a prototype with an inclined beam on the skeleton;

[0024] Figure 3 This is a schematic diagram of the outer side of the skeleton of the prototype machine after the skin is built. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0026] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0027] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0028] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0029] A process for integrating the outer skin of glass fiber reinforced plastics with the foam sandwich structure, such as Figures 1 to 3 As shown, the following steps are included:

[0030] S1. Using the foaming mold as a carrier, a set of principle prototype skeletons are fixed on the inner side of each foaming mold; the principle prototype skeleton includes a plurality of longitudinal partitions arranged at intervals along the axial direction of the cylinder, so that a foaming cavity is formed between two adjacent longitudinal partitions, and each longitudinal partition is connected into a whole by a cross beam arranged at intervals along the circumferential direction of the cylinder;

[0031] S2. Apply glue evenly on the inner end faces of all longitudinal partitions, then close the foaming mold on the outside of the cylinder, and use the foaming mold to lock the two principle prototype skeletons. After all the longitudinal partitions are bonded and fixed to the cylinder, the two principle prototype skeletons are integrally covered on the outer wall of the cylinder; it should be pointed out that the cylinder in the present invention refers to the cylinder of the cylinder products involved in the insulation pipe and underground pipe, that is, the cylinder products that need to be provided with a sandwich structure.

[0032] S3, after the glue is completely solidified, the mold is opened, and the prototype skeleton is formed on the outer surface of the cylinder according to the outer contour determined by the foaming mold;

[0033] S4. Build the skin outside the prototype frame and splice the skin at the crossbeam. At the same time, the skin is riveted and fixed at each longitudinal partition. It should be pointed out that the riveting process is done to ensure that the outer surface of the skin is flat and smooth.

[0034] S5. Use the foaming mold to lock the prototype skeleton with the skin again, and then pour foam into each foaming cavity one by one. After the last foaming cavity is poured, let it stand. During the foam pouring process, the foaming mold serves as a rigid support structure on the outside of the prototype skeleton, which can effectively ensure the stability of the prototype skeleton (skin) and ensure the quality of foam sandwich molding;

[0035] S6. After the foam is completely solidified, demoulding is performed.

[0036] An L-shaped auxiliary connection part is provided on the inner end face of the longitudinal diaphragm (the end face facing the cylinder), and the end cap of the L-shaped auxiliary connection part facing the cylinder is wider than the cross section in the thickness direction of the longitudinal diaphragm. At the same time, the L-shaped auxiliary connection part also plays a role in supporting the longitudinal diaphragm. After the end face of the L-shaped auxiliary connection part facing the cylinder is coated with glue, it can be better bonded and fixed to the cylinder to ensure the reliability of the connection. As an example, a glue injection port can be opened on the skin corresponding to each foaming cavity, and the foam can be poured into the glue injection port using a glue injection machine.

[0037] Usually, the thickness of the skin is 1-2mm. The skin is made of fiberglass. Preferably, the fibers of the skin are continuous in the length direction of the cylinder. Two inclined beams are arranged between the crossbeams within the range of each foaming cavity. The two inclined beams are arranged in an "X" shape to ensure the overall structural strength of the prototype skeleton. It should be pointed out that the height of the inclined beam is lower than the crossbeam. When the foam is injected into the foaming cavity, the foam can smoothly fill the entire cavity. Usually, in step S5, after the foam is poured into the last foaming cavity, it is left to stand for 24 hours. As an example, the skin and the crossbeam are bonded and fixed, which is simple and convenient to operate, easy to implement, and has high work efficiency.

[0038] In the molding process provided by the present invention, the skin and the foam layer structure are integrally molded, a foam cavity is formed in the prototype skeleton, and each foam cavity is cast independently, which can ensure the molding quality of the foam sandwich, not only meet the structural strength of the product, but also meet the use conditions of the product in various practical environments. Compared with the prior art, the polyurethane foam is molded on the outer surface of the cylinder, and then the foam shape is processed, and finally the glass fiber outer skin is vacuum-infused. The outer contour of the sandwich structure in the present invention is directly guaranteed by the foaming mold, and no machining is required. The length of the skin (glass fiber reinforced plastic plate) matches the length of the cylinder, and it can be directly bonded to the prototype skeleton, which can well ensure the continuity of the axial fibers of the cylinder.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A process for integrating the outer skin of glass fiber reinforced plastics with the foam sandwich structure, characterized in that: The steps include: S1. The foaming mold is designed to be a two-flap structure, with the foaming mold as a carrier, and a set of principle prototype skeletons are fixed on the inner side of each flake of the foaming mold; the principle prototype skeleton includes a plurality of longitudinal baffles arranged at intervals along the axial direction of the cylinder, so that a foaming cavity is formed between two adjacent longitudinal baffles, and each longitudinal baffle is connected into a whole by a cross beam arranged at intervals along the circumferential direction of the cylinder; S2. Apply glue evenly on the inner end faces of all longitudinal partitions, then close the foaming mold on the outside of the cylinder, and use the foaming mold to lock the two principle prototype frames, so that all longitudinal partitions are bonded and fixed to the cylinder, and the two principle prototype frames are integrally covered on the outer wall of the cylinder; S3, after the glue is completely solidified, the mold is opened, and the prototype skeleton is formed on the outer surface of the cylinder according to the outer contour determined by the foaming mold; S4. Build the skin on the outside of the prototype frame and splice the skin at the crossbeam. At the same time, the skin is riveted and fixed at the corresponding position of each longitudinal partition. S5. Use the foaming mold to lock and build the prototype skeleton with the skin again, and then pour foam into each foaming cavity one by one. After the last foaming cavity is poured, let it stand; S6. After the foam is completely solidified, demoulding is performed.

2. The process for integrating the outer skin of glass fiber reinforced plastics and the foam sandwich structure according to claim 1, characterized in that: An L-shaped auxiliary connecting portion is arranged on the inner end surface of the longitudinal partition.

3. The process for integrating the outer skin of glass fiber reinforced plastics and the foam sandwich structure according to claim 1, characterized in that: Two oblique beams are arranged between the cross beams within the range of each foaming cavity, and the two oblique beams are arranged in an "X" shape.

4. The process for integrating the fiberglass outer skin and the foam sandwich structure according to claim 1, characterized in that: The thickness of the skin is 1-2 mm.

5. The process for integrating the outer skin of glass fiber reinforced plastics and the foam sandwich structure according to claim 1, characterized in that: The skin is made of glass fiber reinforced plastic.

6. The process for integrating the outer skin of glass fiber reinforced plastics and the foam sandwich structure according to any one of claims 1 to 5, characterized in that: The fibers of the skin are continuous in the length direction of the cylinder.

7. The process for integrating the outer skin of glass fiber reinforced plastics and the foam sandwich structure according to claim 1, characterized in that: In step S5, after the foam is poured into the last foaming cavity, it is left to stand for 24 hours.

8. The process for integrating the fiberglass outer skin and the foam sandwich structure according to claim 1, characterized in that: The skin and the beam are bonded and fixed.

Images