Tool and method for rapid vacuum forming of composite material

Abstract

The invention relates to the field of composite material forming, in particular to a tool and method for rapid vacuumizing forming of a composite material. The tool body comprises a tool molded surface and a groove, the groove surrounds the periphery of the tool molded surface, the tool body is further provided with a communicating hole, and the communicating hole communicates with the groove; when the composite material is formed, prepreg is laid on the molded surface of the tool, the edge of the vacuum bag is sealed and fixed to the periphery of the groove, and the space between the vacuum bag and the tool body is made to be negative pressure through the communicating hole and the groove by means of a vacuumizing device. When the prepreg is subjected to vacuum-pumping pre-compaction after being laid on the molded surface of the tool or is fed into an autoclave to be cured and formed, a vacuum pump can be directly connected into a vacuum-pumping reserved pipeline on the forming tool, and compared with a traditional mode that a vacuum-pumping pipeline needs to penetrate through the combination position of a vacuum bag and sealant, the operation steps are optimized, and the production efficiency is improved. The probability of vacuum bag leakage caused by manual operation flaws is reduced, and meanwhile the production efficiency of composite material products is improved.

Description

Technical Field

[0001] The invention relates to the technical field of composite material forming, and in particular to a tool and method for rapid vacuum forming of composite materials. Background Art

[0002] At present, most large-sized resin-based composite products are formed by autoclave molding. In order to make the prepregs fit better when the product is heated, the product needs to be vacuumed and compacted for a long time during the autoclave curing process. If the joint leading from the vacuum bag leaks during the autoclave molding process, the negative pressure in the vacuum bag cannot meet the vacuum requirement, which may cause the product thickness to exceed the tolerance or even cause the product to be scrapped. Summary of the invention

[0003] The embodiments of the present invention provide a tool and method for rapid vacuum forming of composite materials, which can reduce the risk of vacuum bag leakage.

[0004] In a first aspect, an embodiment of the present invention provides a tool for rapid vacuum forming of composite materials, comprising a tool body, wherein the tool body comprises a tool profile and a groove, wherein the groove surrounds the periphery of the tool profile, and the tool body is further provided with a communication hole, wherein the communication hole is connected to the groove;

[0005] When forming the composite material, the prepreg is spread on the tooling surface, the edge of the vacuum bag is sealed and fixed to the periphery of the groove, and a vacuum device is used to pass through the connecting hole and the groove to make the space between the vacuum bag and the tooling body negative pressure.

[0006] In a possible design, the groove includes a first part and a second part with different groove widths, the first part is close to the outer side of the tooling body, and the groove width is greater than the second part close to the inner layer of the tooling body, the first part is used to place a cover plate matching its shape, and the cover plate is provided with multiple through holes.

[0007] In a possible design, the communicating hole is sealedly connected with a connecting pipe, and the connecting pipe is used to be connected to a vacuum pumping device.

[0008] In a possible design, the distance between the groove and the tooling profile is not less than 20 mm.

[0009] In a possible design, the edge of the vacuum bag and the tooling body are sealed by a sealant.

[0010] In a second aspect, the present invention further provides a method for rapid vacuum forming of composite materials, based on any of the above-mentioned tooling, the method comprising:

[0011] Laying multiple layers of prepreg on the tooling surface;

[0012] Sealing and fixing the edge of the vacuum bag to the periphery of the groove;

[0013] A vacuum device is used to make the space between the vacuum bag and the tooling body to be at negative pressure through the communicating hole and the groove.

[0014] In a possible design, the groove includes a first portion and a second portion with different groove widths, the first portion is close to the outer side of the tool body, and the groove width is greater than the second portion close to the inner layer of the tool body, the first portion is used to place a cover plate matching its shape, and the cover plate is provided with a plurality of through holes;

[0015] After the autoclave curing process is completed, it also includes:

[0016] Open the cover plate and clean the inside of the groove.

[0017] In a possible design, after laying multiple layers of prepreg on the tooling surface and before sealing and fixing the edge of the vacuum bag to the periphery of the groove, the method further includes:

[0018] Laying a porous film on the prepreg;

[0019] The air-permeable felt is laid on the porous membrane.

[0020] In a possible design, before laying multiple layers of prepreg on the tooling surface, the method further includes:

[0021] Clean the surface of the tooling body and apply a release agent.

[0022] Compared with the prior art, the present invention has at least the following beneficial effects:

[0023] Compared with the traditional method in which the vacuum pipeline needs to extend from the sealant into the vacuum bag, the present invention optimizes the operating steps of the traditional vacuum method. The present invention directly opens a groove on the tooling body, and the groove is arranged along the periphery of the tooling surface, which will not affect the performance and function of the tooling surface. Then a connecting hole is opened on the side of the tooling body, and the external vacuum device can directly vacuum the vacuum bag sealed and fixed on the tooling body through the connecting hole. Compared with the traditional tooling that can only realize the prepreg laying function, the rapid vacuum tooling realizes the integration of tooling laying and vacuum structure functions, reduces the sealing links of the pipeline and vacuum bag, reduces the number and location of sealing, and thus reduces the probability of leakage of the vacuum pipeline and explosion of the vacuum bag, shortens the time of vacuum bagging, and shortens the production cycle and labor cost of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of a tooling structure provided by an embodiment of the present invention;

[0026] Figure 2 It is a schematic cross-sectional view of a tool at different angles provided by an embodiment of the present invention;

[0027] Figure 3 It is a schematic diagram of a top view structure of a tool provided by an embodiment of the present invention.

[0028] In the figure:

[0029] 1- pipe joint; 2- step groove cover plate; 3- molding tooling; S100- prepreg layer; S200- vacuum bag sealing. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; unless otherwise specified or explained, the term "multiple" refers to two or more; the terms "connected" and "fixed" should be understood in a broad sense, for example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the description of this specification, it should be understood that the directional words such as "upper" and "lower" described in the embodiments of the present invention are described at the angles shown in the drawings and should not be understood as limiting the embodiments of the present invention. In addition, in the context, it should also be understood that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element.

[0033] like Figures 1 to 3 As shown, an embodiment of the present invention provides a tool for rapid vacuum forming of composite materials, including a tool body, the tool body including a tool profile and a groove, the groove surrounds the periphery of the tool profile, and the tool body is further provided with a connecting hole, the connecting hole is connected to the groove;

[0034] When forming the composite material, the prepreg is spread on the tooling surface, the edge of the vacuum bag is sealed and fixed to the periphery of the groove, and a vacuum device is used to make the space between the vacuum bag and the tooling body negative pressure through the connecting holes and the groove.

[0035] In the present invention, in order to prevent the joints installed on the vacuum bag from being damaged and leaking, a groove is opened on the tooling body for placing the prepreg. The groove is arranged along the periphery of the tooling profile and will not affect the performance and function of the tooling profile. Then a connecting hole is opened on the side of the tooling body, and the external vacuum pumping device can directly vacuum the vacuum bag sealed and fixed on the tooling body through the connecting hole. Compared with the existing tooling for vacuuming vacuum bags, the tooling ply and vacuum pumping structure functions of the present invention are integrated. The probability of vacuum bag explosion is reduced, and the time for vacuuming and bagging is also shortened, saving time and labor costs. In addition, compared with the sealed pipe connection passing through the vacuum bag, the sealing links of the pipe and the vacuum bag are reduced, the number and location of the seal are reduced, and the risk of leakage is reduced.

[0036] In some embodiments of the present invention, the groove includes a first part and a second part with different groove widths. The first part is close to the outer side of the tooling body, and the groove width is greater than the second part close to the inner layer of the tooling body. The first part is used to place a cover plate matching its shape, and the cover plate is provided with multiple through holes.

[0037] In this embodiment, if the groove is not provided with a cover plate, the vacuum bag is easily sucked into the groove during vacuuming and is easily damaged. After the cover plate is provided, the through holes on the cover plate can allow airflow to pass through, and the cover plate itself can also prevent the vacuum bag from being sucked into the groove. In addition, the detachable cover plate is easy to disassemble and clean the groove.

[0038] In some embodiments of the present invention, the communicating hole is sealedly connected with a connecting pipe, and the connecting pipe is used to be connected to a vacuum pumping device.

[0039] In this embodiment, the connecting pipe facilitates the sealed connection between the vacuum device and the communicating hole.

[0040] In some embodiments of the present invention, the distance between the groove and the tooling profile is not less than 20 mm.

[0041] In this embodiment, a certain distance is left between the groove and the tooling profile, so that a certain space can be left for the prepreg material and the groove to be laid. At the same time, the flatness of the tooling profile will not be affected when the groove is opened.

[0042] In some embodiments of the present invention, the edge of the vacuum bag and the tooling body are sealed by a sealant.

[0043] In this embodiment, the sealant has excellent adhesion and sealing properties.

[0044] The present invention also provides a method for rapid vacuum forming of composite materials, based on any of the above-mentioned tooling, the method comprising:

[0045] Laying multiple layers of prepreg on the tooling surface;

[0046] The edge of the vacuum bag is sealed and fixed to the periphery of the groove;

[0047] The vacuum device is used to make the space between the vacuum bag and the tooling body to be negative pressure through the connecting holes and the grooves.

[0048] In some embodiments of the present invention, the groove includes a first portion and a second portion with different groove widths, the first portion is close to the outside of the tooling body, and the groove width is greater than the second portion close to the inner layer of the tooling body, the first portion is used to place a cover plate matching its shape, and the cover plate is provided with a plurality of through holes;

[0049] After the autoclave curing process is completed, it also includes:

[0050] Open the cover and clean the inside of the groove.

[0051] In this embodiment, substances such as resin and glue may enter the groove from the through hole. Once solidified, it is difficult to completely remove them. Therefore, after the vacuum treatment, the cover body needs to be disassembled to clean the groove.

[0052] In some embodiments of the present invention, after laying multiple layers of prepreg on the tooling surface and before sealing and fixing the edge of the vacuum bag to the periphery of the groove, the method further includes:

[0053] Laying a porous film on the prepreg;

[0054] Overlay breathable on a porous membrane.

[0055] Specifically, according to the ply angle, Figure 3Lay the prepreg inside the S100 dotted line. After the prepreg is laid, the vacuum bagging operation is carried out. During the operation, a layer of porous film is first covered on the surface of the prepreg. The boundary of the porous film should be between the S100 dotted line and the S200 dotted line. After the porous film is placed, the breathable felt is placed. The breathable felt should cover the step groove and be inside the S200 dotted line. Paste the sealant at the S200 dotted line. Completely cover the vacuum bag on the surface of the breathable felt. The sealant and the vacuum bag are tightly attached without gaps and the flatness of the vacuum bag is adjusted.

[0056] In some embodiments of the present invention, before laying multiple layers of prepreg on the tooling surface, the method further comprises:

[0057] Clean the surface of the tooling body and apply release agent.

[0058] Before laying prepreg on the tooling, clean the tooling first and apply a release agent on the laying surface of the tooling.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tool for rapid vacuum forming of composite materials, characterized in that: The tool body comprises a tooling profile and a groove, wherein the groove surrounds the periphery of the tooling profile, and the tool body is further provided with a communication hole, wherein the communication hole is communicated with the groove; When forming the composite material, the prepreg is spread on the tooling surface, the edge of the vacuum bag is sealed and fixed to the periphery of the groove, and a vacuum device is used to pass through the connecting hole and the groove to make the space between the vacuum bag and the tooling body negative pressure.

2. The tooling according to claim 1, characterized in that: The groove includes a first part and a second part with different groove widths. The first part is close to the outer side of the tooling body and has a groove width greater than that of the second part close to the inner layer of the tooling body. The first part is used to place a cover plate matching its shape, and the cover plate is provided with multiple through holes.

3. The tooling according to claim 1, characterized in that: The communicating hole is sealedly connected with a connecting pipe, and the connecting pipe is used to be connected with a vacuum pumping device.

4. The tooling according to claim 1, characterized in that: The distance between the groove and the tooling profile is not less than 20 mm.

5. The tooling according to claim 1, characterized in that: The edge of the vacuum bag and the tooling body are sealed by sealant.

6. A method for rapid vacuum forming of composite materials, characterized in that: Based on the tooling described in any one of claims 1 to 5, the method comprises: Laying multiple layers of prepreg on the tooling surface; Sealing and fixing the edge of the vacuum bag to the periphery of the groove; A vacuum device is used to make the space between the vacuum bag and the tooling body to be at negative pressure through the communicating hole and the groove.

7. The method according to claim 6, characterized in that The groove includes a first part and a second part with different groove widths, the first part is close to the outside of the tooling body, and the groove width is greater than the second part close to the inner layer of the tooling body, the first part is used to place a cover plate matching its shape, and the cover plate is provided with a plurality of through holes; After the autoclave curing process is completed, it also includes: Open the cover plate and clean the inside of the groove.

8. The method according to claim 6, characterized in that After laying multiple layers of prepreg on the tooling profile and before sealing and fixing the edge of the vacuum bag to the periphery of the groove, the method further includes: Laying a porous film on the prepreg; The air-permeable felt is laid on the porous membrane.

9. The method according to claim 6, characterized in that Before laying multiple layers of prepreg on the tooling surface, the method further comprises: Clean the surface of the tooling body and apply a release agent.

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