JP2012153068A - Sandwich panel having insert structure, and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sandwich panel having an insert structure of high reliability in strength while minimizing the use of metal insert parts that cause a weight increase, and to provide a method for manufacturing the sandwich panel.SOLUTION: The sandwich panel (10) has the insert structure including outer skins (12) arranged on both faces in the thickness direction of a core material (11) and composed of fiber cloth (12a), and an insert part (13) having holes penetrating the outer skins arranged on both faces and composed of a fiber braid. Fibers in a joint part between the outer skins (12) and the insert part (13) are continuous to form an integral structure.

Description

  The present invention provides an insert structure used for a structural member of a general industrial elevator, a housing panel of a large video machine, a station platform fence, a transportation / transportation device such as a vehicle, or a structure of an aircraft or an artificial satellite. The present invention relates to a sandwich panel and a manufacturing method thereof.

  Conventional CFRP (Carbon Fiber Reinforced Plastic) sandwich panels (using honeycomb cores and foam cores) have a very thin CFRP skin and a low density core material to reduce weight. It is made of a weak material. Therefore, when the CFRP sandwich panels are fastened together or when the device is mounted on the surface, it is indispensable to attach a strong metal interface part.

  However, metal interface parts are heavy, and there are problems in the generation of thermal stress due to the reaction with the carbon fiber and mismatch of the thermal expansion coefficient, and the strength reliability for achieving an adhesive structure. It was rare.

There are the following methods for embedding the insert in the honeycomb panel used for the purpose of ensuring the flatness between the insert and the honeycomb panel skin. Specifically, the following steps are used.
(Step 1) An insert mounting hole is drilled in the honeycomb panel.
(Step 2) Then, after removing the core portion cut by drilling, the insert mounted in the insert mounting hole is fixed flush with the honeycomb skin using an adhesive tape.
(Step 3) After filling the insert mounting hole with a filler such as an epoxy resin to adjust the flatness, the insert is fixed by curing.

  Further, when a filler is injected into the insert mounting hole, it is necessary to prevent the weight from becoming heavy. For this reason, a configuration in which the insert is flange-bonded on the surface of the honeycomb core has been proposed (see, for example, Patent Document 1).

JP-A-6-126869

However, the prior art has the following problems.
The configuration for providing the conventional insert described above has the following problems. First, the conventional insert has a problem that the weight of the honeycomb panel is increased because it is necessary to fix a wide range between the honeycomb core and the skin with a filler. For example, in a satellite honeycomb panel (about 23 kg) of about 2 m × 1 m × 1 int, about 200 inserts for mounting equipment (filler weight; about 2 kg) are required, which causes an increase in weight.

  Further, in the conventional insert, the insert member is made of metal, and it is necessary to form a leaf shape for preventing removal, which causes an increase in weight.

  Further, when the sandwich panel insert is applied to a structural member for general industrial use, the load of strength is stricter than that of a satellite honeycomb panel, and long-term reliability is required. However, insert parts made of metal materials have a significantly different coefficient of thermal expansion from the CFRP panel, and thermal stress is likely to occur at the bonding interface that is fixed. There was a problem with general reliability.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and minimizes the use of metal insert parts that cause an increase in weight and has a sandwich panel having an insert structure with high strength and reliability. And it aims at obtaining the manufacturing method.

  A sandwich panel having an insert structure according to the present invention is disposed on both surfaces in the thickness direction of a core material, and has a skin composed of a fiber cloth and a hole penetrating between the skins disposed on both surfaces, and a fiber blade A sandwich panel having an insert structure provided with an insert portion, wherein the fibers at the joint portion between the skin and the insert portion are continuous and integrated.

  Moreover, the manufacturing method of the sandwich panel which has the insert structure which concerns on this invention is arrange | positioned in the skin comprised by the 1st fiber cloth arrange | positioned on both surfaces of the thickness direction of a core material, and the 2nd fiber cloth, and both surfaces A sandwich panel having an insert structure in which a fiber having a hole penetrating between the outer skins and an insert portion composed of a fiber blade is formed, and fibers at a joint portion between the skin and the insert portion are continuous and integrated. It is a manufacturing method, and without repeating the first fiber cloth, the step of making it unevenly distributed and perforating, the process of opening and spreading one end of the fiber blade, and overlapping the first fiber cloth, are repeated, A first step of laminating the first fiber cloth to a required thickness so that the one end of the fiber blade and the laminated first fiber cloth are integrally structured, and the fiber blade penetrates. A second step of setting the core material subjected to hole processing to the fiber blade integrated with the first fiber cloth in the first step, and opening the other end of the fiber blade to open the core material By repeating the step of spreading the fibers and the step of making the second fiber cloth unevenly distributed, perforating and stacking on the core material, the second fiber cloth is laminated to the required thickness, thereby producing fibers. And a third step of integrally forming the other end of the blade and the laminated second fiber cloth.

  According to the sandwich panel having the insert structure and the manufacturing method thereof according to the present invention, a metal insert that causes an increase in weight due to the continuous and integrated structure of the sandwich panel skin and the insert joint fiber. It is possible to obtain a sandwich panel having a highly reliable insert structure and a method for manufacturing the same, while minimizing the use of parts.

It is sectional drawing which shows the structure of the CFRP sandwich panel in Embodiment 1 of this invention. It is a schematic diagram of the braid | blade used for the insert part in Embodiment 1 of this invention. It is a schematic diagram for demonstrating the cross section of the insert part shown in FIG. 1 in Embodiment 1 of this invention. It is a schematic diagram for showing distribution of the reinforcing fiber around the insert of the epidermis in Embodiment 1 of the present invention. It is a schematic diagram for demonstrating distribution of the skin insert part periphery part of the fiber of the both ends of insert in Embodiment 1 of this invention. It is a schematic diagram of the jig | tool used for shaping | molding of the sandwich panel which has an insert structure in Embodiment 1 of this invention. It is a figure which shows the 1st shaping | molding procedure of the sandwich panel which has an insert structure in Embodiment 1 of this invention. It is a figure which shows the 2nd shaping | molding procedure of the sandwich panel which has an insert structure in Embodiment 1 of this invention. It is a figure which shows the 3rd shaping | molding procedure of the sandwich panel which has an insert structure in Embodiment 1 of this invention.

Hereinafter, preferred embodiments of a sandwich panel having an insert structure of the present invention and a method for manufacturing the same will be described with reference to the drawings.
The present invention is characterized in that the interface part of the sandwich panel is made of a fiber material similar to that of the skin instead of the metal part. Thereby, the influence of the difference of a thermal expansion coefficient is eliminated. Further, the interface part and the skin part are integrally formed. Thereby, the strength reinforcement in the thickness direction of the sandwich panel is possible, and the strength reliability is improved. Further, the reinforcement of the skin around the insert of the sandwich panel and the reinforcement of the core with the filler become unnecessary, and the metal insert becomes unnecessary, so that the weight can be reduced.

  In the following embodiments, the description will focus on the case where CFRP (carbon fiber reinforced plastic) is used as the fiber material applied to the skin and the blade. Examples of the fiber material include other fiber reinforced plastics, It is also possible to use woven fabrics such as glass fibers, carbon fibers, Kevlar fibers and ceramic fibers, or unidirectional sheets, and the same effect can be obtained.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing the structure of a CFRP sandwich panel according to Embodiment 1 of the present invention. Specifically, a sandwich panel (an interface embedded sandwich panel) having an insert structure formed of fiber reinforced plastic is shown as an example of a fiber material. A sandwich panel 10 having an insert structure shown in FIG. 1 includes a foam core 11, a skin 12, and an insert portion 13.

  As shown in FIG. 1, the skin 12 is located on both surfaces of the foam core 11 in the thickness direction, and is made of fiber reinforced plastic. The insert portion 13 is made of a fiber reinforced plastic in which the skin 12 and both end portions are joined and integrated.

  FIG. 2 is a schematic diagram of a blade used for the insert portion 13 in Embodiment 1 of the present invention. As shown in FIG. 2, the blade 14 used for the insert portion 13 is made of fiber reinforced plastic, like the skin 12, and the reinforcing fibers at both ends 14 a of the blade joined to the skin 12 are opened. .

  FIG. 3 is a schematic diagram for explaining a cross section of the insert portion shown in FIG. 1 according to Embodiment 1 of the present invention. As shown in FIG. 3, both ends of the insert portion 13 constituted by the blade 14 are configured such that the fibers of the skin 12 and the opened fibers of the blade end portions 14a are alternately overlapped.

  Moreover, the side wall part of the insert part 13 is comprised with the fiber reinforced plastic, and the inner side is hollow without a filler. Further, the outside of the insert portion 13 is joined and integrated with the core material 11 at the time of molding.

  FIG. 4 is a schematic diagram for illustrating the distribution of reinforcing fibers around the insert of the skin 12 according to the first embodiment of the present invention. As shown in FIG. 4, the reinforcing fiber cloth 12a constituting the skin 12 is unevenly distributed around the hole portion of the insert portion 13 so that the reinforcing fibers bypass the hole portion, and is densely packed around the hole portion, and the fiber density is high. It is high.

  FIG. 5 is a schematic diagram for showing the distribution of the peripheral portion of the skin insert portion of the fiber at both ends of the insert according to Embodiment 1 of the present invention. As shown in FIG. 5 and FIG. 3 above, the joint portion 15 between the insert portion 13 and the skin 12 has an integral structure in which reinforcing fibers are overlapped with each other and are reinforced in strength.

  As described above, the insert portion 13 of the sandwich panel 10 according to the first embodiment is made of fiber reinforced plastic, similar to the skin 12. For this reason, the strength of the sandwich panel in the thickness direction is enhanced.

  Further, the skin 12 and the insert portion 13 are configured so that the reinforcing fiber is wrapped and integrated without interruption, and the insert peripheral portion of the skin 12 is inserted without the reinforcing fiber being cut. It is unevenly distributed around the periphery and the fiber packing density is high. For this reason, the joint portion 15 has higher strength than other portions. As a result, it is possible to obtain the sandwich panel 10 including the insert portion having a light weight and sufficient strength.

  Next, a method for manufacturing the sandwich panel 10 having the above-described insert structure will be described with reference to FIGS. FIG. 6 is a schematic diagram of a jig used for forming the sandwich panel 10 having the insert structure according to the first embodiment of the present invention. In FIG. 6, a surface plate 21 with a pin 22 that matches the shape of the insert portion 13 is prepared. In this case, if the insert portion 13 needs a screw shape, a bolt is used instead of the simple-shaped pin 22.

  Next, FIG. 7 is a diagram showing a first forming procedure of the sandwich panel having the insert structure in the first embodiment of the present invention. The reinforcing fiber cloth 12a for the skin 12 is laid on the prepared surface plate 21. At this time, the portion of the pin 22 is laminated after shifting and spreading the mesh without cutting the cloth fibers. In this case, the reinforcing fiber cloth 12a may use a woven fabric such as glass fiber, carbon fiber, Kevlar fiber, ceramic fiber, or a unidirectional sheet.

  Next, FIG. 8 is a figure which shows the 2nd shaping | molding procedure of the sandwich panel which has an insert structure in Embodiment 1 of this invention. A blade 14 (sleeve) knitted with reinforcing fibers is opened on one side of the pin 22 and covered from the opened side. After the covering, the base portion is pressed, the end portion on the near side that is not opened is pulled, the blade 14 is squeezed and brought into close contact with the pin 22. This operation is repeated a plurality of times, and the reinforcing fiber cloth 12a is laminated to a required thickness.

  In this case, the reinforcing fiber of the blade 14 may be any fiber such as glass fiber, carbon fiber, Kevlar fiber, ceramic fiber and the like, similar to the reinforcing fiber cloth 12a for the skin 12.

  Next, the core material 11 is set. The core material 11 is set after a hole has been drilled in advance at the position of the pin 22.

  Next, FIG. 9 is a figure which shows the 3rd formation procedure of the sandwich panel which has an insert structure in Embodiment 1 of this invention. According to the procedure shown in FIG. 9, the upper skin material is laminated.

  First, the end portion of the outermost layer of the blade 14 placed on the pin 22 is opened and pressed against the core material 11. Next, the reinforcing fiber cloth 12 a for the skin 12 is spread on the core material 11 by spreading the meshes without shifting the cloth fibers of the pins 22. This operation is repeated to laminate the reinforcing fiber cloth 12a to a required thickness.

  After the lamination to the required thickness is completed, auxiliary materials necessary for VaRTM (Vacuum Assist Resin Transfer Molding) molding are sequentially set, and then the whole is covered with a bagging film 23.

  Thereafter, suction is performed using a vacuum pump 25 or the like from one side of the laminate covered with the bagging film 23 to reduce the pressure, and a normal temperature curable resin or a thermosetting resin is sucked from the opposite direction, and the laminated reinforcing fiber portion is resinated. 24 is impregnated. When a thermosetting resin is used as the resin 24, it is put in an oven or the like and heated after the resin is injected to cure the resin 24.

  After the resin 24 is cured, the bagging film 23 is peeled off, and the pins 22 are removed to remove the mold, whereby the sandwich panel 10 having the insert structure of the first embodiment is obtained.

  As mentioned above, according to Embodiment 1, the insert part is comprised with the fiber material. For this reason, it becomes unnecessary to attach a metal insert member, and it is not necessary to use a filler.

  Furthermore, since the insert portion is made of a fiber material, it is lighter than metal and can be made of the same material as the skin. For this reason, there is no influence of the occurrence of thermal distortion and thermal stress due to temperature change, and the reliability of the insert portion can be improved.

  Moreover, the insert part is integrally formed by overlapping the fiber cloth and the end part of the fiber blade. For this reason, the combination of parts having different characteristics can be avoided, the adhesive structure can be eliminated, and reinforcement is not necessary.

  Further, the fiber around the insert hole portion of the sandwich panel skin is not cut, but is unevenly distributed around the fiber to increase the volume content of the reinforcing fiber. For this reason, intensity | strength can be improved and the special reinforcement of an outer skin part is also unnecessary.

  In addition, sandwich panel is formed by repeating the process of making the fiber cloth of the sandwich panel skin unevenly distributed without cutting and the process of opening and spreading the both ends of the fiber blade and shaping the insert part. is doing. As a result, a sandwich panel having an integral insert portion without a discontinuous structure or an adhesive structure is obtained, and reinforcement at both ends of the insert is unnecessary.

  The VaRTM method is used for the molding process. For this reason, instead of the prepreg sheet, a cloth material not impregnated with resin can be used as the raw material to be used, and the molding process cost can be reduced.

  DESCRIPTION OF SYMBOLS 10 Sandwich panel which has insert structure, 11 Foam core (core material), 12 Skin, 12a Reinforcing fiber cloth, 13 Insert part, 14a Blade both ends, 14 Blade, 15 Joint part, 21 Surface plate for molding, 22 pins, 23 Bagging film, 24 resin, 25 vacuum pump.

Claims (6)

A skin made of fiber cloth, arranged on both sides of the core material in the thickness direction,
A sandwich panel having an insert structure having a hole penetrating between the skins disposed on both sides and an insert portion composed of a fiber blade,
A sandwich panel having an insert structure, wherein fibers of a joint portion between the skin and the insert portion are continuous and integrated. A sandwich panel having the insert structure according to claim 1,
The sandwich panel having an insert structure, wherein the joint portion is integrally formed by wrapping the fiber cloth and an end portion of the fiber blade so as to be integrally formed. A sandwich panel having the insert structure according to claim 2,
The sandwich cloth having an insert structure, wherein the fiber cloth is unevenly distributed around the hole without cutting the fiber around the hole of the insert portion. In the sandwich panel having the insert structure according to any one of claims 1 to 3,
The skin is composed of carbon fiber cloth,
The sandwich panel having an insert structure, wherein the insert portion is composed of a carbon fiber blade. A skin composed of a first fiber cloth and a second fiber cloth disposed on both surfaces in the thickness direction of the core material, and a hole penetrating between the skin disposed on both surfaces, and composed of a fiber blade A sandwich panel having an insert structure in which fibers of a joint portion between the skin and the insert portion are continuously and integrally structured,
Without cutting the first fiber cloth, the step of making it unevenly distributed and perforating, and the step of opening and spreading one end of the fiber blade and overlapping the first fiber cloth, the required thickness is repeated. A first step in which the first fiber cloth is laminated so that one end of the fiber blade and the laminated first fiber cloth are integrally structured;
A second step of setting the core material, which has been subjected to hole processing for penetrating the fiber blade, in the fiber blade integrated with the first fiber cloth in the first step;
The step of opening the other end of the fiber blade and spreading it on the core material, and the step of making the second fiber cloth unevenly distributed and perforating without being cut and overlapping the core material are repeated. A second step of laminating the second fiber cloth to a required thickness, thereby providing a third step of integrating the other end of the fiber blade and the laminated second fiber cloth. A method for manufacturing a sandwich panel having an insert structure as described above. In the manufacturing method of the sandwich panel which has an insert structure according to claim 5,
An insert characterized by applying a VaRTM method in a molding process after the first fiber cloth and the second fiber cloth laminated to a required thickness are integrally formed on the fiber blade. A method for manufacturing a sandwich panel having a structure.

Images