JP2005047180A - Method for producing honeycomb sandwich panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a honeycomb sandwich panel which can obtain a high-quality, lightweight product while eminently curtailing labor and costs. <P>SOLUTION: In the method for producing the honeycomb sandwich panel having a honeycomb core 10 and skins of a fiber-reinforced resin composite material which are adhered to both sides of the honeycomb core, prepregs 20 and 30 are laminated on a templates 2 and 3 while deaeration compression treatment is applied to each layer, and the template 3, the prepreg 30, the honeycomb core 10, the prepreg 20, and the template 2 are laminated in turn on a surface plate 1 to form a laminate. The laminate is coated with a vacuum bag film 6, the inside of the bag film 6 is evacuated to pressurize the laminate by a first forming pressure. After that, the pressure in the bag film 6 is increased to the atmospheric pressure at a specified speed, and the bag film 6 is held for a specified length of time. The laminate is heated for a prescribed time while being pressurized by a second forming pressure through the bag film 6. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a honeycomb sandwich panel.

  In recent years, honeycomb sandwich panels that exhibit excellent strength against bending stress, shear stress, and the like have been used as structural materials for aircraft and satellites. As shown in FIG. 7, the honeycomb sandwich panel 100 is configured by adhering skins 120 of a fiber reinforced resin composite material to both surfaces of a honeycomb core 110 made of a metal material or a synthetic resin.

  As a conventional manufacturing method of the honeycomb sandwich panel 100 (hereinafter referred to as “conventional method”), a skin 120 is formed using a prepreg (an intermediate base material in which a reinforcing fiber is impregnated with a resin), and then the skin 120 is formed into a honeycomb. There is a method of adhering to both surfaces of the core 110 (see, for example, Patent Document 1).

In this conventional method, a predetermined number of prepregs are first laminated on a predetermined template, covered with a vacuum bag film, and pressed and heated by an autoclave to form upper and lower skins 120. Next, a lower skin 120 is disposed on a predetermined surface plate (base) 200 via a template 300, and the honeycomb core 110 and the upper skin 120 are disposed on the lower skin 120 via a film adhesive. And the template 300 is arrange | positioned sequentially (refer FIG. 8). Then, a fairing bar 400 is disposed on the side of the laminate (see FIG. 8), the laminate and the fairing bar 400 are covered with a vacuum bag film, and pressurized and heated by an autoclave, thereby forming a honeycomb core. 110 and skin 120 are bonded together.
JP 2001-315228 A (page 4, FIG. 5)

  However, according to the above-described conventional method, it is necessary to use the autoclave in at least two steps of the skin 120 forming step and the bonding step between the honeycomb core 110 and the skin 120. Therefore, the effort for autoclave operation is superimposed. Cost and cost.

  In the conventional method described above, the skin 120 is formed and the honeycomb core 110 and the skin 120 are bonded separately. For this reason, prior to the bonding process between the honeycomb core 110 and the skin 120, it is necessary to perform pre-bonding treatment such as sanding and washing on the skin 120, which is troublesome. In addition, since it is necessary to interpose a film adhesive between the honeycomb core 110 and the skin 120, there is a problem that the weight of the product increases.

  Further, when the honeycomb sandwich panel 100 is manufactured by adopting the above-described conventional method, the thickness of the skin 120 may be partially increased for the purpose of reinforcing the skin 120. It is necessary to form the stepped portion 111 in the honeycomb core 110 so as to correspond to the reinforcing portion 121 (see FIG. 8). In order to form such a stepped portion 111, highly accurate cutting is required, and thus a skilled worker and an expensive cutting machine are required.

  The subject of this invention is providing the manufacturing method of the honeycomb sandwich panel which can obtain a high quality and lightweight product, reducing the labor and cost which shaping | molding requires markedly.

  In order to solve the above problems, the invention according to claim 1 is a method for manufacturing a honeycomb sandwich panel having a honeycomb core and upper and lower skins of a fiber reinforced resin composite material bonded to both surfaces of the honeycomb core. A prepreg laminating step for laminating the upper and lower skin prepregs on each of the upper and lower mold plates while performing deaeration and compression treatment one by one, and the lower die plate and the lower skin prepreg on a base Are disposed in this order, the honeycomb core is disposed on the prepreg for the lower surface skin, and the laminate forming step for disposing the prepreg for the upper surface skin and the upper surface template on the honeycomb core in this order; Side jig fixing work for arranging a side jig on the side surface of the laminate including the upper and lower surface mold plates, the upper and lower surface skin prepregs and the honeycomb core and fixing the side jig to the base. And vacuum drawing step of covering the side jig and the laminate with a vacuum bag film, discharging the air in the vacuum bag film and setting the pressure in the vacuum bag film to a predetermined vacuum pressure, A first pressurizing step of pressurizing the laminated body from the outside to a first molding pressure through the vacuum bag film while maintaining the pressure in the vacuum bag film at the vacuum pressure, and the first molding pressure. An internal pressurization step of maintaining the pressure in the vacuum bag film at atmospheric pressure for a specific time after raising the pressure in the vacuum bag film from the vacuum pressure to atmospheric pressure while holding, and the vacuum A second pressurizing step of pressurizing the laminate from the outside to a second molding pressure via a bag film; and heating the laminate for a predetermined time while maintaining the second molding pressure. Ri is a molding of the upper and lower surfaces skin, adhesion and between the upper and lower surfaces skin and the honeycomb core, and a heating step of performing simultaneously comprising: a.

  According to the first aspect of the present invention, since the formation of the skin and the bonding of the honeycomb core and the skin are performed at the same time, it is not necessary to use the autoclave multiple times. For this reason, the labor for autoclave operation can be reduced and the cost can be reduced.

  Further, according to the invention described in claim 1, since the skin molding and the bonding between the honeycomb core and the skin are performed at the same time, it is not necessary to perform a bonding pretreatment (such as sanding or washing) on the skin, It does not take time and effort. Further, since it is not necessary to interpose a film adhesive between the honeycomb core and the skin, the product can be reduced in weight.

  In addition, according to the first aspect of the present invention, the upper and lower skin prepregs are laminated on the template while performing deaeration and compression treatment for each layer, so that sufficient air can be mixed between the prepregs during lamination. It is possible to prevent the voids from being formed inside the molded skin. Further, since the laminate is heated while being pressurized stepwise by the first molding pressure and the second molding pressure, the honeycomb core is not subjected to load or damage. As a result, the quality of the product can be improved.

  In addition, according to the first aspect of the invention, by defining the pressure increase rate when the pressure in the vacuum bag film is increased from the vacuum pressure to the atmospheric pressure, the honeycomb core is deformed or displaced due to the release to the atmosphere. Can be prevented. Moreover, the pressure imbalance among the cells in the honeycomb core can be eliminated by maintaining the pressure in the vacuum bag film at atmospheric pressure for a specific time. Therefore, the quality of the product can be improved also from this point.

  In addition, according to the first aspect of the present invention, skin molding and adhesion between the skin and the honeycomb core can be realized in a state where the skin prepreg, which is a flexible intermediate substrate, is in close contact with the honeycomb core. Therefore, it is not necessary to perform highly accurate cutting on the honeycomb core. Therefore, it is possible to reduce labor and cost required for manufacturing the panel.

  According to a second aspect of the present invention, in the method for manufacturing a honeycomb sandwich panel according to the first aspect, the specific time in the internal pressurizing step is changed according to the thickness of the honeycomb core.

  According to the second aspect of the invention, the specific time in the internal pressurizing step (the time during which the pressure in the vacuum bag film is maintained at atmospheric pressure) is changed according to the thickness of the honeycomb core. Therefore, even when the honeycomb core is relatively thick or relatively thin, the pressure imbalance between the cells in the honeycomb core can be effectively eliminated.

  According to the first aspect of the present invention, since the skin molding and the bonding of the honeycomb core and the skin are performed at the same time, it is not necessary to pre-bond the skin, and labor and cost for the autoclave operation are reduced. Can be reduced. In addition, the skin prepreg, which is a flexible intermediate base material, can be bonded to the honeycomb core so that the skin can be formed and the skin and the honeycomb core can be bonded together. There is no need to apply. Therefore, also from this point, labor and cost required for manufacturing the panel can be reduced. Further, since it is not necessary to interpose a film adhesive between the honeycomb core and the skin, the product can be reduced in weight.

  According to the invention described in claim 1, since the deaeration compression treatment is performed when the prepreg for upper and lower skins is laminated on the template, voids are formed inside the molded skin. Can be blocked. Further, since the laminated body is pressurized stepwise with the first molding pressure and the second molding pressure, the honeycomb core is not subjected to a load or damage. Therefore, the quality of the product can be improved. In addition, the pressure increase rate when the pressure in the vacuum bag film is increased from the vacuum pressure to the atmospheric pressure is specified to prevent the honeycomb core from being deformed or displaced due to release to the atmosphere, and the pressure in the vacuum bag film is By maintaining the atmospheric pressure for a specific time, the pressure imbalance among cells in the honeycomb core can be eliminated. Therefore, also from this point, it is possible to realize a high quality product.

  According to the second aspect of the present invention, the specific time in the internal pressurizing step (the retention time after release to the atmosphere) is changed according to the thickness of the honeycomb core, so that even when the honeycomb core is relatively thick, it is relatively thin Even in this case, the pressure imbalance among cells in the honeycomb core can be effectively eliminated.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, a method for manufacturing a honeycomb sandwich panel having a honeycomb core 10 and upper and lower skins of a fiber reinforced resin composite material bonded to both surfaces of the honeycomb core 10 will be described.

  First, the jig used in the present embodiment will be described. In the present embodiment, as shown in FIG. 1, a general-purpose surface plate 1, an upper surface call plate 2, a lower surface call plate 3, a fairing bar 4, and the like are used as jigs.

  The surface plate 1 is a base in the present invention, and is placed at a place where molding is performed, and the lower surface call plate 3 and the fairing bar 4 are placed on the surface thereof (see FIG. 1). The surface of the surface plate 1 is polished and subjected to a mold release process.

  The upper and lower surface call plates 2 and 3 are upper and lower surface mold plates in the present invention, and are jigs for pressing the upper and lower surface skin forming prepregs 20 and 30 and the honeycomb core 10 between the upper and lower surfaces (see FIG. 1). . In the present embodiment, a plate-like body having a thickness of 2 mm prepared with a carbon fiber reinforced resin composite material according to the size of the honeycomb sandwich panel to be manufactured is adopted as the upper and lower surface call plates 2 and 3. The contact surface is sufficiently polished to release the mold.

  The fairing bar 4 is a side jig in the present invention, and shields the side surface of the laminated body including the upper and lower surface call plates 2 and 3, the upper and lower surface skin forming prepregs 20 and 30, and the honeycomb core 10. This prevents the side pressure from acting on the core 10. In the present embodiment, as the fairing bar 4, an angle material (a long member having a substantially L-shaped cross section) as shown in FIG. 1 is adopted, and the surface in contact with the laminated body is polished and released. We are processing.

  Next, a method for manufacturing a honeycomb sandwich panel according to the present embodiment will be described.

First, the honeycomb core 10 is processed, and its longitudinal and width dimensions and height dimensions are set to predetermined values, and then degreased and stored so as not to be contaminated (honeycomb core processing step). In the present embodiment, the area of the honeycomb core 10 is set to 1 m ² and the height is set to 25 mm.

  Next, a plurality of prepregs 20 and 30 for forming upper and lower skins having predetermined dimensions are prepared. Then, as shown in FIG. 2, the prepreg 20 for forming the upper skin is laminated on the upper surface call plate 2 and the prepreg 30 for forming the lower skin is laminated on the lower surface call plate 3 (prepreg lamination step).

  At this time, every time one prepreg is laminated, it is covered with a bagging film, the air in the bagging film is discharged, and atmospheric pressure (about 760 mmHg) is applied to the outside of the prepreg (compaction treatment). By such compaction treatment, air existing between the coal plates and the prepreg or between the prepreg layers can be discharged, and the prepreg can be brought into close contact with the coal plate and the prepregs can be brought into close contact with each other. The compaction process is a deaeration compression process in the present invention.

  Next, as shown in FIG. 2, degassing glass yarns 5 are attached at regular intervals to each side of the prepreg 20 for the upper surface skin and each side of the prepreg for the lower surface skin (deaeration means attaching step). In the present embodiment, the interval between adjacent glass yarns 5 is set to 200 mm. When the prepregs 20 and 30 are opposed to each other (see FIG. 3), the glass yarn 5 attached to the prepreg 20 for the upper skin and the glass yarn 5 attached to the prepreg 30 for the lower skin are not overlapped. .

  Next, as shown in FIG. 3, the lower surface call plate 3 and the lower surface skin prepreg 30 are arranged on the surface plate 1 in this order. And the fairing bar 4 is arrange | positioned to two sides used as the reference | standard of these lower surface call plates 3 and the prepreg 30 for lower surface skins, and it fixes to the surface plate 1 with a heat resistant tape. Next, after placing the honeycomb core 10 on the prepreg 30 for the lower skin with the two fairing bars 4 as a reference, the fairing bars 4 are placed on the remaining two sides and fixed with heat-resistant tape or the like. Fix to the board 1 (side jig fixing process). Then, the prepreg 20 for the upper surface skin and the upper surface coal plate 2 are arranged in this order on the honeycomb core 10 (laminated body forming step).

  Next, as shown in FIG. 4, the laminate (the lower surface call plate 3, the lower surface skin prepreg 30, the honeycomb core 10, the upper surface skin prepreg 20, and the upper surface call plate 2) disposed on the surface plate 1. Cover with bagging film 6. At this time, the release film 7 and the air breather 8 are disposed between the laminate and the bagging film 6. Then, the edge of the bagging film 6 is fixed to the surface plate 1 by using the sealant 9, the air in the bagging film 6 is discharged (evacuated), and the pressure in the bagging film 6 is set to a predetermined vacuum pressure ( Vacuuming step). After completion of evacuation, check for air leakage. By this vacuum drawing step, the bagging film 6 can be adapted to the laminate. As the air breather 8, a glass cloth or an air wave can be used.

  Here, the “vacuum pressure” is a pressure generated in the bagging film 6 by discharging (evacuating) air in the bagging film 6. In this embodiment, the vacuum pressure is set to about 100 mmHg (absolute pressure of about 660 mmHg) (see FIG. 5C). For this reason, about 100 mmHg of pressure acts on the laminated body in the bagging film 6 from the outside. The vacuum pressure is preferably set to about 100 mmHg or higher (that is, the vacuum pressure remaining inside is set to about 100 mmHg or lower).

Subsequently, the laminated body arrange | positioned on the surface plate 1 and coat | covered with the bagging film 6 is carried in in the can of an autoclave. And as shown in FIG.5 (b), the pressure in the can of an autoclave is about 40 KPa (about 0.40 kgf / cm < ² >) (1st molding pressure), keeping the pressure in the bagging film 6 with a vacuum pressure. The laminate is pressurized through the bagging film 6 by raising the pressure at a predetermined pressure increase rate (first pressure step).

Next, as shown in FIG. 5B, by introducing air into the bagging film 6 while maintaining the pressure inside the can of the autoclave at about 40 KPa (about 0.40 kgf / cm ² ), the bagging film 6 The internal pressure is increased from a vacuum pressure (about 100 mmHg) to atmospheric pressure at a specific pressure increase rate. In the present embodiment, the specific boosting speed is set to 10 mmHg / min. And as shown in FIG.5 (c), the pressure in the bagging film 6 is hold | maintained for a specific time with atmospheric pressure from the time of recovering to atmospheric pressure (internal pressure | voltage rise process).

Here, the “specific time” is the time from when the pressure in the bagging film 6 is recovered to atmospheric pressure until the start of the increase in the pressure inside the can of the autoclave (the holding time after opening to the atmosphere). The holding time after opening to the atmosphere is set in consideration of the area and thickness of the honeycomb core 10. As a result of obtaining the relationship between the area and thickness of the honeycomb core 10 and the retention time after release to the atmosphere by experiments, a graph as shown in FIG. 6 was obtained. It can be seen that the retention time after release to the atmosphere is proportional to the area of the honeycomb core 10 and inversely proportional to the thickness of the honeycomb core 10 (see FIG. 6). When the area of the honeycomb core 10 is 1.0 m ² and the thickness is 25 mm as in the present embodiment, the holding time after opening to the atmosphere is set to 60 minutes (see FIG. 6).

Next, as shown in FIG. 5B, the pressure inside the can of the autoclave is increased at a predetermined pressure increase rate up to 175 KPa (about 1.75 kgf / cm ² ) (second molding pressure). To pressurize the laminate (second pressurizing step). Next, as shown in FIG. 5 (a), the temperature inside the can of the autoclave is increased, and the predetermined temperature is maintained for the curing completion time of the prepreg, so that the prepregs 20 and 30 for the upper and lower skins are cured and formed. Bonding of 20, 30 and the honeycomb core 10 is performed simultaneously (heating step). Thereafter, the product is cooled by lowering the pressure inside the can of the autoclave and the temperature inside the can, and the whole process is completed.

  Five honeycomb sandwich panels with the same structure were manufactured through the above steps, and the flat values were measured by measuring the flatwise adhesive strength (stripping strength in the direction perpendicular to the surface). It was a tolerable value (2.64 MPa). The flatwise adhesive strength was measured according to the method defined in US Military Standard (MIL-STD) 401.

  In the method for manufacturing a honeycomb sandwich panel according to the embodiment described above, since the skin is formed and the skin, the honeycomb core 10 and the bonding are simultaneously performed, it is not necessary to use an autoclave multiple times. Therefore, the labor for autoclave operation can be reduced and the cost can be reduced.

  Further, in the method for manufacturing a honeycomb sandwich panel according to the present embodiment, the skin is formed and the skin and the honeycomb core 10 are bonded at the same time. Therefore, it is necessary to perform bonding pretreatment such as sanding and washing on the skin. There is no time and effort. Moreover, since it is not necessary to interpose a film adhesive between the skin and the honeycomb core 10, the product can be reduced in weight.

  Further, in the method for manufacturing a honeycomb sandwich panel according to the present embodiment, the prepregs 20 and 30 for the upper and lower skins are compacted (deaeration compression) layer by layer on the upper and lower call plates 2 and 3, respectively. Therefore, the air mixed between the prepregs can be sufficiently discharged. Therefore, it is possible to prevent voids from being formed inside the molded upper and lower skins. Further, since the laminated body (the lower surface coal plate 3, the prepreg 30 for the lower surface skin, the honeycomb core 10, the prepreg 20 for the upper surface skin, and the upper surface coal plate 2) is heated after being stepped at a relatively low pressure, There is no load or damage to the honeycomb core 10. As a result, the quality of the product can be improved.

  In addition, in the method for manufacturing a honeycomb sandwich panel according to the present embodiment, the pressure increase rate when the pressure in the bagging film 6 is increased from the vacuum pressure (about 100 mmHg) to the atmospheric pressure is defined as the result of opening to the atmosphere. It is possible to prevent the honeycomb core 10 from being deformed or displaced. In addition, by setting the pressure inside the autoclave can to a low pressure (about 40 KPa) and the pressure inside the bagging film 6 to the atmospheric pressure, and holding them for a specific time (holding time after opening to the atmosphere), the cells in the honeycomb core 10 are retained. The pressure imbalance between the two can be resolved. Therefore, the quality of the product can be improved also from this point.

  Further, in the method for manufacturing a honeycomb sandwich panel according to the present embodiment, the upper and lower skins are molded and bonded with the prepregs 20 and 30 for the upper and lower skins, which are flexible intermediate substrates, in close contact with the honeycomb core 10. Adhesion between the upper and lower skins and the honeycomb core 10 can be realized. Therefore, even when reinforcing the upper and lower skins by partially increasing the thickness, it is necessary to form a stepped portion in the honeycomb core 10 in accordance with the reinforcing portion (for example, the reinforcing portion 121 in FIG. 8). Absent. That is, since it is not necessary to perform high-precision cutting on the honeycomb core 10, labor and cost required for manufacturing the panel can be reduced.

  In the above embodiment, the first and second molding pressures are set to about 40 KPa and about 175 KPa, respectively. However, depending on the size of the honeycomb sandwich panel to be manufactured, these first and second molding pressures are set. Can be changed as appropriate.

It is a perspective view which shows the jig | tool used with the manufacturing method of the honeycomb sandwich panel which concerns on embodiment of this invention. It is explanatory drawing for demonstrating the prepreg lamination process and the deaeration means attachment process in the manufacturing method of the honeycomb sandwich panel which concerns on embodiment of this invention. It is explanatory drawing for demonstrating the side jig fixing process and laminated body formation process in the manufacturing method of the honeycomb sandwich panel which concerns on embodiment of this invention. It is explanatory drawing for demonstrating the vacuum drawing process in the manufacturing method of the honeycomb sandwich panel which concerns on embodiment of this invention. (A) is a graph showing the relationship between the temperature in the autoclave can and time, (b) is a graph showing the relationship between the pressure in the autoclave can and time, (c) is the vacuum pressure in the bagging film and time. It is a graph which shows the relationship. It is a graph which shows the relationship between the area and thickness of a honeycomb core, and the retention time after air release. It is a perspective view of a honeycomb sandwich panel. It is explanatory drawing for demonstrating the manufacturing method (conventional method) of the conventional honeycomb sandwich panel.

Explanation of symbols

1 Surface plate (base)
2 Upper surface call plate (upper surface template)
3 Lower side call plate (lower side plate)
4 Fairing bar (side jig)
6 Bagging film (vacuum bag film)
10 honeycomb core 20 prepreg for upper skin 30 prepreg for lower skin

Claims (2)

In a method for manufacturing a honeycomb sandwich panel having a honeycomb core and upper and lower skins of a fiber reinforced resin composite material bonded to both surfaces of the honeycomb core,
A prepreg laminating step of laminating prepregs for upper and lower skins on each of the upper and lower surface mold plates while performing deaeration compression treatment for each layer;
The lower surface template and the lower surface skin prepreg are disposed in this order on a base, the honeycomb core is disposed on the lower surface skin prepreg, and the upper surface skin prepreg and the upper surface are disposed on the honeycomb core. A laminated body forming step of arranging the upper surface template in this order;
A side jig fixing step of arranging a side jig on a side surface of the laminate including the upper and lower surface mold plates, the upper and lower surface skin prepregs and the honeycomb core, and fixing the side jig to the base;
A vacuum drawing step of covering the side jig and the laminate with a vacuum bag film, and discharging the air in the vacuum bag film to set the pressure in the vacuum bag film to a predetermined vacuum pressure;
A first pressurizing step of pressurizing the laminate from the outside to a first molding pressure through the vacuum bag film while maintaining the pressure in the vacuum bag film as it is,
The inside of the vacuum bag film is maintained at the atmospheric pressure for a specific time after the pressure in the vacuum bag film is increased from the vacuum pressure to the atmospheric pressure at a specific pressure increase rate while maintaining the first molding pressure. Boosting process;
A second pressurizing step of pressurizing the laminate from the outside to a second molding pressure through the vacuum bag film;
A heating step of simultaneously performing molding of the upper and lower skins and adhesion between the upper and lower skins and the honeycomb core by heating the laminate for a predetermined time while maintaining the second molding pressure;
A method for manufacturing a honeycomb sandwich panel.   The method for manufacturing a honeycomb sandwich panel according to claim 1, wherein the specific time in the internal pressure increasing step is changed according to the thickness of the honeycomb core.

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