JPWO2020178950A1 - Pressure pad, method of manufacturing pressure pad and method of manufacturing honeycomb core sandwich structure - Google Patents

Abstract

The manufacturing process of the honeycomb core sandwich structure can be simplified, and a pressure pad that is easy to manufacture is provided.
The pressure pad 10 has a shape corresponding to the product 2, and has a top surface portion 11, a side surface portion 12, and a peripheral edge portion 13. The pressure pad 10 includes a pressure pad main body 16, a release film 17, and inner shells 18 and 19. The pressure pad body 16 is made of non-silicon synthetic rubber. The first inner shell 18 is inserted at a position straddling the lower portion of the side surface portion 12 and the peripheral edge portion 13. It consists of a fiber reinforced plastic containing a thermoplastic resin, and the thermoplastic resin softens at a relatively low temperature. The second inner shell 19 is inserted at a position corresponding to the top surface portion. It consists of fiber reinforced plastic containing a thermoplastic resin, and the thermoplastic resin softens at a relatively high temperature.

Description

The present invention relates to a pressure pad used when heat-press molding a honeycomb core sandwich structure.

In recent years, fiber reinforced plastics such as carbon fiber reinforced plastics (CFRP) (Carbon Fiber Reinforced Plastics) have attracted attention. Taking advantage of its light weight and high strength, it is applied to various industrial fields as a material for aircraft and automobiles. In addition, glass fiber or aramid fiber may be used.

There is a honeycomb core sandwich structure as a material using FRP which is light and strong. The honeycomb core sandwich structure covers both the upper and lower sides of the core of the honeycomb structure with FRP (see Patent Document 1). This makes it even stronger and ultra-lightweight. In addition, the honeycomb core sandwich structure has high rigidity.

A method for forming a general honeycomb core sandwich structure will be briefly described. A second prepreg laminate to be the lower skin is placed on the jig along the shape of the jig trapezoid. Next, the honeycomb core is arranged on the second prepreg laminated body, and further, the first prepreg laminated body to be the upper skin is placed so as to be familiar with the shape of the honeycomb core to cover the honeycomb core. At this time, shaping may be performed using a hot drape device.

The prepreg laminated body is a laminate of a plurality of prepreg sheets. The prepreg sheet is formed by impregnating a reinforcing material such as carbon fiber with an uncured thermosetting resin and forming a sheet shape.

Further, the shaped honeycomb core sandwich structure is bagged together with the jig base, transported to the autoclave device, and heated and pressurized. As a result, the resin is cured and the honeycomb core sandwich structure is formed.

As the thermosetting resin, unsaturated polyester, epoxy resin, phenol resin and the like are used. Further, a thermoplastic resin such as a polyamide resin or a polypropylene resin may be used instead of the thermosetting resin.

Japanese Unexamined Patent Publication No. 2003-200510

Although the simple honeycomb core sandwich structure has been described above, it actually involves some small steps. The complexity of the process affects product costs. As the process becomes more complicated, the risk of failure increases. Therefore, it is important to reduce the number of steps as much as possible.

Some of the above-mentioned small steps include splice processing and stabilization processing. After the splice treatment, it is heat-molded. After the stabilization treatment, it is heat-molded.

The inventor of the present application has considered omitting the heat molding step after the splice treatment and the stabilization treatment.

The present invention solves the above problems, and an object of the present invention is to provide a pressure pad that can simplify the manufacturing process of a honeycomb core sandwich structure.

The present invention that solves the above problems is a removable pressure pad for evacuating a honeycomb core sandwich structure and heating and pressurizing it for molding. The honeycomb core sandwich structure is composed of a honeycomb core and fiber reinforced plastics provided above and below the honeycomb core. The pressure pad includes a top surface portion facing the upper part of the honeycomb core sandwich structure, a side surface portion facing the side portion of the honeycomb core sandwich structure, and a peripheral edge portion facing the edge portion of the honeycomb core sandwich structure. Has. The honeycomb core sandwich structure has a shape corresponding to the outer shape of the honeycomb core sandwich structure, and is a pressure pad main body made of thermosetting non-silicon synthetic rubber and a release film adhered to the surface of the pressure pad main body. And an inner shell made of fiber reinforced plastic, which is incorporated in the pressure pad main body.

Non-silicon synthetic rubber has a high affinity with fiber reinforced plastics. By heat and pressure molding, the pressure pad body, the release film, and the inner shell are integrally molded. That is, it is easy to manufacture.

In addition, the inner shell resists external pressure during product manufacturing (when using a pressure pad). As a result, some of the conventional steps can be omitted.

Preferably, the first inner shell is interposed at a position straddling the lower portion of the side surface portion and the peripheral edge portion, and the first inner shell is made of a fiber reinforced plastic containing a thermoplastic resin to soften the thermoplastic resin. The temperature is lower than the curing temperature of the synthetic rubber.

As a result, when the pressure pad is used (when the product is manufactured), the first inner shell does not soften at a relatively low temperature and resists the pressure from the outside to the side surface. At a relatively high temperature, it deforms while softening and follows the dimensional error of the honeycomb core sandwich structure.

Further, preferably, a second inner shell is inserted at a position corresponding to the top surface portion, the second inner shell is made of a fiber reinforced plastic containing a thermoplastic resin, and the softening temperature of the thermoplastic resin is set. It is higher than the curing temperature of the synthetic rubber.

As a result, when the pressure pad is used (when the product is manufactured), the second inner shell does not soften and resists the pressure from the outside on the top surface.

Further, preferably, a second inner shell is inserted at a position corresponding to the top surface portion, and the second inner shell is made of a fiber reinforced plastic containing a thermosetting resin, and has a curing temperature range of the synthetic rubber. It overlaps with the curing temperature range of the thermosetting resin.

As a result, when the pressure pad is used (during product manufacturing), the second inner shell maintains a cured state and resists pressure from the outside to the top surface.

More preferably, the second inner shell communicates with the outside through a toe made of carbon fiber.

As a result, the organic solvent gas generated during the manufacturing of the pressure pad (during the manufacturing of the product) is discharged.

The present invention that solves the above problems is a method for manufacturing a pressure pad. A honeycomb core sandwich structure or a mold corresponding to the honeycomb core sandwich structure before molding is installed on the jig base, and the synthetic rubber and the release film are provided so as to cover the honeycomb core sandwich structure or the mold. , The inner shell is arranged, further covered with a vacuum bag, vacuumed and heated and pressurized.

Using the autoclave device used for product manufacturing, the pressure pad can be integrally molded through a process similar to that for product manufacturing. That is, it can be easily manufactured.

Preferably, the jig base has a free curved surface.

When the jig base has a free surface, the effect of facilitating manufacturing becomes remarkable.

The present invention that solves the above problems is a method for manufacturing a honeycomb core sandwich structure. The honeycomb core sandwich structure before molding is installed on the jig base, the pressure pad is attached so as to cover the honeycomb core sandwich structure, and the honeycomb core sandwich structure is further covered by a vacuum back to vacuum the honeycomb core sandwich structure. Pull to heat and pressurize, and remove the vacuum bag and the pressure pad.

As a result, some of the conventional steps can be omitted.

By using the pressure pad according to the present invention, the manufacturing process of the honeycomb core sandwich structure can be simplified.

The pressure pad according to the present invention is easy to manufacture.

Honeycomb core sandwich structure outline Comparison of conventional process and application process Overview of splice processing Overview of stabilization process Heating and pressurizing profile in autoclave equipment Pressure pad appearance Detailed cross section of pressure pad Process explanation (before construction) Process explanation (stacking completed) Process explanation (bagging completed) Process description in the second embodiment Pressure pad according to modification 1 Pressure pad according to modification 2

<Overview>
The outline of the present invention will be described. The subject of the present application includes a honeycomb core sandwich structure.

FIG. 1 is an outline of a honeycomb core sandwich structure. A partial cross-sectional perspective view is shown, and the honeycomb core is extracted and enlarged.

The honeycomb sandwich structure includes a honeycomb core, a lower fiber reinforced plastic provided on the lower surface of the honeycomb core, and an upper fiber reinforced plastic provided on the upper surface of the honeycomb core. The upper part of the fiber reinforced plastic and the lower part of the fiber reinforced plastic are formed by laminating prepreg sheets.

The honeycomb core is strong against a force from the vertical direction and weak against a force from the side surface direction. Therefore, in general, the side surface may be tilted so as not to directly receive the force from the side surface direction. For convenience of explanation, the short side is on the top and the long side is on the bottom.

FIG. 2 is a comparison diagram of the conventional process outline and the present application process outline. First, the outline of the conventional process will be described. First, the honeycomb core is heated and molded (core heat foam). After that, splice processing and stabilization processing are performed.

FIG. 3 is an explanatory diagram of an outline of splice processing. However, a simulated process is shown. If the size of the honeycomb core sandwich structure is large, it is difficult to form a core with one honeycomb core. Therefore, a plurality of honeycomb cores are joined and integrated using a foam adhesive. However, when the FRP sheets are laminated in this state and heated and pressurized in the autoclave device, dents may occur along the corresponding portions. In order to prevent this, it is necessary to reinforce the relevant part.

FIG. 4 is an explanatory diagram of an outline of the stabilization process. The honeycomb core is strong against a force from the vertical direction and weak against a force from the side direction. When heated and pressurized in the autoclave device, the side surface (particularly the lower side surface) may be significantly deformed and damaged. Reinforcement is needed to prevent this.

After the splice treatment, it is heat-molded. After the stabilization treatment, it is heat-molded. This ensures reinforcement.

Then, the prepreg sheets are laminated. After the stacking is completed, the uncured honeycomb core sandwich structure 1 is bagged together with the jig base 30, transported to the autoclave device, and heated and pressurized. As a result, the resin is cured and the honeycomb core sandwich structure (product 2) is formed.

FIG. 5 is an example of a heating and pressurizing profile in an autoclave device. The horizontal axis is time. However, this is just an example, and the present application is not limited to this.

First, the pressure inside the vacuum bag is reduced to −0.1 MPa. Start heating under reduced pressure. Further, pressurization is started while maintaining depressurization. The decompressed state is gradually returned to atmospheric pressure while increasing the pressurization. The temperature at this time is about 120 ° C. (± 10 ° C.) (first heating step). Also, pressurize to 0.3 MPa.

Further, the temperature is set to about 180 ° C. (± 20 ° C.) over several tens of minutes to several hours and maintained for several hours (second heating step). For example, in the case of epoxy resin, curing starts at over 160 ° C. After that, it is cooled to 60 ° C. or lower over about 1 hour, and decompression is started.

Remove the product 2 from the autoclave device together with the jig stand.

Returning to FIG. 2, the outline of the process of the present application will be described. The process of the present application is almost the same as the conventional process, but the process of the present application is characterized in that by using the pressure pad 10, heat molding after the splice line treatment and the stabilization treatment is omitted.

<Pressure pad (first embodiment)>
~ Overview of pressure pad configuration ~
FIG. 6 is a partial cross-sectional perspective view showing a schematic configuration of the pressure pad 10.

The pressure pad 10 is attached to the uncured honeycomb core sandwich structure (laminated body 1) and used to be removed from the cured honeycomb core sandwich structure (product 2). That is, it can be attached to and detached from the product.

Therefore, the pressure pad 10 has a shape corresponding to the product 2. That is, it has a top surface portion 11, a side surface portion 12, and a peripheral edge portion 13.

In a state where the pressure pad 10 is attached to the honeycomb core sandwich structure 1, the top surface portion 11 faces the upper portion of the honeycomb core sandwich structure 1, and the side surface portion 12 faces the side portion of the honeycomb core sandwich structure 1. The peripheral edge portion 13 faces the edge portion of the honeycomb core sandwich structure 1. The peripheral portion 13 of the pressure pad is one size larger than the edge portion of the honeycomb core sandwich structure 1, and the pressure pad 10 completely covers the honeycomb core sandwich structure 1 together with the jig base 30.

The top surface portion 11 has a substantially flat plate shape, the side surface portions 12 are continuously provided downward from the peripheral edge of the top surface portion 11, and the peripheral edge portion 13 is horizontally connected so as to project from the lower end of the side surface portion 12. The result is a hat-like shape with a hollow space.

The pressure pad 10 includes a pressure pad main body 16, a release film 17, and inner shells 18 and 19. The inner shell (first inner shell) 18 is inserted at a position straddling the lower portion of the side surface portion 12 and the peripheral edge portion 13. The inner shell (second inner shell) 19 is inserted at a position corresponding to the top surface portion.

~ Configuration details ~
FIG. 7 is a cross-sectional view showing a detailed configuration of the pressure pad 10.

The pressure pad body 16 has a shape corresponding to the outer shape of the honeycomb core sandwich structure 1. It is made of non-silicone synthetic rubber that is thermoset. However, the non-silicone synthetic rubber may contain a trace amount of silicon component so as not to affect the physical properties.

Regarding the curing temperature, it is preferable to heat cure in the autoclave apparatus used for manufacturing the product. For example, it is preferable to heat cure at about 180 ° C. (± 20 ° C.). Further, it preferably has a heat resistance of about 200 ° C. (± 20 ° C.).

In the prototype model, the product name "Air Pad Rubber" of Airtech International Co., Ltd. was used. The air pad rubber is an uncured non-silicone synthetic rubber, which is heated to 176 ° C. and pressurized to 0.6 MPa, cured in about 2 hours, and has a heat resistance of 204 ° C.

Examples of synthetic rubber having high heat resistance include acrylic rubber ACM, ANM, ethylene vinyl acetate rubber EVA, epichlorohydrin rubber CO, and ECO.

The release film 17 is adhered to the surfaces of both pressure pad bodies 16. Fluorine-based film is preferable. In the prototype model, a tetrafluoroethylene / hexafluoropropylene copolymer (FEP) film was used.

The inner shell 18 is made of a fiber reinforced plastic containing a thermoplastic resin, and the thermoplastic resin is preferably softened at a relatively low temperature (for example, 60 to 100 ° C.). For example, acrylic resin PMMA, polypropylene resin PP, and the like are assumed.

The inner shell 19 is made of a fiber reinforced plastic containing a thermoplastic resin, and the thermoplastic resin is preferably softened at a relatively high temperature (for example, 180 to 220 ° C.). For example, polycarbonate resin PC, nylon 6 resin (polyamide) PA6, polyetherimide resin PEI, polyethylene terephthalate resin PET, polyphenylene sulfide resin PPS, polyetheretherketone resin PEEK, and the like are assumed.

The relationship between the curing temperature of the pressure pad body (synthetic rubber) and the softening temperature of the inner shell (thermoplastic resin) will be described in detail in the manufacturing method.

~ Pressure pad manufacturing method ~
The manufacturing method of the pressure pad 10 is similar to the manufacturing method of the honeycomb core sandwich structure product 2.

A mold equivalent to the honeycomb core sandwich structure is installed on the jig base 30, and the release film 17, the uncured synthetic rubber 16, the semipregs 18, 19, the uncured synthetic rubber 16, the release film are placed so as to cover the mold. Laminate in the order of 17 (see FIG. 7).

After the stacking is completed, the uncured pressure pad 10 is bagged together with the jig base 30 by a vacuum back, transported to an autoclave device, and heated and pressurized.

At this time, the softening temperature of the thermoplastic resin of the first inner shell 18 is lower than the curing temperature of the synthetic rubber 16. Further, the softening temperature of the thermoplastic resin of the second inner shell 19 is higher than the curing temperature of the synthetic rubber 16. Therefore, the autoclave device heats the second inner shell 19 so that the temperature becomes equal to or higher than the softening temperature (relatively high temperature) of the thermoplastic resin.

In the prototype model, the temperature was adjusted to 200 ° C. by heating and 0.6 MPa by pressurization, maintained for about 2 hours, and the temperature was lowered and reduced. The state change of the synthetic rubber 16, the thermoplastic resin of the first inner shell 18, and the thermoplastic resin of the second inner shell 19 will be described.

Synthetic rubber is semi-cured (commonly known as B stage) at room temperature, but it cures at 180 ° C. Curing continues even at 200 ° C. It cures reliably by a series of heating. The cured state is maintained even after the temperature is lowered (solidification).

The thermoplastic resin of the first inner shell 18 softens at a relatively low temperature (for example, 60 to 100 ° C.) and maintains the softened state during heating. When the temperature drops below the softening temperature, it solidifies.

The thermoplastic resin of the second inner shell 19 is softened at, for example, 200 ° C. and solidified by lowering the temperature.

That is, by a series of heating and pressurizing, first, the thermoplastic resin of the first inner shell 18 is softened, the synthetic rubber 16 is cured, and the thermoplastic resin of the second inner shell 19 is softened.

By lowering the temperature, the thermoplastic resin of the first inner shell 18 is solidified, and the thermoplastic resin of the second inner shell 19 is solidified. The synthetic rubber 16 remains cured.

~ Pressure pad manufacturing method effect ~
At this time, since the synthetic rubber is non-silicone, it has a high affinity with the fiber reinforced plastic, and the pressure pad main body 16 and the inner shells 18 and 19 are integrally molded by a series of heating and heating.

Further, due to the adhesiveness of the synthetic rubber, the synthetic rubber 16 and the release film 17 are integrated by a series of heating and heating.

As described above, the pressure pad can be integrally molded through a process similar to that of product manufacturing by using the autoclave device used for product manufacturing. That is, it can be easily manufactured.

Since both the first inner shell 18 and the second inner shell 19 use a thermoplastic resin, the heating time can be shortened as compared with the second embodiment (described later), and a toe (TOW) addition step is not required. Ease becomes remarkable.

Further, especially when the jig base 30 already exists or has a free curved surface, the ease of manufacturing the pressure pad 10 becomes remarkable (described later).

By the way, the subject of the present application is to simplify the manufacturing process of the honeycomb core sandwich structure. At first glance, it seems that the pressure pad 10 manufacturing process is added, which goes against the subject of the present application. However, since the pressure pad 10 is easy to manufacture and can be used repeatedly, the production of the pressure pad 10 does not impose a burden on the entire process.

~ Deformation example of pressure pad manufacturing method ~
In the above embodiment, the semi-pregs to be the second inner shell are laminated and integrally molded, but as a modification, the semi-pregs are heated in advance to form the softened and solidified second inner shell, which is separately molded. The second inner shell 19 may be inserted at the time of laminating.

In the case of the modified example, paying attention to the curing temperature of the synthetic rubber 16, the temperature is set to 180 ° C. (lower than the above embodiment) by heating and 0.6 MPa by pressurization in an autoclave apparatus, and the temperature is maintained for about 2 hours. At this time, the thermoplastic resin of the second inner shell 19 is not softened and maintains a solidified state. Naturally, the solidified state is maintained even after the temperature is lowered.

In the modified example, although it takes time to separately mold the second inner shell 19, judging from the overall process including the product manufacturing process, the same ease of manufacturing as in the embodiment is maintained. Further, the pressure pad manufactured by the modified example has the same configuration as the pressure pad 10 of the embodiment, and can be used in the same manner.

~ Overview of pressure pad usage (product manufacturing) ~
Returning to FIG. 2, the outline of the process of the present application will be described. The product manufacturing process of the present application is almost the same as that of the conventional product manufacturing process, but the product manufacturing process of the present application is characterized by omitting heat molding after the splice line treatment and the stabilization treatment by using the pressure pad 10.

The FRP used in the product will be described below on the premise that it is a thermosetting resin such as an epoxy resin, but a thermoplastic resin may be used. The thermoplastic resin softens when heated, but solidifies when cooled.

8 to 10 are drawings for explaining each state in the product manufacturing process. A prototype model of the pressure pad 10 is shown.

FIG. 8 shows a state before construction. The jig base 30 is described. First, the honeycomb core is heated and molded (core heat foam). After that, splice processing and stabilization processing are performed. However, heat molding after the splice line treatment and the stabilization treatment is omitted.

After that, a honeycomb core is installed and prepreg sheets are laminated to form an uncured honeycomb core sandwich structure (laminated body 1). After the lamination is completed, the pressure pad 10 is attached to the laminate 1 (state in FIG. 9), the laminate 1 is bagged together with the jig base 30 by a vacuum bag (state in FIG. 10), transported to the autoclave device, and heated. Heat and pressurize based on the pressure profile (FIG. 5). As a result, the resin is cured and the honeycomb core sandwich structure (product 2) is formed.

The product 2 is removed from the autoclave device together with the jig base 30. Demolding also includes removing the pressure pad 10 from the product 2. Further, the release film 17 allows the pressure pad 10 to be easily removed from the product 2, and the vacuum bag to be easily removed.

~ Effects when using pressure pads ~
・ Effect 1
In the heating and pressurizing profile in FIG. 5, the first heating step and the second heating step are described. In the first heating step, the laminate 1 is hardly cured. Damage to the lower side surface of the honeycomb core is most likely to occur during the first heating stage, especially when the pressure is increased.

The thermoplastic resin of the first inner shell 18 maintains a solidified state below the softening temperature (for example, 60 to 100 ° C.). Therefore, it can surely counter the pressure from the outside. On the other hand, reinforcement for stabilization treatment is also heat-molded at the same time as heat-molding the product. Therefore, the heat molding process after the stabilization process in the conventional process becomes unnecessary, and the product manufacturing process can be simplified.

・ Effect 2
The thermoplastic resin of the first inner shell 18 softens at a relatively low softening temperature. On the other hand, the first inner shell 18 is restrained in the synthetic rubber 16, and the first inner shell 18 is not extremely deformed. That is, the first inner shell 18 is appropriately deformed together with the synthetic rubber 16. The synthetic rubber 16 has appropriate elasticity even after curing.

By the way, the uncured honeycomb core sandwich structure (laminated body 1) is accompanied by a dimensional error in the laminating process. On the other hand, the pressure pad 10 is assumed to be used repeatedly. As a result, it seems that the pressure pad 10 cannot cope with the dimensional error of the laminated body 1.

On the other hand, after the second heating stage (or the softening temperature or higher), the synthetic rubber 16 and the first inner shell 18 are appropriately deformed to follow the dimensional error of the laminated body 1 and to resist the external pressure. .. During that time, the laminated body 1 is cured, and the laminated body 1 itself can withstand the pressure from the outside.

If the amount is small, the dimensional error of the laminated body 1 can be tolerated, so that the labor of dimensional management can be reduced. Although the dimensional control itself is not unnecessary, as a result of being freed from excessive dimensional control, the product manufacturing process can be simplified in this respect as well.

・ Effect 3
The softening temperature of the thermoplastic resin of the second inner shell 19 is relatively high. In other words, it does not soften at the temperature in the heating and pressurizing profile (FIG. 5) of the product manufacturing process, and maintains the solidified state. Therefore, it can surely counter the pressure from the outside. On the other hand, the reinforcement for the splice treatment is also heat-molded at the same time as the heat-molding of the product. Therefore, the heat molding process after the splice treatment in the conventional process becomes unnecessary, and the product manufacturing process can be simplified.

・ Effect 4
Although the description is omitted above, in the conventional step, a process of fixing the uncured honeycomb core sandwich structure 1 on the jig base 30 is indispensable.

On the other hand, the pressure pad peripheral edge portion 13 is one size larger than the edge portion of the honeycomb core sandwich structure 1, and the pressure pad peripheral edge portion 13 is in close contact with the jig base 30, so that the edge portion of the honeycomb core sandwich structure 1 is formed. It can be pressed against the jig base 30. That is, the uncured honeycomb core sandwich structure 1 can be fixed on the jig base 30 by mounting the pressure pad 10. Therefore, the fixing process to the jig base in the conventional process becomes unnecessary, and the product manufacturing process can be simplified.

~ Example of deformation during use ~
In the above embodiment, the heat molding step after the splice treatment and the heat molding step after the stabilization treatment are omitted by mounting the pressure pad 10, but the reinforcement during the splice treatment and the reinforcement during the stabilization treatment are performed. On the other hand, as a modification, the reinforcement during the splice treatment and the reinforcement during the stabilization treatment may be omitted.

In the pressure pad 10, the first inner shell 18 protects the laminated body 1 from the pressure from the side (the above-mentioned working effects 1 and 2). The second inner shell 19 protects the laminated body 1 from pressure from above (the above-mentioned action effect 3). Therefore, reinforcement during the splice treatment and reinforcement during the stabilization treatment are not required, and the product manufacturing process can be simplified.

~ Effect summary ~
By using the pressure pad 10 at the time of manufacturing the product, the following effects can be obtained.

Since the inner shells 18 and 19 resist the pressure from the outside, the heat molding after the splice line treatment and the stabilization treatment can be omitted. Furthermore, the reinforcement during the splice treatment and the reinforcement during the stabilization treatment may be omitted.

Since the first inner shell 18 is slightly deformed to follow the dimensional error, it is possible to reduce the time and effort required to manage the dimensional error of the laminated body 1. Since the pressure pad peripheral portion 13 is in close contact with the jig base 30, the fixing process to the jig base can be omitted.

As a result, the product manufacturing process can be simplified.

Further, the pressure pad 10 can be easily manufactured by integral molding through a process similar to product manufacturing. Further, the pressure pad 10 can be used repeatedly. Therefore, the production of the pressure pad 10 hardly imposes a burden on the whole process and does not hinder the above effect.

In the above embodiment, the case is not limited to the case where the jig base 30 already exists or has a free curved surface, but when the jig base 30 already exists or has a free curved surface, the curing becomes remarkable (described later). ).

<Pressure pad (second embodiment)>
~ Pressure pad configuration ~
The pressure pad 20 in the second embodiment modifies the second inner shell 19 of the pressure pad 10 in the first embodiment.

That is, the second inner shell 19 of the first embodiment is made of a fiber reinforced plastic containing a thermoplastic resin, whereas the second inner shell 29 of the second embodiment is made of a fiber reinforced plastic containing a thermosetting resin.

The shape formed from the top surface portion 11, the side surface portion 12, and the peripheral edge portion 13, and the configuration including the pressure pad main body 16, the release film 17, and the inner shell 18 are common to the first embodiment.

The second inner shell 29 communicates with the outside via a toe (TOW) 21 made of carbon fiber.

The curing temperature range of the synthetic rubber 16 and the curing temperature range of the thermosetting resin 29 overlap. For example, the synthetic rubber 16 is heat-cured at about 180 ° C. (± 20 ° C.), whereas the thermosetting resin 29 is also heat-cured at about 180 ° C. (± 20 ° C.). Further, the thermosetting resin 29 preferably has a heat resistance of about 200 ° C. (± 20 ° C.).

As a specific example of the thermosetting resin 29, an epoxy resin EP, a cyanate ester resin, a bismaleimide resin, a benzoxazine resin and the like are assumed.

~ Pressure pad manufacturing method ~
The method for manufacturing the pressure pad 20 in the second embodiment is substantially the same as the method for manufacturing the pressure pad 10 in the first embodiment.

A mold equivalent to the honeycomb core sandwich structure is installed on the jig base 30, and the release film 17, the uncured synthetic rubber 16, the semipreg 18, the prepreg 29, the toe 21, and the uncured synthetic rubber 16 are placed so as to cover the mold. , The release film 17 is laminated in this order.

FIG. 11 is a diagram illustrating a state in which toes 21 are arranged on all four sides of the prepreg 29 so that the prepreg 29 is laminated and the prepreg 29 can communicate with the outside.

After the stacking is completed, the uncured pressure pad 10 is bagged together with the jig base 30 by a vacuum back, transported to an autoclave device, and heated and pressurized.

At this time, the softening temperature of the thermoplastic resin of the first inner shell 18 is lower than the curing temperature of the synthetic rubber 16. The curing temperature range of the thermosetting resin of the second inner shell 19 and the curing temperature range of the synthetic rubber 16 overlap (approximately the same). Therefore, the autoclave device is used to heat the synthetic rubber 16 so that the temperature is equal to or higher than the curing temperature.

In the prototype model, the temperature was adjusted to 180 ° C. by heating and 0.6 MPa by pressurization, maintained for about 2 hours, and the temperature was lowered and reduced.

The thermoplastic resin of the first inner shell 18 softens at a relatively low temperature (for example, 60 to 100 ° C.) and maintains the softened state during heating.

The synthetic rubber 16 and the thermosetting resin of the second inner shell 19 are cured at about 180 ° C.

The organic solvent gas generated from the thermosetting resin of the second inner shell 19 during heating is discharged through the toe 21.

By lowering the temperature, the thermoplastic resin of the first inner shell 18 is solidified. The synthetic rubber 16 remains cured, and the thermosetting resin of the second inner shell 19 remains cured.

Like the thermoplastic resin 19 in the first embodiment, the thermosetting resin 29 in the second embodiment has a good affinity with the synthetic rubber 16. The pressure pad main body 16 and the inner shells 18 and 29 are integrally molded by a series of heating and heating. Further, due to the adhesiveness of the synthetic rubber, the synthetic rubber 16 and the release film 17 are integrated by a series of heating and heating. That is, it is easy to manufacture.

~ How to use the pressure pad ~
The method of using the pressure pad 20 in the second embodiment is substantially the same as the method of using the pressure pad 10 in the first embodiment.

That is, the pressure pad 20 is attached to the uncured honeycomb core sandwich structure (laminated body) 1, heat and pressure molding is performed by an autoclave device, and the pressure pad 20 is removed from the product 2 at the time of demolding.

The action and effect of using the pressure pad 20 are almost the same as the action and effect of using the pressure pad 10.

However, since the thermoplastic resin of the second inner shell 19 in the first embodiment softens at a relatively high temperature, it maintains a solidified state in the heating and pressurizing profile of the product manufacturing process, whereas the second embodiment has a second embodiment. The thermosetting resin of the inner shell 29 maintains a cured state.

As a result, it is possible to reliably counter the pressure from the outside, and the point that the heat molding step after the splice treatment in the conventional step becomes unnecessary is the same (action effect 3).

<Pressure pad (deformation example)>
~ Modification example 1 ~
FIG. 12 is a pressure pad according to the first modification. In the first embodiment and the second embodiment, the first inner shell 18 and the second inner shells 19 and 29 are provided, whereas the pressure pad according to the first modification includes only the first inner shell 18. There are no second inner shells 19, 29.

When the product is relatively small and the core division is unnecessary, or when the splice processing is sufficient, the second inner shells 19 and 29 are unnecessary.

~ Modification example 2
FIG. 13 is a pressure pad according to the second modification. In the first embodiment and the second embodiment, the first inner shell 18 and the second inner shells 19 and 29 are provided, whereas the pressure pad according to the second modification has only the second inner shells 19 and 29. The first inner shell 18 is not provided. For the second inner shells 19 and 29, the thermoplastic resin 19 of the first embodiment may be used, or the thermosetting resin 29 of the second embodiment may be used.

When the product is relatively thin (not bulky), there is little risk of lateral deformation, and the first inner shell 18 becomes unnecessary.
<Jig>
The present application is not limited to the case where the jig base 30 already exists or has a free curved surface (may include a new installation, a flat surface, or a simple curved surface), but the jig base 30 may already exist or is free. When it has a curved surface, the effect of the present application becomes remarkable.

A free curved surface is a curved surface expressed by interpolating each intersection with a higher-order equation by setting some intersections and curvatures in space. It is different from a simple curved surface that can be expressed by a simple mathematical formula such as a spherical surface or a cylindrical surface.

Industrial products such as aircraft and automobiles have free curved surfaces. The jig base used in the prototype model shown in FIG. 8 has a free curved surface.

It is troublesome to design the pressure pad in detail based on the numerical data so as to correspond to the free curved surface. In the case of the existing jig stand, the design data of the free-form surface cannot be confirmed, and it may be reacquired by measurement.

Since the pressure pad of the present application is manufactured on an existing jig base having a free curved surface, it inevitably follows the shape of the free curved surface of the existing jig base. Therefore, detailed examination at the design stage is not required, and the product can be manufactured without design data of a free-form surface.

Further, when the product has a free curved surface, dimensional errors are likely to occur, and dimensional control tends to be strict. The pressure pad of the present application can alleviate dimensional errors. As a result of being freed from excessive dimensional control, the product manufacturing process can be simplified.

1 Uncured honeycomb core sandwich structure (laminated body)
2 Honeycomb core sandwich structure (product) after curing
10 Pressure pad 11 Top surface 12 Side surface 13 Periphery 16 Pressure pad body 17 Release film 18 1st inner shell (including thermoplastic resin)
19 Second inner shell (including thermoplastic resin)
20 Pressure pad 21 Toe 29 Second inner shell (including thermosetting resin)
30 Jig stand

Claims (8)

A removable pressure pad for forming a honeycomb core sandwich structure composed of a honeycomb core and fiber reinforced plastics provided above and below the honeycomb core by vacuuming and heating and pressurizing.
It has a top surface portion facing the upper part of the honeycomb core sandwich structure, a side surface portion facing the side portion of the honeycomb core sandwich structure, and a peripheral edge portion facing the edge portion of the honeycomb core sandwich structure. ,
A pressure pad body made of non-silicon synthetic rubber that has a shape corresponding to the outer shape of the honeycomb core sandwich structure and is thermosetting.
The release film adhered to the surface of the pressure pad body and
An inner shell made of fiber reinforced plastic that is built into the pressure pad body,
With
A pressure pad that features that. A first inner shell is inserted at a position straddling the lower portion of the side surface portion and the peripheral edge portion.
The first inner shell is made of a fiber reinforced plastic containing a thermoplastic resin.
The pressure pad according to claim 1, wherein the softening temperature of the thermoplastic resin is lower than the curing temperature of the synthetic rubber. A second inner shell is inserted at a position corresponding to the top surface portion, and the second inner shell is inserted.
The second inner shell is made of fiber reinforced plastic containing a thermoplastic resin.
The pressure pad according to claim 1 or 2, wherein the softening temperature of the thermoplastic resin is higher than the curing temperature of the synthetic rubber. A second inner shell is inserted at a position corresponding to the top surface portion, and the second inner shell is inserted.
The second inner shell is made of a fiber reinforced plastic containing a thermosetting resin.
The pressure pad according to claim 1 or 2, wherein the curing temperature range of the synthetic rubber and the curing temperature range of the thermosetting resin overlap. The pressure pad according to claim 4, wherein the second inner shell communicates with the outside through a toe made of carbon fiber. A honeycomb core sandwich structure before molding or a mold equivalent to the honeycomb core sandwich structure is installed on the jig base.
The synthetic rubber, the release film, and the inner shell are arranged so as to cover the honeycomb core sandwich structure or the mold.
Furthermore, it is covered with a vacuum back and
The method for manufacturing a pressure pad according to claim 1, wherein the pressure pad is evacuated and heated and pressurized. The method for manufacturing a pressure pad according to claim 6, wherein the jig base has a free curved surface. Install the honeycomb core sandwich structure before molding on the jig stand,
The pressure pad according to claim 1 is attached so as to cover the honeycomb core sandwich structure.
Furthermore, it is covered with a vacuum back and
The honeycomb core sandwich structure is evacuated and heated and pressurized.
A method for manufacturing a honeycomb core sandwich structure, which comprises removing the vacuum bag and the pressure pad.

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