JP2004322369A - Honeycomb structure, its manufacturing method and resin transfer forming method using the honeycomb structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the penetration of a resin into the cells of a honeycomb structure while ensuring the weight reduction using the honeycomb structure. <P>SOLUTION: A thermoplastic film 5, a heated honeycomb structure 1, the thermoplastic film 5 and a caul 21 provided with grooves 23 and 25 are successively stacked on a receiving stand 15 having grooves 17 and 19 provided on the surface thereof. The honeycomb structure 1 having the thermoplastic films 5 arranged on both sides thereof is pressurized between the receiving stand 15 and the caul 21. The thermoplastic films 5 are melted at their regions pressed between the regions, which have no grooves 17 and 19 as well as 23 and 25 of the receiving stand 15 and the caul 21, and the honeycomb structure 1 under heating to be welded to the honeycomb structure 1. On the other hand, since the thermoplastic films 5 are not sufficiently brought into contact with the honeycomb structure 1 at the regions corresponding to the grooves 17 and 19 as well as 23 and 25 respectively provided to the receiving stand 15 and the caul 21 thereof even if pressed, those regions of the thermoplastic films 5 become non-welded parts without being melted and the thermoplastic films 5 are brought to a connected state by the non-welded parts without being mutually divided between cells 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a honeycomb structure, a method for manufacturing the same, and a resin transfer molding method using the honeycomb structure.
[0002]
[Prior art]
As a structure of an FRP (Fiber Reinforced Plastic) part, a sandwich structure is generally used in order to improve bending rigidity. This sandwich structure is a structure in which a thin and strong surface material (FRP) is used for a surface layer having high bending stress, and a light core material is sandwiched therebetween.
[0003]
As the core material sandwiched between the honeycomb and the honeycomb, there are acrylic foam and urethane foam. However, as seen in aircraft and racing vehicles, honeycomb is used for parts requiring high strength.
[0004]
In the RTM (resin transfer molding) method, when the resin is filled in the mold, the resin enters into the cells of the honeycomb, and the weight reduction by using the honeycomb is hindered. Therefore, the honeycomb is not generally used. . On the other hand, since a resin having a short curing time can be selected, it is an advantageous method in the production of parts requiring productivity.
[0005]
For this reason, in Patent Literature 1 below, the open portion of the honeycomb cell is covered with an adhesive film made of a thermosetting resin or a thermoplastic resin to prevent the resin to be filled from penetrating into the cell. It allows the use of honeycombs in the law.
[0006]
[Patent Document 1]
JP-A-9-295362
[Problems to be solved by the invention]
However, in this case, the adhesive film is heated and welded in contact with the entire periphery of the cell opening of the honeycomb, so that the adhesive film is divided into the shape of the cell opening by the entire periphery. There is a possibility that the resin may fall into the cell, thereby causing a problem that the resin to be filled enters the cell.
[0008]
Therefore, an object of the present invention is to prevent the resin from entering the cells of the honeycomb and to secure the weight reduction by using the honeycomb.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is directed to a honeycomb structure in which open portions on both sides of each cell in a honeycomb are covered with a heat-sealing film, and the heat-sealing film and ends of partition walls separating the cells of the honeycomb are intermittent. And the end of the partition wall at the welded portion is exposed to the outside of the heat welding film.
[0010]
【The invention's effect】
According to the present invention, since the heat welding film and the end of the partition wall separating the cells of the honeycomb are intermittently welded to each other, the heat welding film is connected without being divided between the cells. Is present, and it is possible to prevent the heat welding film from dropping into the cells. Thus, when the molten resin is filled by the resin transfer molding method, the molten resin can be reliably prevented from entering the cells of the honeycomb by the heat welding film, and the weight can be reduced by using the honeycomb. Can be.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
FIG. 1A is a perspective view of a honeycomb structure 27 showing a first embodiment of the present invention, and FIG. 1B is an enlarged perspective view of a part of the surface of the honeycomb structure 27. As shown in FIG. 1A, the honeycomb structure 27 has a structure in which open portions on both sides of a plurality of cells 3 in a honeycomb 1 are covered with a thermoplastic film 5 as a heat welding film.
[0013]
Then, as shown in FIG. 1 (b), the thermoplastic film 5 and the honeycomb 1 have a welded portion 11 around the end of the joint 9 between the partition walls 7 separating the cells 3. That is, the thermoplastic film 5 is heated and melted at the welding portion 11 and bonded to the honeycomb 1. The portion of the thermoplastic film 5 corresponding to the partition wall 7 between the welded portions 11 is not welded, but is merely in contact with the partition wall 7 of the honeycomb 1. , The adjacent cells 3 are connected to each other.
[0014]
FIG. 2 is a BB cross-sectional view showing the welded portion 11 of FIG. 1 (b), and FIG. 3 is a CC cross-sectional view showing the non-welded portion 13 of FIG. 1 (b).
[0015]
In FIG. 1, the end of the partition wall 7 shown in FIG. 2 appears to be exposed on the surface of the thermoplastic film 5, but the exposed end is omitted here.
[0016]
In the case of the honeycomb structure 27 having such a structure, the thermoplastic film 5 and the end portions of the partition walls 7 separating the cells 3 of the honeycomb 1 are intermittently welded to each other. In addition, there is a portion (non-welded portion 13) connected between the cells 3, and it is possible to prevent the thermoplastic film 5 from dropping into the cells 3. Thereby, when the molten resin is filled by the resin transfer molding method, the intrusion of the molten resin into the cells 3 of the honeycomb 1 can be reliably prevented, and the weight reduction by using the honeycomb 1 can be ensured. .
[0017]
Further, since the thermoplastic film 5 is used as the heat welding film to be welded to the honeycomb 1, the cost can be reduced as compared with the case where a thermosetting film is used.
[0018]
Next, a method for manufacturing the above-described honeycomb structure 27 will be described. As shown in FIG. 4, first, a receiving table 15 as one receiving member is prepared. On the surface of the pedestal 15, grooves 17 and 19 are formed, which cross each other at right angles.
[0019]
One of the two thermoplastic films 5 described above is placed on the pedestal 15, and the previously heated honeycomb 1 is placed on the thermoplastic film 5.
[0020]
FIG. 5 is a plan view showing the positional relationship between the grooves 17, 19 of the receiving base 15 and the cells 3 of the honeycomb 1 at this time. According to this, the grooves 17 and 19 are located at positions substantially corresponding to the respective center portions of the six partition walls 7 separating the cells 3 which are regular hexagons in plan view. That is, the groove 19 extending in the vertical direction in FIG. 5 is formed in a direction crossing the partition wall 7 at a substantially right angle, and the groove 17 extending in the horizontal direction in FIG. It is formed in the direction. A portion (corresponding to the welded portion 11 in FIG. 1B) corresponding to the periphery of the joint portion 9 between the partition walls 7 is located at a position deviated from the grooves 17 and 19.
[0021]
In FIG. 4, the other thermoplastic film 5 is further placed on the honeycomb 1 described above, and a patch plate 21 is placed on the thermoplastic film 5 as the other receiving member. On the surface of the backing plate 21 facing the thermoplastic film 5, lattice-like grooves 23, 25 which intersect at right angles to each other are formed.
[0022]
When the backing plate 21 is placed on the thermoplastic film 5, the lattice-shaped grooves 23 and 25 are aligned with the lattice-shaped grooves 17 and 19 of the receiving base 15. That is, the groove 17 of the cradle 15 and the groove 23 of the backing plate 21 coincide with each other, and the groove 19 of the cradle 15 and the groove 25 of the backing plate 21 coincide with each other. Reference numeral 25 is a position corresponding to substantially the center of each of the six partition walls 7 separating the cells 3 in the same manner as the positional relationship between the grooves 17 and 19 and the cells 3 of the honeycomb 1 shown in FIG.
[0023]
As described above, the honeycomb 1 is sandwiched between the pair of thermoplastic films 5 so as to cover the open portions of the respective cells 3 from both sides, and the both sides are formed on the surfaces facing the thermoplastic film 5 with the grooves 17, 19 and the grooves 23, 25. Are pressed while being sandwiched between the receiving base 15 and the backing plate 21 provided respectively.
[0024]
Then, the portion of the thermoplastic film 5 which is pressurized between the portions without the grooves 17 and 19 and the grooves 23 and 25 of the pedestal 15 and the backing plate 21 and the end of the partition wall 7 of the honeycomb 1 is It is melted by heat and then welded by a decrease in the temperature of the honeycomb 1 to form the welded portion 11 shown in FIG. 1B.
[0025]
On the other hand, the portions of the thermoplastic film 5 corresponding to the grooves 17 and 19 and the grooves 23 and 25 of the cradle 15 and the backing plate 21 do not sufficiently contact the end of the partition wall 7 of the honeycomb 1 even when pressed. Without melting, the non-welded portion 13 shown in FIG.
[0026]
At the time of the above-described pressurization, the pedestal 15 or the backing plate 21 may be vibrated. Thereby, welding at the welding portion 11 between the honeycomb 1 and the thermoplastic film 5 is more effectively performed.
[0027]
Further, instead of heating the honeycomb 1, the pedestal 15 and the backing plate 21 were previously heated, sandwiched between a pair of thermoplastic films 5 so as to cover the open portions of the cells 3 of the honeycomb 1, and this was heated. Pressing may be performed by sandwiching between the cradle 15 and the backing plate 21. Also in this case, the pedestal 15 or the backing plate 21 may be vibrated at the time of pressurization.
[0028]
Then, as shown in FIG. 6, the honeycomb structure 27 manufactured as described above is placed on the reinforcing fiber cloth 31 placed on the lower mold 29, and the reinforcing fibers are further placed on the honeycomb structure 27. The cloth 33 is placed. Each of the reinforcing fiber cloths 31 and 33 is large enough to cover the side surface of the outer peripheral edge of the honeycomb structure 27, and the peripheral edges 31a and 33a are overlapped with each other. Further, a film 35 for sealing is put on the above-mentioned reinforcing fiber cloth 33 to seal it from the outside.
[0029]
In this way, the honeycomb structure 27 in which both sides of the honeycomb 1 are covered with the thermoplastic film 5 and the reinforcing fiber cloths 31 and 33 are covered on both sides is accommodated between the lower mold 29 and the film 35 for sealing. In this state, air is sucked from the suction port 37 of the film 35 to depressurize the inside, and then a thermosetting molten resin is injected from the resin injection port 39 of the film 35 to be cured, whereby the molded article is formed. obtain.
[0030]
The injected molten resin permeates the reinforcing fiber cloths 31 and 33, and the reinforcing fiber cloths 31 and 33 and the end (welded portion 11) of the partition wall 7 of the honeycomb 1 exposed to the outside from the thermoplastic film 5. To join.
[0031]
As described above, the thermoplastic film 5 prevents the molten resin from entering the cells 3 of the honeycomb 1, and the exposed ends of the partition walls 7 of the honeycomb 1 are bonded to the reinforcing fiber cloths 31, 33 by the injected molten resin. Therefore, a highly rigid and lightweight member in which the honeycomb 1 is not filled with the resin can be manufactured by the RTM method with high productivity.
[0032]
Note that an upper mold may be used instead of the sealing film 35 in FIG.
[0033]
When the molded article manufactured as described above is used by being connected to another member using a bolt or the like, as a second embodiment, as shown in FIGS. 7 (a) and 7 (b). A hole 5a for filling a resin is provided in the thermoplastic film 5 corresponding to a part of the plurality of cells 3. 7A is a cross-sectional view of a molded product in which some cells 3 are filled with a resin, and FIG. 7B is a plan view of the molded product in a state where the reinforcing fiber cloth is omitted.
[0034]
Thereby, when the molten resin is injected in the state of FIG. 6, the molten resin enters some of the cells 3 through the holes 5a of the thermoplastic film 5, and the connecting portion 41 is hardened by the entered molten resin. Form. Then, as shown in FIG. 8, the honeycomb molded product is connected to another member 47 by inserting the bolt 43 into the bolt insertion hole 41 a formed in the connecting portion 41 and fastening the nut 45.
[0035]
In this way, by filling the resin into some of the cells 3 of the honeycomb 1 and forming this portion as the connecting portion 41, even if the formed article using the honeycomb 1 is used, the honeycomb 1 is not crushed and the other parts are not crushed. It can be connected to the member 47.
[0036]
In this case, in order to connect the molded product to another member 47, a complicated operation of removing a part of the cells 3 in the honeycomb 1 is unnecessary, and the manufacturing cost can be reduced.
[0037]
FIG. 9 shows a third embodiment of the present invention. In this embodiment, instead of providing the grooves 17 and 19 and the grooves 23 and 25 in the receiving base 15 and the backing plate 21 shown in FIG. 4, the cells 30 in the honeycomb 10 are mutually connected as shown in FIG. A notch 70a is provided at an end of a part of the partition wall 70 that separates. The cutouts 70a here are provided only in the partition walls 70 facing each other in the same direction indicated by the arrow D in FIG. 9B.
[0038]
The above-described honeycomb 10 is folded into a plate-like member as shown in FIG. 9A by folding so that the partition walls 70 having the cutouts 70a facing each other come into contact with each other. During the honeycomb manufacturing process of the honeycomb 10 serving as the plate-like member, a plurality of grooves 49 in the same direction are formed on both front and back surfaces of the plate-like member at portions corresponding to the partition walls 70 facing each other in the same direction indicated by the arrow D. By processing, the notch 70a described above is obtained.
[0039]
The manufacturing method of the honeycomb structure in this embodiment is similar to that shown in FIG. 4 described above, in which both sides of the honeycomb 10 are sandwiched between a pair of thermoplastic films 5, and both sides of the honeycomb 10 are provided with a pedestal having no grooves 17, 19. Alternatively, the thermoplastic film 5 may be heated and pressurized by sandwiching it with a backing plate having no grooves 23 and 25.
[0040]
Thereby, the end of the partition 70 without the notch 70a of the honeycomb 10 is pressurized and welded to the thermoplastic film 5 to form a welded portion similar to the welded portion 11 shown in FIG. . On the other hand, since the thermoplastic film 5 at the portion corresponding to the notch 70a of the honeycomb 10 does not sufficiently contact the end of the partition wall 70, the thermoplastic film 5 does not melt and has the same non-welded portion 13 as the non-welded portion 13 shown in FIG. It becomes a welding part.
[0041]
The honeycomb structure manufactured in this manner can be formed into a molded product by using the RTM method in the same manner as in FIG.
[Brief description of the drawings]
FIG. 1A is a perspective view of a honeycomb structure showing one embodiment of the present invention, and FIG. 1B is an enlarged perspective view of a main part thereof.
FIG. 2 is a BB cross-sectional view showing a welded portion in FIG. 1 (b).
FIG. 3 is a cross-sectional view of the non-welded portion shown in FIG.
FIG. 4 is a perspective view illustrating a method for manufacturing the honeycomb structure of FIG.
5 is a plan view showing a positional relationship between a groove of a receiving table and cells of a honeycomb in the manufacturing method of FIG. 4;
FIG. 6 is a cross-sectional view showing a process of manufacturing a molded product by using the RTM method for the honeycomb structure of FIG.
7A is a cross-sectional view of a molded product in which a portion of the honeycomb in the honeycomb structure of FIG. 1 is filled with a resin, and FIG. 7B is a plan view of the molded product shown in FIG. is there.
8 is a cross-sectional view showing a state where the resin-filled portion of the molded product of FIG. 7A is connected to another member by a bolt.
FIG. 9 is a perspective view showing a state in which grooves are machined in a honeycomb manufacturing process according to another embodiment of the present invention, and FIG. 9 (b) is an enlarged view of a honeycomb material being manufactured in (a). It is a perspective view showing a part made into a honeycomb.
[Explanation of symbols]
1,10 Honeycomb 3,30 Cell 5 Thermoplastic film (heat welding film)
5a Holes for filling resin 7, 70 Partition walls 11 Welding part 15 Cradle (receiving member)
17, 19 Groove 21 Patch plate (receiving member)
23, 25 groove 27 honeycomb structure 31, 33 reinforcing fiber cloth 70a notch

Claims (14)

The open portions on both sides of each cell in the honeycomb are covered with a heat welding film, and the heat welding film and the ends of the partition walls separating the cells of the honeycomb are intermittently welded to each other. An end portion is exposed to the outside of the heat-sealing film. 2. The honeycomb structure according to claim 1, wherein a hole for filling a molten resin in the cell is provided in the heat-sealing film at a portion corresponding to a part of each of the cells. 3. The honeycomb is sandwiched between the heat-welding films so as to cover the open portions of the cells from both sides thereof, and both sides thereof are sandwiched by receiving members provided with grooves on a surface opposed to the respective heat-welding films, and pressed. By heating the heat-welding film to the honeycomb at the groove-free portion of each of the receiving members, the end of the partition wall separating the cells of the honeycomb at the welding portion is formed of the heat-welding film. A method for manufacturing a honeycomb structure, wherein a non-welded portion of the heat-sealing film to the honeycomb is formed at a portion of the receiving member where a groove is provided, the portion being exposed to the outside. Notches are provided at both ends of the partition wall separating each cell of the honeycomb, the honeycomb is sandwiched between both sides by a heat welding film so as to cover the open portion of each cell, and both sides thereof are sandwiched by receiving members and pressurized. By heating the film, the heat-welded film is welded to a portion of the honeycomb where there is no notch, and the end of the partition wall in this welded portion is exposed to the outside of the heat-welded film, and the honeycomb has a notch. A method for manufacturing a honeycomb structure, wherein a non-welded portion of the heat-welded film to the honeycomb is formed at a site. One heat welding film is placed on one of the receiving members, a heated honeycomb is placed on this one heat welding film, and the other heat welding film is placed on this honeycomb, and the other heat welding film is placed on the other. The method for manufacturing a honeycomb structure according to claim 3, wherein the other receiving member is placed on the heat welding film and pressed. The method for manufacturing a honeycomb structure according to claim 3, wherein both sides of the honeycomb are covered with the heat welding film, and the both sides are pressed by the heated receiving members. The method for manufacturing a honeycomb structure according to any one of claims 3 to 6, wherein at least one of the receiving members is vibrated. The hole according to any one of claims 3 to 7, wherein a hole for filling a molten resin in the cell is provided in the heat-sealing film at a portion corresponding to a part of each of the cells. A method for manufacturing a honeycomb structure. The honeycomb is sandwiched between the heat-welding films so as to cover the open portions of the cells from both sides thereof, and both sides thereof are sandwiched by receiving members provided with grooves on a surface opposed to the respective heat-welding films, and pressed. By heating the heat-welding film to the honeycomb at the groove-free portion of each of the receiving members, the end of the partition wall separating the cells of the honeycomb at the welding portion is formed of the heat-welding film. A honeycomb structure is formed by forming a non-welded portion of the heat-sealing film with respect to the honeycomb at a grooved portion of each of the receiving members, so as to form a honeycomb structure. A resin transfer molding method using a honeycomb structure, wherein a molten resin is supplied into the reinforcing fiber cloth and cured. Notches are provided at both ends of the partition wall separating each cell of the honeycomb, the honeycomb is sandwiched between both sides by a heat welding film so as to cover the open portion of each cell, and both sides thereof are sandwiched by receiving members and pressurized. By heating the film, the heat-welded film is welded to a portion of the honeycomb where there is no notch, and the ends of the partition walls in this welded portion are exposed to the outside of the heat-welded film. A non-welded portion of the heat welding film to the honeycomb is formed at a certain portion to form a honeycomb structure, and the honeycomb structure is covered with a reinforcing fiber cloth from both sides, and a molten resin is filled in the reinforcing fiber cloth. A resin transfer molding method using a honeycomb structure, which is supplied and cured. One heat welding film is placed on one of the receiving members, a heated honeycomb is placed on this one heat welding film, the other heat welding film is placed on this honeycomb, and the other heat welding film is placed on the other. 11. The resin transfer molding method using a honeycomb structure according to claim 9, wherein the other receiving member is placed on the heat welding film and pressed. The resin transfer molding using the honeycomb structure according to claim 9, wherein both sides of the honeycomb are covered with the heat-sealing film, and the two sides of the honeycomb are pressed by the heated receiving members. Method. 13. The resin transfer molding method using a honeycomb structure according to claim 9, wherein at least one of the receiving members is vibrated. The hole according to any one of claims 9 to 13, wherein a hole for filling a molten resin in the cell is provided in the heat-sealing film at a portion corresponding to a part of the cells. A resin transfer molding method using a honeycomb structure.

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