JP4751536B2 - Method for manufacturing a structure having a closed space - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce labor from an aspect of manufacture and manufacturing cost and to make a manufacturing cycle rapid in a method for manufacturing a structure having a closed space. SOLUTION: In integrally manufacturing the structure having a closed space without using a mechanical joining means, constituent members 10u and 20 for constituting the closed space are combined through a thermosetting adhesive, and a structure wherein the closed space is filled with a flexible mandrel 50 containing beads 51 made of a silicone rubber as a main constituent element is temporarily formed. This structure is heated to expand the flexible mandrel 50 not only to allow pressing force to act on the outside of the closed space from the inside thereof but also to cure the thermosetting adhesive 60. The flexible mandrel 50 is discharged from the closed space.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a structure having a closed space, and in particular, a structure made of a fiber reinforced resin composite material having a closed space is integrally formed by bonding without using a mechanical coupling means such as a rivet. In addition, the present invention relates to a method for manufacturing a structure having a closed space that can reduce manufacturing labor / cost and speed up a manufacturing cycle.
[0002]
[Prior art]
Aircraft and space structures are desirably high-strength and lightweight because of the particularity of their applications. For this reason, when configuring the main wing, tail wing, fuselage, etc. of an aircraft, a semi-monocoque structure that mainly bears a load on the outer shell member is adopted, and a typical example of this semi-monocoque structure is an aircraft wing. Can be mentioned. The main wing of an aircraft consists of a front edge part, an inter-girder part, and a rear edge part, and the inter-girder part in this is a box type consisting of a front girder, rear girder, upper and lower outer plates, stringers, ribs, etc. It is structured.
[0003]
As a method for constructing a structure having a closed space inside the box-shaped structure as described above, (1) using a plate-like body 100 prepared from a metal material or a composite material, as shown in FIG. A rectangular parallelepiped box-like body 200 having an opening 210 is formed, and an upper plate-like body 300 is disposed above a flange 211 provided in the opening 210. The flange 211 and the upper plate-like body 300 are connected to each other in FIG. As shown in Fig. 2, a method of joining using a mechanical joining means (rivet) 400, or (2) using a plurality of combination-type metal mandrels, a rectangular parallelepiped box-like body having an opening is RTM method. A method has been proposed in which two of the two box-shaped bodies are molded by using a mechanical coupling means.
[0004]
[Problems to be solved by the invention]
However, in the case of the method (1), as shown in FIGS. 7 and 8, a rivet hole is provided in the peripheral portion of the flange 211 provided in the opening 210 of the box-like body 200 and the upper plate-like body 300. Complicated work such as installation work and riveting work was necessary. Further, in the case where a large-sized structure such as the above-described inter-beam part of an aircraft is configured, a large number of rivets 400 are required, which increases the weight, which is against the request for weight reduction. Furthermore, the cost for manufacturing the rivet 400 separately has been increased.
[0005]
Further, in the case of the method (2), since it is necessary to rivet the openings of the box-like body, the above-described work is complicated, the weight of the structure is increased, and the cost is increased. The problem was occurring as well. Further, since it is necessary to use a metal mandrel that matches the shape of the structure, it is necessary to prepare a large number of metal mandrels having different shapes. Furthermore, during the heating process of the RTM method, the molded box-shaped body is thermally shrunk, so it is difficult to pull out the metal mandrel from the inside of the box-shaped body (demolding work), resulting in a delay in the manufacturing cycle. It was.
[0006]
An object of the present invention is to reduce a manufacturing labor and a manufacturing cost by using a flexible mandrel that can be freely deformed and easily removed in a manufacturing method of a structure having a closed space, and a manufacturing cycle. Is to achieve speedup.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, the invention described in claim 1 can be opened and closed freely as shown in FIGS. 1 to 6, for example, a plate-like body, an opening, and an adhesive margin extending inward of the opening. A box-shaped body having a working hole as a constituent member, and a method of integrally manufacturing a structure having a closed space without using a mechanical coupling means,
A box-shaped body forming step of forming a box-shaped body from a plurality of the plate-shaped bodies having an adhesive allowance and filling a flexible mandrel having beads made of silicon rubber as a main component;
Together combine components that constitute the said closed space through a thermosetting adhesive, a closed space formation step of the flexible mandrel temporarily form a structure body filled in the closed space,
A heating step of fixing the structure with a predetermined jig and heating to expand the flexible mandrel to apply a pressing force from the inside of the closed space to the outside and to cure the adhesive,
A discharge step of discharging the flexible mandrel from the closed space.
[0008]
According to the first aspect of the present invention, a structure having a closed space can be integrally manufactured by bonding using a flexible mandrel without going through a rivet joining step. No complicated work such as work is required, and manufacturing labor can be significantly reduced.
[0009]
Further, according to the first aspect of the present invention, a structure having a closed space can be manufactured using a flexible mandrel without using a metal mandrel. There is no need to prepare different types of metal mandrels. Therefore, the manufacturing cost can be significantly reduced.
[0011]
According to the first aspect of the invention, using a flexible mandrel without the use of metallic manufactured mandrel can be produced a structure having a closed space, easily from the operation hole of the flexible mandrel after end of production Can be discharged. Therefore, the demolding operation that has been difficult in the prior art becomes extremely easy, and the production cycle can be speeded up.
[0012]
Further, according to the first aspect of the invention, using a flexible mandrel without the use of metallic manufactured mandrel can be produced a structure having a closed space, producing a flexible mandrel used in the manufacturing process After completion, it can be discharged from the working hole and reused in the next manufacturing process. Therefore, the manufacturing cost can be significantly reduced.
[0013]
According to a second aspect of the invention, in the manufacturing method of a structure having a closed space according to claim 1 Symbol mounting, the flexible mandrel is characterized in that it is one that is composed of only the silicon rubber beads.
[0014]
According to a third aspect of the invention, in the method for manufacturing a structure having a closed space according to claim 1 Symbol placement, for example, as shown in FIG. 2, the flexible mandrel, was mixed with glass beads in a silicon rubber beads It is characterized by being.
[0015]
According to the invention of claim 2, wherein, in addition to the effects achieved by the invention of claim 1 Symbol placement, fill factor of the silicon rubber beads, or change in diameter, hardness appropriate, and silicone rubber beads By appropriately changing the mixing ratio with the glass beads, the magnitude of the pressing force due to the expansion of the flexible mandrel in the heating process can be freely controlled. Therefore, an optimum pressing force can be applied according to the material and size of the constituent member, the type of adhesive, and the like, so that a higher quality structure can be manufactured.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, using the manufacturing method according to the present invention, a process of manufacturing a box-shaped structure (see FIGS. 5 and 6) having a rectangular parallelepiped shape of 50 mm long × 60 mm wide × 25 mm high. explain. Each plate-like body constituting the box-shaped structure is formed by curing using a carbon fiber reinforced resin composite material having an epoxy resin as a base material.
[0017]
In the manufacturing method according to the present embodiment, first, a plate-like body (hereinafter referred to as a “lower plate-like body”) 10 d that is a bottom wall of a box-shaped structure is disposed on the base 30, and this lower plate-like body is formed. A plate-like body (hereinafter referred to as a “side plate-like body”) 10s serving as a side wall of the box-type structure is disposed on each side of the body 10d via a thermosetting adhesive, and the opening 21 and the opening are opened. A rectangular parallelepiped box-like body 20 having an adhesive allowance 22 extending inward and an openable / closable work hole 23 is formed (see FIG. 1). Further, a plate-like body (hereinafter referred to as “upper plate-like body”) 10 u to be arranged on the upper side of the box-like body 20 is prepared (see FIG. 1). Examples of the thermosetting adhesive include an adhesive made of a thermosetting resin typified by an epoxy resin.
[0018]
Each side plate-like body 10s is provided with a bonding allowance for bonding to the upper plate-like body 10u, the lower plate-like body 10d, and the other adjacent side plate-like body 10s. By applying the curable adhesive and arranging in the above-described manner, the side plate-like bodies 10s, the lower plate-like bodies 10d, and the side plate-like bodies 10s are temporarily fixed to each other to form a box shape. The body 20 will be constructed (see FIG. 1). Further, the bonding allowance with the upper plate-like body 10u provided on each side plate-like body 10s is the bonding allowance 22 extending inward of the opening of the box-like body 20 (see FIG. 1).
[0019]
A work hole 23 having a diameter of 10 mm is provided in the side plate-like body 10s disposed on the front surface of the box-like body 20 (see FIG. 1). The work hole 23 is for discharging a flexible mandrel 50 described later. The position, shape, size and the like of the working hole 23 are not particularly limited as long as the function described above can be achieved.
[0020]
Next, the side jig 41 is disposed in close contact with the outer surface of the side plate 10 s of the box-like body 20, and the side jig 41 is fixed to the base 30. The side jig 41 prevents the displacement of the position of the upper plate-like body 10u to be fixed above the box-like body 20 by arranging and fixing the upper jig 42 described later on the upper part thereof. When the flexible mandrel 50 is expanded in the heating process and a pressing force is applied from the inside of the box-shaped body 20, the pressing force is applied to each adhesive portion by the flexible mandrel 50, the side jig 41, and the upper jig 42. It functions as follows.
[0021]
Next, a flexible mandrel 50 configured by mixing glass beads 52 into silicon rubber beads 51 is filled into the inside of the box-shaped body 20 from the opening 21 of the box-shaped body 20 (box-shaped body forming step: FIG. 2). At this time, as shown in FIG. 2, the flexible mandrel 50 is filled up to the upper end of the side plate-like body 10s (that is, the lower surface of the flange 22 of the box-like body 20).
[0022]
In the present embodiment, the silicon rubber beads 51 constituting the flexible mandrel 50 are those having a diameter of 4 mm and a durometer hardness of 50, and the diameter of the glass beads is also 4 mm. The expansion rate due to heating of the glass beads can be ignored in the temperature range necessary for curing the thermosetting adhesive.
[0023]
Subsequently, the upper plate-like body 10u is disposed on the flange 22 of the box-shaped body 20 filled with the flexible mandrel 50 via the thermosetting adhesive 60, and the box-shaped structure having a rectangular parallelepiped closed space is provided. Is temporarily formed (closed space forming step: see FIG. 2). In this step, the peripheral edge portion of the upper plate-like body 10 u is temporarily fixed to the flange 22 of the box-like body 20 by the thermosetting adhesive 60. Although not shown, the upper plate-like body 10u is provided with minute holes for letting air inside the box-like body 20 expanded by a heating process described later.
[0024]
Next, as shown in FIGS. 3 and 4, the upper jig 42 is arranged on the upper side of the upper plate-like body 10 u, and the upper jig 42 is fixed to the side jig 41 described above, so that the upper plate-like body is fixed. 10 u is fixed to the box-shaped body 20. That is, the base plate 30, the side jig 41 and the upper jig 42 surround the upper plate-like body 10 u and the box-like body 20. In the present embodiment, as shown in FIG. 3, the side jig 41 and the upper jig 42 are bonded portions between the lower plate-like body 10d and each side plate-like body 10s, and the side plate-like bodies. Particularly, the bonding portion between 10 s and the bonding portion between each side plate-like body 10 s and the upper plate-like body 10 u are reinforced.
[0025]
Next, in a state where the upper plate 10u and the box 20 are surrounded by the base 30, the side jig 41 and the upper jig 42, the upper plate 10u and the box 20 are removed using an oven. And heating at 180 ° C. for 5 minutes (heating step). By this heating step, the flexible mandrel 50 filled in the box-shaped body 20 is expanded, and the flange 22 of the box-shaped body 20 is pressed from the inside of the box-shaped body 20 to the upper plate-shaped body 10u side. Make it work.
[0026]
Since the flange 22 of the box-shaped body 20 and the peripheral portion of the upper plate-shaped body 10u are fixed in a state of being sandwiched between the side jig 41, the upper jig 42 and the flexible mandrel 50, the flexible mandrel in the heating step. When the pressing force is applied by inflating 50, the thermosetting adhesive 60 disposed between the flange 22 of the box-shaped body 20 and the peripheral edge of the upper plate-shaped body 10 u is heated by the oven and the pressing force. Under cure reaction. As a result, the peripheral edge portion of the upper plate-shaped body 10 u is firmly bonded to the flange 22 of the box-shaped body 20.
[0027]
Next, after cooling the side jig 41 and the upper jig 42 to room temperature, the side jig 41 and the upper jig 42 are removed from the box-shaped structure, and the flexible mandrel 50 filled in the box-shaped body 20 from the work hole 23 provided in the box-shaped body 20. Is discharged (see discharge process, FIG. 5). Thereafter, the work hole 23 is closed to obtain a desired box structure (see FIG. 6).
[0028]
Since the flexible mandrel 50 used in the manufacturing method according to the present embodiment has silicon rubber beads 51 as main components, it is a rectangular parallelepiped closed space formed from the box-shaped body 20 and the upper plate-shaped body 10u. It can be freely deformed according to. Moreover, since the silicon rubber beads 51 constituting the flexible mandrel 50 can be expanded by a heating process and each one is flexible, it is heated and expanded to come into contact with a surface forming a closed space. Silicon rubber beads are deformed along this contact surface. Therefore, a uniform pressing force can be applied to all surfaces forming the closed space.
[0029]
For this reason, the bonded portion between the lower plate-like body 10d and each side plate-like body 10s, the bonded portion between the side plate-like bodies 10s, and the bonding between each side plate-like body 10s and the upper plate-like body 10u. A sufficient pressing force can be applied to the portion. Therefore, a box-type structure can be manufactured only by adhesion without going through a rivet bonding process. As a result, troublesome operations such as the operation of providing rivet holes and the operation of tightening rivets are not required, and manufacturing labor can be significantly reduced.
[0030]
In addition, if the manufacturing method according to the present embodiment is used, a box-shaped structure can be manufactured without going through the rivet coupling step. For example, the box-shaped body 20 and the upper plate-like structure according to the present embodiment are used. Even when the body 10u is large, the weight of the box-type structure does not increase due to the use of rivets. Therefore, it can be used very suitably also for manufacturing the inter-girder part (box-type structure) of the main wing of an aircraft. Furthermore, the cost for manufacturing rivets can be reduced, and the manufacturing cost can be significantly reduced.
[0031]
Furthermore, if the manufacturing method according to the present embodiment is applied so that the closed space surrounded by the dry preform is filled with a flexible mandrel, the metal body necessary for integrally forming the box-shaped body 20 by the RTM method is used. Since a box-type structure can be manufactured without using a mandrel, it is not necessary to prepare many types of metal mandrels according to the size and shape of the box-type structure. Moreover, since the flexible mandrel 50 used for manufacturing the box-shaped structure can be discharged from the working hole after the manufacture is completed and reused in the next manufacturing process, the manufacturing cost can be significantly reduced.
[0032]
Furthermore, if the manufacturing method according to the present embodiment is applied, a box-shaped structure can be manufactured without using a metal mandrel necessary for integrally forming the box-shaped body 20 by the RTM method, The flexible mandrel 50 can be easily discharged from the working hole after the manufacture is completed. Therefore, there is no difficulty in demolding work when using a metal mandrel, and the production cycle is accelerated.
[0033]
In the above-described embodiment, since a pressure of about 1 to 3 × 10 ⁻² MPa is required for bonding, the flexible mandrel 50 is filled in the interior space of the box-shaped body 20. Accordingly, the filling amount of the silicon rubber beads 51 constituting the flexible mandrel 50 can be changed.
[0034]
For example, using a universal testing machine or the like, the relationship between the compression rate and pressure of the silicon rubber beads 51 (that is, how much pressure is applied to the object when the silicon rubber beads 51 are compressed to a predetermined volume) The compression rate of the beads 51 made of silicon rubber for obtaining the pressure necessary for adhesion is obtained using this relationship. Next, the necessary volume (filling amount) of the silicon beads 51 can be appropriately determined from the relationship between the obtained compression rate and the volume of the box-shaped body 20.
[0035]
In the above-described embodiment, the flexible mandrel 50 configured by the silicon rubber beads 51 and the glass beads 51 is configured. However, the flexible mandrel 50 may be configured by only the silicon rubber beads 51.
[0036]
Further, in the above-described embodiment, the box-shaped body 20 is configured by using a plate-shaped body that is cured and molded, but instead of this, the box-shaped body is formed by using a plate-shaped body that is primarily cured and molded. 20 may be configured. In this case, the plate-like body is secondarily cured in the heating step. At this time, the silicon rubber beads 51 and the glass beads 52 are pressed against the plate-like body, so that the spherical mold becomes the plate-like body. In order to prevent the formation, silicon rubber is provided between each plate (the lower plate 10d, the side plate 10s and the upper plate 10u) and the silicon rubber beads 51 and the glass beads 52. It is preferable to arrange a heat-resistant plate having the same degree of hardness as the manufactured beads 51.
[0037]
In the embodiment described above, the flexible mandrel 50 is directly filled into the box-shaped body 20 and heated and expanded. However, the flexible mandrel 50 is filled into a predetermined bag film and the inside of the bag film is filled. The air may be discharged and the shape thereof may be adjusted and stored in the box-like body 20 and then heated and expanded. In this case, the bag film portion in the vicinity of the work hole 23 is broken in the discharging step, and the flexible mandrel 50 inside thereof is discharged.
[0038]
Further, in the above-described embodiment, the side jig 41 and the upper jig 42 are arranged outside the upper plate-like body 10u and the box-like body 20, but the pressure required for bonding is relatively small, and When the plate-like body has sufficient rigidity and the bending deformation due to the pressing force from the inside can be ignored, the step of arranging the jig can be omitted.
[0039]
【The invention's effect】
According to the first aspect of the present invention, a structure having a closed space can be integrally manufactured by bonding using a flexible mandrel without going through a rivet joining step. No complicated work such as work is required, and manufacturing labor can be significantly reduced.
[0040]
Further, according to the first aspect of the present invention, a structure having a closed space can be manufactured using a flexible mandrel without using a metal mandrel. There is no need to prepare different types of metal mandrels. Therefore, the manufacturing cost can be significantly reduced.
[0041]
According to the first aspect of the invention, using a flexible mandrel without the use of metallic manufactured mandrel can be produced a structure having a closed space, easily from the operation hole of the flexible mandrel after end of production Can be discharged. Therefore, the demolding operation that has been difficult in the prior art becomes extremely easy, and the production cycle can be speeded up.
[0042]
Further, according to the first aspect of the invention, using a flexible mandrel without the use of metallic manufactured mandrel can be produced a structure having a closed space, producing a flexible mandrel used in the manufacturing process After completion, it can be discharged from the working hole and reused in the next manufacturing process. Therefore, the manufacturing cost can be significantly reduced.
[0043]
According to the invention of claim 2 or 3, wherein, of course it is to the effect of the invention of claim 1 Symbol placement, fill factor of the silicon rubber beads, or by appropriately changing the diameter, hardness, silicone rubber By appropriately changing the mixing ratio of the beads and the glass beads, the magnitude of the pressing force due to the expansion of the flexible mandrel in the heating process can be freely controlled. Therefore, an optimum pressing force can be applied according to the material and size of the constituent member, the type of adhesive, and the like, so that a higher quality structure can be manufactured.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a state in which a box-like body used in a manufacturing method according to an embodiment of the present invention is placed on a base.
2 is a cross-sectional view taken along the line II-II in a state in which a flexible mandrel is filled in the box-like body of FIG. 1 and an upper plate-like body is disposed.
3 is a perspective view showing a state in which jigs are arranged outside the box-like body and the upper plate-like body of FIG. 2. FIG.
4 is a cross-sectional view taken along the line IV-IV in FIG. 3;
5 is a perspective view showing a state in which a flexible mandrel is discharged from a work hole of a box-type structure formed through a heating process from the state of FIG. 3;
6 is a cross-sectional view taken along the line VI-VI in FIG.
FIG. 7 is a perspective view showing a box-like body and a plate-like body used in a conventional method for producing a structure having a closed space.
8 is a cross-sectional view of the VIII-VIII portion in a state in which a plate-like body is fixed to the box-like body of FIG. 7 by rivet connection.
10u Upper plate 10s Side plate 10d Lower plate 20 Box 21 Opening 22 Flange 23 Work hole 30 Base 41 Side jig 42 Upper jig 50 Flexible mandrel 51 Silicon rubber beads 52 Glass beads 60 Thermosetting adhesive 100 Plate body 200 Box body 210 Opening 211 Flange 300 Upper plate body 400 Rivet

Claims (3)

A plate-shaped body, and a box-shaped body having an opening, an adhesive margin extending inwardly of the opening, and an openable / closable work hole are used as constituent members, and a structure having a closed space is used without using mechanical coupling means. A method of manufacturing integrally,
A box-shaped body forming step of forming a box-shaped body from a plurality of the plate-shaped bodies having an adhesive allowance and filling a flexible mandrel having beads made of silicon rubber as a main component;
Together combine components that constitute the said closed space through a thermosetting adhesive, a closed space formation step of the flexible mandrel temporarily form a structure body filled in the closed space,
A heating step of fixing the structure with a predetermined jig and heating to expand the flexible mandrel to apply a pressing force from the inside of the closed space to the outside and to cure the adhesive,
And a discharging step of discharging the flexible mandrel from the closed space. A method for manufacturing a structure having a closed space. The flexible mandrel method of manufacturing a structure having a closed space according to claim 1 Symbol mounting, characterized in that those composed of only silicone rubber beads. The flexible mandrel method of manufacturing a structure having a closed space according to claim 1 Symbol mounting, characterized in that the silicone rubber bead is obtained by mixing glass beads.

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