JPS5924037B2 - Method for manufacturing a structure having a central axis - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to large structures having a central axis, such as rigid airships, parabolic antennas, and polyhedral cylinders, which are made by bonding structural materials such as metal plates and glass fibers with bonding materials such as adhesives. Related to manufacturing methods for bodies, etc.

Recently, rigid and semi-rigid airships have become increasingly larger, with 100 m long being not uncommon, and some having a total length of 100 m.
Even 00m lengths are being planned.

In addition, materials such as metal adhesives, honeycomb core materials, and reinforced plastics are beginning to be used for ship hulls. In this type of flying vehicle, which is lighter than air, the difference in specific gravity between air and a gas such as helium filled in the air inside the hull is used as the main lift, so generally the structural panels of the hull are 1.3 to 9.
/m2, which requires extremely light weight.

For reference, another example that seems suitable as a sample of lightweight structure is the floor panel of the Boeing 747 jet airliner, which is designed with a ratio of 3.5 to 9/m2. Compared to these advances in size reduction and the diversification of materials, the manufacturing methods remained old-fashioned, no more than imitations of general aircraft fuselages and building materials.

In other words, the conventional manufacturing method for metal rigid or semi-rigid airship hulls is to first divide the hull into multiple small areas vertically and horizontally to create each panel forming each section, and then to In most cases, the entire assembly was assembled by chemically or mechanically bonding the panels together using adhesives, spot welding, rivets, or the like.

Furthermore, even for rigid or semi-rigid airships made of reinforced plastic, etc., which are not made of metal, a large number of sub-section panels are first assembled on a mold, adhesively assembled, and then hardened, and then bonded to the soil of the airship's metal frame. Alternatively, the size of the assembly was increased by successively joining panels with rivets on an overall assembly jig. In these conventional manufacturing methods, instead of inflating the hull using gas pressure to make it to the actual size, as in the case of soft airships, each partial panel is made by subdividing the hull of a predetermined actual size shape, and is made in advance in the required number. Because they are manufactured in advance and then assembled, it is difficult to maintain the shape accuracy necessary to meet the aerodynamic design requirements of the completed hull, and the length of the joints between panels becomes significantly large. This caused an increase in weight and was extremely disadvantageous in terms of performance.

For reference, the number of blind studs required to assemble a 50m class hull is 50.
It is said that there will be up to 10,000 copies. Furthermore, a large number of molding and assembly jigs are required, which increases the site and labor costs required for assembly.
It was not an economically preferable method.

The biggest problem in manufacturing such ultra-light and large structures is thought to be the difficulty in assembling them.

In other words, the larger and lighter the ship is, the greater the amount of distortion that occurs in the panel, and the greater the amount of structural deformation of parts that are being assembled until complete assembly is completed, so the shape accuracy of the completed hull is dependent on aerodynamics. There was a high risk that the result would be unsatisfactory both physically and externally. The various drawbacks of the conventional manufacturing methods described above are due to the fact that very large and lightweight structures are manufactured by sequentially assembling small parts, such as plastic models, for example.

In order to avoid this, it is obvious that the parts should be integrated in a large size to reduce the number of cuts.From this point of view, the present invention has been developed to provide a subdivided assembly system that is superior not only in terms of performance but also in terms of economy. The intention is to provide a manufacturing method that does not depend on the product. It can be considered that the size of a single seamless panel is not limited in terms of manufacturing technology.

From the perspective of material supply, if a combination of glass cloth and room-temperature curing adhesive is used, the size limit of a single panel depends only on the mold, and therefore the panel length can be made almost equal to the overall length of the hull. Therefore, increasing the size of the panel can be considered an essential requirement for this type of product. The present invention provides the following advantages in manufacturing a structure in which the assembled finished product has a central axis.
In a method for manufacturing a large structure divided into a required number of sectors along the central axis of the structure, a structural axis mold is used to attach the base material to the soil, form sectors, and divide the structure. This method is characterized in that the structure is completed in sequence.

Here, a sector refers to a constituent part of a structure formed by dividing the structure into a required number of parts along its central axis.

According to the manufacturing method of the present invention, when one sector is manufactured on a molding jig mold, since the already molded sector is placed adjacent to the same molding jig mold, both Both sectors can be joined while maintaining shape accuracy.

Therefore, in an airship shell manufactured by repeating this process, the above-mentioned problems are effectively solved, and at the same time, the joint processing process is completed as part of the sector forming process on the forming jig mold. A great advantage derives from this. That is, according to the method of the present invention, not only can extremely sophisticated design requirements for the hull shape be fully satisfied in this way, but also only one type of molding jig is required, and only one jig for assembly can be used. Costs and labor costs can be completely eliminated, and all the drawbacks of conventional manufacturing methods can be eliminated. Next, an embodiment in which the present invention is applied to manufacturing an airship hull will be described with reference to the drawings.

FIG. 1 conceptually shows one cycle of the process as a sectional view viewed from the direction of the central axis of the airship, and includes the following steps.

I. Exterior panel layering process: Apply mold release treatment to the surface of the molding jig mold 1, and laminate the required number of glass cloth reinforcing materials of the desired shape for the exterior panel 2 (for example, 1 to 3 sheets of 0.r27 mm material). Apply and impregnate with room temperature curing resin adhesive.

If the mold is made of concrete with a reinforcing core of a welded steel pipe structure, it is preferable to have a plastic layer on the molding surface. The reinforcing material layer is not necessarily made of glass cloth, but may be freely selected from materials that satisfy technical requirements such as Kevlar mono-material equivalent strength, specific rigidity, and weather resistance. The resin adhesive is preferably a weather-resistant epoxy that cures at room temperature (for example, Kohon 927 component), which does not require heat curing. Furthermore, if quality is important, it is desirable to cure the laminated reinforced plastic outer panel in advance without pressure or in a vacuum bag. but,
This curing treatment may be performed at a later stage. In any case, this process can be carried out by applying ordinary FRP molding techniques. Core material 4-up step A core material 3 of honeycomb core or foamed plastic is placed on top of the outer panel placed in the previous step.

The apparent specific gravity of the core material is preferably about 0.05 f/Cd. Furthermore, if the outer panel is pre-cured, it is necessary to sandwich uncured adhesive layers of the same material on both sides of the core material. Inner plate lay-up step Next, the inner plate 4 is laid up and hardened in the same manner as in step 1 above.

The inner plate 4 and the outer plate 2 are cut larger than the core material 3,
Laminating and curing the inner and outer plates is advantageous in terms of joint strength. Through the above steps, one section, ie, one sector, of the airship shell, which is formed by dividing the airship shell into a required number of parts along the axial direction, is formed into a panel shape.

Mold release process The above-mentioned one sector panel consisting of the laminated and hardened outer panel, core material, and inner panel is released from the mold.

As mentioned above, this mold release work can be facilitated by applying a release agent such as general pineal film or wax to the mold surface in advance, but it is possible to release the mold without damaging the panel. To do this, techniques such as blowing high-pressure air into the gap between the panel and mold and letting wires pass through can produce good results. In addition, in order to ensure that the next process is carried out smoothly,
It is advantageous to add a step to move the entire panel a few centimeters away from the mold surface. Rather than lowering a heavy mold, it is more efficient to install an eccentric cam in the mechanism that supports the front and rear of the hull and use this to lift the entire panel. V-sector (panel) rotation process The formed panel is rotated by an angle corresponding to one sector by a motor drive or the like, with the longitudinal axis of the hull (that is, the central axis of the hull) as the center of rotation.

The best place to stop the rotation is a few centimeters before the panel comes off the mold. If necessary, one method is to use the heave in the rotational direction of the panel to perform the rotation in order to prevent the panel from twisting due to its own weight. Sector (panel) lowering process Lower the panel again and bring it into close contact with the molding surface at the end of the mold.

Outer panel layering process Place the skins of adjacent sectors onto the mold.

It is advantageous for the strength of the joint to be stacked so as to partially overlap the ends of the previously formed sectors. Processing can be completed as part of the sector forming process. The same procedure applies to the inner panels. FIG. 2 is a sectional view of the basic joint part formed in this skin lay-up process,
It shows how the sector 6 being molded partially overlaps the end of the adjacent molded sector 5, thereby serving as a joint between the two sectors.

There is no problem in increasing the number of laminated sheets in this joint part or filling the inside of the core material due to strength requirements. Since both the inner and outer plates are extremely thin, it is often not necessary to add the step 7 at the end of the core in advance as shown.
In this way, since the structure is successively completed by joining adjacent sectors on the same mold while maintaining shape accuracy, the completed structure has extremely high shape precision. FIG. 3 shows an example of an airship shell manufactured by the method of the present invention. In FIG. 3A, each sector 10 has a length spanning the entire length of the hull, and in FIG. 3B,
In this case, the hull is manufactured in two parts, front and rear, and the front shell 8 and rear shell 9 are joined in a subsequent process by a conventional fastener type mechanical joining method.

The method shown in FIG. 3B is particularly convenient when the front and rear trunks have the same shape, and also has the advantage that it is easy to assemble the internal gas bag. The above-mentioned embodiment describes a reinforced plastic shell sandwich bonding structure for a large structure with a central axis such as an airship, but other materials such as structural materials such as metal plates and wood plywood, and combinations of binding materials may also be used. Even in the case of a structure according to the present invention, the implementation of the present invention is not hindered and benefits can be obtained.

Embodiments other than airships of the present invention will be further described with reference to the drawings.

Fig. 4 is a conceptual diagram showing the case of a reflecting antenna such as a parabolic radar.
A single panel 11 for one sector is molded along the central axis of the antenna, and after each sector is molded, it is rotated around the central axis and moved from the mold, and then the antenna is sequentially molded while molding the next sector. The basic assembly and connection process can be carried out in the same manner as for the airship shell described above.

FIG. 5 shows a multifaceted cylindrical structure, and it is clear that it can be manufactured in the same manner as in the previous embodiment. Reference numeral 12 in the figure represents each sector. As described above, in the manufacture of a large-sized structure having a central axis, the present invention allows joining to be performed while maintaining shape accuracy in a mold, and extremely simplifies joint processing for assembly. Therefore, the present invention provides a manufacturing method that is extremely superior in size, performance, and economical efficiency.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing each step in the method of the present invention by one cycle, Fig. 2 is a sectional view of the joint part, and Fig. 3A
, B are side views showing an example of assembling an airship shell according to the present invention, and FIGS. 4 and 5 are perspective views showing other embodiments. 1... Molding mold, 2... Outer plate, 3...
... Core material, 4 ... Inner plate, 5 ... Molded sector, 6 ... Sector under molding, 7
. . . Core step processing section, 8 . . . Front body under molding, 9 . . . Rear body already molded.

Claims (1)

[Claims] 1. A method for manufacturing a structure in which the assembled finished product has a central axis, which uses a shaping mold that is divided into a required number of sectors along the central axis of the structure. A method for manufacturing a structure having a central axis, in which the sectors are completed while attaching a base material thereon, and the sectors are successively completed. 2. The method for manufacturing a structure having a central axis according to item 1 above, characterized in that the completed sectors are sequentially rotated about the central axis of the structure by approximately one sector angle at a time. 3. The method of manufacturing a structure according to item 1 above, wherein each sector has a length spanning substantially the entire length of the structure. 4. Manufacturing a structure according to item 1 above, wherein each sector has a length that divides the structure into at least two parts in the front and back, and each of the separately completed structure parts are joined to each other. Method. 5. A method for manufacturing a structure as set forth in item 4 above, wherein the structure is the hull of an airship. 6. The method of manufacturing a structure according to item 2 above, characterized in that the molded sector is lifted from the surface of the mold before the rotation step. 7. The method for manufacturing a structure according to item 1 above, wherein each sector has a side German trench structure consisting of an FRP outer skin and a honeycomb core.