JPH0747299B2 - Method for manufacturing hollow structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a hollow structure in which a resin-impregnated fiber is wound around a mandrel, and the resin impregnated in the wound fiber is cured. The present invention relates to a method for manufacturing a body.

(Summary of the Invention) The present invention is a method for manufacturing a hollow structure in which a resin-impregnated fiber is wound around a mandrel, and the resin impregnated in the wound fiber is cured. Using the mandrel to which the fitting is attached, remove the parts other than the fitting of the mandrel from the fibers in the wound state that have been solidified by the hardened resin, and wind the wound fiber and the opening of this wound fiber. By manufacturing a hollow structure consisting of a fitting that closes the, it is possible to manufacture a hollow structure having a complicated curved shape such as a hemispherical surface and being lightweight and having high strength in a simple manufacturing process, In addition, the manufactured hollow structure can be easily coupled to another mechanism.

[Conventional technology]

Casings such as tanks of aircrafts, rocket chambers, rocket motors for attitude control of artificial satellites, etc., have a substantially hemispherical end shape. Since such a casing is incorporated in a flying body such as an aircraft, a rocket, and an artificial satellite, it is necessary to have the contradictory characteristics of being lightweight and having high pressure resistance. Therefore, in the hollow structure constituting the casing as described above, a very long continuous fiber impregnated with a resin is wound around a mandrel, the resin is cured, and then the mandrel is separated from the wound fiber. It is manufactured by the filament winding method.

[Problems to be solved by the invention]

However, in the method for manufacturing a hollow structure as described above, the fibers in a wound state solidified by the resin, that is, the fibers
When the mandrel is detached from the resin composite, an opening is formed at the end of the fiber / resin composite due to the hole into which the end of the mandrel is inserted, so it is necessary to attach a die or the like to this opening.

[Means for solving problems]

The present invention is made in order to solve the above problems, a step of preparing a mandrel in which a fitting is attached to a mandrel body, and the fitting is partly made of a resin-impregnated fiber. To be covered, the step of winding the fiber around the mandrel, the step of curing the resin impregnated in the wound fiber, from the fiber solidified by the cured resin, And a step of releasing a portion of the mandrel other than the fitting, the wound fiber being solidified by the cured resin, and the fiber so as to close the opening of the wound fiber. The present invention relates to a method for manufacturing a hollow structure, which is configured to manufacture the hollow structure including the fitting bonded to the hollow structure.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a fiber winding step of helically winding a fiber around a mandrel. The mandrel 1 used in this fiber winding step is constructed as shown in FIG.
That is, the mandrel 1 is provided with a rod-shaped core material 2 made of metal or the like having a large diameter portion 2a formed at one end and a small diameter portion 2b formed at the other end. Two pins 2c are provided on the core 2 in the vicinity of the large-diameter portion 2a so as to be substantially orthogonal to each other and penetrate the core 2. The fitting 4 shown in FIG. 3 is fitted and fixed to the small diameter portion 2b.

The fitting 4 is made of an aluminum alloy, various composite materials, etc. in a substantially hemispherical shape, and has a fitting recess 4a in the central portion of the flat surface 4c and an engaging recess in the central portion of the hemispherical surface 4d. Each hole 4b is formed. By fitting and fixing the small diameter portion 2b in the fitting recess 4a, the fitting 4 is slidably fixed to the core material 2 in the axial direction thereof.

The core material 2 is coated with a water-soluble gypsum (paraplast) 3, and the water-soluble gypsum 3 is hardened by drying or the like. The gypsum 3 has a cylindrical shape 3a in the vicinity of the large-diameter portion 2a of the core 2 and has a diameter substantially the same as that of the large-diameter portion 2a so as to be smoothly continuous with the large-diameter portion 2a.
Ellipsoidal shape 3b between 3a and fitting 4
Is configured. And hemisphere 4d of fitting 4
Form one end face of the oblong-shaped portion 3b by smoothly connecting with the oblong-shaped portion 3b, and a cylindrical portion 3a is continuously provided at the other end of the oblong-shaped portion 3b. There is. Further, since the pin 2c is embedded in the oblong shaped portion 3b, it is possible to prevent the gypsum 3 from being displaced in the axial direction and the circumferential direction of the core material 2 by the pin 2c.

Therefore, the mandrel 1 is composed of the core material 2, the fitting 4, and the water-soluble gypsum 3. And, in the mandrel 1 configured in this way, as shown in FIG.
The resin-impregnated fiber is helically wound.

That is, first, the shaft portion 5a of the engaging member 5 is engaged with the engaging hole 4b provided in the hemispherical surface 4d of the fitting 4, and the large diameter portion 2a of the core 2 is used as a rotation driving mechanism (not shown). The mandrel 1 is supported so that the mandrel 1 can be rotationally driven by the rotational drive mechanism.

Next, the carbon fiber 7 impregnated with a thermosetting resin, a thermoplastic resin, or the like is inserted into the insertion hole 6a of the guide ring 6 provided on the reciprocating carriage 10, and the tip of the carbon fiber 7 is moved to a predetermined position of the mandrel 1. Secure in place. Then, while the mandrel 1 is rotationally driven by the rotational drive mechanism described above, the reciprocating moving table 10
The carbon fiber 7 is helically wound around the mandrel 1 by reciprocating in the axial direction of the mandrel 1.

In the winding described above, a wire mesh pattern 9 having a large number of diamond-shaped openings 8 is formed on the mandrel 1. Therefore, if the position where the carbon fiber 7 is wound is shifted little by little, the one side edge of the carbon fiber 7 that has been previously wound is opposite to the one side edge that is opposite to the newly wound carbon fiber 7. Can be layered on top of each other little by little. When the carbon fibers 7 are repeatedly wound many times in this manner, the mandrel 1 is covered with the wound multiple carbon fibers 7 as shown in FIG.

In this case, the oblong-shaped portion 3b of the gypsum 3 is wound with the carbon fibers 7 in a number of layers over the entire portion thereof, and the hemispherical surface 4d of the fitting 4 is also covered with the carbon fibers 7 only at its outer peripheral portion.
Is wound in layers. The central portion of the hemispherical surface 4d remains exposed to the outside, and the number of windings of the carbon fiber 7 is gradually increased from the central portion to the outer peripheral portion. The thickness gradually increases from the portion to the outer peripheral portion. Therefore, the wound fiber 7 and the central portion of the hemisphere 4d of the fitting 4 exposed to the outside are almost smoothly connected to each other.

FIG. 5 shows that the mandrel 1 is removed together with the wound fiber 7 formed as described above from the shaft portion 5a and the rotary drive mechanism described above, and the wound fiber 7 is covered with various members. After that, a vacuum bag step is shown in which the wound fiber 7 is solidified by using the vacuum bag method. That is, the wound fiber 7 is sequentially covered with the release layer 11, the perforated fluorinated ethylene propylene layer 12, the glass cloth layer 13, the non-perforated fluorinated ethylene propylene layer 14 and the glass cloth layer 15. Further, a sealing material layer 16 for maintaining a vacuum state is formed on the core material 2 between the large diameter portion 2a of the core material 2 and the wound fiber 7 and wound from the outside of these layers 11 to 16. The fiber 7 in the state is covered with a backpack 17 in a bag shape so as to prevent air leakage.

The members forming the layers 11 to 15 are each formed into a substantially rectangular sheet shape as a whole, and a large number of cuts extending in the longitudinal direction (axial direction) are formed in parallel in the portion covering the surface of the fitting 4. Has been done. And release layer
Reference numeral 11 is for absorbing excess resin of the resin impregnated in the carbon fiber 7 and adjusting the roughness of the surface of the wound fiber 7. In addition, the perforated fluorinated ethylene propylene layer 12
Is for not adhering the glass cloth layer 13 coated on the upper side to the peeling layer 11. Also glass cloth layer 13
Is for absorbing the above-mentioned extra resin through the perforated fluorinated ethylene propylene layer 12. Therefore, by changing the thickness of the glass cloth layer 13, the resin content (V _f ) and the thickness of the wound fiber 7 can be controlled. The non-porous fluorinated ethylene propylene layer 14 is for blocking the glass cloth layer 13 from the glass cloth layer 15. The non-perforated fluorinated ethylene propylene layer 14 can control the resin content (V _f ) and the thickness of the wound fiber 7 only in the glass cloth layer 13. Further, the glass cloth layer 15 is for helping to make the vacuum state between the mandrel 1 and the backpack 17 uniform over almost the entire circumference of the glass cloth layer 15. Therefore, this glass cloth layer 15
Is connected to the vacuum device in a state where the air around the entire glass cloth layer 15 is easily introduced to the vacuum device when the backpack 17 is evacuated by a vacuum device (not shown). Further, as mentioned above, the non-porous fluorinated ethylene propylene layer 14 exists inside the glass cloth layer 15, so that the absorption of the resin by the glass cloth layer 15 is prevented by the fluorinated ethylene propylene layer 14. To be done.

Then, the inside of the backpack 17 is evacuated by a vacuum device (not shown) and uniform external pressure is applied to remove air and excess resin from the inside of the carbon fiber 7. The condition can be improved. When the entire structure shown in FIG. 5 is heated under a predetermined condition by a hot air circulation type oven (not shown) or the like, the resin is cured and the wound carbon fiber 7 is solidified. A fiber / resin composite 18 is obtained by the resin impregnated with this. In this case, since the fiber 7 is wound around the hemispherical surface 4d of the fitting 4 as described above, the fitting 4 is firmly bonded to the fiber / resin composite 18 through the cured resin.

Next, the backpack 17 is removed, and then the release layer 11 is peeled off from the fiber / resin composite 18 to remove the respective layers 12 to 15 from the mandrel 1 and the fiber / resin composite 18.

FIG. 6 shows a step of pulling out the core material 2 from the fiber / resin composite body 18 formed as described above. That is, since the mandrel 1 is constructed as shown in FIG. 2, the gypsum 3 near the pin c is destroyed and the gypsum 3 is allowed to move in the axial direction with respect to the core material 2. When the core 2 is pulled to the left in FIG. 6 with respect to the fiber / resin composite 18 by the mandrel pulling device, the core 2 can be easily pulled out from the fiber / resin composite 18. In this case, the fitting 4 is a fiber / resin composite as described above.
Since the small diameter portion 2b of the core material 2 is firmly coupled to the fitting 18, the fitting portion 4 is easily pulled out from the fitting recess 4a.

Then, the water-soluble gypsum 3 remaining in the fiber / resin composite 18 is washed away with water to obtain a hollow structure composed of the fiber / resin composite 18 and the fitting 4 bonded to the tip portion thereof.

In this hollow structure, as shown in FIG.
Since the carbon fiber 7 is not wound in the vicinity of the locking hole 4b formed in the central portion of the hemispherical surface 4d of the fitting 4, the locking hole 4b is exposed to the outside of the hollow structure. . Therefore, when the hollow structure is connected to another device, the locking hole 4b can be used as the connecting means. After manufacturing the hollow structure, the hemispherical surface 4d of the fitting 4 may be processed to change the connecting means into a desired shape.

FIG. 4 shows another example of the fitting 4. The fitting 4 has a boring portion 19, and the boring portion 19 forms the fitting 4 into a hemispherical shell shape. The thickness of the hemispherical surface 4d gradually decreases from the central portion to the outer peripheral portion. Therefore, in the state of being incorporated into the fiber / resin composite body 18, the thickness of the composite body 18 and the fitting 4 becomes substantially uniform as a whole. Further, the boring portion 19 has a fitting recess 4a.
Therefore, if the hollow structure is constructed by using the fitting 4 shown in FIG. 4, the weight can be further reduced by the weight corresponding to the boring portion 19.

In the above embodiment, the maximum outer diameter of the mandrel 1 (that is, the maximum outer diameter of the oblong shaped portion 3b of the plaster 3 in the upward direction in FIG. 1) is 110 mm, and the maximum outer diameter (that is, the large diameter portion 2a and The diameter of the cylindrical portion 3a of the gypsum 3 is 50 mm, the outer diameter of the fitting 4 (that is, the outer diameter of the flat surface 4c) is 75 mm, and its thickness (that is, the distance between the central portion of the hemispherical surface 4d and the flat surface 4c).
Was set to 30 mm. Further, carbon roving (trade name: T300-6000) was used as the carbon fiber 7, and an epoxy resin was used as the resin for impregnation. The main component of this epoxy resin is Epocoat 807 (trade name), the curing agent is YH30 (trade name), and the curing accelerator is EM124.
(Product name). The curing of the resin was carried out in the first half and the second half, and the first half was performed at 80 ° C. for 2 hours and the second half was cured at 120 ° C. for 6 hours.

Although one embodiment of the present invention has been described above, various changes and modifications can be made in the above embodiment without departing from the technical idea of the technology of the present invention.

For example, although the carbon fiber 7 is used as the resin-impregnated fiber in the above-described embodiments, it is also possible to use glass fiber or fiber that has been pre-impregnated with the resin to be in a semi-cured state (propreg roving). Is.

Further, as a concave-convex fitting means for fitting and fixing the fitting 4 to the core material 2, the fitting recess 4a is provided in the fitting 4.
Further, the core material 2 is provided with a fitting projection composed of the small diameter portion 2b. However, conversely, the fitting 4 may be provided with a fitting projection, the core material 2 may be provided with a fitting recess, and both may be provided with both a recess and a projection. Considering the ease of pulling out the core material from the hollow structure, it is preferable that the direction of the concave and convex fitting of the concave and convex fitting means coincide with the axial direction of the core material 2. Not even.

The fitting 4 has locking holes as locking means for locking the mandrel 1 to the locking member 5 in a rotatable manner.
4b is provided, but instead of the locking hole 4b, a locking shaft portion is provided in a protruding manner, and the locking member 5 is provided with a bearing portion for rotatably supporting the locking shaft portion. May be. In this case, in order to connect the hollow structure to another device, this locking shaft portion may be used as its engaging means.

Further, the mandrel 1 is composed of the core material 2, the water-soluble gypsum 3 and the fitting 4. However, instead of the water-soluble gypsum 3, another solid substance soluble in water or another liquid may be used, or a hollow to be manufactured. Depending on the shape of the structure, the soluble solid matter described above may be omitted, and the mandrel 1 may be composed of a mandrel body of a predetermined shape corresponding to the core material 2 and the fitting 4.

Further, the outer surface of the fitting 4 exposed to the outside of the hollow structure is the hemispherical surface 4d, but it goes without saying that it may be a plurality of other curved surfaces.

〔The invention's effect〕

The present invention is, as described above, winding a resin-impregnated fiber around a mandrel having a fitting attached to the mandrel body, curing the resin impregnated into the wound fiber, and the cured resin. From the fiber in the wound state solidified by, the part other than the fitting of the mandrel is released, and a hollow structure consisting of the fiber in the wound state and the fitting that closes the opening of the wound fiber is formed. Since it is manufactured, it is possible to manufacture a hollow structure having a plurality of curved surfaces such as hemispherical surfaces and being lightweight and having high strength by a simple manufacturing process.

Further, since the hollow structure according to the present invention is provided with a fitting exposed to the outside thereof, by processing this fitting into a predetermined shape in advance, or by subsequently processing it into a predetermined shape, When coupling the hollow structure to another device, the fitting can be used as the coupling means, and thus coupling to another device can be easily performed.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a perspective view showing a fiber winding step, FIG. 2 is a perspective view of a mandrel shown in FIG. 1, and FIG. 3 is shown in FIG. FIG. 4 is an enlarged cross-sectional view of the fitting, FIG. 4 is a view similar to FIG. 3 showing another example of fitting, and FIG. 5 is a vacuum bag for the wound fiber formed by the fiber winding step shown in FIG. FIG. 6 is an enlarged cross-sectional view of a main part showing a process, and FIG. 6 is a perspective view showing a mandrel drawing process with respect to the hollow structure body subjected to the vacuum bag process shown in FIG. In the reference numerals used in the drawings, 1 ... Mandrel 2 ... Core material 3 ... Water-soluble gypsum 4 ... Fitting 7 ... Carbon fiber 18 ... Fiber / resin composite.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // B29K 105: 08

Claims (1)

[Claims] 1. A mandrel having a fitting attached to a mandrel body; and winding the fiber around the mandrel so that the fitting is partially covered by resin-impregnated fibers. A step of curing the resin impregnated in the wound fiber, and a step of releasing the portion of the mandrel other than the fitting from the fiber solidified by the cured resin, A wound fiber solidified by the cured resin,
A method for producing a hollow structure, comprising: producing a hollow structure comprising the fitting bonded to the fiber so as to close the opening of the wound fiber.