JPH0669727B2 - Pressure vessel manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a pressure vessel using a filament winding method.

(Prior Art) Generally, a multistage rocket is used for launching artificial hygiene. Fig. 8 shows a schematic configuration of this multistage rocket.
In the figure, 1 is a second stage rocket motor, 2 is an apogee motor third stage rocket motor, and 4 is artificial hygiene. 2nd stage rocket motor 1 and 3rd stage rocket motor 2
Are connected by an isogrid structure 5, and the isogrid structure 5 is provided with a flange 5a. The flange 5a and the flange 2a attached to the third stage rocket motor 2 are connected by a separation nut (not shown) having an explosive charged therein.

When the second stage rocket motor 1 is separated, the explosive powder in the separation nut is exploded to separate the second stage rocket motor 1. Further, the third-stage rocket motor 2 and the artificial hygiene 4 are connected by a connecting body 6 similar to an isogrid structure. The connecting body 6 is provided with a flange 6a, and the flange 6a and the flange 2b attached to the third stage rocket motor 2 are connected by bolts or the like.

As a known document showing the above structure, the first published in May 1988.
16th ISTS (PROCEEDINGS OF THE SIXTEENTH INTERNA
TIONAL SYMPOSIUM ON SPACE TECHNOLOGY AND SCI
ENCE 1988 P403 ~ P408).

By the way, since the rocket motors 1 and 2 have a structure in which the front stage and the rear stage are connected, the pressure vessels 1E and 2E of the rocket motors 1 and 2 are subjected to forces such as load, axial compression, and bending at the time of launch, such as the flange 2a. Since the pressure vessels 1E and 2E are made rigid, the flange 2a must be firmly fixed to the pressure vessel 2E. Further, the pressure vessels 1E and 2E are required to have pressure resistance and heat resistance during combustion of the propellant, and also to be lightweight.

In order to meet these requirements, the rocket motor pressure vessel is made of fiber reinforced plastic and manufactured by the filament winding method.

FIG. 9 shows a method of manufacturing the pressure vessel 2E of the rocket motor 2 by the conventional filament winding method. In the figure, 11 is a split-type molding die (mandrel), which is omitted in the figure, on which a reinforcing fiber 10 such as carbon fiber impregnated with a matrix resin such as epoxy resin is wound by implene winding or helical winding, A dome 12 is formed which will be the main body of the pressure vessel. Then, after the matrix resin is cured, the flange 13 is fitted and the hoop winding is performed from above.
14 is applied and cured again. After the curing, the mandrel 11 is disassembled and removed.

(Problems to be solved by the invention) However, in the method for manufacturing a pressure vessel by the above filament winding method, when the reinforcing fiber 10 is wound with a predetermined tension, the matrix resin impregnated on the surface of the reinforcing fiber 10 is wound on the surface. As it rises and hardens, as shown in FIG. 10, unevenness is generated on the surface 12a of the dome 12. For this reason, it is not possible to accurately obtain the joint dimensions of the flange 13, and there is a problem that the mounting strength cannot be ensured because the mounting portion of the flange 13 is mounted on the uneven surface because the surface contact cannot be made. . Therefore, as shown in FIG. 11, there is a method of cutting the surface to obtain accuracy, but since the reinforcing fiber 10 is cut by the cutting, there is a problem that the strength of the pressure vessel decreases. There is also a method of fitting the flange before the impregnated matrix resin is cured, but the resin layer floating from the reinforcing fiber layer tends to become thick, and this resin layer causes the contact strength between the flange and the reinforcing fiber layer to increase. And the flange is not firmly fixed to the pressure vessel.

(Purpose) Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to improve the mounting accuracy of the flange without lowering the strength of the pressure vessel, and to further It is an object of the present invention to provide a method for manufacturing a pressure vessel that can be firmly fixed to the pressure vessel.

(Means for Solving the Problems) In order to achieve the above object, the present invention is a method for manufacturing a pressure vessel using a filament winding method, which is a dome portion that is a continuous fiber impregnated with a matrix resin to form a pressure vessel main body. After integrally forming the, the additional winding portion for the mounting surface is formed with other continuous fibers impregnated with the matrix resin in the fitting portion that fits the flange of the dome portion, and after hardening the impregnated matrix resin, The additional winding portion for the mounting surface is finished to have a predetermined size, the mounting portion of the flange is fitted into the portion, and the additional winding for fixing is performed from above the mounting portion of the flange.

(Working) With the above configuration, the additional winding portion for the mounting surface additionally wound around the fitting portion of the dome portion is cut and finished to a predetermined size, so that the reinforcing fibers of the dome portion are not cut and the dome portion of the dome portion is not cut. The strength can be secured, and the flange can be brought into surface contact with and bonded to the cut portion, so that the bonding strength between the flange and the dome increases.

(Example) Hereinafter, the manufacturing method of the pressure vessel concerning this invention is demonstrated based on drawing.

FIG. 1 is an explanatory view showing a process of forming a dome which is a pressure vessel. In the figure, 21 is a split type molding die (mandrel), on which a carbon fiber impregnated with a matrix resin such as epoxy resin is formed. Continuous reinforcing fibers such as the above are wound by impregnating or helical winding to form the dome portion 23. Then, before the matrix resin is hardened, the middle portion of the dome portion 23 is additionally wound by hoop winding with another continuous reinforcing fiber such as carbon fiber impregnated with plastic such as epoxy resin, and additionally wound for the mounting surface. Form part 24.

After the matrix resin impregnated in these reinforcing fibers has hardened, as shown in FIG.
Fitting portions K, K for fitting (see the drawing) are formed as shown in FIG. Rubber 25, 25 is wound around the fitting portions K, K (see FIG. 6), and the mounting portions 26a of the annular flanges 26, 26 shown in FIG. 3 are shown in FIG. 4 from above the rubber 25, 25. Mate as shown.

In this way, since only the additional winding portion 24 is cut, the fibers of the dome portion 23 are not cut,
The strength of the dome portion 23 serving as the pressure vessel body does not decrease. Further, by the cutting process, a flat surface can be obtained without the uneven surface unlike in the conventional case, and the mounting accuracy of the flanges 26, 26 can be secured.

In addition, the resin impregnated from the reinforcing fiber of the additional winding portion 24 for mounting floats out as in the conventional case, but the resin that has risen is also cut by cutting the additional winding portion 24 for mounting surface, so the fitting portion K The resin layer interposed between the reinforced fiber of K and the rubber 25,25 can be thinned, and the adhesive strength between the rubber of the rubber 25,25 and the reinforced fiber of the fitting part K, K can be increased. Therefore, the flanges 26, 26 fitted to the rubbers 25, 25 can be firmly fixed to the dome portion 23.

Next, from the top of the mounting portion 26a of the flange 26, 26,
As shown in the figure, a woven fabric is wound to form a woven fabric layer 27, and a hoop winding layer (fixing additional winding portion) 28 is formed on the woven fabric layer 27 by hoop winding.

After the woven fabric layer 27 and the hoop winding layer 28 are hardened, the mandrel 21 is disassembled and removed to obtain a pressure vessel as shown in FIG.

By the way, FIG. 7 (A) shows the relationship between the winding angle α of the fiber and the tensile strength and compressive strength of the cylinder E of FIG. 7 (B). The changes in tensile strength and compression strength are large with respect to the winding angle α,
When the winding angle α is small, the tensile strength and compressive strength in the axial direction are considerably large. Therefore, with only the hoop winding layer 28 having a large winding angle α, sufficient strength cannot be obtained against the tensile and compressive loads acting between the pair of flanges 26.

However, by connecting both flanges 26 with a woven fabric layer 27 having fibers having a small wrap angle α, sufficient strength can be exerted against tensile and compressive loads acting between these flanges 26. Moreover, the rubber 25,
Since 25 is provided, the friction between the flange 26 and the rubber 25 is increased, so that the tensile strength and the compression strength are further increased.

The Fsu curve shown in FIG. 7 (A) shows the relationship between the in-plane shear strength of the cylinder E and the fiber winding angle α.

In the above-mentioned embodiment, the case where the two flanges 26 are fitted has been described, but it goes without saying that the number of the flanges 26 may be one.

(Effects) As described above, according to the present invention, it is possible to increase the mounting accuracy of the flange without lowering the strength of the pressure vessel, and further, it is possible to firmly fix the flange to the pressure vessel. Have.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method of forming a dome, FIG. 2 is an explanatory view showing cutting of an additional winding portion, FIG. 3 is an explanatory view of a flange, and FIG. 4 is a case where a flange is fitted to a dome. Illustration of
FIG. 5 is an explanatory view of the pressure vessel, FIG. 6 is an enlarged partial cross-sectional view of the pressure vessel, FIG. 7 (A) is a graph showing the relationship between the hoop winding angle and strength, and FIG. 7 (B) is Explanatory drawing showing the relationship between the cylinder and winding angle α, FIG. 8 is an explanatory drawing of the multistage rocket, 9th
FIG. 10 is an explanatory view showing a conventional pressure vessel manufacturing method using a filament winding method, and FIGS. 10 and 11 are enlarged partial cross-sectional views of a conventional pressure vessel. 23 …… Dome part 24 …… Additional winding part for mounting surface 26 …… Flange 28 …… Hoop layer (additional winding part for fixing)

Claims (1)

[Claims] 1. A method for manufacturing a pressure vessel using a filament winding method, wherein a dome portion which becomes a pressure vessel main body is integrally formed of continuous fibers impregnated with a matrix resin, and then a flange of the dome portion is fitted. An additional winding part for the mounting surface is formed from other continuous fibers impregnated with the matrix resin in the fitting part, and after hardening the impregnated matrix resin, the additional winding part for the mounting surface is finished to a predetermined size A method for manufacturing a pressure vessel, characterized in that a mounting portion of a flange is fitted, and additional fixing winding is performed from above the mounting portion of the flange.