JPS62264915A - Method of molding hollow cone made of fiber reinforced resin - Google Patents

Abstract

PURPOSE:To prevent damage due to a protrusion of a material layer, by providing an elastic cover ring on a boundary part between the material layer and dam ring after the dam ring has been arranged on the inside of a small diameter side of a mandrel. CONSTITUTION:A terminal of a surplus length part is fixed firmly to dam rings 36, 40 through adhesive glass cloth 49 by bonding rosette sheets 45, 47 to an opening part of the dam ring after application of hollowproof to the opening part of the dam ring by applying a thin metallic piece 48 to the same. Then a position of a cover ring 50 is held by elastic force of the said dam ring 40 by applying the cover ring 50 made of an elastic material such as rubber to a place of a bondary part between a material layer 46 and the dam ring 40 on a small diameter side from the inside of a high-strength rosette sheet layer. Then the inside extending from the dam ring 36 to the dam ring 40 is covered by making use of a conical auxiliary cylinder 51 and further a lubricating layer is formed on the inward of the auxiliary cylinder 51.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for molding a hollow cone made of fiber reinforced resin, such as a material for an inner insulator of a rocket nozzle, and more specifically, the present invention relates to a method for molding a hollow cone made of fiber reinforced resin, such as a molded material for an inner insulator of a rocket nozzle. After forming a material layer of fiber-reinforced resin inside and sealing this material layer with an elastic conical cylinder, the cone is formed by curing while applying pressure to the material layer through this cylinder. About how it was done.

[Technology of technology]

A method of manufacturing the rocket nozzle insulator material made of glass fiber reinforced resin (hereinafter referred to as GFRP) using such a conventional molding method will be explained with reference to FIG.

The mandrel l has a hollow conical part 3 with a conical inner surface 2 having the same tendency as the inner surface of the skirt cone constituting the outer shell of the rocket nozzle, a large-diameter right cylindrical part 4 connected to the chain part 3, and a small-diameter straight cylindrical part 4. A dam ring 6 is fitted into the large-diameter right cylindrical portion 4 and secured with screws 8 to form a dam surface 7 rising from the conical inner surface 2. A mandrel 1 is mounted on a stand 10 with the small diameter side facing down.

On the other hand, a large number of rosettes 11 having a fan shape as shown in FIG. 6 are cut and prepared from a so-called prepreg sheet, which is a sheet obtained by impregnating glass cloth with a resin raw material, such as a phenol resin raw material, and semi-curing the impregnated glass cloth. The above fan shape is formed by a conical corresponding portion 11a that roughly corresponds to the shape obtained by vertically dividing the expanded surface of the conical inner surface 2, and an extra length portion llb that extends the chain portion 11a further toward the smaller diameter side. . Then, one piece of the rosette sheet ll is stretched from the conical inner surface 2 to the inner surface of the small diameter right cylindrical portion 5 using a roller while blowing warm air while aligning the fan-shaped large diameter side 2 grade along the dam surface 7. Crimp. Next, the second rosette sheet is overlapped with the first sheet by about 174 cm, and is pressed together in the same manner as above. Thereafter, this procedure is continuously repeated until a predetermined thickness is achieved, thereby forming a layer of pre-pregloss vine sheets, that is, GF
A material layer 12 of RP is formed. A thin metal piece 13 is applied to the screw hole opening of the screw 8 and fixed with adhesive glass cloth or the like.

Next, a conical cylinder 16 made of an elastic material such as rubber is placed inside the mandrel 1 on which the material layer 12 has been formed, and its both ends are folded back to the outside of the mandrel 1.゜18 makes me tense. Then, a perforated end cover 20 with a threaded rod 19 is applied to the small diameter side of the above structure, and another perforated end cover 21 is screwed in from the large diameter side to squeeze the structure, thereby connecting the mandrel 1 and the cylindrical body. The material layer 12 is sealed between the material layer 16 and the material layer 12 .

Next, the above-mentioned structure with an end cover was brought into a hydro-crepe, and the inside of the crepe was first evacuated to perform an airtightness test on the above-mentioned sealed part.
The material layer 12 is delivered according to a predetermined schedule by supplying high-temperature water.
Carry out curing. In this process, the material layer 12 is heated while being pressed toward the mandrel 1 by water pressure through the cylinder 16 made of an elastic body, so that the stacked pre-pregloss vine sheets adhere to each other and reduce the layer thickness. As the impregnated semi-cured resin continues to harden, the rosette sheets are bonded together to form a hollow cone made of integral GFRP.

Once the above curing schedule is completed,
The temperature inside the hydrocrepe is lowered and the pressure is reduced, and after the structure is decomposed, the molded body is released from the mandrel I. FIG. 7 shows the released hollow conical body 22, and the molded body 22 is cut to a machining line 23 shown by a two-dot chain line to manufacture the inner insulator 24 of the rocket nozzle.

[Problem that the invention seeks to solve]

However, in the conventional method, there have been reports that the cylindrical body 16 made of an elastic body is damaged during pressure and heat curing of the material layer. The reason for this is explained below.

As described above, in the process in which the stack of rosette sheets is heated while being pressed toward the mandrel side, the impregnated resin material hardens and rises between layers, and each rosette sheet tends to flow particularly toward the small diameter side of the mandrel. Then, the impregnated resin material is cured and gradually fixed from the outer layer on the mandrel side, which has a high thermal conductivity, so that while the rosette sheet on the inner layer side walks over it, the end portion on the small diameter side of the sheet forms a cylindrical body. It is pushed up from the inside and raised. As a result, a sharp protrusion as shown by the reference numeral 25 in FIG. 7 is formed, and if the cylindrical body is strongly pressed against this protrusion, it will eventually crack and form a hole.

When the cylindrical body is damaged as described above, high-pressure water leaks from the cylindrical body and penetrates into the interlayers of the rosette sheet, resulting in the above-mentioned interlayer bonding being inhibited.

Therefore, an object of the present invention is to prevent the above-mentioned damage from occurring.

[Means for solving problems]

The means of the present invention that solves the above problems is to form the material layer after disposing a dam ring on the inner surface of the small diameter side of the mandrel, and to provide a cover ring made of an elastic material at the boundary between the material layer and the dam ring. The cylindrical body is placed inside the covering ring and the material layer.

[Effect]

According to the above means, when the fiber-reinforced resin material such as the rosette sheet attempts to flow toward the smaller diameter side as described above, this flow is blocked by the dam ring disposed on the inner surface of the smaller diameter side. Then, the dam ring tries to bulge inward along the dam surface, but a cover ring made of an elastic material is placed there, and this is compressed outward by water pressure through the cylindrical body. Therefore, the above-mentioned protrusion is also suppressed.

Due to the above-mentioned effects, it is difficult to form sharp protrusions as in the conventional case, and even if such protrusions are formed, they do not come into direct contact with the cylindrical body, thereby preventing damage to the cylindrical body.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

The mandrel 31 used in the present invention is similar to the conventional one,
It has a hollow conical part 33 forming a conical inner surface 32, a large diameter right cylindrical part 34, and a small diameter right cylindrical part 35, and a dam ring 36 is fitted into the large diameter right cylindrical part 34 to screw the screw. 38 to form a dam surface 37.

Further, another dam ring 40 is fitted inside the small-diameter right cylindrical portion 35 of the mandrel 31 and fixed with screws 42, and a dam surface 41 is formed by this dam ring.

The heights of the dam surfaces 41 and 37 on the small diameter side and large diameter side are made approximately equal to the thickness of the material layer to be formed later.

The mandrel 31 with such a dam ring 36, 40 is mounted on the stand IO.

On the other hand, a predetermined number of fan-shaped rosette sheets 45 as shown in FIG. 3 are cut and prepared from the prepreg sheet made of the glass fiber and phenolic resin raw material. The height H of this fan shape is made approximately equal to the distance between the dam surface 37 and the dam surface 41.

The rosette sheet 45 is then laminated between both dam surfaces in the same manner as in the conventional procedure to form a GFRP material layer 46.

Furthermore, a fan-shaped high-strength rosette sheet 47 with extra length at the top and bottom is cut out from a high-strength prepreg sheet made of, for example, carbon cloth and phenol resin material, as shown by the two-dot chain line in FIG. Then, after applying a thin metal piece 48 (Fig. 2) to the screw hole opening of the dam ring mounting screw 38. In the same way, about two layers are crimped, and the ends of the extra length are attached to the dam rings 36 and 40 using adhesive glass cloth 49 (Fig. 2).
Fix it firmly.

Next, a cover ring 50 made of an elastic material such as rubber is applied from inside the high-strength rosette sheet layer to the boundary between the material layer 46 and the small-diameter dam ring 40, and the elastic force of the ring 40 causes the cover ring 50 to Hold position.

After that, a conical auxiliary cylinder 5 made of an elastic material such as rubber
1 to cover the inner surface from the dam ring 36 to the dam ring 40, and further form a lubricant layer inside the auxiliary cylinder 51.

This lubricant layer is formed by applying a solid lubricant such as graphite, and in the embodiment, Teflon sheets 52 and 53 are stacked. The terminal portions of the auxiliary cylinder 51 and each Teflon seam (52, 53) are fixed to the dam ring 36 on the large diameter side using an adhesive glass cloth 49 (FIG. 2).

Next, a conical cylinder 54 made of an elastic material such as rubber is placed inside the above-mentioned structure, and as in the conventional case, both ends of the cylinder are folded back outside the mandrel 31 and tightened with bands 55 and 56. . Thereafter, the end covers 20 and 21 are attached, the material layer 46 and other parts are sealed, an airtight test is performed, and then pressure and heat curing is performed in a hydrocrepe according to the conventional procedure. In addition, the drawing shows cylinder bodies 51, 54, Teflon sheet 52.
53 etc. are drawn with large distances from each other, but these members are arranged as closely as possible.

FIG. 4 is a sketch of a hollow cone made of GFRP formed by the above method, and shows the material layer 46 of the hollow cone 57.
is connected to the dam surface 41 as well as the dam surface 37, and its layer thickness is gradually reduced.

Since the embodiment is as described above, the dam surface 37 and the same 41
Even if the material rosette sheet of the material layer 46 stacked between the material layer 46 tries to flow toward the small diameter side of the mandrel 31 during pressurized and heated curing, this will be blocked by the dam surface 41, and furthermore, this blocked rosette sheet will not flow inward. Since this is in turn restrained by the cover ring 50, the material layer is molded as shown in FIG. 4 while being restrained in position between the dam surface 37 and the dam surface 41.

In this case, the material layer 46 is joined to the dam rings 36 and 40 by a layer of high-strength rosette sheet 47 in this embodiment, so that the above-mentioned position restraint effect is facilitated. Furthermore, in the embodiment, a Teflon sheet 52 is provided between the cylindrical body 54 and the material layer 46.
．． Since the auxiliary cylinder 51 is arranged through the lubricant layer 53, when high water pressure acts on the cylinder 54 and it expands, the auxiliary cylinder 54 comes into close contact with the material layer 46 while sliding against it. The high water pressure of the material layer can be applied evenly, and in the process where the layer pressure of the material layer is reduced as shown in FIG.
Since the auxiliary cylindrical body 51 is stepped over the auxiliary cylindrical body 51, the above-mentioned close contact state can be maintained well.

〔effect〕

As explained above, according to the present invention, when pressure curing is performed by sealing a material layer of fiber reinforced resin with a cylinder made of an elastic material, harmful protrusions are not formed on the material layer. Therefore, the situation in which the cylindrical body is damaged by the protrusion is avoided, and the problems of forming a defective hollow cone are eliminated.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a device according to an embodiment of the present invention, and FIG.
The figure is an enlarged detailed view of the main part of Figure 1, Figure 3 is a plan view of the fiber-reinforced resin material used in the example of Figure 1, and Figure 4 is of a hollow cone molded according to the example of Figure 1. FIG. 5 is a cross-sectional view of a device related to the conventional method, and FIG. 6 is a plan view of the fiber-reinforced resin material used in the conventional method. FIG. 7 is a half-cut sectional view of a hollow cone formed by a conventional method. 31e... Mandrel 32... Conical inner surface 40... Dam ring 46... Material layer 50... Cover ring 51... Auxiliary cylinder 54... Cylindrical body 57... Hollow conical body No. Figure 5 t46 Figure 7 67-'--' A~... 1 '\j

Claims (1)

[Claims] A material layer of fiber-reinforced resin is formed on the inner surface of a mandrel having a conical inner surface, a conical cylinder made of an elastic body is placed inside this material layer, and the material layer is sealed by this cylinder. In this method, a hollow cone made of fiber-reinforced resin is formed by curing the material layer while pressurizing it through a cylinder, in which a dam ring is provided on the inner surface of the small diameter side of the mandrel, and then the material layer is formed. Then, a cover ring made of an elastic body is applied to the boundary between the material layer and the dam ring, and the cylinder is placed inside the cover ring and the material layer to form a hollow cone made of fiber-reinforced resin. Method.