JPH0328301B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Industrial application field This invention is applicable to fiber-reinforced plastics (hereinafter referred to as
A method for manufacturing a pressure-resistant container body using FRP (FRP),
In particular, the present invention relates to a method of manufacturing a body of an FRP pressure container having a lining layer. (b) Conventional technology and its problems When manufacturing a pressure-resistant container body made of FRP by taking advantage of FRP's light weight and high strength, the winding method is suitable because it has a high fiber utilization rate and product reliability. It is. Generally, the filament winding method (FW
The relationship between the fiber wrapping angle (θ) and the circumferential strength (F) of the cylindrical container body manufactured by the method (see Figure 1), and the fiber wrapping angle (θ) and coefficient of thermal expansion (α)
(see Figure 2) are all extremely anisotropic. Therefore, the ideal configuration is a so-called orthogonal lamination with a ratio of circumferential fibers to axial fibers of 2:1. However, due to the difference in coefficient of thermal expansion between the fiber direction and the direction perpendicular to the fibers due to the above-mentioned anisotropy, and the decrease in strength in the direction perpendicular to the fibers, cracks in the direction perpendicular to the fibers (F _T cracks) are relatively low in orthogonal lamination. Since it is easy to enter under pressure, the reliability of the seal is low, and in general, a 50° to 55° helical winding configuration with a circumferential and axial strength ratio of 2:1, which has a small stress σ _T in the direction perpendicular to the fiber, is generally used. There is. Therefore, as a countermeasure against F _T cracks, a rubber lining is applied to the inner surface of the container based on an orthogonal laminated structure. The first traditional method of applying rubber lining is
The lining layer is formed by pouring uncured rubber into the inner surface of an ERP container and curing it. However, this manufacturing method has the drawback that pinholes and unevenness are likely to occur in the lining layer, making it difficult to maintain inner surface precision. Further, as a second conventional method, there is a method in which an FRP container and a lining layer are manufactured separately in advance, and the lining layer is inserted into the FRP container and bonded. This method requires a bonding process, and at that time, it is necessary to apply internal pressure in order to obtain sufficient bonding strength and improve inner surface accuracy, which has the drawback of being difficult to work with. (C) Means for Solving the Problems The first object of the present invention is to provide a method for manufacturing a pressure-resistant container body made of FRP having a lining layer. An FRP pressure-resistant container body is obtained by forming an FRP layer around the lining layer using the filament winding method, curing it, and then separating the FRP layer integrated with the lining layer from a mandrel. (hereinafter referred to as the first invention). On the other hand, threaded joints are generally used as joint structures for pressure containers, but if threads are cut in an FRP container, the continuous fibers of the FRP are cut, making it impossible to obtain sufficient strength. A second object of the present invention is to provide a method for manufacturing a pressure-resistant container body made of FRP in which threaded portions are formed at the same time, in addition to the object of the first invention. A lining mold is removably attached adjacent to the lining layer, a lining layer is provided around the lining layer, and an FRP layer is formed around the lining layer and the thread mold by the filament winding method. After hardening, the FRP layer integrated with the lining layer is separated from the thread molding die and mandrel to obtain an FRP pressure-resistant container body with a thread (hereinafter referred to as
(referred to as the second invention). (d) Examples [Examples of the first invention] Figures 3 to 6 are examples of the first invention,
Pay out continuous reinforcing fiber 2 from supply roll 1,
The continuous reinforcing fibers 2 impregnated with resin are passed through a resin impregnating tank and are supplied around the mandrel 5 via the traverser 4. A pre-formed rubber lining layer 6 is inserted or molded onto the mandrel 5 to provide a rubber lining layer 6 around the mandrel 5, and the above-mentioned resin-impregnated reinforcing fiber is wound around it to obtain the desired thickness. By forming the FRP layer 7 and then curing it, the FRP layer 7 and the rubber lining layer 6 are integrated, and then, when extracted from the mandrel 5, the rubber lining layer 6 is formed as shown in FIG.
It is possible to obtain the body 8 of the pressure-resistant container made of FRP which is integrated with the above. Incidentally, in order to manufacture the body of the spherical FRP pressure container as shown in FIG. 6, a spherical mandrel 5 as shown in the same figure is used. Further, although the above method is a so-called wet method, it can also be manufactured by a dry method using prepreg. [Embodiment of the second invention] FIGS. 7 and 8 relate to an embodiment of the second invention. The mandrel 5 in the case of the second invention has a lining laminated portion 9 and threaded portions 1 formed on both sides thereof.
0 and 10 are inserted in a removable manner, and the threaded portion forming molds 10 and 10 can be disassembled to reduce their diameter and removed from the mandrel 5. A rubber lining layer 6 is provided around the lining laminated portion 9 as in the case of the first invention, and a rubber lining layer 6 is provided around the rubber lining layer 6 and the thread molding molds 10, 10 as in the case of the first invention. The FRP layer 7 is formed by winding continuous reinforcing fibers impregnated with resin. By heating and hardening the FRP layer 7
The FRP layer 7 and the lining layer 6 are integrated, and then the threaded part mold 10 is disassembled and removed, and the body 12 of the FRP container with the threaded part 11 is obtained by pulling it out from the mandrel 5. [Other Examples] In any of the embodiments of the first invention and the second invention described above, continuous reinforcing fibers in the axial direction of 0° to 15° and continuous reinforcing fibers in the circumferential direction of 75° to 90° are essential components. FRP layers can be formed by orthogonal lamination. Furthermore, carbon fiber reinforced plastic (CFRP) and/or aromatic polyamide fibers can be used. (e) Experimental Example The method of the second invention was carried out using CFRP as reinforcing fibers, and a pressure vessel body as shown in FIG. 8 having a threaded portion and a lining layer was manufactured. The diameter of the CFRP layer is 80mm, length 1000m, thickness 1.5
mm, and the thickness of the lining layer was 1.0 mm. After attaching metal lids to both sides of the above container body,
As a result of the water pressure test, as shown in the table below,
The total failure value far exceeded the F _T crack value, and it was confirmed that water did not leak until the total failure occurred. In addition, in the case of 55° helical winding, the F _T crack value was higher than that of orthogonal lamination, but the overall failure value was lower than that of orthogonal lamination.

[Table] (f) Effects As described above, the first invention provides a method for forming a lining layer on a mandrel by a winding method.
Since the FRP layer is formed, it is possible to manufacture a pressure-resistant container body with high inner surface precision of the lining layer and high reliability of the adhesive portion with the FRP layer. In addition to the above-mentioned effects, the second invention also has the effect of simultaneously molding the threaded portion without cutting the FRP fibers.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the wrapping angle θ and the circumferential strength F, FIG. 2 is a graph showing the relationship between the wrapping angle θ and the coefficient of thermal expansion α, and FIG. 3 is a graph showing the relationship between the wrapping angle θ and the coefficient of thermal expansion α. Schematic diagram, Figure 4 is a sectional view of the product molded on the mandrel, Figure 5 is a sectional view of the finished product, and Figure 6 is a sectional view of the product molded on the mandrel when manufacturing containers of other shapes. , FIG. 7 is a sectional view of the molded product on a mandrel according to the second invention, and FIG. 8 is a sectional view of the finished product. 1... Supply roll, 2... Continuous reinforcing fiber,
3... Impregnated layer, 5... Mandrel, 6... Rubber lining layer, 7... FRP layer, 9... Lining laminated portion, 10... Threaded portion mold.

Claims (1)

[Claims] 1. A fiber-reinforced plastic layer is formed around the lining layer provided on the mandrel by the filament winding method, and after this is cured, the fiber-reinforced plastic layer integrated with the lining layer is separated from the mandrel. A method for producing a pressure-resistant container body made of fiber-reinforced plastic, characterized by: 2. A threaded mold is removably attached adjacent to the lining laminated part of the mandrel, a lining layer is provided around the lining laminated part, and fiber reinforced plastic is formed around the lining layer and the threaded mold by filament winding method. A method for producing a pressure-resistant container body made of fiber-reinforced plastic, characterized by forming a layer, curing the layer, and then separating the fiber-reinforced plastic layer integrated with the lining layer from a thread mold and a mandrel.