JPS6345947B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a bellows made of fiber-reinforced composite material, and more particularly to a bellows made of fiber-reinforced composite material that is highly reliable against bending and in which continuous fibers are arranged in the bellows portion without cutting. Relating to a manufacturing method.

Fiber-reinforced composite materials are used in applications such as gas or liquid transport pipes, or high-speed rotating cylinders due to their excellent specific strength and specific elasticity. Bellows made of fiber-reinforced composite materials are thought to have a wide range of applications, such as absorbing the elastic bending vibrations of high-speed rotating cylinders that rotate at a constant speed exceeding the critical rotational speed and reducing the critical speed. However, unlike homogeneous materials, fiber-reinforced composite materials exhibit extreme anisotropy, so there are various problems in molding them into a bellows shape, and at present they have not been put to practical use. In other words, considering the role of the bellows part, it is essential that it be strong in the circumferential direction, easy to bend in the axial direction, and strong against bending, but the strength of fiber reinforced composite materials largely depends on the arrangement density and continuity of the fibers. However, especially in the case of a bellows shape, the problem is how to arrange the continuous fibers as designed without cutting them and without disturbing the fibers. In addition, when considering high-speed rotating bodies, fiber-reinforced composite materials with excellent specific strength and specific elasticity, such as carbon fiber reinforced plastics (CFRP), are often designed to withstand centrifugal force.
In such a high-speed rotating body, the fiber arrangement is set so that the strength in the circumferential direction is high, so in the axial direction,
It is not possible to increase the ratio, and it is necessary to utilize fibers that contribute in the axial direction, which is effective in bending the bellows, without wasting it. Furthermore, in high-speed rotating bodies with relatively long bodies that reach constant speed rotation beyond the critical rotation speed, there is a risk of elastic bending vibration occurring when passing through the critical speed, so a method is used to minimize vibration by adjusting the balance. However, as the critical speed increases, fine adjustment of the balance becomes necessary, which requires a large amount of time, and from an industrial perspective it is difficult to reduce the critical speed by applying bellows. It can be said to be an extremely effective method.

From this point of view, the present inventors used continuous fibers to obtain a bellows made of a fiber-reinforced composite material that is strong and easy to bend in the axial direction without reducing the strength in the circumferential direction. It was necessary to manufacture a bellows made of fiber-reinforced composite material that does not disturb the fibers while maintaining the designed winding angle while minimizing the machining that would lead to damage, and as a result of intensive research into the manufacturing method, we were able to complete the present invention. Ivy.

In other words, a continuous fiber impregnated with a matrix is wound around a flat or cylindrical surface with a smaller diameter at the position corresponding to the bellows part than the other parts, and then a bellows shape is formed on the inner surface divided in the circumferential direction from above. The wrapped continuous fibers are covered with a cylindrical shape having or a cylindrical shape in which at least the part corresponding to the bellows is made of a rubber-like elastic material, and the diameter of the part corresponding to the bellows part is made smaller than other parts, and A continuous fiber impregnated with a matrix is wound on the surface of this mold, and then a cylindrical shape having a bellows shape covers the wrapped continuous fiber on the inner surface divided in the circumferential direction. By removing the cylindrical mold that supports the cylindrical mold using a rubber-like elastic body and molding it by applying internal pressure to the inner surface of the rubber-like elastic body, it becomes possible to manufacture a bellows made of a fiber-reinforced composite material that has both of the above characteristics. I discovered that.

The present invention will be explained in detail below by giving specific examples. Figures 1 and 2 show an example of a cylindrical body with bellows made of fiber-reinforced composite material manufactured by the manufacturing method according to the present invention, and in Figure 1, the cylindrical part and bellows part are manufactured integrally using continuous fibers. 2, the cylindrical part and the bellows part are manufactured separately using continuous fibers, and then integrated using an adhesive.

Figures 3 to 6 are examples of the winding type according to the present invention, and Figure 3 is an example of a flat cylindrical type, which corresponds to the cylindrical type 1 of the part corresponding to the flat part of the cylinder and the bellows part. A cylindrical mold 2 is placed on a core mold 3, and the core mold 3 may be omitted if necessary, and instead flanges may be provided at both ends of the mold to fix the cylindrical mold. When the continuous fibers impregnated with a matrix are wound using the winding die shown in Fig. 3, the cylindrical die 2 that is divided in the circumferential direction and made into a split shape is removed, and the inner surface of the split in the circumferential direction is given a bellow shape. After covering the fiber surface with a cylindrical mold having
When applying internal pressure, it is also possible to remove the entire cylindrical shape, cover the inner surface of the continuous fiber with a rubber-like elastic body, and apply internal pressure to this inner surface. Figure 4 shows an example of a cylindrical shape in which the diameter of the position corresponding to the bellows part of the cylinder body is smaller than that of the other parts. It is arranged on a core mold 3, and the cylindrical mold 2 corresponding to the bellows part has a structure that penetrates the cylindrical body. When using the winding mold shown in Fig. 4, after winding the continuous fiber impregnated with the matrix, the core mold 3 and the cylindrical mold 2 are removed, and the inner surface of the fiber is divided in the circumferential direction from above to form a bellows shape. The continuous fiber is covered with a cylindrical mold, and the inner surface of the continuous fiber is covered with a rubber-like elastic material, and internal pressure is applied to the inner surface to form the fiber. In this case, it is also possible to omit the core mold 3 and fix both ends of the cylindrical mold 2 with flanges, and the length of the flat part of the cylindrical mold 2, which corresponds to the bellows part, is the total length (L) of the bellows, that is, in the axial direction. The length of the wrapped fiber is equal to or greater than the shortest straight line distance along the bellows, and it is better to deform the wrapped fiber only in this part to form a bellows shape than to let the continuous fiber impregnated with the wrapped matrix slide over its entire length. This is also suitable for preventing disturbances in the flow.

The purpose of this application is to apply internal pressure to resin-impregnated continuous fibers wound into a cylindrical shape through a rubber-like elastic body to deform the continuous fibers into a bellows shape. When subjected to tensile force, each fiber shifts in the axial direction and takes on a bellows shape.

That is, as shown in the conceptual diagram in FIG. 10, when internal pressure is applied to the wound continuous fiber part 11 via the rubber-like elastic body 4, the continuous fiber part 11 receives an axial force in the cylindrical axis direction (state A). ), the continuous fiber is deformed into a shape along a cylindrical shape 21 having a bellows shape on the inside provided on the outside (state B).

At this time, each continuous fiber moves in the axial direction by a length necessary to assume a bellows shape, thereby securing the above shape.

Figure 5 shows an example of using a rubber-like elastic body in the part corresponding to the bellows part of a flat cylindrical body. It is placed on the cylindrical mold (core mold) 3 that supports the cylindrical mold 4 using the body, and the third
The part 2 shown in the figure or the parts 1 and 2, and further the part 2 or the parts 1 and 2 shown in FIG. 4 may be cylindrical using a rubber-like elastic body,
In this case, a continuous fiber impregnated with a matrix is wound on the mold surface, and then covered with a cylindrical mold having a bellows shape on the inner surface divided in the circumferential direction.The core mold 3 is removed and internal pressure is applied to the inside of the rubber-like elastic body. By deforming the rubber-like elastic body into the bellows shape provided in the outer mold by internal pressure, the fibers are molded along the bellows shape. The core mold 3 can also be omitted, in which case both ends of the cylindrical body are fixed with flanges. Again, rather than sliding the fibers along their entire length,
It is preferable to follow the bellows shape within the cylindrical shape of the rubber-like elastic body in order to prevent the winding fibers from being disordered.

Furthermore, Fig. 6 shows a cylindrical bellows portion with a smaller diameter at the position corresponding to the bellows portion than the other portions, and a cylindrical shape using a rubber-like elastic body and a cylindrical shape supporting this inside. In one example, a cylindrical mold 1 corresponding to the flat part of the cylindrical body and a cylindrical mold 4 made of a rubber-like elastic body corresponding to the bellows part are arranged on a cylindrical mold 3 that supports them. 3 is fixed with flanges provided at both ends.

FIGS. 7 and 8 show an example of a state in which a cylindrical mold 21 having a bellows shape divided in the circumferential direction is incorporated, and the cylindrical mold 21 is divided into two parts. That is, the continuous fibers 11 impregnated with a matrix and wound are divided into a cylindrical shape 1 corresponding to the flat part of the cylinder, a cylindrical shape 4 using a rubber-like elastic body corresponding to the bellows part, and a cylindrical shape 8 using a rubber-like elastic body corresponding to the bellows part in FIG. In the figure, internal pressure is applied through a cylindrical mold 4 made of a rubber-like elastic material over the entire surface of a flat cylindrical body, and the cylindrical mold 21 is deformed into a bellows shape. The cylindrical mold 21, which has a bellows shape divided in the circumferential direction, can be fixed by tightening with bolts and nuts, as shown in FIG. Various methods can be considered, such as the method of inserting the cylinder having the structure, and the number of divisions can also be changed as appropriate. When the shape of the bellows is internal, it is preferable to make the diameter of the bellows part smaller than the other diameters in order to prevent the fibers from being disturbed when inserting the cylindrical mold 21. In this case, the diameter of the flat part of the bellows is It is better to make it equal to or less than the diameter of the valley.

Next, as a molding method by applying internal pressure, as shown in Figure 9, the inner surface of the rubber-like elastic body is sealed and internal pressure is applied thereto by hydraulic pressure or air pressure, and as shown in Figure 11, the rubber-like elastic body is formed into a sealed structure. A split die with a bellows shape is inserted into the inner surface of the split die, and internal pressure is applied to the split die by hydraulic, pneumatic, or mechanical means to expand the diameter of the split die to make the continuous fibers wrapped around the cylinder into a bellows shape. Alternatively, as shown in Fig. 12, a metal band divided in the circumferential direction is arranged on the inner surface of a rubber-like elastic body corresponding to the bellows peak, and the diameter of this is expanded by hydraulic, pneumatic, or mechanical means to form a cylinder. Possible methods include a method of forming continuous fibers into a bellows shape by winding them into a shape.

Furthermore, after the continuous fibers wound in a cylindrical shape are made to conform to a bellows shape by internal pressure, the bellows made of fiber-reinforced composite material obtained by applying pressure and heat curing in this state is removed from the mold. This can be easily done by removing 21 and then removing the winding mold. In addition, if the continuous fibers impregnated with a matrix are wound around the part or all of the bellows of the wrapping type and then removed, the matrix may be left as is, but in order to prevent the fibers from becoming disordered, it is necessary to Once solidified, especially when using a thermosetting resin as a matrix, it is better to solidify it at a temperature lower than the molding temperature, or to solidify it by cooling with liquid nitrogen, or after making it into a prepreg state. It is.

As described above in detail with specific examples, the present invention is intended to produce a bellows made of fiber reinforced composite material that is strong against bending in the axial direction and easy to bend without reducing the strength in the circumferential direction. The present invention provides a manufacturing method that uses continuous fibers and minimizes mechanical processing that may lead to cutting of the continuous fibers, and that maintains the designed winding angle without disturbing it. The dividing method and the like are not limited to the specific examples and should be used as appropriate depending on the application.

Regarding the materials used for bellows, various reinforcing fibers such as glass fiber, Kepler fiber, carbon fiber, silicon carbide fiber, alumina fiber, and boron fiber can be used depending on the purpose, but plastics are especially used. A matrix carbon fiber reinforced composite material has excellent specific strength and specific elasticity, so it can be said to be a suitable material for such a cylindrical body with bellows. In addition, the matrix can be plastic, metal, etc., and the fiber form, roving, unidirectional fibers such as yarn, etc.
It should be used appropriately in combination with woven cloth, cylindrical cloth made of cylindrical cloth, and the like.

[Brief explanation of the drawing]

Figures 1 and 2 are examples of cylinders with bellows made of fiber-reinforced composite material manufactured by the manufacturing method according to the present invention; Figures 3 to 6 are examples of winding molds according to the present invention; 2 is a side view, and 2 is a sectional view taken along line A-A' of 1. Figures 7 and 8 are examples of how to apply internal pressure according to the present invention, 2 is a cross-sectional view, and 1 is an A-
It is an A′ cross-sectional view. FIG. 9 Another example of how to apply internal pressure according to the present invention, FIG. 10 FIGS. 1 and 2 Conceptual diagram of deformation due to internal pressure load according to the present invention,
Figures 1 and 12 Another example of how to apply internal pressure according to the present invention 1... Cylindrical shape of the part corresponding to the flat part of the cylindrical body, 2... Cylindrical shape of the part corresponding to the bellows part, 3
...Cylindrical type (core type) that supports a rubber-like elastic body, 4...
...Cylindrical type using a rubber-like elastic body, 5...Fluid inflow pipe, 6...Internal pressure load member, 11...Fibre-reinforced composite material, 21...Cylindrical type having a bellows shape divided in the circumferential direction, 31 ... Bellows shape type divided in the circumferential direction, 32 ... Tapered cylinder with internal pressure load, 41 ...
Metal band, 42... Internal pressure loading jig.

Claims (1)

[Claims] 1. A continuous fiber impregnated with a matrix is wound around a cylindrical surface that is flat or has a smaller diameter at a position corresponding to the bellows portion than other portions, and then divided in the circumferential direction from above. Cover the inner surface of the wrapped continuous fiber with a cylindrical shape having a bellows shape, remove the portion or all of the bellows of the wrapped type, cover the inner surface of the wrapped continuous fiber with a rubber-like elastic material, and A method for manufacturing a bellows made of fiber-reinforced composite material, characterized by forming the bellows by applying internal pressure from the inside. 2. A cylindrical shape that is flat or has a smaller diameter at the position corresponding to the bellows than other parts, and at least the part corresponding to the bellows is made of a rubber-like elastic body, and the cylindrical shape supports this inside the cylindrical shape. After winding continuous fibers impregnated with a matrix on the surface of this mold, the wrapped continuous fibers are covered with a cylindrical shape having a bellows shape on the inner surface divided in the circumferential direction, and a rubber-like elastic material is 2. A method for producing a bellows made of fiber-reinforced composite material according to claim 1, characterized in that the cylindrical mold supporting the cylindrical mold is removed, and internal pressure is applied to the inner surface of the rubber-like elastic body to form the bellows. 3 The length of the flat part, which is located at the position corresponding to the bellows part and has a smaller diameter than other parts, is the total length of the bellows (L).
A method for manufacturing a bellows made of fiber reinforced composite material according to claims 1 and 2, characterized in that the bellows is equal to or greater than . 4 Claim 1 characterized in that the fiber reinforced composite material is carbon fiber reinforced plastics.
A method for manufacturing a bellows made of fiber reinforced composite material according to items 1 to 3.