JPH04201244A - Pipe structure made of fiber reinforced composite material - Google Patents

Abstract

PURPOSE:To provide an integral lightweight pipe structure having dimensional stability against temp. change by a method wherein rods made of a continuous unidirectional fiber reinforced composite material are oriented in the whole of a pipe member and a connection part in a tubular form and connection cores are also incorporated so as to cross in an axial direction using the same short rods to fix crossing contact parts and the inner and outer layers of a pipe are seamed in a crossing direction of + or -30-+ or -60 deg.. CONSTITUTION:A pipe member 2 is formed by integrally bonding an intermediate layer 8 consisting of an inner pipe 6 wherein continuous fibers 5 are oriented in a crossing direction of + or -30-+ or -60 deg. and a rod 7 of a continuous unidirectional fiber reinforced composite material wherein a terminal part 7a protrudes from the end part of the inner pipe 6 and an outer pipe 9 wherein continuous fibers 5 are oriented to the outer periphery of the A connection pipe 4 is formed by integrally bonding a connection core 16 wherein two or more sets of short rods 15 of a continuous unidirectional fiber reinforced material are radially crossed and incorporated so as to be opposed to the inner pipe 6 of the pipe member 2 and the terminal part 7a of the long rod 7 of the intermediate layer 8 incorporated so as to cover the outer peripheral part of the connection core 16 by a resin layer 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fiber-reinforced composite pipe structure used in space structures and the like, and a method for manufacturing the same.

[Conventional technology]

As space structures such as artificial satellites and space stations,
A pipe structure is used that is assembled by joining pipe members made of fiber reinforced plastic (hereinafter referred to as FRP) such as carbon fiber reinforced plastic (hereinafter referred to as CFRP) with joints.

FIG. 6 is a perspective view showing a conventional FRP pipe structure. In the figure, (1) is the pipe structure, and (2) is the FR
Pipe member made of P, (3) is an aluminum fitting, (
3a) is the pipe insertion port.

The above pipe structure (1) has pipe insertion ports (3a
) is assembled by inserting it into the pipe insertion port (3a) of the aluminum joint (3) and gluing and joining.

In the pipe structure described above, the tensile force, compressive force, and bending moment acting on the pipe member (2) are transmitted to the other pipe member (2) through the joint (3).

[Problem to be solved by the invention]

However, in the conventional pipe structure as mentioned above,
The CFRP constituting the pipe member (2) has a specific gravity of 1.4~
It is small at 1.5, has a high specific rigidity, can be oriented according to the load direction, and can be lightweight, but since the joint (3) is made of aluminum, its specific gravity is high at 2.7, and its specific strength and specific rigidity are It is low and heavy, which leads to an increase in weight when launched from the ground. Also, the coefficient of thermal expansion of aluminum is 26
X 10-”C, CFRP pipe member O~
There is a large difference from 2X10-"C, and deformation occurs due to a mismatch in the coefficient of thermal expansion due to temperature fluctuations, making it impossible to satisfy the high precision dimensional stability of space equipment. Furthermore, the pipe member (2) and the joint (3) ) is a method of joining different materials, and has problems such as uneven adhesion, damage due to moisture absorption, etc., and low quality reliability, making it unsuitable for large-scale structures.

This invention was made in order to solve the above-mentioned problems with the prior art.Each part is made of the same material to ensure a uniform coefficient of thermal expansion and to prevent deformation due to temperature fluctuations. Another object of the present invention is to obtain a fiber-reinforced composite pipe structure that is lightweight and capable of continuous force transmission, and a simple manufacturing method thereof.

[Means for Solving the Problems] The present invention provides the following fiber-reinforced composite pipe structure and its manufacturing method.

(1) A pipe structure in which the end portions of a plurality of pipe members made of fiber-reinforced composite materials are joined at a joint, wherein the pipe member has continuous fibers oriented in a cross direction of ±30° to ±60°. The inner layer pipe is made of reinforced composite material and is arranged in the axial direction around the outer circumference of this inner layer pipe.

and an intermediate layer consisting of a long rod made of continuous unidirectional fiber-reinforced composite material, the end of which protrudes beyond the end of the inner layer pipe, and an intermediate layer oriented in the cross direction of ±30° to ±60° around the outer periphery of this intermediate layer. It consists of an outer pipe made of continuous fiber-reinforced composite material and a matrix material that integrates them.

The joint part includes a joint core in which a plurality of sets of short rods made of continuous unidirectional fiber-reinforced composite are radially intersected so as to face the inner layer pipe of the pipe member, and an outer peripheral part of the joint core. An end portion of the elongated rod of the intermediate layer is incorporated to cover the intermediate layer.

A fiber-reinforced composite pipe structure consisting of a matrix material that joins and integrates these.

(2) A process of radially incorporating short rods made of continuous unidirectional fiber reinforced composite material to form a bonded core, and
a step of making an inner layer pipe made of a continuous fiber reinforced composite material oriented in the intersecting direction of 30° to ±60″ to face the outer peripheral portion of the short loft in the radial direction of the joining core;

A long rod made of continuous unidirectional fiber-reinforced composite material is arranged in the axial direction of the outer periphery of the short rod and the inner layer pipe, and the end portion thereof is incorporated into the outer periphery of the joint core to form an intermediate layer,
The process of integrating with matrix material and continuous unidirectional fibers on the outer periphery of this intermediate layer ±30° to ±6
A process of forming an outer layer pipe made of continuous fiber reinforced composite material by winding it in the 0° cross direction, and joining the joint core of the preform thus formed and the end portion of the long rod with a matrix material. A method for manufacturing a fiber-reinforced composite pipe structure comprising a step of integrating to form a joint.

[For production]

The fiber-reinforced composite pipe structure of this invention is:

Short rods made of continuous unidirectional fiber-reinforced composite were incorporated radially to form the bonded core, while pre-aligned between ±30° and ±
An inner layer pipe made of continuous fiber-reinforced composite material oriented in the intersecting direction of 60' is opposed to the outer periphery of the short rod in the radial direction of the joining core, and the inner layer pipe is oriented in the axial direction of the outer periphery of the short rod and the inner layer pipe. A long rod made of continuous unidirectional fiber-reinforced composite material is arranged and its terminal end is incorporated into the outer periphery of the joint core to form an intermediate layer, and continuous unidirectional fibers are attached to the outer periphery of this intermediate layer by ±30''. ~ ±60'' is oriented and wound in the cross direction to form an outer layer pipe made of unidirectional continuous fiber reinforced composite material, and the joint core of the preform thus formed and the end portion of the long rod are connected to the matrix. It is manufactured by joining and integrating the materials to form a joint.

The fiber-reinforced composite pipe structure manufactured in this way is
A long rod made of continuous unidirectional fiber-reinforced composite material is included as a strength member throughout the joint and the entire length of the pipe member, and the tensile force, compressive force, and bending moment acting on the pipe member are continuously transferred to other pipe members through the joint. Since the entire structure 2 is made of the same composite material, no internal stress is generated due to temperature fluctuations, and it has excellent dimensional stability and is lightweight.

〔Example〕

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

Figure 1 is a perspective view of the FRP pipe structure of the example, Figure 2
The figure is a front view with a part of the pipe member cut away, Figure 3 is a sectional view taken along line BB, Figure 4 is a sectional view taken along line A-A in Figure 1, and Figure 5 is a perspective view showing the intersection of rods. The same reference numerals as in FIG. 6 indicate the same or corresponding parts.

The pipe structure (1) includes a plurality of CFRP pipe members (
2) are arranged in a radial direction from the joint part (4) and combined to form a truss-like structure.

As shown in FIGS. 2 and 3, the pipe member (2) is
A perforated or cross-shaped CFRP inner layer pipe (6) as a continuous fiber reinforced composite material in which continuous fibers (5) are oriented in the cross direction of ±30° to ±60°, and this inner layer pipe (6). It is arranged in the axial direction on the outer periphery and its terminal part (
7a) is a long rod made of CFRP as a continuous unidirectional fiber-reinforced composite material that protrudes beyond the end of the inner layer pipe (6).
7), and a continuous fiber reinforced composite material made of CFRP in which continuous fibers (5) are oriented in the cross direction of ±30° to ±60′ around the outer periphery of the intermediate layer (8). The outer layer pipe (9) is joined and integrated by a resin layer (10) as a matrix material that integrates these.

A CFRP anti-fray material (12) oriented in a 90° direction is wrapped around the end portion of the outer layer pipe (9).

As shown in FIGS. 4 and 5, the joint (4) includes a plurality of short rods (15) made of CFRP as a continuous unidirectional fiber-reinforced composite material connected to the inner layer pipe (6) of the pipe member (2). ), and the long rod (7) of the intermediate layer (8) is incorporated to cover the outer periphery of the joining core (16) and the joining core (16) is installed so as to face the joining core (16). The terminal portion (7a) is joined and integrated by a resin layer (17) as a matrix material that joins and integrates these.

The method for manufacturing the above pipe structure (1) begins with a diameter of 0.
Short rods (15) made of CFRP with a diameter of 5 to 2 mm are incorporated radially to form a joining core (16). On the other hand, by filament winding, the angle of ±30° to ±6
A CFRP inner layer pipe (6) formed by orienting continuous fibers (5) in the cross direction of 0'' is opposed to the outer periphery of the short rod (15) in the radial direction of the joining core (16).

Then, a long rod (7) made of CFRP with a diameter of 0.5 to 2 mm is inserted from the joining core (16) on one side in the axial direction of the outer periphery of the short rod (15) and the inner pipe (6). The end portion (7a) is inserted into the outer periphery of the joining core (16) on the opposite side so as to intersect with the other long rod (7) and the short rod (15) to form the intermediate layer (8). ) to form. An outer layer pipe (9) made of CFRP is formed by winding continuous fibers (5) impregnated with resin around the outer periphery of the intermediate layer (8), oriented in a cross direction of ±30° to ±60°, The impregnated resin is cured.

At this time, the impregnated resin is applied to the intermediate layer (8) and the inner layer pipe (6).
) and hardens to form a resin layer (10). 'The whole or part of the preform body thus formed is immersed in a resin diluted with a solvent, and then hardened to form a resin layer (17), which forms a bonding core (16) and a long rod (7). ) and the resin layer (17).
to form a joint (4) and pipe structure (1).
The pipe structure (1) manufactured by manufacturing the joint part (4)
A long rod (7) made of CFRP with continuous unidirectional fibers oriented over the entire length of the pipe member (2) is included as a strength member, and the tensile force, compressive force, and bending moment acting on the pipe member (2) are It is continuously transmitted to other pipe members (2) through the section (4), and since the entire structure is made of the same composite material, no internal stress is generated due to temperature fluctuations, and it has excellent dimensional stability and is lightweight. has been achieved.

In the above examples, carbon fibers were used as continuous fibers, but aramid fibers, glass fibers, silica fibers, alumina fibers, boron fibers, etc. may also be used, and resins were used as matrix materials, but when used for heat resistance. may be a metal such as aluminum or magnesium, and the same effects as in the above embodiments can be achieved.

Furthermore, the present invention can be applied not only to space materials, but also to structures that require high precision dimensional stability and ultra-light weight.As described above, according to the present invention, joints made of different materials can be The rods made of continuous unidirectional fiber-reinforced composite material are oriented in a pipe shape throughout the pipe member and the joint, and the joint core is also the same short rod and is incorporated in the axial direction to form a cross-contact area. Fix the inner and outer layers of the pipe to ±30° to ±60°.
The tensile force, compressive force, and bending moment acting on the pipe member are transmitted continuously, and the pipe can be oriented optimally in the direction of the force, resulting in unprecedented weight reduction, dimensional stability against temperature fluctuations, and It is advantageous in that it has an integrated structure and can be manufactured at low cost.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the FRP pipe structure of the example.
The figure is a front view with a part of the pipe member cut away, FIG. 3 is a sectional view taken along line B-B, FIG.
The figure is a perspective view showing the intersection of rods. FIG. 6 is a perspective view of a conventional pipe structure. (1): Pipe structure, (2): Pipe member, (4):
Joint, (5): Continuous fiber, (6): Inner layer pipe, (7
): Long rod, '(7a): Terminal part, (8): Intermediate layer, (9): Outer layer pipe, (10), (17): Resin layer, (12): Anti-stick material, (15 ): Short rod, (16): Joint core. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A pipe structure in which the end portions of a plurality of pipe members made of fiber-reinforced composite materials are joined at a joint, wherein the pipe member has continuous fibers oriented in a cross direction of ±30° to ±60°. Consists of an inner layer pipe made of reinforced composite material and a long rod made of continuous unidirectional fiber-reinforced composite material that is arranged in the axial direction on the outer circumference of this inner layer pipe and whose terminal end protrudes beyond the end of the inner layer pipe. ±3 between the intermediate layer and the outer periphery of this intermediate layer
It consists of an outer layer pipe made of continuous fiber-reinforced composite material oriented in the cross direction of 0° to ±60°, and a matrix material that integrates these, and the joint part is made of a plurality of sets of continuous unidirectional fiber-reinforced composite material. a joining core in which short rods made of aluminum are incorporated radially intersecting so as to face the inner layer pipe of the pipe member, and an end of the long rod of the intermediate layer is incorporated so as to cover the outer periphery of the joining core. 1. A fiber-reinforced composite pipe structure characterized by comprising: a fiber-reinforced composite material, and a matrix material that joins and integrates these parts. (2) A process of radially incorporating short rods made of continuous unidirectional fiber reinforced composite material to form a bonded core, and
a step of making an inner layer pipe made of a continuous fiber reinforced composite material oriented in a cross direction of 30° to ±60° to face an outer circumferential portion of the short rod in the radial direction of the joining core; and the short rod and the inner layer pipe. A long rod made of a continuous unidirectional fiber-reinforced composite material is arranged in the axial direction of the outer periphery of the joint core, and the end portion thereof is incorporated into the outer periphery of the bonded core to form an intermediate layer,
The process of integrating with the matrix material and the continuous unidirectional fibers on the outer periphery of this intermediate layer ±30° to ±6
A process of forming an outer layer pipe made of continuous fiber reinforced composite material by winding it in the 0° cross direction, and joining the joint core of the preform thus formed and the end portion of the long rod with a matrix material. 1. A method for manufacturing a fiber-reinforced composite pipe structure, comprising a step of integrating the pipe structures to form a joint.