Patent Application
20110287213
This disclosure relates to a process and an apparatus for producing a reinforcing-fiber strip substrate having a circular-arc part curved along a longitudinal direction of the substrate, a layered structure formed using the reinforcing-fiber strip substrate, a preform formed using the layered structure, and a fiber-reinforced resin composite material molded using the preform.
A fiber-reinforced resin composite material is broadly known as a material light in weight and high in strength and rigidity. In cases where a relatively long fiber-reinforced resin composite material is molded, to ensure high strength and rigidity in target directions, a configuration of a layered structure is frequently employed wherein a plurality of reinforcing-fiber strip substrates, in which the orientation directions of reinforcing fibers are set in respective predetermined directions, are stacked. Although there is a case where a layered structure having a configuration of a prepreg impregnated with a non-cured resin into reinforcing fibers is employed, in consideration of easiness for production to a target shape, usually a process is employed wherein a dry reinforcing-fiber layered structure, into which a resin has not been impregnated, is made, the reinforcing-fiber layered structure is formed into a preform having a predetermined shape, a matrix resin is impregnated into the formed preform, and the resin is cured to produce a fiber-reinforced resin composite material having a target shape.
Recently, for example, for a structural member of a body of an airplane, etc., a relatively long fiber-reinforced resin composite material light in weight and high in strength and rigidity has been required. Namely, it has been required to make a long reinforcing material or structural member for an airplane from a fiber-reinforced resin composite material aiming to realize a further light weight. Such a member for an airplane frequently has a cross-sectional shape, for example, such as L, T, I, C, or Z shape, and it is a rare case that the member is straight in the longitudinal direction, and in most cases, the member has a circular-arc part curved along the longitudinal direction at least at a part in the longitudinal direction. As a technology for making a long member of fiber-reinforced resin composite material having such a circular-arc part, for example, WO 2004/016844 discloses a process wherein a flat preform precursor formed from reinforcing fibers and having a circular-arc shape is prepared, and this is bent in the cross-sectional direction along the curved line of the circular-arc shape. In that disclosed process, it is described that the strain caused in the material is decreased as compared with the case of a material prepared by bending an assembly of straight strip-like reinforcing-fiber materials in the cross-sectional direction and by bending it in the longitudinal direction to form a circular-arc shape, and a high-quality composite material less in defect such as wrinkle and waving can be obtained. In that publication, however, it is not shown how the reinforcing-fiber strip substrate curved into a predetermined circular-arc shape is made and, further, how the reinforcing-fiber layered structure stacked with substrates is made.
On the other hand, as a circular-arc reinforcing-fiber layered structure, one is required wherein a plurality of layers each disposed with reinforcing fiber yarns in a plane form at a predetermined angle relative to an axial line extending in a circumferential direction of the circular arc are stacked so that the angles of the respective layers are changed to each other. As a process for making respective curved reinforcing-fiber substrates in such a reinforcing-fiber layered structure, although a process is known for disposing reinforcing-fiber tapes each having a small width at a condition adjacent to each other while maintaining them at a predetermined angle, to dispose the small-width reinforcing-fiber tapes while maintaining them at the predetermined angle relative to the axial line curved in a form of a circular-arc shape, it is necessary to dispose the respective small-width reinforcing-fiber tapes while gradually changing the arrangement directions of the reinforcing-fiber yarns of the small-width reinforcing-fiber tapes, and because a high-accuracy positioning control is required, the cost for apparatus becomes high and, besides, the productivity is poor.
On the other hand, as a process for making a curved reinforcing-fiber substrate in which the arrangement directions of the reinforcing-fiber yarns are set at predetermined directions, a process disclosed in JP-A-2004-218133 is known. In that process, the reinforcing-fiber yarns are fixed by pins, and the arrangement directions of the reinforcing-fiber yarns are curved by changing the mutual positions of the pins. In that process, however, because the tangent lines connecting surfaces of the pins become directions of the reinforcing-fiber yarns, the reinforcing-fiber yarns are disposed at a zigzag form, the adjacent reinforcing-fiber yarns strictly do not become in parallel to each other and, in addition, the fibers extend in a longitudinal form relative to a pin at a position near a turning end portion. To reduce these, required are a thin giber bundle and a small pitch between pins, but if so, the productivity is drastically decreased. Further, that process basically relates a technology for bending a reinforcing-fiber layered structure in lump sum which is formed by stacking a plurality of reinforcing-fiber layers, different from each other in directions of reinforcing fibers of respective layers, at a multi-layer form. In the technology for bending in lump sum, since the layered structure is deformed uniformly as a whole though essentially respective proper deformation forms for respective layers, whose directions of reinforcing fibers are different from each other, are necessary, wrinkles or sags of fibers partially occur.
Paying attention to the limit in the above-described conventional technologies, it could be helpful to provide a process and an apparatus of production which can easily and securely obtain a reinforcing-fiber strip substrate having a circular-arc part in that reinforcing-fiber yarns are arranged over substantially the entire surface of a curved substrate at a desired form.
Further, it could be helpful to provide a reinforcing-fiber layered structure formed using the reinforcing-fiber strip substrate which is produced by such a process, a preform formed using the layered structure, and a fiber-reinforced resin composite material molded using the preform.
We provide a process for producing a reinforcing-fiber strip substrate having a circular-arc part characterized in that one surface of a strip-shaped, unidirectional reinforcing-fiber substrate formed by arranging a plurality of reinforcing-fiber strands in one direction in parallel with each other is brought into contact with a flexible member, the unidirectional reinforcing-fiber substrate being contacted is deformed into a circular-arc shape by deforming at least a part of the flexible member into a circular-arc shape in a direction extending along its contact surface with the unidirectional reinforcing-fiber substrate, and thereafter, the flexible member is separated from the unidirectional reinforcing-fiber substrate having been deformed.
In such a process, in particular a flexible member capable of being curved is used, and a strip-shaped, unidirectional reinforcing-fiber substrate being brought into contact with the flexible member is deformed into a circular-arc shape together with deformation to be curved of the flexible member. Since the flexible member comprising a flexible material can be deformed to be curved uniformly over the whole of the surface of a portion to be deformed to be curved, the unidirectional reinforcing-fiber substrate being contacted with the surface as a contact surface can also be deformed to be curved uniformly into a circular-arc shape over the whole of the contact surface, the respective reinforcing-fiber yarns themselves are moved to desired positions, and a reinforcing-fiber strip substrate having a circular-arc part with a desired target form can be obtained.
In the above-described process for producing a reinforcing-fiber strip substrate, a process may be employed wherein a member, formed by a plurality of elongated small pieces capable of being varied with mutual positions which are disposed adjacent to each other, is used as the above-described flexible member, and at a condition where a longitudinal direction of the small pieces and an extending direction of the reinforcing-fiber strands coincide with each other, the above-described one surface of the unidirectional reinforcing-fiber substrate is brought into contact with the flexible member. In such a configuration, because the respective small pieces can be deformed more finely and more adequately, even as the whole of the flexible member arranged with those small pieces adjacent to each other, the respective parts can be deformed more adequately, and the unidirectional reinforcing-fiber strip substrate being contacted with the flexible member can also be deformed more adequately into desired shapes at respective parts.
Further, in the above-described process for producing a reinforcing-fiber strip substrate, it is possible to employ a process wherein the unidirectional reinforcing-fiber substrate is heated at a condition where the substrate is deformed into the circular-arc shape, and thereafter, by cooling the substrate, the circular-arc shape of the substrate is fixed. Thus, by fixing the circular-arc part of the reinforcing-fiber strip substrate to a predetermined shape, even when the reinforcing-fiber strip substrates are stacked to form a layered structure, it may become possible to handle them easily while maintaining the predetermined shapes thereof.
Further, the process for producing a reinforcing-fiber strip substrate can be applied to a substrate in which reinforcing-fiber strands are arranged in various directions. In a case where a plurality of reinforcing-fiber strip substrates are stacked to form a layered structure, because usually substrates whose reinforcing-fiber strands are arranged in various directions are stacked as reinforcing-fiber layers, if the respective reinforcing-fiber substrates are curved in desired shapes and the reinforcing-fiber strands thereof are arranged in desired directions, desired shape and reinforcing fiber arrangement form can be realized as the whole of the reinforcing-fiber layered structure. For example, in a case where a unidirectional reinforcing-fiber substrate arranged with the reinforcing-fiber strands at an angle of 30 degrees or more and 90 degrees or less relative to a longitudinal direction of the substrate is used, when the above-described flexible member is deformed into the circular-arc shape, an interval between the reinforcing-fiber strands can be changed by contracting an inner-radius side of the circular-arc shape in a circumferential direction and/or expanding an outer-radius side of the circular-arc shape in a circumferential direction. In such a process, it becomes possible to realize a formation in which the reinforcing-fiber strands are adequately distributed over the entire surface of the reinforcing-fiber strip substrate to be formed into a curved shape.
In this process, for example, it is preferred to employ a manner wherein, using a unidirectional reinforcing-fiber substrate formed by connecting the reinforcing-fiber strands to each other by auxiliary yarns extending in a direction across the reinforcing-fiber strands in which a gap between the reinforcing-fiber strands satisfies the following equation, when the flexible member is deformed into the circular-arc shape, the interval between the reinforcing-fiber strands is contracted by contracting an inner-radius side of the circular-arc shape in a circumferential direction:
d/W1≧W2/r1
wherein:
Further, in a case where a unidirectional reinforcing-fiber substrate arranged with reinforcing-fiber strands in a longitudinal direction of the substrate in parallel with each other is used, when the flexible member is deformed into the circular-arc shape, the flexible member can be deformed so that the reinforcing-fiber strands mutually move in their longitudinal directions at a condition of parallel displacement (namely, so that the reinforcing-fiber strands mutually shift from each other in the longitudinal direction). In such a manner, it becomes possible to curve the respective reinforcing-fiber strands, extending in the longitudinal direction, into desired circular-arc shapes, and to prevent undesired local deformation or local stress from being left between the reinforcing-fiber strands.
Further, in the process for producing a reinforcing-fiber strip substrate, a process may be employed wherein, when the flexible member is deformed into the circular-arc shape, a support plate having a flat surface is disposed at a side of the unidirectional reinforcing-fiber substrate, opposite to a side disposed with the flexible member, and the unidirectional reinforcing-fiber substrate is nipped by the flexible member and the support plate. In this case, because the support plate is not deformed to be curved, when the flexible member is deformed into the circular-arc shape, a relative sliding occurs between the support plate and the unidirectional reinforcing-fiber substrate which is deformed into the circular-arc shape together with the deformation of the flexible member. Therefore, the sliding resistance is preferably to be made small so that the curved form of the unidirectional reinforcing-fiber substrate does not collapse.
As such a support plate, for example, an electrostatic attractor plate capable of attracting an object material by a static electricity can be used.
We also provide a reinforcing-fiber layered structure having a circular-arc part wherein a plurality of kinds of reinforcing-fiber strip substrates, each having a circular-arc part, whose directions of reinforcing-fiber strands are different from each other, and which are obtained by the above-described process, are layered. Since the stacked respective reinforcing-fiber strip substrates are formed as desired curved forms, respectively, also as the whole of the layered structure, a reinforcing-fiber layered structure having a desired formation can be realized wherein the reinforcing fibers of the respective reinforcing-fiber layers are adequately arranged in desired directions.
Further, we provide a preform formed by putting a reinforcing-fiber layered structure thus formed along a stereo-shaped mold having a circular-arc part in a longitudinal direction. Since the reinforcing-fiber layered structure is formed in a desired formation, the preform formed by putting it along a mold with a predetermined shape can also be easily formed in a desired formation.
Furthermore, we provide a fiber-reinforced resin composite material produced by impregnating a matrix resin into a preform thus formed and curing the matrix resin having been impregnated. Since the preform is formed in a desired formation, the fiber-reinforced resin composite material produced by impregnating a resin thereinto and curing the resin can also be easily made in a desired target formation.
An apparatus for producing a reinforcing-fiber strip substrate having a circular-arc part is characterized in that the apparatus is for deforming at least a part of a strip-shaped, unidirectional reinforcing-fiber substrate, formed by arranging a plurality of reinforcing-fiber strands in one direction in parallel with each other, into a circular-arc shape, and the apparatus comprises a flexible member having a flat contact surface with the unidirectional reinforcing-fiber substrate in which the contact surface can be bent from a straight state in a longitudinal direction into a circular-arc shape in a direction along the contact surface, a straightening means for straightening the flexible member in the longitudinal direction, and a circular-arc shape achieving means for making the flexible member in a state of the circular-arc shape.
In such an apparatus for producing a reinforcing-fiber strip substrate, the unidirectional reinforcing-fiber substrate disposed on the flexible member is deformed into a circular-arc shape together with deformation of the flexible member. The flexible member is made at a straight state in the longitudinal direction by the straightening means, it is made at a state of a target circular-arc shape by the circular-arc shape achieving means when the above-described unidirectional reinforcing-fiber substrate is curved and deformed and, after the curve deformation of the unidirectional reinforcing-fiber substrate, it is again made at a straight state in the longitudinal direction by the straightening means in preparation for the next curve deformation. Therefore, by this apparatus, it is possible to produce a plurality of curved reinforcing-fiber strip substrates in order. In a case where a different circular-arc shape is formed, the shape of the circular-arc shape achieving means may be changed. By the apparatus having such a structure, desired curved reinforcing-fiber strip substrates are produced one after another efficiently in a short period of time.
In the above-described apparatus for producing a reinforcing-fiber strip substrate, the above-described flexible member can comprise, for example, a plurality of elongated small pieces capable of being varied with mutual positions which are disposed adjacent to each other. In such a structure, as aforementioned, because the respective small pieces can be deformed more finely and more adequately, the whole of the flexible member arranged with those small pieces adjacent to each other can also be desirably deformed more adequately and, using the flexible member, a reinforcing-fiber strip substrate having a desired circular-arc part can be produced.
Further, in the above-described apparatus for producing a reinforcing-fiber strip substrate, a structure may be employed wherein the above-described contact surface of the flexible member is formed by arranging a plurality of elongated small pieces extending in a direction across a longitudinal direction of the contact surface in parallel with each other along the longitudinal direction of the contact surface, longitudinal directions of respective small pieces are set at contact surface, and respective small pieces are provided to be able to be rotated relative to each other or to be able to be rotated relative to each other and moved relative to each other in the longitudinal directions of small pieces. Such a structure is suitable for a substrate in which the arrangement directions of the reinforcing-fiber strands are set at angles of 30 degrees or more and 90 degrees or less relative to the longitudinal direction of the substrate and, in this structure, when the flexible member is made to a circular-arc state by the circular-arc shape achieving means, since the respective small pieces having been arranged at predetermined angles relative to the longitudinal direction can rotate adequately or can move relative to each other in the longitudinal directions of small pieces together with rotation, the respective small pieces can be directed in respective optimum directions under a condition where the flexible member is curved, and along the directions of the respective small pieces, the reinforcing-fiber strands located at the respective parts of the reinforcing-fiber strip substrate disposed at a position corresponding to the small pieces can also be directed in respective optimum directions. As a result, a formation can be easily realized wherein the reinforcing-fiber strands located at the respective parts of the reinforcing-fiber strip substrate formed to be curved are gradually changed with angle along the circumferential direction of the curved shape and, therefore, a desirable arrangement formation of the reinforcing-fiber strands, which has been difficult to be obtained by a conventional apparatus, can be obtained.
Further, in the above-described structure, various formations can be employed as the flexible member and the structure therearound. For example, a formation can be employed wherein the above-described flexible member comprises a deformable member capable of being recovered to a straightened shape from a shape bent into a circular-arc shape, and the above-described small pieces connected thereto. In this formation, a structure may be employed wherein the small pieces are connected to the deformable member at a condition with a constant positional relationship (at a condition where the relative positional relationship is fixed at a substantially constant positional relationship). Alternatively, a structure may also be employed wherein the small pieces are connected to the deformable member at a condition free to rotate. Furthermore, a structure may also be employed wherein a small piece pitch regulating means is provided for regulating a pitch between adjacent small pieces to a predetermined value at an appropriate position in a longitudinal direction of small piece at a state where the flexible member is bent into a circular-arc shape. The regulation of the pitch of small pieces can be performed at an arbitrary position of each small piece and, for example, it is possible to regulate the pitch at the tip side of the small piece or to regulate the pitch at an intermediate position in the longitudinal direction of each small piece.
Further, a structure may be employed wherein the contact surface of the flexible member is formed by arranging a plurality of elongated small pieces extending in a direction along a longitudinal direction of the contact surface in parallel with each other along a direction across the longitudinal direction of the contact surface, and respective small pieces are constituted to be able to be deformed into a circular-arc shape in a direction along the contact surface and are provided so that small pieces adjacent to each other can mutually move in their longitudinal directions at a condition of parallel displacement when deformed into the circular-arc shape. Such a structure is suitable for a case where the arrangement directions of the reinforcing-fiber strands are set at directions along the longitudinal direction of the substrate and, in this structure, when the flexible member is made to a circular-arc state by the circular-arc shape achieving means, since the small pieces adjacent to each other are moved relative to each other in their longitudinal directions at a condition of parallel displacement, the respective small pieces can be curved in respective optimum shapes, and along the curved shapes of the respective small pieces, the reinforcing-fiber strands located at the respective parts of the reinforcing-fiber strip substrate disposed at a position corresponding to the small pieces can also be curved in respective optimum shapes. As a result, a formation can be easily realized wherein the reinforcing-fiber strands of the reinforcing-fiber strip substrate formed to be curved are curved in desirable forms along the circumferential direction of the curved shape, respectively, and therefore, a desirable arrangement formation of the reinforcing-fiber strands of the curved substrate, which has been difficult to be obtained by a conventional apparatus, can be obtained.
Further, in the apparatus for producing a reinforcing-fiber strip substrate, a structure may be employed wherein a support plate is provided which is disposed at a side of the unidirectional reinforcing-fiber substrate, opposite to a side disposed with the flexible member, and which has a flat contact surface capable of being brought into contact with the unidirectional reinforcing-fiber substrate always during a time when the flat contact surface of the flexible member is deformed from the straight state in the longitudinal direction to a state of the circular-arc shape formed by being bent. The unidirectional reinforcing-fiber substrate to be formed to be curved is nipped between the flat contact surface of the flexible member and the flat contact surface of the support plate, and when the substrate is curved, a relative sliding is carried out between the substrate and the flat contact surface of the support plate being contacted therewith. The substrate is curved into a target circular-arc shape at a plan view while being maintained at a flat plate form, and a desired curved substrate can be easily produced. As such a support plate, for example, an electrostatic attractor plate capable of attracting an object material by a static electricity can be used.
Further, a structure may be employed wherein the above-described support plate is provided movably in directions for approaching to and retreating from the contact surface of the flexible member in a direction perpendicular to the contact surface, and movably in a direction parallel to the contact surface, and whereby, in the process for making the curved substrate and in the process for making the reinforcing-fiber layered structure stacked with the curved substrates, the support plate can be moved as needed.
In the process and the apparatus for producing a reinforcing-fiber strip substrate having a circular-arc part, by using a flexible member capable of being curved into a desired shape and curving a unidirectional reinforcing-fiber substrate together with the flexible member, a curved reinforcing-fiber strip substrate having a desirable form can be produced efficiently.
Further, in the reinforcing-fiber layered structure, by being stacked with the above-described curved reinforcing-fiber strip substrates each having a desirable form by a predetermined number, a desired form can be configured as the whole of the layered structure.
Further, in the preform, since the above-described reinforcing-fiber layered structure formed at a desired configuration is formed along a mold having a predetermined shape to make the preform, even in the formation of the preform, a desired arrangement formation of the reinforcing-fiber strands in the curved shape can be maintained.
Furthermore, in the fiber-reinforced resin composite material, since a resin is impregnated into the above-described preform formed in a desired shape and the resin is cured, the fiber-reinforced resin composite material, which is a final molded material, also becomes a composite material capable of realizing desirable properties in which reinforcing-fiber strands are arranged at a desired formation.
Hereinafter, desirable examples will be explained referring to figures.
In
The operation of this apparatus for production will be explained referring to
As shown in
In the above-described deformation into the circular-arc shape of flexible member 12, if a configuration such as one shown in
As the material of small pieces 21 shown in
Although the above-described explanation has been carried out with respect to a case of unidirectional reinforcing-fiber strip substrate 2 in which reinforcing-fiber strands 1 are arranged in parallel to each other in one direction of the substrate longitudinal direction X-X, it can also be applied to a substrate in which the reinforcing-fiber strands are arranged in another direction, for example, the reinforcing-fiber strands are arranged at an angle of 30 degrees or more and 90 degrees or less relative to the longitudinal direction of a substrate. For example, as shown in
For the above described unidirectional reinforcing-fiber strip substrate arranged with the reinforcing-fiber strands at an angle of 90 degrees, for example, the following flexible member can be used. For example, as shown in
Such a relative positional relationship between small pieces 42 and plate spring 43 connecting them can also be set to be shown in
Further, other examples for cases each where the reinforcing-fiber strands are arranged at an angle in a range of 30 degrees or more and 90 degrees or less relative to the longitudinal direction of the substrate will be shown. For example, in
For such a unidirectional reinforcing-fiber strip substrate prepared by arranging reinforcing-fiber strands at an angle of 45 degrees relative to the longitudinal direction X-X of the substrate, to deform it to be curved, for example, a flexible member as shown in
Further, in the above-described case using a unidirectional substrate in which the reinforcing-fiber strands are connected to each other by an auxiliary yarn extending in a direction across them and the reinforcing-fiber strands are arranged at an angle of 30 degrees or more and 90 degrees or less relative to the longitudinal direction of the substrate, it is preferred to provide room to the auxiliary yarn so that the gap between the reinforcing-fiber strands at a state before curving satisfies the following equation and to contract the interval between the reinforcing-fiber strands at the time of curving by contracting the inner-radius side of the circular-arc shape. In such a configuration, can be avoided problems in that the deformation of the reinforcing-fiber substrate is damaged by bridging of the auxiliary yarn caused by receiving a tension at the time of curving and in that the reinforcing-fiber strands come into contact with each other at the inner-radius side of the circular arc because of lack in gap between reinforcing-fiber strands and the deformation of contraction cannot progress, and therefore, a more uniform distribution of the reinforcing-fiber strands can be achieved, and as described later, a pretreatment such as cutting of auxiliary yarn becomes unnecessary.
d/W1W2/r1
The meaning of the respective signs are as follows as shown in
The material of the flexible member is not particularly limited, as long as it is a material capable of being deformed into the above-described curved state, and further, being recovered into a straight state, and as aforementioned, a soft material such as a rubber or an elastomer or a hard material such as a metal or a resin can be used solely or as combination. As its shape, a plate-like or prismatic shape can be applied. As the entire shape, except the configuration having divided small pieces as shown in
Further, the contact surface of the flexible member with the unidirectional reinforcing-fiber substrate is preferably high in friction with the reinforcing-fiber substrate. Concretely, configurations can be employed for the contact surface such as a low-hardness rubber, a material having fine projections such as a sand paper for example, a metal plate sprayed with a ceramic, or various materials whose surfaces are roughened mechanically. Further, in such means for increasing the coefficient of friction, it is not necessary to apply it over the entire contact surface, it may be applied to some of small pieces forming the flexible member selectively, or may be applied to a part of each small piece, and further, a method for nipping a thin wire netting, which is slightly higher than the height of the small piece, between the small pieces, is also preferred, because the reinforcing-fiber substrate can be caught effectively and a shift of the substrate at the time of curving can be prevented.
Further, as the material of reinforcing fibers, although carbon fibers, glass fibers, aramide fibers and the like can be exemplified, in particular, carbon fibers are preferred because of high mechanical properties when made finally into a fiber-reinforced resin composite material, and in a case where an electrostatic attractor plate is used as means for separating and conveying the support plate and/or the curved reinforcing-fiber substrate from the flexible member, particularly carbon fibers are preferably employed because carbon fibers have a conductivity and a high attraction force can be obtained by the static electricity.
Further, with respect to the configuration of the unidirectional reinforcing-fiber substrate as a target of deformation into a curved shape, except the substrate in which the reinforcing-fiber strands are bound by auxiliary yarns as described above, a substrate may be employed wherein the reinforcing-fiber strands are merely arranged over the whole of the substrate. Further, with the substrate using auxiliary yarns, it is also possible to facilitate its deformation into a curved shape by cutting the auxiliary yarns partially or over the whole thereof.
Further, as aforementioned, at an initial condition of a flexible member, a configuration can be employed wherein the respective small pieces are connected to the plate spring as a deformable member at a condition with a constant positional relationship, and a configuration can also be employed wherein the respective small pieces are connected to the deformable member at a condition free to rotate. For example, as shown in
Furthermore, to curve the flexible member, in which the respective small pieces are set at an angle of 30 degrees or more and 90 degrees or less, into a predetermined shape more precisely, or to be able to maintain the curved shape to a predetermined shape as needed, a configuration can be employed wherein a small piece pitch regulating means is provided for regulating a pitch between adjacent small pieces to a predetermined value at an appropriate position in a longitudinal direction of small piece at a state where the flexible member is bent into a circular-arc shape. For example, in
A plate-like reinforcing-fiber layered structure, wherein a plurality of curved unidirectional reinforcing-fiber strip substrates described above are stacked, is formed by repeating the operation of separating and conveying the reinforcing-fiber substrate, deformed by the aforementioned flexible member, from the flexible member, and placing it on a table for layering. This operation for separating and conveying the reinforcing-fiber substrate is efficiently carried out by the aforementioned operation of the support plate. In practice, such a reinforcing-fiber layered structure is used as a material for molding into a target fiber-reinforced composite material.
Using the above-described reinforcing-fiber layered structure, a preform having a predetermined configuration is formed. As the shape of the preform, although an arbitrary shape utilizing the above-described curved shape can be employed, in case where long size and high strength and rigidity are required such as a case for a structural member for a body of an airplane, formed is a shape having a flange portion as its cross-sectional shape.
For example, as shown in
A preform 71 shown in
A preform 81 shown in
Using a dry preform formed in a predetermined cross sectional shape as described above, a fiber-reinforced resin composite material having a desired shape is molded by impregnation a matrix resin into the preform and curing the impregnated resin. In this case, a process can also be employed wherein, at the state where the flange portions of the preform are formed, the formed shape of the preform is fixed by heating for a predetermined time, and thereafter, the resin is impregnated. By fixing the formed shape of the preform by heating, the configuration is prevented from being collapsed even at the time of resin impregnation. The molding of a curved fiber-reinforced resin composite material can be carried out, for example, by RTM process (Resin Transfer Molding), and a matrix resin (for example, a thermosetting resin such as an epoxy resin) is impregnated into the preform, the impregnated resin is cured by heating to a predetermined temperature, and a fiber-reinforced resin composite material having a desired shape is produced.
As the process for producing a fiber-reinforced resin composite material having a curved shape, various processes can be employed. For example, a process using a bag material, a process using a double-sided mold or the like can be employed.
Further, in the molding process shown in
Although the explanation has been carried out based on the case of a unidirectional reinforcing-fiber substrate formed by arranging dry reinforcing-fiber strands in parallel to each other hereinabove, the technology is not limited thereto, a so-called “prepreg,” in which a thermosetting resin such as an epoxy resin or a thermoplastic resin such as a nylon is impregnated into reinforcing-fiber strands, may be employed, and a so-called “semipreg,” in which a resin adheres only to the surfaces of reinforcing-fiber strands, may be employed. In this case, the unidirectional reinforcing-fiber substrate is preferably formed such that a flat reinforcing-fiber sheet is formed wherein reinforcing fibers are continuously arranged in a direction across the fibers by a binding force of a resin, and cut lines are provided to the sheet in a direction parallel to the fibers to form respective reinforcing-fiber strands. Concretely, as shown in
Further, similarly, also with respect to a reinforcing-fiber layered structure and a preform formed therefrom along a mold, the original material is not limited to a dry reinforcing-fiber substrate and, even if a prepreg or a semipreg is used, the technical advantages can be exhibited.
We provide for molding of a large-scaled, long-sized curved fiber-reinforced resin composite material, forming of a preform served to the molding, a reinforcing-fiber layered structure served to the forming of the preform, and a reinforcing-fiber substrate served to the preparation of the layered structure and, for example, suitable to be applied to molding of a reinforcing member of a circular body of an airplane.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-021324 | Feb 2009 | JP | national |
This is a §371 of International Application No. PCT/JP2010/051248, with an international filing date of Jan. 29, 2010 (WO 2010/087443 A1, published Aug. 5, 2010), which is based on Japanese Patent Application No. 2009-021324, filed Feb. 2, 2009, the subject matter of which is incorporated by reference.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2010/051248 | 1/29/2010 | WO | 00 | 7/26/2011 |
