JP2019193979A - Frp cylinder and method for producing the same - Google Patents

Abstract

To provide an FRP cylinder in which fracture is hard to be generated by securing its strength, and a method for producing the same.SOLUTION: An FRP cylinder is obtained by winding a plurality of prepregs and thermally curing the same so as to be an FRP layer. The FRP layer includes a co-multilayer wound layer obtained, in a state where a pair of twist rigidity holding prepregs having a fiber layer oblique in a cylindrical axial direction and a buckling prevention prepreg having a fiber layer orthogonal in a cylindrical axial direction are superimposed, by continuously winding a plurality of plys and thermally curing the same, and off-set is performed in such a manner that the winding end positions of the pair of twist rigidity holding prepregs are mutually differentiated.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an FRP cylinder and a manufacturing method thereof.

  Patent Documents 1 and 2 disclose an FRP cylinder in which a plurality of prepregs obtained by impregnating a reinforcing fiber in a thermosetting resin sheet are wound into a cylindrical shape and thermally cured to form a plurality of FRP layers, and a method for manufacturing the same. ing. The plurality of FRP layers include a simultaneous multi-layer winding layer in which a set prepreg formed by stacking a plurality of prepregs is continuously wound a plurality of times and thermally cured.

  In Patent Documents 1 and 2, a set prepreg includes a torsional rigidity holding prepreg (for example, a bias prepreg) having a fiber layer obliquely intersecting in the cylindrical axis direction and a buckling prevention prepreg (for example, 90) having a fiber layer orthogonal to the cylindrical axis direction. ° prepreg). Alternatively, the set prepreg is configured by adding a bending rigidity holding prepreg (for example, 0 ° prepreg) having a fiber layer parallel to the cylindrical axial direction to the torsional rigidity holding prepreg and the buckling prevention prepreg described above.

  In Patent Documents 1 and 2, the winding start positions of the torsional rigidity holding prepreg and the buckling prevention prepreg in the set prepreg are different from each other, and the torsional rigidity holding layer and the buckling prevention layer in the simultaneous multilayer winding layer are offset. . For example, in Patent Document 2, the winding start position of the torsional rigidity holding prepreg and the buckling prevention prepreg in the set prepreg is wound by at least one ply of the buckling prevention prepreg, and then the torsional rigidity holding prepreg and the buckling prevention. The prepregs are offset from each other so that at least two plies are continuously wound in a stacked state.

International Publication No. 2010/084809 JP 2014-172308 A

  However, the FRP cylinders of Patent Documents 1 and 2 and the manufacturing method thereof have room for improvement because the strength of the FRP cylinders is insufficient, and there is a problem that breakage (for example, peeling or torsional fatigue failure) is likely to occur. There is.

  The present invention has been completed based on the above awareness of problems, and an object of the present invention is to provide an FRP cylinder that secures the strength of the FRP cylinder and is less likely to break down, and a method for manufacturing the same.

  The FRP cylinder of the present invention is an FRP cylinder which is made into an FRP layer by winding and thermosetting a plurality of prepregs, and the FRP layer has a pair of torsional rigidity holdings having a fiber layer obliquely intersecting the cylinder axis direction. A plurality of ply prepregs and a buckling-preventing prepreg having a fiber layer perpendicular to the axial direction of the cylinder. The winding ending positions of the prepreg are offset so as to be different from each other.

  The pair of torsional rigidity holding prepregs and the buckling prevention prepreg are successively continued from the inner layer side toward the outer layer side in a state where the pair of torsional rigidity holding prepregs and the buckling prevention prepreg are overlapped. The buckling prevention prepreg may be offset so that at least one ply is wound alone.

  The pair of torsional rigidity retaining prepregs and the buckling prevention prepreg are wound in order from the inner layer side to the outer layer side, and the buckling prevention prepreg is wound alone by at least two plies. It may be offset so that at least two plies are continuously wound in a state where the anti-bending prepreg is overlapped, and at least one ply is wound alone.

  The pair of torsional rigidity holding prepregs may be offset so that the winding start positions are different from each other.

  The pair of torsional rigidity holding prepregs may be composed of a pair of bias prepregs whose long fiber direction obliquely intersects with the cylinder axis direction at ± α ° (0 <α <90). The buckling prevention prepreg may be a 90 ° prepreg whose long fiber direction is orthogonal to the cylindrical axis direction.

  The FRP cylinder manufacturing method of the present invention is a method for manufacturing an FRP cylinder in which a plurality of prepregs are wound and thermally cured to form an FRP layer, and when the plurality of prepregs are wound, Including a simultaneous multi-layer winding process in which a plurality of plies are continuously wound in a state in which a pair of torsional rigidity holding prepregs having oblique fiber layers and a buckling prevention prepreg having fiber layers perpendicular to the cylindrical axial direction are stacked. The winding end positions of the pair of torsional rigidity holding prepregs are offset so as to be different from each other.

  ADVANTAGE OF THE INVENTION According to this invention, the strength of an FRP cylinder can be ensured and the FRP cylinder which is hard to break down, and its manufacturing method can be provided.

It is a perspective view which shows the FRP cylinder by this embodiment. It is a figure which shows an example of a structure of the several prepreg by this embodiment. It is a figure which shows an example of the laminated structure of the several prepreg by this embodiment. It is a figure which expands and shows the winding end position of the several prepreg by this embodiment. It is a conceptual diagram which shows the difference in the peeling location according to the winding end position of an angle layer (bias layer). It is sectional drawing which shows the FRP cylinder by this embodiment.

  FIG. 1 is a perspective view showing an FRP (Fiber Reinforced Plastics) cylinder 1 according to the present embodiment. The FRP cylinder 1 is a FRP layer 10 formed by winding a plurality of prepregs obtained by impregnating reinforcing fibers into a thermosetting resin sheet into a cylindrical shape and thermosetting them. In FIG. 1, the length of the FRP cylinder 1 is L, the outer diameter of the FRP cylinder 1 is Φ, and the inner diameter of the FRP cylinder 1 is φ. The length L of the FRP cylinder 1 can be appropriately set according to the application of the FRP cylinder 1 (for example, a propeller shaft or a drive shaft of a vehicle). The thickness of the FRP cylinder 1 that is the difference (Φ−φ) between the outer diameter Φ and the inner diameter φ can be set as appropriate according to various parameters (type, thickness, number of sheets, number of plies, etc.) of the plurality of prepregs.

  FIG. 2 is a diagram illustrating an example of a configuration of a plurality of prepregs according to the present embodiment. For the convenience of drawing, the thickness of a plurality of prepregs is exaggerated and drawn larger. Strictly speaking, as the FRP cylinder 1 moves from the inner layer side to the outer layer side, the necessary prepreg width gradually increases even with the same number of plies, but this point is ignored.

  The plurality of prepregs constituting the FRP layer 10 of the FRP cylinder 1 have a bending rigidity holding prepreg 20 and a set prepreg 30 in order from the inner layer side to the outer layer side. The set prepreg 30 has a pair of torsional rigidity retaining prepregs 31 and 32 and a buckling prevention prepreg 33 in order from the inner layer side to the outer layer side.

  The bending rigidity maintaining prepreg 20 has a fiber layer that is parallel to the cylindrical axis direction, and is responsible for strength against a force (bending) applied in a direction parallel to the cylindrical axis direction. The bending rigidity maintaining prepreg 20 can be constituted by a 0 ° prepreg in which the long fiber direction is parallel to the cylindrical axis direction. The bending rigidity holding prepreg 20 is set to a width that allows two-ply winding around the outer periphery of the mandrel M. The width of the bending rigidity holding prepreg 20 has a degree of freedom. For example, the bending rigidity holding prepreg 20 can have a width that allows at least two plies to be wound around the outer periphery of the mandrel M.

  The pair of torsional rigidity holding prepregs 31 and 32 have fiber layers that are oblique to the cylindrical axis direction, and are responsible for the strength against the force (torsion) applied in the direction oblique to the cylindrical axis direction. The pair of torsional rigidity holding prepregs 31 and 32 can be constituted by a pair of bias prepregs whose long fiber direction is obliquely crossed by ± α ° (0 <α <90) in the cylindrical axis direction. The oblique angle α can be set to, for example, ± 30 °, ± 45 °, or ± 60 °. However, the specific value has a degree of freedom, and various design changes are possible. The pair of torsional rigidity retaining prepregs 31 and 32 are set to have a width that allows 11 ply to be wound around the outer periphery of the mandrel M. The width of the pair of torsional rigidity holding prepregs 31 and 32 has a degree of freedom. For example, the width can be wound around at least two plies on the outer periphery of the mandrel M.

  The pair of torsional rigidity holding prepregs 31 and 32 are offset so that the winding start position and the winding end position are different from each other. More specifically, of the pair of torsional rigidity holding prepregs 31 and 32, the outer layer side torsional rigidity holding prepreg 32 is started to wind first, and the inner layer side torsional rigidity holding prepreg 31 is started to wind later, and The outer layer side torsional rigidity holding prepreg 32 is finished winding first, and the inner layer side torsional rigidity holding prepreg 31 is finished winding later. Thereby, delamination which advances from the winding end position of the torsional rigidity holding prepregs 31 and 32 can be prevented.

  Of the pair of torsional rigidity holding prepregs 31 and 32, the inner layer side torsional rigidity holding prepreg 31 is started to wind first, the outer layer side torsional rigidity holding prepreg 32 is started to wind later, and the inner layer side torsional rigidity holding prepreg 31 is started to wind. The torsional rigidity holding prepreg 31 may be finished winding first, and the outer layer side torsional rigidity holding prepreg 32 may be finished winding later. In this case, delamination that progresses from the winding end position of the torsional rigidity retaining prepregs 31 and 32 can be prevented.

  There is a degree of freedom in how to set the offset amount between the winding start position and the winding end position of the pair of torsional rigidity holding prepregs 31 and 32, and various design changes are possible. As an example, when the inner diameter φ of the FRP cylinder 1 is 33 mm and the outer diameter Φ is 44 mm, the offset amount can be set to about 30 mm.

The offset amount O (unit: mm) between the winding start position and the winding end position of the pair of torsional rigidity holding prepregs 31, 32 is, for example, in relation to the outer peripheral length R (unit: mm) of the FRP cylinder 1. It is preferable that the conditional expression (1) is satisfied. If the lower limit of conditional expression (1) is not reached, the offset amount O becomes too small, the strength of the FRP cylinder 1 becomes insufficient, and breakage (for example, peeling or torsional fatigue failure) is likely to occur. If the upper limit of conditional expression (1) is exceeded, the offset amount O becomes too large and the strength in the torsion direction becomes insufficient. By satisfying conditional expression (1), it is possible to secure the strength (including the strength in the torsional direction) of the FRP cylinder 1 and to prevent breakage (for example, peeling or torsional fatigue failure). The above effects can be obtained more remarkably, for example, by satisfying the following conditional expression (1 ′) and further conditional expression (1 ″).
(1) 0.1 <O / R <0.5
(1 ′) 0.2 <O / R <0.4
(1 ") 0.25 <O / R <0.35

  Note that the winding start positions may be matched by changing the winding end positions of the pair of torsional rigidity holding prepregs 31 and 32 only from each other. In this case, of the pair of torsional rigidity retaining prepregs 31 and 32, the width of the one that finishes winding first can be made relatively small, and the width that finishes the winding later can be made relatively large.

  The buckling prevention prepreg 33 has a fiber layer orthogonal to the cylindrical axis direction, and is responsible for strength against a force (buckling) applied in a direction orthogonal to the cylindrical axis direction. The buckling prevention prepreg 33 can be composed of a 90 ° prepreg whose long fiber direction is orthogonal to the cylindrical axis direction. The buckling prevention prepreg 33 is set to a width that can be wound around the outer periphery of the mandrel M by 14 plies. The width of the buckling prevention prepreg 33 has a degree of freedom. For example, the buckling prevention prepreg 33 can have a width that allows at least two plies to be wound around the outer periphery of the mandrel M.

  The buckling prevention prepreg 33 is offset so that the winding start position and the winding end position with respect to the pair of torsional rigidity holding prepregs 31 and 32 are different from each other. More specifically, the buckling prevention prepreg 33 protrudes in the winding start direction by two plies from the winding start position of the pair of torsional rigidity holding prepregs 31, 32. Before the start of winding, it is wound alone for two plies. Further, the buckling prevention prepreg 33 protrudes in the winding end direction by one ply from the winding end position of the pair of torsional rigidity holding prepregs 31, 32, and the winding end of the pair of torsional rigidity holding prepregs 31, 32 ends. Later, only one ply is wound. Here, the winding start position and the winding of either of the pair of torsional rigidity holding prepregs 31 and 32 are ignored, ignoring the offset between the winding start position and the winding end position of the pair of torsional rigidity holding prepregs 31 and 32. This is based on the end position.

  Note that the buckling prevention prepreg 33 may match the winding start position and / or the winding end position with respect to the pair of torsional rigidity holding prepregs 31 and 32. In this case, the width of the buckling prevention prepreg 33 can be set substantially the same as the width of the pair of torsional rigidity holding prepregs 31 and 32.

  When manufacturing the FRP cylinder 1, the bending rigidity holding prepreg 20 and the set prepreg 30 (a pair of torsional rigidity holding prepregs 31 and 32 and a buckling prevention prepreg 33) are wound around the mandrel M. FIG. 3 is a view showing an example of a laminated structure of a plurality of prepregs according to the present embodiment. First, the bending rigidity holding prepreg 20 is wound by two plies independently. Next, the set prepreg 30 is wound around the outer periphery of the bending composite holding prepreg. More specifically, the buckling prevention prepreg 33 is wound by two plies independently, and 11 plies are continuously wound in a state where the pair of torsional rigidity holding prepregs 31 and 32 and the buckling prevention prepreg 33 are overlapped (3 × 11 = 33 ply), and buckling prevention prepreg 33 is wound by one ply alone. The total number of turns is 38 plies. The prepreg winding step is preferably performed in a predetermined preheated state in order to bring each prepreg into close contact.

  When the prepreg winding process is completed, the prepreg is cured by being heated by a heating device (for example, an oven or the like) in a state in which the heat shrink tape is wound and an external pressure is applied while applying tension. This heat curing step is preferably performed in a vacuum atmosphere. By this heat curing, the plurality of prepregs wound around the mandrel M are heat cured to become the FRP layer 10. Finally, by pulling out the mandrel M, an inner diameter φ corresponding to the outer diameter of the mandrel M, an outer diameter φ obtained by adding the thickness of the FRP layer 10 to the inner diameter φ, and a length L corresponding to the length of the prepreg. The FRP cylinder 1 is completed (FIG. 1).

  In the manufacturing method of the FRP cylinder 1 described above, when a plurality of prepregs are wound, a plurality of plies (for example, 11 plies) are continued in a state where the pair of torsional rigidity holding prepregs 31 and 32 and the buckling prevention prepreg 33 are overlapped. And a simultaneous multi-layer winding process of winding. Accordingly, the FRP layer 10 of the FRP cylinder 1 is formed by simultaneously winding a plurality of plies (for example, 11 plies) in a state where the pair of torsional rigidity holding prepregs 31 and 32 and the buckling prevention prepreg 33 are overlapped, and simultaneously thermosetting them. It has a multilayer wound layer. Thereby, the FRP cylinder 1 having high strength in the twisting direction and the buckling direction can be obtained. Further, since the amount of reinforcing fibers can be increased while reducing the amount of resin of the pair of torsional rigidity retaining prepregs 31 and 32 and the buckling prevention prepreg 33 included in the set prepreg 30, it is possible to reduce the weight and increase the strength of the FRP cylinder 1. it can.

  FIG. 4 is an enlarged view showing winding end positions of a plurality of prepregs according to the present embodiment. As shown in FIG. 4, the winding end positions of the pair of torsional rigidity holding prepregs 31 and 32 are offset so as to be different from each other. More specifically, the torsional rigidity holding prepreg 32 on the outer layer side is wound first, and the winding of the torsional rigidity holding prepreg 31 on the inner layer side is finished later. Further, after the simultaneous multilayer winding of the pair of torsional rigidity retaining prepregs 31 and 32 and the buckling prevention prepreg 33 is completed, the buckling prevention prepreg 33 is continuously wound by another ply.

  As a result of intensive studies on the mechanism of torsional fatigue failure of the FRP cylinder, the present inventor has found that delamination that progresses from the winding end position of the angle layer (bias layer) has a great effect. That is, when a force in the torsional direction is applied to the FRP cylinder, a force for peeling in the outer diameter direction is locally generated at the winding end position of the angle layer (bias layer). The angle layer (bias layer) is often composed of a pair of bias prepregs (for example, ± 45 ° prepregs) obliquely crossed at ± α ° in the cylinder axis direction, and the winding end positions of the pair of bias prepregs are the same. If it is, it will receive the force which peels in an outer-diameter direction in the same position in both + direction and-direction, and peeling progress will be accelerated.

  On the other hand, in this embodiment, the delamination progresses from the winding end position of the angle layer (bias layer) by making the winding end positions of the pair of torsional rigidity holding prepregs 31 and 32 different (offset) from each other. Can be effectively prevented (the starting point of delamination can be dispersed).

  FIG. 5A and FIG. 5B are conceptual diagrams showing differences in peeled portions according to the winding end position of the angle layer (bias layer). FIG. 5A shows a peeling portion when the winding end position of the angle layer (bias layer) is the same, and it can be seen that the peeling progress is accelerated because the starting point of the delamination is large. FIG. 5B shows the peeled portion when the winding end position of the angle layer (bias layer) is varied, and it can be seen that the delamination is effectively prevented by dispersing the starting point of the delamination.

  Further, in this embodiment, the pair of torsional rigidity retaining prepregs 31 and 32 and the buckling prevention prepreg 33 of the set prepreg 30 are wound in order of at least two plies independently from the inner layer side toward the outer layer side. The pair of torsional rigidity retaining prepregs 31 and 32 and the buckling prevention prepreg 33 are wound continuously so that at least two plies are wound continuously, and the buckling prevention prepreg 33 is wound alone by at least one ply. Is offset.

  The circumferential fiber layer (90 ° layer) that works effectively against the radial force without bearing the twisting force, and the winding end position of the simultaneous multilayer winding layer including the angle layer (bias layer) By winding at least one ply (preferably 1.5 ply or more) so as to completely cover, the peeling at the winding end position of the angle layer (bias layer) is suppressed and the torsional fatigue strength is dramatically improved. Is possible.

  FIG. 6 is a cross-sectional view showing the FRP cylinder 1 according to the present embodiment. As shown in FIG. 6, the outermost layer of the FRP cylinder 1 is provided with a 90 ° outermost layer that does not receive a load directly against torsion over at least two plies. Even if delamination occurs, the adverse effect can be minimized. Moreover, the delamination range in the circumferential direction of the FRP cylinder 1 can be suppressed.

  The present inventor uses an FRP cylinder (hereinafter referred to as an FRP cylinder of the present embodiment) in which the winding end positions of the pair of torsional rigidity holding prepregs having the laminated structure of FIGS. FRP cylinders (hereinafter referred to as FRP cylinders of comparative examples) in which the winding end positions of a pair of torsional rigidity holding prepregs were made to coincide with each other were actually produced, and a torsional fatigue fracture test was performed. The torsional fatigue fracture test was performed by fixing one end of the FRP cylinder using an RFH electric servo torsional fatigue tester (type 213-050) manufactured by Kinomiya Seisakusho Co., Ltd., with a test torque of 3 kNm and a test speed of 0.1 to 1 Hz. It was done like that.

Three FRP cylinders of this embodiment and three FRP cylinders of comparative examples were produced, respectively, and the torsional fatigue fracture test was performed three times. The number of trials up to torsional fatigue failure is on an average basis, and the FRP cylinder of this embodiment is about 7 times the FRP cylinder of the comparative example, and the FRP cylinder of this embodiment is more than the FRP cylinder of the comparative example. It can be seen that a tremendously high torsional fatigue strength can be realized.
FRP cylinder Number of trials until failure This embodiment 1 47858 times This embodiment 2 57018 times This embodiment 3 44638 times average 49838 times Comparative example 1 5683 times Comparative example 2 6353 times Comparative example 3 9433 times average 7156 times

  The static strength of the FRP cylinder 1 can be improved by winding the buckling-preventing prepreg 33 constituting the set prepreg 30 by only two plies before starting the winding of the pair of torsional rigidity holding prepregs 31 and 32. it can. When an angle layer (bias layer) is provided in the innermost layer of the set prepreg 30, the winding start of the prepreg is easily peeled off in the inner diameter direction by torsional torque, but buckling is prevented in the innermost layer of the set prepreg 30 as in this embodiment. By supporting the prepreg (90 ° prepreg) 33, it is possible to effectively prevent the start of winding of the prepreg from peeling in the inner diameter direction.

  The innermost layer of the FRP layer 10 of the FRP cylinder 1 is a bending stiffness holding layer (0 ° layer) obtained by thermally bending a bending stiffness holding prepreg (0 ° prepreg) 20 by winding two plies independently. As a result, when serrations are inserted (press-fitted) into the inner peripheral surface of the FRP cylinder 1, the innermost layer of the FRP layer 10 is peeled off by filling the gaps in the valleys of the serrations with the bending rigidity holding layer (0 ° layer). It can suppress and can improve the joint strength with serration.

  As described above, in this embodiment, the FRP layer 10 of the FRP cylinder 1 is orthogonal to the pair of torsional rigidity holding prepregs 31 and 32 having a fiber layer obliquely intersecting in the cylinder axis direction. It includes a simultaneous multilayer winding layer in which a plurality of plies are continuously wound and heat-cured in a state where a buckling prevention prepreg (90 ° prepreg) 33 having a fiber layer is overlapped, and a pair of torsional rigidity retaining prepregs ( The winding end positions of the pair of bias prepregs 31, 32 are offset so as to be different from each other. As a result, the strength of the FRP cylinder 1 can be ensured and the destruction (for example, peeling or torsional fatigue failure) can be made difficult to occur.

  In the above embodiment, the pair of torsional rigidity holding prepregs 31 and 32 of the set prepreg 30 is constituted by a pair of bias prepregs, and the buckling prevention prepreg 33 of the set prepreg 30 is constituted by a 90 ° prepreg. explained. However, as the pair of torsional rigidity holding prepregs and buckling prevention prepregs, those in which the fiber direction of the woven prepreg is appropriately set can be used. Examples of the fabric prepreg include a plain fabric prepreg impregnated with a thermosetting resin sheet in a plain fabric and a fiber layer obliquely crossed in the cylindrical axis direction, and a cylinder in which a thermosetting resin sheet is impregnated with a triaxial fabric. A triaxial woven prepreg having a fiber layer obliquely crossed in the axial direction can be used, and a four-axis woven prepreg having a fiber layer obliquely crossed in the cylindrical axial direction obtained by impregnating a thermosetting resin sheet with a tetraaxial woven fabric can be used. .

1 FRP cylinder 10 FRP layer 20 Bending rigidity maintaining prepreg (0 ° prepreg)
30 Set prepregs 31 32 A pair of torsional rigidity retaining prepregs (a pair of bias prepregs)
33 Buckling prevention prepreg (90 ° prepreg)

Claims (6)

An FRP cylinder in which a plurality of prepregs are wound and thermally cured to form an FRP layer,
The FRP layer is formed by continuously winding a plurality of plies in a state in which a pair of torsional rigidity holding prepregs having a fiber layer obliquely intersecting the cylindrical axis direction and a buckling prevention prepreg having a fiber layer perpendicular to the cylindrical axis direction are overlapped. A simultaneous multi-layer wound layer that has been heat-cured and
The winding end positions of the pair of torsional rigidity holding prepregs are offset so as to be different from each other,
FRP cylinder characterized by this. The pair of torsional rigidity holding prepregs and the buckling prevention prepreg are successively continued from the inner layer side toward the outer layer side in a state where the pair of torsional rigidity holding prepregs and the buckling prevention prepreg are overlapped. And the buckling prevention prepreg is offset so that at least one ply is wound alone,
The FRP cylinder according to claim 1. The pair of torsional rigidity retaining prepregs and the buckling prevention prepreg are wound in order from the inner layer side to the outer layer side, and the buckling prevention prepreg is wound alone by at least two plies. At least two plies are continuously wound in a state where the anti-bending prepreg is stacked, and the buckling prevention prepreg is offset so that the at least one ply is wound alone.
The FRP cylinder according to claim 1 or 2, wherein the FRP cylinder is provided. The winding start positions of the pair of torsional rigidity holding prepregs are offset so as to be different from each other,
The FRP cylinder according to any one of claims 1 to 3, wherein the FRP cylinder is provided. The pair of torsional rigidity retaining prepregs is composed of a pair of bias prepregs whose long fiber direction is obliquely intersected by ± α ° (0 <α <90) in the cylindrical axis direction, and the buckling prevention prepreg has a long fiber direction in the cylindrical axis direction. Consisting of 90 ° prepreg orthogonal to
The FRP cylinder according to any one of claims 1 to 4, wherein the FRP cylinder is provided. A method for producing an FRP cylinder, in which a plurality of prepregs are wound and thermally cured to form an FRP layer,
When winding the plurality of prepregs, a plurality of pairs of torsional rigidity holding prepregs having a fiber layer obliquely intersecting in the cylindrical axis direction and a buckling prevention prepreg having a fiber layer orthogonal to the cylinder axis direction are stacked. It includes a simultaneous multi-layer winding process in which plies are continuously wound,
The winding end positions of the pair of torsional rigidity holding prepregs are offset so as to be different from each other,
The manufacturing method of the FRP cylinder characterized by the above-mentioned.