JP2014172308A - Frp cylinder, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an FRP cylinder that can be prevented from being destroyed by establishing long-term reliability of torsional strength to a torsional load acting on the FRP cylinder.SOLUTION: A simultaneously multi-layer-wound layer is positioned at least at an innermost layer of a plurality of FRP layers. The positions to begin winding a torsional rigidity-retaining prepreg and a buckling-preventing prepreg of a set prepreg composing the simultaneously multi-layer-wound layer at the innermost layer are offset each other so that the buckling-preventing prepreg is independently wound by at least 1 ply, and thereafter the torsional rigidity-retaining prepreg and the buckling-preventing prepreg are wound continuously by at least 2 plies while being overlapped each other.

Description

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

  In recent years, in response to a request to reduce carbon dioxide emissions due to improved fuel efficiency, vehicle parts such as drive shafts and propeller shafts are made up of FRP (Fiber Reinforced Plastics) cylinders. Research on weight reduction has been actively conducted, and some have been put into practical use. In addition, by constructing vehicle parts such as drive shafts and propeller shafts with FRP cylinders, it is possible to expect added value such as lower vibration and improved quietness of the vehicle.

  As a manufacturing method of the FRP cylinder, a filament winding method in which a reinforcing fiber (for example, carbon fiber) is impregnated in a resin and wound around a mandrel, and a reinforcing fiber (for example, carbon fiber) is impregnated in a thermosetting resin sheet. A prepreg method is known in which a plurality of prepregs are wound into a cylindrical shape and thermally cured to form a plurality of FRP layers. The FRP cylinder by the filament winding method requires a predetermined amount or more of resin and has an upper limit on the volume content of the reinforcing fiber, so that it cannot sufficiently meet the demand for weight reduction and high strength.

  On the other hand, the FRP cylinder by the prepreg method has a feature that the volume content of the reinforcing fiber can be increased even with the minimum amount of resin, which is advantageous in simultaneously reducing the weight and increasing the strength. In addition, small products with good shape accuracy can be manufactured, and the degree of freedom of the layered configuration is high. However, the FRP cylinder using the prepreg method has a problem that the FRP layers are likely to be displaced from each other.

  In order to solve this problem, the applicant described in Patent Document 1 that a torsional rigidity holding prepreg having a fiber layer obliquely crossed in the cylindrical axis direction in a plurality of FRP layers of the FRP cylinder, and a fiber perpendicular to the cylindrical axis direction. It has been proposed to include a simultaneous multi-layer winding layer in which a set prepreg having a layer having a buckling-preventing prepreg layered thereon is continuously wound a plurality of times and thermally cured.

International Publication No. 2010/084809 Pamphlet

  However, as a result of earnest research by the present inventors, the FRP cylinder according to Patent Document 1 is obliquely crossed in the axial direction of the FRP cylinder when applied to vehicle parts such as a drive shaft and a propeller shaft that are torque transmission shafts. It has been found that there is a possibility of breakage due to a torsional load (torsional force) applied in the direction in which this occurs, and there is room for improvement in this respect. That is, establishment of long-term reliability of torsional strength (torsional rigidity) against torsional load applied to the FRP cylinder is an important technical issue.

  The present invention has been completed based on the above awareness of the problem, and an FRP cylinder capable of establishing long-term reliability of torsional strength against a torsional load applied to the FRP cylinder and reliably preventing its destruction, and its manufacture The purpose is to obtain a method.

  As a result of conducting thorough analysis on the mechanism by which the FRP cylinder is broken by a torsional load, the present inventors firstly caused delamination starting from the winding start point of the prepreg constituting the innermost layer of the FRP cylinder, It was found that this delamination progresses to the outer layer side of the FRP cylinder and leads to final destruction. And if we stop delamination starting from the winding start point of the prepreg constituting the innermost layer of the FRP cylinder, we establish long-term reliability of torsional strength against the torsional load applied to the FRP cylinder. The present invention has been completed with the knowledge that destruction can be reliably prevented.

  The FRP cylinder of the present invention is an FRP cylinder in which a plurality of prepregs formed 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 the plurality of FRP cylinders A set prepreg in which a torsional rigidity holding prepreg having a fiber layer obliquely intersecting the cylinder axis direction and a buckling prevention prepreg having a fiber layer perpendicular to the cylinder axis direction is wound in a layer multiple times in succession is heated. In the FRP cylinder including the cured simultaneous multi-layer winding layer, the simultaneous multi-layer winding layer is located at least in the innermost layer of the plurality of FRP layers; and the simultaneous multi-layer winding layer of the innermost layer The torsional rigidity retaining prepreg and the buckling prevention prepreg of the set prepreg constituting the winding start position are wound at least one ply by itself, Such that said torsional rigidity holding prepreg and the buckling prevention prepreg is wound in succession at least two plies in superimposed state, that are offset from each other; are characterized.

  The set prepreg constituting the innermost simultaneous winding layer preferably has the buckling prevention prepreg in the innermost layer.

  A simultaneous multilayer winding layer different from the innermost simultaneous multilayer winding layer is located on the outer layer side of the innermost simultaneous multilayer winding layer, and constitutes the innermost simultaneous multilayer winding layer. It is preferable that the set prepreg and the set prepreg constituting the simultaneous multilayer winding layer on the outer layer side are wound from winding directions facing each other.

  In the set prepreg constituting the innermost multilayer winding layer of the innermost layer and / or the set prepreg constituting the simultaneous multilayer winding layer on the outer layer side, the torsional rigidity holding prepreg is arranged so that the long fiber direction is in the cylindrical axis direction. A pair of bias prepregs obliquely crossing at ± α ° (0 <α <90) can be formed, and the buckling prevention prepreg can be formed of a hoop prepreg whose long fiber direction is orthogonal to the cylindrical axis direction.

  The pair of bias prepregs can be obliquely crossed so that the long fiber direction is ± 30 °, ± 45 °, or ± 60 ° in the cylindrical axis direction.

  The set prepreg constituting the innermost simultaneous multi-layer winding layer and / or the set prepreg constituting the outer multi-layer simultaneous multi-layer winding layer are arranged in a cylindrical axis line on the torsional rigidity holding prepreg and the buckling prevention prepreg. A bending rigidity holding prepreg having a fiber layer parallel to the direction can be further stacked.

  The bending rigidity maintaining prepreg can be composed of a 0 ° prepreg in which the long fiber direction is parallel to the cylindrical axis direction.

  The prepregs constituting the innermost multilayer winding layer and / or the prepregs constituting the outer multilayer side simultaneous multilayer winding layer have the same length in the cylindrical axis direction and the cylindrical axis line. It is preferable to overlap the entire length in the direction.

  The method for producing an FRP cylinder of the present invention is a method for producing an FRP cylinder in which a plurality of prepregs obtained by impregnating reinforcing fibers in a thermosetting resin sheet are wound into a cylindrical shape and thermally cured to form a plurality of FRP layers. When the plurality of prepregs are wound into a cylindrical shape, the torsional rigidity holding prepreg having a fiber layer obliquely intersecting the cylindrical axis direction and the buckling prevention prepreg having a fiber layer perpendicular to the cylindrical axis direction are stacked. In the manufacturing method of the FRP cylinder having the simultaneous multi-layer winding process in which the winding is continuously performed a plurality of times in the state, the set prepreg obtained by superimposing the torsional rigidity holding prepreg and the buckling prevention prepreg is the first buckling prevention prepreg. And preparing the offset set prepreg to be offset with respect to the torsional rigidity holding prepreg so as to be wound around at least one ply. Is used in the simultaneous multi-layer winding process for forming the innermost layer of the plurality of FRP layers, and the buckling prevention prepreg is wound alone for at least one ply, and then the torsional rigidity holding prepreg and the buckling prevention are used. A step of continuously winding at least two plies in a state where the prepregs are stacked.

  It is preferable that the set prepreg constituting the simultaneous multilayer winding layer which is the innermost FRP layer has the buckling prevention prepreg in the innermost layer.

  In addition to the simultaneous multilayer winding step for forming the innermost FRP layer, the innermost layer includes a simultaneous multilayer winding step for forming an FRP layer on the outer layer side of the innermost FRP layer, The simultaneous multilayer winding step for forming the FRP layer and the simultaneous multilayer winding step for forming the FRP layer on the outer layer side are preferably performed from the winding directions facing each other.

  The simultaneous multilayer winding step for forming the innermost FRP layer and / or the simultaneous multilayer winding step for forming the FRP layer on the outer layer side may be performed between adjacent prepregs in a stacked state. Implementation of a simultaneous multilayer winding step for forming the innermost FRP layer and / or a simultaneous multilayer winding step for forming the outer layer side FRP layer, which is performed with a release sheet sandwiched therebetween It is preferable to have a release sheet removing step for removing the sandwiched release sheet.

  ADVANTAGE OF THE INVENTION According to this invention, the FRP cylinder which can establish the long-term reliability of the torsional strength with respect to the torsion load added to an FRP cylinder, and can prevent the destruction reliably, and its manufacturing method are obtained.

It is a figure which shows the structure of the FRP cylinder by 1st Embodiment of this invention. It is a figure which shows the structure of the set prepreg which forms the simultaneous multilayer winding layer of FIG. It is a figure which shows the structure of the FRP cylinder which made the FRP layer by thermosetting the prepreg wound by the cylinder shape. It is a figure which shows the case where a simultaneous multilayer winding process is performed by putting a release sheet between adjacent prepregs in a stacked state. It is a figure which shows the structure of the FRP cylinder by 2nd Embodiment of this invention. It is a figure which shows the structure of the set prepreg which forms the simultaneous multilayer winding layer of FIG. It is a figure which shows the structure of the FRP cylinder by 3rd Embodiment of this invention. It is a figure which shows the structure of the set prepreg which forms the simultaneous multilayer winding layer of FIG. It is a figure which shows the laminated structure by the side of the innermost layer of the FRP cylinder after heat-hardening.

(First embodiment)
Hereinafter, the FRP cylinder 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4. The FRP cylinder 1 is obtained by winding a plurality of prepregs obtained by impregnating reinforcing fibers into a thermosetting resin sheet into a cylindrical shape and thermosetting them to form a plurality of FRP layers. As the reinforcing fiber, for example, carbon fiber, alumina fiber, aramid fiber, Tyranno fiber, amorphous fiber, glass fiber and the like can be used. For example, epoxy resin, unsaturated polyester resin, phenol resin, vinyl ester resin, peak resin, polyimide resin, or the like can be used as the resin impregnated in such reinforcing fibers.

  As shown in FIG. 1, the FRP cylinder 1 has a simultaneous multilayer wound layer 10 positioned in the innermost layer of a plurality of FRP layers forming a cylindrical body. In FIG. 1, a state in which the simultaneous multilayer wound layer 10 is developed is illustrated. The simultaneous multilayer wound layer 10 is a buckling prevention layer that is responsible for strength against a force (buckling) applied in a direction orthogonal to the axial direction of the FRP cylinder 1 (hereinafter referred to as the cylindrical axial direction) in order from the inner layer side to the outer layer side. 20 and a torsional rigidity retaining layer 30 that takes the strength against the force (torsion) applied in the direction oblique to the cylindrical axis direction. The torsional rigidity holding layer 30 is composed of a pair of bias layers 30A and 30B. The FRP cylinder 1 can also have an FRP layer on the outer layer side of the innermost multilayer winding layer 10, but in the present embodiment, the FRP layer on the outer layer side of the simultaneous multilayer winding layer 10 has a configuration. Since there is a degree of freedom, illustration thereof is omitted.

  As shown in FIG. 2, the simultaneous multilayer wound layer 10 includes, in order from the inner layer side to the outer layer side, a buckling-preventing prepreg 200 having a fiber layer orthogonal to the cylindrical axis direction, and fibers obliquely intersecting the cylindrical axis direction. A set prepreg 100 on which a torsional rigidity holding prepreg 300 having layers is stacked is continuously wound a plurality of times and thermally cured. 2, in order to show the fiber direction of each prepreg 200 and 300 which comprises the set prepreg 100, the state before superimposing these is drawn.

  The buckling prevention prepreg 200 is formed of a hoop prepreg whose long fiber direction is orthogonal to the cylindrical axis direction. The buckling prevention layer 20 (FIG. 1) is formed by heat-curing the buckling prevention prepreg 200 (FIG. 2). The torsional rigidity holding prepreg 300 includes a pair of bias prepregs 300A and 300B in which the long fiber direction obliquely intersects with the cylinder axis direction at ± α ° (0 <α <90). The oblique angle α is, for example, ± 30 °, ± 45 °, or ± 60 °. The torsional rigidity holding prepreg 300 (a pair of bias prepregs 300A and 300B) (FIG. 2) is cured by heating, whereby the torsional rigidity holding layer 30 (the pair of bias layers 30A and 30B) (FIG. 1) is formed. The buckling prevention prepreg 200 and the torsional rigidity retaining prepreg 300 (the pair of bias prepregs 300A and 300B) have the same length L in the cylindrical axis direction and are overlapped over the entire length in the cylindrical axis direction. The length L corresponds to the length of the FRP cylinder 1 and is appropriately set according to the use of the FRP cylinder 1.

  As shown in FIGS. 1 and 2, the width W2 of the buckling prevention prepreg 200 is set to about 7 times the circumferential length when the buckling prevention prepreg 200 is wound in a cylindrical shape. 7 plies can be wound continuously. The width W3 of the torsional rigidity holding prepreg 300 (the pair of bias prepregs 300A and 300B) is set to be about 6 times the circumference when the torsional rigidity holding prepreg 300A and 300B are wound into a cylindrical shape. The bias prepregs 300A and 300B) can be wound continuously in a cylindrical shape with 6 plies. Therefore, when the buckling prevention prepreg 200 and the torsional rigidity holding prepreg 300 (the pair of bias prepregs 300A and 300B) are aligned at the rear end (the right end in FIG. 1), the leading end of the buckling prevention prepreg 200 (FIG. 1). The left end portion in the middle protrudes by one ply from the tip end portion (left end portion in FIG. 1) of the torsional rigidity retaining prepreg 300 (the pair of bias prepregs 300A and 300B). The protruding end of the buckling prevention prepreg 200 is the winding start position of the set prepreg 100. That is, the buckling prevention prepreg 200 and the torsional rigidity maintaining prepreg 300 (the pair of bias prepregs 300A and 300B) are wound at the winding start position by one buckling prevention prepreg 200 alone, and thereafter buckling prevention. The prepreg 200 and the torsional rigidity retaining prepreg 300 (a pair of bias prepregs 300A and 300B) are offset from each other so that six plies are continuously wound. The number of plies when the set prepreg 100 is simultaneously wound in multiple layers in this way is 19.

  The FRP cylinder 1 configured as described above is positioned in the innermost layer of a plurality of FRP layers forming the cylinder body, and a set prepreg 100 in which a buckling prevention prepreg 200 and a torsional rigidity holding prepreg 300 are stacked is continuously provided a plurality of times. Thus, since the simultaneous multilayer wound layer 10 wound and thermally cured is included, the strength in the twisting direction and the buckling direction can be increased. In addition, since the buckling prevention prepreg 200 and a pair of bias prepregs 300A and 300B are preliminarily overlapped, they are wound as a single prepreg (set prepreg 100) from a macro viewpoint. Compared with the case where the same amount of materials are individually wound, the FRP cylinder 1 can be reduced in weight and strength at the same time due to the effect of preventing buckling.

  Then, before starting the simultaneous multi-layer winding in which the overlapped portion of the buckling prevention prepreg 200 and the torsional rigidity holding prepreg 300 (the pair of bias prepregs 300A and 300B) is started, the buckling prevention prepreg 200 alone 1 Since the ply is wound, as shown in FIG. 9, an independent buckling prevention layer 20 is provided in the innermost layer of the FRP cylinder 1, and the buckling prevention layer 20 is provided on the outer layer side of the independent buckling prevention layer 20. The torsional rigidity holding layer 30 (a pair of bias layers 30A and 30B) is provided with the simultaneous multilayer winding layer 10 adjacent to the inside and outside, and the entire multilayer winding layer 10 is prevented from buckling and the cross-sectional shape is maintained. can do. That is, the delamination starting from the winding start point of the prepreg constituting the innermost layer of the FRP cylinder 1 is prevented, and the long-term reliability of the torsional strength (torsional rigidity) against the torsional load (torsional force) applied to the FRP cylinder 1 is improved. It can be established and its destruction can be surely prevented.

  Then, the method to manufacture the FRP cylinder 1 comprised as mentioned above is demonstrated.

  First, a rod-like (columnar) mandrel M (FIG. 1) made of a metal material is prepared. Next, the set prepreg 100 in which the buckling prevention prepreg 200 and the torsional rigidity holding prepreg 300 (a pair of bias prepregs 300A and 300B) are overlapped is placed, and the buckling prevention prepreg 200 is positioned in the innermost layer and the buckling prevention prepreg 200 is First, the torsional rigidity holding prepreg 300 (the pair of bias prepregs 300A and 300B) is prepared by being offset so as to be wound by one ply. Next, the set prepreg 100 prepared by offsetting is used in a simultaneous multi-layer winding process for forming an innermost layer of a plurality of FRP layers, and the buckling prevention prepreg 200 is wound by one ply alone, and then buckling prevention is performed. 6 plies are continuously wound in a state where the prepreg 200 and the torsional rigidity holding prepreg 300 (a pair of bias prepregs 300A and 300B) are overlapped (19 plies in total). This simultaneous multi-layer winding process is preferably performed in a predetermined preheating state, whereby each prepreg can be wound in close contact.

  When all the prepregs have been laminated and wound, the shrink tape to which tension is applied is wound, and the prepreg is cured by heating with a heating device (for example, an oven) so that an external pressure is applied. This heat curing step is preferably performed in a vacuum atmosphere (for example, an autoclave). As a result, the plurality of prepregs wound around the mandrel M are heat-cured and become an integrated FRP cylinder 1. That is, the set prepreg 100 is heated and cured to form the simultaneous multilayer wound 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 a plurality of FRP layers to the inner diameter φ, and a length L corresponding to the length of the prepreg, The FRP cylinder 1 having the above is completed (FIG. 3).

  The simultaneous multi-layer winding process is preferably performed in a state where release paper is sandwiched between adjacent prepregs in a stacked state (release sheet winding). FIG. 4 shows the embodiment, and a release sheet P1 is sandwiched between a buckling prevention prepreg 200 (buckling prevention layer 20) and a torsional rigidity holding prepreg 300 (torsional rigidity holding layer 30), and a pair of bias prepregs. A simultaneous multilayer winding process is performed in a state where the release sheet P2 is sandwiched between 300A and 300B (a pair of bias layers 30A and 30B). Then, during the simultaneous multilayer winding step, the sandwiched release sheets P1 and P2 are pulled out to the rear end side (right side in FIG. 4) and removed. According to this release sheet winding, the set prepreg 100 can be wound uniformly, and the moldability of the FRP cylinder 1 can be remarkably improved and the internal structure and appearance can be improved. Therefore, in order to improve the appearance of the surface of the FRP cylinder 1, it is not necessary to make it smooth by smoothing or painting by post-processing. In addition, as release sheet P1, P2, fluororesin (coating) sheets, such as a PTFE film and a PFA film, can be used, for example.

(Second Embodiment)
An FRP cylinder 1 ′ according to a second embodiment of the present invention will be described with reference to FIGS. The FRP cylinder 1 ′ of the present embodiment has a simultaneous multilayer winding layer 40 different from the simultaneous multilayer winding layer 10 on the outer layer side of the innermost multilayer simultaneous winding layer 10. The simultaneous multi-layer wound layer 40 includes, in order from the inner layer side to the outer layer side, a buckling prevention layer 50 having strength against a force (buckling) applied in a direction orthogonal to the cylindrical axis direction, and a diagonal cross in the cylindrical axis direction. And a torsional rigidity holding layer 60 (a pair of bias layers 60A and 60B) having a strength against a force (torsion) applied in the direction. The simultaneous multilayer wound layer 40 includes, in order from the inner layer side to the outer layer side, a buckling prevention prepreg 500 having a fiber layer orthogonal to the cylindrical axis direction, and a torsional rigidity retaining prepreg having a fiber layer obliquely intersecting the cylindrical axis direction. A set prepreg 400 overlaid with 600 (a pair of bias prepregs 600A and 600B) is continuously wound a plurality of times and thermally cured.

  The configuration of the outer layer set prepreg 400 (simultaneous multilayer winding layer 40) is basically the same as that of the innermost set prepreg 100 (simultaneous multilayer winding layer 10) except for the following points. That is, the width W5 of the buckling prevention prepreg 500 and the width W6 of the torsional rigidity holding prepreg 600 (the pair of bias prepregs 600A and 600B) are both slightly more than about 6 times the circumference when they are wound in a cylindrical shape. The buckling prevention prepreg 500 and the torsional rigidity maintaining prepreg 600 (a pair of bias prepregs 600A and 600B) can be wound continuously in a 6-ply manner in a cylindrical shape. That is, the set prepreg 400 is capable of simultaneous multi-layer winding of 6 plies in succession with the buckling prevention prepreg 500 and the torsional rigidity holding prepreg 600 (a pair of bias prepregs 600A and 600B) completely overlapped. It has become. In this case, the number of plies of the set prepreg 400 is 18, and the total number of plies of the FRP cylinder 1 ′ combined with the number of plies of the set prepreg 100 is 37.

  By including the two simultaneous multilayer winding layers 10 and 40 in the FRP layer as in this embodiment, the strength of the FRP cylinder 1 ′ can be further increased. The number of simultaneous multilayer winding layers included in the FRP layer can be appropriately changed according to the use of the FRP cylinder. For example, three or more simultaneous multilayer winding layers may be included in the FRP layer. . In this case, set prepregs corresponding to the number of simultaneous multilayer winding layers are used.

  The FRP cylinder 1 ′ of the present embodiment can also be manufactured by the same method as the FRP cylinder 1 of the first embodiment described above, but the simultaneous multi-layer winding process of the set prepreg 100 and the set prepreg 400 is performed by mutually opposing windings. It is preferable to execute from the direction. In the example of FIG. 5, after performing the simultaneous multi-layer winding process of the set prepreg 100 in the direction in which the mandrel M rotates clockwise (from left to right), the set prepreg 400 in the direction in which the mandrel M rotates counterclockwise. Perform simultaneous multi-layer winding process (right to left). Thereby, the uniformity in the circumferential direction of the FRP layer of the FRP cylinder 1 ′ increases, the strength increases, and the appearance is improved. In the simultaneous multi-layer winding process of the set prepreg 400, the release sheet winding shown in FIG. 4 may be executed.

(Third embodiment)
The FRP cylinder 1 ″ according to the third embodiment of the present invention will be described with reference to FIGS. 7 and 8. The FRP cylinder 1 ″ according to the present embodiment is a set prepreg constituting the innermost simultaneous winding layer 70. The configuration of 700 is different from the configuration of the set prepreg 100 that configures the simultaneous multilayer winding layer 10 as the innermost layer in the first embodiment and the second embodiment. That is, the set prepreg 700 of the present embodiment includes, in order from the inner layer side to the outer layer side, a bending rigidity holding prepreg 800 having a fiber layer parallel to the cylindrical axis direction, and a torsional rigidity holding prepreg 300 (a pair of bias prepregs 300A, 300B) and the buckling prevention prepreg 200 are overlapped. That is, the buckling prevention prepreg 200 is located not in the innermost layer of the set prepreg 700 but in the outermost layer. The bending rigidity holding prepreg 800 can be configured by, for example, a 0 ° prepreg that is parallel to the cylindrical axis direction. The bending rigidity holding prepreg 800 is cured by heating, whereby the bending rigidity holding layer 80 is formed. By including the bending rigidity maintaining prepreg 800 in the set prepreg 700, it is possible to have strength in the bending direction as well as strength in the twisting direction and buckling direction.

  As shown in FIGS. 7 and 8, the width W8 of the bending rigidity maintaining prepreg 800 is set to about 6 times the circumferential length when the bending rigidity holding prepreg 800 is wound in a cylindrical shape. 6 plies can be wound continuously. Accordingly, when the bending rigidity holding prepreg 800, the torsional rigidity holding prepreg 300 (the pair of bias prepregs 300A and 300B) and the rear end portion (the right end portion in FIG. 7) of the buckling prevention prepreg 200 are aligned, the buckling prevention prepreg 200 is arranged. The tip end portion (left end portion in FIG. 7) is one ply than the tip end portion (left end portion in FIG. 7) of the bending rigidity holding prepreg 800 and the torsional rigidity holding prepreg 300 (the pair of bias prepregs 300A and 300B). Only protrude. The protruding end of the buckling prevention prepreg 200 is the winding start position of the set prepreg 700. That is, the bending rigidity holding prepreg 800, the torsional rigidity holding prepreg 300 (the pair of bias prepregs 300A and 300B) and the buckling prevention prepreg 200 are wound at a winding start position by one buckling prevention prepreg 200 alone. Thereafter, the bending rigidity holding prepreg 800, the torsional rigidity holding prepreg 300 (the pair of bias prepregs 300A and 300B) and the buckling prevention prepreg 200 are offset from each other so that they are wound continuously by 6 plies. ing. The number of plies when the set prepreg 700 is simultaneously wound in multiple layers is 25. When the set prepreg 700 that is simultaneously wound in multiple layers is cured by heating, an independent buckling prevention layer 20 is provided on the innermost layer of the FRP cylinder 1 ″, as shown in FIG. On the outer layer side of the layer 20, a simultaneous multilayer winding layer 70 in which the bending rigidity holding layer 80, the torsion rigidity holding layer 30 (a pair of bias layers 30A and 30B) and the buckling prevention layer 20 are adjacent to each other inside and outside is provided.

The buckling prevention prepreg 200 and the torsional rigidity maintaining prepreg 300 (a pair of bias prepregs 300A and 300B) of the first embodiment, the second embodiment, and the third embodiment, and the buckling prevention prepreg 500 and the torsional rigidity holding of the second embodiment. The prepreg 600 (a pair of bias prepregs 600A and 600B) and the bending rigidity maintaining prepreg 800 of the third embodiment are formed of a unidirectional reinforcing prepreg in which the long fiber directions are aligned in one direction. In this case, the thickness of the reinforcing fiber is preferably 24K (1K is 1000 filaments) or less. If it exceeds 24K, uniform fiber physical properties may not be ensured, and the workability of winding around a mandrel during production may be deteriorated. Further, the weight of the prepreg is preferably 300 g / m ² or less, and more preferably 250 g / m ² or less. If it exceeds 300 g / m ² , it becomes too thick and it is difficult to wind it around a mandrel during production. The resin amount of the prepreg is preferably 20 to 45% by weight, and more preferably 25 to 40% by weight. If the amount is less than 20% by weight, the amount of resin may be too small to produce a shaft having sufficient strength, and if it exceeds 45% by weight, the torsional rigidity may decrease if the cylinder has the same weight. .

  On the other hand, as a buckling prevention prepreg and a torsional rigidity prepreg, a thermosetting resin sheet is impregnated with biaxial woven fibers instead of the unidirectional reinforced prepreg as in the first embodiment, the second embodiment, and the third embodiment. A biaxial woven prepreg, a triaxial woven prepreg obtained by impregnating a thermosetting resin sheet with a triaxial woven fiber, or a four-axis woven prepreg obtained by impregnating a thermosetting resin sheet with a four-axis woven fiber. Embodiments are possible. In this embodiment, the thread thickness of each textile fiber is preferably 6K or less. If it exceeds 6K, the prepreg becomes too thick, and there is a possibility that uniform fiber properties (characteristics) cannot be secured, and the workability of winding around a mandrel during production may be deteriorated.

  In the first embodiment and the second embodiment, in the simultaneous multilayer winding process for forming the innermost simultaneous multilayer winding layer 10, the buckling prevention prepreg 200 is wound alone by one ply, and then buckling prevention is performed. The case where 6 plies are continuously wound while the prepreg 200 and the torsional rigidity holding prepreg 300 (a pair of bias prepregs 300A and 300B) are overlapped is described as an example (total 19 plies). However, the simultaneous multi-layer winding process according to the present invention is not limited to this, and at least one ply of the buckling prevention prepreg 200 is wound alone, and then the buckling prevention prepreg 200 and the torsional rigidity holding prepreg 300 (a pair of bias prepregs 300A). , 300B) with at least two plies continuously wound (at least 7 plies).

  In the third embodiment, in the simultaneous multi-layer winding process for forming the innermost simultaneous multi-layer winding layer 70, the buckling prevention prepreg 200 is wound alone by one ply, and then the bending rigidity maintaining prepreg 800, the torsional rigidity The case where the holding prepreg 300 (the pair of bias prepregs 300A and 300B) and the buckling prevention prepreg 200 are stacked and wound continuously for 6 plies has been described as an example. However, the simultaneous multi-layer winding process according to the present invention is not limited to this, and at least one ply winding of the buckling prevention prepreg 200 alone is performed, and then the bending rigidity holding prepreg 800, the torsion rigidity holding prepreg 300 (a pair of bias prepregs 300A). 300B) and the buckling prevention prepreg 200 may be wound continuously (at least 9 plies).

  In the first embodiment and the second embodiment, the buckling prevention prepreg 200 is positioned in the innermost layer of the set prepreg 100 constituting the innermost simultaneous multilayer wound layer 10. However, the buckling prevention prepreg 200 may be positioned on the outermost layer of the set prepreg 100 (on the outer layer side of the torsional rigidity retaining prepreg 300), or between the pair of bias prepregs 300A and 300B in the set prepreg 100. May be. That is, the position of the inner and outer layers of the buckling prevention prepreg 200 in the innermost set prepreg 100 has a degree of freedom.

  The inventors of the present invention have demonstrated the superiority of the FRP cylinder according to the present invention by making a prototype of the FRP cylinder according to the present invention and a conventional FRP cylinder and comparing them.

The FRP cylinder according to the present invention is an FRP cylinder having the configuration of the first embodiment described above. That is, the FRP cylinder according to the present invention winds the innermost buckling prevention prepreg 200 alone by one ply to form the innermost simultaneous multilayer winding layer 10, and then maintains the torsional rigidity with the buckling prevention prepreg 200. prepreg 300 (pair of bias prepregs 300A, 300B) is obtained by turning 6 ply continuously wound in a laminated state _{([(90 / ± 45)} 6/90], a total of 19 plies).

The FRP cylinder of the conventional configuration has six consecutive plies in a state where the buckling prevention prepreg and the torsional rigidity retaining prepreg (a pair of bias prepregs) are completely overlapped to form the innermost simultaneous winding layer. Wrapped ([90 / ± 45] ₆ , total 18 plies). In other words, the FRP cylinder of the conventional configuration has a configuration in which the simultaneous multilayer winding layer 40 on the outer layer side of the second embodiment described above is arranged in the innermost layer.

  A torque test was performed on each of the FRP cylinder according to the present invention and the FRP cylinder of the conventional configuration. More specifically, each test piece was loaded into an electric servo torsion tester, one end was completely restrained, and an angular displacement was given to the other end with a triangular wave. The torsional moment was measured with a torque detector placed at the fully constrained end. The twist angle was measured by an encoder attached to the displacement side shaft. As a result, while the maximum torque of the FRP cylinder of the conventional configuration was 2071 Nm, the maximum torque of the FRP cylinder according to the present invention was 2304 Nm, and it was confirmed that the strength was improved by about 11%.

  A damage observation experiment using an ultrasonic flaw detector was performed on each of the FRP cylinder according to the present invention and the FRP cylinder of the conventional configuration. More specifically, each test piece is loaded into a holder in the water tank of the ultrasonic flaw detector, and the ultrasonic wave is transmitted through the ultrasonic terminal from the top while rotating the test piece to check whether there is damage inside the test piece. Observed. After measuring one round, the terminal was moved in the axial direction, and one round was measured. This was repeated, and after measuring the total length of the test piece, each data was mapped on a two-dimensional screen to obtain image data. As a result, in the conventional FRP cylinder, the presence of delamination starting from the winding start point constituting the innermost layer of the FRP layer was confirmed, whereas in the FRP cylinder according to the present invention, the innermost layer of the FRP layer was confirmed. Existence of delamination starting from the winding start point constituting the film could not be confirmed.

  Thus, the FRP cylinder according to the present invention prevents delamination starting from the winding start point of the prepreg constituting the innermost layer of the FRP cylinder, and establishes long-term reliability of torsional strength against torsional load applied to the FRP cylinder. It was proved that the destruction can be surely prevented.

1 1 ′ 1 ″ FRP cylinder 10 Innermost simultaneous multilayer wound layer 20 Buckling prevention layer 30 Torsional rigidity holding layer 30A 30B A pair of bias layers 100 Set prepreg 200 Buckling prevention prepreg 300 Torsional rigidity holding prepreg 300A 300B A pair of biases Pre-preg 40 Simultaneous multilayer winding layer 50 on outer layer side Buckling prevention layer 60 Torsional rigidity holding layer 60A 60B Pair of bias layers 400 Set prepreg 500 Buckling prevention prepreg 600 Torsional rigidity holding prepreg 600A 600B Pair of bias prepregs 70 Simultaneously of innermost layers Multilayer wound layer 80 Bending rigidity holding layer 700 Set prepreg 800 Bending rigidity holding prepreg M Mandrel P1 P2 Release sheet

Claims (12)

A FRP cylinder in which a plurality of prepregs obtained by impregnating a reinforcing fiber into a thermosetting resin sheet is wound into a cylindrical shape to be thermoset to form a plurality of FRP layers, and in the plurality of FRP layers, the cylindrical axis direction Simultaneous multi-layer winding in which a set prepreg in which a torsional rigidity prepreg having a fiber layer obliquely crossed and a buckling prevention prepreg having a fiber layer perpendicular to the cylindrical axial direction is wound continuously and heat-cured a plurality of times In an FRP cylinder with layers,
The simultaneous multilayer winding layer is positioned at least in the innermost layer of the plurality of FRP layers; and the torsional rigidity holding prepreg of the set prepreg constituting the innermost multilayer winding layer and the buckling prevention The winding start position of the prepreg is at least 2 plies continuously in a state where the buckling prevention prepreg is wound alone and then the torsional rigidity holding prepreg and the buckling prevention prepreg are overlapped. FRP cylinders characterized in that they are offset from each other so as to be wound. The FRP cylinder of claim 1,
The set prepreg constituting the innermost simultaneous winding layer is an FRP cylinder having the buckling prevention prepreg in the innermost layer. The FRP cylinder according to claim 1 or 2,
A simultaneous multilayer winding layer different from the simultaneous multilayer winding layer of the innermost layer is located on the outer layer side of the simultaneous multilayer winding layer of the innermost layer,
The set prepreg constituting the innermost simultaneous multilayer winding layer and the set prepreg constituting the outer multilayer side simultaneous multilayer winding layer are FRP cylinders wound from winding directions facing each other. In the FRP cylinder according to any one of claims 1 to 3,
In the set prepreg constituting the innermost simultaneous winding layer of the innermost layer and / or the set prepreg constituting the simultaneous multilayer winding layer on the outer layer side,
The torsional rigidity holding prepreg is composed of a pair of bias prepregs whose long fiber direction obliquely intersects the cylinder axis direction at ± α ° (0 <α <90), and the buckling prevention prepreg has a long fiber direction in the cylinder axis direction. FRP cylinder made of hoop prepreg orthogonal to The FRP cylinder according to claim 4,
The pair of bias prepregs are FRP cylinders in which the long fiber direction is obliquely crossed at ± 30 °, ± 45 °, or ± 60 ° in the cylinder axis direction. In the FRP cylinder according to any one of claims 1 to 5,
The set prepreg constituting the innermost simultaneous multi-layer winding layer and / or the set prepreg constituting the outer multi-layer simultaneous multi-layer winding layer are arranged in a cylindrical axis line on the torsional rigidity holding prepreg and the buckling prevention prepreg. An FRP cylinder in which a bending rigidity holding prepreg having a fiber layer parallel to a direction is further stacked. The FRP cylinder according to claim 6,
The bending rigidity maintaining prepreg is an FRP cylinder made of a 0 ° prepreg in which the long fiber direction is parallel to the cylinder axis direction. The FRP cylinder according to any one of claims 1 to 7,
The prepregs constituting the innermost multilayer winding layer and / or the prepregs constituting the outer multilayer side simultaneous multilayer winding layer have the same length in the cylindrical axis direction and the cylindrical axis line. FRP cylinders stacked over the entire length of the direction. A method of manufacturing an FRP cylinder in which a plurality of prepregs obtained by impregnating a reinforcing fiber in a thermosetting resin sheet is wound into a cylindrical shape and thermally cured to form a plurality of FRP layers, wherein the plurality of prepregs are formed into a cylindrical shape When winding, a torsional rigidity holding prepreg 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 continuously wound a plurality of times. In the manufacturing method of the FRP cylinder having the simultaneous multilayer winding step,
A step of preparing a set prepreg obtained by superimposing the torsional rigidity holding prepreg and the buckling prevention prepreg by offsetting the torsional rigidity holding prepreg so that the buckling prevention prepreg is initially wound by at least one ply. And the offset set prepreg is used in the simultaneous multilayer winding step for forming the innermost layer of the plurality of FRP layers, and the buckling prevention prepreg is wound alone for at least one ply, and then the torsional rigidity And a step of continuously winding at least two plies in a state where the holding prepreg and the buckling-preventing prepreg are overlapped with each other. In the manufacturing method of the FRP cylinder of Claim 9,
The set prepreg constituting the simultaneous multilayer wound layer which is the innermost FRP layer is a method for producing an FRP cylinder in which the innermost layer includes the buckling prevention prepreg. In the manufacturing method of the FRP cylinder of Claim 9 or 10,
In addition to the simultaneous multilayer winding step for forming the innermost FRP layer, the method has a simultaneous multilayer winding step for forming an FRP layer on the outer layer side of the innermost FRP layer,
The simultaneous multilayer winding step for forming the innermost FRP layer and the simultaneous multilayer winding step for forming the outer layer side FRP layer are performed from the winding directions facing each other. Method. In the manufacturing method of the FRP cylinder of any one of Claims 9 thru | or 11,
The simultaneous multilayer winding step for forming the innermost FRP layer and / or the simultaneous multilayer winding step for forming the FRP layer on the outer layer side may be performed between adjacent prepregs in a stacked state. Performed with the release sheet sandwiched between them,
During the execution of the simultaneous multilayer winding step for forming the innermost FRP layer and / or the simultaneous multilayer winding step for forming the outer layer side FRP layer, the sandwiched release sheet is removed. The manufacturing method of the FRP cylinder which has a release sheet removal process to perform.

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