JP4771209B2 - FRP cylinder and manufacturing method thereof - Google Patents

Description

  The present invention relates to an FRP cylinder and a method for manufacturing the same, and more particularly to an FRP cylinder suitable for use in an FRP cylinder in which other members are coupled to both ends, such as a propeller shaft, and a method for manufacturing the same.

  Recently, FRP (fiber reinforced plastic) cylinders are being used in various industrial fields. For example, in recent years, weight reduction of automobiles has been strongly demanded from the viewpoints of improving fuel efficiency and environmental conservation, but as one means for achieving this, FRP conversion of propeller shafts has been studied and some of them have already been adopted. . At that time, there are various types of reinforcing fibers to be used. For example, carbon fibers, glass fibers, aramid fibers, and the like have been studied. Among them, carbon is especially used as a cylinder of a propeller shaft in terms of strength and elastic modulus. CFRP (carbon fiber reinforced plastic) cylinders that use fibers as reinforcing fibers are promising, and such CFRP cylinders are mainly formed by the filament winding method.

Since the propeller shaft of an automobile needs to transmit a large torque generated from the engine together with the elastic modulus in the axial direction, it requires a torsional strength of about 1000 to 4000 Nm. Further, it is also required that the dangerous rotational speed is about 5000 to 15000 rpm so that resonance does not occur during high-speed rotation. Conventional CFRP propeller shafts, in particular, the main body cylinder portion, as described in Patent Document 1 and the like, transmit a necessary torque and obtain a high resonance frequency (reinforced fiber helical winding layer (spiral winding layer)). ) And the stacking configuration, shaft size (inner diameter, outer diameter, wall thickness), type of reinforcing fiber used, content of reinforcing fiber, etc. It was not a thing.
JP-A-2-236014

  Especially for propeller shafts, there are many cases where the required resonance frequency is high, and helical winding layers in which reinforcing fibers are arranged in the cylinder axis direction as much as possible are laminated in the cylinder radial direction to increase the bending elastic modulus in the cylinder axis direction. There is a need. The FRP cylinder used in such a propeller shaft is formed by a filament winding method in which a resin-impregnated reinforcing fiber bundle is helically wound on a mandrel while reciprocating. There were the following problems.

  Since the pressing force of the helical winding layer in the circumferential direction of the mandrel is relatively low, when a plurality of layers are stacked, voids tend to stay in each helical winding layer. In particular, as shown in FIG. 1, when a helical wound layer 3 is formed by laminating a plurality of reinforcing fiber bundles 2 impregnated with resin on a mandrel 1, the helical windings of the Nth layer and the (N + 1) th layer are formed. The reinforcing fiber bundles 2 of the layer 3 are arranged in the same phase or in the vicinity of the same phase. Therefore, the width direction end portion 4 (fiber bundle boundary) of the reinforcing fiber bundle 2 is often arranged in the same phase or in the same phase. In such a case, since the helical winding layer pressing force is hardly loaded around the fiber bundle boundary, many voids are generated. In addition, since the phases of the reinforcing fiber bundles 2 in the circumferential direction of the cylinder are aligned, the molded cylinder cross section sometimes has a polygonal shape with the fiber bundle boundary 4 as a vertex.

  As described above, in a configuration in which a plurality of helical winding layers are simply laminated in order, the molded FRP cylindrical body has a polygonal cross section and includes many voids on the same phase in the circumferential direction, and thus requires torsional strength and resonance frequency. It ’s hard to say that it ’s stable enough.

  The object of the present invention is to focus on the above problems, stabilize the shape of each helical winding layer, and eliminate voids generated at the fiber bundle boundary, thereby accurately and stably achieving the target strength characteristics. It is in providing the FRP cylinder which can be expressed dynamically, and its manufacturing method.

In order to solve the above problems, an FRP cylinder according to the present invention is formed by winding a reinforcing fiber bundle impregnated with resin on a mandrel at the same angle to form a plurality of helical winding layers of at least two layers. The phase in the cylinder circumferential direction of the reinforcing fiber bundle of each helical winding layer laminated in the cylinder radial direction is the same or around the same phase in the width direction end portion of each reinforcing fiber bundle. In order to avoid this, it is shifted from each other, and the shift amount in the circumferential direction of the cylinder is set to the following amount .
Shift amount = W2 × (0.3 to 0.7) + N2 × W2 [N2: <a positive integer of N1]
Reinforcing fiber yarn count: N1
Combined yarn width: W1
Single strand yarn width: W2 [= W1 / N1]

In the FRP cylinder, for example, as shown in FIG. 2 showing an FRP cylinder 11 according to an example of the present invention, a helical fiber winding is performed on a mandrel 1 while a reinforcing fiber bundle 12 impregnated with resin is reciprocated in the mandrel axial direction. In the FRP cylinder 11 formed by forming the layer 13, the reinforcing fiber bundle located in the upper layer is arranged so as to cover one end portion in the width direction of the reinforcing fiber bundle located in the lower layer. For example, among the reinforcing fiber bundles laminated in the cylinder radial direction, the phase in the cylinder circumferential direction is shifted between adjacent reinforcing fiber bundles by specifying the shift amount as described above . Preferably, the phases in the circumferential direction of the cylinder are shifted from each other for all of the reinforcing fiber bundles stacked in the radial direction of the cylinder. That is, as shown in FIG. 2, the third-layer helically wound reinforcing fiber bundle has the first and second layers so that the second-layer helically wound reinforcing fiber bundle presses the boundary (one end) of the first-layer helically wound reinforcing fiber bundle. Since the fourth-layer helically wound reinforcing fiber bundle is shaped to hold down the first-layer, second-layer and third-layer helically-wrapping fiber bundle boundaries so as to hold down the layered helically wound reinforcing fiber bundle boundary, In the circumferential direction of the cross section, the phases of the helically wound reinforcing fiber bundles are shifted from each other, and the end positions in the width direction of the reinforcing fiber bundles are prevented from being in the same phase or around the same phase. As a result, as shown in FIG. 1, voids that frequently occur at a specific position in the circumferential direction of the cylinder (where the end portions in the width direction of the reinforcing fiber bundles overlap) are reduced or eliminated, and thereby helical The shape of the wound layer is stabilized, and target strength characteristics such as torsional strength and elastic modulus are accurately and stably expressed.

  When the phases of the reinforcing fiber bundles laminated in the cylindrical radial direction are shifted from each other as described above, the reinforcing fiber bundles laminated in three or more layers as shown in FIG. It is more preferable to sequentially shift the phases in the circumferential direction of the cylinder from the viewpoint of ease of control and shape stability of the molded cylinder.

  Such an FRP cylinder can be configured as a propeller shaft by joining metal joints to both ends thereof. This prevents many voids from occurring at specific positions in the circumferential direction of the cylindrical cross section, stabilizes the shape of the helical winding layer, and accurately sets the target strength characteristics such as torsional strength and resonance frequency. A propeller shaft that can be stably expressed is provided.

In the FRP cylinder manufacturing method according to the present invention, in filament winding molding, a reinforcing fiber bundle impregnated with resin is wound at the same angle on a mandrel to form at least two or more helical wound layers. The phase of the reinforcing fiber bundle of each helical wound layer laminated in the cylinder radial direction in the cylindrical body circumferential direction is the end position in the width direction of each reinforcing fiber bundle. In order to avoid being in the same phase or around the same phase, they are shifted from each other, and the amount of shift in the circumferential direction of the cylinder is set to the following amount.
Shift amount = W2 × (0.3 to 0.7) + N2 × W2 [N2: <a positive integer of N1]
here,
Reinforcing fiber yarn count: N1
Combined yarn width: W1
Single strand yarn width: W2 [= W1 / N1]
It is.

  By the above manufacturing method, it is avoided that many voids are generated at a specific position in the circumferential direction of the cylindrical cross section, and the helical winding layer is laminated and molded in a stable shape in the cylindrical radial direction, and as a whole An FRP cylinder having a stable shape and capable of accurately and stably expressing desired excellent strength characteristics is formed.

  According to the FRP cylinder and the manufacturing method thereof according to the present invention, the boundary between the reinforcing fiber bundles is prevented from being the same position between the helical winding layers, and each helical winding layer presses down the lower helical winding reinforcing fiber bundle boundary. Since it is molded, it is possible to provide an FRP cylinder of excellent quality that does not have a polygonal cross section and does not have a large void around the position estimated as the fiber bundle boundary. Furthermore, since the polygonal shape is prevented and there is no large void around the position estimated to be the fiber bundle boundary, it is possible to prevent a decrease in strength expression rate such as resonance frequency and torsional strength.

Below, the case where the desirable embodiment of the propeller shaft concerning the present invention is applied to the propeller shaft for vehicles is explained.
As described above, the FRP cylinder according to the present invention has a configuration as shown in FIG. When such an FRP cylinder 11 is applied to a propeller shaft, as described above, the cylindrical body is constituted by a helical winding layer for expressing strength characteristics such as torsional strength, resonance frequency, etc. A reinforcing layer composed of a circumferential winding layer for press-fitting a metal joint (not shown) is provided on the peripheral surface side to form an FRP main body cylinder, and yokes as metal joints are joined to both ends thereof, Configure the propeller shaft. The FRP cylinder and the yoke can be joined by pressing the joint of the yoke into the end of the FRP cylinder.

  As the material of the FRP cylinder, for example, carbon fibers are used as reinforcing fibers, and epoxy resin is used as a matrix resin. In addition, other fibers said to have high strength and high elasticity such as aramid fiber and glass fiber can be used as the reinforcing fiber, or it can be used in combination with carbon fiber. Unsaturated polyester resin, phenol resin, vinyl ester as matrix resin Other thermosetting resins such as resins can also be employed.

  As shown in FIG. 2, the helical layer of the FRP cylinder 11 has a resin reinforced fiber bundle 12 (a reinforced fiber bundle bundled in a state in which a plurality of continuous reinforcing fibers are combined) on a mandrel 1 (core material). Helical winding is performed by the filament winding method so that the circumferential phases are shifted from each other, and the respective layers are stacked so as not to generate an extreme gap or overlap. After the resin-impregnated fiber is wound around the mandrel 1 and formed into a cylindrical body, the resin impregnated in the fiber is thermally cured, and then the mandrel is extracted and cut into a predetermined length required as a propeller shaft. An FRP cylinder is created.

  Next, torsion test evaluation and resonance frequency measurement were performed in order to confirm the effect of the FRP cylinder satisfying the constituent requirements of the present invention described in the above embodiment. These will be described in detail below.

  The FRP cylinder for the propeller shaft used for the test evaluation was manufactured by the filament winding method. A carbon fiber bundle ("Torayca" T700S, 24000 filament, elongation at break 2.1%) manufactured by Toray Industries, Inc. was used as the fiber, and a bisphenol A type epoxy resin was used as the matrix resin. Moreover, the mandrel used for manufacture used the thing whose outer diameter (namely, inner diameter of a FRP cylinder) is (phi) 74 mm, and the full length is 1000 mm, and shape | molded one FRP cylinder (product length 900mm).

  First, a roving impregnated with an epoxy resin (a bundle of multiple carbon fibers aligned) is formed on a mandrel surface after forming a hoop-wrapped reinforcing layer at a location corresponding to the end of an FRP cylinder body into which a metal joint is press-fitted. A helical winding reinforcement layer corresponding to the FRP cylinder is continuously formed over the long part. At this time, the helical winding was formed with a winding angle of ± 10 ° and a stacking number of four (the form shown in FIG. 2). Further, from the outer diameter of the mandrel and the width of the helically wound reinforcing fiber bundle, the number necessary for the helically wound reinforcing fiber bundle to cover the entire outer peripheral surface of the mandrel, that is, the number of reciprocations of the helically wound reinforcing fiber bundle required for one layer is 13 It became.

  Regarding the winding state of the helical winding layer, when the first helical winding layer is completed and the second helical winding layer is started by programming for filament winding, the second helical winding reinforcing fiber bundle is 1 When the 2nd helical winding layer is finished and the 3rd helical winding layer is started so as to hold down the boundary (one end in the width direction) of the helical winding reinforcing fiber bundle of the 3rd layer, the 3rd helical winding reinforcement When the third helical winding layer is finished and the fourth helical winding layer is started so that the fiber bundles hold down the boundary between the first and second helical wound reinforcing fiber bundles, the fourth helical layer is started. The wound reinforcing fiber bundles were arranged so as to suppress the boundary of the first, second, and third helical wound reinforcing fiber bundles, thereby forming each helical wound layer. After the helical winding, one layer of hoop winding (circumferential winding) was formed on the outermost layer.

  Next, the epoxy resin was cured in a heating furnace under a predetermined temperature condition, and then the molded product was decentered from the mandrel. After decentering, in order to obtain an FRP cylinder for a propeller shaft, it was cut at a predetermined length.

  The FRP cylinder obtained in this way was cut and the cross section was observed, but the FRP cylinder was not polygonal but circular, with voids at regular positions in each helical winding layer. The so-called void was not generated.

  Metal joints called yokes were attached to both ends of the propeller shaft FRP cylinder manufactured as described above. The FRP cylinder for the propeller shaft obtained by the conventional manufacturing method has a polygonal shape, and there are many large voids around the position estimated as the fiber bundle boundary. The resonance frequency and torsional strength of the FRP cylinder However, there was a tendency for the measured values to be considerably reduced to 100 Hz and 2000 Nm with respect to the design standard value of 150 Hz and 3000 Nm. However, the propeller shaft FRP cylinder obtained in the present example was not polygonal and no large voids could be confirmed. When the resonance frequency and torsional strength of this FRP cylinder were measured, 155 Hz and 3200 Nm were obtained, which were almost the same as the target calculated values.

The FRP cylinder for the propeller shaft used for the test evaluation was manufactured by the filament winding method. A carbon fiber bundle ("Torayca" T700S, 24000 filament, elongation at break 2.1%) manufactured by Toray Industries, Inc. was used as the fiber, and a bisphenol A type epoxy resin was used as the matrix resin. Moreover, the mandrel used for manufacture used the thing whose outer diameter (namely, inner diameter of a FRP cylinder) is (phi) 74 mm, and the full length is 1000 mm, and shape | molded one FRP cylinder (product length 900mm). At this time, based on the shift amount specified in the present invention, the number N1 of reinforcing fiber combined yarns, the combined yarn width W1 = 18 mm, the single strand yarn width W2 = 6 mm, the shift amount = 6 × 0.5 + 0 × 6 = It was set to 3 mm [N2 = 0].

  First, a hoop winding reinforcement layer is provided at a position corresponding to the end of the FRP cylinder body into which a metal joint is press-fitted in a state in which three carbon fiber bundles impregnated with an epoxy resin are aligned (three-fiber combined state). After molding, a helically wound reinforcing layer corresponding to the FRP cylinder is continuously formed on the mandrel surface length portion over the mandrel surface length portion. At this time, the helical winding was formed with a winding angle of ± 10 °, a yarn width of 18 mm in a three-ply yarn state, and a stacking number of four layers (the form shown in FIG. 2). Further, from the outer diameter of the mandrel and the width of the helically wound reinforcing fiber bundle, the number necessary for the helically wound reinforcing fiber bundle to cover the entire outer peripheral surface of the mandrel, that is, the number of reciprocations of the helically wound reinforcing fiber bundle required for one layer is 13 It became.

  Regarding the winding state of the helical winding layer, when the first helical winding layer is completed and the second helical winding layer is started by programming for filament winding, the second helical winding reinforcing fiber bundle starts. The second helical winding layer ends and the third helical winding layer is pressed so that the position is 3 mm away from the starting position of the first helical winding reinforcing fiber bundle and the boundary (one end in the width direction) is pressed down. Is started, the start position of the third-layer helically wound reinforcing fiber bundle is 3 mm away from the starting position of the second-layer helically wound reinforcing fiber bundle, and the first and second layers of helically wound reinforcing fiber bundle When the third helical winding layer ends and the fourth helical winding layer starts so as to hold down the fiber bundle boundary, the starting position of the fourth helical winding reinforcing fiber bundle is the third helical winding. Reinforcing fiber bundle First layer made from the starting position and 3mm Families were located, the helical winding reinforcing fiber bundle boundary second and third layers are arranged as hold down, to form the helical wound layer. After the helical winding, one layer of hoop winding (circumferential winding) was formed on the outermost layer.

  Next, the epoxy resin was cured in a heating furnace under a predetermined temperature condition, and then the molded product was decentered from the mandrel. After decentering, in order to obtain an FRP cylinder for a propeller shaft, it was cut at a predetermined length.

  The FRP cylinder obtained in this way was cut and the cross section was observed, but the FRP cylinder was not polygonal but circular, with voids at regular positions in each helical winding layer. The so-called void was not generated.

  As described above, by forming the boundary between the helical wound reinforcing fiber bundles so as not to be at the same position between the helical winding layers, the cross section does not become polygonal, large voids are not generated inside, and the strength expression rate is reduced. It was also confirmed that it was not generated.

  In the same manner as in Example 1, metal joints called yokes were attached to both ends of the propeller shaft FRP cylinder manufactured as described above. The FRP cylinder for the propeller shaft obtained by the conventional manufacturing method has a polygonal shape, and there are many large voids around the position estimated as the fiber bundle boundary. The resonance frequency and torsional strength of the FRP cylinder However, there was a tendency for the measured values to be considerably reduced to 100 Hz and 2000 Nm with respect to the design standard value of 150 Hz and 3000 Nm.

  However, the propeller shaft FRP cylinder obtained in Example 2 was not polygonal, and no large voids could be confirmed. When the resonance frequency and torsional strength of this FRP cylinder were measured, 155 Hz, 3500 Nm, and a higher torsional strength than those of Example 1 were obtained, and the target results almost as calculated.

  As described above, by forming the boundary between the helical wound reinforcing fiber bundles so as not to be at the same position between the helical winding layers, the cross section does not become polygonal, large voids are not generated inside, and the strength expression rate is reduced. It was also confirmed that it was not generated.

  The FRP cylinder and the manufacturing method thereof according to the present invention can be applied to any FRP cylinder, and are particularly suitable for application to an FRP cylinder of a vehicle propeller shaft.

It is a cross-sectional view of a conventional FRP cylinder. It is a cross-sectional view of the FRP cylinder which concerns on one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mandrel 11 FRP cylinder 12 Reinforcing fiber bundle 13 Helical winding layer

Claims (7)

An FRP cylinder formed by winding a reinforcing fiber bundle impregnated with resin on a mandrel at the same angle to form a plurality of helical winding layers of at least two layers, each laminated in the cylinder radial direction phase in the cylindrical body circumferential direction of the reinforcing fiber bundle of the helical winding layer, so that the width direction end portion position of the reinforcing fiber bundle avoid becoming around the same phase or the same phase, with are offset from each other, the cylindrical body An FRP cylinder characterized in that the amount of shift in the circumferential direction is the following amount .
Shift amount = W2 × (0.3 to 0.7) + N2 × W2 [N2: <a positive integer of N1]
Reinforcing fiber yarn count: N1
Combined yarn width: W1
Single strand yarn width: W2 [= W1 / N1] Among the reinforcing fiber bundles which are stacked in the cylindrical body radially, the reinforcing fiber bundle is located in the upper layer is arranged so as to cover the widthwise end portions of the reinforcing fiber bundle is located in the lower layer, according to claim 1 FRP cylinder. The FRP cylinder according to claim 1 or 2 , wherein, in each of the reinforcing fiber bundles laminated in the cylinder radial direction, phases in the cylinder circumferential direction are shifted from each other between adjacent reinforcing fiber bundles. The FRP cylinder according to any one of claims 1 to 3 , wherein the phases in the cylinder circumferential direction are shifted from each other for all of the reinforcing fiber bundles laminated in the cylinder radial direction. Reinforcing fiber bundle in a cylindrical body radially are stacked three or more layers, the phase in the cylindrical body circumferential direction of each reinforcing fiber bundle are successively shifted in the same circumferential direction, according to any one of claims 1-4 FRP cylinder. The FRP cylinder according to any one of claims 1 to 5 , wherein a metal joint is joined to both ends to constitute a propeller shaft. In filament winding molding, on a mandrel, a reinforcing fiber bundle impregnated with a resin is wound at the same angle to form a plurality of helical wound layers of at least two layers. In order to avoid the phase in the cylindrical circumferential direction of the reinforcing fiber bundle of each helical winding layer laminated in the cylindrical radial direction, the width direction end position of each reinforcing fiber bundle is in the same phase or around the same phase. A method for manufacturing an FRP cylinder, wherein the FRP cylinders are shifted from each other and the shift amounts in the circumferential direction of the cylinder are as follows.
Shift amount = W2 × (0.3 to 0.7) + N2 × W2 [N2: <a positive integer of N1]
Reinforcing fiber yarn count: N1
Combined yarn width: W1
Single strand yarn width: W2 [= W1 / N1]

Images