阅读说明：本技术 纤维增强树脂制螺栓制造方法和纤维增强树脂制螺栓 (Method for manufacturing fiber-reinforced resin bolt and fiber-reinforced resin bolt ) 是由 土田健司 古田泰浩 于 2019-01-11 设计创作，主要内容包括：提供与现有的纤维增强树脂制螺栓相比强度高的纤维增强树脂制螺栓。采用下述工序形成的纤维增强树脂制螺栓(1)：卷绕工序,其中,通过将以CFRP(12)的方向成为纵向方向的方式与热固化性树脂一体化而形成为带状的CFRP树脂带(14)卷绕以使CFRP(12)围绕卷绕轴成为同心状,从而形成CFRP树脂带层(10)；固化工序,其中,通过将采用卷绕工序形成的CFRP树脂带层(10)放入对内径壁面施以螺纹形状的模具(40),将放入了CFRP树脂带层(10)的模具(40)从卷绕轴的方向的一方向另一方加压,用加热器82加热,从而使包含CFRP树脂带层(10)的树脂固化。(Provided is a fiber-reinforced resin bolt having higher strength than conventional fiber-reinforced resin bolts. A fiber-reinforced resin bolt (1) formed by the following steps: a winding step in which a CFRP resin tape layer (10) is formed by winding a CFRP resin tape (14) formed into a tape shape by integrating a thermosetting resin with the CFRP (12) so that the direction of the CFRP (12) is the longitudinal direction, so that the CFRP (12) is concentric around a winding shaft; and a curing step in which the CFRP resin tape layer (10) formed in the winding step is placed in a die (40) having a thread shape on the inner diameter wall surface, the die (40) having the CFRP resin tape layer (10) placed therein is pressed from one side to the other side in the direction of the winding axis, and the resin including the CFRP resin tape layer (10) is cured by heating with a heater (82).)

1. A method for manufacturing a fiber-reinforced resin bolt, characterized in that a fiber-reinforced resin bolt (1) is formed by the following steps:

a winding step in which a reinforcing fiber resin tape (14) formed into a tape shape by integrating a resin so that the direction of a reinforcing fiber (12) becomes the longitudinal direction is wound so that the reinforcing fiber (12) becomes concentric around a winding axis to form a reinforcing fiber resin tape layer (10);

and a curing step of putting the reinforcing fiber resin tape layer (10) formed in the winding step into a mold (40) having an inner diameter wall surface formed into a screw shape, and curing the resin of the reinforcing fiber resin tape layer (10) by pressing the reinforcing fiber resin tape layer (10) put into the mold (40) from one side to the other side in the direction of the winding axis.

2. The method of manufacturing a fiber reinforced resin bolt according to claim 1, characterized by comprising a bending step of bending the reinforcing fiber resin tape layer (10) formed by the winding step to an axis parallel to the winding axis after the winding step.

3. A method for manufacturing a fiber-reinforced resin bolt, characterized in that a fiber-reinforced resin bolt (1) is formed by the following steps:

a winding step in which a reinforcing fiber tape (62) formed in a band shape such that the direction of a reinforcing fiber (12) is the longitudinal direction is wound so that the reinforcing fiber (12) is concentric about a winding axis, thereby forming a reinforcing fiber tape layer (60);

a resin injection step of placing the reinforcing fiber tape layer (60) formed in the winding step in a mold (40) having a thread shape on an inner diameter wall surface, and injecting a resin into the mold (40) in which the reinforcing fiber tape layer (60) is placed;

and a curing step of curing the resin including the reinforcing-fiber tape layer (60) by pressing the mold (40) into which the resin has been injected in the resin injection step from one side in the direction of the winding axis to the other side.

4. The method of manufacturing a fiber-reinforced resin bolt according to claim 3, characterized by comprising a bending step of bending the reinforcing fiber tape layer (60) formed by the winding step to an axis parallel to the winding axis after the winding step, wherein the resin injection step is performed by placing the reinforcing fiber tape layer (60) formed by the bending step in a mold (40) having a thread shape on an inner diameter wall surface, and injecting resin into the mold (40) in which the reinforcing fiber tape layer (60) is placed.

5. A fiber-reinforced resin bolt (1) characterized by comprising: a reinforcing fiber layer (70) in which a reinforcing fiber (12) formed in a band shape such that the fiber direction is the longitudinal direction is formed in a state in which the reinforcing fiber (12) is wound in a spiral shape around a central axis; a resin layer (20) comprising the reinforcing fiber layer (70); and a threaded portion (30) formed on the outer peripheral surface by heating and pressing in a state where the reinforcing fiber layer (70) is contained with the resin layer (20).

6. A bolt (1) made of fiber reinforced resin according to claim 5, wherein the reinforcing fiber (12) is carbon fiber reinforced plastic.

Technical Field

The present invention relates to a high-strength bolt made of a reinforcing fiber and a resin material.

Background

Conventionally, as a fiber-reinforced resin bolt, there is a fiber-reinforced resin bolt formed by press molding a rod-shaped raw material in which long fibers such as carbon fibers are contained in a synthetic resin so as to be arranged in a longitudinal direction, in which at least the long fibers of a straight portion are arranged linearly along an axial direction at an outer peripheral portion of the fiber-reinforced resin bolt and are arranged in a curved shape at an axial center portion (for example, patent document 1).

Disclosure of Invention

Problems to be solved by the invention

However, the above conventional fiber-reinforced resin bolt has a structure in which long fibers of a linear portion are arranged linearly in the axial direction at the outer peripheral portion and in a curved shape at the axial center portion, and therefore has a problem of insufficient strength as a bolt.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a fiber-reinforced resin bolt having higher strength than a conventional fiber-reinforced resin bolt, and a fiber-reinforced resin bolt.

Means for solving the problems

[ application example 1]

The key point of the method for manufacturing the fiber reinforced resin bolt is that the fiber reinforced resin bolt (1) is formed by adopting the following steps:

a winding step in which a reinforcing fiber resin tape (14) formed into a tape shape by integrating a resin so that the direction of a reinforcing fiber (12) becomes the longitudinal direction is wound so that the reinforcing fiber (12) becomes concentric around a winding axis, thereby forming a reinforcing fiber resin tape layer (10);

and a curing step of putting the reinforcing fiber resin tape layer (10) formed in the winding step into a mold (40) having an inner diameter wall surface formed into a screw shape, and curing the resin of the reinforcing fiber resin tape layer (10) by pressing the reinforcing fiber resin tape layer (10) put into the mold (40) from one side to the other side in the direction of the winding axis.

In the method for manufacturing the fiber reinforced resin bolt, a reinforcing fiber resin tape layer (10) is formed by winding a reinforcing fiber resin tape (14) around a winding shaft in a concentric circle.

Then, the formed reinforcing fiber resin tape layer (10) is placed in a mold (40), and pressure is applied from one side of the winding shaft to the other side, thereby curing the resin of the reinforcing fiber resin tape layer (10) (curing step).

Wherein the reinforcing fiber resin tape layer (10) is pressurized, so that the reinforcing fiber layer extends in a spiral shape in the winding axis direction to form a reinforcing fiber layer (70).

The inner wall surface of the mold (40) is threaded, and the reinforcing fiber resin tape layer (10) is placed in the mold (40) such that the winding axis thereof is parallel to the threaded inner wall surface. Therefore, when the resin is cured, a thread is formed on the outer wall surface.

The fiber-reinforced resin bolt (1) manufactured by the manufacturing method is a bolt (1) having a reinforcing fiber layer (70) wound in a spiral shape around a winding shaft inside a cured resin.

When such a fiber-reinforced resin bolt (1) is used, a tensile force in the axial direction and a bending force in the circumferential direction are applied to the fiber-reinforced resin bolt (1). The reinforcing fiber (12) receives the tensile force and the bending force, and the reinforcing fiber layer (70) is formed into a spiral shape, so that the reinforcing fiber (12) receives the forces of both the tensile force and the bending force.

Therefore, a fiber-reinforced resin bolt (1) having higher strength than a conventional bolt having reinforcing fibers arranged only in the axial direction can be obtained.

[ application example 2]

The method of manufacturing a fiber-reinforced resin bolt according to application example 1 is characterized by including a bending step of bending the reinforcing fiber resin tape layer (10) formed by the winding step to an axis parallel to the winding axis after the winding step.

According to the method for manufacturing a fiber-reinforced resin bolt, the reinforcing fiber resin tape layer (10) formed in the winding step is further bent with respect to the axis parallel to the winding axis in the bending step. Therefore, a plurality of layers of the reinforcing fiber resin tape layer (10) are formed, and therefore a fiber-reinforced resin bolt (1) with higher strength can be manufactured.

Furthermore, even if the diameter of the reinforcing fiber resin tape layer (10) formed by winding is increased in the winding step, the reinforcing fiber resin tape layer (10) having an appropriate diameter can be formed by the subsequent bending step, and therefore the winding step can be facilitated.

[ application example 3]

The key point of the method for manufacturing the fiber reinforced resin bolt is that the fiber reinforced resin bolt (1) is formed by adopting the following steps:

a winding step in which a reinforcing fiber tape (62) formed in a band shape such that the direction of a reinforcing fiber (12) is the longitudinal direction is wound so that the reinforcing fiber (12) is concentric about a winding axis, thereby forming a reinforcing fiber tape layer (60);

a resin injection step of placing the reinforcing fiber tape layer (60) formed in the winding step in a mold (40) having a thread shape on an inner diameter wall surface, and injecting a resin into the mold (40) in which the reinforcing fiber tape layer (60) is placed;

and a curing step of curing the resin including the reinforcing-fiber tape layer (60) by pressing the mold (40) into which the resin has been injected in the resin injection step from one side in the direction of the winding axis to the other side.

In the method for manufacturing a fiber-reinforced resin bolt, a reinforcing fiber tape (62) is wound concentrically around a winding shaft to form a reinforcing fiber tape layer (60).

Then, the formed reinforcing fiber tape layer (60) is placed in a mold (40), a resin is injected (resin injection step), the mold (40) into which the resin is injected is pressed from one side of the winding shaft to the other side, and the resin of the reinforcing fiber tape layer (60) is cured (curing step).

Wherein the reinforcing fiber tape layer (60) extends in a spiral shape in the winding axis direction when heated and pressurized. In addition, the inner wall surface of the mold (40) is threaded, and the reinforcing fiber tape layer (60) is placed in the mold (40) so that the winding axis thereof is parallel to the threaded inner wall surface. Therefore, when the resin is cured, a thread is formed on the outer wall surface.

The fiber-reinforced resin bolt (1) manufactured by the manufacturing method can be manufactured into a fiber-reinforced resin bolt (1) having higher strength than a conventional bolt in which reinforcing fibers are arranged only in the axial direction, as in the fiber-reinforced resin bolt (1) of application example 1.

[ application example 4]

The method of manufacturing a fiber-reinforced resin bolt according to application example 3 is characterized by including a bending step of bending a reinforcing fiber tape layer (60) formed by the winding step with respect to an axis parallel to the winding axis after the winding step, wherein the resin injection step includes placing the reinforcing fiber tape layer (60) formed by the bending step in a mold (40) having a thread shape on an inner diameter wall surface, and injecting resin into the mold (40) in which the reinforcing fiber tape layer (60) is placed.

According to the method for manufacturing a fiber-reinforced resin bolt, the same effects as those of application example 3 can be obtained.

[ application example 5]

The invention relates to a fiber-reinforced resin bolt (1) which is characterized by comprising: a reinforcing fiber layer (70) in which a reinforcing fiber (12) formed in a band shape such that the fiber direction is the longitudinal direction is formed in a state in which the reinforcing fiber (12) is wound in a spiral shape around a central axis; a resin layer (20) comprising the reinforcing fiber layer (70); and a threaded portion (30) formed on the outer peripheral surface by heating and pressing in a state where the reinforcing fiber layer (70) is contained with the resin layer (20).

As with the fiber-reinforced resin bolt (1) manufactured by the fiber-reinforced resin bolt manufacturing method of application example 1, such a fiber-reinforced resin bolt (1) can be manufactured as a fiber-reinforced resin bolt (1) having a higher strength than a conventional bolt having reinforcing fibers arranged only in the axial direction.

[ application example 6]

The fiber-reinforced resin bolt (1) according to application example 3 is characterized in that the reinforcing fiber (12) is carbon fiber-reinforced plastic.

In such a fiber-reinforced resin bolt (1), since carbon fiber-reinforced plastic is used as the reinforcing fibers (12), the fiber-reinforced resin bolt (1) can be made lightweight and high in strength.

Drawings

Fig. 1 is a schematic view showing the configuration of a CFRP resin tape, a CFRP resin tape layer, and a CFRP tape layer.

Fig. 2 is a view showing a CFRP resin tape layer or a CFRP tape layer formed in a ring shape placed in a mold.

Fig. 3 is a schematic view showing a structure of a mold.

Fig. 4 is a schematic view showing a state where the insertion tool 50 is inserted into a mold and the resin in the mold is pressurized.

Fig. 5 is a cross-sectional photograph of the fiber reinforced resin bolt.

Fig. 6 is a graph showing the results of a tensile fracture test using a bolt made of a fiber-reinforced resin.

Fig. 7 is a graph showing the results of a tensile fracture test of a fiber-reinforced resin bolt in which the carbon fiber content and the resin content are different.

Fig. 8 is a conceptual diagram for explaining a winding method of the CFRP resin tape and the CFRP tape and a folding method of the CFRP resin tape layer and the CFRP tape layer in the third embodiment and the fifth embodiment.

Detailed Description

Hereinafter, embodiments to which the present invention is applied will be described with reference to the drawings. The embodiments of the present invention are by no means limited to the following embodiments, and various embodiments can be adopted as long as they fall within the technical scope of the present invention.

[ first embodiment ]

(production of fiber-reinforced resin bolt)

A method for manufacturing a fiber-reinforced resin bolt 1 (hereinafter also simply referred to as "bolt 1") will be described with reference to fig. 1 to 4. In the present embodiment, a carbon fiber reinforced plastic (hereinafter also referred to as "CFRP 12") is used as the reinforcing fibers 12.

First, as shown in fig. 1a, the CFRP12 is integrated with a predetermined amount of resin so that the fiber direction is the longitudinal direction, to form a strip-shaped CFRP resin tape 14, which is wound concentrically around a winding axis as shown in fig. 1b (plan view) and 1 c (side view), to form a ring-shaped CFRP resin tape layer 10 (winding step). At this time, the CFRP resin tape 14 is wound around the winding shaft with as little clearance as possible.

The term "integrating CFRP with a predetermined amount of resin" means that long fibers of CFRP are arranged in a band shape, and the long fibers are impregnated with resin and solidified to form a band shape. The amount of CFRP and the amount of resin at this time are the amount of CFRP necessary for the bolt 1 to have a predetermined strength, and the amount of resin (amount of resin after winding) necessary for forming the threaded portion 30 as the bolt 1, or the amount of resin is determined according to the kind of thermosetting resin.

In the present embodiment, a thermosetting resin such as vinyl ester is used as the resin. Further, the ratio of CFRP12 to the thermosetting resin was CFRP 12: 50-60 wt%, thermosetting resin: 50 to 40 wt%, particularly in the present embodiment, CFRP 12: 57% of a thermosetting resin: and 43 percent.

Note that, in fig. 1(a) and 1(c), a conceptual drawing is used to show the fiber of the CFRP12, and in fig. 1(b), the gap is drawn larger than the actual one in order to make it easy to know the laminated state of the CFRP resin tape 14 wound.

Next, power is supplied to the heater 82 of the mold 40, and the mold 40 is preheated (about 90 ℃ in the case of vinyl ester) so as to have a temperature lower than the curing temperature of the thermosetting resin.

Next, as shown in fig. 2, the CFRP resin tape layer 10 formed in a ring shape is put into a portion of the die 40 close to the cylindrical portion 44 of the threaded portion 46 so that the winding axis substantially coincides with the axial direction of the threaded portion 46 of the die 40.

As shown in fig. 3(a) and 3(b), the die 40 is formed by halving a block of a metal such as SUS material (one is the die 40a, and the other is the die 40b), so that it can be integrated with the bolt 41 and the nut 42. The inner surfaces of the half-split molds 40a and 40b are shaped to have the outer diameter of the bolt 1.

In fig. 3, fig. 3(a) and 3(b) are line-symmetrical with respect to the two-dot chain line a-a'.

That is, as shown in fig. 3(a), the bolt 1 has a die shape for forming the head portion 43a, the cylindrical portion 44a, the incomplete thread portion 45a, and the thread portion 46 a. Further, an insertion hole 47a into which an insertion portion 51 of an insertion tool 50 for compressing resin is inserted is provided at one end of the mold 40.

In the mold 40b, a head portion 43b, a cylindrical portion 44b, an incomplete thread portion 45b, a thread portion 46b, and an insertion hole 47b, which have the same shape as the mold 40a, are formed at line-symmetrical positions of the mold 40 b. Hereinafter, the hole formed by the insertion hole 47a and the insertion hole 47b is referred to as an insertion hole 47.

The mold 40a is provided with 4 through holes 49a for integrating the mold 40b with the bolts 41 and the nuts 42, and 2 pins 48a for positioning at the time of integration.

In the die 40b, 4 through holes 49b and 2 holes 48b fitted with the 2 pins 48a are provided at line-symmetrical positions of the die 40 a.

Further, 2 heaters 82 (4 heaters in total in the mold 40) are embedded in each of the molds 40a and 40b, and the mold 40 can be heated by supplying power to the heaters 82 from the outside.

After the CFRP resin tape layer 10 is put into the mold 40, the half-mold 40 is integrated with the bolt 41 and the nut 42, and then the insertion jig 50 is inserted into the insertion hole 47 as shown in fig. 4 (a). The insertion tool 50 is made of a metal such as SUS material, and includes an insertion portion 51 having a slightly smaller outer diameter than the diameter of the insertion hole 47, and a columnar head 52 provided at one end of the insertion portion 51.

As shown in fig. 4(b), in a state where the insertion portion 51 of the insertion tool 50 is inserted into the insertion hole 47, the head 52 is placed on the die 40 on the support plate 80 of the press, the head 52 is pressed down by the slider 81 of the press to pressurize the resin in the die 40, and then power supply to the heater 82 is performed to raise the temperature of the die 40 (i.e., the temperature of the resin — about 150 ℃ in the case of vinyl ester) to the curing temperature of the resin and cure the resin (curing step).

After the curing process is completed, the power supply to the heater 82 is stopped, the nut 42 of the mold 40 is loosened, the mold 40 is separated, and the bolt 1 is taken out from the mold 40.

(characteristics of bolt 1)

The fiber-reinforced resin bolt 1 manufactured by such a manufacturing method includes, as shown in fig. 5(a), a resin layer 20, a threaded portion 30, a head portion 31, a cylindrical portion 32, and an incomplete threaded portion 33. The CFRP resin tape layer 10 of the fiber-reinforced resin bolt 1 formed into a ring shape in the winding step is pressed in the winding axial direction inside the die 40 by pressure in the curing step to form a spiral shape.

Therefore, the fiber reinforced resin bolt 1 is a bolt having the CFRP layer 70 wound in a spiral shape around the winding axis inside the cured resin layer 20. Fig. 5(a) is a photograph showing a cross section of the entire actual fiber-reinforced resin bolt 1, and fig. 5(b) is a photograph showing an enlarged cross section of the threaded portion 30 of the fiber-reinforced resin bolt 1.

As shown in fig. 5(a) and 5(b), the CFRP layer 70 is formed in the entire interior of the resin layer 20 of the fiber-reinforced resin bolt 1.

The CFRP12 receives the axial tensile force and the circumferential bending force applied to the fiber-reinforced resin bolt 1, and the CFRP12 receives both the tensile force and the bending force because the CFRP layer 70 is formed in a spiral shape.

Therefore, the fiber-reinforced resin bolt 1 can be made stronger than a conventional bolt in which the reinforcing fibers are arranged only in the axial direction.

In addition, since CFRP (carbon fiber reinforced plastic) is used as the reinforcing fibers 12 in the fiber-reinforced resin bolt 1, the fiber-reinforced resin bolt 1 can be made lightweight and high in strength.

Fig. 6 shows the results of tensile fracture tests performed on bolts 1 made of M8-sized fiber-reinforced resin, bolts made of RENY (registered trademark) (bolts made of glass fiber 50% reinforced polyamide MXD 6), and bolts made of PEEK (bolts made of polyether ether ketone) by the test method according to JIS B1051. As described above, the fiber-reinforced resin bolt 1 is formed of CFRP 12: 57% by weight, and 43% by weight of a thermosetting resin.

As shown in fig. 6(a) and 6(b), in the fiber-reinforced resin bolt 1, the tensile breaking load at which the bolt breaks is 14346.3[ N ], and a tensile breaking strength of about 2.4 times as high as 6023.5[ N ] of the tensile breaking load of the conventional RENY bolt and about 4.5 times as high as 3158.6[ N ] of the tensile breaking load of the PEEK bolt can be obtained.

[ second embodiment ]

Next, a second embodiment in which the carbon fiber content and the resin content of the fiber-reinforced resin bolt 1 are changed will be described. The material and the manufacturing method of the fiber-reinforced resin bolt 1 according to the second embodiment are the same as those of the fiber-reinforced bolt 1 according to the first embodiment, and therefore, the description thereof is omitted.

Fig. 7 shows the results of the tensile fracture test of the fiber-reinforced resin bolt 1 when the carbon fiber content and the resin content were changed. The tensile break test was carried out by the test method according to JIS B1051 in the same manner as in the case shown in fig. 6.

As a test sample, a bolt 1 made of a fiber-reinforced resin having a size of M3 was used, and as shown in fig. 7(a), the bolt was manufactured by using sample No. 1: carbon fiber content 43.8%, resin content 56.2%, sample No. 2: carbon fiber content 50.9%, resin content 49.1%, sample No. 3: the 3 samples having a carbon fiber content of 56.4% and a resin content of 43.6% were subjected to a tensile fracture test.

As shown in fig. 7(a) and 7(b), the tensile breaking strength of the fiber reinforced resin bolt 1 becomes the tensile breaking load in sample No. 1: 2030[ N ], tensile breaking load in sample No. 2: 2370[ N ], in sample No.3, to obtain a tensile breaking load: 2042[ N ].

On the other hand, the conventional screw bolt made of M3 and made of RENY has a tensile breaking load of 762[ N ], and it is found that the screw bolt 1 made of fiber-reinforced resin has a tensile breaking strength of about 2.7 to 3.1 times as high as that of the screw bolt made of RENY.

Further, it is known that the PEEK bolt of M3 of the related art has a tensile breaking load of 430[ N ], and the fiber reinforced resin bolt 1 has a tensile breaking strength of about 4.7 to 5.5 times as high as that of the PEEK bolt.

As can be seen from the above, the ratio of CFRP12 to thermosetting resin is CFRP 12: 40-60 wt%, thermosetting resin: sufficient tensile breaking strength is obtained even at a content of 60 to 40 wt%.

[ third embodiment ]

Next, a third embodiment in which a bending step is added after the winding step in the first embodiment will be described.

(winding step)

In the winding step in the third embodiment, unlike the winding shape of the CFRP resin tape 14 in the first embodiment, the CFRP resin tape 14 is wound concentrically around a winding shaft so that the diameter becomes several cm, thereby forming an annular CFRP resin tape layer 10.

As a winding method in this case, as shown in fig. 8(a), the bar material is wound around a cylindrical or cylindrical bar material 90, or as shown in fig. 8(b), 2 bar-shaped bar materials 91a and 91b arranged in parallel are wound around the bar material.

(bending step)

In the folding step, as shown in fig. 8(c), the annular CFRP resin tape layer 10 formed in the winding step is flattened from the lateral direction into a tape shape, one end portion is sandwiched by 2 thin metal rods 92a, 92b, and the metal rod 92a is wound into a concentric circle shape around the axis thereof as shown by an arrow in fig. 8(c) and 8 (d). By doing so, a larger number of layers of CFRP resin tape layers 10 can be formed.

(curing step)

The curing step in the third embodiment is the same as that in the first embodiment, and therefore, description thereof is omitted.

The fiber-reinforced resin bolt 1 manufactured by the manufacturing method using the above-described steps has a further multi-layered CFRP layer 60, and therefore the strength (tensile breaking load) as a bolt is improved.

Further, even if the diameter of the CFRP resin tape layer 10 formed by winding is increased in the winding step, the CFRP resin tape layer 10 having an appropriate diameter can be formed by the subsequent bending step, and therefore the winding step can be facilitated.

[ fourth embodiment ]

Next, a fiber reinforced resin bolt 1 using the CFRP belt 62 instead of the CFRP resin belt 14 will be described.

The CFRP resin belt 14 is formed into a belt shape by integrating a predetermined amount of resin so that the direction of the CFRP fibers becomes the longitudinal direction, and the CFRP belt 62 is formed by aligning and bundling long fibers of CFRP so that the direction of the CFRP fibers becomes the longitudinal direction, or by forming a fiber bundle into a belt shape with a small amount of resin.

(winding step)

The winding step in the fourth embodiment is the same as the winding step in the first embodiment except that the CFRP tape layer 60 is formed using the CFRP tape 62 instead of forming the CFRP resin tape layer 10 using the CFRP resin tape 14, and therefore, detailed description thereof is omitted.

(resin injection step)

After the CFRP tape layer 60 is put in the mold 40, the half mold 40 is integrated by the bolt 41 and the nut 42, and a thermosetting resin such as vinyl ester is injected into the mold 40 through the insertion hole 47.

(curing step)

After the resin is injected into the mold 40, the insertion jig 50 is inserted into the insertion hole 47, and in this state, the head 52 is pressed down by the slider 81 of the press to pressurize the resin in the mold 40, and the mold 40 is heated by supplying power to the heater 82 to cure the resin, as in the first embodiment.

After the curing process is completed, the nut 42 of the mold 40 is loosened, the mold 40 is separated, and the bolt 1 is taken out from the mold 40.

The fiber-reinforced resin bolt 1 manufactured by the manufacturing method described above has the same structure and performance as the fiber-reinforced resin bolt 1 according to the first embodiment (see fig. 5 and 6)

[ fifth embodiment ]

Next, a fifth embodiment will be described. The fifth embodiment is an embodiment in which a bending step is added to the fourth embodiment, as in the third embodiment (in the first embodiment, the bending step is added after the winding step). In this case, the same steps as those of the third embodiment are performed except that the CFRP belt 62 is used instead of the CFRP resin belt 14 used in the third embodiment, and therefore, detailed description thereof is omitted (see fig. 8).

The fiber-reinforced resin bolt 1 manufactured by the manufacturing method according to the fifth embodiment has the same configuration and performance as the fiber-reinforced resin bolt 1 manufactured by the manufacturing method according to the third embodiment. In addition, the winding process can be facilitated as in the third embodiment.

[ other embodiments ]

(1) In the above embodiment, CFRP (carbon fiber reinforced plastic) is used as the reinforcing fiber 12, but instead of CFRP, a reinforcing fiber of inorganic fiber system such as Glass Fiber Reinforced Plastic (GFRP) or a reinforcing fiber of organic fiber system such as Aramid Fiber Reinforced Plastic (AFRP) is used.

(2) In the above embodiment, a thermosetting resin such as vinyl ester is used as the resin, but a thermoplastic resin such as PEEK (polyether ether ketone) or teflon (registered trademark) may be used. In this case, in the curing process, it is not necessary to heat the mold 40 to the thermosetting temperature.

(3) In the above embodiment, in the bending step of forming the CFRP resin tape layer 10 and the CFRP tape layer 60, the annular CFRP resin tape layer 10 and the CFRP tape layer 60 are flattened from the lateral direction into a tape shape, and are wound into a concentric circle shape with one end portion thereof being the central axis. In other words, the CFRP resin tape layer 10 and the CFRP tape layer 60 may be bent several times in a direction perpendicular to the direction of the fibers of the CFRP 12.

(4) In the above embodiment, the shape of the inner surface of the mold 40 is shown as an example of the outer shape of the bolt 1, but the shape is not limited to this, and may be other shapes such as a shape without the cylindrical portion 32.

(5) In the above embodiment, the heater 82 is used to heat the mold 40, but a method capable of heating the mold 40 to the curing temperature of the thermosetting resin may be employed, for example, a method of circulating a heated liquid in the mold 40 or a method of winding nichrome wire around the mold 40.

Description of reference numerals

1 … fiber reinforced resin bolt (bolt) 10 … reinforcing fiber resin tape layer (CFRP resin tape layer) 12 … reinforcing fiber (CFRP) 14 … reinforcing fiber resin tape (CFRP resin tape) 20 … resin layer 30 … threaded part 31 … head 32 … cylindrical part 33 … incomplete threaded part 40, 40a, 40b … die 41 … bolt 42 … nut 43, 43a, 43b … head 44, 44a, 44b … cylindrical part 45, 45a, 45b … incomplete threaded part 46, 46a, 46b … threaded part 47 … insert hole 48a … pin, 48b … hole 49a, 49b … through hole 50 … insert 52 51 … insert 52 head 60 … reinforcing fiber tape layer (CFRP tape layer) 62 … reinforcing fiber tape (CFRP tape) 70 … reinforcing fiber layer (CFRP tape layer) 80 … support plate … slider … heater 90, 91a, 91b … Bar 92a, 92b … Metal Bar