A cylindrical body, a barrier rod formed by joining cylindrical bodies, and a method for manufacturing cylindrical bodies.

Abstract

To provide a tubular body made of fiber-reinforced resin that can be disposed of at low cost and has a low environmental impact during disposal. [Solution] A tubular body made of fiber-reinforced resin, containing basalt fibers as reinforcing fibers, wherein the proportion of the basalt fibers oriented at an inclination angle of 45° to 90° with respect to the axial direction is 20% to 40% of the total basalt fibers in the radial cross-section.

Description

Technical Field

[0001] The present invention relates to a fiber-reinforced resin cylindrical body, a blocking bar formed by jointing such fiber-reinforced resin cylindrical bodies end-to-end, and a method for producing a fiber-reinforced resin cylindrical body.

Background Art

[0002] Fiber-reinforced resin cylindrical bodies are sometimes used as blocking bars for traffic control, such as blocking bars for railroad crossings, blocking bars for ETC gates, or blocking bars for entrances and exits of parking lots. Patent Document 1 describes that a cylindrical body obtained by impregnating glass fibers as reinforcing fibers with a thermoplastic resin is jointed end-to-end and applied to a blocking bar.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] Incidentally, blocking bars may deteriorate due to long-term use, or degrade due to contact with vehicles or the like. However, in the case of a fiber-reinforced resin cylindrical body containing glass fibers, when incinerated in an incinerator, the glass fibers melted at high temperature adhere to the wall surface of the incinerator, which may damage the incinerator. Therefore, there are only limited disposal options such as landfill disposal or use as aggregate. However, in landfill disposal, there are concerns about the outflow of harmful substances into the environment, as well as soil pollution and environmental pollution caused by micronized microplastics. In addition, use as aggregate not only requires a large amount of investment to establish a waste cycle, but also makes it difficult to stably supply aggregate.

[0005] There is a demand for tubular fiber-reinforced resin bodies that can be disposed of at low cost and have a minimal environmental impact during disposal. This demand applies not only to barrier arms used for traffic control, but also to tubular fiber-reinforced resin bodies used in other applications. [Means for solving the problem]

[0006] To solve the above problems, the fiber-reinforced resin tubular body of the present invention contains basalt fibers as reinforcing fibers, and the proportion of the basalt fibers oriented at an inclination angle of 45° to 90° with respect to the axial direction is 20% to 40% of the total basalt fibers in the radial cross-section.

[0007] Because basalt fibers are used as reinforcing fibers in the fiber-reinforced resin, the tubular body can be disposed of at low cost. Furthermore, the environmental impact during disposal can be reduced. Of the oriented basalt fibers, the proportion that intersect the tubular body at an inclination angle of 45° to 90° with respect to the axial direction is between 20% and 40% in the radial cross-section. Therefore, when the tubular body breaks, it breaks rather than cracks axially, and the fracture surface is nearly perpendicular to the axial direction. This makes it less likely for fibrous fraying, which is characteristic of fiber-reinforced resins, to occur on the fracture surface, and sharpening of the cut surface is suppressed. Furthermore, it is possible to maintain high rigidity.

[0008] In the above configuration, it is preferable that the cylindrical body comprises a first cylindrical body having a first main body portion in which the amount of basalt fibers per radial cross-section decreases from one end to the other end in the axial direction.

[0009] The above configuration allows for a fiber arrangement design that corresponds to the bending moment distribution when supported in a cantilevered state. This results in high bending rigidity at one end of the tubular body and reduced weight at the other end. When the tubular body is supported in a cantilevered state at one end, the amount of deflection at the other end is suppressed. In addition, since less basalt fiber can be used, manufacturing costs can be reduced.

[0010] To solve the above problems, the barrier rod of the present invention is a barrier rod that is supported in a cantilevered state by joining together a plurality of tubular bodies containing the basalt fiber as a reinforcing fiber and connecting them in parallel, and has at least one of the first tubular bodies on the axial end side.

[0011] According to the above configuration, the bending rigidity is high at the base end, which is the support side of the barrier rod, and the weight can be reduced at the tip end, which is the free end side. Deflection at the tip end is suppressed. It is also advantageous in terms of manufacturing costs.

[0012] In the above configuration, it is preferable that the cylindrical body comprises a second cylindrical body having a second main body portion in which the amount of basalt fibers per radial cross-section is the same over the entire length in the axial direction, with the first cylindrical body on the axial tip side and the second cylindrical body on the axial base end side.

[0013] According to the above configuration, the bending rigidity at the base end of the barrier rod can be increased, and the amount of deflection at the tip end can be further suppressed. In the above configuration, it is preferable that the total axial length of the first cylindrical body is 25% to 70% of the total axial length of the barrier rod.

[0014] According to the above configuration, the bending rigidity at the base end of the barrier rod can be increased, and the amount of deflection at the tip end can be further suppressed. In addition, since the amount of fiber-reinforced resin used can be reduced, manufacturing costs can be lowered.

[0015] To solve the above problems, the present invention provides a method for manufacturing a cylindrical body comprising a lamination step of laminating multiple layers of fiber-reinforced resin prepreg sheets onto a long core material, and a molding step of pressurizing and heating the pre-molded body on which the prepreg sheets are laminated to form a cylindrical molded body, wherein in the lamination step, the prepreg sheets using basalt fibers as reinforcing fibers are laminated, and the proportion of the number of laminated prepreg sheets in which the orientation direction of the basalt fibers is at an inclination angle of 60° to 90° with respect to the axial direction of the molded body in the radial cross-section of the molded body is 20% to 40% of the total number of laminated prepreg sheets.

[0016] According to the above configuration, it is possible to manufacture tubular bodies made of fiber-reinforced resin that can be disposed of at low cost and have a low environmental impact during disposal. Furthermore, it is possible to manufacture tubular bodies in which the fibrous fraying characteristic of fiber-reinforced resin is less likely to occur at the fracture surface. In addition, it is possible to manufacture tubular bodies with high rigidity.

[0017] In the above configuration, the lamination process includes a main body layer forming step in which the prepreg sheet is wrapped around the core material to form a main body layer corresponding to the total length in the axial direction of the cylindrical body, and in the main body layer forming step, it is preferable to laminate the prepreg sheets in such a way that the number of layers decreases from one end to the other end.

[0018] According to the above configuration, it is possible to manufacture a cylindrical body that has high bending rigidity at one end and is lightweight at the other end, thereby suppressing deflection. In the above configuration, in the main body layer formation step, it is preferable to laminate the prepreg sheets, each having a different length in the axial direction of the core material, and to laminate the longer prepreg sheet on the outer layer of the shorter prepreg sheet.

[0019] According to the above configuration, the edge of the inner-layer prepreg sheet can be covered with the outer-layer prepreg sheet. Thereby, even if steps are formed on both sides of the edge of the inner-layer prepreg sheet, the step is less likely to affect the outer peripheral surface of the cylindrical body. A cylindrical body having an excellent outer surface shape can be manufactured.

Effects of the Invention

[0020] According to the present invention, a fiber-reinforced resin cylindrical body that can be disposed of at low cost and has low environmental load at the time of disposal can be obtained.

Brief Description of Drawings

[0021] [Figure 1] It is a schematic diagram of a blocking rod formed by plain-jointing the cylindrical bodies of the present embodiment. [Figure 2] It is a schematic diagram of a first cylindrical body. [Figure 3] It is a diagram explaining the laminated structure of the first cylindrical body. [Figure 4] It is a diagram explaining the laminated structure of a second cylindrical body. [Figure 5] (a) and (b) are photographs of the results of a breaking test of the cylindrical body of an example. [Figure 6] It is a diagram explaining the results of a flexural rigidity test of the blocking rod of an example. [Figure 7] It is a diagram explaining the results of a flexural rigidity test of the blocking rod of an example.

Mode for Carrying Out the Invention

[0022] Hereinafter, an embodiment of the cylindrical body of the present invention will be described based on Figures 1 to 4. In this embodiment, a barrier rod 1 formed by joining six cylindrical bodies 10 made of fiber-reinforced resin will be described. The barrier rod 1 is supported in a cantilevered manner by a circuit breaker to which an alarm light, alarm speaker, etc., are attached. Hereinafter, with respect to the barrier rod 1, the side supported by the circuit breaker will be called the base end side, and the free end side will be called the tip side. Of the six cylindrical bodies 10 that make up the barrier rod 1, they will be called 1st, 2nd, and 3rd in order from the tip side, and the one closest to the base end will be called 6th. Furthermore, with respect to the cylindrical body 10, the axial end located on the tip side of the barrier rod 1 will be called the tip, and the axial end located on the base side of the barrier rod 1 will be called the base end. Note that the axial ends of the cylindrical body 10 may also be called one end and the other end. Also, the axial direction of the cylindrical body 10 may simply be called the axial direction.

[0023] <Regarding the cylindrical body 10> As shown in Figure 1, the cylindrical body 10 is formed in a tapered cylindrical shape, with both the inner and outer circumferential surfaces gradually decreasing in diameter from one end 10a to the other end 10b. The cylindrical body 10 has a cylindrical shape with a circular radial cross-section. The other end 10b, which has a relatively smaller diameter, is lighter than the one end 10a, which has a relatively larger diameter, and the weight gradually decreases from one end 10a to the other end 10b. When the cylindrical bodies 10 are joined together and applied to the barrier rod 1, the relatively lighter other end 10b of each cylindrical body 10 is positioned towards the tip of the barrier rod 1, and the relatively heavier one end 10a is positioned towards the base of the barrier rod 1.

[0024] Here, the statement that the diameter of the cylindrical body 10 gradually decreases from one end 10a to the other end 10b includes not only cases where the diameter decreases continuously, but also cases where the diameter decreases in steps. Furthermore, it is not necessarily limited to cases where the diameter is smaller at the other end 10b than at the first end 10a at all points along the axial direction of the cylindrical body 10. Even if there are cases where the diameter is larger at the other end 10b than at the first end 10a in a part of the cylindrical body 10, it is sufficient as long as the overall diameter decreases from the first end 10a to the other end 10b. The same applies to the point that the weight gradually decreases from the first end 10a to the other end 10b. Note that Figure 1 is a schematic diagram, and the ratio of radial to axial direction differs from the actual values.

[0025] As shown in Figure 2, the cylindrical body 10 comprises a main body portion 11 extending along the entire axial length of the cylindrical body 10, an outer reinforcing portion 13 provided on the outer surface of one end 10a of the cylindrical body 10, and an inner reinforcing portion 12 provided on the inner surface of the other end 10b of the cylindrical body 10. The main body portion 11 is derived from the main body layers 21 and 24 formed by the main body layer formation process of the lamination process, which will be described later. The outer reinforcing portion 13 and the inner reinforcing portion 12 are derived from the outer reinforcing layer 23 and the inner reinforcing layer 22 formed by the reinforcing layer formation process of the lamination process.

[0026] As shown in Figures 3 and 4, the cylindrical body 10 is formed by laminating multiple layers of fiber-reinforced resin prepreg sheets P, which are made by impregnating reinforcing fibers with a molding resin such as a thermosetting resin, and then thermosetting them.

[0027] The fibers that make up fiber-reinforced resin are basalt fibers. Basalt fibers are inorganic fibers made from basalt, which is readily available globally. In the process of melting them into filaments, there is no need to add chemical substances such as boric acid or other minerals. Furthermore, no dust or gases that would be pollutants are dispersed. In addition, they can be crushed and used as aggregate in concrete and asphalt. In short, they are sustainable, recyclable, and environmentally friendly circular fibers. Compared to glass fibers, basalt fibers have higher elastic modulus, tensile strength, heat resistance, chemical resistance to acids and alkalis, moisture resistance, and durability, and are electrically insulating.

[0028] As the molding resin constituting the fiber-reinforced resin, for example, thermosetting resins such as epoxy resins, phenolic resins, polyester resins, vinyl ester resins, and unsaturated polyester resins can be used. Alternatively, conventionally known thermoplastic resins may also be used.

[0029] As shown in the lower part of Figure 2, in the cross-section of the cylindrical body 10, which is formed by laminating multiple layers of fiber-reinforced resin prepreg sheets P, the state in which the prepreg sheets P are laminated can be seen as a state in which layers of fibers F are laminated. In other words, in the main body 11, the inner reinforcement part 12, and the outer reinforcement part 13, the state in which layers of fibers F arranged in the circumferential direction are laminated within the thermosetting resin that has hardened in a molten and integrated state can be seen. Note that the lower part of Figure 2 is a schematic cross-sectional view of the cylindrical body 10, and the corresponding layers of prepreg sheets P are shown with dashed lines to make the layers of fibers F easier to see. Also, the ratio of the radial and axial directions of the cylindrical body 10 differs from that of the actual structure.

[0030] In the main body portion 11 of the cylindrical body 10, the basalt fibers may be oriented in a bias direction of ±45° with respect to the axial direction of the cylindrical body 10, in a hoop direction of 90°, or in a straight direction of 0°. In addition, basalt fibers with different orientation directions may be mixed as appropriate.

[0031] The basalt fibers constituting the cylindrical body 10 have a predetermined proportion of fibers oriented at a predetermined angle intersecting the axial direction of the cylindrical body 10. Hereinafter, fibers oriented at a predetermined angle intersecting the axial direction of the cylindrical body 10 are defined as angle fibers. For the angle fibers to constitute the present invention, the intersection angle with respect to the axial direction of the cylindrical body 10 is 45° or more and 90° or less. The intersection angle is more preferably 70° or more and 90° or less, even more preferably 80° or more and 90° or less, and even more preferably 90°. Note that the numerical value of the intersection angle is not precise and an error of ± a few degrees is permitted. For example, 90° includes a range of approximately 90° ± 5°.

[0032] The proportion of angle fibers in the radial cross-section of the cylindrical body 10 is between 20% and 40% of the total basalt fibers present in the same radial cross-section. More preferably, the proportion of angle fibers is between 25% and 35%. When the proportion of angle fibers is within this range, a fracture surface is obtained that is nearly perpendicular to the axial direction when the cylindrical body 10 is broken. This makes it less likely for fibrous fraying, which is characteristic of fiber-reinforced resins, to occur on the fracture surface.

[0033] Furthermore, from the viewpoint of improving the bending rigidity of the cylindrical body 10, the proportion of basalt fibers oriented in a straight direction along the axial direction of the cylindrical body 10 is preferably 60% to 80% of the total basalt fibers in the radial cross-section, and more preferably 65% ​​to 75%. When the proportion of basalt fibers oriented at 0° is within this range, the bending rigidity of the cylindrical body 10 is improved.

[0034] As shown in Figures 3 and 4, the cylindrical body 10 has a first cylindrical body 14 and a second cylindrical body 15, each with a different main body 11 configuration. The first cylindrical body 14 has a first main body 16 in which the amount of basalt fibers per radial cross-section decreases from one end 10a to the other end 10b in the axial direction of the first cylindrical body 14. The second cylindrical body 15 has a second main body 11 in which the amount of basalt fibers per radial cross-section is constant along the entire length in the axial direction.

[0035] As shown in Figure 2, at one end 10a of the first main body 16, a relatively large number of fiber F layers are laminated, while at the other end 10b, a relatively small number of fiber F layers are laminated. The number of fiber F layers decreases from one end 10a to the other end 10b. Furthermore, because the number of fiber F layers decreases from one end 10a to the other end 10b, the amount of fiber per radial cross-section also decreases from one end 10a to the other end 10b. In other words, at one end 10a of the first main body 16, the amount of basalt fiber per radial cross-section is relatively large, while at the other end 10b, the amount of basalt fiber per radial cross-section is relatively small.

[0036] The statement that the number of layers of fiber F decreases from one end 10a to the other end 10b includes not only cases where the number of layers decreases continuously, but also cases where it decreases in stages, similar to how the cylindrical body 10 gradually becomes smaller in diameter or gradually lighter. Furthermore, it is not necessarily limited to the case where the number of layers of fiber F is less at the other end 10b than at the one end 10a in the entire cylindrical body 10. Even if there is a part of the main body 11 where the number of layers is greater at the tip than at the base, it is sufficient as long as the number of layers decreases overall from one end 10a to the other end 10b. The same applies to the amount of fiber per radial cross-section.

[0037] In the second main body, the fiber F layers are uniform along the entire length in the axial direction. The number of fiber F layers is also uniform along the entire length in the axial direction. As shown in Figure 1, the barrier rod 1 of this embodiment is formed by joining a first cylindrical body 14 and a second cylindrical body 15. From the viewpoint of the strength and deflection of the barrier rod 1, it is preferable to place the second cylindrical body 15 on the base end side of the barrier rod 1 and the first cylindrical body 14 on the tip side of the barrier rod 1. Furthermore, the total axial length of the first cylindrical body 14 in the barrier rod 1 is preferably 25% to 70% of the total axial length of the barrier rod 1, and more preferably 30% to 60%. When the total axial length of the first cylindrical body 14 in the barrier rod 1 is within this range, the bending rigidity of the barrier rod 1 is good and the deflection of the barrier rod 1 is suppressed. As shown in Figure 1, in the barrier rod 1 of this embodiment, the 1st to 3rd cylindrical bodies 10 at the tip are composed of the first cylindrical body 14, and the 4th to 6th cylindrical bodies 10 at the base are composed of the second cylindrical body 15.

[0038] <Regarding the manufacturing method of the cylindrical body 10> The manufacturing method for the cylindrical body 10 of this embodiment comprises a lamination process, a wrapping process, a molding process, and a post-processing process. In the lamination process, multiple layers of fiber-reinforced resin prepreg sheets P are laminated onto a long core material to form a pre-molded body. In the wrapping process, wrapping tape is wrapped around the outer surface of the pre-molded body. In the molding process, the pre-molded body with the wrapping tape wrapped around it is pressurized and heated to form a cylindrical molded body. In the post-processing process, the outer surface of the molded body is polished, painted, or otherwise finished.

[0039] As shown in Figure 3, in the lamination process of the first cylindrical body 14, prepreg sheets P are prepared for the inner reinforcing layer 22 which will become the inner reinforcing part 12, the first main body layer 21 which will become the first main body part 16, and the outer reinforcing layer 23 which will become the outer reinforcing part 13. As shown in Figure 4, in the lamination process of the second cylindrical body 15, prepreg sheets P are prepared for the inner reinforcing layer 22 which will become the inner reinforcing part 12, the second main body layer 24 which will become the second main body part, and the outer reinforcing layer 23 which will become the outer reinforcing part 13. The prepreg sheets P used are those in which basalt fibers are impregnated with a thermosetting resin while having a directional structure. Preferably, the prepreg sheets P used are UD prepreg sheets in which a large number of reinforcing fibers arranged in the same direction are impregnated with a thermosetting resin, or cross prepreg sheets in which a woven or knitted fabric of reinforcing fibers is impregnated with a thermosetting resin. The number of layers of prepreg sheets P in the inner reinforcing layer 22 and the outer reinforcing layer 23 is not particularly limited, but it is preferably about 1 to 2 layers from the viewpoint of the bending rigidity of the cylindrical body 10. Similarly, the number of layers of prepreg sheets P in the main body layers 21 and 24 is not particularly limited, but it is preferably about 8 to 15 layers from the viewpoint of balancing the bending rigidity of the cylindrical body 10 with the manufacturing cost of the cylindrical body 10.

[0040] In the lamination process for the first cylindrical body 14 and the lamination process for the second cylindrical body 15, the lamination structure of the first main layer 21 and the second main layer 24 are different. Specifically, the axial length of the prepreg sheet P used in the first main layer 21 and the axial length of the prepreg sheet P used in the second main layer 24 are different. The lamination process for the first cylindrical body 14 will be described below.

[0041] As shown in Figure 3, multiple layers of fiber-reinforced resin prepreg sheets P are wrapped around a mandrel, which serves as the core material, to form an inner reinforcing layer 22, a first main body layer 21, and an outer reinforcing layer 23. The mandrel has a circular cross-section and is tapered, with a continuously decreasing diameter from one end to the other. The mandrel used is slightly longer in the axial direction than the cylindrical body 10.

[0042] First, a prepreg sheet P is laminated onto the mandrel to form an inner reinforcing layer 22. Preferably, the axial length of the prepreg sheet P that forms the inner reinforcing layer 22 on the mandrel is about 25% to 60% of the axial length of the first cylindrical body 14. In this embodiment, the inner reinforcing layer 22 is formed by laminating a cross prepreg sheet with a length corresponding to about 25% of the axial length onto one end of the mandrel (the side that becomes the other end 10b of the cylindrical body 10).

[0043] Next, multiple layers of prepreg sheets P are laminated to form the first main body layer 21. In this embodiment, the first main body layer 21 is composed of multiple layers of cross prepreg sheets and multiple layers of UD prepreg sheets. Finally, a prepreg sheet P is laminated on the outside of the first main body layer 21 to form the outer reinforcement layer 23. The axial length of the mandrel in the prepreg sheet P that forms the outer reinforcement layer 23 is preferably about 25% to 60% of the length of the first cylindrical body 14. In this embodiment, the outer reinforcement layer 23 is formed by laminating one layer of cross prepreg sheet with a length corresponding to about 25% of the axial length on the other end side of the mandrel (the side that becomes one end 10a of the cylindrical body 10).

[0044] As shown in Figure 3, the first main body layer 21 is formed by laminating multiple types of prepreg sheets P of different sizes on the outer circumference of the inner reinforcing layer 22. The multiple types of prepreg sheets P are formed by cutting the prepreg sheets P so that they have different lengths corresponding to the axial length of the cylindrical body 10. Here, the multiple types of prepreg sheets P that form the first main body layer 21 are each referred to as "unequal length sheets". The length and type of each unequal length sheet are not particularly limited, but can be adjusted to an appropriate length and type from the viewpoint of balancing the desired bending rigidity and manufacturing costs. For example, the length can be set to about 2 to 20 different lengths, selected appropriately within a range from about 25% of the axial length of the first main body layer 21 to a length that is almost the same as the axial length of the first main body layer 21.

[0045] The number of layers of each unequal-length sheet is not particularly limited, but from the viewpoint of balancing the bending rigidity of the first cylindrical body 14 with the manufacturing cost of the first cylindrical body 14, it is preferable to have about 1 to 5 layers. As shown in Figure 3, it is preferable to laminate each unequal-length sheet so that it aligns with the edge on one end 10a of the first cylindrical body 14 and extends toward the edge on the other end 10b of the first cylindrical body 14. Furthermore, it is preferable to laminate unequal-length sheets that are longer in the longitudinal direction towards the outer layers, and to laminate the outermost unequal-length sheet that has a length that extends across the entire axial length of the first cylindrical body 14 in the first main body layer 21.

[0046] In the example shown in Figure 3, the unequal-length sheets are composed of four types with different axial lengths. The unequal-length sheet with the shortest axial length of the first cylindrical body 14 is approximately 25% of the axial length of the first cylindrical body 14 in the first main body layer 21. The unequal-length sheet with the longest longitudinal length is approximately the same length as the axial length of the first cylindrical body 14 in the first main body layer 21. The lengths of the other unequal-length sheets are between the shortest and longest unequal-length sheets, and are configured so that the lengths change by roughly equal amounts.

[0047] Figure 3 shows the lamination structure forming the first main body layer 21 as 10 different layer structures. The numbers on the left indicate the order from the inside out in the lamination structure. In other words, the numbers 2 to 11 represent the lamination structure of the first main body layer 21.

[0048] In the lamination process, when laminating UD prepreg sheets or cross prepreg sheets, the proportion of basalt fibers oriented at an angle of 45° to 90° relative to the axial direction of the mandrel is set to be between 20% and 40% of the total basalt fibers in the radial cross-section. In addition, the proportion of basalt fibers oriented at 0°, along the axial direction of the mandrel, is set to be between 60% and 80% of the total basalt fibers.

[0049] Through the lamination process described above, a pre-molded body of a first cylindrical body 14 is obtained, having a first main body layer 21 in which the amount of basalt fibers per radial cross-section decreases from the base end to the tip end, an inner reinforcing layer 22 laminated on the inner tip side of the first main body layer 21, and an outer reinforcing layer 23 laminated on the outer base side of the first main body layer 21.

[0050] As shown in Figure 4, in the lamination process of the second cylindrical body 15, unequal-length sheets are not used, and the second main body layer 24 is formed using prepreg sheets P of all the same length. The length of the prepreg sheets P forming the second main body layer 24 in the axial direction of the second cylindrical body 15 is equivalent to the total length of the second cylindrical body 15 in the axial direction. After the lamination process of the second cylindrical body 15, a pre-molded body of the second cylindrical body 15 is obtained, which has a second main body layer 24 in which the amount of basalt fibers per radial cross-section is the same throughout the total length in the axial direction, and an inner reinforcing layer 22 is laminated on the inner front end side of the second main body layer 24, and an outer reinforcing layer 23 is laminated on the outer base end side of the second main body layer 24.

[0051] In the wrapping process, wrapping tape is wrapped around the outer surface of the pre-molded body. The wrapping tape is wrapped around the outer surface of the pre-molded body multiple times under tension, with slight shifts along the longitudinal direction.

[0052] After a wrapping process in which wrapping tape is wrapped around the outer surface of the pre-molded body, the pre-molded body is pressurized and heated in a heating process to form a cylindrical molded body. In the heating process, the wrapped pre-molded body is heated in a heating furnace to form a molded body. The heating temperature and heating time can be appropriately determined depending on the type of thermosetting resin in the laminated prepreg sheets and the shape or size of the pre-molded body. Heating the pre-molded body in the heating furnace shapes it into a cylindrical shape. After heating for a certain period of time in the heating furnace, the wrapped pre-molded body is removed from the heating furnace and cooled to room temperature, causing the thermosetting resin in the pre-molded body, in which the inner reinforcing layer 22, main body layers 21, 24, and outer reinforcing layer 23 are integrated, to cool and harden, resulting in a molded body (tubular body 10) with a circular, continuous, integrated outer surface. The fibers F oriented in the prepreg sheets P that constitute the inner reinforcing layer 22, main body layers 21, 24, and outer reinforcing layer 23 are laminated in layers according to the lamination order of the prepreg sheets P (see Figure 2).

[0053] In the post-processing stage, after removing the wrapping tape from the molded body, the outer surface of the molded body is polished, painted, or otherwise finished. The operation of the cylindrical body 10 and the barrier rod 1 in this embodiment will be described below.

[0054] The cylindrical body 10 comprises a first cylindrical body 14 and a second cylindrical body 15. The first cylindrical body 14 has a relatively small diameter and light weight at the other end 10b, and a relatively large diameter and heavy weight at the one end 10a. Furthermore, the first main body portion 16 of the first cylindrical body 14 is formed by laminating multiple types of unequal length sheets with different lengths in the longitudinal direction. As a result, in the first main body portion 16, the amount of basalt fibers per radial cross-section decreases from the one end 10a to the other end 10b. This results in the first cylindrical body 14 having high bending rigidity at the one end 10a and suppressing deflection at the other end 10b.

[0055] The barrier arm 1 of this embodiment is formed by joining six cylindrical bodies 10 together. Each cylindrical body 10 has one end 10a, which is relatively large in diameter and heavy, attached to the barrier, while the other end 10b, which is relatively small in diameter and lighter, is supported in a cantilevered state as a free end. Furthermore, the first to third cylindrical bodies 10 on the tip side of the barrier arm 1 are the first cylindrical bodies 14, and the fourth to sixth cylindrical bodies 10 on the base side are the second cylindrical bodies 15. The second cylindrical bodies 15 have a second main body portion in which the amount of basalt fibers per radial cross-section is the same along the entire length in the axial direction. As a result, the barrier arm 1 has high bending rigidity at the base end and the amount of deflection at the tip end is suppressed.

[0056] In the cylindrical body 10, the proportion of angle fibers oriented at an inclination angle of 45° to 90° with respect to the axial direction is 20% to 40% of the total basalt fibers in the radial cross-section. Therefore, when an external force acts on the cylindrical body 10 and it breaks, it avoids splitting vertically and instead breaks into segments. At the same time, it is less likely for the fracture surface to develop the fibrous fraying characteristic of fiber-reinforced resins. Combined with the fact that the fracture surface is nearly perpendicular to the axial direction, it is possible to suppress sharpening of the fracture surface.

[0057] Furthermore, the proportion of basalt fibers oriented at 0° along the axial direction is between 60% and 80% of the total basalt fibers in the radial cross-section. As a result, the bending rigidity of the cylindrical body 10 is improved, and the amount of deflection is suppressed.

[0058] According to this embodiment, in addition to the effects described in the above section on operation, the following effects can be obtained. (1) The cylindrical body 10 is made of fiber-reinforced resin and contains basalt fiber as a reinforcing fiber. Basalt fiber is a sustainable, recyclable, and environmentally friendly circular fiber. In addition, compared to glass fiber, it has higher elastic modulus, tensile strength, heat resistance, chemical resistance to acids and alkalis, moisture resistance, and durability, and is electrically insulating. Therefore, the cylindrical body 10 made of fiber-reinforced resin can be disposed of at low cost and has a low environmental impact during disposal.

[0059] (2) The sum of the axial lengths of the first cylindrical body 14 provided at the tip of the cylindrical body 10 constituting the barrier rod 1 is 25% to 70% of the total axial length of the barrier rod 1. Therefore, the bending rigidity of the barrier rod 1 is good and the amount of deflection of the barrier rod 1 can be suppressed.

[0060] (3) The manufacturing method of the first cylindrical body 14 of this embodiment includes a lamination step in which a plurality of prepreg sheets P (sheets of unequal length) with different axial lengths are laminated onto a mandrel as a core material to form a preformed body. As a result, the first cylindrical body 14 having a first main body portion 16 in which the amount of basalt fibers per radial cross-section decreases from the one end 10a to the other end 10b in the axial direction can be easily manufactured. This makes it easy to manufacture a cylindrical body 10 (first cylindrical body 14) with excellent bending rigidity due to the suppression of deflection at the other end 10b.

[0061] (4) By reducing the number of layers of prepreg sheet P towards the other end 10b of the first main body 16, the amount of fiber-reinforced resin required to manufacture the cylindrical body 10 can be reduced. In addition, by reducing the amount of basalt fiber per radial cross-section, the amount of fiber-reinforced resin required to manufacture the cylindrical body 10 can be reduced. The manufacturing cost of the cylindrical body 10 can be reduced.

[0062] (5) The bending rigidity and deflection of the first cylindrical body 14 can be adjusted by appropriately changing the lengths of the unequal-length sheets. The bending rigidity and deflection of the first cylindrical body 14 can also be adjusted by appropriately changing the number of layers of unequal-length sheets. By combining the lengths of the unequal-length sheets and the number of layers, it is easy to adjust the number of layers of prepreg sheets P toward the other end 10b, or to adjust the amount of basalt fibers toward the other end 10b. This makes it easy to design a cylindrical body 10 that is excellent in bending rigidity and also advantageous in terms of manufacturing cost.

[0063] (6) In the main layer formation step of the lamination process, multiple types of unequal length sheets are laminated so that their edges on one end 10a of the first cylindrical body 14 are aligned and they extend toward the other end 10b of the first cylindrical body 14. This makes it easy to create a laminated state in which the number of laminated prepreg sheets P decreases from one end 10a of the first cylindrical body 14 toward the other end 10b. This makes it easy to align unequal length sheets of different lengths and allows the work to be carried out smoothly.

[0064] (7) In the lamination process of this embodiment, multiple types of unequal-length sheets with different longitudinal lengths are laminated, and among the multiple unequal-length sheets, the longer unequal-length sheets are laminated on the outside of the shorter unequal-length sheets. Therefore, even if multiple types of unequal-length sheets with different lengths are laminated, the edges of the shorter unequal-length sheets are covered by the longer unequal-length sheets. Even if a step difference due to the thickness caused by the difference in the number of laminated unequal-length sheets occurs at the edge of the unequal-length sheets, it is unlikely to affect the outer surface of the first cylindrical body 14. A cylindrical body 10 with an excellent outer surface shape can be obtained.

[0065] The above embodiment can be modified as follows. Note that the above embodiment and the following modifications can be combined and applied to the extent that they do not contradict each other technically. The cylindrical body 10 can be applied to objects other than the shielding rod 1. Since basalt fibers are electrically insulating, they can be applied to, for example, radio interference prevention poles such as those for communication base stations, radio interference prevention fences, radio interference prevention signs, etc.

[0066] At least one of the inner reinforcing portion 12 or the outer reinforcing portion 13 of the cylindrical body 10 may be omitted. The barrier rod 1 is not limited to being made of six cylindrical bodies 10 joined together. It may be made of five or fewer bodies, or seven or more bodies.

[0067] In the above embodiment of the barrier rod 1, the 1st to 3rd cylindrical bodies 10 are the first cylindrical bodies 14, and the 4th to 6th cylindrical bodies 10 are the second cylindrical bodies 15, but the configuration is not limited to this. Of the six cylindrical bodies 10 that make up the barrier rod 1, at least one first cylindrical body 14 is provided on the axial end side. Alternatively, all of the cylindrical bodies 10 may be the first cylindrical bodies 14.

[0068] • Multiple types of unequal-length sheets for forming the first main body layer 21 do not need to be laminated with their edges aligned at one end 10a of the first cylindrical body 14. Sheets laminated from the edge at one end 10a of the first cylindrical body 14 may be mixed with sheets laminated from the other end 10b.

[0069] In the main layer formation step of the lamination process, sheets of unequal length, starting with those with shorter axial lengths and progressing to those with longer axial lengths, were laminated in order of length, but this is not limited to this. Not all sheets of unequal length have to have longer ones on the outside, and in some cases, shorter sheets of unequal length may be laminated on the outside of longer sheets of unequal length. Even in this case, if there are parts where shorter sheets of unequal length are covered by longer sheets of unequal length, even if a step difference due to the difference in the number of laminated sheets of unequal length occurs, it will not significantly affect the outer surface of the cylindrical body 10.

[0070] The prepreg sheets used to laminate as the first main layer 21, the second main layer 24, the inner reinforcement layer 22, and the outer reinforcement layer 23 may be a combination of UD prepreg sheets and cross prepreg sheets.

[0071] In the above embodiment of the manufacturing method, wrapping tape was wrapped around the outer surface of the pre-molded body and pressed, and the pre-molded body with the wrapping tape wrapped around it was heated to form the molded body, but the method is not limited to this. [Examples]

[0072] The cylindrical body 10 of this embodiment will be described in more detail below based on the barrier rod 1 of the embodiment. Note that the present invention is not limited to the configuration described in the embodiments section. Multiple cylindrical bodies 10 made of fiber-reinforced resin were created, and a barrier rod 1 was made by joining multiple cylindrical bodies 10 together. A fracture test was performed on each cylindrical body 10, and a bending stiffness test was performed on each barrier rod 1. Both the example and comparative example barrier rods 1 have one cylindrical body 10 with an axial length of approximately 1140 mm at the tip end (number 1) and five cylindrical bodies 10 with an axial length of approximately 1500 mm at the base end (numbers 2 to 6).

[0073] <Example 1> The barrier rod 1 of Example 1 was formed using a prepreg sheet P in which basalt fibers were impregnated with epoxy resin. In the barrier rod 1 of Example 1, the tubular bodies 1 to 3 in number 1 are the first tubular bodies 14, and the tubular bodies 4 to 6 in number 6 are the second tubular bodies 15.

[0074] As shown in Figure 3, the first cylindrical bodies 14 of the 1st to 3rd series have a 12-layer laminated structure. The first layer is an inner reinforcing layer 22 which forms the inner reinforcing portion 12, the 2nd to 11th layers are first main body layers 21 which form the first main body portion 16, and the 12th layer is an outer reinforcing layer 23 which forms the outer reinforcing portion 13. Each layer is formed as a single layer structure made by winding a prepreg sheet P once.

[0075] A long, tapered mandrel with a fiber basis weight of 280 g / m 2 An inner reinforcing layer 22 was formed by winding a cross prepreg sheet with a resin content of 38% once. The cross prepreg sheet used was cut into a rectangular shape, with one side corresponding to approximately 25% of the axial length of the first-gauge cylindrical body and the other side corresponding to the circumference of the first-gauge cylindrical body. The cross prepreg sheet was laminated from the tip of the mandrel so that the orientation direction of the basalt fibers was 0° / 90° with respect to the axial direction. The tip of the mandrel here refers to the position of the other end 10b of the cylindrical body 10. The type of prepreg, fiber orientation angle, and lamination position used for the inner reinforcing layer 22 are shown in Table 1.

[0076] Table 1 shows the type of prepreg, fiber orientation angle, and lamination position used for the first main layer 21 (layers 2-11) and the outer reinforcement layer 23 (layer 12). For example, "Basalt UD / 150g / 30%" listed as the prepreg used for the second layer in the table has a fiber basis weight of 150g / m². 2 This represents a UD prepreg sheet with a resin content of 30%. The same applies below.

[0077] [Table 1] As shown in Figure 4, the 4th and 5th cylindrical bodies are second cylindrical bodies 15 having a 12-layer laminated structure. The inner reinforcement portion 12 of the 1st layer and the outer reinforcement portion 13 of the 12th layer are the same as those of the first cylindrical bodies 14 of the 1st to 3rd layers. The type of prepreg, fiber orientation angle, and lamination position used for the second main body layers 24 of the 2nd to 11th layers are as shown in Table 2.

[0078] [Table 2] The sixth cylindrical body 10 is a second cylindrical body 15 having a 15-layer laminated structure. The inner reinforcing part 12 of the first layer and the outer reinforcing part 13 of the fifteenth layer are the same as those of the fourth and fifth second cylindrical bodies 15. The type of prepreg sheet P, fiber orientation angle, and lamination position used for the second main body layers 24 from the second to the 14th layer are shown in Table 3.

[0079] [Table 3] Each of the tubular bodies 10 of counts 1 to 6 was formed by heating them in a heating furnace heated to 135°C for approximately 2 hours during the heating process. The total length, angle fiber ratio, outer diameter, inner diameter, specific gravity, and mass of each formed tubular body of count 10a and the other end (base end) 10b are shown in Table 4.

[0080] [Table 4] <Example 2> The barrier rod 1 of Example 2 was formed using a prepreg sheet P in which basalt fibers were impregnated with epoxy resin. In the barrier rod 1 of Example 2, all of the cylindrical bodies 10 numbered 1 to 6 are second cylindrical bodies 15.

[0081] Table 5 shows the configuration of the 12-layer laminated structure of the second cylindrical bodies 15 numbered 1 to 5.

[0082] [Table 5] The sixth-ranked second cylindrical body 15 has a 15-layer laminated structure. Table 6 shows the configuration of the 15-layer laminated structure of the sixth-ranked second cylindrical body 15.

[0083] [Table 6] The heating time and heating temperature were the same as in Example 1. The total length, angle fiber ratio, outer diameter, inner diameter, specific gravity, and mass of each molded yarn are shown in Table 7.

[0084] [Table 7] <Comparative Example 1> In Comparative Example 1, a cylindrical body 10 with a low proportion of angle fibers was formed. The cylindrical body 10 was formed using a prepreg sheet P in which basalt fibers were impregnated with epoxy resin. The cylindrical body 10 of Comparative Example 1 is a second cylindrical body 15 having a seven-layer laminated structure. It does not have an inner reinforcing layer 22 that becomes an inner reinforcing part 12, nor an outer reinforcing layer 23 that becomes an outer reinforcing part 13; they are all second main body layers 24. The first layer of the second main body layer 24 was laminated so that the orientation direction of the basalt fibers of the cross prepreg sheet was in the bias direction of ±45°, and the second to seventh layers were laminated so that the orientation direction of the basalt fibers of the UD prepreg sheet was all in the 0° direction.

[0085] Table 8 shows the seven-layer laminated structure of the second cylindrical body 15 of Comparative Example 1.

[0086] [Table 8] The heating time and heating temperature were the same as in Example 1 for the cylindrical body 10. The proportion of angle fibers in the molded cylindrical body 10 was 15.6% throughout the entire length of the cylindrical body 10.

[0087] <Comparative Example 2> A barrier rod 1 of Comparative Example 2 was formed using a cross prepreg sheet in which glass fibers were impregnated with epoxy resin. In the barrier rod 1 of Comparative Example 2, all of the tubular bodies 10 of the 1st to 6th counts are second tubular bodies 15. In the barrier rod of Comparative Example 2, the glass fibers were laminated in all layers of each count tubular body so that the orientation direction was 0° / 90°. The laminated structure of the tubular bodies 10 of the 1st to 6th counts is the same.

[0088] Table 9 shows the structure of the 12-layer laminated structure of cylindrical bodies numbered 1 to 6.

[0089] [Table 9] The cylindrical bodies of counts 1 through 6 were each formed by heating them in a heating furnace heated to 135°C for approximately 2 hours during the heating process. The total length, angle fiber ratio, outer diameter, inner diameter, specific gravity, and mass of each formed count are shown in Table 10.

[0090] [Table 10] <Breakage test of cylindrical body 10> Fracture tests were performed on the fourth cylindrical body 15 of Example 1 and the cylindrical body 10 of Comparative Example 1. The fracture test was based on a three-point bending test with a point-to-point distance of 1000 mm, and a bending load was applied until the cylindrical body 10 fractured. Photographs of the fractured cylindrical body 10 are shown in Figure 5. Figure 5(a) is a photograph of the fracture surface of the cylindrical body 10 of Example 1 after the fracture test, and Figure 5(b) is a photograph of the cylindrical body 10 of Comparative Example 1 after the fracture test.

[0091] In Example 1, the second cylindrical body 15 has a proportion of angle fibers oriented at a 90° inclination angle with respect to the axial direction that accounts for 20% to 40% of the total basalt fibers. In Comparative Example 1, the cylindrical body 10 has a proportion of angle fibers oriented at a ±45° inclination angle with respect to the axial direction that accounts for 13.5% of the total basalt fibers throughout the entire length of the cylindrical body 10.

[0092] In the second cylindrical body 15 of Example 1, the fracture surface was nearly perpendicular to the axial direction, and the occurrence of fiber fraying, which is characteristic of fiber-reinforced resins, was suppressed. It was also found that sharpening of the fracture surface was suppressed because the fracture surface was nearly perpendicular. When the proportion of angle fibers oriented at an inclination angle of 45° to 90° with respect to the axial direction is 20% to 40% of the total basalt fibers, the fracture surface becomes nearly perpendicular to the axial direction. Furthermore, good bending rigidity can be obtained.

[0093] On the other hand, in the cylindrical body 10 of Comparative Example 1, a crack occurred in the axial direction while the basalt fibers remained connected. When the proportion of angle fibers oriented at an inclination angle of 45° to 90° with respect to the axial direction is less than 20% of the total basalt fibers, cracks tend to occur in the axial direction, and the fracture surface is unlikely to be perpendicular. Furthermore, when the proportion of angle fibers oriented at an inclination angle of 45° to 90° with respect to the axial direction exceeds 40% of the total basalt fibers, it becomes difficult to obtain good bending rigidity. <Bending stiffness test of barrier rod 1> Bending stiffness tests were performed on the barrier rod 1 of Examples 1 and 2 and Comparative Example 2. The bending stiffness tests were carried out according to the following procedures (a) to (c).

[0094] (a) The load values ​​generated at wind speeds of 0, 10, 20, and 30 m / s were calculated from the outer diameter of each cylindrical body 10 at its axial center based on the following formula (Equation 1). A wind speed of 30 m / s is the required level at which the barrier rod 1 does not break.

[0095] P=1 / 2×ρ×V2×A·Cp (Formula 1) Here, P is the wind load (N) and ρ is the air density (kg / m³). 3 ), V is the design wind speed (m / s), and A is the pressure-receiving area (effective projected area; m 2), Cp represents the drag coefficient. Air density is 1.23 (N·s / m³). 2 The drag coefficient is 0.98, given the cylindrical shape and l / d ratio.

[0096] (b) Each barrier rod 1 was fixed at its base (the base of the 6th rod) so that it extended horizontally, creating a cantilevered configuration. A load equivalent to the load value calculated in (a) was applied to the axial center of each rod. The base fixing position was set at a height sufficient to prevent the tip from touching the ground (horizontal reference plane) due to deflection caused by the load during the test.

[0097] (c) In this state, the distance from the load position of each cylindrical body 10 to the ground (horizontal reference plane) was measured, and the amount of deflection was obtained by subtracting this from the distance from the base end fixing position to the ground (horizontal reference plane).

[0098] Table 11 shows the deflection values ​​for each barricade rod 1 in Examples 1 and 2 and Comparative Example 1. Figure 6 shows a graph of the deflection values ​​at a wind speed of 30 m / s, and Figure 7 shows a graph of the deflection values ​​at a wind speed of 20 m / s.

[0099] [Table 11] A comparison of Example 2 and Comparative Example 2 showed that in all of the tubular bodies 10 of grades 1 to 6, the amount of deflection at the tip was suppressed in the barrier rod 1 of Example 2, which used basalt fibers with a higher modulus of elasticity than glass fibers.

[0100] A comparison of Example 1 and Example 2 revealed that in the tubular bodies 10 of grades 1 to 3, the amount of basalt fibers per radial cross-section decreased from one end to the other in the axial direction, resulting in a more suppressed deflection at the tip of the barrier rod 1. It is thought that the reduced moment due to the lighter tip contributes to the suppression of deflection. [Explanation of symbols]

[0101] F... Fiber (basalt fiber) P...Prepreg sheet 1… Barrier lever 10...Cylindrical body 10a...One end 10b...Other end 11...Main body 12…Inner reinforcement section (reinforcement section) 13...Outer reinforcement part (reinforcement part) 14…First cylindrical body (cylindrical body) 15…Second cylindrical body (cylindrical body) 16…First main body (main body) 21...1st body layer (main body layer) 22…Inner reinforcement layer (reinforcement layer) 23…Outer reinforcement layer (reinforcement layer) 24…Second body layer (main body layer)

Claims

1. It contains basalt fiber as a reinforcing fiber, A tubular body made of fiber-reinforced resin, wherein the proportion of basalt fibers oriented at an inclination angle of 45° to 90° with respect to the axial direction is 20% to 40% of the total basalt fibers in a radial cross-section.

2. The cylindrical body according to claim 1, comprising a first cylindrical body having a first main body portion in which the amount of basalt fibers per radial cross-section decreases from one end to the other end in the axial direction.

3. A barrier rod is formed by joining multiple tubular bodies containing the basalt fiber as a reinforcing fiber and connecting them in parallel, and supported in a cantilevered manner, A barrier rod having at least one of the first cylindrical bodies described in claim 2 on the axial end side.

4. The second cylindrical body comprises a second main body portion having a second main body portion in which the amount of basalt fibers per radial cross-section is the same along the entire length in the axial direction, The barrier rod according to claim 3, having the first cylindrical body on the axial tip side and the second cylindrical body on the axial base side.

5. The barrier rod according to claim 4, wherein the sum of the axial lengths of the first cylindrical bodies is 25% or more and 70% or less of the total axial length of the barrier rod.

6. A lamination process in which multiple layers of fiber-reinforced resin prepreg sheets are laminated onto a long core material, A molding process in which a pre-molded body made of laminated prepreg sheets is pressurized and heated to form a cylindrical molded body. A method for manufacturing a cylindrical body comprising: A method for manufacturing a cylindrical body, comprising the lamination step of laminating the prepreg sheets using basalt fibers as reinforcing fibers, such that the proportion of the number of laminated prepreg sheets in which the orientation direction of the basalt fibers is at an inclination angle of 60° to 90° with respect to the axial direction of the molded body in the radial cross-section of the molded body is 20% to 40% of the total number of laminated prepreg sheets.

7. The lamination process includes a main body layer forming step in which the prepreg sheet is wrapped around the core material to form a main body layer corresponding to the total length in the axial direction of the cylindrical body. The method for manufacturing a cylindrical body according to claim 6, wherein in the main body layer formation step, the number of layers of the prepreg sheets decreases from one end to the other end.

8. The method for manufacturing a cylindrical body according to claim 7, wherein in the main body layer formation step, prepreg sheets of different lengths in the axial direction of the core material are laminated, and the longer prepreg sheet is laminated on the outer layer of the shorter prepreg sheet.

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