WO2015019479A1

WO2015019479A1 - Joint structure

Info

Publication number: WO2015019479A1
Application number: PCT/JP2013/071586
Authority: WO
Inventors: 宗太木村; 博青山; 泰樹北
Original assignee: 株式会社日立製作所
Priority date: 2013-08-09
Filing date: 2013-08-09
Publication date: 2015-02-12
Also published as: JPWO2015019479A1

Abstract

Provided are a small and highly reliable fastening structure by which a FRP pipe and a metal member can be easily fastened and an FRP structure comprising this type of fastening structure. An FRP pipe, which has a straight tubular shape, and a metal member, which is made of segmented pieces that are tapered in the lengthwise axial direction of the FRP pipe and are disposed around the FRP pipe, are inserted into the interior of a tubular metal joint that has on the interior a tapered face that is inclined at the substantially the same angle as the metal member, and another metal joint is mated with the joint, in which state the FRP pipe and the metal member are engaged, thereby configuring the fastening structure. Thus, fastening can be performed easily with a small structure, and the reliability of a fastening structure can be improved.

Description

Joint structure

The present invention relates to a joint structure, and more particularly to a joint structure suitable for fastening to a fiber reinforced plastic member.

Fiber-reinforced plastics (hereinafter referred to as FRP) are not only excellent in specific strength and specific rigidity, but also excellent in corrosion resistance, and their application in various fields is spreading. In the future, application to construction machinery and buildings used in environments where severe loads such as fatigue and impact act is expected to be expanded. In particular, FRP pipes can be manufactured at low cost by drawing molding, filament winding molding, sheet winding molding and the like, and since they have a high degree of freedom in length, thickness, and cross-sectional shape, they can be applied to various structural members.

In the case of using an FRP pipe as a structural member, the reliability of the joint portion is a major issue. When FRP pipes are to be fastened, in the method of screwing and fastening the joint portion or the method of drilling and pin fastening, the reinforcing fibers may be cut by the processing and the strength may be significantly reduced.

As a means to solve such problems, at the end of FRP pipe, the diameter of the FRP pipe itself is changed in the longitudinal direction to provide a tapered portion, and the FRP pipe and the joint member are fastened using this tapered portion (Patent Document 1).

On the other hand, a structure has been proposed in which an FRP pipe and a metal member are fastened in a mode in which the pipe is sandwiched by metal joints from both the inside and outside of the FRP pipe (Patent Document 2).

JP-A-5-164116 JP, 2011-37313, A

In the technology according to Patent Document 1, when a compressive load is applied to the FRP pipe, the diameter of the FRP pipe itself is changed in the longitudinal direction to support the compressive load in supporting the compressive load at the end of the FRP pipe. There is a possibility that compressive fracture of FRP may occur from the end. This is because FRP, when a compressive force is applied to the exposed end of the fiber, causes local buckling of the fiber and fracture between layers, resulting in a significant decrease in compressive strength.

In the technique according to Patent Document 2, it is necessary to provide a slit in the outer joint in order to apply a radial compressive force to the outer peripheral surface of the FRP pipe, and the cross-sectional area of the fastening structure may increase.

The object of the present invention is made in view of the circumstances of the prior art, and it is an object of the present invention to provide a joint structure which is small and can be easily fastened, and which is capable of a highly reliable fastening structure.

In order to achieve the above object, in the present invention, a fiber-reinforced plastic pipe having a straight pipe shape having a uniform outer diameter, a first joint member facing one end of the pipe, and a longitudinal direction of the pipe And an intermediate member disposed around the pipe to contact the pipe, the intermediate member having a tapered portion whose diameter gradually increases from the other side of the pipe to the one side. A second joint member in contact with the tapered portion, the second joint member and the first joint member being pressed such that the second joint member and the pipe are mutually pressed via the tapered portion; It was configured to be concluded.

Specifically, a metal member composed of a straight pipe-shaped FRP pipe and a divided piece tapered in the longitudinal axis direction of the FRP pipe disposed around the FPR pipe is substantially the same as the metal member It is characterized in that it is inserted into the inside of a tubular metal joint having an angled tapered surface inside, and engaged in such a manner that another metallic joint and the joint are fitted. A fastening structure and an FRP structure provided with the fastening structure are achieved.

According to the present invention, by engaging the joint, a compressive force in the radial direction of the joint acts on the contact surface of the FRP pipe with the members disposed around the FRP pipe, so that the FRP pipe can be simply fastened It is possible to At the same time, since it is not necessary to apply complicated processing to FRP pipes and joints, it is possible to miniaturize the fastening structure and to achieve high reliability.

External view of Example 1 Sectional view of Example 1 Sectional view of Example 2 AA sectional view in FIG. 2 Sectional view of Example 3 Sectional view of Example 3 Sectional view of Example 3 Sectional view of Example 4 Sectional view of Example 4 Sectional view of Example 4 Sectional view of Example 5 Sectional view of Example 5 Sectional view of Example 6 Enlarged view of part A in FIG. 13 External view of Example 7 Sectional view of Example 7 Sectional view of Example 7 Sectional view of Example 7 Cross section of Example 8 Cross section of Example 8 Cross section of Example 9 Cross section of Example 10 Cross section of Example 11

Hereinafter, an example of a fastening structure according to the present invention will be described with reference to the drawings.

The fastening structure 1 is shown as Example 1 in FIG. 1 and FIG. The FRP pipe 2 (fiber reinforced plastic pipe 2) has a straight pipe shape, and the outer diameter is uniform d1 in the longitudinal direction. The inner diameter is also uniform d2. The metal member 3 is formed of two members having the same shape, and each has a shape in which the cross-sectional area gradually increases toward the lower side of the drawing (also described as the Y direction for convenience). The metal member 3 has a tapered portion 3-1 by gradually increasing the cross-sectional area in the downward direction (Y direction) in the drawing. The inner diameter of the metal member 3 has a substantially constant radius of curvature d1 (approximately the same as the outer diameter of the FRP pipe 2), and the inner diameter of the metal member 3 is formed in contact with the outer diameter of the FRP pipe 2 in a plane. Here, the virtual diameter equivalent of the bottom is defined as r.

The outer joint 4 is made of metal, and on the inner side, a space is formed so as to gradually reduce the cross-sectional area in the downward direction (Y direction) in the drawing. The outer joint 4 has a tapered portion 4-2 which gradually increases the inner diameter toward the lower side of the drawing (Y direction) by gradually reducing the sectional area. The tapered portion 3-1 of the metal member 3 and the tapered portion 4-2 of the outer joint 4 have the same inclination. The tapered portion 3-1 and the tapered portion 4-2 are in surface contact with each other when the metal member 3 is installed in contact with the outer joint 5 and the outer joint 4 is fastened to the inner joint 5 Is configured. The inner diameter d3 of the lower end (in the Y direction) of the drawing of the tapered portion 3-1 is smaller than the above-mentioned imaginary diameter equivalent r. A female screw 4-1 is cut inside the lower end (in the Y direction) of the outer joint 4 in the drawing.

The inner joint 5 is made of metal and has a cylindrical shape. A male screw 5-1 is cut at the end of the inner joint 5 in the upward direction (X direction) from the paper surface of the inner joint 5. The female screw 4-1 and the male screw 5-1 are formed to be fitted to each other. Therefore, by rotating the female screw 5-1, the inner joint 5 is moved relative to the outer joint 4 in the paper surface upward direction (also described as Y direction for convenience). The inner joint 5 and the outer joint 4 have a structure in which they are fastened to each other at a predetermined moved position.

Thus, the fastening structure 1 shown as Example 1 in FIG. 1 and FIG. 2 has a straight pipe-shaped FRP pipe 2 and the FRP arranged around the FRP pipe as shown in its external appearance and sectional shape. Insert the metal member 3 consisting of divided pieces tapered in the longitudinal axis direction of the pipe into the inside of the tubular metal outer joint 4 having a tapered surface which inclines at substantially the same angle as the metal member In this embodiment, the metal inner joint 5 having the screw portion 5-1 on the outer surface and the joint are engaged.

As a result, when a tensile force in the longitudinal direction acts on the FRP pipe 2, a high fastening force is generated by the frictional force acting between the tapered surfaces of the outer joint 4 and the metal member 3. Further, when the outer joint 4 and the inner joint 5 are engaged, the inner joint 5 and the metal member 3 are in strong contact with each other. As a result, even when a compressive force in the longitudinal direction acts on the FRP pipe 2, the tapered surface of the outer joint 4 and the metal member 3 does not come off, so that it is difficult to loosen, and the compressive force at the contact portion Also has the advantage of being able to prevent compressive fracture at the end of the FRP pipe 2 to support the

Examples 2 to 11 will be described below. The second to eleventh embodiments will be described focusing on differences from the first embodiment. Therefore, the parts whose description is omitted are basically the same as in the first embodiment.

The fastening structure 1 shown as Example 2 in FIG. 3 and FIG. 4 is an embodiment in which a columnar or tubular metal rod 6 is disposed inside the FRP pipe 2 in the fastening structure of Example 1 as shown in its cross sectional shape. is there. As a result, since the metal rod 6 exerts a reaction force on the compressive force applied to the FRP pipe 2 from the metal member 3 at the time of fastening, the fastening force can be improved.

The fastening structure 1 shown as Example 3 in FIGS. 5 to 7 has an embodiment in which the thickness of the circumferential end of the metal member 3 is reduced in the fastening structure of Example 1 or 2 as shown in the cross sectional shape thereof. It is a form.

In the embodiment shown in FIG. 5, a portion of the circumferential end is tapered, and in the embodiment shown in FIG. 6, the thickness is continuously reduced by providing a curved portion at the end. Further, in the embodiment shown in FIG. 7, the portion from the end to a certain distance is thinned with a certain thickness. Thereby, when external force acts on the FRP pipe 2 at the time of fastening or FRP pipe 2, stress concentration near the said end can be reduced, and breakage of FRP pipe 2 which used the stress concentration part as the starting point can be prevented.

The fastening structure 1 shown as Example 4 in FIG. 8 to FIG. 10, as shown in its cross-sectional shape, in the fastening structure of Example 1 or Example 2, extends from the fastening portion to the joint longitudinal end of the metal member 3 in the longitudinal direction. It is embodiment which provided the site | part which protrudes in direction.

In the embodiment shown in FIG. 8, the projecting portion 7a having a taper inclined at an angle larger than the taper surface of the fastening portion is provided, and in the embodiment shown in FIG. 9, the projecting portion 7b whose thickness is continuously reduced by the curved portion. Is provided. Further, in the embodiment shown in FIG. 10, a protrusion 7c having a constant thickness is provided. Thereby, when a bending load is applied to the FRP pipe 2 at the time of fastening, stress concentration at the end of the fastening portion can be reduced, and breakage of the FRP pipe 2 starting from the stress concentration portion can be prevented.

The fastening structure 1 shown as Example 5 in FIGS. 11 and 12 has slits in the longitudinal direction end or the circumferential direction end of the metal member in the fastening structure of the first embodiment or the second embodiment as shown in the cross sectional shape thereof. This embodiment is provided with 8a or 8b.

By providing the slit, it is possible to reduce stress concentration at the end of the fastening portion or at the end of the metal member 3 at the time of fastening or when a bending load is applied to the FRP pipe 2, and FRP starting from the stress concentrating portion Damage to the pipe 2 can be prevented. Further, both of the

slits

8 a and 8 b may be provided in the metal member 3.

The fastening structure 1 shown as Example 6 in FIG. 13 and FIG. 14 has, as shown in its cross-sectional shape, the metal member 3 as a metal member 3a and a metal member 3b arranged in series in the longitudinal direction of the joint structure. It is a divided embodiment. The outer surface of the metal member 3b is provided with a taper, and the inner end of the longitudinal direction of the metal member 3a is provided with a taper inclined at substantially the same angle as the taper and having a shorter length than the taper. There is.

Thereby, when a bending load is applied to the FRP pipe 2 at the time of fastening, stress concentration at the end of the fastening portion can be reduced, and breakage of the FPR pipe 2 starting from the stress concentration portion can be prevented. Further, as shown in FIG. 14, the compressive force applied from the metal member 3b to the FRP pipe 2 is increased by making the angle of the taper provided to the metal member 3b larger than the angle of the taper provided to the metal member 3a. , Can improve the fastening force.

The fastening structure 1 shown as Example 7 in FIG. 15 to FIG. 18 divides the metal member 3 into the metal member 3c and the metal member 3d in the radial direction of the joint structure as shown in its external appearance and sectional shape. It is embodiment which arrange | positioned the metal member in parallel with respect to the longitudinal direction of coupling structure.

In the embodiment shown in FIGS. 15 and 16, the area of the outer surface of the metal member 3d is made larger than the inner surface of the metal member 3c, and in the embodiment shown in FIG. It is divided into As a result, stress concentration at the end of the fastening portion or at the end of the metal member 3 d when fastening or when an external force acts on the FRP pipe 2 can be reduced, and breakage of the FPR pipe 2 starting from the stress concentrating portion can be prevented.

In the embodiment shown in FIG. 18, curved portions with different curvatures are provided on the outer side and the inner side of the metal member 3 d, and fastening is possible even when the inner surface of the joint 4 and the outer surface of the FPR pipe 2 have different curvatures.

In the above embodiment, the ability to conform the metal member 3d to the cross-sectional shape of the FRP pipe 2 is improved by reducing the thickness of the metal member 3d, and the outer surface of the FRP pipe 2 and the inner surface of the metal member 3d are assured It is possible to make contact with

The fastening structure 1 shown as Example 8 in FIG. 19 and FIG. 20 is, as shown in the cross sectional view, the metal member or the metal on the contact surface of the metal member 3 and the FRP pipe 2 or the metal rod 6 and the FRP pipe 2 In this embodiment, a metal film 9 having a thermal conductivity higher than that of a rod is disposed.

When fatigue load is applied to FRP, it is known that FRP and the resin that composes FRP deteriorate due to heat generation caused by heat generation inside the resin and damage inside FRP, and the fatigue life and fatigue strength of FRP decrease. It is done. In the fastening structure shown in FIGS. 19 and 20, even when a fatigue load acts on FRP pipe, heat can be dissipated from the fastening structure by metal film 9. Therefore, degradation of FRP pipe 2 due to heat or degradation is caused. It becomes possible to prevent the deterioration of the fatigue life and the fatigue strength of the FRP pipe 2.

By arranging the metal film 9 on both the contact surface of the metal member 3 and the FRP pipe 2 and the contact surface of the metal rod 6 and the FRP pipe 2, or by arranging to project from the fastening portion in the longitudinal direction of the fastening structure , The heat radiation effect can be improved. Further, in the present embodiment, since the contact surface of the metal film 9 and the FRP pipe 2 can be firmly brought into contact with each other by the compressive force, it is possible to exhibit a high heat radiation effect.

The fastening structure 1 shown as Example 9 in FIG. 21 has the metal plate 10 in a mode of radially projecting around the outer joint 4 in the fastening structures shown in the above-mentioned Examples 1 to 8 as shown in its cross sectional shape. It is the embodiment arrange | positioned.

Thus, even when fatigue load is applied to FRP pipe 2 and heat is generated at the fastening portion, heat can be dissipated from the outer surface of outer joint 4 and deterioration of FRP pipe 2 due to heat can be prevented. Therefore, the fatigue life and fatigue strength of the fastening structure can be improved.

The fastening structure 1 shown as Example 10 in FIG. 22 has a constant value between the end of the FRP pipe 2 and the inner joint 5 in the fastening structure shown in the above-mentioned Examples 1 to 9, as shown in its cross sectional shape. It is an embodiment in which a gap is provided. Thus, when a compressive load is applied to the FRP pipe 2, no compressive force is applied to the end of the FRP pipe 2, so that compressive fracture of the FRP pipe 2 starting from the end is prevented. it can.

Example 11 shown in FIG. 23 is an FRP structure constituted by connecting the fastening structure and the structure 12 shown in the above-mentioned Examples 1 to 10 as shown in the cross-sectional shape thereof.

In each of the above embodiments, the cross section of the FRP pipe is circular or elliptical, but it may be a polygonal cross section such as a square. In this case, a metal member having a circular outer tapered surface and a polygonal inner surface may be disposed around the FRP pipe.

The fastening structure according to the present invention has the advantages of easy production, simple fastening, and high reliability.

DESCRIPTION OF SYMBOLS 1 ... Fastening structure, 2 ... FRP pipe, 3, 3a, 3b, 3c, 3d ... Metal member, 4 ... Outer joint, 5 ... Inner joint, 6 ... Metal rod, 7a, 7b, 7c ... Protrusion part, 8a, 8b ... Slit, 9 ... metal film, 10 ... metal plate, 11 ... gap, 12 ... structure

Claims

A straight pipe-shaped fiber-reinforced plastic pipe having a uniform outer diameter, a first joint member facing one end of the pipe, and the pipe so as to contact the pipe in the longitudinal direction of the pipe A second joint member in contact with the tapered portion, having an intermediate member disposed therearound, the intermediate member having a tapered portion whose diameter gradually increases from the other side of the pipe toward the one side A joint structure characterized in that the second joint member and the first joint member are fastened such that the second joint member and the pipe are mutually pressed through the tapered portion.
The joint structure according to claim 1, further comprising a metal rod of a columnar or tubular shape having the same cross-sectional shape as the inside of the pipe fitted to the inside of the pipe.
The joint structure according to any one of claims 1 and 2, wherein a thickness of a circumferential end of the intermediate member disposed around the pipe is reduced.
In any one of claims 1 and 2, a longitudinal end of the intermediate member disposed around the pipe is provided with a portion projecting in the longitudinal direction of the joint structure from the fastening portion. Joint structure.
The fastening structure according to any one of claims 1 and 2, wherein a slit-like concave portion is provided at a longitudinal end or a circumferential end of the intermediate member disposed around the pipe. Characteristic joint structure.
The outer surface of one member according to any one of claims 1 or 2, wherein the intermediate member disposed around the pipe is divided into two members disposed in series with respect to the longitudinal direction of the joint structure. And the other member is in contact with the tapered surface of the member via a tapered surface which is shorter than the taper provided at the longitudinal end and inclined at substantially the same angle as the taper. A joint structure characterized by
In any one of claims 1 or 2, the intermediate member disposed around the pipe is divided into two members disposed in parallel with respect to the radial direction of the joint structure, and one of the members is the outside thereof. Joint structure characterized in that it is in contact with a joint via a taper provided on the surface, and the other member is in contact with the inner surface of the member via an outer surface larger in area than the inner surface of the member. .
The metal member according to any one of claims 1 to 7, wherein the intermediate member is a metal member, and the metal is formed on the contact surface of the metal member and the pipe or the contact surface of the metal rod and the pipe or both. A joint structure characterized in that a metal higher in thermal conductivity than a member or a metal rod is disposed.
The joint structure according to any one of claims 1 to 8, wherein the intermediate member is a metal member, and a radially projecting metal plate is disposed on an outer surface of the metal joint.
The joint structure according to any one of claims 1 to 9, wherein a fixed gap is provided between the end of the pipe and the joint in the longitudinal direction of the joint.