JPS63247026A - Joint structure for metal cylinder and fiber reinforced plastic cylinder - Google Patents

Abstract

PURPOSE:To enhance the strength of bonding section of a metal cylinder and a FRP cylinder by inserting a projected section of the metal cylinder into a channel of the FRP cylinder and bonding the outer surface of FRP rings integrated with the outer periphery of said projected section to the inner surface of said channel. CONSTITUTION:A projected section 6 is formed by shaving the inner and outer peripheral surfaces of the end of a metal cylinder 5, and a channel 7 of U-shaped section is formed on the end surface of a FRP cylinder 1. Recessed sections 9 are formed respectively on the inner and outer peripheral surfaces of the projected section 6, and a semi-cured fiber-reinforced plastic ring 10 of thermoplastic resin is inserted into said recessed sections 9, outside of which a semi-cured fiber-reinforced plastic ring 8 of U-shaped section prepared by thermoplastic resin is provided. The ring 8 and the rings 10 are heated, cured and integrated with the projected section 6, and said projected section 6 is inserted into the channel section 7, while the outer surface of the ring 8 integrated with the outer surface of the projected section 6 is bonded to inner periphery of the channel 7. By said arrangement, the bonding section of the metal cylinder 5 and the FRP cylinder 1 is constituted of FRP to enhance the bonding strength of both.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a metal cylinder and a fiber-reinforced plastic (hereinafter referred to as
This relates to a cylindrical joint structure (called FRP).

[Conventional technology]

Conventionally, in order to reduce the weight of the FRP cylinder 1, there is a structure in which a buoyant body 4 with a small specific gravity is sandwiched between an inner cylinder 2 and an outer cylinder 3 of FRP.

When connecting the metal cylinder 5 to such an FRP cylinder 1,
If the two are connected by bolting or the like, the fibers of the FRP will be cut, which will significantly reduce the strength of the FRP.

For this reason, conventionally, when connecting the FRP cylinder 1 and the metal cylinder 5, the following joint structure has been adopted.

That is, as shown in FIGS. 2 and 3, the inner circumferential surface and outer circumferential surface of the end of the metal cylinder 5 are shaved to form protrusions 6, and the FRP
A groove 7 having a U-shaped cross section is formed on the end face of the cylinder 1, and an FRP ring 8 having a U-shaped cross section is adhered to the inner surface of the groove 7. The projection 6 of the metal cylinder 5 is fitted into this FRP ring 8. The outer surface of the projection 6 is bonded to the inner surface of the FRP ring 8.

[Problem that the invention seeks to solve]

By the way, joining different materials such as metal and FRP,
Bonding strength varies depending on the surface condition of the metal, and FR
The shear strength is weaker than that of P-to-P bonding.

Therefore, when a bending moment is applied to an FRP cylindrical container using the above joint structure due to an impact, an external force in a direction perpendicular to the axis of the cylinder acts, and the outer surface of the protrusion 6 of the metal cylinder 5 is The adhesive part between the FRP ring 8 and the inner surface of the FRP ring 8 is peeled off due to shear force, and the protrusion 6 of the metal cylinder 5 becomes FR.
There is a risk that the metal cylinder 5 and the FRP cylinder 1 will be separated from each other by being pulled out from the inner surface of the P ring 8.

Therefore, the present invention aims to increase the bonding strength between the metal cylinder 5 and the FRP cylinder 1.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention forms recesses 9 on the inner and outer peripheral surfaces of the protrusion 6, respectively, as shown in FIG. A fiber-reinforced plastic ring 10 is fitted, and a semi-hardened fiber-reinforced plastic ring 8 having a U-shaped cross section is further placed on the outside thereof, and this fiber-reinforced plastic ring 8 having a U-shaped cross section is fitted.
and the fiber-reinforced plastic ring 10 are heat-cured and integrated with the projection 6, and the projection 6 is fitted into the groove 7 of the fiber-reinforced plastic cylinder 1.
The outer surface of the fiber-reinforced plastic ring 8 integrated with the outer periphery was adhered to the inner periphery of the groove 7.

[Effect]

In the joint structure configured as described above, since the FRP ring 10.8 is integrally bonded to the outer surface of the protrusion 6 of the metal cylinder 5, the bond between the metal cylinder 5 and the FRP cylinder 1 is F
Since this is done between RPs, the strength of the joint increases.

〔Effect of the invention〕

As described above, according to the joint structure of the present invention, since the joint portion between the metal cylinder 5 and the FRP cylinder 1 is made of FRP, the joint strength between the two is high.

Therefore, the metal cylinder 5 and the FRP cylinder 1 connected by the joint structure of the present invention have the effect of withstanding a large bending moment. For example, as shown in FIG.
When a three-point bending test was carried out by connecting metal cylinders 5 to both sides of the cylinder 1, the results showed that the joint structure of the present invention was superior to the conventional joint structure as shown in the table below. It had about twice the bending strength.

Therefore, by using the joint structure of this invention,
Since the joint strength between the metal cylinder and the FRP cylinder is increased, it becomes possible to apply it to fields that require more severe usage conditions than conventional joint structures.

[Brief explanation of drawings]

FIG. 1 is a partially enlarged sectional view of a joint structure between a metal cylinder and a fiber-reinforced plastic cylinder according to the present invention, FIG. 2 is a sectional view showing a conventional joint structure, and FIG. 3 is a partially enlarged sectional view of FIG. 2. , FIG. 4 is a schematic diagram showing a joint strength test method.

Claims (1)

[Claims] A protrusion 6 is formed by scraping the inner and outer circumferential surfaces of the end of the metal cylinder 5, a groove 7 having a U-shaped cross section is formed on the end face of the fiber-reinforced plastic cylinder 1, and the protrusion 6 is inserted into the groove 7. In a joint structure of a metal cylinder and a fiber-reinforced plastic cylinder formed by fitting and bonding the outer surface of the projection 6 to the inner surface of the groove 7, recesses 9 are formed on the inner and outer peripheral surfaces of the projection 6, respectively.
A semi-cured fiber-reinforced plastic ring 10 is fitted into the recess 9, and a semi-cured fiber-reinforced plastic ring 8 with a U-shaped cross section is placed over the outside of the ring 9, and this fiber-reinforced plastic ring with a U-shaped cross section is 8 and the fiber-reinforced plastic ring 10 are heat-hardened and integrated into the projection 6, the projection 6 is fitted into the groove 7 of the fiber-reinforced plastic cylinder 1, and the fiber-reinforced plastic ring 10 integrated with the outer periphery of the projection 6 is integrated. A joint structure of a metal cylinder and a fiber-reinforced plastic cylinder, characterized in that the outer surface of the plastic ring 8 is adhered to the inner surface of the groove 7.