JP2012177449A - Power transmission shaft and method for manufacturing power transmission shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission shaft having the same or higher strength and an anti-bending property compared with a conventional power transmission shaft made of an iron-based material alone, and further having a much reduced weight and high reliability.SOLUTION: A laminated body formed by winding at least one of a unidirectional prepreg and a textile prepreg made of at least one of a carbon fiber and a glass fiber and a thermosetting resin around a hollow core material made of rubber, is inserted into a shell made of steel. The laminated body is stuck to the inner surface of the shell by inflating the hollow rubber body and heated, and thus attached and cured to obtain the power transmission shaft of a composite structure.

Description

  The present invention relates to a power transmission shaft used in a power transmission mechanism, and more particularly to a power transmission shaft made of a composite material.

In recent years, in the field of machinery such as automobiles, there has been a strong demand for reducing carbon dioxide emissions in response to global warming, and various components are made of fiber reinforced resin to save energy, which tends to reduce weight. There is.
Among these members, in power transmission members, replacement with FRP materials (GFRP, CFRP) excellent in specific strength and specific rigidity is attempted to reduce the weight and increase the natural frequency to increase the dangerous rotation speed. The use is expanding. However, the FRP material is rarely used alone as a power transmission component, and is used by being joined to a metal joint in order to transmit torque. Since a large force is applied to the joint portion between the FRP and the metal joint, a sufficient fixing force and strength are required at the joint portion of the power transmission component. There was a problem.

As a method to ensure the strength of the metal joint joint attachment part of the power transmission part made of FRP material, a cylindrical outer shell in which the outer shell and the joint of the power transmission part are integrally formed of metal is created. A method is disclosed in which fibers are introduced into the inner surface of a cylindrical outer shell by rotating at a high speed, the fibers are wound up on the inner surface of the cylindrical outer shell, and then the resin is introduced and solidified to form FRP on the inner surface of the cylindrical outer shell. (Prior art document 1)
JP 5-8310).
Further, a method for improving the strength by filling the inner diameter of the hollow shaft has been disclosed (Document 2 of the prior art).
JP 2005-113986).

Japanese Patent Laid-Open No. 5-8310 JP-A-2005-113986

However, in the invention of Prior Art Document 1, the degree of freedom is low in the FRP fiber orientation direction on the inner surface of the cylindrical outer shell, and unevenness is likely to occur in the fiber content of FRP. In the invention of Prior Art Document 2, it is difficult to accurately center the inner diameter of the end portion of the CFRP cylinder and the tooth portion to be serrated by the joint. In addition, because the inner diameter of the end of the CFRP cylindrical body is pressed using the joint teeth, and the inner diameter of the end of the CFRP cylinder and the outer diameter of the joint tooth are varied, pressure input, fixing force, strength The variation becomes large. Further, in the serration coupling, the fixing force in the rotational direction can be secured, but the axial fixing force cannot be sufficiently increased.
Therefore, an object of the present invention is to provide a power transmission shaft made of a composite material that is lightweight and has improved strength in the rotational direction and the axial direction at the connection portion with the joint.

In order to solve the above problem, the invention according to claim 1 is a power transmission shaft having a cylindrical cross section, and a carbon fiber reinforced resin or a glass fiber reinforced resin is formed on an inner peripheral surface of a metal cylindrical outer shell. A fiber reinforced resin layer made of at least one of the above is bonded and cured.
According to a second aspect of the present invention, in the power transmission shaft according to the first aspect, the cylindrical outer shell is made of hardened steel, and the fiber reinforced resin layer is made of at least one of unidirectional or woven prepreg. It consists of the laminated body which becomes.
According to a third aspect of the present invention, in the power transmission shaft according to the second aspect, the cylindrical outer shell has a hardness of HRC30 or higher.
The invention according to claim 4 is a method of manufacturing a power transmission shaft having a cylindrical cross section, wherein the hollow cylindrical core material is formed of at least carbon fiber or glass fiber on the inner diameter of a metal cylindrical outer shell. After inserting a laminated body wound around one side, a fluid is injected into the hollow rubber core material to expand it, and the laminated body is in close contact with the inner peripheral surface of the cylindrical outer shell. The power transmission shaft of the composite structure is obtained by bonding and curing.

  The present invention has the above-described configuration, and can be significantly reduced in weight while having the same or higher curvature than the conventional all-steel power transmission shaft. In addition, the natural frequency is increased by reducing the weight, and the dangerous rotational speed can be increased.

It is a figure which shows the 1st Example by this invention. It is a figure which shows the manufacturing method of the power transmission shaft by this invention.

1 and 2 show a first embodiment according to the present invention.
In FIG. 1, the power transmission shaft 1 includes an outer shell 2 and a fiber reinforced resin layer 3 formed on the inner peripheral surface of the outer shell 2. As shown in FIG. 2 (a), the outer shell 2 is quenched into a steel cylinder to improve surface hardness and strength. Thereafter, a prepreg made of unidirectional or woven fiber and a thermosetting resin is wound around a core material 4 made of hollow rubber, and the laminated body 3a laminated as shown in FIG. 2B is inserted into the inner diameter of the outer shell 2. Then, a fluid such as compressed air (not shown) is injected into the core material 4 in FIG. 2 (c) to bring the laminate 3 a into close contact with the inner surface of the outer shell 2. In this state, the laminated body 3 a is held at 130 ° C. for 2 hours to cure the thermosetting resin contained in the laminated body 3 a and adhere the fiber reinforced resin layer 3 to the inner peripheral surface of the outer shell 2. And the core material 4 is removed and the power transmission shaft 1 is obtained. It is desirable that the prepreg used for the laminate 3a contains 22 to 55% by mass, more preferably 25 to 40% by mass of a thermosetting resin typified by epoxy. When the content of the thermosetting resin is less than 22% by mass, the resin is not sufficiently distributed between the fibers, resulting in a decrease in adhesion between prepregs and generation of voids. On the other hand, if it exceeds 50% by mass, the strength and rigidity decrease due to the decrease in the number of fibers.
A comparison of the weight, durability, and curvature of the power transmission shaft prepared according to the above-described embodiment and the conventional all-steel power transmission shaft will be described below.
The steel pipe was quenched and used as the outer shell. Then, a carbon fiber prepreg containing 25% by mass of a thermosetting resin is wound around a hollow rubber core material, laminated, inserted into the inner diameter of the outer shell, and then inflated by injecting compressed air into the core material. A prepreg was adhered to the inner surface of the plate. In this state, it was held at 130 ° C. for 2 hours, and the prepreg was adhered and cured to the inner surface of the outer shell to obtain Example 1 of the power transmission shaft.
Table 1 shows the results of the weight, durability test, and bending evaluation test of the all-steel power transmission shaft having the same dimensions as in Example 1 above as Comparative Example 1. The numerical value represents the relative value of Example 1 when the value of Comparative Example 1 is 100.

表１に示すように、本発明による炭素繊維強化樹脂と、鋼製の外殻により構成される動力伝達軸は、従来の鋼製動力伝達軸並の強度、耐久性を有しながら軽量化を実現している。 Table 1 shows the comparison results of mass and durability according to Example 1 and Comparative Example 1.
(Table 1)

As shown in Table 1, the power transmission shaft constituted by the carbon fiber reinforced resin according to the present invention and the steel outer shell has the same strength and durability as a conventional steel power transmission shaft, but is reduced in weight. Realized.

  It can be used as a method for manufacturing a composite structural shaft.

DESCRIPTION OF SYMBOLS 1 Power transmission shaft 2 Outer shell 3 Fiber reinforced resin layer 3a Laminated body 4 Core material

Claims (4)

  A power transmission shaft having a cylindrical cross section, wherein a fiber reinforced resin layer made of at least one of carbon fiber reinforced resin or glass fiber reinforced resin is bonded and cured to an inner peripheral surface of a metal cylindrical outer shell. A power transmission shaft with a unique composite structure.   2. The power transmission shaft according to claim 1, wherein the cylindrical outer shell is made of hardened steel, and the fiber reinforced resin layer is made of a laminated body composed of one direction or at least one woven prepreg. Transmission shaft.   The power transmission shaft according to claim 2, wherein the cylindrical outer shell has a hardness of HRC30 or higher.   A method of manufacturing a power transmission shaft having a cylindrical cross section, in which a laminated body in which at least one of carbon fiber or glass fiber is wound around a hollow rubber core material is inserted around an inner diameter of a metal cylindrical outer shell After that, a fluid is injected into the hollow rubber core material to expand it, and the laminated body is bonded and cured in a state of being in close contact with the inner peripheral surface of the cylindrical outer shell. A method of manufacturing a power transmission shaft, wherein the transmission shaft is a transmission shaft.

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