JPS5921804B2 - automotive propeller shaft - Google Patents

Description

[Detailed description of the invention] b) Technical field of this invention The present invention relates to a propeller shaft for an automobile.

(b) Prior art and its disadvantages Automobile propeller shafts have traditionally been made of steel.

However, in recent years, propeller shafts made of fiber-reinforced plastic (hereinafter referred to as FRP) have been considered in order to improve fuel efficiency and reduce vibration and noise, especially during high-speed driving, to improve ride comfort and comfort. It's starting to feel like this. That is, since FRP has a higher specific strength than steel, a propeller shaft using it is lightweight and can save fuel consumption. - Also, since FRP has excellent vibration damping properties, it can be expected to improve riding comfort and livability by reducing vibration and noise. However, F.R.
On the other hand, P has low impact strength, so FRP propeller shafts are vulnerable to external impacts while driving, such as impacts from thrown stones or collisions with the road surface, and are prone to breakage due to such causes. They have the disadvantage that they tend to crack or become unusable. In an attempt to prevent this, a propeller shaft with a so-called hybrid structure has been proposed, in which the inner layer is made of carbon fiber FRP, which has relatively high strength and high elasticity, and the outer layer is made of glass fiber FRP, which is relatively resistant to impact. There is.

However, even with this, the impact strength is still insufficient. ←
→ Purpose of this invention The purpose of this invention is to solve the above-mentioned drawbacks of conventional FRP propeller shafts, and to improve riding comfort and livability by being lightweight, having low fuel consumption, and having low vibration and noise during driving. To provide a propeller shaft for an automobile that is strong against impact and prevents breakage and cracking.

A Structure of the Invention In order to achieve the above object, the present invention has a cylindrical body made of fiber-reinforced plastic, a yoke joined to both sides of the body in the axial direction, and an outer peripheral surface of the envelope. Provided is a propeller shaft for an automobile, characterized in that the propeller shaft is coated with silicone rubber.

To explain one embodiment of the propeller shaft of the present invention, in the drawing (schematic partially cutaway front view), a metal yoke 2 is joined to both sides in the axial direction of a cylindrical body 1 made of FRP, and A silicone rubber tube 3 is placed over the outer peripheral surface of the main body 1 to form a propeller shaft 4.

Note that, of the two yokes, one yoke is coupled to the transmission of the automobile, and the other yoke is coupled to the differential. In the above, the main body has a matrix of resin such as epoxy resin or unsaturated polyester resin, and the matrix resin is reinforced with high strength and high elastic fibers such as carbon fiber, glass fiber, organic high elastic fiber, and boron fiber. F.R.
It consists of P.

However, different types of reinforcing fibers may be used in combination, and so-called hybrid FRP, which is a composite of FRPs made of different reinforcing fibers, may be used.
However, such an FRP main body is made by wrapping reinforcing fibers impregnated with matrix resin around the outer peripheral surface of a mandrel so that the fiber axes are in the desired direction with respect to the axial direction of the mandrel, and then curing the resin. It can be molded by the so-called filament winding method.
After winding or covering a mandrel with a woven or braided reinforcing fiber, it may be impregnated with a resin to serve as a matrix, and after curing, the mandrel may be pulled out. Further, a reinforcing fiber prepreg, for example, a sheet-like or tape-like prepreg made by aligning reinforcing fibers in parallel, may be wound around a mandrel, and after the resin is cured, the mandrel is pulled out and molded. A silicone rubber tube placed over such a body serves to protect the body from external impacts.

Here, silicone rubber is specifically selected and used as a so-called protective material because silicone rubber is heat resistant,
This is because it not only has excellent oil resistance, but also has a strong impact absorption effect even if it is thin, making it extremely suitable as a protective material for automobile propeller shafts. In other words, the propeller shaft is placed near the exhaust pipe (muffler), and its surface is 14
Since it is heated to about 0 to 180°C, the protective material is required to have good heat resistance. In addition, good oil resistance against grease and the like is required. Furthermore, the propeller shaft is required to have a high impact absorption effect even if it is thin, so as not to significantly increase the outer diameter of the propeller shaft and make it difficult to install it in the limited underfloor space of an automobile. Silicone rubber is most suitable for such severe requirements. The outer surface of the main body can be coated with silicone rubber by press-fitting a tube-shaped silicone rubber into the main body, by covering the main body with a tube-shaped silicone rubber and heating it to integrate it, or by extruding silicone rubber around the main body using an extruder. Alternatively, this can be done by wrapping a sheet or tape of silicone rubber around the outer circumferential surface of the main body. The main body and the silicone rubber may be bonded together using an adhesive. Further, the outer circumferential surface of the main body may be provided with a pattern or a protrusion so that the silicone rubber can be locked therein. (E)
Effects of the Invention The automobile propeller shaft of the present invention has an FRP main body covered with silicone rubber, which protects the main body from external impacts such as collisions with stones and road surfaces. This can prevent breakage and cracks from occurring.

Moreover, there is almost no increase in weight due to the silicone rubber coating, and the light weight characteristic of conventional FRP propeller shafts is hardly lost. Therefore, fuel consumption is low and acceleration and deceleration are smooth. Furthermore, since silicone rubber has high heat resistance and oil resistance, it exhibits good durability against exhaust pipe heat and oils such as grease. moreover,
Even though silicone rubber is thin, it exhibits high shock absorption properties, so
There is almost no increase in the outer diameter of the propeller shaft, and there is no difficulty in placing it in the limited underfloor space of an automobile. Furthermore, the main body is made of FR material with excellent vibration absorption properties.
Since it is composed of P, there is less vibration and noise, improving ride comfort and livability. As an example reinforcing fiber, carbon fiber "Torega T-3" manufactured by Toray Industries, Inc.
The outer diameter of
Five main bodies were molded, each having an inner diameter of 54 m, a length of 1,000 m, and a helical winding of carbon fiber with a winding angle of ±45 m relative to the axial direction.

The volume content of reinforcing fibers in each main body was about 60%.
Next, the thickness is 0.1mm 11mm 15m 11110vn
Four types of silicone rubber tubes were prepared, and these silicone rubber tubes were press-fitted into four of the five bodies to obtain four types of silicone rubber coated bodies.

Next, metal yokes were adhered to both axial ends of each of the five types of main bodies to obtain propeller shafts.

Next, regarding the above five types of propeller shafts, 1kf from above! A steel ball was allowed to fall freely at different heights, and the energy (weight of the steel ball x falling height of the steel ball) that caused a crack in the main body was measured.

The measurement results are shown in the table below. From the above measurement results, it can be seen that even when the thickness of the silicone rubber is only 061 mm, the fracture energy is about 1.38 times higher than that without silicone rubber coating.

In other words, the propeller shaft of this invention has a correspondingly high impact strength. Moreover, in the weight measurement of both, 0
．． The weight increase due to coating with 1 mm thick silicone rubber is only about 3.7%. Furthermore, when the thickness of the silicone rubber is 5 mm, a fracture energy of 3.31 < 9 m is obtained, which corresponds to the energy when a 1009 object collides at a speed of 1001 c1n per hour, and the silicone rubber It can be seen that the impact strength improvement effect of rubber is extremely large.

[Brief explanation of drawings]

The drawing is a partially cutaway schematic front view showing one embodiment of a propeller shaft for an automobile according to the present invention. 1...FRP body, 2...Yoke,
3...Silicone rubber tube, 4...
・Propeller shaft.

Claims (1)

[Claims] 1. A propeller shaft for an automobile, comprising a cylindrical body made of fiber-reinforced plastic and a yoke joined to both sides of the body in the axial direction, and an outer circumferential surface of the body being coated with silicone rubber.