JP3034613B2 - Propeller shaft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propeller shaft, and more particularly, to a propeller shaft for transmitting power from a vehicle engine to rear wheels and the like.

[0002]

2. Description of the Related Art Conventionally, a universal joint is provided on the axis of a propeller shaft of this type, so that a yoke is provided at a joint portion at the shaft end, and a hollow tube is connected to the yoke as a shaft tube. Has been used a lot. An example of such a propeller shaft is disclosed in, for example,
The one disclosed in JP 07506 is known.

[0003] In plastically connecting the yoke of the joint portion and the tube of the shaft tube, the yoke shaft portion and the tube end portion are connected to each other in order to increase the strength of the connection while taking advantage of the characteristics of a lightweight shaft. On the serration,
A reinforcing ring member is further mounted on the outside by shrink fitting.

[0004]

However, in the propeller shaft constructed as described above, in order to connect the shaft of the yoke and the end of the tube by serration, the serration is cut into the shaft end of the yoke shaft. In this state, the two members are joined in a plastic region by shrink fitting of the reinforcing ring member. Therefore, the serrations engraved on the outer periphery of the yoke shaft bite into the inner surface of the tube shaft at the end of the yoke shaft for plastic coupling. The discontinuity caused by the sudden disappearance of the bite at the end of the yoke causes stress concentration, resulting in a decrease in strength and a large variation in strength among products. In addition, there has been a problem that the wall thickness of the tube must be increased beyond the required strength.

SUMMARY OF THE INVENTION An object of the present invention is to focus on the above-mentioned conventional problems. In order to solve the problems, it is possible to suppress a decrease in strength due to the serrations in a plastic joint using serrations. An object of the present invention is to propose a durable propeller shaft that does not need to be thickened.

[0006]

According to a first aspect of the present invention, a serration is provided around a shaft of a yoke, and an end of a tube is fitted to the shaft of the yoke. Moreover, in a propeller shaft so as to be plastically bonded via the serrations by the end of the tube narrow down towards the shaft portion, wherein
The shaft of the yoke is the shaft of the yoke in the tube.
Stress concentration at the part where the shaft end of the part is fitted is reduced.
So that it is separated from the shaft end of the shaft portion of the yoke by a predetermined distance.
Serrations in which the serrations are formed at spaced locations
Shaft forming portion, the serration forming portion and the shaft portion of the yoke.
Between the shaft end and the inner surface of the tube.
And a cylindrical portion coupled in a touched state .

Further, according to a second aspect of the present invention, serrations are provided around the shaft of the yoke, and the end of the tube is fitted to the shaft of the yoke, and the end of the tube is directed toward the shaft. In a propeller shaft which is plastically coupled via the serrations by squeezing, the number of teeth of the serrations formed at a portion near the shaft end of the shaft portion is reduced by a portion of the shaft portion near the tube tip. The number of teeth of the serrations to be formed is made smaller.

[0008]

According to the first aspect of the present invention, the shaft of the yoke is connected to the shaft.
At the part where the shaft end of the shaft part of the yoke in the tube is fitted.
The axis of the yoke shaft is reduced so that the resulting stress concentration is reduced.
Serrations are formed at a predetermined distance from the edge
Serration forming part to be formed, Serration forming part
Tube formed continuously with the shaft end of the shaft portion of the yoke
And a cylindrical portion that is joined in contact with the inner surface of the
Further , in the second embodiment of the present invention, of the serrations formed on the shaft portion of the yoke, the number of teeth formed on the portion near the shaft end of the yoke shaft portion is changed to the number of teeth near the tube end of the yoke shaft portion. It is plastically coupled to the tube in a state where the number of teeth formed is smaller than the number of teeth, and the magnitude of stress concentration occurring near the yoke shaft end of the tube can be reduced.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. Here, reference numeral 1 denotes a tube, and 2 denotes a yoke, both of which are formed of a lightweight and plastic metal material such as aluminum or an alloy thereof. The yokes 2 are fitted to both ends of the tube 1 as described later, respectively.
After the plastic connection, the reinforcing ring member 3 is shrink-fitted to the outside of the connection portion, but the structure is the same in all cases. Hereinafter, one of the connection portions (the left portion in FIG. 1) ) Will be described, and description of the other will be omitted.

In this embodiment, the end 1 of the tube 1
The serration portion 4 formed on the shaft portion 2A of the yoke 2 into which A is fitted is limited to an intermediate portion in the axial direction of the shaft portion 2A, and no serration is provided near the shaft end 2B of the shaft portion 2A. Note that the serration portion 4 has a smaller outer diameter toward the shaft end 2B of the shaft portion 2A.
It may be formed in a tapered shape. Therefore, the shaft 2 of the yoke 2
A, the end 1A of the tube 1 is fitted into the tube 1A, and the outer peripheral portion of the tube end 1A is drawn by a drawing process or the like.
A, and in the serration portion 4, the triangular chevron-shaped tooth profile bites into the tube 1 as shown in FIGS. 2 and 3. In the vicinity of the yoke shaft end 2B, as shown in FIG. 4, the tube is connected to the inner surface of the tube 1 in the form of a tube having no serration.

After the tube end 1A is connected to the yoke shaft 2A in this manner, the reinforcing ring member 3 is fitted to the outside thereof by press fitting or shrink fitting. In the propeller shaft 5 integrated as described above, stress generation in the case of the conventional example is caused at the shaft end 2B of the shaft portion 2A of the yoke 2 with respect to the coupling length as shown in FIG. While the maximum stress becomes σ ₁ due to the stress concentration, in the case of this embodiment, the maximum stress can be suppressed to σ ₂ lower than σ ₁ as shown in FIG.

Next, an embodiment of the second embodiment of the present invention will be described with reference to FIG.

In this embodiment, both ends 1 of the tube 1 are also provided.
The fact that the shaft portion 2A of the yoke 2 is fitted into A and is plastically connected is the same as in the first embodiment. However, in this embodiment, a first serration 4A and a second serration 4B are formed around the shaft 2A of the yoke. The first serration portion 4A is formed at a portion of the yoke shaft portion 2A near the yoke, and the second serration portion 4B is formed at a portion of the yoke shaft end 2B near the first serration portion 4A. 7 and FIG.
FIGS. 9 and 10 show cross sections of the serration portion 4A.
2 shows a cross section of the second serration 4B. As is apparent from these figures, the first serration portion 4A has a larger number of triangular tooth shapes than the second serration portion 4B, and the tube 1 is fastened to the shaft portion 2A of the yoke 2 by tightening the tube 1 end 1A. The number of cut grooves formed in the end 1A is much smaller in the second serration 4B than in the first serration 4A. The first serration portion 4A and the second serration portion 4B may be formed in a tapered shape so that their outer diameters decrease toward the yoke shaft end 2B.

Therefore, the structural discontinuity at the tube end 1A can be alleviated as compared with the conventional example, and the stress generated at the tube end 1A near the yoke shaft end 2B is first shown in FIG. As shown by, it can be suppressed lower than in the conventional case. In addition, the tube end 1A is firmly plastically connected to the yoke shaft 2A via the serrations 4A and 4B. In addition, when the reinforcing ring member 3 is fitted, the connection may be loosened and may come off. Can be further prevented.

In the above-described embodiment, the serration is divided into two along the yoke shaft 2A, and the number of teeth of the second serration 4B on the tip end side is reduced, but the serration is divided. In this case, the number of teeth is not limited to two, but may be divided into, for example, three or four, so that the number of teeth decreases toward the tip end of the yoke. Further, the height of the tooth form may be reduced, and the influence on the strength such as stress concentration due to the notch may be reduced by forming a round shape, a trapezoid shape or the like instead of the triangular shape. .

Further, when the yoke shaft portion and the tube are fitted to each other, an adhesive is interposed between the two connecting portions, whereby the connection can be further strengthened. In the case of using a material, it is possible to expect a further effect of preventing electric corrosion by using an insulating adhesive.

[0018]

As described above, according to the present invention, the shaft of the yoke is formed by the shaft of the yoke in the tube.
Stress concentration at the part where the shaft end is fitted is reduced.
A predetermined distance from the shaft end of the shaft portion of the yoke.
Serration forming part where serration is formed at position
Between the serration forming portion and the shaft end of the shaft portion of the yoke.
Formed in series and joined while in contact with the inner surface of the tube
Or comprising a cylindrical portion which is, or is configured to the number of teeth of the serrations formed on the portion of the shaft end side of the yoke shaft, be less than the number of teeth of the serrations formed on the portion of the tube tip-sided . This minimizes the concentration of stress generated at the shaft end of the yoke among the stress generated in the tube at the joint due to the twisting of the propeller shaft.
That it can, as a result, without or increase the thickness of the tube, it is possible to obtain a propeller shaft that is lightweight rigidly plastically bonded. Also, in addition to the cylindrical part
Is provided to reinforce the strength of the tube joint
It has the advantage of being done.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is an enlarged view of a portion A in FIG. 2;

FIG. 4 is a sectional view taken along line YY of FIG. 1;

FIG. 5 is a characteristic curve diagram showing a comparison between stresses generated in a conventional example and a joint part according to the present invention.

FIG. 6 is a sectional view showing another embodiment of the present invention.

FIG. 7 is a sectional view taken along line XX of FIG. 6;

FIG. 8 is an enlarged view of a portion B in FIG. 7;

FIG. 9 is a sectional view taken along line YY of FIG. 6;

FIG. 10 is an enlarged view of a portion C in FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tube 1A End part of tube 2 Yoke 2A Shaft of yoke 3 Reinforcement ring member 4, 4A, 4B Serration

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-154730 (JP, A) JP-A-1-307506 (JP, A) JP-A-49-117855 (JP, A) JP-A-60-1985 103082 (JP, A) JP-A-64-79423 (JP, A) JP-A-63-154701 (JP, U) JP-A-61-176231 (JP, U) (58) Fields investigated (Int. ⁷ , DB name) F16D 1/02 B60K 17/22 F16C 3/02

Claims (3)

(57) [Claims] 1. A serration is provided around a shaft of a yoke, an end of a tube is fitted to a shaft of the yoke, and the end of the tube is squeezed toward the shaft to form the serration. In a propeller shaft adapted to be plastically coupled through a shaft, the shaft portion of the yoke is connected to the yoke of the tube.
Reduction of stress concentration at the part where the shaft end of the shaft part is fitted
A predetermined distance from the shaft end of the shaft portion of the yoke.
A cell in which the serrations are formed at separated positions.
, A serration forming part and the yoke
The tube is formed continuously with the shaft end of the shaft portion of the tube.
Propeller shaft, characterized in that it comprises a cylindrical portion which is coupled in contact with the surface. 2. The serration is provided around the shaft of the yoke, the end of the tube is fitted to the shaft of the yoke, and the end of the tube is squeezed toward the shaft to reduce the serration. The number of teeth of the serrations formed at a portion of the shaft portion near the shaft end is the number of teeth of the serrations formed at a portion of the shaft portion near the tube tip. A propeller shaft characterized by being reduced in number. 3. The propeller shaft according to claim 1, wherein the propeller shaft is plastically coupled via the serrations, and a reinforcing ring is fitted to the coupling portion.