JPH05139170A - Manufacture of propeller shaft - Google Patents

Abstract

PURPOSE:To connect a cylinder body to a yolk so that they can not be relatively rotated by press-fitting the connecting end of the yolk to the end part of the cylinder body consisting of fiber-reinforced plastic, and biting the cutting tooth around the outer circumference of the connecting end of the yolk while notching the inner wall of the end part of the cylinder body. CONSTITUTION:A cylinder body 1 is molded by filament winding method, and in an end part 1b extending over a desired length (1) from a pipe hole 1a, the inner diameter D is fixed, and the circumferential strength is reinforced more than that in the other part 1c. The circumferential strength in the end part 1b of the cylinder body 1 is reinforced so as to have an elastic modulus of 2-10ton/mm<2>. A yolk 2 has a cutting tooth 2b extending in the axial direction on the outer circumferential surface of a connecting end 2a. The connecting end 2a of the yolk 2 is press-fitted from the opening 1a of the cylinder body 1, and bitten thereto while notching the inner wall 1f of the end part 1b of the cylinder body with the cutting tooth 2b of the connecting end 2a, and the cylinder body 1 is connected to the yolk 2 so that they can not be relatively rotated.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method of manufacturing a propeller shaft.

[0002]

2. Description of the Related Art In the field of the automobile industry, it has been attempted to replace various members with fiber reinforced plastics in order to reduce the weight of the vehicle and save fuel consumption. Among these members, for example, a propeller shaft has a structure in which both ends of a fiber reinforced plastic pipe are connected to connection joints for connecting a drive shaft and a driven shaft and transmitting torque thereof. In such a propeller shaft, stress concentration is likely to occur at the connecting portion between the fiber-reinforced plastic pipe and the connecting joint during torque transmission, and therefore, the connecting portion is in a connected state having sufficiently large breaking strength. Is required.

By the way, various methods have heretofore been proposed for connecting the fiber-reinforced plastic pipe and the joint member. For example, two grooves extending in the circumferential direction are provided in parallel on the inner wall of the end portion of the fiber reinforced plastic pipe, and an O-ring having elasticity is fitted into these grooves, and after inserting a joint member into the pipe. A method of injecting an adhesive between O-rings to connect them is disclosed in JP-A-52-127552.

However, the connection portion formed by this method has the problems of low strength and poor durability, and is not applicable to members used under severe conditions such as the above-mentioned propeller shaft. I can hardly do it.
Further, Japanese Patent Laid-Open No. 55-159314 discloses a method for manufacturing a shaft in which a metal sleeve is incorporated into the inner wall of the end of a fiber reinforced plastic pipe.

According to this method, when the fiber reinforced plastic pipe is molded by the filament winding method,
First, place a metal sleeve with a polygonal cross-section on the outer periphery at a predetermined position on the mandrel, and wrap resin-impregnated reinforced fiber over the sleeve to reinforce the metal sleeve integrally incorporated. Plastic tubes are manufactured. Then, the connection joint and the metal sleeve are welded to connect them.

However, this method also has the following problems. That is, first, the work of arranging the metal sleeve on the mandrel is considerably complicated due to the accurate connection with the connection joint, and thus the productivity is likely to be reduced. In addition, since the cross-sectional shape of the outer circumference of the metal sleeve is polygonal, the reinforcing fiber wound around here is susceptible to stress concentration at the top of the polygon, and as a result, the reinforcing fiber is reinforced by the metal sleeve. May peel off from the surface. Further, when welding the connection joint and the metal sleeve, there is a problem that a part of the fiber-reinforced plastic pipe being molded is deteriorated by the heat.

Further, Japanese Patent Publication No. 62-53373 discloses the following connection method. In this method, a notch tooth extending in the axial direction is formed on the outer circumference of the connecting end of the connecting element, and this connecting element is press-fitted from the mouth of the fiber reinforced plastic pipe, and then the metal reinforced plastic pipe is placed outside the fiber reinforced plastic pipe. The support ring is pushed in and the three are concentrically combined. The above-mentioned notch teeth are notched on the inner wall of the fiber-reinforced plastic tube during the press-fitting process, and the notch teeth engage with the notch teeth to prevent relative rotation between the connecting element and the fiber-reinforced plastic tube.

However, in the case of this method, in order to concentrically connect the connecting element, the fiber-reinforced plastic tube and the support ring, the outer circumference of the fiber-reinforced plastic tube after molding by the filament winding method should be made uniform. It needs to be machined. Further, since the support ring is made of metal, the total weight increases, which is contrary to the purpose of realizing weight reduction.

As described above, the conventional method for connecting the fiber reinforced plastic pipe and the connection joint has many problems as described above, and it cannot be said that the method is suitable as a method for manufacturing a propeller shaft.

[0010]

An object of the present invention is to have a sufficient torque transmission force as a torque transmission shaft by solving the above-mentioned problems in the connection between the fiber reinforced plastic pipe and the connection joint. It is an object of the present invention to provide a method for manufacturing a propeller shaft, which is relatively simple to manufacture and therefore inexpensive to manufacture.

[0011]

In order to achieve the above object, in the present invention, a cylindrical body made of fiber reinforced plastic and having a circumferential reinforcing winding layer made of reinforcing fiber at an end thereof is provided. Inside the end portion, a yoke having a cutting tooth extending in the axial direction on the outer peripheral surface and having a tip circle diameter larger than the inner diameter of the end portion of the cylindrical body is press-fitted, and the cylinder is formed by the cutting tooth. While cutting a notch on the inner wall of the end of the body, by making the notch teeth bite into the inner wall of the end, it is possible to connect the cylindrical body and the yoke so as not to rotate relative to each other. A method of making a propeller shaft is provided.

[0012]

According to the method of the present invention, when the connecting end of the yoke is press-fitted into the end of the cylindrical body made of fiber reinforced plastic, the notch teeth formed on the outer periphery of the connecting end of the yoke are While the notch is formed on the inner wall, it bites into the inner wall of the end portion, meshes with the notch formed by itself, and the yoke and the cylindrical body are connected so that relative rotation does not occur.

At this time, since the circumferential direction is reinforced at the end portion of the cylindrical body, even if the yoke is press-fitted into the end opening of the cylindrical body, the tube opening does not deform and retains the original diameter, The incision of the cutting teeth into the inner wall of the cylindrical body progresses reliably, and moreover, the tightening force in the radial direction is received, and the connection state becomes very strong. Further, according to the method of the present invention, since it is not necessary to dispose the support ring on the outer side of the cylindrical body, machining on the outer periphery for producing concentricity is not necessary, and it is necessary for connection in combination with weight reduction. The process is simplified.

[0014]

Embodiments will be described below with reference to the accompanying drawings. In FIG. 1, a cylindrical body 1 is formed by a method such as a usual filament winding method, and at an end 1b extending from the tube mouth 1a to a desired length 1, the inner diameter is constant as D, and The strength in the circumferential direction is the other part 1c
Is more reinforced. Then, a connecting end of a yoke, which will be described later, is press-fitted from the pipe port 1a, so that the end 1b serves as a connecting portion between the both.

When molding this cylinder by the filament winding method, considering that it is used as a torque transmission shaft, in order to increase the bending resonance frequency, the resin-impregnated reinforcing fiber is added to the shaft of the cylinder. 5 for direction
The mandrel is wound around the entire length of the mandrel at a winding angle of -20 ° until a desired thickness is obtained, and then the mandrel is heat-treated.
However, in such a winding mode, since the circumferential elastic modulus of the molded cylindrical body is not so high, when the connecting end of the yoke is press-fitted therein, the inner diameter D of the end portion 1b changes. As a result, a good connection state cannot be obtained.

Therefore, in the case of the cylindrical body 1 used in the present invention, at least this end portion 1b is reinforced so as to have a circumferential strength, specifically, an elastic modulus of ² to 10 ton / mm ² . In order to reinforce the elastic modulus in the circumferential direction of the end 1b to the above value, for example, when the inner diameter D is 50 to 80 mm, when the end 1b is molded, in addition to this, resin-impregnated reinforcing fiber is added to the cylinder. The circumferential reinforcing winding layer 1d may be formed by winding so as to be arranged in the range of 80 to 90 ° with respect to the axial direction of the body, and having 2 to 10 winding layers. Naturally, the end portion 1b is thicker than the other portion 1c.

At this time, the outer diameter allowed for the cylindrical body 1 to be the shaft is determined in relation to other members, so it is not preferable that the outer diameter becomes too large. Also,
When the outer diameter becomes large, there arises a problem that the bending resonance frequency is lowered and the weight is increased. For this reason, it is preferable to limit the thickness of the reinforcing winding layer 1d for reinforcing the end portion 1b to within 1.2 to 2.0 times the thickness of the other portion 1c. In addition, the boundary between the reinforcing winding layer 1d and the other portion 1c does not have a distinctly stepped structure.
It is preferable to form the taper 1e as shown in FIG. This is because local stress concentration can be prevented from occurring.

On the other hand, the yoke 2 connected to the end portion 1b of the cylindrical body 1 is provided with notch teeth 2b extending in the axial direction on the outer peripheral surface of the connection end 2a. This cutting tooth 2b
As shown in the sectional view taken along the line II-II in FIG. 1, it is preferable that the tips have sharp teeth. The diameter Dy of the tip circle of the cutting tooth 2b is larger than the inner diameter D of the end 1b of the cylindrical body 1.

In this case, the difference between Dy and D varies depending on the thickness of the end portion 1b and the value of the elastic modulus in the circumferential direction of the end portion 1b, but is usually in the range of 0.1 to 0.6 mm. It is preferable to be within. When the difference between Dy and D is less than 0.1 mm, when the connecting end 2a of the yoke 2 is press-fitted into the end portion 1b from the pipe port 1a of the cylindrical body 1, the inner teeth 1f of the end portion 1b are formed by the cutting teeth 2b. The depth of the nicks engraved on the
The intermeshing between the cut tooth 2b and the notch is insufficient, so that a high connection strength cannot be obtained between the two, and a sufficiently large breaking strength required for the propeller shaft cannot be obtained. Further, when the difference between Dy and D is larger than 0.6 mm, the load required for press-fitting the yoke 2 increases, so that the press-fitting device becomes large, and when the strength of the end 1b of the cylindrical body 1 is low, the end of the end 1b of the cylindrical body 1 is reduced. This causes a problem that the part 1b itself is destroyed.

From the tube opening 1a of the cylindrical body 1 to the yoke 2
While press-fitting the connecting end 2a of the connecting end 2a and notching the notch 2b of the connecting end 2a into the inner wall 1f of the end 1b of the cylindrical body while cutting the notch 2b into the inner wall 1f of the end 1b of the cylindrical body. By engaging the two with each other, the cylindrical body 1 and the yoke 2 are connected so as not to rotate relative to each other, and the propeller shaft of the present invention is manufactured.

In this case, the press-fitting length (press-fitting length) of the connecting end 2a of the yoke 2 is 0.5 of the inner diameter D of the end 1b of the cylindrical body 1.
It is preferably ˜1.0 times. This press-fit length is D of 0.5
If the length is shorter than the double value, the strength at the connection between the two will be lower than the breaking strength required for the propeller shaft, and if it is longer than 1.0 times the D value, the required breaking strength will be greatly exceeded. This is wasteful, and at the same time, problems such as weight increase and manufacturing cost increase occur.

The connecting end 2a of the yoke 2 may be slightly tapered. Connect the yoke 2 to the end 1 of the cylindrical body 1.
This is because the yoke 2 can be smoothly press-fitted when it is press-fitted inside b. Further, when the yoke 2 is press-fitted, if an adhesive or the like is applied to the inner wall 1f of the end portion of the cylindrical body 1 or the outer peripheral surface of the connecting end 2a of the yoke 2, the mechanical coupling and the coupling by the adhesive are performed. Both can be used together.

[0023]

【Example】

Example 1 A mandrel having a diameter of 55.5 mm was set in a filament winder, and a carbon fiber "Torayca" manufactured by Toray Industries, Inc. was set therein.
Four T300 yarn bundles (6000 filaments) were aligned and fed in a state of being impregnated with an epoxy resin.

The fiber arrangement first forms an inner layer of 8 layers of reinforcing fiber at a winding angle of 15 ° with respect to the axial direction of the mandrel, and then only at both ends, 6 layers at a winding angle of 88 ° with respect to the axial direction. To form a reinforcing winding layer. By rotating the whole in a heating furnace, the epoxy resin is cured, then,
The mandrel was removed to obtain a cylindrical body 1 as shown in FIG.

The inner diameter D of this cylindrical body 1 is 55.5 mm, and the end portion 1 is
The outer diameter of b is 64 mm, the thickness of the inner layer 1c is 2.25 mm,
The reinforcing winding layer 1d had a thickness of 2.0 mm. Also, the end 1b
The elastic modulus in the circumferential direction was 6 ton / mm ² . on the other hand,
As the yoke, an iron yoke for universal joint as shown in FIG. 1 was prepared.

A cutting tooth 2b having a tip circle diameter Dy of 55.94 mm was formed on the outer peripheral surface of the connecting end 2a of the yoke 2. The connecting end 2a of this yoke was press-fitted from the pipe port 1a of the cylindrical body 1 to the inside of the end 1b. The press-fit length was 50 mm.
On the inner wall 1f of the end portion 1b, a notch having a depth of 0.22 mm was formed by the cutting teeth 2b of the connecting end 2a of the yoke 2, and the notches meshed with each other to connect the yoke 2 and the cylindrical body 1.

When a static torsional fracture test of this connection portion was conducted, it was confirmed that the torsional fracture torque was 350 Kg · m, which was sufficiently usable as a propeller shaft for vehicles.

[0028]

As is clear from the above description, according to the method of the present invention, the cylindrical body made of fiber reinforced plastic and the yoke can be firmly connected, and the obtained connecting member is a propeller shaft for a vehicle. Can be used as This means that the circumferential elastic modulus at the end of the cylindrical body is high, so when the yoke is pressed into the end of the cylindrical body, the inner diameter of the end does not change, and the inner wall of the end due to the cutting teeth is not changed. This is because the incisions are formed in a state that is sufficiently satisfied, so that the engagement between the incision teeth and the incisions is good, and the tightening force in the axial direction of the ends is also generated, so that both are firmly connected. ..

Further, since it is not necessary to dispose a metal support ring on the outside of the connecting portion, the weight is reduced as a whole.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a positional relationship between a cylindrical body and a yoke before connection.

FIG. 2 is a sectional view taken along line II-II in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical body 1a made of fiber reinforced plastic 1a Tube mouth of cylindrical body 1b End part 1c of cylinder body 1c Other than end part 1b 1d Circumferential reinforcing winding layer 1e made of fiber reinforced plastic 1e Taper 1f of reinforcing winding layer 1d End part Inner wall 1b 2 Yoke 2a Connection end 2b of yoke 2 Cutting teeth

Claims (5)

[Claims] 1. A fiber reinforced plastic, and
Inside the end of the cylindrical body containing a circumferential reinforcing winding layer of reinforcing fibers at the end, on the outer peripheral surface, extending in the axial direction, and the diameter of the addendum circle of the end of the cylindrical body. Press-fitting a yoke having a cutting tooth larger than the inner diameter, and cutting the cutting tooth into the inner wall of the end portion of the cylindrical body while biting the cutting tooth into the inner wall of the end portion. A method of manufacturing a propeller shaft, characterized in that the cylindrical body and the yoke are connected so as not to rotate relative to each other. 2. The reinforcing winding layer of the cylindrical body is arranged at an angle of 80 to 90 ° with respect to the axial direction of the cylindrical body, and the circumferential elastic modulus of the end portion of the cylindrical body is set to ² to 10 ton / mm ² . The method of manufacturing a propeller shaft according to claim 1, comprising reinforcing fibers. 3. The method for manufacturing a propeller shaft according to claim 1, wherein the cylindrical body has a wall thickness of 1.2 to 2.0 times the wall thickness of the other end. 4. The method for manufacturing a propeller shaft according to claim 1, wherein the difference between the diameter of the tip circle of the cutting tooth and the inner diameter of the end of the cylindrical body is 0.1 to 0.6 mm. 5. The propeller shaft according to claim 1, wherein the press-fitting length of the yoke with respect to the end of the cylindrical body is 0.5 to 1.0 times the inner diameter of the end of the cylindrical body. Production method.