JPH0791432A - Propeller shaft - Google Patents

Abstract

(57) [Summary] [Purpose] FR that can reliably start the target fracture against axial compressive impact load while ensuring high torsional strength.
Provide a P propeller shaft. [Structure] In a propeller shaft in which a metal joint 2 is joined to an end of a FRP main body cylinder 1, a metal joint 2 is
A propeller shaft that is provided with a trigger portion 3 that causes a starting point of breakage in the main body cylinder 1 against a compressive shock load in the cylinder axis direction, or a weak portion that causes the metal joint itself to start breaking.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propeller shaft for automobiles and the like.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for weight reduction of automobiles for the purpose of improving fuel consumption from the viewpoint of energy saving. As one of the means, it is considered to replace the propeller shaft made of metal with that made of FRP (fiber reinforced plastic). At that time, there are various kinds of reinforcing fibers to be used, for example, carbon fibers, glass fibers, aramid fibers, etc. are being studied. Among them, CFRP using carbon fibers as reinforcing fibers is particularly preferable in terms of strength and elastic modulus. (Carbon fiber reinforced plastic) is considered to be influential.

A propeller shaft of an automobile is required to have a torsional strength of about 100 to 400 kgf · m because it is necessary to transmit a large torque generated from an engine. Conventional CFRP propeller shafts, particularly the main body cylinder thereof, have a stacking angle and a stacking structure thereof for transmitting a required torque, and a size of the shaft (as described in JP-A-2-236014, etc.). The inner diameter, outer diameter, and wall thickness), the type of reinforcing fiber used, the fiber content, etc. are used as parameters. By properly setting these design parameters, it is possible to achieve the torsional strength that is practically required as described above.

By the way, in recent years, various studies have been conducted on the safety in the event of an automobile collision. For example, research is being conducted to secure the safety of passengers by making a car body and the like into a crushable structure and effectively absorbing the impact energy at the time of a collision by a car body that gradually destroys.

In designing a propeller shaft made of FRP, if only high rigidity is pursued and a propeller shaft having too high rigidity against an axial impact load is used, the propeller shaft becomes a stub at the time of collision. ,
The effect of having a crushable body structure will be lost.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to
In the RP propeller shaft, while ensuring the high torsional strength required for automobiles, etc., it is possible to surely promote the necessary destruction against an axial impact load according to a crushable vehicle body etc. An object of the present invention is to provide a propeller shaft that can be used.

[0007]

In order to achieve the above-mentioned object, in the present invention, various devises are mainly provided on the metal joint side to cause appropriate breakage against a compressive impact load in the cylinder axial direction. It has been subjected. That is, the propeller shaft of the present invention is a propeller shaft in which a metal joint is joined to the end of an FRP main body cylinder, and the metal joint has a starting point of breakage in the main body cylinder against a compressive impact load in the cylinder axial direction. It is characterized in that it is provided with a triggering part. That is, the metal joint is provided with a trigger for breaking the FRP main body cylinder.

Here, the trigger portion is formed of, for example, a triangular protrusion formed on the joint surface of the metal joint with the main body cylinder.

By appropriately setting the taper angle, position, number, etc. of the triangular protrusions, the target trigger portion is formed.

Another propeller shaft according to the present invention is a propeller shaft in which a metal joint is joined to an end portion of an FRP main body cylinder, wherein the metal joint is connected to the main body against a compression impact load in the cylinder axial direction. It is characterized in that a weak portion having a compressive strength lower than that of the cylinder is provided. That is, the metal joint is provided with a weak portion which is a starting point of its own destruction.

The weak portion is formed, for example, by thinning the cylindrical wall portion of the metal joint, or
It is formed by providing a notch in a metal joint.

Since the weak portion is formed in the metal member, the weak portion can have almost the compressive strength as designed.

Still another propeller shaft according to the present invention is a propeller shaft in which a metal joint is joined to an end portion of an FRP main body cylinder, and the end edge of the main body cylinder is subjected to a compression impact load in the cylinder axial direction. On the other hand, a chamfered portion serving as a starting point of the main body cylinder breaking is provided, and the metal joint is press-fitted so as to face the chamfered portion and movable in the cylinder axial direction according to the compression load in the cylinder axial direction. It is characterized by being joined. That is, the trigger which is the starting point of the breakage is provided on the main body cylinder itself, but in order to operate the trigger, the metal joint is provided so as to be movable in the axial direction along the joint surface with the main body cylinder.

In this structure, if the metal joint does not move in the axial direction along the joint surface with the main body cylinder in a predetermined direction, the metal joint is provided at the end edge of the main body cylinder. However, the chamfered part as a trigger cannot be contacted, and the desired breakage of the main body cylinder will not occur.However, assuming such a case, the metal joint should be used for the main body against axial compressive impact load. It is also possible to form a weak portion having a compressive strength smaller than that of the cylinder.

Furthermore, another propeller shaft according to the present invention is a propeller shaft in which a metal joint is joined to an end portion of an FRP main body cylinder, wherein the maximum turning radius of the metal joint is that of the FRP main body cylinder. The flange portion of the metal joint, which is smaller than the inner radius and serves as the bottom surface of the FRP main body cylinder, forms a weak portion having a bending strength lower than the compressive strength of the main body cylinder against a compressive impact load in the cylinder axial direction. It is characterized by. That is, the metal joint has a specific structure, and a weak portion having a small bending strength and serving as a starting point of fracture of the metal joint itself is formed in the flange portion.

[0016]

In such a propeller shaft, the metal joint side is provided with a trigger portion for causing the FRP main body cylinder to start a break or a weak portion for intentionally breaking the metal joint itself. Therefore, when a compressive shock load in the cylinder axis direction above a certain level is applied to the propeller shaft, in the former case, the FRP corresponding to the trigger portion is inevitable.
In the latter case, the fracture starts and progresses from the main body cylinder portion, and in the latter case, from the weak portion of the metal joint. Since these trigger portions or weak portions have a structure in which the torsional strength of the FRP main body cylinder is not substantially reduced, the torsional strength of the FRP main body cylinder during normal use can be maintained at a sufficiently high value.

Therefore, while satisfying the high torsional strength required for automobiles and the like as the entire propeller shaft, it is possible to surely secure the FRP main body cylinder or the metal body against the compressive impact load in the cylinder axial direction as required. The fracture of the joint can be started, and the impact energy can be effectively absorbed.

[0018]

Embodiments of the propeller shaft of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a propeller shaft according to a first embodiment of the present invention. In the figure, 1 indicates a FRP main body cylinder, and 2 indicates a metal joint which is joined to the end of the main body cylinder 1 by press fitting.

In the present embodiment, the trigger portion 3 which causes the starting point of breakage in the main body cylinder 1 with respect to the compression impact load in the cylinder axis direction is
It is provided on the press-fitting surface of the metal joint 2 with the main body cylinder 1. The trigger portion 3 is formed of a triangular protrusion protruding from the press-fitting surface in the outer diameter direction in a taper shape, and a plurality of the trigger portions 3 are arranged in the circumferential direction of the press-fitting surface.

The triangular trigger portion 3 connects the joint 2 to the FRP.
When press-fitted into the manufactured main body cylinder 1, as shown in the drawing, it digs into the inner peripheral surface of the main body cylinder 1, so that a starting point of breakage against a cylinder axial compression load is generated at this portion. Moreover, since the plurality of trigger portions 3 arranged in the circumferential direction of the press-fitting surface bite into the inner peripheral surface of the main body cylinder 1, the joint strength between the joint 2 and the main body cylinder 1 is improved, and the torsional strength of the joint surface is increased. Direction.

Therefore, the FRP main body cylinder 1 and the main body cylinder 1
Without reducing the torsional strength of the joint between the joint 2 and
With respect to the compressive impact load, the FRP main body cylinder 1 can surely start the targeted compressive failure.

The fracture starting load against compression depends on the taper angle of the trigger portion 3 formed of a triangular protrusion, the disposition position,
It is possible to set the optimum load freely by the number.

FIG. 2 shows a propeller shaft according to a second embodiment of the present invention. In the present embodiment, the metal joint 12 press-fitted to the end portion of the FRP main body cylinder 11 has a weak portion having a compressive strength smaller than that of the FRP main body cylinder 11 against an axial compressive impact load. 13 are provided. The weak portion 13 is formed by thinning the cylindrical wall portion of the metal joint 12. Such a thin weak portion 13 can be bent and destroyed by a compressive load.

In this manner, the metal joint 12 itself may be provided with a starting point of breakage. Since the weak portion 13 is formed on the metal member, the compressive breaking load can be easily set to the target value. Further, since the FRP main body cylinder 11 side is not provided with a weak portion or a breakage trigger, predetermined performance is exhibited as it is, and the torsional strength required for automobiles and the like is maintained as it is. Therefore, it is possible to surely start the desired fracture on the metal joint 12 side against the compressive shock load in the cylinder axis direction without lowering the torsional strength of the entire propeller shaft.

In the above embodiment, the weak portion of the metal joint is formed by thinning the cylindrical wall. However, the invention is not limited to this. For example, as shown in FIG. 3, the metal joint 21 extends annularly in the circumferential direction. The weak portion may be formed by providing the notch 22.

FIG. 4 shows a propeller shaft according to a third embodiment of the present invention. In the present embodiment, a chamfer 32, which is a starting point of destruction of the main body cylinder 31 against a cylinder axis direction compressive impact load, is provided on the end edge of the FRP main body cylinder 31, and the metal joint 33 is arranged in the axial direction. The chamfered portion 32 and the facing surface 34 face each other with a space therebetween, and are movable in the axial direction along the joint surface 35 with the body tube 31 in accordance with the compression load in the tube axial direction. It is press-fitted at the end of. A relief 36 is formed in the press-fitting portion of the metal joint 33.

In such a structure, when a compressive impact load in the cylinder axial direction of a certain level or more is applied, the metal joint 33
Moves in the axial direction, and the facing surface 34 hits the chamfered portion 32 at the end edge of the main body cylinder 31 as the trigger portion, and the necessary breakage occurs in the main body cylinder 31 from that point.

In such a structure, the metal joint 3
3 does not move in the axial direction along the joint surface 35 with the main body cylinder 31 in a predetermined manner, the metal joint 33 is
Since it is impossible to contact the chamfered portion 32, assuming such a case, the metal joint is provided with a weak portion having a compressive strength lower than the compressive strength of the main body cylinder against the compressive impact load in the cylinder axial direction. It can also be formed. For example, in FIG.
As shown in FIG. 3, the relief portion 42 is provided in the metal joint 41, and the thickness of the metal joint 41 in the relief portion 42 is reduced to form the weak portion 43 having a small compressive strength. You can

If done in this way, for some reason,
Even if the metal joint 41 does not move well, desired breakage can be initiated and progressed from the weak portion 43.

FIG. 6 shows a propeller shaft according to the fourth embodiment of the present invention. In this embodiment, the metal joint 5
The maximum turning radius R of 1 is the inner radius r of the FRP main body cylinder 52.
The flange portion 53 of the metal joint 51, which is smaller than the FRP main body cylinder 52 and serves as the bottom surface of the FRP main body cylinder 52, is formed in a weak portion having a bending strength lower than the compressive strength of the main body cylinder 52 against a compressive impact load in the cylinder axial direction. Has been done.

In such a structure, when a compressive impact load in the cylinder axis direction above a certain level is applied, the metal joint 51
Since the bending strength of the flange portion 53 of is small,
The desired destruction can be initiated and proceeded.

As the matrix resin constituting the FRP propeller shaft of the present invention, a thermosetting resin such as an epoxy resin, a phenol resin, a polyimide resin, a vinyl ester resin or an unsaturated polyester is used, but other resins such as, for example, It may be a thermoplastic resin such as polyamide, polyamide, polyetherimide or the like.

The reinforcing fiber is not limited to carbon fiber, but glass fiber, aramid fiber, or the like can be used, and these can be used in combination.

In the propeller shaft of the present invention, a sealing material may be provided at an appropriate position (for example, each member end position) between the FRP main body cylinder and the metal joint. A resin, a ring-shaped elastic body, a film or the like is suitable as the sealing material. By disposing such a sealing material, it is possible to more reliably prevent entry of water and the like and prevent corrosion of the joint portion.

Further, when the metal joint is press-fitted, it is necessary to grip the joint with a press-fitting jig. However, in order to securely grip the joint and to prevent the joint from being damaged by the pressure input, the joint is press-fitted. It is preferable to provide a locking or engaging portion for the tool. Such a locking or engaging portion can be formed by forming a step portion or a groove portion at an appropriate position on the outer surface of the joint.

Further, in order to reduce the press-fitting force of the metal joint as much as possible and press-fitting efficiently, the following method is effective. Lower the temperature of the joint and raise the temperature of the end of the FRP body cylinder to press fit. Use the adhesive as a lubricant. Use a volatile liquid lubricant that does not remain after press fitting.

Further, it is possible to adjust the balance after completion of the propeller shaft by providing a balance weight mounting portion on the metal joint and adding an appropriate balance weight to the mounting portion by welding or the like. If a cooling fin is formed around the balance weight mounting portion, especially on the outer surface of the joint between the balance weight mounting portion and the FRP main body cylinder to be joined, welding at the time of joining the balance weight is performed. It is possible to prevent heat from being transferred to the FRP main body cylinder side.

[0038]

According to the present invention, the metal joint side of the FRP propeller shaft is provided with a trigger portion which causes a starting point of breakage in the FRP main body cylinder against a compressive impact load in the cylinder axial direction, or Since a weak part is formed in the metal joint itself so that the joint itself starts to break, while maintaining high torsional strength required for automobiles, etc. You can reveal the form.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an FRP propeller shaft according to a first embodiment of the present invention.

FIG. 2 is a partial sectional view of an FRP propeller shaft according to a second embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a FRP main body cylinder showing a shape of a weak portion according to a modification of FIG.

FIG. 4 is a partial cross-sectional view of an FRP propeller shaft according to a third embodiment of the present invention.

5 is a partial cross-sectional view of an FRP main body cylinder showing a shape of a weak portion according to a modification of FIG.

FIG. 6 is a partial cross-sectional view of a FRP propeller shaft according to a fourth embodiment of the present invention.

[Explanation of reference numerals] 1, 11, 31, 52 FRP main body cylinder 2, 12, 21, 33, 41, 51 Metal joint 3 Trigger part 13 Thin part as weak part 22 Notch as weak part 32 Chamfer part 34 Opposing surface 35 Bonding surface 36, 42 Escape part 43 Weak part 53 Weak part

Claims (8)

[Claims] 1. A propeller shaft in which a metal joint is joined to an end portion of an FRP main body cylinder, wherein the metal joint has a trigger portion which causes a starting point of fracture in the main body cylinder against a compressive impact load in the cylinder axial direction. Propeller shaft characterized by being provided. 2. The propeller shaft according to claim 1, wherein the trigger portion comprises a triangular protrusion formed on a joint surface of the metal joint with the main body cylinder. 3. A propeller shaft in which a metal joint is joined to an end portion of an FRP main body cylinder, and the metal joint has a compressive strength lower than a compressive strength of the main body cylinder against a compressive impact load in the cylinder axial direction. Propeller shaft characterized by having a weak part. 4. A propeller shaft in which a metal joint is joined to an end portion of an FRP main body cylinder, wherein an end edge of the main body cylinder is
A chamfered portion that serves as a starting point of destruction of the main body cylinder against a compressive impact load in the cylinder axial direction is provided, and the metal joint faces the chamfered portion, and in the cylinder axial direction according to the compressive load in the cylinder axial direction. A propeller shaft characterized by being press-fitted into. 5. The propeller shaft according to claim 4, wherein the metal joint is formed with a weak portion having a compressive strength lower than that of the main body cylinder against a compressive impact load in the cylinder axial direction. 6. The propeller shaft according to claim 3, wherein the weak portion is formed by thinning a metal joint. 7. The propeller shaft according to claim 3, wherein the weak portion is formed by forming a notch in a metal joint. 8. In a propeller shaft in which a metal joint is joined to an end portion of an FRP main body cylinder, the maximum turning radius of the metal joint is smaller than the inner radius of the FRP main body cylinder,
A propeller shaft characterized in that the flange portion of the metal joint which is the bottom surface of the RP main body cylinder forms a weak portion having a bending strength lower than the compressive strength of the main body cylinder against a compressive impact load in the cylinder axial direction. .