JPH04307225A - Shaft for transmitting driving force made of fiber-reinforced resin - Google Patents

Abstract

PURPOSE:To obtain a shaft for transmitting driving force not broken easily even to large torque by forming a section tying the internal surface of the joining section of a pipe made of a fiber-reinforced resin and the straight pipe section of the internal surface of the pipe in a tapered shape having an inclination of 10 deg. or less from the top section of a regular polygonal corner to the pipe straight pipe section. CONSTITUTION:A section from the top section 9 of the corner of the regular polygonal section of the internal surface of a pipe 8 made of FRPs to a pipe straight pipe section is formed at an inclination of 10 deg. or less. On the other hand, the internal and external surfaces of the joining section 2 of the pipe 8 made of FRPs can be reinforced by FRPs. It is desirable that the joining section 2 is reinforced from the balance of lightening, strength and profitability. The reinforcement of the joining section 2 of the pipe 8 made of FRPs is started from the straight pipe section including a tapered section. It is favorable that the reinforcement starting point 11 of the external surface of the straight pipe section of the pipe made of FRPs is kept within 5mm from the end 10 of the straight pipe section of the internal surface of the pipe.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber-reinforced resin drive force transmission shaft suitable for use in automobiles or ships.

0002

2. Description of the Related Art Conventionally, a solid metal rod or hollow metal pipe with metal coupling elements joined to both ends has been used as a driving force transmission shaft for vehicles, ships, etc. In recent years, the demand for lighter cars has increased, and the metal outer panels of car bodies and other parts are made of fiber-reinforced resin (hereinafter sometimes referred to as FRP).
In addition to the weight reduction of structural components, the weight reduction of structural members is also attracting attention. Among these, reducing the weight of the driving force transmission shaft is a rotating part, and the effect of reducing weight is significant, and FRP is attracting particular attention.

[0003] The weight of the FRP drive force transmission shaft has been reduced by 1/2 by changing from the conventional steel to FRP.
It can sometimes be reduced to 4 to 1/2, and is being installed in various types of automobiles.

[0004] In the case of an FRP drive force transmission shaft, it is generally necessary to provide a joint element at both ends of an FRP hollow pipe, so the FRP pipe and joint element are prepared separately and joined by some method. It is manufactured by As such a method, for example, Japanese Patent Application Laid-Open No. 1983
-159930 and Utility Model Application Publication No. 61-162619, the joints at both ends of an FRP pipe are formed into a regular polygonal shape, and a joint element having a joint having almost the same shape is inserted, A method of manufacturing a driving force transmission shaft by joining using mechanical joining or caulking has been proposed.

[0005]

[Problem to be solved by the invention] However, according to this joining method using regular polygonal joints, the torque loaded on the FRP pipe is held by the mechanical reaction force and frictional force of each corner. , when torque is applied, a minute misalignment occurs between the joint element and the FRP pipe joint, and the corners of the joint element act to push the joint part of the FRP pipe apart in the radial direction, resulting in As a result, there were problems in that the joint elements slipped and the joints of the FRP pipes were destroyed.

[0006] As a countermeasure to this problem, it was necessary to further reinforce the joints of the FRP pipes with FRP, metal connectors, sleeves, and the like. However, even when the joint is reinforced, there is a problem in that the stress concentration is large in the area from the straight pipe part of the pipe to the reinforced part, which causes the pipe to break at that part. The present invention has been made to solve these problems, and provides a driving force transmission shaft that does not easily break even under large torques.

[0007]

[Means for Solving the Problems] The present invention provides a joint element and an F
This is an FRP driving force transmission shaft formed by joining RP pipes, and the outer surface of the joint of the joint element and the inner surface of the joint of the fiber-reinforced resin pipe are regular polygons, and the shape of the fiber-reinforced resin pipe is The part connecting the regular polygonal part on the inner surface of the joint and the straight pipe part on the inner surface of the pipe is formed in a tapered shape with an inclination angle of 10 degrees or less from the top of the regular polygonal corner to the straight pipe part. The present invention relates to a shaft for transmitting driving force made of fiber-reinforced resin.

The present invention will be explained in detail below. The feature of the present invention lies in the shape of the inner surface of the FRP pipe. As mentioned above, the angle of inclination from the top of the corner of the regular polygon on the inner surface to the straight pipe portion is 10° or less. Preferably 1°
The angle is larger than 5°, more preferably larger than 1° and smaller than 3°. If this angle is less than 1°, the straight pipe portion will be short when the FRP pipe is formed, making the forming process complicated and increasing the weight. Moreover, if this angle is larger than 10 degrees, the stress concentration between the straight pipe part and the joint element becomes large, and this part breaks with a torque lower than the original strength of the FRP pipe.

[0009] The above-mentioned angle of inclination can be determined by the ring shape of the mandrel used when forming the FRP pipe. On the other hand, the joint portion of this FRP pipe can be reinforced with FRP on its inner and outer surfaces. Weight saving,
It is desirable to reinforce the joint from a balance between strength and economy. Reinforcement of the joints of FRP pipes starts from the straight pipe parts, including the tapered parts. The starting point for reinforcing the outer surface of the straight section of the FRP pipe is 5 points from the end of the straight section on the inner surface of the pipe.
It is preferable to set it within mm. If this distance is 5 mm or more, the pipe will not break at the straight section, but will break near the reinforcement starting point.

[0010] The regular polygonal shape of the joint in the present invention is preferably a regular hexagon or a regular octagon. If the polygonal shape of the joint is uneven, the torque transmitted at each corner will be different, leading to a decrease in power transmission ability due to stress concentration, and a deterioration of dynamic balance due to variations in mass in the circumferential direction. Furthermore, if the number of angles is less than hexagonal, stress concentration increases, and if the number of angles is greater than octagonal, the misalignment at the joint between the FRP and the joint element increases, each of which causes a decrease in power transmission ability.

[0011] The FRP reinforcing fiber used in the present invention is preferably a material with high elastic modulus and strength because it is necessary to increase the resonance frequency during rotation of the shaft for transmitting driving force. Such fibers mainly include carbon fibers, glass fibers, aramid fibers and ceramic fibers. Two or more of these fibers may be used in combination. Fibers with higher specific strength and higher specific stiffness are preferable because they have a more significant weight reduction effect. Carbon fiber is an example of such a material, but hybrid use of carbon fiber and glass fiber is also preferable from the viewpoint of cost reduction.

The matrix resin is not particularly limited. Thermosetting resins such as epoxy resins, unsaturated polyester resins, vinyl ester resins, urethane resins, phenol resins, alkyd resins, xylene resins, melamine resins, furan resins, silicone resins, polyethylene resins,
Polypropylene resin, polyvinyl chloride resin, polymethyl methacrylate resin, ABS resin, fluororesin, polycarbonate resin, polyester resin, polyamide resin (
Nylon 6, 6/6, 6/10, 6/11, 6/12, etc.), polyphenylene sulfide resin, polysulfone resin, polyether sulfone resin, polyether ether
Examples include thermoplastic resins such as terketone resin and polyphenylene oxide resin. Moreover, these resins can be used in combination of two or more types. Among these, epoxy resins, unsaturated polyester resins, and vinyl ester resins are preferred from the viewpoint of ease of handling and physical properties.

[0013]

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples in any way.

Example 1 A mold release agent was applied to the cylindrical mandrel 4 shown in FIG.
Rings 5 were attached to both ends. The diameter of the cylindrical mandrel is 40 mm, the length of the straight tube part is 495 mm, and a chucking shaft 6 with a diameter of 30 mm and a length of 350 mm is attached to both ends of the mandrel. The ring 5 is a hollow ring with an inner diameter of 30 mm, and the outer periphery of the end has a distance between opposite sides of 40 mm and a distance between opposite sides of 4.
It is a regular hexagon of 6.2 mm (in a cross section perpendicular to the axis), and the other end has a circular shape with an outer diameter of 40 mm, and the area from the top of the corner of the regular hexagon to the circular end is smooth.
It formed a narrow tapered part. The length of the regular hexagonal portion was 50 mm, and the length of the tapered portion was 60 mm. Glass fibers and carbon fibers impregnated with epoxy resin were wound around this mandrel by a filament winding method to form an FRP pipe having the following laminated structure. The regular hexagonal part and the tapered part are reinforced with FRP. Here, GF represents glass fiber and CF represents carbon fiber.

[0015] FRP pipe straight pipe inner layer [GF90°/CF±20°/GF90°] Outer layer thickness 0.5mm/4.0mm/0.5mmFRP
Pipe reinforcement inner layer [GF90°/CF±20°/CF90°/GF9
0°] Outer layer thickness 2.0mm/4.0mm /0.5mm/2
．． 0mm

[0016] Next, a release film is wrapped thereon,
It was heat cured at 150°C for 2 hours. After curing, unnecessary parts at both ends are cut off and removed from the mandrel, resulting in an FRP pipe 1 having a regular hexagonal joint 2 as shown in Fig. 3.
I got it. When the dimensions of the inner surface of the regular hexagonal part of this pipe were measured, the distance between the apexes was 46.2 mm, the inner diameter of the straight pipe part was 40.0 mm, and the length of the tapered part was 60 mm, that is, FRP. The inclination angle of the tapered portion of the manufactured pipe was 3°.

On the other hand, a steel joint element having a regular hexagonal joint shown in FIG. 5 was manufactured by machining. FRP
The driving force of the present invention which integrates the joint elements shown in Fig. 1 by applying adhesive Patch Kid (manufactured by Hysol Co., Ltd. - registered trademark) to the entire inner surface of the joint of manufactured pipes and press-fitting the joint element. Obtained a transmission shaft. When this shaft was subjected to a torsion test, the center portion of the straight pipe portion was broken at a torque of 420 kgf-m.

Example 2 Using the same method as in Example 1, the length of the regular hexagonal part was 5.
A pipe was formed with a length of 0 mm and a tapered portion of 30 mm. As a result of measuring the inner dimensions of the regular hexagonal part that is the reinforcement part of this hype, the distance between the vertices is 46.2 mm,
The inner diameter of the straight pipe portion was 40.0 mm, the length of the tapered portion was 30 mm, ie, the inclination angle of the taper was 5.9°. When the joint elements were joined in the same manner as in Example 1 and a torsion test was conducted, the FRP of the straight pipe section of the shaft broke around the starting point of reinforcement at a torque of 300 kgf-m.
It had reached a practical level of strength.

Comparative Example Using the same method as in Example 1, the length of the regular hexagonal part was 50
mm, and the length of the tapered part was 30 mm, and a pipe was molded. As a result of measuring the inner dimensions of the regular hexagonal part that is the reinforcement part of this pipe, the distance between the two apexes is 46.2 mm, the inner diameter of the straight pipe part is 40.0 mm, and the length of the tapered part is 15 mm. The inclination angle of the taper on the inner surface of the pipe was 11.7°. The joint elements were joined in the same manner as in Example 1, and the resulting shaft was subjected to a torsion test. As a result, the shaft fractured around the starting point of reinforcement of the FRP in the straight pipe section at a very low torque of 100 kgf-m. did.

[0020]

[Effect of the invention] The driving force transmission shaft of the present invention is made of FRP.
The joint between the pipe and the fitting element is strong and the original FR
Since it exhibits the strength that P pipe has, it can be suitably used for automobiles, ships, helicopters, etc.

[Brief explanation of drawings]

FIG. 1 is a front view of the FRP driving force transmission shaft of the present invention.

FIG. 2 is a front view of the mandrel used in its production.

FIG. 3 is an axial cross-sectional view of an FRP pipe.

FIG. 4 is a side view of the FRP pipe viewed in the axial direction.

FIG. 5 is a perspective view of the coupling element.

[Explanation of symbols]

1. FRP drive force transmission shaft 2. same joint 3. fitting element 4. mandrel 5. mandrel ring 6. Chucking shaft 7. Joints of fitting elements 8. FRP pipe

Claims (1)

[Claims] 1. A fiber-reinforced resin driving force transmission shaft formed by joining a joint element and a fiber-reinforced resin pipe, the shaft comprising:
The outer surface of the joint of the coupling element and the inner surface of the joint of the fiber-reinforced resin pipe have a regular polygonal shape, and connect the regular polygonal portion of the inner surface of the joint of the fiber-reinforced resin pipe to the straight pipe portion of the inner surface of the pipe. A driving force transmission shaft made of fiber reinforced resin, characterized in that the portion is formed in a tapered shape with an inclination angle of 10° or less from the top of the corner of a regular polygon to the straight pipe portion.