JP2001065538A - Power transmitting member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmitting member of suitable cost, and of suitable performance and durability when applied on an actual vehicle even the power transmitting member is formed of a fiber reinforced resin. SOLUTION: A fitting part 6 of a yoke part 3 is composed of a gear tooth part 8 comprising a tooth crest having larger inner diameter than that of an end 2a of a cylindrical body 2 to be fitted thereto through a serration and an intermediate part 10 with smaller inner diameter than that of the end 2a of the cylindrical body 2 formed between the gear tooth part 8 and a yoke part 7, and sealant 11 is applied on an outer periphery of the intermediate part 10, followed by press fitting of the fitting part 6 into the end 2a of the cylindrical body 2 under a desired press fitting load to generate sufficient torsional torque by serration fitting and surely prevent intrusion of moisture by the sealant 11, and a propeller shaft of suitable cost and of suitable performance and durability when applied on an actual vehicle is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a power transmission member, for example, a propeller shaft of a vehicle.

[0002]

2. Description of the Related Art In recent years, attempts have been made to replace various members with fiber reinforced resin in order to reduce vehicle weight and improve fuel efficiency. Among the members for vehicles, for example, a propeller shaft, which is a power transmission member, has a structure in which a connection joint (yoke) made of carbon steel is press-fitted to both ends of a fiber reinforced resin cylinder and fixed.

[0003] The propeller shaft is adapted to transmit torque by connecting the drive shaft side and the driven shaft side via a yoke, so that at the time of torque transmission, the propeller shaft is inserted into a press-fit portion between the yoke and a fiber reinforced resin cylinder. Stress concentration tends to occur. For this reason, such a propeller shaft is required to be in a connection state having a sufficiently large breaking strength between the yoke and the cylinder made of the fiber-reinforced resin. On the other hand, from the viewpoint of safety in a collision, the propeller shaft is required to have a structure that contracts in the axial direction when a certain load is exceeded with respect to the axial compression load. Further, a high sealing property is required at a connection portion between the yoke and the cylinder made of fiber reinforced resin.

As a propeller shaft satisfying these requirements, for example, as shown in Japanese Patent Application Laid-Open No. 5-139170, a yoke and a fiber-reinforced resin cylinder are connected by serration fitting. Various structures have been conventionally developed.

[0005]

However, it has a sufficiently high breaking strength, contracts in the axial direction when a certain load is exceeded, and has a high sealing performance at the connection between the yoke and the cylindrical portion. The fact is that a propeller shaft made of fiber-reinforced resin, which is suitable for an actual vehicle in terms of cost and durability, has not been developed.

The present invention has been made in view of the above circumstances, and has as its object to provide a power transmission member which can be applied to an actual vehicle and can sufficiently meet required performance even if it is made of fiber reinforced resin. I do.

[0007]

A power transmission member according to the present invention for achieving the above object is a power transmission member in which a fitting portion of a connection joint is pressed into an end of a cylindrical body made of fiber reinforced resin. The fitting part of the joint has a tooth tip circle larger than the inner diameter of the end part of the cylindrical body, and is formed between the tooth part and the joint member, with the tooth part serrated and fitted to the end part of the cylindrical body by press-fitting. A flange formed to have a larger diameter than the inner diameter of the end of the cylindrical body and for regulating the press-fitting position of the fitting part into the cylindrical body,
An intermediate portion formed between the tooth portion and the flange portion, and a sealant applied along at least the flange portion side of the outer periphery of the intermediate portion, while optimizing a press-fit load to prevent a decrease in strength of the cylindrical body, High sealing performance is ensured, and it can be applied to vehicles to sufficiently meet required performance. At this time, the difference between the outer diameter of the intermediate portion and the inner diameter of the end of the cylindrical body is preferably 0.3 mm to 1.2 mm, and the radius R of the tooth tip of the tooth is preferably 0 to 0.1. Further, it is preferable to apply a sealant also to the teeth on the outer periphery of the intermediate portion.

[0008]

FIG. 1 is a perspective view of a propeller shaft as a power transmission member according to an embodiment of the present invention, FIG. 2 is a cross section of a cylindrical body, FIG. 3 is a view taken along the line IV-IV in FIG. 3, FIG. 5 is an enlarged view of a main part in FIG. 4, and FIGS. 6 and 7 are cross-sectional views of a main part of the propeller shaft for explaining a connecting state of the yoke. is there.

As shown in FIG. 1, a propeller shaft 1 as a power transmission member is fitted into a cylindrical body 2 made of carbon fiber reinforced resin (CFRP), which is a fiber reinforced resin, by press-fitting at both ends of the cylindrical body 2. And a yoke 3 as a connection joint made of carbon steel. The CFRP of the cylindrical body 2 is a composite material using an epoxy resin as a base and carbon fiber as a reinforcing material, and the cylindrical body 2 is formed by a filament winding method or the like. That is, the cylindrical body 2 is formed by impregnating the raw yarn of the carbon fiber with the epoxy resin, winding the mandrel around the mandrel, and heat-treating the mandrel.

[0010] As shown in FIG.
The inner peripheral side of the end 2a into which is press-fitted is formed of a hoop layer 4 in which CFRP is wound in the circumferential direction to increase the compressive strength, and the intermediate cylindrical portion including the outer periphery of the hoop layer 4 The helical layer 5 is formed by winding CFRP at a predetermined angle. The hoop layer 4 secures the elastic modulus in the circumferential direction, and a good connection state when the yoke 3 is press-fitted is obtained. The stress generated at the time of axial compression is designed to be larger than the fracture stress of the material, and the stress generated at the time of torque transmission is designed to be much smaller than the fracture stress of the material, so that both axial compression fracture and torque transmission can be achieved.

As shown in FIGS. 3 to 5, the yoke 3 is
The fitting portion 6 is press-fitted into the inner periphery of the end portion 2a of the cylindrical body 2 and a yoke portion 7 as a joint member connected to a yoke member on the drive unit side or the non-drive unit side (not shown). .
The fitting portion 6 is provided with a tooth portion 8 having a tip circle having a diameter D larger than the inner diameter d of the end portion 2a of the cylindrical body 2 and being serrated and fitted to the end portion 2a by press-fitting. The radius R of the tooth tip of the tooth portion 8 is set to 0 to 0.1.

The diameter D of the addendum circle of the tooth portion 8 is set so that the tooth portion 8 bites into the hoop layer 4 with a margin α so that sufficient engagement is obtained and the breaking strength required for the propeller shaft 1 is obtained. The size is set to, for example, about 0.3 mm larger than the inner diameter d. If the diameter D of the addendum circle is too large, the press-fitting load increases, the strength of the cylindrical body decreases, and the press-fitted portion tends to break. If the diameter D of the addendum circle is too small, the engagement with the hoop layer 4 occurs. Is insufficient, and the required bonding strength cannot be obtained.

[0013] As shown in FIG.
And a yoke portion 7, formed with a diameter H larger than the inner diameter d of the end portion 2 a of the cylindrical body 2, and provided with a flange portion 9 for restricting the press-fitting position of the fitting portion 6 into the cylindrical body 2. Have been. Further, the fitting portion 6 is provided with an intermediate portion 10 formed between the tooth portion 8 and the flange portion 9, and the diameter S of the intermediate portion 10 is larger than the inner diameter d of the end 2 a of the cylindrical body 2. 0.3mm to 1.2mm
It has a small diameter. A sealant 11 is applied to the outer periphery of the intermediate portion 10 along the flange portion 9 side. Note that the sealant 11a may be applied along the tooth portion 8 side of the outer periphery of the intermediate portion 10 in addition to the flange portion 9 side.

As shown in FIGS. 6 and 7, the joint 6 of the yoke 3 having the sealant 11 applied to the outer periphery of the intermediate portion 10 is pressed into the end 2a of the cylindrical body 2. At the time of press-fitting, the teeth 8
It is bitten into the hoop layer 4 of 2a, and is pressed into the flange portion 9 until the flange portion 9 comes into contact with the end face of the end portion 2a. Thereby, the cylindrical body 2 and the yoke 3 are connected with a sufficient torsion torque so as not to rotate relative to each other. After connection, middle part 1
The sealant 11 applied to the outer periphery of the cylinder 0 sufficiently spreads to the joint between the cylindrical body 2 and the yoke 3 to ensure the sealing property.

The position of the flange portion 9 after the yoke 3 is connected is a position where the end portion 2a of the cylindrical body 2 comes into contact with the hoop layer 4. The propeller shaft 1 is required to have a structure that contracts in the axial direction when a certain load is exceeded with respect to the axial compression load from the viewpoint of safety in the event of a collision. In the propeller shaft 1 described above, the yoke 3
The hoop layer 4 is pushed in through the flange portion 9 and the hoop layer 4 has a greater compressive strength than the helical layer 5, so that the helical layer 5 is continuously expanded and broken by the wedge effect. Thereby, when the axial compression load exceeds a certain load at the time of collision or the like, it contracts in the axial direction. Therefore, the configuration is such that the function of contracting in the axial direction required as the propeller shaft 1 is sufficiently satisfied.

The above-described propeller shaft 1 has a fitting portion 6
Since the radius R of the tooth tip of the tooth portion 8 is set to 0 to 0.1, the tooth tip can be sufficiently digged into the hoop layer 4 of the end 2a of the cylindrical body 2 without increasing the press-fitting load more than necessary. be able to. As a result, sufficient engagement between the tooth portion 8 and the hoop layer 4 is obtained, and the yoke 3 and the cylindrical body 2 are joined with high joining strength, and a high torsional torque required for the propeller shaft 1 is obtained.

Further, since the diameter S of the intermediate portion 10 of the fitting portion 6 is formed smaller than the inner diameter d of the end 2a of the cylindrical body 2, the press-fitting load can be optimized. That is, the outer diameter S of the intermediate portion 10 is 0.3 mm to 1.2 mm with respect to the inner diameter d of the end portion 2a.
Since the diameter is small, the press-fitting load can be optimized with a sufficiently large breaking torque secured.

The intermediate part 10 is 0.3 m with respect to the inner diameter d of the end part 2a.
m, that is, the outer diameter S of the intermediate portion 10 is smaller than the end 2a.
If the diameter is very close to the inner diameter d, the press-fit load increases, the strength of the cylindrical body 2 decreases, and the press-fit portion is easily broken.
Conversely, the outer diameter S of the intermediate portion 10 is 1.
The diameter is smaller than 2 mm, that is, the outer diameter S of the intermediate portion 10 is equal to the end 2a.
If the diameter is too small with respect to the inner diameter d, the gap becomes large, the sealant does not spread, and the sealing performance is inferior. In addition, there are problems in that a large amount of sealant is required in order to achieve sufficient sealing properties, which leads to an increase in cost and a decrease in productivity.

Also, since the sealant 11 is applied to the outer periphery of the intermediate portion 10 along the flange portion 9 side, after the press-fitting is completed with a minimum amount of sealant, the seal between the cylindrical body and the yoke is sealed. The agent is sufficiently distributed to prevent the penetration of moisture into the serration fitting portion, and rust does not occur on the teeth. When a salt water spray test in which salt water is sprayed on the joint having the above-described structure is continuously performed for 120 hours, it is ensured that the salt water does not enter the inside of the cylindrical body 2 and no deterioration occurs due to no rust or the like. Has been confirmed. Therefore, the durability of the fitting portion can be improved, and the durability required for the propeller shaft 1 of the vehicle can be sufficiently satisfied.

By applying the sealant 11a along the teeth 8 on the outer periphery of the intermediate portion 10 in addition to the flanges 9, the penetration of moisture into the teeth can be more reliably prevented. .

Therefore, the above-described propeller shaft 1
Even if it is made of fiber reinforced resin for weight reduction, it has a sufficiently high breaking strength and the required high torsional torque is obtained, and it shrinks in the axial direction when a certain load is exceeded. Thus, the function of shrinking in the axial direction can be sufficiently satisfied, and at the same time, the connection between the yoke 3 and the cylindrical body 2 has high sealing performance and can sufficiently satisfy the required durability. Therefore, the propeller shaft 1 is suitable for a real vehicle in terms of cost, performance and durability.

[0022]

The power transmission member of the present invention has a sufficiently large breaking strength even when made of fiber reinforced resin, and contracts in the axial direction when the load exceeds a predetermined value, so that the connection joint and the cylindrical body A structure having a high sealing performance at the connecting portion with the power transmission member is a power transmission member capable of obtaining sufficient required performance even when applied to an actual vehicle.

[Brief description of the drawings]

FIG. 1 is an external appearance view of a propeller shaft as a power transmission member according to an embodiment of the present invention.

FIG. 2 is a sectional view of a cylindrical body.

FIG. 3 is a side view of the yoke.

FIG. 4 is a view taken along line IV-IV in FIG. 3;

FIG. 5 is an enlarged view of a main part in FIG. 4;

FIG. 6 is a cross-sectional view of a main part of the propeller shaft for explaining a coupling state of the yokes.

FIG. 7 is a cross-sectional view of a main part of the propeller shaft for explaining a connecting state of the yokes.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Propeller shaft 2 Cylindrical body 3 Yoke 4 Hoop layer 5 Helical layer 6 Joining part 7 Yoke part 8 Teeth part 9 Flange part 10 Intermediate part 11 Sealant

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hirohisa Miyata 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Fuminori Kobayashi 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Automobile Industry Co., Ltd. (72) Inventor Masaki Goto 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Industry Co., Ltd. (72) Inventor Noriyasu Noguchi 1515 Tsutsui, Matsumae-cho, Iyo-gun, Ehime Prefecture Toray Stock Yasushi Iida (72) Inventor Yasushi Iida 1515 Tsutsui, Matsumae-cho, Iyo-gun, Ehime F-term (reference) 3D042 AA07 DA02 DA09 DA12 DA15 3J033 AA01 AB02 BA03 BA08 BA20

Claims (1)

[Claims] 1. A power transmission member comprising: a cylindrical body made of a fiber-reinforced resin; and a connection joint comprising a joint member and a fitting part, wherein a fitting part is press-fitted into an end of the cylindrical body. The fitting portion has a tip circle larger than the inner diameter of the end portion of the cylindrical body, and a tooth portion serrated and fitted to the end portion of the cylindrical body by the press-fitting, and between the tooth portion and the joint member. And a flange portion formed to have a diameter larger than the inner diameter of the end portion of the cylindrical body and for restricting the press-fitting position of the fitting portion to the cylindrical body, and formed between the tooth portion and the flange portion. A power transmission member comprising an intermediate portion and a sealant applied along at least the flange portion side of the outer periphery of the intermediate portion.