JP6374813B2 - Power transmission shaft - Google Patents

Description

  The present invention relates to a power transmission shaft.

  A rear-wheel drive vehicle or a four-wheel drive vehicle in which an internal combustion engine (power source) is mounted on the front side of the vehicle body and the rear wheels are driven by the power of the internal combustion engine includes a propulsion shaft (propeller shaft) at the lower center of the vehicle body. The power of the internal combustion engine is transmitted to the rear wheels via the propulsion shaft.

  More specifically, for example, the propulsion shaft includes an elongated cylindrical power transmission shaft main body, and a carbon steel connecting member (stub yoke, stub shaft) that is press-fitted and fixed to the front end portion of the power transmission shaft main body. (See Patent Document 1). In order to reduce the weight of the propulsion shaft, the power transmission shaft body is made of, for example, CFRP (Carbon Fiber Reinforced Plastic). In this configuration, the CFRP base material (matrix) is formed of a thermosetting resin such as an epoxy resin.

JP 2006-56389 A

  Here, the rotation balance is adjusted by fixing the metal balancer (weight) after the propulsion shaft is assembled and before being attached to the vehicle. However, since the power transmission shaft main body is made of CFRP, a metal balancer cannot be welded to the power transmission shaft main body. Then, although the structure welded to carbon steel stub yoke is considered, in order to form a welding location, a stub yoke will become long in an axial direction. Further, a configuration in which the balancer is bonded to the power transmission shaft main body made of CFRP with an adhesive is conceivable. However, an adhesive application process, an adhesive curing process, and the like are required, resulting in a long manufacturing time.

  Accordingly, an object of the present invention is to provide a power transmission shaft in which a balancer is easily fixed to a power transmission shaft main body and a method for manufacturing the power transmission shaft.

  As means for solving the above-mentioned problems, the present invention provides a power transmission shaft for transmitting power, which is a FRTP-made power transmission shaft main body, fixed to the power transmission shaft main body, and for adjusting the rotational balance. A balancer, wherein the balancer is thermally welded to the power transmission shaft body.

  According to such a configuration, the power transmission shaft main body is made of FRTP (Fiber Reinforced Thermo Plastics) and uses a thermoplastic resin as a base material. Therefore, when the thermoplastic resin is heated, the power transmission shaft main body Becomes soft. Then, the power transmission shaft body can be easily deformed (flowed), and can also be welded (thermally welded) to the balancer.

  That is, since the power transmission shaft main body is made of FRTP, the power transmission shaft main body is softened by heating, and the balancer can be easily heat-welded to the softened portion in a short time. Therefore, the power transmission shaft is not elongated in the axial direction, and no adhesive is used, so that the cycle time required for manufacturing is short.

  The power transmission shaft main body includes a connection member that is fitted to one end of the power transmission shaft main body, and the balancer is thermally welded to one end of the power transmission shaft main body. It is good also as composition which has.

Moreover, it is good also as a structure provided with the cyclic | annular band in the radial direction outer side of the said balancer.
Furthermore, in the balancer, a welding surface with the power transmission shaft main body may be uneven.
Furthermore, the power transmission shaft body may be made of a carbon fiber reinforced thermoplastic resin (CFRTP).

  Further, as a means for solving the above-mentioned problems, the present invention is a method for manufacturing a power transmission shaft for transmitting power, wherein a balancer for adjusting the rotational balance is thermally welded to a power transmission shaft body made of FRTP. It is the manufacturing method of the power transmission shaft characterized by fixing by.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a power transmission shaft by which a balancer is easily fixed to a power transmission shaft main body, and a power transmission shaft can be provided.

It is a top view of the propulsion shaft concerning this embodiment. It is a top view of the power transmission shaft which concerns on this embodiment. It is an enlarged plan view of a power transmission shaft according to the present embodiment. FIG. 4 is a cross-sectional view of the power transmission shaft according to the present embodiment, corresponding to a cross section taken along line X1-X1 in FIG. 3. It is an enlarged plan view of a power transmission shaft according to a modification.

  An embodiment of the present invention will be described with reference to FIGS.

≪Promotion axis≫
A propulsion shaft 100 (propeller shaft) according to this embodiment is mounted on a front-engine front-drive (FF) -based four-wheel drive vehicle (vehicle). The propulsion shaft 100 is a shaft that transmits power output from an internal combustion engine (not shown) arranged on the front side of the vehicle to a final reduction gear (not shown) arranged on the rear side of the vehicle. Extending in the direction.

  The propulsion shaft 100 has a two-piece structure (a two-part structure), and is connected to the front power transmission shaft 1, the rear power transmission shaft 2, the power transmission shaft 1 and the power transmission shaft 2 at a constant speed. And a joint 110. However, the number of pieces (number of divisions) is not limited to this, and may be appropriately changed to a one-piece structure or a three-piece structure (three-division structure).

  The front end of the propulsion shaft 100 is connected to an output shaft on the transfer device (not shown) side via a front cross shaft joint 210. The rear end of the propulsion shaft 100 is connected to the drive pinion shaft of the final reduction gear through a rear cross shaft joint 220. A companion flange 310 is splined to the output shaft. A companion flange 320 is splined to the drive pinion shaft.

<Cross shaft joint>
The front cross shaft joint 210 includes a flange yoke 211, a stub yoke 20, and a cross shaft 213.

  The flange yoke 211 includes a U-shaped yoke 214 extending in a bifurcated manner on the rear side, and a ring-shaped flange portion 215 extending radially outward from the front end portion of the yoke 214. The yoke 214 is connected to a yoke 21 described later of the stub yoke 20 via a cross shaft 213 so as to be bendable. The flange portion 215 is fastened to the companion flange 310 with a bolt.

  The rear cruciform joint 220 has the same configuration as the cruciform joint 210, and includes a flange yoke 221, a stub yoke 222, and a cruciform shaft 223 that flexibly connects the flange yoke 221 and the stub yoke 222. . The rear end portion of the flange yoke 221 is fastened to the companion flange 320 with a bolt. The front end portion of the stub yoke 222 is connected to the rear end portion of the power transmission shaft 2.

<Constant velocity joint>
The constant velocity joint 110 is a joint that connects the power transmission shaft 1 and the power transmission shaft 2 so that power can be transmitted and can be expanded and contracted in the axial direction, and is configured as a tripod type here. However, a double offset type or the like may be used. The constant velocity joint 110 includes an outer ring member 30 whose front side is closed, and an inner ring member 120 that moves in the outer ring member 30 in the axial direction.

  The inner ring member 120 has a cylindrical boss portion 121 fitted and fixed to the stub shaft 131, three shaft portions 122 projecting radially outward from the outer peripheral surface of the boss portion 121, and rotating to each shaft portion 122. And a freely supported roller 123. Each roller 123 is accommodated in a sliding groove 31a described later.

  The stub shaft 131 is a round bar-like member, and the rear end portion thereof is coupled to the front end portion of the power transmission shaft 2. Therefore, the stub shaft 131 rotates together with the power transmission shaft 2. The stub shaft 131 is rotatably supported by the vehicle body via an intermediate bearing unit 140 having a bearing 141 (such as a ball bear rig).

<Power transmission shaft>
The power transmission shaft 1 is a shaft that transmits power from the cross joint 210 to the constant velocity joint 110. The power transmission shaft 2 is a shaft that transmits the power from the constant velocity joint 110 to the cross shaft joint 220. Since the power transmission shaft 1 and the power transmission shaft 2 have the same configuration, the power transmission shaft 1 will be mainly described below.

  The power transmission shaft 1 includes a power transmission shaft main body 10, a stub yoke 20 (connection member), an outer ring member 30 (connection member), and four balancers 41 and 41.

<Power transmission shaft body>
The power transmission shaft main body 10 constitutes a skeleton of the power transmission shaft 1 and has an elongated cylindrical shape. The power transmission shaft body 10 is made of CFRTP (Carbon Fiber Reinforced Thermoplastics), that is, made of carbon fiber reinforced thermoplastic. CFRTP is obtained by dispersing carbon fibers (carbon fiber bundles) in a base material (matrix) made of a thermoplastic resin. In other words, CFRTP is formed by impregnating a carbon fiber with a thermoplastic resin.

<Carbon fiber>
As the carbon fiber, for example, a PAN system or a pitch system can be used. Moreover, the carbon fiber can use the fiber bundle (filament, tow) by which a single fiber is bundled, for example, can use a continuous fiber or a discontinuous fiber. Further, the carbon fiber has an irregular fiber bundle orientation, a fiber bundle oriented in one direction (for example, the axial direction of the power transmission shaft body 10), or a fiber bundle having two or more directions (for example, Those oriented in the + 45 ° direction and the −45 ° direction with respect to the axial direction can be used. Further, braided carbon fibers and woven carbon fibers can also be used.

<Thermoplastic resin>
Examples of the thermoplastic resin include PA6 (polyamide 6 (nylon 6)), PA66 (polyamide 66 (nylon 66)), PA46 (polyamide 46), PA12 (polyamide 12 (nylon 12)), PEEK (polyether ether ketone). ), PPS (polyphenylene sulfide), PE (polyethylene), PET (polyethylene terephthalate), PP (polypropylene), PC (polycarbonate), PBT (polybutylene terephthalate), POM (polyacetal), TPU (thermoplastic polyurethane), Can be used.

  Thus, the power transmission shaft main body 10 is made of CFRTP, and its base material (matrix) is made of a thermoplastic resin. Therefore, the power transmission shaft main body 10 is softened by heating, and can be deformed even with a small load. It becomes a state.

<Stub York>
The stub yoke 20 is formed of carbon steel, for example, and is a member for connecting the power transmission shaft 1 and the output shaft (another power transmission shaft) of the transfer device. The stub yoke 20 includes a U-shaped yoke 21 that is bifurcated on the front side, and a cylindrical cylindrical portion 22 that extends rearward from the rear end portion of the yoke 21.

  The cylindrical portion 22 is a portion that is coupled to the front end portion 11 of the power transmission shaft main body 10. Specifically, the front end portion 11 is externally fitted to the cylindrical portion 22, and the front end portion 11 and the cylindrical portion 22 are coupled to each other by thermally welding the front end portion 11 to the cylindrical portion 22 on the entire circumference. .

  The outer peripheral surface of the cylindrical portion 22 constitutes a welding surface 23 with the front end portion 11. Grooves 24 extending in the axial direction are formed in the welding surface 23 at equal intervals in the circumferential direction. That is, the welding surface 23 is an uneven surface. The groove 24 is also filled with a protruding portion 11a that is a part of the front end portion 11 and protrudes radially inward. The protruding portion 11a is a portion that is deformed by being pressed radially inward while a part of the front end portion 11 is heated.

  Thus, since the welding area (contact area) between the cylindrical portion 22 (stub yoke 20) and the front end portion 11 (power transmission shaft main body 10) is large, the cylindrical portion 22 and the front end portion 11 are in the circumferential direction. It is difficult to shift in the axial direction. Note that the width, depth, and number of the grooves 24 may be changed as appropriate.

  Further, since the groove 24 is along the axial direction, the cylindrical portion 22 and the front end portion 11 are relatively easily displaced in the axial direction. As a result, when the vehicle collides forward, the internal combustion engine and the transmission attempt to move backward, and a backward load is input to the propulsion shaft 100, the cylindrical portion 22 and the front end portion 11 are displaced in the axial direction, and the propulsion shaft 100 is Compressed well. Therefore, the propulsion shaft 100 does not become a support rod, the internal combustion engine and the transmission are retracted, and the bonnet and the like are deformed so that the collision load is absorbed well.

<Outer ring member>
The outer ring member 30 is a bottomed cylindrical member made of, for example, carbon steel and closed at the front side. The outer ring member 30 includes a cylindrical peripheral wall portion 31, a bottom wall portion 32 that extends radially inward from the front end of the peripheral wall portion 31, and a cylindrical coupled portion 33 that protrudes forward from the front end of the peripheral wall portion 31. It is equipped with.

  On the inner peripheral surface of the peripheral wall portion 31, three sliding grooves 31 a that extend in the axial direction and are arranged at equal intervals in the circumferential direction are formed. Each sliding groove 31a accommodates the roller 123 described above so as to be slidable / rollable.

  The coupled portion 33 is a portion coupled to the rear end portion 12 of the power transmission shaft main body 10. Specifically, the rear end portion 12 is externally fitted to the coupled portion 33, and the rear end portion 12 and the coupled portion 33 are coupled to each other by thermally welding the rear end portion 12 to the coupled portion 33. Has been. On the outer peripheral surface of the coupled portion 33, like the cylindrical portion 22, grooves extending in the axial direction are formed at equal intervals in the circumferential direction.

<Balancer>
The balancer 41 is a metal weight for adjusting the rotational balance of the propulsion shaft 100 and is also referred to as a balance piece. The balancer 41 is a thin plate piece having an arc shape when viewed in the axial direction, and is thermally welded to the front end portion 11 and the rear end portion 12 of the power transmission shaft body 10. Specifically, as will be described later, the balancer 41 is thermally welded by being pressed against the front end portion 11 in a heated temperature rising state, and is embedded at, for example, 0.5 to 1.0 mm. Furthermore, it is good also as a structure which provides a cyclic | annular band in the radial direction outer side of the balancer 41 and the front-end part 11, and prevents the balancer 41 from dropping out reliably. Moreover, you may form an unevenness | corrugation in the welding surface with the power transmission shaft main body 10 of the balancer 41 by a process or chemical treatment.

<Others>
In the power transmission shaft 2, the coupling state between the front end portion of the power transmission shaft main body and the stub shaft 131 (connection member) and the coupling state between the rear end portion of the power transmission shaft main body and the stub yoke 222 of the cross shaft joint 220 are determined as follows. Similar to axis 1.

≪Power transmission shaft manufacturing method≫
Next, of the method for manufacturing the power transmission shaft 1, thermal welding between the power transmission shaft main body 10 and the stub yoke 20 will be described. That is, the method for manufacturing the power transmission shaft 1 is characterized in that the stub yoke 20 is thermally welded to the front end portion 11 of the power transmission shaft main body 10 and the power transmission shaft main body 10 and the stub yoke 20 are coupled.

  The power transmission shaft body 10 is obtained by, for example, a pultrusion method (continuous pultrusion molding method). The pultrusion method refers to impregnating a carbon fiber with a thermoplastic resin by passing through a resin tank in which the thermoplastic resin is heated while running carbon fibers (bundles) aligned in a predetermined direction. This is a method of forming by squeezing and defoaming and then drawing through a mold. Here, as the carbon fiber bundle, a commingle impregnated (mixed) with a thermoplastic resin in advance may be used.

  The power transmission shaft main body 10 is formed in, for example, a straight shape having a constant outer diameter and inner diameter in the axial direction. In addition, the front end portion 11 may be partially thicker than others. Note that the inner diameter of the front end portion 11 is larger than the outer diameter of the cylindrical portion 22 of the stub yoke 20.

  The stub yoke 20 is obtained by a known casting method, for example. It is preferable to perform a chemical conversion treatment on the welding surface 23 of the cylindrical portion 22 so as to improve the adhesion with the front end portion 11.

<Heat welding of stub yoke>
Next, the cylindrical portion 22 of the stub yoke 20 is inserted into the front end portion 11 of the power transmission shaft main body 10. In this case, since the inner diameter of the front end portion 11 is larger than the outer diameter of the cylindrical portion 22, it can be inserted with a small force, and the inner peripheral surface of the front end portion 11 is not cut during insertion.

  Next, the front end portion 11 is heated to a temperature equal to or higher than the melting point of the thermoplastic resin by a heating means such as an electric heater. Thereby, the front end part 11 becomes soft and can be deformed.

  Next, the diameter of the front end portion 11 is reduced using an appropriate jig (see FIG. 3, arrow A1), and the front end portion 11 is brought into close contact with the cylindrical portion 22. As the jig, for example, an electric heater is incorporated, and three jig pieces having an arc shape of 1/3 as viewed in the axial direction are used. Then, the three jig pieces are placed on the outer peripheral surface of the front end portion 11, and the three jig pieces are moved radially inward by a pressurizing means such as a hydraulic cylinder, so that the front end portion 11 is reduced in diameter and deformed.

  Then, the deformed front end portion 11 enters and fills the groove 24. That is, the uneven outer peripheral surface of the cylindrical portion 22 is transferred to the inner peripheral surface of the front end portion 11. And the front-end part 11 and the cylindrical part 22 are heat-welded.

<Thermal welding of balancer>
Next, the balancer 41 is thermally welded to the front end portion 11. Specifically, the balancer 41 is heated above the melting point of the thermoplastic resin by a heating means such as an electric heater. Then, the heated balancer 41 is directed to the outer peripheral surface of the front end portion 11 and pushed inward in the radial direction. If it does so, the thermoplastic resin which forms the front-end part 11 will be heated, it will become soft and can deform | transform, and the balancer 41 will be partially embedded in the front-end part 11 and heat-welded.

  In this case, since the metal cylindrical portion 22 serving as a core material exists on the back side (back side) of the front end portion 11, that is, on the radial inner side, the front end can be pressed even if the balancer 41 is pressed against the front end portion 11. The part 11 is not greatly deformed.

  In this way, the balancer 41 can be fixed to the front end portion 11 in a short time by heat welding. That is, for example, when the balancer 41 is fixed with an adhesive, an adhesive application process, a balancer 41 bonding process, an adhesive curing process, and the like are required, and a cycle time required for a series of operations becomes long. Cycle time is significantly shortened by welding.

≪Modification≫
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to this, For example, you may change as follows.

  In the above-described embodiment, the configuration in which the fibers are carbon fibers has been exemplified, but other configurations such as glass fibers and aramid fibers may be used. That is, the power transmission shaft main body 10 may be made of GFRTP.

  In the above-described embodiment, the configuration in which the plurality of grooves 24 extending in the axial direction are arranged in the circumferential direction is exemplified. However, for example, a groove inclined by + 45 ° with respect to the axial direction, and a groove inclined by −45 ° It is good also as a structure provided with these. Further, a plurality of grooves extending in the circumferential direction may be formed in the axial direction.

  In the above-described embodiment, the configuration in which the range of thermal welding is continuous over the entire circumference in the circumferential direction is exemplified. However, for example, it may be formed with a predetermined interval in the circumferential direction.

  As shown in FIG. 5, it is good also as a structure in which the diameter reducing part 11b and the diameter reducing part 22b which were partially diameter-reduced in the front end part 11 and the cylindrical part 22 were formed. The diameter-reduced portion 11b and the diameter-reduced portion 22b are obtained by thermally welding the front end portion 11 and the cylindrical portion 22, and further reducing the diameter of the portion where the front end portion 11 and the cylindrical portion 22 overlap with each other in a linear shape (band shape). (See arrow A2 in FIG. 5). As a result, the front end portion 11 and the cylindrical portion 22 are further thermally welded (adhered), and are not easily displaced in the axial direction. However, the reduced diameter portion 11b and the reduced diameter portion 22b are not continuous in the circumferential direction, and may be at a predetermined interval (90 ° interval), for example.

  In the above-described embodiment, the configuration in which the balancer 41 is fixed to both ends of the power transmission shaft main body 10 is illustrated. However, the fixed position can be freely changed, and for example, a configuration in which the balancer 41 is fixed at an intermediate position in the axial direction may be used.

1, 2 Power transmission shaft 10 Power transmission shaft body 20 Stub yoke (connecting member)
30 Outer ring member (connecting member)
41 Balancer 100 Propulsion shaft

Claims (6)

A power transmission shaft for transmitting power,
FRTP power transmission shaft body,
A balancer fixed to the power transmission shaft body and for adjusting the rotational balance;
With
The balancer is thermally welded to the power transmission shaft main body. A member for coupling with another power transmission member, comprising a coupling member with one end of the power transmission shaft body fitted;
The power transmission shaft according to claim 1, wherein the balancer is thermally welded to one end of the power transmission shaft main body.   The power transmission shaft according to claim 1, wherein an annular band is provided on a radially outer side of the balancer.   The power transmission shaft according to any one of claims 1 to 3, wherein a welding surface of the balancer with the power transmission shaft main body is uneven.   The power transmission shaft according to any one of claims 1 to 4, wherein the power transmission shaft main body is made of a carbon fiber reinforced thermoplastic resin (CFRTP). A method of manufacturing a power transmission shaft for transmitting power,
A balancer for adjusting a rotation balance is fixed to a power transmission shaft body made of FRTP by heat welding.

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