JP7201477B2 - Method for manufacturing tubular body used for power transmission shaft - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a tubular body used for a power transmission shaft.

A propeller shaft (power transmission shaft) of an automobile extends in the longitudinal direction of the vehicle, and transmits power generated by the prime mover and decelerated by the transmission to the final reduction gear. As a conventional example of a propeller shaft, there is one provided with a tubular body made of fiber-reinforced plastic. Patent Literature 1 describes forming a tubular body by winding fiber-reinforced plastic around a mandrel by a filament winding method.

Japanese Patent No. 3398455

When forming an inclined portion on the outer peripheral surface of the tubular body of the propeller shaft, the filament is wound on the mold inclined portion on the mandrel side corresponding to this inclined portion. At this time, depending on the relationship between the inclination angle of the mold slope and the orientation angle of the filament, the filament may slip on the mold slope, making it difficult to wind the filament densely.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to prevent the filament from slipping on the mold sloping portion when the filament is wound around the mold sloping portion of the mandrel. To provide a method for manufacturing a tubular body used for a power transmission shaft which can be tightly wound.

In order to solve the above-mentioned problems, the present invention provides a method of manufacturing a fiber-reinforced plastic tubular body having an inclined portion, which is used for a power transmission shaft by a filament winding method, and comprises a mandrel corresponding to the inclined portion. an annular member attaching step of attaching an annular member having a coefficient of friction larger than that of the mandrel to the outer peripheral surface of the mandrel at a portion through which the filament wound around the mold inclined portion passes; and winding the filament around the annular member. a curing step of curing the tubular body; and a core-removing step of pulling out the mandrel from the tubular body.

According to the present invention, by winding the filament around the annular member having a larger coefficient of friction than the mandrel, the slippage of the filament on the mold slope can be suppressed. This allows the filament to be tightly wound around the die slant.

It is a side view of the power transmission shaft of the first embodiment. It is a sectional side view which shows the annular member attachment process of the manufacturing method in 1st embodiment. It is a sectional side view which shows the winding process of the manufacturing method in 1st embodiment. FIG. 4 is a side cross-sectional view showing a curing step of the manufacturing method in the first embodiment; It is a sectional side view which shows the core removal process of the manufacturing method in 1st embodiment. It is a flow chart of a manufacturing method of a tubular body. It is explanatory drawing of a filament winding method. It is a sectional side view which shows the winding process of the manufacturing method in 2nd embodiment. It is a sectional side view which shows the winding process of the manufacturing method in 3rd embodiment. FIG. 11 is a side view of a modification of the power transmission shaft; FIG. 11 is a side view of another modified example of the power transmission shaft;

Each embodiment will be described with reference to the drawings. In each embodiment, an example in which the power transmission shaft of the present invention is applied to a propeller shaft mounted on a front-engine front-drive (FF)-based four-wheel drive vehicle will be described. In addition, technical elements common to each embodiment are assigned common reference numerals, and overlapping descriptions are omitted.

As shown in FIG. 1, the power transmission shaft 1 includes a tubular body 2 having an axis O1 as a central axis, a stub yoke 3 as a connecting member connected to the inner side of the first connecting portion 120 of the tubular body 2, and the tubular body 2. and a stub shaft 4 as a connecting member connected to the inside of the second connecting portion 130 of the. The tubular body 2 is made of carbon fiber reinforced plastic (CFRP). The reinforcing fibers used in the fiber-reinforced plastic in the present invention are not limited to carbon fibers, and may be glass fibers or aramid fibers.

The tubular body 2 includes a body portion 110, a first connection portion 120 arranged on the front side of the body portion 110, a second connection portion 130 arranged on the rear side of the body portion 110, and a second connection with the body portion 110. and an inclined portion 140 positioned between the portion 130 and the portion 130 .

The outer diameter of the body portion 110 decreases from the central portion 113 toward both ends (the front end portion (the other end portion) 111 and the rear end portion (the one end portion) 112). is larger than the outer diameters of both ends (front end (other end) 111 and rear end (one end) 112). In other words, when the body portion 110 is cut along the axis O1, the cross-sectional shape of the outer peripheral surface of the body portion 110 is an arcuate shape that draws a gentle curve and protrudes outward. Therefore, the main body portion 110 has a barrel shape in which the central portion 113 bulges outward in the radial direction. Further, the plate thickness of the main body portion 110 decreases from both ends (the front end portion (the other end portion) 111 and the rear end portion (the one end portion) 112) toward the central portion 113, and the plate thickness of the central portion 113 is formed thinner than the plate thickness of both ends (front end (other end) 111 and rear end (one end) 112).

The central portion 113 of the main body portion 110, on which bending stress tends to concentrate, has a large outer diameter and has a predetermined bending strength. On the other hand, both ends (the front end (the other end) 111 and the rear end (the one end) 112) of the main body 110, where the bending stress is difficult to concentrate, have a small outer diameter to reduce weight. there is The central portion 113 of the main body portion 110 also has a reduced plate thickness, thereby reducing the weight. Therefore, the power transmission shaft 1 is made lighter while ensuring the predetermined bending rigidity of the central portion 113, and the bending primary resonance point is improved.

The inner peripheral surface of the first connecting portion 120 has a polygonal shape following the polygonal outer peripheral surface of the connecting portion 5 of the stub yoke 3 . The inner peripheral surface of the second connecting portion 130 also has a polygonal shape following the polygonal outer peripheral surface of the connecting portion 6 of the stub shaft 4 .

The outer diameter of the inclined portion 140 gradually decreases from the side of the body portion 110 toward the side of the second connection portion 130 to form a truncated cone shape. The plate thickness of the inclined portion 140 gradually decreases from the end portion on the second connection portion 130 side (rear side) toward the end portion on the main body portion 110 side (front side). Therefore, the thickness of the front end portion of the inclined portion 140 is the thinnest and constitutes a weak portion. As described above, when a vehicle collides with the power transmission shaft 1 from the front and a collision load is input, a shear force acts on the inclined portion 140 inclined with respect to the axis O1. Then, when the shear force acting on the inclined portion 140 exceeds a predetermined value, the front end portion (weak portion) of the inclined portion 140 is damaged. Therefore, in the event of a vehicle collision, the engine and transmission mounted in the front portion of the vehicle body quickly move backward, and the collision energy is absorbed by the front portion of the vehicle body.

The stub yoke 3 is a metal member forming a cardan joint. The connecting portion 5 of the stub yoke 3 has a tubular shape with an open rear end side. The outer peripheral surface of the connecting portion 5 has a polygonal shape when viewed in the direction of the axis O1. The stub shaft 4 is a metal member that constitutes a constant velocity joint. The stub shaft 4 includes a connection portion 7 that is connected to the power transmission member of the constant velocity joint so as to rotate integrally, and a connection portion formed at the front end of the connection portion 7 and connected to the inside of the second connection portion 130 of the tubular body 2. 6 and . The outer peripheral surface of the connection portion 6 has a polygonal shape when viewed in the direction of the axis O1.

FIG. 6 is a flow chart of a method for manufacturing the tubular body 2 used for the power transmission shaft 1. As shown in FIG. The manufacturing method of the tubular body 2 used for the power transmission shaft 1 is as follows. An annular member attaching step (step S1) for attaching an annular member 10 having a coefficient of friction greater than that of the annular member, a winding step (step S2) for winding the filament so as to pass over the annular member 10, and a hardening step for hardening the tubular body 2 ( Step S3) and a core removal step (step S4) of pulling out the mandrel 8 from the tubular body 2 are provided.

[First embodiment]
"Annular member installation process"
As shown in FIG. 2 , the mandrel 8 is formed with a truncated conical mold slope 9 for forming the slope 140 of the tubular body 2 . Although the inclined surface of the mold inclined portion 9 is flat when viewed in the vehicle width direction, it may be curved. The annular member 10 is formed of a material having a coefficient of friction greater than that of the metal mandrel 8, more preferably a resin material, a rubber material, or the like.

In this embodiment, the annular member 10 is composed of a large-diameter first annular member 10A and a small-diameter second annular member 10B, which are arranged in pairs with the mold inclined portion 9 interposed therebetween in the direction of the axis O1. The first annular member 10A is attached to the outer peripheral surface of the mold body portion 12 of the mandrel 8, which is the portion forming the body portion 110 (Fig. 1), and the second annular member 10B is attached to the second connection portion 130 (Fig. 1). It is attached to the outer peripheral surface of the mold second connection portion 13 of the mandrel 8, which is a portion for forming the . The attachment structure may be crimped or may be temporarily fixed with an adhesive having weak adhesion.

"Winding process"
In the winding step, as shown in FIG. 3, the filament 49 is helically wound around the mandrel 8 . At the mold inclined portion 9, it is wound so as to pass over the first annular member 10A and the second annular member 10B. Since the mold inclined portion 9 is inclined with respect to the axis O1, conventionally, depending on conditions such as the size of the orientation angle of the filament 49 and the low viscosity of the impregnated resin material of the filament 49, the filament 49 may not be positioned above the mold inclined portion 9. There was a risk of slipping, opening your eyes and getting wrapped up. On the other hand, by winding the filament 49 so as to pass over the annular member 10 having a coefficient of friction larger than that of the mandrel 8, the filament 49 is held on the annular member 10 by friction, and slipping on the mold inclined portion 9 is prevented. Suppressed. As a result, the filament 49 can be tightly wound around the die slanted portion 9 .

FIG. 7 shows an example of a winding device used in the filament winding method. The winding device 40 includes a plurality of bobbins 41 to 44 each wound with a strand that is a bundle of reinforcing fibers, a resin-impregnated portion 45, an aggregation portion 46, a moving supply portion 47, and a rotating device that rotates the mandrel 8. 48A and 48B.

The strands pulled out from the respective bobbins 41 to 44 are impregnated with a thermosetting resin in a resin impregnating section 45 and collected into a single filament (roving) 49 in a collecting section 46 . The moving supply portion 47 is arranged between the collecting portion 46 and the mandrel 8 and supports the filament 49 so as to be able to pass therethrough. The moving supply unit 47 is configured to be able to reciprocate in the direction of the axis O1. The rotating devices 48A and 48B rotate the mandrel 8 by supporting the front end and the rear end of the mandrel 8, for example.

As described above, the mandrel 8 is rotated by the rotating devices 48A and 48B, and the moving supply portion 47 reciprocates in the direction of the axis O1, thereby winding the filament 49 in a predetermined helical winding. The winding device 40 has a control unit (not shown), and by operating the control unit, the winding method, wrap length, winding speed, etc. of the filament winding can be set.

"Curing process"
In FIG. 4, in the curing step, the tubular body 2 is heated in a heating furnace or the like to cure the impregnated resin of the tubular body 2 . The annular member 10 may be made of a material that melts due to this heating. When the impregnating resin is a thermoplastic resin, the impregnating resin of the tubular body 2 is hardened by cooling.

"Decore process"
After the curing step, as shown in FIG. 5, in the core removing step, the mandrel 8 is pulled out from the tubular body 2 while the annular member 10 remains integral with the tubular body 2 . Even in the case where the body portion 110 of the tubular body 2 has a barrel shape as in the present embodiment, the mandrel 8 can be changed by, for example, making the mandrel 8 a mold with a variable structure or adopting a core structure. It can be pulled out from the tubular body 2 . Since the annular portion 10 is in a state of being fixed to the inner surface of the tubular body 2 or is in a state of being melted by heating, there is no problem caused by remaining.

In the core removal step, the annular member 10 and the mandrel 8 may be pulled out from the tubular body 2 . For example, by fixing the annular member 10 to the mandrel 8 , the annular member 10 can be pulled out from the tubular body 2 together with the mandrel 8 .

As described above, the method for manufacturing the tubular body 2 used in the power transmission shaft 1, which is made of fiber-reinforced plastic and has the inclined portion 140 by the filament winding method, comprises the above-described annular member mounting step and winding. By adopting a method that includes the attaching step, the curing step, and the core removing step, it is possible to form the inclined portion 140 while suppressing the slippage of the filament 49 . The inclined portion 140 can become a starting point of breakage in the event of a frontal collision of the vehicle, and in addition, on the small-diameter side, it is possible to reduce the size of connecting members such as the stub shaft 4 .

Moreover, if the annular member 10 is made of an elastic member such as a resin material or a rubber material, the vibration of the tubular body 2 is damped by the annular member 10 .

By arranging a pair of annular members 10 with the die sloping portion 140 interposed in the direction of the axis O1, the filament 49 is caught at many places, so that the filament 49 can be prevented from slipping.

[Second embodiment]
FIG. 8 is an explanatory diagram of the second embodiment. In the method of manufacturing the tubular body used for the power transmission shaft of the second embodiment, as in the first embodiment, the mold slant portion 9 of the mandrel 8 corresponding to the slant portion 140 or the filament wound around the mold slant portion 9 passes through. An annular member attaching step of attaching an annular member 10 having a coefficient of friction larger than that of the mandrel 8 to the outer peripheral surface of the mandrel 8 at a point, a winding step of winding the filament 49 so as to pass over the annular member 10, and hardening the tubular body 2. and a core removing step of pulling out the mandrel 8 from the tubular body 2. - 特許庁The annular member 10 of the second embodiment is arranged on the die slanted portion 9 and is composed of an annular member 10</b>C formed to have a width narrower than the axial length L of the die slanted portion 9 . 10 C of annular members are also shape|molded by resin material, a rubber material, etc. like 1st embodiment.

The annular member 10C can also form the inclined portion 140 without the filament 49 slipping. The inclined portion 140 can become a starting point of breakage in the event of a frontal collision of the vehicle, and in addition, on the small-diameter side, it is possible to reduce the size of connecting members such as the stub shaft 4 . By arranging one annular member 10</b>C on the mold inclined portion 9 , it is possible to achieve both anti-slipping of the filament 49 and reduction in the number of parts.

[Third Embodiment]
FIG. 9 is an explanatory diagram of the third embodiment. In the method of manufacturing the tubular body used for the power transmission shaft of the third embodiment, as in the first embodiment, the mold slant portion 9 of the mandrel 8 corresponding to the slant portion 140 or the filament wound around the mold slant portion 9 passes through. An annular member attaching step of attaching an annular member 10 having a coefficient of friction larger than that of the mandrel 8 to the outer peripheral surface of the mandrel 8 at a point, a winding step of winding the filament 49 so as to pass over the annular member 10, and hardening the tubular body 2. and a core removing step of pulling out the mandrel 8 from the tubular body 2. - 特許庁The annular member 10 of the third embodiment is composed of an annular member 10</b>D that is formed wide so as to cover the entire mold inclined portion 9 .

The annular member 10D is also made of a resin material, a rubber material, or the like, and has a substantially truncated cone shape. The front side and the rear side of the annular member 10D are applied to the outer peripheral surfaces of the mold body portion 12 and the mold second connection portion 13, respectively.

The annular member 10D can also form the inclined portion 140 without the filament 49 slipping. The inclined portion 140 can become a starting point of breakage in the event of a frontal collision of the vehicle, and in addition, on the small-diameter side, it is possible to reduce the size of connecting members such as the stub shaft 4 . By using the wide annular member 10D that covers the entire mold inclined portion 9 by itself, it is possible to achieve both anti-slipping of the filament 49 and a reduction in the number of parts.

The preferred embodiments of the present invention have been described above. As the tubular body 2, as shown in FIG. 10, it may be provided with a straight body portion 210 having a uniform outer diameter from the front end portion 111 to the rear end portion 112, or as shown in FIG. , the outer diameter is uniform from the central portion 113 to the front end portion (the other end portion) 111, the outer diameter decreases from the central portion 113 toward the rear end portion (one end portion) 112, and the outer peripheral surface is the axis line. A body portion 310 that is curved in the 01 direction may be provided.

In any of the embodiments, after the winding step, an axially oriented layer in which fibers are oriented along the direction of the axis O1 may be formed by a filament winding method or a sheet winding method. In the sheet winding method, a sheet-like prepreg in which reinforcing fibers are impregnated with a resin (thermosetting resin) is wound on a helical layer. In the helical winding of the filament winding method, it is difficult to wind the reinforcing fibers along the direction of the axis O1 even if the orientation angle is small. can be easily arranged to extend in a direction. Thus, by forming an axially oriented layer in which fibers are oriented along the axis O1 direction, it is possible to increase the elasticity of the tubular body 2 in the axis O1 direction. PAN-based (Polyacrylonitrile) fibers are preferable as the fibers oriented in the circumferential direction, and pitch fibers are preferable as the fibers oriented in the direction of the axis O1.

REFERENCE SIGNS LIST 1 power transmission shaft 2 tubular body 3 stub yoke 4 stub shaft 8 mandrel 9 type inclined portion 10 annular member

Claims (7)

A method for manufacturing a tubular body made of fiber-reinforced plastic and having an inclined portion by a filament winding method for use in a power transmission shaft, comprising:
an annular member attaching step of attaching an annular member having a coefficient of friction greater than that of the mandrel to an outer peripheral surface of the mandrel at a portion of the mandrel corresponding to the inclined portion or through which the filament wound around the inclined portion passes;
A winding step of winding a filament around the annular member;
a curing step of curing the tubular body;
a core removing step of pulling out the mandrel from the tubular body while the annular member remains integral with the tubular body on the inner peripheral surface of the tubular body corresponding to the mold inclined portion or the outer peripheral surface ;
A method for manufacturing a tubular body used for a power transmission shaft, comprising: The curing step comprises a step of curing the tubular body by heating,
2. The method of manufacturing a tubular body used in a power transmission shaft according to claim 1 , wherein said annular member is formed of a material that melts when heated in said curing step. 3. The method of manufacturing a tubular body used for a power transmission shaft according to claim 1, wherein said tubular body is made of carbon fiber reinforced plastic. 4. The power transmission shaft according to any one of claims 1 to 3 , wherein a pair of the annular members are arranged on the outer peripheral surface of the mandrel with the die inclined portion interposed therebetween in the axial direction. A method for manufacturing a tubular body used for 4. The annular member according to any one of claims 1 to 3 , wherein the annular member is disposed on the die slanted portion and formed to have a width narrower than the axial length of the die slanted portion. A method for manufacturing a tubular body used for a power transmission shaft. 4. The tubular body used for the power transmission shaft according to any one of claims 1 to 3 , wherein the annular member is formed wide so as to cover the entire mold inclined portion. Production method. After the winding process,
A filament winding method or a sheet winding method is used for the power transmission shaft according to any one of claims 1 to 6 , wherein an axially oriented layer in which fibers are oriented along the axial direction is formed. A method for manufacturing a tubular body.

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