WO2020174697A1

WO2020174697A1 - Method for producing drive shaft

Info

Publication number: WO2020174697A1
Application number: PCT/JP2019/010051
Authority: WO
Inventors: 一希大田; 森　健一; 貴博中山
Original assignee: 株式会社ショーワ
Priority date: 2019-02-27
Filing date: 2019-03-12
Publication date: 2020-09-03
Also published as: JP2020139529A; JP6547081B1

Abstract

A method for producing a drive shaft equipped with a tubular body (2) made of fiber-reinforced plastic, a stub yoke (3) having a through hole (8) that penetrates the axis (01) direction formed therein and being connected to an end of the tubular body (2), and a stub shaft (4), wherein the method is equipped with a connection step for connecting the stub yoke (3) and the stub shaft (4) to a mandrel (30) with a sand mold (20) formed therein, a winding step for winding fiber-reinforced plastic around the sand mold (20) and the stub yoke (3) and stub shaft (4) to form a tubular body (2), a curing step for curing the tubular body (2), an external energy application step for decomposing the sand mold (20), an extraction step for extracting the mandrel (30) from the sand mold (20) and the through hole (8) of the stub yoke (3), and a discharge step for discharging the collapsed sand mold (20) from the through hole (8) of the stub yoke (3) opened by pulling out the mandrel (30).

Description

Method for manufacturing power transmission shaft

The present invention relates to a method for manufacturing a power transmission shaft.

　The propeller shaft (power transmission shaft) of an automobile extends in the front-rear direction of the vehicle and transmits the power generated by the prime mover and decelerated by the transmission to the final reduction gear. As a conventional example of a propeller shaft, one provided with a tubular body made of fiber reinforced plastic can be cited (for example, Patent Document 1). Patent Document 1 describes forming a tubular body by winding a fiber reinforced plastic around a mandrel by a filament winding method.

JP-A-3-265738

As a structure to increase the bending rigidity of the propeller shaft, there is a technology to make the central part of the tubular body larger in diameter than the end part. According to this, by increasing the diameter only around the central portion of the tubular body where bending stress is likely to be concentrated, it is possible to achieve both the securing of bending rigidity and the suppression of weight. However, in the technique of winding the fiber-reinforced plastic around the mandrel, it is necessary to pull out the mandrel from the end of the tubular body after the tubular body is formed. Therefore, the tubular body has to have a constant inner diameter as in Patent Document 1. Absent. It is possible to adopt a core structure or a variable structure capable of pulling out the mandrel, but the mandrel structure becomes complicated and the manufacturing cost of the power transmission shaft tends to increase.

The present invention has been made to solve the above problems, and an object thereof is to form a tubular body by winding a fiber-reinforced plastic around a mandrel without being restricted by the shape of the tubular body. It is to provide a method for manufacturing a power transmission shaft.

In order to solve the above problems, the present invention comprises a tubular body made of fiber reinforced plastic, and a connecting member which is connected to an end portion of the tubular body and has a through hole penetrating in the axial direction of the tubular body. A method of manufacturing a power transmission shaft, comprising: a connecting step of connecting the connecting member to a mandrel on which a mold that is decomposed or melted by application of external energy is formed; and, after the connecting step, a fiber reinforced plastic is added to the mold. And a winding step of winding the tubular body around the connecting member, a hardening step of hardening the tubular body after the winding step, and applying the external energy to the mold after the hardening step. Then, an external energy applying step of decomposing or melting the mold, and after the external energy applying step, a drawing step of drawing the mandrel from the through holes of the mold and the connecting member, and after the drawing step, And a discharging step of discharging the decomposed or melted mold from the through hole of the connecting member opened by pulling out the mandrel.

According to the present invention, by using a mold that decomposes or dissolves by the application of external energy, the tubular body can be formed without being greatly restricted in shape, and the through hole opened by pulling out the mandrel is used to decompose the tubular body. Alternatively, the molten mold can be easily discharged. By winding the fiber reinforced plastic around the mold and the connecting member to form the pipe body, the pipe body and the connecting member can be easily connected.

It is a side view of the power transmission shaft of a first embodiment. It is an appearance perspective view of a stub yoke. It is an external appearance perspective view of a stub shaft. It is a sectional side view which shows the connection process of the power transmission shaft in 1st embodiment. It is a side sectional view showing a winding process of a power transmission shaft in a first embodiment. It is a side sectional view showing a pulling-out process of a power transmission shaft in a first embodiment. It is a sectional side view which shows the discharge process of the power transmission shaft in 1st embodiment. It is a flow chart of a manufacturing method of a power transmission shaft. It is explanatory drawing of a filament winding construction method. It is an explanatory view of a sheet winding method. It is a side sectional view of a power transmission shaft and a sand mold in a third embodiment. It is a sectional side view of a power transmission shaft and a sand mold in a fourth embodiment.

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 an FF (Front-engine Front-drive)-based four-wheel drive vehicle will be described. Further, the same reference numerals are given to the technical elements common to the respective embodiments, and the duplicate description will be omitted.

[First embodiment]
The first embodiment will be described with reference to FIGS. 1 to 8. 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 serving as a connecting member connected to the inside 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. The tube body 2 is made of carbon fiber reinforced plastic (CFRP). The reinforcing fibers used for 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 main body 110, a first connecting portion 120 arranged on the front side of the main body 110, a second connecting portion 130 arranged on the rear side of the main body 110, a main body 110 and a second connection. An inclined portion 140 located between the portion 130 and the portion 130.

The outer diameter of the main body portion 110 is reduced from the central portion 113 toward both ends (front end portion (other end portion) 111 and rear end portion (one end portion) 112). Is larger than the outer diameter of both ends (front end (other end) 111 and rear end (one end) 112). That is, when the main body 110 is cut along the axis O1, the cross-sectional shape of the outer peripheral surface of the main body 110 is an arc shape that draws a gentle curve and projects outward. Therefore, the outer shape of the main body 110 has a barrel shape in which the central portion 113 bulges outward in the radial direction. In addition, the plate thickness of the main body part 110 becomes thinner from both end parts (front end part (other end part) 111 and rear end part (one end part) 112) toward the central part 113. Is formed thinner than the plate thickness of both end portions (front end portion (other end portion) 111 and rear end portion (one end portion) 112).

The inner peripheral surface of the first connecting portion 120 has a polygonal shape following the polygonal connecting portion 7 (FIG. 2) of the stub yoke 3. The inner peripheral surface of the second connecting portion 130 also has a polygonal shape following the polygonal connecting portion 10 (FIG. 3) of the stub shaft 4.

The outer diameter of the inclined portion 140 gradually decreases from the main body 110 side toward the second connecting portion 130 side, and has 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 110 side (front side). For this reason, the plate thickness of the front end portion of the inclined portion 140 is the thinnest and constitutes a weak portion. From the above, when the vehicle collides with the power transmission shaft 1 from the front and a collision load is input, a shearing force acts on the inclined portion 140 inclined with respect to the axis O1. When the shearing force acting on the inclined portion 140 exceeds a predetermined value, the front end portion (fragile portion) of the inclined portion 140 is damaged. Therefore, at the time of a vehicle collision, the engine and the transmission mounted on 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 that constitutes a cardan joint. In FIG. 2, the stub yoke 3 includes a disk-shaped base portion 5 centered on the axis O1, a pair of arm portions 6 extending forward from the base portion 5 and supporting a cross shaft, and a stub yoke 3 extending rearward from the base portion 5 and extending from the base portion 5 of the tube body 2. The connecting portion 7 is connected to the inside of the one connecting portion 120 (FIG. 1). The connecting portion 7 has a tubular shape with an opening on the rear end side. The outer peripheral surface of the connecting portion 7 has a polygonal shape when viewed in the direction of the axis O1. A through hole 8 through which a mandrel 30 to be described later is inserted is formed in the base portion 5 so as to pass through the axis O1.

The stub shaft 4 is a metal member that constitutes a constant velocity joint. In FIG. 3, the stub shaft 4 is connected to the power transmission member of the constant velocity joint so as to rotate integrally with the power transmission member, and the second connection portion 130 of the tubular body 2 formed at the front end of the connection portion 9 (see FIG. 1). ) And the connection part 10 connected inside. The outer peripheral surface of the connecting portion 10 has a polygonal shape when viewed in the direction of the axis O1. A positioning hole 11 into which the rear end of the mandrel 30 fits is formed in the front end surface of the connecting portion 10 around the axis O1.

FIG. 8 is a flowchart of a method for manufacturing the power transmission shaft 1. The method for manufacturing the power transmission shaft 1 includes a connecting step (step S1) of connecting the stub yoke 3 and the stub shaft 4 to a mandrel 30 in which a mold that is decomposed or melted by application of external energy is formed, and a fiber reinforced plastic mold and A winding step of winding the stub yoke 3 and the stub shaft 4 to form the tubular body 2 (step S2), a curing step of curing the tubular body 2 (step S3), and applying external energy to the die to form the die. An external energy applying step of disassembling or dissolving (step S4), a pulling step of pulling out the mandrel 30 from the through holes 8 of the sand mold 20 and the stub yoke 3 (step S5), and a through hole of the stub yoke 3 opened by pulling out the mandrel 30. 8, a discharging step of discharging the decomposed or dissolved mold (step S6). Hereinafter, the case where the mold that decomposes or dissolves when external energy is applied is the sand mold 20 will be described.

"Connecting process"
In the connecting step, as shown in FIG. 4, the stub yoke 3 and the stub shaft 4 are connected to the mandrel 30 on which the sand mold 20 is formed. The mandrel 30 is a round bar-shaped mandrel member arranged around the axis O1. The sand mold 20 is penetrated by a mandrel 30. The sand mold 20 has a barrel-shaped mold body 21 whose outer diameter is reduced from the center toward both ends and whose outer peripheral surface is formed in an arc shape in the direction of the axis O1. At the front end of the die main body portion 21, a die connection portion 22 to which the connection portion 7 of the stub yoke 3 is fitted is formed. At the rear end of the die main body portion 21, a substantially frustoconical die inclination portion 25 is formed, the diameter of which decreases toward the rear. Around the front end of the mandrel 30 extends forward from the mold connecting portion 22. The rear end of the mandrel 30 slightly projects from the rear surface of the mold inclined portion 25.

As the stub yoke 3 is connected to the sand mold 20 and the mandrel 30 configured as described above, the stub yoke 3 is slid through the through hole 8 through the mandrel 30, and the connecting portion 7 is externally fitted to the mold connecting portion 22 of the sand mold 20. Further, as a connection of the stub shaft 4, the positioning hole 11 is fitted to the rear end of the mandrel 30. In order to accurately center the stub yoke 3 and the stub shaft 4 with respect to the mandrel 30, the inner diameters of the through hole 8 and the positioning hole 11 are formed with a predetermined dimensional tolerance with respect to the outer diameter of the mandrel 30.

"Wrapping process"
After the connecting step, as shown in FIG. 5, in the winding step, the fiber reinforced plastic is wound around the sand mold 20, the stub yoke 3, and the stub shaft 4 to form the tubular body 2. In the first embodiment, the fiber-reinforced plastic is wound around the sand mold 20, the stub yoke 3, and the stub shaft 4 by the filament winding method.

Fig. 9 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 of reinforcing fiber, a resin impregnating portion 45, an aggregating portion 46, a moving supply portion 47, and a rotating device for rotating the mandrel 30. And 48A and 48B.

The strands drawn out from the bobbins 41 to 44 are impregnated with the thermosetting resin in the resin impregnation section 45 and then aggregated as one roving 49 in the aggregation section 46. The moving supply unit 47 is disposed between the consolidating unit 46 and the mandrel 30 and supports the roving 49 so that the roving 49 can be inserted therethrough. The moving supply unit 47 is configured to be capable of reciprocating in the direction of the axis O1. The

rotating devices

48A and 48B support the front end of the mandrel 30 and the connecting portion 9 of the stub shaft 4 to rotate the mandrel 30.

As described above, the mandrel 30 is rotated by the

rotating devices

48A and 48B, and the moving supply unit 47 reciprocates in the direction of the axis O1, so that the roving 49 causes the sand mold 20, the connecting portion 7 of the stub yoke 3, and the stub shaft 4 to move. It is wound around the connecting portion 10 by a predetermined winding method such as helical winding or hoop winding. The winding device 40 includes a control unit (not shown), and by operating the control unit, the winding method of the filament winding, the wrap length, the winding speed, and the like can be set.

Through the above winding process, in the tubular body 2, the portion wound around the barrel-shaped mold body portion 21 of the sand mold 20 is formed as the barrel-shaped body portion 110, and the portion wound around the mold inclined portion 25 is the inclined portion. Formed as 140. The portion of the stub yoke 3 wound around the polygonal connecting portion 7 is formed as the first connecting portion 120 having a polygonal inner peripheral surface. Similarly, a portion of the stub shaft 4 wound around the polygonal connecting portion 10 is formed as a second connecting portion 130 having a polygonal inner peripheral surface.

"Curing process"
In the curing step after the winding step, heat treatment is appropriately performed to cure the impregnated resin of the tubular body 2.

"External energy application process"
After the curing step, in the external energy applying step, external energy is applied to the sand mold 20 to decompose the sand mold 20. For example, as the application of external energy to the sand mold 20, the tube body 2 is vibrated. As a result, vibration is transmitted to the sand mold 20, and the sand mold 20 collapses and decomposes.

"Pulling process"
After the external energy applying step, in the drawing step, as shown in FIG. 6, the mandrel 30 is drawn forward from the sand mold 20 and the stub yoke 3. As a result, the through hole 8 of the stub yoke 3 is opened.

"Discharge process"
After the drawing step, in the discharging step, as shown in FIG. 7, the sand mold decomposed from the through hole 8 opened by pulling out the mandrel 30 is discharged to the outside. For example, air is injected into the tube body 2 and the decomposed sand mold is discharged from the through hole 8.

As described above, power transmission including the tubular body 2 made of fiber reinforced plastic and the connecting member (stub yoke 3) that is connected to the end of the tubular body 2 and has the through hole 8 penetrating in the direction of the axis O1. With respect to the shaft 1, if the manufacturing method including the connecting step, the winding step, the hardening step, the external energy applying step, the drawing step, and the discharging step described above, the following effects are exhibited. In the method of manufacturing the tubular body 2 by winding the fiber reinforced plastic around the mold, the mold may be removed from the tubular body 2 depending on the shape of the tubular body 2 such as when the central portion of the tubular body 2 has a large diameter. It becomes difficult to take it out. If the mold has a core structure or a variable structure that can be taken out, the structure of the mold tends to be complicated.

On the other hand, according to the present invention, by using the mold (sand mold 20) that decomposes or dissolves by the application of external energy, the tube body 2 can be formed without being greatly restricted in shape, and the mandrel 30 can be pulled out. The sand mold 20 can be easily discharged by utilizing the through hole 8 opened at. In addition, by winding the fiber reinforced plastic around the sand mold 20 and the connecting member (stub yoke 3, stub shaft 4) to form the tube body 2, the tube body 2 and the connecting member (stub yoke 3, stub shaft 4) can be easily formed. Can be connected.

Further, since the outer peripheral surfaces of the connecting portion 7 of the stub yoke 3 and the connecting portion 10 of the stub shaft 4 are formed in a polygonal shape, the inner peripheral surfaces of the first connecting portion 120 and the second connecting portion 130 of the tubular body 2 are also formed. It is formed in a polygonal shape. That is, since the tubular body 2, the stub yoke 3, and the stub shaft 4 are engaged with each other at the polygonal portions, the power transmission performance of rotation between them is improved.

In the first embodiment, the sand mold 20 is provided with the mold main body portion 21 whose outer diameter is reduced from the central portion toward both end portions, so that the barrel is provided in the main body portion 110 of the tubular body 2 where bending stress is easily concentrated. The shaped portion is formed and has a predetermined bending strength. On the other hand, both end portions (front end portion (other end portion) 111 and rear end portion (one end portion) 112) of the main body portion 110 in which bending stress is hard to concentrate are lightened by forming the outer diameters to be small. There is. Also in the central portion 113 of the main body 110, the weight is reduced due to the thin plate thickness. Therefore, the power transmission shaft 1 is lightened while ensuring a predetermined bending rigidity of the central portion 113, and the bending primary resonance point is improved.

Further, if the fiber-reinforced plastic is wound around the sand mold 20, the stub yoke 3, and the stub shaft 4 by the filament winding method, the manufacturing cost of the power transmission shaft 1 can be suppressed.

[Second embodiment]
Also in the method for manufacturing the power transmission shaft of the second embodiment, as in the first embodiment, a connecting step of connecting the stub yoke 3 and the stub shaft 4 to the mandrel 30 in which a mold that is decomposed or melted by application of external energy is formed. And a step of winding the fiber reinforced plastic around the mold and the stub yoke 3 and the stub shaft 4 to form the tube body 2, a hardening step of curing the tube body 2, and applying external energy to the mold to form the mold. An external energy applying step of disassembling or dissolving, a drawing step of pulling out the mandrel 30 from the through hole 8 of the sand mold 20 and the stub yoke 3, and a mold decomposed or melted from the through hole 8 of the stub yoke 3 opened by pulling out the mandrel 30. And a discharging step for discharging. While the filament winding method is used in the first embodiment, the method of manufacturing the power transmission shaft 61 of the second embodiment is characterized in that the tube body 2 is formed by the sheet winding method.

The sheet winding method is, for example, as shown in FIG. 10, a sheet-shaped prepreg 50 in which reinforcing fibers are impregnated with a resin (thermosetting resin), for example, a plurality of sand molds 20 rotated by rotating

devices

48A and 48B. The pressure rollers 51 to 53 are used for winding. In the helical winding of the filament winding method, it is difficult to wind the reinforcing fibers along the axis O1 direction. However, according to the sheet winding method, the reinforcing fibers contained in the prepreg 50 may extend in the axis O1 direction. Can be easily arranged, and the elasticity of the tube body 2 in the direction of the axis O1 can be increased. PAN-based (Polyacrylonitrile) fibers are preferred as the fibers oriented in the circumferential direction, and pitch fibers are preferred as the fibers oriented in the axis O1 direction.

[Third embodiment]
Also in the method for manufacturing the power transmission shaft of the third embodiment, as in the first embodiment, a connecting step of connecting the stub yoke 3 and the stub shaft 4 to the mandrel 30 in which a mold that is decomposed or melted by application of external energy is formed. And a step of winding the fiber-reinforced plastic around the mold, the stub yoke 3, and the stub shaft 4 to form the tube body 2, a hardening step of hardening the tube body 2, and applying external energy to the mold to form the mold. An external energy applying step of disassembling or dissolving, a drawing step of pulling out the mandrel 30 from the through hole 8 of the sand mold 20 and the stub yoke 3, and a mold decomposed or melted from the through hole 8 of the stub yoke 3 opened by pulling out the mandrel 30. And a discharging step for discharging. In the first embodiment, the sand mold 20 includes the mold body portion 21 whose outer diameter decreases from the central portion toward both ends, whereas the method for manufacturing the power transmission shaft 71 according to the third embodiment. Then, as shown in FIG. 11, the sand mold 20 is characterized by including a mold main body portion 23 having an outer diameter formed uniformly from one end to the other end.

By wrapping the reinforced fiber plastic around the outer surface of the mold main body 23, the pipe body 2 is formed with the main body 210 having a uniform outer diameter from one end to the other end. By making the outer diameter of the main body 210 of the tubular body 2 uniform, the shape of the tubular body 2 can be simplified and the molding cost can be reduced.

[Fourth Embodiment]
Similarly to the first embodiment, the method for manufacturing the power transmission shaft of the fourth embodiment also includes a connecting step of connecting the stub yoke 3 and the stub shaft 4 to the mandrel 30 in which a mold that is decomposed or melted by application of external energy is formed. And a step of winding the fiber-reinforced plastic around the mold, the stub yoke 3, and the stub shaft 4 to form the tube body 2, a hardening step of hardening the tube body 2, and applying external energy to the mold to form the mold. An external energy applying step of disassembling or dissolving, a drawing step of pulling out the mandrel 30 from the through hole 8 of the sand mold 20 and the stub yoke 3, and a decomposed or melted mold from the through hole 8 of the stub yoke 3 opened by pulling out the mandrel 30. And a discharging step for discharging. In the first embodiment, the sand mold 20 is provided with the mold main body portion 21 whose outer diameter decreases from the central portion toward both end portions, whereas the method for manufacturing the power transmission shaft 81 of the fourth embodiment. Then, as shown in FIG. 12, in the sand mold 20, the outer diameter is uniformly formed from the central portion to the other end, the outer diameter is reduced from the central portion toward the one end, and the outer peripheral surface has the axis O1. It is characterized in that it has a mold body portion 24 formed in a curved shape in a direction.

By winding the reinforced fiber plastic around the outer surface of the mold body 24, the tube 2 has a uniform outer diameter from the center to the other end, and the outer diameter is reduced from the center to the one end. A body portion 310 having a diameter and an outer peripheral surface formed in a curved shape in the direction of the axis O1 is formed. By forming such a main body portion 310, both simplification of the shape of the tubular body 2 and improvement of strength can be achieved.

In each of the embodiments, a thermosetting resin is used as the impregnating resin for the fiber reinforced plastic, but a thermoplastic resin may be used in the present invention. When a thermoplastic resin is used, cooling treatment for curing the thermoplastic resin may be performed instead of the heat treatment performed in the curing step.

Further, the mold that decomposes or dissolves by the application of external energy is not limited to the sand mold 20, and a mold that decomposes or melts by external energy such as heat or vibration and can be discharged from the through hole 8. Other types may be used as long as they are. For example, a mold formed of a resin that is melted by heat or vibration can be considered.

1, 61, 71, 81 Power transmission shaft 2 Tubular body 3 Stub yoke (connecting member)
4 Stub shaft (connecting member)
8 through hole 20

sand mold

21, 23, 24 mold body 30 mandrel

Claims

A method for manufacturing a power transmission shaft, comprising: a tubular body made of fiber reinforced plastic; and a connecting member that is connected to an end portion of the tubular body and has a through hole that penetrates in the axial direction of the tubular body.
A connecting step of connecting the connecting member to a mandrel on which a mold that decomposes or dissolves upon application of external energy is formed;
After the connecting step, a winding step of winding the fiber reinforced plastic around the mold and the connecting member to form the tubular body,
A curing step of curing the tubular body after the winding step,
After the curing step, applying the external energy to the mold to decompose or dissolve the mold, an external energy applying step,
After the external energy applying step, a drawing step of drawing the mandrel from the through hole of the mold and the connecting member,
After the drawing step, a discharging step of discharging the decomposed or dissolved mold from the through hole of the connecting member opened by pulling out the mandrel,
A method for manufacturing a power transmission shaft, comprising:
The method for manufacturing a power transmission shaft according to claim 1, wherein an outer peripheral surface of a connecting portion of the connecting member with the tubular body is formed in a polygonal shape.
3. The mold according to claim 1, wherein the mold has a mold main body whose outer diameter is reduced from the center toward both ends and the outer peripheral surface is formed in an arcuate shape in the axial direction. A method for manufacturing a power transmission shaft according to.
The method for manufacturing a power transmission shaft according to claim 1 or 2, wherein the mold includes a mold main body having an outer diameter that is formed uniformly from one end to the other end.
The mold has a uniform outer diameter from the central portion to the other end, the outer diameter is reduced from the central portion toward the one end, and the outer peripheral surface is curved in the axial direction. The method for manufacturing a power transmission shaft according to claim 1 or 2, further comprising a main body portion.
The method for manufacturing a power transmission shaft according to any one of claims 1 to 5, wherein in the winding step, the fiber reinforced plastic is wound around the sand mold and the connecting member by a filament winding method.