KR20040036505A - A drive shaft with a compound material and method thereof - Google Patents

Abstract

PURPOSE: A power transmission shaft and a method for manufacturing the same are provided to improve endurance of the power transmission shaft against impact by preventing a composite material from being laminated caused by external impact. CONSTITUTION: A power transmission shaft includes a driving shaft(10), which is formed by depositing a composite material(12) on an inner surface of a metal tube(11) and a metal yoke(40) press-fitted into both ends of the driving shaft(10). A method for fabricating the power transmission shaft includes the steps of depositing composite material(12) on the inner surface of the metal tube(11), curing the composite material(12) by applying pre-pressure and vacuum to the driving shaft(10), and coupling the driving shaft(10) to the metal yoke(40).

Description

A drive shaft with a compound material and method

The present invention relates to a power transmission shaft used in a rear wheel drive vehicle and a method for manufacturing the same, and more particularly, to a power transmission shaft and a method for manufacturing the same by stacking a composite material on the inner surface of a metal material to improve impact resistance and prevent property degradation. It is about.

The power transmission shaft transmits the rotational force generated by the engine to the rear drive shaft, as in a rear wheel drive vehicle, and generally uses steel or aluminum as its material. In recent years, power transmission shafts using composite materials have been actively studied, and power transmission shafts using such composite materials are directly mounted on automobiles.

Such composites have superior properties in terms of specific stiffness and specific strength compared to steel or aluminum materials. Therefore, the power transmission shaft using the composite material increases the axial rigidity, thereby increasing the natural frequency in the bending direction.

However, power transmission shafts using composite materials must use sufficient composite materials to satisfy the torque transmission capacity and the natural frequency generated in this case, respectively, in order to transfer the torque generated by the engine. Therefore, the power transmission shaft using only the composite material has a disadvantage that the manufacturing cost is higher than the power transmission shaft made of conventional steel or aluminum.

Therefore, the power transmission shaft may be manufactured by joining a composite material (eg, one-way carbon fiber epoxy composite material) having excellent non-rigidity to an inner surface of a metal material (eg, aluminum alloy) having a high torque transmission capacity in consideration of manufacturing cost.

As described above, a method of manufacturing a power transmission shaft using a metal material and a composite material together is described in Korean Patent No. 103245 filed and registered by the present applicant.

In the method of manufacturing a power transmission shaft of the Republic of Korea Patent No. 103245, after wrapping the air tube and the composite material in the mandrel in order, the mandrel is inserted into the metal tube to bond the composite material to the inner surface of the metal tube. The mandrel is then pulled out and air is introduced into the air tube to pressurize the inside of the metal tube, curing the composite material to the metal tube in a suitable curing cycle. However, the power transmission shaft according to the manufacturing method has a difference in the coefficient of thermal expansion of the composite material and the metal tube, so that there is a high residual thermal stress at the interface between the two materials. For this reason, the power transmission shaft has a problem that the composite material bonded to the inner surface of the metal tube is easily peeled off even with a slight external impact, and moisture penetrates into the inner surface of the metal tube on which the composite material is peeled off, thereby deteriorating the properties of the power transmission shaft.

Thus, other power transmission shafts using metal materials and composite materials additionally coat expensive waterproof epoxy paints and urethane paints that block moisture penetration and increase impact resistance in order to overcome the above disadvantages. However, the power transmission shaft using the additional coating agent has a disadvantage in that it is difficult to use because the manufacturing cost is high.

The power transmission shafts are manufactured by forming a drive shaft by winding a composite material on an inner surface of a metal material, and metal yokes are coupled to both ends of the drive shaft. The method for coupling the metal yoke to such a drive shaft is described in Korean Patent Registration No. 197355 filed and registered by the applicant.

The drive shaft using the metal material and the composite material is also coupled to the metal yoke using an adhesive, such a power transmission shaft has a disadvantage in that the torque transfer capacity and the natural frequency conditions are lowered, and the center of the shaft is easily shifted. In addition, the power transmission shaft coupling the drive shaft to the metal yoke by welding has a disadvantage in that strength and rigidity are greatly deteriorated because carbon fiber and epoxy, which are materials of a composite material, are heated.

Thus, in the Republic of Korea Patent No. 197355, the serration is precisely processed on the inner surface of the end of the drive shaft and the outer surface of the metal yoke, thereby coupling the drive shaft and the metal yoke to each other. Due to this, the power transmission shaft coupled to the metal yoke is manufactured integrally unlike a conventional power transmission shaft consisting of two-pieces of about 1.5 m in length, and thus, the intermediate connection part is connected to an intermediate connection to connect the two shafts. The yoke used, the bearings for the center support and the rubber for the damping are eliminated.

However, in order for the drive shaft and the metal yoke to be engaged with each other by coupling, the machining precision must be high, and the manufacturing cost and the production time of the power transmission shaft are increased for such precision machining.

The present invention has been made to solve the problems of the prior art as described above, and after laminating and bonding the composite material to the inner surface of the metal tube, while maintaining the vacuum while simultaneously applying a preload in the axial direction to cure the composite material against external impact It is an object of the present invention to provide a power transmission shaft and a method of manufacturing the same, which prevents interlayer peeling, improves impact resistance, and prevents property degradation due to moisture penetration.

In addition, the present invention forms a plurality of projections or protrusions on the inner surface of the metal yoke by press-fitting the drive shaft to the metal yoke, the manufacturing cost is low, the production time is reduced, and the power transmission shaft having a high torque capacity, high fatigue life even in a short coupling length And other methods for providing the same.

1 is a view showing a power transmission shaft laminated with a composite material on the inner surface of a metal tube according to an embodiment of the present invention,

2 is a longitudinal sectional view and a cross sectional view showing a drive shaft of a power transmission shaft in which a composite material is laminated on an inner surface of the metal tube shown in FIG. 1,

3A is a view illustrating a process of stacking a plurality of composite materials and winding them on a mandrel by the method of manufacturing a drive shaft shown in FIG. 2,

3B is a view illustrating a process of inserting a mandrel wound with a composite material shown in FIG. 3A into a metal tube,

Figure 3c is a view showing a state in which the mandrel wound the composite material shown in Figure 3b is completely inserted into the metal tube,

FIG. 3d is a view illustrating a process of laminating the composite material on the inner surface of the metal tube by rotating the mandrel shown in FIG.

4A is a longitudinal cross-sectional view and a side view separately showing a stopper coupled to both ends of the drive shaft shown in FIG. 2 and a vacuum tube inserted therein, respectively;

4B is a longitudinal cross-sectional view and a side view of the dummy plug, the thrust bearing, and the preload jig which are sequentially coupled to the plug shown in FIG. 4A, respectively;

4C is a longitudinal cross-sectional view and a side view illustrating a state in which a preload shaft is inserted into the drive shaft shown in FIG. 4B, and a stopper, a dummy stopper, a thrust bearing, and a preload jig are sequentially coupled to an end thereof;

5A is a longitudinal sectional view and a side view showing a metal yoke coupled to both ends of the drive shaft shown in FIG.

5B is a longitudinal sectional view and a side view showing another embodiment of a metal yoke coupled to both ends of the drive shaft shown in FIG. 2;

FIG. 6 is a longitudinal cross-sectional view of the power transmission shaft separately showing the drive shaft and the metal yoke coupled to both ends shown in FIG.

♠ Explanation of symbols on the main parts of the drawing ♠

11 metal tube 14 composite layer

21: mandrel 22: overlap

31: stopper 33: vacuum passage

35: dummy stopper 37: preload jig

40: metal tube

The method of manufacturing the power transmission shaft of the present invention for achieving the object as described above includes a drive shaft composed of a composite material laminated on the inner surface of the metal tube, and a metal yoke coupled to both ends of the drive shaft and connected to another device A power transmission shaft is provided. In addition, the present invention is an inner layer stacking step of laminating and bonding the composite material to the inner surface of the metal tube, a curing step of curing the composite material on the inner surface of the metal tube by simultaneously applying a preload and a vacuum to the drive shaft, and the metal And a coupling step of press-fitting the yoke to both ends of the drive shaft.

The inner lamination step may include a first step of cutting the width and length of the composite material equally to the circumferential length and length of the inner surface of the metal tube to be bonded, and a second step of winding the cut composite material on the mandrel. And a third step of inserting the mandrel wound with the composite material into the inside of the metal tube, and bonding the composite material wound with the mandrel to the inner surface of the metal tube such that the composite material abuts on the inner surface of the metal tube. It is preferred to include a fourth step to make.

Further, in the second step, it is more preferable that a protective layer is wound between the composite material and the mandrel to increase the damping ratio of the power transmission shaft.

In addition, it is more preferable to preheat the metal tube in advance between the second or third step in order to easily adhere the composite material to the inner surface of the metal tube.

Further, in the fourth step, it is more preferable to fix the metal tube and rotate the mandrel while pressing the inner surface of the metal tube.

Further, in the fourth step, it is more preferable to fix the mandrel and rotate the metal tube eccentrically.

In addition, the hardening step is a first step of coupling the stopper to maintain the airtight at both ends of the drive shaft, respectively, and a second step of sequentially inserting the vacuum tube and the pre-compression shaft inside the drive shaft through the hollow formed in the stopper And a third step of coupling a preload jig rotatably engaged with the preload shaft to either side of the stopper, and applying the preload to the drive shaft by rotating the preload jig. It is preferred to include a fourth step of sucking air between the tubes to form a vacuum.

In addition, it is more preferable that a ring or a rubber plate is attached to one surface of the stopper in the first step to maintain airtightness.

In addition, the side of the stopper is more preferably formed with a vacuum passage so as to suck the air inside the drive shaft.

Further, in the second step, the other surface of the stopper is more preferably coupled to the dummy stopper for fixing the precompression while maintaining the airtight between the precompression shaft and the hollow of the stopper.

Further, it is more preferable that a thrust bearing for attenuating torque generated while the preload jig rotates is coupled between the stopper and the preload jig in the third step.

In another embodiment, the inner lamination step may include inserting a mandrel having a hollow shaft center into an inner side of a vacuum tube, and having a small outer diameter at the outer surface of the vacuum tube with a small tolerance or coinciding with the inner diameter of the metal tube. It is preferable to include a laminating step of wrapping sequentially, and an insertion step of inserting the mandrel wound around the composite material into the metal tube.

In addition, the curing step of the other embodiment is a first step of coupling the stopper to maintain the airtight to the both ends of the metal tube inserted the mandrel, respectively, and to pass through the hollow formed in the stopper and the hollow of the mandrel A second step of inserting compression, a third step of coupling a preload jig rotatably engaged with the preload shaft to the stopper, and a preload on the drive shaft by rotating the preload jig It is more preferable to include the step of forming a vacuum by sucking the air between the vacuum tube.

Further, in the coupling step, it is more preferable that protrusions or irregularities are formed on the inner surface of the metal yoke so that the driving shaft is press-coupled to the inner surface of the metal yoke.

Further, in the coupling step, it is more preferred to cool the metal yoke after applying heat to the metal yoke, press-fit the drive shaft to the metal yoke.

In addition, it is more preferable to apply an adhesive to the inner surface of the metal yoke or both ends of the drive shaft to press-fit the metal yoke and the drive shaft.

The power transmission shaft of the present invention includes a drive shaft in which a composite material is laminated on an inner surface of a metal tube, and a metal yoke coupled to both ends of the drive shaft and connected to another device. In addition, the drive shaft is applied to the vacuum and pre-pressure at the same time to the hardened the composite material to the metal tube, the metal yoke is formed with a groove therein so that the drive shaft is press-fitted, the inner circumferential circumference of the groove irregularities or protrusions Is formed.

In addition, the surface of the composite material laminated on the inner surface of the metal tube is more preferably laminated with a protective layer to increase the damping ratio is wrapped.

In addition, the groove is formed to be stepped with a guide portion and the coupling portion, the guide portion is formed slightly larger than the outer diameter of the drive shaft to guide the drive shaft to be easily fitted, the coupling portion has the irregularities or protrusions around the inner circumference Is more preferably formed.

In the following, with reference to the accompanying drawings, a preferred embodiment of a power transmission shaft in which a composite material according to the present invention is laminated on the inner surface will be described in detail.

1 is a view showing a power transmission shaft laminated with a composite material on the inner surface of the metal tube according to an embodiment of the present invention, Figure 2 is a drive shaft of the power transmission shaft laminated composite material on the inner surface of the metal tube shown in FIG. Is a longitudinal cross-sectional view and a cross-sectional view.

As shown in FIG. 1 and FIG. 2, the power transmission shaft of the present invention has a drive shaft 10 having a composite material 12 laminated on the inner surface of the metal tube 11 and cured at both ends of the drive shaft 10. The metal yoke 40 is press-fitted.

The method for manufacturing the power transmission shaft includes an internal stacking step of laminating the composite material 12 on the inner surface of the metal tube 11, a curing step of applying a preload and a vacuum to the stacked drive shafts 10 at the same time, and curing them; It consists of a coupling step for coupling the drive shaft 10 to the metal yoke (40).

Hereinafter, a method of manufacturing a drive shaft configured by stacking the composite material 12 on the inner surface of the metal tube 11 will be described.

3A is a view illustrating a process of stacking a plurality of composite materials and winding them on a mandrel by a method of manufacturing a drive shaft shown in FIG. 2, and FIG. 3B is a diagram illustrating a method of inserting a mandrel wound with a composite material shown in FIG. Figure 3c is a view showing a process, Figure 3b is a view showing a state in which the mandrel wound the composite material shown in Figure 3b is completely inserted into the metal tube, Figure 3d is a mandrel shown in Figure 3c by rotating the metal A diagram showing the lamination process on the inner surface of the tube.

2 to 3D, the driving shaft 10 has a composite material 12 laminated on the inner surface of the metal tube 11. In order to manufacture such a drive shaft 10, a plurality of composite materials 12 are laminated, and a protective layer 13 is laminated on the top thereof to form a composite layer 14.

First, the composite material 12 uses a prepreg form in which the base is viscous in a semi-cured state at room temperature and thus can be easily laminated. Then, several prepregs of the composite material 12 are appropriately cut at each designed angle and stacked in multiple layers. The width W of the composite material 12 is made to exactly match the circumferential length of the inner surface of the metal tube 11 to be joined, and the length L of the composite material 12 is equal to the length of the metal tube 11. At this time, the prepreg, which is the composite material 12, is wrapped with a backing film such as polyethylene or Teflon to prevent adhesion between each other in the storage or transportation process. Should be removed and laminated.

The prepreg, which is the composite material 12 stacked on the top, is laminated without removing the backup film and used as the protective layer 13. The protective layer 13 uses a prepreg backup film, but may be used by laminating paper or a thin rubber sheet after removing the backup film. The width W and the axial length L of the protective layer 13 correspond to the circumferential length and the axial length of the inner surface of the metal tube 11, respectively. The protective layer 13 made of such a backup film, paper or rubber sheet serves as a damping layer to reduce the vibration of the power transmission shaft. In addition, the protective layer 13 prevents adhesion between the mandrel 21 and the composite material 12, as shown in FIG. 3D, to facilitate sliding, and a portion 22 of the composite layer 14 overlapping each other. ) To prevent adhesion between the composite layers 14 to be evenly laminated on the inner surface of the metal tube 11.

The composite layer 14 laminated as described above is positioned so that the protective layer 13 of the composite layer 14 abuts on the outer surface of the mandrel 21 and is wound around the mandrel 21. Then, the mandrel 21 wound around the composite layer 14 is inserted into the metal tube 11 and then rotated. Since the inner diameter of the metal tube 11 is larger than the diameter of the mandrel 21 on which the composite layer 14 is wound, the mandrel 21 is rotated while being pressed along the inner surface of the metal tube 11 to FIG. 3D. As shown in FIG. 11, the semi-cured composite layer 14 is laminated on the inner surface of the metal tube 11 by its adhesive force.

The metal tube 11 of the drive shaft 10 is preferably preheated to 40 to 70 ° C. in advance in order to facilitate adhesion between the composite layer 14 and the metal tube 11. The mandrel 21 may be rotated in a clockwise or counterclockwise direction. However, the mandrel 21 should be rotated in a direction in which the composite layer 14 wound on the mandrel 21 can be released again. In addition, in the above, the mandrel 21 rotates inside the metal tube 11, but in the manufacturing method of the power transmission shaft of the present invention, the metal tube 11 is eccentrically rotated relative to the fixed mandrel 21. The composite layer 14 wound around the mandrel 21 may be laminated on the inner surface of the metal tube 11.

Since the composite layer 14 is laminated on the metal tube 14 as described above, the width W of the composite layer 14 is cut to match the inner circumferential length of the metal tube 11. There is no overlapping portion 22 or lacking portion.

After the composite layer 14 is completely stacked on the inner surface of the metal tube 11, the mandrel 21 is removed from the metal tube 11. In addition, the protective layer 13 is not removed even after the composite layer 14 is laminated in order to increase the damping ratio of the power transmission shaft. After the inner lamination step by the manufacturing method of the drive shaft 10 is completed as described above, a curing step of curing the drive shaft 10 is performed.

4A is a longitudinal cross-sectional view and a side view of the stopper coupled to the metal tube in which the composite material shown in FIG. 2 is laminated and the vacuum tube inserted therein, respectively, and FIG. 4B is sequentially connected to the stopper shown in FIG. 4A. A longitudinal cross-sectional view and a side view of the dummy stopper, the thrust bearing, and the preload jig respectively coupled to each other are shown, and FIG. 4C is a precompression insert inserted into the metal tube in which the composite material illustrated in FIG. 4B is laminated, and stoppers at both ends thereof. , Vertical plug, thrust bearing, and preload jig are longitudinally sectional and side views showing a state in which the jig is sequentially coupled.

4A to 4C, first, in the hardening step, the stopper 31 provided with an O-ring 32 and a vacuum passage 33 is firmly fixed at both ends of the drive shaft 10. The stopper 31 is formed with a hole penetrating through the center thereof, one surface in contact with the drive shaft 10 is attached to the O-ring 32 or rubber plate to maintain the air tightness, the side of the stopper 31 a vacuum passage 33 is formed. The stopper 31 configured as described above serves to maintain airtightness so that air does not leak when a vacuum is applied to the inside of the drive shaft 10 through the vacuum passage 33.

After the stopper 31 is fixed, the vacuum tube 34 and the threaded preload shaft 38 are sequentially inserted into the drive shaft 10. Then, the dummy stopper 35 is coupled to the other surface of the stopper 31 that is not in contact with the drive shaft 10, respectively. The dummy stopper 35 serves to fix the precompression shaft 38 while sealing the inside of the drive shaft 10. In addition, one of the dummy plugs 35 sequentially couples a thrust bearing 36 for preventing torque from occurring, and a screw type preload jig 37 having a screw thread formed therein. The preload jig 37 is rotatably coupled to the preload shaft 38 while being engaged with the screw line, thereby applying a preload in the axial direction of the drive shaft 10, and the thrust bearing 36 prevents torque from being transmitted to the drive shaft 10. It plays a role.

Thereafter, the preload jig 37 is rotated to apply a preload calculated in the axial direction of the drive shaft 10 to suppress the generation of the axial residual thermal stress of the drive shaft 10. In the curing step, the vacuum pump 33 is connected to the vacuum passage 33 of the stopper 31 at substantially the same time as the preload, and a vacuum is applied between the composite material of the driving shaft 10 and the vacuum tube to harden the driving shaft 10 by a suitable curing cycle. .

After hardening is completed, the drive shaft 10 is cooled to room temperature, and the preload jig 37, the thrust bearing 36, the dummy stopper 35, the stopper 31, and the preload shaft 38 are sequentially removed. In addition, the vacuum tube 34 inserted into the driving shaft 10 may be easily detached since the vacuum tube 34 is in direct contact with the protective layer 13 without being directly bonded to the excess resin.

Also, in the method of manufacturing the power transmission shaft, the drive shaft can be manufactured in other embodiments.

First, a mandrel is inserted inside the vacuum tube, and a composite material having an outer diameter almost identical to the inner diameter of the metal tube is wrapped on the outer surface of the vacuum tube. The mandrel wound around the composite material is then inserted into the metal tube, causing the composite material to temporarily adhere to the inner surface of the metal tube by its adhesive force. The mandrel is then pulled out of the metal tube to separate it, and the air present between the vacuum tube and the composite material is sucked in so that the composite material is effectively cohesive-cured on the inner surface of the metal tube.

Another embodiment inserts a mandrel with a hollow shaft center inside the vacuum tube, and wraps the composite material having a small outer diameter at the outer surface of the vacuum tube with a tolerance that is substantially equal to or close to the inner diameter of the metal tube. The mandrel wound around the composite material is then inserted inside the metal tube so that the composite material temporarily adheres to the inner surface of the metal tube by its adhesive force.

The precompression is then inserted into the hollow of the mandrel with the mandrel inserted into the metal tube. In addition, the stopper, the dummy stopper and the preload jig are coupled to both ends of the metal tube in the same order as the hardening step of the drive shaft, and the preload and the vacuum are respectively applied to the metal tube to which the composite material is bonded to cure the composite material. At this time, the mandrel is used to be slightly shorter than the length of the metal tube so that mutual interference with the stopper coupled to the metal tube does not occur. And, the mandrel does not separate the vacuum tube and the composite material from each other in the curing step, and serves to make the composite material adhere to the inner surface of the metal tube to a certain thickness. After completing the hardening step, the mandrel is separated from the metal tube to complete the drive shaft.

The drive shaft 10 completed through the curing step as described above is manufactured as a power transmission shaft which is a final product by combining with the metal yoke 40 to be connected to another device.

The following describes the coupling method of the metal yoke and the drive shaft.

FIG. 5A is a longitudinal sectional view and a side view showing a metal yoke coupled to both ends of the metal tube laminated with the composite material shown in FIG. 2, and FIG. 5B is shown at both ends of the metal tube laminated with the composite material shown in FIG. 2. 6 is a longitudinal cross-sectional view and a side view showing another embodiment of the metal yoke to be joined, and FIG. 6 is a longitudinal cross-sectional view of the power transmission shaft separately showing the metal tube laminated with the composite material shown in FIG. 2 and the metal yoke to be bonded to both ends thereof. to be.

As shown in FIGS. 5A to 6, a groove in which the driving shaft 10 is inserted is formed to be stepped in the metal yoke 40, and the groove is composed of a coupling part 41 and a guide part 42. . The guide part 42 is a part for guiding the center shaft to be easily aligned with each other when the driving shaft 10 and the metal yoke 40 are coupled, and the inner diameter of the guide part 42 is the inner diameter of the coupling part 41. Slightly larger than And, the coupling portion 41 is coupled to the drive shaft 10 by interference fit, for this purpose, a plurality of projections 43 or as shown in Figure 5a and 5b on the inner circumference of the coupling portion 41, respectively Unevenness 44 is formed.

Then, the metal yoke 40 formed as described above is coupled to both ends of the drive shaft 10 as shown in FIG. That is, the drive shaft 10 is inserted into the guide portion 42 of the metal yoke 40 so as to be aligned with the center line, and presses the metal yoke 40 by pressing. At this time, the inner diameter of the coupling portion 41 of the metal yoke 40 is manufactured with a tolerance of about 50 μm to 500 μm smaller than the outer diameter of the metal tube 11 of the drive shaft 10. 40 may be press fit with an interference fit.

In the present invention, the metal yoke 40 may be heated to be coupled to the drive shaft 10. That is, in the coupling step, heat is applied to the metal yoke, the drive shaft is pressed into the metal yoke, and the metal yoke is cooled and combined. Then, the power transmission shaft coupled to the indentation process or shrinkage process is engraved into the metal tube 11 of the drive shaft 10 is the projection 43 or the concave-convex 44 shape engraved on the inner surface of the metal yoke 40 is engaged. Such a power transmission shaft may be integrally coupled to transmit rotational force. In the coupling step, when the adhesive is applied to the inner surface of the metal yoke 40 to press the driving shaft 10, the fatigue life may increase because moisture or foreign matter does not penetrate into the gap.

The power transmission shaft manufactured by the coupling method of the metal yoke and the drive shaft greatly improves the torque transmission capacity, and the compressive stress is generated in the protrusion 43 or the concave-convex 44 shape, thereby obtaining high fatigue life. The effect of this power transmission shaft was obtained through the experimental results of the inventors.

As described in detail above, the power transmission shaft of the present invention is because the composite material is laminated and cured on the inner surface of the metal material, the impact resistance and abrasion resistance is improved compared to the conventional power transmission shaft, moisture permeation is blocked to improve the water resistance There is an advantage.

In addition, the present invention because the drive shaft is press-fitted to the metal yoke, which is formed with irregularities or protrusions, the manufacturing cost is lower than that of the prior art, and even with a short coupling length, torque without loss of physical properties, natural frequency and damping of the composite material It has the advantage of increasing the transmission capacity and fatigue life respectively.

In addition, the method of manufacturing the power transmission shaft of the present invention is because the mandrel and the composite material is not bonded by the protective layer, it is possible to easily perform the internal lamination step of laminating the composite material on the inner surface to improve the manufacturing productivity of the power transmission shaft There is this.

In addition, the present invention has the advantage that the manufacturing productivity is improved because at the same time performs a process of applying a preload to the metal tube and a process of applying a vacuum to the composite material laminated on the inner surface of the metal tube.

The technical idea of the power transmission shaft and the method of manufacturing the composite material laminated on the inner surface of the present invention has been described above with the accompanying drawings, but this is illustrative of the best embodiments of the present invention, which is intended to limit the present invention. It is not. In addition, it is obvious that any person skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

Claims (19)

In the method for manufacturing a power transmission shaft comprising a drive shaft composed of a composite material laminated on the inner surface of the metal tube, and a metal yoke coupled to both ends of the drive shaft and connected to another device, An inner layer stacking step of laminating and bonding the composite material to the inner surface of the metal tube; a curing step of curing the composite material on the inner surface of the metal tube by simultaneously applying preload and vacuum to the drive shaft; Method of manufacturing a power transmission shaft laminated on the inner surface of the composite material characterized in that it comprises a coupling step of press-fitting on both ends. The method of claim 1, The inner lamination step includes a first step of cutting the width and length of the composite material equally to the circumferential length and length of the inner surface of the metal tube to be bonded, and a second step of winding the cut composite material on the mandrel; A third step of inserting the mandrel wound with the composite material into the metal tube; and bonding the composite material wound with the mandrel to the inner surface of the metal tube such that the composite material contacts the inner surface of the metal tube. A method of manufacturing a power transmission shaft in which a composite material is laminated on an inner surface, comprising four steps. The method of claim 2, The method of manufacturing a power transmission shaft laminated on the inner surface of the composite material, characterized in that the second layer is wound between the composite material and the mandrel a protective layer for increasing the damping ratio of the power transmission shaft. The method of claim 2, Method of manufacturing a power transmission shaft laminated on the inner surface of the composite material, characterized in that for pre-heating the metal tube in order to easily adhere the composite material to the inner surface of the metal tube between the second or third step. The method of claim 2, In the fourth step, the composite material is laminated to the inner surface of the power transmission shaft, characterized in that for fixing the metal tube and compressing the mandrel along the inner surface of the metal tube. The method of claim 2, In the fourth step, the manufacturing method of the power transmission shaft laminated on the inner surface, characterized in that the mandrel fixed and the metal tube is rotated eccentrically. The method of claim 1, The curing step includes a first step of coupling the stopper to maintain the airtight at both ends of the drive shaft, and a second step of sequentially inserting the vacuum tube and the pre-compression shaft into the drive shaft through the hollow formed in the stopper; And a third step of coupling a preload jig rotatably engaged with the preload shaft to either side of the stopper, and between the composite material of the drive shaft and the vacuum tube while applying the preload to the drive shaft by rotating the preload jig. And a fourth step of forming a vacuum by sucking the air of the composite material. The method of claim 7, wherein The first step of the manufacturing method of the power transmission shaft laminated on the inner surface of the composite material, characterized in that the ring or rubber plate is attached to any one surface of the stopper to maintain the airtight. The method of claim 8, The side of the stopper is a method for manufacturing a power transmission shaft laminated on the inner surface of the composite material characterized in that a vacuum passage is formed to suck the air inside the drive shaft. The method of claim 7, wherein In the second step, the other surface of the plug is coupled to the dummy plug for fixing the pre-compression while maintaining the airtight between the pre-compression shaft and the hollow of the stopper composite material is laminated to the inner surface of the production of power transmission shaft Way. The method of claim 7, wherein And a thrust bearing for attenuating torque generated while the preload jig rotates between the stopper and the preload jig in step 3, wherein the composite material is laminated on the inner surface thereof. The method of claim 1, The inner lamination step inserts a mandrel having a hollow shaft center into the inside of the vacuum tube, and sequentially wraps the composite material having a small outer diameter at the outer surface of the vacuum tube with a small tolerance or matching the inner diameter of the metal tube. And a lamination step and an insertion step of inserting the mandrel wound with the composite material into the metal tube. The method according to claim 1 or 12, The curing step is a first step of coupling the stopper to maintain the airtight to both ends of the metal tube inserted the mandrel, respectively, and inserting the pre-compression through the hollow formed in the stopper and the hollow of the mandrel A second step, a third step of coupling a preload jig which is rotatably engaged with the preload shaft to the stopper, and a composite material of the drive shaft and the vacuum tube while applying a preload to the drive shaft by rotating the preload jig. A method of manufacturing a power transmission shaft in which a composite material is laminated on an inner surface, comprising: forming a vacuum by sucking air therebetween. The method of claim 1, In the coupling step, a projection or unevenness is formed on the inner surface of the metal yoke, the drive shaft is a manufacturing method of the power transmission shaft laminated composite material on the inner surface, characterized in that the press-fit coupled to the inner surface of the metal yoke. The method of claim 14, And applying heat to the metal yoke and press-fitting the drive shaft to the metal yoke to cool the metal yoke. The method of claim 14, The inner surface of the metal yoke or both ends of the drive shaft by applying an adhesive to the metal yoke and the drive shaft is a manufacturing method of the power transmission shaft laminated composite material on the inner surface. In the power transmission shaft comprising a drive shaft laminated on the inner surface of the metal tube and a metal yoke coupled to both ends of the drive shaft and connected to another device, The drive shaft is applied with vacuum and preload simultaneously to harden the composite material on the metal tube, and the metal yoke has a groove formed therein so that the drive shaft is press-fitted, and the groove has a concave-convex or protrusion formed on the inner circumference of the circumference. Power transmission shaft is laminated on the inner surface of the composite material. The method of claim 17, The power transmission shaft laminated on the inner surface of the composite material, characterized in that the composite material laminated on the inner surface of the metal tube is wrapped around the protective layer to increase the damping ratio. The method of claim 17, The groove is formed to be stepped with the guide portion and the coupling portion, the guide portion is formed slightly larger than the outer diameter of the drive shaft to guide the drive shaft to easily fit, the coupling portion is formed with the irregularities or protrusions on the inner circumference of the circumference Power transmission shaft is laminated on the inner surface of the composite material.