KR102216918B1 - Drive shaft for vehicle - Google Patents

Abstract

Disclosed is a CFRP drive shaft for a vehicle. According to the present invention, the CFRP drive shaft for the vehicle comprises: a connection stub which is respectively connected to a constant velocity joint respectively placed on an engine side and a wheel side, and which is formed by metallic materials; and a hollow shaft tube which includes a pressing fixing unit respectively formed on one end unit and the other end unit to be engaged with the connection stub by being pressed, and support embossed units formed on the pressing fixing unit at regular intervals in a circumferential direction, and which is formed by thermally molding carbon fiber reinforced plastic (CRFP) materials. Accordingly, the present invention is able to use the CRFP to form a shaft tube by molding the shaft tube after forming a first carbon fiber sheet layer and a second carbon fiber sheet layer to allow the fiber directions of the carbon fiber to cross each other. Accordingly, the present invention is able to reduce the weight but improve strength and durability.

Description

CFR drive shaft for vehicle{Drive shaft for vehicle}

The present invention relates to a CFRP drive shaft for a vehicle, wherein a shaft tube is formed using carbon fiber reinforced plastic (CFRP), and a stub that is bonded to both sides of the shaft tube to be bonded to a constant velocity joint is formed of metal, It relates to a CFR drive shaft for a vehicle that can improve strength and durability while reducing the value.

In general, in the drive system of a vehicle, the driving force of the engine is transmitted to the wheels via a driver shaft after shifting in accordance with the driving conditions of the vehicle in a transmission.

In addition, automobiles have a front wheel drive method that rotates the front wheel to drive according to the position of the driving wheel, a rear wheel drive method that drives by rotating the rear wheel, and a large rotational torque, such as when driving on rough roads or towing other vehicles, usually If necessary, it can be divided into a four-wheel drive method in which the vehicle runs while rotating the rear wheel.

In recent years, in the case of a passenger vehicle, most of the front-wheel drive method is employed in order to efficiently utilize indoor space and improve fuel efficiency. Front-wheel drive vehicles use a drive shaft to transmit the power generated from the engine to the drive wheels through a transaxle.

The drive shaft used in the drive line of such a vehicle is a device for transmitting the engine power of the vehicle to the drive wheel, and includes an intermediate shaft (intermediate shaft) and a constant velocity joint that is respectively coupled to both sides of the intermediate shaft.

The intermediate shaft is formed in the shape of a round bar that can be formed by forging, and spline grooves are formed at both ends. Then, it is connected to the constant velocity joint through the spline groove.

Recently, a case of using a hollow shaft to reduce the weight of the drive shaft is gradually increasing, and the stub (STUB) is joined by welding to both sides of the hollow shaft. In addition, continuous research is being conducted on the technology of manufacturing a drive shaft using carbon fiber.

However, the drive shaft of the prior art as described above has a problem in that the coupling portion between the CFRP tube and the stud made of carbon fiber is weak, resulting in breakage and easy deformation.

Therefore, there is a need to improve this.

On the other hand, Korean Patent Publication No. 10-2005-0006343 (published date: 2005.01.17) discloses "a hollow drive shaft for automobiles and a manufacturing method thereof", and Korean Patent Publication No. 10-2008-0050342 (Publication Date: Il: 2008.06.05) discloses a "method of manufacturing a drive shaft for a vehicle"

The present invention is created by the above necessity, and reduces the weight by forming a shaft tube using carbon fiber reinforced plastic (CFRP), and forming a metal stub that is bonded to both sides of the shaft tube and bonded to a constant velocity joint. The purpose of this is to provide a CFR drive shaft for vehicles that can improve strength and durability.

In order to achieve the above object, the CFR drive shaft for a vehicle according to an embodiment of the present invention is connected to a constant velocity joint respectively disposed on an engine side and a wheel side, and a connection stub formed of a metal material, one end, and Each press-fit fixing part is formed at the other end by press-fitting to the connection stub, and the support embossing part is formed at equal intervals along the circumferential direction of the press-fit fixing part, and formed by hot forming a carbon fiber reinforced plastic (CFRP) material. It characterized in that it comprises a hollow shaft tube.

In the present invention, the shaft tube comprises: a first carbon fiber sheet layer formed by winding a carbon fiber sheet along the longitudinal direction of the shaft mold form so as to be perpendicular to the axis of the circular shaft mold form; And a second carbon fiber sheet layer formed by winding the carbon fiber sheet obliquely from the outer surface of the first carbon fiber sheet layer to the outer surface so as to be inclined with respect to the axis of the shaft mold form.

In the present invention, the press-fit fixing part is characterized in that the outer diameter gradually decreases toward the end so as to have an outer diameter smaller than the outer diameter of the shaft tube.

In the present invention, the support embossing portion is characterized in that the thickness gradually increases toward the end of the shaft tube and the outer surface area is widened.

In the present invention, the shaft tube is characterized in that a thermosetting resin is applied to the outer surface of the press-fit fixing part, is bonded to the connection stub by press-fitting, and bonded to the connection stub through thermosetting.

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As described above, unlike the prior art, the CFR drive shaft for a vehicle according to the present invention uses a carbon fiber reinforced plastic (CFRP) to form a shaft tube with a first carbon fiber sheet so that the fiber orientation of the carbon fibers crosses. Since the shaft tube is formed after forming the layer and the second carbon fiber sheet layer, it has the effect of improving strength and durability while reducing weight.

In addition, the CFR drive shaft for a vehicle according to the present invention has an effect of improving durability such as strength and rigidity by using a metal foil.

1 is a perspective view illustrating a CFP drive shaft for a vehicle according to an embodiment of the present invention.
2 is a cross-sectional view illustrating a CFP drive shaft for a vehicle according to an embodiment of the present invention.
3 is a front view illustrating a shaft tube according to an embodiment of the present invention.
4 is an enlarged perspective view of a main part for explaining a combination of a press-fit fixing part and a connection stub according to an embodiment of the present invention.
5 is a side view illustrating a press-fit fixing unit according to an embodiment of the present invention.
6 is a view for explaining a molding process of the first carbon fiber sheet layer according to an embodiment of the present invention.
7 is a view for explaining a molding process of the second carbon fiber sheet layer according to an embodiment of the present invention.
8 is a side view of FIG. 7.
9 is a cross-sectional view illustrating a shaft tube according to another embodiment of the present invention.
10 is a side cross-sectional view illustrating a shaft tube according to another embodiment of the present invention.

Hereinafter, a preferred embodiment of a CFR drive shaft for a vehicle according to the present invention will be described with reference to the accompanying drawings. In this process, the thickness of the lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of description.

In addition, terms to be described later are terms defined in consideration of functions in the present invention and may vary according to the intention or custom of users or operators. Therefore, definitions of these terms should be made based on the contents throughout the present specification.

FIG. 1 is a perspective view illustrating a CFR drive shaft for a vehicle according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating a CFR drive shaft for a vehicle according to an embodiment of the present invention, and FIG. It is a front view for explaining the shaft tube according to an embodiment of the present invention.

In addition, FIG. 4 is an enlarged perspective view of a main part for explaining a combination of a press-fit fixing part and a connection stub according to an embodiment of the present invention, and FIG. 5 is a side view illustrating a press-fit fixing part according to an embodiment of the present invention. , Figure 6 is a view for explaining the molding process of the first carbon fiber sheet layer according to an embodiment of the present invention.

In addition, Figure 7 is a view for explaining the forming process of the second carbon fiber sheet layer according to an embodiment of the present invention, Figure 8 is a side view of Figure 7, Figure 9 is a shaft according to another embodiment of the present invention A cross-sectional view for explaining a tube, and FIG. 10 is a side cross-sectional view for explaining a shaft tube according to another embodiment of the present invention.

1 to 8, the CFRP drive shaft 100 for a vehicle according to an embodiment of the present invention is used to transmit the driving force of the transmission to the driving tire, one end is connected to the transmission and the other end is tire Is connected to the disk.

The CFR drive shaft 100 for a vehicle according to this embodiment includes a hollow shaft tube 110 formed of carbon fiber reinforced plastic (CFRP) to reduce weight, and the hollow shaft tube It includes a connection stub 120 coupled to each of both ends of (110). At this time, the shaft tube 110 and the connection stub 120 are coupled to each other through the press-fit fixing unit 130, and the connection stub 120 is connected to the transmission and the tire disk.

It is formed by a prepreg, one of the carbon fiber sheets 140, is formed through hot forming after winding the carbon fiber sheet 140 to a specific thickness. Specifically, the shaft tube 110 winds the carbon fiber sheet 140 on the circular shaft mold form 103, and the shaft mold form 103 on which the carbon fiber sheet 140 is wound is put into a hot mold or an autoclave. It is subjected to compression molding while applying heat.

At this time, the shaft tube 110 is wound so that the directions of fibers of the carbon fiber sheet 140 cross each other so that mechanical strength is further improved after hot forming.

For example, the shaft tube 110 is wound vertically to the shaft mold form 103 so that the fiber orientation of the carbon fiber sheet 140 is perpendicular to the axis of the shaft mold form 103. The formed first carbon fiber sheet layer 141 and the fiber orientation of the carbon fiber sheet 140 are wound on the outer surface of the first carbon fiber sheet layer 141 to be located at an inclined position with respect to the axis of the shaft mold form 103 It consists of a formed second carbon fiber sheet layer 143.

Here, in order to form the second carbon fiber sheet layer 143, the carbon fiber sheet 140 wound around the shaft mold form 103 is wound so that two of the carbon fiber sheets 140 cross each other. At this time, one carbon fiber sheet 140 and the other carbon fiber sheet 140 are wound to form an "X" shape when viewed from the top.

The shaft tube 110 according to the present embodiment may have a thickness of 5.0 mm, a length of 500 mm, and an outer diameter of ø45.

The prepreg according to this embodiment is a sheet-type product in which a matrix is pre-impregnated with reinforced fiber, and is semi-cured by infiltrating a thermosetting resin into carbon or reinforcing fiber as an intermediate material of a composite product. Provided in the state.

In addition, in this embodiment, the shaft tube 110 is molded using a prepreg with a carbon fiber sheet 140, but the carbon fiber sheet 140 is used as an aramid fabric, aramid laminating fabric, and ultra-high molecular weight. Any one selected from polyethylene (UHMWPE, Ultra High Molecular Weight Poly-Ethylene) UD and ultra high molecular weight polyethylene (UHMWPE, Ultra High Molecular Weight Poly-Ethylene) fibers may be used.

The shaft tube 110 formed as described above is closely coupled to the connection stub 120 through the press-fit fixing part 130.

Press-fit fixing parts 130 are respectively formed at both ends of the shaft tube 110 and press-fit into the connection stub 120 to be fixed, and a support embossing part 131 is formed so as to be more tightly and firmly coupled with the connection stub 120 do.

The press-fit fixing part 130 is formed so that the outer diameter gradually decreases toward the end so as to have an outer diameter smaller than the outer diameter of the shaft tube 110. At this time, the outer diameter of the end of the press-fit fixing part 130 may be formed to be ø38.

In addition, the press-fit fixing part 130 is press-fit into the connection stub 120 in a state in which the bonding resin layer is formed through the application of a thermosetting resin on the outer surface when bonded to the connection stub 120. In addition, as the connection stub 120 is coupled to the press-fit fixing part 130, it is thermoformed and the bonding resin layer is thermally cured, so that it is more firmly bonded to the press-fit fixing part 130 and the connection stub 120. At this time, thermal curing may be performed in a thermal chamber.

The support embossing portion 131 is formed at equal intervals along the circumferential direction in the press-fit fixing portion 130, and the thickness gradually increases toward the end of the shaft tube 110 and the outer surface area is widened.

Through this, the press-fitting fixing part 130 is more easily inserted into the connection stub 120, as well as its coupling force and support are improved. In particular, since the support embossing portion 131 is formed to be round, the edge does not occur at the contact portion between the press-fit fixing portion 130 and the connecting stub 120, so that when an external force is applied, the force is diffused while preventing the concentration of the force on one portion. It is possible to improve rigidity and durability.

The press-fit fixing part 130 and the support embossing part 131 according to the present embodiment may have a length L1 of 45 mm.

The connection stub 120 is coupled to both ends of the shaft tube 110 so as to be respectively connected to the transmission and the tire side of the engine side, and is formed of a metal material. This connection stub 120 has a shaft coupling groove portion 121 to which the press-fit fixing portion 130 is pressed, and a support groove portion 123 to which the support embossing portion 131 is coupled to the inner surface of the shaft coupling groove portion 121 Is formed. At this time, the shaft coupling groove 121 is formed to gradually decrease its inner diameter.

A method of manufacturing the CFR drive shaft 100 for a vehicle according to an embodiment of the present invention configured as described above will be described.

First, the carbon fiber sheet 140 is vertically positioned on the shaft mold form 103, and the carbon fiber sheet 140 is wound to a specific thickness by rotating the shaft mold form 103 to form the first carbon fiber sheet layer 141. To form. At this time, while the carbon fiber sheet 140 is wound in two or more layers on the mold foam 103, the first carbon fiber sheet layer 141 may be formed.

In addition, two carbon fiber sheets 140 are arranged inclined to be spaced apart on the surface of the first carbon fiber sheet layer 141, and the shaft mold foam 103 is rotated so that the two carbon fiber sheets 140 are replaced with the first carbon fiber. It is wound on the surface of the sheet layer 141.

In addition, one carbon fiber sheet 140 is wound by arranging the other carbon fiber sheet 140 to be inclined from the lower side of the shaft mold foam 103 on the upper side of the shaft mold foam 103. For example, one carbon fiber sheet 140 and the other carbon fiber sheet 140 are wound in a "X" shape when viewed from the top. At this time, the carbon fiber sheet 140 is wound in two or more layers on the mold form 103 to form a second carbon fiber sheet layer 143.

Through this, a second carbon fiber sheet layer 143 is formed on the surface of the first carbon fiber sheet layer 141. In addition, the carbon fiber sheet 140 is supplied using a carbon fiber winder.

Here, winding the carbon fiber sheet 140 at various angles is to prevent the strength of a specific area from becoming weak by making all parts of the shaft tube 110 have uniform strength by molding the fiber direction in various ways. .

Thereafter, the shaft mold foam 103 on which the second carbon fiber sheet layer 143 is formed is put into a hot mold apparatus, heat and pressure are applied to compress and thermoform, and the shaft tube 110 is molded by cooling.

Then, the shaft mold form 103 is demolded from the shaft tube 110, and a thermosetting resin is applied to the surface of the press-fit fixing part 130, and then press-fitting into the connection stub 120. Thereafter, the shaft tube 110 to which the connection stub 120 is coupled is inserted into the heat chamber to heat-cure the thermosetting resin applied to the press-fit fixing unit 130 to bond the shaft tube 110 and the connection stub 120.

When the shaft tube 110 is formed using carbon fiber reinforced plastic (CFRP), the carbon fiber reinforced plastic (CFRP) according to an exemplary embodiment of the present invention has the first fiber orientation of the carbon fiber sheet 140 to intersect. Since the carbon fiber sheet layer 141 and the second carbon fiber sheet layer 143 are wound, strength and durability may be further improved while reducing weight.

Next, referring to FIGS. 9 and 10, a CFR drive shaft for a vehicle according to another embodiment of the present invention will be described.

In describing the CFR drive shaft for a vehicle according to another embodiment, the same reference numerals are used for configurations that are the same as the CFR drive shaft for a vehicle according to an embodiment, and a detailed description thereof will be omitted.

9 is a cross-sectional view illustrating a shaft tube according to another embodiment of the present invention, and FIG. 10 is a side cross-sectional view illustrating a shaft tube according to another embodiment of the present invention.

As shown in FIGS. 9 and 10, in the CFR drive shaft 100 for a vehicle according to another embodiment of the present invention, a metal layer is formed by a metal foil 150 on the inner surface of the first carbon fiber sheet layer 141 do. For example, by winding a metal foil 150 having a thickness of 0.03 ~ 0.6mm on the shaft mold form 103 in one or two layers, and winding the carbon fiber sheet 140 on the metal foil 150, the first carbon The fiber sheet layer 141 is formed.

When a metal layer is formed using the metal foil 150 as described above, the shaft tube 110 has strong strength, so that it is not easily damaged by a large impact, and has excellent physical properties due to its high hardness.

In addition, when the metal foil 150 is wound on the shaft mold form 103, the first carbon fiber sheet layer 141 is formed with the metal foil 150 bonded to the inner surface of the carbon fiber sheet 140. It can also be formed.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is only illustrative, and those of ordinary skill in the field to which the technology pertains, various modifications and other equivalent embodiments are possible. I will understand.

Therefore, the true technical protection scope of the present invention should be determined by the claims.

100: vehicle CFR drive shaft 103: mold foam
110: shaft tube 120: connecting stub
121: shaft defect groove 123: support groove
130: press-fit fixing portion 131: support embossing portion
140: carbon fiber sheet 141: first carbon fiber sheet layer
143: second carbon fiber sheet layer 150: metal foil

Claims (4)

A connection stub each connected to a constant velocity joint disposed on the engine side and the wheel side, respectively, and formed of a metal material; And press-fitting fixing portions in which one end and the other end are press-fitted to the connection stub, and support embossing portions are formed at equal intervals along the circumferential direction of the press-fit fixing portion, and carbon fiber reinforced plastic (CFRP) material is hot Includes; a hollow shaft tube formed by molding,
The shaft tube may include a first carbon fiber sheet layer formed by winding a carbon fiber sheet along a longitudinal direction of the shaft mold form so as to be perpendicular to the axis of the circular shaft mold form; And a second carbon fiber sheet layer formed by winding the carbon fiber sheet obliquely from the outer surface of the first carbon fiber sheet layer to the outer surface so as to be inclined with respect to the axis of the shaft mold form, and
The press-fit fixing portion gradually decreases as it goes toward the end so as to have an outer diameter smaller than the outer diameter of the shaft tube,
The support embossing unit, a vehicle CFR drive shaft, characterized in that the thickness gradually increases toward the end of the shaft tube, and the outer surface area is widened.
delete The method of claim 1,
The shaft tube is a vehicle CFR drive shaft, characterized in that a thermosetting resin is applied to the outer surface of the press-fit fixing part, is press-fitted to the connection stub, and bonded to the connection stub through thermal curing.
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