WO2005009824A1

WO2005009824A1 - Steering wheel and method of manufacturing the same

Info

Publication number: WO2005009824A1
Application number: PCT/KR2004/001775
Authority: WO
Inventors: Man-Ho Cho
Original assignee: Hwajin Tech Co., Ltd.
Priority date: 2003-07-25
Filing date: 2004-07-16
Publication date: 2005-02-03
Also published as: KR20030066573A

Abstract

Provided is a steering wheel having a surface on which heat wires are plated and a method of manufacturing the steering wheel. The steering wheel includes a boss coupled to a steering column, and a rim portion connected to the boss by a spoke, in which a heat conductor is plated on a surface of the rim portion in a predetermined pattern and heated by a power supplied thereto. A transfer sheet is transferred by a water pressure to a plated heat conductor and a surface of a body of the rim portion. Thus, a high quality steering wheel is obtained by the transfer sheet on which a predetermined pattern is formed. Heat conductivity of the plated heat conductor due to a thin transfer sheet makes the steering wheel warm. .

Description

Description STEERING WHEEL AND METHOD OF MANUFACTURING THE SAME Technical Field

[1] The present invention relates to a steering wheel and a method of manufacturing the same, and more particularly, to a steering wheel which stably maintains a heat conductor on a surface of a rim of the steering wheel and quickly transfer heat generated from the heat conductor to a driver, and to a method of manufacturing the same. Background Art

[2] A steering wheel which can dissipate heat to make driver's hands warm during a winter season or when necessary has been known.

[3] Korean Patent Publication No. 2001-0100408 discloses an example of a steering wheel including a heat wire, which is shown in FIGS. 1 and 2.

[4] Referring to FIGS. 1 and 2, a steel frame 1 constituting a core member of a rim portion of the steering wheel for an automobile is wrapped with plastic rein 2 and heat wires 3 are embedded in the plastic resin 2.

[5] The heat wires 3 are connected to a control box 5 including a temperature set άrcuit and a relay. A power 7 is supplied to or cut off from the control box 5 by a switch 6. A temperature detection sensor 4 is provided in the plastic resin 2 to measure driver's temperature throigh the hands of the driver so that the power 7 is turned on or off.

[6] The steering wheel provides a warm sensation to the driver throigh the heated heat wires 3 in a winter season, but has the following problems.

[7] First, the steering wheel is manufactured by first forming the plastic resin 2 around the steel frame 1, arranging in parallel the heat wires 3 on a surface of a first plastic resin, and finally coating the surface of the first plastic resin having the heat wires 3 arranged thereon, with a second plastic resin. In this case, the transfer speed of heat generated from the heat wires 3 is reduced by the second plastic resin. As a result, it takes a long time to heat the surface of the steering wheel by the heat generated from the heat wires 3 after starting an automobile in a winter season. Thus, such a delay degrades reliability of a product.

[8] Second, when the second plastic resin is formed after the heat wires 3 are arranged on the surface of the plastic resin 2, the interval between the heat wires 3 may change so that a difference in temperature occurs partially on the surface of the steering wheel. Thus, such a difference in temperature may prevent the driver from safe driving.

[9] Third, since the steering wheel is formed by arranging the heat wires 3 in a coil shape around the surface of the first plastic resin and coating the second plastic resin around the outer circumferential surface of the first plastic resin having the heat wires 3 wound thereon, the first and second plastic resins are separated from each other due to a twist of the second plastic resin during driving and the heat wires 3 may be deformed. Disclosure of Invention Technical Problem

[10] To solve the above and other problems, the present invention provides a steering wheel having an improved heat transfer speed from the heat wires to the surface of the steering wheel, and a method of manufacturing the same.

[11] Also, the present invention provides a steering wheel in which the heat wires are stably maintained at a constant interval, and a method of manufacturing the same.

[12] Also, the present invention provides a steering wheel which prevents deformation of the heat wires during driving so that a malfunction rate is much decreased, and a method of manufacturing the same. Technical Solution

[13] According to an aspect of the present invention, there is provided a steering wheel comprising a boss coupled to a steering column and a rim portion connected to the boss by a spoke, wherein a heat conductor is plated on a surface of the rim portion in a predetermined pattern and heated by a power supplied thereto.

[14] A transfer sheet is transferred to the surfaces of the plated heat conductor and the rim portion by a water pressure. In this case, the steering wheel can be made luxurious by the transfer sheet having a predetermined pattern formed therein and the transfer speed of heat generated from the heat conductor is increased owing to the thin transfer sheet so that a drive can drive while grapping a warm steering wheel in a winter season.

[15] A primer layer, which is adhesive, is further provided between the surfaces of the heat conductor and the rim portion and the transfer sheet. A primer is used for the primer layer which improves a degree of adhesion between the transfer sheet and the heat conductor and the rim portion and prevents corrosion of the heat conductor during water pressure transfer.

[16] The heat conductor is deposition-plated in a vacuum state by utilizing plasma and formed of one or two or more elements selected from a group consisting of aluminum (Al), stainless (SUS), nickel (Ni), copper (Cu) and chromium (Cr).

[17] An outer circumferential surface of the rim portion is wrapped with leather.

[18] According to another aspect of the present invention, there is provided a method of manufacturing a steering wheel including a boss coupled to a steering column and a rim portion connected to the boss by a spoke, in which a heat conductor heated by a power supplied thereto is formed on the rim portion, wherein the heat conductor is plated on a surface of the rim portion.

[19] The heat conductor is formed of one or two or more elements selected from a group consisting of aluminum (Al), stainless (SUS), nickel (Ni), copper (Cu) and chromium (Cr). In the plating step, the heat conductor is deposited in a vacuum state by utilizing plasma.

[20] Before the plating step, further comprising a step of attaching a masking tape where a connection hole is formed in a predetermined pattern, on the surface of the rim portion, so that the heat conductor is plated on the rim portion along the connection hole of the masking tape.

[21] The method further comprises a step of transferring a transfer sheet to the surfaces of the heat conductor and the rim portion by a water pressure. Before the water pressure transfer step, further comprising a step of forming a primer layer, which is adhesive, on the surface of the heat conductor and the rim portion. Thus, the corrosion of the heat conductor is prevented and a degree of adhesion between the heat conductor and the transfer sheet is improved.

[22] The method further comprises a step of wrapping an outer circumferential surface of the transferred transfer sheet with a finishing material.

[23] According to another aspect of the present invention, there is provided a steering wheel which comprises a boss coupled to a steering column, a rim portion connected to the boss by a spoke and having at least one pair of a first rim portion and a second rim portion which are connected each other while maintaining a predetermined gap, a heat conductor plated on each of surfaces of the first and second rim portions in a predetermined pattern, a connection port electrically connecting the heat conductors formed on the first and second rim portions, and a power supply portion supplying power to the heat conductor to heat the heat conductor.

[24] A primer layer, which is adhesive, is formed on the surface of the first rim portion, a transfer sheet is transferred to a surface of the primer layer by a water pressure, and an outer circumferential surface of the second rim portion is wrapped with a finishing material.

[25] The heat conductor is formed of one or two or more elements selected from a group consisting of aluminum (Al), stainless (SUS), nickel (Ni), copper (Cu) and chromium (Cr).

[26] According to yet another aspect of the present invention, there is provided a method of manufacturing a steering wheel including a boss coupled to a steering column and a rim portion connected to the boss by a spoke, the method comprising the steps of forming a first rim portion which is hard and constitutes part of the rim portion, forming a second rim portion which is soft and constitutes the remaining part of the rim portion, so as to maintain a predetermined gap with the first rim portion, plating a heat conductor on surfaces of the first rim portion and the second rim portion, electrically connecting the heat conductors formed on the first and second rim portions, and electrically connecting a power supply portion to heat the heat conductor by supplying power to the heat conductor, to the heat conductor.

[27] The heat conductor is formed of one or two or more elements selected from a group consisting of aluminum (Al), stainless (SUS), nickel (Ni), copper (Cu) and chromium (Cr).

[28] Before the plating step, further comprising a step of attaching a masking tape where a connection hole is formed in a predetermined pattern, on the surfaces of the first and second rim portions, so that the heat conductor is plated on the surfaces of the first and second rim portions along the connection hole of the masking tape.

[29] The method further comprises steps of coating a primer layer, which is adhesive, on the surface of the first rim portion where the heat conductor is plated, and transferring a transfer sheet having a predetermined pattern formed therein on a surface of the primer layer by a water pressure and wrapping an outer circumferential surface of the second rim portion with a finishing material.

[30] The heat conductor is plated by electrolysis and the heat conductor is plated by electrolysis. Description of Drawings

[31] FIGS. 1 and 2 are views illustrating the conventional steering wheel;

[32] FIGS. 3 throigh 5 are perspective views illustrating steering wheels according to preferred embodiments of the present invention;

[33] FIGS. 6A throigh 6G are views for explaining a method of manufacturing a steering wheel according to a preferred embodiment of the present invention;

[34] FIGS. 7A throigh 7F are views for explaining a method of manufacturing a steering wheel according to another preferred embodiment of the present invention; and

[35] FIG. 8 is a sectional view illustrating a transfer sheet used for the steering wheel according to the present invention. Mode for Invention

[36] A steering wheel for an automobile according to a preferred embodiment of the present invention includes heat wires heated as a power is supplied so that the steering wheel is heated in a winter season or when necessary to provide a warm sensation to a driver. Also, the heat wires are formed by plating a surface of the steering wheel with a heat conductor to be thin and a transfer sheet is transferred onto the surface in a water pressure method. Thus, when the heat wires are heated, the transfer speed of heat increases so that the driver can feel warmth at the initial stage of driving.

[37] FIGS. 3 throigh 5 show completed steering wheels according to preferred embodiments of the present invention.

[38] In a steering wheel 10 shown in FIG. 3, heat wires are deposition-plated and a transfer sheet is transferred to the entire surface of a rim portion thereof in a water pressure method. In a steering wheel 20 shown in FIG. 4, heat wires are deposition- plated on a surface of a rim portion of a steering wheel 20 and the surface of the rim portion is wrapped with a finishing material such as leather.

[39] In a steering wheel 30 shown in FIG. 5, a rim portion of the steering wheel 30 is formed by a first rim portion that is hard and a second rim portion that is soft. Heat wires are deposition-plated on surfaces of the first and second rim portions in a predetermined pattern. A transfer sheet is transferred to the surface of the first rim portion in a water pressure method while the second rim portion is wrapped with a finishing material such as leather.

[40] The steering wheels according to the preferred embodiments of the present invention and methods of manufacturing the same are sequentially described below in detail.

[41] Referring to FIGS. 3 throigh 6G, the steering wheel 10 includes a boss 11 coupled to a steering column (not shown) and a rim portion 13 connected to the boss 11 by a spoke 12. A heat conductor 61 is plated on a surface of the rim portion 13 in a predetermined pattern. The heat conductor 61 is connected to a power supply portion (not shown) for supplying power to heat the heat conductor 61, so as to be electrically connected or disconnected.

[42] As the power supply portion, a typical battery used for a car to drive an airbag or horn is used.

[43] A transfer sheet 80 is transferred to the surfaces of the plated heat conductor 61 and the rim portion 13 in a water pressure method as shown in FIGS. 6E throigh 6G. In this case, the transfer sheet 80 on which a predetermined pattern is formed makes the steering wheel 10 luxurious. Also, since the transfer sheet 80 is thin, heat generated form the plated heat conductor 61 can be quickly transferred so that the steering wheel 10 can be warmed during driving in a winter season.

[44] In the steering wheel 10 according to a preferred embodiment of the present invention, a primer layer 70, which is adhesive, is coated between the transfer sheet 80 and the surfaces of the heat conductor 61 and the rim portion 13. A primer is used for the primer layer 70, which enhances a degree of adhesion between the transfer sheet 80, the heat conductor 61, and the rim portion 13 and prevents corrosion of the heat conductor 61 during a water pressure transfer.

[45] The plating is formed by depositing the heat conductor 61 by utilizing plasma in a vacuum state. As the heat conductor 61, one or two or more elements of aluminum (Al), stainless (SUS), nickel (Ni), copper (Cu) or chromium (Cr) are selected and deposited.

[46] For example, if aluminum alone is deposited, deposition could be made easy. However, since the deposition is easily oxidized in air, it is preferable to mix aluminum and stainless and deposit the mixture.

[47] Also, the plating pattern can be formed zigzag as shown in FIG. 6D or on the entire surface of the rim portion 13.

[48] In a method of manufacturing the steering wheel 10 having the above structure, the heat conductor 61 is plated on the surface of the rim portion 13, a power supply portion for supplying power electrically is connected to the heat conductor 61, and i a switch (not shown) for supplying or cutting off the power is installed between the power supply portion (not shown) and the heat conductor 61.

[49] A typical battery which is used for an automobile to drive an airbag or a horn is used as the power supply portion. A supply wire is drawn from the battery to connect the heat conductor 61 and a switch to open/shut the power is installed.

[50] A method of manufacturing the steering wheel 10 is described in detail with reference to FIGS. 6 A throigh 6G.

[51] First, as shown in FIG. 6 A, a masking tape 40 where a connection hole 41 in a predetermined pattern is attached on the surface of the rim portion 13. As shown in FIG. 6B, one or two or more elements are selected from aluminum (Al), stainless (SUS), nickel (Ni), copper (Cu) or chromium (Cr) and deposition-plated by utilizing plasma in a vacuum state. During the deposition-plating, the steering wheel 10 is rotated or revolved so that the deposition plating can be performed uniformly on the rim portion 13. Here, the entire surface of the rim portionl3 can be plated without using the masking tape 40.

[52] When the deposition process is completed, as shown in FIG. 6C, the masking tape 40 is removed so that the pattern of the heat conductor 61 deposited along the connection hole 41. After metal is completely deposited on the surface of the rim portion 13 along the connection hole 41, as shown in FIG. 6D, the primer layer 70 is coated on the surfaces of the rim portion 13 and the deposited heat conductor 61. The primer layer 70 enhances a degree of adhesion between the rim portion 13 and the heat conductor 61 and the transfer sheet 80 in a post process and prevents corrosion of the heat conductor 61.

[53] Next, as shown in FIGS. 6E and 6F, the transfer sheet 80 floats on a water surface and the rim portion 13 coated with the primer layer 70 is lowered so that the transfer sheet 80 is transferred to the surface of the rim portion 13 by a water pressure. The transfer sheet 80, as shown in FIG. 8, includes a print layer 81 where a predetermined pattern is printed and a polyvinyl alcohol (PVA) layer 82.

[54] In the transfer process, after an activating agent like thinner activates an upper surface of the transfer sheet 80 floating on the water surface, when the rim portion 13 is lowered onto the water surface, as shown in FIG. 6G, the transfer sheet 80, or actually the print layer 81, is transferred to the surface of the rim portion 13 by the water pressure.

[55] Referring to FIG. 4, which shows the steering wheel 20 according to another preferred embodiment of the present invention, the heat conductor 61 is deposition- plated on the surface of the rim portion 13 by utilizing plasma as shown in FIG. 6C and the outer circumferential surface of the rim portion 13 is wrapped with leather. As shown in FIG. 6G, after the transfer sheet 80 is transferred to he surfaces of the rim portion 13 and the heat conductor 61, the outer circumferential surface can be wrapped with leather.

[56] Referring to FIG. 5, which shows the steering wheel 30 according to yet another preferred embodiment of the present invention, and referring to FIG. 7F, which is a sectional view illustrating major portions of the steering wheel 30 of FIG. 5, a rim portion 33 of the steering wheel 30 includes a first rim portion 31 and a second rim portion 32 which are connected each other while maintaining a predetermined gap. [57] The first rim portion 31 is formed of hard urethane while the second rim portion 32 is formed of soft urethane. Finally, the transfer sheet 80 on which a pattern such as a wood pattern is printed is transferred to the outer circumferential surface of the first rim portion 31 so as to provide a sense of grapping an actual wood during driving. The second rim portion 32 is wrapped with leather 36, thus enhancing a sense of cushion.

[58] The heat conductor 61 is formed on the surfaces of the first and second rim portions 31 and 32 in a predetermined pattern. The heat conductors 61 of the first and second rim portions 31 and 32 are electrically connected by a connection port 34 between the first and second rim portions 31 and 32.

[59] The heat conductor 61 is deposited in a vacuum state by utilizing plasma. As the heat conductor 61, one or two or more elements of aluminum (Al), stainless (SUS), nickel (Ni), copper (Cu), or chromium (Cr) are selected and deposited. The primer layer 70 is coated on the surface of the first rim portion 31 where the heat conductor 61 is formed. The transfer sheet 80 is transferred to the outer circumferential surface of the primer layer 70.

[60] Also, the outer circumferential surface of the second rim portion 32 where the heat conductor 61 is wrapped with the leather 36. A typical battery which is used for an automobile to drive an airbag or a horn is used as a power supply portion (not shown) for supplying power to the heat conductor 61 to heat the same.

[61] A method of manufacturing the steering wheel 30 according to the above preferred embodiment shown in FIG. 5 is described below.

[62] First, as shown in FIG. 7 A, the first rim portion 31 that is hard and constitutes part of the rim portion 33 is formed around a core rim 35 which is a frame of the steering wheel rim. Then, the second rim portion 32 that is soft and constitutes the remaining portion of the rim portion 33 is formed while maintaining a predetermined gap with the first rim portion 31.

[63] Next, in the subsequent process, the connection port 34 electrically connecting the heat conductors 61 plated on the first and second rim portions 31 and 32 is installed. One end of the connection port 34 is forcibly inserted in an end portion of the second rim portion 32 formed of soft urethane to be fixed therein while the other end of the connection port 34 contacts the surface of the first rim portion 31.

[64] As shown in FIGS. 6 A and 7B, the masking tape 40 having the connection hole 41 formed therein is attached on the outer circumferential surface of the rim portion33 and, as shown in FIG. 6B, a heat conductor is deposition-plated by utilizing plasma in a vacuum chamber. The heat conductor is deposited by selecting one or two or more elements of aluminum (Al), stainless (SUS), nickel (Ni), copper (Cu) or chromium (Cr).

[65] When the masking tape 40 is removed after the deposition-plating is completed, as shown in FIG. 7C, the heat conductor 61 is deposition-plated in a predetermined pattern on the surfaces of the first and second rim portions 31 and 32. The heat conductors 61 of the first and second rim portions 31 and 32 are electrically connected by the connection port 34.

[66] Next, the transfer sheet 80 is transferred to the surface of the first rim portion 31 ad the surface of the second rim portion 32 is wrapped with leather.

[67] First, as shown in FIG. 7D, the primer layer 70, which is adhesive, is coated on the surface of the first rim portion 31 where the heat conductor 61 is plated. As shown in FIG. 7E, the transfer sheet 80 where a predetermined pattern is formed is transferred to the surface of the primer layer 70 by water pressure. Lastly, as shown in FIG. 7F, the outer circumferential surface of the second rim portion 32 is wrapped with the leather 36.

[68] In the above preferred embodiments, the thickness of deposition of the heat conductor 61 is shown exaggerated in the drawings for the convenience of explanation. The actual thickness of deposition may be several micrometers.

[69] The present invention is not limited to the above-described preferred embodiments and may be modified in various ways within a scope of the technical concept of the present invention. For example, in the steering wheel according to the present invention and a method of manufacturing the same, the heat conductor maybe plated by electrolysis. Also, althoigh in the above description the material of the heat conductor is limited to aluminum (Al), stainless (SUS), nickel (Ni), copper (Cu) or chromium (Cr), the present invention is not limited thereto and any material capable of conducting electricity can be used therefor.

[70] Furthermore, instead of the transfer sheet, a thin wood laminate may wrap the surface of the plated heat conductor. Also, althoigh the masking tape is used to form a pattern of the heat conductor in the above preferred embodiments, the heat conductor can be formed by plating the entire surface of the rim portion without using the masking tape. Industrial Applicability

[71] As described above, according to the steering wheel according to the present invention and a method of manufacturing the same, since the heat conductor is deposition-plated on the surface of the rim portion, the transfer speed of heat is remarkable improved so that the speed of heating the steering wheel at the initial stage of driving in a winter season gets faster, thus providing convenience to a driver and improving reliability of a product.

[72] Also, since the heat conductor is attached to the surface of the rim portion by plating using deposition, the heat conductor can be stably maintained. Since the deformation of the heat conductor during driving is prevented, a malfunction rate is greatly reduced.

[73] Furthermore, since the surface of the plated heat conductor is finished with the transfer sheet or the thin wood laminate, the steering wheel is made luxurious and the quality of a product is improved.

Claims

[I] 1. A steering wheel comprising: a boss coupled to a steering column; and a rim portion connected to the boss by a spoke, wherein a heat conductor is plated on a surface of the rim portion in a predetermined pattern and heated by a power supplied thereto.

[2] 2. The steering wheel as claimed in claim 1, wherein a transfer sheet is transferred to the surfaces of the plated heat conductor and the rim portion by a water pressure.

[3] 3. The steering wheel as claimed in claim 2, wherein a primer layer, which is adhesive, is further provided between the surfaces of the heat conductor and the rim portion and the transfer sheet.

[4] 4. The steering wheel as claimed in any of claims 1 throigh 3, wherein the heat conductor is deposition-plated in a vacuum state by utilizing plasma.

[5] 5. The steering wheel as claimed in claim 4, wherein the heat conductor is formed of one or two or more elements selected from a group consisting of aluminum (Al), stainless (SUS), nickel (Ni), copper (Cu) and chromium (Cr).

[6] 6. The steering wheel as claimed in either claim 1 or claim 2, wherein an outer circumferential surface of the rim portion is wrapped with leather.

[7] 7. A method of manufacturing a steering wheel including a boss coupled to a steering column and a rim portion connected to the boss by a spoke, in which a heat conductor heated by a power supplied thereto is formed on the rim portion, wherein the heat conductor is plated on a surface of the rim portion.

[8] 8. The method as claimed in claim 7, before the plating step, further comprising a step of attaching a masking tape where a connection hole is formed in a predetermined pattern, on the surface of the rim portion, so that the heat conductor is plated on the rim portion along the connection hole of the masking tape.

[9] 9. The method as claimed in either claim 7 or claim 8, further comprising a step of transferring a transfer sheet to the surfaces of the heat conductor and the rim portion by a water pressure.

[10] 10. The method as claimed in claim 9, before the water pressure transfer step, further comprising a step of forming a primer layer, which is adhesive, on the surface of the heat conductor and the rim portion.

[I I] 11. The method as claimed in claim 10, further comprising a step of wrapping an outer circumferential surface of the transferred transfer sheet with a finishing material.

[12] 12. The method as claimed in either claim 7 or claim 8, wherein the heat conductor is formed of one or two or more elements selected from a group consisting of aluminum (Al), stainless (SUS), nickel (Ni), copper (Cu) and chromium (Cr).

[13] 13. The method as claimed in either claim 7 or claim 8, wherein, in the plating step, the heat conductor is deposited in a vacuum state by utilizing plasma.

[14] 14. A steering wheel comprising: a boss coupled to a steering column; a rim portion connected to the boss by a spoke and having at least one pair of a first rim portion and a second rim portion which are connected each other while maintaining a predetermined gap; a heat conductor plated on each of surfaces of the first and second rim portions in a predetermined pattern; a connection port electrically connecting the heat conductors formed on the first and second rim portions; and a power supply portion supplying power to the heat conductor to heat the heat conductor.

[15] 15. The steering wheel as claimed in claim 14, wherein a primer layer, which is adhesive, is formed on the surface of the first rim portion, a transfer sheet is transferred to a surface of the primer layer by a water pressure, and an outer circumferential surface of the second rim portion is wrapped with a finishing material.

[16] 16. The steering wheel as claimed in either claim 14 or 15, wherein the heat conductor is deposition-plated in a vacuum state by utilizing plasma.

[17] 17. The steering wheel as claimed in either claim 14 or 15, wherein the heat conductor is formed of one or two or more elements selected from a group consisting of aluminum (Al), stainless (SUS), nickel (Ni), copper (Cu) and chromium (Cr).

[18] 18. A method of manufacturing a steering wheel including a boss coupled to a steering column and a rim portion connected to the boss by a spoke, the method comprising the steps of: forming a first rim portion which is hard and constitutes part of the rim portion; forming a second rim portion which is soft and constitutes the remaining part of the rim portion, so as to maintain a predetermined g^p with the first rim portion; plating a heat conductor on surfaces of the first rim portion and the second rim portion; electrically connecting the heat conductors formed on the first and second rim portions; and electrically connecting a power supply portion to heat the heat conductor by supplying power to the heat conductor, to the heat conductor.

[19] 19. The method as claimed in claim 18, wherein in the plating step the heat conductor is deposited in a vacuum state by utilizing plasma.

[20] 20. The method as claimed in either claim 18 or claim 19, before the plating step, further comprising a step of attaching a masking tape where a connection hole is formed in a predetermined pattern, on the surfaces of the first and second rim portions, so that the heat conductor is plated on the surfaces of the first and second rim portions along the connection hole of the masking tape.

[21] 21. The method as claimed in claim 20, further comprising a step of coating a primer layer, which is adhesive, on the surface of the first rim portion where the heat conductor is plated, and transferring a transfer sheet having a predetermined pattern formed therein on a surface of the primer layer by a water pressure.

[22] 22. The method as claimed in claim 20, wherein the heat conductor is formed of one or two or more elements selected from a group consisting of aluminum (Al), stainless (SUS), nickel (Ni), copper (Cu) and chromium (Cr).

[23] 23. The method as claimed in claim 21, further comprising a step of wrapping an outer circumferential surface of the second rim portion with a finishing material.

[24] 24. The steering wheel as claimed in any of claims 1, 2, 3, 14, and 15, wherein the heat conductor is plated by electrolysis.

[25] 25. The method as claimed in any of claims 7, 8, and 18, wherein the heat conductor is plated by electrolysis.