[invention Title] ELECTRO POLISHING COMBINED ELECTRIC PLATING APPARATUS AND ELECTROLESS PLATING APPARATUS USING THE SAME [Technical Field] The present invention relates to a plating, and more particularly, to an electro polishing combined electric plating apparatus. Also, the present invention relates to an electroless plating system having an electro polishing combined electric plating apparatus and an electroless plating apparatus. [Background Art] Since fluorine resin has characteristics, such as a strong endurance capability against chemicals, a superior electrical properties, a high temperature stability, it is generally coated on surfaces of mechanical parts, electrical and electronic parts, and the like. Prior to coating such a fluorine resin film on a workpiece, a process for roughening a surface of the workpiece is performed so as to enhance the adhesivity of the fluorine resin film to the surface of the workpiece. The conventional fluorine resin film coating is performed using an electric plating apparatus or an electroless plating apparatus. However, the conventional plating apparatuses have a drawback that when the workpiece shaped in a pipe is 1 in or more long, the fluorine resin film is not uniformly coated throughout the entire surface of the workpiece. Also, the conventional electroless plating apparatus for forming only an electroless plating film on a workpiece has a drawback that when the workpiece is made of a noble metal, a stainless steel or an aluminum alloy, the possibility of the occurrence of pin holes in the surface of the workpiece increases and accordingly the plated film is easily delaminated. [Disclosure] [Technical Problem] Accordingly, the present invention is provided to solve the above problems, and an object of the present invention is to provide an electro polishing combined electric plating apparatus and an electroless plating apparatus using the same that can be applied to a workpiece shaped in a pipe made of a noble metal, a stainless steel or an aluminum alloy. Another object of the present invention is to provide an electro polishing combined electric plating apparatus and an electroless plating apparatus using the same that can enhance the adhesivity of the plating film to the surface of the workpiece by suppressing the occurrence of pin holes between the plating film and the workpiece. [Technical Solution] To accomplish the above objects, there is provided an electro polishing combined electric plating apparatus comprising: a transferring means transferring a plating target along an inner passage of a workpiece shaped in a pipe dipped in an electrolyte; and a workpiece transferring unit applying a positive voltage to the plating target connected with the transferring means and a negative voltage to the workpiece or applying a negative voltage to the plating target and a positive voltage to the workpiece and transferring the workpiece.

lOPreferably, the workpiece is made of a material selected from the group consisting of a noble metal, a stainless steel and a molybdenum steel, and is at least 1 m long. In another aspect of the present invention, there is provided a plating apparatus comprising: an electro polishing combined electric plating apparatus including: a first transferring means transferring a plating target along an inner passage of a workpiece shaped in a pipe dipped in an electrolyte; and a workpiece transferring unit applying a positive voltage to the plating target connected with the transferring means and a negative voltage to the workpiece or applying a negative voltage to the plating target and a positive voltage to the workpiece and transferring the workpiece; and an electroless plating apparatus for forming at least one layer of electroless plating film on a surface of the workpiece which has bee subject to an electro polishing and/or an electro plating. Preferably, the electroless plating apparatus includes a second workpiece transferring means for transferring the workpiece with holding the workpiece perpendicularly or at a predetermined slope with respect to a horizontal surface of the electrolyte. Preferably, the second workpiece transferring means has a function for rotating the workpiece. Alternatively, the above plating apparatus further include a temperature maintaining means for maintaining the electrolyte at a constant temperature. Preferably, the temperature maintaining means includes: an outer bath enclosing an inner bath in which the electrolyte is received, and receiving a heat transfer oil; and a cooling and heating unit disposed below the inner bath, for cooling and heating the inner bath at a predetermined temperature. [Adbantageous Effects] According to the present invention, the occurrence of pin holes between the plating film and the workpiece shaped in a pipe made of a noble metal, a stainless steel or a molybdenum steel can be suppressed to form an electric plating film or an electroless plating film having a high adhesivity to the workpiece. [Description of Drawings] FIG. 1 is a schematic view of an electro polishing combined electric plating apparatus according to an embodiment of the present invention. FIG. 2 is a schematic view of an electroless plating apparatus according to another embodiment of the present invention. FIG. 3 is a schematic view of an electroless plating apparatus according to another embodiment of the present invention. [Best Mode] Hereinafter, preferred embodiments of an electro polishing combined electric plating apparatus and an electroless plating apparatus using the same will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic view of an electro polishing combined electric plating apparatus according to an embodiment of the present invention. Referring to FIG. 1, the electro polishing combined electric plating apparatus 10 includes a transferring unit 13 for transferring a plating target 14 along an inner passage of a workpiece 16 shaped in a pipe dipped in an electrolyte solution contained in an electrolyte bath 11, and a workpiece transferring unit 18 applying a positive voltage to the plating target 14 connected with the transferring unit 13 and a negative voltage to the workpiece 16 or applying a negative voltage to the plating target 14 and a positive voltage to the workpiece 16 and transferring the workpiece 16. To use the electro polishing combined electric plating apparatus 10 as an electric plating apparatus, a negative voltage is applied to the workpiece 16 and a positive voltage is applied to plating targets 14, 15, as shown in FIG. 1. As the negative and positive voltages are applied to the workpiece 16 and the plating targets 14, 15, metal ions are ionized from the plating targets 14, 15 and are precipitated on a surface of the workpiece 16 to form a plating film. The plating film is formed at a uniform thickness on an inner surface of the workpiece 16, which is due to the operation that the plating target 14 is transferred along the inner passage of the workpiece 16 during the electric plating. In other words, by transferring the plating target 14 along the inner passage of the workpiece 16, the metal ions ionized from the plating tart 14 has a shortened precipitation path from the plating target 14 to the inner surface of the workpiece 16, which results in the uniform thickness of the plating film. Although not shown in FIG. 1, in order to use the electro polishing combined electric plating apparatus 10 as an electro polishing apparatus, a positive voltage is applied to the workpiece 16 and a negative voltage is applied to the plating target 14, 15. As the positive and negative voltages are applied to the workpiece 16 and the plating targets 14, 15, metal ions are ionized from the workpiece 16 and are precipitated on a surface of the plating target 14, 15. Resultantly, the surface of the workpiece 16 is electro-polished. In the electric plating or electro polishing operation, it is preferable that the workpiece 16 be made of a material selected from the group consisting of a noble metal, a stainless steel, and a molybdenum steel. Also, the above electro polishing combined electric plating apparatus 10 is applicable regardless of the length of the workpiece 16. In particular, it is more effective when the workpiece 16 is at least 1 m long. In FIG. 1, non-described reference numeral 24 is a pump which is used to feed electrolyte 12 to the electrolyte bath 11, and non-described reference numeral 22 is a filtering unit, which filters the overflowing electrolyte 12 such that the electrolyte 12 overflowing from the electrolyte bath 11 can be re-used. FIG. 2 is a schematic view exemplarily showing an electroless plating apparatus used in combination with the electro polishing combined electric plating apparatus of FIG. 1. Referring to FIG. 2, the electroless plating apparatus 40 includes a workpiece transferring unit 45 for transferring the workpiece 16 with perpendicularly holding the workpiece 16 shaped in a pipe dipped in an electrolyte solution 43 contained in a first inner bath 41, a temperature maintaining unit (not shown) for maintaining the electrolyte solution 43, 53 at a constant temperature, pumps 46, 56 for feeding the electrolyte 43, 53 from the first inner bath 41 to a second inner bath 51 or from the second inner bath 51 to the first inner bath 41, and filtering units 47, 57 for filtering the electrolyte solution fed to the first inner bath 41 or the second inner bath 51. Herein, the second inner bath 51 is an auxiliary tank containing the electrolyte to be fed to the first inner bath 41. The temperature maintaining unit includes first and second outer baths 42 and 52 enclosing the first and second inner baths 41 and 51 and containing heat transfer oil 48 therein, and a cooling and heating unit disposed below the first and second inner baths 41 and 51, for cooling or heating the first and second inner baths 41 and 51 to a predetermined temperature. Meanwhile, the electroless plating apparatus 60 shown in FIG. 3 includes a workpiece transferring and rotating unit 65 for transferring and rotating the workpiece 16 shaped in a pipe dipped in an electrolyte solution 63 contained in a first electroless plating inner bath 61 with holding the workpiece 16 at a predetermined angle with respect to a horizontal plane, a temperature maintaining unit for maintaining the electrolyte solution 63, 73 at a constant temperature, pumps 66, 76 for feeding the electrolyte solution 63, 73 from the first electroless plating inner bath 61 to a second electroless plating inner bath 71 or vise versa, and filtering units 67, 77 for filtering the electrolyte 63, 73 fed to the first electroless plating inner bath 61 or the second electroless plating inner bath 71. The temperature maintaining unit includes first and second electroless plating outer baths 62 and 72 enclosing the first and second inner electroplating inner baths 61 and 71 containing the electrolyte solution 63, 73 and containing heat transfer oil 68 therein, and cooling and heating units 69 and 79 disposed below the first and second electroless plating inner baths 61 and 71, for cooling or heating the first and second electroless plating inner baths 61 and 71 to a predetermined temperature. As aforementioned, unlike in the electroless plating apparatus 40 of FIG. 2, in the electroless plating apparatus 60 of FIG. 3, the workpiece 16 is disposed inclined at a predetermined angle with respect to a horizontal plane of the electrolyte solution 63, and the workpiece transferring and rotating unit 65 rotates the workpiece while the electroless plating is performed. The inclined arrangement and rotation of the workpiece 16 allow the electroless plating film to be formed on the surface of the workpiece at a uniform thickness. It is possible to form an electroless plating film using the electro polishing combined electric plating apparatus of FIG. 1 in combination with the electroless plating apparatus of FIG. 2 or FIG. 3. Hereinafter, a method of forming an electroless plating film using the electro polishing combined electric plating apparatus of FIG. 1 in combination with the electroless plating apparatus of FIG. 2 or FIG. 3 will be described. First, a surface of the workpiece is electro-polished using the electro polishing combined electric plating apparatus of FIG. 1. Specifically, a positive voltage is applied to the workpiece 16 that is a first electrode such that the workpiece 16 serves as an anode, and a negative voltage is applied to the plating target that is a second electrode such that the second electrode 14 serves as a cathode. As the positive and negative voltages are applied to the workpiece 16 and the plating targets 14, the surface of the workpiece 16 is electro-polished. Specifically, the surface of the workpiece 16 before the electro polishing is performed has a structure that convex portions and concave portions are alternatively formed and the concave portions are very deep. While the electro polishing is performed, the surface of the concave portions of the workpiece 16 is concentratively polished and accordingly a height difference between upper surfaces of the convex portions and bottom surfaces of the concave portions is decreased. As a result, the occurrence possibility of pinholes in the concave portions is remarkably decreased and the adhesive force between the surface of the workpiece and the plating film is increased. Accordingly, the delamination possibility of the plating film is remarkably decreased. In other words, when the electro polishing is completed, the surface roughness of the workpiece is decreased and the gloss is remarkably increased. After the electro polishing is completed, it is preferable that the workpiece be plated three times. In other words, once electric plating using the electro polishing combined electric plating apparatus of FIG. 1 and two times of electroless platings using the electroless plating apparatus of FIG. 2 or FIG. 3 are performed. Alternatively, after the electro polishing is completed, only once electroless plating for forming a coating film containing a fluorine resin may be performed. Also, after the electro polishing is completed, once electroless plating for forming a plating film not containing a fluorine resin and once electroless plating for forming a plating film containing a fluorine resin may be performed. Again referring to FIG. 1, after the electro polishing is completed, in order to form an electric plating film on the surface of the workpiece 16, a negative voltage is applied to the workpiece 16 and a positive voltage is applied to the plating target 14. At this time, the plating target 14 located inside the workpiece 16 moves at a predetermined speed along the inner passage of the workpiece 16. As a result of the electric plating, a first plating film is formed on the surface of the workpiece 16. Next, referring to FIG. 2, a first electroless plating film is formed on the first plating film using the electroless plating apparatus 40. Specifically, the workpiece 16 is vertically loaded in the first electroless plating solution 43 contained in the first inner bath 41 using the workpiece transferring unit 45, and is dipped for a predetermined time. Thereafter, the workpiece 16 is taken out of the first electroless plating solution 43, is rinsed in water and then dried under the room temperature environment. The first electroless plating solution 43 contains nickel sulfate as a metal salt, sodium hypophosphite as a reducing agent, malic acid, succine acid or lactic acid as a complexing agent, conditioner, pH conditioner, and the like. Next, the workpiece 16 having the first electric plating film and the first electroless plating film is dipped inclined at a predetermined angle in the second electroless plating solution 63 of the electroless plating apparatus of FIG. 3 to form a second electroless plating film. Thereafter, the workpiece 16 is taken out of the second electroless plating solution 63, rinsed in water, and dried under the room temperature environment. Thereafter, the workpiece is loaded in a furnace whose inner temperature is elevated up to and kept at 300 °C and is baked for 60 minutes to thereby obtain a final plated workpiece coated with the electroless plating film. The second electroless plating solution 63 contains nickel sulfate as a metal salt, sodium hypophosphite as a reducing agent, PTEF as a fluorine resin. The final plated workpiece has a very high flatness and an adhesivity compared with the products disclosed in the prior art. Alternatively, it is possible to form the first and second electroless plating films using either the electroless plating apparatus of FIG. 2 or the electroless plating apparatus of FIG. 3. [industrial Applicability] For this, the electroless plating solution contained in the inner bath is changed into the aforementioned composition. While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.