Patent Publication Number: US-2022220625-A1

Title: Anodizing device

Description:
TECHNICAL FIELD 
     The disclosure relates to an anodizing apparatus, and more specifically, an anodizing apparatus that may selectively perform an anodizing surface treatment on a portion of a target product such as a sliding part of a hydraulic block. 
     BACKGROUND ART 
     In general, anodizing refers to a surface treatment process that paints a surface of a metal product. When a metal being an anode is electrolyzed in an acidic electrolyte, an oxide film with high adhesion is formed on the surface of the metal by oxygen generated from the anode, which is an anodizing process. 
     Metal products made of aluminum are widely applied in a variety of industries due to advantages in castability, productivity, strength and dimensional accuracy. Despite the advantages and applicability, however, aluminum has low corrosion resistance, and thus aluminum products processed by anodizing surface treatment for increasing corrosion resistance and abrasion resistance and promoting appearance and reliability of the products are being used. 
     Meanwhile, in a brake system for braking of a vehicle, an aluminum hydraulic block is widely used to form hydraulic pressure in a pressurized medium such as brake oil, etc., and transmit the hydraulic pressure to a wheel cylinder. Inside of the hydraulic block, a plurality of sliding parts in which various pistons reciprocate and a plurality of valve bores in which a variety of valves are installed are provided. 
     In the sliding parts where pistons such as a master cylinder and a pump reciprocate and form hydraulic pressure or negative pressure in a pressurized medium, the hydraulic block may be worn due to the repeated movement of the piston, and thus metal components of the hydraulic block may be contained in the pressurized medium. Accordingly, the sliding parts are required to be treated by anodizing surface treatment to increase corrosion resistance and abrasion resistance of the hydraulic block. 
     To prevent the disadvantage described above, in a conventional art, a process of partially removing a portion which is not required to be surface treated through grinding, and the like has been additionally performed after putting the entire hydraulic block in an electrolyte, applying power, and performing anodizing surface treatment on the outer and inner surface of the hydraulic block. Also, in a conventional art, a method of pretreatment of sealing a portion which does not require anodizing surface treatment has been used. However, such processes are complicated and the manufacturing period is long, which results in a decrease in productivity and an increase in manufacturing cost. 
     Disclosure 
     Technical Problem 
     Therefore, it is an aspect of the disclosure to provide an anodizing apparatus that may easily and selectively perform an anodizing surface treatment on a portion which requires the anodizing surface treatment in a target product such as a hydraulic block, and the like. 
     It is an aspect of the disclosure to provide an anodizing apparatus that may rapidly perform an anodizing surface treatment on a portion which requires the anodizing surface treatment in a target product such as a hydraulic block, and the like. 
     It is an aspect of the disclosure to provide an anodizing apparatus that may improve quality of an anodizing surface treatment. 
     It is an aspect of the disclosure to provide an anodizing apparatus that may improve a performance and reliability of a target product such as a hydraulic block, and the like. 
     It is an aspect of the disclosure to provide an anodizing apparatus that may simplify a process. 
     It is an aspect of the disclosure to provide an anodizing apparatus that may improve productivity and reduce a manufacturing cost of a target product such as a hydraulic block, and the like. 
     According to an aspect of the disclosure, there is provided an anodizing apparatus, including: a anodizing apparatus, including: a base configured to support a target product including a first bore that requires an anodizing surface treatment and a second bore that is connected to the first bore and excluded from the anodizing surface treatment; a working part configured to perform the anodizing surface treatment on the first bore; and a cover part configured to cover an outer surface of the target product, wherein the working part includes at least one electrode bar configured to access and enter the first bore, and a plurality of spray nozzles provided integrally with each of the at least one electrode bar and configured to selectively supply one of a degreasing solution, an electrolyte, and a cleaning solution to the first bore. 
     A lower surface of the target product is covered by the base, and the cover part includes a plurality of first sealing blocks configured to cover a lateral surface of the target product, a second sealing block configured to cover a upper surface of the target product, a plurality of first driving parts configured to approach or separate each of the plurality of first sealing blocks toward/from the target product, and a second driving part configured to approach or separate the second sealing block toward/from the target product. 
     Each of the plurality of first driving parts includes a main body fixed to the base, a support body configured to support each of the plurality of first sealing blocks, and a first cylinder provided between the main body and the support body and operating extendable and contractible. 
     The second driving part includes a plurality of columns extending upward from the base, a frame supported by the plurality of columns, and a second cylinder provided between the frame and the second sealing block and operating extendable and contractible. 
     The anodizing apparatus further includes: a leakage prevention part configured to form an inner space of the cover part or the first bore to be a vacuum partial vacuum. 
     The leakage prevention part includes at least one suction nozzle formed in each of the at least one electrode bar. 
     The anodizing apparatus further includes: a pressure sensor configured to sense whether the inner space is sealed. 
     The at least one electrode bar and the plurality of spray nozzles are inserted through the base. 
     The at least one electrode bar and the plurality of spray nozzles are inserted through at least one of the plurality of first sealing blocks and supported by the support body. 
     Each of the plurality of first driving parts further includes a guide part configured to guide reciprocation of the support body with respect the main body. 
     The guide part includes a guide rod extended parallel to a driving direction of the first cylinder and a guide groove formed through an inside of the main body and on which the guide rod slides. 
     The at least one electrode bar is extended along an axial direction of the first bore. The plurality of spray nozzles are positioned at regular intervals on a lateral surface of an end of each of the at least one electrode bar. 
     The working part further includes a sealing member provided on an outer circumferential surface of each of the at least one electrode bar. 
     The plurality of first sealing blocks and the second sealing block are formed corresponding to an outer shape of the target product. 
     Advantageous Effects 
     The anodizing apparatus according to an aspect of the disclosure can easily and selectively perform an anodizing surface treatment on a portion which requires the anodizing surface treatment in a target product such as a hydraulic block, and the like. 
     The anodizing apparatus according to an aspect of the disclosure can rapidly perform an anodizing surface treatment on a portion which requires the anodizing surface treatment in a target product such as a hydraulic block, and the like. 
     The anodizing apparatus according to an aspect of the disclosure can improve quality of an anodizing surface treatment. 
     The anodizing apparatus according to an aspect of the disclosure can improve a performance and reliability of a target product such as a hydraulic block, and the like. 
     The anodizing apparatus according to an aspect of the disclosure can simplify a process. 
     The anodizing apparatus according to an aspect of the disclosure can improve productivity and reduce a manufacturing cost of a target product such as a hydraulic block, and the like. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view and a cross-sectional view illustrating a first bore that requires an anodizing surface treatment and a second bore that is excluded from the anodizing surface treatment in a target product of the anodizing surface treatment according to an embodiment of the disclosure. 
         FIG. 2  is a perspective view illustrating an anodizing apparatus according to an embodiment of the disclosure. 
         FIG. 3  is a cross-sectional view taken along a line A-A′ of  FIG. 2 . 
         FIG. 4  is a cross-sectional view taken along a line B-B′ of  FIG. 2 . 
         FIG. 5  is a cross-sectional view taken along a line C- C′ of  FIG. 2 . 
         FIG. 6  is a perspective view illustrating an open state of an inner space of a cover part before an anodizing surface treatment of an anodizing apparatus according to an embodiment of the disclosure. 
         FIG. 7  is a perspective view illustrating a state where a target product is placed in an inner space of a cover part for an anodizing surface treatment of an anodizing apparatus according to an embodiment of the disclosure. 
         FIG. 8  is a perspective view illustrating a state where an inner space of a cover part is sealed during an anodizing surface treatment of an anodizing apparatus according to an embodiment of the disclosure. 
     
    
    
     MODE OF THE DISCLOSURE 
     Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following embodiments are provided to fully convey the spirit of the disclosure to a person having ordinary skill in the art to which the present disclosure belongs. The disclosure is not limited to the embodiments shown herein but may be embodied in other forms. The drawings are not intended to limit the scope of the disclosure in any way, and the size of components may be exaggerated for clarity of illustration. 
       FIG. 1  is a perspective view and a partial cross-sectional view illustrating a target product  100  of an anodizing surface treatment according to an embodiment of the disclosure. 
     Referring to  FIG. 1 , the target product  100  applied to an anodizing apparatus  1000  according to an embodiment of the disclosure may include a portion  11  that requires the anodizing surface treatment, and a portion  12  that is excluded from the anodizing surface treatment. The anodizing apparatus  1000  according to an embodiment of the disclosure may selectively perform an anodizing surface treatment with respect to the portion  11  which requires the anodizing surface treatment. 
     For example, the target product  10  may be a hydraulic block applied to a brake system for braking a vehicle. The hydraulic block  10  may include a plurality of first bores  11  where various pistons reciprocate and a plurality of second bores  12  where various valves are mounted and fixed. 
     The first bore  11  may be a sliding part where a piston such as a master cylinder, a pump, and etc., reciprocate and form hydraulic pressure in a pressurized medium such as brake oil, etc. The first bore  11  may be worn due to repeated movement of the piston, and thus metal components of the hydraulic block  10  may be contained in the pressurized medium. Accordingly, the first bore  11  such as the sliding part requires to increase corrosion resistance and abrasion resistance through formation of an oxide film by the anodizing surface treatment. 
     Meanwhile, a sealing member (not shown) provided in the piston is inserted and installed in a sealing groove  11   a  which is recessed along an inner circumferential surface of the first bore  11 . The sealing groove  11   a  is recessed by grinding after performing the anodizing surface treatment on the first bore  11 , and thus the anodizing surface treatment is removed. 
     Also,  FIG. 1  illustrates only cross-sectional view of the first bore  11  formed on a lateral side of the hydraulic block  10 , which is only an example to help understanding of the disclosure. That is, as shown in  FIGS. 3 and 4 , the plurality of first bores  11  may be formed on a lower surface of the hydraulic block  10 . Each of the second bores  12  is a valve bore where a variety of valves are installed. 
     Because the valves are fixed and operated, corrosion and wear do not occur. Accordingly, the second bores  12  are required to be excluded from the anodizing surface treatment to improve efficiency of manufacturing process and reduce a manufacturing cost of the target product  10 . 
     In a conventional art, to selectively perform an anodizing surface treatment on a target product, a process of partially removing a portion which is not required to be surface treated through grinding has been additionally performed after putting an entire target product in an electrolyte, applying power, and performing anodizing surface treatment on an outer and inner surface of the target product. Also, in a conventional art, an anodizing surface treatment has been performed after masking bores or a portion required to be excluded from the anodizing surface treatment one by one. However, such processes including a pretreatment or a post-treatment such as grinding or sealing are complicated, a manufacturing period is long, and a member for masking the portion to be excluded from the anodizing surface treatment is required to be separately designed and arranged according to a specification of the target product. That is, inefficiency of the manufacturing process is caused. 
     According to an embodiment of the disclosure, the anodizing apparatus  1000  may selectively perform an anodizing surface treatment only on the first bores  11  of the target product  10  without a separate member or an additional process. 
       FIG. 2  is a perspective view illustrating an anodizing apparatus  1000  according to an embodiment of the disclosure.  FIGS. 3 through 5  are cross-sectional views taken along a line A-A′ of  FIG. 2 , a line B-B′ of  FIG. 2 , and a line C-C′ of  FIG. 2 , respectively. 
     Referring to  FIGS. 2 through 5 , according to an embodiment of the disclosure, the anodizing apparatus  1000  may include a base  1100 , a working part  1200 , a cover part  1300 , a leakage prevention part and a pressure sensor (not shown). The base  1100  supports a target product  10  including a first bore  11  and a second bore  12 . The working part  1200  performs the anodizing surface treatment on the first bore  11  and the cover part  1300  closely covers an outer surface of the target product  10 . The leakage prevention part forms an inner space  1500  (referring to  FIG. 6 ) partitioned and formed by the cover part  1300  or the first bore  11  to be a vacuum. The pressure sensor senses whether the inner space  1500  partitioned and formed by the cover part  1300  is sealed. 
     The base  1100  supports a lower surface of the target product  10  and various components to be described later, and also various components may be mounted on the base  1100 . The base  1100  has a shape of plate and may be in contact with the lower surface of the target product  10 . Also, a plurality of bridges  1110  may be extended in a vertical direction on four edges of the base  1100  to support the base  1100  in a workplace or a supportable structure. The working part  1200  and the cover part  1300  to be described later may be mounted on and supported by a upper surface of the base  1100 . In a lower surface of the base  1100 , an electrode bar  1210  and a plurality of spray nozzles  1220  of the working part  1200  may be formed to penetrate the base  1100  and be protruded upward, which will be described in detail later. 
     The working part  1200  is provided to perform the anodizing surface treatment on the first bore  11 . 
       FIG. 6  is a perspective view illustrating a state before the target product  10  is put in the anodizing apparatus  1000  according to an embodiment of the disclosure. Referring to  FIGS. 2 through 6 , the working part  1200  may include at least one electrode bar  1210  and the plurality of spray nozzles  1220 . The at least one electrode bar  1210  is provided to access and enter at least one first bore  11 . The plurality of spray nozzles  1220  are provided integrally with each of the at least one electrode bar  1210  and selectively supply one of a degreasing solution, an electrolyte, and a cleaning solution to the first bore  11 . 
     The at least one electrode bar  1210  may have a shape of a bar extending parallel to an axial direction of the first bore  11  to easily access and enter an inside of the first bore  11 . Also, the at least one electrode bar  1210  may be provided according to the number of first bores  11  formed in the target product  10 . Each of the at least one electrode bar  1210  may be electrically connected to the target product  10  and positive (+) voltage and current may be applied and transmitted to the target product  10  by a power supplier (not shown). 
     The plurality of spray nozzles  1220  may be provided in an end of the electrode bar  1210  to supply and spray one of the degreasing solution, the electrolyte, and the cleaning solution to the first bore  11 . A sealing member  1211  may be provided on an outer circumferential surface of the electrode bar  1210  and be in contact with an inner circumferential surface of the first bore  11  to prevent the degreasing solution, the electrolyte, and the cleaning solution from leaking. When the electrode bar  1210  is formed to penetrate and be inserted into the base  1100  or a first sealing block  1310 , the sealing member  1211  may be provided between the electrode bar  1210  and the base  1100 . The first sealing block  1310  will be described later. 
     As an example to help understanding of the disclosure, it is illustrated that one first bore  11  is provided on a lateral surface of the target product  10  and two first bores  11  are provided on a lower surface of the target product  10 , and corresponding to the above, one electrode bar  1210  is provided in the first sealing block  1310  and two electrode bars  1210  are provided in the base  1100 . That is, the electrode bar  1210  may be provided at different positions according to a position and the number of first bores  11  that require the anodizing surface treatment. 
     Also, although not illustrated, at least one of a position and an angle of the electrode bar  1210  and the plurality of spray nozzles  1220  may be adjusted and modified automatically by a position adjustment unit (not shown) or manually by an operator. That is, the position and the angle of the electrode bar  1210  and the plurality of spray nozzles  1220  may be adjusted even when the position and angle of the first bore  11  vary according to a type of the target product  10 . Accordingly, the anodizing surface treatment may be effectively performed and applicability and compatibility of the anodizing apparatus  1000  may be improved. The plurality of spray nozzles  1220  may be provided integrally with the electrode bar  1210  by being inserted into the electrode bar  1210 . Also, the plurality of spray nozzles  1220  may be positioned at regular intervals on a lateral surface of an end of the electrode bar  1210  to face an inner circumferential surface of the first bore  11 . The plurality of spray nozzles  1220  may be connected to each of a degreasing solution supplier (not shown), an electrolyte supplier (not shown), and a cleaning solution supplier (not shown), and selectively supply and spray at least one of the degreasing solution, the electrolyte, or the cleaning solution to the first bore  11 . 
     The anodizing surface treatment includes a degreasing process, a plating process, and a cleaning process. Foreign substances in an area to be surface treated are removed and cleaned in the degreasing process, and an oxide film is formed on a surface of the target product  10  by applying power while supplying an acidic electrolyte in the plating process. Also, the electrolyte remaining in the target product  10  is cleaned in the cleaning process. The spray nozzles  1220  may be selectively supplied with at least one of the degreasing solution used for degreasing process, the electrolyte used for plating process, or the cleaning solution used for cleaning process, and may selectively supply and spray the at least one of the degreasing solution, the electrolyte, or the cleaning solution to the first bore  11 . 
     The target product  10  may be directly or indirectly in contact with a power supplier (not shown) and a positive (+) voltage and current may be applied to the target product  10 . The anodizing surface treatment may be performed by forming the oxide film by supplying the electrolyte to the first bore  11  through the spray nozzles  1220  while a negative (−) voltage and current are applied to each of the at least one electrode bar  1210 . 
     The electrode bar  1210  and the spray nozzles  1220  to perform the anodizing surface treatment on the first bore  11  provided on the lateral surface of the target product  10  may be inserted through the first sealing block  1310 , and may be supported by a support body  1322  of one of a plurality of first driving parts  1320 . The first sealing block  1310  and the plurality of first driving parts  1320  are described in detail later. As the first driving part  1320  operates, the electrode bar  1210  and the spray nozzles  1220  may approach or be spaced apart from the target product  10  or the first bore  11  together with the first sealing block  1310 . In addition, the electrode bar  1210  and the spray nozzles  1220  to perform the anodizing surface treatment on the first bore  11  provided on the lower surface of the target product  10  may be mounted and supported on the base  1100  via a support bracket  1120 , and be installed by being inserted through the base  1100 . The sealing member  1211  may be provided on the outer circumferential surface of the electrode bar  1210  and be in contact with the inner circumferential surface of the first bore  11 . 
     Meanwhile, the electrode bar  1210  may include a suction nozzle  1400  to prevent various fluids used for the anodizing surface treatment, particularly, the electrolyte, from leaking. For the above, the suction nozzle  1400  forms the inner space  1500  of the cover part  1300  or the first bore  11  of the target product  10  to be a vacuum, which will be described in detail later. 
     The cover part  1300  provided to cover an outer surface of the target product  10  may prevent the degreasing solution, the electrolyte, and the cleaning solution from leaking and simultaneously exclude the second bore  12  of the target product  10  from the anodizing surface treatment. 
     The cover part  1300  includes the plurality of first sealing blocks  1310 , a second sealing block  1350 , the plurality of first driving parts  1320  and a second driving part  1360 . The plurality of first sealing blocks  1310  cover the lateral surface of the target product  10 , and the second sealing block  1350  covers a upper surface of the target product  10 . Also, the plurality of first driving parts  1320  approach or separate each of the plurality of first sealing blocks  1310  toward/from the target product  10 , and the second driving part  1360  approaches or separates the second sealing block  1350  toward/from the target product  10 . 
     As described above, the lower surface of the target product  10  may be covered and supported by the base  1100 , and the lateral surface and the upper surface of the target product  10  may be covered by the first sealing block  1310  and the second sealing block  1350 , respectively. 
     The plurality of first sealing blocks  1310  may be provided to be in contact with and cover the lateral surface of the target product  10 . For example, as illustrated, when the target product  10  is a hydraulic block  10  having a hexahedral shape, four groups of the first sealing blocks  1310  may be provided to cover the four lateral surfaces of the hydraulic block  10 . A surface of the first sealing block  1310  facing the target product  10  may be formed corresponding to a shape of the lateral surface of the target product  10  in order to be in contact with an outer surface of the target product  10 . Because the first sealing block  1310  is in contact with and cover the lateral surface of the target product  10 , even when the second bore  12  excluded from the anodizing surface treatment is provided on the lateral surface of the target product  10 , the electrolyte may be prevented from transferring to the second bore  12  along the outer surface of the target product  10  without a separate component for sealing the second bore  12 . Accordingly, the anodizing surface treatment may be selectively and effectively performed. Further, a leakage prevention part to be described later forms an inner space of the first bore  11  to be a vacuum or a partial vacuum, and thus the electrolyte may be prevented from transferring to the second bore  12  along a flow path formed inside of the target product  10 , which will be described in detail later. 
     The plurality of first driving parts  1320  may be provided to approach or separate each of the first sealing blocks  1310  toward/from the target product  10 . Each of the plurality of first driving parts  1320  may include a main body  1321 , a support body  1322  and a first cylinder  1323 . 
     The main body  1321  is fixed to and supported by the base  1100 , the support body  1322  supports the first sealing blocks  1310 , and the first cylinder  1323  provided between the main body  1321  and the support body  1322  operates extendable and contractible. 
     The main body  1321  may be fixedly installed on the base  1100  by fastening bolts, and a hydraulic device  1323   a  of the first cylinder  1323  may be mounted therein. The support body  1322  supporting the first sealing blocks  1310  may be fixedly connected to an operation rod  1323   b  which is protruded and retracted by the hydraulic device  1323   a  of the first cylinder  1323 . When the hydraulic device  1323   a  of the first cylinder  1323  operates and the operation rod  1323   b  protrudes, the first cylinder  1323  is extended, and thus the first sealing blocks  1310  may approach the target product  10 . When the operation rod  1323   b  is retracted, the first cylinder  1323  may be contracted, and thus the first sealing blocks  1310  may be spaced apart from the target product  10 . 
     Specifically, to close the inner space  1500  of the cover part  1300  where the target product  10  is placed for the anodizing surface treatment on the first bore  11 , the first sealing blocks  1310  supported by the support body  1322  may be in contact with and cover the lateral surface of the target product  10  by providing hydraulic pressure to the hydraulic device  1323   a  of the first cylinder  1323  and protruding the operation rod  1323   b . To open the inner space  1500  of the cover part  1300  or after completing the anodizing surface treatment on the first bore  11 , the first sealing blocks  1310  supported by the support body  1322  may be spaced apart from the lateral surface of the target product  10  by discharging hydraulic pressure from the hydraulic device  1323   a  of the first cylinder  1323  and retracting the operation rod  1323 b. The first cylinder  1323  may operate extendable and contractible by providing or removing hydraulic pressure manually by an operator or automatically by a control system (not shown). 
     Each of the plurality of first driving parts  1320  may include a guide part  1330  that guides reciprocation of the support body  1322  with respect to the main body  1321 . The guide part  1330  may include a guide rod  1331  and a guide groove  1332 . The guide rod  1331  is extended in parallel with a longitudinal direction of the operation rod  1323   b  of the first cylinder  1323 , and the guide groove  1332  is formed through an inside of the main body  1321  and the guide rod  1331  slides thereon. 
     Meanwhile, the first driving parts  1320  approach or separate the electrode bar  1210  and the plurality of spray nozzles  1220  toward/from the target product  10  or the first bore  11 . Here, the electrode bar  1210  and the plurality of spray nozzles  1220  perform the anodizing surface treatment on the first bore  11  provided on the lateral surface of the target product  10 . Specifically, the electrode bar  1210  and the spray nozzles  1220  inserted through the first sealing block  1310  are supported by one of the support body  1322 , and thus hydraulic pressure is provided to the hydraulic device  1323   a  of the first cylinder  1323  and the operation rod  1323   b  is protruded. Accordingly, the electrode bar  1210  and the spray nozzles  1220  may approach the target product  10  and the first bore  11  together with the first sealing block  1310 . Also, hydraulic pressure is removed from the hydraulic device  1323   a  of the first cylinder  1323 , the operation rod  1323   b  is retracted, and thus the electrode bar  1210  and the spray nozzles  1220  may be spaced apart from the target product  10  and the first bore  11  together with the first sealing block  1310 . 
     The second sealing block  1350  may be provided to be in contact with and cover the upper surface of the target product  10 . For the above, a surface of the second sealing block  1350  facing the target product  10  may be formed corresponding to a shape of the upper surface of the target product  10  in order to be in contact with the outer surface of the target product  10 . Because the second sealing block  1350  is in contact with and cover the upper surface of the target product  10 , even when the second bore  12  excluded from the anodizing surface treatment is provided on the upper surface of the target product  10 , the electrolyte may be prevented from transferring to the second bore  12  along the outer surface of the target product  10  without a separate component for sealing the second bore  12 . Accordingly, the anodizing surface treatment may be selectively and effectively performed. Further, a leakage prevention part to be described later forms an inner of the first bore  11  to be a vacuum or a partial vacuum, and thus the electrolyte may be prevented from transferring to the second bore  12  along a flow path formed inside of the target product  10 . 
     The second driving part  1360  approaches or separates the second sealing block  1350  toward/from the target product  10 . The second driving part  1360  includes a plurality of columns  1361 , a frame  1362 , and a second cylinder  1363 . The plurality of columns  1361  extend upward from the base  1100 , and the frame  1362  is supported by the plurality of columns  1361 . The second cylinder  1363  operates extendable and contractible between the frame  1362  and the second sealing block  1350 . Also, the second cylinder  1363  may be fixed to the frame  1362  via a support bracket  1365 . 
     The columns  1361  may be provided as four groups and be fixedly installed on the base  1100  by fastening bolts. The frame  1362  may be fixedly supported on the plurality of columns  1361  by fastening bolts. The second cylinder  1363  may be mounted on the frame  1362 , and the second sealing block  1350  may be fixedly connected to an operation rod  1363   b  of the second cylinder  1363 . When a hydraulic device  1363   a  of the second cylinder  1363  operates and the operation rod  1363   b  protrudes, the second cylinder  1363  is extended, and thus the second sealing block  1350  may approach the target product  10 . When the operation rod  1363   b  is retracted, the second cylinder  1363  is contracted, and thus the second sealing block  1350  may be spaced apart from the target product  10 . 
     Specifically, to close the inner space  1500  of the cover part  1300  where the target product  10  is placed for the anodizing surface treatment on the first bore  11 , the second sealing block  1350  supported by the operation rod  1363   b  of the second cylinder  1363  may be in contact with and cover the upper surface of the target product  10  by providing hydraulic pressure to the hydraulic device  1363   a  of the second cylinder  1363  and protruding the operation rod  1363   b . To open the inner space  1500  of the cover part  1300  or after completing the anodizing surface treatment on the first bore  11 , the second sealing block  1350  supported by the operation rod  1363 b of the second cylinder  1363  may be spaced apart from the upper surface of the target product  10  by discharging hydraulic pressure from the hydraulic device  1363 a of the second cylinder  1363  and retracting the operation rod  1323   b . Like the first cylinder  1323 , the second cylinder  1363  may operate extendable and contractible by providing or removing hydraulic pressure manually by an operator or automatically by a control system (not shown). 
     Meanwhile, the second cylinder  1363  may be directly connected to and support the second sealing block  1350 , and also be connected to the second sealing block  1350  via a support body  1366 . In addition, although not illustrated, a guide part (not shown) may be provided between the support body  1366  and the frame  1362  to guide reciprocation of the second sealing block  1350  by the second driving part  1360 . 
     The leakage prevention part may form the inner space  1500  formed by the first bore  11  or the cover part  1300  to be a vacuum in order to prevent the electrolyte and the cleaning solution from leaking from the first bore  11  or from the inner space  1500  formed by the cover part  1300 . 
     The leakage prevention part may include a vacuum pump (not shown) and at least one suction nozzle  1400  connected to the vacuum pump. The at least one suction nozzle  1400  may be provided at an end of the electrode bar  1210 . Also, the at least one suction nozzle  1400  may suck air remaining in the inner space  1500  of the cover part  1300  or the first bore  11 , and thus the inner space  1500  partitioned and sealed by the first bore  11  or the cover part  1300  may be in a vacuum state. 
     As described above, when the anodizing surface treatment is performed on the first bore  11 , the plurality of spray nozzles  1220  of the electrode bar  1210  supply and spray one of the degreasing solution, the electrolyte, and the cleaning solution. In this instance, when the electrolyte leaks to an outside of the inner space  1500  partitioned and sealed by the cover part  1300 , the acidic electrolyte is exposed outside, which causes a safety accident. In particular, when the electrolyte leaks outside of the first bore  11 , the electrolyte leaks into the second bore  12  excluded from the anodizing surface treatment, which leads to a deterioration of quality of the anodizing surface treatment. To prevent the degreasing solution, the electrolyte, and the cleaning solution from leaking to the outside of the inner space  1500  of the cover part  1300 , the suction nozzle  1400  of the leakage prevention part sucks air remaining in the inner space  1500  of the cover part  1300  and make a pressure of the inner space  1500  to be lower than an external pressure. Accordingly, surrounding facilities may be protected and safety accidents may be prevented. Further, the suction nozzle  1400  of the leakage prevention part makes a pressure of the first bore  11  to be lower than a pressure of the second bore  12 , and thus the electrolyte may be prevented from leaking to the second bore  12  and a quality of the anodizing surface treatment may be improved. A pressure sensor (not shown) may be provided to sense whether the inner space  1500  of the cover part  1300  where the target product  10  is placed is sealed. 
     The pressure sensor may be provided on one of the at least one electrode bar  1210 , and sense whether the inner space  1500  is sealed by measuring an internal pressure of the inner space  1500  before and after an operation of the suction nozzle  1400  of the leakage prevention part. 
     Specifically, in a state where the first sealing blocks  1310  and the second sealing block  1350  are in contact with the outer surface of the target product  10  by extending the first driving parts  1320  and the second driving part  1360  of the cover part  1300  for the anodizing surface treatment, the pressure sensor measures a pressure value of the inner space  1500 , and then measures a pressure value of the inner space  1500  in a state where the suction nozzle  1400  of the leakage prevention part is operating. By comparing the two pressure values, when the pressure value measured when the suction nozzle  1400  is operating decreases by a preset or predicted pressure level compared to the other pressure value, a control part may determine that a vacuum or a partial vacuum state is stably formed by the suction nozzle  1400  and the inner space  1500  is sealed. Accordingly, the anodizing surface treatment may be continuously performed. 
     By contrast, when the pressure value measured when the suction nozzle  1400  is operating does not decrease by the preset or predicted pressure level compared to the other pressure value, the control part may determine that the inner space  1500  is not normally sealed by the cover part  1300 , and notify an operator of a risk of electrolyte leakage using a display (not shown) or a warning light and stop the anodizing surface treatment simultaneously. 
     Hereinafter, operations of the anodizing apparatus  1000  according to an embodiment of the disclosure is described. 
       FIGS. 6 through 8  are perspective views illustrating operation states of the anodizing apparatus  1000  according to an embodiment of the disclosure.  FIG. 6  illustrates an open state of the inner space  1500  of the cover part  1300  before an anodizing surface treatment, and  FIG. 7  illustrates a state where the target product  10  is placed in the inner space  1500  of the cover part  1300  for the anodizing surface treatment.  FIG. 8  illustrates a state where the inner space  1500  of the cover part  1300  is sealed during the anodizing surface treatment. 
     Referring to  FIG. 6 , to open the inner space  1500  of the cover part  1300  for the anodizing surface treatment, the first sealing blocks  1310  and the second sealing block  1350  are spaced apart from the inner space  1500 . Specifically, the first sealing blocks  1310  supported by the support body  1322  and the support body  1322  are moved outwardly by discharging hydraulic pressure from the hydraulic device  1323   a  of the plurality of first cylinders  1323  manually by an operator or automatically by the control part (not shown) and by contracting the operation rod  1323   b . Simultaneously, the second sealing block  1350  is moved upward by discharging hydraulic pressure from the hydraulic device  1363   a  of the second cylinder  1363  and by contracting the operation rod  1363   b . Accordingly, the inner space  1500  may be open to place the target product  10 . 
     Afterwards, the target product  10  where the anodizing surface treatment is to be performed is placed on an upper surface of the base  1100  and put into the inner space  1500  of the cover part  1300  simultaneously. In this instance, when the first bore  11  that requires the anodizing surface treatment exists on a lower surface of the target product  10 , the first bore  11  is arranged to be close to the electrode bar  1210  and the plurality of spray nozzles  1220  protruded from the base  1100 . (referring to  FIG. 7 ) 
     After the target product  10  is placed on the base  1100  and put into the inner space  1500  of the cover part  1300 , the inner space  1500  of the cover part  1300  is sealed for the anodizing surface treatment. Specifically, the first sealing blocks  1310  supported by the support body  1322  and the support body  1322  may be moved to and be in contact with the lateral surface of the target product  10  by providing hydraulic pressure to the hydraulic device  1323   a  of each of the plurality of first cylinders  1323  manually by an operator or automatically by the control part (not shown) and by extending the operation rod  1323   b . Here, the support body  1322  is fixedly connected to the operation rod  1323   b . At the same time, the second sealing block  1350  may be moved to and in contact with the upper surface of the target product  10  by providing hydraulic pressure to the hydraulic device  1363   a  of the second cylinder  1363  and extending the operation rod  1363   b , and thus the inner space  1500  of the cover part  1300  may be sealed. Afterwards, the working part  1200  sequentially supplies and sprays the degreasing solution, the electrolyte, and the cleaning solution to the first bore  11 , and thus the anodizing surface treatment may be performed on the first bore  11 . 
     As described above, a variety of fluids sprayed by the spray nozzles  1220  of the electrode bar  1210  for the anodizing surface treatment, such as the degreasing solution, the electrolyte, and the cleaning solution, can be prevented from leaking by sealing, by the cover part  1300 , the inner space  1500  where the target product  10  is placed. In particular, the acidic electrolyte can be prevented from leaking, and thereby can prevent a safety accident and protect surrounding facilities. Further, the base  1100  and the cover part  1300  can be in contact with and cover the outer surface of the target product  10  regardless of a shape of the target product  10  and a position of the second bore  12 , and thus a separate member for sealing the second bore  12  is not required to be designed and arranged. Accordingly, a process for selective anodizing surface treatment on the first bore  11  can be simplified and productivity can be improved. In addition, the suction nozzle  1400  can form the first bore  11  or the inner space  1500  of the cover part  1300  to be a vacuum or partial vacuum, and thereby can effectively prevent various fluids from leaking and prevent the electrolyte from leaking into the second bore  12  excluded from the anodizing surface treatment. Accordingly, a quality and reliability of the anodizing surface treatment can be improved. 
     Although embodiments of the disclosure have been described with reference to the accompanying drawings, a person having ordinary skilled in the art will appreciate that other specific modifications may be easily made without departing from the technical spirit or essential features of the disclosure. Therefore, the foregoing embodiments should be regarded as illustrative rather than limiting in all aspects.