Abstract:
A method for machining a metallic member to provide a finished appearance uses a lathe and a scraping process. A metallic member comprising a top portion and a peripheral sidewall is provided, the metallic member is positioned on the worktable. The worktable is rotated with the metallic member, the lathe tool moved backwards and forwards to machine the top portion of the rotary metallic member circumferentially. The lathe tool is moved by the moving device along a predetermined path relative to the worktable to machine curved surfaces of the top portion of the metallic member. The scraping cutter is moved to contact the peripheral sidewall of the metallic member. The scraping cutter is moved along a predetermined path, and the scraping cutter is fed the metallic member to achieve the required shape and finish.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims all benefits accruing under 35 U.S.C. §119 from China Patent Application No. 201210554320.2, filed on Dec. 19, 2012, in the China Intellectual Property Office, the disclosure of which is incorporated herein by reference. The application is also related to co-pending applications entitled, “METHOD FOR MACHINING METALLIC MEMBER USING LATHING AND MILLING” (Ser. No. 14/070,671); “METHOD FOR MACHINING METALLIC MEMBER USING LATHING AND MILLING” (Ser. No. 14/070,681); “METHOD FOR MACHINING METALLIC MEMBER USING LATHING AND SCRAPING” (Ser. No. 14/070,688); “METHOD FOR MACHINING METALLIC MEMBER USING LATHING AND SCRAPING” (Ser. No. 14/070,694); “MACHINE TOOL WITH LATHE TOOL AND MILLING CUTTER” (Ser. No. 14/070,705); “MACHINE TOOL WITH LATHE TOOL AND SCRAPING CUTTER” (Ser. No. 14/070,717); “MACHINE CONTROL SYSTEM EMPLOYING LATHE TOOL AND MILLING CUTTER” (Ser. No. 14/070,722), “MACHINE CONTROL SYSTEM EMPLOYING LATHE TOOL AND SCRAPING CUTTER” (Ser. No. 14/070,728), “MILLING METHOD FOR MACHINING METALLIC MEMBER” (Ser. No. 14/070,736). 
     BACKGROUND 
     1. Technical Field 
     The present disclosure generally relates to methods for machining a metallic member, and particularly, to a method for machining member using lathing and scraping. 
     2. Description of the Related Art 
     An electronic device such as a tabletop computer or a mobile phone may have a housing made of metal. The metallic housing includes a top portion and a peripheral sidewall extending from a peripheral edge of the top portion. The top portion has a greater surface area than that of the peripheral sidewall and has a non-circular flat surface or non-circular curved surface. The peripheral sidewall has four side surfaces arranged in order and adjacent two side surfaces connected by corners. In related manufacturing fields, if a milling process is employed to machine the metallic housing, some tracks occur on the top portion that has been milled because of intermittent contact and interrupted milling by the milling cutter. Then a milling process needs to be applied for a better appearance, thus the efficiency of the milling process is reduced. If a lathe process is adopted to machine the metallic member, it is difficult to machine a surface which is not circular. The lathe is not suitable to machine the peripheral sidewalls because of the four corners of the peripheral sidewall. Thus a number of additional machining processes must be added to machine the metallic housing. 
     Therefore, there is room for improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The components in the drawings are not necessarily drawn to scale, the emphasis instead placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an isometric view of a first embodiment of a machine equipped with a lathe feeding mechanism and a scraping feeding mechanism, and a worktable. 
         FIG. 2  is an exploded, isometric view of the machine of  FIG. 1 . 
         FIG. 3  is a partial, exploded, isometric view of the lathe feeding mechanism and the scraping feeding mechanism of  FIG. 2 . 
         FIG. 4  is an exploded, isometric view of the lathe feeding mechanism of  FIG. 3 . 
         FIG. 5  is an isometric view of a metallic member to be machined. 
         FIG. 6  is a sectional view of the metallic member of  FIG. 5 , taken along line VI-VI of  FIG. 5 . 
         FIG. 7  is a flow chart of a first embodiment of the method for machining the metallic member. 
         FIG. 8  is a schematic view of a second embodiment of the machine with a part thereof removed. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  show a first embodiment of a machine  100  adopting a scraping method for machining a metallic member  300  (see  FIG. 5 ). The machine  100  includes a machine support  10 , a worktable  20 , a moving device  30 , a lathe feeding mechanism  40 , a scraping feeding mechanism  50 , and a controller  60 . The worktable  20  holds a workpiece in place and is supported by the machine support  10 . The moving device  30  is movably positioned on the machine support  10  above the worktable  20 . The lathe feeding mechanism  40  and the scraping feeding mechanism  50  are arranged side by side and slidably mounted on the moving device  30 . The controller  60  is electrically connected to the worktable  20 , the moving device  30 , the lathe feeding mechanism  40 , and the scraping feeding mechanism  50  for controlling the machine  100 . Under the control of the controller  60 , the moving device  30  can be driven to move with the lathe feeding mechanism  40  and the scraping feeding mechanism  50 , such that the lathe feeding mechanism  40  and the scraping feeding mechanism  50  can be driven three-dimensionally along Cartesian coordinates, that is, along the X, the Y, and the Z axes. 
     The machine support  10  includes a base  11  and a pair of support bodies  13  positioned on the base  11 . The pair of support bodies  13  is parallel to each other and arranged apart. Each support body  13  includes a first sliding rail  131  on a surface away from the base  11 . In the illustrated embodiment, the first sliding rail  131  extends substantially parallel to the X-axis (a first direction). 
     The worktable  20  is rotatably positioned on the base  11  between the two support bodies  13 . The worktable  20  includes a pair of mounting bases  21 , a first rotating member  23 , a rotating shaft  25 , and a second rotating member  27 . The pair of mounting bases  21  is located in the middle portion of the base  11 , in parallel. The pair of mounting bases  21  is located between the two support bodies  13 . The first rotating member  23  is mounted on one mounting base  21 . The rotating shaft  25  interconnects the first rotating member  23  and the other one mounting base  21 . The first rotating member  23  is capable of rotating the rotating shaft  25  around an α axis. The α axis is parallel to the Y-axis but is not co-linear (a second direction). The second rotating member  27  is positioned on a middle portion of the rotating shaft  25 , and capable of rotating the metallic member  300  placed thereupon around an β axis. The β axis is parallel to the Z-axis (a third direction) but is not co-linear. The first rotating member  23  and the second rotating member  27  are electrically connected to the controller  60 . In the illustrated embodiment, the first rotating member  23  and the second rotating member  27  are direct drive motors. 
     The moving device  30  is slidably mounted on the pair of support bodies  13  and located above the worktable  20 . The moving device  30  includes a cross beam  31 , a pair of sliding bases  33 , a pair of first driving mechanisms  35 , and a second driving mechanism  37 . The extending direction of the cross beam  31  is substantially parallel to the Y-axis. Opposite ends of the cross beam  31  are slidably positioned on the support bodies  13 . The cross beam  31  includes a pair of second sliding rails  311  positioned on a side surface and extending substantially parallel to the Y-axis. The pair of sliding bases  33  is installed on the opposite ends of the cross beam  31  to slidably connect with the first sliding rail  131 . The first driving mechanism  35  is mounted on a surface of the sliding base  33  away from the cross beam  31  and located adjacent to an end of the first sliding rail  131 . The pair of first driving mechanisms  35  is employed to drive the cross beam  31  to move along the X-axis direction. 
     The second driving mechanism  37  is mounted on the cross beam  31  to drive the lathe feeding mechanism  40  and the scraping feeding mechanism  50  to move along the second sliding rails  311 . The first driving mechanisms  35  and the second driving mechanism  37  are electrically connected to the controller  60 . In the illustrated embodiment, the first driving mechanisms  35  and the second driving mechanism  37  are high performance linear motors. In other embodiments, the first driving mechanisms  35  and the second driving mechanism  37  may be other drivers, such as hydraulic cylinders or rams. The number of the first driving mechanisms  35 , and the second driving mechanism  37  may be set according to the application. 
       FIGS. 3 to 4  show the lathe feeding mechanism  40  slidably positioned on the cross beams  31 . The lathe feeding mechanism  40  includes a sliding saddle  41  (see  FIG. 2 ), a mounting seat  43 , a tool holder  45 , a pair of feeding assemblies  47 , and a lathe tool  49 . The sliding saddle  41  is assembled to the cross beams  31  and movably engages with the pair of second sliding rails  311 . The sliding saddle  41  is driven by the second driving mechanism  37  to slide along the Y-axis direction together with the lathe feeding mechanism  40  and the scraping feeding mechanism  50 . The mounting seat  43  is fitted to the sliding saddle  41  away from the cross beam  31  and equipped with four guiding rails  413  extending along the Z-axis direction. The four guiding rails  413  are divided in two sets spaced from each other in pairs. The sliding saddle  41  further includes a mounting block  415  adjacent to the base  11 . The mounting block  415  is located between the two sets of guiding rails  413 . The mounting seat  43  is assembled to the sliding saddle  41  and spaced from the four guiding rails  413 . 
     The mounting seat  43  includes a frame  431  and two mounting boards  433  assembled to opposite sides of the frame  431 . The frame  431  includes a first side wall  4311  and a second side wall  4313 . The first side wall  4311  and the second side wall  4313  are positioned substantially parallel to each other and cooperatively define a receiving space  4315 . The first side wall  4311  is slidably connected with the sliding saddle  41 . Two separate guiding portions  4317  protrude from an inner surface of the first side wall  4311  facing the second side wall  4313  and extending substantially parallel to the Z-axis. A through groove  4318  is defined in the second side wall  4313  and extends along a direction substantially parallel to the Z-axis corresponding to the guiding portions  4317 . Two sliding portions  4319  protrude from an outer surface of the second side wall  4313  at two sides of the through groove  4318 . In the illustrated embodiment, the sliding portions  4319  are sliding rails, and the frame  431  is integrally formed. The two mounting boards  433  are installed on opening sides of the frame  431 . Each mounting board  433  is connected substantially perpendicularly to the first side wall  4311  and the second side wall  4313  to close the two opening sides of the frame  431 . 
     The tool holder  45  slidably connects with the mounting seat  43 . The tool holder  45  is substantially “T” shaped, and includes a main body  451  and a sliding board  453  protruding substantially perpendicularly from the main body  451 . The main body  451  is a bar of material tapering at both ends, and positioned outside of the mounting seat  43 . Two distanced holding portions  4511  are positioned on a surface of the main body  451  facing the sliding board  453 . The two holding portions  4511  slidably engage with the pair of sliding portions  4319  of the mounting seat  43 . The sliding board  453  passes through the through groove  4318  and is slidably assembled to the two guiding portions  4317 , dividing the receiving space  4315  into two parts. 
     The pair of feeding assemblies  47  is mounted in the mounting seat  43 , and includes two drivers  471  electrically connected to the controller  60 . The two drivers  471  are capable of driving the tool holder  45  into reciprocating motion at high speed along the direction of the Z-axis, relative to the guiding portions  4317  and the sliding portions  4319 . The two drivers  471  are received in the receiving space  4315  and positioned on two sides of the sliding board  453 . In the illustrated embodiment, the drivers  471  are linear motors. Each driver  471  includes a forcer  4711  and a stator  4713 . Each forcer  4711  is fixed to a surface of each of the mounting boards  433 . The sliding board  453  is positioned between the two forcers  4711 . The two stators  4713  are positioned on the opposite surfaces of the sliding board  453 . In other embodiments, the number of drivers  471  may be set according to application. For example, the two drivers  471  can replace a more powerful single driver, or three or more drivers can be positioned to drive the tool holder  45  to maximize the available power, and the assembly of the drivers is simpler. 
     The lathe tool  49  is fixedly assembled to the main body  451  of the tool holder  45  adjacent to the base  11 . 
     The scraping feeding mechanism  50  includes a linear driving assembly  53 , a linking board  54 , a fixing seat  55 , a mounting base  56 , a rotatable driving member  57  and a scraping cutter  59 . The linear driving assembly  53  includes a driving member  531 , a screw leading rod  533 , and a nut  535 . The driving member  531  is mounted on the sliding saddle  41  above the cross beam  31 . The screw leading rod  533  interconnects the driving member  531  and the mounting block  415 . The nut  535  is sleeved on the screw leading rod  533  and engages with the screw leading rod  533 . The linking board  54  is slidably assembled to the two sets of guiding rails  413  and fixed to the nut  535 . The fixing seat  55  is mounted on an end of the linking board  54  adjacent to the base  11 . The mounting base  56  is mounted on an end of the linking board  54  opposite to the fixing seat  55 . The rotatable driving member  57  extends through the fixing seat  55  and the mounting base  56 , and is fittingly supported by the fixing seat  55 . The scraping cutter  59  is mounted on an end of the rotatable driving member  57  adjacent to the base  11 . 
     The driving member  531  is capable of rotating the screw leading rod  533  and drives the linking board  54 , the rotatable driving member  57 , and the scraping cutter  59  to slide along Z-axis direction. The rotatable driving member  57  is capable of rotating the scraping cutter  59 . The scraping cutter  59  is driven by the cross beam  31  to move along the X-axis direction or the Y-axis direction, and driven by the linear driving assembly  53  to move along Z-axis direction. 
     In assembly, the worktable  20  is positioned between the two support bodies  13 . The cross beam  31  is installed on the two support bodies  13  via the pair of sliding bases  33 . The pair of first driving mechanisms  35 , and the second driving mechanism  37  are mounted on the base  11  and the cross beam  31  respectively. The lathe feeding mechanism  40  and the scraping feeding mechanism  50  are mounted to the cross beam  31  side by side. The worktable  20 , the moving device  30 , the lathe feeding mechanism  40 , and the scraping feeding mechanism  50  are electrically connected to the controller  60 . 
       FIGS. 5 and 6  show that the metallic member  300  to be machined is a housing of a tablet computer or a mobile phone. The metallic member  300  is substantially rectangular and hollow, and includes a top portion  301  and a peripheral sidewall  303  extending from a peripheral edge of the top portion  301 . The top portion  301  has a curved surface with a relatively greater surface area than that of the peripheral sidewall  303 . In the embodiment, the peripheral sidewall  303  has four side surfaces  3031  arranged in order and every two of the adjacent side surfaces  3031  are connected by a corner  3033 . The four side surfaces  3031  are substantially flat surfaces, each corner  3033  interconnects two adjacent side surfaces  3031 . The peripheral sidewall  303  further includes an end edge  305  away from the top portion  301 . 
       FIG. 7  shows that a method for machining the metallic member includes steps as follows: 
     In step S 101 : a machine  100  is provided, the machine  100  includes a worktable  20 , a lathe feeding mechanism  40 , and a scraping feeding mechanism  50 , the lathe feeding mechanism  40  includes a lathe tool  49 , and the scraping feeding mechanism  50  includes a scraping cutter  59 . In the embodiment, the machine  100  is provided as previously described. 
     In step S 102 : a metallic member  300  is placed and held on the worktable  20  of the machine  100 . The metallic member  300  includes a top portion  301  and a peripheral sidewall  303  extending from a peripheral edge of the top portion  301 . 
     In step S 103 : the second driving mechanism  37  drives the lathe feeding mechanism  40  to move along the Y-axis, thereby positioning the lathe tool  49  at an original position above the metallic member  300 . 
     In step S 104 : the second rotating member  27  rotates the metallic member  300  around the β axis; 
     In step S 105 : the lathe feeding mechanism  40  drives the lathe tool  49  to move along the Z-axis reciprocally with a high frequency to machine the top portion  301  of the metallic member  300  according to the depth of cutting required for each machining portion of the top portion  301 , thereby machining the rotary metallic member  300  circumferentially. 
     In step S 106 : the moving device  30  moves the lathe feeding mechanism  40  moves along the X-axis to enable the lathe tool  49  to radially machine the top portion  301  of the metallic member  300 . 
     In step S 107 : the second rotating member  27  is held to stop rotating, the metallic member  300  stops rotating, and the lathe tool  49  stops working. 
     In step S 108 : the scraping feeding mechanism  50  drives the scraping cutter  59  to contact the peripheral sidewall  303  of the metallic member  300 . In detail, firstly, the pair of first driving mechanisms  35  drives the cross beam  31  to slide along the X-axis, and the second driving mechanism  37  drives the scraping feeding mechanism  50  to move along the Y-axis, such that the scraping cutter  59  moves toward one first sliding rail  131  and arrives at a position above an end of one side surface  3031  of the peripheral sidewall  303 . Secondly, the linear driving assembly  53  drives the scraping cutter  59  to slide along the two sets of guiding rails  413  until the scraping cutter  59  meets the peripheral sidewall  303  of the metallic member  300 . 
     In step S 109 : the scraping feeding mechanism  50  moves along a predetermined path, and simultaneously controlling a feed of the scraping cutter  59  relative to the metallic member  300 , thereby machining the peripheral sidewall  303 . In detail, the pair of first driving mechanisms  35  drives the cross beam  31  to slide along the X-axis to enable the scraping cutter  59  to scrap the one side surface  3031  of the peripheral sidewall  303 . When the scraping cutter  59  arrives at the corner  3033 , the pair of first driving mechanisms  35  and the second driving mechanism  37  drive the scraping cutter  59  to adjust a feeding direction. The rotatable driving member  57  rotates to enable the scraping cutter  59  to scrap the corner  3033  along a tangent line of the outer surface of the corner  3033 . The second rotating member  27  rotates the metallic member  300  to a preset angle, the moving device  30  drives the scraping feeding mechanism  50  to enable the scraping cutter  59  to scrape the next side surface  3031  straightly. In other embodiments, the second rotating member  27  rotates the metallic member  300  around the β axis all the time, the scraping feeding mechanism  50  is moved by the moving device  30  to move along the metallic member  300  in a straight line, and simultaneously control a movement of the scraping cutter  59 . 
     The scraping feeding mechanism  50  may scrape the peripheral sidewall  30  first, then the lathe feeding mechanism  40  drives the lathe tool  49  to machine the top portion  301  of the metallic member  300 . 
     The scraping feeding mechanism  50  may scrap the peripheral sidewall  30  first, then the lathe feeding mechanism  40  drives the lathe tool  49  to machine the top portion  301  of the metallic member  300 . 
     In other embodiments, the sliding saddle  41 , the mounting seat  43 , the tool holder  45  may be omitted. Other driving assemblies assembled to the pair of second guiding rails  311  may be substituted for the pair of feeding assemblies  47 . The driving assembly is capable of directly reciprocating the lathe tool  49  along the Z direction at a high speed. 
     The scraping feeding mechanism  50  may not be assembled to the sliding saddle  41 , but assembled to a sliding plate (not shown) slidably mounted on the pair of second guiding rails  311 , such that the lathe feeding mechanism  40  and the scraping feeding mechanism  50  may be controlled independently. 
     The driving member  531 , the screw leading rod  533 , and the nut  535  may be substituted by other driving assembly, such as a linear cylinder. The linear cylinder is assembled to the pair of second guiding rails  311 . The rotatable driving member  57  is mounted on an output shaft of the linear cylinder. Accordingly, the linking board  54  of the scraping feeding mechanism  50  may be omitted. 
     The worktable  20  may include the second rotating member  27  only, the second rotating member  27  is assembled to the base  11 , and rotates around the β axis only. The worktable  20  may be a multi-axis worktable, and rotates the metallic member  300  along a plurality of axis to enable a multi-workstations machining. 
       FIG. 8  shows that a second embodiment of machine  200  is employed in a second embodiment of method for machining the metallic member  300 . The machine  200  is similar to the machine  100  in structure, save that a sliding saddle  41   a  is slidably assembled to a cross beam  31   a , and a second rotating member  27   a  is mounted on a rotating shaft  25   a . The metallic member  300  is placed and held on the second rotating member  27   a . The difference between the machines  100 / 200  is that, a mounting seat  43   a  of the machine  200  is slidably mounted on the sliding saddle  41   a  and capable of sliding along the Z1-axis direction relative to the sliding saddle  41   a , and a lathe tool  49  is slidably mounted on the mounting seat  43   a.    
     When the lathe feeding mechanism  40  machines the top portion  301  of the metallic member  300 , the pair of first driving mechanisms  35  drive the cross beam  31  to slide along the X-axis. In addition, the second driving mechanism  37  drives the lathe feeding mechanism  40  to move along the Y-axis, such that the lathe tool  49  arrives at an original position above the worktable  20  for machining. The original position is located at a middle of a side of the top portion  301 . Then the mounting seat  43   a  drives the lathe tool  49  to move downward along the Z1-axis to reach a preset position near the metallic member  300 . Finally, the pair of feeding assemblies  47  drives the lathe tool  49  to reciprocate at a high speed along the Z-axis according to the depth of cutting required for each machined portion of the top portion  301 , to machine the rotary metallic member  300  circumferentially. Because the mounting seat  43   a  can slide along the Z1-axis to place the lathe tool  49  at the preset position, a reciprocating distance of movement of the lathe tool  49  relative to the metallic member  300  can be reduced, thereby enhancing a reaction response of the lathe tool  49 . 
     Accordingly, in the second embodiment of the method for machining the metallic member  300 , after driving the cross beam  31  to slide along the Y-axis by the second driving mechanisms  37 , a sub-step of moving the mounting seat  43   a  downward along the Z1-axis direction to reach a preset position is interposed. 
     The scraping feeding mechanism  50  is not assembled to the sliding saddle  41 , but is assembled to a sliding plate (not shown) slidably mounted on the pair of second guiding rails  311 , such that the lathe feeding mechanism  40  and the scraping feeding mechanism  50  may be controlled independently. 
     The moving device  30  is capable of moving the lathe feeding mechanism  40  along X/Y-axis directions, and the lathe feeding mechanism  40  is capable of reciprocating the lathe tool  49  along the Z-axis at a high speed, the scraping feeding mechanism  50  scrapes the peripheral sidewall  303 , thereby accomplishing the one time machining of the metallic member  300 . The worktable  20  is capable of rotating the metallic member  300  to match the feed of the lathe feeding mechanism  40 . In addition, the lathe feeding mechanism  40  is capable of moving along the Y-axis direction, such that a uninterrupted machine is achieved, the finish of top portion  301  of the metallic member  300  is enhanced, and the machining process is time saving. The scraping cutter  59  scrapes the corner  3033  along the tangent line, such that a finish is enhanced. The worktable  20  is capable of rotating along the α axis and the β axis to conveniently facilitate the scraping cutter  59  machining of the metallic member  300 . 
     While the present disclosure has been described with reference to particular embodiments, the description is illustrative of the disclosure and is not to be construed as limiting the disclosure. Therefore, various modifications can be made to the embodiments by those of ordinary skill in the art without departing from the true spirit and scope of the disclosure, as defined by the appended claims.