Abstract:
To provide work processing apparatus capable of positioning and stably supporting various types of works of different shapes and capable of performing processing effectively by supporting a work in an arbitrary posture. 
     A work processing apparatus positions a reference support member to a center portion of a work, moves support members in directions in which they approach and separate from each other and an up-down direction in accordance with supporting portions of the work, and performs required processing by controlling movement of a work processing section in a state where the work is supported in a given posture by the reference support member and two support members.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a work processing apparatus that positions a work using a support member capable of carrying out position adjustment of the work according to a size and a shape thereof and applies required processing to the work in a stably supported state. 
         [0003]    2. Description of the Related Art 
         [0004]    For example, a molded work, such as a resin molded article, has a burr which is integrally formed with an outer periphery thereof. In order to bring this work to market, the burr needs to be removed. Further, before marketing the work, various processing such as drilling and trimming need to be applied to the work. When such processing is performed, the work needs to be set in a work support jig that supports/holds the work in a positioned state. However, when a work to be processed is changed to another one that has a different size or a different shape, the work support jig needs to be changed accordingly to another one adapted to the another work. 
         [0005]    Thus, there is a need to prepare a plurality of different work support jigs in accordance with a type of the work, which disadvantageously increases facility cost and requires a large stock space. 
         [0006]    A work support disclosed in, e.g., Patent Document 1 (Jpn. Pat. Appln. Laid-Open Publication No. 2008-235700) is proposed to solve the above problem. The work support includes: a support base having a plurality of cylinder chambers each in which a support piston that causes a support rod to move between a forward movement limit position to be in contact with a work and a rearward movement limit position is accommodated so as to be capable of reciprocating and each partitioned into a forward movement pressure chamber on a rear end surface side of the support piston and a rearward movement pressure chamber on a front end surface side thereof; a changeover valve accommodated, in a valve chamber formed in the support base in communication with the forward movement pressure chamber, so as to be capable of reciprocating in an axial direction thereof and having an opposing surface opposed to the rear end surface of the support piston to constitute the forward movement pressure chamber, a pressure receiving surface positioned on an opposite side to the opposing surface and having a diameter larger than a diameter of the opposing surface, and a through hole allowing communication between the opposing surface and pressure receiving surface; a changeover piston accommodated, in an accommodation hole formed in the support base in communication with the valve chamber, so as to be opposed to the pressure receiving surface of the changeover valve and so as to be capable of reciprocating and driving the support piston through the changeover valve to a preparation position between the forward movement limit position and rearward movement limit position; a changeover flow path formed in the support base and supplying the changeover piston with a pressure of fluid flowing toward the preparation position; a forward movement flow path formed in the support base and designed such that a communication state with the forward movement pressure chamber is made possible through the through hole of the changeover valve in a state where the support piston driven by the changeover piston through the changeover valve is situated at the preparation position and that the communication state is shut off by the changeover valve in a state where the support piston is situated at the rearward movement limit position; and a rearward flow path formed in the support base and communicating with the rearward movement pressure chamber. With this configuration, the work is supported by some support rods that are selectively moved to the forward movement limit position according to a support portion of the work. 
         [0007]    However, a size of a work to be supported by the above work support is restricted to a size comparable to or smaller than the support base, that is, the above work support cannot support a work having a size larger than the support base. In addition, when the support pins are displaced with respect to the support portions of a work, the work cannot be supported stably in a positioned state. 
         [0008]    In actual processing step of a work, there is a need to change a posture (e.g., forward inclined state, rearward inclined state, or horizontal state) of the work to be processed according to the size or shape of the work. However, in the above work support, the support pins are projected to a fixed height position for supporting the work, so that the work cannot be set in the forward inclined state or rearward inclined state, resulting in failing to perform effective processing. 
         [0009]    Further, in the above work support, the changeover valve is provided for each support pin, and each changeover pin is controlled so as to move the support pins selected according to the support points. This complicates a control mechanism of the changeover valve, leading to an increase in device cost. 
         [0010]    Further, in applying processing, such as drilling or cutting by using a drilling machine or a rotary blade, to a predetermined portion to be processed of a work supported by the above work support, a processing member such as the drilling machine or rotary blade is pressed against a portion to be processed of the work. However, the above work support can support portions distanced from the portion to be processed but is not designed to support portions around the portion to be processed. Therefore, the work may be bent or displaced by being pressed by the processing member to deteriorate processing accuracy. 
       SUMMARY OF THE INVENTION 
       [0011]    Problems to be solved are: that the maximum size of a work to be supported is restricted to the size of the support base and, thus, a work having a size larger than the support base cannot be supported; when the support pins are displaced with respect to the support portions of a work, the work to be subjected to required processing cannot be supported stably in a positioned state; the work cannot be supported in an arbitrary posture, thus failing to perform processing effectively; and the work is supported at portions distanced from a portion to be processed, so that the work may be bent or displaced by being pressed by the processing member to deteriorate processing accuracy. 
         [0012]    An object of the present invention is to provide a work processing apparatus capable of: positioning and stably supporting various types of works of different shapes to be subjected to required processing; performing processing effectively by supporting a work in an arbitrary posture; and supporting portions around portions to be processed to prevent the work to be processed from being bent or displaced due to press contact of a processing member to achieve precise processing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a schematic perspective view of a burr removing apparatus as a work processing apparatus provided with work support; 
           [0014]      FIG. 2  is a partly exploded perspective view illustrating a front side work support mechanism; 
           [0015]      FIG. 3  is a partly exploded perspective view illustrating a rear side work support mechanism; 
           [0016]      FIG. 4  is a partly exploded perspective view illustrating a work support mechanism in an intermediate part; 
           [0017]      FIG. 5  is a plan view illustrating a state where front side holding members are moved to the maximum extent in front-rear and left-right directions and rear side holding members are moved to the maximum extent in the left-right direction; 
           [0018]      FIG. 6  is a side view illustrating a state where a work is supported in a horizontal state; 
           [0019]      FIG. 7  is a side view illustrating a state where a work is supported in a forward inclined state; 
           [0020]      FIG. 8  is a side view illustrating a state where the work is supported in a rearward inclined state; 
           [0021]      FIG. 9  is a schematic plan view of a work processing apparatus according to a second embodiment; 
           [0022]      FIG. 10  is a schematic explanatory view of a movable support according to the second embodiment; 
           [0023]      FIG. 11  is an explanatory view illustrating a movable area of a support member of the movable support according to the second embodiment; and 
           [0024]      FIG. 12  is an explanatory view illustrating a modification of the movable support according to the second embodiment. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
       [0025]    Hereinafter, the present invention will be described based on an embodiment of a work processing apparatus embodied as a burr removing apparatus for resin molding that cuts off a burr integrally formed with a resin molding as a work. 
         [0026]    As illustrated in  FIGS. 1 to 4 , a burr removing apparatus  1  for resin molding embodied as a work processing apparatus provided with a work support  7  has, on a body frame  3  thereof, a burr cutting apparatus  5  as a work processing section and a work support  7 . The burr cutting apparatus  5  is disposed on a rear side of the body frame  3  in a direction (hereinafter, sometimes referred to as “front-rear direction”) orthogonal to a longitudinal direction of the body frame  3  and the work support  7  is disposed on a front side thereof. A vehicle panel or a vehicle bumper  14  which is a resin molding as a work is supported in a positioned state by the work support  7 . 
         [0027]    The burr cutting apparatus  5  as a work processing section includes a multi-joint robot that rotates and swings first and second arms  9 ,  11  connected to each other in multiaxial directions and attached with a cutting member  13  as a work processing member. The burr cutting apparatus  5  rotates and turns the first and second arms  9 ,  11  such that the cutting member  13  moves in at least three-axis directions. 
         [0028]    The cutting member  13  has a structure obtained by attaching a rotary blade  13   b  to an output shaft of an electric motor  13   a  and is configured to move the rotating rotary blade  13   b  along an outer edge of the vehicle bumper  14  to cut off the burr (not illustrated). 
         [0029]    The work processing section is not limited to the above-mentioned burr cutting apparatus  5 , but may be an apparatus that performs trimming processing of cutting off a projecting piece projecting from an outer edge of a work, a drilling apparatus that performs drilling for a work using a drill bit, or the like. In a case where the above processing apparatus is robotized, an orthogonal-type robot, etc., that moves the work processing section in orthogonal three directions may be adopted. 
         [0030]    The work support  7  is configured as follows. First and second front-rear frames  15 ,  17 , each extending in a front-rear direction, are fixed respectively to longitudinal direction right and left side portions of a front side of the body frame  3 . First and second front-rear movable bodies  19 ,  21  are supported by the front-rear frames  15 ,  17 , respectively, so as to be movable in the front-rear direction. First and second electric motors  23 ,  25  (numerically-controllable servo motors, etc.) mounted to the corresponding front-rear frames  15 ,  17  are drive-connected respectively to the first and second front-rear movable bodies  19 ,  21 . The first and second front-rear movable bodies  19 ,  21  are driven by the electric motors  23 ,  25 , respectively, to reciprocate in an independent manner in the front-rear direction. 
         [0031]    First and second left-right frames  27 ,  29 , each extending in a left-right direction in the drawings, are fixed to the front-rear movable bodies  19 ,  21 , respectively, at their left-right direction intermediate portions. First and second left-right movable bodies  31 ,  33  are supported by the first and second left-right frames  27 ,  29 , respectively, so as to be movable in the left-right direction. Third and fourth electric motors  35 ,  37  (numerically-controllable servo motors, etc.) mounted to the corresponding first and second left-right frames  27 ,  29  are drive-connected respectively to the first and second left-right movable bodies  31 ,  33 . The first and second left-right movable bodies  31 ,  33  are driven by the electric motors  35 ,  37 , respectively, to reciprocate in an independent manner in the left-right direction. 
         [0032]    First and second up-down frames  39 ,  41  are mounted to the first and second left-right movable bodies  31 ,  33 , respectively. First and second up-down movable bodies  43 ,  45  are supported by the up-down frames  39 ,  41 , respectively, so as to be movable in an up-down direction. Fifth and sixth electric motors  47 ,  49  (numerically-controllable servo motors, etc.) mounted to the corresponding up-down frames  39 ,  41  are drive-connected respectively to the first and second up-down movable bodies  43 ,  45 . The first and second up-down movable bodies  43 ,  45  are driven by the electric motors  47 ,  49 , respectively, to reciprocate in an independent manner in the up-down direction. 
         [0033]    Mounting arms  51 ,  53  are mounted to the first and second up-down movable bodies  43 ,  45 , respectively. Holding members  57 ,  59  are mounted to upper portions of the mounting arms  51 ,  53 , respectively. The holding members  57 ,  59 , which constitute a one-end-side support member, are each an elastic member abutting against a rear surface of the vehicle bumper  14  to be processed to elastically support it, an adsorbing member connected to a negative pressure generator (not illustrated) to adsorb and hold the rear surface of the vehicle bumper  14 , or a gripping member that grips a projecting piece (not illustrated) integrally formed with the rear surface of the vehicle bumper  14  (in this example, the holding members  57 ,  59  are each formed as the absorbing member). 
         [0034]    Although the front-rear movable bodies  19 ,  21  are moved in the front-rear direction in an independent manner to move the holding members  57 ,  59  to desired positions in the front-rear direction in the above description, a single front-rear frame extending in the front-rear direction may be mounted to the body frame  3  so as to move the holding members  57 ,  59  in an integrated manner in the front-rear direction. 
         [0035]    Third and fourth left-right frames  61 ,  63  each extending in the left-right direction in the drawings, are fixed respectively to a rear side of the body frame  3 . Third and fourth left-right movable bodies  65 ,  67  are supported by the left-right frames  61 ,  63  respectively, so as to be movable in the left-right direction. Seventh and eighth electric motors  69 ,  71  (numerically-controllable servo motors, etc.) mounted to the corresponding third and fourth left-right frames  61 ,  63  are drive-connected respectively to the third and fourth left-right movable bodies  65 ,  67 . The third and fourth left-right movable bodies  65 ,  67  are driven by the electric motors  69 ,  71  respectively, to reciprocate in an independent manner in the left-right direction. 
         [0036]    Third and fourth up-down frames  73 ,  75  are mounted to the third and fourth left-right movable bodies  65 ,  67 , respectively. Third and fourth up-down movable bodies  77 ,  79  are supported by the up-down frames  73 ,  75 , respectively, so as to be movable in an up-down direction. Ninth and tenth electric motors  81 ,  83  (numerically-controllable servo motors, etc.) mounted to the corresponding up-down frames  73 ,  75  are drive-connected respectively to the third and fourth up-down movable bodies  77 ,  79 . The up-down movable bodies  77 ,  79  are driven by the electric motors  81 ,  83 , respectively, to reciprocate in an independent manner in the up-down direction. 
         [0037]    Mounting arms  85 ,  87  are mounted to the third and fourth up-down movable bodies  77 ,  79 , respectively. Holding members  89 ,  91  are mounted to upper portions of the mounting arms  85 ,  87 , respectively. The holding members  89 ,  91 , which constitute the other-end-side support member, are each an elastic member abutting against a rear surface of the vehicle bumper  14  to be processed to elastically support it, an adsorbing member connected to a negative pressure generator (not illustrated) to adsorb and hold the rear surface of the vehicle bumper  14 , or a gripping member that grips a projecting piece (not illustrated) integrally formed with the rear surface of the vehicle bumper  14  (in this example, the holding members  89 ,  91  are each formed as the absorbing member). 
         [0038]    A third front-rear frame  93 , extending in the front-rear direction in the drawings, is fixed to a center portion of the body frame  3 . A third front-rear movable body  95  is supported by the front-rear frame  93  so as to be movable in the front-rear direction. An eleventh electric motor  97  (numerically-controllable servo motor, etc.) mounted to the third front-rear frame  93  is drive-connected to the third front-rear movable body  95 . The third front-rear movable body  95  is driven by the electric motor  97  to reciprocate in the front-rear direction. 
         [0039]    A fifth up-down frame  99  is mounted to the third front-rear movable body  95 . A holding member  101  is mounted to an upper portion of the fifth up-down frame  99 . The holding member  101 , which serves as a reference support member, is an elastic member abutting against a rear surface of the vehicle bumper  14  to be processed to elastically support it, an adsorbing member connected to a negative pressure generator (not illustrated) to adsorb and hold the rear surface of the vehicle bumper  14 , or a gripping member that grips a projecting piece (not illustrated) integrally formed with the rear surface of the vehicle bumper  14  (in this example, the holding member  101  is formed as the absorbing member). 
         [0040]    A reciprocating mechanism of each of the movable bodies  19 ,  21 ,  31 ,  33 ,  43 ,  45 ,  65 ,  67 ,  77 ,  79 ,  95  corresponding to the first to eleventh electric motors  23 ,  25 ,  35 ,  37 ,  47 ,  49 ,  69 ,  71 ,  81 ,  83 ,  97  may be a known reciprocating mechanism such as a feed screw and nut mechanism or a feed belt mechanism. Further, a linear servo may be employed, in place of the electric motor, to constitute the reciprocating mechanism. In this example, a feed screw and nut mechanism is adopted as the reciprocating mechanism. 
         [0041]    The following describes operations in which the resin molding burr removing apparatus  1  having the above configuration removes the burr of the vehicle bumper  14  and supports the vehicle bumper  14 . First, the eleventh electric motor  97  is drive-controlled to move the third front-rear movable body  95  forward or backward, to thereby move the holding member  101  to a predetermined intermediate portion of the vehicle bumper  14  to be subjected to the burr removal in the front-rear and left-right directions. 
         [0042]    In parallel to or after the above operation, the first and second electric motors  23 ,  25  are selectively drive-controlled to move the first and second front-rear movable bodies  19 ,  21  in the front-rear direction, to thereby move the first and second left-right frames  27 ,  29  such that the holding members  57 ,  59  are positioned at a front side of the vehicle bumper  14 . In parallel to or after the above operation, the third and fourth electric motors  35 ,  37  are selectively drive-controlled to move the first and second left-right movable bodies  31 ,  33  in the left-right direction, to thereby move the holding members  57 ,  59  to left and right support portions of the vehicle bumper  14 , which are previously set according to a longitudinal direction length of the vehicle bumper  14 . 
         [0043]    In the above state, the fifth and sixth electric motors  47 ,  49  are selectively drive-controlled to move the first and second up-down movable bodies  43 ,  45  in the up-down direction, to thereby move the holding members  57 ,  59  to height positions of the vehicle bumper  14  on the left and right sides thereof, which are previously set according to a processing posture. 
         [0044]    In parallel to or after the above operation, the seventh and eighth electric motors  69 ,  71  are selectively drive-controlled to move the third and fourth left-right movable bodies  65 ,  67  in the left-right direction, to thereby move the holding members  89 ,  91  to support portions of the vehicle bumper  14  previously set according to the longitudinal direction length of the vehicle bumper  14 . 
         [0045]    In parallel to or after the above operation, the ninth and tenth electric motors  81 ,  83  are selectively drive-controlled to move the third and fourth up-down movable bodies  77 ,  79  in the up-down direction, to thereby move the holding members  89 ,  91  to height positions of the vehicle bumper  14  set on the left and right sides thereof. 
         [0046]    With the above operations, the holding members  57 ,  59 ,  89 ,  91  are moved to the left-right and height positions set on the front and rear sides of the vehicle bumper  14  with the holding member  101  to support the center portion of the vehicle bumper  14  as the center, thereby stably holding the vehicle bumper  14  in an optimum supporting or holding posture according to a size and a shape thereof. 
         [0047]      FIG. 5  illustrates a state where the front side holding members  57 ,  59  are moved forward and leftward/rightward, respectively, to a maximum extent and the rear side holding members  89 ,  91  are moved leftward and rightward, respectively, to a maximum extent, with the holding member  101  positioned at the center moved forward.  FIGS. 6 to 8  illustrate states where supporting heights of the holding members  57 ,  59 ,  89 ,  91  are variably controlled so as to support the vehicle bumper  14  in a horizontal posture, in a forward-inclined posture, and in a rearward-inclined posture, respectively. 
         [0048]    In the above respective states, the vehicle bumper  14  is transferred so as to be supported or held at the front side and rear side holding members  57 ,  59 ,  89 ,  91  which are arranged in the left-right direction with the center portion of the vehicle bumper  14  set to the center holding member  101 . As a result, the vehicle bumper  14  is stably supported or held in a state where displacement with respect to the holding members  57 ,  59 ,  89 ,  81 ,  101  is restricted. 
         [0049]    The burr cutting apparatus  5  is drive-controlled in the state where the vehicle bumper  14  is supported or held at the previously set support portions of the work support  7  to rotate and turn the first and second arms  9 ,  11  such that the cutting member  13  moves along a boundary between the outer edge of the vehicle bumper  14  and burr, to thereby cut and remove the burr from the vehicle bumper  14 . 
         [0050]    In the present embodiment, with the holding member  101  set to the center of the vehicle bumper  14 , the holding members  57 ,  59  and holding members  89 ,  91  are moved with respect to the front-side and rear-side left and right portions of the vehicle bumper  14 , thus making it possible to stably support the vehicle bumper  14  in an optimum processing posture while coping with various sizes and shapes of the vehicle bumper  14  and restricting the displacement. 
         [0051]    Although the holding member  101  mounted to the third front-rear movable body  95  which is mounted at the center of the body frame  3  so as to be movable in the front-rear direction is fixed in height in the above description, the holding member  101  may be configured to be movable in the up-down direction as well as the front-rear direction. In this case, an up-down frame is mounted to the third front-rear movable body  95 , and a support member is mounted, through a mounting arm, to an up-down movable body supported by the up-down frame so as to be movable in the up-down direction. 
         [0052]    In the above description, the reference support member is mounted to the front-rear movable body which is mounted to the center portion of the body frame  3  so as to be movable in the front-rear direction, and end-side support members supported frontward and rearward of the reference support member so as to be movable both in the left-right direction and up-down direction. Alternatively, however, in a case where a small-sized work is to be supported, a three-point support configuration may be adopted so as to correspond to claim  1 , in which two support members capable of moving both in the longitudinal direction and up-down direction are mounted on longitudinal direction both sides of the reference support member. 
         [0053]    Further, for a large-sized work like, e.g., a resin-molded vehicle panel, required to be supported at the five or more points, a plurality of support members each moving in the left-right direction, up-down direction, and directions inclined to the above directions may be mounted, in addition to the above three support members, so as to support predetermined supporting portions other than the supporting portions supported by the above three members. 
       Second Embodiment 
       [0054]    As illustrated in  FIG. 9  (illustrating a drilling apparatus as a work processing apparatus in which a drilling machine as a work processing section is omitted) and  FIG. 10 , a drilling apparatus  201  as a work processing apparatus according to a second embodiment is an apparatus that forms a hole in a predetermined portion of the vehicle bumper  14  as a work. The drilling apparatus  201  as the work processing apparatus includes, on both sides at a rear side thereof, two movable supports  203  that support a rear surface of a peripheral edge of a portion to be drilled in the vehicle bumper  14 . 
         [0055]    The drilling machine as the work processing section of the present embodiment has a configuration in which a drilling tool such as a drill is provided in place of the cutting member  13  provided at a leading end of the second arm in the burr cutting apparatus  5  of the first embodiment, and illustration thereof is omitted. The work processing member is not limited to the above-mentioned drilling tool, but may be a rotary blade, a laser output head that performs cutting using laser beam, or the like. Configurations of the drilling apparatus  201  other than the two movable supports  203  and drilling machine are the same as those of the first embodiment, so the same reference numerals are used for the identical components, and the description thereof is omitted. 
         [0056]    The movable supports  203  each have a multi-joint structure that moves, at least three-dimensional directions, a movable support member  205  that abuts against and supports the rear surface of the peripheral edge of the portion to be drilled in the vehicle bumper  14 . The movable supports  203  includes, as illustrated in  FIG. 10 , first to sixth joints  209 ,  211 ,  213 ,  215 ,  217 ,  219 , and a fixing member  221 . The first joint  209  is supported by a base  207  so as to be rotatable about a horizontal axis thereof and is connected to a built-in electric motor (not illustrated). The second joint  211  is supported at a leading end of the first joint  209  so as to be rotatable about an axis inclined at a predetermined angle relative to an extending direction of the first joint  209  and is connected to a built-in electric motor (not illustrated). The third joint  213  is supported at a leading end of the second joint  211  so as to be rotatable about an axis inclined at a predetermined angle relative to an extending direction of the second joint  211  and is connected to a built-in electric motor (not illustrated). The fourth joint  215  is supported at a leading end of the third joint  213  so as to be rotatable about an axis inclined at a predetermined angle relative to an extending direction of the third joint  213  and is connected to a built-in electric motor (not illustrated). The fifth joint  217  is supported at a leading end of the fourth joint  215  so as to be rotatable about an axis orthogonal to an extending direction of the fourth joint  215  and is connected to a built-in electric motor (not illustrated). The sixth joint  219  is supported at a leading end of the fifth joint  217  so as to be rotatable about an axis orthogonal to an extending direction of the fifth joint  217  and is connected to a built-in electric motor (not illustrated). The mounting member  221  is supported at a leading end of the sixth joint  219  so as to be rotatable about an axis coinciding with an extending direction of the sixth joint  219  and is connected to a built-in electric motor (not illustrated). Numerically-controllable servo motors, etc. are suitably used as the above electric motors. 
         [0057]    The movable support member  205  is fixed to each of the mounting members  221  so as to extend at a predetermined angle. The movable support member  205  is drive-controlled by the electric motor to be moved in seven-axis directions and then supports the rear surface of the peripheral edge of the portion to be drilled by abutting, at a leading end thereof, thereagainst. 
         [0058]    The number of joints of the movable support  203  is not limited to the above example, but may be increased/decreased in accordance to the number of movement dimensions required for the movable support member  205 . 
         [0059]    The following describes operations to be performed by the drilling apparatus  201  having the above configuration. The operation for supporting the vehicle bumper  14  as a work is the same as that performed by the work support  7  provided in the resin molding burr removing apparatus  1  according to the first embodiment, so the detailed description thereof is omitted. 
         [0060]    Prior to the drilling with respect to a predetermined portion of the vehicle bumper  14  supported by the work support  7 , the electric motors are drive-controlled to rotate or swing the first to sixth joints  209 ,  211 ,  213 ,  215 ,  217 ,  219 , thereby moving each of the movable support members  205  within a region among positions denoted by a long dashed short dashed line and a long dashed double-shirt dashed line in  FIG. 11  and causing the same to abut against and support the rear surface of the peripheral edge of the portion to be drilled set in the vehicle bumper  14 . 
         [0061]    In the above state, the arms of the drilling machine is drive-controlled to move the drilling tool to an upper surface of the portion to be drilled in the vehicle bumper  14 , and then the arms are drive-controlled to press the drilling tool against the portion to be drilled to perform drilling. At this time, the periphery of the portion to be drilled may be warped or position of the vehicle bumper  14  may be displaced due to the pressing of the drilling tool against the portion to be drilled, which may result in failing to drill a desired hole in the portion to be drilled with high accuracy. However, since the rear surface of the peripheral edge of the portion to be drilled in the vehicle bumper  14  is supported by the movable support member  205  as described above, the warp of the periphery of the portion to be drilled or displacement of the position of the vehicle bumper  14  is restricted, thereby performing the drilling for the vehicle bumper  14  with high accuracy. 
         [0062]    The second embodiment may be modified in the same manner as the first embodiment. Further, although the movable support  203  moves, in a multi-dimensional manner, the movable support member  205  to the rear surface of the peripheral edge of the portion to be drilled in the vehicle bumper  14  based on the rotation and swing of the first to sixth joints  209 ,  211 ,  213 ,  215 ,  217 ,  219  in the second embodiment, the movable support  203  according to the present invention may have an orthogonal three-axis structure. 
         [0063]    That is, as illustrated in  FIG. 12 , a first movable body  305  extending in the front-rear direction in the drawing is supported by a support table  303  of a movable support  301  such that both end portions of the first movable body  305  reciprocate in the left-right direction in the drawing. The first movable body  305  is caused to reciprocate in the left-right direction in the drawing by a feed screw or a timing belt connected to an electric motor  304  (numerically-controllable servo motor, etc.) mounted in the support table  303  or a linear motor mounted therein ( FIG. 12  illustrates an example in which the electric motor  304  is employed). A second movable body  307  is supported by the first movable body  305  so as to reciprocate in the front-rear direction in the drawing. The second movable body  307  is caused to reciprocate in the front-rear direction in the drawing by a feed screw or a timing belt connected to an electric motor  306  (numerically-controllable servo motor, etc.) mounted in the first movable body  305  or a linear motor mounted therein ( FIG. 12  illustrates an example in which the electric motor  306  is employed). 
         [0064]    A base end of an up-down frame  309  extending in the up-down direction in the drawing is fixed to the second movable body  307 , and a lifting mounting member  311  is supported by the up-down frame  309  so as to reciprocate in the up-down direction. The lifting mounting member  311  is caused to reciprocate in the up-down direction in the drawing by a feed screw or a timing belt connected to an electric motor  312  (numerically-controllable servo motor, etc.) mounted in the up-down frame  309  or a linear motor mounted therein ( FIG. 12  illustrates an example in which the electric motor  312  is employed). A base end of a movable support member  313  extending in the up-down direction or extending inclined relative to the up-down direction at an appropriate angle is fixed to the lifting mounting member  311 . A leading end of the movable support member  313  is made to rise and fall between a support position at which it abuts against the rear surface of the peripheral edge of the portion to be drilled in the vehicle bumper  14  and a standby position spaced downward from the support position along with rise and fall of the lifting mounting member  311 . 
         [0065]    The movable support  301  having the three-dimensional movement structure is configured to, prior to the drilling with respect to a predetermined portion of the vehicle bumper  14  supported by the work support  7 , drive-control the electric motors to move the first and second movable bodies  305 ,  307  such that the movable support member  313  is positioned at the peripheral edge of the portion to be drilled set in the vehicle bumper  14 . 
         [0066]    In the above state, the electric motor is drive-controlled to move the lifting mounting member  311  upward to cause the leading end of the movable support member  313  to abut against and support the rear surface of the peripheral edge of the portion to be drilled. Since the movable support member  313  abuts against and supports the rear surface of the peripheral edge of the portion to be drilled in the vehicle bumper  14  when the drilling is performed by pressing the drilling tool positioned at the portion to be drilled thereagainst, the warp of the periphery of the portion to be drilled or displacement of the position of the vehicle bumper  14  is restricted, thereby performing the drilling for the vehicle bumper  14  with high accuracy.