Patent Publication Number: US-2022234157-A1

Title: Gantry type conveying device and processing line

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is continuation of a U.S. patent application Ser. No. 15/761,087 filed on Mar. 17, 2018, which is a U.S. National Stage Application under 35 U.S.C. § 371 of International Patent Application No. PCT/JP2016/075652 filed Sep. 1, 2016, which claims the benefit of priority to Japanese Patent Application No. 2015-183535 filed Sep. 17, 2015, the disclosures of all of which are hereby incorporated by reference in their entities. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a gantry type conveying device and a processing line. 
     BACKGROUND ART 
     Patent Document 1 (JP2002-178238 A) discloses an automatic supply and removal device for supplying and removing a work to/from a machine tool, as an example of a conventional gantry type conveying device. 
     This automatic supply and removal device is provided with a beam horizontally supported by two posts, a robot main-body (runner) moving along this beam, and a robot hand provided to this robot main-body to hold a work (see paragraphs [0020], FIG. 9, etc.). 
     RELATED ART DOCUMENT 
     Patent Document 
     Patent Document 1: JP2002-178238 A 
     DISCLOSURE OF THE INVENTION 
     Problems to be Solved by the Invention 
     However, on the automatic supply and removal device (gantry type conveying device) described in Patent Document 1, the robot hand, which is a part for holding a work, has a complicated structure because the robot hand clamps and conveys the work during conveying. Further, as it is necessary to mount units such as clamp driving means on the robot hand, the number of components is large and the cost is high. 
     The present invention has been developed in this situation, and an object of the invention is to provide a gantry type conveying device and a processing line that enables reduction in the number of components and has a compact and simple structure. 
     Means for Solving the Problems 
     In order to solve the above-described problems, a gantry type conveying device according to the invention includes: a beam horizontally arranged; a runner that runs along the beam; an elevator that is supported movably in upper-lower direction relatively to the runner; and a mount that is supported at a lower portion of the elevator to mount thereon a conveyance object. 
     By this structure, the conveyance object is conveyed such as to be mounted on the mount that is supported at the lower portion of the elevator movable in the upper/lower direction relatively to the runner running along the beam. In other words, the conveyance object is lifted by the mount and moved (lift and carry). In such a manner, on the gantry type conveying device, just by mounting a conveyance object on the mount without clamping a conveyance object such as a work as conventionally done, the conveyance object can be held and conveyed. Thus, according to the present invention, a unit such as clamp driving means in unnecessary. 
     Consequently, according to the invention, it is possible to provide a gantry type conveying device that enables reduction in the number of components and has a compact and simple structure. 
     Further, on the gantry type conveying device, the conveying time can be shortened because clamping operation of a conveyance object is not performed. Still further, as the mount has a simple structure without driving means nor electrical wires, even when the kind of a conveyance object such as a work is changed, it is possible to easily replace the mount, corresponding to the kind of the conveyance object. 
     The above-described gantry type conveying device is preferably arranged such that: a plurality of the conveyance objects can be mounted on the mount; and the mount is supported at the lower portion of the elevator rotatably around a vertical axis. 
     By this structure, as it is possible to mount a plurality of, for example, works on a single mount and simultaneously convey them, efficient conveyance is possible. For example, on a gantry type conveying device on which conventional clamping of works, in order to replace a work before processing and a work after processing by a machine tool, it is necessary to provide two robot hands to the device as one set for work replacement. In contrast, by this structure, for example, by mounting a work before processing and a work after processing on a single mount and rotating the mount around a vertical axis, it is possible to selectively move one work to a position facing a machine tool. In such a manner, it is possible to replace a work before processing and a work after processing, using a single mount. 
     The above-described gantry type conveying device is preferably arranged such that: the mount is provided with a positioning member that positions the conveyance object on the mount. 
     By this structure, it is possible to prevent a conveyance object from being shifted from the mount, and ensure the delivery of the conveyance object between the mount and, for example, a machine tool. 
     In order to solve the above-described problems, a processing line according to the present invention includes: the above-described gantry type conveying device; and a machine tool that performs processing of a work, wherein the conveyance object include the work, and wherein the machine tool is provided with a base, and a work support device that is arranged movably in a direction perpendicular to an extension direction of the beam in a plan view and supports the work. 
     By this structure, it is possible to provide a processing line for which a gantry type conveying device, which has a compact and simple structure and enables reduction in the number of components, is applied for a machine tool. 
     Further, using the work support device of the machine tool, as a mechanism for conveying a conveyance object in a direction perpendicular to a beam, it is possible to convey this conveyance object to an arbitrary position in three-dimensional direction. In such a manner, it is possible to make the structure of the entire processing line more compact and simple. 
     The above-described processing line is preferably arranged such that: the work support device includes a carriage movable in the direction perpendicular to the extension direction of the beam in the plan view, and a holding section that is installed to the carriage and holds the work: and the holding section is rotatable around an axis that is parallel to the beam. 
     By this structure, in making the holding section hold a work, it is possible to select one of the upper surface and the lower surface of the work, as the fitting reference surface, the one facing the holding section. That is, it is possible to replace the fitting reference surface, of the work, which faces the holding section. In such a manner, for example, processing of both the upper surface and the lower surface of the work is made possible. 
     The above-described gantry type conveying device preferably further includes: a shifting device that delivers the conveyance object between itself and the mount and moves the conveyance object in a direction perpendicular to an extension direction of the beam in a plan view. 
     By this structure, it is possible by the shifting device to move a conveyance object in a direction perpendicular to the beam, the conveyance object being lifted by the mount and moved along the beam. In such a manner, the conveyance object can be conveyed to a three dimensionally arbitrary position. 
     Advantageous Effect of the Invention 
     According to the present invention, it is possible to provide a gantry type conveying device and a processing line that enables reduction in the number of components and has a compact and simple structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic front view of a processing line in an embodiment of the present invention; 
         FIG. 2  is a schematic side view of the processing line; 
         FIG. 3  is a schematic perspective view showing the periphery of a work support device of a machine tool shown in  FIG. 1 ; 
         FIG. 4  is an enlarged front view of the periphery of a runner of a gantry type conveying device shown in  FIG. 1 ; 
         FIG. 5  is an enlarged side view of the periphery of the runner of the gantry type conveying device; 
         FIG. 6  is an enlarged plan view of the periphery of the runner of the gantry type conveying device; 
         FIG. 7A  is an enlarged plan view of a mount and  FIG. 7B  is an enlarged side view of the mount; 
         FIGS. 8A to 8D  are schematic side views for illustrating a method of conveying a work, with the lower surface of the work as a fitting reference surface facing a jig; 
         FIGS. 9A to 9D  are schematic side views for illustrating the method of conveying a work following  FIGS. 8A to 8D ; 
         FIGS. 10A and 10D  are schematic side views for illustrating the method of conveying a work following  FIGS. 9A to 9D ; 
         FIG. 11  is a schematic perspective view showing the periphery of the work support device in a state that a jig of a hold section is at an upper position as a result of being rotated by 180 degrees around A-axis from a lower position shown in  FIG. 3 ; 
         FIGS. 12A to 12D  are schematic side views for illustrating a method of conveying a work, with the upper surface of the work as a fitting reference surface facing a jig; 
         FIGS. 13A to 13D  are schematic side views for illustrating the method of conveying a work following  FIGS. 12A to 12D ; and 
         FIGS. 14A to 14D  are schematic side views for illustrating the method of conveying a work following  FIGS. 13A to 13D . 
     
    
    
     EMBODIMENTS FOR CARRYING OUT THE INVENTION 
     Embodiments of the present invention will be described in detail, referring to the drawings, as appropriate. 
     In the respective figures, the same reference symbols will be assigned to the same elements, and overlapping description will be omitted. Further, the size and the shape of a member may be schematically represented with a change or exaggeration for the convenience of illustration. 
       FIG. 1  is a schematic front view of a processing line  100  in an embodiment of the present invention.  FIG. 2  is a schematic side view of the processing line  100 .  FIG. 3  is a schematic perspective view showing the periphery of a work support device  85  of a machine tool  80  shown in  FIG. 1 . 
     In  FIG. 1  and  FIG. 2 , X-axis direction corresponds to the left-right direction (horizontal direction), Y-axis direction corresponds to the upper-lower direction (vertical direction), and Z-axis direction corresponds to the front-rear direction (depth direction) (likewise in  FIGS. 3 to 6 ). In  FIG. 2 , a gantry type conveying device  10  is shown only partially, for the brevity of illustration. 
     As shown in  FIG. 1  and  FIG. 2 , the processing line  100  is provided with the gantry type conveying device  10  for conveying a work W as a conveyance object, and machine tools  80  for processing the work W. On the processing line  100 , a plurality of machine tools  80  are arranged along X-axis direction, however, in  FIG. 1 , only one unit is shown for the convenience of description. In this case, the gantry type conveying device  10  conveys the work W into the machine tool  80  installed at the upstream end of the flow of the work W, conveys the work W to a neighboring one of the machine tools  80 , and conveys the work W out from the machine tool  80  installed at the downstream end. However, only one machine tool  80  may be arranged on the processing line  100 . In this case, the gantry type conveying device  10  conveys the work W from a work storage section for conveying-in into a machine tool  80 , and conveys the work W out from the machine tool  80  to a work storage section for conveying-out. 
     As shown in  FIG. 2 , in the present embodiment, a machine tool  80  is a horizontal type machine tool on which a main shaft  81  is arranged such as to be along the horizontal direction. The machine tool  80  is provided with a base  82 , a column  83 , a saddle  84 , a work support device  85 , and a cover  86 . 
     The column  83  is arranged on the base  82 , movably in X-axis direction (the direction perpendicular to the sheet of  FIG. 2 ), the movement being relative to the base  82 . The column  83  is moved along X-axis direction by screw transfer by forward and reverse rotation of a screw shaft (not shown) driven by a motor (not shown) installed to the base  82 . The saddle  84  is arranged movably in Y-axis direction (upper-lower direction), the movement being relative to the column  83 . The saddle  84  is moved along Y-axis direction by screw transfer by forward and reverse rotation of a screw shaft (not shown) driven by a motor (not shown) installed to the column  83 . 
     The saddle  84  rotatably supports the main shaft  81 , a tool T being installed to the tip end of the main shaft  81 . Inside the saddle  84 , a rotation shaft (not shown) is disposed; one end side of the rotation shaft is connected to the main shaft  81 ; and the other end side of the rotation shaft is connected to a motor (not shown). When this motor is driven, the main shaft  81  is rotated. 
     The work support device  85  supports a work W, which is an object of processing. The work support device  85  is disposed movably, the movement being relative to the base  82  and in the horizontal direction perpendicular in a plan view to the extension direction of a beam  11  (see  FIG. 1 ), in other words Z-axis direction (front-rear direction). The work support device  85  is moved along Z-axis direction by screw transfer by forward and reverse rotation of a screw shaft (not shown) driven by a motor (not shown) installed to the base  82 . 
     As shown in  FIG. 3 , the work support device  85  is provided with a carriage  87  movable in Z-axis direction, and a holding section  88  installed to the carriage  87  to hold a work W. The holding section  88  is installed to the carriage  87 , rotatably around A-axis, which is parallel to the beam  11  (see  FIG. 1 ). The holding section  88  is provided with a turn table  90  rotated through a driving force transmission mechanism (not shown) such as gears or belt, by driving a motor  89 , and a jig  91  that is installed to the turn table  90  to position and set the work W. 
     As shown in  FIG. 1  and  FIG. 2 , the cover  86  is arranged such as to cover the processing region in processing a work W, the work support device  85 , and the like, so as to prevent scattering and leaking of coolant and the like. 
     A front upper surface  92  of the cover  86  is formed such as to be located lower than the rear upper surface. In such a manner, a mount  14  of the gantry type conveying device  10  can be made close to the work support device  85  to a larger extent in the height direction (Y-axis direction). Accordingly, it is possible to make it easy to convey the work W into or out from the work support device  85 . 
     Further, the front upper surface  92  of the cover  86  is provided with a door  93  openable and closable, for example, such as to slide in left-right direction (X-axis direction). The door  93  is opened when a work W is conveyed into or out from the machine tool  80 , and is closed when the work W is processed. 
     The gantry type conveying device  10  is provided with the beam  11  horizontally arranged, a runner  12  that is driven along the beam  11 , an elevator  13  that is supported movably in upper-lower direction relatively to the runner  12 , and the mount  14  supported at the lower portion of the elevator  13  to mount the work W. The beam  11  is fixed at the upper portions of the plural posts  15 ,  15 . 
       FIG. 4  is an enlarged front view of the periphery of the runner  12  of the gantry type conveying device  10  shown in  FIG. 1 .  FIG. 5  is an enlarged side view of the periphery of the runner  12  of the gantry type conveying device  10 .  FIG. 6  is an enlarged plan view of the periphery of the runner  12  of the gantry type conveying device  10 .  FIG. 7A  is an enlarged plan view of the mount  14  and  FIG. 7B  is an enlarged side view of the mount  14 . Incidentally, in  FIG. 6 , the mount  14  and the like are not shown, for the brevity of description. 
     As shown in  FIG. 4 , the runner  12  is provided with a running plate  16  in a rectangular shape in a front view. A running servo motor  17  is mounted on the running plate  16 . 
     As shown in  FIG. 5 , a pinion  18  is connected to the drive shaft of the running servo motor  17 . The pinion  18  is engaged with a rack  20  installed to the beam  11  through a reference block  19 . Accordingly, the runner  12  can run (see arrow A 1  in  FIG. 4 ) along the beam  11 , driven by the running servo motor  17 . 
     An upper rail  21  is installed to the upper surface of the reference block  19 , and a lower rail  22  is installed to the lower surface of the beam  11 . On the other hand, a load receiving roller  23  is installed to the running plate  16  to be rotatable. The load receiving roller  23  rolls in sliding contact with the upper surface of the upper rail  21 , and receives and supports the load of the runner  12  and the like. Further, the upper rail  21  and the lower rail  22  are sandwiched respectively by guide rollers  24 ,  25  from the respective both ends so that the runner  12  is guided in running. 
     As shown in  FIG. 6 , the elevator  13  is provided with a longitudinal elevation member  26  with a horizontal cross-section substantially in a C-shape (U-shape). The elevator  13  is supported on the running plate  16  by a movement guide mechanism  27 , such as to be movable in vertical direction (Y-axis direction). The movement guide mechanism  27  is provided with two guide rails  28  installed to the back surface (rear surface) of the elevation member  26 , and plural sliders  29  slidably engaged with the respective guide rails  28 , and is a known linear movement mechanism. 
     As shown in  FIG. 4 , an elevation servo motor  30  is mounted on the running plate  16 . A pinion  31  is connected to the drive shaft of the elevation servo motor  30 . The pinion  31  is engaged with a rack  32  installed to the side surface of the elevation member  26  of the elevator  13 . Accordingly, being driven by the elevation servo motor  30 , the elevator  13  is movable in upper-lower direction (see arrow A 2  in  FIG. 4 ), relatively to the runner  12 . 
     Accompanying the upward-downward movement of the elevator  13 , the mount  14  is moved up and down between the upper position (see  FIG. 8A , etc.) taken when the work W is conveyed along the beam  11  and a lower position (see  FIG. 8B , etc.) taken when the work W is supplied to or removed from the machine tool  80 . 
     The elevation member  26  of the elevator  13  is provided with a bottom wall  33  on the lower end side. A rotary servo motor  34  is mounted on the upper surface of the bottom wall  33  of the elevation member  26 . A rotation shaft  35  is connected to the drive shaft of the rotary servo motor  34 . The mount  14  is fixed at the lower end of the rotation shaft  35 . That is, the mount  14  is supported by the bottom wall  33  at the lower portion of the elevator  13  through the rotary servo motor  34  and the rotation shaft  35 , such as to be able to rotate around a vertical axis (Y-axis) (see arrow A 3  in  FIG. 4 ). 
     As shown in  FIGS. 7A and 7B , the mount  14  has a plate shape that is substantially rectangular. Herein, the concept ‘rectangular shape’ includes not only ‘strictly rectangular’ but also ‘substantially rectangular shape’, for example, a rectangular shape whose corner portions are chamfered, rounded, or partially notched. Plural works W (herein, two) can be mounted on the mount  14 . Concretely, the mount  14  is in a point symmetric shape with respect to a fitting center  36  of the rotation shaft  35 , and the works W can be mounted on the both sides, with the fitting center  36  therebetween. 
     The mount  14  is provided with positioning pins  37 ,  38 , which serve as positioning members for positioning the works W in a horizontal surface on the mount  14 , the positioning pins  37 ,  38  being fixed by screw fastening or the like. Further, the mount  14  is provided with support pads  39  and guides  40  fixed by screw fastening or the like. The works W are positioned on a horizontal surface such that the positioning pins  37 ,  38  come in contact with the side surfaces of the works W while the works W are guided by the guides  40 . The works W are supported such that the support pads  39  receive loads. 
     Incidentally, the structure of positioning and mounting the works W on the mount  14  is not limited to the above-described structure. For example, the works W may be positioned on the horizontal surface such that positioning pins, which are fixed on the mount  14 , are inserted in hole portions formed on the works W. In this case, large diameter portions in a stepped shape may be arranged at the lower portions of the positioning pins so that these large diameter portions receive the loads of the works W to support the works W. 
     In the present embodiment, the work support device  85  (see  FIG. 2 ) of the machine tool  80  has also a function to deliver a work W between the work support device  85  and the mount  14  and move the work W in Z-axis direction (front-rear direction). 
     In the following, operations in the above-described present embodiment will be described. First, referring to  FIGS. 8 to 10 , a method of conveying a work W with the lower surface of a work W as a fitting reference surface, which faces the jig  91  will be described. 
     The jig  91  in  FIGS. 8 to 10  is used to fit a work W to the holding section  88  of the work support device  85 , with the lower surface of the work W as the fitting reference surface. In  FIGS. 8 to 10 , the work W without hatching shows a work W before processing on the machine tool  80  concerned, while the hatched work W shows a work W after processing (likewise in  FIGS. 12 to 14 ). 
     As shown in  FIG. 8A , when the gantry type conveying device  10  starts operation upon an instruction from a control device (not shown, likewise hereinafter), the runner  12  (see  FIG. 4 , likewise hereinafter) is driven by the running servo motor  17  (see  FIG. 4 , likewise hereinafter) to run along the beam  11  (see  FIG. 4 , likewise herein). Then, the runner  12  moves to and stops at a position right above the door  93  arranged on the front upper surface  92  of the cover  86  of the machine tool  80  (see  FIG. 2  for each, likewise hereinafter). 
     Herein, the mount  14  is located at the upper position when the work W is conveyed along the beam  11 . The work support device  85  is located at a rear position that is set posterior to the mount  14  of the gantry type conveying device  10  in Z-axis direction (front-rear direction). The work W after processing is clamped by a clamp mechanism (not shown, likewise hereinafter) provided on the holding section  88  of the work support device  85  (see  FIG. 3 , likewise hereinafter). 
     Subsequently, the door  93  is opened, and as shown in  FIG. 8B , the elevator  13  is driven by the elevation servo motor  30  (see  FIG. 4 , likewise hereinafter) to move down. Accompanying this, the mount  14  moves down to and stops at the lower position taken when the mount  14  supplies the work W to or removes the work W from the machine tool  80 . 
     Subsequently, as shown in  FIG. 8C , the work support device  85  moves forward to and stops at a front position taken when the work support device  85  delivers the work W. Then, a portion of the mount  14 , at which portion a work W is not mounted on the mount  14  and the portion is free, is inserted below the work W which is after processing and fitted to the jig  91  of the work support device  85 . 
     Subsequently, the clamp of the work W by the clamp mechanism is released, and as shown in  FIG. 8D , the elevator  13  is driven by the elevation servo motor  30  to move up by a predetermined distance. Accompanying this, the mount  14  moves up to and stops at a middle position that is between the above-described upper position and the lower position and is a little higher than the lower position. Thus, the work W is lifted by the predetermined distance to be mounted on the mount  14 . 
     Subsequently, as shown in  FIG. 9A , the work support device  85  moves backward to and stops at an off-position that is between the above-described front position and the rear position and is a little posterior to the front position. 
     Subsequently, as shown in  FIG. 9B , the mount  14  is driven by the rotary servo motor  34  to rotate by 180 degrees around the vertical axis (Y-axis). Thus, the positions of the work W before processing and the work W after processing are switched to each other in the front-rear direction. 
     Subsequently, as shown in  FIG. 9C , the work support device  85  moves forward from the off-position to the front position and stops. 
     Subsequently, as shown in  FIG. 9D , the elevator  13  is driven by the elevation servo motor  30  to move down by the predetermined distance. Accompanying this, the mount  14  moves down from the middle position to the lower position and stops. Thus, the work W before processing is mounted onto the jig  91  and clamped by the clamp mechanism. 
     Subsequently, as shown in  FIG. 10A , the work support device  85  moves backward to the above-described rear position and stops. Then, the portion, at which the work W before processing has been mounted on the mount  14 , is relatively drawn out from below the work W before processing and comes to appear. 
     Subsequently, as shown in  FIG. 10B , the elevator  13  is driven by the elevation servo motor  30  to move up. Accompanying this, the mount  14  moves up to the above-described upper position and stops, and the door  93  gets closed. Thereafter, the machine tool  80  performs certain processing of the work W, which is supported by the work support device  85  and is before processing. 
     Subsequently, referring to  FIGS. 11 to 14D , a method of conveying a work W, with the upper surface of the work W as a fitting reference surface facing the jig  91 , will be described. 
       FIG. 11  is a schematic perspective view showing the periphery of the work support device  85  in a state that the jig  91  of the hold section  88  is at an upper position as a result of being rotated by 180 degrees around A-axis from a lower position shown in  FIG. 3 .  FIGS. 12A to 14D  are schematic side views for illustrating a method of conveying a work W, with the upper surface of the work W as a fitting reference surface facing the jig  91 . 
     The jig  91  in  FIGS. 12A to 14D  is a jig for fitting the work W to the holding section  88  of the work support device  85 , with the upper surface of the work W as the fitting reference surface. 
     As shown in  FIG. 12A , when the gantry type conveying device  10  starts operation upon an instruction from the control device, the runner  12  is driven by the running servo motor  17  to run along the beam  11 . Then, the runner  12  moves to and at the position right above the door  93  arranged on the front upper surface  92  of the cover  86  of the machine tool  80 . 
     In this occasion, the mount  14  is at the upper position taken when the work W is conveyed along the beam  11 . The work support device  85  is at the rear position that is set posterior to the mount  14  in Z-axis direction (front-rear direction). The work W is clamped by the clamp mechanism arranged on the holding section  88  at an upper position, as shown in  FIG. 11 . 
     Subsequently, the door  93  gets opened, and as shown in  FIG. 12B , the elevator  13  is driven by the elevation servo motor  30  to move down. Accompanying this, the mount  14  moves down to and stops at the lower position taken when the work W is supplied to or removed from the machine tool  80 . 
     Subsequently, as shown in  FIG. 12C , the work support device  85  moves forward to and stops at the front position taken when the work support device  85  delivers the work W. Then, a portion of the mount  14 , at which portion a work W is not mounted on the mount  14  and the portion is free, is relatively inserted below the work W which is after processing and installed to the jig  91  of the work support device  85 . 
     Subsequently, as shown in  FIG. 12D , the elevator  13  is driven by the elevation servo motor  30  to move up by a predetermined distance. Accompanying this, the mount  14  moves up to and stops at the middle position that is between the above-described upper position and the lower position and is a little higher than the lower position. The clamp of the work W by the clamp mechanism is released at this middle position, and the work W after processing gets mounted onto the mount  14 . 
     Subsequently, as shown in  FIG. 13A , the elevator  13  is driven by the elevation servo motor  30  to move down by the predetermined distance. Accompanying this, the mount  14  moves down to the above-described lower position and stops. 
     Subsequently, as shown in  FIG. 13B , the work support device  85  moves backward to and stops at the off-position that is between the above-described front position and the rear position and is a little posterior to the front position. 
     Subsequently, as shown in  FIG. 13C , the mount  14  is driven by the rotary servo motor  34  to rotate by 180 degrees around the vertical axis (Y-axis). Thus, the positions of the work W before processing and the work W after processing are switched to each other in the front-rear direction. 
     Subsequently, as shown in  FIG. 13D , the work support device  85  moves forward from the off-position to the front position and stops. 
     Subsequently, as shown in  FIG. 14A , the elevator  13  is driven by the elevation servo motor  30  to move up by the predetermined distance. Accompanying this, the mount  14  moves up to the above-described middle position and stops. The work W before processing is clamped at this middle position by the clamp mechanism. 
     Subsequently, as shown in  FIG. 14B , the elevator  13  is driven by the elevation servo motor  30  to move down by the predetermined distance. Accompanying this, the mount  14  moves down to the above-described lower position and stops. 
     Subsequently, as shown in  FIG. 14C , the work support device  85  moves backward to the above-described rear position and stops. Then, the portion, at which the work W before processing has been mounted on the mount  14 , is relatively drawn out from below the work W and comes to appear. 
     Subsequently, as shown in  FIG. 14D , the elevator  13  is driven by the elevation servo motor  30  to move up. Accompanying this, the mount  14  moves up to the above-described upper position and stops, and the door  93  is closed. Thereafter, the machine tool  80  performs certain processing of the work W, which is supported by the work support device  85  and is before processing. 
     As described above, the gantry type conveying device  10  in the present embodiment is provided with the runner  12 , which runs along the beam  11 , the elevator  13 , which is supported movably in upper-lower direction relatively to the runner  12 , and the mount  14 , which is supported at the lower portion of the elevator  13  to mount a work W on. 
     Accordingly, in the present embodiment, a work W is conveyed in such a manner that the work W is mounted on the mount  14  that is supported at the lower portion of the elevator  13 , which is movable in upper-lower direction relatively to the runner  12  which runs along the beam  11 . That is, the work W is lifted by the mount  14  and moved (lift and carry). In such a manner, on the gantry type conveying device  10 , it is possible to hold and convey a work W by just mounting the work W on the mount  14 , without the necessity of clamping the work W as conventional. Accordingly, a unit such as clamp-driving means is unnecessary. 
     Consequently, according to the present embodiment, it is possible to provide a gantry type conveying device  10  that enables reduction in the number of components and has a compact and simple structure. 
     Further, as clamping operation of a work W is not performed on the gantry type conveying device  10 , the conveyance time can be shortened. Further, as the mount  14  has a simple structure without driving means and electrical wires, even when the kind of a work W is changed, it is possible to easily replace the mount  14 , corresponding to the kind of the work W. 
     Further, in the present embodiment, plural works W can be mounted on the mount  14 , and the mount  14  is supported at the bottom wall  33 , which is the lower portion of the elevator  13 , such as to be able to rotate around the vertical axis via the rotary servo motor  34  and the rotation shaft  35 . 
     By this structure, efficient conveying is enabled because plural works W can be mounted on a single mount  14  and simultaneously conveyed. For example, for a gantry type conveying device, on which conventional clamping of works W is performed, it is necessary to provide two robot hands as one set for replacing works in order to replace, for a machine tool  80 , between a work W before processing and a work W after processing. On the other hand, according to the present embodiment, for example, by mounting a work W before processing and a work W after processing on a single mount  14  and turning the mount  14  around a vertical axis, it is possible to selectively move one work W to a position facing a machine tool  80 . In such a manner, it is possible to replace a work W before processing and a work W after processing, using a single mount  14 . 
     Further, in the present embodiment, the mount  14  is provided with the positioning pins  37 ,  38  for positioning works W on the mount  14 . 
     By this structure, it is possible to prevent works W from deviating from the mount  14 , and ensure the delivery of a work W between the mount  14  and, for example, the work support device  85  of a machine tool  80 . 
     Still further, the processing line  100  in the present embodiment is provided with the gantry type conveying device  10  and the machine tool  80 . The machine tool  80  is provided with the base  82  and the work support device  85 , which is arranged such as to be movable, in a direction perpendicular to the extension direction of the beam  11  in a plan view, relatively to the base  82 . 
     By this structure, it is possible to provide a processing line  100  for which a gantry type conveying device  10 , which has a compact and simple structure and enables reduction in the number of components, is applied to a machine tool  80  or machine tools  80 . Further, using the work support device  85  of the machine tool  80 , as a mechanism for conveying a work W in a direction perpendicular to a beam, it is possible to convey this conveyance object to an arbitrary position in three-dimensional direction. In such a manner, it is possible to make the structure of the entire processing line  100  more compact and simple. 
     Yet further, in the present embodiment, the work support device  85  is provided with the carriage  87  movable in a direction perpendicular to the extension direction of the beam  11  in a plan view, and the holding section  88  installed to the carriage  87  to hold a work W, and the holding section  88  can rotate around A-axis in parallel to the beam  11 . 
     By this structure, in making the holding section  88  hold a work W, it is possible to select one of the upper surface and the lower surface of the work W, as the fitting reference surface, the one facing the holding section  88 . That is, it is possible to replace the fitting reference surface, of the work, which faces the holding section. In such a manner, for example, processing of both the upper surface and the lower surface of the work W is made possible. 
     The present invention has been described above, based on embodiments, however, the present invention is not limited to the structures described in the above-described respective embodiments, and it is possible to change or modify the structures described in the respective embodiments in a range without departing from the spirit, including appropriate combination and selection. Further, the structures in the above-described embodiments allow partial addition, deletion, and substitution. 
     For example, the above embodiments have been described, taking an example of applying the invention to a horizontal type machine tool, however, without being limited thereto, the invention can be applied to various machine tools. The present invention can be applied, for example, to vertical type machine tools, and machining centers provided with an automatic tool replacing device. 
     Further, although, the above embodiments have been described, taking an example where conveyance objects conveyed by the gantry type conveying device  10  are works W, however, the invention is not limited thereto. The gantry type conveying device  10  can also convey, for example, the jig  91  for setting a work W provided on the work support device  85 . By such a structure, even if the kind of works W has been changed, the gantry type conveying device  10  can convey and replace the jig  91 , corresponding to the kind of the works W. 
     Still further, although, in the above-described embodiments, as the driving force transmission mechanism in moving the runner  12  and the elevator  13  by a motor, a mechanism using a rack and pinion is used, the invention is not limited thereto. Other driving force transmission mechanisms, for example, a screw transfer mechanism, a mechanism using a belt and a pulley, or the like, may be used. Still further, in the above-described embodiments, as the mechanism for rotating the mount  14 , a mechanism in which the rotation shaft  35  is connected to the drive shaft of the rotary servo motor  34  is used, however, the invention is not limited thereto. For example, a mechanism in which a gear fixed to the drive shaft of the rotary servo motor  34  is engaged with a gear fixed to the rotation shaft  35  may be used. 
     Further, although, in the above-described embodiments, the mount  14  allows mounting two works W thereon, the invention is not limited thereto, and a structure allowing mounting more than two works W thereon may be applied. In this case, the mount  14  may have a structure on which plural kinds of works W can be simultaneously mounted. Further, although the mount  14  has a rectangular plate shape, the invention is not limited thereto. The mount  14  may have other shapes, for example, an elliptical shape, a cross shape, or the like in a plan view. 
     Still further, in the above-described embodiments, as the mechanism for conveying a work W in the direction perpendicular to a beam, the work support device  85  of the machine tool  80  is used, however, the invention is not limited thereto. For example, the gantry type conveying device  10  may be provided with a shifting device that delivers a work W between itself and the mount  14  and moves the work W in a direction (front-rear direction) perpendicular in a plan view to the extension direction of the beam may be provided. By this structure, it is possible to move a work W that is lifted by the mount  14  and moved along the beam  11  can be moved by the shifting device in a direction perpendicular to the beam  11 . In such a manner, the work W can be conveyed to a three dimensionally arbitrary position. 
     DESCRIPTION OF REFERENCE SYMBOLS 
     
         
           10  gantry type conveying device 
           11  beam 
           12  runner 
           13  elevator 
           14  mount 
           15 ,  15  post 
           16  running plate 
           17  running servo motor 
           18  pinion 
           19  reference block 
           20  rack 
           21  upper rail 
           22  lower rail 
           23  load receiving roller 
           24 ,  25  guide roller 
           26  elevation member 
           27  movement guide mechanism 
           28  guide rail 
           29  slider 
           30  elevation servo motor 
           31  pinion 
           32  rack 
           33  bottom wall 
           34  rotary servo motor 
           35  rotation shaft 
           36  fitting center 
           37 ,  38  positioning pin (positioning member) 
           39  support pad 
           40  guide 
           80  machine tool 
           81  main shaft 
           82  base 
           83  column 
           84  saddle 
           85  work support device 
           86  cover 
           87  carriage 
           88  holding section 
           89  motor 
           90  turn table 
           91  jig 
           92  front upper surface 
           93  door 
           100  processing line 
         T tool 
         W work (conveyance object)