JP3847437B2 - Linear motor driven machine tool - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a machine tool that processes a workpiece by moving a tool spindle in three directions orthogonal to the workpiece, and more particularly to a machine tool of a type in which feed of the tool spindle in at least one direction is driven by a linear motor.
[0002]
[Prior art]
This main machine tool is disclosed in JP-A-8-318445. As shown schematically in FIGS. 9 and 10, the machine tool disclosed in this published patent publication has a rectangular frame 81 standing on a base 80 and opened in the center of the box frame. A box-shaped gantry 83 is guided by the upper and lower ends of the window 82, and the pair of linear motors 84 and 85 provided between the upper and lower ends of the gantry 83 and the opposing surface of the frame 81 are used to move the gantry 83 to the left and right X. Configured to send in the direction.
[0003]
Further, the gantry 83 is formed with a vertically long rectangular window 86, and the saddle 87 is guided in the rectangular window 86 so as to be movable up and down by a pair of left and right linear guide mechanisms (not shown) and vertically moved by a pair of left and right linear motors 88. Sent in the direction. A ram 90 is guided to the saddle 87 by a linear guide mechanism (not shown) so as to be movable back and forth, and is moved in the front and rear Z direction by a linear motor. The ram 90 supports a tool spindle 91 rotated by a drive motor (not shown) so as to be rotatable around an axis extending in the Z direction.
[0004]
The linear guide mechanism that guides the gantry 83 left and right includes a lower guide mechanism 91 and an upper guide mechanism 92 each including a guide rail and a bearing block that runs on the rail. The lower guide mechanism 91 is disposed between the lower surface of the gantry 83 and the lower cross beam member 81a of the box-shaped frame 81, and the upper guide mechanism 92 is disposed on the front surface of the cross beam 81a of the frame 81 and the upper portion of the gantry 83 facing the same. It is arranged between the back.
[0005]
[Problems to be solved by the invention]
In the above-described conventional linear motor driven machine tool, the gantry 83 is arranged so as to be moved in the rectangular window 82 opened in the center of the frame 81, so that the left / right movement stroke of the gantry 83 is the left / right movement of the frame 81. This is limited by the column member 81b.
[0006]
Further, since the cross beam 81a of the frame 81 is arranged so as to cover the upper end surface of the gantry 83, the height of the frame 81 becomes high and the machine becomes large.
Further, since the lower linear guide mechanism 91 for guiding the lower end portion of the gantry 83 in the left-right direction is attached to the lower surface of the base plate 83a of the gantry 83, the saddle 87 mounted on the left and right inner end surfaces of the rectangular window 86 of the gantry 83. When inspecting, repairing, or replacing the linear guide mechanism and linear motor 88 for the vertical movement of the gantry 83, all the upstanding components on the base plate 81a of the gantry 83 must be individually separated and removed from the machine. In addition, reassembly after inspection or repair / replacement work is laborious work.
[0007]
Accordingly, a main object of the present invention is to increase the left-right stroke of the gantry without being restricted by the left-right stroke of the gantry due to the interference between the gantry and the column member of the fixed frame.
Another object of the present invention is to prevent the cross beam connecting the upper ends of the column members of the fixed frame from increasing the height of the machine tool, thereby reducing the size of the machine tool and increasing its rigidity.
[0008]
Another object of the present invention is that even when the pair of left and right stringers constituting the gantry are separated from each other, these stringers are held on the guide rail of the linear guide mechanism that guides the lower end of the gantry. It is to be able to maintain the state that has been made, and to perform reassembly after disassembly efficiently.
An additional object of the present invention is to constitute a guide mechanism for guiding the gantry and the saddle so that it can firmly oppose the cutting force acting on the tool spindle.
[0009]
[Means for Solving the Problems]
  The above-mentioned problems of the present invention and the objects related thereto are solved and achieved by providing the machine tools described in the following claims. That is, the invention according to claim 1 is capable of moving in the first horizontal direction on the base with a base, a fixed frame extending and fixed on the base in the vertical direction, and a vertically long window opened in the center. A gantry, a saddle guided vertically in the vertically long window of the gantry, a ram guided by the saddle so as to be movable in a second horizontal direction perpendicular to the first horizontal direction, and the ram A tool spindle that is rotatably supported around an axis extending in the second horizontal direction and on which a tool can be mounted at the front end, a spindle drive motor that rotationally drives the tool spindle, and a tool spindle that is disposed in front of the tool spindle A work table to which a work can be attached, and the gantry is arranged on the front surface of the fixed frame so as to be movable in a longitudinal relationship with the fixed frame, and a lower surface of the gantry; A guide means for guiding the gantry in the first horizontal direction is composed of a lower guide means disposed between the upper frame and a top guide means disposed between the upper front surface of the fixed frame and the upper rear surface of the gantry. The lower linear motor for driving the lower surface of the gantry and the upper linear motor for driving the upper rear surface of the gantry constitute driving means for driving the gantry in the first horizontal direction, and the upper linear motor and the lower The respective center points of the suction force acting on the linear motor are in the same vertical plane parallel to the first horizontal direction including the center of gravity of the gantry or the center of gravity of the assembly moving together with the gantry.On both sides of the center of gravityLocated inThe upper and lower linear motors are configured such that the lower linear motor exerts a suction force on the lower surface of the gantry in the vertical direction with respect to the base, and the upper linear motor moves the upper rear surface of the gantry to the upper portion of the fixed frame. Are arranged in different directions so as to apply a suction force substantially in the longitudinal directionIt is characterized by that.
[0010]
The invention according to claim 2 uses the upper and lower rail means as the upper and lower guide means described above, and exceeds the square window that opens both ends of the rail means in the first horizontal direction to the center of the fixed frame. Extend. As a result, the first horizontal end of the gantry can be moved to the front side of the left and right column members of the fixed frame, and the support rigidity of the gantry in this state is the same as when the gantry is at the center in the left-right direction. Highly maintainable.
[0012]
  Claim3According to the invention described above, the front end of the cross beam of the fixed frame is extended to the vicinity of the middle position of the width in the front-rear direction of the gantry so that the upper rail means and the upper linear motor can be arranged at the middle position in the front-rear direction of the gantry. Claim4The lower linear motor is arranged vertically below the upper rail means and the upper linear motor, the lower rail means is two rails extending in the first horizontal direction, and these rails are used as the lower linear motor. It arrange | positions on the both sides of the lower linear motor in the said front-back direction in the state put in between.
[0013]
  Claim5The slant surface which inclines upwards toward back is formed in the base of description. The column members at both ends in the first horizontal direction of the fixed frame are tilted forward so that the upper ends project forward toward the gantry side. The lower surface and upper rear surface of the gantry are formed in parallel with the slant surface portion and the column member, respectively. Claim6The invention described in claim5The lower linear motor is disposed vertically below the upper rail means between the slant surface of the base and the lower surface of the gantry parallel to the slant surface, and the lower rail means has the lower linear motor interposed therebetween. A pair of guide rails fixed on the slant surface of the base in the state and spaced apart in the second horizontal direction.
[0014]
  Claim7In the invention described in, the gantry is composed of a pair of left and right string members, and four members composed of a lower and upper beam members that detachably connect the lower end portions and the upper end portions of the string members. . Even when at least a pair of bearing blocks constituting the lower guide means are directly attached to the lower surface of the stringer member and the stringer members are separated, the stringer member runs on the guide rails of the lower guide means via these bearing blocks. It can be so.
[0015]
  Claim8According to the present invention, the cross beam of the fixed frame can be separated from the left and right column members, a pair of guide rails are provided as the lower guide rails of the gantry, and the guide rails separate from the guide rails that guide the stringers of the gantry Even when the left and right vertical girder members and the upper and lower horizontal girder members constituting the gantry are separated into four members for inspection or repair / replacement, each of these four members is It is made to maintain the state guided by one guide rail.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
1 to 3 show a plan view, a right side view, and a front view, respectively, of a first embodiment of a linear motor driven machine tool according to the present invention. The machine tool according to the present embodiment is guided by the base 10 and the fixed frame 15 on the front side of the work table 11 disposed at the front portion of the base 10, the fixed frame 15 disposed at the rear portion of the base 10, and the fixed frame 15. A gantry 20 that horizontally moves in the X direction, a saddle 50 that is guided by the gantry 20 and moves up and down in the Y direction, a ram 60 that horizontally moves in the Z direction by the saddle 50, and an electric that moves the gantry 20, saddle 50, and ram 60, respectively. The tool spindle 71 rotatably supported by the linear motors 35, 37, 51, 52, 67 and the ram 60 is a main component.
[0017]
A work table 11 is supported by a table support mechanism 12 on the upper surface of the front portion of the base 10. The work table 11 has a horizontal mounting surface 11a for mounting the workpiece W on the upper surface. The table support mechanism 12 may be of a type in which the work table 11 is simply fixed and held, but is preferably of a type that incorporates a known rotary indexing mechanism (not shown).
[0018]
This rotary indexing mechanism may be configured such that the work table 11 is indexed in four planes every 90 degrees around a vertical axis, but can be set at an arbitrary angular position by a servo motor NC-controlled by a numerical control device (not shown). An indexable form may be used. Further, the table support mechanism 12 may take various other forms including a form in which the work table 11 can be indexed around an axis parallel or perpendicular to the axis of the tool spindle 71 described later.
[0019]
A fixed frame 15 is erected on the upper surface of the rear part of the base 10 having a width that is somewhat wider than the front width of the front part on which the work table 11 is arranged. As shown in FIG. 3, the fixed frame 15 includes two column members 16 and 16 that are spaced apart from each other in the horizontal X direction (first horizontal direction) that is the left and right direction of the machine tool, and upper end surfaces of these column members. And a cross beam 17 whose both lower surfaces are separably connected by bolts (not shown), and is defined by a rear upper surface of the base 10, inner facing surfaces of the pillar members 16, 16 and a lower surface of the cross beam 17. The window 18 is opened in the horizontal Z direction (second horizontal direction) that is the front-rear direction of the machine tool.
[0020]
On the front side of the fixed frame 15, as shown in FIG. 3, a box-shaped gantry 20 is opened by wrapping a vertical rectangular window 24 at the center with a rectangular window 18 of the fixed frame 15. 15 is provided so as to be movable in the X direction (first horizontal direction). The gantry 20 is constructed by assembling left and right vertical beam members 21 and upper and lower horizontal beam members 22 and 23 into a box shape, and a vertically long rectangular window 24 is opened toward the front side of the machine tool at the center.
[0021]
More specifically, the lower cross girder member 23 has a width in the Z direction that is narrower than that of the vertical girder member 21, and as shown in FIG. A stepped surface 23a whose side is higher than the rear side is formed, and a seating surface 23b on which the lower end of the stringer member 21 is seated and a vertical receiving surface 23c for receiving the inner surface of the lower end of the stringer member 21 are formed on the upper surfaces of both ends. ing. The left and right vertical receiving surfaces 23c are integrally coupled by a vertical rim 23d.
[0022]
The lower end portion of each stringer member 21 is fixed on the seating surface 23b of the lower transverse beam member 23 as shown in FIG. This fixing is performed by inserting bolts from pockets 21b and 21c opened at the lower outer end of the stringer member 21 and screwing them into screw holes (reference numerals omitted) opened on the seating surface 23b. The inner surface of the lower end portion of the stringer member 21 is detachably coupled to the vertical receiving surface 23 c of the lower beam member 23. This connection is made by inserting a bolt from the vertical rim 23d side into the screw hole of the stringer member 21 through the vertical receiving surface 23c.
[0023]
The upper end portions of the stringer member 21 are connected to each other by the upper cross beam member 22 with both end portions of the upper cross beam member 22 fixed to the upper end surface in a separable manner. More specifically, bolts are inserted from the horizontal portions 22 a at the left and right ends of the upper cross beam member 22, inserted through the horizontal portions 22 a and screwed into the screw holes at the upper end of the vertical beam member 21. In this way, the left and right vertical girder members 21 and the horizontal girder members 22 and 23 are assembled in a box shape, and the vertical rectangular window 24 is opposed to the inner side surface of the vertical girder member 21 and the opposed lower and upper surfaces of the upper and lower horizontal girder members 22 and 23. And is defined by
[0024]
A linear guide mechanism 27 as a lower guide means is provided between a portion on the base 10 in front of the fixed frame 15 and the lower surface of the gantry 20, while the upper front surface of the fixed frame 15 and the upper rear surface of the gantry 20 are provided. A linear guide mechanism 28 as an upper guide means is provided therebetween. The lower guide mechanism 27 includes two linear rails 29 and 29 that extend in the X direction and are fixed on the base 10 at positions separated from each other in the Z direction, and two for each rail that runs on these rails. The two pairs of bearing blocks 30 and 31 are included.
[0025]
The pair of front bearing blocks 30 are directly attached to the front sides of the lower surfaces of the stringers 21. This attachment is performed by inserting a bolt from the front pocket 21 a shown in FIG. 5, passing through the lower end surface of the stringer member 21 and screwing it into the screw hole of the bearing block 30.
The left and right bearing blocks 31 on the rear side are attached to the lower surface of each seating surface 23 b of the lower cross beam member 23 directly below the vertical beam member 21. This attachment is performed prior to coupling the vertical girder member 21 to the lower cross girder member 23, and a screw is inserted through the lower cross girder member 23 from the upper surface side of the seating surface 23 b and opened to the upper surface of the bearing block 31. Screwed into the hole. In this case, for example, hexagon socket head bolts are used as the bolts, and their heads are prevented from protruding from the seating surface 23b.
[0026]
Here, because the bearing block 31 is attached to the lower cross beam member 21, the upper surface of the base 10 to which the rear guide rail 29 is attached is equal to the plate thickness of the seating surface 23 b as compared with the front guide rail 29 to be attached. It will be understood that it has only been lowered.
The upper guide mechanism 28 includes a single guide rail 32 that extends in the X direction in parallel with the guide rail 29 and is fixed to the front surface of the cross beam 17 and a pair of left and right bearing blocks 33 that run on the guide rail 32. Since the guide rail 32 is disposed at an intermediate position of the width of the gantry 20 in the Z direction, that is, an intermediate position in the Z direction between the pair of lower guide rails 29, the front side of the cross beam 17 is the rear side of the upper end of the stringer member 21. It protrudes forward so as to cover almost half of the area.
[0027]
For the same purpose, the upper cross girder member 22 of the gantry 20 has a width in the Z direction narrowed to about half of the width in the same direction of the vertical girder member 21, and its front edge is the front surface of the vertical girder member 21. The two ends in the longitudinal direction are fixed to the upper surface of the stringer member 21 by bolts (not shown) so as to be separable from each other, as described above, in a state of being close to the front half side of the upper surface of the stringer member 21 so as to be substantially aligned. The upper cross beam member 22 has a vertical back surface 22b, and bearing blocks 33 are attached to both ends in the longitudinal direction of the vertical back surface 22b, which is directly above the vertical beam member 21, respectively (see FIG. 3).
[0028]
One of the features of the embodiment according to the present invention is that the fixed frame 15 guides the upper back surface of the gantry 20, and this configuration makes the upper end of the gantry 20 and the upper end of the fixed frame 15 substantially the same height. This makes it possible to reduce the overall height of the machine tool under the condition that the required Y-direction stroke of the saddle 50 is ensured, thereby contributing to the downsizing and strengthening of the machine tool.
[0029]
As another feature of the embodiment according to the present invention, the gantry 20 is not present in the rectangular window 18 of the fixed frame 15 but is disposed on the front side of the fixed frame 15, and preferably the lower guide rail 29. And both ends of the upper guide rail 32 are extended to the front side of the corresponding column member 16. As a result, the gantry 20 can advance so as to wrap each of the left and right string members 21 on the front side of the column member 16 on the corresponding side of the fixed frame 15, and under the condition that the required X-direction stroke of the gantry 20 is ensured. The interval in the X direction of the column members 16 is narrowed, and the front opening of the machine tool can be narrowed.
[0030]
The linear guide mechanism 28 composed of the guide rail 32 and the bearing block 33 is attached in a direction against the maximum load acting in the Z direction. The linear guide mechanism 28 is mounted in a direction that resists the maximum load in the Z direction, and the mounting direction of the pair of lower linear guide mechanisms 27 that are mounted so as to resist the maximum load acting in the Y direction is 90 degrees different from the mounting direction. This configuration will be noted as one of the other features of the embodiment according to the present invention.
[0031]
The gantry 20 is driven by a lower electric linear motor 35 and an upper electric linear motor 37 whose lower and upper ends are synchronously controlled, respectively. The lower linear motor 35 is mounted on the lower surface of the lower cross beam member 23 so as to face the fixed magnet plate unit 35a laid on the base 10 between the two guide rails 29. It is comprised with the electromagnetic coil unit 35b. The magnet plate unit 35 a is configured by arranging a plurality of magnet plates in series in the moving direction of the gantry 20.
[0032]
On the other hand, the upper linear motor 37 has a fixed magnet plate unit 37a laid on the front surface of the cross beam 17 of the fixed frame 15 along the guide rail 32 and the upper cross girder member 22 of the gantry 20 facing this. And an electromagnetic coil unit 37b attached to the back surface.
These linear motors 35 and 37 control the excitation relationship between the coil units 35b and 37b and the magnet plate units 35a and 37a facing them by synchronizing the coil units 35b and 37b with a numerical controller (NC) (not shown). The gantry 20 operates to move on the base 10 and the fixed frame 15 by moving in the traveling direction according to the program. In this feeding operation process, the coil unit 35b generates a magnetic force so as to be attracted to the magnet plate unit 35a, thereby acting to press the gantry 20 downward toward the base 10. On the other hand, the coil unit 37 b generates a magnetic force so as to press the gantry 20 backward toward the cross beam 17 of the fixed frame 15.
[0033]
As another feature of the embodiment according to the present invention, the upper and lower linear motors 35 and 37 pass through the center of gravity of the gantry 20, preferably the center of gravity of the assembly of the gantry 20 and the mechanism that moves up and down therewith.In the vertical planeThe gantry 20 is disposed in the middle of the width of the gantry 20 so as to drive the upper and lower ends of the gantry 20. As one of the further features of the embodiment according to the present invention, the resultant force of the suction forces F1 and F2 generated by the linear motors 35 and 37 presses the gantry 20 downward obliquely rearward as shown by an arrow Ft in FIG. Acts as follows. For this reason, the gantry 20 moves up and down (Y) with respect to the base 10 and the fixed frame 15 even when the cutting force acting on the tool spindle 71 works in the direction of lifting the gantry 20 upward or when the cutting force fluctuates intermittently. The gantry 20 is fixed to the base 10 and the fixed frame 15 by a gap that is held firmly in the direction and the front and rear (Z) direction and exists in the sliding engagement portion between the guide rails 29 and 32 and the bearing blocks 30, 31, and 33. This prevents wobbling in the front-rear direction and the up-down direction, and ensures high machining accuracy.
[0034]
Similarly, a box-shaped saddle 50 is guided in the vertical rectangular window 24 of the gantry 20 so as to be movable in the vertical direction. This guide mechanism is the same as the linear guide mechanism 51 as the front guide means provided at the front of the inner facing end face of the stringer member 21 of the gantry 20, and the linear guide mechanism 52 as the rear guide means provided at the rear of the opposite end face. Become. The pair of guide rails 53 constituting the front guide mechanism 51 has an overall length substantially equal to the width in the height direction of the vertically long rectangular window 24, and is fixed to the inner facing surface at the front portion of the stringer member 21. Has been. The bearing blocks 54, 54 that can run on the respective guide rails 53 are fixed to upper and lower ends of the side surface of the saddle 50 that faces the guide rails 53, respectively.
[0035]
The pair of left and right guide rails 55 constituting the rear guide mechanism 52 have a length shorter than the total length of the guide rail 53, and are moved to the lower side of the rectangular window 24 at the rear part of the stringer member 21 to the inner facing surfaces. It is fixed. A single bearing block 56 that can run on each guide rail 55 is fixed to the lower end of the side surface of the saddle 50 that faces the guide rail. As a result, the saddle 50 is guided by the four bearing blocks 54 whose front part is fixed to its four corners, and whose rear part is guided by the two bearing blocks 56 fixed to its two lower corners.
[0036]
As one of the additional features in the embodiment according to the present invention, as shown in the mechanism diagram of FIG. 6, when viewed from the right side view direction of FIG. A line connecting one bearing block 56 is a right triangle, and has a high rigidity against a cutting force acting on the tool spindle 71. Similarly, when viewed from the right side view of FIG. 2, the line connecting the front and rear bearing blocks 30 and 31 that guide the lower part of the gantry 20 and the one bearing block 33 that guides the upper part is an isosceles triangle. Has high rigidity against cutting force.
[0037]
As shown by a broken line in FIG. 2, the feeding means for feeding the saddle 50 in the vertical (Y) direction includes electric linear motors 57 arranged between both side surfaces of the saddle 50 and the inner side surface of the stringer member 21. . Each linear motor 57 is opposed to a magnet plate unit 57a laid on the corresponding inner side surface of the stringer member 21 along the vertical direction between the front and rear guide rails 53, 55 on each side surface of the saddle 50. The coil unit 57b is fixed to the side surface of the saddle 50.
[0038]
The saddle 50 is box-shaped and has a long cylindrical shape in the front-rear direction, and the rear part faces the rectangular window 18 of the fixed frame 15. A ram 60 is guided in the central window 50a of the saddle 50 so as to be movable in the front-rear (Z) direction. When viewed from the front of FIG. 3, the ram 60 has a hexagonal shape that is inclined from both sides toward the narrow upper surface, and the saddle 50 is inserted and the rectangular windows 24 and 18 are also inserted, and the rear end is fixed. It has an elongated shape in the front-rear (Z) direction so as to protrude from the rear of the frame 15.
[0039]
Guide means for guiding the ram 60 in the front-rear direction is a single lower linear guide mechanism 61 disposed between both sides of the wide lower surface and the saddle 50 and a single upper surface disposed between the narrow upper surface and the saddle 50. It consists of an upper linear guide mechanism 62. Each of the guide mechanisms 61 and 62 is composed of linear guide rails 63 and 64 and one or two bearing blocks 65 and 66 that run on the rails as in the linear guide mechanism described above.
[0040]
The feature of the longitudinal (Z) direction guide means of the ram 60 is that the guide rails 63 and 64 are fixed to the ram 60 and the bearing blocks 65 and 66 are fixed to the saddle 50. More specifically, as shown in FIG. 7, in each of the lower linear guide mechanisms 61, two bearing blocks 65 are fixed to the front part and the intermediate part in the longitudinal direction of the ram 60, and in the upper linear guide mechanism 62, one bearing block is provided. 66 is secured to the front of the ram 60.
[0041]
As another additional feature in the embodiment according to the present invention, as shown in the mechanism diagram of FIG. 7, when viewed from the right side view direction of FIG. 2, the arrangement of the upper and lower bearing blocks 65 and 66 is as follows. The line connecting them forms a right triangle, and has a structure having high rigidity against the machining resistance acting on the tool spindle 71.
An electric linear motor 67 disposed between the lower surface of the ram 60 and the saddle 50 is used as driving means for feeding the ram 60 in the front-rear (Z) direction. The linear motor 67 is attached to the lower surface of the ram 60 so as to face the coil unit 67b with a plurality of magnet plates in series in the Z direction and the electromagnetic coil unit 67b attached to the saddle 50 between the guide rails 63 and 63. And a magnet plate unit 67a.
[0042]
The ram 60 accommodates a cylindrical bearing case (not shown), and this case supports a tool spindle 71 rotatably around an axis extending in the Z direction via a bearing device (not shown). The case 70 also incorporates a built-in motor (not shown) that rotationally drives the tool spindle 71. The bearing device is of a type that uses one or a combination of a ball bearing, a roller bearing, a fluid bearing that uses air or liquid as a bearing medium.
[0043]
The tool spindle 71 has a built-in mechanism for mounting the tool T at the front end, whereby various tools such as a drill, an end mill, a milling cutter, a tap, a reamer, a grinding wheel, and a tool as necessary are provided at the front end of the tool spindle 71. It is possible to perform various processing on the workpiece W by hand replacement or automatic replacement by ATC.
The operation of the first embodiment configured as described above will be described.
[0044]
The work W is mounted on the work table 11 via an appropriate jig. The NC device (not shown) rotates the tool spindle 71 in accordance with the input NC program and moves the gantry 20, the saddle 50 and the ram 60 in the X, Y and Z directions, respectively. The workpiece W is cut by abutting the cutting tool T mounted on the workpiece W on the workpiece W.
[0045]
Here, when the tool T is a drill, the NC device drives the linear motors 35 and 37 synchronously, moves the gantry 20 in the X direction at a rapid feed speed at both upper and lower ends of the gantry 20, and the drill T should be machined on the workpiece W. Position to the X coordinate position (left-right direction position) of the hole position. In this case, depending on the size of the workpiece W, the gantry 20 advances to a position where the left and right string members 21 are wrapped on the column member 16 of the corresponding fixed frame 15.
[0046]
In parallel with this positioning operation or after this positioning operation, the NC device drives the linear motors 57, 57 synchronously, moves the saddle 50 in the Y direction at the fast feed speed at the left and right ends of the saddle 50, and moves the drill T to the workpiece W. Is positioned at the Y coordinate position (vertical position) of the hole position to be processed. Thereby, it becomes concentric with the hole position which the drill T should process.
[0047]
After making the drill T concentric with the hole position to be machined, the NC device drives the linear motor 67 to rapidly feed the ram 60 toward the workpiece W, and the tip of the drill T is positioned at a predetermined distance from the surface of the workpiece W. , The forward feed speed is switched to the cutting feed speed, and the workpiece W is subjected to predetermined drilling. The start and end processes of fast-forwarding of the gantry 20, the saddle 50 and the ram 60 are performed, for example, with acceleration and deceleration of 1G or more.
[0048]
When one hole is finished, the ram 60 is retracted to a position where a predetermined clearance is secured between the tip of the drill T and the surface of the workpiece W, and then the gantry 20 and the saddle 50 are moved at a rapid feed speed. The drill T is aligned with the position of the hole to be processed next, and the ram 60 is cut and fed again to process the next hole. In this way, a large number of holes are sequentially processed at a high speed on the surface of the workpiece W.
[0049]
When the tool T is for milling, for example, a milling cutter or an end mill, the gantry 20 and the saddle 50 are controlled to fast-feed as in the case of the above-described drilling, and are cut to the X and Y coordinates of the machining start position of the workpiece W. Alternatively, the end mill T is positioned. Thereafter, the ram 60 is cut and fed to cause the cutter or end mill T to bite into the surface of the workpiece W to a predetermined depth, and then the gantry 20 or saddle 50 is selectively or simultaneously moved in the X and Y directions at the cutting feed speed, respectively. And milling the surface of the workpiece W.
[0050]
In this case, a large cutting resistance acts on the tool spindle 71. In the machine tool according to the present invention, the lower linear guide mechanism 27 for guiding the gantry 20 is arranged so as to have a large rigidity against the force in the direction in which the gantry 20 sinks downward, and the upper linear guide mechanism 28 is The gantry 20 is disposed in a direction different by 90 degrees with respect to the lower linear guide mechanism 27 so as to have a large rigidity with respect to a force in a direction in which the gantry 20 moves backward. The lower linear motor 35 and the upper linear motor 37 that drive the lower and upper ends passing through the center of gravity of the gantry 20 respectively suck the gantry 20 downward toward the base 10 and the gantry 20 backward toward the fixed frame 15. Yes. For this reason, it repels strongly against the force which acts in the direction which lifts the gantry 20 at the time of processing of the workpiece | work W, and it also repels strongly also to the intermittent fluctuation | variation of the force which acts on a Z direction. As a result, the gantry 20 may be displaced in the vertical direction or the front-rear direction with respect to the base 10 and the fixed frame 15 by the amount of clearance or play existing between the rails of the lower linear guide mechanism 27 and the upper linear guide mechanism 28 and the bearing block. It is avoided and adverse effects on machining accuracy are eliminated.
[0051]
Next, the separation and reassembly operation of the four members constituting the gantry 20, that is, the left and right vertical beam members 21 and the upper and lower horizontal beam members 22 and 23 will be described. Such an operation is mainly required when the lower linear motor 35 of the gantry 20 is inspected and replaced, and further, the components on the saddle 50 guided by the gantry 20 are inspected and replaced.
[0052]
The separation operation of the gantry 20 is performed by first removing unillustrated bolts that fix the both ends of the cross beam 17 of the fixed frame 15 to the upper end surfaces of the left and right column members 16 and the both ends of the upper cross beam member 22 of the gantry 20. Is performed by removing bolts (not shown) that are fixed to the upper end surfaces of the left and right string members 16. Thus, with the upper cross beam member 22 guided to the cross beam 17, the upper cross beam member 22 and the cross beam 17 are lifted by a hoist crane (not shown) and separated from the machine tool.
[0053]
Next, the saddle 50 is suspended by a hoist crane (not shown) and lifted upward, and the bearing blocks 54 and 56 of the saddle 50 are disengaged from the guide rails 53 and 55 on the left and right stringers 21. As a result, the saddle 50, the ram 60 supported by the saddle 50, and the tool spindle 71 are separated from the machine tool together with the saddle 50, transferred to a work table (not shown), and inspected and disassembled and reassembled as necessary. Is performed in an easy-to-work state.
[0054]
Next, the bolts inserted in the pockets 21 b and 21 c of FIG. 5 and fixing the vertical beam members 21 to the lower horizontal beam members 23 are loosened and removed, and the vertical beam members 21 are separated from the lower horizontal beam members 23. Thereby, the connection of the lower end parts of the left and right string members 21 is released. In this state, each stringer member 21 is still movably guided on the front guide rail 29 by the bearing block 30 fixed to the lower surface thereof.
[0055]
Accordingly, each of the left and right string members 21 can be arbitrarily moved independently of each other, and the operator can enter between the left and right string members 21 with a wide space between them. Thus, inspection, repair, and replacement of the magnet plate unit 57a of the linear motor 57 for vertical driving and the front and rear guide rails 53 and 55 attached to the inner surface of the motor 21 can be easily performed. Since this inspection, repair, and replacement work can be performed without separating each string member 21 and the bearing block 30 on the lower surface thereof, the guide direction in the X direction of the bearing block 30 and the guide rail 51 for the vertical guide of the saddle 50, Since the perpendicularity of the guide direction in the Y direction of 52 is secured, there is an advantage that reassembly can be easily performed after this operation and the guide accuracy before separation can be reliably reproduced.
[0056]
Further, inspecting and exchanging the lower linear motor 35 of the gantry 20, particularly the electromagnetic coil unit 35b, after separating the string member 21 from the lower cross member 23 as described above, the coil unit 35b is then moved to the lower cross member 23. The bolts attached to the lower cross beam member 23 are loosened and removed from the receiving surfaces 23b side of both ends of the lower cross beam member 23, and the coil unit 35b is separated from the lower cross beam member 23. Thereby, the inspection and replacement work of the coil unit 35b can be easily performed.
[0057]
In this state, the lower cross girder member 23 is still fixedly held by the bearing block 31 guided by the rear guide rail 29, so that the seating surfaces 23b at both ends of the lower girder member 23 and the vertical girder members 21 The degree of parallelism with the lower end surface and the degree of parallelism between the vertical receiving surface 23c of the lower girder member 23 and the lower inner surface of each vertical girder member 21 are also secured. Therefore, after the inspection and replacement work of the coil unit 38 is completed. The work of re-assembling each string member 21 to the lower cross-girder member 23 can be easily performed, and the guide accuracy as an assembly in which both the string members 21 are assembled to the lower cross-girder member 23 is easily and highly accurate. Can be reproduced.
[0058]
After the inspection and repair / replacement as necessary, as described above, the assembly comprising the saddle 50, the ram 60 supported on the saddle 50 and the tool spindle 71 is suspended on the hoist crane, and the bearing blocks on both sides of the saddle 50 are suspended. 54 and 56 can be easily reassembled on the left and right stringer members 21 by fitting the upper and lower guide rails 53 and 55 from the upper end side of the stringer member 21. In this reassembly, unless the bearing blocks 54 and 56 are separated from the saddle 50, the arrangement relationship including the parallelism between the bearing blocks 54 and 56 and the guide rails 53 and 55 is maintained unchanged. Not only reassembly is easy, but also the guidance accuracy after reassembly can be reproduced easily and with high accuracy.
[0059]
After the saddle 54 is reassembled to the left and right vertical girder members 21, the cross beam 17 of the fixed frame 15 and the upper girder member 22 of the gantry 20 are suspended by a hoist crane in a state where both are assembled. The column member 16 and the left and right string members 21 are assembled again. This assembling work can be easily reproduced in the state before separation as described above in the reassembly of the left and right string members 21, and the string member 21 and the bearing block 30 at the lower end Since the assembly relationship between the three members of the front guide rail 29 is maintained unchanged, the upper beam member 22 and the left and right vertical members are simultaneously reproduced while reproducing the assembled state of the cross beam 17 and the left and right column members 16. The assembly state with the girder member 21 can be easily reproduced, and the guidance accuracy on the base 10 and the fixed frame 15 of the gantry 20 is restored to the original state in a state where the assembly before separation is reproduced.
[0060]
Although the explanation is omitted, since the assembly of the left and right vertical girder members 21 and the lower cross girder member 23 is not only fixed by bolts, but also a taper pin is driven between them as is well-known and commonly used. The taper pin is pulled out by loosening and removing it. Conversely, when reassembling, the taper pin is first driven between the two and then the bolt is screwed in, so that the relative position in the fixed state between the two is reliably reproduced. Such a taper pin is similarly used for the assembly of both ends of the cross beam 17 and the column member 16 and the assembly of both ends of the upper cross beam member 22 and the left and right vertical beam members 21.
[0061]
Another additional feature of the embodiment according to the present invention is that at least the left and right vertical girder members 21 and the upper and lower horizontal girder members 22 and 23 constituting the gantry 20 are separated into four members. The spar member 21, preferably each of the four members, is held in a state of being guided through a bearing block with respect to one guide rail, whereby the gantry 20 can be easily reassembled as described above, and Guide accuracy after reassembly is reliably reproduced with high accuracy before separation.
[0062]
Furthermore, when the saddle 50 can be shortened so that the rear end of the saddle 50 does not face the rectangular window 18 of the fixed frame 15, another separation method can be adopted. In this method, the assembly of the ram 60 that supports the tool spindle 71 is extracted from the front surface or the back surface of the saddle 50 by removing a stop mechanism (not shown) that mechanically restricts the front and rear stroke ends of the ram 60. Thereafter, a not-illustrated stop mechanism for mechanically restricting the left and right stroke ends of the gantry 20 is removed, and the left and right vertical girder members 21 and the upper and lower horizontal girder members 22 and 23 are integrated with the gantry 20 as a unit. In the state where the saddle 50 is assembled and the saddle 50 is guided, it can be extracted to the right or left of the fixed frame 15.
[0063]
The gantry 20 is removed from the base 10 and the fixed frame 15 in this manner, and after necessary inspections, repairs and replacement operations are performed, the gantry 20 is reassembled so as to be guided to the base 10 and the fixed frame 15 again.
In this separation method, one characteristic configuration of the present invention in which the gantry 20 is guided on the front side of the fixed frame 15, the X-direction drive mechanism of the gantry 20, and preferably the Z-direction drive mechanism of the ram 60 is a linear motor. It can be easily achieved based on a synergistic combination of the configured points.
[0064]
Next, a second embodiment of the present invention will be described with reference to FIG. The reference numerals of the constituent elements in this embodiment are shown in the 100th digit, and each constituent element has the same function as the member whose number in the tenth digit or less matches that in the first embodiment described above. Have.
In this embodiment, the upper surface of the rear portion of the base 110 is formed as a slant surface 110b inclined upward toward the rear, and the right and left sides of the fixed frame 115 are perpendicular to the slant surface 110b from the rear end portion of the slant surface 110b. The column member 116 is erected.
[0065]
The column member 116 has a shape that is inclined forward toward the upper end side, and the lower surfaces of both ends of the cross beam 117 are separably fixed to the upper end surfaces thereof. The front surface 117a of the cross beam 117 is inclined forward as it goes upward so as to align with the front surfaces of the column members 116 at both ends.
In the gantry 120, the bottom surface of the lower cross beam member 123 serving as the bottom surface thereof is substantially parallel to the slant surface 110b, and the back surface 122b of the upper cross beam member 122 serving as the upper rear surface thereof and the upper back surfaces of the left and right vertical girder members 121 are disposed horizontally. The front surface 117a of the beam member 117 and the upper front surface of the column member 116 are parallel to each other. Thereby, when viewed from the front of the machine tool, the gantry 120 has a box shape as in the first embodiment, but when viewed from the right side view of FIG. It has an approximate shape.
[0066]
The lower guide means 127 for guiding the lower part of the gantry 120 in the X direction includes a front linear guide mechanism and a rear linear guide mechanism, and the bearing block 130 of the front guide mechanism is provided on the lower surface of the front part of the left and right stringers 121. Although directly attached, the bearing block 131 of the rear guide mechanism is attached to the lower surface of the lower cross beam member 123. A lower linear motor 135 is disposed along and between the front and rear guide rails 129, and the electromagnetic coil unit 135b is separably attached to the lower surface of the lower cross beam member 123.
[0067]
A single upper linear guide mechanism 128 that guides the upper part of the gantry 120 in the X direction is provided on the front surface 117a of the cross beam 117 with its guide rail 132 extending horizontally along the upper edge of the front surface 117a of the cross beam 117. It is fixed.
The upper linear motor 137 that drives the upper part of the gantry 120 in the X direction attaches the magnet plate unit 137a to the front surface 117a of the cross beam 117 below the upper linear guide mechanism 128, and attaches the electromagnetic coil unit 137b to the upper cross beam member 122. It is attached to the back surface 122b.
[0068]
Here, the front and rear linear guide mechanisms in the lower part are arranged so as to resist the maximum load F1 in a direction perpendicular to the slant surface 110b, while the upper linear guide mechanism 128 has a direction parallel to the slant surface 110b. It is arranged so as to resist the maximum load F2, and is directed in a direction different from the lower linear guide mechanism by 90 degrees. Similarly, the lower rear motor 135 sucks the gantry 120 in the direction of the maximum load F1 of the lower linear guide mechanism 127, and the upper linear motor 137 sucks the gantry 120 in the direction of the maximum load F2 of the upper linear guide mechanism 128.
[0069]
The suction directions of the lower and upper linear motors 135 and 137 and the corresponding directions of the maximum loads F1 and F2 of the linear guide mechanisms 127 and 128 are the same direction, and the guide rails 129 and 132 of the linear guide mechanisms 127 and 128 are the same. In this way, uneven wear does not occur on the guide surfaces on both sides.
Further, the resultant force Ft of the maximum loads F1 and F2 acts in a direction that slightly decreases as it goes rearward. As a result, even if the cutting force acting on the tool spindle 171 is applied with a continuous or intermittent force that tends to lift the gantry 120, the gantry 120 can be firmly held against such lifting tendency force, and linear It is excluded that the play existing in the guide portions of the guide mechanisms 127 and 128 causes the gantry 120 to fluctuate in the front-rear and vertical directions.
[0070]
Further, the upper linear motor 137 is positioned immediately above the lower linear motor 135, and the linear motors 137 and 135 are made to have the X direction and the gravity action direction.In the vertical planeIn the X direction. Preferably thisVertical planeIs selected to be in this plane the center of gravity of the gantry 120, preferably the center of gravity of the gantry 120 and the assembly that moves up and down with it. The upper and lower linear motors 137 and 135 include the center of gravity of the gantry 120.In the vertical planeBy disposing the gantry 120, the meandering of the gantry 120 during movement in the X direction can be reliably eliminated.
[0071]
The left and right linear motors 157 that drive the saddle 150 in the vertical direction within the vertical rectangular window of the gantry 120 include the linear motors 137 and 135 whose upper and lower linear motors 137 and 135 are orthogonal to the drive direction and the center of gravity of the gantry 120 as described above.In the vertical planeAre arranged to exist. Other mechanisms that guide and drive the saddle 150 in the vertical direction, a mechanism that guides and drives the ram 160 in the rectangular window of the saddle 150, and further supports the ram 160 so that the tool spindle 171 can rotate. Since the mechanisms are the same as those in the first embodiment described above, a detailed description of these mechanisms is omitted.
[0072]
Also, since the operation of this embodiment is the same as described in the first embodiment, it will be omitted, but the difference in operation between the first embodiment and the second embodiment is the second embodiment. The lower linear guide mechanism 127 in the embodiment is more positively opposed to the machining reaction force in the Z direction than the lower linear guide mechanism 27 in the first embodiment.
[0073]
In each of the embodiments described above, the rectangular windows 18 and 118 are formed in the fixed frames 15 and 115, and the rear ends of the saddles 50 and 150 and the rams 60 and 160 are movable in the rectangular windows. In a machine tool having a short movement stroke, the rectangular windows 18 and 118 are unnecessary, and the rear end portions of the saddles 50 and 150 and the rams 60 and 160 can be moved in front of the fixed frames 15 and 115. Good.
[0074]
In the above-described embodiments, the lower cross beam members 23 and 123 of the gantry 20 and 120 are fixed to the flat lower surface of the vertical beam members 21 and 121. The guide rails 29 and 129 of the front and rear linear guide mechanisms 27 and 127 disposed at the lower portion of the stringer members 21 and 121 are provided with a step at the rear of the lower surfaces of the stringer members 21 and 121 by the thickness of the receiving surface 23b. It may be configured to be laid on a single plane on the base 10 or 110.
[0075]
Further, although the guide mechanisms 27 and 127 for guiding the lower surfaces of the gantry 20 and 120 are provided as a pair in the Z direction, the guide mechanisms are not necessarily a pair, and the front linear guide mechanisms 29 and 30 (129 , 130) may be provided.
In each of the linear guide mechanisms described above, each bearing block holds a large number of rolling elements such as balls or rollers as an antifriction medium so that they can circulate, and only the longitudinal direction of the rails on the guide rails via these rolling elements. Other types can be used, such as a guide mechanism that uses a pressure fluid as the anti-friction medium, although it is of a type that can run.
[0076]
【The invention's effect】
  As described in detail above, according to the first aspect of the present invention, the gantry is arranged so as to be movable in the first horizontal direction on the front side of the fixed frame, so that the gantry overlaps with the fixed frame in the front-rear direction. The moving stroke end of the gantry is not limited to the members constituting the fixed frame, and the front end of the machine tool can be narrowed while ensuring the required moving stroke of the gantry. Upper and lower guide means for moving the gantry in the first horizontal direction and upper and lower linear motors for driving the gantry along the guide means are provided between the lower surface of the gantry and the upper surface of the base, and the upper rear surface of the gantry. And the upper front surface of the fixed frame, the height of the fixed frame can be reduced while satisfying the requirements for guiding and driving the gantry from the top and bottom, and the front opening can be narrowed to make the machine tool small. Can be Further, the upper and lower linear motors are moved in the same vertical plane parallel to the first horizontal direction including the gravity center of the gantry or the gravity center of the assembly that moves together with the gantry.Located on both sides of the barycentric point across the barycentric pointThus, the gantry can be moved smoothly without meandering.In addition, the upper and lower linear motors are arranged so that each generates a suction force in different directions, and the resultant force of these suction forces presses the gantry against the fixed frame in a rearward and diagonal direction. Even when an intermittent load is applied to the gantry, the relative positions of the gantry relative to the base and the fixed frame in the vertical direction and the front-rear direction perpendicular to the moving direction can be maintained immovable.
[0077]
Preferably, as in the invention described in claim 2, by extending both ends of the rail means constituting the upper and lower guide means of the gantry beyond the window opening in the center of the fixed frame, the gantry is moved in each of the moving strokes. Ensures rigidity when positioned at the endit can.
[0079]
  Claim3According to the invention described in the above, since the cross beam of the fixed frame is projected to the gantry side up to the middle position of the gantry in the second horizontal direction orthogonal to the first horizontal direction, and the upper guide means is disposed on the front surface of the projecting portion. The gantry can be guided at the upper end above the center of gravity of the gantry and can be smoothly moved in the first horizontal direction without meandering.
[0080]
  Preferably, the claim4In the second horizontal direction, the lower linear motor is disposed vertically below the upper guide rail means, and the lower guide means is disposed on both sides of the lower linear motor in the second horizontal direction. The lower part of the gantry can be guided and driven in the first horizontal direction vertically below the center of gravity of the gantry, and the first horizontal direction of the gantry can cooperate with the upper guide means. Can be moved more smoothly.
[0081]
  Claim5According to the invention described above, the slant surface inclined upward rearward is formed on the rear upper surface in the second horizontal direction of the base, and the left and right column members of the fixed frame are perpendicular to the surface on the slant surface. Since the cross beam connecting the upper ends of the column members projects forward toward the gantry, the upper guide means and the upper linear motor for guiding and driving the upper end of the gantry in the first horizontal direction are provided. The gantry can be disposed directly above the center of gravity in the second horizontal direction, and can smoothly guide and drive the upper end of the gantry without meandering in the first horizontal direction.
[0082]
  Claim6According to the invention described in claim5In the invention described in claim 1,4The effect which this invention show | plays can be exhibited. Claim7According to the invention described in the above, the gantry is constituted by the left and right stringer members and the upper and lower beam members that detachably couple the upper and lower parts of these stringer members, and the lower guide means Since the two bearing blocks that run on the guide rail are attached to the lower surface of the stringer member, the left and right stringer members are separated even when the gantry is separated into four members, the left and right stringer members and the upper and lower beam members. A saddle provided on the inner surface of each stringer member with a gap between the left and right stringer members that can be held upright and individually movable on the guide rail of the lower guide means via a bearing block attached to the lower surface Inspection, repair, and replacement of the guide means and drive means are facilitated.
[0083]
  Claim8According to the present invention, the cross beam of the fixed frame can be separated from the left and right column members, and a pair of guide rails are provided as lower guide means of the gantry, separate from the guide rails for guiding the gantry stringer members. Since the lower girder members of the gantry are guided to the guide rails of the left and right, even when the left and right vertical girder members and the upper and lower girder members constituting the gantry are separated into four members for inspection or repair, All can be kept guided by the guide rail. For this reason, in the separated state, the guide state of each of these four members and the guide rail that guides the four members is maintained in the state before the separation, so that reassembly after inspection or repair is facilitated.
[Brief description of the drawings]
FIG. 1 is a plan view showing a first embodiment of the present invention.
FIG. 2 is a right side view of the first embodiment.
FIG. 3 is a front view of the first embodiment viewed from the direction of arrows AA in FIG. 1;
FIG. 4 is a perspective view showing a right end portion of a lower cross beam member constituting the gantry in the first embodiment.
FIG. 5 is a perspective view showing a coupling relationship between a stringer member and a lower beam member constituting the gantry in the first embodiment.
FIG. 6 is an explanatory view showing the arrangement relationship of bearing blocks for guiding the saddle in the vertical direction in addition to the arrangement relationship of bearing blocks for guiding the gantry in the left-right direction in the first embodiment.
FIG. 7 is an explanatory view showing the arrangement relationship of bearing blocks for guiding the ram in the front-rear direction together with the arrangement relationship of bearing blocks for guiding the saddle in the vertical direction in the first embodiment.
8 is a right side view of the second embodiment of the present invention corresponding to FIG. 2; FIG.
FIG. 9 is a front view of a conventional linear motor driven machine tool.
10 is a cross-sectional view in the direction of arrows BB in FIG. 9;
[Explanation of symbols]
10, 110 ... Base
15, 115 ... fixed frame
20, 120 ... Gantry
50,150 ... saddle
60, 160 ... ram
71,171 ... Tool spindle
28, 27, 128, 127 ... upper and lower linear guide mechanisms
37, 35, 137, 135 ... Upper and lower linear motors
29, 32, 129, 132 ... guide rails
18 ... Square window
16, 116 ... pillar member
17, 117 ... Cross beam
110b ... Slant surface
21, 121 ... string member
22, 122 ... Upper cross girder member
23, 123 ... Lower girder members
30, 31, 33, 130, 131, 133 ... bearing block

Claims (8)

A base, a fixed frame extending vertically on the base and fixed; a vertically long window opening in the center; and a gantry movable in a first horizontal direction on the base; and in the vertically long window of the gantry And a ram guided by the saddle so as to be movable in a second horizontal direction perpendicular to the first horizontal direction, and rotated about an axis extending in the second horizontal direction by the ram. A tool spindle that is freely supported and capable of mounting a tool at the front end, a spindle drive motor that rotationally drives the tool spindle, and a work table that is disposed in front of the tool spindle and is capable of mounting a workpiece to be machined; A lower guide disposed between the lower surface of the gantry and the base is disposed on the front surface of the fixed frame so that the gantry can be moved in a longitudinal relationship with the fixed frame. A guide means for guiding the gantry in the first horizontal direction by means and upper guide means disposed between the upper front surface of the fixed frame and the upper back surface of the gantry, and a lower portion for driving the lower surface of the gantry The linear motor and the upper linear motor that drives the upper rear surface of the gantry constitute drive means for driving the gantry in the first horizontal direction, and the respective suction force action center points of the upper linear motor and the lower linear motor Rutotomoni are located on either side of the center of gravity or heavy center point across the center of gravity in the first horizontal direction parallel to the same vertical plane containing the center of gravity of the assembly that moves with the gantry of the gantry, The upper and lower linear motors share a force when the lower linear motor exerts a suction force on the lower surface of the gantry in the vertical direction with respect to the base. Machine tool, characterized in that the upper linear motor are arranged in different orientations so as to exert a suction force to the upper rear of the gantry in a substantially longitudinal direction with respect to the upper portion of the fixed frame. 2. The machine tool according to claim 1, wherein the upper and lower guide means include upper and lower rail means, and both ends of the rail means in the first horizontal direction extend beyond a window opened in the center of the fixed frame. A machine tool that extends to both ends of a fixed frame. 3. The machine tool according to claim 2 , wherein the fixed frame includes a pair of column members fixed to both ends of the base in the first horizontal direction, and both ends fixed to the upper surfaces of the column members. The upper rail means is attached to the front end surface of the cross beam and is substantially in the middle of the width of the gantry in the second horizontal direction. A machine tool characterized by being arranged. 4. The machine tool according to claim 3 , wherein the lower linear motor is disposed vertically below the upper rail means and between the lower surface of the gantry and the upper surface of the base, and the lower rail means interposes the lower linear motor. A machine tool comprising a pair of guide rails fixed on the base while being placed on the base and spaced apart in the second horizontal direction. 2. The machine tool according to claim 1, wherein the base has a slant surface inclined upward in a rearward direction in the second horizontal direction, and the fixed frame extends in the first horizontal direction at a rear end of the slant surface. consists horizontal crossbeam upper is secured to both end portions connecting the upper ends of the pair of pillar members and their columns of anteversion to protrude forward, the gantry is sandwiched between the fixed frame and the slant surface is disposed at a position, the upper linear motor for driving the upper back surface of said gantry opposite to the lower linear motor surface which is inclined forward of the fixed frame, each slant face that drives the lower surface of said gantry opposite to the slant surface and A machine tool formed substantially parallel to the column member. 6. The machine tool according to claim 5 , wherein the lower linear motor is disposed vertically below the upper rail means and between the slant surface of the base and the lower surface of the gantry parallel to the slant surface. Includes a pair of guide rails fixed on the slant surface of the base with the lower linear motor in between and spaced apart in the second horizontal direction. 2. The machine tool according to claim 1, wherein the gantry is detachably connected to a pair of left and right stringers separated in the first horizontal direction and inner facing surfaces of the stringers in the first horizontal direction. A rail comprising: a lower cross beam member extending; and an upper cross beam member that is detachably coupled to the upper end surface of the vertical beam member and extends in the first horizontal direction, and wherein the lower guide means is fixed to the base. And a machine tool comprising at least two bearing blocks which can run on the rail and are attached to the lower surfaces of the pair of string members. The machine tool according to claim 7, wherein the upper guide means comprises a rail which is fixed to the upper front surface of the fixed frame, bearing block attached to the rear surface of the upper beam member freely travel on the rail A machine tool characterized by that.

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