JPH1086038A - Machining method of work and machine tool therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machine tool capable of quickly changing among a plurality of machining actions using a plurality of tools without requiring tool changing actions, maintaining rotating precision of a high speed rotating tool spindle for a long period of time, and also being appropriate as a component constituting a so-called flexible transfer line. SOLUTION: A plurality of tool spindle heads are arranged and secured to a base 1 along the moving direction of a first moving body 13 movable on the base 1. A second movable body 16 and a third movable body 27 are stacked over the first movable body 13 in succession and guided so that a-work holding device 40 disposed on the third movable body 27 together with a work W may move in three dimensions by numerical control of the first to third movable bodies 13, 16 and 27 relative to each cutting tool T and that, when changing from one machining with one tool T to another, the work W is indexed to another tool T utilizing the movement of the first movable body 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work holding device for holding a work, which is selectively brought into contact with a plurality of working tools arranged in a line to perform various processings on the work. More particularly, the present invention relates to a machine tool that implements the method and a machine tool that implements the method, and also relates to a machine tool that is suitable for forming a part of a machining system that moves a workpiece in a linear transport direction.

[0002]

2. Description of the Related Art A conventional machine tool called a machining center or a grinding center automatically performs various kinds of machining on a workpiece held on a work table by using various cutting tools or grinding tools or by using both tools. And it is comprised so that it may apply continuously. In this case, an automatic tool changer, abbreviated as ATC, is used to remove a used tool from the tool spindle and attach another tool to the tool spindle when machining with one tool is completed. The tool spindle has a built-in tool clamping mechanism for fixing the tool conveyed by the ATC to the tool spindle or releasing the tool from the tool spindle.

Further, a plurality of the above-mentioned ATC-equipped machine tools are arranged and arranged in the direction in which the workpiece is transported, and a workpiece transfer device sequentially transports the workpieces to these machine tools to advance a flexible transfer line (FTL). ) Are also known. In this processing system, a machine tool and a workpiece transfer device for transferring a workpiece between the machine tools are provided as independent mechanisms. In order to transfer the work or its pallet from each machine tool to the transfer device and from the transfer device to the machine tool in the next process, a work fixing device is provided on each machine tool side, while the work fixing device is provided on the transfer device side. Also, the number of machine tools is substantially the same as the number of machine tools.

[0004]

The conventional ATC described above.
In the case of a machine tool with a tool, when tool change is frequently required, the time involved in the tool change operation including the rotation stop and restart of the tool spindle occupies a considerable part of the machine tool operating time, and is substantially This is a factor that reduces the processing time and decreases the performance of the machine tool, that is, the productivity. Also, since the tool clamp mechanism is built into the tool spindle, the outer diameter of the tool spindle is inevitably increased, and the bearing that rotatably supports the tool spindle becomes larger,
Due to the imbalance of the tool clamping mechanism, it is difficult to rotate the tool spindle at high speed and to guarantee the rotation accuracy of the tool spindle for a long period of time.

[0005] This problem is frequently encountered in the processing of an aluminum material, in which the tool spindle which is rotated at a high speed (for example, 20,000 revolutions per minute) is rapidly stopped for tool change, and then rapidly accelerated again after the tool change. This is particularly noticeable when required. Accordingly, an object of the present invention is to eliminate the above-mentioned various problems caused by providing a mechanism for performing a tool changing operation on a tool spindle performed in a conventional ATC machine tool.

Further, in the above-mentioned FTL, since the machine tool and the transfer device for connecting the machine tools are separate and independent mechanisms, not only a machine or a pallet fixing device is required on each machine tool side, but also Since the number of machine tools is also required on the transfer device side, it is difficult to reduce the manufacturing cost of the FTL. In addition, every time the machining process of the workpiece is progressed, the release / fixing operation of the workpiece or pallet with respect to the fixing device on the machining table of each machine tool, and the fixing / fixing of the workpiece or pallet with respect to the fixing device on the transfer device. Release operations must be performed, and these non-machining times hinder the improvement of the productivity of the machining system.

Further, the workpiece is designed so as to be fixed at the same position on the processing table of each machine tool, but is "changed" each time it is conveyed to the machine tool in the next process. The machining surface to be machined in the next process on the basis of the machining surface in the previous process suffers a reduction in machining accuracy due to “grabbing”. Therefore, another object of the present invention is that it is suitable for constructing an FTL, and can eliminate the need for a conventional transport device specifically designed only for transport between machine tools, and at the same time equip this transport device with An object of the present invention is to provide a machine tool that can eliminate the need for a work fixing device. Still another object of the present invention is to prevent the workpiece from being "grabbed" while passing through the machining system, thereby not only reducing the non-machining time, but also reducing the machining accuracy due to "grabbing". It is an object of the present invention to provide a machine tool suitable for FTL that can eliminate the problem.

Another object of the present invention is to enable a machine tool maker to easily determine the size of a machine tool, particularly the width in the transport direction of a workpiece, in accordance with specifications required by a customer user. An object of the present invention is to provide a machine tool capable of easily remodeling the size of the machine tool according to a load change imposed on the machine tool.

[0009]

The first object of the present invention and the objects related thereto are solved and achieved by providing a machining method according to claim 1 and a machine tool according to claim 2. Is done. That is, in the machining method according to the first aspect, the work piece once attached to the work holding apparatus is, together with the work holding apparatus, a selected one of a plurality of tool spindle heads arranged along the first direction. In this indexing position, the workpiece holding device is rotated in accordance with a numerical control command for the tool on the selected tool spindle head while rotating the tool of the selected tool spindle head. The workpiece is moved in a three-dimensional space to perform a first process on the workpiece. After the first machining, the workpiece holding device is indexed before the next tool to be used in a state where the workpiece is held by the workpiece holding device, and the second machining is performed by the next tool in the rotating state. In this way, after the workpiece is held by the workpiece holding device in a single mounting operation, the holding state is maintained, and processing by a plurality of processing tools is sequentially performed on the workpiece.

In the machine tool according to the present invention, the first, second and third movable bodies sequentially superimposed on the base are provided so as to be individually movable by drive motors, respectively. The workpiece holding device supported on the body can move a workpiece to be machined to an arbitrary position in a three-dimensional space with respect to the base by moving the first, second, and third movable bodies. Is done. A plurality of tool spindle heads each rotatably supporting a tool spindle holding a processing tool by a drive motor are arranged along any one of the moving directions of the first, second and third movable bodies and within this moving range. It is arranged in line.

With this configuration, the workpiece held by the workpiece holding device is indexed in front of one tool spindle head that holds a desired tool, and the movement of the first, second and third movable bodies is numerically controlled. By doing so, desired processing can be performed on the workpiece. Switching of the tool used for machining is achieved simply by indexing the workpiece holding device by moving the movable body in front of the tool spindle head holding the tool to be used next.

The plurality of tool spindle heads are preferably arranged along the direction of linear movement of the first movable body on which the second and third movable bodies are loaded, as defined in claim 3. Preferably, the workpiece holding device is provided on a third movable body and is indexable around an axis inclined at 45 degrees to the moving direction of the movable body, as defined in claim 4. A first rotary table, a second rotary table provided on the first rotary table and indexable around an axis inclined at an angle of 45 degrees with respect to the rotation axis of the rotary table, and mounted on the second rotary table. It comprises a work pallet that can be used, and a pallet clamp mechanism that further releasably clamps the work pallet. First
By indexing the second rotary table to an arbitrary angle by an individual indexing drive device, five surfaces, excluding the surface on which the hexahedral workpiece is mounted on the work pallet, can be selectively directed to the tool.

The machine tool according to the present invention is preferably further provided with a tool changing device for performing a tool changing operation on the plurality of tool spindle heads. The tool changing device may include a traveling body movable in a direction parallel to an arrangement direction of the plurality of tool spindle heads on a side opposite to the first movable body, as defined in claim 6. It comprises a tool mounting / dismounting head for performing a tool changing operation on each of the tool spindle heads, and an access mechanism for bringing the tool mounting / dismounting head closer to the tool spindle head in cooperation with the movement of the traveling body.

[0014] More preferably, as defined in claim 7, a pallet storage device capable of detachably holding at least one of the work pallets within a range in which the second swivel table can move is provided. In particular, FTL
The problem in configuring (1) is solved by the machine tool according to claims 8 to 10. In order to be able to easily adjust the width of the machine tool in the direction of transport of the workpiece according to the processing capacity required of the FTL system, at least a part of the base is defined as in claim 8, A plurality of base modules having a predetermined width in the moving direction of the first movable body are stacked and fixed in the moving direction of the first movable body.

In this case, it is preferable that at least the driving device for the first movable body is constituted by a linear motor. Preferably, the movable coil is attached to the first movable body,
A configuration in which fixed magnet pieces having substantially the same length as the width of each module are arranged and arranged on each of the plurality of base modules fixed by lamination. From the viewpoint of minimizing the adhesion of chips, the arrangement relationship between the movable coil and the magnet may be reversed.

Preferably, the width of the base module is reduced in order to reduce the time required to transport the workpiece from the machining position by the tool on one tool spindle head to the machining position in front of the tool on the adjacent tool spindle head. As defined in claim 9, it is determined in relation to an arrangement interval of the plurality of tool spindle heads. Further, as defined in claim 10, it is preferable that each tool spindle head is mounted and fixed at a substantially central position of each base module in the tool transport direction in order to secure the mounting rigidity of the tool spindle head.

According to yet another embodiment of the present invention, as defined in claim 11, the base is a pair of columns having both ends in the horizontal direction perpendicular to the direction of transport of the workpiece upward. The first movable body is moved so as to move the workpiece holding device along the U-shaped space on the top surfaces of the pair of column portions, thereby forming the U-shaped portion. A workpiece is configured to be machined in the U-shaped space.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] Of the FIGS. 1 to 7 showing the first embodiment, FIG. 1 is a side view of a machine tool viewed from upstream in a workpiece conveying direction in a state where each movable element is at an original position. This figure 1
In FIG. 1, a machine tool includes a base 1 and a workpiece feeding / transporting unit 10 each mounted on the base 1.
And a plurality of tool spindle head groups 60 and a tool changing device 8
It is roughly constituted by 0.

The base 1 has a horizontal upper surface 2 on which the workpiece feeding / transporting unit 10 is mounted on the upper surface on the left side, and a cross section V for collecting cutting chips, cutting fluid, and the like at the center upper portion.
A first channel 3 having a V-shape is formed, and a second channel 4 having a V-shaped cross section for mounting the tool spindle head group 60 and the tool changing device 80 is formed on the upper right side. A pair of linear guide rails 1 extending horizontally in a direction perpendicular to the drawing is provided on a left horizontal upper surface 2 on which the unit 10 is mounted.
1 and 11 are fixed in parallel, and two sets (two sets for each rail) of circulating ball holders 12 and 12 that can move on these rails are provided with horizontal Xs that match the workpiece transfer direction.
It is fixed to the lower surface of the first movable body 13 that can move in the direction. On the horizontal upper surface 2, the pair of rails 11, 11
Between them, a long magnet plate 14a constituting a servo-controlled linear motor 14 is fixed, and a movable coil 14b of the linear motor 14 is fixed to the lower surface of the first movable body 13 facing the long magnet plate 14a.

A second movable body 16 having an L-shaped cross section is guided on the first movable body 13 so as to be movable in a horizontal Z direction at right angles to the X direction. For this Z-direction guidance, the first
Two sets of circulating ball retainers 1 fixed on movable body 13
7, 17 and the second movable body 1 guided and moved by these
6 and two linear guide rails 18 fixed to the lower surface. In FIG. 1, the rail on the near side in the x direction and a set of circulating ball retainers guided by the rail are not shown.

The driving mechanism of the second movable body 16 is a ball nut 1 fixed to the rear end of the horizontal portion 16a of the movable body 16.
And a ball screw 20 which is screw-engaged with the nut 19 and is thrust-beared at the left end of the first movable body 13.
And a servo motor 2 that rotationally drives the bolt 20
1 and a rotary encoder 22 attached to the rear of the motor 21.

On the front surface of the upright column portion 16b of the second movable body 16, two linear guide rails 25 perpendicular to both the X and Z directions are fixed in parallel, and two sets guided by these rails 25 are provided. Are fixed to the rear surface of the third movable body 27, and the third movable body 27 and the workpiece holding device 40 fixed to the front surface thereof can be moved up and down. In FIG. 1, the rail on the near side in the x direction that constitutes the guide device of the third movable body 27 and the 1
The set of circulating ball retainers is not shown.

The vertical drive mechanism of the third movable body 27, like that for the second movable body 16, allows only the ball nut 28 fixed to the third movable body 27 and the second movable body 16 to rotate only. And a servomotor 30 for rotating the screw 29 and a rotary encoder 31 provided at the rear of the motor. The workpiece holding device 40 includes a first rotary table 41 that can be rotated and indexed around an axis of the ball screw 29, that is, an axis that intersects the vertical direction of the third movable body 27 at an angle of 45 degrees. On the first rotary table 41, a second rotary table 42 is rotatable around an axis crossing the rotary axis of the table at an angle of 45 degrees at a portion protruding from one radial side of the table. It is supported by.

As shown in FIG. 6, the second rotary table 42 has a back surface of a work pallet 43 on which a workpiece to be machined (generally, a hexagonal hexagonal shape, but not limited thereto) is mounted. Conical shank part 4 extending vertically from
4 is formed at the center thereof and a pull stud 4 projecting from the rear end of the conical shank.
5 has a built-in clamp mechanism 42a for releasably restraining it. For the work pallet 43 and its clamping mechanism, the device disclosed in Japanese Patent Publication No. 4-29497 can be used.

Therefore, the second work pallet 43
The workpiece W fixed on the rotary table 42 is moved to the base 1 or each tool T of the tool spindle head group 60 fixed to the base 1 by the movement of the first, second and third movable bodies 13, 16, 27. On the other hand, it can be moved to any position in the three-dimensional space, and the first and second turntables 41,
By the indexing operation of 42, it is possible to direct the other five surfaces except the mounting surface of the work pallet 43 to the tool T. In the drawings, reference numerals 47 and 48 denote servomotors for driving the first and second rotary tables 41 and 42, respectively.

The first and second rotary tables 41, 4
2 are not described in detail because the mechanism itself does not constitute a feature of the present invention. However, preferably, the table indexing mechanism is a "rotary indexing apparatus" previously proposed by the present applicant. Patent application for the title of the invention (Japanese Patent Application No. 8-20)
No. 2832: filed on Jul. 15, 1996) shown in FIG. 1 or FIG. For example, by interposing the mechanism shown in FIG. 1 of the same application between the main body 40a of the workpiece holding device 40 and the first rotary table 41 and between the table 41 and the second rotary table 42 in the present application. The work holding device 40 of the present application is configured.

As is apparent from FIGS. 2 and 3, the tool spindle head group 60 includes a plurality of tool spindle heads 6.
1a to 61e. These heads are aligned and fixed on the vertical rising wall 5 adjacent to the first V-shaped channel 3 of the second V-shaped channel 4 along the moving direction of the first movable body 13. ing. As shown in FIG. 4, each of the tool spindle heads 61a to 61e has bearings 63, 6 at upper and lower ends in a head housing 62.
A tool main shaft 66 rotatably supported via the motor 4 and driven to rotate by a built-in motor 65, and a collet-type tool fixing mechanism 67 provided at an upper end portion of the main shaft 66.

The tool fixing mechanism 67 includes a collet member 69 which fits into a tapered hole 68 opened at the upper end of the tool spindle 66.
0 is engaged with the screw. The fixing ring 70 is taperedly engaged with the upper end conical portion 69a of the collet member 69. When the fixing ring 70 is rotated in the forward direction, the diameter of the straight inner hole of the collet member 69 is reduced, and a drill inserted into this inner hole is provided. The shank portion of the cutting tool T such as a tap or an end mill is clamped to the main shaft, and when the cutting tool T is rotated in the opposite direction, the collet member 69 is released from the restraint by the tapered hole 68 of the tool main shaft to expand the straight inner hole of the collet member 69. The tool T is operated to unclamp the tool T.

At the outer periphery of the flange provided at the upper end of the tool spindle 66 and the outer periphery of the fixing ring 70 to form a labyrinth seal, a tool attaching / detaching head, which will be described later, at the time of tool exchange, attaches the fixing ring 70 to the tool spindle. Positive for 66
Spline engagement portion 66a for allowing reverse rotation
And 70a are formed. FIG. 5 shows the tool changer 8
0 is used to replace a cutting tool T that has reached the end of its life among the plurality of tool spindle heads 61a to 61e with a new tool. This tool changing operation is executed when the life end tool is not used. One of the features of the present invention is that the tool changing operation can be performed when the life reaching tool is not used, and during this time, the machining operation on the workpiece W can be continued using another non-life reaching tool. No. 80 is characterized in that high speed as in the conventional machine tool is not required.

The tool changing device 80 includes a tool spindle head group 6
0 is provided on the opposite side of the workpiece feed / transport unit 10. More specifically, it is fixed to the wall surface 4a that rises vertically on the right side of the second V-shaped channel 4 and is parallel to the arrangement direction of the plurality of tool spindle heads 61a to 61e, that is, parallel to the movement direction of the first movable body 13. A guide rail 81 extending horizontally is provided, and a self-propelled traveling body 82 is movably guided on the guide rail 81. The traveling body 82 is provided with an optional tool spindle head by rolling a pinion 82a driven by a servo motor (not shown) provided on the traveling body 82 on a rack member 82b fixed in parallel with the guide rail 81. Can be indexed before.

FIG. 3 exemplifies a state in which the traveling body 82 is positioned in order to replace the life end tool on the tool spindle head 61e at the right end. The indexing of the traveling body 82 is performed under a known numerical control, or is controlled by a fixed sequence in which the proximity switches (not shown) provided at the corresponding positions of the tool spindle heads 61a to 61e are sequentially operated. Can be run below. Further, as is apparent from FIG. 3, the traveling body 82 has a plurality of tool holding holes H1 to H3 which function as a tool holder or tool storage means.
Prior to the tool change operation, some of these holes will hold a new tool and the remaining holes will be empty to accept the end of life tool.

Referring again to FIG. 5, the tool changing device 80
It further includes an access mechanism 83 provided on the traveling body 82, which is generally used for a known vertical articulated robot, and a tool attaching / detaching head 84 provided at a tip of the access mechanism. The access mechanism 83 includes a horizontal turntable 85 and a first arm 86 that turns on the horizontal turntable 85 in a vertical plane.
And a second arm 87 which is also rotatable in the vertical plane at the tip of the arm, a swivel base 85 and a first arm 86
And a plurality of servomotors (not shown) for driving the second arm 87 in accordance with a predetermined tool change operation sequence.

The tool attachment / detachment head 84 mainly includes a detent sleeve 88, a drive sleeve 89, and a plurality of tool holding jaws 90. The detent sleeve 88 is allowed to move only in the axial direction and is urged downward by the spring 91, and engages with the spline portion 66a (FIG. 4) of the tool spindle 66 to prevent the rotation of the tool spindle 66. Drive sleeve 89
Is urged downward by a spring 93 while allowing only axial movement in the cylindrical body 92, and engages with the spline portion 70 a of the fixing ring 70 which is screw-engaged on the tool spindle 66. When the rotation of a drive motor (not shown) is transmitted to the cylindrical body 92 via the worm-worm wheel mechanism 94, the fixing ring 70 rotates with respect to the tool spindle 66, which is prevented from rotating by the detent sleeve 88. I do.

The jaws 90 have their rear surfaces engaged with scroll gears formed in the inner hole of the worm wheel 95, and the rotation of a motor (not shown) on the head 84 via a worm / worm wheel mechanism 96. When transmitted to the worm wheel 95, it expands or contracts its effective gripping inner diameter. The access mechanism 83 includes a tool attaching / detaching head 84.
A well-known parallel link mechanism that keeps the attitude of the head 84 constant (vertical) in any vertical position.

FIG. 3 shows a pair of unworked and machined work pallet holders 1 of the same construction fixedly mounted on the base 1 on both sides of a plurality of tool spindle heads 61a to 61e.
00 and 101 are shown. Each cage 100, 101
6 has a bifurcated pallet support 102 which is open on the tool changer 80 side at the top, as shown in detail in FIG. Is formed with an arc-shaped groove 103, and an outer peripheral edge of the pallet 43 which is opposed in a diametrical direction is fitted into the arc-shaped groove 103.

Next, the operation of the first embodiment configured as described above will be described. In the original position state, each movable element of the machine tool except for the first movable body 13 is at the position shown in FIG. 1, and at this time, the position of the first movable body 13 in the X direction is the center of the second rotary table 42. 3, the unprocessed work pallet 100 located on the left side (upstream side in the work transfer direction)
Are located in the same plane as the center of

In this original position, when a machining start command is given, the numerical controller 110 (hereinafter referred to as CN)
C device) includes a linear motor 14 for driving the first to third movable bodies 13, 16 and 27, servo motors 21 and 30, servo motors 47 and 48 for driving the first and second rotary tables 41 and 42, Further, the tool spindle head 61a
Through 61e, (1) work pallet mounting operation, (2) processing operation, and (3) work pallet removal operation are sequentially executed as follows.

(1) Work pallet mounting operation In response to the machining start command, the CNC device 110 moves the second movable body 16 and moves the second rotary table 42 to the work pallet held in the unprocessed pallet storage device 100. Position it just above 43. Next, the third movable body 27 is moved down so that the tapered shank portion 44 of the work pallet 43 is inserted into the second rotary table 42, and the clamp mechanism 42a in the table 42 is operated to operate the work pallet 43. Are fixed to the second turntable 42. Third
The movable body 27 is configured such that the periphery of the work pallet 43 is
00, the second movable body 16 moves forward to the right in FIG. 1, pulls out the work pallet 43 from the front opening of the storage device 100, The pallet mounting operation is completed.

(2) Processing Operation After the work pallet 43 is extracted from the pallet storage device 100, the first to third movable bodies 13, 16, 27 are moved and mounted on the work pallet 43 on the second rotary table 42. The workpiece W is brought into contact with a desired one of the tools T on the plurality of tool spindle units 61a to 61e, and machining with one tool is executed. In this case, the first and second turntables 41,
42 is operated, whereby the processing by the first tool T can be executed also on the other five surfaces excluding the seating surface on the work pallet 43.

When the machining with the first tool T is completed, the first movable body 13 is moved, and the workpiece W on the work pallet 43 is conveyed before the second tool T to be used. Is performed. Also in this machining operation, the first to third movable bodies 13, 16, 27 and the first and second turntables 41, 42 are appropriately driven in accordance with a command from the CNC device 110. When the machining with the second tool T is completed, the machining operation is advanced using the third, fourth, and fifth tools T in order.

In connection with the progress of this series of machining operations, the tool spindles 66 of the tool spindle heads 61a to 61e are selectively started to rotate in accordance with the order of use planned on the numerical control program, and gradually after the completion of machining. Stopped. In this case, the rotation start of each tool spindle 66 is also performed gently in parallel with the machining operation by the preceding tool or the transfer operation of the workpiece W.

As described above, the machine tool according to the present invention conveys the workpiece W in front of the plurality of tools T, advances the machining by these tools T, and shifts the machining from one tool to another one tool. This is characterized in that a tool change operation to the tool spindle 66, which is required in a conventional machine tool, is not required when the process is shifted to the machining by the conventional method. As a result, not only the so-called chip-to-chip time can be significantly reduced, but also the high speed operation can be easily achieved by reducing the outer diameter of the tool spindle 66 by eliminating the need to incorporate a tool clamping mechanism in the tool spindle 66. Since the rotation of each tool spindle 66 can be started and stopped gently, the rotation accuracy of the tool spindle 66 that requires high-speed rotation, for example, 20,000 revolutions per minute, can be maintained for a long period of time.

In particular, each fixed tool spindle head 61a
One of a plurality of feed mechanisms (in this embodiment, the linear motor 14) for moving the workpiece W three-dimensionally for a machining operation with respect to the tool T on the
Another major feature of the machine tool according to the present invention is that the machine tool according to the present invention also serves as a transport mechanism for sequentially transporting before a to 61e. The reference point in the X direction of the first movable body 13 in the creation of the numerical control program is, as illustrated in FIG. 7, an arbitrary position X0 in the X direction (for example, a position passing through the center of the unprocessed pallet storage device 100). ) Is selected, and the machining operation of the workpiece using the tool on each of the tool spindle heads 61a to 61e is programmed by a general method such as designating L1, L2, L3,... From this reference point X0. be able to.

However, the tool T on each tool spindle 66
In order to facilitate the programming of the movement coordinates of the first movable body 13 for the machining operation using the above, the above-mentioned reference point X0 is used as the main reference point, and in addition to the main reference point X0, the first and second reference points are used. A plurality of sub-reference points X1 are located at positions where the rotation axis of the second rotation table 42 in the state where the rotation tables 41 and 42 assume the posture of FIG. 1 is aligned in the X direction with the axis of the tool spindle 66 of each of the tool spindle heads 61a to 61e. , X
2, X3, X4, and X5 may be set. In this way, the machining operation using each of the tools X
The operation in the direction can be easily programmed using the corresponding sub reference points X1 to X5, that is, the rotation axis of the corresponding tool spindle 66 as a reference origin.

In this case, each sub-reference point X1, X2, X3,
X4 and X5 are provided with position sensors S1 to S5 for detecting the arrival of the first movable body 13, and by controlling the X-direction coordinate of the first movable body 13 using the output signal from these sensors as the origin signal, the base 1 and the Accumulation of errors due to thermal deformation of the scale SCL (see FIG. 1) for X-direction coordinate detection fixed to the above can be eliminated. (3) Work Pallet Removal Operation When the machining operation of selecting and using a plurality of tools according to the numerical control program is completed, the third movable body 27 and the turntables 41 and 42 are returned to the original positions in FIG. The movable body 13 moves to the right end of the base 1 in FIG. 3 and aligns with the processed pallet storage device 101. Next,
The second movable body 16 advances the work pallet 43 further than the forked open end of the processed pallet storage device 101 in the Z direction, and the third movable body 27 descends by a predetermined amount. Second again
The movable body 16 is retracted and the work pallet 43 is stored in the storage device 10.
1, and finally, the third movable body 27 is lowered by a predetermined amount to seat the peripheral edge of the work pallet 43 in the arc-shaped groove of the storage device 102, and thereafter, the clamp mechanism 42 a in the second work pallet 43 Releases the work pallet 43, and the pallet removing operation is completed.

Thereafter, when another work pallet 43 holding another unprocessed workpiece W is loaded into the unprocessed pallet storage device 100 at the left end of FIG. 3, the first movable body 13 is moved to the storage device 100. And the pallet mounting operation described above is started. As the processing operation is repeated as described above,
The tool T on the tool spindle heads 61a to 61e is consumed,
Reach lifetime limit. This life limit can be easily detected by a known method of accumulating the use time of each tool in the CNC device 110, for example. When this is detected, the CNC
The device 110 indexes the traveling body 82 of the tool changing device 80 from the standby position (not shown) to the front surface of the tool spindle head that holds the tool at the end of the life limit, and then incorporates a sequence control unit (see FIG. ) To execute a tool changing operation in a predetermined sequence.

Thus, first, the access mechanism 83 shown in FIG.
Operates to position the tool mounting and dismounting head 84 above and concentric with the tool spindle head. Access mechanism 83
Then, the tool attaching / detaching head 84 is lowered vertically, and this is put on the upper end of the tool spindle head.
8 and the drive sleeve 89, respectively, as shown in FIG.
6 and the spline portion 70a of the fixing ring 70.

In this state, the worm wheel 95 is rotated forward to cause the jaw 90 to grip the tool which has reached the end of its life, and the drive sleeve 89 is rotated backward to release the fixing ring 70.
Next, the access mechanism 83 vertically raises the tool attachment / detachment head 84 to extract the tool T from the tool spindle 66, turns the swivel 85 by 90 degrees, and then lowers the tool attachment / detachment head 84 vertically to travel the used tool T. It is held in an empty hole (for example, H3 in FIG. 3) on the body 82. Tool detachable head 84
After the used tool T is released, the access mechanism 83 causes the new tool on the traveling body 82 to be held by the tool attachment / detachment head 84, and positions the new tool directly above the same tool spindle head and descends. Insert into.

In this state, the tool attaching / detaching head 84
Rotates the drive sleeve 93 and the worm wheel 95 forward and backward sequentially to fix the new tool to the tool spindle 66 and release it from the jaw 90. The access mechanism 83 vertically raises the tool attaching / detaching head 84, and thereafter the traveling body 82 is returned to the standby position (not shown), and the tool changing operation is completed. [Modification of First Embodiment] In the first embodiment described above, the base 1 is formed as one solid, but as shown in FIG. 8, a plurality of bases having a predetermined width D in the X direction are provided. The base module 1m can be laminated and fixed in the X direction to constitute the whole or a part of the base 1. In such a modified example, the machining target of the machine tool is limited according to the number of tools used in the machine tool in which the machining target is limited to several types.
It has the advantage that the width in the direction can be easily changed.

In this case, the plurality of base modules are 1 m
Is used to connect a plurality of through bolts 120 to the module 1 at both ends.
m, 1 m and integrally fixed. The through bolt 120 may have a length for fixing only the adjacent modules 1m. In order to align the plurality of base modules 1m in the stacking direction, for example, grooves having a rectangular cross section are formed on the front and rear surfaces thereof over the entire width in the stacking direction, and the reference bars 121 and 122 having the same rectangular cross section are tightly fitted. Is inserted at

The width D in the X direction of each base module 1 m
Is designed so that it does not interfere with adjacent tools while the largest workpiece of interest is machined by a tool on a certain tool spindle head. As shown in FIG. 8, each tool spindle head is attached to the center of the width of the corresponding base module 1 m in the X direction as illustrated in FIG. 8.

In the modification in which the base module 1m is stacked to form the base 1 in this manner, the pair of guide rails 11, 11 for the first movable body 13 and the fixed magnet plate 14a of the linear motor 14 are also provided. , Rail piece 1 corresponding to width D in the stacking direction of each base module 1m
1p, the magnet plate piece 14p and the rail piece 11p and the magnet plate piece 1 which are divided into the respective guide rails 11
4p is fixed in line with the lamination direction of the base module 1m. The joint surface between the adjacent rail pieces 11p, 11p and the joint surface between the adjacent magnet plate pieces 14p are inclined at a predetermined angle with respect to the joint surface of the base module 1m.
The first movable body 13 is smoothly moved in the X direction.

In the embodiment shown in FIG. 1, the linear motor 14 is used as the drive motor of the first movable body 13, but the work and the work load specified in the design stage of the machine tool are made permanently invariable. In the case where it is not necessary to maintain the flexibility with respect to the fluctuation of the workload, the use is not limited to the use of the linear motor 14, but the second and third movable bodies 16,
A ball screw type feed mechanism such as that used for the 27 may be employed.

In the embodiment shown in FIG. 1, the work pallets 43 are put in and taken out of the storage devices 101 and 102 through the forked open ends in front of the storage devices 101 and 102.
The work pallet 43 may be put in and taken out from directly above the work pallet 02. Further, both ends of the magnet plate piece 14p and the rail piece 11p mounted on each base module 1m are, in the embodiment of FIG.
m is inclined with respect to the mating surface, but may be parallel to the mating surface.

As described above, when the base 1 is configured by stacking a plurality of modules 1m, the base module 1m can be added or deleted according to the increase or decrease of the work load applied to the machine tool. There is an advantage that the machine tool can be easily modified in response to a change in load. On the other hand, machine tool manufacturers do not need to design machine tools in response to the requirements of the user each time, but expect to produce standardized parts such as the base module 1m, etc. There is an advantage that a machine tool that satisfies customer's required specifications can be manufactured in a short time by combining a large number of base modules 1m.

Although such an advantage can be achieved considerably only by modularizing only the base 1, it is possible to use a modularized tool spindle head shown in FIG.
As shown in FIG. 8, the use of the guide rails 11 and the fixed magnets 14a for the linear motors in a modular form can further improve the results. Further, in the embodiment shown in FIG. 1, a linear motor can be used instead of the ball screw type feed mechanism of the second and third movable bodies 16 and 27. In this embodiment, a plurality of tool spindle heads 61a to 61
1e are arranged in parallel with the movement direction (X direction) of the first movable body 13, but such an arrangement configuration has a large number of tools such as 10, 10, or even 100 tools. This is particularly advantageous when a flexible transfer line (FTL) is configured using a spindle head.

In the case of such an FTL, the CNC device 110 is placed on the back of the second movable base 16 without being placed on the floor, and the CNC device 110 is mounted on the first movable base 1.
3, the workpiece may be moved in the transport direction of the workpiece. In this case, the supply of power and the supply of control signals to the CNC device and various motors and the like may be in a usual wired form, or a trolley system may be adopted.

On the other hand, when the machine tool shown in FIG. 1 is used as a single-purpose machine using several tool spindle heads, the tool spindle head is moved in the moving direction of the second movable body 16 or the third movable body 27. Can be adopted. The second and third movable bodies 16 and 27 are Z-
Although a rectangular coordinate system for moving the workpiece W in the Y plane is configured, in order to move the workpiece W in the ZY plane, a rotating coordinate system is used instead of the rectangular coordinate system. You can also. In this case, the first rotating body is rotatably provided on the first movable body 13 around an axis extending in the X direction, and the second rotating body is rotatably supported in the first rotating body. A workpiece holding device 40 is provided at an eccentric portion of the body, and the workpiece holding mechanism is formed by combining the rotational movements of the first and second rotating bodies with a ZY.
It can be moved in a plane.

Further, in the embodiment shown in FIG. 1, the work pallet 43 is supported by the third movable body 27 via the first and second rotary tables 41 and 42. However, in the case where five-side machining is not required. Alternatively, the work pallet 43 may be configured to be directly detachably attached to the third movable body 27. Next, second to fifth embodiments of the present invention will be described with reference to FIGS. Note that FIG.
Each of FIG. 12 to FIG. 12 is a side view showing a part of each aspect cut away from the upstream in the workpiece conveying direction, similarly to FIG. 1 showing the first embodiment described above. In these drawings, components indicated by the same reference numerals as those in FIG. 1 are components having the same function as the corresponding components in FIG. 1, and the following description of each embodiment will The characteristic configuration will be described.

[Second Embodiment] In a second embodiment shown in FIG. 9, a relatively short column portion 1h stands upright on the right end of the base 1. In the column portion 1h, a plurality of tool spindle heads 61a to 61e are arranged in the moving direction (X direction) of the first movable body 13 with the tool T horizontal. A tool changing device 80 is installed on the upper surface of the column portion so as to be movable in the X direction by a traveling platform 82.

[Third Embodiment] In the third embodiment shown in FIG. 10, the column 1h at the right end of the base 1 is made tall, and the tool is located at a considerably higher position than the embodiment shown in FIG. The spindle heads 61a to 61e are arranged. Also,
The first rotary table 41 is supported on the third movable body 27 with the direction of inclination of the rotation axis of the first rotary table 41 reversed from that in the embodiment of FIG.
Thus, the workpiece can be machined while being supported from below.

[Fourth Embodiment] In a fourth embodiment shown in FIG. 11, the base 1 has column sections 1h, 1h rising vertically at both ends and a U-shaped cross section perpendicular to the conveying direction of the workpiece W. Is formed. The first movable base 13 includes the column unit 1
h, 1h, a pair of guide rails 11, 1 laid on the upper surface
11, along the top surfaces of the column portions 1h, 1h
Horizontally in the X direction perpendicular to the plane of the drawing. In this embodiment, the feed mechanism of the first movable body 13 is a general ball screw mechanism as indicated by reference numeral 14a. However, a fixed magnet plate is laid on the upper surfaces of the two column portions 1h, 1h, and a movable coil is attached to the lower surface of the first movable body 13 opposed thereto, so that a linear motor type feed mechanism is used instead of the ball screw mechanism. it can.

The second movable body 16 is placed on the first movable body 13
The third movable body 27 is guided on the second movable body 16 so as to be movable in the Y direction (vertical direction). The feed mechanism of the second and third movable bodies 16 and 27 is of a ball screw type, as in the embodiment of FIG. The third movable body 27 has a first
The rotary table 41 is supported so as to be indexable around an axis extending in the Y direction.

The first rotary table 41 has a suspension portion 41a vertically suspended from one side in the radial direction. In the suspension portion 41a, the second rotary table 42 is orthogonal to the rotation axis of the first rotary table 41. It is supported so as to be indexable around an axis. The plurality of tool spindle units 61a to 61e are arranged in the vertical middle part of the right column part 1h in FIG. 11 along the moving direction of the first movable base 13. An approximately square cylinder in which the distance between the two opposing surfaces is slightly smaller than the distance between the column portions 1h, 1h of the base 1 and the distance between the remaining two opposing surfaces is considerably larger than the width of the first movable body 13 in the moving direction. The side cover 130 is fixed to the lower surface of the first movable base 13 so as to move integrally therewith.

On the other hand, a plate-like top cover 131 for closing the upper opening of the side cover 130 over the entire moving stroke of the second movable body 16 is provided with a bracket 133 so as to move integrally with the second movable body 16. Via the second movable body 16
It is fixed to. Thereby, the side cover 130 is
In cooperation with the top cover 131, the upper opening of the U-shaped base 1 is closed at each of a plurality of processing positions corresponding to each tool, and functions to prevent the cutting chips and the coolant from scattering outside the machine.

[Fifth Embodiment] FIG. 12 shows an embodiment similar to that of FIG. The difference between this embodiment and that of FIG. 11 is that the first rotary table 4
The only difference is that the mounting posture of the first device is different. That is, in this embodiment, the third movable body 27 is similar to the embodiment of FIG.
First around an axis that intersects the direction of travel at an angle of 45 degrees.
The rotary table 41 can be indexed, and the second rotary table 42 is connected to the rotation axis of the first rotary table 41 by 45 degrees.
It is configured to be indexable about axes that intersect at an angle of degrees.

By arranging the first rotary table 41 in such a posture, the workpiece W can be moved to the second rotary table 4.
The four surfaces surrounding the mounting surface to the second rotary table 42 in a suspended state from 2 are processed by the tip of the tool T and the surface opposite to the mounting surface by the circumferential portion of the tool T. In contrast, in the embodiment shown in FIG. 11, the workpiece W has four surfaces surrounding the mounting surface and a surface opposite to the mounting surface with the tool T while the mounting surface is cantilevered by the second turntable 42.
It is processed by.

[0068]

As described above in detail, according to the first and second aspects of the present invention, a workpiece is placed on one of a plurality of movable bodies for moving the workpiece in a three-dimensional space. A plurality of tool spindle heads each supporting a holding device and rotatably supporting a spindle to which a tool is attached are arranged and arranged along one moving direction of the plurality of movable bodies, and the workpiece holding device is provided on the workpiece holding device. Since the held workpiece is sequentially indexed in front of the plurality of tool spindle heads, and the plurality of movable bodies are numerically controlled so that the workpiece is machined, the machining using a certain tool is performed next. The transition to machining using a tool does not require a tool change operation as in a conventional machine tool, and is achieved by simply indexing a workpiece in front of the next tool.・ Significantly shortened chip time It can be.

In particular, according to the second aspect of the present invention, a workpiece transfer mechanism for indexing a workpiece in front of a plurality of tools is provided by the movable body feeder for processing the workpiece with respect to each tool. A high-speed tool changer specially designed for a tool changing operation performed between two different tools by using one tool is not required, thereby significantly reducing the manufacturing cost of the machine tool. .

Further, if necessary, a rapid stop from the high-speed rotation region of the tool spindle and a subsequent high-speed start-up, which have conventionally been performed for a high-speed tool change operation, can be eliminated. Since a small diameter can be designed without the need for a built-in mechanism, various effects such as maintaining the rotation accuracy of the tool spindle with high accuracy over a long period of time can be obtained.

In the case where the rotation of the tool spindle with the next tool to be used is gradually started in parallel with the machining operation by the tool on one tool spindle, a tip-to-tool
This not only contributes to further shortening of the chip time, but also to the use of a motor having a small capacity for driving the tool spindle, thereby contributing to energy saving and cost reduction. According to the invention described in claim 4, the work pallet is supported via the first and second rotary tables on the third movable body that moves in a direction perpendicular to the moving direction of the first and second movable bodies. Therefore, the workpiece mounted on the work pallet can face the tool on the five surfaces excluding the mounting surface on the work pallet.

According to the fifth aspect of the present invention, each tool spindle of the tool spindle head is provided with a detachable tool, and a tool changing device for performing a tool changing operation on the tool spindle is provided. By utilizing the time during which the machining operation is performed, the tool change can be automatically performed on another tool spindle head that is not rotating. In particular, according to the invention of claim 6, this tool changing device is moved in parallel with the arrangement direction of the plurality of tool spindle heads on the side opposite to the movable body supporting the workpiece holding device with respect to the plurality of tool spindle heads. Since it is provided as possible, even when the number of tool spindle heads is increased, it can be dealt with without any particular change in the tool changing device.

According to the seventh aspect of the present invention, since the pallet storage device for the work pallet is provided within the moving range of the second rotary table, the work pallet on which the unprocessed workpiece is mounted is set in the pallet storage device. By doing so, the pallet loading / unloading operation between the pallet storage device and the second rotary table can be realized by using the movement of the movable body or the like without providing a loading / unloading device specifically designed for this purpose, The manufacturing cost of the machine tool can be further reduced.

Further, according to the present invention, at least a part of the base is formed by stacking and fixing a base module having a predetermined width in the moving direction of the first movable body, and One of the magnet and the coil constituting the linear motor functioning as the driving device of the first movable body is fixed on each base module in accordance with the width of each base module. The width of the base can be selected arbitrarily according to the machining capacity required and the number of required tool spindle heads.Machine tool manufacturers can immediately respond to the specifications required by customers, while users require the tool spindle according to load fluctuations. There is an advantage that facility modification such as addition or deletion of a base module with a head can be easily performed.

In particular, since the width of each base module is determined in accordance with the arrangement interval of the plurality of tool spindle heads, the arrangement direction of the tool spindle heads is determined as in the ninth and tenth aspects of the present invention. The required floor area of the machine tool can be reduced by making the width of the base as small as possible, and each tool spindle unit is fixed in the center of each base module in the width direction, so that the tool spans between the base modules. There is also an effect that a decrease in rigidity caused when the spindle head is fixed can be eliminated.

Further, as in the eleventh aspect of the present invention, the cross section of the base in a direction perpendicular to the direction in which the plurality of tool spindle heads are arranged is U-shaped, and a pair of vertically rising sides of the U-shaped cross section is provided. First on the top of the column
The movable body is guided so as to be able to move horizontally, and the workpiece holding device is suspended so as to face between the column parts.Therefore, a space between the pair of column parts can be used as a machining area, and scattering of cutting chips and cutting fluid to the outside of the machine The effect which can be prevented by the column portion is achieved.

[Brief description of the drawings]

FIG. 1 is a partial sectional side view of a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG. 1 of the first embodiment.

FIG. 3 is a plan view of the first embodiment.

FIG. 4 is a sectional view of the tool spindle head in the first embodiment, taken along line BB in FIG. 3;

FIG. 5 is a partial cross-sectional side view of the tool changing device according to the first embodiment, as viewed in the direction of arrow C in FIG. 3;

FIG. 6 is a cross-sectional view of the pallet storage device according to the first embodiment, taken along line DD in FIG. 3;

FIG. 7 is an explanatory diagram illustrating a coordinate system for facilitating designation of coordinates of a first movable body when creating an NC program.

FIG. 8 is a modified example of the base in the first embodiment,
FIG. 4 is a perspective view showing a plurality of stacked base modules and an arrangement of guide rail pieces and fixed magnet plate pieces fixed to the upper surface thereof.

FIG. 9 is a side view of a second embodiment of the present invention.

FIG. 10 is a partial sectional side view of a third embodiment of the present invention.

FIG. 11 is a side view of a fourth embodiment of the present invention.

FIG. 12 is a side view of a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 13 1st movable body 14 Linear motor 16 2nd movable body 27 3rd movable body 21, 30 Servo motor 40 Workpiece holding device 41, 42 1st, 2nd rotary table 43 Work pallet 60 Tool spindle head group 80 Tool Exchanger 1m Base module 14p Fixed magnet plate 100,101 Pallet storage

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Sentaro Sugita 1-1-1 Asahi-cho, Kariya-shi, Aichi Pref.

Claims (11)

[Claims] 1. A workpiece holding device for arranging a plurality of tool spindle heads each rotatably supporting a tool spindle on which a tool for a machining operation is mounted, along a first direction, and holding a workpiece. Move parallel to the first direction to index the workpiece in front of the tool supported on a selected one of the tool spindle heads, and at this indexing position, select the selected tool. While rotating the workpiece holding device, the selected tool is moved in a three-dimensional space in accordance with a numerical control command to perform a first machining on the workpiece.
In a state where the holding of the workpiece by the workpiece holding device is maintained after machining, the workpiece holding device is indexed before the next tool to be used, and the second machining by the next tool in the rotating state is executed, Machining the workpiece, wherein the workpiece is held by the workpiece holding device in a single mounting operation, and the holding state is maintained, and machining with the plurality of tools is sequentially performed on the workpiece. Method. 2. A base, a first movable body supported linearly on the base, a workpiece holding device for holding a workpiece to be machined, and a work holder provided on the first movable body. A second movable body movable with respect to the first movable body,
The workpiece holding device is movably provided on the second movable body to move the workpiece holding device to an arbitrary position in a three-dimensional space with respect to the base in cooperation with the movement of the first and second movable bodies. A third movable body that supports the workpiece holding device, and a tool spindle that holds a tool, each of which is rotatably supported by a drive motor, and that the first movable body moves within a movement range of the first movable body. A plurality of tool spindle heads fixedly arranged on the base in alignment with each other, and further provided in pairs with the first, second, and third movable bodies, respectively, and held by the workpiece holding device. Indexing the workpiece in front of any one of the plurality of tool spindle heads and moving the workpiece relative to a tool mounted on the arbitrary one tool spindle head to process the workpiece. Above 1, a machine tool, characterized in that it comprises a driving device for moving the second and third movable member under numerical control. 3. The machine tool according to claim 2, wherein the second and third movable bodies are in a direction perpendicular to each other.
It is linearly movable in a direction perpendicular to the moving direction of the movable body, and the axis of the tool spindle supported by the plurality of tool spindle heads is parallel to any of the moving directions of the second and third movable bodies. Machine tool characterized by the following. 4. The machine tool according to claim 3, wherein the workpiece holding device is in a plane including a moving direction of the second and third movable bodies and is in a moving direction of the third movable body. A first rotary table supported by the third movable body so as to be indexable around one axis inclined at 45 degrees, and one rotary table provided on the first rotary table and including a rotation axis of the first rotary table; A second turntable which is indexable about one axis lying in a plane and inclined at 45 degrees to the rotation axis of the first turntable, and for indexing the first and second turntables individually; A first and a second indexing drive device, a work pallet detachably mounted on the second rotary table and capable of attaching the workpiece, and a work pallet built in the second rotary table and A machine tool comprising: a pallet clamp mechanism for releasably clamping a two-turn table. 5. The machine tool according to claim 2, wherein each of the plurality of tool spindle heads includes a fixing device for detachably fixing a tool to a spindle, and the machine tool includes at least one tool spindle. Tool storage means that can store a set of tools, and access to each tool spindle head, removal of used tools from each tool spindle and installation of new tools on each tool spindle in cooperation with the fixing device on this tool spindle head A machine tool, further comprising: 6. The machine tool according to claim 5, wherein the tool changer is provided on a side opposite to the first movable body with respect to the plurality of tool spindle heads, and the tool changer is provided with the plurality of tools. A traveling body movable in a direction parallel to the arrangement direction of the spindle heads and provided with the tool storage means, capable of gripping the used tool and the new tool, and cooperating with the fixing device of each tool spindle. A tool attachment / detachment head for releasing the used tool from the tool spindle and fixing the new tool; and a tool attachment / detachment head provided on the traveling body and cooperating with the movement of the traveling body. A machine tool comprising: an access mechanism for approaching a head. 7. The pallet storage device according to claim 2, wherein the second rotary table is provided within a movable range, and the at least one work pallet can be detachably held. A machine tool, further comprising: 8. The machine tool according to claim 2, wherein the base includes a plurality of base modules each having a predetermined width in a moving direction of the first movable body. A driving device for moving the first movable body, wherein one member of a movable coil and a magnet attached to the first movable body,
The base module has a length substantially equal to a width of the first movable body in the movement direction of the first movable body and faces the one member of the movable coil and the magnet and is aligned in the movement direction of the first movable body. A machine tool comprising: the movable coil fixed to each of the base modules; and the other member of the magnet. 9. The machine tool according to claim 8, wherein the plurality of tool spindle heads are arranged such that the tool spindles maintain a predetermined interval, and the predetermined width of each of the base modules is set. Is determined in relation to the arrangement interval of the tool spindles. 10. The machine tool according to claim 8, wherein each of at least some of the plurality of tool spindle heads has an axis of the tool spindle that each has a second axis of the base module. (1) A machine tool fixed to the base module so as to be located at a center position in a moving direction of a movable body. 11. The machine tool according to claim 2, wherein
The base is formed in a U-shape having a pair of column portions that stand upright at both ends in a horizontal direction perpendicular to a horizontal movement direction of the first movable body, and the first movable body is formed of the pair of column portions. Is guided in the horizontal movement direction on the top surface, and the workpiece holding device is suspended between the pair of column portions, whereby the workpiece is formed in a U-shaped space formed between the pair of column portions. A machine tool characterized by being machined within.