FORM 2
THE PATENT ACT 1970 (39 of 1970)
&
The Patents Rules, 2003 COMPLETE SPECIFICATION
(See Section 10, and rule 13)
1. TITLE OF INVENTION MACHINE TOOL
2. APPLICANT (S)

a) Name : MITSUBISHI HEAVY INDUSTRIES, LTD.
b) Nationality : JAPANESE Company
c) Address : 16-5, KONAN 2-CHOME,
MINATO-KU, TOKYO 1088215, JAPAN
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed : -

TECHNICAL FIELD
The present invention relates to a machine tool which automatically measures the machining position, the shape, and the inclination angle of a machining object and the distance to the machining position.
BACKGROUND ART
In general, machine tools can machine a workpiece by moving a tool mounted to a spindle and the workpiece attached to a table relative to each other in a horizontal direction and a vertical direction. Thus, if the workpiece has an attachment defect or the workpiece has a shape defect, a portion of the workpiece may possibly be left unmachined after machining, and large machining load may possibly be exerted on the workpiece and the tool during the machining.
To solve this, conventional machine tools, before machining a workpiece, measure coordinates of a designated spot on the workpiece and determine whether or not the workpiece has an attachment defect and whether or not the workpiece has a shape defect on the basis of the result of the measurement. A conventional machine tool as described above is disclosed in Patent Document 1, for example.
PRIOR ART DOCUMENT PATENT DOCUMENT
Patent Document 1: Japanese Patent Application Publication No. 2004-338065
SUMMARY OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
The above conventional machine tool measures the coordinates of a designated spot on a workpiece by using a probe mounted to a spindle. However, measurement using

the probe mounted to the spindle as described above requires not only the work of mounting the probe to the spindle for each workpiece to be machined, but also the work of changing the probe to a tool and vice versa for the spindle. Further, as for the measuring method using a probe, the speed at which to bring the probe toward the workpiece needs to be set low so as to prevent excessive load from being exerted on the probe when the probe is brought into contact with the workpiece. For this reason, the conventional machine tool requires a longer period of time than necessary when measuring a workpiece.
The present invention has been made to solve the above problems, and an object thereof is to provide a machine tool which can measure a machining object easily and quickly and machine the machining object accurately.
MEANS FOR SOLVING THE PROBLEMS
A machine tool according to the present invention for solving the above problems is
a machine tool for machining a machining object with a tool by moving a spindle to
which the tool, is attachable and the machining object relative to each other in a
horizontal direction and a vertical direction, characterized in that the machine tool
comprises:
a saddle which supports the spindle rotatably and which is supported movably at
least in the vertical direction;
measuring means for measuring a machining position, a shape, and an inclination
angle of a machining object and a distance to the machining position in a non-contact
manner;
transferring means, provided to the saddle, for transferring the measuring means
between a measurement position at which the measuring means is capable of
measuring the machining object and a retreat position to which the measuring means
retreats from the measurement position; and
controlling means for determining whether or not the machining object has an
attachment defect and a shape defect on the basis of the machining position, the

shape, and the inclination angle of the machining object and the distance to the machining position measured by the measuring means, and then controlling movement of at least one of the tool and the machining object on the basis of a result of the determination.
A machine tool according to the present invention for solving the above problems is a machine tool for machining a machining object with a tool by moving a spindle to which the tool is attachable and the machining object relative to each other in a horizontal direction and a vertical direction, characterized in that the machine tool comprises:
a table to which a machining object is detachably attached and which is supported movably in the horizontal direction;
measuring means for measuring a machining position, a shape, and an inclination angle of the machining object and a distance to the machining position in a non-contact manner;
transferring means, provided on the spindle side facing a moving range of the machining object, for supporting the measuring means movably in the vertical direction and transferring the measuring means between a measurement position at which the measuring means is capable of measuring the machining object and a retreat position to which the measuring means retreats from the measurement position; and
controlling means for determining whether or not the machining object has an attachment defect and a shape defect on the basis of the machining position, the shape, and the inclination angle of the machining object and the distance to the machining position measured by the measuring means, and then controlling movement of at least one of the tool and the machining object on the basis of a result of the determination.
A machine tool according to the present invention for solving the above problems is
characterized in that
the machine tool further comprises:

a saddle which supports the spindle rotatably; and
a column which supports the saddle in the vertical direction, and
the transferring means is provided to the column,
A machine tool according to the present invention for solving the above problems is
characterized in that
the machine tool further comprises:
a saddle which supports the spindle rotatably; and
a column which supports the saddle in the vertical direction, and
the transferring means is provided on a floor surface supporting the column.
A machine tool according to the present invention for solving the above problems is characterized in that the transferring means transfers the measuring means in an axial direction of the spindle between the measurement position and the retreat position.
A machine tool according to the present invention for solving the above problems is
characterized in that
the transferring means are provided in such a way as to face each other in a thickness
direction of the machining object, and
the machining position, the shape, and the inclination angle of the machining object
and the distance to the machining position are measured from both sides in the
thickness direction of the machining object by the measuring means attached
individually to the transferring means facing each other.
EFFECTS OF THE INVENTION
Thus, the machine tool according to the present invention can measure a machining object easily and quickly since it includes the transferring means for transferring the measuring means for measuring a machining object in a non-contact manner between the measurement position and the retreat position, and since the transferring means is provided at such a position as not to affect attachment and detachment of the tool to

and from the spindle. Moreover, the machine tool according to the present invention can accurately machine a machining object since it determines whether or not the machining object has an attachment defect and a shape defect on the basis of the result of the measurement by the measuring means, and controls movement of the tool and the machining object in accordance with the result of the determination.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic configuration diagram of a machine tool according to a first embodiment of the present invention.
Fig. 2 is an enlarged view of a main part of Fig. 1 and is a view showing a state of including one transferring unit.
Fig. 3 is a block diagram showing the configuration of the machine tool according to the first embodiment of the present invention.
Fig. 4 is an enlarged view of the main part of Fig. 1 and is a view showing a state of including multiple transferring units.
Fig. 5 is a plan view of the machine tool according to the first embodiment of the present invention set in opposed arrangement.
Fig. 6 is a schematic configuration diagram of a machine tool according to a second embodiment of the present invention.
Fig. 7 is a view showing an example of a transferring unit provided to the machine tool according to the second embodiment of the present invention.
Fig. 8 is a set of views showing another example of the transferring unit provided to the machine tool according to the second embodiment of the present

invention, Part (a) being a view showing a state where a workpiece measuring device is transferred to a measurement position, Part (b) being a view showing a state where the workpiece measuring device is transferred to a retreat position.
MODES FOR CARRYING OUT THE INVENTION
Hereinbelow, a machine tool according to the present invention will be described in detail with reference to the drawings.
EMBODIMENTS
First, a machine tool according to a first embodiment will be described in detail with reference to Figs. 1 to 5.
As shown in Fig. 1, in a machine tool 1, a column 11 is provided upright. Moreover, a saddle 12 is supported on a side surface of this column 11 in such a way as to be movable up and down in a vertical direction (hereinafter, referred to as the Y-axis direction).
A spindle head 13 is supported inside the saddle 12 movably in a horizontal direction (hereinafter, referred to as the Z-axis direction). A spindle 14 is supported inside this spindle head 13 movably in the direction of the axis thereof (Z-axis direction) and rotatably about the axis. Moreover, a tool T is detachably mounted to the tip of the spindle 14. In addition, as will be described later in detail, a transferring unit (transferring means) 15 is provided on a side surface of the saddle 12.
Further, in the machine tool 1, a table bed 16 is provided in front of the column 11, and a table 17 is supported on the upper surface of this table bed 16 movably in a horizontal direction (hereinafter, referred to as the X-axis direction). Furthermore, a workpiece (machining object) W is detachably attached to the upper surface of the

table 17.
Thus, by driving the saddle 12, the tool T and the transferring unit 15 can be moved in the Y-axis direction. Moreover, by driving the spindle head 13, the spindle 14 and the tool T can be moved in their axial direction through movement of the spindle head 13 in the Z-axis direction. Further, by driving the spindle 14, the tool T can be moved in its axial direction through movement of the spindle 14 in the Z-axis direction. Meanwhile, by driving the table 17, the workpiece W can be moved in the X-axis direction along with the table 17.
Moreover, as shown in Figs. 1 to 3, the transferring unit 15 includes a unit body 15a, a transferring rod 15b, a motor 15c, and an amplifier 15d. The unit body 15a is attached to the side surface of the saddle 12, and the transferring rod 15b is supported inside the unit body 15a slidably in the Z-axis direction, i.e. feedably toward and away from the workpiece W. Thus, by driving the motor 15c, the transferring rod 15b can be moved in the Z-axis direction.
Moreover, a workpiece measuring device (measuring means) 30 is attached to the tip of the transferring rod 15b. This workpiece measuring device 30 is a non-contact measuring device which, before machining a workpiece W, measures the machining position (coordinates of a machining portion), the shape (dimensions of the machining portion), and the inclination angle (the amount of the machining allowance) of the workpiece W, and the distance from the workpiece measuring device 30 to the machining position in a non-contact manner. Here, the machine tool 1 employs a CCD camera 31 or a laser length measuring device 32 as the workpiece measuring device 30.
Note that Fig. 1 shows a state where one workpiece measuring device 30 is attached to the tip of the transferring rod 15b while Figs. 2 and 3 show a state where two workpiece measuring devices 30 are attached to the tip of the transferring rod 15b.

Specifically, as shown in Fig. 3, in the case where the workpiece measuring device 30 is a CCD camera 31, a predetermined imaging portion of the workpiece W is imaged by means of the CCD camera 31 to thereby obtain image data thereof. Then, the image data is inputted to an analyzing unit 19 through a controller 33. Further, the analyzing unit 19 recognizes the inputted image data as the shape of the workpiece W and then outputs it to an NC unit 20 to be described later.
Moreover, as shown in Fig. 3, in the case where the workpiece measuring device 30 is a laser length measuring device 32, a laser beam outputted from the laser length measuring device 32 is applied to the predetermined irradiation points on the workpiece W to measure the distances from the laser length measuring device 32 to the irradiation points in the Z-axis direction. Moreover, each measured distance is inputted to the analyzing unit 19 through the controller 33. Further, the analyzing unit 19 outputs the inputted measured distance as is to the later-described NC unit 20 as the distance to the machining position, and also recognizes the inputted measured distance as the shape of the workpiece W and outputs it to the NC unit 20.
Thus, by driving the saddle 12 and the table 17, the transferring unit 15 can be moved relative to the workpiece W in the X-axis direction and the Y-axis direction, i.e. the transferring unit 15 can be positioned to a position facing the predetermined imaging portion of and the predetermined irradiation points on the workpiece W. Further, by driving the thus positioned transferring unit 15 to slide the transferring rod 15b in the Z-axis direction, the workpiece measuring device 30 (CCD camera 31 or laser length measuring device 32) can be transferred between a measurement position (imaging position or irradiation position) PI at which the workpiece measuring device 30 can measure (image or apply a laser beam to) the workpiece W and a retreat position P2 to which the workpiece measuring device 30 retreats from the measurement position PI, with the tool T mounted to the spindle 14.
Note that the measurement position PI is set to a location beyond the position of the tip of the tool T mounted to the spindle 14 in the Z-axis direction (a location closer to

the workpiece W). Moreover, the retreat position P2 is set to a location behind the position of the tip of the tool T mounted to the spindle 14 in the Z-axis direction (a location farther away from the workpiece W).
Meanwhile, as shown in Fig. 1, the machine tool 1 is provided with the NC unit (controlling means) 20 which integrally controls the machine tool 1. The saddle 12, the spindle head 13, the spindle 14, the transferring unit 15, the table 17, the analyzing unit 19, the workpiece measuring device 30, and the like are connected to this NC unit 20, for example.
Specifically, the NC unit 20 controls movement of the tool T mounted to the spindle 14 in the Y-axis direction and the Z-axis direction and movement of the workpiece W attached to the table 17 in the X-axis direction on the basis of machining conditions (such as the number of rotations, the feed speed, the cut-in amount, etc. of the spindle 14) corresponding to the shape of the workpiece W before machining and the amount of its machining allowance. Further, before machining with the tool T, the NC unit 20 controls measurement operation with the transferring unit 15 and the workpiece measuring device 30 to measure the machining position, the shape, and the inclination angle of the workpiece W and the machining distance from the workpiece measuring device 30 to the machining position. Then, based on the results of the measurements, the NC unit 20 determines whether or not the workpiece W has an attachment defect and a shape defect. Further, based on the result of the determination, the NC unit 20 controls movement of the tool T and the workpiece W so as to make the machining allowance of the workpiece W even.
Note that the analyzing unit 19, the NC unit 20, the workpiece measuring device 30, the CCD camera 31, the laser length measuring device 32, and the like constitute measuring means.
Next, measurement and machining of a workpiece W by the machine tool 1 will be specifically described. Meanwhile, the following description will representatively

show a case where the CCD camera 31 and the laser length measuring device 32 are attached to the tip of the transferring rod 15b.
First, a workpiece W is attached to the table 17. Note that multiple prepared holes Wc which will be through-holes are machined in advance in side surfaces Wa and Wb of the workpiece W.
Then, the transferring unit 15 is positioned to face a prepared hole Wc in the workpiece W, and thereafter its transferring rod 15b is extended. As a result, the CCD camera 31 and the laser length measuring device 32 are transferred from the retreat position P2 to the measurement position PI.
Moreover, the CCD camera 31 captures an image of the prepared hole Wc in the workpiece W. The captured image of the prepared hole Wc is converted into image data and inputted into the NC unit 20 through the analyzing unit 19. Here, based on the inputted image data, the analyzing unit 19 computes the center and the inner diameter of the prepared hole VJc.
Moreover, the laser length measuring device 32 measures the distances to multiple irradiation points on the side surface Wa of the workpiece W, and the multiple measured distances obtained by the measurement are inputted to the NC unit 20 through the analyzing unit 19. Here, based on the multiple measured distances thus inputted, the analyzing unit 19 computes the inclination angle of the side surface Wa and the distance to an end surface of the prepared hole Wc. Note that in the case of using the laser length measuring device 32 as described above, the distance measurement by the laser length measuring device 32 is performed at least twice.
Then, based on the inputted center and inner diameter of the prepared hole Wc, the inputted inclination angle of the side surface Wa, and the inputted distance to the end surface of the prepared hole Wc, the NC unit 20 determines whether or not the workpiece W has an attachment defect and whether or not the workpiece W has a

shape defect.
Here, if determining that the workpiece W has no attachment defect and that the workpiece W has no shape defect, the NC unit 20 moves the tool T in the Y-axis direction and the Z-axis direction and also moves the workpiece W in the X-axis direction on the basis of preset machining conditions, so that predetermined machining is performed on the prepared hole Wc in the workpiece W and the end surface of the prepared hole Wc.
On the other hand, if determining that the workpiece W has an attachment defect or that the workpiece W has a shape defect, the NC unit 20 corrects the movement of the tool T in the Y-axis direction and the Z-axis direction and the movement of the workpiece W in the X-axis direction on the basis of the center and inner diameter of the prepared hole Wc, the inclination angle of the side surface Wa, and the distance to the end surface of the prepared hole Wc. In this way, even if the workpiece W is attached to the table 17 in a tilting posture or the workpiece W has a shape defect, the attached position of the workpiece W is corrected, so that predetermined machining is performed on the prepared hole Wc in the workpiece W and the prepared hole Wc.
Moreover, if determining that a portion of the workpiece W will be left unmachined despite the correction of the movement of the tool T and the workpiece W, the NC unit 20 stops the machining by the machine tool 1 and activates a warning alarm for notifying of the attachment defect or shape defect of the workpiece W.
Note that although one transferring unit 15 is provided on the side surface of the saddle 12 in the embodiment described above, multiple transferring units 15 may be provided instead.
For example, as shown in Fig. 4, two transferring units 15 may be aligned vertically and provided on the side surface of the saddle 12, in which case the workpiece measuring device 30 in one transferring unit 15 is a CCD camera 31 whereas the

workpiece measuring device 30 in the other transferring unit 15 is a laser length measuring device 32. In this way, the positions to place the transferring units 15 can be designated individually so that the imaging portion for the CCD camera 31 and the irradiation points for the laser length measuring device 32 can be set at different positions.
Moreover, although a machine tool 1 including one column 11 is employed as a machine tool for machining a workpiece W in the embodiment described above, the machine tool may instead have two columns 11 disposed in such a way as to face each other in the thickness direction of a workpiece W attached to the table 17, as shown in Fig. 5.
Specifically, with two columns 11 disposed in such a way as to sandwich a workpiece W therebetween in its thickness direction, the workpiece measuring device 30 attached to the transferring unit 15 on the side surface Wa side measures the center and inner diameter of the prepared hole We opening at the side surface Wa, the inclination angle of the side surface Wa, and the distance to the end surface of the prepared hole Wc opening at the side surface Wa, whereas the workpiece measuring device 30 attached to the transferring unit 15 on the side surface Wb side measures the center and inner diameter of the prepared hole Wc opening at the side surface Wb, the inclination angle of the side surface Wb, and the distance to the end surface of the prepared hole Wc opening at the side surface Wb. In this way, the centers and inner diameters of the prepared hole Wc, the inclination angles of the side surfaces Wa and Wb, and the distances to the end surfaces of the prepared hole Wc can be measured simultaneously from both sides in the thickness direction of the workpiece W by the workpiece measuring devices 30 attached individually to the facing transferring units 15. Accordingly, the workpiece W can be measured quickly and accurately.
Further, although the column 11 is fixed in the embodiment described above, the column 11 may instead be movable in the X-axis direction and the Z-axis direction.

Thus, according to the machine tool 1 according to the present invention, the center and inner diameter of each prepared hole We, the inclination angles of the side surfaces Wa and Wb, and the distance to the end surface of the prepared hole Wc can be measured easily and quickly since the transferring unit 15 which transfers the non-contact workpiece measuring device 30 is provided on the side surface of the saddle 12. Moreover, the workpiece W can be machined accurately since it is determined whether or not the workpiece W has an attachment defect and a shape defect on the basis of the results of the four measurements by the workpiece measuring device 30, and the movement of the tool T and the workpiece W is controlled in accordance with the result of the determination.
Moreover, since the measurement position PI can be set as close as possible to the workpiece W by making the workpiece measuring device 30 transferable between the measurement position PI and the retreat position P2, it is possible to improve the measurement accuracy of the workpiece measuring device 30. On the other hand, since the retreat position P2 can be set as far as possible from the workpiece W, it is possible to prevent breakage and malfunction of the workpiece measuring device 30 which would otherwise be caused by cut chips flying due to the machining and cutting oil.
Further, the measurement time can be further shortened since multiple workpiece measuring devices 30 may be used to simultaneously measure the centers and inner diameters of each prepared hole Wc, the inclination angles of the side surfaces Wa and Wb, and the distances to the end surfaces of the prepared hole Wc from both the side surface Wa side and the side surface Wb side of the workpiece W.
Next, a machine tool according to a second embodiment will be described in detail with reference to Figs. 6 to 8. Note that the same members as those in the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted.

As shown in Fig. 6, a machine tool 2 is provided with a column bed 41, and a column 42 is supported on the upper surface of this column bed 41 movably in an X-axis direction. Further, a saddle 12 is supported on the inner surface of the column 42 in such a way as to be movable up and down in a Y-axis direction.
Here, in the machine tool 2, transferring units (transferring means) 15 and 45 shown in Fig. 7 and Parts (a) and (b) of Fig. 8 are each attachable at attachment positions HI and H2. The attachment position HI shows the position of the transferring unit 15 or 45 attached to a side surface of the column 42, whereas the attachment position H2 shows the position of the transferring unit 15 or 45 attached to a floor surface F around one end of the column bed 41.
Thus, by driving the column 42, a tool T and the transferring unit 15 or 45 attached at the attachment position HI can be moved in the X-axis direction.
Moreover, as shown in Fig. 7, the transferring unit 15 includes a supporting member 15e in addition to the unit body 15a, the transferring rod 15b, the motor 15c, and the amplifier 15d mentioned above. A side surface of the supporting member 15e is attached to the side surface of the column 42 in the case of attaching the transferring unit 15 at the attachment position HI, while the bottom surface of the supporting member 15e is attached to the floor surface F in the case of attaching the transferring unit 15 at the attachment position H2. The supporting member 15e supports the unit body 15a in such a way that the unit body 15a is movable up and down in the Y-axis direction.
Thus, by driving the transferring unit 15, the workpiece measuring device 30 attached to the tip of the transferring rod 15b can be moved in the Y-axis direction and also transferred in a Z-axis direction between a measurement position PI and a retreat position P2.
On the other hand, as shown in Parts (a) and (b) of Fig. 8, the transferring unit 45

includes a unit body 45a, a first transferring arm 45b, a second transferring arm 45c, connecting shafts 45d, a motor 15c, and an amplifier 15d. A side surface of the unit body 45a is attached to the side surface of the column 42 in the case of attaching the transferring unit 45 at the attachment position HI, while the bottom surface of the unit body 45a is attached to the floor surface F in the case of attaching the transferring unit 45 at the attachment position H2.
Moreover, the base end of the first transferring arm 45b is turnably supported on the unit body 45a through a connecting shaft 45d, and the base end of the second transferring arm 45c is turnably supported on the tip of the first transferring arm 45b through a connecting shaft 45d. Further, a workpiece measuring device 30 is attached to the tip of the second transferring arm 45c.
Thus, by driving the motor 15c to turn the first transferring arm 45b and the second transferring arm 45c about their respective two connecting shafts 45d, the workpiece measuring device 30 attached to the tip of the second transferring arm 45c can be moved in the Y-axis direction and also transferred in the Z-axis direction between the measurement position PI and the retreat position P2.
Moreover, as shown in Fig. 6, the machine tool 2 is provided with an NC unit 20 which integrally controls the machine tool 2. The saddle 12, a spindle head 13, a spindle 14, the transferring unit 15 or 45, a table 17, an analyzing unit 19, the workpiece measuring device 30, the column 42, and the like are connected to this NC unit 20, for example.
Specifically, the NC unit 20, before machining with the tool T, controls measurement operation with the transferring unit 15 or 45 and the workpiece measuring device 30 to measure the machining position, the shape, and the inclination angle of the workpiece W and the distance from the workpiece measuring device 30 to the machining position. Then, based on the results of the measurements, the NC unit 20 determines whether or not the workpiece W has an attachment defect and a shape

defect. Further, based on the result of the determination, the NC unit 20 controls movement of the tool T and the workpiece W so as to make the machining allowance of the workpiece W even.
Thus, the transferring unit 15 can be moved in the X-axis direction and the Y-axis direction relative to the workpiece W and positioned to a position facing a predetermined imaging portion of and the predetermined irradiation points on the workpiece W by driving the transferring unit 15, the table 17, and the column 42 in the case where the transferring unit 15 is attached at the attachment position HI, or by driving the transferring unit 15 and the table 17 in the case where the transferring unit 15 is attached at the attachment position H2. Further, by driving the thus positioned transferring unit 15 to slide the transferring rod 15b in the Z-axis direction, the workpiece measuring device 30 can be transferred between the measurement position PI and the retreat position P2 with the tool T mounted to the spindle 14.
Alternatively, the transferring unit 45 can be moved in the X-axis direction and the Y-axis direction relative to the workpiece W and positioned to the position facing the predetermined imaging portion of and the predetermined irradiation points on the workpiece W by driving the transferring unit 45, the table 17, and the column 42 in the case where the transferring unit 45 is attached at the attachment position HI, or by driving the transferring unit 45 and the table 17 in the case where the transferring unit 45 is attached at the attachment position H2. Further, by driving the thus positioned transferring unit 45 to turn the first transferring arm 45b and the second transferring arm 45c in the Z-axis direction, the workpiece measuring device 30 can be transferred between the measurement position PI and the retreat position P2 with the tool T mounted to the spindle 14.
Thus, according to the machine tool 2 according to the present invention, the center and inner diameter of each prepared hole We, the inclination angles of side surfaces Wa and Wb, and the distance to the end surface of the prepared hole Wc can be measured easily and quickly since the transferring unit 15 or 45 which transfers the

non-contact workpiece measuring device 30 is provided on the column 42 side facing the moving range of the workpiece W in the X-axis direction; i.e. the side surface of the column 42 or the floor surface F supporting the column bed 41. Moreover, the workpiece W can be machined accurately since it is determined whether or not the workpiece W has an attachment defect and a shape defect on the basis of the results of the four measurements by the workpiece measuring device 30, and the movement of the tool T and the workpiece W is controlled in accordance with the result of the determination.
Note that although a machine tool 2 including one column 42 is employed as a machine tool for machining a workpiece W in the embodiment described above, the machine tool may instead have two columns 42 disposed in such a way as to face each other in the thickness direction of a workpiece W attached to the table 17.
Moreover, in the two embodiments described above, in the case where two workpiece measuring devices 30 are attached to one transferring unit 15 or 45, a CCD camera 31 and a laser length measuring device 32 are used as the two workpiece measuring devices 30. However, only CCD cameras 31 or laser length measuring devices 32 may be used instead.
Further, in the two embodiments described above, the transferring unit 15 or 45 is provided to a machine tool 1 that rotates its spindle 14 about a horizontal axis (e.g. a horizontal boring machine). However, the transferring unit 15 or 45 may also be provided to a machine tool that rotates its spindle about a vertical axis (e.g. a double-column machining center).
INDUSTRIAL APPLICABILITY
The present invention is applicable to machine tools configured to prevent any portion of a workpiece from being left unmachined after machining and large machining load from being exerted on a workpiece and a tool during machining.

WE CLAIM:
1] A machine tool for machining a machining object with a tool by moving a spindle to which the tool is attachable and the machining object relative to each other in a horizontal direction and a vertical direction, characterized in that the machine tool comprises:
a saddle which supports the spindle rotatably and which is supported movably at least in the vertical direction;
measuring means for measuring a machining position, a shape, and an inclination angle of a machining object and a distance to the machining position in a non-contact manner;
transferring means, provided to the saddle, for transferring the measuring means between a measurement position at which the measuring means is capable of measuring the machining object and a retreat position to which the measuring means retreats from the measurement position; and controlling means for determining whether or not the machining object has an attachment defect and a shape defect on the basis of the machining position, the shape, and the inclination angle of the machining object and the distance to the machining position measured by the measuring means, and then controlling movement of at least one of the tool and the machining object on the basis of a result of the determination.
2] A machine tool for machining a machining object with a tool by moving a spindle to which the tool is attachable and the machining object relative to each other in a horizontal direction and a vertical direction, characterized in that the machine tool comprises:
a table to which a machining object is detachably attached and which is supported movably in the horizontal direction;
measuring means for measuring a machining position, a shape, and an inclination angle of the machining object and a distance to the machining position in a non-contact manner;

transferring means, provided on the spindle side facing a moving range of the machining object, for supporting the measuring means movably in the vertical direction and transferring the measuring means between a measurement position at which the measuring means is capable of measuring the machining object and a retreat position to which the measuring means retreats from the measurement position; and
controlling means for determining whether or not the machining object has an attachment defect and a shape defect on the basis of the machining position, the shape, and the inclination angle of the machining object and the distance to the machining position measured by the measuring means, and then controlling movement of at least one of the tool and the machining object on the basis of a result of the determination.
3] The machine tool according to claim 2, characterized in that the machine tool further comprises: a saddle which supports the spindle rotatably; and a column which supports the saddle in the vertical direction, and the transferring means is provided to the column.
4] The machine tool according to claim 2, characterized in that the machine tool further comprises: a saddle which supports the spindle rotatably; and a column which supports the saddle in the vertical direction, and the transferring means is provided on a floor surface supporting the column.
5] The machine tool according to claim 1, characterized in that the transferring means transfers the measuring means in an axial direction of the spindle between the measurement position and the retreat position.
6] The machine tool according to claim 1, characterized in that
the transferring means are provided in such a way as to face each other in a

thickness direction of the machining object, and
the machining position, the shape, and the inclination angle of the machining object and the distance to the machining position are measured from both sides in the thickness direction of the machining object by the measuring means attached individually to the transferring means facing each other.
7] The machine tool according to claim 2, characterized in that the transferring means transfers the measuring means in an axial direction of the spindle between the measurement position and the retreat position.
8] The machine tool according to claim 2, characterized in that
the transferring means are provided in such a way as to face each other in a thickness direction of the machining object and
the machining position, the shape, and the inclination angle of the machining object and the distance to the machining position are measured from both sides in the thickness direction of the machining object by the measuring means attached individually to the transferring means facing each other.