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 : NUMERICALLY-CONTROLLED MACHINE TOOL
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 numerically-controlled machine tool such as a
machining center, a horizontal boring machine or a double column plano milling
machine.
Background Art
A numerically-controlled machine tool such as a machining center, a horizontal
boring machine or a double column plano milling machine has heretofore been
configured to determine a machining start point, an inclination of a reference plane,
and the like prior to machining by measuring a position of a predetermined portion
of a workpiece fixed and supported onto a table, and the like by use of a contact
sensor such as a touch probe.
Citation List
Patent Literatures
Patent Literature 1: Japanese Patent Application Publication No. Hei 6-055407
Patent Literature 2: Japanese Patent Application Publication No. 2009-163414
Patent Literature 3: Japanese Patent Application Publication No. 2010-108292
Summary of Invention
Technical Problem
In the meantime, when a contact sensor such as a touch probe is used in an attempt
to three-dimensionally measure a shape of a workpiece, a moving speed (a feeding
speed) of the contact sensor such as a touch probe cannot be set very fast in the light
of accuracy and significant time is wasted as a consequence.
In view of the above, an object of the present invention is to provide a numerically controlled
machine tool which is capable of quickly measuring an actual three-dimensional
condition of a workpiece attached onto a table via a jig or the like.
Solution to Problem
A numerically-controlled machine tool of the present invention for solving the above
problem is characterized in that the machine tool comprises: a main spindle to which
a tool is detachably attached and which is configured to rotate the tool; a table
configured to fix and support a workpiece; tool measuring means for measuring a
length and a diameter of the tool attached to the main spindle; workpiece measuring
t
means for measuring a three-dimensional shape, a position, and an orientation of the
workpiece fixed and supported onto the table in a non-contact manner; information
displaying means for displaying information; and controlling means for finding a
position of a machining start point and an inclination of a reference plane on the
basis of information from the work measuring means, then determining at least one
of presence of a machining load equal to or above a prescribed value and presence of
a portion of the workpiece left unmachined by performing simulation of machining
the workpiece on the table to an intended final shape on the basis of an inputted
machining program while using information from the tool measuring means and the
workpiece measuring means as well as the position of the machining start point and -
the inclination of the reference plane, and displaying a determined result by using
the information displaying means.
Meanwhile, a numerically-controlled machine tool of the present invention
according to the numerically-controlled machine tool described above is -
characterized in that the controlling means is configured to further determine
presence of interference of the workpiece side with the tool side by performing the
simulation of machining the workpiece on the table to the intended final shape on
the basis of the machining program while using the information from the tool
measuring meaneand the workpiece measuring means as well as the position of the
machining start point and the inclination of the reference plane, and to display a
determined result-by using the information displaying means.
Meanwhile, a numerically-controlled machine tool of the present invention
according to the numerically-controlled machine tool described above is
characterized in that the controlling means is configured to compare the found
position of the machining start point and the found inclination of the reference plane
1
with a position of a machining start point and an inclination of a reference plane
assumed in the inputted machining program, and when at least one of the found
position of the machining start point and the found inclination of the reference plane
does not comply with at least one of the assumed position of the machining start
point and the assumed inclination of the reference plane, to display information
indicating the non-compliance by using the information displaying means.
Meanwhile, a numerically-controlled machine tool of the present invention
according to the numerically-controlled machine tool described above is
characterized in that the controlling means is configured to compare the shape of the
workpiece on the table measured by the workpiece measuring means with a shape of
the workpiece assumed in the inputted machining program, and when the shape of
the workpiece on the table does not comply with the assumed shape of the
workpiece, to display information indicating the non-compliance by using the
information displaying means.
Advantageous Effect of Invention
According to a numerically-controlled machine tool of the present invention, the
three-dimensional shape, the position, and the orientation of-the workpiece fixed
and supported onto the table are measured with the workpiece measuring means in
a non-contact manner. Thus, an actual three-dimensional condition of the workpiece
attached onto the table via a jig or the like can be quickly measured.
Brief Description of Drawings
Fig. 1 is a schematic configuration diagram of a main embodiment of a
numerically-controlled machine tool according to the present
invention.
Fig. 2 is a control block diagram of principal part of the main embodiment of
the numerically-controlled machine tool according to the present
invention.
Fig. 3 is a control flowchart of the principal part of the main embodiment of
the numerically-controlled machine tool according to the present
invention.
Description of Embodiments
An embodiment of a numerically-controlled machine tool according to the present
invention will be described below with reference to the drawings. It is to be noted, -
however, that the present invention is not limited only to the embodiment described
with reference to the drawings.
A main embodiment of a numerically-controlled machine tool according to the - present invention will be described with reference to Figs. 1 to 3.
As shown in Fig. 1, a numerically-controlled machine tool 100 of this embodiment
includes: a main spindle 102 to which a tool 101 can be detachably attached and
which is configured to rotate the tool 101; a table 103 configured to fix and support a
workpiece 1; a tool measuring sensor 104 serving as tool measuring means for
measuring two-dimensional shapes, namely, a length and a diameter of the tool 101
attached to the main spindle 102; and workpiece measuring sensors 105 serving as
workpiece measuring means for measuring a three-dimensional shape of a
combination of a jig and the workpiece 1 fixed and supported onto the table 103 in a
non-contact mannk with a laser beam or the like.
In addition, as shown in Fig. 2, the tool measuring sensor 104 and the workpiece
measuring sensors 105 are electrically connected to an input unit of a control device
106 serving as controlling means. Moreover, an input device 107 serving as
inputting means for inputting various machining conditions imluding a machining
program and the like is electrically connected to the input unit of the control device
106.
In the meantime, an output unit of the control device 106 is electrically connected to .
each of: a drive motor 108 which is configured to rotate the tool 101 attached to the
main spindle 102; drive motors 109 to 111 which are configured to move the main
spindle 102 and the table 103 in such a manner as to move the tool 101 and the
workpiece 1 relatively in X, Y, and Z axis directions; and a display device 112 serving
as information displaying means such as a speaker or a monitor for displaying a
variety of information in the form of sounds or images. The control device 106 is
capable of controlling actions of the motors 108 to 111 on the basis of information
from the sensors 104,105 and information inputted from the input device 107, and of
displaying the variety of information on the display device 112 (to be described later
in detail).
Next, actions of the numerically-controlled machine tool 100 of this embodiment will
be described.
First, various machining conditions including the machining program are inputted
to the control device 106 by using the input device 107 (S1 in Fig. 3). When the tool
101 is attached to the main spindle 102, the control device 106 activates the motors
109 to 111 and thereby moves the tool 101 and the tool measuring sensor 104
relatively in the X, Y, and Z axis directions (52 in Fig. 3) in such a manner as to
measure the two-dimensional external sizes including the length and the diameter of
the tool 101 with the tool measuring sensor 104.
*
Thus, the control device 106 determines the actual two-dimensional external sizes of
the tool 101 including a length between an end of the main spindle and a tip of the
tool 101, a diameter on the tip side, and the like on the basis of the information from
the tool measuring sensor 104.
Subsequently, when the workpiece 1 is fixed and supportea onto the table 103 via
the jig, the control device 106 activates the motors 109 to 111 and thereby moves the
workpiece measuring sensors 105 and the workpiece 1 relatively in the X, Y, and Z
axis directions (S3 in Fig. 3) in such a manner as to measure the three-dimensional
external shape, agosition, and an orientation of the combination of the jig and the
workpiece 1 on the table 103 with the workpiece measuring sensors 105.
Thus, the control device 106 determines the actual three-dimensional external shape,
position, and orientation of the combination of the jig and the workpiece 1 on the
table 103 on the basis of the information from the workpiece meisuring sensors 105.
Next, the control device 106 determines compliance between the inputted machining
program and the workpiece 1 on the basis of the actual external shape of the tool 101
and the actual external shape, position, and orientation of the workpiece 1
determined as described above.
Specifically, the control device 106 first compares a shape of the workpiece assumed
in the machining program inputted from the input device 107 with the actual shape
of the workpiece 1 on the table 103 on the basis of the actual external shape of the
workpiece 1, and determines whether or not a content of machining to be carried out
complies with the workpiece 1 to be machined (S4 in Fig. 3). When the shape of the
workpiece assumed in the machining program does not comply with the shape of
the workpiece 1 on the table 103, namely, when the content of machining to be
carried out does not conform to the workpiece 1 to be machined, the control
device 106 warns an operator by displaying such a fact on the display device 112
(S5 in Fig. 3).
When the shape of the workpiece assumed in the machining program complies with
the shape of the workpiece 1 on the table 103, namely, when the content of
machining to be carried out conforms to the workpiece 1 to be machined, the control
device 106 subsequently finds machining reference values including a position of a
machining start point, an inclination of a reference plane, and the like on the basis of
the position and orientation of the workpiece 1 (S6 in Fig. 3).
Then, the control device 106 determines whether or not the actual position and
orientation of the workpiece 1 on the table 103 comply within normal ranges (S7 in
Fig. 3) by comparing the actual machining reference values including the position of
the machining start point, the inclination of the reference plane, and the like thus
found with assumed machining reference values including the position of the
machining start point, the inclination of the reference plane, and the like which are
assumed in the inputted machining program. When the actual machining reference
values do not comply with the assumed machining reference Glues, namely, when
the actual position and orientation of the workpiece 1 on the table 103 are
misaligned, the control device 106 warns the operator by displaying such a fact on
the display unit 112, and displays the information indicating the position and
orientation of thepon-compliant workpiece 1 (58 in Fig. 3).
When the actual machining reference values comply with the assumed machining
reference values, namely, when the actual position and orientation of the workpiece
1 on the table 103 are compliant, the control device 106performs simulation of
machining the actual workpiece 1 inclusive of the jig on the table 103 to an intended
..c
final shape (S9 in Fig. 3) on the basis of the various machining conditions including
the inputted machining program and the like, the measured actual two-dimensional
shapes including the length and the diameter of the tool 101, the measured actual
three-dimensional shape of the workpiece 1, and the found actual machining
reference values including the position of the machining start point, the inclination
of the reference plane, and so forth.
Presence of any of the following machining problems is checked (S10 in Fig. 3) by
carrying out the machining simulation of the actual workpiece 1 to the intended final
shape:
(1) Presence of interference of the workpiece 1 side inclusive of the jig or the like
with the tool 101 side such as a slide (a ram);
(2) Presence of a machining load equal to or above a prescribed value (a machining
allowance of a size equal to or above the prescribed value); and
(3) Presence of a portion of the workpiece 1 left unmachined.
Here, if there is any of the above-mentioned problems, the control device 106 warns
the operator by displaying such a fact on the display device 112, and displays details
(position, magnitude, and the like) of such a problem (S11 in Fig. 3).
On the other hand, when there are none of these problems, the control device 106
starts control of the actions of the motors 108 to 111 in or&r to perform actual
machining on the workpiece 1 on the table 103 in a similar manner to the machining
simulation (S12 in Fig. 3).
Then, the control device 106 continues the actual machining on the basis of the -
machining simulation. In a machining region where the tool 101 is in contact with
the workpiece 1 (S13 in Fig. 3), the control device 106 controls the actions of the
motors 109 to 111 (S14 in Fig. 3) in such a manner as to relatively move the main
spindle 102 and the table 103 according as defined in the machining program. On
the other hand, in a non-machining region where the tool 101 moves without being
in contact with the workpiece 1, the control device 106 controls (overrides) the
actions of the motors 109 to 111 (S15 in Fig. 3) in such a manner as to move the tool
101 relatively to the workpiece 1 at a higher speed than the moving speed such as the
feeding speed of the tool 101 defined in the machining program.
Then, the actualmachining on the workpiece 1 is terminated as the machining
program is terminated (S16 in Fig. 3).
In other words, the numerically-controlled machine tool 100 of this embodiment is
configured to find the actual three-dimensional shape of the workpiece 1 inclusive of
the jig or the like by using the workpiece measuring sensor% 105 which perform
measurement in a non-contact manner with a laser beam or the like.
Accordingly, the numerically-controlled machine tool 100 of this embodiment can
quickly measure the actual three-dimensional condition of the workpiece 1 attached
onto the table 103 via the jig or the like. In addition, the following advantageous
effects can be achieved as well.
(1) It is possible to considerably simplify a conventional operation so-called a
debugging operation, in which the machining program is executed while moving the
main spindle 102 away before machining is actually performecPon the workpiece 1;
meanwhile, the operator visually checks a relation concerning an acting position
(such as the presence of the interference, the degree of fluctuation of the machining
allowance or the presence of the portion left unmachined) of the main spindle 102
with the workpiece 1 and the operator performs adjustment so as to reflect a result of
the check in the actual machining. Thus, a burden on the operator can be
significantly reduced and fluctuation attributed to an experience level of the
operator can be eliminated.
(2) The moving speed such as the feeding speed of the tool 101 is overridden when
the tool 101 is in the non-machining region in the course of z e actual machining.
Thus, processing time can be significantly reduced.

The foregoing embodiment has described the case of providing the workpiece
measuring sensors 105 configured to measure the three-dimensional shape and the
like of the workpiece 1 in a non-contact manner with a laser beam or the like.
Instead, as another embodiment, it is possible to provide a CCD camera configured
to shoot the three-dimensional shape and the like of the workpiece 1, for example.
Meanwhile, in the foregoing embodiment, the tool measuring sensor 104 configured
to measure the shapes including the length, the diameter, and the like of the tool 101,
and the workpiece measuring sensors 105 configured to measure the threedimensional
shape and the like of the workpiece 1 in a non-contact manner are
provided. Instead, as another embodiment, it is possible to provide measuring
means for measuring the shapes including the length, the diameter, and the like of
the tool 101 and measuring the three-dimensional shape and the like of the
workpiece 1 in such a manner as to serve as both of the tool measuring sensor 104
and the workpiece measuring sensors 105, for example.
Meanwhile, in the foregoing embodiment, the interference of the workpiece 1 side
inclusive of the jig or the like with the tool 101 side such as the slide (the ram) is
checked in the machining simulation prior to the actual machining. Instead, as
another embodiment, it is possible to conduct machining while performing
simulation of a state ahead of a point of machining (such as 5 seconds ahead) during
the actual machining, for example. Here, when occurrence of the interference of the
workpiece 1 side kclusive of the jig or the like with the tool 101 side such as the slide
(the ram) is predicted, the controlling means is caused to warn the operator by
displaying such a fact on the displaying means, to display a position of the
interference, and to suspend the machining. In other words, the controlling means
can be provided with a crash prevention function (see M'L 1, for example).
In the meantime, the foregoing embodiment has described the case of checking the
presence of both the machining problems of the machining load equal to or above
the prescribed value (the machining allowance of a size equal to or above the
prescribed value) and the portion of the workpiece 1 left unmachined. However,
depending on various conditions such as accuracy associated with a manufacturing
history of the workpiece 1, it is possible to check the presence of only one of the
t
machining problems of the machining load equal to or above the prescribed value
(the machining allowance of a size equal to or above the prescribed value) and the
portion of the workpiece 1 left unmachined.
In addition, the present invention is applicable as described in the foregoing
embodiment to a numerically-controlled machine tool such as Bmachining center, a
horizontal boring machine or a double column plano milling machine.
Industrial Applicability
*
A numerically-controlled machine tool according to the present invention is capable
of quickly measuring an actual three-dimensional condition of a workpiece attached
onto a table via a jig or the like, and is therefore extremely useful in metal processing
industries and the like.
Reference Signs List
1 workpiece
100 numerically-controlled machine tool
101 tool
102 Main spindle
103 table
104 tool measuring sensor
105 workpiece measuring sensor
106 control a'evice
107 input device
108 to 111 drive motor
112 display device

WE CLAIM :
1. A numerically-controlled machine tool characterized in that the machine tool
comprises:
a main spindle to which a tool is detachably attached and which is configured
to rotate th3 tool;
a table configured to fix and support a workpiece;
tool measuring means for measuring a length and a diameter of the tool
attached to the main spindle;
workpiece measuring means for measuring a three-dimensional shape, a
position, and an orientation of the workpiece fixed andsupported onto the
table in a non-contact manner;
information displaying means for displaying information; and
controlling means for finding a position of a machining start point and an
inclination of a reference plane on the basis of information from the work measuring means, then determining at least one of presence of a machining
load equal to or above a prescribed value and presence of a portion of the
workpiece left unmachined by performing simulation of machining the
workpiece on the table to an intended final shape on the basis of an inputted
machining program while using information from the tool measuring means
and the workpiece measuring means as well as the posiEon of the machining
start point and the inclination of the reference plane, and displaying a
determined result by using the information displaying means.
2. The numerically-controlled machine tool according to claim 1, characterized
in that the-controlling means is configured to further determine presence of
interference of the workpiece side with the tool side by performing the
simulation of machining the workpiece on the table to the intended final
shape on the basis of the machining program while using the information
from the tool measuring means and the workpiece measuring means as well as
the position of the machining start point and the inclination of the reference
plane, and to display a determined result by using the information displaying
means.
3. The numerically-controlled machine tool according to claim 1, characterized
in that the controlling means is configured to compare +he found position of
the machining start point and the found inclination of the reference plane
with a position of a machining start point and an inclination of a reference
plane assumed in the inputted machining program, and when at least one of
the found position of the machining start point and the found inclination of
the reference plane does not comply with at least one of the assumed position
of the machining start point and the assumed inclination of the reference
plane, to display information indicating the non-compliance by using the
information displaying means.
4. The numerically-controlled machine tool according to $aim 1, characterized
in that the controlling means is configured to compare the shape of the
workpiece on the table measured by the workpiece measuring means with a
shape of the workpiece assumed in the inputted machining program, and
when the ehape of the workpiece on the table does not comply with the
assumed shape of the workpiece, to display information indicating the noncompliance
by using the information displaying means.