Machining method and machining system

#1. Field of the Invention

#The present invention relates to a method and a system for machining (e.g., cutting or grinding) a workpiece with a machining device, and particularly to a method and a system suitable for machining a plurality of workpieces in an unmanned manner, i.e., without needing any human operators.

#2. Discussion of Related Art

#The above and other objects, features, advantages and technical and industrial significance of the present invention will be better understood by reading the following detailed description of preferred embodiments of the invention, when considered in connection with the accompanying drawings, in which:

#FIG. 1 is a schematic plan view of a machining system to which the present invention is applied;

#FIG. 2 is a plan view of each of three machining centers of the machining system;

#FIG. 1 schematically illustrates a machining system to which the present invention is applied. The present machining system includes a machining line consisting of a plurality of (e.g., three) machining centers 1 arranged along a straight reference line. A movable-type robot 2 is movable in opposite directions parallel to the reference line. The robot 2 is movable along a guide 3 extending above the three machining centers 1, while performing prescribed operations. In a most upstream portion of the machining line, there is provided a workpiece carry-in device 5 which automatically carries in a plurality of workpieces 4 and positions each of the workpieces, at a prescribed position. In a most downstream portion of the machining line, there is provided a workpiece carry-out device 6 which receives each machined workpiece 4, at a prescribed position, and automatically carries out the received workpiece 4. Between the workpiece carry-in device 5 and the most upstream one of the three machining centers 1, there is provided an attaching device 8 which attaches each workpiece 4 to a jig 7. Between the workpiece carry-out device 6 and the most downstream one of the three machining centers 1, there is provided a removing device 9 which removes each workpiece 4 from the jig 7.

#The robot 2 carries in the jig 7 with the workpiece 4 attached thereto by the attaching device 8, to each of the three machining centers 1, attaches and detaches the jig 7 to and from the each machining center 1, and carries out the jig 7 from the each machining center 1. In addition, the robot 2 returns the jig 7 from which the workpiece 4 was removed by the removing device 9, to the attaching device 8. Moreover, the robot 2 receives the workpiece 4 positioned at the prescribed position by the workpiece carry-in device 5, and transfers the workpiece 4 to the jig 7 positioned at the attaching device 8. Thus, the robot 2 functions as a transferring device as part of the attaching device 8. In addition, the robot 2 functions as a transferring device which receives the workpiece 4 from the jig 7 positioned at the removing device 9, and transfers the workpiece 4 to the workpiece carry-out device 6. Since each machining center 1 performs a complex machining operation including plural sorts of machining operations, on a workpiece 4, the each center 1 needs a lot of time to finish the complex machining operation. Therefore, the single robot 2 can do all needed operations, i.e., carrying in and carrying out the jig 7 and attaching and detaching the jig 7 to and from each machining center 1. However, in the case where the single robot 2 cannot do all needed operations, it is possible to employ a plurality of movable-type robots 2, or alternatively it is possible to employ an exclusive or special robot (i.e., “attaching” robot) which receives each workpiece 4 from the workpiece carry-in device 5 and attaches the each workpiece 4 to the jig 7, and/or a special robot (i.e., “removing” robot) which removes each workpiece 4 from the jig 7 and transfers the each workpiece 4 to the workpiece carry-out device 6.

#As shown in FIGS. 2 and 3, each machining center 1 includes a bed 10 as a main frame; a tool rest 12 which holds and rotates a tool 26; and a workpiece rest 14 which holds the workpiece 4. The workpiece rest 14 includes an X-axis slide 16 which is movable in a horizontal, X-axis direction parallel to a lengthwise direction of the machining line; and a revolving table 18 which is provided on the X-axis slide 16 and is revolveable about a vertical axis line. The revolving table 18 is provided with a workpiece spindle 20 which holds the workpiece 4 and rotates the same 4 about an axis line parallel to a horizontal, Y-axis direction perpendicular to the X-axis direction. The tool rest 12 includes a Y-axis slide 22 which is movable in the Y-axis direction. The Y-axis slide 22 includes a vertical column which supports a Z-axis slide 24 such that the Z-axis slide 24 is movable in a Z-axis direction perpendicular to the X-axis and Y-axis directions. The Z-axis slide 24 is provided with a tool spindle 28 which holds the tool 26 and rotates the same 26 about an axis line parallel to the Y-axis direction. Each of the X-axis slide 16, the revolving table 18, the workpiece spindle 20, the Y-axis slide 22, and the Z-axis slide 24 is driven by a drive device including an electric servomotor as its drive source, and can be moved, revolved, or rotated to any arbitrary position or angle (i.e., angular position or phase). Those devices 16, 18, 20, 22, 24 cooperate with one another to provide a moving device which moves at least one of the workpiece 4 and the tool 26 relative to the other of the workpiece 4 and the tool 26, so that the workpiece 4 can be machined by the tool 26. The workpiece spindle 20 and the tool spindle 28 are provided with a workpice chuck 30 and a tool chuck 32, respectively, each of which is driven by a chuck drive device.