Turning – Process of turning
Patent
1992-11-05
1994-05-24
Bilinsky, Z. R.
Turning
Process of turning
82118, 82124, 82129, 318632, 36447412, B23B 100
Patent
active
053138619
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a workpiece exchanging system, and in particular to a CNC (numerical control device) lathe including at least two spindle heads.
BACKGROUND ART
Conventionally, a four-axis lathe including two spindle heads and two tool posts is widely used for a more effective machining of a workpiece. In the four-axis lathe, a turning is carried out by a chuck of one spindle head, and when that machining is finished, the workpiece is clamped by a chuck of another spindle head and a turning of the surface opposite to the machined side is carried out.
A brief description of the prior art is now given, with reference to the attached drawings. FIGS. 4 (a), (b) and (c) are respectively diagrams illustrating the exchanging the workpiece in a CNC lathe having two spindle heads. FIG. 4 (a) shows an outline of a workpiece exchanging operation. In the FIG. 4 a chuck A2 is mounted at a spindle head A1 and is clamping the workpiece 5, and when the machining thereof by a tool post A3 is completed, a spindle head B6 is moved close to the workpiece 5, and the workpiece 5 is clamped by a chuck B7 mounted at the spindle head B6. At that time, the chuck A2 is opened, the spindle head B6 is returned to the machining position, and the workpiece 5 is machined by a tool post 8. FIG. 4 (b) shows the state wherein the workpiece 5 is normally clamped by the chuck B7 of the spindle head B6, and FIG. 4 (c) shows the state wherein the workpiece 5 is not normally clamped by the chuck B7 of the spindle head B6.
According to a workpiece exchanging system in a conventional CNC lathe having two spindle heads a clearance exists between the workpiece and the chuck. For example, when a foreign substance has intruded between the workpiece and the chuck, the workpiece is again machined, and as a result, the finished workpiece is not accurately machined to a desired dimension. In addition, on occasion, problems arise such that the workpiece is not correctly clamped by the chuck, and thus falls out during the machining, or the tool and the workpiece come into violent contact due to a quick feeding thereof.
DISCLOSURE OF THE INVENTION
The present invention has been made in view of the foregoing problems, and a main object of the present invention is to provide a workpiece exchanging system in a CNC lathe having two spindle heads, which ensures that the chucks thereof accurately clamp the workpiece, whereby a precise workpiece machining is accomplished.
To solve the above-mentioned problems, a workpiece exchanging system according to the present invention is characterized by a CNC lathe having at least two spindle heads, and comprises the following steps;
machining the workpiece with a first spindle head,
feeding a second spindle head toward the first spindle head while a servo motor is controlled by the feeding of the second spindle head while being loaded,
detecting any error occurring in the servo motor at the time that the movement of the second spindle head is completed.
and determining whether the workpiece has been normally clamped by a chuck mounted at the second spindle head.
Namely, when the turning of the workpiece by the first spindle head is finished, the second spindle head is moved to a machining position while loading the servo motor for a feed axis of the second spindle head with a torque limit. Next, an error at the servo motor is detected, and then it is determined whether the workpiece has been normally clamped by the second spindle head. According to whether or not an error is detected, the workpiece is machined as it is or is machined after being moved by a coordinate corresponding to the detected error. The CNC lathe is stopped by the sounding of an alarm.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flowchart of the workpiece exchanging system according to the present invention;
FIGS. 2 (a), (b) and (c) are diagrams illustrating the workpiece exchanging system according to an embodiment of the present invention;
FIG. 3 is a block diagram showing hardware of a numerical control dev
REFERENCES:
patent: 4101817 (1978-07-01), Maeda et al.
patent: 4682089 (1987-07-01), Tamari
patent: 4909521 (1990-03-01), Ovanin
patent: 5058029 (1991-10-01), Uemura
Bilinsky Z. R.
Fanuc Ltd.
LandOfFree
Workpiece exchanging system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Workpiece exchanging system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Workpiece exchanging system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1965742