Electric heating – Metal heating – By arc
Patent
1990-10-23
1993-04-27
Albritton, C. L.
Electric heating
Metal heating
By arc
21912161, 36447408, B23K 2602
Patent
active
052064735
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to an NC laser device which including combination of a numerical control device and a laser oscillator, and more particularly, to an NC laser device able to detect an abnormaly generated during a non-operative period thereof before machining is started.
2. Background Art
A gas laser oscillator using a CO.sub.2 gas laser and so forth provides a high output with a high efficiency and has excellent beam characteristics, and thus is widely used as an NC laser device combined with a numerical control device (CNC) for metal machining and so forth. In such an NC laser device, the alignment of a rear mirror, a return mirror and an output mirror is precisely adjusted, and careful attention is paid to vibration from outside and to temperature control of cooling water for optical parts during operation, to avoid any misalignment.
Nevertheless, misalignment can be caused by an unexpected mechanical impact during a non-operative period of the device, such as during transporting and so forth, and when such a misalignment occurs, the laser output is greatly reduced and the beam mode becomes poor. In practice, a reduced laser output can be corrected by a power correction function or the like, but it is not wise to continually use this function as the oscillation efficiency is lowered and remains in that state. Moreover, the deterioration of beam mode cannot be corrected, and this leads directly to a lowering of the machining performance.
Such an abnormality generated during a non-operative period cannot be detected until an operator examines the machined state after actual machining, and thus if an abnormal condition has occurred, the whole workpiece becomes useless and the machining efficiency is lowered.
SUMMARY OF THE INVENTION
This invention was created in view of the above circumstances, and an object of the present invention is to provide an NC laser device able to detect an abnormality generated during a non-operative period of the device before machining is started.
To achieve the above object, according to the invention, there is provided an NC laser device having a combination of a numerical control device and a laser oscillator, and including a command means for commanding a specific laser output at the time of starting, monitoring means for monitoring the laser output, ratio calculating means for obtaining a ratio of a command value output from the above command means to a monitored value output from the above monitoring means, non-volatile memory means for storing the above ratio, and an abnormality detecting means for obtaining the difference between the above ratio and the ratio obtained at the previous start, and for displaying an alarm on a display screen when the above difference is higher than a predetermined set value.
A specific laser output is commanded at each start, and the ratio of the commanded value to a monitored value is obtained and stored. When a difference higher than a predetermined value exists between the ratio of this start and that of the previous start, it is concluded that an abnormality occurred during the non-operative period and an alarm is displayed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing an arrangement of an NC laser device according to one embodiment of this invention;
FIG. 2 is a flowchart of processing at a start of an NC laser device according to one embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of this invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an arrangement of an NC laser device of one embodiment of this invention. In FIG. 1, a processor (CPU) 1 controls the operation of the entire laser device in accordance with machining commands in a machining program, not shown. The processor 1 outputs a command value Pc, as described later, to an output control circuit 2 at the time of starting. The output control circuit 2 has a D/A converter therein and converts an output command value
REFERENCES:
patent: 5059760 (1991-10-01), Iehisa et al.
Iehisa Nobuaki
Suzuki Kazuhiro
Albritton C. L.
Fanuc Ltd.
LandOfFree
NC laser device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with NC laser device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and NC laser device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2329222