Laser apparatus
AssigneeMiyachi Technos Corporation
InventorsMakoto Ogawa, Yasushi Matsuda
Life of this patent
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Abstract
To adapt temperature control of a secondary cooling water to the temperature of a primary cooling water: A control apparatus computes duty factor D from measured open time period T.sub.ON and closed time period T.sub.OFF of a solenoid valve (step B3) for each cycle of the solenoid valve operation (step B2). The apparatus classifies the computed duty factor into one of a plurality of predetermined ranges and conditionally updates the reference temperature Pt of the secondary cooling water based on the classification (B5, B6, B7). If the reference temperature has reached an upper limit P.sub.MAX and if the duty factor has exceeded an upper limit, e.g., 95 percent (B8), the apparatus stops the operation of a laser oscillator and provides an alarm.
Claims5
A laser apparatus including means for controlling temperature of the secondary cooling water at a desired temperature by a water-cooled heat exchanger providing heat exchange between primary and secondary cooling water, and for supplying the temperature-controlled secondary cooling water to a laser oscillator, said laser apparatus, comprising:
- temperature detecting means for detecting temperature of the secondary cooling water;
- a solenoid valve disposed in piping which supplies the primary cooling water to the heat exchanger;
- temperature control means for comparing a signal from the temperature detecting means indicative of the temperature of the secondary cooling water with a reference value and for selectively opening or closing the solenoid valve depending on the result of the comparing;
- duty factor computing means for computing duty factor of open and closed time period of the solenoid valve;
- and
- reference control means for variably controlling the reference value based on the computed duty factor.
Dependencies are inferred from the claim text.