| 摘要 |
<p>1298867 Automatic temperature control PAUL FERD PEDDINGHAUS 24 Nov 1970 [19 Dec 1969] 55890/70 Heading G3R [Also in Division C7] The temperature of a workpiece undergoing a surface hardening process, is maintained at a desired value by controlling the rate of movement of a burner flame relative to the workpiece or by controlling the application of heat in the case of induction heating. The temperature is sensed by a radiation pyrometer. In Fig. 1 a burner 3 is moved parallel to a workpiece 1 by means of a D.C. motor 14 driving a spindle 9 which moves a carriage 5 carrying the burner. The carriage also carries a spray head 4, which directs a quenching spray of water on to the workpiece to cool it rapidly, and an optical pyrometer sensor 15 which senses the workpiece temperature at a point between the burner flame and the spray zone. The sensor 15 output voltage is fed to a temperature indicator 16 Fig. 2 and thence to a D.C. chopper 20 which converts it to an A.C. voltage. This A.C. voltage is amplified in a proportional integral controller 30 wherein it is also compared with a desired temperature value signal from a potentiometer 31. The controller produces an error voltage which is fed via a thyristor unit 32 to control the speed of the D.C. motor accordingly and hence the temperature of the workpiece. In the case of induction heating the error voltage is used to control the output of a frequency converter supplying the induction heater.</p> |
