Dispositif pour protéger les moteurs à gaz chaud contre des températures excessives.

摘要

934,634. Engine temperature monitoring apparatus. PHILIPS' GLOEILAMPENFABRIEKEN N.V. Feb. 8, 1960 [Feb. 11, 1959], No. 4363/60. Class 40 (3). [Also in Groups XXXV and XL (c)] In an apparatus for safeguarding a hot-gas engine, a safety valve is operated if the temperature in any cylinder exceeds a predetermined temperature. The device may also vary the setting of a fuel control valve in accordance with cylinder temperature variation. Each cylinder is provided with a temperaturesensitive device which is connected to an indicator, Fig. 1, calibrated in degrees. When one cylinder only is to be monitored the circuit of Fig. 2 is used. Three lamps 11, 21, 31 are placed such that they shine through holes 1, 2, 3, respectively, in the indicator face on to photo-transistors 5, 7, 6. A vane 4 mounted on the indicator needle interrupts the beam from lamp 31 when the cylinder temperature becomes too high, so that current in resistor 13 falls and transistor 9 becomes biased to cut-off. If the indicator needle falls to the zero position, the light from lamp 11 is interrupted, this also causing transistor 9 to be cut-off. In either case no current now flows in any of the lamps 11, 21, 31, or in the control coil 11 of a safety valve, which therefore operates. Depression of a switch 8 switches the lamps on again. Under normal temperature conditions the vane 4 lies near the hole 2 and, as the cylinder temperature varies, so the amount of light falling on photo-transistor 7 also varies. This transistor controls, via a transistor 10, the current in a coil 12, which adjusts the setting of a fuel valve. Where more than one cylinder is to be monitored an indicator and a circuit similar to that of Fig. 2 are used for each cylinder. To ensure that faulty operation of any cylinder causes the engine to be stopped, the lamp circuit is modified, Fig. 3 (not shown), in that the lamps 2 and 3 of any one circuit are in series with the lamp 1 of the following circuit.