From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Study on the performance and injection delay of a magnetic injection valve using three-dimensional graphs.
| Identifier | ExFiles\Box 158\5\ scan0039 | |
| Date | 22th April 1939 | |
| MAGNETIC INJECTION VALVE 535 Fig. 11. The influence of injection pressure and condenser capacity on the weight of fuel discharged by the nozzle per injection. Nozzle orifice diameter 0.022 inches. 600 injections per minute delay as indicated by the solid surface above that formed by the dotted-dashed line is the delay due to the time required to discharge the condenser through the valve circuit, and the action of the breaker points as influenced by breaker-cam speed. The results shown are referred to zero cam angle for 1000 lb. per sq. in. oil pressure and 300 r.p.m. The surface formed by the dotted-dashed line indicates the time required for the oil to start issuing from the tip of the nozzle after the needle lifted from its seat. This delay is constant with time and independent of oil pressure for the range tested. The Injection Delay The injection delay as a function of oil, pressure and engine speed is shown in Fig. 13. The results indicate the time (degrees cam angle) elapsed between the beginning of current flow and the initial motion of the plunger of the nozzle. The results as shown in Fig. 13 apply to all values of condenser charge. The Fig. 12. The influence of speed (injections per minute) and condenser capacity on the weight of fuel discharged by the nozzle per injection. Nozzle orifice diameter 0.022 inches. Injection pressure 2000 lb. per sq. in. Fig. 13. The influence of injection pressure and speed (injections per minute) on the injection delay results were obtained on the screen of the cathode-ray oscillograph with the aid of voltage curves across the valve (Fig. 7). The initial motion of the needle was indicated on the oscillogram by a definite break in the wave; a second break, or sweep, was caused at the instant the stroboscope circuit was closed. This sweep is clearly shown in Fig. 7, occurring at the instant the oil could be seen issuing from the nozzle. When the stroboscope was synchronized with the initial motion of the needle, the sweep on the oscillogram coincided with the initial break in the curve, thus allowing this portion of the injection delay to be recorded in degrees cam angle. Since the delay is—for all practical purposes—constant as a function of time, it is a simple matter to govern the system to give the proper injection advance to allow for delay of injection and combustion. Automotive Industries Graph Axes Labels: Fig 11: Y-Axis: FUEL DISCHARGED LB. PER STROKE x 10⁶, X-Axis 1: INJECTION PRESSURE - LB./SQ.IN, X-Axis 2: CONDENSER CAPACITY-MF Fig 12: Y-Axis: FUEL DISCHARGED LB. PER STROKE X 10⁶, X-Axis 1: INJECTIONS PER MINUTE, X-Axis 2: CONDENSER CAPACITY-MF Fig 13: Y-Axis: INJECTION DELAY - DEG. CAM ANGLE, X-Axis 1: INJECTION PRESSURE - LB./SQ.IN, X-Axis 2: INJECTIONS PER MINUTE | ||