| 摘要 |
980,081. Regulating. BORG-WARNER CORPORATION. May 16, 1961 [May 25, 1960], No. 17895/6 Heading FIB. [Also in Division F2] A control mechanism for a fuel injection pump for an I.C. engine having an air-intake manifold, comprises a movable member for controlling the output of the pump, a manifold vacuum operated servomotor for moving the member, a reference vacuum operated servomotor for moving the member for compensating for changes in ambient pressure, and a vacuum pump for operating the reference vacuum servomotor. The depression created in an air intake manifold 14, Fig. 1, of an I.C. engine is communicated through a conduit 46 to the left side of a spring-pressed diaphragm 42 which is subjected to atmospheric pressure on its right side. Variation in these pressures causes the diaphragm 42 to move a shaft 21 and a cam 20, guided by arm 22, longitudinally. The cam surface 26 acts on a roller 35 to rotate an arm 24 about a pivot 34 and raise or lower a shaft 25 of a fuel injection pump to vary the pump output. A port 45 is connected to an air bleed mechanism (not shown) to adjust the effect of manifold vacuum on the diaphragm 42 to modify the pump output for certain engine conditions. To prevent the manifold vacuum from completely overruling the effect of the air bleed, a restriction 47 is provided in the conduit 46. A spring-pressed diaphragm 52 is subjected on its left side to atmospheric pressure and on its right side to a reference vacuum produced by a pump 15 driven at constant speed as by a motor 16. Thus variations in atmospheric pressure produce longitudinal movement of a shaft 56 and a cam 23 to cause a roller 32, connected to arm 22, to roll along the cam surface 33 and thereby rotate the arm 22 with the cam 20 about a pivot 31. The combined effect of the diaphragms 42 and 52 on the position of the cam 20 compensates for variations in atmospheric pressure. An alternative embodiment is shown in Fig. 2 in which the manifold vacuum and reference vacuum diaphragms 132 and 142 respectively, are of the same diameter and arranged so as to cancel out the forces exerted by atmospheric pressure. Both diaphragms are connected through a common shaft 144 to a modified output shaft mechanism 111 in which the guide arm 122 is rigidly secured to the machine casing by screws 125 and 126. A further embodiment (not shown), which may employ actuating mechanism as at 111 in Fig. 2, has a single diaphragm exposed on opposite sides to the manifold vacuum and reference vacuum. A diaphragm 74 Fig. 1, acted on by the manifold vacuum through conduit 80 and a diaphragm 73 acted on by the reference vacuum through conduit 78, jointly actuate a pivoted lever 76 which, for example, may operate the ignition advance and retard mechanism of the engine and control a valve of an automatic gear-box. In applications in which it is desired to compensate for atmospheric pressure variation only, the diaphragm 74 and related structure may be eliminated. |
