Patent GB-812420-A (GB)
Title: Improvements in or relating to internal combustion engines
IPC: F02B71/00
Filed: 1956-01-18
Abstract: 812,420. Compressors; fuel injection pumps. BUSH, V. Jan. 18, 1956 [Jan 25, 1955], No. 1693/56. Classes 8(1) and 102(1). [Also in Groups XXVI and XXVII]. An opposed-piston oscillator. Fig. 10, scavenging and super-charging an opposedpiston combustion-product engine (see Group XXVII), has outer air-pump (or air-motor) spaces 129, 130 and a central air-motor (or air-pump) space with fluid-pressure operated inlet and outlet valves 133, 135 (see Group XXVI). To centralize the pistons during operation, the pressure in the upper space 129 during suction may be reduced sufficiently to cause an average difference of pressure on the outer faces of the two pistons equal to their combined weight, such reduction being effected in a similar manner to that by which the pistons of the combustion-product engine are centralized, the latter having a throttle valve 58, Fig. 2, in the upper branch of the suction conduit to its air-compressing cylinder ends and controlled by the relative length of time that two auxiliary cylinder ports 61, 62 remain uncovered. To maintain oscillator piston synchronism, a conduit 131, Fig. 10, connecting end buffer volumes of the spaces 129, 130 may have an adjustable throttle valve therein. The oscillator is started by raising the pistons to centre position by compressed air, and introducing a pulse of compressed air between them by momentarily opening the valve 133 or a by-pass therearound, in an analogous manner to that described in connection with the combustion-product engine, which may be served by the same starting mechanism. The oscillator may be constructed to convert a large volume of lowpressure air to a small volume of high-pressure air or vice versa, and a similar oscillator may be operated by the combustion-product engine exhaust gases to supply air for external use. Fuel nozzles such as 118, Fig. 5, of the combustion-product engine are served by a pump 2 receiving fuel from a float chamber via a check valve 81 and actuated by a delivery spring 80 adjustable to control injection rate. The piston on which the spring 80 acts is forced back by high pressure air supplied to a chamber 85 from a conduit 79 leading from a supply tank, until almost at T.D.C. of the engine pistons one uncovers a port 78, Fig. 2, when balancing pressures from ducts 76, 88 allowing a spring 89 to hold a control piston 84 to the left are disturbed and the piston 84 moves to the right to vent the chamber 85 via a conduit 87 and allow injection. To control the injection timing, the piston 84 has a dashpot device 90 which retards its movement to the right until a duct 93 by-passes the adjustable dashpot leak valve 92. The amount of injection is controlled by a wedge 96 adjustably limiting the stroke of the pump 2 and slid by a piston 98 responsive to the maximum pressure in one engine bounce chamber 34, Fig. 2, which via a conduit 75 and check valve 103 tops up a reservoir 100 having a slow leak 104 and connected to both sides of the piston 98, an adjustable stabilizing damping valve 101 being provided. Tubes 118a leading to the nozzles 118 are so fine that fuel hardly recedes in them during periods of suction.