GB611909A - Improvements in means for regulating the pressure in the induction piping of internal-combustion engines - Google Patents

Abstract

611,909. Fluid pressure servomotor-control systems. BENDIX AVIATION CORPORATION. July 18, 1946, No. 18399. Convention date, Aug. 24, 1944. [Class 135] [Also in Group XXVII] In a supercharged engine having a boost control which acts to regulate the flow of air from the supercharger so as to maintain a predetermined pressure in the induction piping when anti-knock fluid is not being injected and to maintain a higher pressure therein when antiknock fluid is being injected, the anti-knock fluid when being supplied to the engine acts on pressure sensitive means to adjust the boost control so as to maintain the higher pressure in the induction piping and manually operable means are provided for adjusting both the pressures. In the arrangement shown, a supercharger 12 driven directly by the engine or otherwise draws in air past a butterfly valve 16 and supplies it through an induction pipe 10 past a carburetter 4 and hand-controlled throttle valve 6 to an induction pipe 5 and the inlet of a second supercharger 2 driven directly by the engine. The supercharger 2 supplies the engine cylinders through pipes 3. A nozzle 20a in the induction pipe 5 is supplied with fuel from the carburetter and may be provided with a supply of anti-knock fluid from a container 24, the supply being controlled by a solenoidoperated valve 26. The butterfly valve 16 is controlled by a regulator 18 which is responsive to the induction pipe pressure and affected by the pressure of anti-knock fluid supplied to the nozzle 20a. The regulator includes three bellows 45, 46, 47. The spaces within the bellows are separated by plates 50, 51. A spring 80 of adjustable tension is provided in the bellows 45 and a spring 90 is housed in the bellows 46 and acts between plates 50, 51. The bellows 46 is evacuated. The plate 50 has connected to it a valve 152. The induction pipe is connected by a pipe 70 with the interior of the bellows 45 and the interior of the bellows 47 is connected by a pipe 31 with the pipe 23 supplying anti-knock fluid to the nozzle 20a. The arrangement is such that when the valve 26 controlling the supply of anti-knock fluid is closed, the bellows operates upon the valve 152 which controls the supply of an operating fluid such as oil from the engine to a piston 153 so that the piston is controlled to vary the opening of the butterfly valve 16. The pressure in the induction pipe is thus kept at a desired value. When the pressure is at the desired value, the valve 152 is in a neutral position in which both ports 155 and 156 from opposite ends of the cylinder 154 of the piston 153 are cut-off. If the pressure changes the valve moves from this position and supplies oil to the piston so that the pressure is corrected by a change in the position of the butterfly valve. If the valve 26 is opened, the pressure of antiknock fluid in the bellows 47 changes and causes the bellows to expand, thus affecting the valve 152 and effecting an opening of the butterfly valve 16. The valve 152 then takes up a neutral position at a new and higher pressure in the induction pipe and functions to keep the pressure at this value. When operating without anti-knock fluid, the position of the plate 51 is determined by the end 106 of a member 93 which abuts against the end 105 of a stem 110. When anti-knock fluid is being supplied, the position of the plate is determined by a nut 102 engaging the interior of a portion 100 of a member 52. The position of the stem 110 can be varied by turning a sleeve 111 relative to a sleeve 114 and the position of the nut 102 on the member 93 can be adjusted by turning the sleeve 114 which turns the nut through the medium of a pin 140. A detailed description of the construction and adjustment of the regulator is given in the Specification. The anti-knock fluid is supplied by a pump 25 having a byepass 29 and is metered by a metering device 22.