Patent Publication Number: US-3874352-A

Title: Fuel supply system for an internal combustion engine

Description:
United States Patent 119 1111 3,874,352 Ishida 5] Apr. 1, 1975 FUEL SUPPLY SYSTEM FOR AN INTERNAL 3,636,931 1/1972 Sada et a1 123/32 EA COMBUSTION ENGINE 3,695,245 10/1972 151m 123/119 R Inventor: Takashi Ishida, N0. 649, Kamisi,  
 Oimachi, Ashigarakamigun, Kanagawa-ken, Japan Filed: Aug. 29, 1972 Appl. No.: 284,555  
 Related US. Application Data Continuation-impart of Ser. No. 91,618, Nov. 23, 1970, Pat. No. 3,695,245.  
 US. Cl. 123/119 R, 123/D1G. 10 Int. Cl. F02b 33/00, F02m 7/00 Field of Search 123/119 R, DIG. 10  
 References Cited UNITED STATES PATENTS 4/1955 ..123/119 R 11/1957 White et a1 123/139 AW 2/1959 Olson 123/139 AW 3/1959 Dolza et al. 123/139 AW Gianini Primary Examiner-Manuel A. Antonakas Assistant Examiner-Daniel J. OConnor Attorney, Agent, or FirmAndrus, Sceales, Starke &amp; Sawall [57] ABSTRACT The present invention relates to a fuel supply system for an internal combustion engine, accurate fuel injection may be attained every suction stroke of engine by the provision of a fluid element in a fuel injection control circuit.  
 And the present invention is less cost, and is not influenced by vibration, heat, electromagnetic wave, and the like. In particular, with respect to the injection principle, there is not employed a mechanical method but collosion of liquid and gas so that atomization of fuel is greatly improved and combustion efficiency can be improved.  
 7 Claims, 27 Drawing Figures PATENTED I T874352 sum mar 18- ATENIEDAPR H975 SHEET ESOF 18 PATENTED I975 SHEET 07UF 18 PMEMED APR 1 I975 SHEET QF L) PATENTED 1 5 SHEET 110F18 PATENTEU APR 1 1975 SHEET PATENTEU APR 3 i975 SHEET PATENTED APR 1 i975 SHEET 150F18 mmi PATENTEB R 1 ms SHEET 18 0F 18 WNE PATENTEDAPR&#39; 1 ms SHEET 170F 18 FUEL SUPPLY SYSTEM FOR AN INTERNAL COMBUSTION ENGINE This is a continuation-in-part of application, Ser. No. 91,618 filed Nov. 23, I970, now U.S. Pat. No. 3,695,245.  
  The present invention relates to a fuel supply system for an internal combustion engine, and has its object to provide a fuel supply system wherein accurate fuel injection may be attained every suction stroke of engine by the provision of a fluid element in a fuel injection control circuit.  
  The fuel supply apparatus for an internal combustion engine has a carbureter system and an injection system. The injection system is roughly divided into a mechanical system and an electrical system. As shown in FIG. 1, the mechanical system is to operate an injection nozzle by detecting number of revolution of engine, opening of air valve and pressure in the engine manifold and then inputing them into a mechanical arithmetic unit. As shown in FIG. 2, the electrical system is to open and close a valve for a fuel injection nozzle by inputing the number of revolution of engine and manifold boosted pressure. However, in this case, unless injection is effected under the injection pressure of fuel of high pressure such as 23Okg/cm an error in injection amount becomes great under the influence of manifold boost. Particularly, in the case of the mechanical system, considerably high accurate working is required with respect to the mechanical computing device, fuel pump injection nozzle and the like. Yet. when fuel flow is small in amount, for example, in the case of idling, a satisfactory and ideal injection may not be carried out and the stability in operation of engine is often inferior to carburetor.  
  In the case of an electric injection in which all circuits are formed by electronics, there is a possibility of malfunction of an electric computing circuit under the influence of vibration, engine temperature, electromagnetic wave, and the like. It is natural that considerably fine working is similarly required with respect to a nozzle portion.  
  This invention is proposed to remove disadvantages as described above. As shown in the block diagram of FIG. 3, a fluid element without having a movable member in a part of arithmetic section, which controls injection of fuel, is either used, or the fluid element and an electronics circuit are used so that fuel may be injected every suction stroke of engine by utilization of air pressure for on and off operation of fuel at the injection part. With such a construction as above, the present invention is less cost in manufacture than that of injection system heretofore used, and is not influenced by vibration, heat. electromagnetic wave, and the like. In particular. with respect to the injection principle, there is not employed a mechanical method but collosion of liquid and gas so that atomization (pulverization) of fuel is greatly improved and combustion efficiency can be improved, cousting cut is much more simpler than engine provided with a carburetor, having such effects as reduction in cost of fuel, reduction in waste noxious matter, and the like.  
  Generally, the fuel flow characteristic of reciprocating engine can be represented by two factors, number of revolution of engine and manifold boosted pressure. Therefore, fuel consumption is either given as shown in FIG. 4 fuel consumption to number of revolution of en gine with boosted pressure as a parameter, or as shown in FIG. 5 fuelv consumption to boosted pressure with number of revolution of engine as a parameter to thereby make possible to cover the whole range of operating conditions.  
  For this reason, fuel flow can cover the whole operation by forming a function to number of revolution of engine and a function to manifold boosted pressure. In accordance with the foregoing conception, the present invention is to control fuel injection wherein the number of revolution of engine is detected by air pressure and electrically, and said detection and manifold boosted pressure are inpect into an air pressure system arithmetic circuit.  
  The present invention will be illustrated with reference to the accompanying drawings;  
  FIGS. 1 and 2 are block diagrams of a fuel supply system heretofore used;  
  FIG. 3 is a block diagram of the same according to the present invention;  
  FIG. 4 is a curve showing fuel flow characteristics with engine manifold boosted pressure as a parameter;  
  FIG. 5 is a curve showing fuel flow characteristics with number of revolution of engine as a parameter;  
  FIGS. 6 to 9 illustrate one embodiment in which FIG. 6 is an overall circuit diagram, FIGS. 7 and 8 are longitudinal sections showing a fuel injection element in FIG. 6 mounted on the engine manifold or manifold take pipe, and FIG. 9 is an enlarged section showing a fuel injection nozzle portion;  
  FIG. 10 is an enlarged explanatory view ofa detector portion of number of revolution for engine;  
  FIG. 11A is an output diagram of a one shot circuit in FIG. 10;  
  FIG. 11B is an output diagram showing results of output obtained by operation of collosion element;  
  FIGS. 12 and 13 are modified circuit diagrams of a mixed air supply stage;  
  FIG. 14 is an overall circuit diagram showing the second embodiment according to the present invention;  
  FIGS. 15 and 16 are longitudinal sections showing a fuel injection element in FIG. 14&#39; mounted on the engine manifold or manifold take pipe;  
  FIGS. 17 and 18 are modified circuit diagrams of a mixed air supply stage;  
  FIG. 19 is an overall circuit diagram showing the third embodiment with the detector portion of number of revolution for engine replaced by electronics;  
  FIGS. 20 and 21 are modified circuits of the mixed air supply stage in FIG. 19;  
  FIG. 22 is an overall circuit diagram showing the fourth embodiment with the detector portion of number of revolution of engine replaced by electronics;  
  FIGS. 23 and 24 are modified circuit diagrams of a mixed air supply stage in FIG. 22;  
  FIG. 25 is another modified circuit diagram of the detector portion of number of revolution of engine in FIG. 6;  
  and FIG. 26 is another circuit diagram of the detector portion of number of revolution of engine in FIG. 14.  
  The embodiments according to the present invention will now be described with reference to drawing. FIG. 3 is a block diagram according to the present system, diagramatically showing the status in which detection valve of number of revolution of engine and detection valveof manifold boostedpressure are input into an arithmetic circuit, and controlled amount is fed into an engine manifold through a fuel injection element.