INJECTION AND REGULATING SYSTEM FOR INTERNAL COMBUSTION ENGINES

Abstract: An injection- and regulating system for internal combustion engines with injection nozzles (32) for at least one fluid, for example the fuel and/or an additive, and incorporating pneumatically operable pressure sensors (17, 19) communicating with the inside of the inlet manifold (14), on both sides of a throttle valve (15), said pressure sensors governing a valve (26) or the like for metering the fluid. One, the first, pressure sensor (17) is arranged behind, that is downstream of, the throttle valve (15) to sense the coefficient of fullness of the engine. Means for sensing the pressure in the inlet manifold (14) is arranged in front of, that is upstreams, the throttle valve (15) and directed in such a manner that the second pressure sensor (19) is actuated by the incoming air flow to the engine. The output signals/deflections from both pressure sensors (17, 19) are coordinated and integrated in such a manner that each pressure sensor (17, 19) is arranged to regulate the metering valve (26) independently of the other, and the total output signal/deflection is composed by the output signals/deflections of both pressure sensors.

Description: INJECTION AND REGULATING SYSTEM FOR INTERNAL COMBUSTION ENGINES Injection and regulating system for internal combustion engines with injection nozzles for at least one fluid, for example the fuel and/or an additive and incorporating pneu cally operable pressure sensors communicating with the insi the inlet manifold, on both sides of a throttle valve, pressure sensors governing a valve or the like for metering fluid. BACKGROUND OF THE INVENTION The advantage of a fuel injection system compared to carbur is above all that the engine responds more willingly on accel tion, gives a higher maximum power output, and better eco since the distribution of fuel is more efficient. One advantage with fuel injection systems is a considerable hi cost for the injection system, which are complex, and mainte and repare work is a task for experts. This is true for mec cal as well as electronic systems, the latter are if poss even more complicated. If an extra liquid as for example w and/or alcohol is to be added, the regulating of the injec systems will become even more complicated. Another problem with conventional injection systems is feeding valve for the fuel, which due to the high grad exactness are wery expensive. Besides these valves have a linearity at the opening thereof. THE PURPOSE AND MOST ESSENTIAL FEATURES OF THE INVENTION The purpose of the present invention is to provide a regula unit, controlling at least one metering valve, so that automatic fuel regulation is achieved, which is satisfac under most load conditions. The regulating unit may control m metering valves, one for each fluid, for example a main fuel an extra fuel or such. Another purpose of the invention is provide a metering valve having a good linearity, long stro and low production cost. This has been achieved -through characterizing parts of the claims. DESCRIPTION OF THE DRAWINGS The invention will be described below in some embodiements w reference to the attached drawings. Fig. 1 is a schematic presentation of a combustion eng equipped with a regulating device in accordance with invention. Fig. 2 shows on an enlarged scale, seen from above, a doub regulating unit in acordance with the invention controlling metering valves, one for each fluid. Fig. 3 shows a side view of the regulating unit illustrated fig. 2. Fig. 4 shows another embodiement of the invention, partly cross section. Fig. 5 is an axial section through a metering valve in accord with the invention. Fig. 6 is a cross section through the valve illustrated in 5. Fig. 7 is a section through a part of a modified metering v in accordance with the invention. DESCRIPTION OF EMBODIMENTS In fig. 1 a regulating unit acording to the invention is app on a combustion engine 12, of which only one cylinder is show throttle 15 is arranged in the intake manifold 14 in a con tional manner, where the throttle is actuated by, for exam the throttle pedal (not shown). Downstreams of the throttle a conduit 16 is connected to the intake manifold 14, the con 16 communicating with a first pressure sensor 17, and upstr of the throttle 15 another pressure sensor 19 is connected v conduit 18. Both pressure sensors 17 and 18 are constructe the same way, and the difference in size is dependent on fact that the negative pressure downstreams of the throttle 1 much stronger than upstreams of the throttle. The variation pressure compared to the atmospheric pressure will act on diaphragm 20 in both pressure sensors. Onto these diaphragm 21 and 22 are attached, the free end of both of these rods connected to a first link 23, which constitutes a part of th regulating unit 11. A second link 24 is adjustably connecte this first link 23, which second link can be fixed at position along the first link 23. The other end of link 24 on a lever 25, thus controlling the metering valve 26. metering valve is a part of the fuel system of the combustion engine. The fuel system comprises a fuel tank 27, a feeding 28 and a filter 29, which via a conduit 30 are connected to metering valve 26. From this a conduit 31, one for each cylin leads to the injection valve 32, which may be the free end of the conduit 31 or an injection valve 33. In order to further adjustment possibilities the connection of the leve is adjustable in order to change the effective length of lever 25. FUNCTION OF THE INVENTION At idling, when the throttle 15 is practically closed, negative pressure downstreams of the throttle is that strong the rod 22 of the pressure sensor 17 is fully retracted, whe the linkage 23, 24 turns the lever 25 towards its closed posi according to fig. 1, so that the fuel supply to the inject nozzles 32 is at minimum. The pressure sensor 19 is adjusted to react on the airflow at idling. The metering valve 26 adjusted to give fuel for idling in this position. When the throttle 15 opens the negative pressure in the i manifold 14, downstreams of the throttle 15 is decrea whereby the spring 34 expands, opening the metering valve 26 increasing the fuel supply. As the rpm increases, more air sucked in through the inlet manifold 14, causing pressure senso 19 to retract its rod 21 and thus, through the linkage 23, 2 increasing the fuel flow through the metering valve 26. When t rpm is stabilised the negative pressure downstreams of t throttle 15 builds up again if it's not full throttle. Th means that pressure sensor 17 retracts its rod 22, thus closin the metering valve 26. Regulating units in accordance with the invention are feasab for regulating many fluids through separate regulating system One example can be that the first medium is petrol, diesel straight run, and the the second medium can be for example wat with an anti-freeze agent, or an alcohol, as ethanol or methano The medium may also be a suitable gas, for example PG. An embodiment for two different fluids are shown in fig. 2 a 3. In this embodiment the pressure sensors 19a and 19b a attached to the engine block 12, while the pressure sensors 1 and 17b are attached to the arm 25 of each metering valve 26a a 26b. The diaphragm rods 21 and 22 are jointed together throu the link 23. At an increase in pressure in one of the pressure sensors, f example in sensor 17a, the other sensor 19a will act as a more less solid holder-on. This means that the retraction of t diaphragm and rod of the sensor 17a will cause the sensor 17a move, and thus move the arm 25 on which it is mounted. Another way of achieving this regulating function is shown fig. 4, where both sensors 17 and 19 are fixedly mounted. T diaphragm rods 21 and 22 are connected to a slide 36 and 37 ea of a common slide valve 38. The slides 36 and 37 opens or clos their own outlet opening more or less. These outlet openings a connected through a branch pipe to the fuel feed conduit31, o for each cylinder. At varying pressures in the intake manifol the slide valve 38 will meter the fuel in the same manner described above, and deliver a correct amount of fuel for ea load condition. Each pressure sensor may as well function wi its own slide valve or similar. The slides 36 and 37 may have the form of the slide 41 in fig. 5. In fig. 5, the metering valve 26 has a cylindric slide 41, one end of the slide has a very elongated coniform chamfe 42. The housing 44 of the metering valve 26 has outlet ope 43, one for each cylinder 13, which are positioned symmetri at the same height. This gives low production cost, linearit a long stroke. If for example the outlet openings 43 ha diameter of one millimeter and the angle of the coniform pa is two degrees, the stroke will be approximately eight m meters. The valve in this case is linear exept for the millimeter. If linearity is desired also for the first milli one can either have square holes 43, or let the holes 4 round, and instead let the first part of the coniform se start with a steper angle which gradually changes to the c angle of the coniform part. Instead of, or in combination the coniform section 42 of the slide 41, the outlet openings may 43 have wide shallow recesses. Also here the angle m approximately two degrees. The conicity, or the inclinatio vary betwen 10:1 and 40:1, at which the first figure indi the length and the second figure the height of the inclin with respect to the horizontal plane. A regulating unit in accordance with the invention may als used as an indication device in combination with the described devices, or separate. The arm 25 of the metering 26, or a corresponding unit may thereby form a pointer 40, can be used as an econometer, supplying the driver with information of the fuel consumption. The invention is not limited to the embodiments shown, b plurality of variations are possible within the scope of claims. It is thus possible to connect more than one met valve 26 to the link 23 via a second link 24 for the distrib of one or more extra medium. It is further possible to pressure sensors giving electric output, regulating at least metering valve.

Claims: CLAIMS 1. An injection- and regulating system for internal combus engines with injection nozzles (32) for at least one fluid, example the fuel and/or an additive, and incorporating pneum cally operable pressure sensors (17,19) communicating with inside of the inlet manifold (14), on both sides of a thro valve (15), said pressure sensors governing a valve (26) or like for metering the fluid, c h a r a c t e r i z e d t h e r e b y, that one, the first, pressure sensor (17) is arranged beh that is downstream of, the throttle valve (15) to sense coefficient of fullness of the engine, and that means for sen the pressure in the inlet manifold (14) is arranged in front that is upstreams, the throttle valve (15) and directed in su manner that the second pressure sensor (19) is actuated by incoming air flow to the engine, and that the output signa de lections from both pressure sensors (17,19) are coordin and integrated in such a manner that each pressure sensor (17 is arranged to regulate the metering valve (26) independentl the other, and the total output signal/deflection is compose the output signals/deflections of both pressure sensors. 2. A system according to claim 1, c h a r a c t e r i z e d t h e r e b y, that the regulating unit (11) comprises a first link ( pivotally connected to both pressure sensors (17,19), a second link (24), which is adjustably connected to the f link, so that it can be fixed in different positions along first link (23), and the other end of the second link (24 arranged to actuate the metering valve (26). 3. A system according to claim 1, c h a r a c t e r i z e d t h e r e b y, that each pressure sensor (17,19) is arranged to cooperate one valve or slide each (36,37) of a feeding valve (38) metering the fluid. 1 4. A system according to claim 1, c h a r a c t e r i z e d t h e r e b y, that each pressure sensor (17,19) is effected by the air pres in the intake manifold, against the action of at least resilient element (34,35). 5. A system according to claim 1, c h a r a c t e r i z e d t h e r e b y, that the pressure sensors (17,19) are arranged to give electric output signal in response to pressure and air flo the inlet manifold at the respective measuring point and the output signals are intended to govern the metering v (26). 6. A system acording to claim 1, where the metering valve comprises two interacting surfaces being in fluidtight con with each other and movable in relation to each other, on them equipped with at least one dosing opening, the othe arranged that it, dependent on its position closes or opens opening, c h a r a c t e r i z e d t h e r e b y, that a part of the interacting surface provided with the ope (43) and/or a section in the absolute vicinity of the ope (43) are formed with such a small inclination or conicity, on one hand the length of the inclined surface is consider longer than the height of it with respect to the horizo plane, and on the other hand that the length of the incl surface is considerably longer than the diameter of the 7. A system according to claim 1, c h a r a c t e r i z e d t h e r e b y, that the inclination/conicity varies betwen 40:1 and preferably 30:1.

Inventors: OLSSON BERTIL, OLSSON GUNNAR, OLSSON JOHN, OLSSON, BERTIL, OLSSON, GUNNAR, OLSSON, JOHN
Applicants: OLSSON BERTIL, OLSSON GUNNAR, OLSSON JOHN, OLSSON, BERTIL, OLSSON, GUNNAR, OLSSON, JOHN
Application year: 1988
Main classification: F02D3
IPC codes: F02M69