Claims
- 1. In a fuel injection control system for an internal combustion engine comprising a chamber that varies in volume during a cycle of engine operation and fuel injection means for delivering fuel to an air charge, the improvement comprising means for controlling the fuel delivered by said fuel injection means in response to the pressure in said chamber during only a predetermined portion of said cycle.
- 2. In a fuel injection control system as claimed in claim 1 wherein the controlling means is responsive to the maximum pressure in the chamber during a part of the cycle of operation before the pressure normally reaches its maximum value.
- 3. In a fuel injection control system as claimed in claim 1 wherein the controlling means is responsive to the pressure in the chamber during a part of the cycle of operation before the pressure normally reaches its minimum value.
- 4. In a fuel injection control system as claimed in claim 2 wherein the controlling means is responsive to the pressure in the chamber during a part of the cycle of operation before the pressure normally reaches its minimum value.
- 5. In a fuel injection control system as claimed in claim 4 wherein the controlling means is responsive to the difference between the maximum pressure sensed and the minimum pressure sensed.
- 6. In a fuel injection control system as claimed in claim 5 wherein the pressures are sensed by a pressure responsive device and further including means for precluding the pressure responsive device from generating a pressure signal except during the predetermined portions of the engine cycle.
- 7. In a fuel injection control system as claimed in claim 6 wherein the means for precluding the pressure sensing device from providing a pressure signal comprises valving means.
- 8. In a fuel injection control system as claimed in claim 7 wherein the valving means comprises a port formed in a cylinder of the engine, the engine further including a piston being slidably supported in said cylinder bore and cooperating with said port to function as said valving means.
- 9. In a fuel injection control system as claimed in claim 7 wherein the means for precluding the pressure sensing from generating a pressure signal comprises electronic means responsive to the portion of the cycle.
- 10. In a fuel injection control system as claimed in claim 1 wherein the variable volume chamber is a crankcase of the engine.
- 11. In a fuel injection control system as claimed in claim 10 wherein the controlling means is responsive to the maximum pressure in the crankcase during a part of the cycle of operation before the pressure normally reaches its maximum value.
- 12. In a fuel injection control system as claimed in claim 10 wherein the controlling means is responsive to the pressure in the crankcase during a part of the cycle of operation before the pressure normally reaches its minimum value.
- 13. In a fuel injection control system as claimed in claim 11 wherein the controlling means is responsive to the pressure in the crankcase during a part of the cycle of operation before the pressure normally reaches its minimum value.
- 14. In a fuel injection control system as claimed in claim 13 wherein the controlling means is responsive to the difference between the maximum pressure sensed and the minimum pressure sensed.
- 15. In a fuel injection control system for an internal combustion engine having a chamber that varies in volume during a cycle of engine operation, an induction system for delivering a charge to said chamber, and a fuel injection means for delivering fuel, the improvement comprising means for controlling the fuel delivered by said fuel injection means in response to a pressure existing during only a predetermined portion of a single cycle of engine operation.
- 16. In a fuel injection control system as claimed in claim 15 wherein the controlling means is responsive to the maximum pressure in the chamber during a part of the cycle of operation before the pressure normally reaches its maximum value.
- 17. In a fuel injection control system as claimed in claim 15 wherein the controlling means is responsive to the pressure in the chamber during a part of the cycle of operation before the pressure normally reaches its minimum value.
- 18. In a fuel injection control system as claimed in claim 16 wherein the controlling means is responsive to the pressure in the chamber during a part of the cycle of operation before the pressure normally reaches its minimum value.
- 19. In a fuel injection control system as claimed in claim 18 wherein the controlling means is responsive to the difference between the maximum pressure sensed and the minimum pressure sensed.
- 20. In a fuel injection control system as claimed in claim 19 wherein the pressures are sensed by a pressure responsive device and further including means for precluding the pressure responsive device from generating a pressure signal except during the predetermined portions of the engine cycle.
- 21. In a fuel injection control system as claimed in claim 20 wherein the means for precluding the pressure sensing device from providing a pressure signal comprises valving means.
- 22. In a fuel injection control system as claimed in claim 21 wherein the valving means comprises a port formed in a cylinder of the engine, the engine further including a piston being slidably supported in said cylinder bore and cooperating with said port to function as said valving means.
- 23. In a fuel injection control system as claimed in claim 21 wherein the means for precluding the pressure sensing from generating a pressure signal comprises electronic means responsive to the portion of the cycle.
- 24. A method of controlling a fuel injection system for an internal combustion engine comprising a chamber that varies in volume during a cycle of operation and in which an intake charge is compressed during engine operation and fuel injection means for delivering fuel to an air charge comprising the steps of measuring the pressure in the chamber only during a portion of the engine cycle and controlling the amount of fuel delivered by the fuel injection means in response to the measured pressure.
- 25. A method of controlling a fuel injection system for an internal combustion engine having a chamber that varies in volume during a cycle of operation, an induction system for delivering a charge to the chamber, and a fuel injection means for delivering fuel comprising the steps of measuring a pressure that varies during a single cycle of engine operation during only a portion of the cycle and controlling the amount of fuel discharged in response to the measured pressure.
- 26. A method of controlling a fuel injection system as set forth in claim 25 wherein the pressure is measured as a maximum pressure during a portion of the cycle wherein the pressure does not reach its full maximum pressure and a minimum pressure measured during a portion of the cycle when the pressure does not reach its minimum pressure and the controlling is responsive to the pressure difference.
Priority Claims (1)
| Number |
Date |
Country |
Kind |
| 57-112579 |
Jul 1982 |
JPX |
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of our application entitled "Fuel Injection Apparatus For An Internal Combustion Engine," Ser. No. 446,726, filed Dec. 3, 1982 and assigned to the Assignee of this application.
This invention relates to a fuel injection apparatus for an internal combustion engine and more particularly to an improved control arrangement for a fuel injection system.
In fuel injected engines, it is, of course, extremely important to accurately control the quantity of fuel injected in accordance with the air inducted in order to achieve the optimum fuel/air ratio for a given operating condition of the engine. Various devices have been proposed for measuring the air flow in an induction system of an engine to control the amount of fuel injected. Coventionally, such air flow measuring devices have been large and complicated and have been positioned in the induction system, normally upstream of the point of discharge of the fuel. In one type of flow detector, a flap type arrangement is provided in the intake passage and has a member that swings open to an amount that is determined by the air flow. The angular position of this detector is then measured and used to provide an air flow signal for the fuel injection system. Alternatively, vortex type air flow meters have been positioned in the induction system for determining air flow. Still another type of measuring device employs a hot wire anemometer which provides an electrical resistance wire interposed in the air stream to have its resistance vary in relation to the speed, i.e., cooling effect, of the air flowing through the induction system. The use of such flow meters in the induction system has several disadvantages.
In the first instance, the provision of an air flow measuring device in the induction system can oftentimes reduce the volumetric efficiency of the induction system. Furthermore, such devices substantially increase the size of the induction system. Also, devices of the type aforenoted are not particularly efficient with engines having a low number of cylinders or specifically with single cylinder engines due to the pulsations in the intake flow. Although such pulsations may be reduced to some extent through the use of a plenum chamber, this adds still further to the size of the induction system. Furthermore, if the flow meter is used in conjunction with the internal combustion engine of an outboard motor or other marine application, there is a high likelihood of corrosion in the moving components of the flow meter due to the salt in the atmosphere.
In our aforenoted co-pending application, there is disclosed a control for a fuel injection system that has none of the foregoing disadvantages. The system disclosed in that patent application senses the pressure in the crankcase of a two-cycle engine and uses the sensed pressure to control the amount of fuel injected. It has been found that the pressure in the crankcase is, if accurately measured, indicative of the amount of air inducted.
Although the arrangement shown in our earlier patent application is particularly effective in controlling the amount of fuel injected without the disadvantages of the prior art type air flow measuring devices, there are some instances when the crankcase pressure is not actually related to the amount of air inducted. For example, with two-cycle crankcase compression engines it has been found that the peak pressure immediately prior to the piston reaching bottom dead center is abnormally raised when the transfer or scavenge port is open due to the back flow of exhaust gases into the crankcase. As noted in our earlier patent application, one desirable method for controlling the amount of fuel injected involves sensing both the minimum and maximum pressures in the chamber. However, since the maximum pressure is abnormally high due to the opening of the scavenge port and the back flow of exhaust gases such a control arrangement is not as accurate as might be.
It is, therefore, a principal object of this invention to provide an improved fuel flow control device for the fuel injection system of an internal combustion engine.
It is another object of this invention to provide an improved air flow detecting device for controlling the fuel injection system of an engine.
It is yet another object of this invention to provide a fuel control device for a fuel injection system of an internal combustion engine that accurately controls fuel flow in response to the amount of air flowing through the intake system.
It is a yet further object of this invention to provide a fuel control for a fuel injection system that does not rely upon a device that is interposed in the air induction system.
It is yet another object of this invention to provide a fuel injection control system that senses differences in crankcase pressure and which eliminates the effects of abnormal changes in crankcase pressure due to effects other than the amount of air inducted.
A first feature of the invention is adapted to be embodied in a fuel injection control system for an internal combustion engine comprising a chamber that varies in volume during a cycle of operation and in which an intake charge is compressed during engine operation and fuel injection means for delivering fuel to an air charge. In accordance with this feature of the invention, means control the fuel delivered by the fuel injection means in response to the pressure in the chamber for only a predetermined portion of the engine cycle.
Another feature of this invention is also adapted to be embodied in a fuel injection control system for an internal combustion engine. Such an engine has a variable volume chamber, an induction system for delivering a charge to the chamber and a fuel injection means for delivering fuel. In accordance with this feature of the invention, means control the fuel delivered by the fuel injection means in response to a pressure that varies during a single cycle of engine operation for only a predetermined portion of the engine cycle.
Another feature of the invention is adapted to be embodied in a method for controlling the fuel discharge of a fuel injection system for an internal combustion engine having a chamber that varies in volume during a cycle of engine operation and in which the intake charge is compressed during engine operation. In accordance with this method, the pressure in the chamber is measured for only a predetermined portion of the engine cycle and the amount of fuel discharged by the fuel injection system is controlled in response to this pressure.
Yet another feature of the invention is also adapted to be embodied in a method for controlling the fuel discharge of a fuel injection system in connection with an engine that has a chamber that varies in volume during a cycle of engine operation, an induction system for delivering a charge to the chamber and fuel injection means for delivering fuel. In accordance with this method, the variable pressure in the chamber during only a predetermined portion of a single cycle of engine operation is measured and the amount of fuel delivered by the injection system is controlled in response to this pressure.
US Referenced Citations (6)
Foreign Referenced Citations (1)
| Number |
Date |
Country |
| 747534 |
Apr 1956 |
GBX |
Continuation in Parts (1)
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Number |
Date |
Country |
| Parent |
446726 |
Dec 1982 |
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Patent Grant
4461260
