Internal-combustion engines – Charge forming device – Heating of combustible mixture
Reexamination Certificate
1998-11-17
2001-05-08
Wolfe, Willis R. (Department: 3747)
Internal-combustion engines
Charge forming device
Heating of combustible mixture
C123S550000
Reexamination Certificate
active
06227178
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to a technology of heating related elements to an internal combustion engine and, more particularly, to a control system of a combustion heater for heating constituting elements of the internal combustion engine with heat generated when burning a fuel.
In the internal combustion engine, an operability is deteriorated with an increased friction in a low-temperature state, and with this deterioration a fuel efficiency worsens or causing an increase in noises. Further, there arises a problem, wherein a related device operating in connection with the internal combustion engine such as, in a vehicle, for example, a car-room heater with the cooling water of the internal combustion engine serving as a thermal source, is deteriorated in its function when the internal combustion engine is at the low temperature, i.e., when the temperature of the cooling water is low.
Accordingly, it is required that the internal combustion engine is provided with a heating device for increasing the temperature of the internal combustion engine itself or a temperature of the related element to the internal combustion engine itself when in a warm-up process after a start-up or when an exothermic quantity of the engine itself is small. This necessity is remarkable especially in a diesel engine with a small exothermic quantity and becomes more remarkable with a tendency of reducing the fuel consumption in recent years.
Such being the case, Japanese Patent Laid-Open Publication No. 62-75069 discloses a technology of improving a starting characteristic by speeding up the warm-up of the internal combustion engine. According to this technology, a rise in temperature of the internal combustion engine body is speeded up by speeding up a rise in temperature of the cooling water by providing a combustion heater for heating the cooling water. In this technology, the attention is paid to a temperature when starting the internal combustion engine. In addition to the starting time of the internal combustion engine, however, the temperature of the internal combustion engine becomes comparatively low also when the exothermic quantity of the internal combustion engine itself is small, e.g., when a quantity of fuel consumption in the combustion chamber is small. In such a case also, it is advantageous to the internal combustion engine itself or the related element thereto to provide the combustion heater.
Although the combustion of the combustion heater continues during an operation of the internal combustion engine for a short while after the start-up thereof, the exhaust gas from the combustion heater is led into the combustion chamber via the intake passageway. Therefore, the heat of the exhaust gas can be collected in the internal combustion engine, and it follows that an effect of rising the temperature of the internal combustion engine is obtained.
In the case of introducing the exhaust gas of the combustion heater into the intake passageway during the operation of the internal combustion engine, however, if the exhaust gas is led into the intake passageway without taking into consideration a combustion state in the combustion chamber of the internal combustion engine, there arises a problem of causing a deterioration of the combustion state in the combustion chamber. For instance, a quantity of the exhaust gas introduced into the combustion chamber from the combustion heater becomes larger, a quantity of fresh air taken in from the atmospheric air becomes smaller. If the quantity of fuel supplied to the combustion chamber is large and a load on the internal combustion engine is high, an air/fuel ratio in the combustion chamber might change to be rich, with the result that more smoke is emitted.
SUMMARY OF THE INVENTION
It is a primary object of the present invention, which was devised to obviate the problems described above, to provide a control system of a combustion heater for an internal combustion engine that is constructed to provide satisfactory combustion in the combustion chamber of the internal combustion engine even when an exhaust gas of the combustion heater is led into an intake system of the internal combustion engine.
To accomplish the above object, the control system of the combustion heater for the internal combustion engine according to the present invention takes the following construction.
Specifically, the present invention is based on the knowledge that if the exhaust gas of the combustion heater is introduced into the intake system when the quantity of fuel supplied to the combustion chamber is large (at the time of high load), the quantity of fresh air taken in is reduced, and, therefore, it is concluded that introduction of the exhaust gas of the combustion chamber to the intake system should be better discontinued when the quantity of fuel supplied to the combustion chamber is large. From this point of view, the present invention is accomplished such that in a control system of a combustion heater for an internal combustion engine in which a related element to said internal combustion engine is heated by burning a fuel and an exhaust gas produced when burning the fuel is discharged into an intake system of said internal combustion engine, the control system controls a combustion state of the combustion heater based on an engine load.
Specifically, the engine load can be determined from such parameters as the number of revolutions of the engine, the quantity of intake air, an engine fuel injection quantity, a degree of opening of accelerator, and the like. Thus, the control system of the present invention can be exemplified to control the combustion state of the combustion heater by a fuel control device according to the quantity of fuel supplied to the combustion chamber of the internal combustion engine, or the number of revolutions of the engine, the quantity of intake air, the degree of opening of accelerator, and the like.
According to a second aspect, in the control system of the combustion heater for the internal combustion engine according to the first aspect of the invention, the control system controls, when the engine load is large, for example, the quantity of fuel supplied to the combustion chamber by the fuel control device is large, the combustion state of the combustion heater so that the quantity of the exhaust gas produced is lowered than when the engine load is small, for example, the quantity of fuel supplied to the combustion chamber is small.
According to a third aspect of the present invention, in the control system of the combustion heater for the internal combustion engine according to the second aspect of the invention, the combustion heater performs the combustion with the fuel fed by pressure from a fuel pump and air supplied by an air supplying device, and the control system controls the combustion state of the combustion heater by controlling at least one or both of the fuel pump and the air supplying device.
According to a fourth aspect of the present invention, in the control system of the combustion heater for the internal combustion engine according to the first aspect of the invention, the related element to the internal combustion engine is a cooling liquid for cooling the internal combustion engine.
According to a fifth aspect of the present invention, in the control system of the combustion heater for the internal combustion engine according to the fourth aspect of the invention, the internal combustion engine is a power source for driving a vehicle, the vehicle has a car room heater for heating a car room, and the car room heater uses the cooling water as a thermal source.
According to the present invention, the control system controls the combustion state of the combustion heater according to the quantity of fuel supplied to the combustion chamber by the fuel control device, the specific controls are exemplified as follows.
When the fuel injection quantity is larger than a predetermined value, the quantity of fuel supplied to the combustion heater is reduced, and when the fuel inject
Huynh Hai
Kenyon & Kenyon
Toyota Jidosha & Kabushiki Kaisha
Wolfe Willis R.
LandOfFree
Control system of combustion heater for internal combustion... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Control system of combustion heater for internal combustion..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control system of combustion heater for internal combustion... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2540428