Internal-combustion engines – Charge forming device – Fuel injection system
Patent
1998-03-17
2000-04-11
Moulis, Thomas N.
Internal-combustion engines
Charge forming device
Fuel injection system
123357, 123381, 123501, 123447, F02M 3704
Patent
active
060476826
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to an accumulator type fuel injection control device for controlling the injection of fuel with the use of an accumulator type unit injector.
BACKGROUND ART
Generally, an accumulator type fuel injection control device is mounted in a fuel supply system of a diesel engine, and provided with an accumulator type unit injector in the fuel supply system, a fuel pressure pump, and a controller which functions as a control system.
In the accumulator type fuel injection control device for a diesel engine, therefore, a plunger is driven by an eccentric cam, which is driven in interlock with a crank shaft of the engine, and a fuel of a low pressure, which has been fed into a pump chamber by means of a feed pump, is pressurized to a high pressure and then fed to an accumulator. In accordance with the operating condition of the engine, a drive command is outputted from the controller to an electromagnetic actuator to open or close a spill valve, whereby the fuel pressure in the accumulator is controlled to a high level. On the other hand, a signal indicating the fuel pressure in the accumulator is fed back to the controller from a fuel pressure sensor.
The high-pressure fuel, present in the accumulator, is fed to a fuel reservoir through a feed hole of a fuel injection nozzle to urge a needle valve in its opening direction. When the fuel injection nozzle is not in operation, an electromagnetic actuator of a three-way solenoid valve is de-energized and the high-pressure fuel in the accumulator is fed to an oil chamber. A hydraulic piston applies a depressing force based on such hydraulic pressure to the needle valve, whereby the needle valve is held in its closed position.
When the electromagnetic actuator is energized in accordance with a drive command outputted from the controller, the oil chamber is connected to a fuel tank by the three-way solenoid valve and the fuel pressure exerted on the hydraulic piston is relieved, so that the needle valve is opened by the spring force of a pressure spring, and the high-pressure fuel, present in the fuel reservoir, is injected into a cylinder through the nozzle hole.
In such an accumulator type fuel injection control device for a diesel engine, the volume of fuel to be injected is calculated and set in the controller on the basis of both engine speed and accelerator opening. Fuel injection pressure and fuel injection timing are set on the basis of both engine speed and fuel injection volume. Therefore, the control system controls the electromagnetic actuator on the basis of both fuel injection pressure and fuel injection volume so that a required amount of fuel is injected at a required pressure.
Such an accumulator type fuel injection control device is disclosed, for example, in Japanese Unexamined Patent Publication No. 93936/94.
In the accumulator type fuel injection control device for a diesel engine as described above, the fuel tank is provided on the vehicle body side, while the fuel pressure pump and the injection nozzle, with fuel supplied thereto from the fuel tank, are provided on the engine side. Since the engine vibrates during operation, it is supported by a mount so as to be rollable with respect to the vehicle body. Therefore, a hose on the engine side extending from the injection nozzle is connected to a piping on the vehicle body side through a rubber hose, and this piping is extended to the fuel tank. On the other hand, a piping on the engine side, extended from the fuel pressure pump through the feed pump, is also connected to the piping on the vehicle body side through a rubber hose, and this piping is extended to the fuel tank.
In the injection nozzle, the electromagnetic actuator is energized in accordance with a drive command outputted from the controller, and by the operation of the three-way solenoid valve, the fuel in the oil chamber is discharged to the fuel tank through a piping and a rubber hose or the like. The amount of fuel, thus discharged into the fuel tank, is almost equal to or larger than th
REFERENCES:
patent: 4522177 (1985-06-01), Kawai et al.
patent: 5176120 (1993-01-01), Takahashi
patent: 5313924 (1994-05-01), Regueiro
patent: 5423302 (1995-06-01), Glassey
patent: 5586538 (1996-12-01), Barnes
patent: 5848583 (1998-12-01), Smith et al.
Fujino Yutaka
Sekiguchi Akihiko
Mitsubishi Jidosha Kogyo Kabushiki Kaisha
Moulis Thomas N.
LandOfFree
Accumulating type fuel injection control does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Accumulating type fuel injection control, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Accumulating type fuel injection control will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1169440