Internal-combustion engines – Engine speed regulator – Responsive to deceleration mode
Reexamination Certificate
2000-03-28
2001-08-07
Moulis, Thomas N. (Department: 3747)
Internal-combustion engines
Engine speed regulator
Responsive to deceleration mode
Reexamination Certificate
active
06269792
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an internal combustion engine with compressor function, comprising inlet and exhaust valves for each cylinder, a fuel injection system with a unit injector and an electrically operated spill valve for each cylinder, an extra exhaust valve at at least one cylinder, said valve being a disc valve with a valve disc and a spindle disposed in a bore and cooperating with spring means, which bias the disc valve towards a closed position, and a hydraulic plunger cylinder device, by means of which the disc valve can be opened.
BACKGROUND OF THE INVENTION
It is previously known to use one or more cylinders in diesel engines as compressor cylinders by providing each of the cylinders with an extra exhaust valve and equipping the engine injection system with devices through which the fuel supply can be cut off to the engine cylinders functioning as compressor cylinders. Such a compressor arrangement can i.a. be designed to supplement the ordinary engine unit air compressor, which normally supplies the vehicle compressed air system when its capacity is not sufficient for some reason, or it can function as the sole compressed air source for the vehicle.
SE 9003735-9 describes an internal combustion engine of the type described by way of introduction. The extra east valve is hydraulically operated with the air of a hydraulic pump with control valves. When the engine cylinder with the extra exhaust valve is to work as a compressor, the valve is set in the open position and the fuel supply via the associated unit injector is cut off by holding its spill valve open. The exhaust valve is kept constantly open as long as the compressor function is to be maintained, and re-entry of air via the extra exhaust valve is prevented during the intake stroke by means of a non-return valve disposed in the exhaust channel.
An arrangement of this type functions satisfactorily when the engine is to work as a compressor at low load, for example, during engine braking when driving downhill. If an extra air supplement is required even when the engine is loaded, several problems will arise, however. The vibrations arising when an engine cylinder is completely decoupled, can be so great that the vehicle gearbox in particular will be subjected to unacceptable wear, which reduces its useful life to less than half of the normal useful life. If the engine is turbocharged, there is lost not only a sixth of the normal power (in a six-cylinder engine with one cylinder decoupled) but as much as half of the power can be lost due to the loss of charge air pressure which occurs when the gas flow to the turbine of the turbocompressor is reduced An additional problem is that the high air pressure in the cylinder in combination with the constriction of the non-return valve generates very high temperatures in the non-return valve, placing heavy requirements on its design to make its function and useful life acceptable.
SUMMARY OF THE INVENTION
The purpose of the present invention is in general to provide an internal combustion engine of the type described by way of introduction, in which the compressor function can be utilized even when the engine is loaded, without problems arising with vibrations and heavy power losses.
This is achieved according to the invention by virtue of the fact that the plunger of the plunger cylinder device is subjected to the pressure in a pump chamber which communicates with the fuel injection system and which belongs to pump means which are driven by a cam element having a cam curve, which initiates a pump stroke in said pump means before cam means driving pump means in the unit injector initiate a pump stroke, and that the valve means comprise a control valve which, in its closed position, blocks the communication of the pump chamber of the first mentioned pump means with the fuel injection system, so that the fuel volume enclosed during the pump stroke produces a displacement of the plunger of the plunger cylinder device with associated displacement of the disc valve towards it open position.
By using the fuel, instead of the engine oil as a hydraulic medium and controlling the fuel in the same manner as the injection system, a very rapid engagement and disengagement of the compressor function can be achieved Thus, the control valve can be an electrically operated spill valve of the same type as the unit injector spill valve and can also be controlled by the same control unit that controls the fuel injection. The rapid engagement and disengagement of the compressor function, i.e. the opening and closing of the extra exhaust valve, can be determined however desired by the software in the engine-controlled computer m the same manner as the fuel injection is determined. This rapidity means that the compressor function does not need to be engaged during each cycle during power extraction from the engine; only at certain intervals, e.g. each fifth cycle. This in turn reduces engine vibrations and allows the charge pressure to be kept high, thus also power losses. If, for example, one engine cylinder in a six-cylinder engine works as a compressor each fifth cycle, the loss will be 20 % of slightly more than 16%, or ca 3,5%. This loss can be easily compensated for with a somewhat increased amount of fuel. Finally, the rapid control (within milliseconds) of the extra exhaust valve provides complete force control/time control of the valve, so that the non-return valve and the problems associated therewith can be eliminated.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail below with reference to examples shown in the accompanying drawings, where
FIG. 1
shows schematically a cross-section through a first embodiment of a portion of an engine according to the invention,
FIG. 2
shows a corresponding cross-section through a second embodiment of a portion of an engine according to the invention, and
FIG. 3
shows a cam profile of a cam element cooperating with the unit injector.
REFERENCES:
patent: 4742806 (1988-05-01), Tart, Jr. et al.
patent: 5379737 (1995-01-01), Hu
patent: 5636611 (1997-06-01), Frankle et al.
patent: 5735242 (1998-04-01), Kahlenbeck et al.
patent: 0 608 522 (1994-08-01), None
patent: 0 640 751 (1995-03-01), None
patent: WO 92/09792 (1992-06-01), None
patent: WO 96/10125 (1996-04-01), None
Moulis Thomas N.
Volvo Lastvagnar AB
Young & Thompson
LandOfFree
Internal combustion engine with compressor function does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Internal combustion engine with compressor function, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Internal combustion engine with compressor function will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2485566