|Title of Invention||
PROCESS FOR CONTROLLING THE OIL FLOW RATE IN A TWO-STROKE ENGINE WITH ASSOCIATED LUBRICATION AND AN ATTACHED ENGINE
|Abstract||A process for controlling a flow rate of lubricating oil to a two-stroke internal combustion engine in which oil is delivered to the two-stroke internal combustion engine separated from gasoline comprising the scope of providing an oil injection circuit which provides lubricating oil to the two-stroke internal combustion engine separated from the gasoline with a flow rate of the lubricating oil provided by the injection circuit being based on a temperature representing a heat load of the engine obtained from a constituent element of the two-stroke internal combustion engine.|
This invention relates to the field of two-stroke internal combustion engines in which the oi1 is injected independently of the gasoline. These engines are also called engines with separate lubrication.
More specifically, this invent ion describes the monitoring of the flow rate, or metering, of the oil that is injected into this type of engine.
The known systems for oil metering generally comprise a mechanical metering pump that is controlled based on paramet era such as the engine speed and/or the position of the gas thrott]e valve, whereby this last parameter represents the load of the engine.
These parameters, which are now used to control the meteri ng of oi 1, have several drawbacks, however, particularly in the case of air-cooled engines. They do not make it possible, in particular, to ensure good metering regardless of the load and/or the speed of the engine. In particular, metering is unsuitable when the thermal level of the engine varies: when climbing a steep grade or in the event of a failure of the cooling system, for example.
Improvements have therefore already been proposed, such as, for example, in Patent Application EP-Al-0577081.
amount; of oil that is injected based on thresholds shored in a computer memory; it i s also possible to vary the length of time between two injections.
This technological solution is based primarily on the load and speed values of the engine.
This invention is based on a different technical choice. Actually, this invention proposes that the monitoring of the oil flow rate be based on the temperature of an element of the engine that represents the heat load level of the engine.
Thi s solution makes it possible to achieve reliable and accurate metering which, by ensuring better management; makes it possible to reduce oil consumption considerably, on the order of 30% to 50%.
of the engine in the event of defects in the cooling system or major overheating.
To resolve these kinds of problems, the current lubrication systems are designed to guarantee a margin of safety in the event of major overheating of the engine (c 1 inibing of a long grade, for example) *
These adjustment s therefore lead to over-consurnpt ion of oil. when the engine operates under normal conditions, which are Less demanding because the safety margin exists regardless of the operating conditions.
Tin-? re are currently few systems that are able to actually optimize oil consumption.
Moreover, as emphasized above, the systems with the best performances operate based on parameters such as load and/or engine speed .
Compared to these known techniques, this invention makes it possible to solve the problems mentioned above, particu1ar1y these that are 1inked to overheating of the engine and excessive oil consumption.
Thus, this invention has as its object a process for monitoring the oil flow rate for lubricating a two-stroke internal combustion engine that comprises an oil injection circuit for lubrication; said process consists in influencing the oil flow rate for lubrication based on a
temperature that represents the heat load of the engine.
More speci.fiea 1 ly, the temperature that represents the heat 1 oad i s the temperature of an element: that const i lutes said ong i no.
Are ording to the invention, the engine comprises an ignition element that is equipped with a gasket.
In agreement with this embodiment of the invention, the temperature that represents the heat load of the engine is the temperature of said gasket.
Without, exceeding the scope of the invent! on, the temperature that represents the heat load of the engine is the temperature of the ignition element.
In particular, the flow rate of lubricating oil that is injected into the engine when the temperature that represents the heat load of the engine exceeds a predetermined threshold value is increased.
Furthermore, when the oil injection circuit comprises a leal circuit, the lubricating oil flow rate can be influenced by controlling the closing of said leak circuit.
Additionally, the oil flow rate is influenced based on themechanical load and/or the, speed o£ the engine.
The invention alsoaims at a two-stroke internal combust, on engi ne that comprises a circui for injeating a lubricating oil flow.
Characteristiea11 y, the engine comprises :
n output a signa1 that represent s said temperature,
- - a modu]e for processing said signal, equipped with an that is connected to the output of the sensor for measuring said temperature and an output which issues a control .signal,
-- means for adjusting the lubricating oil flow rate, equipped with an input that is connected to the output of the processing module,
who eby said adjusting means react to the control signal that is shaped the processing module in such a way that the J.ubri eating oi 1 flow rate is modi f ied based on a temperature that represents the heat load of the engine, measured by sai d temperature sensor, which is placed on a constituent element of said engine.
According to an embodiment of the invention, the eng i no i s cooJ ed by air and comprises an ignition element that j s equipped with a gasket; and the sensor for measuring the temperature that represents the heat load of the engine is then placed on said gasket.
The engine which, according to the invention, comprises an ignition element, the sensor for measuring the temperatuie, is placed on said ignition element.
In addjtion, the engine accordi ng to the invention can comprise a sensor for measuring the load and/or a sensor for measuring the speed of said engine, whereby the output of each oi them is connected to an input of said processing module in such a way that the lubricating oil flow rate is a! no modified baaed on the load and/or the speed of the engine.
this Invention will be better understood, and other elements, details, and characteristics will become clearer from reading the following description, which is given by way of illustration and is in no way limiting, in reference to the accompanying figures:
Figure 1 is a diagram that shows the main elements that are necessary for the implementation of the invention; and
Figure 2 shows a set of curves of the torque-engine based on the temperature of a characteristic element of the engine.
Figure 1 shows a two-stroke engine 1 that is air-cooled with an oil i ntake pipe 2 The oi 1 f ] ow rate in
this intake is controlled by an element 3 such as a valve that is actuated by a so1enoid .
A;: i s done conventionally, an oil reservoir 4 and a constitut e the supply of oil that is control led by ttolonoi d 3 .
The gasoline intake, not shown in Figure 1, is provided separately from oil intake 2.
Jn the? system that is presented in Figure 1 the flow rate of the oil that comes out of pump 5 is divided into two pipes: main supply pipe 2 of the engine and a by-pass pipe 10 where a portion of the oil is recycled upstream from pump 5. It is preferable to insert an anti-return valve 6 into by-pass pipe 10,
A second anti-return valve 13. can also be inserted into main pipe 2, close to the oil intake of the engine, in paiticular to keep the engine from being supplied with oil when it is stopped. The setting of second flap 11 is then a function of the setting of flap 6.
Main supply pipe 2 and by-pass pipe 10 will be sized to feed a minimum flow rate that is required by the engine whet: by paas pipe 10 isopen and a maximum flow rate that is required by the engine when by-pass pipe 10 is closed.
Oil pump can also bo connected to a pulley 9 that is itself connected tothe gas throttle valve. This system makes it possible* to control the flow rate via the load of the engine. Said system is not necessary for the implementat ion of the invention. It is an addi tional element that can make it possible to improve the monitoring of the JJow rate via the temperature.
This additional element may prove useful in the event: of a failure of the control system that is related to temperature. Tt can thus be considered a redundant element .
it is possible to envision the control of the oil flow 2 aby unit 7 being exercised via a temperature sensor t hat represents the heat load level of the engine. Thus, in the case of a liquid-cooled engine, a coolant temperature sensor can make this control possible. Without exceedi ng the scope of the i nvent i on, a temperature sensor of the casJ ng of the crankease or of the exhaust can also be provided, in particular in the case of an air-cooled engine.
Jn all ol" the cases, the principle is the same: it is t.o correct aud to control the oil flow rate based on the
5. Process according to any of claims 3 to 4, wherein injctioin oil cu it (2 - 5) for 1 ubr i ca t ing oil comprises a leak circuit;, and the effect on the lubricating oil flow rate .153 obtained by controlling the closing of said leak cirouit .
f). Process according to any of claims 1 to 5, wherein 3 also consists in influencing the oil flow rate based on the mechanical load and/or the speed of the engine.
7. Two-stroke internal combustion engine that comprises an injection circuit of a lubricating oil flow wherein i t comprises •
a sensor (8) for measuring a temperature that oprosents the heat load of said engine (1) which feeds to the output a signal that represents said temperature,
a module (7) for processing said signal, equipped with an input that is connected to the output of the sensor for measuring said temperature and an output that feeds a control signal,
-- means (3) for adjusting the lubricating oil flow rate, equipped with an input that js connected to the output of the processing module,
whereby said adjusting means (3) react to the control signal that is shaped by processing module (7) in such a
|Indian Patent Application Number||2631/MAS/1998|
|PG Journal Number||40/2007|
|Date of Filing||20-Nov-1998|
|Name of Patentee||HONDA R&D CO. LTD|
|Applicant Address||Wako R & D Center, 1-4-1 Cruyo, Wako-shi, Saitama 351-01|
|PCT International Classification Number||F01M3/02|
|PCT International Application Number||N/A|
|PCT International Filing date|