Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/14—Introducing closed-loop corrections
  • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
  • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
  • F02D41/1459—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being a hydrocarbon content or concentration
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02N—STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR
  • F02N11/00—Starting of engines by means of electric motors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/22—Safety or indicating devices for abnormal conditions
  • F02D2041/224—Diagnosis of the fuel system
  • F02D2041/225—Leakage detection

Definitions

• This invention concerns a power train unit for an automotive vehicle. It also concerns a method for controlling the working conditions of such a power train unit and an automotive vehicle equipped with such a power train unit.
• Automotive vehicles are usually provided with an internal combustion engine which belongs to a power train unit installed in an engine compartment of the vehicle.
• fluid under pressure e.g. fuel or oil
• fluid under pressure e.g. fuel or oil
• the leaking fluid might come into contact with a hot part of the engine, which might induce the beginning of a fire within the engine compartment. In most cases, this will destroy the power train unit, and potentially the whole vehicle
• the invention aims at providing a new power train unit for an automotive vehicle which takes into consideration a leak of fluid, like oil or fuel, early enough to take appropriate measures in order to avoid, as much as possible, any potentially dangerous situation.
• the invention concerns a power train unit for an automotive vehicle, this unit including an internal combustion engine, at least one hydrocarbon sensor, located in the same compartment as the engine, and a control unit receiving an output signal from the sensor and adapted, on the basis of this signal, to modify the working conditions of the engine and/or to send a warning message, without stopping the power train unit.
• the hydrocarbon sensor can detect a leak of oil or fuel and the control unit can immediately take appropriate measures to limit this leak and its consequences, without stopping the power unit, since an automotive vehicle like a truck cannot be suddenly stopped because the driver must be given an opportunity to park his vehicle aside from the ongoing traffic or to reach a garage or a maintenance facility.
• detection of a leak in an engine compartment of a vehicle should not induce, except in extreme cases, an abrupt stop of the power train unit because this would immediately and assistance to the brake and steering systems of the vehicle.
• abrupt stop of the power train unit could induce a sudden stop of the vehicle, which might be dangerous, depending on the traffic conditions.
• a power train unit might incorporate one or several of the following features:
• the sensor is located next to a part of a lubricant circuit of the internal combustion engine.
• the sensor is located next to a part of a fuel circuit of the internal combustion engine.
• the sensor can be located next to this high pressure line.
• the sensor can be located next to this sub-assembly.
• sensors can be located within the engine compartment.
• the invention also concerns an automotive vehicle, in particular a truck, equipped with a power unit as mentioned here-above. Such a vehicle is safer than the ones of the prior art.
• the invention also concerns a method which can be implemented with a power train unit as described here above and which comprises the steps of: a) controlling the presence of hydrocarbon gases in an engine compartment of a vehicle; b) providing a control unit with a signal representative of hydrocarbon gases control ; and c) if this signal corresponds to the detection of hydrocarbon gases, modify the working conditions of an internal combustion engine of the power train unit or send a warning message, without stopping the power train unit.
• An alarm message is emitted in the driver space of the vehicle or towards a remote receiving device.
• This message might include an invitation to reduce or limit engine torque and/or speed.
• This message might also include some information with respect to a time period after which the engine will be stopped.
• the control unit controls the engine in such a way that its rotation speed and/or the torque developed by this engine remains under a predetermined value.
• the control unit controls the engine in such a way that fuel pressure within a part of the engine remains under a predetermined volume.
• the control unit stops fuel supply to a diesel particulate filter regeneration sub-assembly.
• At least one cylinder of the engine is not fed with fuel.
• the control unit pilots a gear box of the vehicle in order to keep it in one given gear, preferably a low gear, or in one of a predetermined set of gears.
• the control unit activates an electrical motor belonging to the power train unit and adapted to drive a transmission set of the vehicle, whereas the control unit stops the internal combustion engine.
• FIG. 1 is a schematic longitudinal cut view of the front part of a truck ' according to the invention equipped with a power train unit according to the invention, and
• figure 2 is a block diagram of a method implemented with the power train unit of figure 1.
• Tractor 2 includes a cabin 21 where a driver and, possibly, one or several passengers are seated when the truck is running. Cabin 21 is provided with a driver seat 22, a steering wheel 23 and a dashboard 24. Nevertheless, the invention could be implemented on other types of vehicles, and especially on other types of trucks such as rigid trucks.
• Underneath cabin 21 tractor is provided with an engine compartment 25 where a Diesel internal combustion engine 4 is installed.
• This engine has several cylinders, five of which are shown on figure 1 with reference 41.
• Cylinders 41 are fed with fuel under pressure from a common rail 42 located in an upper part of engine 4.
• Individual feed lines 43 connect rail 42 to each cylinder 41.
• Lines 43 connect rail 42 to fuel injectors located in the cylinder heads of cylinders 41.
• Engine 4 belongs to a power train of tractor 2 which also includes a power transmission line 4' towards the rear wheels 21 of tractor 2.
• An hydrocarbon sensor 5 is located within engine compartment 25, in the vicinity of rail 42 and lines 43. This sensor can be of the type marketed by Sensor
• Sensor 5 is connected to a control unit 6, which can be for example integrated to a dashboard area 24.
• An electric line 7 connects sensor 5 to unit 6 and allows to provide unit 6 with an output signal S 5 of sensor 5.
• Sensor 5 could also be connected to control unit 6 through a shared communication bus, e.g. a CAN-bus.
• Sensor 5 may be fed with electrical power, either from unit 6 or from a non represented main electrical circuit of tractor 2.
• Sensor 5 permanently monitors hydrocarbon gases presence within compartment 25.
• Sensor 5 is located next to parts 42 and 43 which are parts of a fuel circuit which feeds cylinders 41 and which is formed externally with respect to the main body of engine 4. A leak of fuel under pressure is more likely to take place at the level of items 42 and 43. This is why sensor 5 is located in their vicinity.
• a first step 100 of a method according to the invention sensor 5 is activated to sense the presence of hydrocarbon gases within compartment 25.
• sensor 5 provides unit 6 with signal S 5 .
• unit 6 compares the level of hydrocarbon gases concentration CH within compartment 25 to a predetermined value VH. This value VH is chosen so that one can consider that, if CH is smaller than VH, then no fuel leak occurs within compartment 25. On the contrary, when CH is larger than VH, one considers that a fuel leak takes place in or around engine 4 within compartment 25.
• step 106 is actuated to modify the working conditions of engine 4, without stopping this engine.
• a further step 106 is actuated to modify the working conditions of engine 4, without stopping this engine.
• the driver In such a situation, that is when a risk of fire has been detected within compartment 25, it is essential to give to the driver an opportunity to move truck 1 outside the traffic and, if possible, to reach a garage or another maintenance facility.
• some power must be available from engine 4 in order to move truck 1. This is why the power train unit comprising items 4 and 4' is not stopped.
• unit 6 activates an emergency light 61 mounted on dashboard 24 in order to warn the driver of the potentially dangerous situation.
• a speaker 62 speaks out a message within cabin 21 in order to inform the driver of the situation.
• the driver is invited to limit the rotation speed of engine 4 and the torque delivered by this engine.
• the driver is invited to drive slowly, in order not to request high power from engine 4. This induces that fuel flow to cylinders 41 will be limited, so that the leak should normally also be limited.
• unit 6 might count the time from the instant where it receives a signal S 5 corresponding to an actual hydrocarbon detection within compartment 25. Then, unit 6 can compute a time period after which it will cut engine 4. In such a case, the message sent to the driver via speaker 62 also states the time left before the engine 4 is cut, which takes place in a further step 108.
• step 106 in addition to the message sent to the driver by items 61 and 62, unit 6 can activate a communication module 63 which can send to a remote operator a telecommunication signal S 63 with the information that hydrocarbon gases have been detected within compartment 25.
• a communication module 63 which can send to a remote operator a telecommunication signal S 63 with the information that hydrocarbon gases have been detected within compartment 25. This gives to the remote operator the possibility to contact the driver, for example via his cellular phone, in order to check the situation and organize the necessary maintenance operations.
• unit 6 in step 106, can send to an electronic control unit 44 which controls operation of engine 4 a signal S 6 which activates unit 44 to limit the maximum rotation speed of engine 4 and/or a maximum torque delivered by this engine.
• a signal S 6 which activates unit 44 to limit the maximum rotation speed of engine 4 and/or a maximum torque delivered by this engine.
• unit 6 which automatically adjusts the working conditions of engine 4, via unit 44, irrespective of the attitude of the driver.
• Another electric line 8 connects unit 6 to unit 44.
• step 106 unit 6 can also activate some external warning lights 64 of truck 1 in order to inform other drivers of the potentially dangerous situation.
• step 106 unit 44 can be piloted to decrease fuel pressure within common rail 42 and/or feed lines 43 in order to limit the leak.
• gearbox in case tractor 2 is provided with an electronic gearbox, if hydrocarbon presence has been detected by sensor 5, the gearbox can be blocked in one gear, e.g. the first or second gear, or in one of a predetermined set of gears, which implies that the truck can only be moved slowly.
• step 106 another approach might be implemented, in addition or alternatively to the ones already considered: one or several auxiliary equipments, such as an alternator 45 or a motor for accessories, can be stopped or deactivated in order to avoid the creation of sparks which could ignite hydrocarbon gases within compartment 25.
• auxiliary equipments such as an alternator 45 or a motor for accessories
• Diesel particulate filter 46 used to temporarily store soot and non-burnt particulars present in the exhaust gases, such a filter must be regularly cleaned by oxidation of the particulate materials.
• a sub-assembly 47 is used to inject a small quantity of fuel before a catalyst module 48 in an exhaust line 49 of engine 4.
• unit 6 can inhibit fuel supply to sub-assembly 47 so that no fuel is injected within the exhaust line 49 of engine 4.
• another hydrocarbon sensor might be installed in the vicinity of sub- assembly 47.
• control unit 6 can be used to stop the electrical motor and to stop engine 4 as soon as sensor 5 senses hydrocarbon gases within compartment 25.
• the power train unit remains active, even if engine 4 is stopped, since mechanical power is generated by the electric motor.
• sensor 5 can also detect a leak of oil, in particular in a part of lubricant circuit running on a side of engine 4. Since oil pressure within engine 4 is mainly dependent on engine speed, a limitation of the engine speed, either by action of the driver or directly via unit 44, should limit oil leaking.
• several sensors 5 can be installed within compartment
• a first advantage is that it will allow earlier detection of any leak.
• a second advantage is that, by comparing the signals delivered by the different sensors, it may be possible to perform a more refined determination of the leak source, so that the best corrective strategy can be chosen and implemented.
• control unit 6 tests several of the above alternative approaches, and evaluates the impact of each of the corresponding corrective strategies to determine if it has an effect on the level of hydrocarbon concentration measured by the sensor(s). Depending on the determined impact, the control unit may choose to maintain one or several control strategies and to discard others.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Control Of Vehicle Engines Or Engines For Specific Uses (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

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• 2006
  • 2006-12-19 EP EP06849469.9A patent/EP2094534B1/de not_active Not-in-force
  • 2006-12-19 WO PCT/IB2006/004118 patent/WO2008075131A2/en not_active Ceased

Non-Patent Citations (1)

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