Classifications

• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
  • G05D23/00—Control of temperature
  • G05D23/19—Control of temperature characterised by the use of electric means
  • G05D23/30—Automatic controllers with an auxiliary heating device affecting the sensing element, e.g. for anticipating change of temperature
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P7/00—Controlling of coolant flow
  • F01P7/14—Controlling of coolant flow the coolant being liquid
  • F01P7/16—Controlling of coolant flow the coolant being liquid by thermostatic control
  • F01P7/167—Controlling of coolant flow the coolant being liquid by thermostatic control by adjusting the pre-set temperature according to engine parameters, e.g. engine load, engine speed
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P2025/00—Measuring
  • F01P2025/08—Temperature
  • F01P2025/32—Engine outcoming fluid temperature
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P2037/00—Controlling
  • F01P2037/02—Controlling starting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P2070/00—Details
  • F01P2070/04—Details using electrical heating elements

Definitions

• the present invention relates to the field of motor control, and more particularly to a method and a device for controlling the first opening of an electronic thermostat regulating the temperature of an internal combustion engine including a vehicle.
• Engine control is the management technique of an internal combustion engine with all its sensors, actuators and inter-system links (LIS).
• LIS inter-system links
• the set of control laws (software strategies) and characterization parameters (calibrations) of an engine is contained in a computer called electronic control unit (ECU).
• ECU electronice control unit
• Cooling is achieved by means of the 3 fluids present in the environment:
• the air is mainly used for heat exchangers (radiator, air - air exchangers), as well as for the natural cooling of the calories present by conduction on the external faces of the engine and the exhaust.
• the oil removes calories from the pistons, the camshaft, the connecting rod heads, the crankshaft bearings and the valves.
• An objective of this regulation is the reduction of consumption and therefore a quantitative reduction of pollutants such as nitrogen oxides.
• the lubricating oil of the heat engine has a high viscosity which causes additional friction in the engine and therefore an overconsumption of fuel. This occurs especially when starting the vehicle when the engine and oil are cold.
• the production of nitrogen oxides (NOX) is related in particular to the temperature of the mixture of gas introduced into the cylinders of the engine of the vehicle. The higher the temperature of the mixture, the greater the production of nitrogen oxides.
• the coolant bypasses the main radiator by a bypass line to return directly into the internal combustion engine arriving in the lower part thereof, namely at the engine block.
• a valve opens a second coolant path through the main radiator which cooperates with a fan to extract excess heat from the coolant.
• the difference in temperature on either side of the thermostat increases as the engine warms up.
• a thermal shock will occur. Once the coolant circulation has occurred once, it will not return to the flow temperature. Even if the motor suffers another heat shock, the most important is when the first opening of the thermostat.
• This thermal shock will have negative effects on the surrounding components surrounding the engine and, in particular, the cooling systems for the engine itself and other cooling systems (cabin air heater, EGR exchangers, water / oil exchangers, air conditioning radiator and sound condenser, charge air cooler, BVA radiator, ...) which are sensitive to changes or passages from one temperature to another operating temperature setpoint of the engine which causes additional stress on it.
• the position of the various elements with respect to each other has an influence on the quality of temperature regulation and the associated constraints. For example, if the cooling system shut-off system is at the motor input or output.
• US Patent 2002/0053325 proposes a solution to this problem with a device for regulating the engine temperature by controlling the circulation of the coolant between the engine and a heat exchanger such as a radiator.
• This device comprises a first conventional thermostat as described above whose activation temperature is around 102 ° C and a thermostat having a resistance in its center and whose activation temperature is 25 ° C higher than that of the first thermostat, and is therefore around 127 ° C. These two thermostats each control a different opening of a valve allowing the coolant to arrive in the radiator to be cooled.
• the expansive material contained in the first thermostat will activate a piston which will itself open a valve thus allowing the coolant to flow via the radiator with a certain debit. If the temperature of the liquid is higher and is around 127 ° C expansive material contained in the second thermostat will activate a second piston that will allow a larger opening of the valve. The liquid will thus flow with a greater flow to the radiator, so in the same time period a larger amount of liquid will be cooled. This device makes it possible to cool the liquid more quickly and thus prevent the engine from staying too long at too high a temperature.
• a disadvantage, however, of this device is that it acts only once the temperature of the engine is higher than an ideal operating temperature which is around 90 ° C (or according to the calibration of the thermostat). It does not prevent thermal shock. The different parts of the engine concerned by this overheating will therefore suffer the stresses and deformities mentioned above.
• the present invention therefore aims to reduce these disadvantages by a device whose adapted control of the winnowing system (in this case a thermostat) makes it possible to reduce the amplitude of the thermal shock on the components by carrying out a command according to a criterion chosen in relation to at the coolant temperature and by monitoring the effective opening of the valve system, always in relation to the temperature.
• a device whose adapted control of the winnowing system (in this case a thermostat) makes it possible to reduce the amplitude of the thermal shock on the components by carrying out a command according to a criterion chosen in relation to at the coolant temperature and by monitoring the effective opening of the valve system, always in relation to the temperature.
• the invention proposes a device for controlling the opening of a valve system of a cooling circuit of an internal combustion engine, the valve system being arranged on a pipe connecting the engine to a combustion engine. radiator, the pipe comprising a temperature sensor disposed at the output of the engine and upstream of the valve system whose opening is activated automatically under the effect of a cooling of the coolant to a standard temperature characterized in that it comprises means, controlled by calculation means arranged in a computer, for triggering an anticipated controlled opening of the valve system when the temperature of the coolant is higher than a predetermined activation temperature value and safety means allowing to activate the anticipated controlled opening only when it is the first opening of the winnowing system.
• the means for triggering an anticipated controlled opening of the valve system consist of a heating resistor which prematurely increases the temperature of a wax capsule of the valve system.
• the computing means arranged in the computer are constituted by at least a first comparator module making it possible to compare the temperature of the coolant with the activation temperature, a second comparator module making it possible to measure a fall coolant temperature after opening the valve system and compare it with a predetermined temperature drop setpoint, a third comparator module for comparing the temperature of the engine output coolant after opening the valve system with a temperature threshold indicating the effective opening of the winnowing system and storage means of these different temperature value.
• Another object of the invention is to propose a method for controlling the opening of a system for turning on a cooling circuit using the device according to the invention consisting in providing a controlled opening of the winnowing system.
• a cooling circuit located upstream of a radiator before the temperature of the coolant reaches an activation temperature value of the opening of the valve system itself lower than the standard temperature, this controlled opening n being realized only when it is the first opening of the winnowing system, characterized in that the method comprises the following steps:
• the conditions confirming the opening are as follows:
• the threshold temperature indicating the activation of the valve system is greater than the activation setpoint temperature.
• the temperature drop is sufficient when the difference between the temperature measured during the opening of the valve system and the temperature measured after the opening is greater than the predetermined value of the temperature drop.
• the opening of the throttling system is carried out by controlling the start-up of a heating means situated at the level of the throttling system which will cause the standard temperature to be reached early, allowing the opening of the system. winnowing.
• the closure of the winnowing system is performed when the conditions confirming the opening are made, or after a time T if the conditions confirming the opening are not realized.
• the time T is determined as a function of the temperature of the coolant at start-up according to a predetermined relationship and stored in storage means of a computer.
• the activation of the opening of the winnowing system initializes a security module to a predetermined value indicating the activation of the opening of the winnowing system.
• the anticipated controlled activation only during the first opening is ensured by the fact that the security module is at the predetermined value indicating the activation of the winnowing system and the fact that the two conditions of achievements are realized.
• FIG. 2 is a schematic representation of the evolution of the temperature as a function of time for a first controlled opening according to the invention
• FIG. 3 is a schematic representation of the device according to the invention.
• FIG. 4 is a schematic representation of the method according to the invention.
• FIG. 1 illustrates a first opening of the conventional, uncontrolled, winnowing system.
• the device allowing the opening of the valve system comprises a conventional thermostat, as presented above, the expansible liquid allows the opening of a valve at a given temperature.
• the curve A1 represents the temperature of the coolant, as a function of time, which corresponds to the temperature rise of the engine from the moment of starting.
• the thermostat is set at 90 ° C.
• the temperature rises which triggers the opening of the winnowing system.
• This opening allows a passage of the coolant in the heat exchange system, for example a radiator, whose temperature will increase sharply (represented by the curve B1), while that measured at the motor output will drop. There is thus a very significant thermal shock (here in the passage figure of 22 ° C to 92 ° C or more depending on the engine load, the thermostat does not have an immediate response).
• FIG. 2 illustrates a first opening of the winnowing system but this time controlled with the method and the device according to the invention.
• the curve A2 represents the temperature of the coolant also corresponding to the temperature rise of the engine from the moment of starting. It is observed on this graph that the rise in temperature is partially interrupted before reaching the set temperature of the thermostat (TT) set, for example, at 110 ° C.
• the time when the temperature falls corresponds to the moment when the controlled opening is activated, at the time of the thermostat setpoint change (TT) (represented by the curve C2) which passes here from 1 10 ° C to 90 ° C, to avoid reaching a too high temperature level, and to avoid at the same time that the radiator input temperature, represented by the curve B2, does not rise too high following the opening of the thermostat which results by the brutal rise of the temperature in radiator input.
• FIG. 3 illustrates an embodiment of the device according to the invention making it possible to obtain the results presented in FIG. 2.
• This device comprises an internal combustion engine (1) and a radiator (2) interconnected by a pipe (11, 11 ') for circulation (10) of the coolant, so as to form a loop circuit.
• This circuit allows the coolant to flow from the engine (1) to the radiator (2) and then to leave the radiator to the engine by a different path (1 1 ').
• a second conduit forms a bypass (12) allowing the cooling liquid to return directly to the engine (1) without passing through the radiator (2).
• This valve system (3) shown in the form of a housing has a passage (not shown) for the coolant between the engine (1) and the radiator (2) closable by a valve, and a thermostatic control element of this valve.
• This thermostatic control element (3) does not allow the circulation of the liquid cooling the motor (1) towards the radiator (2) only when the latter has reached a certain temperature.
• the thermostatic control element is of the same type as that described previously. It works on the principle of dilation of a volume of wax included in a capsule. Under the effect of the temperature of the coolant, the wax capsule controls, by its thermal expansion calibrated on a temperature point, the opening of a valve (32) via a working piston. The valve (32) will thus open or close to regulate the flow of coolant, and possibly the bypass circuit (12).
• the thermostat (3) used opens when the coolant temperature reaches a standard temperature (TT) of 1 10 ° C.
• This thermostat (3) comprises a heating means (31) of resistance type (31), which will make it possible to artificially increase the temperature of the wax and thus to change its set temperature.
• thermostat (3) which normally causes an opening of the valve (32) when the coolant is at 110 ° C, will now open when the coolant is at 90 ° C, thanks to the resistor (31) which will artificially bring the thermostat to 110 ° C.
• the purpose of this resistance (31) is to allow an early opening of the winnowing system (3).
• This resistor (31) is connected to the computer (4) of the vehicle that performs the commands necessary for the process.
• the cooling circuit also comprises at least one temperature sensor (101) disposed in the pipe (1 1) of the cooling circuit at the outlet of the engine (1) and upstream of the valve system (3).
• a second sensor (102) may be disposed in the cooling circuit line (11) downstream of the valve system (3) and at the radiator inlet (2). These two temperature sensors are also connected to the computer (4).
• the first sensor (101) makes it possible to measure the temperature (T1) of the coolant at the outlet of the engine. This measurement is sent to the computer (4) which will store it by means of storage means arranged in a storage module (47).
• the second sensor (102) makes it possible to measure the temperature of the coolant at the inlet of the radiator (2) or at the outlet (103) of the radiator. For reasons of high cost, conventional motor vehicles are not equipped with this second sensor (102) which is only used during engine testing. All the measures necessary to regulate the temperature of the engine during operation of a motor vehicle is therefore performed with the first temperature sensor (101).
• the first sensor (101) is therefore used to measure the temperature (T1) of the engine output coolant at the time of starting, that is to say before the first opening of the valve system (3), and the temperature (T2) of the engine output coolant after activation (230) of the throttle opening (T2), as shown in FIG.
• the temperature (T1) measured at the time of starting will be stored in the storage module (47) of the computer (4). It is this temperature (Tl) which is compared with a first comparator module (41) located in the computer (4) with an activation temperature (T3) of the valve system (3).
• This temperature (T3) corresponds to the temperature from which the opening of the valve system (3) will be activated (230).
• the optimum operating temperature of the engine is around 90 ° C
• the activation temperature (T3) of the opening is between 80 ° C and 95 ° C, and preferably is equal to 85 ° C.
• the activation temperature (T3) is set at about 85 ° C if a thermostat setpoint temperature is desired at 90 ° C so as to allow the resistor (31) to heat up to open (230) when the coolant is at 90 ° C. Indeed, if we set the activation temperature to 90 ° C, the time required to heat the resistor (31) and the response time of the cooling circuit assembly and thermostat will make the opening will be when the coolant will have exceeded 90 ° C.
• This temperature (T3) is stored in the storage module (47) of the computer (4) before starting the engine (1).
• the first comparator (41) sends a signal to a resistance control module (46) in order to change the temperature setpoint (TT) of the thermostat for which pass from 110 ° C to 90 ° C, that is to say that the valve (3) opens when the coolant is at 90 ° C and no longer at 110 ° C, to operate the resistor (31) heating so to artificially increase the temperature of the wax and to open the valve (32).
• the temperature (T2) of the engine output coolant after activation of the throttle opening (3) is measured, with the temperature sensor (101), continuously from the moment the activation of the opening is triggered and at least until the first closing of the winnowing system (3).
• This temperature (T2) after activation of the opening is analyzed by the computer (4) at a second comparator module (42) of the computer (4).
• the temperature (T2) after activation of the opening is compared with the temperature (T1) before activation of the opening to determine a difference (E1) corresponding to a temperature drop.
• This temperature drop (E1) is then compared with a temperature drop setpoint (T5) pre-stored in the storage module (47) of the computer (4).
• the temperature (T2) is also compared, at a third comparator module (43) of the computer (4), with a threshold temperature (T4) indicating that the opening of the winnowing system has been activated.
• the threshold temperature (T4) indicating the activation of the opening of the valve system (3) is predetermined and is greater than the activation setpoint temperature (T3). It is stored before operation of the motor in the storage module (47).
• the three comparators (41, 42, 43) are connected to the storage module (47). Comparisons made by the second (42) and the third comparator module (43) are used to determine the closure of the winnowing system. Indeed, so that the winnowing system (3) can to be closed two conditions must be realized.
• the first condition is realized when the temperature drop (E1) is greater than the temperature drop setpoint (T5).
• the second condition is realized when the temperature (T2) after opening of the valve system (3) is greater than the threshold temperature (T4) indicating the activation of the opening of the valve system (3).
• T5 the temperature drop setpoint
• T4 threshold temperature
• the system is closed again after a time T which is predetermined and stored in the storage module of the computer.
• This time T is determined according to the temperature of the coolant at startup according to a predetermined relationship and plays the role of safety not to keep the system open too long.
• the predetermined relation consists of a standard curve representing the temperature as a function of the opening time and makes it possible to estimate the opening time necessary to obtain a sufficient temperature drop.
• the computer (4) comprises a counter (44), initialized to zero before the opening of the winnowing system (3), which begins to operate when the opening is activated. For this purpose a signal is sent through the first comparator (41) to the counter (44). When the counter arrives at the time T the winnowing system (3) is closed again.
• the computer (4) also comprises a security means to ensure that the activation of the first opening is performed only once after startup.
• the safety means consists on the one hand in the fulfillment of the two conditions indicating the opening of the winnowing system (3). And secondly to check the value of a security module (45) initialized to a predetermined value when opening the winnowing system (3). If the value of the module corresponds to the predetermined value and if both conditions indicating the opening of the unlocking system (3) are realized, then the security means is activated.
• the counter (44) can be used as a security module (44) by verifying that it is no longer at zero.
• the values of activation temperature (T3), activation threshold (T4) and temperature drop set point (T5) are determined and stored (203, 204, 205) in the storage module (47) of the computer.
• the temperature thereof When starting the engine (1), the temperature thereof will increase rapidly and the temperature of the coolant (T1) output of the engine (1) will also be high.
• This temperature (Tl) is measured (210) at the engine output by the temperature sensor disposed in the cooling circuit line and is stored (210) in the storage module (47) of the computer (4).
• the first comparator module (41) uses this temperature to compare it (220) with the activation temperature (T3). If the start temperature (T1) exceeds the activation temperature value (T3) which is 85 ° C, and if the motor (1) is in stand-alone operation mode, the opening process (230) is started .
• the motor (1) is in stand-alone mode when the ignition is switched on and when the rotational speed of the engine is sufficient for the starter to be no longer useful.
• the first comparator (41) sends a signal to the resistance control module (46) which will raise the temperature set point from 110 ° C. to 90 ° C. and thus turn on the resistor (31) located in the thermostat (3).
• the heat released by the resistor (31) will cause the valve (32) of the throttling system to open.
• the coolant will then flow to the radiator (2) to be cooled.
• the liquid thus cooled by the radiator (2) will flow to the engine (1) inside the pipe (1 1 ') connecting the radiator (2) to the motor (1) and will in turn cool the motor (1).
• the temperature (T2) of the coolant is then measured (240) after the activation of the opening (230). So that the engine temperature decrease is not too great, that is to say it does not fall below the optimum operating temperature threshold of the engine, the system (3) will then be closed again (260). ).
• the first condition (251) is that the temperature drop (E1) of the coolant after the opening must be sufficient, that is to say greater than the predetermined minimum temperature drop (T5).
• the temperature drop corresponding to the difference between the temperature (T1) of the coolant at the time of opening of the valve system (3) and the temperature (T2) of the coolant after opening of the valve system (3) and after passing in the radiator and the engine.
• the second condition (252) is that the temperature value (T2) of the cooling system after the opening must be greater than the threshold temperature (T4) indicating the activation of the system. In this way the temperature does not fall below the activation threshold.
• the throttle system (3) closes (260) and the temperature thus remains at a value allowing optimum operation of the engine.
• the device uses (233) the counter (44) activated during the opening (230) of the throttling system (3) and the predetermined time T with the temperature (T1) of the coolant at startup. That is, if the conditions are not realized at the end of time T the counter (44) sends (233) a signal to the control module (46) of the resistor (31) to control its stop.
• This counter (44) plays a security role so that the system does not remain open for too long.
• control module (46) which has received the necessary signals, changes the temperature set point of the thermostat from 90 ° C to 1 10 ° C, which causes the shutdown of the control the resistor (31), which will allow the closing of the valve (32).
• this method is activated only once (270) per rolling cycle.
• the security module (45) has taken (231) a value indicating the opening (230) of the valve system (3). So, if this security module (45) is at the determined value (234) and if both conditions
• the operation of the device according to the invention thus comprises the following steps:
• the throttling system (3) is of the thermostat type, but it is possible to use another system for turning off the coolant, such as for example an electrically controlled valve and thus to regulate on other criteria. additional than the temperature.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Automation & Control Theory (AREA)
• Combined Controls Of Internal Combustion Engines (AREA)
• Temperature-Responsive Valves (AREA)
• Control Of Temperature (AREA)

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• 2006
  • 2006-01-19 FR FR0600486A patent/FR2896272B1/fr not_active Expired - Fee Related
• 2007
  • 2007-01-18 RU RU2008134002/06A patent/RU2411372C2/ru active
  • 2007-01-18 US US12/161,590 patent/US8201524B2/en not_active Expired - Fee Related
  • 2007-01-18 JP JP2008550820A patent/JP4999863B2/ja not_active Expired - Fee Related
  • 2007-01-18 CN CN2007800059516A patent/CN101809263B/zh not_active Expired - Fee Related
  • 2007-01-18 WO PCT/FR2007/050662 patent/WO2007083064A2/fr active Application Filing
  • 2007-01-18 EP EP07718158A patent/EP1974133A2/fr not_active Withdrawn

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