JP5803818B2 - Control device for cooling system - Google Patents

Description

  The present invention relates to control of a vehicle including an internal combustion engine (engine).

  2. Description of the Related Art Conventionally, there has been known a technique for controlling a water flow rate of a cooling water channel that can cool an engine or the like by passing cooling water. For example, in Patent Document 1, in a cooling system having a pump for controlling the flow rate of engine cooling water and having a water temperature sensor disposed in a cooling water channel near the outlet of the engine, the cooling water is based on the output of the water temperature sensor. A technique for estimating the cooling water temperature and the combustion chamber (bore) wall temperature during circulation stop and controlling the output of the pump is disclosed. In addition, technologies related to the present invention are disclosed in Patent Literature 2 and Patent Literature 3.

JP 2006-342680 A JP 2006-214280 A JP 2007-056722 A

  A cold correction is known in which the coolant temperature is used as an index representing the state of the bore wall temperature, and various control amounts of the engine at the cold start are corrected. When this cold correction is performed at the time of cooling water circulation stoppage, the technology described in Patent Document 1 is used to estimate the cooling water temperature during circulation stoppage based on the output of a water temperature sensor installed in the vicinity of the engine outlet. It is possible to perform cold correction based on the cooling water temperature. However, when the circulation of the cooling water is stopped, the cooling water temperature may be lower than that during the circulation even when the bore wall temperature is higher than that during the circulation of the cooling water. In this case, although the bore wall temperature is high, the cooling water temperature is estimated or measured low, so that the cold correction of the engine control amount becomes overcorrection, which may lead to deterioration of emissions.

  The present invention has been made to solve the above-described problems, and provides a control device for a cooling system capable of suppressing overcorrection when cold correcting the engine control amount. Main purpose.

In one aspect of the present invention, an engine, a cooling water channel capable of cooling the engine by cooling water flow, cooling water temperature acquisition means for acquiring the cooling water temperature, and a flow rate of the cooling water can be adjusted. A cooling system control device comprising: a cooling water adjusting means; and a control means for controlling the engine based on the water temperature, wherein the cooling water adjusting means has the water temperature completed to warm up the engine. When the temperature is lower than the warm-up completion temperature, the flow rate is limited, and the control means starts the engine within a period when the water temperature is lower than the warm-up completion temperature and shorter than the period. the period after the predetermined period immediately has elapsed, at the time of restriction of the through water, based on the value obtained by correcting the temperature of the cooling water temperature acquisition means has acquired a high temperature side, and controls the engine, and the predetermined period So even time limit of the through water, based on the cooling water temperature water temperature acquisition means has acquired, to control the engine.

The control device of the cooling system is mounted on a vehicle and includes an engine, a cooling water channel, a cooling water temperature acquisition unit, a cooling water adjustment unit, and a control unit. The cooling water channel cools the engine by passing cooling water. The coolant temperature acquisition means acquires the coolant temperature by estimating or actually measuring the coolant temperature. The cooling water adjusting means adjusts the flow rate of the cooling water. Here, the cooling water adjusting means limits the amount of cooling water flow when the acquired cooling water temperature is lower than the warm-up completion temperature at which it is determined that the engine has been warmed up. When the predetermined water flow condition is satisfied, the restriction on the flow rate of the cooling water is released. The control means is within a period in which the acquired cooling water temperature is lower than the warm-up completion temperature, and after a predetermined period immediately after engine startup that is shorter than the period , the cooling water temperature is limited when the flow rate is limited. Based on the value obtained by correcting the water temperature acquired by the acquisition means to the high temperature side, the engine is controlled, and within the predetermined period , based on the water temperature acquired by the cooling water temperature acquisition means even when the amount of water flow is limited. Control the engine .

  Generally, when the cooling water flow rate is limited, the movement of the cooling water in the cooling water channel is limited, so the heat transfer efficiency from the bore (combustion chamber) to the cooling water is poor, and compared to when cooling water is flowing. Even though the bore wall temperature is high, the obtained cooling water temperature is low. In this case, the cooling water temperature is less accurate as an index representing the bore wall temperature. The cooling system, in principle, stops cooling water flow when the cooling water temperature is equal to or lower than the warm-up completion temperature at which it is determined that the engine has been warmed up, while a predetermined water flow condition is satisfied. However, it is necessary to restart the flow of the cooling water, and there are situations where the cooling water is allowed to flow or is stopped even at the same cooling water temperature. In consideration of the above, the control device of the cooling system makes the relationship between the cooling water temperature and the engine control amount at the time of limiting the water flow rate different from that during the release of the water flow rate restriction. However, immediately after the engine is started, the engine is not easily warmed up, that is, the heat capacity is high. Therefore, the above-described difference between the bore wall temperature and the cooling water temperature when the cooling water flow restriction is performed does not occur. Therefore, the control device for the cooling system determines the engine control amount based on the relationship between the cooling water temperature and the engine control amount during the release of the cooling water flow restriction during a predetermined period immediately after engine startup. By doing in this way, the control apparatus of a cooling system can suppress the overcorrection at the time of carrying out cold correction of the engine control amount.

In one aspect of the control device of the cooling system, the control means, as the heating value of the bore wall of the engine is large, sets shorter the predetermined period. When the engine heat generation amount is large, the bore wall temperature when the circulation of the cooling water is stopped increases, and the temperature difference between the bore wall temperature and the cooling water temperature increases. Therefore, according to this aspect, the control device of the cooling system can accurately perform the cold correction of the engine control amount according to the state of the engine.

In another aspect of the control device of the cooling system, wherein, in the limited time of the passing water quantity in the case where the water temperature is lower than the warm-up completion temperature, the stop time before the start of the engine is less than or equal to a predetermined time In this case, even within the predetermined period, the engine is controlled based on a value obtained by correcting the water temperature acquired by the cooling water temperature acquisition means to the high temperature side . Generally, when the stop time before starting the engine (so-called soak time) is short, the engine is more easily warmed up than when the soak time is long. The temperature difference between the temperature and the cooling water temperature increases. Therefore, according to this aspect, the control device of the cooling system can appropriately perform cold correction of the engine control amount.

In a preferred example of the control device of the cooling system, the control unit determines the control amount of the engine by correcting the water temperature acquired by the cooling water temperature acquisition unit to a high temperature side when the flow rate is limited. Thereby, the control apparatus of a cooling system can correct | amend the cooling water temperature used for cold correction | amendment to the value according to the bore wall temperature, and can perform cold correction | amendment of engine control amount appropriately. Further, according to this aspect, the control device for the cooling system can be used in common even when the water flow restriction is performed, such as a map or a calculation formula for determining the engine control amount to be used while releasing the water flow restriction. It is possible to reduce the man-hours for creating a map or the like for determining the engine control amount when the water flow is restricted.

  In another aspect of the control device for the cooling system, the control amount determination means may perform the first heat from the engine to the cooling water at the water temperature acquisition position while the restriction of the water flow amount is being released. A correction amount for correcting the water temperature to the high temperature side is determined based on the difference between the transfer efficiency and the second heat transfer efficiency from the engine to the cooling water at the water temperature acquisition position when the water flow rate is limited. According to this aspect, the control device of the cooling system can correct the cooling water temperature used for cold correction to a value corresponding to the bore wall temperature, and can appropriately perform cold correction of the engine control amount.

In a preferred example of the control device for the cooling system, the control means includes a calculation means for calculating the control amount of the engine for the water temperature that is different from when the restriction of the water flow amount is released when the water flow amount is restricted. Have. For example, the control device of the cooling system stores, in advance, the engine control amount for the acquired water temperature or a map of the correction amount or the like for cold correction at the time of restricting water flow as the above-described calculation means. As described above, the control device of the cooling system corrects the acquired water temperature by changing the calculation method of the engine control amount between when the cooling water flow is restricted and when the flow restriction is released. It is possible to calculate the engine control amount at the time of cold start.

In a preferred example of the control device of the cooling system, the cooling water channel includes a water channel for cooling the LPLEGR cooler, and the water flow condition is established when the water temperature is equal to or higher than the exhaust dew point temperature. If the cooling water temperature is equal to or higher than the exhaust dew point temperature, the exhaust water in the vicinity of the EGR cooler can be maintained in the temperature range equal to or higher than the exhaust dew point temperature by supplying the cooling water to the water channel for cooling the LPLEGR cooler. Accordingly, it is effective from the viewpoint of suppressing the generation of condensed water that the water flow restriction is canceled when the cooling water temperature reaches the exhaust dew point temperature while the engine is warming up at the time of starting. Even when the water flow conditions are determined in this way, the control device of the cooling system can accurately perform the cold correction of the engine control amount during the cold start period.

The schematic block diagram of the cooling system common to each embodiment is shown. It is a schematic sectional drawing of an engine. It is a figure which illustrates the relationship between a CCV rotation angle and the opening degree of each cooling water channel. It is a graph which shows the time change of the measured value of the cooling water temperature after a cold start. It is a figure which shows the positional relationship and the temperature in each position of a bore wall and the water temperature measurement position in which the water temperature sensor was installed. It is a flowchart which shows the process sequence of the cold correction control in 1st Embodiment. (A) A map of the correction amount of the intake air amount with respect to the engine speed and the fuel injection amount when the coolant temperature in the cold correction control is 48 ° C. is shown. (B) A map of the correction amount of the intake air amount with respect to the engine speed and the fuel injection amount when the coolant temperature is 50 ° C. is shown. (A) The map of the correction amount of the LPLEGR ratio with respect to an engine speed and fuel injection amount in case a cooling water temperature is 48 degreeC is shown. (B) A map of the correction amount of the LPLEGR ratio with respect to the engine speed and the fuel injection amount when the coolant temperature is 50 ° C. is shown. (A) The time change of the NOx emission amount in the cold start period from the start of the engine to 300 seconds is shown. (B) In the cold start period, the time variation of the NOx emission amount when the cold correction control is performed based on the estimated water temperature and when the cold correction control is performed based on the water temperature sensor value is shown. The time change of the bore wall temperature in the cold start period from the start of the engine to the elapse of 400 seconds is shown. It is a flowchart which shows the process sequence of the cold correction control in 2nd Embodiment. It is a flowchart which shows the process sequence of the cold correction control in 3rd Embodiment. It is a flowchart which shows the process sequence of the cold correction control in 4th Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
[Schematic configuration of engine system]
FIG. 1 is a schematic configuration diagram of a cooling system 100 common to each embodiment of the present invention. In FIG. 1, a solid line arrow indicates a cooling water channel and a flowing water direction, and a broken line arrow indicates signal input / output.

  The cooling system 100 is mounted on a vehicle, and mainly includes an engine 2, a coolant control valve (CCV) 3, an electric water pump (also simply referred to as “electric W / P”) 4, and the like. Water temperature sensor 5, thermostat 6, LPL (Low Pressure Loop) EGR cooler 7, heater 8, HPL (High Pressure Loop) EGR valve 9, oil cooler 10, radiator 11, ECU 15, cooling water channel CCVi , CCVo1 to CCVo3, WPi, WPo.

  The engine 2 includes a cylinder head 21 and a cylinder block 22. Here, a detailed configuration of the engine 2 will be described with reference to FIG. FIG. 2 is a schematic sectional view of the engine 2. In FIG. 2, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof is omitted as appropriate.

  In FIG. 2, the engine 2 has a cylinder 201 accommodated in a metal cylinder block 22. A part of the fuel injection valve of the injector 202 is exposed in the combustion chamber formed in the cylinder 201, and high pressure spray of fuel can be supplied to the combustion chamber. A piston 203 is installed inside the cylinder 201 so as to be able to reciprocate. The reciprocating motion of the piston 203 caused by ignition of a mixture of fuel and intake air in the compression stroke is caused by the crankshaft via the connecting rod 204. It is converted into 205 rotational motion.

  A crank position sensor 206 that detects a crank angle “θcr” that is a rotation angle of the crankshaft 205 is provided in the vicinity of the crankshaft 205. The crank position sensor 206 is electrically connected to the ECU 15 and the detected crank angle θcr is supplied to the ECU 15 at a constant or indefinite period. The ECU 15 controls the fuel injection timing of the injector 202 based on the crank angle θcr detected by the crank position sensor 206. Further, the ECU 15 calculates the engine speed (also referred to as “engine speed Ne”) of the engine 2 by time-processing the detected crank angle θcr.

  In the engine 2, the air sucked from the outside passes through the intake pipe 207 and is sucked into the cylinder 201 when the intake valve 210 is opened through the throttle valve 208 and the intake port 209 in order.

  The air-fuel mixture combusted inside the cylinder 201 becomes exhaust gas, and is guided to the exhaust pipe 213 through the exhaust port 212 when the exhaust valve 211 that opens and closes in conjunction with the opening and closing of the intake valve 210 is opened. The exhaust port 212 and an exhaust manifold (not shown) interposed between the exhaust port 212 and the exhaust pipe 213 are accommodated in the cylinder head 21.

  A DPF 214 is installed in the exhaust pipe 213. The DPF 214 is a filter configured to be able to capture PM (Particulate Matter) in the exhaust gas. The engine 2 is provided with various catalysts such as a CCO (oxidation catalyst), an SCR or an NSR (Nox Storage Reduction) catalyst (also referred to as a lean NOx catalyst) in addition to or instead of the DPF 214. May be.

  On the other hand, one end of an LPLEGR pipe 320 made of a metal material is connected to the exhaust pipe 213 on the downstream side of the DPF 214. The other end of the LPLEGR pipe 320 is connected to the intake pipe 207 on the upstream side of the throttle valve 208, and a part of the exhaust is recirculated to the intake system as EGR gas.

  The LPLEGR pipe 320 is provided with an LPLEGR cooler 7. The LPLEGR cooler 7 is an EGR gas cooling device provided in the LPLEGR pipe 320. A water jacket in which cooling water is sealed is stretched around and heat exchange with the cooling water is performed to remove EGR gas. It is configured to be coolable.

  Furthermore, an LPLEGR valve 330 is provided on the downstream side of the LPLEGR cooler 7 in the LPLEGR pipe 320. The LPLEGR valve 330 is an electromagnetically driven valve, and the opening degree of the valve changes continuously by energizing the solenoid through the ECU 15. The flow rate of the EGR gas flowing through the LPLEGR pipe 320, that is, the EGR amount continuously changes in accordance with the differential pressure between the intake pipe 207 and the exhaust pipe 213 and the valve opening degree. The LPLEGR pipe 320, the LPLEGR cooler 7, and the LPLEGR valve 330 constitute an LPLEGR device 30.

  On the other hand, one end of an HPLEGR pipe 720 made of a metal material is connected to the exhaust pipe 213 on the upstream side of the DPF 214. The other end of the HPLEGR pipe 720 is connected to the intake port 209 on the downstream side of the throttle valve 208, and a part of the exhaust is recirculated to the intake system as EGR gas.

  The HPLEGR pipe 720 is provided with an HPLEGR valve 9. The HPLEGR valve 9 is an electromagnetically driven valve, and the opening degree of the valve changes continuously by energizing the solenoid through the ECU 15. The flow rate of EGR gas flowing through the HPLEGR pipe 320, that is, the EGR amount continuously changes in accordance with the differential pressure between the intake port 209 and the exhaust pipe 213 and the valve opening. The HPLEGR pipe 720 and the HPLEGR valve 9 constitute an HPLEGR device 70.

  Returning to FIG. 1, each component of the cooling system 100 will be described again.

  The cooling water control valve 3 is a rotary valve device capable of switching the cooling water flow path according to each mode described later. The cooling water control valve 3 includes an input port which is an input side interface of cooling water connected to the cooling water channel CCVi and three output ports which are output side interfaces of cooling water connected to the cooling water channels CCVo1 to CCVo3. Have.

  Here, the cylindrical aggregation part which connects an input port and each output port accommodates the cylindrical resin valve which can rotate in one direction in the said aggregation part. A plurality of notches corresponding to each output port are formed in the side surface portion of this resin valve, and the communication area between each notch and each output port is the rotation angle of the resin valve. It changes continuously according to the CCV rotation angle “Accv”. When the resin valve makes one round, that is, when the CCV rotation angle Accv reaches 360 °, the state of the cooling water control valve 3 returns to the previous state. The CCV rotation angle Accv is controlled based on a control signal S3 transmitted from the ECU 15.

  The cooling water channel CCVi is a cooling water channel including a water jacket (not shown) that sequentially passes through the cylinder block 22 and the cylinder head 21. The cooling water channel CCVi is connected to the input port of the cooling water control valve 3.

  The cooling water channel CCVo1 is a cooling water channel that is connected to the first output port of the cooling water control valve 3 and includes a water jacket (not shown) that passes through the LPLEGR cooler 7 and the heater 8. Cooling water channel CCV1 is connected to cooling water channel WPi at connection point “P1”.

  The cooling water channel CCVo2 is connected to the second output port of the cooling water control valve 3. The cooling water channel CCVo2 branches into the cooling water channel for cooling the HPLEGR valve 9 described above and the cooling water channel for cooling the oil cooler 10, and the cooling water channel branched downstream of the HPLEGR valve 9 and the oil cooler 10 is again connected. Join. The cooling water channel CCVo2 is connected to the cooling water channel WPi at the connection point “P2”.

The cooling water channel CCVo3 is a cooling water channel connected to the third output port of the cooling water control valve 3.
The cooling water channel CCVo 3 is connected to the thermostat 6 via the radiator 11.

  The cooling water channel WPi is a cooling water channel connected to the input side port of the electric W / P4. The cooling water channel WPo is a cooling water channel connected to a port on the output side of the electric W / P4. The cooling water channel WPo is connected to the cooling water channel CCVi.

  The electric W / P4 is a known electric drive type centrifugal pump. The electric W / P4 sucks the cooling water input from the cooling water passage WPi through the input port by the rotational force of the motor (not shown), and cools the cooling water in an amount corresponding to the motor rotation speed through the output port. Supply to waterway WPo. As described above, the electric W / P 4 adjusts the flow rate of the cooling water based on the control signal S4 supplied from the ECU 15.

  The water temperature sensor 5 is a sensor that detects the temperature of the cooling water. The water temperature sensor 5 is installed in the cooling water channel CCVi between the cylinder head 21 and the cooling water control valve 3. The water temperature sensor 5 transmits a detection signal S5 indicating the detected cooling water temperature (also referred to as “water temperature sensor value Tsr”) to the ECU 15.

  The thermostat 6 is a known temperature regulating valve configured to open at a preset temperature (for example, about 80 degrees Celsius). The thermostat 6 is connected to the cooling water channel CCVo1.

  The heater 8 is a known heating device that supplies air heated by heat exchange with cooling water into the vehicle. The oil cooler 10 cools the engine 2 by filling the inside of the thin tube with the lubricating oil and connecting the oil jacket of the engine 2 filled with the lubricating oil to circulate the lubricating oil.

  The ECU 15 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown), and controls various components of the cooling system 100 based on each received detection signal. I do.

  For example, the ECU 15 determines that the engine 2 is in the cold start period when the coolant temperature is lower than the temperature at which it is determined that the engine 2 has been warmed up (also referred to as “warm-up completion temperature”). In principle, the cooling water control valve 3 is controlled so as to stop the flow of the cooling water. Thereby, ECU15 improves a fuel consumption. On the other hand, even if the coolant temperature is lower than the warm-up completion temperature, the ECU 15 allows the coolant to flow when a predetermined water flow condition is satisfied. The water flow conditions will be described in the [Water Route Pattern] section.

  In the cold start period of the engine 2, the ECU 15 performs control (also referred to as “cold correction control”) for correcting the control amount of the engine 2 based on the coolant temperature. Specifically, in this case, the ECU 15 causes the fuel injection amount, fuel injection timing, fuel injection interval, rail pressure, supercharging pressure, intake air amount, EGR ratio in the LPLEGR passage 320 (also referred to as “LPLEGR ratio”), and the like. The control amount of the engine 2 (also simply referred to as “engine control amount Vc”) is corrected.

  The water temperature sensor 5 and the ECU 15 function as “cooling water temperature acquisition means” in the present invention. Further, the cooling water control valve 3, the electric W / P 4, the thermostat 6, and the ECU 15 function as “cooling water adjusting means” in the present invention. The ECU 15 functions as a “control amount determining unit” in the present invention.

  The configuration in FIG. 1 is an example, and the configuration to which the present invention is applicable is not necessarily limited to this. For example, the cooling system 100 may include a cooling water channel that passes through the cylinder head 21 and a cooling water channel that passes through the cylinder block 22. Further, the mounting position of the cooling water control valve 3 is not limited to the position shown in FIG. 1, and may be mounted between the electric W / P 4 and the engine 2, for example.

[Water flow pattern]
Next, a cooling water flow path pattern based on the state of the cooling water control valve 3 will be described. The cooling water flow path is different for each of the four modes M0 to M4 corresponding to the CCV rotation angle Accv of the cooling water control valve 3. The cooling water control valve 3 circulates and supplies the cooling water sealed in the cooling water channel in the cooling water channel selected as appropriate, so that the engine 2, the LPLEGR cooler 7, the heater 8, and the HPLEGR valve 9 are cooled. And the oil cooler 10 is cooled.

  FIG. 3 is a diagram illustrating the relationship between the CCV rotation angle Accv and the opening degree of each of the cooling water channels CCVo1 to CCVo3. In FIG. 3, the graph “Go1” indicates the opening degree of the cooling water channel CCVo1, the graph “Go2” indicates the opening degree of the cooling water channel CCVo2, and the graph “Go3” indicates the opening degree of the cooling water channel CCVo3. The opening degree of the cooling water channel is equivalent to the communication area between the input port and the output port, which is changed by the action of the notch of the resin valve described above, and the standard is defined as 100% when the communication area is maximum. It is a converted value. That is, the case where the opening degree of the cooling water channel is 0% means that the cooling water channel is closed and the cooling water flow is stopped.

  Here, when the CCV rotation angle Accv is 0 to “A1” (A1> 0), the state of the cooling water control valve 3 becomes the mode M0, and all the cooling water channels CCVo1 to CCVo3 are closed. Next, when the CCV rotation angle Accv is A1 to “A2” (A2> A1), the state of the cooling water control valve 3 becomes the mode M1, and only the cooling water channel CCVo1 is opened. Further, when the CCV rotation angle Accv is A2 to “A3” (A2> A3), the state of the cooling water control valve 3 becomes the mode M2, and the cooling water channel CCVo2 is opened in addition to the cooling water channel CCVo1. And when CCV rotation angle Accv is A3- "A4" (A4> A3), the mode of the cooling water control valve 3 becomes mode M3, and all the cooling water channels CCVo1 to CCVo3 are opened. The period in which the CCV rotation angle Accv is A4 to “A5” (360 °> A5> A4) is a period in which each cooling water passage is shifted to a closed state. Moreover, in the period when the CCV rotation angle Accv is A5 to 360 ° (0 °), the mode of the cooling water control valve 3 is the mode M0.

  Therefore, the ECU 15 controls the mode of the cooling water control valve 3 based on the cooling water temperature, thereby stopping the water flow of the cooling water and improving the fuel consumption when the engine 2 is cold started. . For example, the ECU 15 first sets the CCV rotation angle Accv to be equal to or less than the angle A1 from the start of the engine 2 at which the cooling water temperature is lower than the warm-up completion temperature to a predetermined time (for example, 200 seconds) to all the cooling water channels CCVo1 to CCVo3. After the predetermined time has elapsed, the CCV rotation angle Accv is set to an intermediate angle between the angle A1 and the angle A2, and only a small amount of water is passed through the cooling water channel CCVo1. Then, the ECU 15 sets the CCV rotation angle Accv from the angle A3 to the angle A4 when a predetermined time (for example, 800 seconds) has elapsed since the engine 2 is started, and allows all the cooling water channels CCVo1 to CCVo3 to flow.

  Moreover, even if the cooling water temperature is lower than the warm-up completion temperature, the ECU 15 allows the cooling water channel CCVo1 to flow when predetermined water flow conditions are satisfied. Here, the water flow condition is established when there is a request for cooling the EGR cooler 7 or other heat source, and is established, for example, when the cooling water temperature is equal to or higher than the exhaust dew point temperature. Here, the exhaust dew point temperature is set as a temperature value in which condensed water is generated from the EGR gas in the LPLEGR pipe 320 in a temperature region lower than that (regardless of whether or not it actually occurs). In this way, the cooling water in the temperature region equal to or higher than the exhaust dew point temperature is supplied to the cooling water channel CCVo1, so that warming up of the LPLEGR cooler 7 is promoted, and the temperature of the EGR gas near the LPLEGR cooler 7 is higher than the exhaust dew point temperature. Maintained. Therefore, the ECU 15 can suppress corrosion or the like in the LPLEGR device 30 by changing the state of the cooling water control valve 3 to any of modes M1 to M3 when the cooling water temperature becomes the exhaust dew point temperature.

[Cold correction control]
Next, cold correction control executed by the ECU 15 in the first embodiment will be described. Schematically, when the ECU 15 performs the cold correction control and the cooling water flow is stopped, the ECU 15 controls the engine control amount Vc based on a value obtained by correcting the estimated value of the cooling water temperature to the high temperature side. Correct. Thus, the ECU 15 suppresses overcorrection of the engine control amount Vc at the time of cold start, and suppresses emission deterioration. Hereinafter, the estimated value of the cooling water temperature when the cooling water flow is stopped is referred to as “estimated water temperature Tes”, and the corrected value of the estimated water temperature Tes is also referred to as “corrected water temperature Tam”.

  Here, the reason why the cold correction control is performed based on the corrected water temperature Tam obtained by correcting the estimated water temperature Tes will be described with reference to FIGS. 4 and 5.

  FIG. 4 is a graph showing the change over time of the actual measured value of the cooling water temperature after the cold start. Specifically, the graph “Ghstp” indicates the time change of the water temperature in the water jacket of the cylinder head 21 when the coolant flow is stopped. The graph “Gbnml” shows the time change of the water temperature in the water jacket of the cylinder block 22 when the cooling water flows. The graph “Gbstp” shows the time change of the water temperature in the water jacket of the cylinder block 22 when the cooling water flow is stopped.

  As shown in FIG. 4, the water temperature in the water jacket of the cylinder block 22 (refer to the graph Gbstp) when the cooling water flow is stopped during a certain period after the cold start is the cylinder block 22 when the cooling water is flowing. It becomes lower than the water temperature in the water jacket (see graph Gbnml). In general, when the cooling water is passed, the heat transfer efficiency from the engine 2 to the cooling water is high, so that the heat of the bore wall surface is taken and the cooling water temperature rises according to the load of the engine 2. On the other hand, when the cooling water flow is stopped, the heat transfer efficiency from the engine 2 to the cooling water is low, so the responsiveness to the load of the engine 2 is deteriorated, and the cooling water temperature is hardly increased. Therefore, based on the difference in responsiveness to the load of the engine 2, the temperature difference of the cooling water temperature described above occurs. Therefore, in this case, if the ECU 15 performs the cold correction control using the cooling water temperature as an index representing the state of the bore wall temperature, the ECU 15 cannot appropriately correct the engine control amount Vc. This will be described in more detail with reference to FIG.

  FIG. 5 is a diagram showing the positional relationship between the bore wall and the position where the water temperature sensor 5 is installed (also referred to as “water temperature measurement position”) and the temperature at each position. In FIG. 5, the position closer to the inner wall position of the bore wall is indicated as the position is closer to the left side. In FIG. 5, the plot point “Pnml1” indicates the temperature of the bore wall (bore wall temperature) when cooling water flows, and the plot point “Pnml2” indicates cooling at the water temperature measurement position when cooling water flows. Indicates water temperature. The plot point “Pstp1” indicates the bore wall temperature when the cooling water flow is stopped, and the plot point “Pstp2” indicates the cooling water temperature at the water temperature measurement position when the cooling water flow is stopped, that is, the estimated water temperature Tes. Indicates the ideal value. The plot point “Pstp3” represents the corrected water temperature Tam.

  As shown in FIG. 5, when the cooling water flow is stopped, the cooling water temperature (see the plot point Pstp2) at the water temperature measurement position is low even though the bore wall temperature (see the plot point Pstp1) is high. As described with reference to FIG. 4, this is because the cooling water does not move when the cooling water flow is stopped, and the heat transfer efficiency from the bore to the cooling water at the water temperature measurement position is poor. Therefore, the ECU 15 overcorrects the engine control amount Vc when performing cold correction control based on the estimated water temperature Tes corresponding to the plot point Pstp2 at the time of cold start, resulting in emission deterioration and fuel consumption deterioration. It will be.

  Considering the above, in the first embodiment, when the cooling water flow is stopped, the ECU 15 accurately sets the cooling water temperature at the water temperature measurement position (see the plot point Pstp2) to the value corresponding to the bore wall temperature. Cold correction control is performed using the corrected water temperature Tam (see the plot point Pstp3). At this time, the ECU 15 performs heat transfer efficiency (also referred to as “first heat transfer efficiency”) from the bore wall at the time of water flow to the cooling water at the water temperature measurement position, and the water temperature measurement position from the bore wall temperature at the time of water flow stop. The correction amount of the estimated water temperature Tes is determined based on the difference from the heat transfer efficiency to the cooling water (also referred to as “second heat transfer efficiency”). Specifically, the ECU 15 determines the difference between the bore wall temperature when the water flow is stopped and the water flow time (that is, the temperature difference between the plot point Pstp1 and the plot point Pnml1), and the cooling water temperature when the water flow is stopped and when the water flow is stopped. The corrected water temperature Tam is determined so that the difference (that is, the temperature difference between the plot point Pstp2 and the plot point Pstp3) becomes equal. In other words, the ECU 15 indicates the line “Lnml” indicating the temperature transition from the bore wall temperature during water flow to the cooling water temperature at the water temperature measurement position, and the temperature from the bore wall temperature during water flow to the cooling water temperature at the water temperature measurement position. The corrected water temperature Tam is determined so that the line “Lstp” indicating the transition is parallel.

  By doing in this way, ECU15 can suppress overcorrection of engine control amount Vc by cold correction control. In this case, since the ECU 15 can execute the cold correction control based on the cooling water temperature as in the conventional case, the map for determining the correction amount of the engine control amount Vc shown in FIGS. 7 and 8 to be described later. It is not necessary to create and maintain a new etc., and the number of matching man-hours can be reduced.

  Next, specific processing of the cold correction control in the first embodiment will be described with reference to FIGS.

  FIG. 6 is a flowchart showing a processing procedure of cold correction control executed by the ECU 15 during the cold start period. The ECU 15 repeatedly executes the process of the flowchart shown in FIG. 6 according to a predetermined cycle during the cold start period of the engine 2. As described above, the ECU 15 stops the water flow through the cooling channel in principle during the cold start period, and when there is a cooling request for a heat source such as the LPLEGR cooler 7, the ECU 15 is in the cold start period. Also, the cooling water channel shall be made to flow.

  First, the ECU 15 determines whether or not the coolant flow rate is equal to or less than a predetermined threshold (step S101). Specifically, the ECU 15 determines whether or not the current cooling water flow rate is a cooling water flow rate at which the heat transfer efficiency is reduced in the same manner as when the water flow is stopped. For example, in this case, the ECU 15 determines that the coolant flow rate is equal to or less than a predetermined threshold when the CCV rotation angle Accv is in a predetermined angle range, for example, an angle range corresponding to the mode MO.

  When the ECU 15 determines that the cooling water flow rate is equal to or lower than the predetermined threshold (step S101; Yes), it is assumed that water flow to the cooling water channel is stopped, and the corrected water temperature that corrects the estimated water temperature Tes. Tam is calculated (step S102). Specifically, first, the ECU 15 calculates the estimated water temperature Tes based on the water temperature sensor value Tsr detected by the water temperature sensor 5. For example, the ECU 15 receives the cooling water heat amount calculated from the load of the engine 2 based on the fuel injection amount with respect to the water temperature sensor value Tsr detected by the water temperature sensor 5 in the water flow state immediately before stopping the cooling water flow. The estimated water temperature Tes is a value obtained by adding the temperature corresponding to the above and the temperature corresponding to the heat radiation amount of the engine 2 calculated from the vehicle speed and the outside air temperature. Then, the ECU 15 calculates the corrected water temperature Tam by adding a predetermined temperature to the calculated estimated water temperature Tes. As described in the explanation of FIG. 5, the above-mentioned predetermined temperature includes the first heat transfer efficiency from the bore wall during water flow to the cooling water at the water temperature measurement position, and the water temperature measurement position from the bore wall when water flow is stopped. Taking into account the difference with the second heat transfer efficiency up to the cooling water, it is determined in advance based on experiments and the like.

  Then, the ECU 15 performs cold correction control based on the corrected water temperature Tam (step S103). In this way, the ECU 15 performs cold correction control based on the corrected water temperature Tam according to the bore wall temperature, thereby suppressing emission deterioration and improving fuel efficiency without over-correcting the engine control amount Vc. Can be made.

  On the other hand, when the ECU 15 determines that the cooling water flow rate is not equal to or less than the predetermined threshold (step S101; No), the ECU 15 performs cold correction control based on the water temperature sensor value Tsr (step S104). That is, in this case, the ECU 15 has sufficient heat transfer efficiency between the bore wall and the cooling water due to the flow of the cooling water, and the water temperature sensor value Tsr is a value corresponding to the bore wall temperature. And cold correction control is performed based on the water temperature sensor value Tsr. Thereby, ECU15 suppresses emission deterioration and improves fuel consumption.

  Next, a method for determining the engine control amount Vc to be corrected in the cold correction control in steps S103 and S104 will be described. Schematically, the ECU 15 refers to maps shown in FIGS. 7 and 8 to be described later, and calculates a correction amount for the engine control amount Vc based on each operation condition of the engine 2.

  FIG. 7A shows an example of a map of the correction amount (mg / hub) of the intake air amount with respect to the engine speed Ne and the fuel injection amount when the cooling water temperature in the cold correction control is 48 ° C. b) shows an example of a map of the correction amount (mg / hub) of the intake air amount with respect to the engine speed Ne and the fuel injection amount when the coolant temperature is 50 ° C. FIG. 8A shows an example of a map of the correction amount (%) of the LPLEGR ratio with respect to the engine speed Ne and the fuel injection amount when the cooling water temperature is 48 ° C., and FIG. 8B shows the cooling water temperature. An example of the map of the correction amount (%) of the LPLEGR ratio with respect to the engine speed Ne and the fuel injection amount when is 50 ° C. is shown. 7A and 7B, the intake air amount correction amount map is such that the intake air amount increases as the cooling water temperature decreases from the viewpoint of preventing misfire when the cooling water temperature is low. Is set.

  Here, if the estimated water temperature Tes is 48 ° C. and the corrected water temperature Tam is 50 ° C. during the cold start period when cooling water flow is stopped, the ECU 15 refers to the map shown in FIG. Then, the correction amount of the intake air amount is determined, and the correction amount of the LPLEGR ratio is determined with reference to the map shown in FIG. That is, in this case, the ECU 15 compares the intake air amount and the correction amount of the LPLEGR ratio with reference to the maps shown in FIGS. 7 (a) and 8 (a) based on the estimated water temperature Tes. The amount of air is reduced, the amount of EGR in the LPLEGR pipe 320 is increased, and the LPLEGR ratio is increased. Thereby, ECU15 can reduce discharge | emission of NOx.

  Next, as a comparative example with respect to the first embodiment, the NOx emission amount when the cold correction control is performed based on the estimated water temperature Tes when the water flow is stopped during the cold start period will be described with reference to FIG.

  FIG. 9A shows a graph of the temporal change in the NOx emission amount during the cold start period from the start of the engine 2 to 300 seconds. Specifically, the graph “Ges1” indicates a temporal change in the NOx emission amount when the cold correction control is performed based on the estimated water temperature Tes, and the graph “Gsr1” is the cold correction control based on the water temperature sensor value Tsr. Shows the change over time in the amount of NOx emissions when the above is performed. FIG. 9B shows a bar graph “Ges2” indicating the NOx emission amount when the cold correction control is performed based on the estimated water temperature Tes and the cold temperature based on the water temperature sensor value Tsr in the cold start period described above. A bar graph “Gsr2” indicating the NOx emission amount when the correction control is performed is shown.

  As shown in the frame 90 of FIG. 9A and FIG. 9B, when the cold correction control is performed based on the estimated water temperature Tes when the water flow is stopped during the cold start period, the water temperature sensor value Tsr Compared with the case where the cold correction control is performed based on this, the NOx emission amount is increased. That is, when the cold correction control is performed based on the estimated water temperature Tes, the engine control amount Vc is overcorrected, and the emission is deteriorated.

  Moreover, as shown in the frame 91 of FIG. 9A, either of the case where the cold correction control is performed based on the estimated water temperature Tes and the case where the cold correction control is performed based on the water temperature sensor value Tsr. However, there is a period in which the NOx emission amount increases.

  On the other hand, in the first embodiment, the ECU 15 performs the cold correction control based on the corrected water temperature Tam in accordance with the actual state of the engine 2, thereby suppressing overcorrection of the engine control amount Vc and NOx emission. The amount can be reduced.

Second Embodiment
In the second embodiment, the ECU 15 performs cold correction control based on the estimated water temperature Tes instead of the cold correction control based on the corrected water temperature Tam according to the first embodiment within a predetermined period from the start of the engine 1. Thereby, ECU15 suppresses generation | occurrence | production of misfire etc. more reliably.

  This will be described with reference to FIG. FIG. 10 shows the change over time in the bore wall temperature during the cold start period from the start of the engine 2 to 400 seconds. In FIG. 10, a graph “Gstp” indicates a temporal change in the bore wall temperature when the cooling water flow is stopped, and a graph “Gnml” indicates a temporal change in the bore wall temperature when the cooling water is passed.

  As shown in FIG. 10, the bore wall temperature (that is, the combustion chamber temperature) at the time when the cooling water flow is stopped, from 0 second to about 80 seconds from the start of the engine 2, which is a period immediately after the start of the engine 2, There is almost no difference from the bore wall temperature during cooling water flow. Thus, immediately after the engine 2 is started, due to the heat capacity of the engine 2, there is a period in which there is almost no difference between the bore wall temperature when the water flow is stopped and the bore wall temperature when the water is passed. Therefore, during this period, the ECU 15 may overcorrect the engine control amount Vc when the cold start control is performed based on the corrected water temperature Tam higher than the estimated water temperature Tes.

  Considering the above, in the second embodiment, the ECU 15 has an elapsed time width (also referred to as “elapsed time width Tw”) from the start of the engine 2 equal to or less than a predetermined threshold value (also referred to as “threshold value Twth”). In the period, cold correction control is performed based on the estimated water temperature Tes. The above-mentioned threshold value Twth is based on, for example, an upper limit value of the elapsed time width Tw in which there is almost no difference between the bore wall temperature when the cooling water flow is stopped and the bore wall temperature when the cooling water is flowing. Predetermined. Thereby, ECU15 can implement cold correction control suitably based on a suitable cooling water temperature, and can control generation | occurrence | production of misfire etc., just after the engine 2 starts.

  FIG. 11 is a flowchart showing a cold correction control processing procedure executed by the ECU 15 based on the second embodiment at the time of cold start. The ECU 15 repeatedly executes the processing of the flowchart shown in FIG. 11 according to a predetermined period during the cold start period of the engine 2.

  First, the ECU 15 determines whether or not the coolant flow rate is equal to or less than a predetermined threshold (step S201). If the cooling water flow rate is equal to or lower than the predetermined threshold (step S201; Yes), the ECU 15 regards the cooling water flow as stopped and executes the process of step S202. On the other hand, when the cooling water flow rate is larger than the predetermined threshold (step S201; No), the ECU 15 performs cold correction control based on the water temperature sensor value Tsr (step S205). That is, in this case, the ECU 15 has sufficient heat transfer efficiency between the bore wall and the cooling water due to the circulation of the cooling water, and the water temperature sensor value Tsr is a value corresponding to the bore wall temperature. Judgment is made and cold correction control is performed based on the water temperature sensor value Tsr. Thereby, ECU15 suppresses emission deterioration and improves fuel consumption.

  Next, in step S202, the ECU 15 determines whether or not an elapsed time width Tw after the cold start of the engine 2 is larger than a threshold value Twth (step S202). When the elapsed time width Tw is larger than the threshold value Twth (step S202; Yes), the ECU 15 calculates a corrected water temperature Tam obtained by correcting the estimated water temperature Tes (step S203), and cold correction is performed based on the corrected water temperature Tam. Control is performed (step S204). That is, in this case, the ECU 15 determines that the bore wall temperature when the water flow is stopped is higher than the bore wall temperature during the water flow, and performs cold correction control based on the corrected water temperature Tam. Thereby, ECU15 can correct | amend engine control amount Vc appropriately according to the actual state of the engine 2, and can implement | achieve suppression of an emission deterioration, improvement in a fuel consumption, etc.

  On the other hand, when the elapsed time width Tw is equal to or smaller than the threshold value Twth (step S202; No), the ECU 15 performs cold correction control based on the estimated water temperature Tes (step S206). That is, in this case, the ECU 15 determines that the difference between the bore wall temperature at the time of stopping water flow and the bore wall temperature at the time of water passage does not occur, and performs cold correction control based on the estimated water temperature Tes. Thereby, even immediately after the cold start, the ECU 15 can appropriately set the engine control amount Vc, and can realize suppression of deterioration of the emission of the engine 2 and improvement of fuel consumption.

<Third Embodiment>
In the third embodiment, in addition to the processing of the second embodiment, the ECU 15 dynamically sets the threshold value Twth according to the operating conditions of the engine 2. Thereby, ECU15 sets exactly the period which performs cold correction | amendment control based on estimated water temperature Tes.

  In general, depending on the operating conditions of the engine 2, the width of the period after the start of the engine 2 in which there is no difference between the bore wall temperature when the cooling water flow is stopped and the bore wall temperature when the cooling water is flowing varies. . In consideration of the above, the ECU 15 determines the threshold temperature Twth according to the operating conditions of the engine 2, thereby more appropriately determining the cooling water temperature used for the cold correction control, and realizing suppression of emission deterioration and improvement of fuel consumption. Can do. For example, the ECU 15 estimates the heat generation amount of the engine 2 from the operation conditions of the engine 2 recognized based on the detection signals transmitted from various sensors and / or the command value of the engine control amount Vc. Then, the ECU 15 shortens the threshold value Twth as the estimated heat generation amount of the engine 2 is larger.

  FIG. 12 is a flowchart showing a cold correction control processing procedure executed by the ECU 15 based on the third embodiment at the time of cold start. ECU15 repeatedly performs the process of the flowchart shown in FIG. 12 according to a predetermined period at the time of cold start.

  First, the ECU 15 determines whether or not the cooling water flow rate is equal to or less than a predetermined threshold (step S301). If the cooling water flow rate is equal to or lower than the predetermined threshold (step S301; Yes), the ECU 15 regards the cooling water flow as stopped and executes the process of step S302. On the other hand, when the cooling water flow rate is larger than the predetermined threshold (step S301; No), the ECU 15 performs cold correction control based on the water temperature sensor value Tsr as in the first and second embodiments (step S306).

  Next, in step S302, the ECU 15 sets the threshold value Twth based on the operating condition of the engine 2 (step S302). For example, the ECU 15 stores in advance a map of each operating condition of the engine 2 and the threshold value Twth, and determines the threshold value Twth by referring to the map based on the current operating condition of the engine 2.

  Next, the ECU 15 determines whether or not the elapsed time width Tw after the cold start of the engine 2 is larger than the threshold value Twth (step S303). If the elapsed time width Tw is larger than the threshold value Twth (step S303; Yes), the ECU 15 calculates a corrected water temperature Tam obtained by correcting the estimated water temperature Tes (step S304), and cold correction is performed based on the corrected water temperature Tam. Control is performed (step S305). In this case, since the ECU 15 appropriately sets the threshold value Twth based on the operating condition of the engine 2 in step S302, a difference occurs between the bore wall temperature when the water flow is stopped and the bore wall temperature during the water flow. It is possible to execute the processing of step S304 and step S305 by accurately limiting the period.

  On the other hand, when the elapsed time width Tw is equal to or less than the threshold value Twth (step S303; No), the ECU 15 performs cold correction control based on the estimated water temperature Tes (step S307). In this case, since the ECU 15 appropriately sets the threshold value Twth based on the operating condition of the engine 2 in step S302, a difference occurs between the bore wall temperature when the water flow is stopped and the bore wall temperature when the water is flowing. The process of step S307 can be executed with an accuracy limited to a period that is not present.

<Fourth embodiment>
In the fourth embodiment, in addition to the processing of the second embodiment or the third embodiment, the ECU 15 has a stop time (also referred to as “soak time Ts”) from the stop of the engine 2 to a predetermined threshold value (“ Also referred to as “threshold value Tsth”.) In the following cases, cold correction control is performed based on the corrected water temperature Tam regardless of the elapsed time width Tw. As a result, the ECU 15 performs the cooling correction control with higher accuracy.

  Generally, when the soak time Ts is short, the temperature of the engine 2 does not sufficiently decrease, and the engine 2 has heat even immediately after starting. Therefore, in this case, the rise delay of the combustion chamber temperature (that is, the bore wall temperature) due to the heat capacity of the engine 2 is small. Considering the above, in the fourth embodiment, when the soak time Ts is equal to or less than the threshold value Tsth, the ECU 15 determines the bore wall temperature at the time when the cooling water flow is stopped and the cooling water regardless of the elapsed time width Tw. It is determined that there is a difference from the bore wall temperature during water flow, and cold correction control is performed based on the corrected water temperature Tam. The above-described threshold value Tsth is set in advance based on experiments and the like in consideration of the amount of heat remaining in the engine 2 for each soak time Ts. Thereby, the ECU 15 can execute the cooling correction control with higher accuracy.

  FIG. 13 is a flowchart showing a cold correction control processing procedure executed by the ECU 15 based on the fourth embodiment at the time of cold start. ECU15 repeatedly performs the process of the flowchart shown in FIG. 13 according to a predetermined period at the time of cold start.

  First, the ECU 15 determines whether or not the coolant flow rate is equal to or less than a predetermined threshold (step S401). When the cooling water flow rate is equal to or lower than the predetermined threshold (step S401; Yes), the ECU 15 regards the cooling water flow as stopped and executes the process of step S402. On the other hand, when the coolant flow rate is larger than the predetermined threshold (step S401; No), the ECU 15 performs cold correction control based on the water temperature sensor value Tsr, similarly to the first to third embodiments (step S406).

  Next, in step S402, the ECU 15 determines whether or not the soak time Ts is equal to or less than the threshold value Tsth (step S402). If the soak time Ts is equal to or less than the threshold Tsth (step S402; Yes), the ECU 15 advances the process to step S404 regardless of the elapsed time width Tw. That is, in this case, the ECU 15 determines that the bore wall temperature is immediately higher than the bore wall temperature when the cooling water is passed due to the heat remaining before the engine 2 is started, and based on the corrected water temperature Tam. Perform cold correction control.

  On the other hand, when the soak time Ts is larger than the threshold Tsth (step S402; No), the ECU 15 determines whether or not the elapsed time width Tw after the cold start of the engine 2 is larger than the threshold Twth (step S403). When the elapsed time width Tw is larger than the threshold value Twth (step S403; Yes), the ECU 15 calculates a corrected water temperature Tam by correcting the estimated water temperature Tes (step S404), and cold correction is performed based on the corrected water temperature Tam. Control is performed (step S405).

  On the other hand, when the elapsed time width Tw is equal to or less than the threshold value Twth (step S403; No), the ECU 15 performs cold correction control based on the estimated water temperature Tes (step S407). That is, in this case, the ECU 15 determines that the current bore wall temperature does not change from the bore wall temperature during water flow due to the heat capacity of the engine 2, and performs cold correction control based on the estimated water temperature Tes.

<Modification>
Next, modified examples that can be commonly applied to the first to fourth embodiments will be described.

  In the description of FIG. 7, FIG. 8, and the like, the ECU 15 displays a map similar to that at the time of cooling water flow based on the corrected water temperature Tam obtained by correcting the estimated water temperature Tes to the high temperature side when the cooling water flow is stopped. With reference to this, the correction amount of the engine control amount Vc was determined.

  Instead, the ECU 15 may calculate the correction amount of the engine control amount Vc when the cooling water flow is stopped by a different calculation method than when the cooling water is flowing. For example, in this case, the ECU 15 adds the engine control amount for the estimated water temperature Tes used when the cooling water flow is stopped, in addition to the map or calculation formula of the correction amount of the engine control amount Vc for the water temperature sensor value Tsr used when the cooling water flows. It has a map or calculation formula for the correction amount of Vc. The above-described map or calculation formula is created in advance based on experiments or the like so as to be the correction amount of the engine control amount Vc suitable for each water temperature sensor value Tsr or the estimated water temperature Tes. And ECU15 memorize | stores the above-mentioned map etc., When the water flow stop of cooling water, based on the estimated water temperature Tes, with reference to the above-mentioned map or calculation formula used at the time of water flow stop, engine control amount Vc The correction amount can be appropriately determined. That is, in this case, the ECU 15 can appropriately determine the correction amount of the engine control amount Vc without correcting the estimated water temperature Tes.

2 Engine 3 Cooling water control valve (CCV)
4 Electric W / P
5 Water temperature sensor 6 Thermostat 7 LPLEGR cooler 8 Heater 9 HPLEGR valve 10 Oil cooler 11 Radiator 15 ECU
100 engine system

Claims (4)

Engine,
A cooling water channel capable of cooling the engine by passing cooling water;
Cooling water temperature acquisition means for acquiring the water temperature of the cooling water;
A cooling water adjusting means capable of adjusting a flow rate of the cooling water;
A control device for a cooling system having control means for controlling the engine based on the water temperature,
The cooling water adjusting means limits the amount of water flow when the water temperature is lower than a warm-up completion temperature at which it is determined that the engine has been warmed-up,
Wherein, in the period after the water temperature is a predetermined period immediately after the start of the shorter the engine than the period in the A and the period which is less than the warm-up completion temperature has elapsed, at the time of restriction of the through water, based water temperature of the cooling water temperature acquisition means has acquired the value obtained by correcting the high-temperature side, and controls the engine, and, in the the predetermined period, even limiting the time of the passing water quantity, said cooling water temperature acquisition means A control device for a cooling system , wherein the engine is controlled based on the acquired water temperature . 2. The cooling system control device according to claim 1, wherein the control unit sets the predetermined period to be shorter as the amount of heat generated in the bore wall of the engine is larger. When the water flow rate is limited when the water temperature is lower than the warm-up completion temperature and the stop time before starting the engine is less than or equal to a predetermined time, the control means may be within the predetermined period. The control device for a cooling system according to claim 1 or 2 , wherein the engine is controlled based on a value obtained by correcting the water temperature acquired by the cooling water temperature acquisition means to a high temperature side . The control means includes a first heat transfer efficiency from the engine to the cooling water at the acquisition position of the water temperature while releasing the restriction of the water flow rate, and the engine from the engine when the water flow rate is restricted. based on the difference between the second heat transfer efficiency of the the cooling water in the acquisition position of the water temperature, in any one of claims 1 to 3, characterized in that determining the correction amount for correcting the temperature on the high temperature side The control device of the cooling system described.

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