JP2006105105A - Engine cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent overheating of an engine by detecting failure of a flow rate regulating means such as blocking flow of cooling water in a cooling water circulating route. <P>SOLUTION: A cooling device 10 is provided with the cooling water circulation routes 11, 12 of the engine 1, a radiator 13 in the circulation routes 1, 12 and a flow rate control valve 16 regulating cooling water flow rate of the radiator 13. An engine system is provided with a fuel injection valve 51, an electronic throttle 53 and a blower 55 having a function preventing the engine 1 from being heated. An electronic control device 30 fully opens the flow rate control valve 16 to make flow of cooling water in the cooling water circulation routes 11, 12 maximum, when engine outlet water temperature is 100°C or higher and radiator outlet water temperature is 80°C or lower, and increases injection quantity of the fuel injection valve 51 to prevent the engine 1 form being heated and fully closes the electronic throttle 53 and drives the blower 55 at the maximum when engine outlet water temperature does not drop after that. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cooling device that cools an engine by circulating cooling water through a cooling water circulation path including a radiator, and adjusts a cooling water flow rate that passes through the radiator by a flow rate adjusting means to target cooling water temperature. The present invention relates to a cooling device for an engine which is controlled to a water temperature.

  An engine cooling device is mounted on a conventional vehicle or the like. As this type of cooling device, for example, there is a water-cooling type cooling device described in Patent Document 1 below. In this cooling device, cooling water flowing in the holes of the engine block is supplied to the engine. The cooling water flows to the cooler (radiator) through the pipe. The radiator is cooled by running air and a cooling fan. The cooling water cooled by the radiator is returned to the engine via a pipe. A short-circuit pipe is separately provided between the cooling water circulation paths composed of the pipes and the like. Through this short-circuit pipe, the cooling water can be returned directly to the engine without passing through the radiator. A mixing valve is provided in a region where the short-circuit pipe communicates with the pipe connected to the radiator. The mixing valve is adjusted by the control device, so that more or less cooling water flows through the radiator. By adjusting the coolant flow rate in this way, the engine coolant temperature is controlled to be the target coolant temperature.

  In addition, the cooling device is diagnosed for a malfunction in the open state of the mixing valve. At the time of diagnosis, a short circuit of the lead wire of the mixing valve of the mixing valve is detected, but if it is detected that the function of the mixing valve is normal, the cooling is intentionally shut off, that is, the mixing valve is forced By closing the valve, the temperature of the engine can be raised. In this way, when the cooling is shut off, if the temperature does not increase significantly, it can be considered that the mixing valve is in the open state and has failed.

Japanese Patent No. 3345435 (page 3-5, FIG. 1) JP 2003-286843 A (2nd and 5th pages, FIGS. 2 and 4)

  However, although the above-mentioned Patent Document 1 describes the diagnosis when the mixing valve is in a failure state in the open state, there is nothing about the diagnosis when the mixing valve is in a failure state in the closed state. Not listed. For this reason, when the mixing valve has failed in the closed state, for example, when the valve body is stuck in the closed state, or the motor is disconnected with the valve body closed, The cooling water does not flow, and there is an unavoidable concern about overheating of the engine.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to determine a failure of the flow rate adjusting means in a state where the cooling water flow is interrupted with respect to the flow rate adjusting means for adjusting the flow of the cooling water in the cooling water circulation path. It is an object of the present invention to provide an engine cooling device that can prevent engine overheating by detecting the above.

  In order to achieve the above object, an invention according to claim 1 is directed to a cooling water circulation path through which engine cooling water circulates, a radiator provided in the cooling water circulation path, and a flow rate of cooling water passing through the radiator. An engine cooling device comprising a flow rate adjusting means and controlling the flow rate adjusting means so that the engine coolant temperature becomes a target coolant temperature, and is a heating suppression means for suppressing heating of the engine The cooling water temperature after passing through the engine after the cooling water passes through the engine is equal to or higher than a predetermined reference temperature, and the cooling water temperature after passing through the radiator after the cooling water passes through the radiator is lower than a predetermined reference temperature. In some cases, the flow rate adjusting means is controlled to maximize the cooling water flow in the cooling water circulation path, and when the cooling water temperature does not decrease after passing through the engine, And purpose that a control means for controlling the heating suppression means for suppressing the heating.

According to the configuration of the present invention, the engine coolant passes through the radiator while circulating through the coolant circulation path, and the flow rate of the coolant passing through the radiator is adjusted by the flow rate adjusting means. Then, the degree of cooling of the engine is controlled by controlling the flow rate adjusting means so that the engine coolant temperature becomes the target coolant temperature.
Here, when the flow rate adjusting means breaks down in a state where the cooling water flow is interrupted, the cooling water does not flow to the engine via the cooling water circulation path, the engine is not cooled, and the engine may be overheated. At this time, the coolant temperature after passing through the engine becomes high, and the coolant temperature after passing through the radiator becomes low. In the present invention, when the coolant temperature after passing the engine is equal to or higher than the predetermined reference temperature and the coolant temperature after passing the radiator is equal to or lower than the predetermined reference temperature, the coolant flow in the coolant circulation path is maximized. When the flow rate adjusting means is controlled by the control means and the cooling water temperature does not decrease after passing through the engine, the heating suppression means is controlled by the control means. Therefore, when the cooling water temperature does not decrease after passing through the engine even though the flow rate adjusting means is controlled to maximize the cooling water flow, the cooling water does not actually flow through the cooling water circulation path. It can be determined that the adjusting means has failed in a state where the cooling water flow is interrupted, and at this time, heating of the engine is suppressed.

  In order to achieve the above object, according to a second aspect of the present invention, in the configuration of the first aspect of the present invention, the heating suppression means includes a fuel supply device that supplies fuel to the engine, and the control means includes the fuel The purpose is to increase the amount of fuel supplied by the supply device.

  According to the configuration of the invention described above, the cooling water temperature after passing through the engine is equal to or higher than a predetermined reference temperature and the cooling water temperature after passing through the radiator is equal to or lower than a predetermined reference temperature. In some cases, the flow rate adjusting means is controlled by the control means to maximize the cooling water flow in the cooling water circulation path, and when the cooling water temperature does not decrease after passing through the engine, the fuel supply amount by the fuel supply device is increased. . Therefore, when it can be determined that the flow rate adjusting unit is malfunctioning in a state where the coolant flow is cut off, the increase in the fuel suppresses the temperature increase in the combustion chamber and suppresses the heating of the engine.

  In order to achieve the above object, according to a third aspect of the present invention, in the configuration of the first aspect of the present invention, the heating suppression means includes a blower that sends air to the cooling water circulation path, and the control means includes cooling water. The purpose is to drive the blower as much as possible to cool it.

  According to the configuration of the invention described above, the cooling water temperature after passing through the engine is equal to or higher than a predetermined reference temperature and the cooling water temperature after passing through the radiator is equal to or lower than a predetermined reference temperature. In some cases, the flow rate adjusting means is controlled by the control means to maximize the cooling water flow in the cooling water circulation path, and when the cooling water temperature does not drop after passing through the engine, the blower is maximized to cool the cooling water. Driven. Therefore, when it can be determined that the flow rate adjusting means is malfunctioning in a state where the cooling water flow is interrupted, an increase in the cooling water temperature is suppressed and heating of the engine is suppressed.

  In order to achieve the above object, according to a fourth aspect of the present invention, in the configuration of the first aspect of the present invention, the heating suppression means includes an electronic throttle that adjusts the intake air of the engine, and the control means includes the engine The purpose is to close the electronic throttle to reduce the output.

  According to the configuration of the invention described above, the cooling water temperature after passing through the engine is equal to or higher than a predetermined reference temperature and the cooling water temperature after passing through the radiator is equal to or lower than a predetermined reference temperature. In some cases, the flow rate adjusting means is controlled by the control means to maximize the cooling water flow in the cooling water circulation path, and when the cooling water temperature does not decrease after passing through the engine, an electronic throttle is installed to reduce the engine output. Closed. Therefore, when it can be determined that the flow rate adjusting means is malfunctioning in a state where the coolant flow is cut off, combustion in the engine is suppressed and heating to the engine is suppressed.

  In order to achieve the above object, according to a fifth aspect of the present invention, in the configuration of the first aspect of the present invention, the heating suppression means includes an ignition device that ignites fuel supplied to the engine, and the control means includes The purpose is to control the ignition timing by the ignition device in order to reduce the output of the engine. Here, as control of the ignition timing, it is conceivable that the advance of the ignition timing is suppressed or retarded.

  According to the configuration of the invention described above, the cooling water temperature after passing through the engine is equal to or higher than a predetermined reference temperature and the cooling water temperature after passing through the radiator is equal to or lower than a predetermined reference temperature. In some cases, the flow rate adjusting means is controlled by the control means to maximize the cooling water flow in the cooling water circulation path, and when the cooling water temperature does not drop after passing through the engine, the ignition device is used to reduce the engine output. The ignition timing is controlled. Therefore, when it can be determined that the flow rate adjusting means has failed with the cooling water flow cut off, for example, by retarding the ignition timing, the temperature rise in the combustion chamber is suppressed and heating to the engine is suppressed. .

  According to the first aspect of the present invention, the flow rate adjusting means for adjusting the cooling water flow in the cooling water circulation path can detect a failure of the flow rate adjusting means in a state where the cooling water flow is interrupted. Engine overheating can be prevented.

  According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, overheating of the engine can be prevented by controlling the fuel supply device.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 1, overheating of the engine can be prevented by controlling the blower.

  According to the invention described in claim 4, in addition to the effect of the invention described in claim 1, overheating of the engine can be prevented by controlling the electronic throttle.

  According to the invention described in claim 5, in addition to the effect of the invention described in claim 1, overheating of the engine can be prevented by controlling the ignition device.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an engine cooling device according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an engine system in this embodiment. A multi-cylinder engine 1 mounted on a vehicle includes an engine body 2 including a cylinder block and a cylinder head. The engine body 2 is provided with a fuel injection valve 51 and an ignition device (not shown) corresponding to the combustion chamber of each cylinder (cylinder). Each fuel injection valve 51 is provided in a delivery pipe 52. The delivery pipe 52 is supplied with fuel from a fuel tank (not shown) through a fuel line (not shown). Each fuel injection valve 51, delivery pipe 52, fuel line, fuel tank, and the like constitute the fuel supply device of the present invention. This fuel supply device corresponds to the heating suppression means of the present invention. As is well known, the fuel injection valve 51 is composed of an electromagnetic valve, and opens when energized to inject fuel. The fuel supply amount (fuel injection amount) to each combustion chamber can be adjusted by each fuel injection valve 51. By adjusting the fuel injection amount, the output of the engine 1 can be adjusted, and heating of the engine body 2 can be suppressed. The engine body 2 is provided with a piston (not shown) for each cylinder and a crankshaft 3 that is linked to each piston. The engine body 2 is provided with an intake passage 4 for taking air into each combustion chamber. The engine body 2 is provided with an exhaust passage 5 for exhausting exhaust gas from each combustion chamber. An air cleaner 6 and a throttle body 7 are provided in the intake passage 4. The air cleaner 6 cleans the air taken into each combustion chamber through the intake passage 4. The throttle body 7 is provided with a throttle valve 8 that is opened and closed to adjust the amount of air flowing through the intake passage 4 (intake amount), and a motor 9 that drives the valve 8 to open and close. The throttle body 7, the throttle valve 8 and the motor 9 constitute an electronic throttle 53 of the present invention. The electronic throttle 53 opens and closes when the motor 9 is driven by energization. By opening and closing the throttle valve 8, intake to each combustion chamber can be adjusted. By this intake air adjustment, the output of the engine 1 can be adjusted, and heating to the engine body 2 can be suppressed. This electronic throttle 53 corresponds to the heating suppression means of the present invention.

  The fuel injected from each fuel injection valve 51 is supplied to each combustion chamber of the engine body 2. In each combustion chamber, the combustible mixture of fuel and air explodes and burns when the ignition device operates. When the piston operates by receiving this combustion energy, the crankshaft 3 rotates and power is generated in the engine 1. The exhaust gas after combustion generated in each combustion chamber is discharged to the outside through the exhaust passage 5. A part of the combustion energy generated in the engine 1 remains in the engine body 2 as heat. In order to prevent the engine main body 2 from being overheated by this residual heat, the engine 1 is provided with a water-cooled cooling device 10.

  The cooling device 10 includes a water jacket 11 provided in the engine body 2. The inlet 11 a and the outlet 11 b of the water jacket 11 are connected to the radiator 13 through the radiator passage 12. A water pump (W / P) 14 is provided in the vicinity of the inlet 11 a of the water jacket 11. The water pump 14 is drivingly connected to the crankshaft 3 via a pulley, a belt, and the like, and operates in conjunction with the operation of the engine 1. The water pump 14 sucks the cooling water flowing through the radiator passage 12 and discharges it to the water jacket 11. By this cooling water suction / discharge, the cooling water circulates in the clockwise direction indicated by the arrow in FIG. 1 starting from the water pump 14. During this circulation, the cooling water absorbs heat from the engine body 2 and rises in temperature in the process of passing through the water jacket 11. The raised cooling water releases heat in the process of passing through the radiator 13 to lower the temperature.

  A bypass passage 15 that bypasses the radiator 13 is connected to the radiator passage 12. One end of the bypass passage 15 (the right end in FIG. 1) is connected between the radiator 13 and the outlet 11 b of the water jacket 11 in the radiator passage 12. The other end (the left end in FIG. 1) of the bypass passage 15 is connected between the radiator 13 and the water pump 14 in the radiator passage 12. The water jacket 11 and the radiator passage 12 described above constitute a cooling water circulation path in the present invention.

  A flow rate control valve 16 is provided at a connection portion between the other end of the bypass passage 15 and the radiator passage 12. The flow rate control valve 16 is configured with a step motor as a drive source, and adjusts the flow rate of the cooling water flowing through the radiator passage 12 and the bypass passage 15 by controlling the valve opening degree ODV. Here, the flow rate control valve 16 is configured such that the flow rate of cooling water passing through the radiator passage 12 increases as the valve opening degree ODV increases.

  In this embodiment, as the flow control valve 16, for example, a flow control valve having the same structure as the flow control valve disclosed in Japanese Patent Application Laid-Open No. 2003-286843 is applied. FIG. 2 is a graph showing the flow characteristics of the flow control valve 16. In this graph, the horizontal axis represents the number of steps of the step motor corresponding to the valve opening ODV of the flow control valve 16, and the vertical axis represents the cooling water flow rate. There are two coolant flow rates: a “radiator-side flow rate” flowing from the radiator passage 12 to the water pump 14 and a “bypass-side flow rate” flowing from the bypass passage 15 to the water pump 14, which are indicated by a solid line and a broken line, respectively. In this graph, when the number of steps is “0”, the valve opening ODV of the flow control valve 16 is “fully closed”. When the number of steps is “239”, the valve opening degree ODV of the flow control valve 16 is “fully open”. Furthermore, when the number of steps is “25”, both the radiator-side flow rate and the bypass-side flow rate start to increase. As is apparent from this graph, the radiator-side flow rate tends to increase with an increase in the number of steps (opening increase). Further, the bypass flow rate increases and decreases as the number of steps increases (opening increase). In this embodiment, the flow control valve 16 corresponds to the flow rate adjusting means in the present invention.

  The flow rate control valve 16 controls the coolant temperature for cooling the engine body 2 by adjusting the coolant flow rate in the radiator passage 12. That is, by controlling the valve opening degree ODV of the flow control valve 16 to increase the coolant flow rate in the radiator passage 12, the ratio of the coolant water cooled by the radiator 13 out of the coolant water flowing through the engine body 2 is large. Thus, the temperature of the cooling water for cooling the engine body 2 is lowered. Further, by controlling the flow rate control valve 16 to reduce the cooling water flow rate in the radiator passage 12, the ratio of the cooling water cooled by the radiator 13 out of the cooling water flowing through the engine main body 2 is reduced. The temperature of the cooling water for cooling is increased.

  The radiator 13 is provided with a cooling fan 54. The cooling fan 54 is for forcibly supplying cooling air necessary for heat radiation from the radiator 13. The cooling fan 54 includes a motor 54a and a fan 54b that is rotationally driven by the motor 54a. By supplying cooling air to the radiator 13 by the cooling fan 54, the temperature of the cooling water can be lowered, and heating to the engine body 2 can be suppressed. The cooling fan 54 corresponds to the blower of the present invention. This blower corresponds to the heating suppression means of the present invention. The radiator 13 is provided with a radiator outlet water temperature sensor 21 for detecting a cooling water temperature (radiator outlet water temperature T2) after passing through the radiator 13. Here, the radiator outlet water temperature T2 corresponds to the cooling water temperature after passing through the radiator. The engine body 2 is provided with an engine outlet water temperature sensor 22 for detecting the coolant temperature (engine outlet water temperature TO) after passing through the outlet 11 b of the water jacket 11 as the coolant temperature of the engine body 2. Here, the engine outlet water temperature TO corresponds to the coolant temperature after passing through the engine.

  In addition to the bypass passage 15, the cooling device 10 further includes a plurality of heat receiving and radiating circuits provided in the radiator passage 12 so as to bypass the radiator 13. As these heat receiving and radiating circuits, a throttle body hot water circuit 31, an EGR cooler circuit 32, a hot water heating type hot air intake circuit 33, a heater circuit 34, and an oil cooler circuit 35 are provided.

  The throttle body warm water circuit 31 is connected to the throttle body 7, and the throttle body 7 is warmed in the process of cooling water (warm water) flowing through the circuit body 31. As a result, the operation of the throttle valve 8 at the time of extreme cold or the like is stabilized.

  The EGR cooler circuit 32 is connected in series downstream of the throttle body warm water circuit 31. A part of the EGR cooler circuit 32 is provided along the EGR device 36. As is well known, the EGR device 36 reduces the maximum combustion temperature of the combustible mixture by recirculating a part of the exhaust gas to the intake passage 4 in order to reduce nitrogen oxide (NOx) in the exhaust gas. It is. The EGR device 36 includes an EGR passage 37, an EGR valve 38, and an EGR chamber 39. The EGR passage 37 is provided between the exhaust passage 5 and the intake passage 4. The EGR valve 38 is provided in the middle of the EGR passage 37 and is configured to adjust the flow rate of EGR gas flowing through the EGR passage 37. The EGR chamber 39 is provided on the downstream side of the EGR passage 37, and is configured to guide EGR gas evenly to each cylinder. The EGR chamber 39, the EGR valve 38, and the intake passage 4 are cooled by the cooling water flowing through the EGR cooler circuit 32.

  The hot air intake circuit 33 is connected to the air cleaner 6. The circuit 33 includes a heater core (not shown) provided in the vicinity of the air cleaner 6, and air sucked into the intake passage 4 is warmed in the process in which cooling water passes through the heater core.

  The heater circuit 34 is connected to the heater core 40 of the vehicle interior heating device. The cooling water flowing through the heater circuit 34 is guided to the heater core 40 as a heat source, so that the vehicle compartment heating device functions. A blower 55 is provided in the vicinity of the heater core 40. The blower 55 is a blower of an air conditioner and can forcibly supply cooling air necessary for heat radiation from the heater core 40. The blower 55 includes a motor 55a and a fan 55b that is rotationally driven by the motor 55a. By supplying cooling air to the heater core 40 and the like by the blower 55, the temperature of the cooling water can be lowered, and heating to the engine body 2 can be suppressed. The blower 55 corresponds to the blower of the present invention. This blower corresponds to the heating suppression means of the present invention.

  The oil cooler circuit 35 is connected to an oil cooler 41 for cooling the lubricating oil in the lubricating device of the engine 1 and the hydraulic oil (automatic transmission fluid: ATF) in the automatic transmission. When the cooling water flows through the oil cooler 41, the lubricating oil and ATF are quickly cooled at high temperatures. The oil cooler 41 also functions as an oil warmer when the temperature of the lubricating oil or ATF is low.

  The upstream portion of each of the above described heat receiving and radiating circuits is connected to the radiator passage 12 between the outlet 11 b of the water jacket 11 and the radiator 13. The downstream portions of these heat receiving and radiating circuits merge with each other and are connected to the water pump 14. A junction water temperature sensor 23 for detecting the cooling water temperature in the junction 42 as a junction water temperature T3 is provided in the vicinity of the junction 42 of each receiving and radiating circuit. Here, the junction water temperature T3 corresponds to the coolant temperature after passing through each circuit.

  The vehicle is provided with various sensors for detecting the operating state of the engine 1. In other words, the accelerator sensor 24 is provided in the accelerator pedal 43 provided in the driver's seat. The accelerator sensor 24 detects the depression amount (accelerator opening) ACCP of the accelerator pedal 43. A throttle sensor 25 provided in the throttle body 7 detects the opening degree (throttle opening degree) TA of the throttle valve 8. An intake pressure sensor 26 provided in the intake passage 4 downstream of the throttle body 7 detects the intake pressure PM in the intake passage 4. A rotational speed sensor 27 provided corresponding to the crankshaft 3 detects a rotational angle (crank angle) and a rotational speed (engine rotational speed) NE of the crankshaft 3.

  The cooling device 10 controls the valve opening ODV of the flow control valve 16 based on the operating state of the engine 1 in order to control the degree of cooling of the engine 1 according to the operating state of the engine 1, The coolant circulation flow rate in the radiator passage 12 and the bypass passage 15 is adjusted. In order to control this control, the cooling device 10 includes an electronic control unit (ECU) 30. A radiator outlet temperature sensor 21, an engine outlet water temperature sensor 22, a junction water temperature sensor 23, a flow control valve 16, a motor 9, a fuel injection valve 51, a cooling fan 54, and a blower 55 are connected to the ECU 30. In addition, an accelerator sensor 24, a throttle sensor 25, an intake pressure sensor 26, and a rotational speed sensor 27 are connected to the ECU 30 in order to capture the operating state of the engine 1. The ECU 30 is connected to an ignition switch (IGSW) 28. The ignition switch 28 is operated to start and stop the engine 1. In addition, a check lamp 56 is connected to the ECU 30. This check lamp 56 is provided in the instrument panel of the driver's seat. When a failure occurs in the cooling device 10, the check lamp 56 is lit to warn the driver of the failure.

  In this embodiment, the ECU 30 performs cooling water temperature control, and corresponds to warm-up control means in the present invention. As is well known, the ECU 30 includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a backup RAM, an external input circuit, an external output circuit, and the like. The ECU 30 configures a logical operation circuit formed by connecting a CPU, a ROM, a RAM, a backup RAM, an external input circuit, an external output circuit, and the like through a bus. The ROM stores in advance a predetermined control program related to cooling water temperature control and the like. The RAM temporarily stores the calculation result of the CPU. The backup RAM stores data stored in advance. The CPU executes cooling water temperature control and the like according to a predetermined control program based on detection signals from various sensors 21 to 28 inputted via the input circuit.

  Next, the content of the coolant temperature control executed by the ECU 30 will be described with reference to the flowcharts of FIGS. The ECU 30 periodically executes these routines.

  When the processing shifts to this routine, in step 100, the ECU 30 calculates the cooling loss heat quantity QW based on the engine rotational speed NE and the engine load LE obtained from the detected values of the rotational speed sensor 27 and the intake pressure sensor 26. In this calculation, the ECU 30 refers to function data (map) as shown in FIG. This map predetermines the relationship of the cooling loss heat quantity QW to the engine speed NE and the engine load LE. This map is prepared for each value of the engine outlet water temperature TO. In this map, the cooling loss heat quantity QW is small when the engine rotational speed NE is low, and increases as the engine rotational speed NE increases. This is because the higher the engine speed NE is, the more fuel is supplied to the combustion chamber per unit time, and the more heat is generated in the engine body 2, and the more heat is taken away from the engine body 2 by the cooling water. Because it becomes. In this map, the cooling loss heat quantity QW is small when the engine load LE is small, and increases as the engine load LE increases. However, in the region where the engine speed NE is high, the degree of increase in the cooling loss heat quantity QW becomes moderate as the engine load LE increases. This is because, as described above, the amount of fuel supplied per unit time increases due to the increase in the engine rotational speed NE, the temperature of the combustion chamber decreases due to the cooling effect accompanying the increase in the amount of fuel, and the amount of heat taken away from the engine body 2 by the cooling water. This is because of the decrease.

  An engine load factor can be used instead of the engine load LE described above. The engine load factor is a parameter indicating a load ratio with respect to the maximum load. In this case as well, a map according to FIG. 6 can be used.

  The above-described cooling loss heat quantity QW basically depends on the amount of heat generated from the engine body 2, and therefore, the engine load LE is a parameter related to the amount of heat generated from the engine body 2, for example, one combustion cycle. The fuel injection amount, the intake air amount, etc. can be used. The amount of intake air is a parameter indirectly related to the amount of heat generated from the engine body 2 because fuel according to the amount of intake air is injected in fuel injection control separately executed. In addition, as the engine load LE, it is possible to use the intake pressure PM detected by the intake pressure sensor 26, the throttle opening degree TA detected by the throttle sensor 25, etc., but in this case, the correction is made appropriately. It is desirable.

  Next, in step 200, the ECU 30 calculates a coolant flow rate (merging portion flow rate) V3 in the merging portion 42 based on the valve opening ODV of the flow control valve 16 and the engine speed NE. In this calculation, the ECU 30 refers to function data (map) as shown in FIG. This map predetermines the relationship of the junction flow rate V3 with respect to the valve opening degree ODV of the flow rate control valve 16 and the engine rotational speed NE. In this map, in the region where the valve opening degree ODV is small, as the valve opening degree ODV increases, the junction flow rate V3 gradually decreases. In the region where the valve opening degree ODV is medium to large, the junction flow rate V3 is substantially constant regardless of the valve opening degree ODV. Further, the merging portion flow rate V3 is small when the engine speed NE is low and increases as the engine speed NE increases. Here, the junction flow rate V3 corresponds to the coolant flow rate after passing through the circuit. As the above-described valve opening degree ODV, for example, the command opening degree ODC used by the ECU 30 for the flow control valve 16 in the previous control cycle can be applied.

Next, in step 300, the ECU 30 calculates the amount of received and radiated heat Qetc based on the various parameters obtained this time, that is, the merging portion flow rate V3, the merging portion water temperature T3, and the engine outlet water temperature TO. The ECU 30 calculates the amount of received and radiated heat Qetc (the total sum of the amounts of received and radiated heat in each of the circuits 31 to 35) in all the received and radiated circuits according to the following calculation formula (1). In the following calculation formula (1), [C] is a coefficient for converting the temperature into the flow rate, and is determined by, for example, the product of the specific heat of the cooling water and the density.
Qetc = C · V3 · (TO-T3) (1)

Next, in step 400, the ECU 30 calculates the required radiator flow rate V2 based on the various parameters obtained this time, that is, the cooling loss heat quantity QW, the target engine outlet water temperature Tt, the radiator outlet water temperature T2, and the received and radiated heat quantity Qetc. The ECU 30 calculates the flow rate V2 according to the following calculation formula (2). In the following calculation formula (2), “C” is the same coefficient as described above.
V2 = (QW−Qetc) / {C · (Tt−T2)} (2)
Here, the target engine outlet water temperature Tt is determined according to the operating state of the engine 1 and corresponds to the target cooling water temperature in the present invention. For example, when the engine 1 is in the idling operation state, the target engine outlet water temperature Tt is set to a slightly lower temperature (for example, “90 ° C.”) for measures against knocking at the time of start. On the other hand, when the engine 1 is in a partial load (partial) operation state, the target engine outlet water temperature Tt is set to a higher temperature (for example, “100 ° C.”) to reduce friction loss. When the engine 1 is in the full load (WOT) operation state, the target engine outlet water temperature Tt is set to a lower temperature (for example, “80 ° C.”) in order to increase the filling rate. Each value (90 ° C., 100 ° C., 80 ° C.) related to the target engine outlet water temperature Tt is merely an example.

  Next, in step 500, the ECU 30 calculates a command opening degree ODC for the flow rate control valve 16 based on the calculated required radiator flow rate V2 and the engine speed NE. In this calculation, the ECU 30 refers to function data (map) as shown in FIG. This map predetermines the relationship of the command opening degree ODC with respect to the required radiator flow rate V2 and the engine speed NE. In this map, the command opening degree ODC is small when the required radiator flow rate V2 is small, and increases as the required radiator flow rate V2 increases. Further, the command opening degree ODC changes greatly even when the required radiator flow rate V2 slightly changes when the engine speed NE is low. On the other hand, the command opening degree ODC does not change much when the engine speed NE is high unless the required radiator flow rate V2 changes much.

  Next, in step 600, the ECU 30 executes failure diagnosis processing for the flow control valve 16. After that, in step 700, the ECU 30 drives and controls the flow rate control valve 16 based on the command opening degree ODC calculated or set, and then temporarily terminates the subsequent processing. By controlling the flow control valve 16 in this way, when the flow control valve 16 is normal, the flow rate of the cooling water passing through the radiator 13 is adjusted, and the engine outlet water temperature TO converges to the target engine outlet water temperature Tt. It will be.

  Here, the contents of the failure diagnosis process in step 600 will be described in detail according to the flowchart shown in FIG.

  First, in step 601, the ECU 30 detects that the engine outlet water temperature TO detected by the engine outlet water temperature sensor 22 is equal to or higher than “100 ° C.” as a predetermined reference temperature, and the radiator outlet water temperature sensor 21 detects the radiator outlet. It is determined whether or not the water temperature T2 is equal to or lower than “80 ° C.” as a predetermined reference temperature. This determination is based on the assumption that the coolant flow in the water jacket 11 and the radiator passage 12 is stopped. If the determination result is affirmative, the ECU 30 determines that the cooling water flow in the water jacket 11 and the radiator passage 12 is stopped, and the ECU 30 performs step to maximize the cooling water flow in the water jacket 11 and the radiator passage 12. At 602, the command opening degree ODC of the flow control valve 16 is set to “fully open”.

  Next, in step 603, the ECU 30 sets a fully open counter CFO representing the elapsed time since the command opening degree ODC is set to “fully open”. That is, the ECU 30 starts timing by the fully open counter CFO toward a predetermined time.

  Next, at step 604, the ECU 30 determines whether or not the fully open counter CFO has timed up. If the determination result is negative, the ECU 30 proceeds to step 700 because the predetermined time has not elapsed since the command opening degree ODC was fully opened. In this case, the ECU 30 controls to drive the flow control valve 16 based on the command opening degree ODC set to “fully open” in step 700. On the other hand, if the above determination result is affirmative, the ECU 30 resets the fully open counter CFO in step 605 because a predetermined time has elapsed since the command opening degree ODC was fully opened.

  Thereafter, in step 606, the ECU 30 determines whether or not the engine outlet water temperature TO is “100 ° C.” or more and the radiator outlet water temperature T2 is “80 ° C.” or more. This determination assumes that cooling water is flowing in the water jacket 11 and the radiator passage 12. If the determination result is negative, the cooling opening is not flowing through the water jacket 11 and the radiator passage 12 even though the flow control valve 16 is driven and controlled with the command opening ODC set to “fully open”, and the flow control is performed. Assuming that the valve 16 is malfunctioning in a fully closed state or a state close to a fully closed state, that is, for example, the valve body is stuck in a closed state or the step motor is disconnected in a closed state of the valve body. The ECU 30 proceeds to step 620 assuming that a failure such as being present has occurred. In step 620, the ECU 30 executes the “overheat suppression process” of the engine body 2, and then shifts the process to step 700. The contents of the “overheat suppression process” will be described later. On the other hand, when the above determination result is affirmative, the command opening degree ODC is set to “fully open” and the flow control valve 16 is driven and controlled, so that the cooling water sufficiently flows into the water jacket 11 and the radiator passage 12. As a thing, ECU30 transfers a process to step 608. FIG.

  On the other hand, when the determination result in step 601 is negative, the ECU 30 proceeds to step 607 on the assumption that cooling water is flowing in the water jacket 11 and the radiator passage 12. In step 607, the ECU 30 determines whether or not the engine outlet water temperature TO is equal to or higher than “100 ° C.” as a predetermined reference temperature, and the radiator outlet water temperature T2 is equal to or higher than “80 ° C.” as a predetermined reference temperature. Determine whether. This determination is based on the assumption that cooling water is flowing through the water jacket 11 and the radiator passage 12 and that the cooling air needs to be supplied to the radiator 13. If this determination result is affirmative, the ECU 30 proceeds to step 608, assuming that the radiator 13 needs to be supplied with cooling air.

  In step 608 after shifting from step 606 or step 607, the ECU 30 drives the cooling fan 54 in order to supply cooling air to the radiator 13. In step 609, the ECU 30 sets a cooling fan counter CCF that represents an elapsed time since the cooling fan 54 was driven. That is, the ECU 30 starts measuring time by the cooling fan counter 54 toward a predetermined time.

  Next, at step 610, the ECU 30 determines whether the cooling fan counter CCF has timed up or whether the radiator outlet water temperature T2 is equal to or lower than “80 ° C.” which is a predetermined reference temperature. This determination is based on the assumption that the cooling air is sufficiently supplied to the radiator 13 by the cooling fan 54 or that the cooling water sufficiently dissipates heat in the radiator 13. If this determination result is negative, the ECU 30 proceeds to step 700 in order to continue supplying cooling air by the cooling fan 54. On the other hand, if the above determination result is affirmative, the ECU 30 proceeds to step 611 assuming that the cooling water has sufficiently dissipated heat in the radiator 13.

  In step 611, the ECU 30 determines whether or not the engine outlet water temperature TO is equal to or higher than “100 ° C.” as a predetermined reference temperature. If the determination result is affirmative, the ECU 30 determines that the temperature rise of the engine body 2 tends to be excessive, and executes the “overheat suppression process” in step 620, and then shifts the process to step 700. If the determination result is negative, assuming that the engine body 2 is at an appropriate temperature, the ECU 30 resets the full-open counter CFO and the cooling fan counter CCF and stops the cooling fan 54 in step 613. After that, the process proceeds to step 700.

  On the other hand, if the determination result in step 607 is negative, the ECU 30 resets the full-open counter CFO and the cooling fan counter CCF in step 614, and then proceeds to step 700.

  Here, the content of the “overheat suppression process” in step 620 will be described in detail according to the flowchart shown in FIG.

  First, in step 621, the ECU 30 processes the electronic throttle 53 to be fully closed in order to suppress heating of the engine body 2. That is, the ECU 30 drives the motor 9 to fully close the throttle valve 8. Thereby, the amount of intake air supplied to each combustion chamber is reduced, combustion in each combustion chamber is suppressed, and heating to the engine body 2 is suppressed.

  Next, in step 622, the ECU 30 for suppressing heating of the engine main body 2 executes a fuel injection increasing process. That is, the ECU 30 increases the fuel injection amount from each fuel injection valve 51. As a result, the amount of fuel supplied to each combustion chamber increases, the temperature rise in each combustion chamber is suppressed, and heating to the engine body 2 is suppressed.

  Next, in step 623, the ECU 30 for suppressing heating of the engine main body 2 performs a maximum driving process for the blower 55. That is, the ECU 30 rotates the fan 55b to the maximum by the motor 55a of the blower 55, and supplies the cooling air to the heater core 41 and the like to the maximum. Thereby, the cooling water flowing through the heater circuit 34 is cooled, the cooling water flowing through the water jacket 11 and the radiator passage 12 is cooled, the rise in the cooling water temperature is suppressed, and the heating to the engine body 2 is suppressed.

  Next, in step 624, the ECU 30 performs a lighting process on the check lamp 56 in order to warn the driver that the flow rate control valve 16 has failed due to a closed state or the like. Here, the check lamp 56 may be blinked in order to enhance the warning effect.

  Thereafter, in step 625, the flow control valve 16 has failed in a state where the coolant flow in the radiator passage 12 is interrupted, that is, the flow control valve 16 has failed in a closed state or a state close to closing. In order to record this, the ECU 30 writes the failure code in the backup RAM. The written failure code can be read from the ECU 30 and confirmed during vehicle maintenance. As described above, the “overheat suppression process” is executed.

  According to the engine cooling device 10 in this embodiment described above, the cooling water of the engine 1 passes through the radiator 13 while circulating through the water jacket 11 and the radiator passage 12, and the flow rate of cooling water passing through the radiator 13 is as follows. It is adjusted by the flow control valve 16. Then, the degree of cooling of the engine 1 is controlled by controlling the flow rate control valve 16 so that the engine outlet water temperature TO becomes the target engine outlet water temperature Tt.

  Here, when the flow control valve 16 fails in a state where the coolant flow is interrupted, that is, when the flow control valve 16 fails in a closed state or close to a closed state, the water jacket 11 and the radiator passage 12 and the like. The cooling water does not flow to the engine body 12 via the engine, the engine body 2 is not cooled, and the engine body 2 may be overheated. At this time, the engine outlet water temperature TO becomes high, and the radiator outlet water temperature T2 becomes low.

  On the other hand, in the cooling device 10 in this embodiment, when the engine outlet water temperature TO is equal to or higher than “100 ° C.” and the radiator outlet water temperature T2 is equal to or lower than “80 ° C.”, the water jacket 11 and the radiator passage 12 are used. In order to maximize the cooling water flow in the engine, the flow control valve 16 is controlled by the ECU 30 based on the fully-open command opening degree ODC, and thereafter the “overheat suppression process” is executed when the engine outlet water temperature TO does not decrease. The That is, in order to suppress the heating of the engine main body 2, the electronic throttle 53 fully closing process, the fuel injection increasing process, and the blower 55 maximum driving process are executed. Therefore, even when the flow control valve 16 is controlled based on the fully open command opening degree ODC in order to maximize the cooling water flow in the water jacket 11 and the radiator passage 12, the engine outlet water temperature TO does not decrease. Actually, cooling water does not flow through the water jacket 11 and the radiator passage 12, and it is determined that the flow rate control valve 16 is broken in a state where the cooling water flow is interrupted, that is, in a fully closed state or a state close to full closing. At this time, heating to the engine body 2 is suppressed. As a result, the flow control valve 16 that adjusts the cooling water flow in the water jacket 11 and the radiator passage 12 can detect a failure of the flow control valve 16 when the cooling water flow is interrupted. Overheating can be prevented. In particular, in this embodiment, overheating of the engine body 2 can be prevented by controlling each fuel injection valve 51. Further, by controlling the blower 55, overheating of the engine body 2 can be prevented. Furthermore, by controlling the electronic throttle 53, overheating of the engine body 2 can be prevented.

  In this embodiment, since the electronic throttle 53 is fully closed and the fuel injection increasing process is executed in the “overheat suppression process”, the engine 1 is detected when a failure of the flow control valve 16 is detected while the vehicle is running. The output of the vehicle is reduced and the vehicle is decelerated. At the same time, the check lamp 56 is turned on to notify the driver of the failure of the cooling device 10 (flow control valve 16). For this reason, the driver can recognize that a failure has occurred in the cooling device 10 (flow rate control valve 16), and can then retreat the vehicle to the road shoulder or the like.

  In this embodiment, since the failure of the flow control valve 16 can be detected using the engine outlet water temperature sensor 22 and the radiator outlet water temperature sensor 21 provided in the cooling device 10, there is a special case for detecting the failure of the flow control valve 16. There is no need to provide a sensor or the like.

  In addition, in this embodiment, as described above, the engine rotational speed NE and the engine load LE are reflected in the control of the valve opening degree ODV of the flow control valve 16 as the parameters relating to the operating state of the engine 1. For this reason, unlike the case where the valve opening degree ODV of the flow rate control valve 16 is controlled based solely on the temperature of the cooling water, the actual engine outlet water temperature TO is determined based on the engine rotational speed NE and the engine load LE. The target engine outlet water temperature Tt can be controlled. For example, when the engine 1 has a high output, the engine outlet water temperature TO can be lowered to increase the cooling efficiency of each cylinder. Further, when the engine 1 is operated with low fuel consumption, the engine outlet water temperature TO can be increased to improve the combustion efficiency in each cylinder. For this reason, the engine performance can be improved while satisfying the conflicting performances of high output and low fuel consumption.

  In this embodiment, the engine speed NE and the engine load LE are applied as parameters relating to the operating state of the engine 1 in order to calculate the cooling loss heat quantity QW. Thus, by applying the engine rotation speed NE and the engine load LE that influence the heat generation from the engine body 2 as parameters, the cooling loss heat quantity QW can be calculated with high accuracy. Further, since the cooling loss heat quantity QW is calculated based on both the engine rotation speed NE and the engine load LE, the calculation accuracy of the cooling loss heat quantity QW can be improved compared to the case where the engine rotation speed NE or the engine load LE is applied alone. Improvements can be made.

  In this embodiment, the cooling loss heat quantity QW is calculated based on the engine rotational speed NE indicating the operating state of the engine 1 and the engine load LE, and the calculated cooling loss heat quantity QW is reflected in the calculation of the required radiator flow rate V2. . Then, the valve opening degree ODV of the flow rate control valve 16 is controlled based on the calculated required radiator flow rate V2. For this reason, even if the operating state of the engine 1 changes and the cooling loss heat quantity QW changes, the valve opening degree ODV of the flow control valve 16 can be controlled according to the change in the cooling loss heat quantity QW, and the engine outlet The water temperature TO can be controlled to the target engine outlet water temperature Tt with good responsiveness.

  Here, in the case where the valve opening degree of the flow rate control valve is feedback-controlled based only on the deviation (water temperature difference) between the cooling water temperature and the target cooling water temperature, it corresponds to the change in the cooling loss heat quantity QW in the engine body 2. Since this is not possible, it is difficult to obtain good responsiveness regarding control as in this embodiment. For this reason, in this embodiment, the engine outlet water temperature TO can be quickly decreased during the high-power operation of the engine 1 described above, and the engine outlet water temperature TO can be quickly increased during the low fuel consumption operation of the engine 1. It is possible to reduce the control loss that occurs when realizing both high output and low fuel consumption.

  Here, if the command opening degree ODC of the flow control valve 16 is directly calculated from the operating state of the engine 1 and the valve opening degree ODV of the flow control valve 16 is to be controlled based on the calculated command opening degree ODC. When flow control valves having different flow characteristics are used, it is necessary to calculate the command opening degree ODC again for each flow control valve, and the versatility is lacking. In contrast, in this embodiment, the required radiator flow rate V2 with respect to the radiator outlet water temperature T2 is once calculated, and the command opening degree ODC of the flow control valve 16 is calculated based on the calculated required radiator flow rate V2. . For this reason, even when flow control valves having different flow characteristics are used, it is not necessary to newly calculate the command opening degree ODC corresponding to the flow characteristics for each flow control valve.

  By the way, in this embodiment, since the radiator passage 12 is provided with a plurality of heat receiving and radiating circuits (each circuit 31 to 35) so as to bypass the radiator 13, in the process of cooling water passing through each circuit 31 to 35, each part Heat is received and released (received and radiated) between the cooling water and the cooling water. The cooling water after receiving and radiating heat passes through the radiator passage 12 from the junction 42 through the water pump 14 and again passes through the water jacket 11 of the engine body 2. When the amount of heat received and radiated heat Qetc in each circuit 31 to 35 is large, it is difficult to converge the engine outlet water temperature TO to the target engine outlet water temperature Tt unless the received and radiated heat amount Qetc is taken into consideration, and the cooling water temperature is exceeded. There is concern that shooting and undershooting will occur. Here, “overshoot” is a phenomenon in which the target engine outlet water temperature Tt cannot be maintained after the engine outlet water temperature TO reaches the target engine outlet water temperature Tt, and rises. The “undershoot” is a phenomenon in which, after the engine outlet water temperature TO reaches the target engine outlet water temperature Tt, the target engine outlet water temperature Tt cannot be maintained and falls.

  In this way, when many overshoots and undershoots occur in the cooling water temperature, it is necessary to consider the heat resistance of each component such as the engine body 2 to ensure the normal operation of each component. It is necessary to lower Tt. On the other hand, if the target engine outlet water temperature Tt is simply lowered, the engine outlet water temperature TO is lowered, so that friction increases in the engine 1 or the automatic transmission, which may lead to deterioration in fuel consumption of the engine 1.

  On the other hand, in this embodiment, the amount of received and radiated heat Qetc in all the heat receiving and radiating circuits (all of the circuits 31 to 35) is calculated, and the calculated amount of received and radiated heat Qetc is reflected in the calculation of the required radiator flow rate V2. . Therefore, even if the amount of received and radiated heat Qetc in each circuit 31 to 35 changes, the convergence property of the engine outlet water temperature TO with respect to the target engine outlet water temperature Tt is improved. For this reason, overshoot and undershoot in the cooling water temperature control can be reduced, and it is not necessary to lower the target engine outlet water temperature Tt in consideration of the heat resistance related to the components such as the engine body 2. As a result, it is possible to suppress an increase in friction associated with a decrease in the target engine outlet water temperature Tt, and thus a deterioration in fuel consumption of the engine 1.

  In this embodiment, when the water temperature difference between the merging portion water temperature T3 and the engine outlet water temperature TO is small, the amount of received and radiated heat Qetc in each circuit 31 to 35 is small, and conversely, when the water temperature difference is large, each circuit 31 to The amount of heat received and radiated at Q35 is large. Further, when the junction flow rate V3 is small, the amount of received and radiated heat Qetc in each circuit 31 to 35 is small, and when the junction portion flow rate V3 is large, the amount of received and radiated heat Qetc in each circuit 31 to 35 is large. With this point, in this embodiment, the amount of received and radiated heat Qetc in each of the circuits 31 to 35 is calculated based on the merge portion flow rate V3, the merge portion water temperature T3, and the engine outlet water temperature TO. Therefore, since the merging portion flow rate V3, the merging portion water temperature T3, and the engine outlet water temperature TO as parameters that influence the received and radiated heat quantity Qetc as described above are applied to the calculation, the received and radiated heat quantity Qetc can be accurately calculated. . Therefore, the required radiator flow rate V2 can be calculated with high accuracy, and the flow control valve 16 can be controlled with high accuracy.

  In this embodiment, the merging portion flow rate V3 is calculated based on the valve opening degree ODV and the engine rotational speed NE, which are control amounts of the flow rate control valve 16, and accordingly, according to the cooling water flow rate in the cooling water circulation path such as the radiator passage 12. Thus, the amount of received and radiated heat Qetc is calculated more accurately. As a result, the required radiator flow rate V2 can be calculated more accurately, the command opening degree ODC of the flow control valve 16 can be calculated more accurately, and the flow control valve 16 can be controlled more accurately. Can do. Thereby, the engine outlet water temperature TO can be more suitably converged to the target engine outlet water temperature Tt, and the controllability of the cooling water temperature of the engine 1 can be further improved.

  In addition, this invention is not limited to the said embodiment, In the range which does not deviate from the meaning of invention, it can also implement as follows.

  (1) In the above-described embodiment, the electronic throttle fully closing process, the fuel injection increasing process, and the blower maximum drive process are executed as the “overheat suppression process”, but one or two of these processes are executed. It may be. Also in this case, basically, the same effect as that of the above embodiment can be obtained.

  (2) In the above embodiment, the electronic throttle fully closing process, the fuel injection increasing process and the blower maximum drive process are executed as the “overheat suppression process”, but the engine output is reduced instead of these processes. Therefore, the ignition timing by the ignition device may be controlled. Here, as control of the ignition timing, it is conceivable that the advance of the ignition timing is suppressed or retarded. In this case, the ignition device corresponds to the heating suppression means of the present invention, and the ECU that controls the ignition timing corresponds to the control means of the present invention. Accordingly, when it can be determined that the flow rate control valve is malfunctioning in a state where the coolant flow is interrupted (fully closed state or nearly fully closed state), for example, the ignition chamber is retarded to increase the temperature in the combustion chamber. It is suppressed and heating to the engine is suppressed. Thereby, engine overheating can be prevented.

  (3) In the above embodiment, a plurality of circuits, that is, the throttle body hot water circuit 31, the EGR cooler circuit 32, the hot air intake circuit 33, the heater circuit 34, and the oil cooler circuit 35 are provided as the heat receiving and radiating circuits. On the other hand, all these circuits 31 to 35 may not be used as the heat receiving and radiating circuits, and at least one of the circuits 31 to 35 can be provided as the receiving and radiating circuits. Also in this case, basically, the same effect as that of the above embodiment can be obtained.

  (4) In the above-described embodiment, in a cooling device having a plurality of heat receiving / dissipating circuits (all of the circuits 31 to 35), the heat receiving / dissipating heat amount Qetc in these heat receiving / dissipating circuits is calculated and the heat receiving / dissipating heat amount Qetc is calculated as a required radiator. This was reflected in the calculation of the flow rate V2. On the other hand, a cooling device that does not have a heat receiving / dissipating circuit can be embodied in a cooling device that calculates the required radiator flow rate V2 without calculating the amount of heat received and radiated.

The schematic block diagram which shows an engine system. The graph which shows the flow volume characteristic of a flow control valve. The flowchart which shows the content of cooling water temperature control. The flowchart which shows a part of content of cooling water temperature control in detail. The flowchart which shows a part of content of cooling water temperature control in detail. The map which shows the relationship between the engine rotation speed and the cooling loss heat quantity with respect to the engine load. The map which shows the relationship of the valve opening degree and the flow volume of a junction part with respect to an engine speed. A map showing the relationship between the required radiator flow rate and the command opening relative to the engine speed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Engine 10 ... Cooling device 11 ... Water jacket (cooling water circulation path)
12. Radiator passage (cooling water circulation path)
13 ... Radiator 16 ... Flow rate control valve (flow rate adjusting means)
30 ... ECU (control means)
51 ... Fuel injection valve (fuel injection device, heating suppression means)
52 ... Delivery pipe (fuel injection device, heating deterring means)
53 ... Electronic throttle (heating suppression means)
55 ... Blower (blower, heating suppression means)

Claims (5)

A cooling water circulation path through which engine cooling water circulates; a radiator provided in the cooling water circulation path; and a flow rate adjusting means for adjusting a cooling water flow rate passing through the radiator; An engine cooling apparatus configured to control the flow rate adjusting means so as to have a cooling water temperature,
Heating suppression means for suppressing heating of the engine;
The cooling water temperature after passing through the engine after the cooling water passes through the engine is equal to or higher than a predetermined reference temperature, and the cooling water temperature after passing through the radiator after the cooling water passes through the radiator is a predetermined reference temperature. In order to suppress heating to the engine when the flow rate adjusting means is controlled to maximize the cooling water flow in the cooling water circulation path and the cooling water temperature does not decrease after passing through the engine when And a control means for controlling the heating suppression means. 2. The engine cooling apparatus according to claim 1, wherein the heating suppression unit includes a fuel supply device that supplies fuel to the engine, and the control unit increases a fuel supply amount by the fuel supply device. . 2. The engine according to claim 1, wherein the heating suppression unit includes a blower that sends air to the cooling water circulation path, and the control unit drives the blower to the maximum to cool the cooling water. Cooling system. 2. The engine according to claim 1, wherein the heating suppression unit includes an electronic throttle that adjusts intake air of the engine, and the control unit closes the electronic throttle to reduce the output of the engine. Cooling system. The heating suppression means includes an ignition device for igniting fuel supplied to the engine, and the control means controls ignition timing by the ignition device in order to reduce the output of the engine. Item 4. The engine cooling device according to Item 1.

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