JP2015105604A - Control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a deterioration in fuel economy performance in cold start under the condition that outside air temperature is low.SOLUTION: There is provided a control device of an internal combustion engine in which a heat exchanger for exchanging heat between fluid for use in a transmission and cooling water of the internal combustion engine to raise the temperature of the fluid, and a control valve capable of switching whether to cause the cooling water to flow into the heat exchanger, are provided in a cooling water system. The control device sets a target number of revolutions according to the present temperature of the cooling water, sets a target number of revolutions t according to the present temperature of the fluid, employs the higher target number of revolutions between them and cause engine speed to follow the employed target number of revolutions. When outside air temperature is low upon starting the internal combustion engine, the control device opens a control valve earlier as compared with a case where outside air temperature is high to cause the cooling water to flow into the heat exchanger.

Description

  The present invention relates to a control device for an internal combustion engine mounted on a vehicle.

  In recent internal combustion engines for vehicles, the cooling water system is provided with a heat exchanger for exchanging heat between the fluid (so-called ATF or CVTF) used in the transmission and the cooling water. (For example, see the following patent document). This heat exchanger serves to raise the temperature of the fluid early at the time of cold start and reduce mechanical loss (including friction loss) in the transmission.

  A cooling water system including a fluid heat exchanger includes a thermostat for switching whether or not cooling water is allowed to flow into the heat exchanger, and a thermostat for switching whether or not cooling water is allowed to flow into the radiator. Is installed. Usually, the cooling water temperature at which the former thermostat opens is lower than the cooling water temperature at which the latter thermostat opens. Both thermostats are closed immediately after the cold start, but when the cooling water temperature rises above a predetermined temperature, the former thermostat opens and fluid heating begins. When the cooling water temperature becomes high, the latter thermostat is opened, and the radiator and the overheating of the internal combustion engine are suppressed by the radiator.

JP 2002-340161 A

  The target rotational speed of the internal combustion engine (particularly during idle operation) is set according to the current temperature of the cooling water. When the cooling water temperature is relatively low, the target rotational speed is increased to promote warming up of the internal combustion engine and the transmission, while when the cooling water temperature is relatively high, the target rotational speed is decreased to suppress the temperature increase of the internal combustion engine. .

  The same is true for fluid temperature. That is, the target rotational speed is increased when the fluid temperature is relatively low, and the target rotational speed is decreased when the fluid temperature is relatively high.

  When the target rotational speed corresponding to each of the cooling water temperature and the fluid temperature is given, a control with which the higher target rotational speed is adopted and the engine rotational speed follows the target rotational speed is executed.

  Due to the difference between the characteristics of the internal combustion engine and the engine oil used therein and the characteristics of the transmission and the fluid used therein, the target rotational speed based on the coolant temperature and the target rotational speed based on the fluid temperature are different. If the cooling water temperature and the fluid temperature are higher than a certain level, the target rotational speed based on the fluid temperature is lower than the target rotational speed based on the cooling water temperature. On the other hand, when the cooling water temperature and the fluid temperature are low, the target rotational speed based on the fluid temperature is higher than the target rotational speed based on the cooling water temperature.

  At the time of cold start in a situation where the outside air temperature is not low, the cooling water and the fluid are at a certain temperature or more from the beginning, and a target rotational speed mainly based on the cooling water temperature is employed. When the thermostat on the heat exchanger side opens and the cooling water flows into the heat exchanger, the temperature rise of the cooling water becomes moderate, but instead the temperature of the fluid rises and the mechanical loss in the transmission is reduced. As a whole, fuel efficiency is improved.

  However, at the time of cold start under conditions where the outside air temperature is remarkably low, such as in cold districts and winter, the initial cooling water and fluid temperatures are extremely low, so the target speed based mainly on the fluid temperature is adopted. The And since the thermostat on the heat exchanger side remains closed for a while from the start, the cooling water does not flow into the heat exchanger and the fluid is not warmed. As a result, the state where the engine speed is controlled to the high target speed based on the low fluid temperature has continued, and the fuel efficiency has deteriorated.

  The present invention has been made by paying attention to the above-mentioned problem for the first time, and an object of the present invention is to suppress deterioration of fuel consumption performance in cold start under a situation where the outside air temperature is low.

  In the present invention, a heat exchanger that exchanges heat between the fluid used in the transmission and the cooling water of the internal combustion engine to raise the temperature of the fluid, and switching whether or not the cooling water flows into the heat exchanger. A control valve that can be used controls an internal combustion engine provided in the cooling water system, sets a target rotation speed according to the current cooling water temperature, and sets a target rotation speed according to the current fluid temperature. The higher target rotational speed is adopted to make the engine rotational speed follow the target rotational speed, and when the outside air temperature at the start of the internal combustion engine is low, the outside air temperature is high, and In comparison, the control device for the internal combustion engine configured to open the control valve earlier and allow cooling water to flow into the heat exchanger was configured.

  The control valve is opened when the target rotational speed corresponding to the current fluid temperature is higher than the target rotational speed corresponding to the current coolant temperature, and the target according to the current coolant temperature. It is preferable to close the valve when the target rotational speed corresponding to the current fluid temperature is lower than the rotational speed.

  ADVANTAGE OF THE INVENTION According to this invention, the deterioration of the fuel consumption performance in the cold start under the condition where external temperature is low can be suppressed.

The figure which shows schematic structure of the internal combustion engine mounted in a vehicle in one Embodiment of this invention. The figure which shows the structure of the drive system mounted in the vehicle in the same embodiment. The figure which shows the structure of the cooling water system | strain of the internal combustion engine in the embodiment. The figure explaining the content of the control which the control apparatus of the embodiment implements.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of an internal combustion engine for a vehicle in the present embodiment. The internal combustion engine in the present embodiment is a spark ignition type 4-stroke gasoline engine, and includes a plurality of cylinders 1 (one of which is shown in FIG. 1). In the vicinity of the intake port of each cylinder 1, an injector 11 for injecting fuel is provided. A spark plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1. The spark plug 12 receives spark voltage generated by the ignition coil and causes spark discharge between the center electrode and the ground electrode.

  The intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1. On the intake passage 3, an air cleaner 31, an electronic throttle valve 32, a surge tank 33, and an intake manifold 34 are arranged in this order from the upstream.

  The exhaust passage 4 for discharging the exhaust guides the exhaust generated as a result of burning the fuel in the cylinder 1 from the exhaust port of each cylinder 1 to the outside. An exhaust manifold 42 and an exhaust purification three-way catalyst 41 are disposed on the exhaust passage 4.

  An external EGR device 2 is attached to the internal combustion engine of the present embodiment. The external EGR device 2 realizes a so-called high-pressure loop EGR. The EGR device 21 communicates the upstream side of the catalyst 41 in the exhaust passage 4 and the downstream side of the throttle valve 32 in the intake passage 3, and the EGR passage 21. The EGR cooler 22 provided in the EGR passage and the EGR valve 23 that opens and closes the EGR passage 21 and controls the flow rate of the EGR gas flowing through the EGR passage 21 are used as elements. The inlet of the EGR passage 21 is connected to the exhaust manifold 42 in the exhaust passage 4 or a predetermined location downstream thereof. The outlet of the EGR passage 21 is connected to a predetermined location downstream of the throttle valve 32 in the intake passage 3, specifically to a surge tank 33.

  There is an oil pan for storing engine oil at the bottom of the crankcase. The engine oil is sucked in by an oil pump (not shown) assembled in the cylinder block 52 and is pumped through the main gallery in the cylinder block 52 toward each part of the internal combustion engine requiring lubrication. This oil pump is of a known mechanical type (non-electric type) that operates by receiving torque transmitted from a crankshaft of an internal combustion engine. The engine oil is used as hydraulic fluid (hydraulic fluid) that transmits hydraulic pressure (hydraulic) force, and maintains the tension of the chain wound around the crankshaft side sprocket and the camshaft side sprocket at an appropriate level. A chain tensioner (not shown) is supplied to another hydraulic device.

  FIG. 2 shows an example of a drive system provided in the vehicle. This drive system includes a torque converter 7 and automatic transmissions 8 and 9. In particular, in the present embodiment, a forward / reverse switching device 8 using a planetary gear mechanism and a belt-type CVT (Continuously Variable Transmission) 9 which is a type of continuously variable transmission are adopted as components of the automatic transmissions 8 and 9. doing.

  The rotational torque output from the internal combustion engine is input from the crankshaft of the internal combustion engine to the pump impeller 71 on the input side of the torque converter 7 and transmitted to the turbine runner 72 on the output side. The rotation of the turbine runner 72 is transmitted to the drive shaft 94 of the CVT 9 via the forward / reverse switching device 8 and rotates the driven shaft 95 through a shift in the CVT 9. The rotation of the driven shaft 95 is transmitted to the output gear 101. The output gear 101 meshes with the ring gear 102 of the differential device, and rotates the axle 103 and the drive wheels (not shown) via the differential device.

  The torque converter 7 includes a lockup mechanism. The lock-up mechanism is known in this field, and a lock-up clutch 73 that fastens the input side and the output side of the torque converter 7 so as not to rotate relative to each other, and an operation for switching the connection of the lock-up clutch 73. A lock-up solenoid valve (not shown) for controlling the hydraulic pressure (hydraulic pressure) is used as an element. The lockup solenoid valve is a flow rate control valve that receives the control signal m and changes its opening.

  In a vehicle equipped with CVT 9, when the vehicle speed is a predetermined value (for example, 10 km / h) or more, the torque converter 7 is almost always locked up. When the vehicle speed is equal to or lower than the predetermined value, the lockup of the torque converter 7 is released. During lockup, the lockup clutch 73 is pressed against the torque converter cover 74 and rotates together with the torque converter cover 74. The engine torque input to the input side (drive plate) of the torque converter 7 at the time of lock-up is output from the torque converter cover 74 via the lock-up clutch 73 and thus to the forward / reverse switching device 8. Communicated directly to. At the time of lockup, the speed ratio, which is the ratio of the output side rotational speed of the torque converter 7 to the input side rotational speed, is 1.

  In turn, the lock-up clutch 73 is separated from the torque converter cover 74 at the time of non-lock-up. At the time of non-lock-up, the engine torque input to the input side of the torque converter 7 is transmitted from the torque converter cover 74 to the pump impeller 71 and the turbine 72 and is transmitted to the forward / reverse switching device 8. At the time of non-lock-up, the speed ratio of the torque converter 7 becomes smaller or larger than 1 depending on the driving state.

  In the forward / reverse switching device 8, the sun gear 81 communicates with the turbine runner 72, and the ring gear 82 communicates with the drive shaft 94. Between the planetary carrier 83 that supports the planetary gear 831 and the transmission case, a forward brake 84 that is a hydraulic clutch that can be connected and disconnected is interposed. Further, a reverse clutch 85, which is a hydraulic clutch capable of switching connection / disconnection, is also interposed between the planetary carrier 83 and the sun gear 81 (or the output side of the torque converter 7).

  In the D range of the traveling range, the forward brake 84 is engaged and the reverse clutch 85 is disconnected. As a result, the rotation of the output shaft of the torque converter 7 is reversed and decelerated and transmitted to the drive shaft 94 for forward travel. In turn, in the R range, the reverse clutch 85 is engaged and the forward brake 84 is disconnected. As a result, the sun gear 81 and the planetary carrier 83 rotate integrally, and the output shaft of the torque converter 7 and the drive shaft 94 are directly connected to perform reverse travel. A solenoid valve (not shown) that controls the hydraulic pressure for driving the forward brake 84 or the reverse clutch 85 to connect / disconnect is a flow rate control valve that receives a control signal n and changes its opening.

  In the N range and P range, which are non-traveling ranges, both the forward brake 84 and the reverse clutch 85 are disconnected.

  The CVT 9 includes a driving pulley 91 and a driven pulley 92, and a belt 93 wound around the pulleys 91 and 92 as elements. The drive pulley 91 is disposed behind the movable sheave 912, a fixed sheave 911 fixed to the drive shaft 94, a movable sheave 912 supported on the drive shaft 91 via a roller spline so as to be displaceable in the axial direction. A hydraulic servo 913 is provided, and the gear ratio can be changed steplessly by operating the hydraulic servo 913 and displacing the movable sheave 912. The driven pulley 92 is disposed on the back of the movable sheave 922, a fixed sheave 921 fixed to the driven shaft 95, a movable sheave 922 supported on the driven shaft 95 via a roller spline so as to be axially displaceable. A hydraulic servo 923 is provided, and a belt thrust necessary for torque transmission is applied by operating the hydraulic servo 923 and displacing the movable sheave 922.

  The hydraulic fluid (hydraulic fluid) supplied to the forward brake 84 or the reverse clutch 85 to operate the travel range and the hydraulic fluid supplied to the hydraulic servos 913 and 923 to operate the gear ratio are used for the torque converter 7. It is common with the fluid to be used. This fluid is referred to as transmission fluid (CVTF). The oil pump 76 that sucks and discharges the fluid is located between the torque converter 7 and the forward / reverse switching device 8 and operates by receiving torque from the crankshaft of the internal combustion engine. Formula). The fluid is also used for lubrication of the forward / reverse switching device 8 and the belt 93 of the CVT 9 and for preventing sliding friction of the belt 93 with respect to the pulleys 91 and 92.

  FIG. 3 shows a cooling water system of the internal combustion engine of the present embodiment. The cooling water pump 51 that sucks and discharges cooling water is a known mechanical (non-electric) type that operates by receiving torque from the crankshaft of the internal combustion engine. The cooling water discharged from the cooling water pump 51 first flows into the cylinder block 52, a part thereof goes to the EGR cooler 22, and the rest goes to the cylinder head 53. The cylinder head 53 branches to a heater core 54 for air conditioning, a CVTF warmer 55, or a radiator 56.

  The CVTF warmer 55 is a heat exchanger that exchanges heat between the coolant of the internal combustion engine and the fluid used in the torque converter 7 and the automatic transmissions 8 and 9. A control valve 57 for opening and closing the passage is installed on the cooling water passage connecting the cylinder head 53 and the CVTF warmer 55. The control valve 57 is an on-off valve that opens and closes in response to the control signal q, or a flow rate control valve that changes its opening, and is, for example, a solenoid valve.

  The radiator 56 is a radiator that reduces the temperature of the cooling water by natural air cooling or forced air cooling. A thermostat 58 for opening and closing the passage is installed on the cooling water passage connecting the cylinder head 53 and the radiator 56. The thermostat 58 opens when the temperature of the cooling water becomes higher than a predetermined temperature, and closes when the temperature is lower than that.

  The cooling water that has flowed through the EGR cooler 22, the heater core 54, the CVTF warmer 55, or the radiator 56 flows down toward the cylinder block 52 after gathering, and is sucked into the cooling water pump 51 again.

  An ECU (Electronic Control Unit) 0 serving as a control device for an internal combustion engine according to the present embodiment is a microcomputer system having a processor, a memory, an input interface, an output interface, and the like.

  The input interface includes a vehicle speed signal a output from a vehicle speed sensor that detects the actual vehicle speed of the vehicle, a crank angle signal b output from an engine rotation sensor that detects the rotation angle and engine speed of the crankshaft, and depression of an accelerator pedal. The accelerator opening signal c output from the sensor that detects the amount or the opening of the throttle valve 32 as the accelerator opening (so-called required load), the outside air temperature signal d output from the temperature sensor that detects the temperature of the outside air, and the intake air The intake air temperature / intake pressure signal e output from the temperature / pressure sensor for detecting the intake air temperature and intake pressure in the passage 3 (especially the surge tank 33), the temperature of the cooling water of the internal combustion engine (indicating the engine temperature) The coolant temperature signal f output from the detected water temperature sensor and the fluid output from the fluid temperature sensor that detects the temperature of the transmission fluid. Over de temperature signal g, a cam angle signal h or the like to be output from the cam angle sensor is input in a plurality of cam angle of the intake camshaft or an exhaust camshaft.

  From the output interface, the ignition signal i for the igniter of the spark plug 12, the fuel injection signal j for the injector 11, the opening operation signal k for the throttle valve 32, and the opening operation signal l for the EGR valve 23. , The opening control signal m for the lockup solenoid valve for switching connection / disconnection of the lockup clutch 73, and the opening control signal n, CVT9 for the solenoid valve for switching connection / disconnection of the forward brake 84 or the reverse clutch 85. On the other hand, the gear ratio control signal p, the open / close control signal q, etc. are output to the control valve 57.

  The processor of the ECU 0 interprets and executes a program stored in the memory in advance, calculates operation parameters, and controls the operation of the internal combustion engine. The ECU 0 acquires various information a, b, c, d, e, f, g, and h necessary for operation control of the internal combustion engine via the input interface, knows the engine speed, and is filled in the cylinder 1. Estimate the intake volume. Based on the engine speed and intake air amount, etc., the required fuel injection amount, fuel injection timing (including the number of times of fuel injection for one combustion), fuel injection pressure, ignition timing, and torque converter 7 lock-up are adjusted. Various operation parameters such as whether or not to perform the transmission and the gear ratio of the automatic transmissions 8 and 9 are determined. The ECU 0 applies various control signals i, j, k, l, m, n, p, q corresponding to the operation parameters via the output interface.

  Further, the ECU 0 sends a control signal o to a starter motor (or a cell motor, not shown) that is an electric motor when the internal combustion engine is started (a cold start or a return from an idling stop). The cranking is performed by rotating the crankshaft of the internal combustion engine by engaging the pinion gear of the starter motor with the ring gear on the outer periphery of the drive plate. Cranking ends from the first explosion to the consecutive explosion, and ends when the engine speed exceeds a threshold determined according to the cooling water temperature or the like (assuming that the explosion has been completed).

  The ECU 0 of the present embodiment has a throttle valve according to the deviation between the actually measured engine speed and the target rotational speed so that the engine rotational speed converges to the target rotational speed in idle operation where the accelerator pedal depression amount is 0 or close to 0. Feedback control for operating the opening degree of 32 and the fuel injection amount from the injector 11 is performed.

  The target rotational speed is determined based on the current cooling water temperature and fluid temperature. The target rotation speed based on the cooling water temperature increases as the cooling water temperature decreases. Similarly, the target rotational speed based on the fluid temperature also increases as the fluid temperature decreases. The magnitude relationship between the target rotational speeds of both changes depending on the cooling water temperature and the fluid temperature. If the cooling water temperature and the fluid temperature are higher than a certain level, the target rotational speed based on the fluid temperature is lower than the target rotational speed based on the cooling water temperature. On the other hand, when the cooling water temperature and the fluid temperature are low, the target rotational speed based on the fluid temperature is higher than the target rotational speed based on the cooling water temperature.

  The memory of the ECU 0 stores in advance map data that defines the relationship between the cooling water temperature and the outside air temperature and the target rotational speed, and map data that defines the relationship between the fluid temperature and the outside air temperature and the target rotational speed. The ECU 0 searches the former map using the current cooling water temperature and the outside air temperature as keys, and obtains the target rotation speed based on the cooling water temperature. In addition, the latter map is searched using the current fluid temperature and the outside air temperature as keys, and another target rotation speed based on the fluid temperature is obtained. The higher one of the target rotational speeds is used as the target rotational speed in the feedback control.

  Therefore, the ECU 0 of the present embodiment performs the target rotation based on the cooling water temperature at a time immediately after the cold start of the internal combustion engine, in other words, at a time when the cooling water temperature has not risen to the predetermined temperature and the warm-up is not completed. The timing at which the control valve 57 is opened, that is, the timing at which the cooling water of the internal combustion engine is caused to flow into the CVTF warmer 55 and the heating of the fluid is started is changed in consideration of the number and the target rotational speed based on the fluid temperature.

  At the time of cold start in a situation where the outside air temperature is not low, the cooling water and the fluid are at a certain temperature or more from the beginning. At this time, the target rotational speed based on the cooling water temperature is higher than the target rotational speed based on the fluid temperature, and the target rotational speed based on the cooling water temperature is employed in the feedback control. The ECU 0 of the present embodiment closes the control valve 57 when the target rotational speed based on the cooling water temperature is higher than the target rotational speed based on the fluid temperature, and the cooling water (and the internal combustion engine itself) rather than the fluid heating. ) Give priority to temperature rise. However, when the cooling water is sufficiently heated (for example, 80 ° C.) or higher, the control valve 57 may be used even if the target rotational speed based on the cooling water temperature is higher than the target rotational speed based on the fluid temperature. May be opened to start heating the fluid.

  On the other hand, at the time of cold start under a condition where the outside air temperature is remarkably low, such as in a cold region or in winter, the initial cooling water and fluid temperatures are extremely low. At this time, the target rotational speed based on the fluid temperature is higher than the target rotational speed based on the coolant temperature, and the target rotational speed based on the fluid temperature is employed in the feedback control described above. In the present embodiment, the ECU 0 opens the control valve 57 when the target rotational speed based on the cooling water temperature is lower than the target rotational speed based on the fluid temperature, so that the fluid temperature is higher than the temperature rise of the cooling water (the internal combustion engine itself). Prioritize heating and reduce fluid viscosity as quickly as possible. Thereby, the mechanical loss in the torque converter 7 and the automatic transmissions 8 and 9 is reduced as much as possible, and the fuel efficiency is improved.

  Supplementary information regarding cold start in situations where the outside air temperature is low. FIG. 4 exemplifies the transition of the cooling water temperature of the internal combustion engine, the engine speed during idle operation, and the fluid temperature at the time immediately after the start under the condition where the outside air temperature is low. In FIG. 4, the thin line represents the transition when the control valve 57 is not opened (cooling water is not allowed to flow into the CVTF warmer 55), and the thick line represents the control valve 57 being opened (the cooling water is allowed to flow into the CVTF warmer 55). This represents the transition of the case. Regarding the engine speed, the broken line represents the target speed based on the coolant temperature, and the chain line represents the target speed based on the fluid temperature.

  If the control valve 57 is left unopened after the engine is started, the engine speed during idling will change along a thin chain line. On the other hand, if the control valve 57 is opened immediately after the engine is started, as shown by a thin arrow in FIG. 4, the initial state changes along the thick chain line, and the point where the thick chain line and the thick broken line intersect. After that, it will change along a thick broken line. Thus, by opening the control valve 57 at an early stage, the engine speed can be reduced as shown by the thick white arrow in FIG. 4, so the fuel consumption is suppressed.

  In the present embodiment, heat exchange is performed between the fluid used in the transmissions 7, 8, and 9 and the cooling water of the internal combustion engine to raise the temperature of the fluid, and the cooling water is supplied to the heat exchanger 55. A control valve 57 capable of switching whether or not to flow in controls the internal combustion engine provided in the cooling water system, sets a target rotational speed according to the current temperature of the cooling water, and A target rotational speed is set according to the fluid temperature, and the higher target rotational speed is adopted to make the engine rotational speed follow the target rotational speed. When the temperature is low, the control device 0 for the internal combustion engine is configured such that the control valve 57 is opened earlier and the cooling water flows into the heat exchanger 55 as compared with the case where the outside air temperature is high.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to suppress the deterioration of the fuel consumption performance in the cold start under the condition where external temperature is low. Further, the idling speed of the internal combustion engine is stabilized by warming the fluid as quickly as possible and reducing the mechanical loss in the transmissions 7, 8, and 9.

  In addition, when the target rotational speed corresponding to the current fluid temperature is higher than the target rotational speed corresponding to the current cooling water temperature, the control valve 57 is opened, and the current cooling water temperature is set. Since the control valve 57 is closed when the target rotational speed corresponding to the current fluid temperature is lower than the corresponding target rotational speed, even if the state where the vehicle stops idling continues for a long time. Both the internal combustion engine and the transmissions 7, 8, and 9 can be warmed up uniformly, which contributes to improvement in fuel efficiency and stabilization of idle rotation.

  The present invention is not limited to the embodiment described in detail above. In the above embodiment, the control valve 57 is opened when the target rotational speed corresponding to the current fluid temperature is higher than the target rotational speed corresponding to the current coolant temperature, and the current coolant temperature The control valve 57 is closed when the target rotational speed corresponding to the current fluid temperature is lower than the target rotational speed corresponding to the engine speed, but the internal combustion engine is simply referred to without referring to the target rotational speed. Depending on the outside air temperature at the time of cold start, the timing of opening the control valve 57 or the cooling water temperature or fluid temperature which is the condition for opening the control valve 57 may be adjusted. In that case, the lower the outside air temperature during cold start, the earlier the control valve 57 is opened, or the control valve 57 is opened from a lower cooling water temperature or fluid temperature.

  Alternatively, when the outside air temperature during the cold start of the internal combustion engine is equal to or lower than a predetermined threshold, the control valve 57 may be opened immediately after the start of the internal combustion engine.

  The outside air temperature at the time of cold start of the internal combustion engine is not only measured through the outside air temperature sensor, but can also be grasped from the cooling water temperature or the fluid temperature at the time of cold start.

  In the feedback control of the engine speed, in the above embodiment, the opening of the electronic throttle valve 32 is corrected according to the deviation between the engine speed and the target speed, but an idle speed control valve is mounted. In an internal combustion engine, the opening degree of the idle speed control valve may be corrected. As is well known, the idle speed control valve is a flow control valve that opens and closes a bypass that communicates the upstream side and the downstream side of the throttle valve 32 in the intake passage 3.

  Other specific configurations of each part can be variously modified without departing from the spirit of the present invention.

  The present invention can be applied to control of an internal combustion engine mounted on a vehicle.

0 ... Control unit (ECU)
11 ... Injector 32 ... Throttle valve 55 ... Heat exchanger (CVTF warmer)
57 ... Control valve

Claims (2)

A heat exchanger for exchanging heat between the fluid used in the transmission and the cooling water of the internal combustion engine to raise the temperature of the fluid, and a control valve capable of switching whether or not the cooling water flows into the heat exchanger Controls the internal combustion engine provided in the cooling water system,
Set the target speed according to the current cooling water temperature, set the target speed according to the current fluid temperature, and adopt the target speed that is the higher of the two. While making the engine speed follow the number,
A control apparatus for an internal combustion engine that opens the control valve earlier and causes cooling water to flow into the heat exchanger when the outside air temperature at the start of the internal combustion engine is low than when the outside air temperature is high. When the target rotational speed corresponding to the current fluid temperature is higher than the target rotational speed corresponding to the current coolant temperature, the control valve is opened, and the target rotational speed is determined according to the current coolant temperature. 2. The control device for an internal combustion engine according to claim 1, wherein the control valve is closed when a target rotational speed corresponding to the current fluid temperature is lower than the number.

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