WO2021006036A1

WO2021006036A1 - Control device for flow control valve

Info

Publication number: WO2021006036A1
Application number: PCT/JP2020/024677
Authority: WO
Inventors: 大介中西
Original assignee: 株式会社デンソー
Priority date: 2019-07-08
Filing date: 2020-06-23
Publication date: 2021-01-14
Also published as: JP7346948B2; JP2021011856A

Abstract

A control device (40) for a flow control valve (12) comprises a target opening degree setting unit (50), an opening degree control unit (60), and a control parameter changing unit (70). The target opening degree setting unit sets a target opening degree of the flow control valve. The opening degree control unit controls an actual opening degree of the flow control valve to match the target opening degree. The control parameter changing unit changes a control parameter for controlling the operation of the flow control valve. The target opening degree setting unit sets a target wall temperature in accordance with a load state of an internal combustion engine. When the absolute value of a difference between an actual wall temperature and the target wall temperature is larger than a prescribed value, the control parameter changing unit changes the control parameter such that a response speed of the actual wall temperature is faster than when the absolute value of the difference is not larger than the prescribed value.

Description

Flow control valve control device

Cross-reference of related applications

This application is based on Japanese Patent Application No. 2019-126763 filed on July 8, 2019, claiming the benefit of its priority, and the entire contents of the patent application Incorporated herein by reference.

The present disclosure relates to a control device for a flow control valve.

Conventionally, there is a control device for a flow control valve described in Patent Document 1 below. The flow rate control valve described in Patent Document 1 is mounted on a vehicle and is provided in a cooling water circulation circuit that circulates cooling water between an internal combustion engine and a radiator. The radiator cools the cooling water by exchanging heat between the cooling water and the outside air. The flow control valve regulates the flow rate of the cooling water supplied to the internal combustion engine. The control device described in Patent Document 1 controls the opening degree of the flow control valve according to the load of the internal combustion engine.

Specifically, this control device increases the flow rate of the cooling water flowing through the radiator by opening the flow rate control valve when the internal combustion engine is in a high load state, and the temperature of the cooling water. To reduce. As a result, the cylinder wall temperature of the internal combustion engine can be lowered, so that the internal combustion engine can be appropriately cooled even when the combustion gas temperature of the internal combustion engine rises due to a high load state. Become.

Further, when the internal combustion engine is in a low load state, this control device closes the flow rate control valve to reduce the flow rate of the cooling water flowing through the radiator and raise the temperature of the cooling water. .. As a result, the cylinder wall temperature of the internal combustion engine can be raised, so that the temperature of the lubricating oil of the internal combustion engine rises due to the heat of the cooling water. As a result, the viscosity of the lubricating oil is lowered, so that the friction generated between the piston and the cylinder of the internal combustion engine can be reduced. Further, since the wall temperature of the cylinder can be raised, the cooling loss of the internal combustion engine can be reduced. The cooling loss of the internal combustion engine is a loss of energy that cannot be taken out as power from the internal combustion engine as a result of the heat energy generated by the combustion of the internal combustion engine being absorbed by the cylinder. By reducing friction and heat loss in such an internal combustion engine, it is possible to improve the fuel efficiency of the internal combustion engine.

Japanese Unexamined Patent Publication No. 2004-84526

In the control device described in Patent Document 1, when the opening degree of the flow rate control valve is changed according to the load of the internal combustion engine, the cylinder has a cylinder with respect to the target wall temperature, which is the target value of the cylinder wall temperature, due to various factors. A response delay occurs in the actual wall temperature, which is the actual wall temperature. Factors that cause such a response delay in the actual wall temperature of the internal combustion engine are, for example, the influence of the control response delay, the response delay of the actuator that drives the valve body of the flow control valve, the response delay of the radiator, and the heat capacity of the cooling water. And so on. If the response of the actual wall temperature of the internal combustion engine to the target wall temperature is delayed and they deviate from each other, the actual wall temperature of the internal combustion engine deviates from the optimum temperature in each region of the load of the internal combustion engine. There is a risk of deteriorating the fuel efficiency of the internal combustion engine.

Specifically, when the internal combustion engine becomes a low load state when the vehicle is decelerated, if the actual wall temperature of the internal combustion engine deviates to a lower temperature side than the target wall temperature, the cooling loss of the internal combustion engine increases and the cooling loss of the internal combustion engine increases. Since the friction of the internal combustion engine increases, the fuel consumption of the internal combustion engine deteriorates. In addition, when the internal combustion engine is in a high load state during vehicle acceleration and the actual wall temperature of the internal combustion engine deviates to a higher temperature side than the target wall temperature, knocking in the internal combustion engine can be avoided. It is necessary to shift the ignition timing of the internal combustion engine to the retard side. When such control to shift the ignition timing to the retard side is performed, the amount of heat of the exhaust increases. This corresponds to an increase in the energy discarded as the thermal energy of the exhaust gas among the energy generated by the combustion of the internal combustion engine, which may result in deterioration of the fuel efficiency of the internal combustion engine.

An object of the present disclosure is to provide a control device for a flow control valve capable of further improving the fuel efficiency of an internal combustion engine.

The flow control valve control device according to one aspect of the present disclosure regulates the flow rate of the cooling water circulating between the internal combustion engine of the vehicle and the radiator. The control device includes a target opening degree setting unit, an opening degree control unit, and a control parameter changing unit. The target opening degree setting unit sets the target opening degree of the flow control valve for making the actual wall temperature, which is the actual temperature of the cylinder wall temperature of the internal combustion engine, follow the target wall temperature. The opening degree control unit controls the actual opening degree, which is the actual opening degree of the flow control valve, to the target opening degree. The control parameter changing unit changes the control parameter that controls the operation of the flow control valve. The target opening setting unit sets the target wall temperature to the first target wall temperature set value when the internal combustion engine is in a high load state, and sets the target wall temperature when the internal combustion engine is in a low load state. Set to the second target wall temperature set value, which is higher than the first target wall temperature set value. When the absolute value of the deviation between the actual wall temperature and the target wall temperature is larger than the predetermined value, the control parameter changing unit is more than when the absolute value of the deviation between the actual wall temperature and the target wall temperature is less than or equal to the predetermined value. Change the control parameters so that the response speed of the actual wall temperature becomes faster.

According to this configuration, the target wall temperature of the internal combustion engine can be switched according to the load state of the internal combustion engine, so that the fuel efficiency of the internal combustion engine can be improved. In addition, when the absolute value of the deviation between the actual wall temperature of the internal combustion engine and the target wall temperature becomes larger than the predetermined value, the response speed of the actual wall temperature of the internal combustion engine becomes faster by changing the control parameter of the flow control valve. Therefore, the actual wall temperature of the internal combustion engine changes rapidly toward the target wall temperature. As a result, the period in which the actual wall temperature of the internal combustion engine deviates significantly from the target wall temperature can be shortened, and therefore, deterioration of fuel efficiency of the internal combustion engine caused by such dissociation can be suppressed. In other words, the fuel efficiency of the internal combustion engine can be further improved.

FIG. 1 is a block diagram showing a schematic configuration of a vehicle cooling water circulation system according to the first embodiment. FIG. 2 is a perspective view showing a perspective structure of the flow control valve of the first embodiment. FIG. 3 is a diagram schematically showing the positional relationship between the inner wall surface of the main body and the valve body in the flow control valve of the first embodiment. 4 (A) to 4 (C) are graphs showing the relationship between the rotational position of the valve body of the flow control valve and the opening ratio of the first to third outflow ports. FIG. 5 is a block diagram showing an electrical configuration of the flow control valve of the first embodiment. FIG. 6 is a flowchart showing a procedure of processing executed by the ECU of the first embodiment. FIG. 7 is a control block diagram showing a procedure of control processing of the ECU of the first embodiment. FIG. 8 is a map for calculating the calorific value from the rotation speed and load of the internal combustion engine used by the ECU of the first embodiment. FIG. 9 is a map for calculating the target outlet water temperature from the rotation speed and load of the internal combustion engine used by the ECU of the first embodiment. FIG. 10 is a map for calculating the flow rate when the valve is fully opened from the rotation speed of the internal combustion engine used by the ECU of the first embodiment. FIG. 11 is a map for obtaining the flow rate ratio from the rotation position of the valve body of the flow rate control valve used by the ECU of the first embodiment. FIG. 12 is a control block diagram showing a procedure of control processing of the ECU of the first embodiment. FIG. 13 is a graph showing the relationship between the duty ratio and the displacement speed of the valve body in the flow control valve of the first embodiment. FIG. 14 is a graph showing an example of changes in the temperature of the cooling water. FIG. 15 is a diagram schematically showing the factors of response delay in the cooling water circulation system. FIG. 16 is a map for calculating the target outlet water temperature from the rotation speed and load of the internal combustion engine used by the ECU of the first embodiment. FIG. 17 is a flowchart showing a procedure of processing executed by the control parameter changing unit of the first embodiment. FIG. 18 is a graph schematically showing a mode of changing the wall temperature of the internal combustion engine by the flow rate control valve of the first embodiment. 19 (A) to 19 (G) are graphs showing changes in the intake air amount, outlet water temperature, outlet water temperature deviation, duty ratio, valve position, flow rate, and internal combustion engine wall temperature in the cooling water circulation system of the first embodiment. Is. FIG. 20 is a control block diagram showing a procedure of control processing of the ECU of the second embodiment. FIG. 21 is a flowchart showing a procedure of processing executed by the ECU of the second embodiment. FIG. 22 is a flowchart showing a procedure of processing executed by the control parameter changing unit of the second embodiment. 23 (A) to 23 (D) are graphs showing changes in the valve position, the displacement speed of the valve body, the integrated value displacement amount, and the operation frequency in the flow control valve of the cooling water circulation system of the second embodiment. FIG. 24 is a graph showing the relationship between the absolute value of the outlet water temperature deviation of the second embodiment and the duty ratio. FIG. 25 is a control block diagram showing a procedure of control processing of the filtering unit of the third embodiment. FIG. 26 is a control block diagram showing a procedure of control processing of the ECU of the third embodiment. FIG. 27 is a flowchart showing a procedure of processing executed by the control parameter changing unit of the third embodiment. FIG. 28 is a graph showing the relationship between the absolute value of the outlet water temperature deviation used by the control parameter changing unit of the third embodiment and the smoothing time constant. FIGS. 29 (A) to 29 (G) show changes in the intake air amount, outlet water temperature, outlet water temperature deviation, valve position, smoothing time constant, flow rate, and internal combustion engine wall temperature in the cooling water circulation system of the third embodiment. It is a graph which shows. FIG. 30 is a control block diagram showing a procedure of control processing of the ECU of the fourth embodiment. FIG. 31 is a diagram schematically showing the relationship between the control executed by the control parameter changing unit of the fourth embodiment and the outlet water temperature deviation. FIG. 32 is a flowchart showing a procedure of processing executed by the control parameter changing unit of the fourth embodiment. 33 (A) to 33 (G) are graphs showing changes in intake air amount, outlet water temperature, outlet water temperature deviation, valve position, control state, flow rate, and internal combustion engine wall temperature in the cooling water circulation system of the fourth embodiment. Is. 34 (A) to 34 (C) are graphs showing the relationship between the rotational position of the valve body of the flow control valve of the fifth embodiment and the opening ratio of the first to third outflow ports. FIG. 35 is a diagram schematically showing the relationship between the control executed by the control parameter changing unit of the fifth embodiment and the outlet water temperature deviation. FIG. 36 is a flowchart showing a procedure of processing executed by the control parameter changing unit of the fifth embodiment. 37 (A) to 37 (G) are graphs showing changes in intake air amount, outlet water temperature, outlet water temperature deviation, valve position, control state, flow rate, and internal combustion engine wall temperature in the cooling water circulation system of the fifth embodiment. Is. 38 (A) to 38 (C) are graphs showing the relationship between the rotational position of the valve body of the flow control valve of the sixth embodiment and the opening ratio of the first to third outflow ports. FIG. 39 is a flowchart showing a part of the processing procedure executed by the control parameter changing unit of the fifth embodiment. FIG. 40 is a flowchart showing a part of the processing procedure executed by the control parameter changing unit of the fifth embodiment.

Hereinafter, embodiments of the control device for the flow control valve will be described with reference to the drawings. In order to facilitate understanding of the description, the same components are designated by the same reference numerals as much as possible in each drawing, and duplicate description is omitted.
<First Embodiment>
First, an outline of the vehicle cooling water circulation system 10 provided with the flow control valve 12 of the first embodiment shown in FIG. 1 will be described. The cooling water circulation system 10 is a system that circulates cooling water to an internal combustion engine 20, a radiator 21, a heater core 22, an EGR (Exhaust Gas Recirculation) cooler 23, and an oil cooler 24 mounted on a vehicle. The internal combustion engine 20 and the radiator 21 are connected in an annular shape by the flow path W10. The cooling water circulation system 10 includes a pump 11 and a flow rate control valve 12 in the annular flow path W10. The pump 11 is provided on the upstream side of the internal combustion engine 20 in the annular flow path W10. The flow rate control valve 12 is provided on the downstream side of the internal combustion engine 20 in the annular flow path W10.

The pump 11 sucks the cooling water flowing through the annular flow path W10 and pumps the sucked cooling water to the internal combustion engine 20. By the operation of the pump 11, the cooling water circulates in the annular flow path W10. The pump 11 is a mechanical pump driven by the power of the internal combustion engine 20.
In the internal combustion engine 20, the cooling water pumped from the pump 11 passes through the cylinder block 201 and the cylinder head 202 in this order. When the cooling water passes through the cylinder block 201 and the cylinder head 202, heat exchange is performed between them and the cooling water to cool the cylinder block 201 and the cylinder head 202. The cooling water discharged from the cylinder head 202 flows into the flow rate control valve 12 through the annular flow path W10.

The flow rate control valve 12 includes an inflow port P10 and first to third outflow ports P11 to P13. The internal combustion engine 20 is connected to the inflow port P10 via the annular flow path W10. A radiator 21 is connected to the first outflow port P11 via an annular flow path W10. The first bypass flow path W11 is connected to the second outflow port P12. The first bypass flow path W11 is a flow path that connects the second outflow port P12 of the flow control valve 12 to the intermediate portion between the radiator 21 and the pump 11 in the annular flow path W10. A second bypass flow path W12 is connected to the third outflow port P13. The second bypass flow path W12 is a flow path that connects the third outflow port P13 of the flow control valve to the intermediate portion between the radiator 21 and the pump 11 in the annular flow path W10. The flow rate control valve 12 controls the open / closed state of each outflow port P11 to P13 to control the flow rate of the cooling water flowing through the radiator 21, the flow rate of the cooling water flowing through the first bypass flow path W11, and the second bypass flow path W12. Control the flow rate of cooling water flowing through.

Cooling water flows into the radiator 21 from the flow control valve 12 via the annular flow path W10. The radiator 21 cools the cooling water by exchanging heat between the cooling water flowing inside the radiator 21 and the outside air blown by the radiator fan 21a. The outside air is the air outside the vehicle. The cooling water cooled in the radiator 21 is returned to the pump 11 through the annular flow path W10.

A heater core 22 and an EGR cooler 23 are arranged in the first bypass flow path W11. The heater core 22 is arranged in an air conditioning duct of an air conditioner mounted on a vehicle. The heater core 22 heats the air by exchanging heat between the cooling water flowing inside the heater core 22 and the air in the air conditioning duct blown by the heating blower 22a. The heated air is blown into the vehicle interior through the air conditioning duct to heat the vehicle interior. The EGR cooler 23 is arranged in an EGR passage that returns a part of the exhaust gas flowing through the exhaust pipe of the internal combustion engine 20 to the intake pipe of the internal combustion engine 20. The EGR cooler 23 cools the exhaust gas returned to the intake pipe by exchanging heat between the cooling water flowing inside the EGR cooler 23 and the exhaust gas flowing through the EGR passage. The cooling water that has passed through the heater core 22 and the EGR cooler 23 is returned to the pump 11 through the first bypass flow path W11 and the annular flow path W10.

An oil cooler 24 is arranged in the second bypass flow path W12. The oil cooler 24 cools the lubricating oil by exchanging heat between the cooling water flowing inside the oil cooler 24 and the lubricating oil that lubricates each part of the internal combustion engine 20. The cooling water that has passed through the oil cooler 24 is returned to the pump 11 through the second bypass flow path W12 and the annular flow path W10.

In the present embodiment, the heater core 22, the EGR cooler 23, and the oil cooler 24 correspond to the in-vehicle device. Further, the first outflow port P11 of the flow control valve 12 corresponds to the radiator port, and the second outflow port P12 and the third outflow port P13 of the flow control valve 12 correspond to the in-vehicle device port. Further, the second outflow port P12 corresponds to the heater core port, and the third outflow port P13 corresponds to the oil cooler port.

Next, the structure of the flow control valve 12 will be described in detail.
As shown in FIG. 2, the flow rate control valve 12 includes a main body 120 and an actuator device 121.
First to third outflow ports P11 to P13 are provided on the side surface of the main body 120. An inflow port P10 (not shown) is provided on the bottom surface of the main body 120. Further, inside the main body 120, a cylindrical valve body for switching the open / closed state of the first to third outflow ports P11 to P13 is provided. FIG. 3 is a developed view of a cylindrical valve body 122 provided inside the main body 120. The X direction shown in FIG. 3 indicates the circumferential direction of the valve body 122, and the Y direction indicates a direction parallel to the axial direction of the valve body 122. Hereinafter, the X1 direction, which is one of the X directions, is referred to as a forward rotation direction, and the X2 direction, which is the opposite direction, is referred to as a reverse rotation direction.

As shown in FIG. 3, the valve body 122 is formed with three openings 123a to 123c so as to be arranged in a direction parallel to the axial direction Y. The openings 123a to 123c are formed in a slit shape so as to extend in the circumferential direction X of the valve body 122.
In FIG. 3, the rotation positions in which the openings 123a to 123c are not formed in the circumferential direction X of the valve body 122 are indicated by “P0”, and the rotations are sequentially arranged at positions deviated from the rotation position P0 in the normal rotation direction X1. The positions are indicated by "P1", "P2", "P3", and "P4".

The opening 123a is formed so as to extend from the rotation position P3 to the rotation position P4. The opening 123b is formed so as to extend from the rotation position P2 to the rotation position P4. The opening 123c is formed so as to extend from the rotation position P1 to the rotation position P4.
Further, on the inner peripheral surface 120a of the main body 120 facing the valve body 122, three communication holes 124a to 124c are formed side by side in the axial direction Y. The communication holes 124a to 124c are communicated with the first to third outflow ports P11 to P13 shown in FIG. 2, respectively.

The actuator device 121 shown in FIG. 2 has a motor, and applies torque to the valve body 122 based on energization of the motor to rotate the valve body 122 in the circumferential direction X. The relative positions of the communication holes 124a to 124c formed in the inner peripheral surface 120a of the main body 120 and the openings 123a to 123c formed in the valve body 122 by rotating the valve body 122 in the circumferential direction X. Changes, and the opening degree of each outflow port P11 to P13 changes.

Specifically, when the line passing through the center of each of the communication holes 124a to 124c is set as the reference line DL1, the position of the reference line DL1 in the valve body 122 changes with the rotation of the valve body 122. In the following, for convenience, the position of the reference line DL1 on the valve body 122 will be referred to as “communication position DL1”. The valve body 122 rotates relative to the main body 120 within a range in which the communication position DL1 is displaced from the rotation position P0 to the rotation position P5. The rotation position P5 is set between the rotation position P3 and the rotation position P4.

For example, when the communication position DL1 of the valve body 122 is located between the rotation position P0 and the rotation position P3, the communication hole 124a of the main body 120 is not communicated with the opening 123a of the valve body 122. 1 The outflow port P11 is in a closed state. When the communication position DL1 of the valve body 122 reaches the rotation position P3, the communication position DL1 of the valve body 122 changes to the forward rotation direction X1 so that the communication hole 124a of the main body 120 and the opening 123a of the valve body 122 The area where and overlaps gradually increases. Therefore, the opening degree of the first outflow port P11 gradually increases. When the entire communication hole 124a of the main body 120 overlaps with the opening 123a of the valve body 122, the opening degree of the first outflow port P11 is fully opened. After that, the opening degree of the first outflow port P11 is maintained in the fully open state until the communication position DL1 of the valve body 122 reaches the rotation position P5. Similarly, the opening degree of the second outflow port P12 changes according to the relative positional relationship between the communication hole 124b of the main body 120 and the opening 123b of the valve body 122, and the communication hole 124c and the valve of the main body 120 change. The opening degree of the third outflow port P13 changes according to the relative positional relationship of the body 122 with the opening 123c. 4 (A) to 4 (C) show the aperture ratios of the outflow ports P11 to P13 with respect to the communication position DL1 of the valve body 122. The aperture ratio is defined as "0 [%]" when the outflow port is fully closed, "100 [%]" when the outflow port is fully open, and the opening of the outflow port is "0 [%]". ] ”To“ 100 [%] ”.

In the following, for convenience, the communication position DL1 of the valve body 122 will be referred to as "the valve position of the flow control valve 12."
Next, the electrical configuration of the cooling water circulation system 10 will be described.

As shown in FIG. 5, the cooling water circulation system 10 includes a first water temperature sensor 30, a second water temperature sensor 31, a crank angle sensor 32, an air flow meter 33, and an ECU (Electronic Control Unit) 40. There is.
As shown in FIG. 1, the first water temperature sensor 30 is provided in a portion of the annular flow path W10 on the upstream side of the internal combustion engine 20. The first water temperature sensor 30 detects the inlet water temperature TWin, which is the temperature of the cooling water flowing into the internal combustion engine 20, and outputs a signal corresponding to the detected inlet water temperature TWin.

The second water temperature sensor 31 is provided in a portion of the annular flow path W10 on the downstream side of the internal combustion engine 20. The second water temperature sensor 31 detects the outlet water temperature TWout, which is the temperature of the cooling water discharged from the internal combustion engine 20, and outputs a signal corresponding to the detected outlet water temperature TWout.

The crank angle sensor 32 shown in FIG. 5 detects the crank angle θc, which is the output shaft of the internal combustion engine 20, and outputs a signal corresponding to the detected crank angle θc.
The air flow meter 33 is provided in the intake pipe of the internal combustion engine 20, detects the flow rate GA of the air sucked into the internal combustion engine 20, and outputs a signal corresponding to the detected intake air amount GA.

The ECU 40 is mainly composed of a microcomputer having a CPU, a memory, and the like. The ECU 40 controls the drive of the flow control valve 12 by executing a program stored in advance in the memory.
Specifically, the output signals of the sensors 30 to 33 are taken into the ECU 40. The ECU 40 acquires information on the inlet water temperature TWin, the outlet water temperature TWout, the crank angle θc, and the intake air amount GA based on the output signals of the sensors 30 to 33. Further, the flow rate control valve 12 is provided with a position sensor 125 for detecting the valve position. The ECU 40 also acquires information on the valve position of the flow control valve 12 detected by the position sensor 125. The ECU 40 sets the target rotation position of the valve body 122 of the flow rate control valve 12 based on the inlet water temperature TWin, the outlet water temperature TWout, the crank angle θc, and the intake air amount GA, and the valve position of the flow rate control valve 12 is the target rotation. The flow control valve 12 is controlled so as to be in the position. In this embodiment, the ECU 40 corresponds to the control device. Further, the control for making the valve position of the flow rate control valve 12 follow the target rotation position corresponds to the control for making the actual opening degree of the flow rate control valve 12 follow the target opening degree.

Next, the control of the flow rate control valve 12 executed by the ECU 40 will be specifically described.
The ECU 40 executes the process shown in FIG. 6 based on the outlet water temperature TWout. The ECU 40 starts the process shown in FIG. 6 when the internal combustion engine 20 starts.

As shown in FIG. 6, the ECU 40 first executes the water stop control as the process of step S10. In the water stop control, the valve position of the flow rate control valve 12 is set in the range from the rotation position P0 to the rotation position P1 shown in FIG. That is, in the water stop control, all the outflow ports P11 to P13 of the flow rate control valve 12 are set to the closed state. In this case, in the cooling water circulation system 10 shown in FIG. 1, since the cooling water does not circulate, heat dissipation from the cooling water in the flow paths W10 to W12 other than the internal combustion engine 20, that is, heat loss is suppressed. As a result, the heat generated from the internal combustion engine 20 can be effectively used for warming up the internal combustion engine 20. For example, the internal combustion engine 20 can be warmed up at an early stage even at the time of cold start of the internal combustion engine 20.

As shown in FIG. 6, the ECU 40 determines whether or not the outlet water temperature TWout becomes larger than the first temperature threshold value TWth1 as the process of step S11 following step S10. When the outlet water temperature TWout is equal to or less than the first temperature threshold value TWth1, the ECU 40 makes a negative determination in the process of step S11 and continues the water stop control in step S10.

When the outlet water temperature TWout becomes larger than the first temperature threshold value TWth1, the ECU 40 makes an affirmative judgment in the process of step S11 and executes heat distribution control as the process of step S12. In the heat distribution control, the valve position of the flow control valve 12 is set in the range from the rotation position P1 to the rotation position P3 shown in FIG. That is, in the heat distribution control, the second outflow port P12 of the flow control valve 12 is set to the open state or the closed state, and the third outflow port P13 is also set to the open state or the closed state. Further, the first outflow port P11 is maintained in the closed state. In this case, in the cooling water circulation system 10 shown in FIG. 1, a state in which the cooling water heated in the internal combustion engine 20 is supplied to the heater core 22 and the EGR cooler 23 through the second outflow port P12 of the flow control valve 12 and to them. It is possible to switch between a state in which the supply of cooling water is stopped. Similarly, a state in which the cooling water heated in the internal combustion engine 20 is supplied to the oil cooler 24 through the third outflow port P13 of the flow rate control valve 12 and a state in which the supply of the cooling water to the oil cooler 24 is stopped. You can switch. As described above, in the heat distribution control, the heater core 22, the EGR cooler 23, and the oil cooler 24 can be warmed up by utilizing the heat of the cooling water.

As shown in FIG. 6, the ECU 40 determines whether or not the outlet water temperature TWout becomes larger than the second temperature threshold value TWth2 as the process of step S13 following step S12. The second temperature threshold value TWth2 is set to a value larger than the first temperature threshold value TWth1. When the outlet water temperature TWout is equal to or lower than the second temperature threshold value TWth2, the ECU 40 makes a negative determination in the process of step S13 and continues the heat distribution control in step S12.

When the outlet water temperature TWout becomes larger than the second temperature threshold value TWth2, the ECU 40 makes an affirmative judgment in the process of step S13, and executes wall temperature switching control as the process of step S14. In the wall temperature switching control, the valve position of the flow rate control valve 12 is set in the range from the rotation position P6 to the rotation position P5 shown in FIG. The rotation position P6 is set at a position slightly deviated from the rotation position P3 in the reverse direction X2. By setting the valve position of the flow control valve 12 from the rotation position P6 to the rotation position P5 shown in FIG. 4, the first outflow port P11 of the flow control valve 12 is set to the valve open state or the valve closed state. , The second outflow port P12 and the third outflow port P13 are maintained in the fully open state. In this case, in the cooling water circulation system 10 shown in FIG. 1, the cooling water that has absorbed the heat of the internal combustion engine 20 is supplied to the radiator 21 through the first outflow port P11 of the flow control valve 12, so that the cooling water is supplied to the radiator 21. Can be cooled. In the wall temperature switching control, the ECU 40 adjusts the temperature of the cooling water flowing through the internal combustion engine 20 by changing the open / closed state of the first outflow port P11 according to the load state of the internal combustion engine 20.

Specifically, when the load state of the internal combustion engine 20 is a high load state, the ECU 40 changes the flow rate of the cooling water supplied to the radiator 21 by changing the first outflow port P11 in the valve opening direction. increase. As a result, the cooling water is easily cooled in the radiator 21, so that the temperature of the cooling water supplied to the internal combustion engine 20 is lowered. Therefore, since the wall temperature of the

cylinders

201 and 202 of the internal combustion engine 20 is lowered, knocking is less likely to occur in the internal combustion engine 20. Therefore, it is not necessary to execute the control of shifting the ignition timing of the internal combustion engine 20 to the retard side in order to suppress knocking. As a result, it becomes easy to maintain the ignition timing of the internal combustion engine 20 at the optimum timing, so that the fuel consumption of the internal combustion engine 20 can be improved. In the following, the actual wall temperature of the

cylinders

201 and 202 of the internal combustion engine 20 is simply referred to as "the wall temperature of the internal combustion engine 20".

On the other hand, when the load state of the internal combustion engine 20 is a low load state, the ECU 40 reduces the flow rate of the cooling water supplied to the radiator 21 by changing the first outflow port P11 in the valve closing direction. As a result, it becomes difficult for the cooling water to be cooled, so that the temperature of the cooling water flowing through the internal combustion engine 20 rises. Therefore, since the actual wall temperature of the internal combustion engine 20 rises, the cooling loss of the internal combustion engine 20 is reduced and the friction of the internal combustion engine 20 is reduced. Therefore, the fuel efficiency of the internal combustion engine 20 can be improved.

Next, the details of the wall temperature switching control executed by the ECU 40 will be described. The ECU 40 of the present embodiment utilizes the fact that there is a correlation between the wall temperature of the internal combustion engine 20 and the outlet water temperature TWout of the internal combustion engine 20 as a parameter indicating the wall temperature of the internal combustion engine 20. The outlet water temperature TWout of 20 is used.

As shown in FIG. 5, the ECU 40 includes a target opening degree setting unit 50 and an opening degree control unit 60 for executing wall temperature switching control.
The target opening degree setting unit 50 sets the target outlet water temperature according to the load state of the internal combustion engine 20, and of the valve body of the flow rate control valve 12 for making the actual outlet water temperature TWout follow the set target outlet water temperature. Set the target rotation position Pvb *. In the present embodiment, the control to make the outlet water temperature TWout follow the target outlet water temperature corresponds to the control to make the actual wall temperature of the internal combustion engine 20 follow the target wall temperature. Further, the outlet water temperature TWout corresponds to the temperature of the cooling water flowing through the internal combustion engine 20, and the target outlet water temperature TWout * corresponds to the target water temperature of the cooling water flowing through the internal combustion engine 20. As shown in FIG. 7, the target opening degree setting unit 50 includes a feedforward control unit 51, a feedback control unit 52, and a multiplication unit 53.

The feedforward control unit 51 sets a target outlet water temperature according to the load of the internal combustion engine 20, and then calculates a target rotation position Pv * for feedforward controlling the outlet water temperature TWout of the internal combustion engine 20 to the target outlet water temperature. It is a part. The feed forward control unit 51 includes a rotation speed calculation unit 510, an intake air amount calculation unit 511, an inlet water temperature calculation unit 512, a calorific value calculation unit 513, a target outlet water temperature calculation unit 514, and a flow rate calculation unit 515. It has a subtraction unit 516, a

division units

517a and 517b, a reference target opening degree calculation unit 518, and a filtering unit 519.

The output signal of the crank angle sensor 32 is input to the rotation speed calculation unit 510. The rotation speed calculation unit 510 calculates the rotation speed Np of the internal combustion engine 20 by calculating the crank angle θc based on the output signal of the crank angle sensor 32 and calculating the amount of time change of the calculated crank angle θc. To do.

The output signal of the air flow meter 33 is input to the intake air amount calculation unit 511. The intake air amount calculation unit 511 calculates the intake air amount GA based on the output signal of the air flow meter 33. Since there is a correlation between the intake air amount GA and the load of the internal combustion engine 20, in the present embodiment, the intake air amount GA is used as a parameter representing the load state of the internal combustion engine 20.

The output signal of the first water temperature sensor 30 is input to the inlet water temperature calculation unit 512. The inlet water temperature calculation unit 512 calculates the inlet water temperature TWin of the internal combustion engine 20 based on the output signal of the first water temperature sensor 30.
The rotation speed Np of the internal combustion engine 20 calculated by the rotation speed calculation unit 510 and the intake air amount GA calculated by the intake air amount calculation unit 511 are input to the calorific value calculation unit 513. The calorific value calculation unit 513 calculates the calorific value Q based on the rotation speed Np of the internal combustion engine 20 and the intake air amount GA by using the map shown in FIG. The calorific value Q is the amount of heat transferred from the internal combustion engine 20 to the cooling water. In the map shown in FIG. 8, the calorific value Q increases as the rotational speed Np of the internal combustion engine 20 increases and the intake air amount GA increases.

As shown in FIG. 7, the target outlet water temperature calculation unit 514 includes a rotation speed Np of the internal combustion engine 20 calculated by the rotation speed calculation unit 510 and an intake air amount GA calculated by the intake air amount calculation unit 511. Is entered. The target outlet water temperature calculation unit 514 calculates the target outlet water temperature TWout * based on the rotation speed Np of the internal combustion engine 20 and the intake air amount GA by using the map shown in FIG. In the map shown in FIG. 9, in the region where the rotation speed Np of the internal combustion engine 20 is slow and the intake air amount GA is large, that is, in the region where the internal combustion engine 20 is in a high load state, the target outlet water temperature TWout * is the first low temperature. The target water temperature set value TWa1 is set. Further, in the region where the rotation speed Np of the internal combustion engine 20 is high and the intake air amount GA is small, that is, in the region where the internal combustion engine 20 is in a low load state, the target outlet water temperature TWout * is higher than the first target water temperature set value TWa1. It is set to the high temperature second target water temperature set value TWa2. In the present embodiment, the first target water temperature set value TWa1 corresponds to the first target wall temperature set value, and the second target water temperature set value TWa2 corresponds to the second target wall temperature set value.

As shown in FIG. 7, the rotation speed Np of the internal combustion engine 20 calculated by the rotation speed calculation unit 510 is input to the flow rate calculation unit 515. The flow rate calculation unit 515 calculates the flow rate m when the valve is fully opened based on the rotation speed Np of the internal combustion engine 20 by using the map shown in FIG. The flow rate m when the valve is fully open is the flow rate of the cooling water that passes through the internal combustion engine 20 when all the outflow ports P11 to P13 are in the fully open state. In the present embodiment, since the pump 11 shown in FIG. 1 is a mechanical pump driven based on the power of the internal combustion engine 20, the flow rate m when the valve is fully opened is basically as shown in FIG. , Is proportional to the rotation speed Np of the internal combustion engine 20.

As shown in FIG. 7, the target outlet water temperature TWout * calculated by the target outlet water temperature calculation unit 514 and the inlet water temperature TWin calculated by the inlet water temperature calculation unit 512 are input to the subtraction unit 516. By subtracting the inlet water temperature TWin from the target outlet water temperature TWout *, the subtraction unit 516 calculates the target inlet / outlet water temperature difference ΔT (= TWout * −TWin), which is a deviation between them.

In the division unit 517a, the calorific value Q of the internal combustion engine 20 calculated by the calorific value calculation unit 513 and the target water inlet / outlet temperature difference ΔT calculated by the subtraction unit 516 are input. The division unit 517a calculates the target flow rate m * of the cooling water based on the following equation f1. In addition, "c" in formula f1 shows the specific heat of cooling water. Further, in the formula f1, the mass of the cooling water is approximated by the flow rate of the cooling water.

m * = Q / (c × ΔT) (f1)
The target flow rate m * calculated by the division unit 517a and the valve fully open flow rate m calculated by the flow rate calculation unit 515 are input to the division unit 517b. The division unit 517b calculates the target flow rate ratio Rf (= (m * / m) × 100 [%]) by dividing the target flow rate m * by the flow rate m when the valve is fully open.

The target flow rate ratio Rf calculated by the division unit 517b is input to the reference target opening calculation unit 518. The reference target opening degree calculation unit 518 calculates the target rotation position Pvb * of the valve body 122 of the flow rate control valve 12 from the target flow rate ratio Rf by using the map shown in FIG. The map shown in FIG. 11 is a map for converting the flow rate ratio into the rotation position of the valve body of the flow rate control valve 12. This map is prepared in advance based on the opening ratio characteristic of the first outflow port P11 according to the valve position of the flow control valve 12.

As shown in FIG. 7, the target rotation position Pvb * calculated by the reference target opening degree calculation unit 518 is input to the filtering unit 519. The filtering unit 519 smoothes the target rotation position Pvb * by performing a filtering process based on the low-pass filter on the target rotation position Pvb * calculated by the reference target opening degree calculation unit 518. The target rotation position Pvb * that has been filtered by the filtering unit 519 is input to the multiplication unit 53 as a calculated value of the feedforward control unit 51.

The feedback control unit 52 is a part that calculates a target rotation position Pvb * for feedback controlling the outlet water temperature TWout of the internal combustion engine 20 to the target outlet water temperature. The feedback control unit 52 includes an outlet water temperature calculation unit 520, a subtraction unit 521, and a PI control unit 522.

The output signal of the second water temperature sensor 31 is input to the outlet water temperature calculation unit 520. The outlet water temperature calculation unit 520 calculates the outlet water temperature TWout of the internal combustion engine 20 based on the output signal of the second water temperature sensor 31.
The outlet water temperature TWout of the internal combustion engine 20 calculated by the outlet water temperature calculation unit 520 and the target outlet water temperature TWout * calculated by the target outlet water temperature calculation unit 514 of the feedforward control unit 51 are input to the subtraction unit 521. .. The subtraction unit 521 calculates the outlet water temperature deviation ΔTWout, which is a deviation thereof, by subtracting the outlet water temperature TWout from the target outlet water temperature TWout *.

The outlet water temperature deviation ΔTWout calculated by the subtraction unit 521 is input to the PI control unit 522. The PI control unit 522 calculates the feedback correction amount α for making the outlet water temperature TWout follow the target outlet water temperature TWout * by executing the PI control based on the outlet water temperature deviation ΔTWout. The feedback correction amount α calculated by the PI control unit 522 is input to the multiplication unit 53 as a calculated value of the feedback control unit 52.

The multiplication unit 53 calculates the final target rotation position Pv * by multiplying the target rotation position Pvb *, which is the calculated value of the feedforward control unit 51, by the feedback correction amount α, which is the calculated value of the feedback control unit 52. .. The final target rotation position Pv * calculated by the multiplication unit 53 is output to the opening degree control unit 60 shown in FIG. 5 as a calculated value of the target opening degree setting unit 50.

As shown in FIG. 12, the opening degree control unit 60 includes a subtraction unit 61, a proportional control unit 62, an integration unit 63, an integration control unit 64, an addition unit 65, and a restriction unit 66. ..
The final target rotation position Pv * calculated by the target opening degree setting unit 50 and the valve position Pv of the flow rate control valve 12 detected by the position sensor 125 of the flow rate control valve 12 are input to the subtraction unit 61. .. The subtraction unit 61 calculates the rotation position deviation ΔP (= Pv * −Pv) by subtracting the actual rotation position Pv from the final target rotation position Pv *.

The rotation position deviation ΔP calculated by the subtraction unit 61 is input to the proportional control unit 62. The proportional control unit 62 calculates the proportional term Dp of the duty ratio D by executing the proportional control based on the rotation position deviation ΔP.
The duty ratio D indicates the ratio of the energization time of the actuator device 121 of the flow control valve 12. The duty ratio D of this embodiment is set in the range of "-100 [%] ≤ D ≤ 100 [%]". When the duty ratio D is set to a positive value, the actuator device 121 is energized so that the valve body 122 rotates in the forward rotation direction X1. When the duty ratio D is set to a negative value, the actuator device 121 is energized so that the valve body 122 rotates in the reverse direction X2. Further, the larger the absolute value of the duty ratio D, the longer the energization time of the actuator device 121. Therefore, a substantially proportional relationship as shown in FIG. 13 is established between the duty ratio D and the displacement speed of the valve body 122 of the flow control valve 12.

As shown in FIG. 12, the rotation position deviation ΔP calculated by the subtraction unit 61 is input to the integration unit 63. The integrating unit 63 calculates a temporal integrated value of the rotation position deviation ΔP.
The integral value of the rotation position deviation ΔP calculated by the integral unit 63 is input to the integral control unit 64. The integration control unit 64 calculates the integration term Di of the duty ratio D by executing the integration control based on the integration value of the rotation position deviation ΔP.

The proportional term Dp of the duty ratio D calculated by the proportional control unit 62 and the integral term Di of the duty ratio D calculated by the integral control unit 64 are input to the addition unit 65. The addition unit 65 calculates the final duty ratio D by adding the proportional term Dp of the duty ratio D and the integral term Di of the duty ratio D.

The duty ratio D calculated by the addition unit 65 is input to the restriction unit 66. The limiting unit 66 limits the value of the duty ratio D to "-40 [%] ≤ D ≤ 40 [%]". For example, when the duty ratio D calculated by the addition unit 65 is "60 [%]", the duty ratio D is limited to "40 [%]". Further, for example, when the duty ratio D calculated by the addition unit 65 is "-60 [%]", the duty ratio D is limited to "-40 [%]". By limiting the duty ratio D of the flow control valve 12 in this way, it is possible to suppress the heat generation of the motor of the actuator device 121 and reduce the load applied to the drive unit such as the gear of the actuator device 121. Therefore, it becomes easy to satisfy the requirement for durability of the actuator device 121. The duty ratio D calculated by the limiting unit 66 is input to the flow control valve 12 as an output signal of the ECU 40. By controlling the energization of the actuator device 121 of the flow control valve 12 based on this duty ratio D, the valve position Pv of the valve body 122 of the flow control valve 12 is controlled to follow the final target rotation position Pv *. To.

By the way, when the target outlet water temperature TWout * calculated by the subtraction unit 516 shown in FIG. 7 changes due to a change in the intake air amount GA of the internal combustion engine 20, that is, a change in the load of the internal combustion engine 20. , There is a time delay until the actual outlet water temperature TWout changes to the target outlet water temperature TWout *.

For example, as shown in FIG. 14, if the internal combustion engine 20 is in a high load state due to vehicle acceleration or the like at time t10, the target outlet water temperature TWout * is set at time t10 as shown by the alternate long and short dash line in the figure. 2 The target water temperature set value TWa2 is changed to the first target water temperature set value TWa1. In this case, the actual outlet water temperature TWout reaches the first target water temperature set value TWa1 at the time t11 when the predetermined time T11 has elapsed from the time t10. The delay time T11 at this time is about 5 to 20 seconds.

Further, when the internal combustion engine 20 becomes a low load state due to deceleration of the vehicle at time t12, the target outlet water temperature TWout * increases from the first target water temperature set value TWa1 to the second target water temperature set value TWa2. In this case, the actual outlet water temperature TWout reaches the second target water temperature set value TWa2 at the time t13 when the predetermined time T12 has elapsed from the time t12. The delay time T12 at this time is about 10 to 20 seconds.

Factors that cause such a response delay of about several tens of seconds include, for example, a delay in control instructions in the ECU 40, a delay in response to the valve body 122 of the flow rate control valve 12, a delay in response to the flow rate of cooling water in the cooling water circulation system 10, and cooling. There is a delay in the response of the water temperature.
Specifically, for example, when the internal combustion engine 20 shifts from the low load state to the high load state, the temperature of the cooling water flowing through the internal combustion engine 20 changes in the flow as shown in FIG. As shown in FIG. 15, when the driver first depresses the accelerator pedal, the intake air amount GA of the internal combustion engine 20 increases. Since the target outlet water temperature TWout * is changed as the intake air amount GA increases, the target rotation position Pvb * is changed so as to correspond to the changed target outlet water temperature TWout *. As a result, the valve position Pv of the flow control valve 12 is changed. As a result, the opening degrees of the outflow ports P11 to P13 of the flow rate control valve 12 are changed, so that the flow rate of the cooling water flowing through the cooling water circulation system 10 changes. The amount of heat radiated from the radiator 21 and the amount of heat received by the internal combustion engine 20 change based on the change in the flow rate of the cooling water, resulting in a change in the temperature of the cooling water.

At this time, various response delays occur in the change of each parameter. Specifically, when the amount of depression of the accelerator pedal changes, the response of the intake air amount GA to the change is delayed. This first response delay is due to a delay in the operation of the internal combustion engine 20 and the like.
Further, after the intake air amount GA changes, the response of the valve position Pv of the flow rate control valve 12 and the response of the flow rate of the cooling water of the cooling water circulation system 10 to the change are delayed. This second response delay is due to a response delay of the control logic of the flow control valve 12, a mechanical response delay of the flow control valve 12, and the like.

Further, after the flow rate of the cooling water changes, there is a delay in the response of the heat radiation amount of the radiator 21 and the heat reception amount of the internal combustion engine 20 to the change. This third response delay is due to the performance of the radiator 21, the calorific value of the internal combustion engine 20, and the like.
Further, after the amount of heat radiated from the radiator 21 and the amount of heat received by the internal combustion engine 20 change, there is a delay in the response of the temperature of the cooling water to the change. This fourth response delay is due to the heat capacity of the cooling water and the like.

As described above, if the response of the temperature of the cooling water to the change in the load state of the internal combustion engine 20 is delayed, the wall temperature of the internal combustion engine 20 may deviate from an appropriate temperature for a long period of time.
For example, in the wall temperature switching control, when the internal combustion engine 20 shifts from the low load state to the high load state, the outlet water temperature TWout is lowered to the first target water temperature set value TWa1. In such a situation, if the response of the cooling water temperature is delayed, the state in which the outlet water temperature TWout deviates from the first target water temperature set value TWa1 to the high temperature side may continue. That is, there is a possibility that the wall temperature of the internal combustion engine 20 will continue to be high. In this case, knocking is likely to occur in the internal combustion engine 20, so that the ignition timing control or the like for avoiding knocking is executed in the internal combustion engine 20, which may deteriorate the fuel consumption of the internal combustion engine 20.

Further, in the wall temperature switching control, when the internal combustion engine 20 shifts from the high load state to the low load state, the outlet water temperature TWout is raised to the second target water temperature set value TWa2. In such a situation, if the response of the temperature of the cooling water is delayed, the state in which the outlet water temperature TWout deviates to the low temperature side with respect to the second target water temperature set value TWa2 may continue. That is, there is a possibility that the wall temperature of the internal combustion engine 20 will continue to be low. In this case, the cooling loss of the internal combustion engine 20 increases and the friction increases, so that the fuel consumption of the internal combustion engine 20 may deteriorate.

Deterioration of fuel efficiency of the internal combustion engine due to such a delay in the response of the cooling water temperature has become a remarkable problem in vehicles in recent years. In order to comply with recent fuel economy regulations, internal combustion engines are required to have a high compression ratio, high supercharging, and downsizing. In such an internal combustion engine, knocking is more likely to occur as compared with a conventional internal combustion engine. More specifically, knocking may occur in a region where the wall temperature of the internal combustion engine is lower than before. In such an internal combustion engine, in the map for setting the target outlet water temperature TWout * shown in FIG. 16, the boundary line between the first target water temperature set value TWa1 and the second target water temperature set value TWa2 is set from the first boundary line L11. Knocking can be suppressed by changing to the second boundary line L12, that is, by expanding the region where the target outlet water temperature TWout * is set to the low temperature first target water temperature set value TWa1.

On the other hand, when the vehicle is traveling in the urban mode, the region that the rotation speed Np of the internal combustion engine 20 and the intake air amount GA can take is, for example, the region surrounded by the alternate long and short dash line L20 in FIG. In the map shown in FIG. 16, when the boundary line between the first target water temperature set value TWa1 and the second target water temperature set value TWa2 is set to the first boundary line L11, the area surrounded by the alternate long and short dash line L20. Most of them are in the setting area of the second target water temperature set value TWa2. Therefore, the target outlet water temperature TWout * is rarely switched between the first target water temperature set value TWa1 and the second target water temperature set value TWa2.

On the other hand, when the boundary line between the first target water temperature set value TWa1 and the second target water temperature set value TWa2 is set to the second boundary line L12, the region surrounded by the alternate long and short dash line L20 is the first. It is located so as to straddle the setting area of the target water temperature set value TWa1 and the setting area of the second target water temperature set value TWa2. Therefore, the target outlet water temperature TWout * is frequently switched between the first target water temperature set value TWa1 and the second target water temperature set value TWa2. Therefore, the deterioration of the fuel efficiency of the internal combustion engine due to the delay in the response of the temperature of the cooling water described above becomes remarkable.

In order to eliminate such deterioration of fuel efficiency of the internal combustion engine, the response speed of the temperature of the cooling water should be increased. As described above, the factors that deteriorate the responsiveness of the temperature of the cooling water include the factors corresponding to the first to fourth response delays as shown in FIG. In the present embodiment, among the factors corresponding to the first to fourth response delays, the factor corresponding to the second response delay, that is, the response delay of the flow rate control valve 12 is improved to respond to the temperature of the cooling water. Increase the speed.

Next, a control procedure for increasing the response speed of the temperature of the cooling water executed by the ECU 40 of the present embodiment will be described.
As shown in FIG. 5, the ECU 40 further includes a control parameter changing unit 70. The control parameter changing unit 70 increases the response speed of the temperature of the cooling water by changing the control parameter of the flow rate control valve 12. As shown in FIG. 12, the control parameter changing unit 70 of the present embodiment changes the limit value of the duty ratio D set in the limiting unit 66 as a change of the control parameter of the flow rate control valve 12.

FIG. 17 is a flowchart showing a procedure of a process in which the control parameter changing unit 70 changes the limit value of the duty ratio D. The control parameter changing unit 70 repeatedly executes the process shown in FIG. 17 at a predetermined cycle during the period during which the wall temperature switching control is being executed in the ECU 40.

As shown in FIG. 17, first, as the process of step S20, the control parameter changing unit 70 sets the absolute value | ΔTWout | of the outlet water temperature deviation, which is the deviation between the target outlet water temperature TWout * and the outlet water temperature TWout, as a predetermined value Tth10. Determine if it is greater than. As the outlet water temperature deviation ΔTWout, the calculated value of the subtraction unit 521 shown in FIG. 7 is used. In the present embodiment, the outlet water temperature TWout is set to the actual wall of the internal combustion engine 20 by utilizing the correlation between the outlet water temperature TWout of the cooling water discharged from the internal combustion engine 20 and the actual wall temperature of the internal combustion engine 20. It is used as warm. The outlet water temperature TWout also corresponds to the temperature of the cooling water flowing through the internal combustion engine 20. Further, the target outlet water temperature TWout * corresponds to the target wall temperature, which is the target value of the actual wall temperature of the internal combustion engine.

The control parameter changing unit 70 processes in step S20 when the absolute value | ΔTWout | of the outlet water temperature deviation is equal to or less than the predetermined value Tth10, that is, when the outlet water temperature TWout does not deviate from the target outlet water temperature TWout *. To make a negative judgment. In this case, the control parameter changing unit 70 executes normal control as the process of step S22. The normal control is a process of limiting the value of the duty ratio D to a normal range, that is, a range of “| D | ≦ 40 [%]”.

On the other hand, the control parameter changing unit 70 is in step S20 when the absolute value | ΔTWout | of the outlet water temperature deviation is larger than the predetermined value Tth10, that is, when the outlet water temperature TWout deviates from the target outlet water temperature TWout *. Make a positive judgment in the processing of. In this case, the control parameter changing unit 70 executes the response speed improvement control as the process of step S21. The response speed improvement control is a process of setting the value of the duty ratio D in the range of “| D | ≦ 100 [%]”. That is, the response speed improvement control is a control that relaxes the limitation of the duty ratio D.

When the limitation of the duty ratio D is relaxed from "| D | ≤40 [%]" to "| D | ≤100 [%]", as shown in FIG. 13, the valve body 122 of the flow control valve 12 The displacement speed is likely to be set to a higher speed. Therefore, the flow rate of the cooling water changes earlier. As a result, the actual wall temperature of the internal combustion engine 20 tends to change to the target wall temperature at an early stage.

For example, as shown in FIG. 18, in a situation where the actual wall temperature of the internal combustion engine 20 is the temperature Ts, consider a situation in which the actual wall temperature is changed to the target temperature Tsa. As the flow rate of the cooling water is gradually increased, the temperature of the cooling water also gradually decreases as shown by the dashed arrow in the figure. When the temperature of the cooling water is lowered in this way, the response speed of the temperature of the cooling water is slow, and it takes a long time for the actual wall temperature of the internal combustion engine 20 to change to the target temperature Tsa.

In this regard, if the duty ratio D limitation is relaxed to "| D | ≤100 [%]", the valve body 122 of the flow rate control valve 12 is displaced at high speed, so that the flow rate of the cooling water changes significantly. Therefore, as shown by the solid arrow in FIG. 18, the flow rate of the cooling water increases sharply before the temperature of the cooling water changes. After that, as the temperature of the cooling water decreases, the actual wall temperature of the internal combustion engine 20 changes to the target temperature Tsa. The response rate of the flow rate of the cooling water is faster than the response rate of the temperature of the cooling water. Therefore, it is possible to improve the response speed of the temperature of the cooling water by changing the flow rate of the cooling water as shown by the solid line in FIG.

Next, an operation example of this embodiment will be described with reference to FIG. In FIGS. 19B to 19G, the change of each parameter when the duty ratio D is limited to “| D | ≦ 40 [%]” is shown by a chain double-dashed line, and the duty ratio D is shown. The change of each parameter when the limitation of is relaxed to "| D | ≤100 [%]" is shown by a solid line.

As shown in FIG. 19A, when the intake air amount GA increases at time t20, that is, when the internal combustion engine 20 is in a high load state, the target outlet water temperature TWout * changes from the second target water temperature set value TWa2 to the first target water temperature. The set value is changed to TWa1. Therefore, as shown in FIG. 19C, the outlet water temperature deviation ΔTWout, which is the deviation between the target outlet water temperature TWout * and the outlet water temperature TWout, changes to a negative value. At this time, as shown in FIG. 19C, when the outlet water temperature deviation ΔTWout becomes smaller than “−Tth10”, the response speed improvement control is executed, and the duty ratio D is limited to “| D | ≦”. It is relaxed to "100 [%]".

On the other hand, as the outlet water temperature deviation ΔTWout changes as shown in FIG. 19C, the final target rotation position set based on the outlet water temperature deviation ΔTWout as shown by the alternate long and short dash line in FIG. 19E. Pv * increases. As a result, the rotation position deviation ΔP, which is the deviation between the final target rotation position Pv * and the valve position Pv of the flow control valve 12, increases, so that the duty ratio D calculated by the ECU 40 also increases. As a result, the duty ratio D is set to "100 [%]" as shown in FIG. 19 (D).

By the way, assuming that the duty ratio D is limited to "| D | ≤40 [%]", the valve position Pv of the flow control valve 12 changes as shown by the alternate long and short dash line in FIG. 19 (E). To do. That is, the valve position Pv of the flow control valve 12 changes steeperly to the final target rotation position Pv * when the duty ratio D limitation is relaxed than when the duty ratio D is limited. Therefore, as shown in FIG. 19F, the flow rate of the cooling water changes significantly when the duty ratio D limitation is relaxed than when the duty ratio D is limited. As a result, as shown in FIG. 19 (G), the initial wall temperature of the internal combustion engine 20 is higher when the duty ratio D limitation is relaxed than when the duty ratio D is limited. The change becomes steep.

As shown in FIG. 19 (E), when the valve position Pv of the flow control valve 12 reaches the final target rotation position Pv * after the time t20, the flow rate of the cooling water is changed as shown in FIG. 19 (F). Converges to a predetermined flow rate. As the flow rate of the cooling water increases, as shown in FIG. 19B, the outlet water temperature TWout of the internal combustion engine 20 begins to decrease toward the target outlet water temperature TWout * after time t20. As a result, as shown in FIG. 19C, the outlet water temperature deviation ΔTWout changes toward zero. When the outlet water temperature deviation ΔTWout reaches “−Tth10” at time t21, normal control is executed.

As shown in FIGS. 19 (A), when the intake air amount GA decreases at time t22, that is, when the internal combustion engine 20 becomes a low load state, FIGS. 19 (B) to 19 (G) show. As shown, the outlet water temperature TWout of the internal combustion engine 20, the outlet water temperature deviation ΔTWout, the duty ratio D, the valve position Pv of the flow rate control valve 12, the flow rate of the cooling water, and the actual wall temperature of the internal combustion engine 20 change. Also in this case, as shown in FIG. 19 (G), the actual wall temperature of the internal combustion engine 20 is higher when the duty ratio D limitation is relaxed than when the duty ratio D is limited. Can be changed sharply.

As described above, the target opening degree setting unit 50 of the present embodiment sets the target outlet water temperature TWout * to the first target water temperature set value TWa1 when the internal combustion engine 20 is in a high load state, and the internal combustion engine 20. Is in a low load state, the target outlet water temperature TWout * is set to the second target water temperature set value TWa2. Further, the control parameter changing unit 70 is an internal combustion engine when the absolute value | ΔTWout | of the outlet water temperature deviation is larger than the predetermined value Tth10 than when the absolute value | ΔTWout | of the outlet water temperature deviation is equal to or less than the predetermined value Tth10. The limitation of the duty ratio D is relaxed so that the response speed of the temperature of the cooling water flowing through 20 is increased. As described above, in the present embodiment, the duty ratio D corresponds to the control parameter changed according to the absolute value | ΔTWout | of the outlet water temperature deviation.

Next, the operation and effect of the ECU 40 of the present embodiment will be described.
According to the ECU 40 of the present embodiment, the temperature of the cooling water flowing through the internal combustion engine 20 is switched according to the load state of the internal combustion engine 20, so that the fuel consumption of the internal combustion engine 20 can be improved.

Further, when the absolute value | ΔTWout | of the outlet water temperature deviation becomes large, the limitation of the duty ratio D is relaxed, so that the response speed of the temperature of the cooling water flowing through the internal combustion engine 20 becomes faster. As a result, the outlet water temperature TWout changes rapidly toward the target outlet water temperature TWout *. That is, the actual wall temperature of the internal combustion engine 20 rapidly changes toward the target wall temperature. Therefore, since the time during which the actual wall temperature of the internal combustion engine 20 deviates significantly from the target wall temperature can be shortened, deterioration of fuel efficiency of the internal combustion engine 20 caused by such dissociation can be suppressed. In other words, the fuel efficiency of the internal combustion engine 20 can be improved.

<Second Embodiment>
Next, the ECU 40 of the flow rate control valve 12 of the second embodiment will be described. Hereinafter, the differences from the ECU 40 of the first embodiment will be mainly described.
As shown in FIG. 20, the outlet water temperature deviation ΔTWout, the operating frequency Fv of the actuator device 121 of the flow control valve 12, and the outlet water temperature TWout of the internal combustion engine 20 are input to the control parameter changing unit 70 of the present embodiment. There is. The control parameter changing unit 70 uses these parameters to execute the process shown in FIG. 21 instead of the process shown in FIG.

As shown in FIG. 21, when the control parameter changing unit 70 makes an affirmative judgment in the process of step S20, that is, when the absolute value | ΔTWout | of the outlet water temperature deviation is larger than the predetermined value Tth10, step S23. As the process of, the operation frequency Fv of the actuator device 121 and the outlet water temperature TWout of the internal combustion engine 20 are acquired. The outlet water temperature TWout of the internal combustion engine 20 is used as a parameter representing the temperature of the cooling water flowing through the flow control valve 12.

On the other hand, the control parameter changing unit 70 acquires the operation frequency of the actuator device 121 by repeatedly executing the process shown in FIG. 22 at a predetermined calculation cycle. As shown in FIG. 22, the control parameter changing unit 70 first acquires the valve position Pv from the flow rate control valve 12 as the process of step S30. The control parameter changing unit 70 acquires the valve position Pv of the flow control valve 12 at a predetermined calculation cycle by executing the process of step S30 each time the process shown in FIG. 22 is repeatedly executed at a predetermined calculation cycle. doing.

The control parameter changing unit 70 calculates the differential value of the valve position Pv based on the time-series data of the valve position Pv of the flow rate control valve 12 repeatedly acquired in a predetermined calculation cycle as the process of step S31 following step S30. By doing so, the displacement speed Vv of the valve body 122 of the flow control valve 12 is calculated. Further, as the process of step S32 following step S31, the control parameter changing unit 70 calculates the integrated value of the absolute value | Vv | of the displacement speed of the valve body 122 of the flow control valve 12 in the predetermined period from the present to the predetermined time before. By calculating, the actual integrated displacement amount IDv of the valve body 122 of the flow control valve 12 is calculated.

Further, the control parameter changing unit 70 executes the processes of steps S33 and S34 in parallel with the processes of steps S31 and S32. As the process of step S33, the control parameter changing unit 70 reads the maximum displacement speed Vvmax of the valve body 122 of the flow control valve 12 when the duty ratio D is “100 [%]” from the memory. The maximum displacement speed Vvmax of the valve body 122 of the flow control valve 12 is stored in the memory as a predetermined default value. As the process of step S34, the control parameter changing unit 70 calculates the integrated value of the maximum displacement speed Vvmax of the valve body 122 of the flow control valve 12 in a predetermined period from the present to a predetermined time before, thereby causing the flow control valve 12 to change. The maximum integrated displacement amount IDvmax of the valve body 122 is calculated.

Following the processing of steps S32 and S34, the control parameter changing unit 70 calculates the operation frequency Fv of the valve body 122 of the flow control valve 12 based on the following equation f2 as the processing of step S35.
Fv = IDv / IDvmax (f2)
FIG. 23 shows the valve position Pv of the flow control valve 12, the displacement speed Vv of the valve body 122 of the flow control valve 12, the actual integrated displacement amount IDv, and the operation calculated by the control parameter changing unit 70 through the process shown in FIG. It shows the transition of the frequency Fv. When the valve position Pv of the flow control valve 12 changes as shown in FIG. 23 (A), the displacement velocity Vv of the valve body 122 of the flow control valve 12 changes as shown in FIG. 23 (B). In this case, the actual integrated displacement amount IDv of the valve body 122 of the flow control valve 12 changes as shown in FIG. 23 (C).

For example, when the valve position Pv of the flow control valve 12 does not change at time t30 as shown in FIG. 23 (A), the displacement speed Vv also does not change as shown in FIG. 23 (B). Therefore, as shown in FIG. 23C, the actual integrated displacement amount IDv does not increase after the time t30. On the other hand, the maximum integrated displacement amount IDvmax increases monotonically with the passage of time as shown by the alternate long and short dash line in FIG. 23 (C).

Then, the operation frequency Fv calculated from the actual integrated displacement amount IDv and the maximum integrated displacement amount IDvmax based on the above equation f2 changes as shown in FIG. 23 (D). That is, after the time t30, the operation frequency Fv decreases.
On the other hand, as shown in FIG. 21, the control parameter changing unit 70 has an operation frequency Fv smaller than a predetermined frequency Fth20 and a cooling water temperature Tv of the flow rate control valve 12 as the process of step S24 following the process of step S23. It is determined whether or not the temperature is lower than the predetermined temperature Tth20. When the operation frequency Fv is smaller than the predetermined frequency Fth20 and the cooling water temperature Tv of the flow rate control valve 12 is smaller than the predetermined temperature Tth20, the control parameter changing unit 70 makes an affirmative judgment in the process of step S24, and the subsequent step As the process of S21, the response speed improvement control is executed. The control parameter changing unit 70 uses a map as shown in FIG. 24 in the response speed improvement control to limit the upper limit value DLmax and the lower limit value of the duty ratio D according to the absolute value | ΔTWout | of the outlet water temperature deviation. Change the value DLmin. As shown in FIG. 24, the control parameter changing unit 70 sets the upper limit DLmax from "40 [%]" to "100 [%] as the absolute value | ΔTWout | of the outlet water temperature deviation becomes larger than the predetermined value Tth10. Gradually increase until. Further, the control parameter changing unit 70 gradually sets the lower limit value DLmin from "-40 [%]" to "-100 [%]" as the absolute value | ΔTWout | of the outlet water temperature deviation becomes larger than the predetermined value Tth10. To reduce.

On the other hand, as shown in FIG. 21, the control parameter changing unit 70 steps when the operation frequency Fv is a predetermined frequency Fth20 or more, or when the cooling water temperature Tv of the flow rate control valve 12 is a predetermined temperature Tth20 or more. A negative determination is made in the process of S24, and normal control is executed as the process of the following step S22.

Next, the operation and effect of the ECU 40 of the present embodiment will be described.
When the operation frequency Fv is a predetermined frequency Fth20 or more, the temperature of the actuator device 121 may rise due to heat generated by the actuator device 121 of the flow control valve 12. Further, when the cooling water temperature Tv of the flow control valve 12 is equal to or higher than the predetermined temperature Tth20, the temperature of the actuator device 121 may rise in the same manner. In a situation where the temperature of the actuator device 121 is rising, if the limitation of the duty ratio D of the flow control valve 12 is relaxed by further executing the response speed improvement control, the actuator device 121 is more likely to generate heat. The temperature of 121 may rise excessively. An excessive rise in the temperature of the actuator device 121 is not preferable because it may adversely affect the durability of the actuator device 121.

In this regard, according to the ECU 40 of the present embodiment, when the operation frequency Fv is a predetermined frequency Fth20 or more, or when the cooling water temperature Tv of the flow rate control valve 12 is a predetermined temperature Tth20 or more, that is, the durability of the actuator device 121 When there is a possibility of adversely affecting the sex, the normal control is executed without executing the response speed improvement control. Therefore, deterioration of the durability of the actuator device 121 can be avoided.

<Third Embodiment>
Next, the ECU 40 of the flow rate control valve 12 of the third embodiment will be described. Hereinafter, the differences from the ECU 40 of the first embodiment will be mainly described.
In the ECU 40 of the present embodiment, the filtering unit 519 shown in FIG. 7 performs filtering processing on the target rotation position Pvb * as shown in FIG. 25. As shown in FIG. 25, the filtering unit 519 includes a subtraction unit 5190, a division unit 5191, and an addition unit 5192.

In the following, the target rotation position Pvb * input to the filtering unit 519, that is, the target rotation position Pvb * before the filtering process is performed is referred to as "target rotation position Pvb * _in before the filter". Further, the target rotation position Pvb * output from the filtering unit 519, that is, the target rotation position Pvb * after the filtering process is performed is referred to as "target rotation position Pvb * _out after filtering".

The subtraction unit 5190 calculates the deviation ΔPvb * by subtracting the target rotation position Pvb * _out after the filter from the target rotation position Pvb * _in before the filter.
The division unit 5191 calculates the amount of change DPvb * by dividing the multiplication value of the deviation ΔPvb * calculated by the subtraction unit 5190 and the calculation cycle dT by a predetermined smoothing time constant τ.

The addition unit 5192 calculates the next target rotation position Pvb * _out by adding the change amount DPvb * to the target rotation position Pvb * _out one calculation cycle before.
The process executed by the filtering unit 519 shown in FIG. 25 can be expressed by the following equation f3. In addition, in the formula f3, "target rotation position Pvb * _out (n-1)" indicates the target rotation position Pvb * _out calculated one calculation cycle before.

Pvb * _out = Pvb * _out (n-1) + {Pvb * -Pvb * _out (n-1)} x dT / τ (f3)
On the other hand, as shown in FIG. 26, the control parameter changing unit 70 of the present embodiment replaces the method of relaxing the limit value of the duty ratio D in the response speed improvement control, and the smoothing time constant of the filtering unit 519. By adopting the method of changing τ, the response delay of the flow control valve 12 is improved, and the response speed of the temperature of the cooling water is increased.

Next, a procedure of processing executed by the control parameter changing unit 70 of the present embodiment will be described.
As shown by the broken line in FIG. 5, the output signals of the outside air temperature sensor 34 and the vehicle speed sensor 35 mounted on the vehicle are captured in the ECU 40 of the present embodiment. The outside air temperature sensor 34 detects the outside air temperature Tout, which is the outside air temperature of the vehicle, and outputs a signal according to the detected outside air temperature Tout. The vehicle speed sensor 35 detects the vehicle speed Vc, which is the traveling speed of the vehicle, and outputs a signal corresponding to the detected vehicle speed Vc.

The control parameter changing unit 70 further uses the outside air temperature Tout and the vehicle speed Vc to execute the process shown in FIG. 27. The control parameter changing unit 70 repeatedly executes the process shown in FIG. 27 at a predetermined cycle during the period when the wall temperature switching control is being executed in the ECU 40.
As shown in FIG. 27, first, as the process of step S40, the control parameter changing unit 70 determines whether or not the absolute value | ΔTWout | of the outlet water temperature deviation is larger than the predetermined value Tth10. When the absolute value | ΔTWout | of the outlet water temperature deviation is equal to or less than the predetermined value Tth10, the control parameter changing unit 70 makes a negative determination in the process of step S40, and executes normal control as the process of step S44. The normal control is a control using a predetermined first time constant τ1 as the smoothing time constant τ.

On the other hand, when the absolute value | ΔTWout | of the outlet water temperature deviation is larger than the predetermined value Tth10, the control parameter changing unit 70 acquires the outside air temperature Tout and the vehicle speed Vc as the process of step S41, and then the process of step S42. As a result, it is determined whether or not the outside air temperature Tout is larger than the predetermined temperature Tth30 and the vehicle speed Vc is smaller than the predetermined speed Vth30. When the outside air temperature Tout is larger than the predetermined temperature Tth30 and the vehicle speed Vc is smaller than the predetermined speed Vth30, the control parameter changing unit 70 makes an affirmative judgment in the process of step S42, and determines the response speed as the subsequent process of step S43. Perform improvement control. The control parameter changing unit 70 changes the smoothing time constant τ according to the absolute value | ΔTWout | of the outlet water temperature deviation by using the map as shown in FIG. 28 in the response speed improvement control. As shown in FIG. 28, the control parameter changing unit 70 sets the smoothing time constant τ from the first time constant τ1 to the second time constant τ2 as the absolute value | ΔTWout | of the outlet water temperature deviation becomes larger than the predetermined value Tth10. Reduce to.

On the other hand, as shown in FIG. 27, when the outside air temperature Tout is the predetermined temperature Tth30 or less and the vehicle speed Vc is the predetermined speed Vth30 or more, the control parameter changing unit 70 makes a negative determination in the process of step S42. To do. In this case, the control parameter changing unit 70 executes normal control as the process of step S44. That is, the control parameter changing unit 70 sets the smoothing time constant τ to the first time constant τ1.

As described above, in the present embodiment, the smoothing time constant τ corresponds to the control parameter changed according to the absolute value | ΔTWout | of the outlet water temperature deviation.
Next, the operations and effects of the flow control valve 12 and the ECU 40 of the present embodiment will be described.

In the filtering unit 519 shown in FIG. 25, the larger the value of the smoothing time constant τ, the easier it is for the calculated value of the target rotation position Pvb * _out to be stable. Therefore, in order to secure the control stability of the flow control valve 12, it is necessary to increase the value of the smoothing time constant τ to some extent. However, when the smoothing time constant τ is still set to the first time constant τ1 of the normal control, the response speed of the target rotation position Pvb * _out changes when the intake air amount GA of the internal combustion engine 20 changes. As a result, the response speed of the actual wall temperature of the internal combustion engine 20 may decrease.

Specifically, as shown in FIG. 29 (A), when the intake air amount GA increases at time t40, that is, when the internal combustion engine 20 is in a high load state, it is shown by a alternate long and short dash line in FIG. 29 (B). The target outlet water temperature TWout * is changed from the second target water temperature set value TWa2 to the first target water temperature set value TWa1. Therefore, as shown in FIG. 29 (C), the outlet water temperature deviation ΔTWout changes to a negative value. Due to this, as shown in FIG. 29C, the outlet water temperature deviation ΔTWout changes in the negative direction at time t40. In response to such a change in the outlet water temperature deviation ΔTWout, if the time constant τ as shown by the alternate long and short dash line in FIG. 29 (E) remains fixed to the first time constant τ1, FIG. The target rotation position Pvb * _out changes as shown by the alternate long and short dash line on 29 (D). As a result, the outlet water temperature TWout of the internal combustion engine 20, the flow rate of the cooling water, and the wall temperature of the internal combustion engine 20 change as shown by the alternate long and short dash lines in FIGS. 29 (B), (C), and (G).

On the other hand, in the cooling water circulation system 10 of the present embodiment, as shown in FIG. 29C, the outlet water temperature TWout changes in the negative direction at the time t40, so that the outlet water temperature deviation ΔTWout is smaller than “−Tth10”. Then, as shown by the solid line in FIG. 29 (E), the smoothing time constant τ decreases from the first time constant τ1 to the second time constant τ2. As a result, as shown by the solid line in FIG. 29 (D), the response speed of the target rotation position Pvb * _out is higher than that in the case where the smoothing time constant τ remains fixed to the first time constant τ1. Will respond faster. As a result, as shown by solid lines in FIGS. 29 (B), (C), and (G), the outlet water temperature TWout of the internal combustion engine 20, the flow rate of the cooling water, and the wall temperature of the internal combustion engine 20 have a smoothing time constant τ. Will respond faster than if it remains fixed at the first time constant τ1.

Further, as shown in FIG. 29 (A), even when the intake air amount GA decreases at time t41, that is, when the internal combustion engine 20 is in a low load state, the smoothing time constant τ is similarly obtained. The response speed of each parameter is improved as compared with the case where is fixed to the first time constant τ1.

Further, in the cooling water circulation system 10 of the present embodiment, when the absolute value | ΔTWout | of the outlet water temperature deviation is equal to or less than the predetermined value Tth10, the smoothing time constant τ is larger than the second time constant τ2 at the first hour. Since the constant τ1 is set, the stability of the calculated value of the target rotation position Pvb * _out can be ensured.

On the other hand, in a situation where the outside air temperature Tout is low or the vehicle speed Vc is high, the heat dissipation performance of the radiator 21 is improved, so that the controllability of the cooling water temperature may deteriorate. In such a situation, if the stability of the calculated value of the target rotation position Pvb * _out is lowered by reducing the smoothing time constant τ, it may become extremely difficult to appropriately control the wall temperature of the internal combustion engine 20. Highly sexual.

In this respect, in the cooling water circulation system 10 of the present embodiment, even when the absolute value | ΔTWout | of the outlet water temperature deviation is larger than the predetermined value Tth10, the outside air temperature Tout is the predetermined temperature Tth30 or less and the vehicle speed Vc. When is equal to or higher than the predetermined speed Vth30, the normal control is executed without executing the response speed improvement control. That is, since the smoothing time constant τ is still set to the first time constant τ1 which is larger than the second time constant τ2, the stability of the calculated value of the target rotation position Pvb * _out can be ensured. As a result, it is possible to appropriately control the wall temperature of the internal combustion engine 20.

<Fourth Embodiment>
Next, the ECU 40 of the flow rate control valve 12 of the fourth embodiment will be described. Hereinafter, the differences from the ECU 40 of the first embodiment will be mainly described.
The ECU 40 of the present embodiment has factors corresponding to the third response delay and the fourth response delay among the factors corresponding to the first to fourth response delays shown in FIG. 15, that is, the performance of the radiator 21 and the internal combustion engine. By improving the calorific value of 20 and the heat capacity of the cooling water, the response speed of the temperature of the cooling water is increased. Hereinafter, the configurations of the flow rate control valve 12 and the ECU 40 of the present embodiment will be described.

As shown in FIG. 30, the target rotation position calculation value Pv * calculated by the multiplication unit 53 and the outlet water temperature deviation ΔTWout calculated by the subtraction unit 521 are input to the control parameter change unit 70 of the ECU 40. There is. The control parameter changing unit 70 sets the final target rotation position Pv ** as shown in FIG. 31 based on the outlet water temperature deviation ΔTWout.

That is, when the outlet water temperature deviation ΔTWout is smaller than “−Tth10”, the control parameter changing unit 70 executes the first response speed improvement control. The first response speed improvement control is a control for setting the aperture ratio of the first outflow port P11 to "100 [%]". Specifically, the control parameter changing unit 70 sets the final target rotation position Pv ** at the rotation position P5 shown in FIG.

Further, as shown in FIG. 31, the control parameter changing unit 70 executes normal control when the outlet water temperature deviation ΔTWout is in the range of “−Tth10” to “Tth10”. The normal control is a control in which the aperture ratio of the first outflow port P11 is variably set in the range of "0 [%]" to "100 [%]". Specifically, the control parameter changing unit 70 uses the target rotation position calculation value Pv * that is variably set according to the outlet water temperature deviation ΔTWout as the final target rotation position Pv **.

Further, as shown in FIG. 31, the control parameter changing unit 70 executes the second response speed improvement control when the outlet water temperature deviation ΔTWout is larger than “Tth10”. The second response speed improvement control is a control for setting the aperture ratio of the first outflow port P11 to "0 [%]". Specifically, the control parameter changing unit 70 sets the final target rotation position Pv ** to the rotation position P0 shown in FIG.

FIG. 32 is a flowchart showing a procedure of processing executed by the control parameter changing unit 70. The control parameter changing unit 70 repeatedly executes the process shown in FIG. 32 at a predetermined calculation cycle.
As shown in FIG. 32, the control parameter changing unit 70 first determines, as the process of step S40, whether or not the outlet water temperature deviation ΔTWout is larger than “−Tth10”. When the outlet water temperature deviation ΔTWout is larger than “Tth10”, the control parameter changing unit 70 makes an affirmative determination in the process of step S40, and executes the second response speed improvement control as the subsequent process of step S41. That is, the control parameter changing unit 70 sets the final target rotation position Pv ** at the rotation position P0 shown in FIG. As a result, the aperture ratio of the first outflow port P11 is set to "0 [%]".

As shown in FIG. 32, when the outlet water temperature deviation ΔTWout is “Tth10” or less, the control parameter changing unit 70 makes a negative determination in the process of step S40, and determines that the outlet water temperature deviation ΔTWout is the subsequent process of step S42. Judges whether or not is smaller than "-Tth10". When the outlet water temperature deviation ΔTWout is smaller than “−Tth10”, the control parameter changing unit 70 makes an affirmative determination in the process of step S42, and executes the first response speed improvement control as the subsequent process of step S43. That is, the control parameter changing unit 70 sets the final target rotation position Pv ** at the rotation position P5 shown in FIG. As a result, the aperture ratio of the first outflow port P11 is set to "100 [%]".

As shown in FIG. 32, when the control parameter changing unit 70 makes a negative judgment in the process of step S42, that is, when the outlet water temperature deviation ΔTWout is “−Tth10” or more and “Tth10” or less. , Normal control is executed as the process of step S44. That is, the control parameter changing unit 70 uses the target rotation position calculation value Pv * that is variably set according to the outlet water temperature deviation ΔTWout as the final target rotation position Pv **.

As described above, in the present embodiment, the target rotation position of the flow rate control valve 12 corresponds to the control parameter changed according to the absolute value | ΔTWout | of the outlet water temperature deviation.
Next, the operations and effects of the flow control valve 12 and the ECU 40 of the present embodiment will be described.

As shown in FIG. 33 (A), when the intake air amount GA increases at time t50, that is, when the internal combustion engine 20 is in a high load state, the target outlet water temperature is shown by the alternate long and short dash line in FIG. 33 (B). TWout * is changed from the second target water temperature set value TWa2 to the first target water temperature set value TWa1. Therefore, as shown in FIG. 33C, the outlet water temperature deviation ΔTWout changes to a negative value. At this time, as shown by the alternate long and short dash line in FIG. 33 (E), when the control parameter changing unit 70 is executing the normal control, it is indicated by the alternate long and short dash line in FIG. 33 (D). , The final target rotation position Pv ** gradually changes to the rotation position P6 with the passage of time. Therefore, as shown by the alternate long and short dash line in FIGS. 33 (B), (F), and (G), the outlet water temperature TWout, the flow rate of the cooling water, and the wall temperature of the internal combustion engine 20 also change with the passage of time after time t50. It changes gradually.

On the other hand, in the flow rate control valve 12 of the present embodiment, as shown by the solid line in FIG. 33 (C), when the outlet water temperature deviation ΔTWout becomes smaller than “−Tth10” at time t50, it is shown in FIG. 33 (E). As described above, the first response speed improvement control is executed. Therefore, as shown by the solid line in FIG. 33 (D), the final target rotation position Pv ** is immediately set to the rotation position P6, and the aperture ratio of the first outflow port P11 is set to "100 [%]". Will be done. As a result, as shown by the solid line in FIG. 33 (F), the flow rate of the cooling water changes sharply at time t50. As a result, the flow rate of the cooling water flowing through the radiator 21 is immediately increased, so that the responsiveness of the heat radiation amount in the radiator 21 can be improved. As a result, as shown by the solid line in FIG. 33 (B), the response speed of the outlet water temperature TWout is improved as compared with the case where the normal control is executed, and as a result, it is shown by the solid line in FIG. 33 (G). As a result, the response speed of the wall temperature of the internal combustion engine 20 can be improved. Therefore, the fuel efficiency of the internal combustion engine 20 can be improved.

Further, as shown in FIG. 33 (A), when the intake air amount GA decreases at time t51, that is, when the internal combustion engine 20 is in a low load state, the target is shown by the alternate long and short dash line in FIG. 33 (B). The outlet water temperature TWout * is changed from the first target water temperature set value TWa1 to the second target water temperature set value TWa2. Therefore, as shown by the solid line in FIG. 33C, the outlet water temperature deviation ΔTWout changes to a positive value. At this time, if the control parameter changing unit 70 is executing the normal control as shown by the alternate long and short dash line in FIG. 33 (E), FIGS. 33 (B), (D), (F), As shown by the alternate long and short dash line in (G), the outlet water temperature TWout, the final target rotation position Pv **, the flow rate of the cooling water, and the wall temperature of the internal combustion engine 20 gradually change.

On the other hand, in the flow control valve 12 of the present embodiment, when the outlet water temperature deviation ΔTWout becomes larger than “Tth10” at time t51 as shown in FIG. 33 (C), it is shown by a solid line in FIG. 33 (E). The second response speed improvement control is executed so that the opening ratio of the first outflow port P11 is set to "0 [%]". As a result, as shown by solid lines in FIGS. 33 (B), (D), (F), and (G), the outlet water temperature TWout, the final target rotation position Pv **, the flow rate of the cooling water, and the internal combustion engine 20. The wall temperature will respond faster than when performing normal control.

As described above, according to the flow control valve 12 and the ECU 40 of the present embodiment, when the load state of the internal combustion engine 20 changes, the wall temperature of the internal combustion engine 20 changes rapidly toward the target wall temperature. .. As a result, the time during which the wall temperature of the internal combustion engine 20 deviates significantly from the target wall temperature can be shortened, so that deterioration of fuel efficiency of the internal combustion engine 20 caused by such dissociation can be suppressed. That is, the fuel efficiency of the internal combustion engine 20 can be improved.

(Modification example)
Next, a modification of the ECU 40 of the flow rate control valve 12 of the fourth embodiment will be described.
In the control parameter changing unit 70 of this modification, when the outlet water temperature deviation ΔTWout changes from a value smaller than “−Tth10” to a value larger than “−Tth10”, the outlet water temperature deviation ΔTWout becomes “−Tth10 + β”. By exceeding the above, the first response speed improvement control is shifted to the normal control. Further, in the control parameter changing unit 70, when the outlet water temperature deviation ΔTWout changes from a value larger than “Tth10” to a value smaller than “Tth10”, the outlet water temperature deviation ΔTWout exceeds “Tth10-β”. Then, the second response speed improvement control is shifted to the normal control. The predetermined value β is set to a value larger than zero.

As described above, in the control parameter changing unit 70 of the present modification, the threshold value used when switching between the normal control and the first response speed improvement control, and when switching between the normal control and the second response speed improvement control. Hysteresis is provided at the threshold used. According to such a configuration, it is possible to avoid a situation in which control is frequently switched when the outlet water temperature deviation ΔTWout changes near the threshold value.

<Fifth Embodiment>
Next, the ECU 40 of the flow rate control valve 12 of the fifth embodiment will be described. Hereinafter, the differences from the ECU 40 of the fourth embodiment will be mainly described.
As shown by the broken line in FIG. 5, the output signal of the oil temperature sensor 36 mounted on the vehicle is captured in the ECU 40 of the present embodiment. The oil temperature sensor 36 detects the oil temperature Toil, which is the temperature of the lubricating oil that lubricates the internal combustion engine 20, and outputs a signal corresponding to the detected oil temperature Toil.

Further, the ECU 40 can communicate with the air conditioning ECU 37 mounted on the vehicle. The air-conditioning ECU 37 heats and cools the interior of the vehicle by comprehensively controlling the air-conditioning device 38 mounted on the vehicle. For example, the air conditioning ECU 37 controls the air conditioning device 38 so that the air flowing through the air conditioning duct flows through the heater core 22 shown in FIG. 1 when heating the interior of the vehicle. As a result, the air heated in the heater core 22 is blown into the vehicle interior through the air conditioning duct to heat the vehicle interior. By communicating with the air-conditioning ECU 37, the ECU 40 can acquire information on whether or not heating or cooling of the vehicle interior is being performed, for example.

In the flow control valve 12 of the present embodiment, the opening ratios of the outflow ports P11 to P13 with respect to the position of the valve body 122 are set as shown in FIGS. 34 (A) to 34 (C). As shown in FIGS. 34 (A) to 34 (C), in the flow control valve 12 of the present embodiment, the rotation position P7 is further set as the valve position. The rotation position P7 is a position set in the normal rotation direction X1 with respect to the rotation position P5. When the valve position of the flow control valve 12 reaches the rotation position P7, the opening ratio of the first outflow port P11 is set to "100 [%]", and the second outflow port P12 and the third outflow port P13 The aperture ratio is set to "0 [%" ".

Similar to the control parameter changing unit 70 of the fourth embodiment shown in FIG. 30, the control parameter changing unit 70 of the present embodiment also has the target rotation position calculation value Pv * calculated by the multiplication unit 53 and the subtracting unit 521. The calculated outlet water temperature deviation ΔTWout is input. The control parameter changing unit 70 sets the final target rotation position Pv ** as shown in FIG. 35 based on the outlet water temperature deviation ΔTWout.

That is, when the outlet water temperature deviation ΔTWout is smaller than “−Tth10”, the control parameter changing unit 70 executes the first response speed improvement control. The first response speed improvement control is a control in which the aperture ratio of the first outflow port P11 is set to "100 [%] and the aperture ratios of the other outflow ports P12 and P13 are set to" 0 [%] ". is there. Specifically, the control parameter changing unit 70 sets the final target rotation position Pv ** at the rotation position P7 shown in FIG. 34.

Further, as shown in FIG. 35, the control parameter changing unit 70 executes normal control when the outlet water temperature deviation ΔTWout is in the range of “−Tth10” to “Tth10”. The normal control is a control using the target rotation position calculation value Pv * that is variably set according to the outlet water temperature deviation ΔTWout as the final target rotation position Pv **.

Further, as shown in FIG. 35, the control parameter changing unit 70 executes the second response speed improvement control when the outlet water temperature deviation ΔTWout is larger than “Tth10”. The second response speed improvement control is a control for setting the aperture ratios of all the outflow ports P11 to P13 to "0 [%]". Specifically, the control parameter changing unit 70 sets the final target rotation position Pv ** to the rotation position P0 shown in FIG. 34.

FIG. 36 is a flowchart showing a procedure of processing executed by the control parameter changing unit 70. The control parameter changing unit 70 repeatedly executes the process shown in FIG. 36 at a predetermined calculation cycle.
As shown in FIG. 36, the control parameter changing unit 70 first determines whether or not the outlet water temperature deviation ΔTWout is larger than “Tth10” as the process of step S50. When the outlet water temperature deviation ΔTWout is larger than “Tth10”, the control parameter changing unit 70 makes an affirmative decision in the process of step S50, and acquires the operating state of the air conditioner 38 from the air conditioner ECU 37 as the subsequent process of step S51. At the same time, information on the oil temperature Tool is acquired through the oil temperature sensor 36. In addition to the information on whether or not the air conditioner 38 is operating, the operating state of the air conditioner 38 includes information on whether cooling or heating is performed when the air conditioner 38 is operating. include.

The control parameter changing unit 70 determines whether or not the air conditioner 38 is not heated and the oil temperature Tool is smaller than the predetermined temperature Tth50 as the process of step S52 following step S51. When the air conditioner 38 is not heated and the oil temperature Tool is smaller than the predetermined temperature Tth50, the control parameter changing unit 70 makes an affirmative judgment in the process of step S52, and as the subsequent process of step S53, determines affirmatively. The second response speed improvement control is executed. That is, the control parameter changing unit 70 sets the final target rotation position Pv ** at the rotation position P0 shown in FIG. 34. As a result, the aperture ratios of all the outflow ports P11 to P13 are set to "0 [%]".

When the control parameter changing unit 70 makes a negative determination in the process of step S50, it determines whether or not the outlet water temperature deviation ΔTWout is smaller than “−Tth10” as the process of step S54. When the outlet water temperature deviation ΔTWout is smaller than “−Tth10”, the control parameter changing unit 70 makes an affirmative judgment in the process of step S54, and acquires the operating state of the air conditioner 38 from the air conditioner ECU 37 as the subsequent process of step S55. At the same time, the oil temperature Tool information is acquired through the oil temperature sensor 36.

The control parameter changing unit 70 determines whether or not the air conditioner 38 is not heated and the oil temperature Tool is smaller than the predetermined temperature Tth50 as the process of step S56 following step S55. When the air conditioner 38 is not heated and the oil temperature Tool is smaller than the predetermined temperature Tth50, the control parameter changing unit 70 makes an affirmative judgment in the process of step S56, and as the subsequent process of step S57, determines affirmatively. The first response speed improvement control is executed. That is, the control parameter changing unit 70 sets the final target rotation position Pv ** at the rotation position P7 shown in FIG. 34. As a result, the opening ratio of the first outflow port P11 is set to "100 [%]", and the opening ratios of the other outflow ports P12 and P13 are set to "0 [%]".

When the control parameter changing unit 70 makes a negative determination in the process of step S54, that is, when the outlet water temperature deviation ΔTWout is “−Tth10” or more and “Tth10” or less, the process of step S58 is usually performed. Take control. That is, the control parameter changing unit 70 uses the target rotation position calculation value Pv * that is variably set according to the outlet water temperature deviation ΔTWout as the final target rotation position Pv **. Further, when the control parameter changing unit 70 makes a negative determination in the process of step S52, or when a negative determination is made in the process of step S56, that is, when heating is performed in the air conditioner 38, or when the oil temperature Tool is set. When the predetermined temperature is Tth50 or higher, normal control is executed as the process of step S58.

Next, the operations and effects of the flow control valve 12 and the ECU 40 of the present embodiment will be described.
As shown in FIG. 37 (A), when the intake air amount GA increases at time t60, that is, when the internal combustion engine 20 is in a high load state, the target outlet water temperature is shown by the alternate long and short dash line in FIG. 37 (B). TWout * is changed from the second target water temperature set value TWa2 to the first target water temperature set value TWa1. Therefore, as shown in FIG. 37 (C), the outlet water temperature deviation ΔTWout changes to a negative value. At this time, if the normal control is executed as shown by the alternate long and short dash line in FIG. 37 (E), the final target rotation position Pv is shown by the alternate long and short dash line in FIG. 37 (D). ** gradually changes to the rotation position P6 with the passage of time. Therefore, as shown by the alternate long and short dash line in FIGS. 37 (B), (F), and (G), the outlet water temperature TWout, the flow rate of the cooling water, and the wall temperature of the internal combustion engine 20 also change with the passage of time after time t60. It changes gradually with it.

On the other hand, in the flow control valve 12 of the present embodiment, as shown by the solid line in FIG. 37 (C), when the outlet water temperature deviation ΔTWout becomes smaller than “−Tth10” at time t60, the solid line is shown in FIG. 37 (E). As shown, the first response speed improvement control is executed. As a result, as shown by the solid line in FIG. 37 (D), the final target rotation position Pv ** is immediately set to the rotation position P7, so that the aperture ratio of the first outflow port P11 is "100 [%]". The aperture ratios of the other outflow ports P12 and P3 are set to "0 [%]". Therefore, as shown by the solid line in FIG. 37 (F), the flow rate of the cooling water increases beyond the flow rate feasible by normal control. As a result, the flow rate of the cooling water flowing through the radiator 21 increases sharply, so that the responsiveness of the heat radiation amount in the radiator 21 can be improved. Therefore, as shown by the solid line in FIG. 37 (B), the response speed of the outlet water temperature TWout is improved as compared with the case where the normal control is executed, and as a result, as shown in FIG. 37 (G). , The response speed of the wall temperature of the internal combustion engine 20 can be improved. Therefore, the fuel efficiency of the internal combustion engine 20 can be improved.

Further, as shown in FIG. 37 (A), when the intake air amount GA decreases at time t61, that is, when the internal combustion engine 20 is in a low load state, the final chain line is shown in FIG. 37 (B). The target rotation position Pv ** is changed from the first target water temperature set value TWa1 to the second target water temperature set value TWa2. Therefore, as shown by the solid line in FIG. 37 (C), the outlet water temperature deviation ΔTWout changes to a positive value. At this time, as shown by the alternate long and short dash line in FIG. 33 (E), when the normal control is executed, the two points are shown in FIGS. 33 (B), (D), (F), and (G). As shown by the chain line, the outlet water temperature TWout, the final target rotation position Pv **, the flow rate of the cooling water, and the wall temperature of the internal combustion engine 20 gradually change.

On the other hand, in the flow rate control valve 12 of the present embodiment, when the outlet water temperature deviation ΔTWout becomes larger than “Tth10” at time t61, the second response speed improvement control is executed as shown in FIG. 37 (E). Will be done. Therefore, the aperture ratios of all the outflow ports P11 to P13 are set to "0 [%]". As a result, as shown by solid lines in FIGS. 33 (B), (D), (F), and (G), the outlet water temperature TWout, the final target rotation position Pv **, the flow rate of the cooling water, and the internal combustion engine 20. The wall temperature will respond faster than when performing normal control.

On the other hand, when the first response speed improvement control or the second response speed improvement control is executed, the aperture ratios of the second outflow port P12 and the third outflow port P13 are set to "0 [%]". Cooling water does not flow to the heater core 22 and the oil cooler 24. Therefore, during the period when the first response speed improvement control and the second response speed improvement control are being executed, the air conditioner 38 may not be able to properly perform heating, or the oil temperature Toil may be appropriately managed. It gets harder. In this respect, in the ECU 40 of the present embodiment, even when the absolute value | ΔTWout | of the outlet water temperature deviation is larger than the predetermined value Tth10, the heating is performed in the air conditioner 38, or the oil temperature Tool is predetermined. In a situation where the temperature is Tth50 or higher, the execution of the first response speed improvement control and the second response speed improvement control is avoided, and the normal control is executed. Therefore, the air conditioner 38 can be appropriately heated and the oil temperature Toil can be appropriately managed.

In the ECU 40 of the present embodiment, as in the ECU 40 of the modified example of the fifth embodiment, the threshold value used when switching between the normal control and the first response speed improvement control, and the normal control and the second response speed improvement are also performed. Hysteresis may be provided in the threshold value used when switching to the control.

<Sixth Embodiment>
Next, the ECU 40 of the flow rate control valve 12 of the sixth embodiment will be described. Hereinafter, the differences between the flow control valve 12 of the fifth embodiment and the ECU 40 will be mainly described.
In the flow control valve 12 of the present embodiment, the opening ratios of the outflow ports P11 to P13 with respect to the position of the valve body 122 are set as shown in FIGS. 38 (A) to 38 (C). As shown in FIGS. 38 (A) to 38 (C), the rotation position P8 is further set as the valve position of the flow control valve 12. The rotation position P8 is a position set between the rotation position P5 and the rotation position P7. When the valve position of the flow control valve 12 is set to the rotation position P8, the opening degree of each of the first outflow port P11 and the third outflow port P13 is set to "100 [%]", and the second outflow port The opening degree of P12 is set to "0 [%]".

Further, the control parameter changing unit 70 of the present embodiment executes the processes shown in FIGS. 39 and 40. In the flowcharts shown in FIGS. 39 and 40, the same processes as those shown in FIG. 36 are designated by the same reference numerals, so that overlapping description is omitted. Further, the processing of steps S58a and 58b shown in FIGS. 39 and 40 is the same processing as the processing of step S58 shown in FIG. 36.

As shown in FIG. 39, when a negative determination is made in the process of step S52, the control parameter changing unit 70 determines whether or not the oil temperature Tool is lower than the predetermined temperature Tth50 as the process of step S60. The control parameter changing unit 70 determines that the air conditioner 38 is performing the heating operation when the affirmative determination is made in the process of step S60, that is, when the oil temperature Tool is lower than the predetermined temperature Tth50. To do. In this case, the control parameter changing unit 70 executes the third response speed improvement control as the process of step S61. Specifically, the control parameter changing unit 70 sets the final target rotation position Pv ** at the rotation position P2 shown in FIG. 38 as the third response speed improvement control. As a result, the opening ratios of the first outflow port P11 and the second outflow port P12 are set to "0 [%]", and the opening ratio of the third outflow port P13 is set to "100 [%]". To.

When the control parameter changing unit 70 makes a negative determination in the process of step S60, that is, when the oil temperature Tool is at a predetermined temperature Tth50 or higher and the air conditioner 38 is heating, the process of step S58a As normal control is executed.
As shown in FIG. 40, when a negative determination is made in the process of step S56, the control parameter changing unit 70 determines whether or not the oil temperature Tool is lower than the predetermined temperature Tth50 as the process of step S62. The control parameter changing unit 70 executes the fourth response speed improvement control as the process of step S63 when affirmative determination is made in the process of step S62, that is, when the oil temperature Tool is lower than the predetermined temperature Tth50. The control parameter changing unit 70 sets the final target rotation position Pv ** at the rotation position P8 shown in FIG. 38 as the fourth response speed improvement control. As a result, the opening ratios of the first outflow port P11 and the third outflow port P13 are set to "100 [%]", and the opening ratio of the second outflow port P12 is set to "0 [%]". To.

When the control parameter changing unit 70 makes a negative determination in the process of step S62, that is, when the oil temperature Tool is at a predetermined temperature Tth50 or higher and the air conditioner 38 is heating, the process of step S58b As normal control is executed.
Next, the operations and effects of the flow control valve 12 and the ECU 40 of the present embodiment will be described.

As shown in FIG. 36, in the flow rate control valve 12 of the fifth embodiment, when the control parameter changing unit 70 makes an affirmative decision in the process of step S50 and makes a negative decision in the process of step S52, the normal control is performed. Will be executed. Therefore, in a situation where the target outlet water temperature TWout * is larger than the predetermined value Tth10 with respect to the outlet water temperature TWout, heating is performed in the air conditioner 38, and normal control is performed even in a situation where the oil temperature Tool is lower than the predetermined temperature Tth50. Will be executed. However, when the oil temperature Tool is lower than the predetermined temperature Tth50, it is not necessary to flow the cooling water to the oil cooler 24, so that the circulation of the cooling water to the oil cooler 24 can be stopped. Further, since the target outlet water temperature TWout * is larger than the predetermined value Tth10 with respect to the outlet water temperature TWout, it is not necessary to circulate the cooling water in the radiator 21. Further, if the circulation of the cooling water to the radiator 21 and the oil cooler 24 can be stopped, the flow rate of the cooling water can be increased by that amount, so that the responsiveness of the wall temperature of the internal combustion engine 20 can be improved. It is possible.

In this respect, in the flow rate control valve 12 of the present embodiment, the situation where the control parameter changing unit 70 makes a positive judgment in the process of step S60, that is, the oil temperature Tool is lower than the predetermined temperature Tth50, and the air conditioner 38 is heated. In such a situation, the third response speed improvement control is executed. As a result, only the opening ratio of the third outflow port P13 is set to "100 [%]", so that the cooling water can be circulated in the heater core 22. Therefore, it is possible to perform heating of the air conditioner 38. Further, when the opening ratios of the first outflow port P11 and the second outflow port P12 are set to "0 [%]", the circulation of the cooling water to the radiator 21 and the oil cooler 24 is stopped. As a result, the flow rate of the cooling water can be increased, so that the responsiveness of the wall temperature of the internal combustion engine 20 can be improved.

On the other hand, as shown in FIG. 36, in the flow rate control valve 12 of the fifth embodiment, even when the control parameter changing unit 70 makes a positive judgment in the process of step S54 and makes a negative decision in the process of step S56, it is normal. Control is executed. Therefore, in a situation where the target outlet water temperature TWout * is smaller than the predetermined value Tth10 with respect to the outlet water temperature TWout, heating is performed in the air conditioner 38, and normal control is performed even in a situation where the oil temperature Tool is lower than the predetermined temperature Tth50. Will be executed. However, when the oil temperature Tool is lower than the predetermined temperature Tth50, it is not necessary to flow the cooling water to the oil cooler 24 as described above, so that the circulation of the cooling water to the oil cooler 24 can be stopped. .. Further, if the circulation of the cooling water to the oil cooler 24 can be stopped, the flow rate of the cooling water can be increased by that amount, so that the responsiveness of the outlet water temperature TWout to the target outlet water temperature TWout * can be improved. It is possible. However, since the target outlet water temperature TWout * is smaller than the predetermined value Tth10 with respect to the outlet water temperature TWout, it is necessary to circulate the cooling water in the radiator 21.

In this regard, in the flow control valve 12 of the present embodiment, the control parameter changing unit 70 makes a positive judgment in the process of step S62, that is, the oil temperature Tool is lower than the predetermined temperature Tth50, and the air conditioner 38 is heated. In such a situation, the fourth response speed improvement control is executed. As a result, the opening ratio of the third outflow port P13 is set to "100 [%]", so that the cooling water can be circulated in the heater core 22. Therefore, it is possible to perform heating of the air conditioner 38. Further, since the opening ratio of the first outflow port P11 is set to "100 [%]", it is possible to circulate the cooling water to the radiator 21. Further, by setting the opening ratio of the second outflow port P12 to "0 [%]", the circulation of the cooling water to the oil cooler 24 is stopped. As a result, the flow rate of the cooling water can be increased, so that the responsiveness of the wall temperature of the internal combustion engine 20 can be improved.

<Other embodiments>
In addition, each embodiment can also be implemented in the following embodiments.
In the process of step S24 shown in FIG. 21, the control parameter changing unit 70 of the second embodiment determines whether or not the operation frequency Fv is smaller than the predetermined frequency Fth20, and determines whether the cooling water temperature Tv of the flow rate control valve 12 is determined. Either one of the determinations as to whether or not the temperature is lower than the predetermined temperature Tth20 may be performed.

In the process of step S42 shown in FIG. 27, the control parameter changing unit 70 of the third embodiment determines whether or not the outside air temperature Tout is larger than the predetermined temperature Tth30, and the vehicle speed Vc is smaller than the predetermined speed Vth30. Either one of the judgments may be made.

The control parameter changing unit 70 of the fifth embodiment determines whether or not heating is being performed in the air conditioner 38 in the processes of steps S52 and S56 shown in FIG. 36, and the oil temperature Tool is set from the predetermined temperature Tth50. You may make one of the judgments as to whether or not the temperature is small. The same applies to the control parameter changing unit 70 of the sixth embodiment.

The ECU 40 of the fifth embodiment may determine whether or not it is necessary to further operate the EGR cooler 23 in the processes of steps S52 and S56 shown in FIG. The same applies to the processes of step S52 shown in FIG. 39 and step S56 shown in FIG. 40, which are executed by the ECU 40 of the sixth embodiment.

-The devices arranged in the first bypass flow path W11 and the second bypass flow path W12 can be changed as appropriate.
The ECU 40 and its control methods described in the present disclosure are provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. It may be realized by a dedicated computer. The ECU 40 and its control method described in the present disclosure may be realized by a dedicated computer provided by configuring a processor including one or more dedicated hardware logic circuits. The ECU 40 and its control method described in the present disclosure are configured by a combination of a processor and memory programmed to perform one or more functions and a processor including one or more hardware logic circuits. It may be realized by one or more dedicated computers. The computer program may be stored on a computer-readable non-transitional tangible recording medium as an instruction executed by the computer. The dedicated hardware logic circuit and the hardware logic circuit may be realized by a digital circuit including a plurality of logic circuits or an analog circuit.

・ This disclosure is not limited to the above specific examples. Specific examples described above with appropriate design changes by those skilled in the art are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element included in each of the above-mentioned specific examples, and their arrangement, conditions, shape, and the like are not limited to those illustrated, and can be changed as appropriate. The combinations of the elements included in each of the above-mentioned specific examples can be appropriately changed as long as there is no technical contradiction.

Claims

It is a control device (40) of a flow rate control valve (12) that adjusts the flow rate of cooling water circulating between the internal combustion engine (20) and the radiator (21) of the vehicle.
A target opening degree setting unit (50) for setting a target opening degree of the flow rate control valve for making the actual wall temperature, which is the actual temperature of the cylinder wall temperature of the internal combustion engine, follow the target wall temperature.
An opening control unit (60) that controls the actual opening, which is the actual opening of the flow control valve, to the target opening.
A control parameter changing unit (70) for changing a control parameter that controls the operation of the flow control valve is provided.
The target opening setting unit is
When the internal combustion engine is in a high load state, the target wall temperature is set to the first target wall temperature set value, and at the same time,
When the internal combustion engine is in a low load state, the target wall temperature is set to a second target wall temperature set value higher than the first target wall temperature set value.
The control parameter changing unit
When the absolute value of the deviation between the actual wall temperature and the target wall temperature is larger than the predetermined value, the absolute value of the deviation between the actual wall temperature and the target wall temperature is greater than or equal to the predetermined value. A control device for a flow control valve that changes the control parameters so that the response speed of the actual wall temperature becomes faster.
The opening degree control unit sets a duty ratio indicating the ratio of the energization time of the flow rate control valve in order to make the actual opening degree of the flow rate control valve follow the target opening degree.
The flow rate control valve has an actuator device for operating the valve body, and the opening degree of the valve body is changed by operating the actuator device based on the duty ratio set by the opening degree control unit. Is a thing,
The control parameter changing unit uses the limit value of the duty ratio as the control parameter, and when the absolute value of the deviation between the actual wall temperature and the target wall temperature becomes larger than the predetermined value. In addition, the response of the actual wall temperature is changed by changing the absolute value of the deviation between the actual wall temperature and the target wall temperature in a direction of relaxing the limit value of the duty ratio as compared with the case where the deviation value is equal to or less than the predetermined value. The control device for a flow control valve according to claim 1, wherein the speed is increased.
The control parameter changing unit
The operating frequency of the valve body in the period from the present to a predetermined time ago is calculated.
When the absolute value of the deviation between the actual wall temperature and the target wall temperature becomes larger than the predetermined value, the limitation value of the duty ratio is relaxed based on the fact that the operation frequency is smaller than the predetermined frequency. The control device for a flow control valve according to claim 2, wherein the flow control valve is changed in the direction of the operation.
The control parameter changing unit
The duty is based on the fact that the temperature of the cooling water flowing through the flow control valve is smaller than the predetermined temperature when the absolute value of the deviation between the actual wall temperature and the target wall temperature becomes larger than the predetermined value. The control device for a flow control valve according to claim 2, wherein the limit value of the ratio is changed in a direction of relaxation.
The control parameter changing unit
The operating frequency of the valve body in the period from the present to a predetermined time ago is calculated.
When the absolute value of the deviation between the actual wall temperature and the target wall temperature becomes larger than the predetermined value, the operation frequency is smaller than the predetermined frequency, and the temperature of the cooling water flowing through the flow control valve is predetermined. The control device for a flow control valve according to claim 2, wherein the limit value of the duty ratio is changed in a direction to be relaxed based on the temperature being smaller than the temperature.
The target opening degree setting unit smoothes the target opening degree of the flow rate control valve using a predetermined smoothing time constant.
The control parameter changing unit uses the smoothing time constant as the control parameter, and when the absolute value of the deviation between the actual wall temperature and the target wall temperature becomes larger than the predetermined value. 1. The response speed of the actual wall temperature is increased by making the smoothing time constant smaller than that when the absolute value of the deviation between the actual wall temperature and the target wall temperature is equal to or less than the predetermined value. The control device for the flow control valve according to.
In the control parameter changing unit, when the absolute value of the deviation between the actual wall temperature and the target wall temperature becomes larger than the predetermined value, the outside air temperature, which is the outside air temperature of the vehicle, is equal to or higher than the predetermined temperature. The control device for the flow control valve according to claim 6, wherein the smoothing time constant is reduced based on the above.
The control parameter changing unit said that the traveling speed of the vehicle is equal to or less than the predetermined speed when the absolute value of the deviation between the actual wall temperature and the target wall temperature becomes larger than the predetermined value. The control device for a flow control valve according to claim 6, wherein the smoothing time constant is reduced.
In the control parameter changing unit, when the absolute value of the deviation between the actual wall temperature and the target wall temperature becomes larger than the predetermined value, the outside air temperature, which is the outside air temperature of the vehicle, is equal to or higher than the predetermined temperature. The flow control valve control device according to claim 6, wherein the smoothing time constant is reduced based on the traveling speed of the vehicle being equal to or lower than a predetermined speed.
The control parameter changing unit
The target opening degree is used as the control parameter.
When the absolute value of the deviation between the actual wall temperature and the target wall temperature is not more than a predetermined value, the target opening degree is set to the target opening degree at which the opening degree of the flow control valve is fully opened or fully closed. The control device for the flow control valve according to claim 1, wherein the response speed of the actual wall temperature is made faster than when the absolute value of the deviation between the actual wall temperature and the target wall temperature is equal to or less than the predetermined value. ..
The flow control valve is
It is possible to further adjust the flow rate of the cooling water circulating between the in-vehicle device (22, 24) different from the radiator and the internal combustion engine.
A radiator port (P11) through which cooling water circulating between the radiator and the internal combustion engine flows, and
It has ports (P12, P13) for in-vehicle equipment through which cooling water circulating between the in-vehicle equipment and the internal combustion engine flows.
The flow rate of the cooling water circulating between the radiator and the internal combustion engine can be adjusted by adjusting the opening degree of the radiator port, and the in-vehicle device and the internal combustion engine can be adjusted by adjusting the opening degree of the in-vehicle device port. The flow rate of cooling water circulating between the engine and the engine can be adjusted.
The target opening setting unit is
When the internal combustion engine is in a high load state, the target opening degree of the radiator port for making the actual wall temperature follow the first target wall temperature set value is set, and the opening degree of the in-vehicle device port is set. Is set to the fully open state,
When the internal combustion engine is in a low load state, the target opening degree of the radiator port for making the actual wall temperature follow the second target wall temperature set value is set, and the opening degree of the in-vehicle device port is set. Is set to the fully open state,
The control parameter changing unit
The opening degree of the in-vehicle device port is used as the control parameter, and when the absolute value of the deviation between the actual wall temperature and the target wall temperature becomes larger than the predetermined value, the in-vehicle device The control device for a flow control valve according to claim 1, wherein the response speed of the actual wall temperature is increased by making the opening degree of the port fully closed.
The in-vehicle device includes a heater core (22) that heats air blown into the vehicle interior in the vehicle air conditioner.
The in-vehicle device port includes a heater core port (P12) corresponding to the heater core.
The control parameter changing unit determines that the air conditioner of the vehicle does not heat the interior of the vehicle when the absolute value of the deviation between the actual wall temperature and the target wall temperature becomes larger than the predetermined value. The control device for a flow control valve according to claim 11, wherein the opening degree of the heater core port is fully closed based on the above.
The in-vehicle device includes an oil cooler (24) that cools the lubricating oil of the internal combustion engine.
The in-vehicle device port includes an oil cooler port (P13) corresponding to the oil cooler.
The control parameter changing unit determines that the temperature of the lubricating oil of the internal combustion engine is lower than the predetermined temperature when the absolute value of the deviation between the actual wall temperature and the target wall temperature becomes larger than the predetermined value. The control device for a flow control valve according to claim 11, wherein the opening degree of the oil cooler port is fully closed based on the above.
The in-vehicle device includes a heater core (22) that heats air blown into the vehicle interior in the vehicle air conditioner, and an oil cooler (24) that cools the lubricating oil of the internal combustion engine.
The in-vehicle device port includes a heater core port (P12) corresponding to the heater core and an oil cooler port (P13) corresponding to the oil cooler.
In the control parameter changing unit, when the absolute value of the deviation between the actual wall temperature and the target wall temperature becomes larger than the predetermined value, the temperature of the lubricating oil of the internal combustion engine is lower than the predetermined temperature and The flow control valve according to claim 11, wherein the opening degree of each of the heater core port and the oil cooler port is fully closed based on the fact that the air conditioner of the vehicle does not heat the interior of the vehicle. Control device.
The control parameter changing unit opens the heater core port based on the fact that the temperature of the lubricating oil of the internal combustion engine is lower than the predetermined temperature and the air conditioner of the vehicle is heating the interior of the vehicle. The control device for the flow control valve according to claim 14, wherein the oil cooler port is fully opened and the opening degree of the oil cooler port is fully closed.