JP2017067016A - Cooling control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling control device capable of stably maintaining control responsiveness of a flow control valve.SOLUTION: A cooling control device includes: a coolant pump of which rotation speed is set in accordance with rotation speed of an engine E; a coolant flow passage and a heat exchanger for cooling a coolant delivered from the engine E; a flow control valve V provided in the coolant flow passage and adjusting a flow rate of the coolant by varying an opening by driving of a motor VM; and a control section 10 for feed-back controlling the opening of the flow control valve V based on the difference between a temperature of the coolant and a target temperature of the coolant, and correcting a feed-back control gain in accordance with the rotation speed of the engine E.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a cooling control device, and more particularly to a technique for managing the temperature of an engine with a coolant.

  Patent Document 1 discloses an engine cooling device in which a cooling flow path for circulating cooling water is formed between an engine and a radiator, and a flow rate control valve and a coolant pump are interposed in the cooling flow path. . In this cooling device, the electronic control unit (ECU) sets the target water temperature based on the operating conditions and running conditions of the engine, changes the opening of the flow rate control valve by comparison with the actual water temperature, and the amount of cooling water flowing to the radiator A control form for setting is shown.

  In the cooling device of Patent Document 1, an operation amount of feedback control of the flow control valve is corrected in consideration of deterioration of control responsiveness of the flow control valve due to frictional resistance with a seal member or the like. Specifically, the operation amount calculation unit calculates an operation amount based on feedback control, and the state determination unit determines whether the flow control valve is in a steady state with a small change amount or a transient state with a large change amount. When the steady state is determined, the control amount is corrected.

  In the cooling device described in Patent Document 2, in order to maintain high responsiveness while suppressing the occurrence of overshoot in the flow rate control of the cooling flow path, based on the deviation between the target water temperature and the actual water temperature and the change speed of the actual water temperature. The operation amount of the flow rate adjusting means is corrected. For example, when the deviation is small and the change speed is large, the target temperature may be overshooted, so the operation amount is reduced.

JP 2014-156828 A JP 2010-190142 A

  For example, when the coolant pump is operated using the driving force of the engine, the number of revolutions of the coolant pump is set according to the number of revolutions of the engine. For this reason, as the engine speed increases, the coolant pump speed increases, the flow rate of the cooling passage increases, and the fluid pressure increases. However, when the flow control valve receives a high fluid pressure, the valve body may be pressed against the valve main body, making it difficult to open and close. For this reason, for example, when the control gain is increased, the control response of the flow control valve is good when the fluid pressure is high, but when the fluid pressure is low, the opening of the flow control valve is greatly fluctuated up and down from the target opening. Hunting will occur. On the other hand, if the control gain is lowered, hunting of the flow control valve when the fluid pressure is low can be avoided, but the response of the flow control valve when the fluid pressure is high is delayed. As described above, in the engine cooling apparatus, the control response of the flow rate control valve may be deteriorated due to the fluctuation of the fluid pressure in the cooling flow path.

  In view of the above circumstances, there is a need for a cooling control device that can stably maintain the control response of the flow control valve.

The characteristic configuration of the cooling control device according to the present invention includes a coolant pump in which the rotational speed is set according to the rotational speed of the engine, and
A cooling flow path and a heat exchanger for cooling the coolant discharged from the engine;
A flow rate control valve which is provided in the cooling flow path and adjusts the flow rate of the coolant by changing the opening degree by driving the motor;
A control unit that feedback-controls the opening degree of the flow rate control valve based on a difference between a coolant temperature and a coolant target temperature, and corrects the feedback control gain according to the engine speed. It is in the point.

According to this configuration, the coolant pump in which the rotational speed is set according to the rotational speed of the engine is provided. For this reason, the rotational speed of the coolant pump increases as the rotational speed of the engine increases. As the number of revolutions of the coolant pump changes, the fluid pressure in the cooling channel increases or decreases. When the fluid pressure in the cooling flow path increases, the valve body of the flow control valve may be held by the fluid pressure, making it difficult to open and close. Therefore, in this configuration, the gain of feedback control is corrected according to the engine speed. For example, when the engine speed is low and the fluid pressure is low, the feedback control gain is corrected. When the engine speed is high and the fluid pressure is high, the feedback control gain is corrected. Thereby, delay of hunting and response can be suppressed in the flow control valve. As a result, the coolant temperature can be stably controlled, and the engine temperature can be maintained within an appropriate range.
In the flow control valve, the fluid pressure may act as a propulsion force instead of a resistance force to the opening / closing operation. In that case, the gain may be corrected so as to decrease as the engine speed increases.

  Another characteristic configuration of the cooling control apparatus according to the present invention is that the gain is varied according to an opening operation or a closing operation of the flow control valve.

  The fluid pressure acting on the flow control valve varies depending on the operation direction of the opening operation or the closing operation. When the flow control valve is opened, the flow rate in the communication portion, which is the open region of the flow control valve, increases, and the fluid pressure in the inflow portion on the upstream side of the valve body decreases. For this reason, the resistance force during the opening operation is reduced. On the other hand, when the closing operation is performed, the flow rate of the communication portion decreases and the fluid pressure of the inflow portion increases. For this reason, the resistance force during the closing operation increases. Therefore, in this configuration, the gain is varied depending on the opening operation or closing operation of the flow control valve. In the above example, correction is performed so that the gain at the closing operation is larger than the gain at the opening operation. Thereby, the gain of the feedback control when the flow control valve is opened and closed can be set appropriately, and variations in the control response of the flow control valve can be suppressed.

  Another characteristic configuration of the cooling control device according to the present invention is that the gain is varied according to the opening of the flow control valve.

  The fluid pressure acting on the flow control valve varies depending on the opening degree. When the flow control valve is at a low opening, the fluid pressure at the inflow portion of the flow control valve becomes high. At this time, since the valve body of the flow control valve is pressed against the valve body, the frictional force with the valve body becomes a resistance force when the valve body is opened or closed. On the other hand, when the flow control valve is at a high opening, the fluid pressure at the inflow portion is lower than when the flow control valve is at a low opening. For this reason, the resistance force generated based on the fluid pressure in the inflow portion is smaller when the flow control valve is at a high opening than at a low opening. Thus, since the resistance force when operating the flow control valve differs depending on the opening, in this configuration, the gain is varied according to the opening of the flow control valve. When the resistance force decreases as the flow control valve becomes higher as described above, the gain is corrected so that the gain decreases as the opening of the flow control valve increases. Thereby, the gain of the feedback control of the flow control valve can be appropriately set even at different opening degrees, and variations in control responsiveness of the flow control valve can be suppressed.

  Another characteristic configuration of the cooling control device according to the present invention is that the coolant pump is a mechanical pump driven by the engine.

  If the coolant pump is a mechanical pump driven by the engine as in this configuration, the rotational speed of the coolant pump is linked to the rotational speed of the engine. For this reason, the rotation speed of the coolant pump cannot be arbitrarily changed. However, by correcting the feedback control gain of the flow rate control valve in accordance with the engine speed, the engine temperature can be appropriately controlled even if the coolant pump is an inexpensive mechanical pump.

It is a figure which shows the structure of a cooling control apparatus. It is a chart which shows the opening degree of each valve part with respect to the operation amount of a valve body. It is a block diagram which shows the structure of a control unit. It is a block diagram which shows the structure of the control unit of another form. It is a graph which shows the responsiveness of the flow control valve according to control gain. It is a figure which shows the state in which the valve body of a high opening receives fluid pressure. It is a figure which shows the state which the valve body of a low opening receives a fluid pressure. It is a figure which shows the state in which a valve body receives a fluid pressure when changing the flow direction of a fluid. It is a figure which shows the state which the valve body of another opening degree receives a fluid pressure. It is a figure which shows the state in which the valve body of another high opening degree receives a fluid pressure.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Basic configuration]
As shown in FIG. 1, a water pump WP (an example of a coolant pump) that sends cooling water (an example of a coolant) of an engine E as an internal combustion engine, a plurality of flow paths F formed in parallel, and a plurality of channels A control circuit is provided that includes a cooling circuit including a heat exchanger provided in each of the flow paths F and a flow rate control valve V that controls the flow of cooling water (an example of a coolant) and sets the opening degree of the flow rate control valve V. A cooling control device is configured including the unit 10 (an example of a control unit).

  This cooling control device detects the water temperature of the cooling water (cooling liquid) with a water temperature sensor S (an example of a liquid temperature sensor), and the control unit 10 controls the flow rate control valve V based on the detection result to exchange heat. Heat exchange in the vessel is managed.

  As a heat exchanger, the EGR cooler 1, the oil cooler 2, and the radiator 3 which are mentioned later are provided in the corresponding flow path F. Further, the water pump WP is arranged in a return flow path FR (a part of the flow path F) between the flow control valve V and the engine E.

  The cooling control device is configured to perform temperature management of an engine E (internal combustion engine) of a vehicle such as a passenger car. The engine E has a water jacket formed in a region extending from the cylinder block to the cylinder head. The cooling control device is configured to send the cooling water in the water jacket to the flow path F, supply the cooling water to the heat exchanger to exchange heat, and then return the water jacket to the water jacket by the water pump WP. The engine E is configured to transmit a driving force from a crankshaft as an output shaft to the transmission. The engine E can be used not only for reciprocating engines but also for internal combustion engines in general. Further, the engine E is not limited to the configuration in which the driving force is directly applied to the transmission, but may be one that transmits the driving force to the electric motor, for example, like a hybrid vehicle.

[Flow path / Heat exchanger]
The water temperature sensor S is provided in the engine E, and a plurality of flow paths F branched from the main flow path FM through which the cooling water discharged from the engine E is sent. As a plurality of flow paths F (an example of cooling flow paths), a first flow path F1, a second flow path F2, and a third flow path F3 are formed. As a heat exchanger, the EGR cooler 1 is provided in the first flow path F1, the oil cooler 2 is provided in the second flow path F2, and the radiator 3 is provided in the third flow path F3.

  Technology that improves exhaust gas components and improves fuel efficiency by taking out part of the exhaust gas from the engine E and returning it to the intake system is called EGR (Exhaust Gas Recirculation). Part of the exhaust gas taken out from the chamber is heat exchanged (cooled) with cooling water.

  The oil cooler 2 has a configuration in which the lubricating oil stored in the oil pan 5 of the engine E is supplied by the oil pump 6, and performs heat exchange with the cooling water. The lubricating oil that has been subjected to heat exchange in the oil cooler 2 is supplied to hydraulic operating devices such as a valve opening / closing timing control device or lubricating portions of various parts of the engine. The oil pump 6 is a variable hydraulic mechanical oil pump capable of controlling the hydraulic pressure level in two or more stages, and is driven by the engine E.

  The radiator 3 has a function of managing the temperature of the engine E by radiating the cooling water, and the cooling air is supplied from the radiator fan 7. The radiator fan 7 is driven by a fan motor 7M configured by an electric motor.

(Flow control valve)
The flow control valve V is configured as a rotary operation type in which a valve body is rotatably accommodated in a valve case. Moreover, the valve motor VM (an example of a motor) comprised with an electric motor so that a valve body may be rotationally operated, and the valve sensor VS (an example of an opening degree sensor) which detects the rotation angle of a valve body are provided. The flow control valve V may be a slide operation type in which a valve body that slides is accommodated inside the valve case.

  The flow control valve V includes a first valve portion V1 that opens and closes the first flow path F1, a second valve portion V2 that opens and closes the second flow path F2, and a third valve portion V3 that opens and closes the third flow path F3. have. FIG. 2 shows the opening degrees of the first valve portion V1, the second valve portion V2, and the third valve portion V3 with respect to the operation amount of the valve body in the flow rate control valve V having this configuration. The first valve portion V1, the second valve portion V2, and the third valve portion V3 are collectively referred to as valve portions.

  In FIG. 2, the vertical axis indicates the opening degree of the first valve part V1, the second valve part V2, and the third valve part V3 (the opening degree is expressed as a percentage), and the horizontal axis indicates the valve operating amount. (Rotation amount) is shown. As can be understood from the figure, when the valve body is in the initial position, the first valve portion V1, the second valve portion V2, and the third valve portion V3 are in the fully closed mode M0 in which they are closed, Cooling water does not flow through the first flow path F1, the second flow path F2, and the third flow path F3.

  Next, the opening degree of the first valve portion V1 is adjusted while the second valve portion V2 and the third valve portion V3 are maintained in the closed state by operating the valve body in the opening direction from the fully closed mode M0. Shifts to the first supply mode M1 in which

  Further, by operating the valve body in the opening direction beyond the fully opened state from the first supply mode M1, the opening degree of the first valve unit V1 is maintained in the fully opened state (the third valve unit V3 is in the closed state). Maintained), the operation proceeds to the second supply mode M2 in which the opening degree of the second valve portion V2 can be adjusted.

  And the state which maintained the opening degree of the 1st valve part V1 and the opening degree of the 2nd valve part V2 part by operating a valve body from the 2nd supply mode M2 to an open direction exceeding a fully open state Thus, the operation proceeds to the third supply mode M3 in which the opening degree of the third valve portion V3 can be adjusted.

  In particular, in this flow control valve V, the cooling water is not supplied by the second valve portion V2 before the opening degree of the first valve portion V1 reaches full open. Similarly, the cooling water is not supplied by the third valve portion V3 before the opening degree of the second valve portion V2 reaches the fully open position. The flow control valve V is not limited to this configuration. For example, the flow control valve V may be provided with four or more valve parts, or may be operated to be opened simultaneously in association with the opening degrees of a plurality of valve parts.

〔Controller unit〕
The control unit 10 shown in FIG. 3 manages the entire engine, and also manages the amount of heat exchanged by the heat exchanger by controlling the amount of cooling water flowing through the flow path F with the flow control valve V when the engine E is in operation. I do. In particular, when temperature management of the engine E is performed, the flow rate of the cooling water supplied to the radiator 3 can be set optimally by the control of the flow rate control valve V.

  In the control unit 10, a target flow rate is set based on the difference between the coolant temperature detected by the water temperature sensor S and the target temperature, and the rotational speed (per unit time) of the engine E so as to obtain the target flow rate. The target valve opening degree of the flow control valve V is set corresponding to the rotation speed).

  As shown in FIG. 3, the control unit 10 receives signals from a water temperature sensor S (liquid temperature sensor), a rotational speed sensor 21, and a valve sensor VS (opening sensor). Further, the control unit 10 outputs a control signal to the valve motor VM that controls the opening degree of the flow control valve V.

  The water temperature sensor S is provided in the engine E so as to detect the water temperature of the cooling water, and includes a thermistor or the like. The rotation speed sensor 21 is composed of a non-contact type sensor that measures the rotation speed of the crankshaft of the engine E. From the detection of the rotation speed sensor 21, the rotation speed of the crankshaft (the rotation speed per unit time) can be detected. To.

  The valve sensor VS includes a Hall IC, a potentiometer, and the like, and detects the rotation angle of the valve body of the flow control valve V. This detection enables the flow rate control valve V to detect the opening of the valve portion in each supply mode.

  The control unit 10 includes a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), and the like. Further, the control unit 10 uses a load correction gain 11, an opening / closing direction correction term 12, and a valve opening correction term 13 calculated by software as necessary.

  In the control unit 10, based on the detection result of the water temperature sensor S, one of the first supply mode M1, the second supply mode M2, and the third supply mode M3 is selected. In the first supply mode M1 and the second supply mode M2, the opening degrees of the first valve unit V1 and the second valve unit V2 are set based on the detection result of the water temperature sensor S, and the EGR cooler 1 and the oil cooler 2 Control for managing the amount of cooling water supplied to the is performed.

  In the third supply mode M3, the target flow rate of the cooling water supplied to the radiator 3 by the third flow path F3 is set, and the target valve opening degree of the flow rate control valve V is set based on the rotational speed of the engine E. Control for driving the valve motor VM is performed so as to obtain the target valve opening degree. In the third supply mode M3, when the vehicle is traveling at a low speed and the water temperature is high, the fan motor 7M is driven to drive the radiator fan 7 and supply the cooling air to the radiator 3. However, the fan motor 7M is not driven during high speed travel.

A control mode in the third supply mode M3 will be described below.
In the control unit 10, the opening degree of the third valve portion V3 (flow rate control valve V) is changed to control the flow rate of the third flow path F3, thereby controlling the temperature of the engine E. A control signal is output from the control unit 10 to the valve motor VM. The control unit 10 includes a PWM circuit that performs PWM control, and controls the valve motor VM by changing the duty ratio of the pulse width based on the corrected control gain. Thereby, the 3rd valve part V3 can be operated easily and rapidly.

  Based on the target flow rate of the third flow path F3, the target valve opening degree of the third valve portion V3 is calculated. Based on the difference between the target valve opening and the actual valve opening, a control gain for feedback control of the opening of the third valve unit V3 is calculated.

  On the other hand, the load correction gain 11 in the feedback control of the third valve unit V3 is calculated according to the engine speed. Further, the load correction gain 11 is corrected based on the opening / closing direction correction term 12 and the valve opening correction term 13. The opening / closing direction correction term 12 is a parameter for correcting the control gain in accordance with the opening operation or the closing operation of the third valve portion V3. The valve opening correction term 13 is a parameter for correcting the control gain according to the opening of the third valve portion V3. A control amount based on the actual valve opening and the target valve opening and the load correction gain are multiplied to obtain a final control gain, and a control signal based on the control gain is output to the valve motor VM.

  The control unit 10 may have a control form different from the configuration shown in FIG. For example, in the example shown in FIG. 4, the control gain based on the actual valve opening and the target valve opening is multiplied by the load correction gain 11 calculated according to the engine speed, and corrected based on the engine speed. Obtained control gain. Thereafter, the final control gain is obtained by adding the opening / closing direction correction term 12 and the valve opening correction term 13 to the control gain.

  FIG. 5 shows the relationship between the engine speed and the fluid pressure (water pressure) and the responsiveness for each gain in the feedback control of the opening degree of the third valve portion V3. The rotational speed of the water pump WP is set according to the rotational speed of the engine E. For this reason, when the rotation speed of the engine E is low, the rotation speed of the water pump WP is also low, and the fluid pressure received by the third valve portion V3 is low. On the other hand, when the rotational speed of the engine E is increased, the rotational speed of the water pump WP is also increased, so that the fluid pressure received by the third valve portion V3 is also increased.

  Under such conditions, setting a gain suitable for the high water pressure ensures an appropriate response when the fluid pressure is high. However, when the engine speed is low and the fluid pressure is low, the valve opening greatly fluctuates up and down from the target opening, causing hunting. On the other hand, when a gain suitable for a low water pressure is set, an appropriate response is ensured when the fluid pressure is low. However, when the engine speed is high and the fluid pressure is high, the time until the valve opening reaches the target opening becomes long, and the responsiveness of the feedback control of the valve opening decreases.

  On the other hand, in the control unit 10 of this embodiment, the gain of feedback control is corrected by the load correction gain 11 calculated according to the engine speed. For example, the load correction gain 11 suitable for a low fluid pressure is set when the engine speed is low, and the load correction gain 11 suitable for a high fluid pressure is set when the engine speed is high. Thereby, in the 3rd valve part V3, delay of hunting and a response can be controlled. As a result, the coolant temperature can be stably controlled, and the engine temperature can be maintained within an appropriate range.

  The opening / closing direction correction term 12 is a parameter for correcting the control gain in accordance with the opening / closing direction of the third valve portion V3, that is, the opening operation or the closing operation. The relationship between the fluid pressure and the opening or closing operation, which is the operation direction of the third valve portion V3, will be described. The third valve portion V3 is provided with an inflow portion 15 on the upstream side of the valve body 32, a communication portion 16 formed by opening the valve body 32, and an outflow portion 17 on the downstream side of the valve body 32. . In the rotary valve, when the valve body 32 is opened so as to change from the state of FIG. 6 to the state of FIG. 7, the flow rate of the communication part 16 increases and the fluid pressure of the inflow part 15 of the valve body 32 decreases. Moreover, since the open end surface 32a of the valve body 32 is pressed toward the opening operation side by the fluid pressure, the resistance force of the opening operation is reduced.

  On the other hand, when the valve body 32 is closed so as to change from the state of FIG. 7 to the state of FIG. 6, the flow rate of the communication portion 16 decreases and the fluid pressure of the inflow portion 15 increases. Moreover, since the high fluid pressure in the communication part 16 acts on the open end surface 32a, the resistance force when the valve body 32 is closed is increased. Thus, when the resistance force during the closing operation of the opening operation and the closing operation of the valve body 32 is large, the control gain during the closing operation is larger than the control gain during the opening operation as the opening / closing direction correction term 12. Set the parameter.

  The valve opening correction term 13 is a parameter for correcting the control gain according to the opening of the third valve portion V3. The relationship between the opening degree of the third valve portion V3 and the fluid pressure will be described. For example, in the rotary valve, as shown in FIG. 6, when the valve body 32 has a low opening, the fluid pressure in the inflow portion 15 increases. For this reason, when the valve body 32 opens or closes from the state shown in FIG. 6 having a low opening, the frictional force generated by the valve body 32 being pressed against the valve body 33 becomes the resistance force.

  On the other hand, as shown in FIG. 7, when the valve body 32 is at a high opening, the fluid pressure in the inflow portion 15 is lower than in the case of FIG. 6 where the opening is low. For this reason, when the valve body 32 has a high opening degree, the resistance force generated based on the fluid pressure in the inflow portion 15 is smaller than in the case of a low opening degree. In this way, when the resistance force decreases as the valve body 32 becomes higher in opening degree, a parameter that decreases the control gain as the opening degree of the third valve portion V3 increases as the valve opening degree correction term 13 is set. .

[Modification of First Embodiment]
In the present embodiment, the coolant flows in the opposite direction to the first embodiment with respect to the third valve portion V3. As shown in FIG. 8, the outflow portion 17 includes an arcuate valve body 32, and the cooling water flows from the inflow portion 15 toward the outflow portion 17. In this case, since the fluid pressure of the inflow portion 15 presses the outer peripheral surface of the arc-shaped valve body 32, the magnitude and direction of the fluid pressure received by the valve body 32 are different from those of the first embodiment. For example, the fluid pressure in the inflow portion 15 may act to promote the opening operation with respect to the valve body 32. For this reason, in this embodiment, control gain correction different from that of the first embodiment is performed, for example, the control gain during the opening operation of the third valve unit V3 is further reduced.

[Second Embodiment]
In the present embodiment, the third valve portion V3 (flow rate control valve V) is configured to include a gate-type valve body 32 that operates linearly. In this case, as shown in FIG. 9, the fluid pressure in the inflow portion 15 acts to hold the valve body 32, and the fluid flow in the communication portion 16 also acts on the open end surface 32 a of the valve body 32. Here, when the valve body 32 is opened as shown in FIG. 10, the flow rate of the communication portion 16 increases and the fluid pressure of the inflow portion 15 decreases. For this reason, the resistance force received by the valve body 32 when opening the third valve portion V3 tends to be small.

  On the other hand, when the valve body 32 is closed so as to change from the state of FIG. 10 to the state of FIG. 9, the flow rate of the communication part 16 decreases and the fluid pressure of the inflow part 15 increases. For this reason, the resistance force received by the valve body 32 when the third valve portion V3 is closed tends to increase. Therefore, also in the valve body 32, as the opening / closing direction correction term 12, a parameter is set such that the control gain during the closing operation is larger than the control gain during the opening operation of the third valve portion V3.

  Regarding the relationship between the opening degree of the third valve part V3 and the fluid pressure, as shown in FIG. 9, when the valve body 32 is at a low opening degree, the fluid pressure of the inflow part 15 becomes high. For this reason, when the valve body 32 opens or closes from the state shown in FIG. 9 having a low opening, the frictional force generated by the valve body 32 being pressed against the valve body 33 becomes the resistance force. On the other hand, as shown in FIG. 10, when the valve body 32 is at a high opening, the fluid pressure in the inflow portion 15 is lower than in the case of FIG. 9 where the opening is low. For this reason, when the valve body 32 has a high opening degree, the resistance force generated based on the fluid pressure in the inflow portion 15 is smaller than in the case of a low opening degree.

[Another embodiment]
(1) In the above embodiment, the control unit 10 is used to correct the gain when feedback controlling the third valve unit V3 in the third supply mode M3. Similarly, the first supply mode M1 is used. You may correct | amend the gain at the time of feedback-controlling the 2nd valve part V2 in the 1st valve part V1 in 2nd, and the 2nd supply mode M2.

(2) In the above embodiment, an example has been shown in which the control unit 10 performs correction so as to increase the gain when the flow rate control valve V is feedback-controlled as the engine speed increases. When the resistance force received by the flow control valve V decreases, the gain is corrected so as to decrease.

(3) In the above embodiment, as the opening / closing direction correction term 12, an example in which a parameter is set such that the control gain when the flow rate control valve V is closed is larger than the control gain when the flow control valve V is opened is shown. When the resistance force during the opening operation is large in the closing operation, a parameter is set such that the control gain during the opening operation is larger than the control gain during the closing operation of the flow rate control valve V.

(4) In the above embodiment, an example has been shown in which the valve opening correction term 13 is a parameter in which the control gain decreases as the opening of the flow control valve V increases. In the case where the resistance force to be applied is larger than the resistance force when the opening degree is low, a parameter is set such that the control gain becomes larger as the opening degree of the flow control valve V becomes higher.

(5) In the above embodiment, an example in which the water pump WP is a mechanical pump driven by the engine E has been described, but the water pump WP may be an electric pump. Even if the water pump WP is an electric pump, the rotational speed of the pump can be set according to the rotational speed of the engine E. When an electric pump is used as the water pump WP, the control unit 10 may correct the gain of feedback control in accordance with the rotation speed of the pump. In addition, instead of changing the gain of the feedback control, an appropriate response in the feedback control of the flow control valve V may be ensured by making the rotation speed of the water pump WP constant.

(6) In the above embodiment, an example in which the valve body 32 of the flow control valve V is formed in an arc shape and a flat plate shape is shown, but the valve body 32 may have another shape such as a sphere or a circle.

  The present invention can be used in a cooling control device that manages the temperature of an engine by circulating a coolant.

3: Radiator (heat exchanger)
10: Control unit 11: Load correction gain 12: Opening / closing direction correction term 13: Valve opening correction term 32: Valve element E: Engine F3: Third flow path (cooling flow path)
S: Water temperature sensor V: Flow control valve V3: Third valve unit (flow control valve)
VM: Valve motor VS: Valve sensor WP: Water pump (coolant pump)

Claims (4)

A coolant pump whose rotational speed is set according to the rotational speed of the engine;
A cooling flow path and a heat exchanger for cooling the coolant discharged from the engine;
A flow rate control valve which is provided in the cooling flow path and adjusts the flow rate of the coolant by changing the opening degree by driving the motor;
A control unit that feedback-controls the opening degree of the flow rate control valve based on a difference between a coolant temperature and a coolant target temperature, and corrects the feedback control gain according to the engine speed. Cooling control device.   The cooling control device according to claim 1, wherein the gain is varied according to an opening operation or a closing operation of the flow control valve.   The cooling control device according to claim 1 or 2, wherein the gain is varied according to an opening of the flow control valve.   The cooling control device according to any one of claims 1 to 3, wherein the coolant pump is a mechanical pump driven by the engine.

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