WO2000031389A1

WO2000031389A1 - Cooling control device for internal combustion engines

Info

Publication number: WO2000031389A1
Application number: PCT/JP1999/006555
Authority: WO
Inventors: Hiroshi Suda
Original assignee: Nippon Thermostat Co., Ltd.
Priority date: 1998-11-26
Filing date: 1999-11-25
Publication date: 2000-06-02
Also published as: JP2000161063A

Abstract

A cooling control device capable of improving the heat dissipation effect in engines particularly in a high load state and effectively avoiding the worst situation that can lead to knocking or overheating. The cooling control device comprises a flow control unit (11) for controlling the flow rate of the cooling medium, a variable grille unit (22) making it possible to regulate the amount of draft to a radiator (2), and an instruction signal generating unit (15) for generating an instruction signal to control the flow rate of a cooling medium in the flow control unit (11) and the amount of draft to a heat exchanger (2) in the variable grille unit (22) on the basis of at least the information about the temperature of the cooling medium. The instruction generating unit (15) controls the states of the flow control unit and variable grille unit on the basis of the temperature and other information in the cooling medium in the operating state of the engine, the two functions providing a proper heat dissipation effect covering the range from engine warming-up to high load operation.

Description

Description Cooling control device for internal combustion engine

The present invention relates to a cooling control device for forming a circulation path of a cooling medium between an internal combustion engine such as an automobile engine and a heat exchanger to cool the internal combustion engine, and is particularly arranged in front of the heat exchanger. The present invention relates to a cooling control device that employs a variable grill unit capable of adjusting a flow rate of air to a heat exchanger, thereby controlling a temperature of a cooling medium circulated in an internal combustion engine to an optimal state. Background art

In an internal combustion engine (hereinafter referred to as an engine) used for an automobile or the like, some cooling control means for cooling the engine have been proposed.

A typical example is a water-cooled cooling control device using a radiator. Most of the current automobile engines employ a water-cooled cooling control device using the radiator. For example, Japanese Unexamined Patent Publication No. Hei 6-10671 discloses cooling control means that includes a grill unit that adjusts the amount of ventilation to the radiator, and that controls the amount of ventilation by the grill unit based on the temperature of cooling water. Have been.

It has also been proposed that information such as vehicle speed as well as cooling water temperature be incorporated as information for controlling the above-described cooling control means.Furthermore, a fan for cooling the radiator was provided. A method of driving and controlling a cooling fan based on information has also been proposed.

By the way, for example, in a gasoline engine or the like, immediately after starting the engine in a low outside temperature such as in winter, the emission of harmful gases such as HC is increased and the fuel efficiency is reduced. I have. Therefore, in such a situation, the engine cooling water Need to increase the degree.

On the other hand, especially when the engine is subjected to high loads for a long time, such as in summer when the outside temperature is high and the vehicle is climbing a long sloping road, the combustion temperature rises due to the rise in cooling water temperature. Has risen abnormally, causing knocking and, in the worst case, engine overheating.

Generally, this type of engine has the property of being able to operate at a high temperature that does not cause overheating, thereby improving fuel efficiency and suppressing the generation of harmful gases. It is desirable to be able to maintain a constant high temperature state that does not cause overheating under any operating conditions.

However, in the cooling control means using the grille unit disclosed in the above-mentioned publication, since only the amount of air flowing through the front opening of the Lager is controlled, cooling control for various engine operating environments and load conditions is not possible. It was sufficient, and it was impossible to provide an appropriate heat radiation effect from the warm-up state of the engine to the high-load operation state.

The present invention has been made in view of such problems, and has a flow control unit that controls a flow rate of cooling water with respect to a radiator, and a flow control unit that is disposed in front of a radiator and that can adjust a ventilation amount to the radiator. An object of the present invention is to provide a cooling control device that can sufficiently cope with the above-mentioned severe changes in the operating conditions by using the variable grill unit in combination. Disclosure of the invention

A cooling control device for an internal combustion engine according to the present invention, which has been made to solve the above-mentioned problem, comprises: a circulation path for a cooling medium between a fluid passage formed in the internal combustion engine and a fluid passage formed in a heat exchanger. A cooling control device for an internal combustion engine, wherein heat generated in the internal combustion engine is radiated by the heat exchanger by circulating a cooling medium in the circulation path. A flow control unit for controlling the flow rate of the cooling medium in the circulation path between the units, a variable grill unit disposed in front of the heat exchanger and capable of adjusting the amount of ventilation to the heat exchanger, and at least the cooling medium Based on the temperature information, the flow rate control And a command signal generation unit for generating a command signal for controlling the flow rate of the cooling medium in the knit and a command signal for controlling the amount of air flow to the heat exchanger in the variable grill unit.

In this case, the command signal generation unit controls the flow rate from a control mode in which the flow rate of the cooling medium by the flow rate control unit is controlled to the minimum state and the amount of air flow to the heat exchanger by the variable grill unit is controlled to the minimum state. It is configured to generate a command signal to control a flow rate of the cooling medium by the unit to a maximum state and to reach a control mode in which a variable grill unit controls a ventilation amount to a heat exchanger to a maximum state.

Preferably, the command signal generating unit further includes information indicating an operation or non-operation state of a blower fan for forcibly cooling the heat exchanger, information indicating an outside air temperature, and information indicating a traveling speed of the vehicle. It is configured to be added.

The flow control unit preferably includes a heater that generates heat based on a command signal supplied from a command signal generation unit, a thermoelement driven in response to the heat generated by the heater, and a driving force of the thermoelement. And a flow control valve whose degree of valve opening is controlled by the valve.

The flow control unit includes an electric motor driven based on a command signal supplied from a command signal generation unit, and a flow control valve whose degree of valve opening is controlled by the driving force of the electric motor. In some cases.

On the other hand, the variable grill unit preferably includes a heater that generates heat based on a command signal supplied from a command signal generation unit, a thermoelement that is driven in response to the heat generated by the heater, and a drive that drives the thermoelement. It is opened and closed by force and controls the air flow to the heat exchanger.

Also, the variable grill unit controls an electric motor driven based on a command signal supplied from a command signal generation unit, and is opened and closed by a driving force of the electric motor, and controls a ventilation amount to a heat exchanger. In some cases.

According to the cooling control device configured as described above, the cooling control device in the circulation path between the internal combustion engine and the heat exchanger The flow force of the cooling medium is adjusted by, for example, the degree of opening of a flow control valve having a butterfly valve. In addition to this, a variable grill unit located in front of the heat exchanger allows the airflow to the heat exchanger to be adjusted.

Then, the command signal generation unit generates parameters such as information on cooling water temperature, information indicating the operation or non-operation of the blower fan for forcibly cooling the heat exchanger, information indicating the outside air temperature, and information indicating the traveling speed of the vehicle. A command signal is generated based on the command signal, and the command signal controls the degree of opening of the flow control valve and the amount of air flow to the heat exchanger by the variable grill unit.

With this configuration, the flow rate of the cooling medium by the flow rate control unit can be changed from the warm-up control mode in which the flow rate of the cooling medium by the flow rate control unit is controlled to the minimum state, and the amount of air flow to the heat exchanger by the variable grille unit is controlled to the minimum state. A maximum cooling control mode is executed in which the maximum cooling state is controlled and the amount of air flow to the heat exchanger by the variable grill unit is controlled to the maximum state.

Thus, it is possible to provide a cooling control device that promotes warm-up in the warm-up operation of the internal combustion engine and can sufficiently cope with severe changes in operating conditions of the internal combustion engine. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a configuration diagram showing an embodiment in which a cooling control device according to the present invention is applied to an automobile engine, and FIG. 2 is a flow control unit having a first configuration used in the device shown in FIG. FIG. 3 is a configuration diagram showing the flow control unit of a second configuration used in the apparatus shown in FIG. 1 in a partial cross-sectional state.

FIG. 4 is a configuration diagram showing a partial section of a grill actuator in the variable grill unit used in the apparatus shown in FIG. 1, and FIG. 5 is a command signal generation unit (ECU) shown in FIG. 3 is a block diagram showing a basic configuration of FIG.

Fig. 6 is a connection diagram showing the configuration of the PTC heater drive circuit in the flow control unit and the heater element drive circuit in the variable grill unit. Fig. 7 is a diagram showing the drive of the fan motor. FIG. 2 is a connection diagram showing a configuration of a motor drive circuit for performing the above. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a cooling control device for an internal combustion engine according to the present invention will be described based on an embodiment shown in the drawings.

FIG. 1 shows an overall configuration in which the present invention is applied to a cooling control device for an automobile engine. In FIG. 1, reference numeral 1 denotes an engine including a cylinder block 1a and a cylinder head 1b, and a fluid passage indicated by an arrow c is formed in the cylinder block 1a and the cylinder head 1b of the engine 1. Have been.

Reference numeral 2 denotes a heat exchanger, that is, a radiator, and a fluid passage 2c is formed in the radiator 2 as is well known, and a cooling water inlet 2a and a cooling water outlet 2b of the radiator 2 It is connected to a cooling water channel 3 that circulates cooling water with the engine 1.

The cooling water passage 3 includes an outlet-side cooling water passage 3a communicating from a cooling water outlet 1d provided at an upper portion of the engine 1 to a cooling water inlet 2a provided at an upper portion of the radiator 2, and a radiator 2 Connecting the inlet cooling water passage 3b communicating from the cooling water outlet 2b provided in the lower part of the cooling water inlet 1e provided in the lower part of the engine 1 with the cooling water passages 3a and 3b. It consists of a bypass waterway 3c.

Reference numeral 5 denotes a water pump disposed at the inlet 1e of the engine 1, which rotates a rotation shaft by rotation of a crankshaft (not shown) of the engine 1 to forcibly circulate cooling water. . Reference numeral 6 denotes a fan unit for forcing cooling air into the radiator 2, and includes a cooling fan 6a and a fan motor 6b for rotating the fan.

An outlet side cooling water passage 3a disposed between the cooling water outlet 1d of the engine 1 and the cooling water inlet 2a provided at the upper part of the radiator 2 has a flow rate control described in detail later. Unit 11 is interposed. Thereby, a circulation path of the cooling medium, that is, the cooling water is formed so as to include the flow control unit 11. Further, a temperature sensor 13 such as a thermistor is disposed at an outlet 1 d of the cooling water in the engine 1. The value detected by the temperature sensor 13 is converted by a converter 14 into data recognizable by a command signal generation unit (hereinafter referred to as an ECU) 15, and the ECU 15 controls the operating state of the entire engine. Is configured to be supplied.

In the embodiment shown in FIG. 1, the opening information from the throttle opening sensor 17 for detecting the opening of the throttle valve 16 of the engine 1 is also supplied to the ECU 15. I have. Further, although not shown, the ECU 15 further includes information indicating the operation or non-operation of a blower fan (fan motor) for forcibly cooling the radiator 2, information indicating the outside air temperature, and information regarding the progress of the vehicle. It is configured such that information indicating the speed and the like are further added.

On the other hand, the ECU 15 is configured to supply a PWM signal for heating the PTC heater, which will be described later, to the PTC drive circuit 18, and the ECU 15 supplies a fan motor drive circuit 19 to the fan motor drive circuit 19. In addition, a PWM signal for fan motor drive control described later is supplied. Further, the ECU 15 is configured to supply a PWM signal for heating the heater element to a grill unit drive circuit 20 also described later.

The PTC drive circuit 18, the fan motor drive circuit 19, and the grill unit drive circuit 20 control the current supplied from the battery 21 by a PWM signal (command signal) generated by the ECU 15, respectively. The control power is supplied to a PTC heater described later provided in the flow control unit 11, a fan motor 6b, and a heater element controlling opening and closing of a grill unit described later.

In front of the radiator 2, a variable grill unit 22 is provided which is capable of adjusting the amount of air passing through the radiator 2. The variable grill unit 22 includes, for example, a grill 23 configured so that a plurality of strip-shaped glycerol bodies can be linked to change the tilt angle. By changing the air flow, it is possible to adjust the air flow to the Laje night and the second side.

The actuator 24 that controls the opening and closing of the grill 23 changes the angle of the grill 23 by being controlled by a command signal (PWM signal) from the drive circuit 20. The air flow to the radiator 2 can be adjusted.

Next, Fig. 2 shows a first configuration of the flow rate control unit "! 1" in a cross-sectional state. The flow rate control unit 11 includes a tubular body 31 connected to the engine side. A support shaft 32 is disposed at the center of the inner bottom of the cylindrical portion 31, and a butterfly valve 33 rotatably supported by the support shaft 32 is disposed.

This butterfly valve 33 is closed by a return spring (not shown) arranged on the support shaft 32 as shown in FIG. 2 (a) when a thermoelement described later is not operated. It is configured. When the butterfly valve 33 is in a closed state, the valve seat 34 made of a flexible substance disposed on the inner bottom of the cylindrical body 31 is configured to contact the valve body.

As is well known, the valve body of the butterfly valve 33 is formed in a disk shape, and the angle of the plane direction with respect to the flowing direction of the cooling water is rotationally driven by the support shaft 32 so that the flow rate of the cooling water is reduced. It is made to be controlled. That is, the valve is closed when the angle in the plane direction is about 90 degrees with respect to the flow direction of the cooling water, and is fully opened when the angle in the plane direction is near 0 degrees. By appropriately setting the intermediate angle, the flow rate of the cooling water is controlled almost linearly.

A thermo-element 35 is disposed on the outflow side of the cooling water of the butterfly valve 33, that is, on the radiator side. In the example shown in FIG. 2, the thermoelement 35 is disposed in the cooling water of the cooling water passage 3a, and is configured to be able to make thermal contact with the cooling water.

The thermoelement 35 is disposed so as to be positioned in the cooling water by a cylindrical wax element 36 in which wax as a thermal expansion body is sealed. Further, a piston member 37 buried so as to be vertically movable in accordance with the degree of expansion of the wax is disposed in the wax element 36. Above the piston member 37, a cylindrical retainer 38 is arranged so as to surround the piston member 37, and the piston member 37 is moved upward by the support shaft 32. The cam member 39 is arranged coaxially with the cam member 39, and can be rotated about the support shaft 32. Therefore, with the rotation of the cam member 39 by the operation of the piston member 37, the butterfly valve 33 is opened as shown in FIG. 2 (b), and the cooling water is circulated.

On the other hand, an annular PTC heater 40 having a positive temperature coefficient thermistor as a heating element is disposed so as to surround the wax element 36, and above and below the PTC heater 40, a current for supplying a current to the PTC heater 40 is provided. A pair of electrodes 41 and 42 each formed in an annular shape are arranged. The electrodes 41 and 42 are configured to be supplied with current through a lead wire from a socket 43 formed on a side surface of the flow control unit 11.

Accordingly, by energizing the PTC heater 40 via the socket 43, the wax element 36 can be heated. Therefore, due to the thermal expansion of the wax sealed in the wax element 36, the piston member 3 protrudes upward as described above, and the butterfly valve 33 can be opened. According to the flow control unit 11 of the first configuration shown in FIG. 2, the opening degree of the butterfly valve 33 can be controlled in accordance with the temperature of the cooling water and the amount of electric power applied to the PTC heater. .

Next, FIG. 3 shows a second configuration of the flow control unit 11 in a cross-sectional state. In FIG. 3, the same parts as those in FIG. 2 are denoted by the same reference numerals, and therefore, detailed description thereof will be omitted.

The thermoelement 35 in the flow control unit 11 shown in FIG. 3 is configured to be thermally insulated from the cooling water. For this purpose, a wall body 44 is provided at the outlet side of the butterfly valve 33 to shut off the heat of the cooling water with the thermoelement 35. Then, the disc-shaped PTC heater 40 is arranged between the disc-shaped electrodes 41 and 42 at the lower bottom of the thermo-element 35.

The wall 44 can be formed from a material such as a synthetic resin, so that the thermal insulation can be further improved.

Here, FIG. 3 shows a closed state of the butterfly valve 33, and when the PTC heater 40 is energized, the piston member 37 projects upward due to thermal expansion of the wax sealed in the wax element 36, and The butterfly valve 33 is opened by the same operation as that shown in FIG. Can be made.

According to the flow control unit 11 of the second configuration shown in FIG. 3, it is possible to control the degree of opening of the butterfly valve 33 in accordance with the amount of power applied to the C heater irrespective of the temperature of the cooling water. it can.

Next, FIG. 4 shows a configuration of the grille cutter 24 in the variable grill unit 22 in a sectional state. The actuator 24 includes a thermoelement 51 and a heater element 52. The thermoelement 51 has a housing 53 in which a wax 54 as a thermal expansion body is sealed, and the wax 54 is sealed by a diaphragm 55. Then, a semi-fluid 56 is sealed with the diaphragm 55 as a partition, and a rubber piston 57, a backup plate 58, and a piston rod 59 are arranged in series with the semi-fluid 56.

A heater 60 constituting the heater element 52 is disposed so as to abut on the wax-filled position of the housing 53, and the heater 60 is housed together with the housing 53 in an actuator case 61.

Therefore, by conducting electricity to the heater 60 through the grill unit drive circuit 20 shown in FIG. 1, the wax 54 expands, and the diaphragm 55, the semi-fluid 56, the rubber piston 57 and the backup plate 58 are connected. As a result, the piston rod 59 can be driven straight in the direction of arrow A. By stopping the power supply to the heater element 52, the piston rod 59 can be driven in the direction opposite to the arrow A.

By controlling the amount of power (electric power) to the heater 60 by the PWM signal from the drive circuit 20 as described above, the amount of drive (projection) of the piston rod 59 in the direction of arrow A can be adjusted. .

One end of a return bar 63 having a fulcrum 64 at the center is loosely fitted to the piston rod 59, and the other end of the return bar 63 has a rod 25 for controlling opening and closing of the grill 23 in the variable grill unit 22. One end is connected. Therefore, the degree of opening and closing of the grill 23 is controlled in accordance with the amount of projection of the piston rod 59 in the direction of arrow A, and the amount of air flow from the grill 22 to the radiator 2 is adjusted. With this configuration, by increasing the amount of electricity supplied to the heater 60, the piston rod 59 is driven in the direction of arrow A, whereby the grilles 23 are both in the horizontal state and are in the released state, and the radiator 2 is in the open state. The airflow is controlled so as to be large.

Next, FIG. 5 shows a basic configuration of the ECU 15 shown in FIG. The ECU 15 includes a signal processing unit 15a that converts a signal supplied from each sensor into a digital signal or the like recognizable by the ECU, input data processed by the signal processing unit 15a, a ROM and the like. A comparison unit 15b for comparing with various data stored in a table format in the memory 15c of this unit, and a comparison unit 15b [a signal processing unit for processing the comparison result and outputting a PWM signal as a control signal It consists of 15d.

Then, the PWM signal output from the signal processing unit 15d is sent to the PTC drive circuit 18 or the grill unit drive circuit 20 having the configuration shown in FIG. 6, and the PWM signal output from the signal processing unit 15d is It is configured to be supplied to the fan motor drive circuit 19 having the configuration shown in FIG.

As shown in FIG. 6, the PTC drive circuit 18 is composed of an NPN transistor 18b, and the PWM signal output from the signal processing unit 15d is a transistor via a base input resistor 18a. It is configured to be supplied to a base of 18b.

The collector of the transistor 18b is connected to the battery via the PTC heater 40 arranged in the flow control unit 11, and the emitter is connected to the reference potential point (the body of the automobile). A protection diode 18c is connected in parallel with the PTC heater 40. Here, a heater heating control pulse signal whose duty (DUTY) value is controlled is supplied from the ECU 15 to the base of the transistor 18b as shown as PWM1 and PWM2 in FIG. Therefore, the transistor 18b allows a current to flow to the PTC heater 40 according to the duty value of the pulse signal, thereby controlling the amount of heat generated by the PTC heater 40, and consequently the amount of cooling water.

The grill unit drive circuit 20 has the same configuration as that shown in FIG. 6, and connects the heater element 52 of the grill actuator 24 to the collector of the transistor 18b. With this configuration, the amount of heat generated by the heater element 52 is controlled, and as a result, the amount of air flow to the radiator 2 side in the variable grill unit 22 is controlled.

Similarly, the fan motor drive circuit 19 shown in FIG. 5 is also configured by an NPN transistor 19b, and the PWM signal output from the signal processing unit 15d is supplied to the transistor 1 via a base input resistor 19a. 9b is configured to be supplied to the base. The collector of the transistor 19b is connected to the battery via the fan motor 6b, and its emitter is connected to the reference potential point (the body of the vehicle).

Here, a pulse signal for controlling the fan motor whose duty (DUTY) value is controlled is supplied from the ECU 15 to the base of the transistor 19b in the same manner as shown in FIG. 6 as PWM1 and PWM2. You. Therefore, the transistor 19b allows a current to flow to the fan motor 6b in accordance with the duty value of the pulse signal, thereby setting the rotation speed of the fan motor 6b and controlling the radiation efficiency of the radiator.

In the above configuration, as described above, the ECU 15 stores information on the coolant temperature from the temperature sensor 13, information on the opening degree from the throttle opening degree sensor 17, and information indicating the operation or non-operation state of the fan motor 6 b. , Information indicating the outside air temperature, and information indicating the traveling speed of the vehicle. Based on these parameters, the ECU 15 compares the various data stored in the ROM 15c in Fig. 5 in the form of a table, for example, with the PTC drive circuit 18, the fan motor drive circuit 19, and the grille unit drive. A command signal for the circuit 20, that is, a PWM signal is calculated and output.

Here, as shown in FIG. 2, as the flow control unit 11, a thermo-element 35 is disposed in the cooling water of the cooling water passage 3a and is configured to be in thermal contact with the cooling water. The use will be described.

First, during the warm-up operation immediately after the start of the engine, the deviation of the cooling water temperature obtained by the temperature sensor 13 from the target setting temperature of the cooling water is negative. Therefore, the duty factor of the PWM signal output from the ECU 15 to the PTC drive circuit 18, the fan motor drive circuit 19, and the grill unit drive circuit 20 is minimized (= 0).

As a result, the conduction angle of the current applied from the PTC drive circuit 18 to the PTC heater 40 is minimized (= 0). Therefore, the butterfly valve 33 in the flow control unit 11 is closed. Further, the conduction angle of the current applied from the fan motor drive circuit 19 to the fan motor 6b is also minimum (= 0), and the fan motor 6b is stopped. In addition, the conduction angle of the current applied to the heater 60 in the grill actuator 24 is also minimized (= 0) by the grill unit drive circuit 20, so that the grill 23 is closed and the ventilation to the radiator 2 side is performed. The amount is taken to a minimum.

Therefore, the engine is quickly warmed up, the emission harmful gas can be reduced and the fuel efficiency can be improved, and the capacity of the heater for heating the cabin can be quickly increased.

In the normal running state of the vehicle, the wax element 36 in the flow control unit 11 controls the opening degree of the butterfly valve 33 in response to the cooling water temperature, thereby varying the cooling efficiency. On the other hand, the ECU 15 outputs the information to the fan motor drive circuit 19 and the grill unit drive circuit 20 based on the information on the outside air temperature, the information on the cooling water temperature, the operation state of the radial fan and the opening degree of the throttle valve. Control the duty factor of the PWM signal. As a result, the rotation speed of the fan motor 6b is controlled, and the amount of air flow to the radiator 2 by the variable grill unit 22 is also controlled. Therefore, the heat radiation effect of the radiator 2 is also controlled by these, and ideal combustion control of the engine is performed.

Also, when the engine load is large, for example, when the vehicle is climbing a hill or traveling at high speed, the ECU 15 power, the PTC drive circuit 18, the fan motor drive circuit 19, and the grille unit drive circuit The duty factor of the PWM signal output to 20 becomes the maximum.

Therefore, the conduction angle of the current applied to the PTC heater 40 in the flow control unit 11 is maximized, and the butterfly valve 33 in the flow control unit 11 is almost fully opened. The rotation speed of the fan motor 6b is also set to the maximum.

In addition, the conduction angle of the current applied to the heater 60 of the grill actuator 24 is also maximized, whereby the grill 23 is fully opened, and the air flow to the radiator 2 is maximized. Accordingly, the heat radiation effect of the radiator 2 is promoted, and an excessive temperature rise of the engine can be prevented.

On the other hand, as shown in FIG. 3 as the flow control unit 11, the thermoelement 35 On the other hand, the case where a device configured to be thermally insulated is used has the following effect. That is, in the normal running state of the vehicle, the PTC heater 40 is controlled by the ECU 15 in accordance with the load state of the engine to control the opening state of the butterfly valve. When the engine load is large, such as when the vehicle is climbing a hill or traveling at high speed, the amount of current applied to the PTC heater 40 is maximized, whereby the butterfly valve 33 in the flow control unit 11 is almost completely changed. It is in a fully opened state.

In the above-described embodiment, the flow control unit 11 controls the opening degree of the butterfly valve 33 by using the PTC heater 40 and the thermoelement 35, and the power is controlled by an electric motor. It can also be controlled by driving.

That is, for example, a worm gear is interposed between the electric motor and the drive shaft of the butterfly valve, and the electric motor is rotated in the forward and reverse directions by a PWM signal supplied from the ECU, thereby opening the butterfly valve. It is possible to control the valve degree. Further, in the embodiment described above, the actuator constituted by the heater element 52 and the thermowax element 51 is used as the actuator 24 in the variable grill unit 22, but this is also controlled by the drive by the electric motor. can do. In other words, the rotation of the gear wheel is reduced by a worm gear or the like, and the rotation of the gear wheel is transmitted to a rod for controlling the opening and closing of the grill, so that the opening and closing of the grill can be controlled.

Further, the cooling control device of the present invention has been described based on the embodiment applied to an automobile engine.However, the present invention is not limited to such a specific one, but may be applied to other internal combustion engines. Thus, the same function and effect can be obtained.

As apparent from the above description, the cooling control device for an internal combustion engine according to the present invention includes a flow control unit that controls the flow rate of the cooling medium, a variable grill unit that can adjust the amount of air flow to the heat exchanger, A command signal generating unit for generating a command signal for controlling a flow rate of the cooling medium in the flow rate control unit and a flow rate of air to the heat exchanger in the variable grill unit based on at least temperature information of the cooling medium. The flow control unit and variable grill By operating with the unit, an appropriate heat radiation effect can be provided from the warm-up operation state of the internal combustion engine to the high load operation state.

As described above, since the action of the variable grill unit acts synergistically with the action of the flow control unit, it is possible to quickly increase the temperature of the cooling water during warm-up operation. It is possible to effectively suppress an excessive rise in temperature of the internal combustion engine when the load on the internal combustion engine is large, such as during high-speed running.

In particular, in the case where the load on the internal combustion engine is large, the worst case condition of knocking or overheating can be effectively avoided, and the cooling control device can sufficiently follow severe changes in operating conditions. Can be provided.

Claims

The scope of the claims

1. A circulation path of a cooling medium is formed between a fluid passage formed in the internal combustion engine and a fluid passage formed in the heat exchanger, and the cooling medium is circulated through the circulation path to reduce the internal combustion engine. A cooling control device for an internal combustion engine configured to radiate heat generated by the heat exchanger,

A flow control unit for controlling a flow rate of a cooling medium in a circulation path between the internal combustion engine and the heat exchanger; and a variable grill disposed in front of the heat exchanger and capable of adjusting a flow rate to the heat exchanger. A command signal for controlling the flow rate of the cooling medium in the flow rate control unit based on at least the temperature information of the cooling medium, and an air flow rate to the heat exchanger in the variable grill unit. A cooling control device for an internal combustion engine, comprising: a command signal generation unit that generates a command signal for control.

2. The command signal generation unit controls the flow rate from the control mode in which the flow rate control unit controls the flow rate of the cooling medium to the minimum state and the variable grille unit controls the flow rate to the heat exchanger to the minimum state. The control unit is configured to control the flow rate of the cooling medium by the unit to a maximum state, and to generate a command signal leading to a control mode for controlling the ventilation amount to the heat exchanger by the variable grill unit to a maximum state. The cooling control device for an internal combustion engine according to claim 1, wherein

3. The command signal generation unit further includes information indicating the operation or non-operation state of the blower fan for forcibly cooling the heat exchanger, information indicating the outside air temperature, and information indicating the traveling speed of the vehicle. 3. The cooling control device for an internal combustion engine according to claim 1, wherein the cooling control device is configured to be added to the internal combustion engine.

4. The flow control unit includes a heater that generates heat based on a command signal supplied from a command signal generation unit, a thermoelement that is driven in response to the heat generated by the heater, and a valve that is opened by a driving force of the thermoelement. 4. The cooling control device for an internal combustion engine according to claim 1, further comprising a flow control valve whose degree is controlled.

5. The flow control unit includes an electric motor driven based on a command signal supplied from a command signal generation unit, and a flow control valve whose valve opening degree is controlled by a driving force of the electric motor. 4. The cooling control device for an internal combustion engine according to claim 1, wherein

6. The variable grill unit includes a heater that generates heat based on a command signal supplied from a command signal generation unit, a thermoelement that is driven in response to the heat generated by the heater, and a driving force of the thermoelement. The cooling control device for an internal combustion engine according to any one of claims 1 to 5, further comprising: a grill that is opened and closed and controls a ventilation amount to the heat exchanger.

The variable grill unit includes an electric motor that is driven based on a command signal supplied from a command signal generation unit, and a grill that is opened and closed by a driving force of the electric motor and controls a ventilation amount to a heat exchanger. The cooling control device for an internal combustion engine according to any one of claims 1 to 5, characterized by comprising: