JP7234890B2 - Cooling system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cooling system, and more particularly, to a cooling system mounted on a vehicle having an engine and a transmission and having an engine cooling system, a lubrication cooling system, and an oil temperature control system.

Conventionally, as this type of cooling device, it is proposed that it is mounted on a vehicle equipped with an engine and a transmission (automatic transmission) and includes an engine cooling device, a lubricating cooling device, and an oil temperature adjusting device. (See Patent Document 1, for example). The engine cooling device cools the engine using cooling water. The lubrication and cooling system uses transmission oil to lubricate and cool the transmission. The oil temperature adjustment device adjusts the temperature of the transmission oil by exchanging heat between the cooling water and the transmission oil. This cooling device supplies transmission oil to the oil temperature adjustment device when the temperature of the transmission oil reaches the cooling start temperature. The oil temperature adjustment device supplied with the transmission oil cools the transmission oil by exchanging heat between the cooling water and the transmission oil. Then, when the degree of deterioration of the transmission oil exceeds a predetermined threshold value, that is, when the transmission oil temperature continues to be high and the deterioration of the transmission oil progresses, the cooling start temperature is lowered. As a result, overheating of the transmission oil is suppressed, and further deterioration of the transmission oil is suppressed.

2008-303918 publication

Since the cooling device described above allows the degree of deterioration of the transmission oil to exceed a predetermined threshold, it is inevitable that the deterioration of the transmission oil progresses to some extent. Since transmission oil deteriorates more rapidly as it becomes hotter, a method to further suppress the deterioration of transmission oil is to increase the flow rate of the cooling water and lower the temperature of the cooling water, thereby reducing the temperature of the transmission oil. A method for suppressing it is conceivable. However, for example, increasing the flow rate of cooling water increases the power consumption and loss (cooling loss) of the engine cooling device for increasing the amount of cooling water, resulting in a decrease in the energy efficiency of the vehicle as a whole.

A main object of the cooling device of the present invention is to suppress deterioration of the transmission oil while suppressing a decrease in energy efficiency.

The cooling device of the present invention employs the following means in order to achieve the above main object.

The cooling device of the present invention is
An engine, a torque converter connected to the output shaft of the engine, and a transmission connected to the drive shaft connected to the torque converter and the axle, and the power from the engine is changed and output to the drive shaft. mounted on a vehicle comprising a transmission that
an engine cooling device that cools the engine using cooling water;
a lubricating and cooling device that uses transmission oil to lubricate and cool the transmission;
an oil temperature adjustment device that adjusts the temperature of the transmission oil by exchanging heat between the cooling water and the transmission oil;
a control device that controls the engine cooling device and the lubrication cooling device;
A cooling device comprising
The control device is
Average value of vehicle speed during a third period, excluding a second period during which the vehicle has been stopped for a predetermined time or longer, during the first period from when the system started and the vehicle started running until now. When both the first condition that the average vehicle speed is equal to or lower than the predetermined vehicle speed and the second condition that the smoothing oil temperature, which is the average value of the transmission oil temperature during the first period, is equal to or higher than the predetermined temperature are satisfied. , controlling the engine cooling device so that the flow rate of the cooling water increases compared to when at least one of the first and second conditions is not satisfied;
This is the gist of it.

In the cooling device of the present invention, the vehicle speed in the third period, excluding the second period in which the vehicle has been stopped for a predetermined time or more, is Both the first condition that the smoothed average vehicle speed, which is the average value of When satisfied, the engine cooling system is controlled to increase the flow rate of the cooling water compared to when at least one of the first and second conditions is not satisfied. When the first condition is satisfied, it is considered that the transmission oil tends to reach a high temperature because the number of gear changes of the vehicle is large. When the second condition is satisfied, it is considered that the transmission oil remains hot for a long time. Therefore, when both the first condition and the second condition are satisfied, the flow rate of the cooling water is increased compared to when at least one of the first and second conditions is not satisfied. By properly controlling the engine cooling device, the temperature rise of the transmission oil can be suppressed, and the deterioration of the transmission oil can be suppressed. This increase in the flow rate of cooling water is performed only when both the first condition and the second condition are satisfied (not performed when at least one of the first and second conditions is not satisfied). , the decrease in energy efficiency can be suppressed as compared with the case where the flow rate of the cooling water is increased regardless of whether the first and second conditions are satisfied. As a result, deterioration of the transmission oil can be suppressed while suppressing a decrease in energy efficiency.

The cooling device of the present invention includes a vehicle speed sensor that detects the vehicle speed and an oil temperature sensor that detects the temperature of the transmission oil, and the smoothed average vehicle speed is detected by the vehicle speed sensor during the third period. The smoothed oil temperature may be an average value of the transmission oil temperatures detected by the oil temperature sensor during the first period.

1 is a configuration diagram showing an outline of the configuration of an automobile 20 equipped with a cooling device as one embodiment of the present invention; FIG. 2 is a configuration diagram showing an outline of the configuration of an engine cooling device 28 and a lubrication cooling device 32; FIG. 4 is a flowchart showing an example of an electric WP control routine executed by an ECU 60; FIG. 5 is an explanatory diagram for explaining an example of the relationship between the cooling water temperature Tw and the oil temperature To when the vehicle runs for a long time at a low vehicle speed; FIG. 5 is an explanatory diagram showing an example of temporal changes in smoothed average vehicle speed Vave, cooling water temperature Tw, and oil temperature To in an automobile equipped with a cooling device of a comparative example; FIG. 4 is an explanatory diagram showing an example of temporal changes in smoothed average vehicle speed Vave, cooling water temperature Tw, and oil temperature To in the automobile 20 equipped with the cooling device of the embodiment;

Next, a mode for carrying out the present invention will be described using examples.

FIG. 1 is a configuration diagram showing the outline of the configuration of an automobile 20 equipped with a cooling device as one embodiment of the present invention. FIG. 2 is a configuration diagram showing an outline of the configurations of the engine cooling device 28 and the lubrication cooling device 32. As shown in FIG. As shown in FIGS. 1 and 2, the automobile 20 includes an engine 22, an engine cooling device 28, a transmission 30, a lubrication cooling device 32, an oil cooler 34, and an electronic control unit (hereinafter referred to as "ECU"). ) 60 and

The engine 22 is configured as an internal combustion engine that outputs power using gasoline, light oil, or the like as fuel, and a crankshaft 23 is connected to a transmission 30 . The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24 .

The engine cooling device 28 is configured as a device that cools the engine 22 using cooling water. The engine cooling device 28 includes a circulation flow path 280 , a radiator 282 , and an electric water pump (hereinafter referred to as “electric WP”) 284 , as shown in FIG. 2 .

The circulation flow path 280 has a heat exchange portion (not shown) formed in the cylinder block or cylinder head of the engine 22 and forms a flow path for circulating cooling water.

Radiator 282 is attached to the front of the vehicle. The radiator 282 exchanges heat between the outside air taken in as running air and the cooling water in the circulation passage 280, and cools the cooling water with the outside air.

The electric WP 284 is configured as an electric variable flow rate pump capable of pressure-feeding cooling water to the circulation flow path 280 and changing the flow rate of the cooling water. The electric WP 284 is driven and controlled by the engine ECU 24 .

Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU. In addition to the CPU, the engine ECU 24 includes a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. Prepare.

Signals from various sensors necessary for controlling the operation of the engine 22 are input to the engine ECU 24 through an input port. A signal input to the engine ECU 24 is, for example, a crank angle θcr from a crank position sensor that detects the rotational position of the crankshaft 23 of the engine 22 . A cooling water temperature Tw from a temperature sensor 28a that is attached between the electric WP 284 of the circulation passage 280 of the engine cooling device 28 and the oil cooler 34 and detects the temperature of cooling water (cooling water temperature) Tw that circulates in the circulation passage 280. can also be mentioned. The cam angle from the cam position sensor that detects the rotational position of the camshaft, the throttle opening TH from the throttle position sensor that detects the position of the throttle valve, the intake air amount Qa from the air flow meter attached to the intake pipe, and the intake air Intake air temperature from a temperature sensor attached to the pipe can also be mentioned. An air-fuel ratio AF from an air-fuel ratio sensor attached to the exhaust pipe and an oxygen signal O2 from an oxygen sensor attached to the exhaust pipe can also be mentioned.

Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 through an output port. Signals output from the engine ECU 24 include a control signal to a throttle motor that adjusts the position of a throttle valve, a control signal to a fuel injection valve, and a control signal to a spark plug. Control signals to the electric WP 284 of the engine cooling system 28 can also be mentioned.

The engine ECU 24 is connected to the ECU 60 via a communication port.

The engine ECU 24 calculates the rotation speed of the engine 22 based on the crank angle θcr from the crank position sensor. The engine ECU 24 controls the electric WP 284 based on the coolant temperature Tw from the temperature sensor 28a.

Transmission 30 includes a torque converter 300 and an automatic transmission 304 .

The torque converter 300 is configured as a general hydraulic transmission device, and transmits the power of the crankshaft 23 of the engine 22 to the intermediate rotary shaft 302 after amplifying the torque, or transmits the torque as it is without amplifying it. or The torque converter 300 includes a pump impeller connected to the crankshaft 23 of the engine 22, a turbine runner connected to an intermediate rotating shaft 302, a stator for rectifying the flow of hydraulic oil from the turbine runner to the pump impeller, and the stator. It has a one-way clutch that restricts the rotation direction to one direction, and a hydraulically driven lockup clutch 300a that connects the pump impeller and the turbine runner. The lockup clutch 300 a is driven and controlled by an automatic transmission electronic control unit (hereinafter referred to as "ATECU") 40 .

The automatic transmission 304 is connected to the intermediate rotary shaft 302 and also to a drive shaft 37 that is connected to axles connected to the drive wheels 36a and 36b via differential gears. The automatic transmission 304 includes a plurality of planetary gears and a plurality of hydraulically driven friction engagement elements (clutches, brakes). The automatic transmission 304 transmits power between the intermediate rotary shaft 302 and the drive shaft 37 by forming forward gears from first gear to sixth gear and reverse gears by engaging and disengaging a plurality of frictional engagement elements. . The automatic transmission 304 is driven and controlled by the AT ECU 40 .

The lubricating/cooling device 32 is configured as a device that lubricates and cools the transmission 30 using transmission oil (ATF: Automatic Transmission Fluid). As shown in FIG. 2, the lubrication cooling device 32 includes a first flow path 320, a second flow path 322, an oil pan 324, an oil pump 326, a return flow path 332, a protection flow path 334, and a relief flow path 334. a valve 336;

First flow path 320 forms a flow path through which ATF flows between oil pan 324 and transmission 30 .

The second flow path 322 branches off from the first flow path 320 upstream of the oil pump 326 and joins the first flow path 320 before the transmission 30 .

Oil pan 324 is arranged below transmission 30 and stores ATF.

The oil pump 326 is configured as an internal tooth meshing type (internal contact type) gear pump that is connected to the intermediate rotary shaft 302 and driven by the power from the engine 22 . The oil pump 326 sucks up the ATF stored in the oil pan 324 and pumps it to the first flow path 320 . The oil pump 326 is driven and controlled by the AT ECU 40 .

Return flow path 332 is a flow path through which ATF supplied to transmission 30 returns to oil pan 324 . In the embodiment, the gaps between the planetary gears and frictional engagement elements (such as clutches and brakes) that constitute the transmission 30, and the gaps between these planetary gears and frictional engagement elements and the inner wall of the case that accommodates the transmission 30 The gap forms the return channel 332 .

The protection flow path 334 circulates ATF between the oil pump 326 of the first flow path 320 and the branch point Br where the second flow path 322 branches from the first flow path 320 and between the oil pan 324. forming a flow path.

A relief valve 336 is attached to the protection channel 334 . The relief valve 336 closes when the pressure of the ATF upstream of the relief valve 336, that is, the pressure of the ATF between the oil pump 326 of the first flow path 320 and the branch point Br is less than or equal to a predetermined pressure. The relief valve 336 opens when the pressure of the ATF between the oil pump 326 of the first flow path 320 and the branch point Br exceeds a predetermined pressure to protect the ATF of the first flow path 320 from the flow path 334. supplied to the oil pan 324 via the This prevents the pressure of the ATF in the first flow path 320 from increasing excessively.

The lubrication cooling device 32 configured in this way sucks up the ATF stored in the oil pan 324 using the oil pump 326 , supplies the ATF to the first flow path 320 , and supplies it to the transmission 30 . The ATF supplied to the transmission 30 lubricates and cools the planetary gears and friction engagement elements of the automatic transmission 304 of the transmission 30 , and then returns to the oil pan 324 through the return passage 332 . That is, ATF circulates between oil pan 324 and transmission 30 .

The oil cooler 34 is attached to the second passage 322 of the lubrication cooling device 32 and between the electric WP 284 and the engine 22 of the circulation passage 280 of the engine cooling device 28 . The oil cooler 34 adjusts the temperature of the ATF by exchanging heat between the cooling water flowing through the circulation flow path 280 and the ATF flowing through the second flow path 322 .

In addition to lubricating and cooling transmission 30, ATF is also used as hydraulic fluid for hydraulically controlling a plurality of friction engagement elements of automatic transmission 304 and as hydraulic fluid in torque converter 300. . Therefore, the automobile 20 uses the ATF as hydraulic oil in addition to the first and second flow paths 320 and 322, the return flow path 332, and the protection flow path 334 in a plurality of friction engagement elements of the automatic transmission 304 and a torque converter. It also has a flow path and a hydraulic circuit (not shown) for supplying to the inside of 300 .

Although not shown, the AT ECU 40 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. .

Signals necessary for controlling the transmission 30 and the lubricating/cooling device 32 are input to the AT ECU 40 . The signal input to the AT ECU 40 is, for example, the oil temperature To from a temperature sensor 320a that detects the temperature of the ATF between the oil pump 326 of the first flow path 320 of the lubrication cooling device 32 and the branch point Br. be able to.

Various control signals for controlling the transmission 30 and the lubricating/cooling device 32 are output from the AT ECU 40 via output ports. Signals output from the AT ECU 40 include a control signal to the lockup clutch 300a of the torque converter 300, a shift control signal to the automatic transmission 304, and the like.

The AT ECU 40 is connected to the ECU 60 via a communication port.

The AT ECU 40 controls the shift of the automatic transmission 304 according to the shift control signal from the ECU 60 . The AT ECU 40 also outputs data regarding the state of the automatic transmission 304 to the ECU 60 as necessary.

Although not shown, the ECU 60 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. .

The ECU 60 receives an ignition signal from an ignition switch 70, a shift position SP from a shift position sensor 72 that detects the operating position of a shift lever 71, and an accelerator opening from an accelerator pedal position sensor 74 that detects the depression amount of an accelerator pedal 73. Acc, the brake pedal position BP from a brake pedal position sensor 76 that detects the amount of depression of the brake pedal 75, and the vehicle speed V from a vehicle speed sensor 78 are input via input ports. The shift position SP includes a parking position (P position), a neutral position (N position), a drive position (D position, forward gear), a reverse position (R position, reverse gear), and the like.

The ECU 60 is connected to the engine ECU 24 and the AT ECU 40 via communication ports, and exchanges various control signals and data with the engine ECU 24 and the AT ECU 40 .

The ECU 60 inputs the vehicle speed V from the vehicle speed sensor 78 every predetermined time (for example, several milliseconds) after the ignition switch 70 is turned on, and stores the input vehicle speed V in the RAM as a vehicle speed history. Then, when the ignition switch 70 is turned off, the vehicle speed history stored in the RAM is erased.

The automobile 20 of the embodiment constructed in this manner outputs the power from the engine 22 to the drive wheels 36a and 36b in response to the operation of the accelerator pedal 73 by the driver to run.

Further, in the automobile 20 of the embodiment, the automatic transmission 304 is controlled according to the shift position SP. When the shift position SP is in the D position or the R position, basically, a plurality of friction coefficients of the automatic transmission 304 are set so that the automatic transmission 304 is in one of the first to sixth speeds or in reverse. control the combination factor. When the shift position SP is the N position or the P position, all of the plurality of friction engagement elements (clutch, brake) are released.

Next, the operation of the automobile 20 equipped with the cooling system of the embodiment configured as described above, in particular, the operation of the electric WP 284 of the engine cooling system 28 will be described. FIG. 3 is a flow chart showing an example of an electric WP control routine executed by the ECU 60. As shown in FIG. This routine is repeatedly executed by the ECU 60 at predetermined time intervals (for example, several milliseconds).

When this routine is executed, the CPU of the ECU 60 executes a process of inputting the vehicle speed V and the oil temperature To (step S100). A value detected by the vehicle speed sensor 78 is input as the vehicle speed V. FIG. For the oil temperature To, a value detected by the temperature sensor 320a is inputted through the AT ECU 40 by communication.

Subsequently, the smoothing oil temperature Toave is calculated (step S110). The tempered oil temperature Toave is the value detected by the temperature sensor 320a in the first period P1 from the start of the system to the present, that is, the average value of the oil temperature To, for example, according to the following equation (1): Calculated. In equation (1), Toave last time is the annealed oil temperature Toave calculated when this routine was executed last time. In general, when the ATF is in a high temperature state for a long time, the tempering oil temperature Toave becomes a large value. Therefore, the tempering oil temperature Toave serves as an index for detecting that the ATF has been in a high temperature state for a long period of time.

Toave=(previous Toave+To)/2 (1)

Next, it is determined whether or not the vehicle has been stopped for a long time (step S120). This determination determines that the vehicle has been stopped for a long time when the vehicle speed V is equal to or less than 0 for a period of time VTstop (for example, 2 minutes, 3 minutes, 4 minutes, etc.).

If it is determined in step S120 that the vehicle has not been stopped for a long time, a smoothed average vehicle speed Vave is calculated (step S130). Here, the smoothed average vehicle speed Vave is calculated by the following equation (2), for example, as the average value of the vehicle speed V detected by the vehicle speed sensor 78 in the first period P1. In equation (2), the previous Vave is the smoothed average vehicle speed Vave calculated when this routine was executed last time. In general, when the vehicle continues to run at a low speed, the frequency of starting and stopping increases, and the frequency of changing gears increases. In such a running state, the torque converter 300 slips and the multiple frictional engagement elements (clutches and brakes) constituting the automatic transmission 304 are switched more frequently, and the ATF is likely to become hot. Therefore, the smoothed average vehicle speed Vave serves as an index for detecting that the vehicle is running in a state where the ATF tends to reach a high temperature.

Vave=(Previous Vave+V)/2 (2)

In step S120, when the vehicle has been stopped for a long time, it is determined that the vehicle has been stopped for a long time from the first period P1 to the second period P2 (the state in which the vehicle speed V is equal to or less than 0 continues for the time VTstop or longer). A smoothed average vehicle speed Vave in the third period P3 excluding the period) is calculated (step S140). Here, the smoothed average vehicle speed Vave is the average value of the vehicle speed V detected by the vehicle speed sensor 78 in the third period P3 from the vehicle speed history stored in the RAM, and applying the above equation (2), Calculated. Here, the average value of the vehicle speed V in the third period P3 excluding the first period P1 to the second period P2 is set as the smoothed average vehicle speed Vave because the transmission 30 (the torque converter 300, the automatic transmission 304 ), and the ATF does not reach a high temperature. In this way, the average value of the vehicle speed V in the third period P3 excluding the first period P1 to the second period P2 is set as the smoothed average vehicle speed Vave. It is considered to be an appropriate indicator for detecting that the temperature is likely to become high.

When the smoothed oil temperature Toave and the smoothed average vehicle speed Vave are calculated in this manner, the first condition that the smoothed average vehicle speed Vave is equal to or lower than the threshold value Vmin and the second condition that the smoothed oil temperature Toave is higher than the threshold value Toh are different. It is determined whether or not both are established (step S150). Threshold value Vmin determines whether or not the running state is such that the torque converter 300 slips and the frequency of switching of a plurality of frictional engagement elements (clutches and brakes) constituting the automatic transmission 304 increases and the ATF tends to become hot. This is a threshold for determination. The threshold Vmin is set to 15 km/h, 20 km/h, 25 km/h, etc., for example. The threshold Voh is a threshold for determining whether or not there is a high possibility that deterioration of the ATF will occur if the temperature of the ATF further rises. The threshold Voh is set to a temperature slightly lower than the temperature at which the ATF deteriorates due to high temperatures, for example, 98°C, 100°C, 102°C, and the like.

When the first condition is not satisfied or the second condition is not satisfied in step S150, the driving condition is not likely to cause the ATF to become hot, or the ATF is not in a high temperature state for a long period of time. It is determined that there is, and the target cooling water temperature Ttrgl, which is the target temperature of the cooling water circulating in the circulation passage 280 of the engine cooling device 28, is set to the value T1 (step S160). The value T1 is set to 96°C, 97°C, 98°C, or the like, for example.

After setting the target cooling water temperature Ttrgl in this manner, the target cooling water temperature Ttrgl is transmitted to the engine ECU 24 (step S180), and this routine ends. Upon receiving the target cooling water temperature Ttrgl, the engine ECU 24 controls the electric WP 284 so that the cooling water temperature Tw detected by the temperature sensor 28a becomes the target cooling water temperature Ttrgl. Through such control, the cooling water temperature Tw can be set to the value T1.

FIG. 4 is an explanatory diagram for explaining an example of the relationship between the cooling water temperature Tw and the oil temperature To when the vehicle runs for a long time at a low vehicle speed. In the drawing, the relationship between the cooling water temperature Tw and the oil temperature To when the vehicle is running at low speed for a long time is indicated by hatching. When the vehicle is traveling at a low speed for a long time, the frequency of changing the gear stage of the automatic transmission 304 increases, causing slipping of the torque converter 300 and a plurality of frictional engagement elements (clutches and brakes) constituting the automatic transmission 304. , the ATF tends to reach a high temperature. However, since the cooling water in the circulation passage 280 of the engine cooling device 28 and the ATF in the second passage 322 of the lubrication cooling device 32 exchange heat in the oil cooler 34, the oil temperature To is It converges to the cooling water temperature Tw. Therefore, by controlling the electric WP 284 so that the coolant temperature Tw detected by the temperature sensor 28a becomes the target coolant temperature Ttrgl (value T1), the oil temperature To can be set to the value T1.

When both the first condition and the second condition are satisfied in step S150, it is determined that the ATF is likely to become hot during driving and that the high temperature of the ATF continues for a long period of time. Ttrgl is set to the value T2 (step S170). The value T2 is a temperature lower than the value T1 and is set to, for example, 86°C, 88°C, 90°C. The time when both the first condition and the second condition are satisfied is when the vehicle is traveling on a congested road for a relatively long time or when the engine 22 is not cold-started. In the case of short trips (driving in a short time) such as shopping in a nearby area, or traveling on expressways where there are no users or traffic jams, the frequency in which both the first condition and the second condition are satisfied is not so high.

After setting the target cooling water temperature Ttrgl in this manner, the target cooling water temperature Ttrgl is transmitted to the engine ECU 24 (step S180), and this routine ends. Upon receiving the target coolant temperature Ttrgl, the engine ECU 24 controls the electric WP 284 so that the coolant temperature Tw detected by the temperature sensor 28a becomes the target coolant temperature Ttrgl (value T2). That is, the electric WP 284 is controlled to increase the flow rate of the cooling water compared to when the electric WP 284 is controlled so that the cooling water temperature Tw detected by the temperature sensor 28a is set to the value T1.

FIG. 5 is an explanatory diagram showing an example of temporal changes in smoothed average vehicle speed Vave, cooling water temperature Tw, and oil temperature To in an automobile equipped with the cooling device of the comparative example. FIG. 6 is an explanatory diagram showing an example of temporal changes in smoothed average vehicle speed Vave, cooling water temperature Tw, and oil temperature To in the automobile 20 equipped with the cooling device of the embodiment. In the comparative example, in the electric WP control routine of FIG. 3, after step S140 is executed, step S160 is executed without executing steps S150 and S170. 5 and 6, dashed lines indicate an example of the vehicle speed V detected by the vehicle speed sensor 78 (only part of the period is shown). In FIG. 6, the dashed line indicates the tempering oil temperature Toave.

When the vehicle speed V continues to be low, the smoothed average vehicle speed Vave decreases to become equal to or lower than the threshold value Vmin (time t1). At such a low vehicle speed, the ATF tends to become hot, so the oil temperature To rises with time. In the comparative example, as shown in FIG. 5, the target cooling water temperature Ttrgl is set to a value T1, and the electric WP 284 is controlled so that the cooling water temperature Tw detected by the temperature sensor 28a becomes the target cooling water temperature Ttrgl. As a result, the cooling water temperature Tw converges to the value T1 (time t2), the oil temperature To converges to the same value T1 as the cooling water temperature Tw, and the ATF continues to be at a high temperature. In the embodiment, as shown in FIG. 6, when the smoothed average vehicle speed Vave becomes equal to or lower than the threshold value Vmin and the oil temperature To rises with time, the smoothed oil temperature Toave rises. When the smoothing oil temperature Toave reaches or exceeds the threshold value Toh, the target cooling water temperature Ttrgl is set to a value T2 lower than the value T1, and the electric WP 284 is operated so that the cooling water temperature Tw detected by the temperature sensor 28a becomes the target cooling water temperature Ttrgl. control (time t3). The cooling water temperature Tw converges to the value T2, and the oil temperature To converges to the same value T2 as the cooling water temperature Tw. As a result, the temperature of the ATF can be lowered, and deterioration of the ATF can be suppressed.

Such an increase in the flow rate of cooling water is performed only when both the first condition and the second condition are satisfied in step S150 (when at least one of the first and second conditions is not satisfied). ), power consumption of the electric WP 284 can be suppressed, and a decrease in energy efficiency can be suppressed, compared to the case where the flow rate of the cooling water is increased regardless of whether the first and second conditions are satisfied. Therefore, deterioration of the ATF can be suppressed while suppressing a decrease in energy efficiency.

According to the automobile 20 equipped with the cooling device of the embodiment described above, the first period P1 from the start of the system to the present time, excluding the second period P2 in which the vehicle has been stopped for a long time or more, is The first condition is that the smoothed average vehicle speed Vave, which is the average value of the vehicle speed V in the third period P3, is equal to or lower than the threshold value Vmin, and the smoothed oil temperature To, which is the average value of the ATF temperature in the first period P1, is higher than or equal to a predetermined temperature. The electric WP 284 is operated so that when both a certain second condition and and are satisfied, the flow rate of the cooling water increases compared to when at least one of the first and second conditions is not satisfied. By controlling, deterioration of the ATF can be suppressed while suppressing a decrease in energy efficiency.

In the automobile 20 equipped with the cooling device of the embodiment, in step S110, for example, the smoothing oil temperature Toave is calculated from the oil temperature detected by the temperature sensor 320a during the first period P1 from the start of the system to the present. It is calculated by applying the above formula (2) to To. However, the smoothed oil temperature Toave is the oil temperature To obtained by applying the oil temperature low-pass filter to the oil temperature To detected by the temperature sensor 320a in the first period P1 from the start of the system to the present. may be a component below a predetermined frequency (the upper limit of the frequency that is passed by the low-pass filter).

In the automobile 20 equipped with the cooling device of the embodiment, in steps S130 and S140, the smoothed average vehicle speed Vave is converted to the value detected by the vehicle speed sensor 78 in the first period P1 or the third period P3 using the above equation (2). is calculated by applying However, the smoothed average vehicle speed Vave is obtained by applying a vehicle speed low-pass filter to the values detected by the vehicle speed sensor 78 in the first period P1 and the third period P3, and the predetermined frequency of the vehicle speed V (passed by the low-pass filter upper limit of frequency) or less.

In the automobile 20 equipped with the cooling device of the embodiment, the target cooling water temperature Ttrgl is set in steps S160 and S170. However, in steps S160 and S170, instead of the target cooling water temperature Ttrgl, a target flow rate Vtrg, which is a target value for the flow rate of cooling water in the circulation flow path 280, may be set. In this case, in step S170, the target flow rate Vtrg is made larger than in step S160. In step S180, the electric WP 284 may be controlled so that the flow rate of the cooling water in the circulation flow path 280 becomes the target flow rate Vtrg.

In the automobile 20 equipped with the cooling device of the embodiment, the oil cooler 34 causes heat exchange between the cooling water circulating in the circulation passage 280 and the ATF circulating in the second passage 322 to adjust the temperature of the ATF. there is However, the oil cooler 34 may be any device that can adjust the temperature of the ATF. For example, the second flow path 322 may be attached to the radiator 282 to allow the ATF to exchange heat with the outside air.

In the automobile 20 equipped with the cooling device of the embodiment, the electric WP 284 adjusts the flow rate of the cooling water in the circulation passage 280 . However, instead of the electric WP 284, for example, a device that can variably control the flow rate of the cooling water in the circulation flow path 280, such as a flow control valve that can control the flow rate of the cooling water in the circulation flow path 280 or a mechanical variable flow rate pump. Anything can be used.

The correspondence relationship between the main elements of the embodiments and the main elements of the invention described in the column of Means for Solving the Problems will be described. In the embodiments, the engine 22 corresponds to the "engine", the transmission 30 corresponds to the "transmission", the engine cooling system 28 corresponds to the "engine cooling system", and the lubrication cooling system 32 corresponds to the "lubrication cooling system". , the oil cooler 34 corresponds to the "oil temperature adjustment device", and the ECU 60 and the engine ECU 24 correspond to the "control device".

Note that the correspondence relationship between the main elements of the examples and the main elements of the invention described in the column of Means for Solving the Problems is the Since it is an example for specifically explaining the mode for solving the problem, it does not limit the elements of the invention described in the column of the means for solving the problem. That is, the interpretation of the invention described in the column of Means to Solve the Problem should be made based on the description in that column, and the Examples are based on the description of the invention described in the column of Means to Solve the Problem. This is only a specific example.

Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to such embodiments at all, and can be modified in various forms without departing from the scope of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention can be used in the cooling device manufacturing industry and the like.

20 automobile, 22 engine, 23 crankshaft, 24 engine ECU, 26 engine electronic control unit (engine ECU), 28 engine cooling device, 28a, 320a temperature sensor, 30 transmission, 32 lubrication cooling device, 34 oil cooler, 36a , 36b drive wheel, 37 drive shaft, 40 automatic transmission electronic control unit (ATECU), 60 electronic control unit (ECU), 70 ignition switch, 71 shift lever, 72 shift position sensor, 73 accelerator pedal, 74 accelerator pedal position sensor, 75 brake pedal, 76 brake pedal position sensor, 78 vehicle speed sensor, 280 circulation path, 282 radiator, 284 electric water pump (electric WP), 300 torque converter, 300a lockup clutch, 302 intermediate rotary shaft, 304 automatic transmission machine, 320 first flow path, 322 second flow path, 324 oil pan, 326 oil pump, 332 return flow path, 334 protection flow path, 336 relief valve, Br branch point.

Claims (1)

An engine, a torque converter connected to the output shaft of the engine, and a transmission connected to the drive shaft connected to the torque converter and the axle, and the power from the engine is changed and output to the drive shaft. mounted on a vehicle comprising a transmission that
an engine cooling device that cools the engine using cooling water;
a lubricating and cooling device that uses transmission oil to lubricate and cool the transmission;
an oil temperature adjustment device that adjusts the temperature of the transmission oil by exchanging heat between the cooling water and the transmission oil;
a control device that controls the engine cooling device and the lubrication cooling device;
A cooling device comprising
The control device is
The smoothed average vehicle speed, which is the average value of the vehicle speed in the third period, excluding the second period in which the vehicle has been stopped for a predetermined time or longer, is less than or equal to the predetermined vehicle speed. When both the first condition and the second condition that the smoothing oil temperature, which is the average value of the transmission oil temperature during the first period, is equal to or higher than a predetermined temperature, the first and second conditions are satisfied. Controlling the engine cooling device to increase the flow rate of the cooling water compared to when at least one of the conditions is not satisfied;
Cooling system.

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