Vehicular cooling device

Abstract

To provide a vehicular cooling device that enables improvement of fuel consumption (electricity consumption), suppression of vibration and noise or the like by appropriately controlling operation of cooling liquid cooling means and suppressing waste energy consumption on the basis of a temperature of cooling liquid used for a power transmission regardless of a traveling state of a vehicle.SOLUTION: A vehicular cooling device 10 that cools inside of a belt type continuously variable transmission (power transmission device) 3 mounted to a vehicle by using cooling liquid includes: a liquid temperature sensor (cooling liquid temperature acquisition means) 23 for acquiring a cooling liquid temperature that is a temperature of cooling liquid; cooling liquid cooling means (shutter grill 13, radiator fan 14, electric liquid pump 22, mechanical water pump 16, electric water pump 18, belt type continuously variable transmission 3, and engine 1) for cooling the cooling liquid; and a TCU (cooling liquid cooling means control device) 30 for controlling the cooling liquid cooling means. The TCU 30 actuates the cooling liquid cooling means on the basis of a cooling liquid temperature T when the cooling liquid temperature is acquired, and a temperature rise coefficient K.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cooling device for a vehicle that appropriately cools a coolant used to lubricate and cool a vehicle's power transmission device before the temperature of the coolant reaches an upper limit temperature, thereby keeping the temperature below the upper limit temperature. [Background technology]

[0002] Conventionally, power transmission devices such as transmissions mounted on vehicles use a coolant (Automatic Transmission Fluid (ATF)) to cool and lubricate their internal components. However, the temperature of this coolant rises as the vehicle absorbs and generates heat while traveling. In particular, when the vehicle is traveling at high speeds or climbing steep inclines, the coolant temperature is likely to rise and exceed its upper limit. Vehicle power transmission devices include planetary-type stepped automatic transmissions, belt-type continuously variable transmissions (CVTs), dual-clutch transmissions, manual transmissions, hybrid drive systems, and gearboxes for electric vehicles.

[0003] However, if the temperature of the coolant rises above a predetermined temperature (upper limit temperature) as the vehicle is running, the cooling and lubricating performance of the coolant will deteriorate, so it is necessary to prevent the temperature of the coolant from rising above the predetermined temperature (upper limit temperature).

[0004] Therefore, the following methods 1) to 3) have conventionally been used to cool the coolant. 1) Using an oil cooler to naturally cool the coolant and release heat 2) Forced air cooling by placing a fan on the oil cooler 3) A method of providing a separate water-cooled circuit with a radiator and radiator fan, and cooling the coolant by heat exchange between the coolant and the cooling water circulating through this water-cooled circuit.

[0005] Regarding the above methods 2) and 3), Patent Documents 1 and 2 propose a cooling device that detects the temperature of the coolant, and when the detected temperature reaches a set temperature, drives a cooling fan to keep the temperature of the coolant below the set temperature. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 58-156772 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-340322 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the method 1), there is no other method that can be adopted other than controlling the flow rate of the coolant flowing through the oil cooler based on the coolant temperature, and there is a problem in that it is difficult to freely control the coolant temperature.

[0008] Furthermore, in the cooling devices proposed in Patent Documents 1 and 2 regarding methods 2) and 3) above, if the predetermined set temperature is set high and the amount of heat generated is large, the coolant temperature may easily exceed the set temperature even when cooling operations such as driving the cooling fan are started. Conversely, if the set temperature is set low, the cooling fan may be driven even in situations where cooling operations are not necessary, which may result in problems such as reduced fuel efficiency (electricity cost) due to excess energy consumption and increased noise and vibration.

[0009] The present invention has been made in consideration of the above problems, and its purpose is to provide a cooling device for a vehicle that can appropriately control the operation of a coolant cooling means based on the temperature of the coolant used in the power transmission device, regardless of the vehicle's driving state, thereby reducing wasteful energy consumption and improving fuel efficiency (electricity cost) and suppressing vibration and noise. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention provides a vehicle cooling device (10) that cools the inside of a power transmission device (3) mounted on a vehicle with a coolant, the vehicle cooling device (10) including: a coolant temperature acquisition means (23) that acquires a coolant temperature, which is the temperature of the coolant; coolant cooling means (1, 3, 13, 14, 16, 18, 22) that cools the coolant; and a coolant cooling means control device (30) that controls the coolant cooling means (1, 3, 13, 14, 16, 18, 22), wherein the coolant cooling means control device (30) operates the coolant cooling means (1, 3, 13, 14, 16, 18, 22) based on the coolant temperature (T) when the coolant temperature is acquired and a temperature rise coefficient (K).

[0011] Here, the temperature rise coefficient (K) is calculated from the coolant temperature (T) when the coolant temperature is acquired, the coolant temperature (T0) acquired a predetermined time (t) before the coolant temperature (T) is acquired, and the upper limit temperature (Tc) using the following formula: K=(T-T0) / (Tc-T0) is calculated by

[0012] Alternatively, the temperature rise coefficient (K) is calculated from the coolant temperature (T) when the coolant temperature is acquired, the time differential (ΔT) of the coolant temperature when the coolant temperature (T) is acquired, and the upper limit temperature (Tc) using the following formula: K=ΔT / (Tc-T) is calculated by

[0013] The vehicle cooling device (10) according to the present invention includes n ith (i=1 to n) coolant cooling means (1, 3, 13, 14, 18, 22) as the coolant cooling means, and the coolant cooling means control device (30) sets n coolant temperature thresholds (Ti) and n temperature rise coefficient thresholds (Ki), and activates the ith coolant cooling means when the coolant temperature (T) acquired when the coolant temperature exceeds the ith coolant temperature threshold (Ti) and the temperature rise coefficient (K) exceeds the ith temperature rise coefficient threshold (Ki). Here, the coolant temperature thresholds (T1 to Tn) are set to increase in the order of the first coolant temperature threshold (T1) to the nth coolant temperature threshold (Tn). The temperature rise coefficient thresholds (K1 to Kn) are set to increase in the order of the first temperature rise coefficient threshold (K1) to the nth temperature rise coefficient threshold (Kn).

[0014] Specifically, the opening amount of the opening / closing unit (13) serving as the first coolant cooling means is increased, the rotation speed of the radiator fan (14) serving as the second coolant cooling means is increased, the operating amount of the electric coolant pump (22) serving as the third coolant cooling means is increased, and the operating amount of the mechanical water pump (16) serving as the fourth coolant cooling means is increased. The operating amount of the electric water pump (18) serving as the fifth coolant cooling means is also increased. The sixth coolant cooling means changes the gear ratio of the automatic transmission (3) in a direction that improves the efficiency of the automatic transmission (3) while keeping the output of the prime mover (1) and the vehicle speed constant, and the seventh coolant cooling means limits the output of the prime mover (1).

[0015] The coolant cooling means control device (30) sets n ith (i = 1 to n) coolant temperature release thresholds (TRi), and releases the operation of the ith coolant cooling means when the coolant temperature (T) obtained when the coolant temperature is acquired falls below the ith coolant temperature release threshold (TRi). Here, the ith coolant temperature release threshold (TRi) is set to a value different from the ith coolant temperature threshold (Ti). The vehicle may have an engine as the prime mover (1), and the power transmission device (3) may be a belt-type continuously variable transmission. [Effects of the Invention]

[0016] According to the present invention, the coolant cooling means control device (30) controls the operation of the seven first to seventh coolant cooling means (1, 3, 13, 14, 16, 18, 22) using the coolant temperature (T) acquired by the coolant temperature acquisition means (23) and the temperature rise coefficient (K) as parameters. Therefore, the coolant temperature (T) can be predicted based on the value of the temperature rise coefficient (K) to predict the future increase in the coolant temperature (T) when the coolant temperature is acquired. Based on this prediction, the operation of each coolant cooling means (1, 3, 13, 14, 16, 18, 22) can be appropriately controlled to keep the coolant temperature (T) below the upper limit temperature (Tc). As a result, regardless of the vehicle's running state, it is possible to achieve the effects of keeping energy consumption low, improving fuel economy (electricity efficiency), and suppressing vibration and noise. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram showing a schematic configuration of a vehicle cooling device according to the present invention and a power transmission system of a vehicle equipped with the same; [Figure 2] FIG. 10 is a diagram showing the change in coolant temperature over time, illustrating a method for calculating the temperature rise coefficient K. [Figure 3] FIG. 10 is a diagram showing the change in coolant temperature over time, illustrating another method for calculating the temperature rise coefficient K. [Figure 4] FIG. 10 is a diagram illustrating a coolant temperature threshold and a temperature rise coefficient threshold. [Figure 5] FIG. 10 is a diagram illustrating a coolant temperature release threshold and a temperature rise coefficient. [Figure 6A] 10 is a flowchart (part 1) showing the control procedure of the first to seventh coolant cooling means by the coolant cooling means control device. [Figure 6B] 10 is a flowchart (part 2) showing the control procedure of the first to seventh coolant cooling means by the coolant cooling means control device. [Figure 6C] 10 is a flowchart (part 3) showing the control procedure of the first to seventh coolant cooling means by the coolant cooling means control device. [Figure 7]FIG. 4 is a diagram showing changes in power transmission efficiency with respect to the gear ratio of a belt-type continuously variable transmission. [Figure 8] 1 is a diagram schematically illustrating a configuration of a vehicle cooling device according to the present invention when applied to a hybrid vehicle, and a power transmission system of the vehicle equipped with the same; DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0019] [Vehicle power transmission system configuration] First, the configuration of a vehicle cooling device according to the present invention and a power transmission system of a vehicle equipped with the same will be described with reference to Fig. 1. In Fig. 1, the directions indicated by arrows are the "front of the vehicle" and the "rear of the vehicle," respectively.

[0020] As shown in Fig. 1, an engine 1 is mounted at the front of the vehicle as a prime mover that is a drive source, and a belt-type continuously variable transmission (CVT) 3 that is a transmission is connected to the engine 1. Here, the engine 1 is an internal combustion engine such as a gasoline engine, but it may also be a diesel engine.

[0021] Although not shown, the belt-type continuously variable transmission (CVT) 3 is configured by wrapping an endless metal belt around a drive pulley on the driving side and a driven pulley on the driven side. By adjusting the axial thrust acting on the drive pulley and the driven pulley, the winding diameter of the metal belt around these drive pulley and driven pulley is changed, thereby continuously changing the gear ratio (speed ratio). A coolant (ATF) flows inside the belt-type continuously variable transmission (CVT) 3 to lubricate and cool various components and drive the drive pulley and driven pulley. The cooling device 10 according to the present invention cools this coolant and keeps its temperature (coolant temperature) below a predetermined set value (hereinafter referred to as the "upper limit temperature"). Details of this will be described later.

[0022] Therefore, the rotation of the engine 1 is changed in speed by a belt-type continuously variable transmission (CVT) 3 and transmitted to the drive shaft 4. The rotation of the drive shaft 4 is transmitted to a pair of left and right drive wheels (not shown) attached to the drive shaft 4 via a differential mechanism (not shown), thereby allowing the vehicle to travel at a predetermined speed.

[0023] [Cooling system configuration] Next, the configuration of a vehicle cooling device 10 according to the present invention will be described with reference to FIG.

[0024] The engine 1 reaches high temperatures due to the heat generated by combustion of fuel such as gasoline and friction between sliding parts such as pistons, and is therefore cooled by cooling water flowing through a water jacket (not shown) formed inside the engine 1. The temperature of the coolant (ATF) inside the belt-type continuously variable transmission (CVT) 3 rises due to frictional heat and agitation generated in various parts, and if that temperature (coolant temperature) exceeds a predetermined value, the cooling and lubricating performance of the coolant will decrease, so the coolant is cooled by heat exchange with cooling water (LLC: Long Life Coolant).

[0025] A radiator 11, which is a heat exchanger, is located in front of the engine 1 at the front of the vehicle. In front of this radiator 11 are a grill 12 through which the wind generated when the vehicle is moving passes, and a shutter grill 13 which adjusts the opening area of ​​this grill 12 to control the volume of the wind. Behind the radiator 11 is a radiator fan 14 which draws in outside air including the wind and promotes heat exchange between the outside air and the coolant in the radiator 11.

[0026] Here, the shutter grill 13 is opened and closed by an electric actuator (not shown) to adjust the opening area of ​​the grill 12, and this shutter grill 13 is electrically connected to a transmission control unit (hereinafter abbreviated as "TCU") 30 which serves as a coolant cooling means control device, and its operation is controlled by the TCU 30. Also, the radiator fan 14 is driven to rotate by an electric motor 15, and this electric motor 15 is electrically connected to the TCU 30, and its rotation is controlled by the TCU 30.

[0027] The belt-type continuously variable transmission (CVT) 3 is also provided with a heat exchanger (CVT warmer) 20, and as will be described later, cooling water and coolant flow through this heat exchanger 20. As a result, the coolant is cooled by the cooling water through heat exchange between them.

[0028] The coolant circulates through a water-cooled circuit 17 including the radiator 11. The water-cooled circuit 17 is configured as a closed circuit including a water pipe a that guides the coolant, which has cooled the engine 1 and reached a high temperature, to an inlet of a heat exchanger 20, a water pipe b that guides the coolant that has been subjected to heat exchange with the coolant in the heat exchanger 20, to an electric water pump 18, a water pipe c that guides the coolant discharged from the electric water pump 18 to the inlet of the radiator 11, and a water pipe d that guides the coolant cooled by the radiator 11 and flowing out of the outlet of the radiator 11 to a mechanical water pump 16. A water temperature sensor 19 that detects the temperature of the coolant (coolant temperature) is provided in the water pipe a, and is electrically connected to the TCU 30. The coolant temperature detected by the water temperature sensor 19 is transmitted to the TCU 30. The mechanical water pump 16, which is an auxiliary device of the engine 1, is driven by part of the power of the engine 1. Furthermore, even when either the electric water pump 18 or the mechanical water pump 16 is not operating, the water cooling circuit 17 is configured to function by operating the other water pump via a bypass circuit (not shown).

[0029] The coolant circulates through a liquid cooling circuit 21 that forms a closed circuit. This liquid cooling circuit 21 is made up of a liquid pipe e that extends from the outlet of the heat exchanger 20 and is connected to the inlet of the heat exchanger 20. This liquid pipe e is provided with an electric liquid pump 22 that circulates the coolant, a liquid temperature sensor 23 that is a coolant temperature acquisition means that detects the coolant temperature, and a mechanical liquid pump 24 that is driven by part of the power of the engine 1. The electric liquid pump 22 is electrically connected to the TCU 30, and its operation is controlled by the TCU 30. The liquid temperature sensor 23 is also electrically connected to the TCU 30, and the coolant temperature detected by the liquid temperature sensor 23 is sent to the TCU 30.

[0030] [Cooling device function] Next, the operation of the vehicle cooling device 10 configured as above will be described below.

[0031] While the engine 1 is operating, the coolant is circulated through a water-cooled circuit 17 by an electric water pump 18 and a mechanical water pump 16 driven by part of the power of the engine 1 to cool the engine 1, and the coolant is also cooled by heat exchange with the coolant circulating in a liquid-cooled circuit 21. That is, the coolant, which has become hot by flowing through a water jacket (not shown) of the engine 1 to cool the engine 1, is guided through water pipe a of the water-cooled circuit 17 to a heat exchanger 20, where it is cooled by heat exchange with the coolant flowing in the liquid-cooled circuit 21. After that, the coolant is supplied to the electric water pump 18 through pipe b, and after being pressurized by the electric water pump 18, is guided to the radiator 11 through pipe c. In the radiator 11, outside air passes through the radiator 11 via the grille 12 by a radiator fan 14 rotated by an electric motor 15, and in the radiator 11, the coolant is cooled by heat exchange with the outside air (traveling wind when the vehicle is traveling) passing through the radiator 11, thereby lowering its temperature. The flow rate of the outside air passing through the grille 12 is adjusted by opening and closing the shutter grille 13. That is, the opening and closing of the shutter grille 13 is controlled by the TCU 30 to adjust the opening area of ​​the grille 12, and the flow rate of the outside air (traveling wind) passing through the grille 12 is controlled by adjusting the opening area of ​​the grille 12.

[0032] As described above, the coolant, which has been cooled by passing through the radiator 11 and has a lowered temperature, is guided from the radiator 11 through the water pipe d to the mechanical water pump 16, and is then introduced into the engine 1 by the mechanical water pump 16 and cools the engine 1 as it flows through a water jacket (not shown) inside the engine 1. In the liquid-cooling circuit 21, the coolant is circulated by the electric liquid pump 22 and the mechanical liquid pump 24, and the temperature of this coolant is detected by the liquid temperature sensor 23, and the detection result is sent to the TCU 30. In addition, the temperature of the coolant flowing through the water pipe a of the water-cooling circuit 17 (coolant temperature) is detected by the water temperature sensor 19, and the detection result is sent to the TCU 30.

[0033] The above-described actions are continuously repeated, and the engine 1 is cooled by the cooling water, and the cooling liquid inside the belt-type continuously variable transmission (CVT) 3 is cooled by the cooling water, thereby keeping the temperature of the cooling liquid below a certain value.

[0034] [Coolant temperature control method] Next, a method for controlling the coolant temperature in the vehicle cooling device 10 according to the present invention configured as described above will be described below with reference to FIGS.

[0035] In this embodiment, the vehicle cooling device 10 employs the following first to seventh coolant cooling means as coolant cooling means for cooling the coolant. 1) First coolant cooling means: shutter grill opening amount 2) Second coolant cooling means: radiator fan rotation speed 3) Third coolant cooling means: Operation amount of electric coolant pump 4) Fourth coolant cooling means: Operating amount of mechanical water pump 5) Fifth coolant cooling means: Operation amount of electric water pump 6) Sixth coolant cooling means: Speed ​​ratio of belt-type continuously variable transmission (CVT) 7) Seventh coolant cooling means: engine output

[0036] In this embodiment, the first to seventh coolant cooling means are controlled as follows by the TCU 30, which is a coolant cooling means control device.

[0037] That is, the TCU 30 starts operation of the first to seventh coolant cooling means using the coolant temperature T obtained when the coolant temperature is acquired by the liquid temperature sensor 23 and the temperature rise coefficient K as control parameters, and deactivates the operation of the first to seventh coolant cooling means when the coolant temperature T obtained when the coolant temperature is acquired by the liquid temperature sensor 23 falls below the coolant temperature deactivation threshold TR.

[0038] Here, as shown in FIG. 2, the temperature rise coefficient K is calculated from the coolant temperature T when the coolant temperature is acquired, the coolant temperature T0 acquired a predetermined time t before the coolant temperature T is acquired, and the upper limit temperature Tc using the following formula: K=(T-T0) / (Tc-T0) =ΔT / ΔTc …(1) Here, ΔT=T-T0, ΔTc=Tc-T0 Therefore, the time tc until the upper limit temperature Tc is reached t seconds before the start of the test can be calculated using the following formula: tc=t×ΔTc / ΔT …(2)

[0039] Alternatively, as shown in FIG. 3, the temperature rise coefficient K is calculated from the coolant temperature T when the coolant temperature is acquired, the time differential ΔT of the coolant temperature T when the coolant temperature T is acquired, and the upper limit temperature Tc using the following equation: K=ΔT / (Tc-T) …(3) Here, ΔT is the increase in the coolant temperature T per unit time (1 second). Therefore, the time tc from the present time until the upper limit temperature Tc is reached can be calculated using the following formula: tc=t×ΔT / ΔTc=ΔT / (Tc-T) …(4)

[0040] 4, the TCU 30 sets seven first to seventh coolant temperature threshold values ​​T1 to T7 (T3 to T6 are not shown in FIG. 4) corresponding to the first to seventh coolant cooling means as threshold values ​​for the coolant temperature T when the coolant temperature is acquired, and sets seven first to seventh temperature rise coefficient threshold values ​​K1 to K7 (K3 to K6 are not shown in FIG. 4) as threshold values ​​for the temperature rise coefficient K. Here, the following magnitude relationships are established among the first to seventh coolant temperature threshold values ​​T1 to T7 and among the first to seventh temperature rise coefficient threshold values ​​K1 to K7. T1 <T2<T3<…<T7 …(5) K1 <K2<K3<…<K7 …(6) The seventh coolant temperature threshold T7, which is the highest, is set to a value smaller than the upper limit temperature Tc (see FIGS. 2 and 3) (T7 <Tc)。

[0041] Furthermore, the TCU 30 sets first to seventh coolant temperature release thresholds TR1 to TR7 (TR3 to TR6 are not shown in FIG. 5) for releasing the operation of the first to seventh coolant cooling means, as shown in FIG. 5. The following magnitude relationships are established among these first to seventh coolant temperature release thresholds TR1 to TR7. TR1 <TR2<TR3<…<TR7 …(7) Since the TCU 30 performs hysteresis control on the first to seventh coolant cooling means, the first to seventh coolant temperature threshold values ​​T1 to T7 and the first to seventh coolant temperature release threshold values ​​TR1 to TR7 are set to different values.

[0042] Thus, the TCU 30 operates the first to seventh coolant cooling means and deactivates the first to seventh coolant cooling means in the following seven cases under predetermined conditions. Each case will be described below with reference to Figures 6A to 6C.

[0043] 1)Case 1: In case 1, when the coolant temperature T obtained (detected) by the coolant temperature sensor 23 exceeds the first coolant temperature threshold T1 shown in FIG. 4 (T>T1), and the temperature rise coefficient K calculated by the equation (1) or (3) exceeds the first temperature rise coefficient threshold K1 shown in FIG. 4 (K>K1), the TCU 30 drives the electric motor 15 shown in FIG. 1 to open the shutter grill 13, which is the first coolant cooling means, and increases the opening area of ​​the grill 12.

[0044] That is, as shown in FIG. 6A, when the engine 1 shown in FIG. 1 is started, the coolant temperature T, which is the temperature of the coolant, is acquired by the coolant temperature sensor 23 (step S1 in FIG. 6A). Based on this coolant temperature T, the coolant temperature T0 acquired t seconds before the acquisition of the coolant temperature T, and the upper limit temperature Tc, the temperature increase coefficient K is calculated by the above formula (1), or based on the time derivative ΔT of the coolant temperature T when the coolant temperature T is acquired and the difference ΔTc between the coolant temperature T and the upper limit temperature Tc, the temperature increase coefficient K is calculated by the above formula (3) (step S2 in FIG. 6A). Then, the TCU 30 determines whether the coolant temperature T exceeds the first coolant temperature threshold value T1 shown in FIG. 4 (T>T1) and whether the temperature increase coefficient K exceeds the first temperature increase coefficient threshold value K1 shown in FIG. 4 (K>K1) (step S3 in FIG. 6A).

[0045] As a result of the above determination, when the coolant temperature T exceeds the first coolant temperature threshold value T1 (T>T1) and the temperature increase coefficient K exceeds the first temperature increase coefficient threshold value K1 (K>K1) (step S3 in FIG. 6A: Yes), as described above, the shutter grill 13, which is the first coolant cooling means, is opened to increase the opening area of the grill 12 (step S4 in FIG. 6A). Then, the flow rate of the outside air (running air) passing through the grill 12 increases, and the heat exchange between the outside air and the cooling water in the radiator 11 is promoted, and the cooling water is effectively cooled. As a result, the heat exchange in the heat exchanger 20 between the cooling water with the lowered temperature and the coolant of the belt-type continuously variable transmission (CVT) 3 is efficiently performed, and the coolant is effectively cooled by the cooling water. When the coolant temperature T does not exceed the first coolant temperature threshold value T1 (T<T1) or the temperature increase coefficient K does not exceed the first temperature increase coefficient threshold value K1 (step S3 in FIG. 6A: No), the above processing (steps S1 to S3) is repeated (step S7).

[0046] Then, after opening the shutter grill 13, which is the first coolant cooling means as described above, to increase the opening area of the grill 12, the TCU 30 determines whether or not the coolant temperature T when the coolant temperature is acquired is lower than the first coolant temperature release threshold TR1 shown in FIG. 5 (T < TR1) (step S5 in FIG. 6A). When the coolant temperature T is lower than the first coolant temperature release threshold TR1 (step S5 in FIG. 6A: Yes), the operation of the shutter grill 13, which is the first coolant cooling means, is stopped (step S6 in FIG. 6A).

[0047] On the other hand, when the coolant temperature T when the coolant temperature is acquired is equal to or higher than the first coolant temperature release threshold TR1 shown in FIG. 5 (T ≧ TR1) (step S5 in FIG. 6A: No), the process proceeds to the process described in the following case 2.

[0048] 2) Case 2: In case 2, when the coolant temperature T acquired by the liquid temperature sensor 23 exceeds the second coolant temperature threshold T2 shown in FIG. 4 (T > T2) and the temperature increase coefficient K obtained by the above formula (1) or (3) exceeds the second temperature increase coefficient threshold K2 shown in FIG. 4 (K > K2), the TCU 30 increases the rotational speed of the radiator fan 14 shown in FIG. 1, which is the second coolant cooling means.

[0049] That is, as shown in FIG. 6A, the coolant temperature T, which is the temperature of the coolant, is acquired by the liquid temperature sensor 23 (step S8 in FIG. 6A), and the temperature increase coefficient K is calculated by the above formula (1) or the above formula (3) (step S9 in FIG. 6A). Then, the TCU 30 determines whether or not the coolant temperature T exceeds the second coolant temperature threshold T2 shown in FIG. 4 (T > T2) and the temperature increase coefficient K exceeds the second temperature increase coefficient threshold K2 shown in FIG. 4 (K > K2) (step S10 in FIG. 6A).

[0050] As a result of the above determination, when the coolant temperature T exceeds the second coolant temperature threshold value T2 (T > T2) and the temperature increase coefficient K exceeds the second temperature increase coefficient threshold value K2 (K > K2) (step S10: Yes in FIG. 6A), as described above, the rotational speed of the radiator fan 14, which is the second coolant cooling means, is increased (step S11 in FIG. 6A). Then, the flow rate of the outside air (traveling wind) guided to the radiator 11 through the grille 12 increases, heat exchange between the outside air and the cooling water in the radiator 11 is promoted, and the cooling water is effectively cooled. As a result, heat exchange in the heat exchanger 20 between the cooling water with reduced temperature and the coolant of the belt-type continuously variable transmission (CVT) 3 is efficiently performed, and the coolant is effectively cooled by the cooling water. When the coolant temperature T does not exceed the second coolant temperature threshold value T2 (T < T2) or the temperature increase coefficient K does not exceed the second temperature increase coefficient threshold value K2 (K < K2) (step S10: No in FIG. 6A), the above processing (steps S1 to S10) is repeated (step S7).

[0051] Then, after increasing the rotational speed of the radiator fan 14, which is the second coolant cooling means, as described above, the TCU 30 determines whether or not the coolant temperature T when the coolant temperature is acquired is lower than the second coolant temperature release threshold value TR2 shown in FIG. 5 (T < TR2) (step S12 in FIG. 6A). When the coolant temperature T is lower than the second coolant temperature release threshold value TR2 (step S12: Yes in FIG. 6A), the operation of increasing the rotational speed of the radiator fan 14, which is the second coolant cooling means, is stopped (step S13 in FIG. 6A), and the above processing (steps S1 to S13) is repeated (step S7 in FIG. 6A).

[0052] On the other hand, when the coolant temperature T when the coolant temperature is acquired is equal to or higher than the second coolant temperature release threshold value TR2 shown in FIG. 5 (T ≥ TR2) (step S12: No in FIG. 6A), the process proceeds to the process described in Case 3 below.

[0053] 3) Case 3: In Case 3, when the coolant temperature T obtained by the coolant temperature sensor 23 exceeds the third coolant temperature threshold value T3 (T>T3), and the temperature increase coefficient K obtained by the above formula (1) or (3) exceeds the third temperature increase coefficient threshold value K3 (K>K3), the TCU 30 increases the operation amount (rotation speed) of the liquid pump 22 shown in FIG. 1 to increase the flow rate (flow velocity) of the coolant in the liquid cooling circuit 21.

[0054] That is, as shown in FIG. 6A, the coolant temperature T is obtained by the coolant temperature sensor 23 (step S14 in FIG. 6A), and the temperature increase coefficient K is calculated by the above formula (1) or the above formula (3) (step S15 in FIG. 6A). Then, the TCU 30 determines whether the coolant temperature T exceeds the third coolant temperature threshold value T3 (T>T3) and whether the temperature increase coefficient K exceeds the third temperature increase coefficient threshold value K3 (K>K3) (step S16 in FIG. 6A).

[0055] As a result of the above determination, when the coolant temperature T exceeds the third coolant temperature threshold value T3 (T>T3) and the temperature increase coefficient K exceeds the third temperature increase coefficient threshold value K3 (K>K3) (step S16 in FIG. 6A: Yes), as described above, the operation amount (rotation speed) of the electric liquid pump 22, which is the third coolant cooling means, is increased (step S17 in FIG. 6A). Then, the flow velocity (flow rate) of the coolant in the liquid cooling circuit 21 increases, and the heat exchange between the coolant and the cooling water in the heat exchanger 20 is promoted, and the coolant is effectively cooled by the cooling water. When the coolant temperature T does not exceed the third coolant temperature threshold value T3 (T<T3) or the temperature increase coefficient K does not exceed the third temperature increase coefficient threshold value K3 (K<K3) (step S16 in FIG. 6A: No), the above processing (steps S1 to S16) is repeated (step S7).

[0056] After increasing the operation amount (rotation speed) of the electric liquid pump 22, which is the third coolant cooling means, as described above, the TCU 30 determines whether or not the coolant temperature T when the coolant temperature is acquired is lower than the third coolant temperature release threshold value TR3 (T < TR3) (step S18 in FIG. 6A). When the coolant temperature T is lower than the third coolant temperature release threshold value TR3 (step S18 in FIG. 6A: Yes), the operation of increasing the operation amount (rotation speed) of the electric liquid pump 22, which is the third coolant cooling means, is stopped (step S19 in FIG. 6A), and the above processing (steps S1 to S18) is repeated (step S7 in FIG. 6A).

[0057] On the other hand, when the coolant temperature T when the coolant temperature is acquired is equal to or higher than the third coolant temperature release threshold value TR3 (T ≧ TR3) (step S18 in FIG. 6A: No), the process proceeds to the process described in Case 4 below.

[0058] 4) Case 4: In Case 4, when the coolant temperature T acquired by the liquid temperature sensor 23 exceeds the fourth coolant temperature threshold value T4 (T > T4) and the temperature increase coefficient K obtained by the above formula (1) or (3) exceeds the fourth temperature increase coefficient threshold value K4 (K > K4), the TCU 30 increases the operation amount (rotation speed) of the mechanical water pump 16 driven by the engine 1 shown in FIG. 1.

[0059] That is, as shown in FIG. 6B, the coolant temperature T is acquired by the liquid temperature sensor 23 (step S20 in FIG. 6B), and the temperature increase coefficient K is calculated by the above formula (1) or the above formula (3) (step S21 in FIG. 6B). Then, the TCU 30 determines whether or not the coolant temperature T exceeds the fourth coolant temperature threshold value T4 (T > T4) and the temperature increase coefficient K exceeds the fourth temperature increase coefficient threshold value K4 (K > K4) (step S22 in FIG. 6B).

[0060] As a result of the above determination, when the coolant temperature T exceeds the fourth coolant temperature threshold value T4 (T > T4) and the temperature increase coefficient K exceeds the fourth temperature increase coefficient threshold value K4 (K > K4) (step S22: Yes in FIG. 6B), as described above, the operation amount (rotation speed) of the mechanical water pump 16, which is the fourth coolant cooling means, is increased (step S23 in FIG. 6B). Then, the flow rate of the cooling water flowing through the water cooling circuit 17 increases, the heat exchange between the coolant and the cooling water in the heat exchanger 20 is promoted, and the coolant is effectively cooled by the cooling water. When the coolant temperature T does not exceed the fourth coolant temperature threshold value T4 (T < T4) or the temperature increase coefficient K does not exceed the fourth temperature increase coefficient threshold value K4 (K < K4) (step S22: No in FIG. 6B), the above processing (steps S1 to S22) is repeated (step S7).

[0061] After increasing the operation amount (rotation speed) of the mechanical water pump 16, which is the fourth coolant cooling means, as described above, the TCU 30 determines whether the coolant temperature T at the time of acquiring the coolant temperature is lower than the fourth coolant temperature release threshold value TR4 (T < TR4) (step S24 in FIG. 6B). When the coolant temperature T is lower than the fourth coolant temperature release threshold value TR4 (step S24: Yes in FIG. 6B), the operation of increasing the operation amount (rotation speed) of the mechanical water pump 16, which is the fourth coolant cooling means, is stopped (step S25 in FIG. 6B), and the above processing (steps S1 to S24) is repeated (step S7 in FIG. 6A).

[0062] On the other hand, when the coolant temperature T at the time of acquiring the coolant temperature is equal to or higher than the fourth coolant temperature release threshold value TR4 (T ≥ TR4) (step S24: No in FIG. 6B), the process proceeds to the process described in Case 5 below.

[0063] 5) Case 5: In Case 5, when the coolant temperature T acquired by the liquid temperature sensor 23 exceeds the fifth coolant temperature threshold value T5 (T > T5) and the temperature increase coefficient K obtained by the above formula (1) or (3) exceeds the fifth temperature increase coefficient threshold value K5 (K > K5), the TCU 30 increases the operation amount (rotation speed) of the electric water pump 18 shown in FIG. 1.

[0064] That is, as shown in FIG. 6B, the coolant temperature T is acquired by the coolant temperature sensor 23 (step S26 in FIG. 6B), and the temperature increase coefficient K is calculated by the above formula (1) or the above formula (3) (step S27 in FIG. 6B). Then, the TCU 30 determines whether the coolant temperature T exceeds the fifth coolant temperature threshold value T5 (T>T5) and whether the temperature increase coefficient K exceeds the fifth temperature increase coefficient threshold value K5 (K>K5) (step S28 in FIG. 6B).

[0065] As a result of the above determination, when the coolant temperature T exceeds the fifth coolant temperature threshold value T5 (T>T5) and the temperature increase coefficient K exceeds the fifth temperature increase coefficient threshold value K5 (K>K5) (step S28 in FIG. 6B: Yes), as described above, the operation amount (rotation speed) of the electric water pump 18, which is the fifth coolant cooling means, is increased (step S29 in FIG. 6B). Then, the flow rate of the cooling water circulating in the water cooling circuit 17 increases, and the heat exchange between the coolant and the cooling water in the heat exchanger 20 is promoted. As a result, the coolant is effectively cooled by the cooling water.

[0066] After increasing the operation amount (rotation speed) of the electric water pump 18, which is the fifth coolant cooling means, as described above, the TCU 30 determines whether the coolant temperature T at the time of acquiring the coolant temperature is lower than the fifth coolant temperature release threshold value TR5 (T<TR5) (step S30 in FIG. 6B). When the coolant temperature T is lower than the fifth coolant temperature release threshold value TR5 (step S30 in FIG. 6B: Yes), the operation of increasing the operation amount (rotation speed) of the electric water pump 18, which is the fifth coolant cooling means, is stopped (step S31 in FIG. 6B), and the above processing (steps S1 to S30) is repeated (step S7 in FIG. 6A).

[0067] On the other hand, when the coolant temperature T at the time of acquiring the coolant temperature is equal to or higher than the fifth coolant temperature release threshold value TR5 (T≧TR5) (step S30 in FIG. 6B: No), the process proceeds to the process described in the following case 6.

[0068] 6) Case 6: In case 6, when the coolant temperature T obtained by the coolant temperature sensor 23 exceeds the sixth coolant temperature threshold T6 shown in Figure 4 (T>T6), and the temperature rise coefficient K calculated by equation (1) or (3) exceeds the sixth temperature rise coefficient threshold K6 (K>K6), the TCU 30 changes the gear ratio of the belt-type continuously variable transmission (CVT) 3 shown in Figure 1, which is the sixth coolant cooling means, in a direction that improves the efficiency (power transmission efficiency) of the belt-type continuously variable transmission 3.

[0069] 6B, the coolant temperature T is acquired by the coolant temperature sensor 23 (step S32 in FIG. 6B), and the temperature rise coefficient K is calculated by the formula (1) or (3) (step S33 in FIG. 6B). Then, the TCU 30 determines whether the coolant temperature T exceeds the sixth coolant temperature threshold T6 (T>T6) and whether the temperature rise coefficient K exceeds the sixth temperature rise coefficient threshold K6 (K>K6) (step S34 in FIG. 6B).

[0070] If the result of the above judgment is that the coolant temperature T exceeds the sixth coolant temperature threshold T6 (T>T6) and the temperature rise coefficient K exceeds the sixth temperature rise coefficient threshold K6 (K>K6) (step S34 in Figure 6B: Yes), as described above, the gear ratio of the belt-type continuously variable transmission (CVT) 3, which is the sixth coolant cooling means, is changed in a direction to improve the efficiency (power transmission efficiency) of the belt-type continuously variable transmission 3 (step S35 in Figure 6B).

[0071] Here, Figure 7 shows the change in power transmission efficiency with respect to the gear ratio of the belt-type continuously variable transmission 3. As shown in the figure, the power transmission efficiency of the belt-type continuously variable transmission 3 is highest when the gear ratio is 1, and it can be seen that the power transmission efficiency decreases as the gear ratio becomes smaller than 1 and as the gear ratio becomes larger than 1.

[0072] Therefore, when the belt-type continuously variable transmission 3 is operated such that the gear ratio (ratio) of the belt-type continuously variable transmission 3 becomes 1, the power transmission efficiency of the belt-type continuously variable transmission 3 is improved, so the heat generation amount of the belt-type continuously variable transmission 3 decreases, and the temperature rise of the coolant is suppressed to a low level. The coolant with a low temperature rise is cooled by heat exchange with the cooling water in the heat exchanger 20.

[0073] Then, as described above, after the belt-type continuously variable transmission 3 is operated such that the gear ratio (ratio) of the belt-type continuously variable transmission 3 becomes 1, the TCU 30 determines whether or not the coolant temperature T when the coolant temperature is acquired is lower than the sixth coolant temperature release threshold TR6 (T < TR6) (step S36 in FIG. 6B). When the coolant temperature T is lower than the sixth coolant temperature release threshold TR6 (step S30 in FIG. 6B: Yes), the operation of changing the gear ratio (ratio) of the belt-type continuously variable transmission 3 in the direction of improving the efficiency of the belt-type continuously variable transmission 3, which is the sixth coolant cooling means, is released (step S37 in FIG. 6B), and the above processing (steps S1 to S36) is repeated (step S7 in FIG. 6A).

[0074] On the other hand, when the coolant temperature T when the coolant temperature is acquired is equal to or higher than the sixth coolant temperature release threshold TR6 (T ≥ TR6) (step S36 in FIG. 6B: No), the process proceeds to the process described in Case 7 below.

[0075] 7) Case 7: In Case 7, when the coolant temperature T acquired by the liquid temperature sensor 23 exceeds the seventh coolant temperature threshold T7 shown in FIG. 4 (T > T7) and the temperature rise coefficient K obtained by the above formula (1) or (3) exceeds the seventh temperature rise coefficient threshold K7 shown in FIG. 4 (K > K7), the TCU 30 operates the engine 1 shown in FIG. 1, which is the seventh coolant cooling means, so that its output decreases.

[0076] That is, as shown in FIG. 6C, the coolant temperature T, which is the temperature of the coolant, is acquired by the coolant temperature sensor 23 (step S38 in FIG. 6C), and the temperature increase coefficient K is calculated by the above formula (1) or the above formula (3) (step S39 in FIG. 6C). Then, the TCU 30 determines whether the coolant temperature T exceeds the seventh coolant temperature threshold value T7 shown in FIG. 4 (T>T7) and whether the temperature increase coefficient K exceeds the seventh temperature increase coefficient threshold value K7 shown in FIG. 4 (K>K7) (step S40 in FIG. 6C).

[0077] As a result of the above determination, when the coolant temperature T exceeds the seventh coolant temperature threshold value T7 (T>T7) and the temperature increase coefficient K exceeds the seventh temperature increase coefficient threshold value K7 (step S40: Yes in FIG. 6C), as described above, the engine 1, which is the seventh coolant cooling means, is operated so that its output decreases (step S41 in FIG. 6C). Then, the heat generation of the engine 1 is suppressed, and the temperature of the cooling water that cools the engine 1 is kept low. As a result, the heat exchange between the cooling water and the coolant in the heat exchanger 20 is promoted, and the coolant is effectively cooled by the cooling water. When the coolant temperature T does not exceed the seventh coolant temperature threshold value T7 (T<T7) or the temperature increase coefficient K does not exceed the seventh temperature increase coefficient threshold value K7 (step S40: No in FIG. 6C), the above processing (steps S1 to S40) is repeated (step S7 in FIG. 6A).

[0078] After the output of the engine 1, which is the seventh coolant cooling means, is restricted as described above, the TCU 30 determines whether the coolant temperature T at the time when the coolant temperature is acquired is lower than the seventh coolant temperature release threshold value TR7 shown in FIG. 5 (T<TR7) (step S42 in FIG. 6C). When the coolant temperature T is lower than the seventh coolant temperature release threshold value TR7 (step S42: Yes in FIG. 6C), the operation of restricting the output of the engine 1, which is the seventh coolant cooling means, is stopped (step S43 in FIG. 6C), and the above processing (steps S1 to S42) is repeated (step S7 in FIG. 6A).

[0079] On the other hand, if the coolant temperature T when acquired is equal to or greater than the seventh coolant temperature release threshold TR7 (T≧TR7) shown in FIG. 5 (step S42: No in FIG. 6C), the above processing (steps S1 to S42) is repeated (step S7 in FIG. 6A).

[0080] As described above, in this embodiment, first through seventh coolant temperature thresholds T1 through T7 and first through seventh temperature rise coefficient thresholds K1 through K7 are set for the coolant temperature T and temperature rise coefficient K acquired (detected) by the coolant temperature sensor 23. The first through seventh coolant cooling means are activated in this order each time the coolant temperature T and temperature rise coefficient K exceed the respective coolant temperature thresholds T1 through T7 and the respective first through seventh temperature rise coefficient thresholds K1 through K7. Also, first through seventh coolant temperature release thresholds TR1 through TR7 are set to stop the operation of the first through seventh coolant cooling means. The operation of the seventh through first coolant cooling means is stopped in this order each time the coolant temperature T falls below the first through seventh coolant temperature release thresholds TR1 through TR7. However, not all of the first through seventh coolant cooling means are activated or stopped; rather, the number of coolant cooling means activated or stopped corresponds to the value of the coolant temperature T.

[0081] Therefore, according to the vehicle cooling device 10 of this embodiment, the TCU 30, which is a coolant cooling means control device, controls the operation of the seven first to seventh coolant cooling means using the coolant temperature T and the temperature rise coefficient K when the coolant temperature is acquired by the liquid temperature sensor 23 as parameters.Therefore, the future rising trend of the coolant temperature T when the coolant temperature is acquired can be predicted based on the value of the temperature rise coefficient K, and based on this prediction, the operation of each coolant cooling means can be appropriately controlled to keep the coolant temperature T below the upper limit temperature Tc, thereby achieving the effects of keeping energy consumption low regardless of the vehicle's driving state, improving fuel efficiency (electricity cost), and suppressing vibration and noise.

[0082] In the above embodiment, the shutter grille 13, radiator fan 14, electric water pump 22, mechanical water pump 16, electric water pump 18, belt-type continuously variable transmission 3, and engine 1 are used as coolant cooling means, but the present invention is not limited to these and other means may be used, and the number of such means is arbitrary. Furthermore, the order in which the multiple coolant cooling means are activated or deactivated depending on the values ​​of the coolant temperature T and the temperature rise coefficient K is not limited to the order given in the above embodiment and may be arbitrary.

[0083] Furthermore, in the above embodiment, an example has been described in which the present invention is applied to a vehicle cooling device 10 that cools the coolant (ATF) used in a belt-type continuously variable transmission 3, but the present invention can also be applied to cooling devices that cool fluids used in a torque converter 2 or other power transmission devices.

[0084] Furthermore, the vehicle cooling device of the present invention can be applied not only to vehicles driven by an engine as shown in the above embodiment, but also to hybrid vehicles (HEVs) driven by both an engine and an electric motor. Figure 8 is a diagram showing a schematic configuration of a vehicle cooling device and a power transmission system of a vehicle equipped with the vehicle cooling device when the vehicle cooling device of the present invention is applied to a hybrid vehicle. In this figure, components that are the same as or common to those in Figure 1 are given the same reference numerals, and the following explanation will focus only on the differences from Figure 1.

[0085] 8 includes two radiators for cooling the coolant: a first radiator 11-1 for the engine and a second radiator 11-2 for the electric motor (for HEV). The cooling circuit 17-2 includes a first closed circuit including a water pipe e that guides the coolant, which has been heated after cooling the engine 1, to the first radiator 11-1, and a water pipe f that returns the coolant cooled by the first radiator 11-1 to the engine 1. The second closed circuit includes a water pipe g that guides the coolant that has been subjected to heat exchange with the coolant circulating in the DU (Drive Unit) 3-2 in the heat exchanger 20 to the electric water pump 18, a water pipe h that guides the coolant discharged from the electric water pump 18 to the inlet of the second radiator 11-2, and a water pipe i that returns the coolant cooled by the second radiator 11-2 and flowing out from the outlet of the second radiator 11-2 to the heat exchanger 20. The second closed circuit also includes a bypass water pipe (bypass pipe) j for supplying cooling water to a PDU (Power Drive Unit) 40, which is a power control device for controlling the power supplied to the electric motor, etc., to cool the PDU 40.

[0086] Furthermore, the present invention is not limited to the application of the above-described embodiments, and it goes without saying that various modifications are possible within the scope of the claims and the technical ideas described in the specification and drawings. [Explanation of symbols]

[0087] 1 Engine (7th coolant cooling means) 3 Belt-type continuously variable transmission (power transmission device: sixth coolant cooling means) 10 Vehicle cooling system 11 Radiator 12 Grill 13 Shutter grill (opening / closing part: first coolant cooling means) 14 Radiator fan (second coolant cooling means) 16 Mechanical water pump (fourth coolant cooling means) 17 Water cooling circuit 18 Electric water pump (fifth coolant cooling means) 19 Water temperature sensor 20 Heat exchanger 21 Liquid cooling circuit 22 Electric liquid pump (third coolant cooling means) 23 Liquid temperature sensor (coolant temperature acquisition means) 24 Mechanical fluid pump 30 TCU (coolant cooling means control unit) K temperature rise coefficient K1~K7 1st to 7th temperature rise coefficient thresholds T Coolant temperature T1~T7 Coolant temperature thresholds TR1~TR7 1st~7th coolant temperature release thresholds

Claims

1. A cooling device for a vehicle that cools the inside of a power transmission device mounted on a vehicle with a coolant, a coolant temperature acquisition means for acquiring a coolant temperature, which is the temperature of the coolant; a coolant cooling means for cooling the coolant; a coolant cooling means control device for controlling the coolant cooling means; and The coolant cooling means control device includes: the coolant temperature when the coolant temperature is acquired; and The temperature rise coefficient, a cooling means for cooling the cooling liquid based on the cooling liquid cooling means;

2. The temperature rise coefficient is The coolant temperature at the time of acquisition, the coolant temperature acquired a predetermined time before the acquisition of the coolant temperature, and the upper limit temperature are calculated using the following formula: K=(T-T0) / (Tc-T0) 2. The vehicle cooling device according to claim 1, wherein the temperature is determined by the following formula:

3. The temperature rise coefficient is The coolant temperature when the coolant temperature is acquired, the time differential of the coolant temperature when the coolant temperature is acquired, and the upper limit temperature are calculated using the following equation: K=ΔT / (Tc-T) 2. The vehicle cooling device according to claim 1, wherein the temperature is determined by the following formula:

4. When i=1, 2, ..., n (n is a natural number), The coolant cooling means includes n i-th coolant cooling means, The coolant cooling means control device includes: Setting n coolant temperature thresholds and n temperature rise coefficient thresholds; The coolant temperature when the coolant temperature is acquired is 2. The vehicle cooling device according to claim 1, wherein the i-th coolant cooling means is activated when the i-th coolant temperature threshold is exceeded and the temperature rise coefficient exceeds the i-th temperature rise coefficient threshold.

5. The coolant temperature threshold is:

5. The vehicle cooling device according to claim 4, wherein the first coolant temperature threshold value to the nth coolant temperature threshold value are set in order of increasing coolant temperature.

6. The temperature rise coefficient threshold is 5. The vehicle cooling device according to claim 4, wherein the first temperature rise coefficient threshold to the n-th temperature rise coefficient threshold are set in order of increasing value.

7. The vehicle is an opening / closing unit for controlling the amount of airflow from outside the vehicle that is introduced into the vicinity of the power transmission device while the vehicle is running; The coolant cooling means control device includes:

5. The vehicle cooling device according to claim 4, wherein the opening amount of the opening / closing portion, which is the first coolant cooling means, is increased when the coolant temperature when acquired exceeds the first coolant temperature threshold and the temperature rise coefficient exceeds the first temperature rise coefficient threshold.

8. The vehicle is A radiator and a radiator fan that cools the cooling water passing through the radiator; a heat exchanger that exchanges heat between the cooling water and the cooling liquid; and The coolant cooling means control device includes:

5. The vehicle cooling device according to claim 4, wherein the rotation speed of the radiator fan, which is the second coolant cooling means, is increased when the coolant temperature when the coolant temperature is acquired exceeds the second coolant temperature threshold and the temperature rise coefficient exceeds the second temperature rise coefficient threshold.

9. The power transmission device is a heat exchanger that exchanges heat between the cooling water and the cooling liquid; an electric fluid pump that controls the flow rate of the cooling fluid circulating inside the heat exchanger; and The coolant cooling means control device includes:

5. The vehicle cooling device according to claim 4, wherein the operating amount of the electric fluid pump, which is the third coolant cooling means, is increased when the coolant temperature when the coolant temperature is acquired exceeds the third coolant temperature threshold and the temperature rise coefficient exceeds the third temperature rise coefficient threshold.

10. The vehicle is The prime mover and a water cooling circuit for cooling the engine; a mechanical water pump driven by the motor to control the flow rate of cooling water flowing through the water cooling circuit; a heat exchanger that exchanges heat between the cooling liquid and the cooling water; and The coolant cooling means control device includes:

5. The vehicle cooling device according to claim 4, wherein the operating amount of the mechanical water pump, which is the fourth coolant cooling means, is increased when the coolant temperature when the coolant temperature is acquired exceeds the fourth coolant temperature threshold and the temperature rise coefficient exceeds the fourth temperature rise coefficient threshold.

11. The vehicle is The prime mover and a water cooling circuit for cooling the engine; an electric water pump for controlling the flow rate of cooling water flowing through the water cooling circuit; a heat exchanger that exchanges heat between the cooling liquid and the cooling water; and The coolant cooling means control device includes:

5. The vehicle cooling device according to claim 4, wherein the operation amount of the electric water pump, which is the fifth coolant cooling means, is increased when the coolant temperature when the coolant temperature is acquired exceeds the fifth coolant temperature threshold and the temperature rise coefficient exceeds the fifth temperature rise coefficient threshold.

12. The vehicle is The prime mover and an automatic transmission as the power transmission device; and The coolant cooling means control device includes:

5. The vehicle cooling device according to claim 4, wherein when the coolant temperature when the coolant temperature is acquired exceeds the sixth coolant temperature threshold and the temperature rise coefficient exceeds the sixth temperature rise coefficient threshold, a sixth coolant cooling means changes the gear ratio of the automatic transmission in a direction that improves the efficiency of the automatic transmission while keeping the output of the engine and the vehicle speed constant.

13. The vehicle is It has a prime mover, The coolant cooling means control device includes:

6. The vehicle cooling device according to claim 5, wherein the seventh coolant cooling means limits the output of the prime mover when the coolant temperature when the coolant temperature is acquired exceeds the seventh coolant temperature threshold and the temperature rise coefficient exceeds the seventh temperature rise coefficient threshold.

14. When i=1, 2, ..., n (n is a natural number), The coolant cooling means control device includes: n ith coolant temperature release thresholds are set; 5. The vehicle cooling device according to claim 4, wherein the operation of the i-th coolant cooling means is deactivated when the coolant temperature when the coolant temperature is acquired falls below the i-th coolant temperature deactivation threshold value.

15. The i-th coolant temperature release threshold value is The vehicle cooling device according to claim 14, wherein the i-th coolant temperature threshold value is set to a value different from the i-th coolant temperature threshold value.

16. The vehicle is 2. The cooling system for a vehicle according to claim 1, wherein the prime mover is an engine.

17. The power transmission device is 2. The cooling device for a vehicle according to claim 1, wherein the cooling device is a belt-type continuously variable transmission.

Images