Vehicle drive unit

Abstract

To achieve a technique for facilitating setting of supply amount of cooling water to an oil cooler to desired amount according to an occasional situation when supplying cooling water to both of the oil cooler for cooling oil stored in a case with the cooling water together with a rotary electric machine and an inverter cooling section for cooling an inverter unit with the cooling water.SOLUTION: A cooling water passage 4 includes: a first water passage 41 which connects a radiator 5 and an inverter cooling section 7; a second water passage 42 which connects the inverter cooling section 7 and an oil cooler 6; a third water passage 43 which connects the oil cooler 6 and the radiator 5; and a bypass water passage 49 which connects the second water passage 42 and the third water passage 43. In a branch section 90 in which the bypass water passage 49 is branched from the second water passage 42, a flow rate control valve 91 is provided to control the ratio of cooling water C flowing toward the oil cooler 6 in the second water passage 42 to cooling water C flowing from the second water passage 42 to the bypass water passage 49.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle drive device. [Background technology]

[0002] An example of a vehicle drive system is disclosed in Japanese Patent Laid-Open No. 2002-276364 (Patent Document 1). In the following description of the background art, the reference numerals in parentheses refer to those in Patent Document 1. The vehicle drive system of Patent Document 1 includes an internal combustion engine (110) and an electric motor (120) as power units. Patent Document 1 also discloses a technology for integrating cooling systems for the internal combustion engine (110) and the electric motor (120).

[0003] As described in paragraphs 0019 and 0027 of Patent Document 1, in the vehicle drive system of Patent Document 1, cooling water at a flow rate adjusted by the flow rate adjustment valve (210) is supplied to the electric motor and the inverter of the electric motor (120) to cool them. As described above, in the vehicle drive system of Patent Document 1, the valve that adjusts the amount of cooling water supplied to the electric motor and the valve that adjusts the amount of cooling water supplied to the inverter are the same valve, the flow rate adjustment valve (210). Therefore, the amount of cooling water supplied to the electric motor and the amount of cooling water supplied to the inverter cannot be adjusted independently. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-276364 Summary of the Invention [Problem to be solved by the invention]

[0005] Although Patent Document 1 does not specifically describe a method for cooling a rotating electric machine (an electric motor in Patent Document 1) using coolant, it is conceivable to use a configuration in which the rotating electric machine is cooled by oil housed in a case together with the rotating electric machine, and the oil after cooling the rotating electric machine is cooled by heat exchange in an oil cooler with the coolant. In such a configuration, the amount of coolant supplied to the oil cooler needs to be reduced when it is desired to increase the oil temperature in the case, for example, immediately after the vehicle is turned on. On the other hand, when it is desired to lower the oil temperature in the case or to recover more heat from the oil in the case, it is desired to increase the amount of coolant supplied to the oil cooler. In other words, the desired amount of coolant supplied to the oil cooler changes depending on the situation at the time. On the other hand, an inverter cooling section that cools an inverter unit (an inverter in Patent Document 1) generally needs to be supplied with a large amount of coolant to cool the inverter unit, which generates heat as the rotating electric machine operates.

[0006] As described above, in the vehicle drive system of Patent Document 1, the amount of coolant supplied to the rotating electric machine and the amount of coolant supplied to the inverter unit cannot be adjusted independently. Therefore, if the vehicle drive system of Patent Document 1 were to adopt the above-described method for cooling the rotating electric machine, the amount of coolant supplied to the oil cooler and the amount of coolant supplied to the inverter cooling unit cannot be adjusted independently. Therefore, the adjustable range of the amount of coolant supplied to the oil cooler is limited to a range in which the amount of coolant supplied to the inverter cooling unit can be maintained at an appropriate amount, making it difficult to adjust the amount of coolant supplied to the oil cooler to a desired amount depending on the situation at hand.

[0007] Therefore, when supplying cooling water to both the oil cooler, which cools the oil housed in the case together with the rotating electric machine, and the inverter cooling section, which cools the inverter unit with cooling water, it is desirable to realize technology that makes it easy to adjust the amount of cooling water supplied to the oil cooler to the desired amount depending on the situation at hand. [Means for solving the problem]

[0008] A vehicle drive device according to the present disclosure includes a drive unit including a rotating electric machine and a drive transmission mechanism that transmits the drive force of the rotating electric machine to wheels, an inverter unit that drives and controls the rotating electric machine, a drive case that houses the drive unit and oil for cooling and lubricating the drive unit, a cooling water passage through which cooling water circulates, a radiator that exchanges heat between the cooling water and outside air and cools the cooling water, an oil cooler that exchanges heat between the oil and the cooling water and cools the oil, and an inverter cooling section that exchanges heat between the inverter unit and the cooling water and cools the inverter unit. and a vehicle drive device comprising: the cooling water passage includes a first water passage connecting the radiator outlet and the inverter cooling unit, a second water passage connecting the inverter cooling unit and the oil cooler, a third water passage connecting the oil cooler and the radiator inlet, and a bypass water passage connecting the second water passage and the third water passage, and a flow control valve is provided at a branching point where the bypass water passage branches off from the second water passage to control the ratio of the cooling water flowing through the second water passage towards the oil cooler and the cooling water flowing from the second water passage to the bypass water passage.

[0009] According to this configuration, the cooler inflow rate, which is the rate of coolant flowing through the second water passage toward the oil cooler out of the total amount of coolant flowing from the inverter cooling unit into the branching unit, can be adjusted by the flow control valve. Therefore, by lowering the cooler inflow rate when the desired amount of coolant to be supplied to the oil cooler is low, and by increasing the cooler inflow rate when the desired amount of coolant to be supplied to the oil cooler is high, the amount of coolant to be supplied to the oil cooler can be adjusted to a desired amount according to the situation at the time while maintaining an appropriate amount of coolant supplied to the inverter cooling unit.

[0010] As described above, with this configuration, when cooling water is supplied to both the oil cooler that cools the oil contained in the case (drive case) together with the rotating electric machine with cooling water, and the inverter cooling section that cools the inverter unit with cooling water, it is easy to adjust the amount of cooling water supplied to the oil cooler to the desired amount depending on the situation at the time.

[0011] In addition, with this configuration, the temperature of the coolant flowing into the radiator inlet can be adjusted by adjusting the coolant inflow rate, so that the amount of heat supplied to the radiator that exceeds the limit of the radiator's heat dissipation performance can be controlled, thereby protecting the radiator and its peripheral devices.

[0012] Further features and advantages of the vehicle drive system will become apparent from the following description of the embodiments, which is given with reference to the drawings. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram illustrating, in a simplified form, the overall configuration of a vehicle drive device according to an embodiment; [Figure 2] FIG. 1 is a schematic diagram illustrating, in a simplified form, the overall configuration of a vehicle drive device according to an embodiment; [Figure 3] 1 is a flowchart showing a control method for a flow control valve according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of a vehicle drive device will be described with reference to the drawings. As shown in Fig. 1, a vehicle drive device 100 includes a drive unit 1, an inverter unit 2, a drive case 3, a cooling water passage 4, a radiator 5, an oil cooler 6, and an inverter cooling section 7.

[0015] The drive unit 1 includes a rotating electric machine 10 and a drive transmission mechanism 13 that transmits the driving force of the rotating electric machine 10 to wheels W (wheels W of a vehicle on which the vehicle drive device 100 is mounted). The rotating electric machine 10 includes a stator 12 fixed to a drive case 3 and a rotor 11 rotatably supported relative to the stator 12. The rotating electric machine 10 is electrically connected to an electric storage device such as a battery or a capacitor via an inverter unit 2, and receives electric power from the electric storage device for power running, or supplies electric power generated by the inertial force of the vehicle to the electric storage device for storage. The drive unit 1 includes at least the rotating electric machine 10 as a driving force source for the wheels W. In this specification, the term "rotating electric machine" is used to refer to a motor (electric motor), a generator (electric generator), and, if necessary, a motor-generator that functions as both a motor and a generator.

[0016] The drive transmission mechanism 13 includes various members (e.g., shafts, gear mechanisms, belts, chains, etc.) that transmit rotation at a constant speed or at a variable speed. The drive transmission mechanism 13 includes, for example, a transmission that changes the speed of the rotation transmitted from the rotating electric machine 10 and transmits it to the wheels W. In the example shown in FIG. 1, the drive transmission mechanism 13 is configured to transmit the driving force of the rotating electric machine 10 to a pair of wheels W (e.g., a pair of left and right front wheels, or a pair of left and right rear wheels). Therefore, in the example shown in FIG. 1, the drive transmission mechanism 13 includes an output differential gear mechanism that distributes the input rotation to the pair of wheels W.

[0017] The inverter unit 2 is a unit that drives and controls the rotating electric machine 10. The inverter unit 2 includes an inverter (inverter circuit) that converts power between DC power and AC power. The inverter is, for example, a power module in which multiple elements (switching elements, etc.) are modularized. The inverter unit 2 may further include components associated with the inverter. The components associated with the inverter are, for example, a control board on which a control device that controls the inverter is mounted, a smoothing capacitor that smooths the voltage between the positive and negative poles on the DC side of the inverter, etc.

[0018] The drive case 3 is a case that houses the drive unit 1 and oil L for cooling and lubricating the drive unit 1. A circulation path for the oil L is formed inside the drive case 3, passing through the drive unit 1 (specifically, the rotating electric machine 10 and the drive transmission mechanism 13) and the oil cooler 6. For example, the oil L supplied to heat-generating parts of the rotating electric machine 10, such as coil end portions (not shown) of the coil wound around the stator 12 that protrude from the stator 12, cools the heat-generating parts. The oil L supplied to parts to be lubricated, such as gears and bearings in the drive transmission mechanism 13, lubricates the parts to be lubricated. Although it is possible to circulate the oil L only by having the gears scoop up the oil L, in this embodiment, as shown in FIG. 1, the oil L is circulated using an oil pump 96.

[0019] The radiator 5 is a device (heat exchanger) that exchanges heat between the coolant C and outside air (here, the atmosphere) to cool the coolant C. The cooling water passage 4 is formed to pass through the radiator 5. The radiator 5 cools the coolant C by transferring the heat of the coolant C flowing through the cooling water passage 4 to the outside air. The radiator 5 is provided, for example, in the front of the vehicle.

[0020] The oil cooler 6 is a device (heat exchanger) that exchanges heat between the oil L and the cooling water C and cools the oil L. The cooling water passage 4 and the oil passage through which the oil L flows are formed to pass through the oil cooler 6. The oil cooler 6 cools the oil L by transferring the heat of the oil L flowing through the oil passage to the cooling water C flowing through the cooling water passage 4.

[0021] The inverter cooling section 7 is a device that exchanges heat between the inverter unit 2 and the cooling water C to cool the inverter unit 2. The inverter unit 2 includes a heat sink (e.g., a heat dissipation fin) for dissipating heat generated in the inverter unit 2, and the inverter cooling section 7 includes a water channel formed in the heat sink. The cooling water channel 4 is formed so that the water passes through the water channel provided in the inverter cooling section 7. The inverter cooling section 7 cools the inverter unit 2 by transferring heat from the inverter unit 2 (specifically, the heat sink) to the cooling water C.

[0022] The cooling water passage 4 is a passage through which the cooling water C circulates. As shown in FIG. 1, a water pump 97 (here, an electric pump) is provided in the cooling water passage 4, and the water pump 97 circulates the cooling water C in the cooling water passage 4. In the example shown in FIG. 1, the water pump 97 is provided in the first water passage 41.

[0023] 1, the cooling water passage 4 includes a first water passage 41 connecting the outlet 51 of the radiator 5 and the inverter cooling unit 7, a second water passage 42 connecting the inverter cooling unit 7 and the oil cooler 6, a third water passage 43 connecting the oil cooler 6 and the inlet 52 of the radiator 5, and a bypass water passage 49 connecting the second water passage 42 and the third water passage 43. The bypass water passage 49 connects the second water passage 42 and the third water passage 43 without passing through the oil cooler 6. A flow control valve 91 is provided at a branching point 90 where the bypass water passage 49 branches off from the second water passage 42 to control the ratio of the cooling water C flowing through the second water passage 42 toward the oil cooler 6 and the cooling water C flowing from the second water passage 42 to the bypass water passage 49. 1, a check valve 98 that restricts the flow of oil L toward the upstream side is provided upstream of the junction of the bypass water passage 49 in the third water passage 43. In this specification, the "upstream side" means the upstream side along the flow of the cooling water C, and the "downstream side" means the downstream side along the flow of the cooling water C.

[0024] In this way, the inverter cooling unit 7, flow control valve 91, and oil cooler 6 are arranged in this order downstream from the radiator 5 along the flow of the cooling water C in the cooling water passage 4. The flow control valve 91 controls the ratio between the flow rate of the cooling water C flowing to the oil cooler 6 and the flow rate of the cooling water C flowing to the bypass water passage 49 (a water passage for bypassing the oil cooler 6 and returning the cooling water C to the radiator 5).

[0025] Here, the ratio of the cooling water C flowing through the second water passage 42 toward the oil cooler 6 to the total amount of cooling water C flowing from the inverter cooling section 7 into the branch section 90 is referred to as the cooler inflow ratio. In Figures 1 and 2, the flow direction of the cooling water C in the cooling water passage 4 is indicated by an arrow. Figure 1 shows a case where the cooler inflow ratio is low (for example, 0%), and Figure 2 shows a case where the cooler inflow ratio is high (for example, 100%).

[0026] As shown in FIG. 1, in this embodiment, the vehicle drive device 100 includes a waste heat recovery device 92 that is provided in the third water passage 43 and recovers heat by heat exchange with the coolant C. In the example shown in FIG. 1, the waste heat recovery device 92 is provided downstream of the junction with the bypass water passage 49 in the third water passage 43. The heat recovered by the waste heat recovery device 92 is utilized in a heat utilization device 94 mounted on the vehicle. Examples of the heat utilization device 94 include a heating device for the vehicle cabin and a temperature regulator for a battery (for example, a battery serving as the above-mentioned power storage device).

[0027] As described above, in this embodiment, the vehicle drive system 100 further includes a waste heat recovery device 92 that is provided in the third water passage 43 and recovers heat through heat exchange with the coolant C. With this configuration, waste heat from the inverter unit 2 and the drive unit 1 is recovered by the waste heat recovery device 92 upstream of the inlet 52 of the radiator 5, and the recovered heat can be used in devices mounted on the vehicle (e.g., a heating device for the passenger compartment, a temperature regulator for the battery, etc.). With this configuration, as the cooler inflow ratio increases, the amount of heat provided by the oil cooler 6 to the coolant C flowing through the third water passage 43 can be increased, and therefore the amount of heat provided to the waste heat recovery device 92 can be increased. Therefore, it is easy to provide the required amount of heat to the waste heat recovery device 92 depending on the vehicle condition (in other words, vehicle requirements).

[0028] 1, in this embodiment, the vehicle drive device 100 includes a heat transfer device 93 that transfers heat from the rotating electric machine 10 to the drive case 3. In the example shown in FIG. 1, the heat transfer device 93 is a device that transfers heat from the coil end portion of the rotating electric machine 10 to the drive case 3. In this case, the heat transfer device 93 is configured using, for example, a non-conductive member (e.g., resin) that is arranged so as to be in contact with both the coil end portion and the drive case 3.

[0029] As described above, in this embodiment, the vehicle drive device 100 further includes a heat transfer device 93 that transfers heat from the rotating electric machine 10 to the drive case 3. With this configuration, even when the cooler inflow rate is reduced, the heat generated in the rotating electric machine 10 can be appropriately dissipated from the drive case 3. Therefore, even in a situation where the amount of heat generated from the rotating electric machine 10 is relatively large, it is easy to reduce the cooler inflow rate while maintaining the temperature of the rotating electric machine 10 within an appropriate range.

[0030] Next, adjustment of the cooler inflow rate by the flow control valve 91 will be described. In this vehicle drive system 100, the cooling water passage 4 is configured to supply the coolant C to both the oil cooler 6 and the inverter cooling unit 7. The vehicle drive system 100 adjusts the cooler inflow rate using the flow control valve 91. When the desired amount of coolant C to be supplied to the oil cooler 6 is low, the cooler inflow rate is lowered. When the desired amount of coolant C to be supplied to the oil cooler 6 is high, the cooler inflow rate is increased. This makes it possible to maintain the amount of coolant C supplied to the inverter cooling unit 7 at an appropriate amount while adjusting the amount of coolant C supplied to the oil cooler 6 to a desired amount depending on the situation at the time. In particular, in this embodiment, since the vehicle drive system 100 includes the waste heat recovery device 92, adjusting the amount of coolant C supplied to the oil cooler 6 can control the balance between waste heat (for example, heat exhausted from the drive case 3 to the atmosphere) and heat reuse (heat recovery by the waste heat recovery device 92).

[0031] In this embodiment, the flow control valve 91 adjusts the cooler inflow ratio through control by the control device 8 (specifically, control of the actuator of the flow control valve 91). That is, as shown in FIG. 1, the vehicle drive device 100 includes the control device 8 that controls the flow control valve 91. The control device 8 includes an arithmetic processing device such as a CPU (Central Processing Unit) as a core component, and also includes a storage device that can be accessed by the arithmetic processing device, such as a RAM (Random Access Memory) or a ROM (Read Only Memory). Each function of the control device 8 is realized by software (programs) stored in a storage device such as a ROM, or by hardware such as a separately provided arithmetic circuit, or by both. The arithmetic processing device included in the control device 8 operates as a computer that executes each program.

[0032] As described above, in this embodiment, the vehicle drive device 100 includes the waste heat recovery device 92. In this embodiment, as shown in FIG. 1, the control device 8 is configured to receive a waste heat recovery request from the device control device 9 that controls the device (heat utilization device 94) that utilizes the heat recovered by the waste heat recovery device 92. Note that the control device 8 and the device control device 9 are at least conceptually distinct and do not necessarily need to be physically distinct. In other words, the control device 8 and the device control device 9 may have a common hardware configuration. Furthermore, the device control device 9 may be at least a part of an integrated control device that performs integrated control of the entire vehicle.

[0033] In this embodiment, the control device 8 controls the cooler inflow rate based on the temperature of the oil L. As shown in FIG. 1 , in this embodiment, the vehicle drive device 100 includes an oil temperature sensor 95 that detects the temperature of the oil L, and the control device 8 acquires the temperature of the oil L based on the detection result of the oil temperature sensor 95. The oil temperature sensor 95 is provided to detect, for example, the temperature of the oil L before being cooled by the oil cooler 6 (for example, the temperature of the oil L flowing into the oil cooler 6, or the temperature of the oil L after cooling the rotating electrical machine 10). Alternatively, instead of this configuration, the control device 8 may acquire the temperature of the oil L (estimated temperature) based on a temperature correlated with the temperature of the oil L. In this case, the vehicle drive device 100 includes a sensor that detects a temperature correlated with the temperature of the oil L, and the control device 8 acquires the temperature of the oil L (estimated temperature) based on the detection result of the sensor. The temperature correlated with the temperature of the oil L may be, for example, the temperature of the coolant C discharged from the oil cooler 6. As such, in this specification, the term "temperature of the oil L" is used as a concept that includes an estimated temperature based on a temperature correlated with the temperature of the oil L.

[0034] In this embodiment, when the temperature of the oil L is equal to or higher than a predetermined warm-air threshold, the control device 8 increases the cooler inflow rate compared to when the temperature of the oil L is below the warm-air threshold. The warm-air threshold is set, for example, to correspond to the lower limit of the temperature range of the oil L that allows the drive unit 1 to operate properly. In other words, the warm-air threshold is set, for example, to correspond to the upper limit of the temperature range of the oil L that requires the drive unit 1 to be warmed up.

[0035] Furthermore, in this embodiment, when the temperature of the oil L is higher than the warm-up threshold and equal to or higher than a rotating-machine upper limit threshold set corresponding to the upper limit temperature at which the function of the rotating electric machine 10 can be maintained, the control device 8 controls the flow control valve 91 to increase the cooler inflow rate compared to when the temperature of the oil L is equal to or higher than the warm-up threshold and lower than the rotating electric machine upper limit threshold. The rotating electric machine upper limit threshold is set, for example, corresponding to the upper limit of the temperature range of the oil L at which demagnetization of the permanent magnets provided in the rotating electric machine 10 (specifically, the rotor 11) does not occur (one example of a temperature range of the oil L at which the function of the rotating electric machine 10 can be maintained). Note that there is a correlation between the temperature of the rotating electric machine 10 and the temperature of the oil L inside the drive case 3, and the temperature range of the oil L at which the function of the rotating electric machine 10 can be maintained can be set based on this correlation.

[0036] In addition, in this embodiment, when the control device 8 receives a waste heat recovery request from the equipment control device 9, it controls the flow control valve 91 to increase the cooler inflow ratio compared to when the temperature of the oil L is above the rotating motor upper limit threshold.

[0037] As described above, in this embodiment, the vehicle drive device 100 further includes a control device 8 that controls the flow control valve 91. The cooler inflow ratio is the ratio of the coolant C flowing through the second water passage 42 toward the oil cooler 6 to the total amount of coolant C flowing from the inverter cooling unit 7 into the branch unit 90. The control device 8 controls the flow control valve 91 so that, when the temperature of the oil L is equal to or higher than a predetermined warm-air threshold, the cooler inflow ratio is higher than when the temperature of the oil L is lower than the warm-air threshold, and, when the temperature of the oil L is higher than the warm-air threshold and equal to or higher than a rotating electric machine upper limit threshold set corresponding to the upper limit temperature at which the function of the rotating electric machine 10 can be maintained, the cooler inflow ratio is higher than when the temperature of the oil L is equal to or higher than the warm-air threshold and lower than the rotating electric machine upper limit threshold.

[0038] According to the above configuration, when the temperature of the oil L is below the warm-up threshold, the cooler inflow rate is reduced to relatively quickly raise the temperature of the oil L to the warm-up threshold, and when the temperature of the oil L is equal to or higher than the upper limit threshold of the rotating electrical machine, the cooler inflow rate is increased to relatively quickly lower the temperature of the oil L to a temperature below the upper limit threshold of the rotating electrical machine. Thus, the cooler inflow rate can be appropriately adjusted according to the temperature of the oil L at any given time so that the temperature of the oil L is within a range in which the drive unit 1 can exhibit its original performance.

[0039] In this embodiment, the vehicle drive device 100 further includes a waste heat recovery device 92 that is provided in the third water passage 43 and recovers heat by heat exchange with the coolant C, and the control device 8 is configured to receive a waste heat recovery request from an equipment control device 9 that controls equipment (heat utilization equipment 94) that utilizes the heat recovered by the waste heat recovery device 92. When the control device 8 receives the waste heat recovery request, it controls the flow control valve 91 to increase the cooler inflow rate compared to when the temperature of the oil L is equal to or higher than the upper limit threshold of the rotating electrical machine.

[0040] According to the above configuration, waste heat from the inverter unit 2 and the drive unit 1 is recovered by the waste heat recovery device 92 upstream of the inlet 52 of the radiator 5, and the recovered heat can be used by a heat utilization device 94 that utilizes the heat (for example, a heating device for the vehicle interior or a temperature regulator for the battery). Furthermore, according to the above configuration, when the control device 8 receives a waste heat recovery request from the device control device 9, the cooler inflow rate is increased, thereby promoting the utilization of heat by the heat utilization device 94.

[0041] Next, an example of a method for controlling the flow control valve 91 by the control device 8 will be described with reference to Fig. 3. In the example shown in Fig. 3, step #02 and subsequent steps are repeatedly executed from the time the vehicle starts to travel until the time the vehicle stops traveling (step #01: Yes, step #09: No).

[0042] When the oil temperature (temperature of oil L) is less than the warm-up threshold (step #02: No), the control device 8 controls the flow control valve 91 so that the cooler inflow ratio becomes a first ratio (zero in this example). On the other hand, when the oil temperature is equal to or greater than the warm-up threshold (step #02: Yes), the control device 8 controls the flow control valve 91 so that the cooler inflow ratio becomes a ratio higher than the first ratio (in this example, any one of a second ratio, a third ratio, or a fourth ratio, which will be described later).

[0043] Specifically, when there is no waste heat recovery request from the equipment control device 9 (step #04: No) and the oil temperature is below the upper limit threshold for the rotating electrical machine (step #06: No), the control device 8 controls the flow control valve 91 so that the cooler inflow ratio becomes a second ratio (in this example, a ratio indicated as "small") higher than the first ratio. Also, when there is no waste heat recovery request from the equipment control device 9 (step #04: No) and the oil temperature is equal to or higher than the upper limit threshold for the rotating electrical machine (step #06: Yes), the control device 8 controls the flow control valve 91 so that the cooler inflow ratio becomes a third ratio (in this example, a ratio indicated as "medium") higher than the second ratio. Also, when there is a waste heat recovery request from the equipment control device 9 (step #04: Yes), the control device 8 controls the flow control valve 91 so that the cooler inflow ratio becomes a fourth ratio (in this example, a ratio indicated as "large") higher than the third ratio. In this way, in the example shown in FIG. 3, when the oil temperature is lower than the warm-up threshold, the flow control valve 91 is controlled so that the cooler inflow ratio becomes the first ratio, regardless of whether or not there is a waste heat recovery request.

[0044] Other Embodiments Next, other embodiments of the vehicle drive device will be described.

[0045] (1) In the above embodiment, the controller 8 controls the flow control valve 91 to increase the cooler inflow rate when the controller 8 receives a waste heat recovery request compared to when the temperature of the oil L is equal to or higher than the upper limit threshold of the rotating electrical machine. However, the present disclosure is not limited to such a configuration. Alternatively, the controller 8 may control the flow control valve 91 to increase the cooler inflow rate when the controller 8 receives a waste heat recovery request, such that the cooler inflow rate is the same as when the temperature of the oil L is equal to or higher than the upper limit threshold of the rotating electrical machine. Alternatively, the controller 8 may control the flow control valve 91 to decrease the cooler inflow rate compared to when the temperature of the oil L is equal to or higher than the upper limit threshold of the rotating electrical machine. In the latter case, the cooler inflow rate is preferably higher than when the temperature of the oil L is lower than the warm-air threshold. For example, the cooler inflow rate in the latter case may be the second rate described above, or a rate between the second rate and the third rate described above.

[0046] Furthermore, the waste heat recovery requests may be classified into a plurality of levels according to the amount of heat used by the heat utilization equipment 94, and when the control device 8 receives a waste heat recovery request, the flow control valve 91 may be controlled according to the level of the received waste heat recovery request so that the cooler inflow rate increases as the amount of heat used increases. In this case, for example, it is preferable to set the cooler inflow rate higher when at least the level of the waste heat recovery request is the level at which the amount of heat used is the highest, compared to the cooler inflow rate set when the temperature of the oil L is equal to or higher than the upper limit threshold of the rotating electrical machine.

[0047] (2) In the above embodiment, the vehicle drive device 100 is described as including the heat transfer device 93. However, the present disclosure is not limited to such a configuration, and the vehicle drive device 100 may be configured not to include the heat transfer device 93.

[0048] (3) In the above embodiment, the vehicle drive device 100 is described as including the waste heat recovery device 92. However, the present disclosure is not limited to such a configuration, and the vehicle drive device 100 may be configured not to include the waste heat recovery device 92.

[0049] (4) Note that the configurations disclosed in the above-described embodiments can be applied in combination with configurations disclosed in other embodiments (including combinations of embodiments described as other embodiments) as long as no contradictions arise. Regarding other configurations, the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications can be made as appropriate within the scope of the present disclosure. [Explanation of symbols]

[0050] 1: drive unit, 2: inverter unit, 3: drive case, 4: cooling water passage, 5: radiator, 6: oil cooler, 7: inverter cooling section, 8: control device, 9: equipment control device, 10: rotating electric machine, 13: drive transmission mechanism, 41: first water passage, 42: second water passage, 43: third water passage, 49: bypass water passage, 51: outlet, 52: inlet, 90: branching section, 91: flow control valve, 92: waste heat recovery device, 93: heat transfer device, 100: vehicle drive unit, C: cooling water, L: oil, W: wheel

Claims

1. a drive unit for a vehicle, the drive unit including a rotating electric machine and a drive transmission mechanism that transmits a drive force of the rotating electric machine to a wheel; an inverter unit that drives and controls the rotating electric machine; a drive case that accommodates the drive unit and oil for cooling and lubricating the drive unit; a cooling water passage through which cooling water circulates; a radiator that exchanges heat between the cooling water and outside air and cools the cooling water; an oil cooler that exchanges heat between the oil and the cooling water and cools the oil; and an inverter cooling unit that exchanges heat between the inverter unit and the cooling water and cools the inverter unit, The cooling water channel a first water passage connecting an outlet of the radiator and the inverter cooling unit; a second water passage connecting the inverter cooling unit and the oil cooler; a third water passage connecting the oil cooler and an inlet of the radiator; a bypass waterway connecting the second waterway and the third waterway; Equipped with a flow control valve for controlling a ratio of the cooling water flowing through the second water passage toward the oil cooler to the cooling water flowing from the second water passage to the bypass water passage is provided at a branching point where the bypass water passage branches off from the second water passage, Further, a control device for controlling the flow control valve is provided. a cooler inflow ratio is a ratio of the cooling water flowing through the second water passage toward the oil cooler to the total amount of the cooling water flowing from the inverter cooling portion to the branch portion, The control device controls the flow control valve to adjust the cooler inflow rate to three or more levels in which the cooler inflow rate increases as the oil temperature increases.

2. a drive unit for a vehicle, the drive unit including a rotating electric machine and a drive transmission mechanism that transmits a drive force of the rotating electric machine to a wheel; an inverter unit that drives and controls the rotating electric machine; a drive case that accommodates the drive unit and oil for cooling and lubricating the drive unit; a cooling water passage through which cooling water circulates; a radiator that exchanges heat between the cooling water and outside air and cools the cooling water; an oil cooler that exchanges heat between the oil and the cooling water and cools the oil; and an inverter cooling unit that exchanges heat between the inverter unit and the cooling water and cools the inverter unit, The cooling water channel a first water passage connecting an outlet of the radiator and the inverter cooling unit; a second water passage connecting the inverter cooling unit and the oil cooler; a third water passage connecting the oil cooler and an inlet of the radiator; a bypass waterway connecting the second waterway and the third waterway; Equipped with a flow control valve for controlling a ratio of the cooling water flowing through the second water passage toward the oil cooler to the cooling water flowing from the second water passage to the bypass water passage is provided at a branching point where the bypass water passage branches off from the second water passage, Further, a control device for controlling the flow control valve is provided. a cooler inflow ratio is a ratio of the cooling water flowing through the second water passage toward the oil cooler to the total amount of the cooling water flowing from the inverter cooling portion to the branch portion, The control device increases the cooler inflow ratio when the oil temperature is equal to or higher than a predetermined warm-up threshold value compared to when the oil temperature is lower than the warm-up threshold value.

3. The control device, a vehicle drive device as described in claim 2, controls the flow control valve so that when the oil temperature is higher than the warm-up threshold and is equal to or higher than a rotating motor upper limit threshold set corresponding to the highest temperature at which the function of the rotating motor can be maintained, the cooler inflow rate is higher than when the oil temperature is equal to or higher than the warm-up threshold and lower than the rotating motor upper limit threshold.

4. 3. The vehicle drive system according to claim 1, further comprising a waste heat recovery device provided in the third water passage and configured to recover heat by heat exchange with the cooling water.

5. 3. The vehicle drive system according to claim 1, further comprising a heat transfer device that transfers heat from the rotating electric machine to the drive case.

6. a waste heat recovery device provided in the third water passage and configured to recover heat by heat exchange with the cooling water; the control device is configured to receive a waste heat recovery request from an equipment control device that controls an equipment that utilizes the heat recovered by the waste heat recovery device; 3. The vehicle drive device according to claim 2, wherein, when the control device receives the waste heat recovery request, the control device controls the flow control valve so that the cooler inflow ratio is higher than when the oil temperature is equal to or higher than the rotating electric machine upper limit threshold.

Images