vehicle

Abstract

To provide a vehicle which can suppress overshoot at the moment of changing the flow rate of a second temperature control medium.SOLUTION: A vehicle V comprises: a battery BAT; a motor MOT1; an electric power conversion system PCU; a temperature control circuit 60; and a controller ECU which controls the temperature control circuit 60. The temperature control circuit 60 includes: a first temperature control circuit 61 which circulates a first temperature control medium TCM1 through a first pump 611a, 611b to cool the motor MOT1; a second temperature control circuit 62 with a second pump 621 and a radiator 622 which circulates a second temperature control medium TCM2 through the second pump 621 to cool the electric power conversion system PCU; and a heat exchanger 63 which performs heat exchange between the first temperature control medium of the first temperature control circuit 61 and the second temperature control medium TCM2 of the second temperature control circuit 62. The controller ECU increases, when the temperature of the first temperature control medium TCM1 becomes equal to or higher than a duty-up threshold value To1, the flow rate of the second pump 621.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] In recent years, efforts to realize a low-carbon or carbon-free society have been intensifying as a concrete measure against global climate change. In automobiles and other vehicles, there is a demand for reducing CO2 emissions and improving energy efficiency, and the electrification of drive sources is progressing. For example, electric vehicles and hybrid electric vehicles have been developed that include a motor as a drive source for driving the drive wheels, a battery as a power source for supplying power to the motor, and a power conversion device that converts the battery's power and supplies it to the motor.

[0003] For example, the following Patent Document 1 discloses a vehicle temperature control system including a first temperature control circuit that controls the temperature of a motor, a second temperature control circuit that controls the temperature of a power conversion device, and a heat exchanger that exchanges heat between the first temperature control medium circulating in the first temperature control circuit and the second temperature control medium circulating in the second temperature control circuit. The first temperature control medium is typically ATF (Automatic transmission fluid), and the second temperature control medium is typically LLC (Long Life Coolant).

[0004] The power conversion device is equipped with chips such as IGBTs (Insulated Gate Bipolar Transistors), and is cooled by circulating the second temperature control medium cooled by the radiator using an electric pump. The electric pump can control the flow rate by increasing or decreasing its duty (duty ratio).

[0005] In this vehicle temperature control system, heat is exchanged between the first temperature medium in the first temperature control circuit and the second temperature control medium in the second temperature control circuit, and the heat of the motor and the power conversion device is dissipated by a radiator provided in the second temperature control circuit. The electric pump provided in the second temperature control circuit is controlled at a low duty ratio based on constraints from the standpoint of noise and fuel efficiency when the vehicle is under low load, and the duty ratio is increased and controlled when the internal component temperature of the power conversion device, the temperature of the second temperature control medium, the temperature of the internal component temperature of the motor, the temperature of the first temperature control medium, etc. approach their respective upper limit temperatures, thereby ensuring cooling performance.

[0006] Furthermore, Patent Document 2 discloses that when the LLC temperature is hotter than the ATF temperature, the ATF pump and the LLC pump are driven to cool the LLC using cold ATF. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2022-108684 A [Patent Document 2] Patent Publication No. 2021-13287 Summary of the Invention [Problem to be solved by the invention]

[0008] The first temperature control circuit including the motor has a very large heat capacity compared to the second temperature control circuit including the power conversion device. Therefore, when the heat exchange amount in the heat exchanger changes due to an increase or decrease in the flow rate of the second temperature control medium or the flow rate of the first temperature control medium, the temperature of the first temperature control circuit does not change immediately, but the temperature of the second temperature control circuit changes suddenly. In particular, when the flow rate of the second temperature control medium increases, the amount of heat received by the second temperature control medium from the heat exchanger temporarily increases, and the temperature of the second temperature control medium increases. Over time, as the temperature of the first temperature control medium gradually decreases, the heat exchange amount also decreases, and when the temperature of the second temperature control medium also decreases, the temperature reaches saturation.

[0009] That is, in this vehicle temperature control system, a phenomenon (overshoot) may occur in which the water temperature of the second temperature control medium at the moment the flow rate of the second temperature control medium is changed becomes higher than the water temperature at temperature saturation. As a result, when the flow rate of the second temperature control medium is increased in response to a cooling request from the internal components of the power conversion device, the temperature of the second temperature control medium increases due to the increased flow rate, and the temperature of the internal components of the power conversion device may actually increase.

[0010] Patent Document 2 did not take into consideration the possibility that the ATF may become hotter than the LLC during driving, causing an overshoot, leaving room for improvement.

[0011] The present invention provides a vehicle capable of suppressing an overshoot that occurs at the moment when the flow rate of the second temperature control medium is changed. [Means for solving the problem]

[0012] The present invention relates to A battery; A motor; a power conversion device disposed on a power transmission path between the battery and the motor; a temperature control system for controlling temperatures of the motor and the power conversion device; A vehicle comprising: a control device for controlling the temperature adjustment system; The temperature control system includes: a first temperature control circuit that circulates a first temperature control medium by a first pump to cool the motor; a second temperature control circuit including a second pump and a radiator, the second pump circulating a second temperature control medium to cool the power conversion device; a heat exchanger for exchanging heat between a first temperature medium of the first temperature control circuit and a second temperature control medium of the second temperature control circuit; The control device includes: When the temperature of the first temperature control medium reaches or exceeds a predetermined value, the flow rate of the second pump is increased. Effect of the Invention

[0013] According to the present invention, it is possible to suppress an overshoot that occurs at the moment when the flow rate of the second temperature control medium is changed. [Brief description of the drawings]

[0014] [Figure 1] 1 is a diagram showing an example of a schematic configuration of a vehicle V according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing an example of a schematic configuration of a main drive unit DU1 and a power conversion unit PCU. [Diagram 3] 2 is a diagram showing an example of a schematic configuration of a temperature adjustment circuit 60. FIG. [Figure 4] FIG. 13 is a diagram showing a control logic in flow rate control of a second pump 621 by a control device ECU. [Diagram 5] 13 is a graph showing the influence of the temperature of the first temperature control medium TCM1 (ATF oil temperature) on the temperature of the second temperature control medium TCM2 (LLC water temperature) when the flow rate (LLC flow rate) of the second pump 621 is changed. [Figure 6] 10 is a graph showing the relationship between the temperature of the second temperature control medium TCM2 (LLC water temperature) and the temperature of the first temperature control medium TCM1 (ATF oil temperature). [Figure 7] FIG. 11 is a diagram showing the relationship between the required duty and the temperature (ATF oil temperature) of the first temperature control medium TCM1. [Figure 8] FIG. 13 is a diagram showing a modified temperature adjustment circuit 60. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of a vehicle according to the present invention will be described in detail with reference to the accompanying drawings. The drawings are to be viewed in the direction indicated by the reference symbols. In the following, the same or similar elements are denoted by the same or similar reference symbols, and their description may be omitted or simplified as appropriate.

[0016] [vehicle] Fig. 1 is a diagram showing an example of a schematic configuration of a vehicle V according to an embodiment of the present invention, in which thick solid lines indicate mechanical connections, dashed lines indicate electrical wiring, and solid arrows indicate control signals or detection signals.

[0017] As shown in FIG. 1, a vehicle V of this embodiment includes a main drive unit DU1.

[0018] The main drive unit DU1 includes a motor MOT1 and is configured to be capable of driving the front wheels FWR of the vehicle V by at least the power of the motor MOT1. The main drive unit DU1 is temperature-regulated (e.g., cooled) by a temperature regulation circuit 60 (e.g., a first temperature regulation circuit 61 described later) provided in the vehicle V.

[0019] In this way, the vehicle V equipped with the main drive unit DU1 is configured to be capable of driving the front wheels FWR, but may also be a so-called "four-wheel drive vehicle" equipped with a slave drive unit that drives the rear wheels RWR.

[0020] The vehicle V further includes a battery BAT, a power conversion unit PCU, various sensors SNSR, and a control unit ECU.

[0021] The battery BAT is a chargeable and dischargeable secondary battery, has multiple storage cells connected in series or series-parallel, and is configured to be capable of outputting a high voltage of, for example, 100 to 400 V. As the storage cells of the battery BAT, lithium ion batteries (including so-called "all-solid-state batteries" using a solid electrolyte), nickel-metal hydride batteries, etc. can be used.

[0022] The power converter PCU is a device that converts the power exchanged between the main drive unit DU1 (for example, the motor MOT1) and the battery BAT. The power converter PCU will be described in detail later, and therefore will not be described here.

[0023] The various sensors SNSR are sensors for acquiring information (hereinafter also referred to as "vehicle information") related to the vehicle V. For example, the various sensors SNSR include a vehicle speed sensor that detects the traveling speed (hereinafter also referred to as "vehicle speed") of the vehicle V, an accelerator pedal sensor that detects the amount of operation of the accelerator pedal (hereinafter also referred to as "AP opening"), a temperature sensor (for example, a power conversion device temperature sensor 62b described later) that detects the temperature of each part of the vehicle V (for example, the power conversion device PCU), and the like. The detection results by the various sensors SNSR are sent to the control device ECU as detection signals.

[0024] The control device ECU is a device (computer) that performs overall control of the entire vehicle V. The control device ECU controls the power conversion device PCU, the main drive unit DU1, and the temperature adjustment circuit 60, for example, based on vehicle information acquired by various sensors SNSR. An example of specific control by the control device ECU will be described later, and therefore will not be described here.

[0025] The control device ECU is realized by, for example, an ECU (Electronic Control Unit) including a processor that performs various calculations, a storage device having a non-transitory storage medium that stores various information, an input / output device that controls input and output of data between the inside and outside of the control device ECU, etc. The control device ECU may be realized by one ECU, or may be realized by multiple ECUs working together.

[0026] [Power conversion device] Fig. 2 is a diagram showing an example of a schematic configuration of the main drive unit DU1 and the power converter PCU. As shown in Fig. 2, the power converter PCU includes a converter VCU, a first inverter INV1, and a second inverter INV2.

[0027] The converter VCU is a DC-DC converter having switching elements (semiconductor elements) formed as chips, such as coils, capacitors, diodes, IGBTs (insulated gate bipolar transistors) and MOSFETs (metal oxide semiconductor field effect transistors), and has a function of converting an input voltage into a predetermined voltage and outputting it by switching the switching elements. For example, the output voltage of a battery BAT is input to the converter VCU, and the converter VCU outputs the boosted voltage by boosting the output voltage of the battery BAT.

[0028] The converter VCU is provided with a current sensor 11, which detects a current output from the battery BAT to the converter VCU. A voltage sensor 12 is provided between the converter VCU and the first inverter INV1 and the second inverter INV2, which detects a boosted voltage supplied from the converter VCU to the first inverter INV1 and the second inverter INV2.

[0029] The boosted voltage output from the converter VCU can be supplied to the motor MOT1 via the second inverter INV2.

[0030] In addition, the converter VCU may step down the voltage input via the first inverter INV1 and the second inverter INV2 and output the stepped down voltage to the battery BAT. That is, the converter VCU may output the input voltage to be input (i.e., charged) to the battery BAT.

[0031] The first inverter INV1 and the second inverter INV2 have a plurality of switching elements (not shown) formed as chips, such as IGBTs (insulated gate bipolar transistors) and MOSFETs (metal oxide semiconductor field effect transistors), and have the function of converting direct current to alternating current and vice versa by switching these switching elements.

[0032] For example, the first inverter INV1 may receive power (AC) generated by a generator GEN (described later) of the main drive unit DU1. In this case, the first inverter INV1 converts the AC received from the generator GEN into DC and outputs the DC to the converter VCU and a part or all of the second inverter INV2.

[0033] The second inverter INV2 may receive the power (DC) of the battery BAT received via the converter VCU, or the power (DC) of the generator GEN received via the first inverter INV1. In this case, the second inverter INV2 converts the DC received from the battery BAT or the generator GEN to AC and outputs (i.e., supplies) it to the motor MOT1 of the main drive unit DU1. In addition, when regenerative power generation is performed by the motor MOT1, the second inverter INV2 may convert the power (AC) received from the motor MOT1 to DC and output it to the converter VCU, etc.

[0034] [Main drive unit] As shown in Fig. 2, the main drive unit DU1 includes an engine ENG, a generator GEN, a motor MOT1, and a first transmission mechanism T1. A gasoline engine, a diesel engine, or the like can be used as the engine ENG. For example, a three-phase AC motor can be used as the generator GEN and the motor MOT1. Details of the first transmission mechanism T1 will be omitted.

[0035] [Temperature control circuit] 3 is a diagram showing an example of a schematic configuration of the temperature adjustment circuit 60. As shown in FIG. 3, the temperature adjustment circuit 60 includes a first temperature adjustment circuit 61, a second temperature adjustment circuit 62, and a heat exchanger 63.

[0036] The first temperature control circuit 61 circulates the non-conductive first temperature control medium TCM1, and controls the temperature of the motor MOT1, the generator GEN, and the first speed change mechanism T1 (i.e., the main drive unit DU1). The first temperature control circuit 61 is provided with a first temperature sensor 61a that detects the temperature of the first temperature control medium TCM1 circulating through the first temperature control circuit 61. In this embodiment, the first temperature sensor 61a is provided in a storage section 612 that is an oil pan, and detects the temperature of the first temperature control medium TCM1 stored in the storage section 612. The first temperature sensor 61a outputs a detection value of the temperature of the first temperature control medium TCM1 stored in the storage section 612 to the control device ECU. This allows the control device ECU to obtain the temperature of the first temperature control medium TCM1.

[0037] The second temperature control circuit 62 circulates the conductive second temperature control medium TCM2, and controls the temperature of the power conversion device PCU. The second temperature control circuit 62 is provided with a second temperature sensor 62a that detects the temperature of the second temperature control medium TCM2 circulating through the second temperature control circuit 62. In this embodiment, the second temperature sensor 62a is provided in the pressure-feeding flow path 620a between the radiator 622 and the branching portion 624, and detects the temperature of the second temperature control medium TCM2. The second temperature sensor 62a outputs a detection value of the temperature of the second temperature control medium TCM2 discharged from the radiator 622 to the control device ECU. This allows the control device ECU to obtain the temperature of the second temperature control medium TCM2.

[0038] Further, the power converter PCU whose temperature is adjusted by the second temperature adjustment circuit 62 is provided with a power converter temperature sensor 62b for detecting the temperature of the power converter PCU. The power converter temperature sensor 62b outputs a detection signal indicating a detection value of the temperature of the power converter PCU to the control device ECU. Here, the power converter temperature sensor 62b may be configured to be capable of detecting the temperatures of the switching elements formed as chips that are built into the first inverter INV1, the second inverter INV2, and the converter VCU, respectively. This allows the control device ECU to acquire the chip temperatures built into the power converter PCU.

[0039] The heat exchanger 63 exchanges heat between the first temperature control medium TCM1 circulating through the first temperature control circuit 61 and the second temperature control medium TCM2 circulating through the second temperature control circuit 62. As the first temperature control medium TCM1, for example, oil called ATF (Automatic Transmission Fluid) is used, which lubricates and controls the temperature of the motor MOT1, the generator GEN, and the first transmission mechanism T1. On the other hand, as the second temperature control medium TCM2, for example, cooling water called LLC (Long Life Coolant) is used.

[0040] The first temperature control circuit 61 is provided with first pumps 611a and 611b and a storage section 612. The first pump 611a is driven by the rotation of the engine ENG, and the first pump 611b is driven by the rotation of the axle DS of the vehicle V. The first pumps 611a and 611b are mechanical pumps that pump the first temperature control medium TCM1. That is, the rotation speed of the first pump 611a varies according to the rotation speed of the engine ENG, and the rotation speed of the first pump 611b varies according to the vehicle speed. The storage section 612 stores the first temperature control medium TCM1 circulating through the first temperature control circuit 61. The storage section 612 is, for example, an oil pan provided at the bottom of a housing (not shown) that accommodates the motor MOT1, the generator GEN, and the first speed change mechanism T1.

[0041] The first temperature control circuit 61 also has a pumping passage 610a in which two first pumps 611a, 611b are arranged in parallel, a first branch passage 610b1 in which a motor MOT1 and a generator GEN are provided, a second branch passage 610b2 in which a first speed change mechanism T1 is provided, and a branch section 613 that branches the pumping passage 610a into the first branch passage 610b1 and the second branch passage 610b2.

[0042] The pressure-feeding passage 610a has an upstream end connected to the storage section 612, and passes through first pumps 611a and 611b, and has a downstream end connected to the branch section 613. The first branch passage 610b1 has an upstream end connected to the branch section 613, and passes through the motor MOT1 and the generator GEN, and has a downstream end connected to the storage section 612. The second branch passage 610b2 has an upstream end connected to the branch section 613, and passes through the first speed change mechanism T1, and has a downstream end connected to the storage section 612.

[0043] In the first temperature control circuit 61, the heat exchanger 63 is disposed upstream of the motor MOT1 and the generator GEN in the first branch flow path 610b1. Therefore, in the first temperature control circuit 61, (i) a first flow path is formed in parallel in which the first temperature control medium TCM1 pumped from the first pumps 611a and 611b passes through the first branch flow path 610b1 from the branch portion 613, is cooled by heat exchange with the second temperature control medium TCM2 in the heat exchanger 63, is supplied to the motor MOT1 and the generator GEN to lubricate and regulate the temperature of the motor MOT1 and the generator GEN, and is then stored in the storage portion 612, and (ii) a second flow path is formed in parallel in which the first temperature control medium TCM1 passes through the second branch flow path 610b2 from the branch portion 613, is supplied to the first speed change mechanism T1 to lubricate and regulate the temperature of the first speed change mechanism T1, and is then stored in the storage portion 612. The first temperature control medium TCM1 stored in the storage unit 612 flows through the pressure-feeding flow path 610a and is supplied to the first pumps 611a and 611b, and circulates between the first flow path and the second flow path.

[0044] The first temperature control circuit 61 further includes a pressure control circuit 610c provided with a pressure control valve 619. The pressure control circuit 610c has an upstream end connected to the reservoir 612 and a downstream end connected to the pumping flow path 610a downstream of the first pumps 611a and 611b. The pressure control valve 619 may be a check valve or an electromagnetic valve such as a solenoid valve. When the liquid pressure of the first temperature control medium TCM1 pumped from the first pumps 611a and 611b reaches a predetermined pressure or higher, the pressure control valve 619 opens, and a portion of the first temperature control medium TCM1 pumped from the first pumps 611a and 611b is returned to the reservoir 612. As a result, the liquid pressure of the first temperature control medium TCM1 flowing through the first branch flow path 610b1 and the second branch flow path 610b2 is maintained at a predetermined pressure or lower.

[0045] The second temperature control circuit 62 is provided with a second pump 621, a radiator 622, and a storage tank 623. The second pump 621 is an electric pump that is driven by, for example, the power of a battery BAT or the power generated by a generator GEN, and pumps the second temperature control medium TCM2, and is controlled by a control device ECU. The flow rate of the second pump 621 increases by increasing the duty and decreases by decreasing the duty.

[0046] Further, a rotation speed sensor 621a is attached to the second pump 621 to detect the rotation speed of the second pump 621. The rotation speed sensor 621a outputs a detection signal indicating the detection value of the rotation speed of the second pump 621 to the control device ECU. The control device ECU can estimate the flow rate of the second pump 621 based on the detection value of the rotation speed sensor 621a, i.e., the rotation speed of the second pump 621.

[0047] The radiator 622 is disposed at the front of the vehicle V, and is a heat dissipation device that cools the second temperature control medium TCM2 by wind generated when the vehicle V is traveling. The storage tank 623 is a tank that temporarily stores the second temperature control medium TCM2 circulating through the second temperature control circuit 62. Even if cavitation occurs in the second temperature control medium TCM2 circulating through the second temperature control circuit 62, the second temperature control medium TCM2 circulating through the second temperature control circuit 62 is temporarily stored in the storage tank 623, so that the cavitation occurring in the second temperature control medium TCM2 disappears.

[0048] The second temperature control circuit 62 has a branching section 624 and a junction section 625. In the second temperature control circuit 62, a storage tank 623, a second pump 621, and a radiator 622 are provided in this order from the upstream side. The second temperature control circuit 62 further has a pressure-feeding flow path 620a. The upstream end of the pressure-feeding flow path 620a is connected to the junction section 625, and passes through the storage tank 623, the second pump 621, and the radiator 622, and is connected to the branching section 624 at the downstream end. The second temperature control medium TCM2 stored in the storage tank 623 is pressure-fed by the second pump 621 through the pressure-feeding flow path 620a, and is cooled by the radiator 622.

[0049] The second temperature adjustment circuit 62 further includes a first branch flow path 620b1 in which the power converter PCU is provided, and a second branch flow path 620b2 in which a heat exchanger 63 is provided and which is provided in parallel to the first branch flow path 620b1.

[0050] Specifically, the first branch flow path 620b1 has an upstream end connected to the branch section 624, passes through the power converter PCU, and has a downstream end connected to the junction section 625. The second branch flow path 620b2 has an upstream end connected to the branch section 624, passes through the heat exchanger 63, and has a downstream end connected to the junction section 625.

[0051] In this embodiment, a valve device 626 serving as a flow rate control valve for adjusting the flow rate of the second temperature control medium TCM2 flowing through the second branch flow path 620b2 (in other words, the flow rate of the second temperature control medium TCM2 flowing through the first branch flow path 620b1) is provided upstream of the heat exchanger 63 in the second branch flow path 620b2.

[0052] In this embodiment, the valve device 626 is an ON-OFF valve. That is, the valve device 626 fully opens the second branch flow path 620b2 when opened, and fully closes the second branch flow path 620b2 when closed. The valve device 626 is not limited to an ON-OFF valve, and may be a variable flow rate valve that can adjust the flow rate of the second temperature control medium TCM2 flowing through the second branch flow path 620b2. The valve device 626 is controlled by the control device ECU.

[0053] The second temperature control medium TCM2, which is pumped by the second pump 621 in the pumping passage 620a and cooled by the radiator 622, branches into a first branch passage 620b1 and a second branch passage 620b2 at the branching section 624. The second temperature control medium TCM2 flowing through the first branch passage 620b1 cools the power converter PCU and merges with the second branch passage 620b2 and the pumping passage 620a at the merging section 625. The second temperature control medium TCM2 flowing through the second branch passage 620b2 cools the first temperature control medium TCM1 by exchanging heat with the first temperature control medium TCM1 in the heat exchanger 63, and merges with the first branch passage 620b1 and the pumping passage 620a at the merging section 625. The second temperature control medium TCM2 that has flowed through the first branch flow path 620b1 and the second temperature control medium TCM2 that has flowed through the second branch flow path 620b2 join at the junction 625, flow through the pumping flow path 620a, and are temporarily stored in the storage tank 623. The second temperature control medium TCM2 stored in the storage tank 623 is then supplied again to the second pump 621 through the pumping flow path 620a, and the second temperature control medium TCM2 circulates through the second temperature control circuit 62.

[0054] As an example, in the first temperature control circuit 61, if the temperature of the first temperature control medium TCM1 stored in the storage section 612 after cooling the motor MOT1, the generator GEN, and the first transmission mechanism T1 is approximately 100 [°C], then the first temperature control medium TCM1 of approximately 100 [°C] is supplied to the heat exchanger 63.

[0055] On the other hand, in the second temperature control circuit 62, if the temperature of the second temperature control medium TCM2 cooled by the radiator 622 is approximately 40°C, the second temperature control medium TCM2 supplied to the heat exchanger 63 does not pass through the power conversion unit PCU, which is the temperature-controlled device, and therefore the second temperature control medium TCM2 of approximately 40°C is supplied to the heat exchanger 63.

[0056] In this case, the heat exchanger 63 exchanges heat between the first temperature control medium TCM1 of about 100° C. and the second temperature control medium TCM2 of about 40° C., both of which are supplied to the heat exchanger 63. Then, for example, the first temperature control medium TCM1 of about 80° C. is discharged from the heat exchanger 63 to the downstream side of the first branch flow path 610b1 in the first temperature control circuit 61, and the second temperature control medium TCM2 of about 70° C. is discharged to the downstream side of the second branch flow path 620b2 in the second temperature control circuit 62.

[0057] In this way, the first temperature control medium TCM1 is cooled by the heat exchanger 63, so that the first temperature control medium TCM1 can be cooled without providing a separate radiator for cooling the first temperature control medium TCM1 in the temperature control circuit 60. Therefore, the temperature control circuit 60 can cool the first temperature control medium TCM1 flowing through the first temperature control circuit 61 and the second temperature control medium TCM2 flowing through the second temperature control circuit 62 with one radiator 622, so that the temperature control circuit 60 can be made compact.

[0058] 3, the power converter PCU is provided in the first branch flow path 620b1 between the branch portion 624 and the junction portion 625, and the heat exchanger 63 is provided in the second branch flow path 620b2 in parallel with the power converter PCU, but this is not limited thereto. For example, as shown in FIG. 8, the storage tank 623, the second pump 621, the radiator 622, the power converter PCU, and the heat exchanger 63 may be provided in the pressure-feed flow path 620a, and the power converter PCU and the heat exchanger 63 may be provided in series.

[0059] [Control device] Next, a specific example of control by the control unit ECU will be described. First, the control of the main drive unit DU1 by the control unit ECU will be described.

[0060] When the vehicle V runs, the control device ECU derives a required driving force (in other words, a driving force required for running the vehicle V) which is a target value for the driving force of the vehicle V, based on the vehicle speed detected by the vehicle speed sensor and the AP opening degree detected by the accelerator pedal sensor. Then, the control device ECU controls the output from the main drive unit DU1 so that the driving force of the vehicle V becomes the required driving force.

[0061] In this embodiment, the control device ECU is configured to be able to drive the main drive unit DU1 in a plurality of drive modes described below, and drives the vehicle V while appropriately switching the drive mode of the main drive unit DU1. This makes it possible to drive the vehicle V in an appropriate drive mode according to the state of the vehicle V.

[0062] <<1. EV driving mode>> The EV driving mode is a drive mode in which power from the battery BAT is supplied to the motor MOT1, and the vehicle V is driven by the power output by the motor MOT1 in response to this power.

[0063] In the EV driving mode, the output of power from the engine ENG is stopped, no power is input to the generator GEN, and no power is generated by the generator GEN.

[0064] <<2. Hybrid driving mode>> The hybrid driving mode is a drive mode in which at least electric power generated by the generator GEN is supplied to the motor MOT1, and the vehicle V is driven by power output by the motor MOT1 in response to this electric power.

[0065] In the hybrid driving mode, the control unit ECU injects fuel into the engine ENG, inputs power from the engine ENG to the generator GEN, and generates power using the generator GEN. The control unit ECU supplies the electric power generated by the generator GEN to the motor MOT1, and causes the motor MOT1 to output power corresponding to this electric power.

[0066] In the hybrid driving mode, the control unit ECU can also supply electric power from the battery BAT to the motor MOT1 as necessary. That is, in the hybrid driving mode, the control unit ECU can supply electric power from both the generator GEN and the battery BAT to the motor MOT1.

[0067] <<3. Engine driving mode>> The engine driving mode is a drive mode in which the power output by the engine ENG is transmitted to the front wheels FWR through the power transmission path of the first transmission mechanism T1 to cause the vehicle V to travel.

[0068] In the engine drive mode, when the vehicle V is braked, regenerative power may be generated by the motor MOT1, and the battery BAT may be charged with the generated power.

[0069] In addition, in the engine running mode, the control device ECU can supply electric power from the battery BAT to the motor MOT1 as necessary. As a result, in the engine running mode, the vehicle V can be run using the power output by the motor MOT1 using the electric power supplied from the battery BAT.

[0070] The vehicle V has a fuel-saving control mode that prioritizes fuel efficiency and a normal mode that consumes more power than the fuel-saving control mode. In the fuel-saving control mode, the outputs of the engine ENG and the motor MOT1 are limited, and the flow rate of the second pump 621 is also limited to a low flow rate.

[0071] [Control of temperature control circuit] Next, a description will be given of the control of the temperature adjustment circuit 60 by the control unit ECU. Fig. 4 is a diagram showing a control logic in the flow rate control of the second pump 621 by the control unit ECU.

[0072] As shown in FIG. 4, the control device ECU controls the flow rate of the second pump 621 based on the temperature of the first temperature control medium TCM1 (ATF oil temperature in the figure), the temperature of the second temperature control medium TCM2 (LLC water temperature in the figure), and the temperatures of the chip-shaped switching elements built into the first inverter INV1, the second inverter INV2, and the converter VCU (chip temperatures in the figure; hereinafter also referred to as chip temperatures).

[0073] More specifically, the control device ECU controls the flow rate of the second pump 621 based on the largest duty request among the temperature of the first temperature control medium TCM1 (ATF oil temperature), the temperature of the second temperature control medium TCM2 (LLC water temperature), and the chip temperature. A threshold temperature is set for each temperature, and the temperature is controlled to output a low duty (Duty_L) request when the temperature is below the threshold temperature, and is controlled to output a high duty (Duty_H) request when the temperature is equal to or higher than the threshold temperature. For example, the temperature of the second temperature control medium TCM2 (LLC water temperature) is controlled to output a low duty (Duty_L) request when the temperature is below the upper limit water temperature Tw1, and is controlled to output a high duty (Duty_H) request when the temperature is equal to or higher than the upper limit water temperature Tw1. When the control unit ECU drives the second pump 621 at a low duty (Duty_L), the second pump 621 drives at a basic rotation speed, and when the control unit ECU drives the second pump 621 at a high duty (Duty_H), the second pump 621 drives at a rotation speed higher than the basic rotation speed.

[0074] Here, the first temperature control medium TCM1 has a much larger heat capacity than the second temperature control medium TCM2 (for example, 10 times larger). Also, the chip temperature momentarily increases in heat generation (loss) during strong regeneration when the regenerative torque is large and during WOT (Wide-Open-Throttle) when the accelerator opening is at its maximum in the EV driving mode and the hybrid driving mode. Therefore, it is considered that the control device ECU controls the flow rate of the second pump 621 based only on the temperature (LLC water temperature) and chip temperature of the second temperature control medium TCM2, which has a smaller heat capacity.

[0075] Fig. 5 is a graph showing the effect of the temperature of the second temperature control medium TCM2 (LLC water temperature) on the temperature of the first temperature control medium TCM1 (ATF oil temperature) when changing the flow rate (LLC flow rate) of the second pump 621. The vertical axis of Fig. 5 is the temperature of the second temperature control medium TCM2 (LLC water temperature), the horizontal axis is the flow rate (LLC flow rate) of the second pump 621, and the solid lines show the change in the temperature of the second temperature control medium TCM2 (LLC water temperature) at three types of temperatures of the first temperature control medium TCM1 (low oil temperature, medium oil temperature, high oil temperature).

[0076] For example, the bottom solid line indicates the transition of the temperature of the second temperature control medium TCM2 (LLC water temperature) that changes with the flow rate (LLC flow rate) of the second pump 621 when the temperature of the first temperature control medium TCM1 is a low oil temperature.

[0077] As shown in FIG. 5, regardless of the temperature of the first temperature control medium TCM1 (ATF oil temperature), when the second pump 621 is increased from low duty (Duty_L) to high duty (Duty_H) to increase the flow rate (LLC flow rate) of the second pump 621, heat exchange between the first temperature control medium TCM1 and the second temperature control medium TCM2 in the heat exchanger 63 is promoted, and the temperature of the second temperature control medium TCM2 (LLC water temperature) rises.

[0078] On the other hand, when the temperature (ATF oil temperature) of the first temperature control medium TCM1 is different, the effect on the temperature (LLC water temperature) of the second temperature control medium TCM2 is also different. That is, when the temperature (ATF oil temperature) of the first temperature control medium TCM1 is low, the temperature (LLC water temperature) of the second temperature control medium TCM2 can be maintained below the upper limit water temperature Tw1 even if the duty is increased. On the other hand, when the temperature (ATF oil temperature) of the first temperature control medium TCM1 is medium oil temperature, increasing the duty causes the temperature (LLC water temperature) of the second temperature control medium TCM2 to rise to the vicinity of the upper limit water temperature Tw1. Furthermore, when the temperature (ATF oil temperature) of the first temperature control medium TCM1 is high oil temperature, increasing the duty causes the temperature (LLC water temperature) of the second temperature control medium TCM2 to exceed the upper limit water temperature Tw1.

[0079] Due to the difference in heat capacity between the first temperature control medium TCM1 and the second temperature control medium TCM2, immediately after changing the duty of the second pump 621, the temperature of the first temperature control medium TCM1 (ATF oil temperature) does not change immediately, and the temperature of the second temperature control medium TCM2 (LLC water temperature) reacts abruptly, which may exceed the upper limit of the management water temperature Tw1. For example, when the temperature of the second temperature control medium TCM2 (LLC water temperature) is lower than the upper limit of the management water temperature Tw1 and the chip temperature exceeds a predetermined threshold temperature, the control device ECU increases the duty of the second pump 621 to increase the flow rate, but if the temperature of the first temperature control medium TCM1 (ATF oil temperature) is a high oil temperature at this time, the temperature of the second temperature control medium TCM2 (LLC water temperature) will exceed the upper limit of the management water temperature Tw1 immediately after the duty is increased.

[0080] Therefore, the control unit ECU controls the flow rate of the second pump 621 based on the temperature of the first temperature control medium TCM1 (ATF oil temperature) in addition to the temperature of the second temperature control medium TCM2 (LLC water temperature) and the chip temperature.

[0081] 6 is a graph showing the relationship between the temperature of the second temperature control medium TCM2 (LLC water temperature) and the temperature of the first temperature control medium TCM1 (ATF oil temperature). In the figure, the dashed line indicates the case where the second pump 621 is driven at a low duty (Duty_L), and the dashed line indicates the case where the second pump 621 is driven at a high duty (Duty_H).

[0082] The water temperature reached by the second temperature control medium TCM2 due to overshoot is determined by three factors: the amount of ATF heat dissipation determined by the ATF oil temperature and ATF flow rate, the amount of radiator heat dissipation determined by the air temperature and air speed, and the amount of PCU loss. Figure 6 assumes the worst conditions (the most unfavorable conditions for the temperature of the second temperature control medium TCM2 (LLC water temperature)) for the ATF flow rate, air temperature, air speed, and PCU loss.

[0083] From FIG. 6, it can be seen that in order to maintain the temperature of the second temperature control medium TCM2 (LLC water temperature) at the upper limit of management water temperature Tw1, the duty of the second pump 621 should be increased to increase the flow rate while the temperature of the first temperature control medium TCM1 (ATF oil temperature) is equal to or lower than the duty-up threshold value To1. Conversely, in a situation where the temperature of the first temperature control medium TCM1 (ATF oil temperature) exceeds the duty-up threshold value To1, under the worst conditions, the temperature of the second temperature control medium TCM2 (LLC water temperature) will exceed the upper limit of management water temperature Tw1 immediately after the duty is increased. In other words, if the temperature of the first temperature control medium TCM1 (ATF oil temperature) is kept at the duty-up threshold value To1 and the duty of the second pump 621 is increased to increase the flow rate, no overshoot of the temperature of the second temperature control medium TCM2 (LLC water temperature) will occur under any conditions.

[0084] FIG. 7 is a diagram showing the relationship between the required duty and the temperature of the first temperature control medium TCM1 (ATF oil temperature). The required duty according to the temperature (ATF oil temperature) of the first temperature control medium TCM1 is set to a low duty (Duty_L) when the temperature is less than the duty-up threshold To1, and is set to a high duty (Duty_H) when the temperature is equal to or greater than the duty-up threshold To1, as described with reference to Fig. 6. Therefore, when the temperature (ATF oil temperature) of the first temperature control medium TCM1 becomes equal to or greater than the duty-up threshold To1, the control device ECU raises the duty of the second pump 621 to increase the flow rate.

[0085] The duty-up threshold value To1 is a value lower than the upper limit oil temperature To2 of the temperature (ATF oil temperature) of the first temperature control medium TCM1 shown in FIG. 7. That is, the control of the flow rate of the second pump 621 based on the temperature (ATF oil temperature) of the first temperature control medium TCM1 is not for protecting the temperature (ATF oil temperature) of the first temperature control medium TCM1, but for protecting the temperature (LLC water temperature) of the second temperature control medium TCM2 from a sudden temperature rise of the temperature (LLC water temperature) of the second temperature control medium TCM2. In this way, when the temperature (ATF oil temperature) of the first temperature control medium TCM1 becomes equal to or higher than the duty-up threshold value To1, the flow rate of the second pump 621 is increased to suppress an overshoot at the moment when the flow rate of the second temperature control medium TCM2 is changed. In addition, by suppressing the rise in water temperature when the flow rate of the second temperature control medium TCM2 increases, the chip size of the radiator 622 and the switching elements of the power conversion unit PCU can be designed based on the water temperature reached at temperature saturation, thereby reducing costs and improving layout freedom.

[0086] Moreover, this duty-up threshold value To1 is set to a temperature higher than the maximum achievable temperature in the fuel-saving control mode (in the figure, fuel-saving control mode oil temperature To3). Therefore, while the vehicle V is running in the fuel-saving control mode, an increase in the flow rate of the second pump 621 and an increase in the power consumption of the second pump 621 are suppressed.

[0087] Furthermore, control of the flow rate of the second pump 621 based on the temperature of the first temperature control medium TCM1 (ATF oil temperature) is prohibited during idling stop of the vehicle V, i.e., when the rotation speeds of the motor MOT1 and the generator GEN are equal to or lower than predetermined values. That is, the control device ECU prohibits an increase in the flow rate of the second pump 621 based on the temperature of the first temperature control medium TCM1 (ATF oil temperature) during idling stop.

[0088] If the flow rate of the second pump 621 is increased according to the temperature of the first temperature control medium TCM1 (ATF oil temperature), when the first temperature control medium TCM1 is high temperature and background noise is low, the driving noise of the second pump 621 becomes an issue. The driving noise of the second pump 621 is small compared to driving noise and engine noise, so it does not become an issue while driving or while the engine is running, but if the vehicle is stopped or the engine is stopped immediately after the temperature of the first temperature control medium TCM1 increases during high-speed driving, a situation may arise in which the driving noise of the second pump 621 becomes noticeable.

[0089] However, in an idling stop state, the first pump 611a linked to the engine ENG and the first pump 611b linked to the vehicle speed are also stopped, so the flow rate of the first temperature control medium TCM1 becomes zero, and the amount of heat dissipated in the heat exchanger 63 becomes almost zero regardless of the flow rate of the second temperature control medium TCM2, so no overshoot of the second temperature control medium TCM2 occurs whenever the flow rate is increased. For this reason, by prohibiting an increase in the flow rate of the second pump 621 based on the temperature of the first temperature control medium TCM1 during idling stop, the noise problem can be avoided.

[0090] Although the embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can come up with various modified or amended examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention. In addition, the components in the above embodiment may be arbitrarily combined within the scope of the invention.

[0091] For example, in the above-described embodiment, the main drive unit DU1 drives the front wheels FWR, but the main drive unit DU1 may drive the rear wheels RWR.

[0092] In the above embodiment, the engine ENG is provided in the main drive unit DU1, and the vehicle V is a hybrid electric vehicle, but this is not limited to this. For example, the engine ENG may not be provided in the main drive unit DU1, and the vehicle V may be an electric vehicle.

[0093] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and modifications, improvements, etc. are possible as appropriate.

[0094] This specification describes at least the following items. Note that, in parentheses, components corresponding to those in the above-mentioned embodiment are shown, but the present invention is not limited to these.

[0095] (1) A battery (battery BAT), A motor (motor MOT1) and a power conversion unit (power conversion unit PCU) disposed on a power transmission path between the battery and the motor; a temperature control system (temperature control circuit 60) that adjusts the temperature of the motor and the power conversion device; A vehicle (vehicle V) including a control device (control device ECU) that controls the temperature adjustment system, The temperature control system includes: a first temperature control circuit (first temperature control circuit 61) that circulates a first temperature control medium (first temperature control medium TCM1) by a first pump (first pumps 611a, 611b) to cool the motor; a second temperature control circuit (second temperature control circuit 62) including a second pump (second pump 621) and a radiator (radiator 622), and circulating a second temperature control medium (second temperature control medium TCM2) by the second pump to cool the power conversion device; a heat exchanger (heat exchanger 63) for exchanging heat between a first temperature medium of the first temperature control circuit and a second temperature control medium of the second temperature control circuit; The control device includes: When the temperature of the first temperature control medium becomes equal to or higher than a predetermined value, the flow rate of the second pump is increased.

[0096] In an integrated cooling system in which heat is exchanged between a first temperature medium in a first temperature control circuit and a second temperature control medium in a second temperature control circuit, and a radiator provided in the second temperature control circuit dissipates heat from a motor and a power conversion device, a phenomenon (overshoot) may occur in which the water temperature of the second temperature control medium at the moment the flow rate of the second temperature control medium is changed becomes higher than the water temperature at the temperature saturation. According to (1), instead of increasing the flow rate of the second pump based on the first temperature control medium to protect the first temperature control medium, the flow rate of the second pump is increased based on the temperature of the first temperature control medium to protect the temperature of the second temperature control medium from a sudden temperature rise of the second temperature control medium at the time of a change in the rotation speed of the second pump caused by a difference in heat capacity between the first temperature control medium and the second temperature control medium. This makes it possible to suppress an overshoot at the moment the flow rate of the second temperature control medium is changed. In addition, by suppressing the water temperature rise when the flow rate of the second temperature control medium is increased, the chip size of the radiator and the switching element of the power conversion device can be designed based on the water temperature reached at the time of temperature saturation, which can reduce costs and improve the layout freedom.

[0097] (2) A vehicle as described in (1), The first pump has a rotation speed that varies depending on the vehicle speed, the second pump has a basic rotation speed set according to the temperature of the second temperature control medium; The control device drives the second pump at a rotation speed higher than the basic rotation speed when a temperature of the first temperature control medium becomes equal to or higher than a predetermined value.

[0098] According to (2), by rotating the second pump at the basic rotation speed during normal operation, the power consumption and driving noise of the second pump can be suppressed. On the other hand, by increasing the rotation speed of the second pump from the basic rotation speed as necessary, the temperature of the internal parts of the power conversion device, the temperature of the second temperature control medium, the temperature of the internal parts of the motor, the temperature of the first temperature control medium, etc. can be maintained at their respective control temperatures.

[0099] (3) A vehicle as described in (2), The predetermined value is a temperature lower than a management upper limit temperature (management upper limit oil temperature To2) of the first temperature medium.

[0100] According to (3), by controlling the second pump so as to increase the flow rate at a temperature lower than the upper limit temperature management of the first temperature medium, overshooting of the second temperature control medium can be suppressed.

[0101] (4) A vehicle as described in (1), A fuel-saving control mode that prioritizes fuel efficiency and a normal mode that is less efficient than the fuel-saving control mode, The predetermined value is set to a value that is not reached in the fuel saving control mode.

[0102] According to (4), the temperature of the first temperature control medium that increases the flow rate of the second pump is set to a value that is not reached in the fuel-saving control mode, so that an increase in the flow rate of the second pump and an increase in the power consumption of the second pump are suppressed while driving in the fuel-saving control mode.

[0103] (5) A vehicle as described in (2), The control device prohibits an increase in the flow rate of the second pump based on the temperature of the first temperature control medium during an idling stop.

[0104] According to (5), when the flow rate of the second pump is increased according to the temperature of the first temperature control medium, the driving noise of the second pump becomes an issue when the first temperature control medium is at a high temperature and the background noise is low. The driving noise of the second pump is small compared to the driving noise and the engine noise, so it is not an issue while driving or the engine is running. However, if the vehicle is stopped or the vehicle is stopped idling immediately after the temperature of the first temperature control medium increases during high-speed driving, the driving noise of the second pump may become noticeable. However, if the vehicle is in an idling stop state, the oil pump linked to the vehicle speed is also stopped, so the flow rate of the first temperature control medium becomes zero, and the amount of heat dissipated in the heat exchanger is almost zero regardless of the flow rate of the second temperature control medium. Therefore, no overshoot of the second temperature control medium occurs no matter when the flow rate is increased. For this reason, the noise issue can be avoided by prohibiting the increase in the flow rate of the second pump based on the temperature of the first temperature control medium during idling stop. [Explanation of symbols]

[0105] 60 Temperature control circuit (temperature control system) 61 1st temperature control circuit 62 2nd temperature control circuit 63 Heat exchanger 611a, 611b First pump 621 Second Pump 622 Radiator BAT Battery ECU Control Unit MOT1 motor PCU Power conversion unit TCM1 1st temperature control medium TCM2 Second temperature control medium To2 Management upper limit oil temperature (Management upper limit temperature) V Vehicle

Claims

1. A battery; A motor; a power conversion device disposed on a power transmission path between the battery and the motor; a temperature control system for controlling temperatures of the motor and the power conversion device; A vehicle comprising: a control device for controlling the temperature adjustment system; The temperature control system includes: a first temperature control circuit that circulates a first temperature control medium by a first pump to cool the motor; a second temperature control circuit including a second pump and a radiator, the second pump circulating a second temperature control medium to cool the power conversion device; a heat exchanger for exchanging heat between a first temperature medium of the first temperature control circuit and a second temperature control medium of the second temperature control circuit; The control device includes: When the temperature of the first temperature control medium becomes equal to or higher than a predetermined value, the flow rate of the second pump is increased.

2. 2. A vehicle as claimed in claim 1, The first pump has a rotation speed that varies depending on a vehicle speed, the second pump has a basic rotation speed set in accordance with a temperature of the second temperature control medium, The control device drives the second pump at a rotation speed higher than the basic rotation speed when a temperature of the first temperature control medium becomes equal to or higher than a predetermined value.

3. 3. A vehicle according to claim 2, The predetermined value is a temperature lower than an upper limit temperature control temperature of the first temperature medium.

4. 2. A vehicle as claimed in claim 1, A fuel-saving control mode that prioritizes fuel efficiency and a normal mode that is less efficient than the fuel-saving control mode, The predetermined value is set to a value that is not reached in the fuel saving control mode.

5. 3. A vehicle according to claim 2, The control device prohibits an increase in the flow rate of the second pump based on the temperature of the first temperature control medium during an idling stop.

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