JP2012162132A - Power output apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set a temperature of transmission oil for adjusting a temperature of a motor to a satisfactory temperature according to a situation in a power output apparatus including an engine and the motor.SOLUTION: The power output apparatus 20 includes: the engine 22 that is cooled by engine cooling water; motors MG1, MG2 where temperatures are adjusted by heat exchange with the transmission oil; a transaxle 25 having a power control unit 45 or the like; and a heat exchanger 207 that can perform heat exchange between the engine cooling water and the transmission oil. The execution and halt of heat exchange between the engine cooling water and the transmission oil in the heat exchanger 207 may be switched according to the temperatures of the transmission oil and the engine cooling water.

Description

  The present invention includes an engine, an electric motor capable of outputting power, engine cooling means for cooling the engine with engine cooling water, and motor temperature adjusting means for adjusting the temperature of the electric motor by exchanging heat between the electric motor and transmission oil. It is related with the power output device containing.

  Conventionally, a hybrid vehicle including an engine cooled by engine cooling water, a motor capable of outputting driving power, a mechanical oil pump that supplies lubricating cooling oil for lubricating and cooling the motor, and an electric oil pump Is known (see, for example, Patent Document 1). In this hybrid vehicle, when it is determined that any of in-vehicle elements such as lubricating cooling oil, an inverter that drives a motor, a motor, and engine cooling water is in a high temperature state, the upper limit vehicle speed Vlim that is a practical maximum vehicle speed is The vehicle speed is limited to a second vehicle speed V2 lower than the first vehicle speed V1, which is the maximum practical vehicle speed when any of the vehicle-mounted elements is not in a high temperature state. As a result, the temperature increase of the target vehicle-mounted element is suppressed by suppressing the increase in the vehicle speed V, and the driving torque is clearly felt by the driver during high-speed cruising by suppressing the practical maximum vehicle speed itself. It can suppress that it falls so much.

JP 2009-190511 A

  In the conventional hybrid vehicle, the temperature rise of the lubricating cooling oil for cooling the motor can be suppressed by limiting the upper limit vehicle speed Vlim. However, in order to set the motor temperature more appropriately and further improve the energy efficiency of the hybrid vehicle, the lubricating cooling oil should be set to a suitable temperature according to the situation.

  In view of this, the main object of the present invention is to enable the temperature of transmission oil for adjusting the temperature of the motor to be set to a suitable temperature according to the situation in a power output device including an engine and an electric motor.

  The power output apparatus according to the present invention adopts the following means in order to achieve the main object.

The power output device according to the present invention is:
An engine, an electric motor capable of outputting power, engine cooling means for cooling the engine with engine cooling water, and electric motor temperature adjusting means for adjusting the temperature of the electric motor by exchanging heat between the electric motor and transmission oil. In the power output device,
A heat exchanger capable of exchanging heat between the engine coolant and the transmission oil, and heat exchange between the engine coolant and the transmission oil in the heat exchanger according to a temperature of the transmission oil; It is characterized in that it can be switched between execution and stop.

  The power output device includes an engine cooled by engine cooling water and an electric motor whose temperature is adjusted by heat exchange with transmission oil, and a heat exchanger capable of exchanging heat between engine cooling water and transmission oil. Have The execution and stop of heat exchange between the engine coolant and the transmission oil in the heat exchanger can be switched according to the temperature of the transmission oil. In this way, the heat exchanger performs heat exchange between the engine coolant and the transmission oil according to the temperature of the transmission oil, or stops the heat exchange between the two to adjust the temperature of the electric motor. It becomes possible to set the temperature of the transmission oil to a suitable temperature according to the situation.

It is a schematic block diagram of the hybrid vehicle 10 provided with the power output device 20 which concerns on the Example of this invention. It is a schematic block diagram which shows the power output device 20 of an Example. It is a flowchart which shows an example of the oil temperature adjustment routine performed by motor ECU40 of an Example. It is a schematic block diagram which shows the power output device 20B which concerns on a modification. It is a schematic block diagram which shows 20 C of power output devices which concern on another modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a schematic configuration diagram of a hybrid vehicle 10 including a power output apparatus 20 according to an embodiment of the present invention. A hybrid vehicle 10 shown in the figure includes an engine (internal combustion engine) 22 that outputs power using a hydrocarbon-based fuel such as gasoline and light oil, and a transaxle 25 that constitutes the power output device 20 of the embodiment together with the engine 22. With. As shown in the figure, the transaxle 25 supports a sun gear (first element) 31, a ring gear (second element) 32 connected to a ring gear shaft 32a as a drive shaft, and a plurality of pinion gears 33, and via a damper 28. A single-pinion planetary gear 30 having a planetary carrier (third element) 34 connected to a crankshaft (output shaft) 26 of the engine 22 and a motor that is connected to the sun gear 31 of the planetary gear 30 and mainly operates as a generator. MG1, motor MG2 connected to ring gear 32 through reduction gear mechanism 35 and ring gear shaft 32a and inputting / outputting power to / from ring gear shaft 32a, and coupled to ring gear shaft 32a through gear mechanism 37 and differential gear 38. Wheel 39a, which is a drive wheel, And a 9b.

  Further, hybrid vehicle 10 includes an engine electronic control unit (hereinafter referred to as “engine ECU”) 24 that controls engine 22, a power control unit 45 that includes inverters 41, 42 for driving motors MG 1, MG 2, and the like. , A battery 50 which is a lithium ion secondary battery or nickel hydride secondary battery connected to inverters 41 and 42, and a motor for driving and controlling motors MG1 and MG2 via a power control unit 45 (inverters 41, 42, etc.) An electronic control unit (hereinafter referred to as “motor ECU”) 40, a battery electronic control unit (hereinafter referred to as “battery ECU”) 52 for managing the battery 50, and a hybrid electronic control unit (hereinafter referred to as “battery ECU”). 7) “Hybrid ECU” Provided with a door. The engine ECU 24, the motor ECU 40, the battery ECU 52, and the hybrid ECU 70 are all configured as a microcomputer centered on a CPU (not shown).

  The engine ECU 24 is provided for the engine 22 such as a cooling water temperature sensor 23 that detects a cooling water temperature Tw that is a temperature of engine cooling water (cooling medium) for cooling the engine 22 such as LLC (long life coolant). In addition to inputting signals from various sensors that detect the operating state of the engine 22, a control signal for controlling the intake air amount, fuel injection amount, ignition timing, and the like of the engine 22 is output. Motor ECU 40 inputs signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of motors MG1 and MG2, phase currents applied to motors MG1 and MG2 detected by a current sensor (not shown), and the like. Then, based on the signals from the rotational position detection sensors 43 and 44, the rotational speeds Nm1 and Nm2 of the rotors of the motors MG1 and MG2 are calculated and a switching control signal and the like to the inverters 41 and 42 are output. The battery ECU 52 inputs the voltage between terminals of the battery 50, the charge / discharge current, the battery temperature Tb, etc., and also the remaining capacity (charge ratio) SOC of the battery 50, the charge / discharge required power Pb *, the charge allowable power Win, the discharge allowable power. The power Wout and the like are calculated. The hybrid ECU 70 detects the shift range SR from the shift range sensor 82 that detects the ignition signal from the ignition switch (start switch) 80, the shift range SR corresponding to the operation position (shift position) of the shift lever 81, and the depression of the accelerator pedal 83. Input the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the amount (accelerator operation amount), the vehicle speed V from the vehicle speed sensor 87, etc., and control the entire vehicle based on these data and signals from other ECUs To do.

  As shown in FIG. 2, the power output apparatus 20 of the embodiment lubricates the engine cooling system 100 that cools the engine 22 with engine cooling water, the transaxle 25, and the temperatures of the transaxle 25 and the power control unit 45. And a hybrid lubrication temperature control system 200 for adjusting the pressure. The engine cooling system 100 includes a circulation flow path 101 that forms a circulation path of engine cooling water including a heat exchange portion formed in a cylinder block or a cylinder head of the engine 22 in the middle, and engine cooling water in the circulation flow path 101. A mechanical or electric water pump 102 that circulates the engine, a radiator 103 that cools engine cooling water by outside air, and a thermostat 104 that is incorporated in the circulation passage 101 so as to be positioned between the engine 22 and the radiator 103. And a bypass channel 105 that is connected to the thermostat 104 and merges with the circulation channel 101 at a junction between the cooling water inlet of the radiator 103 and the water pump 102.

  The hybrid lubrication temperature control system 200 is a mechanical oil pump that is driven by the engine 22 when the engine 22 is in operation and pressure-transmits transmission oil (ATF) from an oil pan 201 disposed under the case of the transaxle 25. 202, an electric oil pump 203 that is driven and controlled by the motor ECU 40 when the operation of the engine 22 is stopped, and pumps transmission oil (ATF) from the oil pan 201, and is formed in the case of the transaxle 25. Gears such as the motors MG1 and MG2, the planetary gear 30, the gear mechanism 37, and the like of the power control unit 45 that are lubricated and temperature controlled are transmission oil pumped by the mechanical oil pump 202 or the electric oil pump 203. The oil flow path 204 that leads to the side and the oil flow at the junction at the downstream side of the discharge outlet of the mechanical oil pump 202 and the electric oil pump 203 and the oil flow at the junction at the downstream side of the branch section. A bypass flow path 205 that merges with the path 204, an electromagnetic valve (open / close valve) 206 that is incorporated in the middle of the bypass flow path 205 and controlled to be opened and closed by the motor ECU 40, and a bypass flow that is positioned downstream of the electromagnetic valve 206. And a heat exchanger 207 incorporated in the passage 205. In the embodiment, the heat exchanger 207 is configured to exchange heat between the transmission oil pumped by the mechanical oil pump 202 or the electric oil pump 203 and the engine cooling water radiated by the radiator 103 of the engine cooling system 100. ing. As shown in the figure, an oil temperature sensor 208 for detecting the temperature of transmission oil in the oil pan 201 is installed in the oil pan 201, and the oil temperature Toil detected by the oil temperature sensor 208 is And sent to the motor ECU 40.

  In the hybrid lubrication temperature control system 200 configured as described above, when the electromagnetic valve 206 is closed, the transmission oil pumped by the mechanical oil pump 202 or the electric oil pump 203 is transmitted to the motor via the oil passage 204. MG1 and MG2, planetary gear 30, gears 37 and other gears are guided to the periphery of the power control unit 45 and exchange heat with these lubrication / temperature control objects. Flow down to pan 201. When the electromagnetic valve 206 is opened, at least a part of transmission oil pumped by the mechanical oil pump 202 or the electric oil pump 203 is guided to the heat exchanger 207 via the bypass flow path 205, Transmission oil that has exchanged heat with engine coolant in the heat exchanger 207 is guided to the periphery of the power control unit 45 and the gears such as the motors MG1 and MG2, the planetary gear 30, and the gear mechanism 37 via the oil flow path 204. Also in this case, the transmission oil that has exchanged heat with the lubrication / temperature control target flows down to the oil pan 201.

  Next, the procedure for adjusting the temperature of the transmission oil in the power output apparatus 20 of the embodiment will be described with reference to FIG. FIG. 3 is a flowchart illustrating an example of an oil temperature adjustment routine that is repeatedly executed by the motor ECU 40 at predetermined intervals in order to adjust the temperature of the transmission oil.

  At the start of the routine of FIG. 3, the CPU (not shown) of the motor ECU 40 inputs necessary data such as the oil temperature Toil from the oil temperature sensor 208 and the engine coolant temperature, that is, the coolant temperature Tw (step S100). The coolant temperature Tw is detected by the coolant temperature sensor 23 and transmitted from the engine ECU 24. As the oil temperature Toil, an estimated value derived based on the temperatures of the motors MG1 and MG2, for example, may be used instead of the actual value detected by the oil temperature sensor 208. After the data input process in step S100, it is determined whether or not the input oil temperature Toil is lower than a predetermined reference temperature Tref (step S110). The reference temperature Tref is determined in advance through experiments and analysis as a lower limit value of the oil temperature Toil when heating of the transmission oil is not required. If it is determined in step S110 that the oil temperature Toil is lower than the reference temperature Tref, it is further determined whether or not the oil temperature Toil is lower than the cooling water temperature Tw input in step S100 (step S120).

  When the oil temperature Toil is lower than the coolant temperature Tw, the motor MG1 is used after at least a part of the transmission oil pumped by the mechanical oil pump 202 or the electric oil pump 203 exchanges heat with the engine coolant in the heat exchanger 207. , MG2, etc., the solenoid valve 206 is opened so as to be supplied to the target for lubrication / temperature control (step S130), and this routine is temporarily terminated. As a result, the transmission oil can be heated (heated up) using the heat exchanger 207 as an oil warmer using engine coolant as a heat source. On the other hand, when the oil temperature Toil is equal to or higher than the cooling water temperature Tw, the transmission oil pumped by the mechanical oil pump 202 or the electric oil pump 203 does not exchange heat with the engine cooling water in the heat exchanger 207. The electromagnetic valve 206 is closed so that the motors MG1 and MG2 and the like are supplied to the lubrication and temperature control targets (step S140), and this routine is temporarily terminated.

  If it is determined in step S110 that the oil temperature Toil is equal to or higher than the reference temperature Tref, it is further determined whether or not the oil temperature Toil exceeds the coolant temperature Tw input in step S100 (step S150). ). When the oil temperature Toil exceeds the cooling water temperature Tw, at least a part of the transmission oil pumped by the mechanical oil pump 202 or the electric oil pump 203 exchanges heat with the engine cooling water by the heat exchanger 207. The electromagnetic valve 206 is opened (step S130) so that the motor MG1 and MG2 and the like are supplied to the lubrication and temperature control targets later, and this routine is temporarily terminated. This makes it possible to cool (lower the temperature of) the transmission oil using the heat exchanger 207 as an oil cooler using engine cooling water as a heat source (cold heat source). In contrast, when the oil temperature Toil is equal to or lower than the cooling water temperature Tw, the transmission oil pumped by the mechanical oil pump 202 or the electric oil pump 203 does not exchange heat with the engine cooling water in the heat exchanger 207. The electromagnetic valve 206 is closed so that the motors MG1 and MG2 and the like are supplied to the lubrication and temperature control targets (step S140), and this routine is temporarily terminated.

  As described above, the power output apparatus 20 according to the embodiment includes the engine 22 that is cooled by the engine coolant, the motors MG1 and MG2 that are temperature-controlled by heat exchange with the transmission oil, the power control unit 45, and the like. The heat exchanger 207 includes the axle 25 and can exchange heat between the engine coolant and the transmission oil. The heat exchange between the engine coolant and the transmission oil in the heat exchanger 207 can be switched according to the temperature of the transmission oil (oil temperature Toil) and the temperature of the engine coolant (cooling water temperature Tw). It is said that. That is, in the above embodiment, when the oil temperature Toil is lower than the reference temperature Tref and lower than the cooling water temperature Tw, and when the oil temperature Toil is higher than the reference temperature Tref and higher than the cooling water temperature Tw, the heat exchanger 207 The solenoid valve 206 is opened so that the heat exchange between the engine coolant and the transmission oil is executed in the case where the oil temperature Toil is lower than the reference temperature Tref and is equal to or higher than the coolant temperature Tw, and the oil temperature Toil is the reference temperature. When the temperature is equal to or higher than Tref and equal to or lower than the cooling water temperature Tw, the electromagnetic valve 206 is closed so that the heat exchanger 207 does not perform heat exchange between the engine cooling water and the transmission oil. As described above, heat exchange between the engine coolant and the transmission oil is performed in the heat exchanger 207 according to the oil temperature Toil and the coolant temperature Tw, or the heat exchange between the two is stopped, that is, the heat exchanger. By using 207 as an oil warmer or oil cooler with engine cooling water as a heat source, or by stopping its use, the temperature of the transmission oil for adjusting the temperature of the motors MG1, MG2, etc. according to the situation It becomes possible to set to a suitable temperature.

  FIG. 4 is a schematic configuration diagram showing a power output apparatus 20B according to a modification. The engine cooling system 100B included in the power output apparatus 20B shown in the figure is different from the circulation channel 101 of the engine cooling system 100 shown in FIG. An electromagnetic valve (open / close valve) 106 controlled by the engine ECU 24 to be opened / closed by the engine ECU 24 is incorporated in the circulation flow path 101 so as to be positioned between the coolant inlet and the electric pump driven / controlled by the engine ECU 24 as the water pump 102B. Is equivalent to Further, the hybrid lubrication temperature control system 200B included in the power output apparatus 20B shown in FIG. 4 omits the bypass flow path 205 and the electromagnetic valve 206 from the hybrid lubrication temperature control system 200 shown in FIG. On the other hand, it corresponds to the one in which the heat exchanger 207 is incorporated so as to be positioned between the mechanical oil pump 202 and the electric oil pump 203 and the lubrication / temperature control objects such as the motors MG1, MG2.

  In the power output apparatus 20B provided with the engine cooling system 100B and the hybrid lubrication temperature control system 200B as described above, the solenoid valve 106 is opened and closed when the oil temperature Toil is lower than the reference temperature Tref and lower than the cooling water temperature Tw. Along with the control of the water pump (electric pump) 102B, the discharge amount of the engine cooling water from the water pump 102B is adjusted and the engine cooling water is circulated to the heat exchanger 207, whereby the mechanical oil pump 202 or the electric oil pump At least a part of the transmission oil pressure-fed by 203 can be heated by a heat exchanger 207 as an oil warmer and then supplied to lubrication / temperature control objects such as motors MG1, MG2. When the oil temperature Toil is equal to or higher than the reference temperature Tref and exceeds the cooling water temperature Tw, the solenoid valve 106 is opened and closed, and the discharge amount of the engine cooling water from the water pump 102B is controlled by the water pump 102B. By adjusting and circulating the engine cooling water to the heat exchanger 207, at least a part of the transmission oil pumped by the mechanical oil pump 202 or the electric oil pump 203 is cooled by the heat exchanger 207 as an oil cooler. To the motors MG1, MG2 and the like for lubrication and temperature control. When the oil temperature Toil is lower than the reference temperature Tref and equal to or higher than the cooling water temperature Tw and when the oil temperature Toil is equal to or higher than the reference temperature Tref and equal to or lower than the cooling water temperature Tw, the solenoid valve 106 is opened and closed and It is only necessary to adjust the discharge amount of the engine cooling water from the water pump 102B by controlling the pump 102B so that the engine cooling water does not flow through the heat exchanger 207. Thus, in the power output apparatus 20B provided with the engine cooling system 100B and the hybrid lubrication temperature control system 200B, the engine cooling system 100 and the hybrid lubrication temperature control system 200 described above are changed by changing the flow path of the engine coolant. It is possible to obtain the same effects as those in the power output device 20 provided.

  FIG. 5 is a schematic configuration diagram showing a power output apparatus 20C according to another modification. The engine cooling system 100C included in the power output apparatus 20C shown in the figure replaces the thermostat 104 of the engine cooling system 100 shown in FIG. 2 with an electromagnetic three-way valve 107 whose flow path is controlled by the engine ECU 24, and the engine ECU 24 The water pump 102 </ b> C, which is an electric pump driven and controlled by the above, corresponds to a configuration in which the water pump 102 </ b> C is disposed between the cooling water inlet of the radiator 103 and the junction between the circulation channel 101 and the bypass channel 105. The three-way valve 107 communicates the first state where the coolant outlet of the engine 22 and the coolant inlet of the radiator 103 are communicated with each other, and the discharge port of the water pump 102C and the coolant inlet of the radiator 103 without passing through the engine 22. One of the second states to be formed can be formed. The hybrid lubrication temperature control system 200C included in the power output apparatus 20C has the same structure as the hybrid lubrication temperature control system 200B of FIG.

  In the power output apparatus 20C provided with the engine cooling system 100C and the hybrid lubrication temperature control system 200C as described above, the cooling water outlet of the engine 22 and the cooling water inlet of the radiator 103 communicate with each other during the hybrid running in which the engine 22 is operated. The three-way valve 107 is controlled so as to form the first state, and the operation of the engine 22 is stopped and the driving power is output only from the motor MG2, so that the discharge port of the water pump 102C and the radiator 103 are The three-way valve 107 is controlled so as to form a second state for communicating with the cooling water inlet. In this way, if the three-way valve 107 is controlled so as to form a second state in which the discharge port of the water pump 102C and the cooling water inlet of the radiator 103 are communicated during motor travel, the engine 22 is disconnected from the engine cooling system 100C. Therefore, even if the engine 22 is operated before the motor travels and the engine 22 accumulates heat energy, the heat exchanger 207 is kept in a state in which the temperature rise of the engine cooling water due to heat exchange with the engine 22 is eliminated. This makes it possible to cool the transmission oil well. This makes it possible to satisfactorily suppress the temperature rise of the motors MG1, MG2, etc., so that the power output device 20C in FIG. 5 can charge the battery with electric power from an external power source such as a household power source. This is very suitable for a so-called plug-in hybrid vehicle.

  Here, the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. That is, in the above embodiment, the engine 22 corresponds to the “internal combustion engine”, the motor MG2 capable of outputting power corresponds to the “electric motor”, and the engine cooling systems 100, 100B, and 100C that cool the engine 22 with engine cooling water. Corresponds to the “engine cooling means”, and the hybrid lubrication temperature control systems 200, 200B and 200C for adjusting the temperature of the motor MG2 by exchanging heat between the motor MG2 and the transmission oil correspond to the “motor temperature adjusting means”. The output devices 20, 20B, and 20C correspond to “power output devices”, and the heat exchanger 207 that can exchange heat between the engine coolant and the transmission oil corresponds to “heat exchangers”. However, the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the invention described in the column of means for solving the problem by the embodiment. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. In other words, the examples are merely specific examples of the invention described in the column of means for solving the problem, and the interpretation of the invention described in the column of means for solving the problem is It should be done based on the description.

  As mentioned above, although the embodiment of the present invention has been described using examples, the present invention is not limited to the above-described examples, and various modifications can be made without departing from the scope of the present invention. Needless to say.

  The present invention can be used in the manufacturing industry of power output devices.

  DESCRIPTION OF SYMBOLS 10 Hybrid vehicle, 20, 20B, 20C Power output device, 22 Engine, 23 Cooling water temperature sensor, 24 Engine electronic control unit (engine ECU), 25 Transaxle, 30 Planetary gear, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 45 Power control unit, 50 Battery, 70 Hybrid electronic control unit (Hybrid ECU), 100, 100B, 100C Engine cooling system, 101 Circulating flow path, 102, 102B, 102C Water pump, 103 Radiator, 104 Thermostat, 105, 205 Bypass channel, 106, 206 Solenoid valve, 107 Three-way valve, 200, 200B, 200C Hybrid lubrication temperature control system, 201 Oil pan, 20 Mechanical oil pump, 203 electric oil pump, 204 an oil passage, 207 heat exchanger, 208 oil temperature sensor, MG1, MG2 motor.

Claims (1)

An engine, an electric motor capable of outputting power, engine cooling means for cooling the engine with engine cooling water, and electric motor temperature adjusting means for adjusting the temperature of the electric motor by exchanging heat between the electric motor and transmission oil. In the power output device,
A heat exchanger capable of exchanging heat between the engine coolant and the transmission oil, and heat exchange between the engine coolant and the transmission oil in the heat exchanger according to a temperature of the transmission oil; A power output device configured to be switchable between execution and stop.

Images