JP5214573B2 - Hybrid vehicle - Google Patents

Description

  The present invention relates to a hybrid vehicle including an internal combustion engine and an electric motor.

  In a hybrid vehicle including an internal combustion engine and an electric motor, the electric motor includes a rotor including a permanent magnet and a stator. When the motor continues to be in a high rotation state or an overload state, the motor generates heat due to the generated eddy current and becomes high temperature. The higher the rotor temperature, the lower the magnetic force of the permanent magnet and the lower the maximum torque of the motor at high temperatures.

  Patent Document 1 discloses a motor drive control device that limits the output torque of a motor when the motor (motor) is at a high temperature. According to this apparatus, the detected motor temperature is higher than the first predetermined temperature and lower than the second predetermined temperature, and the output of the motor according to different limiting characteristics in the temperature range higher than the second predetermined temperature. Limits are added to the torque.

JP 2007-244072 A

  In a vehicle equipped with the device described in Patent Document 1 described above, severe restrictions are applied in a high temperature region higher than the second predetermined temperature, so that the EV travel performance is reduced even when the electric motor is at a high temperature. The drivability may be reduced.

  By the way, a known hybrid vehicle has a connecting / disconnecting device capable of connecting / disconnecting an electric motor capable of driving a driven portion (driving wheel) and the engine, and the engine can be started by the electric motor.

  In this hybrid vehicle, for example, when an engine stop condition (for example, during deceleration regeneration) is satisfied while driving by driving the engine and the electric motor in a state where power is transmitted between the engine and the electric motor by the connection / disconnection device. First, the connection between the engine and the electric motor is cut off, the fuel supply to the engine is stopped, and the engine is stopped (low fuel consumption).

  Also, when the engine is stopped and the electric motor is in a state where power can be transmitted to and from the drive wheels (during EV travel), engine start conditions (for example, when a driving torque greater than the torque by the electric motor is requested) When the condition is satisfied, the electric motor and the engine are connected to each other, and the engine is started by the electric motor, so that the driving wheels are driven by the electric motor and the engine.

  As shown in FIG. 6, when the motor temperature is T1, T2 (T1 <T2), the motor torque Tr1, Tr2 is the maximum torque Tr3, Tr4 when the motor rotation speed (rotational speed) Nm is low. It becomes. The maximum torque Tr4 of the motor at high temperature (T2) is lower than the maximum torque Tr3 at low temperature (T1).

  When starting the engine during EV travel, torque Trs for starting the engine with an electric motor is required as shown in FIG. At a low temperature (T1), EV traveling is performed by a torque Tr5 obtained by subtracting the engine starting torque Trs from the maximum torque Tr3 of the electric motor.

  However, at the time of high temperature (T2), the torque Tr6 that can be used for EV traveling is smaller than the torque Tr5 at the time of low temperature (T1). For this reason, the drivability when the electric motor is at a high temperature (T2) may be lower than that at a low temperature (T1).

  The present invention has been made in view of such a background, and provides a hybrid vehicle capable of reducing the load on an electric motor without reducing drivability even when the electric motor becomes relatively high in temperature. Objective.

  It is another object of the present invention to provide a hybrid vehicle capable of reducing the temperature of the electric motor in a relatively short time without reducing drivability even when the electric motor becomes relatively high in temperature.

The hybrid vehicle according to the present invention includes an internal combustion engine, an electric motor, a power transmission device capable of transmitting power between the internal combustion engine and / or the electric motor and a driven portion, and the power transmission according to a traveling state of the vehicle. The power transmission device includes a connection / disconnection device capable of connecting / disconnecting the internal combustion engine and the electric motor, and the control unit is configured to control a temperature of the electric motor. A temperature detection unit that detects the internal combustion engine when the temperature detected by the temperature detection unit is less than a predetermined temperature and a condition for disconnecting the internal combustion engine from the motor is satisfied. A connection / disconnection device control unit for cutting off the connection between the motor and the electric motor, and when the temperature of the electric motor detected by the temperature detection unit is equal to or higher than a predetermined temperature , the disconnection is performed regardless of whether the condition is satisfied. Equipment And having a more the electric motor at high temperature processing unit that controls to hold an internal combustion engine and the electric motor in the connected state.

  According to the hybrid vehicle of the present invention, the temperature detection unit detects the temperature of the electric motor. Detecting the temperature of the electric motor may be, for example, detecting the temperature of the electric motor with a temperature detection device, or may be estimating the temperature based on parameters relating to the operation of the electric motor. The motor high temperature processing unit controls the internal combustion engine and the motor to be held in a connected state by the connection / disconnection device when the temperature of the motor detected by the temperature detection unit is equal to or higher than a predetermined temperature. As this predetermined temperature, the lower limit value of the temperature at which the motor torque required for starting the engine cannot be secured, the lower limit value of the temperature at which drivability is not good when starting the internal combustion engine during EV traveling, The lower limit value of the temperature at which torque cannot be obtained.

That is, when the electric motor is at a high temperature equal to or higher than a predetermined temperature, the connection between the internal combustion engine and the electric motor is disconnected even when a condition for disconnecting the internal combustion engine from the electric motor (for example, a condition for stopping the internal combustion engine) is satisfied. Therefore, the internal combustion engine and the electric motor are in a connected state, and the torque for starting the internal combustion engine by the electric motor can be made unnecessary. That is, it is possible to provide a hybrid vehicle that can reduce the load on the electric motor without reducing drivability even when the electric motor becomes relatively hot.

  Further, in the hybrid vehicle of the present invention, when the electric motor is at a high temperature, the internal combustion engine and the electric motor are connected so as to be able to transmit power, so the load on the electric motor is reduced and the temperature of the electric motor is lowered in a relatively short time. It is possible. That is, the high-temperature electric motor becomes low temperature in a relatively short time, and can return to the normal traveling mode (when the electric motor is low temperature) in a relatively short time.

  Further, in the hybrid vehicle of the present invention, when the electric motor is at a high temperature, a driving torque to the driven part can be secured by the internal combustion engine and the electric motor, and a drivability can be prevented from being lowered.

  In addition, even when the motor is performing deceleration regeneration when the motor is at a relatively high temperature, since the connection state is maintained between the internal combustion engine and the motor by the connecting / disconnecting device, the load on the motor during regeneration can be reduced. The temperature can be lowered in a relatively short time.

The power transmission device transmits the power by a first or second transmission mechanism that establishes a plurality of shift stages, and the first transmission mechanism is connected to the electric motor, And the second speed change mechanism is disconnected from or connected to the internal combustion engine, and the control unit performs a predetermined speed change in the second speed change mechanism for transmitting the power when the temperature of the electric motor is equal to or higher than the predetermined temperature. When the gear is established, the gear for transmitting the power may be switched to a gear having a smaller gear ratio than the predetermined gear realized by the first gear mechanism .

According to the above control unit, when a predetermined speed is established in the second speed change mechanism for transmitting the power when the electric motor is at a high temperature , the speed for transmitting the power is changed to the first speed change. It controls the switching so that the low gear stage having a gear ratio lower than the predetermined gear stage is established by a mechanism. In other words, the first speed change mechanism side is controlled so as to select a higher gear speed than the gear speed established on the second speed change mechanism side. By doing so, the rotational speed of the motor (the number of revolutions per unit time) can be made relatively low, and the load on the motor can be reduced. That is, the temperature of the electric motor can be lowered in a relatively short time.
Another hybrid vehicle of the present invention is a hybrid vehicle that includes an internal combustion engine and an electric motor, shifts power from the internal combustion engine and / or the electric motor, and transmits the power to an output shaft connected to a driven part. A first transmission mechanism that receives power input to the input shaft from the internal combustion engine by a first drive gear shaft, shifts the power at an established gear among a plurality of gears, and transmits the power to the output shaft; A second speed change mechanism that receives power input from the internal combustion engine to the input shaft by a second drive gear shaft, changes speed at an established speed among a plurality of speeds, and transmits it to the output shaft; and the input A first clutch for connecting / disconnecting the shaft and the first drive gear shaft, a second clutch for connecting / disconnecting power transmission between the input shaft and the second drive gear shaft, the first transmission mechanism and the second clutch. Establishment of a shift stage in the transmission mechanism and the first clutch; And a control unit that controls connection and disconnection of the second clutch, the first drive gear shaft is connected to the electric motor, the control unit detects a temperature of the electric motor, and the temperature When the temperature of the electric motor detected by the detection unit is lower than a predetermined temperature, and the condition for disconnecting the internal combustion engine from the electric motor is satisfied, the first clutch disconnects the connection between the internal combustion engine and the electric motor. When the temperature of the electric motor detected by the contact control unit and the temperature detection unit is equal to or higher than a predetermined temperature, the internal combustion engine and the electric motor are controlled by the first clutch regardless of whether the condition is satisfied. When the temperature of the electric motor detected by the temperature detection unit is equal to or higher than a predetermined temperature, a predetermined gear stage is established in the second transmission mechanism, and the second clutch When switch is in the connected state, the gear position of the smaller speed ratio than the predetermined gear stage may be a shift speed control unit for establishing in the first transmission mechanism.
According to another hybrid vehicle of the present invention, as in the hybrid vehicle of the present invention, the connection between the internal combustion engine and the electric motor is disconnected even when the condition for disconnecting the internal combustion engine from the electric motor is satisfied. Therefore, the same effect as the hybrid vehicle of the present invention can be obtained. Further, according to the shift speed control unit in another hybrid vehicle of the present invention, similar to the control unit in the hybrid vehicle of the present invention, a predetermined shift speed is established in the second speed change mechanism when the electric motor is at a high temperature. Since the control is performed so as to switch to a gear stage having a gear ratio smaller than the predetermined gear stage, similarly to the control unit in the hybrid vehicle of the present invention, the load on the motor is reduced, and The temperature can be lowered.
In the hybrid vehicle of the present invention or another hybrid vehicle, when the control unit establishes a gear stage having a gear ratio smaller than the predetermined gear stage, the control unit shifts one gear higher than the predetermined gear stage. A stage may be established.
In the hybrid vehicle of the present invention or another hybrid vehicle, the control unit drives the internal combustion engine when the temperature of the electric motor is equal to or higher than a predetermined temperature even if the stop condition of the internal combustion engine is satisfied. You may make it leave. According to this, it is possible to reliably avoid the necessity of starting the internal combustion engine by the electric motor, and to reliably eliminate the torque for starting the internal combustion engine.

The hybrid vehicle or another hybrid vehicle may include a cooling unit that cools the electric motor, and the control unit may increase a cooling amount for cooling the electric motor according to the detected temperature.

According to the hybrid vehicle or another hybrid vehicle , the temperature of the electric motor can be lowered in a relatively short time by increasing the amount of cooling for cooling the electric motor according to the temperature of the electric motor.

In addition, the hybrid vehicle or another hybrid vehicle has a driving force setting unit that sets a driving force required for the driven unit, and the control unit, when the temperature of the electric motor is equal to or higher than the predetermined temperature, The traveling mode in which the rotational speed of the electric motor is the lowest is selected from the traveling modes that satisfy the driving force requirement set by the driving force setting unit.

According to the hybrid vehicle or another hybrid vehicle , the control unit rotates the motor in a travel mode that satisfies the driving force request based on the driving force request set by the driving force setting unit when the electric motor is at a high temperature. Select the driving mode with the lowest speed. In other words, when the motor is at a high temperature, by selecting a travel mode in which the rotation speed of the motor is the lowest, the load on the motor can be reduced, and the temperature of the motor can be reduced in a relatively short time.

1 is an overall configuration diagram of a hybrid vehicle according to an embodiment of the present invention. The functional block diagram of ECU of embodiment of this invention. The figure which shows correlation with the driving mode of the hybrid vehicle of embodiment of this invention, and the rotational speed of an electric motor. The flowchart explaining operation | movement of the hybrid vehicle of embodiment of this invention. It is a figure explaining operation | movement of the hybrid vehicle of embodiment of this invention, (a) is a figure which shows the time change of a vehicle speed, (b) is a figure which shows the rotational speed Ne of an engine, (c) is the rotational speed of an electric motor. The figure which shows Nm, (d) is a figure which shows the temperature of an electric motor. The figure which shows the temperature change of the torque of an electric motor.

  A hybrid vehicle according to an embodiment of the present invention will be described with reference to the drawings. First, the structure of the hybrid vehicle of this embodiment is demonstrated, referring FIG.

  As shown in FIG. 1, the hybrid vehicle of this embodiment includes a power transmission device 1, and includes an engine 2 as a power generation source and an electric motor (motor / generator) 3 that can start the engine 2. The engine 2 corresponds to the internal combustion engine in the present invention.

  The power transmission device 1 is configured to be able to drive the driving wheels 4 by transmitting the power (driving force) of the engine 2 and / or the electric motor 3 to the driving wheels 4 that are driven parts. The power transmission device 1 is configured to transmit power from the engine 2 and / or power from the drive wheels 4 to the electric motor 3 so that the electric motor 3 can perform a regenerative operation. The power transmission device 1 is configured to be able to drive the auxiliary machine 5 mounted on the vehicle with the power of the engine 2 and / or the electric motor 3. The auxiliary machine 5 is, for example, an air conditioner compressor, a water pump, an oil pump, or the like.

  The engine 2 is an internal combustion engine that generates power (torque) by burning fuel such as gasoline, light oil, and alcohol. The engine 2 has a driving force input shaft 2 a for inputting generated power to the power transmission device 1. The driving force input shaft 2a corresponds to the input shaft in the present invention. The engine 2 controls the power of the engine 2 by controlling the opening degree of a throttle valve (not shown) provided in an intake passage (not shown) in the same manner as a normal automobile engine. The

  In the present embodiment, the electric motor 3 is a three-phase DC brushless motor. The electric motor 3 includes a hollow rotor (rotary body) 3a that is rotatably supported in a housing, and a stator (stator) 3b. The rotor 3a of the present embodiment is provided with a plurality of permanent magnets. A stator (armature winding) 3ba for three phases is mounted on the stator 3b. The stator 3b is fixed to a housing provided in a stationary part that is stationary with respect to the vehicle body, such as an outer case of the power transmission device 1.

  The coil 3ba is electrically connected to a battery (power storage device, secondary battery) 7 as a DC power source via a power drive unit (hereinafter referred to as “PDU”) 6 which is a drive circuit including an inverter circuit. Yes. The PDU 6 is electrically connected to an electronic control unit (hereinafter referred to as “ECU”) 8.

  ECU8 is electrically connected to each component of vehicles, such as power transmission device 1, engine 2, and electric motor 3, other than PDU6. The ECU 8 corresponds to a control unit in the present invention. The ECU 8 of this embodiment is an electronic circuit unit including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an interface circuit, and the like, and executes a control process defined by a program. Thus, the power transmission device 1, the engine 2, the electric motor 3, and the like are controlled.

  As shown in FIG. 2, the ECU 8 is a connecting / disconnecting device control unit 8a, an electric motor temperature detection unit 8b, an electric motor high temperature processing unit 8c, a shift speed control unit 8d, as means for realizing the functions of the present invention. And a cooling controller 8e. The function of this ECU 8 will be described later.

  Further, functions realized by the control process of the ECU 8 include a function of controlling the operation of the engine 2 through an actuator for engine control such as an actuator for a throttle valve (not shown), and operations of various clutches and sleeves of various synchronizers described later. Is received through a signal from a driving force setting unit 9 for setting a driving force required for the driving wheel 4 from a function of controlling the vehicle via an actuator or a driving circuit (not shown), a vehicle speed, a rotation speed of the engine 2, and the like. The function etc. which control each component according to a driving state are controlled.

  Further, the ECU 8 controls the current (torque) output from the rotor 3a by the motor 3 by controlling the current flowing through the coil 3ba via the PDU 6. In this case, by controlling the PDU 6, the electric motor 3 performs a power running operation for generating a power running torque in the rotor 3 a with the electric power supplied from the battery 7 and functions as a motor. That is, the electric power supplied to the stator 3b is converted into power by the rotor 3a and output. Further, by controlling the PDU 6, the electric motor 3 performs a regenerative operation for generating regenerative torque in the rotor 3 a while generating electricity by the rotational energy given to the rotor 3 a and charging the battery 7. That is, the electric motor 3 also functions as a generator. That is, the power input to the rotor 3a is converted into electric power by the stator 3b.

  The driving force setting unit 9 can set the driving force required for the driving wheels 4 based on, for example, the driver's operation and the running state. As the driving force setting unit 9, for example, an accelerator sensor that detects the amount of depression of an accelerator pedal provided in the accelerator pedal, a throttle opening sensor that detects a throttle opening, and the like can be employed.

  The various sensors 10 include, for example, a vehicle speed sensor, an acceleration sensor, an engine rotation speed sensor, a shift speed detection sensor, and the like, and send signals indicating detection results by the sensors to the ECU 8.

  The temperature detector 11 detects the temperature of the electric motor 3 and sends a signal indicating the detection result to the ECU 8. The temperature detection part 11 of this embodiment detects the temperature of the rotor 3a of the electric motor 3, and sends the signal which shows a detection result to ECU8.

  The cooling unit 12 is configured to cool the electric motor 3 under the control of the ECU 8. The cooling unit 12 is configured such that a cooling amount (cooling amount per unit time) for cooling the electric motor 3 can be controlled by the ECU 8. As the cooling unit 12, an oil cooling device, a water cooling device, an air cooling device, or the like can be employed. The cooling unit 12 includes, for example, a heat receiver provided in the electric motor 3, a heat radiator provided on the heat dissipation side, a pump that circulates the refrigerant between the heat receiver and the heat radiator, a temperature sensor that detects the temperature of the refrigerant, and heat dissipation An electric fan or the like capable of forcibly cooling the chamber is provided, and the electric motor 3 is cooled by circulating the refrigerant. By providing this temperature sensor in the refrigerant flow path from the heat receiving portion to the radiator, it is possible to detect the temperature, temperature change, and the like of the electric motor 3. As the temperature detection unit 11, a temperature sensor of the cooling unit 12 may be adopted. Further, as the refrigerant of the cooling unit 12, lubricating / hydraulic oil (ATF: Automatic transmission fluid) of the power transmission device 1, cooling water for cooling the engine 2 (cooling water for the radiator), or the like may be employed. By doing so, the cooling unit 12 can be configured relatively easily.

  Next, each component of the power transmission device 1 of the present embodiment will be described. The power transmission device 1 includes a power combining mechanism 13 that combines the power of the engine 2 and the power of the electric motor 3. As the power combining mechanism 13, a planetary gear device is employed in this embodiment. The power combining mechanism 13 will be described later.

  A first main input shaft 14 is connected to the driving force input shaft 2 a of the engine 2. The first main input shaft 14 is disposed in parallel with the driving force input shaft 2a, and power from the engine 2 is input via the first clutch C1. The first main input shaft 14 extends from the engine 2 side to the electric motor 3 side. The first main input shaft 14 is configured to be connected to and disconnected from the driving force input shaft 2a of the engine 2 by the first clutch C1. Further, the first main input shaft 14 of the present embodiment is connected to the rotor 3 a of the electric motor 3.

  The first clutch C <b> 1 is configured to be able to connect and disconnect the driving force input shaft 2 a and the first main input shaft 14 under the control of the ECU 8. When the driving force input shaft 2a and the first main input shaft 14 are connected by the first clutch C1, power can be transmitted between the driving force input shaft 2a and the first main input shaft 14. Further, when the connection between the driving force input shaft 2a and the first main input shaft 14 is disconnected by the first clutch C1, the power transmission is interrupted between the driving force input shaft 2a and the first main input shaft 14. .

  A first sub input shaft 15 is coaxially arranged with respect to the first main input shaft 14. The power from the engine 2 is input to the first auxiliary input shaft 15 via the second clutch C2. The second clutch C <b> 2 is configured to be able to connect and disconnect between the driving force input shaft 2 a and the first sub input shaft 15 under the control of the ECU 8. When the driving force input shaft 2a and the first auxiliary input shaft 15 are connected by the second clutch C2, power transmission between the driving force input shaft 2a and the first auxiliary input shaft 15 becomes possible. Further, when the connection between the driving force input shaft 2a and the first auxiliary input shaft 15 is disconnected by the second clutch C2, power transmission is interrupted between the driving force input shaft 2a and the first auxiliary input shaft 15. . The first clutch C1 and the second clutch C2 are arranged adjacent to each other in the axial direction of the first main input shaft 14. The first clutch C1 and the second clutch C2 of the present embodiment are constituted by wet multi-plate clutches.

  As described above, in the power transmission device 1, the first clutch C1 transmits the rotation of the driving force input shaft 2a to the first main input shaft 14 (first driving gear shaft) in a releasable manner, and the second clutch C2 The rotation of the driving force input shaft 2a is releasably transmitted to the second main input shaft 22 (second driving gear shaft).

  A reverse shaft 16 is disposed in parallel to the first main input shaft 14. A reverse gear shaft 17 is rotatably supported on the reverse shaft 16. The first main input shaft 14 and the reverse gear shaft 17 are always coupled via a gear train 18. The gear train 18 is configured by meshing a gear 14 a fixed on the first main input shaft 14 and a gear 17 a provided on the reverse gear shaft 17.

  The reverse shaft 16 is provided with a reverse gear 17c fixed on the reverse gear shaft 17 and a reverse synchronizer SR capable of switching connection and disconnection with the reverse shaft 16.

  An intermediate shaft 19 is arranged with respect to the reverse shaft 16 and in parallel with the first main input shaft 14. The intermediate shaft 19 and the reverse shaft 16 are always connected via a gear train 20. The gear train 20 is configured by meshing a gear 19 a fixed on the intermediate shaft 19 and a gear 16 a fixed on the reverse shaft 16. The intermediate shaft 19 and the first auxiliary input shaft 15 are always connected via a gear train 21. The gear train 21 is configured by meshing a gear 19 a fixed on the intermediate shaft 19 and a gear 15 a fixed on the first auxiliary input shaft 15.

  A second main input shaft 22 is arranged parallel to the first main input shaft 14 with respect to the intermediate shaft 19. The second main input shaft 22 and the intermediate shaft 19 are always connected via a gear train 23. The gear train 23 is configured by meshing a gear 19 a fixed on the intermediate shaft 19 and a gear 22 a fixed on the second main input shaft 22.

  The first main input shaft 14 has gears of odd-numbered or even-numbered gears (odd-numbered third and fifth gears in this embodiment) among the plurality of gears having different gear ratios. The row drive gears are rotatably supported and connected to the motor 3. The first main input shaft 14 corresponds to the first drive gear shaft in the present invention.

  Specifically, the second sub input shaft 24 is coaxially disposed with respect to the first main input shaft 14. The second sub input shaft 24 is disposed closer to the electric motor 3 than the first sub input shaft 15. The first main input shaft 14 and the second auxiliary input shaft 24 are connected via a first synchronous meshing mechanism S1 (in this embodiment, a synchromesh mechanism). The first synchronous meshing mechanism S1 is provided on the first main input shaft 14, and selectively connects the third speed gear 24a and the fifth speed gear 24b to the first main input shaft 14. Specifically, the first synchronous meshing mechanism S1 is a well-known one such as a synchro clutch, and by moving the sleeve S1a along the axial direction of the second sub input shaft 24 by an actuator and a shift fork (not shown), The third speed gear 24 a and the fifth speed gear 24 b are selectively connected to the first main input shaft 14. Specifically, when the sleeve S1a moves from the illustrated neutral position to the third speed gear 24a side, the third speed gear 24a and the first main input shaft 14 are connected. On the other hand, when the sleeve S1a moves from the illustrated neutral position to the fifth speed gear 24b side, the fifth speed gear 24b and the first main input shaft 14 are connected.

  The second main input shaft 22 has gears of even-numbered or odd-numbered gears (even-numbered 2nd gear and 4th gear in this embodiment) among a plurality of gears having different gear ratios. The drive gear of the row is supported rotatably. The second main input shaft 22 corresponds to the second drive gear shaft in the present invention. Specifically, the third sub input shaft 25 is coaxially arranged with respect to the second main input shaft 22. The second main input shaft 22 and the third sub input shaft 25 are connected via a second synchronous meshing mechanism S2 (in this embodiment, a synchromesh mechanism). The second synchromesh mechanism S2 is provided on the second main input shaft 22, and is configured to selectively connect the second speed gear 25a and the fourth speed gear 25b to the second main input shaft 22. The second synchromesh mechanism S2 is a well-known one such as a synchro clutch, and the second-speed gears 25a and 4 are moved by moving the sleeve S2a in the axial direction of the third auxiliary input shaft 25 by an actuator and shift fork (not shown). The speed gear 25 b is selectively connected to the second main input shaft 22. When the sleeve S2a moves from the illustrated neutral position to the second speed gear 25a side, the second speed gear 25a and the second main input shaft 22 are connected. On the other hand, when the sleeve S2a moves from the illustrated neutral position to the fourth speed gear 25b side, the fourth speed gear 25b and the second main input shaft 22 are connected.

  The third sub input shaft 25 and the output shaft 26 are coupled via a second speed gear train 27. The second gear train 27 is configured by meshing a gear 25 a fixed on the third sub input shaft 25 and a gear 26 a fixed on the output shaft 26. Further, the third sub input shaft 25 and the output shaft 26 are coupled via a fourth speed gear train 28. The fourth speed gear train 28 is configured by meshing a gear 25 b fixed on the third sub input shaft 25 and a gear 26 b fixed on the output shaft 26.

  The output shaft 26 and the second auxiliary input shaft 24 are coupled via a third speed gear train 29. The third speed gear train 29 is configured by meshing a gear 26 a fixed to the output shaft 26 and a gear 24 a fixed to the second auxiliary input shaft 24. The output shaft 26 and the second auxiliary input shaft 24 are coupled via a fifth speed gear train 30. The fifth speed gear train 30 is configured by meshing a gear 26b fixed to the output shaft 26 and a gear 24b fixed on the second sub input shaft 24. The gears 26a and 26b of each gear train fixed to the output shaft 26 are referred to as driven gears.

  A final gear 26 c is fixed to the output shaft 26. The rotation of the output shaft 26 is configured to be transmitted to the drive wheels 4 via the final gear 26c, the differential gear unit 31 and the axle 32.

  The power combining mechanism 13 of this embodiment is provided inside the electric motor 3. Part or all of the rotor 3a, the stator 3b, and the coil 3ba constituting the electric motor 3 are arranged so as to overlap the power combining mechanism 13 along a direction orthogonal to the axial direction of the first main input shaft 14. .

  The power combining mechanism 13 includes a differential device that can differentially rotate the first rotating element, the second rotating element, and the third rotating element. In the present embodiment, the differential device that constitutes the power combining mechanism 13 is a single pinion type planetary gear device, and includes three rotation elements: a sun gear 13s (first rotation element) and a ring gear 13r (second rotation element). And a carrier (third rotating element) 13c that rotatably supports a plurality of planetary gears 13p engaged with the sun gear 13s and the ring gear 13r between the sun gear 13s and the ring gear 13r. These three rotating elements 13s, 13r, and 13c can transmit power between each other, and rotate while maintaining a constant collinear relationship between the respective rotational speeds (rotational speeds).

  The sun gear 13 s is fixed to the first main input shaft 14 so as to rotate in conjunction with the first main input shaft 14. The sun gear 13s is fixed to the rotor 3a so as to rotate in conjunction with the rotor 3a of the electric motor 3. Thereby, the sun gear 13s, the first main input shaft 14, and the rotor 3a rotate in conjunction with each other.

  The ring gear 13r is configured to be switchable between a fixed state and a non-fixed state with respect to the housing 33, which is a non-moving portion, by the third synchronous meshing mechanism SL. Specifically, by moving the sleeve SLa of the third synchronous meshing mechanism SL along the rotation axis direction of the ring gear 13r, the state in which the housing 33 and the ring gear 13r are fixed and the non-fixed state can be switched. It is configured as follows.

  The carrier 13 c is connected to one end of the second sub input shaft 24 on the electric motor 3 side so as to rotate in conjunction with the second sub input shaft 24.

  The input shaft 5 a of the auxiliary machine 5 is arranged in parallel to the reverse shaft 16. The reverse shaft 16 and the input shaft 5a of the auxiliary machine 5 are coupled via, for example, a belt mechanism 34. The belt mechanism 34 is configured by connecting a gear 17b fixed on the reverse gear shaft 17 and a gear 5b fixed on the input shaft 5a via a belt. An auxiliary machine clutch 35 is interposed on the input shaft 5 a of the auxiliary machine 5. The gear 5b and the input shaft 5a of the auxiliary machine 5 are connected coaxially through an auxiliary machine clutch 35.

  The auxiliary device clutch 35 is a clutch that operates so as to connect or disconnect between the gear 5 b and the input shaft 5 a of the auxiliary device 5 under the control of the ECU 8. In this case, when the auxiliary machine clutch 35 is operated in the connected state, the gear 5b and the input shaft 5a of the auxiliary machine 5 are coupled via the auxiliary machine clutch 35 so as to rotate integrally with each other. Further, when the auxiliary machine clutch 35 is operated in the disconnected state, the coupling between the gear 5b and the input shaft 5a of the auxiliary machine 5 by the auxiliary machine clutch 35 is released. In this state, power transmission to the first main input shaft 14 and the input shaft 5a of the auxiliary machine 5 is interrupted.

  Next, each gear stage will be described. As described above, the power transmission device 1 of the present embodiment shifts the rotational speed of the input shaft to a plurality of stages via the gear trains of a plurality of shift stages having different speed ratios, and outputs it to the output shaft 26. It is configured. Further, in the power transmission device 1, it is defined that the gear ratio is smaller as the gear position is larger.

  When the engine is started, the first clutch C1 is connected, the electric motor 3 is driven, and the engine 2 is started. That is, the electric motor 3 also has a function as a starter.

  The first gear is established by bringing the ring gear 13r and the housing 33 into a connected state (fixed state) by the third synchronous meshing mechanism SL. When traveling by the engine 2, the second clutch C <b> 2 is disengaged (hereinafter referred to as OFF state) and the first clutch C <b> 1 is engaged (hereinafter referred to as ON state). The driving force output from the engine 2 is transmitted to the drive wheels 4 through the sun gear 13s, the carrier 13c, the gear train 29, the output shaft 26, and the like.

  In addition, when the engine 2 is driven and the electric motor 3 is driven, the assist traveling by the electric motor 3 at the first gear (the traveling in which the driving force of the engine 2 is assisted by the electric motor 3) can be performed. Furthermore, if the first clutch C1 is in the OFF state, EV traveling that travels only by the electric motor 3 can be performed.

  Further, during the deceleration regenerative operation, the electric motor 3 is braked so that the vehicle is decelerated to generate electric power with the electric motor 3 and the battery 7 can be charged via the PDU 6.

  In the second gear, the ring gear 13r and the housing 33 are unfixed by the third synchronous mesh mechanism SL, and the second synchronous mesh mechanism S2 is connected to the second main input shaft 22 and the second gear 25a. It is established by that. When traveling by the engine 2, the second clutch C2 is turned on. In this second speed, the driving force output from the engine 2 is the first main input shaft 14, the gear train 21, the intermediate shaft 19, the gear train 23, the second main input shaft 22, the gear train 27, and the output shaft 26. Or the like to be transmitted to the drive wheel 4.

  If the first clutch C1 is turned on to drive the engine 2 and drive the electric motor 3, assist driving by the electric motor 3 at the second gear can be performed. Furthermore, in this state, driving by the engine 2 can be stopped and EV traveling can be performed. When stopping the driving by the engine 2, for example, the engine 2 may be in a fuel cut state or a cylinder resting state. Further, the decelerating regenerative operation can be performed at the second speed stage.

  When the first clutch C1 is in the OFF state and the second clutch C2 is in the ON state, and the ECU 8 is traveling at the second speed by driving the engine 2, the ECU 8 is expected to upshift to the third speed depending on the traveling state of the vehicle. If the determination is made, the first synchronous meshing mechanism S1 sets the first main input shaft 14 and the third speed gear 24a in a connected state or a pre-shifted state approaching this state. As a result, the upshift from the second gear to the third gear can be performed smoothly.

  The third speed is established by bringing the first synchronous meshing mechanism S1 into a state where the first main input shaft 14 and the third speed gear 24a are connected. When traveling by the engine 2, the first clutch C1 is turned on. At the third speed, the driving force output from the engine 2 is transmitted to the drive wheels 4 via the first main input shaft 14, the third speed gear train 29, the output shaft 26, and the like.

  In addition, if the 1st clutch C1 is made into an ON state, the engine 2 is driven, and the electric motor 3 is driven, the assist driving | running | working by the electric motor 3 in 3rd speed can also be performed. Furthermore, the EV clutch can be performed with the first clutch C1 in the OFF state. Note that during EV traveling, the first clutch C1 can be turned on to stop driving by the engine 2, and EV traveling can be performed. Further, the decelerating regenerative operation can be performed at the third speed stage.

  During traveling at the third gear, the ECU 8 predicts whether the next gear to be shifted is the second gear or the fourth gear based on the traveling state of the vehicle. When the ECU 8 predicts a downshift to the second speed, the second synchronous meshing mechanism S2 is connected to the second speed gear 25a and the second main input shaft 22, or is in a preshift state in which this state is approached. And When the ECU 8 predicts an upshift to the fourth speed stage, the second synchronous meshing mechanism S2 is connected to the fourth speed gear 25b and the second main input shaft 22 or is in a preshift state in which this state is approached. And Thereby, the upshift and the downshift from the third gear can be performed smoothly.

  The fourth speed is established by bringing the second synchronous meshing mechanism S2 into a state where the second main input shaft 22 and the fourth speed gear 25b are connected. When traveling by the engine 2, the second clutch C2 is turned on. In the fourth speed, the driving force output from the engine 2 is transmitted via the first main input shaft 14, the gear train 21, the intermediate shaft 19, the gear train 23, the second main input shaft 22, the output shaft 26, and the like. It is transmitted to the drive wheel 4.

  If the second clutch C2 is turned on, the first clutch C1 is turned on, the engine 2 is driven, and the electric motor 3 is driven, the assist traveling by the electric motor 3 at the fourth speed can be performed. Furthermore, in this state, driving by the engine 2 can be stopped and EV traveling can be performed.

  The second clutch C2 is turned off, the first clutch C1 is turned on, and the ECU 8 is driven at the fourth speed by driving the engine 2, and the ECU 8 is next shifted based on the running state of the vehicle. Predict whether it is 3rd gear or 5th gear. When the ECU 8 anticipates a downshift to the third speed, the first synchronous meshing mechanism S1 connects the first main input shaft 14 and the third speed gear 24a, or a preshift approaching this state. State. When the ECU 8 expects an upshift to the fifth speed, the first synchronous mesh mechanism S1 connects the first main input shaft 14 and the fifth speed gear 24b, or a preshift approaching this state. State. Thereby, the upshift and the downshift from the fourth gear can be performed smoothly.

  The fifth speed is established by bringing the first synchronous meshing mechanism S1 into a state where the first main input shaft 14 and the fifth speed gear 24b are connected. When traveling by the engine 2, the first clutch C1 is turned on. At the fifth speed, the driving force output from the engine 2 is transmitted to the drive wheels 4 via the first main input shaft 14, the third gear train 29, the output shaft 26, and the like.

  In addition, if the 1st clutch C1 is made into an ON state, the engine 2 is driven, and the electric motor 3 is driven, the assist driving | running | working by the electric motor 3 in 5th speed can also be performed. Furthermore, the EV clutch can be performed with the first clutch C1 in the OFF state. Further, the EV clutch can be performed by turning on the first clutch C1 and stopping the driving by the engine 2. Further, the decelerating regenerative operation can be performed at the fifth gear.

  When the ECU 8 determines that the next gear to be shifted is the fourth gear based on the traveling state of the vehicle while traveling at the fifth gear, the ECU 8 sets the second synchromesh mechanism S2 to 4 A state in which the speed gear 25b and the second main input shaft 22 are connected to each other, or a pre-shift state close to this state is set. Thereby, the downshift from the fifth gear to the fourth gear can be performed smoothly.

  In the reverse gear, the reverse synchronous meshing mechanism SR is connected to the reverse shaft 16 and the reverse gear 17c, and the second synchronous meshing mechanism S2 is connected to, for example, the second main input shaft 22 and the second speed gear 25a. It is established by setting it to the state. When traveling by the engine 2, the first clutch C1 is turned on. In this reverse speed, the driving force output from the engine 2 is the first main input shaft 14, the gear train 18, the reverse gear 17c, the reverse shaft 16, the gear train 20, the intermediate shaft 19, the gear train 23, the second main input. It is transmitted to the drive wheel 4 via the shaft 22, the third auxiliary input shaft 25, the gear train 27, the output shaft 26, and the like. In addition, if the engine 2 is driven and the electric motor 3 is driven, assist traveling by the electric motor 3 in the reverse speed can be performed. Furthermore, EV traveling can also be performed by setting the first clutch C1 to the OFF state. Deceleration regenerative operation can be performed in the reverse gear.

  Next, functions of the ECU 8 of this embodiment will be described.

  In the normal travel mode (when the temperature of the electric motor 3 is relatively low), the connection / disconnection device control unit 8a of the present embodiment controls the first clutch C1 in accordance with the travel state (travel mode) of the vehicle, and the engine 2 and the electric motor 3 are selectively controlled between a connection state and a cutoff state. For example, in the normal travel mode, the connection / disconnection device control unit 8a performs a process of disconnecting the connection between the engine 2 and the electric motor 3 by the first clutch C1 when the engine stop condition is satisfied. By doing so, fuel consumption by the engine 2 is reduced. Further, the connecting / disconnecting device control unit 8a controls the second clutch C2 in accordance with the traveling state (traveling mode) of the vehicle.

  The electric motor temperature detector 8 b detects the temperature of the electric motor 3. The temperature of the electric motor 3 is preferably the temperature of the rotor 3a provided with permanent magnets. Specifically, the electric motor temperature detection unit 8 b detects the temperature of the electric motor 3 based on a signal indicating the temperature of the electric motor 3 from the temperature detection unit 11. The electric motor temperature detector 8b corresponds to the temperature detector in the present invention. In addition, the motor temperature detection unit 8b may detect the temperature of the motor 3 by estimating the temperature of the motor 3 by calculation based on parameters related to the operation of the motor 3. Examples of the operating parameters of the electric motor 3 include the rotational speed Nm of the electric motor 3, the driving current and driving voltage of the electric motor 3, the gear stage selected by the power transmission device 1, the engine rotational speed Ne, the vehicle speed, and the like. .

  In addition, for example, a map that associates the operation parameter with the temperature of the electric motor 3 is stored in advance in a storage unit (not shown), and the electric motor temperature detection unit 8b reads the map read from the storage unit and the various sensors 10. The temperature of the electric motor 3 may be detected based on this detection signal.

  When the temperature of the electric motor 3 detected by the electric motor temperature detector 8b is equal to or higher than a predetermined temperature (for example, 200 ° C.), the motor high temperature processing unit 8c uses the first clutch C1 (connecting / disconnecting device) to connect the engine 2 and the electric motor 3 to each other. Is controlled to be kept in a connected state. The predetermined temperature includes a lower limit value of a temperature at which the torque of the electric motor 3 required for starting the engine cannot be secured, a lower limit value of a temperature at which drivability is not good when starting the engine 2 during EV traveling, and an electric motor in accordance with a driving force request The lower limit of the temperature at which the torque of 3 cannot be obtained.

  Specifically, the motor high temperature processing unit 8c disconnects the connection between the engine 2 and the electric motor 3 even when the electric motor 3 is at a high temperature equal to or higher than a predetermined temperature, for example, when the engine stop condition is satisfied. By inhibiting this, the engine 2 and the electric motor 3 are held in the connected state by the first clutch C1. By doing so, it is possible to eliminate the need for torque for starting the engine 2 by the electric motor 3. That is, even when the electric motor 3 becomes relatively high in temperature, the load on the electric motor 3 can be reduced without reducing drivability.

  Further, the ECU 8 is set to a normal travel mode (a travel mode when the motor 3 is at a low temperature) when the temperature of the motor 3 detected by the motor temperature detection unit 8b shifts from a state higher than a predetermined temperature to a lower state. Take control.

  For example, based on the driving force request set by the driving force setting unit 9, the gear position control unit 8d selects a traveling mode in which the rotational speed of the electric motor 3 is the lowest among the traveling modes that satisfy the driving force request.

  In the present embodiment, for example, as shown in FIG. 3, the traveling mode A (A1 to AN), the rotational speed Nm (Nm1 to NmN) of the electric motor 3, the engine rotational speed Ne (Ne1 to NeN), and the vehicle speed V ( The ECU 8 stores a map that associates (V1 to VN) and the gear stage G (G1 to GN) in advance in a storage unit (not shown). Based on the map read from the storage unit and the driving force request set by the driving force setting unit 9, the gear position control unit 8d extracts the traveling mode A that satisfies the driving force request, and the extracted traveling mode A Among them, the traveling mode A in which the rotational speed Nm of the electric motor 3 is the lowest is selected. By doing so, the load on the electric motor 3 can be reduced, and the temperature of the electric motor 3 can be lowered in a relatively short time.

  The rotation speed Nm (Nm1 to NmN), the engine rotation speed Ne (Ne1 to NeN), and the vehicle speed V (V1 to VN) of the electric motor 3 may be values within a range having specified widths.

  Further, in this embodiment, the shift speed control unit 8d performs the upshift and the downshift with a preshift to an odd speed when the motor 3 is in a traveling mode with an even speed and the motor 3 is at a temperature lower than a predetermined temperature. Either can be selected. Further, the shift speed control unit 8d performs control so that only the upshift is defined when pre-shifting to an odd speed when the motor 3 is in a traveling mode with an even speed and the motor 3 is at a temperature higher than a predetermined temperature. .

  Specifically, the gear position control unit 8d uses one of the drive gears (even-numbered gears) supported by the second main input shaft 22 (second drive gear shaft) by the second synchromesh mechanism S2. When connected to the second main input shaft 22 and the second clutch C2 is in a connected state, the transmission gear ratio is smaller than the gear ratio of the drive gear connected by the second synchronous meshing mechanism S2 (even gear stage). Control is performed to connect the drive gear of the gear stage (odd number of gear stages) to the first main input shaft 14 (first drive gear shaft) by the first synchronous meshing mechanism S1.

  The cooling control unit 8e increases the cooling amount (cooling amount per unit time) for cooling the electric motor 3 in accordance with the temperature of the electric motor 3 detected by the electric motor temperature detecting unit 8b. Specifically, the cooling control unit 8e performs control so that the cooling amount (cooling amount per unit time) for cooling the electric motor 3 by the cooling unit 12 is increased when the electric motor 3 is at a high temperature than when the electric motor 3 is at a low temperature. Do.

  Next, the operation of the hybrid vehicle of this embodiment will be described with reference to FIG. The following operations are executed by the ECU 8.

  In step ST1, the ECU 8 detects the temperature of the electric motor 3, more specifically, the temperature of the rotor of the electric motor 3, by the electric motor temperature detection unit 8b. For example, the electric motor temperature detection unit 8 b detects the temperature of the electric motor 3 based on a signal indicating the temperature of the electric motor 3 from the temperature detection unit 11. In addition, the motor temperature detection unit 8b may detect the temperature of the motor 3 by estimating the temperature of the motor 3 based on the operation parameter of the motor 3.

  In step ST2, the ECU 8 determines whether or not the temperature of the electric motor 3 detected by the electric motor temperature detector 8b is equal to or higher than a predetermined temperature (for example, 200 ° C.), and determines that the temperature of the electric motor 3 is equal to or higher than the predetermined temperature. If so, the process proceeds to step ST4. Otherwise, the process proceeds to step ST3.

  In step ST3, when the temperature of the electric motor 3 is lower than the predetermined temperature, the ECU 8 enters the normal travel mode and returns to the process of step ST1. In this normal travel mode, the connection / disconnection device control unit 8a selectively controls the connection state and the disconnection state between the engine 2 and the electric motor 3 by the first clutch C1 according to the travel state of the vehicle. That is, when a condition for disconnecting the engine 2 from the electric motor 3 (for example, an engine stop condition) is satisfied, the first clutch C1 disconnects the connection between the engine 2 and the electric motor 3 (engine disconnection permission). Further, when the condition for disconnecting the engine 2 from the electric motor 3 is not satisfied, the first clutch C <b> 1 brings the engine 2 and the electric motor 3 into a connected state.

  In step ST4, the ECU 8 holds the engine 2 and the motor 3 in the connected state by the first clutch C1 when the temperature of the motor 3 detected by the motor temperature detecting unit 8b is equal to or higher than the predetermined temperature by the motor high temperature processing unit 8c. Control to do. That is, the motor high temperature processing unit 8c suppresses disconnection of the connection between the engine 2 and the electric motor 3 when the electric motor 3 is at a predetermined temperature or higher even when the engine stop condition is satisfied, for example. . By doing so, it is possible to eliminate the need for torque for starting the engine 2 by the electric motor 3.

  Further, when the temperature of the electric motor 3 is higher than the predetermined temperature, the ECU 8 preferably performs any one of steps ST5 to ST8. The order of steps ST5 to ST8 may be changed as appropriate.

  In step ST5, when the electric motor 3 is at a high temperature, the ECU 8 causes the gear stage control unit 8d to change the electric motor 3 among the travel modes that satisfy the driving force request based on the driving force request set by the driving force setting unit 9, for example. Select the driving mode with the lowest rotation speed. Specifically, the gear position control unit 8d extracts the driving mode A that satisfies the driving force request based on the map read from the storage unit and the driving force request set by the driving force setting unit 9, and extracts the driving mode A. Among the travel modes A, the travel mode A with the lowest rotation speed Nm of the electric motor 3 is selected.

  In step ST6, when the electric motor 3 is at a high temperature, the ECU 8 uses the shift speed control unit 8d to drive the gear in the even speed mode, and when the motor 3 is at a temperature higher than a predetermined temperature, Control to specify only upshifts. In this way, when the motor 3 is at a high temperature, the travel mode in which the rotation speed of the motor 3 is the lowest is selected, and the load on the motor 3 can be reduced. Further, the temperature of the electric motor 3 can be reduced in a relatively short time.

  In step ST7, when the motor 3 is at a high temperature, the ECU 8 causes the cooling control unit 8e to increase the cooling amount (cooling amount per unit time) by which the motor 3 is cooled by the cooling unit 12 more than when the motor 3 is at a low temperature. Take control. By doing so, even when the electric motor 3 becomes hot, the temperature of the electric motor 3 can be lowered in a relatively short time.

  Next, the operation of the hybrid vehicle will be described with reference to FIG. In FIGS. 5B to 5D, the operation of the hybrid vehicle of the present embodiment is indicated by a solid line, and the operation of the hybrid vehicle of the comparative example is indicated by a dotted line. The threshold temperature T0 shown in FIG. 5 (d) corresponds to the predetermined temperature in the present invention.

  As shown in FIG. 5 (a), the vehicle speed of the hybrid vehicle is a constant speed v1 from time t1 to time t2, decelerates from time t2, becomes zero at time t3, and accelerates from time t4 to time t5. A case where the speed becomes v2 will be described.

  First, the operation of the hybrid vehicle of the comparative example will be described.

  The hybrid vehicle of the comparative example travels from time t1 to time t2 while being driven by the electric motor 3 and the engine 2 with the electric motor 3 and the engine 2 being connected by the first clutch C1. At this time, the engine rotational speed Ne is substantially constant, and the rotational speed Nm of the electric motor 3 is substantially constant. The temperature T of the electric motor 3 is a temperature T1 lower than the threshold temperature T0 at the time t1, increases from the time t1 to the time t1a, reaches the threshold temperature T0 at the time t1, further increases from the time t1a to the time t2, At time t2, the temperature T2 is higher than the threshold temperature T0.

  For example, when the throttle opening decreases at time t2, the hybrid vehicle of the comparative example determines that the engine stop condition is satisfied for reducing fuel consumption, and the first clutch C1 determines that the engine 2 and the motor 3 are Is disconnected, the fuel supply is stopped, and the engine 2 is stopped. At time t2, the engine rotational speed Ne becomes 0 rpm.

  From time t2 to time t3, the decelerating regeneration mode is set, and the rotational speed Nm of the electric motor 3 decreases and becomes zero at time t3. At this time, the load of the electric motor 3 is relatively high, and the temperature motivation temperature T of the electric motor is slightly reduced.

  From time t3 to time t4, the vehicle is stopped, the vehicle speed V is 0 km / h, the engine rotational speed Ne is 0 rpm, and the rotational speed Nm of the electric motor 3 is 0 rpm. The temperature T of the electric motor 3 is only slightly decreased.

  For example, when a driving force request is received by a driver's operation at time t4, in the hybrid vehicle of the comparative example, the electric motor 3 is rotationally driven to start the vehicle. At this time, the temperature T of the electric motor 3 is relatively high. For this reason, the torque by the electric motor 3 is low compared with the time of low temperature. Further, at time t4, the hybrid vehicle of the comparative example performs a starting operation with a torque obtained by subtracting the engine starting torque from the maximum torque of the electric motor 3 at a high temperature. For this reason, the load on the electric motor 3 is larger than that at a low temperature.

  At time t4a, in the hybrid vehicle of the comparative example, at the time of acceleration, for example, when it is determined that a driving force request equal to or greater than the torque by the electric motor 3 is set and the engine start condition is satisfied, the first clutch C1 is turned on. Power is transmitted from 3 to the engine 2, and the engine 2 is started by the electric motor 3. At this time, the electric motor 3 has a high load, and the temperature may further increase. Moreover, since the drive torque by the electric motor 3 is relatively small, drivability is relatively low. At time t5, the temperature T of the electric motor 3 is higher than the threshold temperature T0.

  Next, the operation of the hybrid vehicle according to the embodiment of the present invention will be described.

  From time t1 to time t2, since it is the same as the operation of the hybrid vehicle of the comparative example, the description is omitted.

  At time t2, in the hybrid vehicle of the present embodiment, for example, even when the throttle opening is reduced due to the running state and the engine stop condition (when the motor 3 is low temperature) is satisfied, the motor high temperature processing unit 8c suppresses disconnection of the connection between the engine 2 and the motor 3 by the first clutch C1 when the temperature of the motor 3 detected by the motor temperature detection unit 8b is equal to or higher than the predetermined temperature T0 (high temperature state). The engine 2 and the electric motor 3 are controlled to be held in the connected state by the first clutch C1.

  From time t2 to time t3, in the hybrid vehicle of the present embodiment, the deceleration regenerative operation is performed in a state where the engine 2 and the electric motor 3 are connected by the first clutch C1. During the deceleration regenerative operation, the electric energy generated by the electric motor 3 is charged to the battery 7 via the PDU 6.

  As described above, in the present embodiment, the decelerating regeneration operation is performed in a state where the engine 2 and the electric motor 3 are connected by the first clutch C1, for example, the connection of the electric motor 3 and the engine 2 by the first clutch C1. Compared with the load of the electric motor 3 at the time of the deceleration regeneration only by the electric motor 3 in the state where is disconnected, the load of the electric motor 3 of this embodiment is small. For this reason, in this embodiment, the temperature decrease rate of the electric motor 3 becomes relatively large, and the temperature of the electric motor 3 decreases.

  Further, the ECU 8 determines that the temperature of the electric motor 3 detected by the electric motor temperature detecting unit 8b is equal to or higher than a predetermined temperature, and sets a cooling amount (cooling amount per unit time) for cooling the electric motor 3 by the cooling unit 12. The control is performed so that the electric motor 3 is increased more than when the temperature is low. By doing so, the temperature decrease rate of the electric motor 3 is further increased, and the temperature of the electric motor 3 is decreased.

  From time t3 to time t4, the vehicle is stopped, and the engine 2 and the motor 3 perform an idling operation at a predetermined idling speed while the motor 3 and the engine 2 are connected by the first clutch C1.

  For example, when a driving force request is received by a driver's operation at time t <b> 4, the hybrid vehicle according to the present embodiment starts the vehicle by driving the electric motor 3 and the engine 2. At this time, since it is not necessary to start the engine 2, the load on the electric motor 3 is smaller than that in the comparative example.

  From time t4 to time t5, the vehicle is accelerated by driving the engine 2 and the electric motor 3 during vehicle acceleration. For this reason, the load to the electric motor 3 is low, and the temperature rise of the electric motor 3 is low. At this time, the ECU 8 may perform control so that the driving of the electric motor 3 is stopped and only the engine 2 is driven in a state where the engine 2 and the electric motor 3 are connected by the first clutch C1. By doing so, the load on the electric motor 3 is reduced, the temperature lowering speed of the electric motor 3 is further increased, and the temperature of the electric motor 3 is lowered.

  In the present embodiment, at time t4a, the ECU 8 determines that the temperature of the electric motor 3 detected by the electric motor temperature detection unit 8b is lower than a predetermined temperature, and shifts to a normal driving mode (driving mode when the electric motor 3 is at a low temperature). To do.

  As described above, the hybrid vehicle according to the present embodiment generates power between the engine 2, the electric motor 3 that can start the engine 2, and the engine 2 and / or the electric motor 3 and the drive wheels 4 (driven parts). The power transmission device 1 capable of transmission and the ECU 8 (control unit) that controls the power transmission device 1 in accordance with the traveling state of the vehicle. The power transmission device 1 includes a first clutch C <b> 1 that can connect and disconnect between the engine 2 and the electric motor 3. The ECU 8 uses the first clutch C1 to connect the engine 2 and the electric motor 3 when the temperature of the electric motor 3 detected by the electric motor temperature detecting unit 8b is equal to or higher than a predetermined temperature T0. And an electric motor high temperature processing unit 8c which is controlled to be held in a connected state.

  That is, according to the hybrid vehicle, even when the electric motor 3 is at a high temperature that is equal to or higher than the predetermined temperature, for example, when the stop condition of the engine 2 is satisfied, such as during EV traveling, the electric vehicle 3 is By suppressing the disconnection, the engine 2 and the electric motor 3 are held in the connected state by the first clutch C1, so that the torque for starting the engine 2 by the electric motor 3 can be made unnecessary.

  That is, it is possible to provide a hybrid vehicle capable of reducing the load on the electric motor 3 without reducing drivability even when the electric motor 3 becomes relatively high in temperature.

  In the hybrid vehicle of the present invention, even when the electric motor 3 becomes relatively high in temperature, the engine 2 and the electric motor 3 are held in the connected state by the first clutch C1, so that the load on the electric motor 3 is reduced. It is possible to reduce the temperature of the electric motor 3 in a relatively short time.

  Further, when the electric motor 3 is at a relatively high temperature, the engine 2 and the electric motor 3 can ensure the driving torque to the driving wheels 4 and can prevent the drivability from being lowered.

  Further, even when the motor 3 performs deceleration regeneration when the motor 3 is relatively high in temperature, since the engine 2 and the motor 3 are kept connected by the first clutch C1, the load on the motor 3 can be reduced. 3 can be lowered in a relatively short time.

  In the present embodiment, the permanent magnet is provided on the rotor 3a of the electric motor 3, but the present invention is not limited to this configuration. A permanent magnet may be provided on the stator (stator) 3b.

  Although the embodiment has been described above, the present invention is not limited to the above embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Power transmission device, 2 ... Engine (internal combustion engine: ENG), 2a ... Driving force input shaft (input shaft), 3 ... Electric motor, 3a ... Rotor, 3b ... Stator, 4 ... Drive wheel (driven part), 5 ... Auxiliary machine, 6 ... Power drive unit (PDU), 7 ... Battery (power storage device, secondary battery), 8 ... Electronic control unit (ECU), 8a ... Connecting / disconnecting device controller, 8b ... Motor temperature detector , 8c ... High temperature motor processing unit, 8d ... Shift speed control unit, 8e ... Cooling control unit, 9 ... Driving force setting unit, 10 ... Various sensors, 11 ... Temperature detection unit, 12 ... Cooling unit, 13 ... Power synthesizing mechanism (Planetary gear unit), 13c ... carrier, 13p ... planetary gear, 13r ... ring gear, 13s ... sun gear, 14 ... first main input shaft (first drive gear shaft), 15 ... first auxiliary input shaft, 16 ... reverse shaft, 17 ... Reverse gear shaft, 18 ... 19 ... Intermediate shaft, 20 ... Gear train, 21 ... Gear train, 22 ... Second main input shaft (second drive gear shaft), 23 ... Gear train, 24 ... Second sub input shaft, 25 ... Third Sub-input shaft, 26 ... output shaft, 26a, 26b ... driven gear, 27 ... 2-speed gear train, 28 ... 4-speed gear train, 29 ... 3-speed gear train, 30 ... 5-speed gear train, 31 ... differential gear unit 32 ... axle, 33 ... housing (non-moving part), 34 ... belt mechanism, C1 ... first clutch (connecting / disconnecting device), C2 ... second clutch, S1 ... first synchronous meshing mechanism, S2 ... second synchronous meshing mechanism , SL: third synchronous meshing mechanism, SR: reverse synchronous meshing mechanism.

Claims (7)

An internal combustion engine, an electric motor, a power transmission device capable of transmitting power between the internal combustion engine and / or the electric motor and a driven portion, and a control unit for controlling the power transmission device in accordance with a running state of a vehicle; A hybrid vehicle having
The power transmission device includes a connection / disconnection device capable of connecting / disconnecting the internal combustion engine and the electric motor,
The controller is
A temperature detector for detecting the temperature of the electric motor;
When the temperature of the electric motor detected by the temperature detection unit is lower than a predetermined temperature, and when a condition for disconnecting the internal combustion engine from the electric motor is satisfied, the connection / disconnection device disconnects the internal combustion engine from the electric motor. A connecting / disconnecting device control unit,
When the temperature of the electric motor detected by the temperature detection unit is equal to or higher than a predetermined temperature , the internal combustion engine and the electric motor are held in a connected state by the connecting / disconnecting device regardless of whether the condition is satisfied. A hybrid vehicle characterized by having an electric motor high temperature processing section that is controlled as described above. The power transmission device transmits the power by a first or second speed change mechanism that establishes a plurality of shift speeds, respectively.
  The first speed change mechanism is connected to the electric motor;
  The first and second transmission mechanisms are disconnected or connected to the internal combustion engine;
  The control unit shifts the power for transmission when the second speed change mechanism has established a predetermined gear position for transmitting the power when the temperature of the electric motor is equal to or higher than the predetermined temperature. 2. The hybrid vehicle according to claim 1, wherein the speed is switched to a speed established by the first speed change mechanism and having a speed ratio smaller than the predetermined speed. A hybrid vehicle comprising an internal combustion engine and an electric motor, shifting power from the internal combustion engine and / or the electric motor and transmitting it to an output shaft connected to a driven part,
  A first speed change mechanism that receives power input to the input shaft from the internal combustion engine by a first drive gear shaft, changes speed at an established speed among a plurality of speeds, and transmits the speed to the output shaft;
  A second speed change mechanism that receives power input from the internal combustion engine to the input shaft by a second drive gear shaft, changes speed at an established speed among a plurality of speeds, and transmits the speed to the output shaft;
  A first clutch that connects and disconnects the input shaft and the first drive gear shaft;
  A second clutch that connects and disconnects transmission of power between the input shaft and the second drive gear shaft;
  A control unit that controls establishment of a gear position in the first transmission mechanism and the second transmission mechanism, and connection / disconnection of the first clutch and the second clutch;
  The first drive gear shaft is coupled to the electric motor;
  The controller is
  A temperature detector for detecting the temperature of the electric motor;
  When the temperature of the electric motor detected by the temperature detection unit is lower than a predetermined temperature, and when a condition for disconnecting the internal combustion engine from the electric motor is satisfied, the connection between the internal combustion engine and the electric motor is disconnected by the first clutch. A connecting / disconnecting device control unit,
  When the temperature of the electric motor detected by the temperature detection unit is equal to or higher than a predetermined temperature, the internal combustion engine and the electric motor are held in a connected state by the first clutch regardless of whether or not the condition is satisfied. A motor high temperature treatment section;
  When the temperature of the electric motor detected by the temperature detection unit is equal to or higher than a predetermined temperature, a predetermined shift stage is established in the second transmission mechanism, and when the second clutch is in an engaged state, the predetermined shift stage A hybrid vehicle comprising: a shift speed control unit that establishes a shift speed having a smaller speed ratio in the first speed change mechanism. 4. The control unit according to claim 2, wherein the control unit establishes a shift step that is higher by one step than the predetermined shift step when establishing a shift step having a gear ratio smaller than the predetermined shift step. The described hybrid vehicle.   5. The control unit according to claim 1, wherein, when the temperature of the electric motor is equal to or higher than a predetermined temperature, the control unit drives the internal combustion engine even if the stop condition of the internal combustion engine is satisfied. The hybrid vehicle according to item 1. A cooling unit for cooling the electric motor;
The hybrid vehicle according to claim 1, wherein the control unit increases a cooling amount for cooling the electric motor in accordance with the detected temperature. A driving force setting unit for setting a driving force required for the driven unit;
When the temperature of the electric motor is equal to or higher than the predetermined temperature , the control unit selects a traveling mode in which the rotational speed of the electric motor is the lowest among the traveling modes that satisfy the driving force requirement set by the driving force setting unit. The hybrid vehicle according to any one of claims 1 to 6 , characterized in that:

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