JP2014101042A - Hybrid vehicle drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid vehicle drive device which comprises an engine and an electric motor as power sources to drive driving wheels, and a circulation pump to circulate a refrigerant for cooling down the electric motor, and efficiently cools down the electric motor at low cost.SOLUTION: A circulation pump 51 to circulate a refrigerant for cooling down an electric motor 3 is provided so as to be driven by power of the electric motor 3, switching to a non-transmission state in which power of the electric motor 3 is not transmitted to driving wheels is performed, and the electric motor 3 drives the circulation pump 51 to cool down the electric motor 51 itself.

Description

  The present invention relates to a hybrid vehicle drive device including an engine, an electric motor, and a transmission mechanism that transmits power from the engine and the electric motor to drive wheels.

  A hybrid vehicle drive device that includes an engine, an electric motor, and a transmission mechanism that transmits power from the engine and the electric motor to drive wheels is conventionally known. However, when the output of the electric motor is increased, the amount of heat generated increases. On the contrary, the output may decrease.

  In order to prevent a decrease in output due to this heat generation, a hybrid vehicle drive device is provided which is provided with a circulation pump for circulating the refrigerant and cools the electric motor by the refrigerant circulation (see, for example, Patent Document 1).

JP-A-5-330348

  However, in the hybrid vehicle drive device of the above-mentioned document, it is necessary to separately provide a power source for driving the circulation pump, which increases the number of parts, increases the manufacturing cost, and increases the amount of heat generated by the electric motor and the circulation pump. Depending on the output value of the motive power source, there is a possibility that the output of the electric motor may decrease without being cooled in time.

  The present invention provides a drive device for a hybrid vehicle that includes an engine and an electric motor as a power source for driving drive wheels, a circulation pump that circulates a refrigerant that cools the electric motor, and can efficiently cool the electric motor at a low cost. The issue is to provide.

  A hybrid vehicle drive device according to the present invention is a hybrid vehicle drive device including an engine, an electric motor, and a transmission mechanism that transmits power from the engine and the electric motor to drive wheels, and cools the electric motor. A circulation pump for circulating the refrigerant to be driven is provided so as to be driven by the power of the electric motor, and the transmission mechanism is switched between a transmission state in which the power of the electric motor is transmitted to the drive wheels and a non-transmission state in which the transmission is not transmitted. And a control unit for controlling the switching between the transmission state and the non-transmission state in the transmission mechanism and for controlling the drive of the electric motor. The control unit switches to the non-transmission state and is circulated by the electric motor. It has a self-cooling mode in which the electric motor itself is cooled by driving a pump.

  With the above configuration, the circulation pump that circulates the refrigerant that cools the electric motor is driven by the power of the electric motor, so there is no need to separately provide a power source that drives the circulation pump. Has a simplified self-cooling mode that cools the electric motor itself by switching to a non-transmission state where the power of the electric motor is not transmitted to the drive wheels and driving the circulation pump by the electric motor. Therefore, when the amount of generated heat increases, the electric motor can be rapidly cooled in the self-cooling mode, and therefore, it is possible to cope with a rapid temperature increase of the electric motor due to a high load.

  It is good also as what provided the interlocking means which links the rotation speed of a circulation pump with the rotation speed of an electric motor.

  By providing the transmission mechanism with intermittent means for interrupting the power transmitted from the electric motor to the drive wheels, the transmission mechanism can be switched between a transmission state and a non-transmission state, and between the intermittent means and the electric motor. A circulation pump may be arranged in the transmission path.

  A circulation pump may be arranged on a transmission shaft that rotates synchronously with a transmission gear that transmits power from the electric motor toward the intermittent means, and the circulation pump may be driven by the transmission shaft.

  A circulation pump may be disposed on the output shaft of the electric motor, and the circulation pump may be driven by the output shaft.

  A power transmission path through which the power of the output shaft of the electric motor is transmitted is provided separately from the power transmission path to the drive wheels, a circulation pump is disposed in the transmission path, and the power transmitted from the electric motor through the power transmission path The circulating pump may be driven by

  Since the circulation pump that circulates the refrigerant that cools the electric motor is driven by the power of the electric motor, there is no need to separately provide a power source that drives the circulation pump, and the configuration is simplified and the manufacturing cost is reduced. And a self-cooling mode in which the electric motor itself is cooled by switching to a non-transmission state in which the power of the electric motor is not transmitted to the drive wheels and driving the circulation pump by the electric motor. Since the electric motor can be rapidly cooled by the self-cooling mode, it becomes possible to cope with a rapid temperature increase of the electric motor due to a high load.

It is a transmission system diagram of a drive device to which the present invention is applied. It is a hydraulic circuit diagram of a cooling device. It is a block diagram of a control part. It is a processing flow figure of transmission control by a connection sleeve.

  FIG. 1 is a transmission system diagram of a drive device to which the present invention is applied. A driving device 1 shown in the figure is mounted on a hybrid vehicle such as a four-wheeled vehicle or a two-wheeled vehicle that drives driving wheels (not shown) by an engine (internal combustion engine) 2 and an electric motor 3.

  The drive device 1 includes an engine 2, a motor generator that is an electric motor 3 that performs driving and power generation, a drive / power generation unit 4 that switches between driving and power generation of the motor generator 3, and a motor generator via the drive / power generation unit 4. A battery 6 that supplies electric power to the motor 3 and the electric power generated by the motor generator 3 is supplied via drive / power generation means, and a transmission that can transmit one or both of the power of the engine 2 and the motor generator 3 to the drive wheels ( Transmission mechanism) 7.

  The transmission 7 is provided with a crankshaft 8 from which the power of the engine 2 is output, an input shaft 9 having the same axial center as the crankshaft 8, and disposed between the crankshaft 8 and the input shaft 9. The main clutch 11 that interrupts power transmission to the input shaft 9, the first output shaft 12 and the second output shaft 13 that are arranged in parallel with the input shaft 9, the drive shaft 14 that drives the drive wheels, and the two A traveling speed change mechanism 16 that is installed on the output shafts 12 and 13 and the input shaft 9 and shifts the power to the drive shaft 14 (that is, traveling system power), and the rotational power generated by the electric motor 3 are transmitted to the traveling speed change mechanism 16. Motor-side transmission mechanism 17, the first output gear 18 provided to rotate synchronously (specifically, integrally) with the first output shaft 12, and the synchronous rotation (specifically, rotate with the second output shaft 13). Provided to rotate integrally) An output gear 19 and a drive gear 21 provided on the drive shaft 14 so as to rotate synchronously (specifically rotate integrally) with the two output gears 18 and 19 and the meshing drive shaft 14 are provided. .

  The travel transmission mechanism 16 bears on the first output shaft 12 and the small-diameter low-speed input gear 22 and large-diameter high-speed input gear 23 provided to rotate synchronously (specifically, integrally rotate) with the input shaft 9. The first low-speed output gear 24 that is supported so as to be relatively rotatable (freely rotatable) via the first gear and always meshes with the low-speed input gear 22, and is relatively rotatable (freely rotatable) via the bearing to the first output shaft 12. A first high-speed output gear 26 that is supported and always meshed with the high-speed input gear 23, and a second output shaft 13 that is supported so as to be relatively rotatable (freely rotatable) via a bearing and always meshed with the low-speed input gear 22. A second low-speed output gear 27; a second high-speed output gear 28 that is supported by the second output shaft 13 via a bearing so as to be relatively rotatable (freely rotatable) and that is always meshed with the high-speed input gear 23; 24 and first high-speed output gear 26 Between the first sleeve 29, which is a synchronous mesh clutch disposed on the first output shaft 12 so as to be positioned between the second low-speed output gear 27 and the second high-speed output gear 28. And a second sleeve 31 that is a synchronous mesh clutch disposed on the second output shaft 13.

  The first sleeve 29 is configured to be slidable in the axial direction of the first output shaft 12 and to rotate synchronously (specifically, rotate integrally) with the first output shaft 12.

  When the first sleeve 29 is slid to the first low-speed output gear 24 side, the first sleeve 29 and the first low-speed output gear 24 mesh with each other while being synchronized by the synchronizing means 24a and are completely meshed. Then, the 1st low speed output gear 24 and the 1st output shaft 12 will be in the state (1st output state) which carries out synchronous rotation (specifically integral rotation). In this first output state, the power of the input shaft 9 is as follows: low speed input gear 22 → first low speed output gear 24 → first sleeve 29 → first output shaft 12 → first output gear 18 → drive gear 21 → drive shaft 14 → It is transmitted in the order of drive wheels.

  On the other hand, by sliding the first sleeve 29 toward the first high-speed output gear 26, the first sleeve 29 and the first high-speed output gear 26 are meshed while being synchronized by the synchronizing means 26a, and are completely meshed. In this state, the first high speed output gear 26 and the first output shaft 12 are in a state of rotating synchronously (specifically, integrally rotating) (third output state). In this third output state, the power of the input shaft 9 is as follows: high-speed input gear 23 → first high-speed output gear 26 → first sleeve 29 → first output shaft 12 → first output gear 18 → drive gear 21 → drive shaft 14 → It is transmitted in the order of drive wheels.

  Further, by positioning the first sleeve 29 in the middle between the first low speed output gear 24 and the first high speed output gear 26, the power of the input shaft 9 is not transmitted to the first output shaft 12.

  The second sleeve 31 is configured to be slidable in the axial direction of the second output shaft 13 and to rotate synchronously (specifically, rotate integrally) with the second output shaft 13.

  When the second sleeve 31 is slid to the second low-speed output gear 27 side, the second sleeve 31 and the second low-speed output gear 27 mesh with each other while being synchronized by the synchronization means 27a and are completely meshed. Then, the second low-speed output gear 27 and the second output shaft 13 are in a state of rotating synchronously (specifically, integrally rotating) (second output state). In this second state, the power of the input shaft 9 is as follows: low speed input gear 22 → second low speed output gear 27 → second sleeve 31 → second output shaft 13 → second output gear 19 → drive gear 21 → drive shaft 14 → It is transmitted in the order of the drive wheels.

  On the other hand, by sliding the second sleeve 31 toward the second high-speed output gear 28, the second sleeve 31 and the second high-speed output gear 28 mesh with each other while being synchronized by the synchronization means 28a. The second high-speed output gear 28 and the second output shaft 13 are in a state of rotating synchronously (specifically, integrally rotating) (fourth output state). In this fourth output state, the power of the input shaft 9 is as follows: high speed input gear 23 → second high speed output gear 28 → second sleeve 31 → second output shaft 13 → second output gear 19 → drive gear 21 → drive shaft 14 → It is transmitted in the order of drive wheels.

  Further, by positioning the second sleeve 31 between the second low-speed output gear 27 and the second high-speed output gear 28, the power of the input shaft 9 is not transmitted to the second output shaft 13.

  Incidentally, the second low-speed gear 27 has a smaller diameter and fewer teeth than the first low-speed output gear 24, and the second high-speed output gear 28 has a smaller diameter and fewer teeth than the first high-speed output gear 26. The speed ratio of the power transmitted from the input shaft to the drive shaft is set at high speed in the order of the first output state → second output state → third output state → fourth output state. That is, by selecting which of the four output gears 24, 26, 27, 28 is transmitted to the output shafts 12, 13, a total of four travel shifts are performed by the travel transmission mechanism 16.

  In other words, all of the four output gears 24, 26, 27, and 28 are in a disconnected state, or only one of them is in a connected state. In addition, at the time of traveling shift, the main clutch 11 is disconnected before shifting and the engine power is not transmitted to the input shaft 9, and the main clutch 11 is again connected after shifting.

  The traveling speed change mechanism 16 is also provided with means for transmitting reverse power for moving the vehicle backward. Specifically, a reverse gear 32 is provided so as to rotate synchronously (specifically, rotate integrally) with the input shaft 9, and outer peripheral teeth 29 a are formed over the entire circumference of the first sleeve 29. A reversing gear 33 that can mesh with the outer peripheral teeth 29 a and the reverse gear 32 is rotatably supported by a reversing shaft 34 that is parallel to the input shaft 9.

  The reversing gear 33 is slidable in the axial direction of the reversing shaft 34. When the reversing gear 33 is engaged with the outer peripheral teeth 29a and the reversing gear 32 by the sliding operation, the reversing gear 32, the reversing gear 33 and the The reverse (reverse) power is transmitted from the input shaft 9 to the first output shaft 12 via the 1 sleeve 29, and the vehicle is driven to travel backward.

  The motor-side transmission mechanism 17 is a motor shaft that is coaxial with the output shaft 3a of the electric motor 3 parallel to the input shaft 9 and is connected to the output shaft 3a in a synchronized rotation (specifically, an integral rotation). 36, a motor gear 37 provided on the motor shaft 36 and rotating synchronously (specifically, integrally rotating) with the motor shaft 36, an intermediate shaft (transmission shaft) 38 parallel to the motor shaft 36, and the intermediate shaft 38 An intermediate gear 39 that rotates synchronously with the intermediate shaft 38 (specifically, integrally rotates), and is supported by the input shaft 9 so as to be relatively rotatable (freely rotatable) via a bearing. An input shaft side connection gear 41 that is always meshed, and a first output shaft side connection gear that is supported by the first output shaft 12 so as to be relatively rotatable (freely rotatable) via a bearing and always meshes with the input shaft side connection gear 41. 42 and bearing the second output shaft 13 The second output shaft side connection gear 43 that is supported so as to be relatively rotatable (freely rotatable) and always meshes with the input shaft side connection gear 41, and an input that is a synchronous meshing clutch disposed on the input shaft 9. A shaft-side connecting sleeve (intermittent means) 44, a first output shaft-side connecting sleeve (intermittent means) 46, which is a synchronous mesh clutch disposed on the first output shaft 12, and a second output shaft 13 And a second output shaft side connection sleeve (intermittent means) 47 which is a synchronous mesh type clutch.

  The input shaft side connection sleeve 44 is configured to be slidable in the axial direction of the input shaft 9 and to rotate synchronously with the input shaft 9 (specifically, rotate integrally).

  By sliding the input shaft side connection sleeve 44 toward the input shaft side connection gear 41, the input shaft side connection sleeve 44 and the input shaft side connection gear 41 are meshed while being synchronized by the synchronization means 41a. In the state where the input shaft side connection gear 41 and the input shaft 9 are rotated synchronously (specifically, integrally rotated) (first connection state), the input shaft side connection sleeve 44 is By sliding the input shaft side connection gear 41 away from the input shaft side connection gear 41, the engagement between the input shaft side connection sleeve 44 and the input shaft side connection gear 41 is released. Is powered off.

  In the first connection state, the output shaft 3a of the electric motor 3 is connected to the travel transmission mechanism 16 through the motor shaft 36, the motor gear 37, the intermediate gear 38, the input shaft side connection gear 41, and the input shaft 9 so as to be capable of power transmission. Connected. For this reason, the power from the electric motor 3 is transmitted to the input shaft 9 during driving, and the power from the input shaft 9 is transmitted to the electric motor 3 during power generation.

  The first output shaft side connection sleeve 46 is configured to be slidable in the axial direction of the first output shaft 12 and to rotate synchronously (specifically, integrally) with the first output shaft 12.

  By sliding the first output shaft side connection sleeve 46 toward the first output shaft side connection gear 42, the first output shaft side connection sleeve 46 and the first output shaft side connection gear 42 are synchronized with each other by the synchronizing means 42a. The first output shaft side connection gear 42 and the first output shaft 12 are rotated synchronously (specifically, integrally rotated) (second connection state) in a state of being meshed while being synchronized with each other and completely engaged. On the other hand, the first output shaft side connection sleeve 46 and the first output shaft side connection gear are moved by sliding the first output shaft side connection sleeve 46 away from the first output shaft side connection gear 42. The meshing with 42 is released, and the first output shaft side connection gear 42 and the first output shaft 46 are mechanically disconnected.

  In the second connection state, the output shaft 3a of the electric motor 3 passes through the motor shaft 36, the motor gear 37, the intermediate gear 38, the input shaft side connection gear 41, the first output shaft side connection gear 42, and the first output shaft 12. Thus, it is connected to the traveling speed change mechanism 16 so as to be capable of power transmission. Therefore, the power from the electric motor 3 is transmitted to the first output shaft 12 during driving, and the power from the first output shaft 12 is transmitted to the electric motor 3 during power generation.

  The second output shaft side connection sleeve 47 is configured to be slidable in the axial direction of the second output shaft 13 and to rotate synchronously (specifically, integrally) with the second output shaft 13.

  By sliding the second output shaft side connection sleeve 47 to the second output shaft side connection gear 43 side, the second output shaft side connection sleeve 47 and the second output shaft side connection gear 43 are synchronized with each other by the synchronizing means 43a. The second output shaft side connection gear 43 and the second output shaft 13 are synchronously rotated (specifically, integrally rotated) (specifically, in the third connection state) in a state where they are meshed while being synchronized with each other. On the other hand, the second output shaft side connection sleeve 47 and the second output shaft side connection gear are moved by sliding the second output shaft side connection sleeve 47 away from the second output shaft side connection gear 43. The meshing with 43 is released, and the second output shaft side connection gear 43 and the second output shaft 13 are mechanically disconnected.

  In the third connection state, the output shaft 3a of the electric motor 3 passes through the motor shaft 36, the motor gear 37, the intermediate gear 39, the input shaft side connection gear 41, the second output shaft side connection gear 43, and the second output shaft 13. Thus, it is connected to the traveling speed change mechanism 16 so as to be capable of power transmission. For this reason, the power from the electric motor 3 is transmitted to the second output shaft 13 during driving, and the power from the second output shaft 13 is transmitted to the electric motor 3 during power generation.

  As described above, all the three connection gears 41, 42, 43 are disconnected, or only one of the three connection gears 41, 42, 43 is connected and the remaining two are connected. Intermittent control is performed so as to be in a disconnected state. At this time, when the output side or the input side of the traveling speed change mechanism 16 is connected to the electric motor 3 so as to be capable of power transmission, or to the output side, the electric motor 3 is further connected to the two output shafts 12. , 13 can be selected as appropriate according to the configuration described above.

  The drive device 1 configured as described above is configured to be switchable between an engine traveling state, an assist traveling state (motor transmission state), and a motor traveling state (motor transmission state).

  In addition, the drive device 1 can be switched between a transmission state in which the power of the electric motor 3 is transmitted to the traveling speed change mechanism 16 (drive wheel) and a non-transmission state in which the transmission is not transmitted by the connection sleeves 44, 46 and 47. It is configured. Incidentally, in the transmission state, only one of the three connection gears 41, 42, 43 is in the connection state.

  In the engine running state, the main clutch 8 is switched to the connection to connect the engine 2 and the running speed change mechanism 16 so that power can be transmitted. In the running speed change mechanism 16, any one of the four output gears 24, 26, 27, and 28 is connected. Is transmitted to the drive shaft 14 or the reverse drive power is transmitted to the drive shaft 14 via the reversing gear 33 to drive the vehicle by engine power alone.

  In the assist travel state, the main clutch 11 is switched to the connection and the engine 2 and the travel transmission mechanism 16 are connected so as to be capable of power transmission, and the motor-side transmission mechanism 17 is switched to the transmission state described above to switch between the electric motor 3 and the travel speed change. The mechanism 16 is connected so as to be capable of power transmission. In the traveling speed change mechanism 16, any one of the four output gears 24, 26, 27, 28 is transmitted to the drive shaft 9, and the power from the engine 2 and the electric motor 3 are transmitted. The vehicle is driven to travel by power from the vehicle.

  In the motor running state, the main clutch 11 is switched to disengagement to cut off the power transmission to the engine 2 and the travel transmission mechanism 16, and the motor side transmission mechanism 17 is switched to the transmission state to switch the electric motor 3 and the travel transmission mechanism 16 to each other. The vehicle is driven to travel only by the power from the electric motor 3.

  Incidentally, in this motor running state, the driving of the engine 2 is stopped, and when the power from the electric motor 3 is transmitted to the input shaft 9, the traveling transmission mechanism 16 has four output gears 24, 26, 27, 28. Either one of the powers is transmitted to the drive shaft 14, or the reverse power is transmitted to the drive shaft 14 via the reverse gear 33.

  By the way, it is preferable to increase the output of the electric motor 3 in order to optimally assist the driving of the vehicle. However, the electric motor 3 having a high output has a large amount of power generation, and the temperature of the electric motor 3 itself is increased and output. May decrease. In order to prevent this, the drive device 1 is provided with a cooling device 48 (see FIG. 2) for cooling the electric motor 3.

  FIG. 2 is a hydraulic circuit diagram of the cooling device. The cooling device 48 includes an oil tank 49 in which oil as a refrigerant is stored, a circulation pump 51 that pumps oil from the oil tank 49 to the electric motor 3 that is a cooling target, and the oil tank 49 to the circulation pump 51. An oil strainer 52 that is a filter that is disposed in the middle of the oil flow path and removes foreign matter in the oil sent from the oil tank 49 to the electric motor 3 side, and in the middle of the flow path from the circulation pump 51 to the electric motor 3. An oil cooler 53 that cools the oil that is disposed and pumped by a radiation fin or the like, and a flow path that returns the oil to the oil tank 49 side after cooling the electric motor 3, and makes the hydraulic circuit of the cooling device 48 a predetermined pressure And a relief valve 54 to be held at the center.

  In this example, the oil tank 49 is a transmission case that houses the drive device 1, and the oil to be used is lubricating oil in the transmission case, but an oil tank 49 may be separately provided in addition to the transmission case.

  The circulation pump 51 cools and circulates oil as shown in the figure, and the electric motor 3 is cooled by using the oil cooled by this cooling cycle as a refrigerant. The circulation pump 51 is driven by power from the electric motor 3.

  Specifically, a circulation pump 51 is disposed in a transmission path between the connection sleeves 44, 46, and 47 that connect the electric motor 3 and the travel transmission mechanism 16 so that power transmission is possible, and the electric motor 3. More specifically, the circulation pump 51 is disposed on the shaft of the intermediate shaft 38 disposed in the transmission path between the connection sleeves 44, 46, 47 and the electric motor 3, and the input shaft (not shown) of the circulation pump 51 is connected to the intermediate shaft 38. The intermediate shaft 38 and the intermediate shaft 38 are coupled so as to rotate synchronously (specifically, rotate integrally) and have the same axis.

  Thus, by directly inputting the power of the electric motor 3 to the circulation pump 51, the rotation speed of the input shaft of the circulation pump 51 (the rotation speed of the circulation pump 51, It constitutes interlocking means that interlocks the supply amount.

  Since the electric motor 3 generates heat while the electric motor 3 is being driven, in principle, it is not necessary to drive the circulation pump 51 when the electric motor 3 is not driven. For this reason, in the drive stop state of the electric motor 3, it is set as the disconnection state mentioned above.

  The connection sleeves 44, 46, 47, the first and second sleeves 29, 31 and the main clutch 11 are intermittently controlled, the engine 2 is driven / stopped, and the electric motor 3 is driven / generated / stopped. The control unit 56 (see FIG. 3) is configured to switch between the engine traveling state, the assist traveling state, and the motor traveling state.

  FIG. 3 is a block diagram of the control unit. On the input side of the control unit 56, a shift operation detecting means 57 for detecting a traveling shift operation of a driver who has entered the vehicle, a temperature sensor 58 which is a temperature detecting means for detecting the temperature of the electric motor 3, and a vehicle A vehicle speed sensor 59 which is a vehicle speed detection means for detecting the traveling speed (vehicle speed) and an on / off detection means 61 for detecting on / off of the main clutch 11 are connected.

  On the output side of the control unit 56, there are three speed change actuators 63, 64 such as a hydraulic clutch and a hydraulic cylinder for switching the intermittent state of the first and second sleeves 29, 31 and three connection sleeves 44, 46, 47. The switching actuators 65, 66, and 67, which are hydraulic clutches and hydraulic cylinders that switch the intermittent state of the main clutch 11, and the intermittent actuator 68 that switches the intermittent state of the main clutch 11 are connected. Incidentally, the intermittent state of the three connection sleeves 44, 46, 47 and the first and second sleeves 29, 31 can be determined by the control unit 56 itself based on a signal output from the control unit 56.

  In addition, the controller 56 is connected to the above-described drive / power generation means 4 and the engine control means 69 such as an ECU that controls the drive / stop of the engine 2 and can also acquire the engine speed. Has been.

  The control unit 56 switches between the non-transmission state and the transmission state as described above so that the fuel efficiency is good based on the detection result from the shift operation detection unit 57 and the acquired engine speed, vehicle speed, and the like. And the above-described engine running state, assist running state, and motor running state are switched.

  Further, as described above, the control unit shuts off the power transmission between the electric motor 3 and the travel transmission mechanism 16 in the above-described disconnected state in order to stop driving the circulation pump 51 as described above in the engine running state. At the same time, the drive of the electric motor 3 is stopped.

  However, when the temperature sensor 58 detects that the temperature of the electric motor 3 itself is high in this engine running state or in a state where the vehicle has stopped running, When it is predicted that the temperature is high, it is effective to drive the electric motor 3 for a purpose other than the traveling purpose and forcibly cool itself.

  For this reason, the control unit 56 switches to the above-described non-connected state when the engine is running or when the vehicle is stopped to cut off the power transmission between the electric motor 3 and the running speed change mechanism 16, and It has a self-cooling mode in which the motor 3 is driven to drive the circulation pump 51 to self-cool the electric motor 3 itself.

  Further, when it is detected that the load is low by obtaining the engine speed or the like during the engine running state, efficient running is possible by storing surplus energy in the battery 6. For this reason, when a low load or the like of the engine 2 is confirmed by the control unit 56 during the engine running state, the electric motor 3 is switched to the power generation state by the driving / power generation means 4 while the engine running state is maintained. The controller 56 switches to the charging mode in which the traveling power is branched and transmitted from the traveling transmission mechanism 16 to the electric motor 3 by switching to the connected state.

  That is, the control unit 56 that switches between the engine running state, the assist running state, and the motor running state has the above-described self-cooling mode and charging mode, and each connection at the time of state switching or mode switching. By appropriately controlling the interruption of the sleeves 44, 46, 47 by the control unit 56, the above-described object can be reliably achieved.

  FIG. 4 is a process flow diagram of transmission control by the connection sleeve. When the transmission control process is started, the control unit 56 proceeds to step S1. In step S1, it is confirmed whether or not the electric motor 3 is in a driving state by the driving / power generation means 4. If it is in a driving state, the process proceeds to step S2. In step S2, it is confirmed whether or not the mode is shifted to the self-cooling mode. If the mode is not shifted to the self-cooling mode or should not be shifted, it is assumed that the vehicle is in the assist traveling state or the motor traveling state. The process proceeds to step S3.

  In step S3, it is confirmed whether or not it is in the above-described transmission state. If it is in the non-transmission state, the process proceeds to step S4. Since it is only necessary to continue the traveling state, the process returns to step S1. In step S4, switching to the above-described transmission state is performed, the electric motor 3 and the traveling speed change mechanism 16 are connected so as to be capable of power transmission, and the process returns to step S1 as the assist traveling state or the motor traveling state.

  If the stop state of the electric motor 3 is detected by the drive / power generation means 4 in step S1, the process proceeds to step S5. In step S5, it is confirmed whether or not the mode is shifted to the charging mode. If the mode is shifted to the charging mode or is to be shifted, the electric motor 3 and the traveling speed change mechanism 16 are powered. In order to establish a connection to allow transmission, the process proceeds to step S3. On the other hand, if the charging mode is not shifted or should not be shifted, the engine is running and the driving of the electric motor 3 is stopped and cooling is performed. Since it is considered unnecessary, the process proceeds to step S6.

  In step S6, it is confirmed whether or not the power transmission path between the electric motor 3 and the travel transmission mechanism 16 is interrupted. If it is interrupted, the power loss is small as described above, and the state is maintained as it is. Therefore, the process returns to step S1, while if not interrupted, the process proceeds to step S7 in order to reduce power loss. In step S7, the power transmission between the electric motor 3 and the traveling speed change mechanism 16 is interrupted by switching to the above-described disconnected state, and the process returns to step S1.

  If it is determined in step S2 that the self-cooling mode is set, the process proceeds to step S6 so that the power of the driving electric motor 3 is not transmitted to the traveling speed change mechanism 16 side.

  According to such control contents, the stopping means for stopping the driving of the circulation pump 51 is constituted by the process of step S1, step S5, step S6, and step S7 when the engine is running. According to this stopping means, when cooling of the electric motor 51 is unnecessary, the driving of the circulation pump 51 is stopped, and the power from the engine 2 is not transmitted to the circulation pump 51. Is reduced.

  1, the circulation pump 51 is disposed on the output shaft 3a of the electric motor 3, and the output shaft 3a and the pump shaft of the circulation pump 51 can be rotated synchronously with the same axis ( More specifically, the motor shaft 36 may be used for connection.

  Further, as indicated by phantom lines in FIG. 1, a transmission path through which the power of the output shaft 3a of the electric motor 3 is transmitted is provided separately from the transmission path to the drive wheels, and a circulation pump 51 is provided in the transmission path. The circulation pump 51 may be driven by power that is disposed and transmitted from the electric motor 51 via a transmission path.

  Specifically, a dedicated shaft 71 parallel to the motor shaft 36 is provided in addition to the intermediate shaft 38, and the dedicated gear 72 is provided in synchronized rotation (specifically, integral rotation) with the dedicated shaft 71 and always meshes with the pump gear 37. The circulating pump 51 is disposed on a dedicated shaft 71, and the dedicated shaft 71 and the pump shaft can be connected to each other so as to be able to rotate synchronously (more specifically, integrally rotate). Good.

DESCRIPTION OF SYMBOLS 1 Drive device 2 Engine 3 Electric motor 3a Output shaft 7 Transmission mechanism 39 Intermediate gear (transmission gear)
38 Intermediate shaft (transmission shaft)
44, 46, 47 Connection sleeve (intermittent means)
51 Circulating pump 56 Control unit

Claims (6)

A hybrid vehicle drive device comprising an engine and an electric motor, and a transmission mechanism for transmitting power from the engine and the electric motor to drive wheels,
A circulation pump for circulating a refrigerant for cooling the electric motor is provided to be driven by the power of the electric motor,
The transmission mechanism is configured to be switched between a transmission state in which the power of the electric motor is transmitted to the drive wheels and a non-transmission state in which transmission is not performed.
A control unit for controlling the switching between the transmission state and the non-transmission state in the transmission mechanism and controlling the drive of the electric motor is provided.
The control unit has a self-cooling mode in which the electric motor itself is cooled by switching to a non-transmission state and driving the circulation pump by the electric motor. The hybrid vehicle drive device according to claim 1, further comprising interlocking means for interlocking the rotational speed of the circulation pump with the rotational speed of the electric motor. By providing the transmission mechanism with intermittent means for interrupting the power transmitted from the electric motor to the drive wheels, the transmission mechanism can be switched between a transmission state and a non-transmission state,
The hybrid vehicle drive device according to claim 2, wherein a circulation pump is disposed in a transmission path between the intermittent means and the electric motor. The drive device for a hybrid vehicle according to claim 3, wherein a circulation pump is disposed on a transmission shaft that rotates in synchronization with a transmission gear that transmits power from the electric motor toward the intermittent means, and the circulation pump is driven by the transmission shaft. The hybrid vehicle drive device according to claim 2, wherein a circulation pump is disposed on an output shaft of the electric motor, and the circulation pump is driven by the output shaft. A power transmission path through which the power of the output shaft of the electric motor is transmitted is provided separately from the power transmission path to the drive wheels, a circulation pump is disposed in the transmission path, and the power transmitted from the electric motor through the power transmission path The hybrid vehicle drive device according to claim 2, wherein the circulation pump is driven by the drive unit.

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