JP2015112958A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve fuel economy performance of a hybrid vehicle incorporating a dual-clutch type transmission.SOLUTION: In a state where a vehicle travels using an even-numbered transmission stage by connecting a second clutch C2, an ECU connects a first clutch C1 while maintaining the connection of the second clutch C2. This enables a motor-generator 30 to perform a regenerating operation and a rotary driving operation. In a case where vehicle requirement torque that is deviated from a most effective position of an operation point of an engine 20 occurs, by causing the motor-generator 30 to perform a regenerating operation and a rotary driving operation, the operation point of the engine 20 is adjusted to improve an engine efficiency.

Description

  The present invention relates to a hybrid vehicle, and more particularly to a hybrid vehicle equipped with a so-called dual clutch type transmission.

  2. Description of the Related Art In recent years, dual clutch transmissions that perform gear shifting by selectively switching two clutches are known in order to eliminate transmission of mechanical power during gear shifting.

  The dual clutch transmission has an odd number of gears on the first clutch side and an even number of gears on the second clutch side. Then, by switching the first clutch and the second clutch in accordance with the selection of these shift speeds, switching between the odd speed and the even speed can be performed alternately.

  Patent Document 1 (Japanese Patent Application Laid-Open No. 2012-166574) discloses a motor generator that couples a motor output shaft to a first input shaft (odd-stage shaft) of one transmission mechanism in a dual clutch transmission as described above. It is disclosed. In such a dual-clutch transmission, a motor rotational driving force is applied to the first input shaft to which the electric motor is coupled, so that the running torque at the start can be increased.

JP 2012-166574 A International Publication No. 2011-122243 International Publication No. 2011-37211

  However, in the dual clutch transmission of Patent Document 1, since the electric motor is structurally not coupled to the second input shaft (even-numbered shaft) side, the power passing through the even-numbered gears on the second clutch side. When the vehicle is traveling using the transmission path, the engine load cannot be controlled using the motor generator.

  For this reason, when driving with an even number of gears selected, the engine operating point position is uniquely determined with respect to the output of the drive shaft (number of revolutions × torque) according to the selected parameters such as vehicle speed, running resistance, and gear. It will be confirmed. As a result, when the determined engine operation point is out of the high efficiency region, the fuel consumption performance may be deteriorated.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to improve fuel efficiency of a hybrid vehicle equipped with a dual clutch transmission.

  A hybrid vehicle according to the present invention is input from an engine that rotationally drives an engine output shaft, a motor generator that outputs torque to the motor output shaft with power transfer to and from the battery, and the engine output shaft and the motor output shaft. A transmission that outputs the rotational driving force from a drive output shaft connected to a drive wheel of a vehicle via a selected shift stage among a plurality of shift stages, and a control that controls switching of the shift stage by the transmission A part. The transmission includes a first input shaft that receives rotational driving force from the engine output shaft and the motor output shaft, a second input shaft that receives rotational driving force from the engine output shaft, and an engine output shaft and a first input shaft. A first clutch that connects / disconnects between the second clutch, a second clutch that connects / disconnects between the engine output shaft and the second input shaft, and an odd number of shift stages selected from among the shift stages selected by the control unit. A first transmission mechanism that forms an odd-numbered gear stage that connects between the first input shaft and the drive output shaft when selected, and an even gear stage selected from the gear stages selected by the controller; And a second speed change mechanism that forms an even number of speed stages that connect between the second input shaft and the drive output shaft when the second speed stage is selected. The controller is configured to drive the first clutch while the second clutch is connected in a state where the second speed change mechanism is running using an even number of shift stages formed between the second input shaft and the drive output shaft. Connect and rotate the motor output shaft of the motor generator.

  According to the present invention, the control unit is connected to the first clutch together with the second clutch while traveling using even-numbered gears, and the motor output shaft of the motor generator is connected to the engine output shaft. The

  For this reason, it is possible to control the load applied to the engine by the output of the motor generator. As a result, the position of the engine operation point can be changed with respect to the same drive shaft output, so that even when the vehicle is traveling using even-numbered gear positions, the engine operation point is set by the motor generator. It can be adjusted to be located in the most efficient area. As a result, the fuel efficiency of a hybrid vehicle equipped with a dual clutch transmission can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel consumption performance of the hybrid vehicle carrying a dual clutch type transmission can be improved.

1 is a schematic configuration diagram of a hybrid vehicle of an embodiment. It is a skeleton figure explaining the structure of the transmission shown in FIG. 2 is a flowchart for explaining processing by a control unit in the hybrid vehicle shown in FIG. 1. 2 is a graph for explaining the relationship between engine efficiency and engine operating points in the hybrid vehicle shown in FIG. 1. It is a flowchart explaining the process by the control part in the hybrid vehicle of embodiment. 6 is a graph for explaining the relationship between engine efficiency and driving points in the hybrid vehicle of FIG. 5.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

FIG. 1 is a schematic configuration diagram of hybrid vehicle 100 according to the embodiment of the present invention.
The hybrid vehicle 100 of this embodiment includes an electronic control unit (hereinafter also referred to as ECU) 10, an engine 20, a motor generator 30 that can be driven to rotate according to electric power and can generate regenerative power, and a motor generator 30. A motor generator control unit (hereinafter also referred to as PCU) 40 for controlling rotational driving force or regenerative power, a battery 50 for supplying power to the motor generator 30, and a dual clutch transmission (hereinafter referred to as DC)
60). The ECU 10 controls the operation of each component of the hybrid vehicle 100.

  The engine 20 is provided with an engine output shaft 25 that is rotationally driven. A DCT 60 is connected to the engine output shaft 25 and the motor output shaft 35 of the motor generator 30. In addition, the DCT 60 is provided with a plurality of shift stages G1 to G7. The ECU 10 performs switching control of the gear stages G1 to G7 in the DCT 60.

  ECU10 selects any one gear stage of suitable gear ratio from these gear stages G1-G7. Then, the DCT 60 outputs the rotational driving force input from the engine output shaft 25 and the motor output shaft 35 as the traveling driving force via any one of the gears selected from the gears G1 to G7 by the ECU 10. The travel driving force is transmitted from the left and right drive shafts 80L, 80R to the drive wheels 90L, 90R via the differential mechanism 70 from the DCT 60.

  FIG. 2 is a skeleton diagram of a typical dual clutch transmission, which is a shift control device for hybrid vehicle 100 in FIG. Since the basic configuration is substantially the same as that of the above-described Japanese Patent Application Laid-Open No. 2012-166574, detailed description other than the main part will not be repeated.

  The DCT 60 is a twin-clutch transmission that has a parallel shaft system of 7 forward speeds and 1 reverse speed, and includes two dry first and second clutches C1 and C2.

  The DCT 60 has a multi-axis (here, 6-axis) structure, and forms a first input shaft IMS of the first transmission mechanism D1 that provides an odd number of shift stages and an outer cylinder of the first input shaft IMS. A second transmission mechanism that is arranged in parallel with the outer input shaft OMS, the first input shaft IMS, and the outer input shaft OMS, and that provides even-numbered speeds with a speed ratio different from the speed of the first input shaft IMS. And a second input shaft SS of D2.

  Among these, the first input shaft IMS is directly coupled so as to be rotatable integrally with the motor output shaft 35 of the motor generator 30. Further, the first input shaft IMS is configured to be able to be connected to and disconnected from the engine output shaft 25 of the engine 20 by engagement or disengagement of the first clutch C1.

  Further, the outer input shaft OMS located outside the first input shaft IMS is always meshed (not shown) with the second input shaft SS via the transmission gear of the idle shaft IDS, and the rotational driving force is generated. It is configured to be transmitted from the second clutch C2.

  Further, the rotational driving force of the idle shaft IDS is transmitted to the reverse shaft RVS from the reverse gear stage GR constituted by connecting the reverse gear to the reverse shaft RVS and used for traveling in the reverse direction. It can also be used as the driving force of the oil pump OP connected to the RVS.

  The DCT 60 is provided with a countershaft CS whose axial direction is parallel to the first input shaft IMS, the second input shaft SS, and the like. The counter shaft CS is connected to the differential mechanism 70 shown in FIG. 1 corresponding to the driving of the DCT 60.

  The first input shaft IMS is connected to a first clutch C1 for odd-numbered stages. A ring gear 115 of the planetary gear mechanism 110 is fixed to an end edge portion (a base end portion of the motor output shaft 35) opposite to the first clutch C1 and the second clutch C2 in the axial extending direction of the first input shaft IMS. ing. The ring gear 115 is located on the radially inner side of the motor generator 30. Planetary gear mechanism 110 is inserted to a position overlapping motor generator 30 along the extending direction of motor output shaft 35.

  Further, in the planetary gear mechanism 110, a carrier 113 is fixedly provided at the tip of the outer input shaft OMS. The carrier 113 rotatably supports a plurality of planetary gears 112, respectively.

  The planetary gear 112 is meshed with internal teeth formed on the inner peripheral surface of the ring gear 115 and also meshed with a sun gear 111 fixed to the end of the first input shaft IMS on the motor generator 30 side. Yes.

  The ring gear 115 is provided with a first-speed synchromesh mechanism 114. The first speed synchromesh mechanism 114 is configured to restrict the rotation of the ring gear 115 so that the ring gear 115 cannot be rotated when the first speed is selected.

  Next, the configuration of the transmission mechanism of the DCT 60 of this embodiment will be described. The speed change mechanism has a first speed change mechanism D1 and a second speed change mechanism D2.

  First, the first transmission mechanism D1 will be described in detail. On the outer periphery of the first input shaft IMS, in order from the left side in the figure, there are a carrier 113 of the planetary gear mechanism 110 that constitutes the first speed gear stage G1 that constitutes the first speed change mechanism D1, and a third speed gear stage G3. The drive gear 131, the drive gear 171 serving as the seventh speed gear stage G7, and the drive gear 151 serving as the fifth speed gear stage G5 are rotatably supported with respect to the first input shaft IMS.

  Among these, the drive gear 131 is connected to the carrier 113 of the planetary gear mechanism 110 via the outer input shaft OMS. On the first input shaft IMS, a 3-7 speed synchromesh mechanism 134 is provided between a 3rd speed drive gear 131 and a 7th speed drive gear 171 so as to be slidable in the axial direction. Further, a 5-speed synchromesh mechanism 152 is provided on the first input shaft IMS so as to be slidable in the axial direction in correspondence with the 5-speed drive gear 151.

  Then, the synchromesh mechanism corresponding to the desired gear stage G3, G5, G7 is slid to selectively synchronize the drive gears 131, 151, 171 of any gear stage with the outer peripheral surface of the first input shaft IMS. Connect. As a result, desired odd-numbered shift stages G3, G5, and G7 are formed between the first input shaft IMS and the countershaft CS.

  The drive gears 131, 151, 171 related to the first input shaft IMS are meshed with corresponding driven gears 51, 53, 52 provided on the countershaft CS in synchronization with the synchromesh mechanism. In this synchronized state, the first clutch C1 is engaged. Due to the engagement of the first clutch C1, the engine output shaft 25 of the engine 20 is connected to the first input shaft IMS via the first clutch C1.

  In the first speed change mechanism D1, any one of the selected odd-numbered speed stages G3, G5, and G7 is set between the first input shaft IMS and the counter shaft CS. It is formed. The first input shaft IMS is connected to the countershaft CS via the odd-numbered shift speeds. Therefore, the rotational driving force of the engine 20 or the motor generator 30 is transmitted from the left and right drive shafts 80L and 80R to the drive wheels 90L and 90R via the differential mechanism 70 from the counter shaft CS. Then, the drive wheels 90L and 90R can be rotated at a desired rotation speed according to the selected gear ratio of any of the gear stages G3, G5, and G7.

  Next, the second speed change mechanism D2 will be described in detail. Around the outer periphery of the second input shaft SS, there is a drive gear 142 for the second speed gear stage G2, a drive gear 146 for the sixth speed gear stage G6, and a fourth speed gear stage G4. The drive gear 144 is pivotally supported so as to be relatively rotatable, and is arranged in order from the left side in the drawing.

  Further, on the second input shaft SS, a 2-6 speed synchromesh mechanism 183 is provided between the 2nd speed drive gear 142 and the 6th speed drive gear 146 so as to be slidable in the axial direction. A 4-speed synchromesh mechanism 184 is slidably provided along the axial direction corresponding to the 4-speed drive gear 144.

  Then, the synchromesh mechanism 183 or 184 corresponding to the desired even speed stage G2, G4, G6 is slid along the axial direction of the second input shaft SS, and one of the speed stages G2, G4, G6 is The drive gears 142, 144, and 146 are selectively coupled in synchronization with the outer peripheral surface of the second input shaft SS. As a result, desired even speed stages G2, G4, G6 are formed between the second input shaft SS and the countershaft CS.

  The drive gears 142, 144, and 146 related to the second input shaft SS are meshed with corresponding driven gears 51, 53, and 52 provided on the countershaft CS in synchronization with the synchromesh mechanism. In a synchronized state, the second clutch C2 is engaged.

  Due to the engagement of the second clutch C2, the engine output shaft 25 of the engine 20 is connected to the second input shaft SS via the second clutch C2.

  In the second speed change mechanism D2, any of the selected even-numbered speeds G2, G4, G6 causes the selected even-numbered speed to be changed to the secondary shaft (hereinafter also referred to as a second input shaft) SS. And the countershaft CS. Then, the second input shaft SS is connected to the countershaft CS via the even speed stages. Therefore, the rotational driving force of the engine 20 is transmitted from the left and right drive shafts 80L and 80R to the drive wheels 90L and 90R through the differential mechanism 70 from the counter shaft CS. Then, the drive wheels 90L and 90R can be rotated at a desired rotational speed in accordance with the selected gear ratio of any of the gear stages G2, G4, and G6.

  As described above, in the transmission mechanism of the DCT 60, in response to the gear change request, the ECU 10 is one of the first, third, and fifth gears G1, G3, which is constituted by the first input shaft IMS. At least one of the gear shifts G5 and G7 or the second, fourth, and sixth gear stages G2, G4, and G6 configured by the second input shaft SS is selectively switched. In the normal shift control, when the rotational driving force is output from the countershaft CS using the switched shift speed, the first clutch C1 or the second clutch corresponding to the first input shaft IMS or the second input shaft SS. When one of the clutches C2 is engaged and the other is disengaged, one of the first input shaft IMS and the second input shaft SS is connected to the engine output shaft 25 of the engine 20.

  In the DCT 60, the motor output shaft 35 of the motor generator 30 is directly connected to the first input shaft IMS in a state where the shift stages G1, G3, G5 on the first input shaft IMS side forming the odd-numbered stages are selected. For this reason, in a state in which the shift stages G1, G3, and G5 are selected, torque generated by the rotational drive operation or the regenerative operation is transmitted to the engine output shaft 25 as a load. Therefore, by adjusting the rotational torque output from the motor output shaft 35 of the motor generator 30, the position of the engine operating point of the engine 20 can be adjusted to be within the most efficient region.

  However, in the normal shift control of the DCT 60, the first clutch C1 is disconnected when the shift stages G2, G4, G6 on the second input shaft SS side are selected and the second clutch C2 is connected. For this reason, the motor torque generated by the rotational drive operation or the regenerative operation of the motor output shaft 35 of the motor generator 30 cannot be transmitted to the engine output shaft 25.

  Therefore, as described below, the transmission mechanism of the present embodiment performs fuel saving control by connecting the first clutch C1 while the second clutch C2 is connected.

  The fuel saving control is performed by selecting any one of even-numbered shift stages G2, G4, and G6 configured between the second input shaft SS and the countershaft CS according to the vehicle request torque Treq from the ECU 10. This is performed with the clutch C2 connected and running.

  FIG. 3 is a flowchart corresponding to a fuel-saving control subroutine performed in even stages, assuming that normal shift control is the main routine.

  The ECU 10 of the hybrid vehicle 100 starts a shift control process according to a main routine (not shown). The ECU 10 executes the fuel saving control shown in FIG. 3 according to the vehicle required torque Treq input by the even-numbered shift stages G2, G4, G6 and the user's accelerator operation not shown.

  In step S10, the ECU 10 compares the required vehicle torque Treq generated by the user's accelerator input and the like with the optimum engine torque Tpe at the engine operation point when the fuel efficiency is the best.

  FIG. 4 is a graph illustrating the relationship between engine efficiency and engine operating points. Referring to FIG. 4, optimal engine operation curve TL is stored in advance in a memory device (not shown). Good fuel efficiency can be obtained by positioning the engine operation point on the optimum engine operation curve TL.

  Here, the engine power Pe at each engine operating point is indicated by the product of the engine speed Ne and the engine torque Te. Therefore, the engine torque Te is a value obtained by dividing the engine power Pe by the engine speed Ne.

  Therefore, when the engine power Pe on the optimum engine operating curve TL is divided by the engine speed target value Nereq corresponding to the vehicle required torque Treq, the optimum engine torque Tpe having the best fuel efficiency at the engine speed Ne is calculated. can do.

  Referring to FIG. 3 again, in step S10, the ECU 10 compares the vehicle request torque Treq with the calculated optimum engine torque Tpe. If the vehicle required torque Treq is smaller than the optimum engine torque Tpe (YES in step S10), the process proceeds to the next step S20.

  Further, when the vehicle required torque Treq is larger than the optimum engine torque Tpe (NO in step S10), the ECU 10 returns the process to the main routine (return).

  In step S20, the ECU 10 determines whether or not the SOC (State Of Charge) of the battery 50 is less than a preset threshold value D (%). If the SOC (%) of battery 50 is less than threshold value D (%) in step S20 (YES in step S20), ECU 10 proceeds to the next step S30. If the ECU 10 is not less than the threshold value D (%) (NO in step S20), the process returns to the main routine (return).

  When the ECU 10 proceeds with the process to step S30, the ECU 10 engages the first clutch C1 provided in the DCT 60. By engagement of the first clutch C1, the motor output shaft 35 of the motor generator 30 is connected to the counter shaft CS and the second input shaft SS. Thereby, the engine output shaft 25 and the motor output shaft 35 of the motor generator 30 are connected. Therefore, the motor generator 30 can perform the rotational drive operation (assist drive operation) or control the engine power Pe of the engine output shaft 25 by the regenerative operation (regeneration control by the PCU 40).

  The ECU 10 proceeds to the next step S40. In step S40, a torque load is generated from the connected motor output shaft 35 due to the regenerative operation performed by the motor generator 30. The electric power generated by the regenerative operation of motor generator 30 is sent from PCU 40 to battery 50 and battery 80 is charged.

  Referring to FIG. 2 again, the transmission path of the rotational driving force will be described. The ECU 10 connects the first clutch C1 while maintaining the second clutch C2. Due to the connection of the first clutch C1, the motor output shaft 35 of the motor generator 30 is connected to the engine via the first input shaft IMS and the first clutch C1 even when the vehicle is traveling at even gears G2, G4, G6. Connected to the output shaft 25.

  In FIG. 4, the torque load T <b> 1 is applied from the motor generator 30 to the engine output shaft 25, whereby the engine power Pe of the engine 20 is maintained at a position where the most efficient operation can be performed. Therefore, the magnitude of torque load T1 is controlled according to the difference between vehicle request torque Treq and optimum engine torque Tpe when it is generated in association with the regenerative operation of motor generator 30. Therefore, when the fuel saving control is performed, the position of the engine power Pe of the engine 20 can be adjusted so as to be maintained within a desired most efficient region, and the operation can be continued with high fuel efficiency.

  As described above, the regenerative operation of the motor generator 30 is performed even when the vehicle is traveling using even-numbered gears G2, G4, and G6 on the second clutch C2 side due to the connection of the first clutch C1 that is not connected in normal control. Thus, by adding the torque load T1, the position of the engine operating point of the engine 20 can be adjusted to be in the most efficient region.

  Referring to FIG. 3 again, ECU 10 determines in step S50 whether or not the SOC of charged battery 50 exceeds a preset threshold value D (%) by the regenerative operation of motor generator 30.

  If the ECU 10 determines that the SOC of the battery 50 exceeds the threshold value D (%) (YES in step S50), the ECU 10 determines that the SOC of the battery 50 is sufficient to store the power that can travel. . If it will be in such a state, ECU10 will advance a process to the following step S60.

  If ECU 10 determines that the SOC of battery 50 does not exceed threshold value D (%) (NO in step S50), ECU 10 determines that the SOC of battery 50 is not sufficient. Then, the process returns to step S40, and the regeneration operation by the motor generator 30 is continued.

  When the process proceeds to step S60, the ECU 10 releases the engagement of the first clutch C1, disconnects the motor output shaft 35 of the motor generator 30 from the engine output shaft 25, finishes the fuel saving control process, and performs the process in the main routine. Return to (Return).

  In the shift control of the hybrid vehicle 100 of the embodiment configured as described above, the motor output shaft 35 of the motor generator MG is connected to the engine output shaft 25, and the load applied to the engine 20 is controlled by the motor torque. Thus, the position of the engine operation point can be changed and adjusted with respect to the same drive shaft output. Therefore, according to the present invention, the fuel efficiency of the hybrid vehicle 100 equipped with the DCT 60 can be improved.

  So far, the case where the vehicle required torque Treq is smaller than the optimum engine torque Tpe has been described. However, conversely, the vehicle required torque Treq may be larger than the optimum engine torque Tpe.

  Therefore, hereinafter, description will be given of switching control by formation of a shift stage when the vehicle required torque Treq is larger than the most efficient region of the engine operating point of the engine 20 (on the optimum engine operation curve TL shown in FIG. 6).

  In such a case, if the engine operating point of the engine 20 is set to the optimum engine torque Tpe obtained according to the optimum engine operation curve TL, the vehicle required torque Treq cannot be ensured only with the optimum engine torque Tpe.

  For this reason, when the vehicle required torque Treq is larger than the optimum engine torque Tpe, it is necessary to perform control so that the assist torque T2 is output from the motor generator 30.

  In other words, the assist torque T2 in the fuel saving control is applied to the first clutch C1 from the motor output shaft 35 of the motor generator 30 so that the torque load T1 obtained by the regenerative operation of the motor generator 30 described above is in the reverse rotation direction. Via the countershaft CS.

  Since this assist torque T2 is applied in the same direction as the rotation direction of the engine output shaft 25 of the engine 20, even when the vehicle required torque Treq is larger than the optimum engine torque Tpe, the vehicle required torque Tr is satisfied. The position of the engine operating point of the engine 20 can be adjusted to be maintained in the most efficient region.

  FIG. 5 corresponds to a fuel saving control subroutine that is performed in a state in which an even speed is selected as a shift speed, assuming that normal shift control is the main routine, as in FIG.

  The ECU 10 of the hybrid vehicle 100 increases the vehicle required torque Treq by the input of a user's accelerator operation (not shown) in the even-numbered shift stages G2, G4, G6 during the shift control process according to the main routine (not shown). Then, the fuel saving control shown in FIG. 5 is started.

  The vehicle required torque Treq input in step S110 is compared with the preset optimum engine torque Tpe and it is determined that the fuel saving control is to be executed (YES in step S110), and then the motor according to the SOC of the battery 50 is determined. The determination in the case where the fuel saving control is not executed (return) by the processing and determination until the determination as to whether or not to assist with torque is performed (step S120) is the same as the flowchart in FIG. .

  When the SOC of the battery 50 exceeds the preset threshold value E (%) in step S120, the ECU 10 has a problem even if the ECU 10 consumes the electric power stored in the battery 50 as the driving force. Judge that there is no charge level.

  When the process proceeds to the next step S130, the ECU 10 engages the first clutch C1 provided in the DCT 60. When the ECU 10 proceeds to the next step S140, the motor output shaft 35 of the motor generator 30 is also connected to the drive wheels 90R and 90L via the first clutch C1 via the engine output shaft 25 and the countershaft CS. Is done.

  The rotational driving force output from the motor output shaft 35 is added to the rotational driving force from the engine 20, and assists when the driving wheels 90L and 90R are rotationally driven via the counter shaft CS.

  By assisting the driving force by the motor generator 30, the required vehicle required torque Treq can be output from the counter shaft CS even when the engine 20 alone cannot obtain a sufficient optimum engine torque Tpe. it can.

  Therefore, good fuel efficiency can be obtained by maintaining the engine power Pe at the engine operation point on the optimum engine operation curve TL (see FIG. 6).

  For example, by connecting the first clutch C1 while maintaining the connection of the second clutch C2, the motor output shaft 35 of the motor generator 30 is in the first state even when traveling at even speed stages G2, G4, G6. The input shaft IMS is connected to the engine output shaft 25 via the first clutch C1. When the torque assist is performed, the position of the engine operation point where the engine power Pe is exhibited can be maintained in the most efficient region in the same manner as the fuel saving control with the regeneration operation, and the operation can be performed with high efficiency.

  Next, the ECU 10 determines whether or not the SOC of the consumed battery 50 has fallen below a preset threshold value E due to the rotational drive during assist of the motor generator 30 in step S150.

  If the ECU 10 determines that the SOC of the battery 50 has fallen below the threshold value E (%) (YES in step S150), the ECU 10 proceeds to the next step S160 to disengage the first clutch C1. End fuel saving control (return).

  Further, when ECU 10 determines that the SOC of battery 50 is not lower than threshold value E (%) (NO in step S150), ECU 10 returns to step S140, and torque assist of engine 20 is performed by rotational driving of motor generator 30. Will continue.

  As described above, in hybrid vehicle 100 of this embodiment, torque load T1 or assist is obtained from motor output shaft 35 of motor generator 30 connected to engine output shaft 25 while obtaining an output corresponding to vehicle required torque Tr. Torque T2 is applied.

  That is, when vehicle required torque Tr is smaller than the position of engine power Pe of engine 20, torque load T1 of motor generator 30 that applies load to engine 20 to the most efficient position is applied. Further, when the vehicle required torque Tr is larger than the position of the engine power Pe of the engine 20, the assist torque T2 of the motor generator 30 that assists the engine 20 to the most efficient position is added and assisted.

  Thus, regardless of the magnitude of the vehicle required torque Treq, the engine power Pe is maintained in a region on the most efficient optimum engine operation curve TL. For this reason, it is possible to drive the engine 20 with high efficiency and improve fuel efficiency.

  Furthermore, in the hybrid vehicle 100 of the present embodiment, the first clutch C1 is connected together with the second clutch C2 in the state where the even gears G2, G4, and G6 of the DCT 60 are running. The motor output shaft 35 of the motor generator 30 can be connected to the engine output shaft 25.

  As a result, in the hybrid vehicle 100 shown in FIG. 1, even-numbered gears G2, G4, and G6 are added to the odd-numbered gears G1, G3, and G5 of the DCT 60, and all the gears G1 to G7 are saved. Fuel consumption can be controlled. Thereby, the engine 20 is driven with high efficiency, and the fuel efficiency of the hybrid vehicle 100 can be improved.

  In this embodiment, the vehicle required torque Tr has been described as being both larger and smaller than the position of the engine power Pe of the engine 20. However, the vehicle required torque Tr is equal to the engine power Pe of the engine 20. It is also possible to cause the ECU 10 to control only one of the case where the position is smaller than the position or the case where the vehicle required torque Tr is larger than the position of the engine power Pe of the engine 20.

  Finally, the hybrid vehicle 100 according to the embodiment of the present invention will be summarized. Referring to FIG. 1, engine 20 for rotating engine output shaft 25, motor generator 30 for outputting torque to motor output shaft 35 with power exchange with battery 50, engine output shaft 25, and The rotational driving force input from the motor output shaft 35 is output from the countershaft CS connected to the drive wheels 90L and 90R of the hybrid vehicle 100 via the selected gear stage among the plurality of gear stages G1 to G7. DCT60 and ECU10 which controls switching of the gear stage by DCT60 are provided. As shown in FIG. 2, the DCT 60 includes a first input shaft IMS that receives rotational driving force from the engine output shaft 25 and the motor output shaft 35, a second input shaft SS that receives rotational driving force from the engine output shaft 25, and The first clutch C1 for connecting / disconnecting the engine output shaft 25 and the first input shaft IMS, the second clutch C2 for connecting / disconnecting the engine output shaft 25 and the second input shaft SS, and the ECU 10 are selected. The first shift that forms an odd-numbered shift stage that connects between the first input shaft IMS and the countershaft CS when any one of the shift stages G1 to G7 is selected. When even-numbered gears of the mechanism D1 and any of the gears G1 to G7 selected by the ECU 10 are selected, the even-numbered gears that connect the second input shaft SS and the counter shaft CS are selected. Shift stage And a second transmission mechanism D2 for forming. The ECU 10 travels using the even number of shift stages formed between the second input shaft SS and the countershaft CS by the second transmission mechanism D2 while the second clutch C2 is connected. The clutch C1 is connected and the motor output shaft 35 of the motor generator 30 is rotated.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  10 ECU, 20 engine, 25 engine output shaft, 30 motor generator, 35 motor output shaft, 40 PCU, 50 battery, 60 DCT, 70 differential mechanism, 80L, 80R drive shaft, 90L, 90R drive wheel, 100 hybrid vehicle, 111 Sun gear, 112 planetary gear, 113 carrier, 114, 134, 152, 183, 184 synchromesh mechanism, 115 ring gear, 131, 142, 144, 146, 151, 171 drive gear, C1 first clutch, C2 second clutch, CS counter Shaft, IDS idle shaft, IMS first input shaft, OMS outer input shaft, OP oil pump, RG reverse gear, RVS reverse shaft, SS second input shaft, D1 first transmission mechanism , D2 Second speed change mechanism.

Claims (1)

An engine that rotates the engine output shaft;
A motor generator for outputting torque to the motor output shaft with power exchange with the battery;
A transmission that outputs the rotational driving force input from the engine output shaft and the motor output shaft from a drive output shaft connected to the drive wheels of the vehicle via a selected gear among a plurality of gears;
A control unit that controls switching of the gear position by the transmission,
The transmission is
A first input shaft for receiving a rotational driving force from the engine output shaft and the motor output shaft;
A second input shaft for receiving a rotational driving force from the engine output shaft;
A first clutch that connects and disconnects between the engine output shaft and the first input shaft;
A second clutch that connects and disconnects between the engine output shaft and the second input shaft;
The odd-numbered gear stage that connects between the first input shaft and the drive output shaft when an odd-numbered gear position is selected from the gear stages selected by the control unit. A first speed change mechanism to be formed;
When an even-numbered shift stage is selected from among the shift stages selected by the control unit, the even-numbered shift stage that connects between the second input shaft and the drive output shaft is selected. A second speed change mechanism to be formed,
The controller connects the second clutch in a state where the second speed change mechanism is running using the even-numbered speed stage formed between the second input shaft and the drive output shaft. A hybrid vehicle that connects the first clutch while rotating the motor output shaft of the motor generator.

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