JP6554030B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle, and more particularly to a control device for a hybrid vehicle capable of switching between travel driving by a motor and travel driving by an engine when the vehicle starts.

  In recent years, parallel hybrid vehicles that use an internal combustion engine and an electric motor (hereinafter simply referred to as a motor) as power sources for traveling driving have been widely used.

  In such a hybrid vehicle, the motor output is based on the required power corresponding to the operation input of the driver, the SOC (State Of Charge) indicating the state of charge of the battery, etc. so as to achieve low fuel consumption while ensuring drivability. There is mounted a control device for setting the EV driving mode for driving the vehicle alone and the other driving mode for driving the vehicle using the engine output so as to be switched by connecting / disconnecting the clutch.

  As a conventional control device for a hybrid vehicle, for example, at the time of vehicle start when the SOC is less than a predetermined value, while driving to drive the hybrid vehicle by an engine with an automatic clutch connected, the vehicle is driven to start the hybrid vehicle. It is known that the automatic clutch is disengaged and is driven to travel by a motor generator, and when the vehicle speed increases, the engine is switched to a traveling drive state by an engine (see, for example, Patent Document 1).

JP 2000-343965 A

  However, the conventional former hybrid vehicle control device that switches between driving by the engine or driving by the motor when the vehicle starts is not sufficient SOC depending on whether or not the SOC of the battery is less than a predetermined value. In this case, the vehicle is started at a low gear (for example, second gear) by engine driving while connecting the automatic clutch. For this reason, for example, in buses and other commercial vehicles, the frequency of starting by motor driving is low, and it is not only easy to improve fuel consumption, but there are cases where smooth starting is not possible.

  In addition, since the vehicle is started by driving the engine by setting the automatic clutch to a half-clutch state, the demand for the durability of the clutch cannot be sufficiently satisfied in a commercial vehicle or the like that requires a high durability of the clutch. There was also a problem.

  The present invention has been made to solve such an unsolved problem, and it is possible to smoothly start the hybrid vehicle while the configuration is such that the motor start mode and the engine start mode are switched by the clutch. An object of the present invention is to provide a control device for a hybrid vehicle that can be improved.

  In order to achieve the above object, a hybrid vehicle control apparatus according to the present invention includes a travel drive source having both an engine and an electric motor, a clutch disposed on a power transmission path from the engine to a drive wheel, and the power. A control device for a hybrid vehicle equipped in a hybrid vehicle comprising: a transmission connected to and disconnected from the engine by the clutch on a transmission path; and a rechargeable battery that supplies electric power to the motor, An engine start mode in which driving of the hybrid vehicle is started by the engine using the first start gear position among the plurality of shift speeds of the transmission, and at least a plurality of charging rates different in the charging rate of the battery On the condition that it is equal to or higher than the first charging rate on the high charging rate side, a second start change on the higher speed side than the first shift position of the transmission. A first motor start mode in which the travel drive is started only by the motor using a stage, and at least a charge rate of the battery is less than the first charge rate and a lower charge rate side among the different charge rates The traveling drive by only the motor at the second start gear, and the period of the traveling drive by the motor only in the first motor start mode, provided that the second charging rate is equal to or higher than Is selected and set according to the charging rate of the battery.

  With this configuration, the present invention utilizes the characteristics of the motor, and in the first and second motor start modes, the hybrid vehicle is smoothly driven by driving at a higher speed than the engine start mode. Start is possible. In addition, when the charging rate of the battery is equal to or higher than the first charging rate, the first motor start mode is set. When the charging rate is less than the first charging rate, the first motor start mode is set. Also, the second motor start mode is set in which the driving by the motor is limited to a short time. Therefore, at the time of start of the hybrid vehicle, the case where it is possible to start in the second motor start mode even if the charge rate is not sufficient occurs, so that the frequency of motor start increases, and smooth start of the hybrid vehicle And fuel economy can be improved.

  In the second motor start mode, the hybrid vehicle control device of the present invention is limited to the motor only during a period until the rotational speed of the clutch on the transmission side reaches a preset switching rotational speed. Can be configured to execute the traveling drive according to

  Further, in the control device for a hybrid vehicle according to the present invention, when the charging rate is higher than the first charging rate and the driving load of the traveling drive source is lower than a first set load. The first motor start mode is set, and the charging rate is less than the first charging rate and greater than or equal to the second charging rate, and the driving load of the traveling drive source is set in advance to the first charging rate. The second motor start mode is set when the load is equal to or less than a second load set to a value smaller than the load, and the charge ratio is equal to or more than the first charge ratio. When the drive load exceeds the first load, the charge rate is less than the first charge rate and greater than or equal to the second charge rate, and the drive load of the travel drive source is the second load. And the charging rate is less than When it is less than the charging rate, it may be configured respectively to set the engine start mode.

  In this case, the drive load of the traveling drive source may be set based on the slope of the traveling road surface of the hybrid vehicle.

  According to the present invention, it is possible to provide a control device of a hybrid vehicle capable of smooth start of the hybrid vehicle and capable of improving the fuel efficiency while having a configuration in which the motor start mode and the engine start mode are switched by the clutch. .

FIG. 1 is a schematic configuration diagram of a control device of a hybrid vehicle according to an embodiment of the present invention. FIG. 6 is an explanatory view for explaining a switching condition of a traveling drive mode at the time of start of the vehicle in the control device of the hybrid vehicle according to one embodiment of the present invention. It is a flowchart which shows the procedure of the start mode selection process in the control apparatus of the hybrid vehicle which concerns on one embodiment of this invention. It is a flowchart which shows the processing procedure of start control in EV2 start mode in the control apparatus of the hybrid vehicle which concerns on one embodiment of this invention. It is operation | movement explanatory drawing which shows the difference in the rotational speed change on the power line in each driving | running drive mode at the time of vehicle start in the hybrid vehicle control apparatus which concerns on one embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(One embodiment)
FIGS. 1 to 4 show a drive control system for a hybrid vehicle provided with a control device for a hybrid vehicle according to an embodiment of the present invention. In the present embodiment, the present invention is applied to a parallel hybrid vehicle. However, the present invention can also be applied to a plug-in hybrid vehicle.

  As shown in FIG. 1, in the vehicle 1 of the present embodiment, the engine 11, the auto clutch 12 (clutch), the motor generator 13, the automated manual transmission (AMT) 14, the propulsion shaft 15 and the differential device 16 are front and rear of the vehicle 1. It is sequentially arranged in the direction. A power transmission for transmitting power from at least one of the engine 11 and the motor generator 13 to the left and right drive wheels 18a and 18b via the AMT 14, the propulsion shaft 15, the differential device 16 and the left and right drive shafts 17a and 17b. A path 19 is configured.

  The vehicle 1 is also equipped with an inverter 22 and a high voltage battery 23, and the vehicle 1 is constituted by the inverter 22, the high voltage battery 23, the engine 11, the auto clutch 12, the motor generator 13, the AMT 14, and the propulsion shaft 15. A hybrid travel drive system 20 that travels is configured.

  The engine 11 is a multi-cylinder internal combustion engine, for example, a four-stroke diesel engine. Further, the auto clutch 12 has a function to connect or disconnect the output shaft 11a, which is a crankshaft of the engine 11, and the input / output shaft 13a of the motor generator 13 so that power can be transmitted.

  The auto clutch 12 can be switched between connection and disconnection by controlling the supply and discharge of the hydraulic pressure to the hydraulic operation cylinder that variably operates the stroke of the friction clutch disk. The hydraulic pressure to the hydraulic operation cylinder here is generated by an electrohydraulic actuator (not shown) (which may be a clutch master cylinder) that responds to a hydraulic control command from an AMT-ECU 32 described later, for example.

  The motor generator 13 has a function of an electric motor (electric motor) that converts supplied electric power into rotational power and outputs it, and a function of a generator that converts input rotational power into electric power and outputs it. It is.

  When the motor generator 13 functions as an electric motor, the motor generator 13 outputs rotational power that can drive the vehicle 1 while the engine 11 is idling, or the engine 11 is operated in order to drive the engine 11 in a driving range with high fuel efficiency. The rotational power that assists the output of 11 can be output. Further, the motor generator 13 cooperates with the inverter 22 when the regenerative braking of the vehicle 1 is operated, outputs a braking torque to the drive wheels 18a and 18b, operates as a generator, and can charge the high voltage battery 23. Yes.

  The AMT 14 is a known transmission mounted on a main body frame (not shown) of the vehicle 1 together with the engine 11. The AMT 14 incorporates a gear transmission mechanism capable of multi-stage shifting similar to a manual transmission, and can automatically control the shifting operation. It is configured as a semi-automatic transmission. The AMT 14 is capable of performing a multi-stage smooth speed change operation, for example, a speed change operation from the first speed to the sixth speed, in cooperation with the auto clutch 12.

  The propulsion shaft 15 is connected to the output shaft 14 b of the AMT 14 and the input shaft 16 a of the differential device 16 via a universal joint or the like, and is movably connected between the AMT 14 and the differential device 16.

  The differential device 16 is a known differential device that can distribute the rotational power input from the propulsion shaft 15 to the left and right drive shafts 17a and 17b while allowing a differential.

  High-voltage battery 23 is a secondary battery capable of supplying electric power to motor generator 13 and storing electric power generated by motor generator 13. The inverter 22 also has a function of boosting the voltage of the high voltage battery 23 and converting it into a three-phase alternating current for the motor generator 13.

  Such traveling drive system 20 is controlled by a control device 30 described below.

  The control device 30 includes a plurality of electronic control units (ECUs), for example, an HV-ECU 31 that is a hybrid drive control unit, an AMT-ECU 32 that controls a clutch operation of the auto clutch 12 and a shift operation of the AMT 14, a vehicle control ECU 33, an engine The ECU 34 and the battery ECU 35 are included.

  The HV-ECU 31 includes a CPU, a RAM, a ROM, a backup memory, an input interface circuit, an output interface circuit, and a communication interface circuit for CAN (Controller Area Network) communication. For example, an accelerator opening sensor 41 and a vehicle speed sensor 42 are connected to the input interface circuit of the HV-ECU 31 as a sensor group for detecting the traveling state of the vehicle 1.

  The HV-ECU 31 uses the CPU to send and receive data to and from the RAM according to the hybrid control program stored in advance in the ROM, and for example, outputs the total output value of the travel drive system 20 as the required power corresponding to the accelerator opening. Further, based on the sensor information such as the current vehicle speed V and the rotational speed Nj of the engine 11 and the motor generator 13 and the map information in the backup memory regarding the engine performance of the engine 11 and the characteristics of the motor generator 13 The torque Te required for the engine 11 and the command value of the torque Tm required for the motor generator 13 are sequentially calculated so that the operating condition of the drive system 20 is high in energy efficiency. The torque Te is output as a command value to the engine ECU 34 via the CAN bus 36, and the torque Tm is input as a command value to a built-in MG control unit described later.

  The backup memory of the HV-ECU 31 is a memory that can hold stored information even when the CPU is stopped, and is configured of, for example, an EEPROM. The AMT-ECU 32 and the vehicle control ECU 33 are connected to the communication interface circuit of the HV-ECU 31 via the CAN bus 36. For example, the HV-ECU 31 to the engine ECU 34 via the vehicle control ECU 33 having a gateway function. A torque command value Te is output.

  The battery ECU 35 constantly monitors the charge / discharge amount of the high-voltage battery 23, calculates the ratio of the charge amount to the total battery capacity of the high-voltage battery 23, that is, calculates SOC (State Of Charge) [%] corresponding to the charge rate, The SOC can be transmitted to the HV-ECU 31. It goes without saying that the battery ECU 35 and the HV-ECU 31 can be connected so that CAN communication is possible.

  Then, the HV-ECU 31 executes control of drive output and regenerative brake operation by the motor generator 13 so as to maintain the SOC fluctuation range within a range suitable for the life of the high-voltage battery 23 and reliability. Thus, the SOC of the high voltage battery 23 is controlled between a preset upper limit value (for example, 80%) and a lower limit value (for example, 40%). Note that the SOC upper limit value may temporarily increase, or the SOC may temporarily fall below the lower limit value when regenerative power charging is expected.

  The input interface circuit of the AMT-ECU 32 includes a shift switch 43 that detects a shift lever operation input of the driver, and a resolver that detects a rotational speed Nj of the motor generator 13 that is also a disk rotational speed of the transmission of the auto clutch 12. A rotational speed sensor 44 and a clutch stroke sensor 45 for detecting a disc stroke which is an operating position of the auto clutch 12 are connected. Then, detection information from these sensor groups 43 to 45 is taken into the AMT-ECU 32.

  Based on the control information from the HV-ECU 31 and the vehicle control ECU 33 and the detection information from the sensor groups 43 to 45, the AMT-ECU 32 optimizes the gear position of the AMT 14 corresponding to the required traveling drive power and the current vehicle speed V. While setting the (optimum gear), the degree of connection of the auto clutch 12 can be controlled. In order to execute such control, bidirectional communication of information relating to mutually necessary control values and detection values is performed between the HV-ECU 31, the vehicle control ECU 33, and the AMT-ECU 32.

  On the other hand, the auto clutch 12 is connected to the output interface circuit of the AMT-ECU 32, and the AMT-ECU 32 is based on the control request from the HV-ECU 31 and the vehicle control ECU 33 and the detection position of the clutch stroke sensor 45. The connection and disconnection of the auto clutch 12 and the disc stroke can be controlled.

  In the input interface circuit of the vehicle control ECU 33, a brake sensor 46 that detects a brake operation state, a gradient sensor 47 that includes a G sensor, and the like, information related to the operating state of the engine 11 and the state of the vehicle 1 is acquired. Other sensor groups not shown are connected. Then, detection information from these sensor groups 46, 47, etc. is taken into the vehicle control ECU 33, and the vehicle control ECU 33 cooperates with other ECUs to control the start of the engine 11, brake control, and other vehicle running performance. It is possible to execute the vehicle control program regarding.

  The vehicle control ECU 33 also detects the gradient of the traveling road surface of the vehicle 1 based on the detection information of the gradient sensor 47 at least when the vehicle 1 starts or stops. The stop referred to here includes a temporary stop for waiting for a signal or the like, a stop at a predetermined waiting place, or a parking etc.

  The gradient sensor 47 detects an inclination angle of the traveling road surface in the longitudinal direction of the vehicle based on, for example, an output ratio of a two-axis acceleration sensor that detects acceleration in the longitudinal direction of the vehicle and the vertical direction of the vehicle.

  A crank angle sensor 48 is connected to an input interface circuit of the engine ECU 34. The engine rotational speed Ne [rpm] detected by the crank angle sensor 48 is taken into the engine ECU 34, and an HV is controlled by a vehicle control ECU 33 having a gateway function. -It transmits to other ECUs, such as ECU31 and AMT-ECU32.

  The engine ECU 34 incorporates various programs and maps for controlling the output of the engine 11 based on the required torque Te. When the command value of the torque Te is input, the engine ECU 34 calculates the fuel injection amount and the injection timing corresponding to the command value, and controls the engine 11.

  These HV-ECU 31, AMT-ECU 32, vehicle control ECU 33, and engine ECU 34 ROM and backup memory of the control device 30 include a hybrid control program, a shift control program, a vehicle control program, an engine control program, and a cooperation program for these control programs. A plurality of other control programs that work (hereinafter, these are collectively referred to as a plurality of control programs), for example, a start control program including clutch control is stored, and various setting values used in a plurality of control programs Maps etc. are stored.

  The control device 30 is configured to perform a plurality of functions as described below by executing the plurality of control programs.

  As described above, the control device 30 has a function of controlling the SOC of the high voltage battery 23 between the preset upper limit value and the lower limit value. Before starting the vehicle 1, the control device 30 causes the HV-ECU 31, the AMT-ECU 32, and the vehicle control ECU 33 to cooperate with each other as shown in FIG. Switching control of engagement / disengagement of the auto clutch 12 according to the slope of the road surface on which the vehicle 1 is stopped, and one of the engine start mode, the EV1 start mode and the EV2 start mode shown in FIG. Is selected and set to be switchable.

  Specifically, the engine start mode is a mode in which driving is started so that the vehicle 1 is started using the output of the engine 11, and in this embodiment, the gear stage of the AMT 14 at the time of start (hereinafter, referred to as the engine start mode). This is a mode in which the traveling drive of the vehicle 1 using the output of the engine 11 can be continued until the conditions for shifting to another shift stage are satisfied from the start shift stage).

  The EV1 start mode and the EV2 start mode are modes in which traveling drive is started so as to start the vehicle 1 using only the output of the motor generator 13, respectively. And after starting in either of these EV1 start mode and EV2 start mode, it can shift to other travel drive states using the output of engine 11 according to the charge state and drive load of high voltage battery 23.

  In the EV1 start mode, the SOC of the high-voltage battery 23 is equal to or higher than the first value S1 (first charge rate) on the high charge rate side among a plurality of different charge rate values between the lower limit value and the upper limit value. The first motor start mode set when the first value S1 is, for example, 60%. The start shift speed in the EV1 start mode is set to the first start shift speed, for example, the third speed (3rd in FIG. 2).

  In the EV2 start mode, the SOC of the high voltage battery 23 is less than the first value S1 and is equal to or higher than the second value S2 (second charge rate) on the low charge rate side among the plurality of different charge rate values described above. This is the second motor start mode that is sometimes set, and the second value S2 is 45%, for example. The starting shift speed in the EV2 start mode is set to a second shift speed on the higher speed side than the first start shift speed, for example, the third speed (3rd in FIG. 2).

  The EV2 start mode is a setting condition in which use (amount of use) of the motor generator 13 is restricted from the EV1 start mode. Specifically, traveling drive by only motor generator 13 in the EV2 start mode is performed until rotation speed Nj of motor generator 13 which is also the disc rotation speed on the transmission side of auto clutch 12 reaches a preset switching rotation speed. It is limited to a period of time and runs under that limit. Further, the switching rotational speed here is slightly higher than, for example, the idling operation rotational speed (for example, 550 [rpm]) of the engine 11 and is a predetermined rotational speed Ni that can output an effective travel driving torque when the vehicle 1 starts. For example, about 700 rpm.

  Therefore, in the EV2 start mode, acceleration by only the motor generator 13 is not continued to a vehicle speed capable of shifting to a higher gear side in the start gear stage at start, and travel by only the motor generator 13 in the EV2 start mode The drive ends during acceleration at the start gear.

  On the other hand, in the EV1 start mode, acceleration by only the motor generator 13 is continued until the vehicle speed allows the AMT 14 to shift to a higher speed side than the above-mentioned start shift speed. Ends. However, if the required driving force can not be output only by the motor generator 13 due to a drop in SOC after start-up in the EV1 start mode or a steep slope, the traveling drive mode or charging by the engine is possible before shifting to the high speed side. Transition to a different driving mode may occur. This is determined from the SOC, the value of the road surface gradient, the vehicle speed, the accelerator opening, and the like.

  When the SOC of high voltage battery 23 is equal to or higher than the first value S1 and the drive load of travel drive system 20, which is a travel drive source, is equal to or less than the first load G1 set in advance. , Set the first motor start mode. Further, when the SOC of high voltage battery 23 is less than the first value S1 and is greater than or equal to the second value S2, control device 30 determines that the drive load of traveling drive system 20 is less than or equal to second load G2. The second motor start mode is set. The first load G1 referred to here is set, for example, as the maximum value of the slope that allows a suitable start in the EV1 start mode, and the second load G2 is, for example, the first load in advance. It is set to a value of an uphill gradient smaller than the load G1.

  Control device 30 further determines that SOC is less than first value S1 when the SOC of high-voltage battery 23 is equal to or greater than first value S1 and the drive load of traveling drive system 20 exceeds first load G1. When the driving load of the traveling drive system 20 exceeds the second load G2 and when the SOC is less than the second value S2, the engine start mode is set. It is supposed to be.

  The driving loads G1 and G2 of the traveling drive system 20 are set based on the slope of the traveling road surface of the vehicle 1, respectively, and the first load G1 climbs the vehicle 1 in a standard loading state set in advance, for example. It is a driving load of the traveling drive system 20 when the vehicle is started at a predetermined starting speed on a traveling road surface having a slope of 7%. The second load G2 is a driving load of the traveling drive system 20 when, for example, the vehicle 1 in the above-described standard loading state is started at a predetermined starting speed on a traveling road surface with a climbing slope of 3%.

  Next, the operation will be described.

  In the hybrid vehicle control device 30 of the present embodiment configured as described above, when the vehicle 1 is started, a start mode selection process as shown in FIG. 3 is executed.

  First, the latest SOC value calculated by the HV-ECU 31 and the road surface gradient value detected by the gradient sensor 47 are fetched (step S11), and then the SOC value is equal to or greater than the first value S1 It is determined whether or not it is (step S12).

  If the SOC is equal to or greater than the first value S1 (in the case of yes in step S12), it is then determined whether or not the road surface gradient value is equal to or less than the first load G1 (step S13). If the result is yes, the EV1 start mode is selected as the current start mode (step S14).

  On the other hand, if the value of SOC is not the first value S1 or more (in the case of no in step S12), it is then determined whether the value of SOC is the second value S2 or more (step S15).

  If the SOC is equal to or greater than the second value S2 (Yes in step S15), then whether or not the road surface gradient value is equal to or smaller than the second load G2 corresponding to the relatively gentle uphill gradient. Is determined (step S16), and if the determination result is yes, the EV2 start mode is selected as the current start mode (step S17).

  In addition, when the value of the road surface gradient exceeds the first load G1 (in the case of no in step S13), when the value of the SOC has decreased below the second value S2 (in the case of no in step S15), and If the value of the road surface gradient exceeds the second load G2 although the SOC value is equal to or greater than the second value S2, the engine start mode is selected in any case (step S18).

(When starting in EV1 start mode)
Now, assuming that the EV1 start mode is selected, in this case, first, the gear stage of the AMT 14 at the start in this start mode is set to the second start gear stage, for example, the third speed (3rd in the figure). . At this time, the auto clutch 12 is in a disconnected state in which the engine 11 is disconnected from the AMT 14. The engine 11 is started by a starter motor (not shown) at the same time as the EV1 start mode is selected, and is in an idle operation state.

  Next, in response to an acceleration request mainly for the driver's accelerator pedal operation, the motor generator 13 starts rotating to increase its rotational speed, and accelerates while starting the vehicle 1. Then, normally, when the shift condition for the next high-speed gear (for example, fourth gear) is satisfied based on the acceleration request and the vehicle speed of the vehicle 1, the AMT 14 is shifted to the high-speed gear. At the same time, the auto clutch 12 is controlled to the connection side, and the EV1 drive mode is switched to another drive mode using the engine output, for example, the engine drive mode or the parallel drive mode.

  In the present embodiment, as described above, since the transition timing from the EV1 travel mode to another travel mode using the engine output is set at the time of shifting, a shock accompanying the connection operation of the auto clutch 12 does not occur other than at the time of shifting. .

(When starting in EV2 start mode)
Next, assuming that the EV2 start mode is selected, in this case, as shown in FIG. 4, first, the start gear position in this EV2 start mode is set to, for example, the third speed (step S21). At this time, the auto clutch 12 is in a disconnected state in which the engine 11 is disconnected from the AMT 14. The engine 11 is started at the same time as the EV2 start mode is selected.

  Next, in response to an acceleration request mainly based on the driver's accelerator pedal operation, the motor generator 13 starts rotation to increase its rotational speed, and accelerates while starting the vehicle 1 (step S22).

  Next, the rotational speed (MG rotational speed in FIG. 4) Nj of the input / output shaft 13a of the motor generator 13, which is the rotational speed on the transmission side of the auto clutch 12, is effective when the vehicle 1 starts in the EV2 start mode. A determination is made as to whether or not the predetermined rotation speed Ni (switching rotation speed) has reached a level at which the driving torque can be output (step S23). Further, the determination as to whether or not the predetermined rotation speed Ni has been reached is repeated until the determination result becomes yes.

  Then, when the rotational speed Nj of the motor generator 13 reaches the predetermined rotational speed Ni (in the case of yes in step S23), the engine rotational speed Ne of the engine 11 in the idle operation state then matches the predetermined rotational speed Ni. Slightly increased (step S24).

  Next, after the auto clutch 12 is connected (step S25), the torque load ratio of the engine 11 is gradually increased while the output rotational speeds of the engine 11 and the motor generator 13 are increased according to the acceleration request. The output torque of the engine 11 is increased while the output torque of the motor generator 13 is decreased (step S26). Then, when the motor generator 13 shifts to an output stop state in which the output of the engine 11 is not resistant to output rotation, the processing of the current EV2 start mode ends.

  Therefore, in this EV2 start mode, acceleration by only the motor generator 13 is not continued until the vehicle speed at which the speed can be shifted to the high speed side from the start speed stage is not reached, and thereafter, another travel mode using the engine output, for example, It will shift to the engine running mode.

(When starting in engine start mode)
Next, assuming that the engine start mode is selected, first, for example, the second gear is set as the start gear in this start mode. At this time, the auto clutch 12 is in a disconnected state in which the engine 11 is disconnected from the AMT 14. The engine 11 is started by the starter motor at the same time as the engine start mode is selected.

  Next, the engine speed Ne of the engine 11 was increased in response to the acceleration request, and the stroke of the auto clutch 12 was controlled to place the auto clutch 12 in a half-clutch state and to start transmitting the rotational power from the engine 11 to the AMT 14. Thereafter, the auto clutch 12 is gradually shifted to the fully connected state, and the vehicle 1 is accelerated while being started. Then, when a condition for shifting to a shift stage (for example, third speed) higher than the start shift stage is established, the AMT 14 is shifted to the next shift stage.

  As described above, in this embodiment, in any of EV1 start mode and EV2 start mode, which are motor start modes, engine start is performed by utilizing the characteristics of motor generator 13 that can generate large torque in a short time in a low speed region. The vehicle is started at a higher speed gear (for example, 3rd) than the start gear (for example, 2nd) in the mode. Therefore, compared with the 2nd start at the engine start mode shown by the broken line A in FIG. 5, the EV1 start mode shown by the alternate long and short dash line B in the same figure and the EV2 start mode shown by the solid line C in the same figure As shown in a portion surrounded by a dotted line D, it is possible to eliminate the sudden acceleration at the start of the start, and the vehicle 1 can be smoothly started.

  Moreover, in the motor start mode, when the SOC of the high voltage battery 23 is equal to or higher than the first value S1 and the drive load of the traveling drive system 20 is smaller than the first load G1, the EV1 start mode is set. Is less than the first value S1 and greater than or equal to the second value S2, and when the driving load of the travel drive source is less than or equal to the second load G2, the use of the motor generator 13 is restricted more than in the EV1 start mode. Set to the EV2 start mode. Therefore, smooth travel of vehicle 1 can be performed in a wide range in the control range of SOC while securing travel drive output according to drive load at the time of vehicle start, and moreover, by increasing the frequency of motor start mode. Fuel consumption can be improved.

  Further, in the present embodiment, the output of the motor generator 13 in the EV2 start mode is stopped while the AMT 14 is in the start gear (for example, 3rd), and the output of the motor generator 13 in the EV1 start mode is the start of the vehicle 1 The AMT 14 can be continued until a condition for shifting from the starting shift speed to the high speed speed is established. Therefore, it is possible to effectively and widely utilize the output of motor generator 13 at the time of start of vehicle 1 while increasing the frequency of smooth start in a commercial vehicle or the like while performing automatic shift operation using AMT 14. Fuel consumption can be improved. In addition, the durability of the auto clutch 12 can be increased by reducing the frequency of use of the auto clutch 12.

  Furthermore, in this embodiment, since the driving load of the traveling drive source is set based on the climb slope of the traveling road surface of the vehicle 1, the driving load of the traveling drive system 20 can be accurately grasped, and not only the SOC but also the driving load The frequency of use of the motor generator 13 can be increased in consideration of

  As described above, according to the present embodiment, the EV start mode that is driven by the motor generator 13 and the other mode that is driven by the engine 11 are switched by connecting / disconnecting the auto clutch 12, but the vehicle 1 can be smoothly operated. It is possible to provide a control device of a hybrid vehicle that can be started, can improve the fuel efficiency, and can improve the durability of the auto clutch 12.

  In the above-described embodiment, the traveling drive system 20 sequentially arranges the engine 11, the auto clutch 12, the motor generator 13, the AMT 14, and the like in the vehicle front-rear direction. As such, it may be possible to combine the output of the engine and the output of the motor generator transmitted through separate paths.

  The gradient sensor 47 uses a biaxial acceleration sensor, but, of course, a multi-axis acceleration sensor or another type of tilt angle sensor (for example, a membrane spring capacity type, a liquid sealing type, etc.) may be used. Good. In addition, road surface gradient information (altitude change amount per predetermined time / travel distance) calculated one by one immediately before the stop of the vehicle 1 is stored in the backup memory when the vehicle 1 stops, and the drive load is calculated based on the gradient information at the start. It is also possible to calculate. In that case, while the vehicle 1 is traveling, for example, based on the acceleration of the vehicle 1 calculated from the detection signal of the vehicle speed sensor 42 and the detection information of the gradient sensor 47, the road surface gradient angle (arc sin (the acceleration of the G sensor-acceleration ) / Gravity acceleration) can also be calculated sequentially.

  Further, in the above-described embodiment, the EV start mode is divided into two different use restrictions depending on the SOC and the driving load, and the three start control modes are used. However, the EV start mode has different use restrictions. It is also conceivable to use four or more start control modes divided into three or more. Of course, another measured value or calculated value corresponding to the SOC can be substituted.

  In addition, although the start mode selection processing is performed when starting the vehicle, it may be performed when the vehicle is stopped in preparation for the next start. In this case, when the vehicle starts, the engine is started when the ignition switch is turned on.

  As described above, the present invention can provide a control device of a hybrid vehicle capable of smooth start and improving fuel efficiency while being configured to switch the motor start mode and the engine start mode by connection and disconnection of the clutch. . The present invention as described above is useful for general control devices of a hybrid vehicle that can switch between the start drive by the motor and the start drive by the engine at the start of the vehicle.

1 Vehicle 11 Engine (Internal Combustion Engine)
12 Auto clutch (clutch)
13 Motor generator (electric motor)
14 AMT (Transmission)
19 Power transmission path 20 Travel drive system (travel drive source)
23 High-voltage battery (battery)
30 Controller 31 HV-ECU
32 AMT-ECU
33 Vehicle control ECU
34 Engine ECU
41 accelerator opening sensor 42 vehicle speed sensor 43 shift switch (shift operation detection means)
44 Rotational speed sensor (Motor rotational speed detection means)
47 Slope sensor 48 Crank angle sensor G1 1st driving load (uphill slope)
G2 Second drive load (uphill slope)
S1 first value (first charging rate)
S2 Second value (second charging rate)

Claims (4)

A traveling drive source having both an engine and an electric motor, a clutch disposed on a power transmission path from the engine to a drive wheel, and a transmission connected to and disconnected from the engine by the clutch on the power transmission path A control device for a hybrid vehicle equipped in a hybrid vehicle comprising: and a rechargeable battery for supplying power to the motor,
An engine start mode in which driving of the hybrid vehicle is started by the engine using a first start gear position among the plurality of gear positions of the transmission;
On the condition that at least the first charging rate value on the high charging rate side among the plurality of charging rate values with different charging rates of the battery is equal to or higher than the second speed on the higher speed side than the first shift stage of the transmission. A first motor start mode in which the traveling drive is started only by the motor using a start gear position of
The second start is performed on condition that at least the charging rate of the battery is less than the first charging rate value and is equal to or higher than the second charging rate value on the low charging rate side among the plurality of different charging rate values. Any one of a second motor start mode in which the travel drive by only the motor at a shift stage is executed with a period of the travel drive by only the motor being limited rather than the first motor start mode. A control device for a hybrid vehicle, wherein one mode is selected and set according to a charging rate of the battery.   In the second motor start mode, the travel drive by the motor alone is executed only during a period until the rotational speed of the clutch on the transmission side reaches a preset switching rotational speed. The control device of a hybrid vehicle according to claim 1. The first motor start mode is set when the charging rate of the battery is equal to or higher than the first charging rate value and the driving load of the traveling drive source is equal to or lower than a preset first load. And
A second case where the charge rate is less than the first charge rate value and greater than or equal to the second charge rate value, and the driving load of the traveling drive source is set to a value smaller than the first load in advance. Setting the second motor start mode when the load is less than
When the charging rate is equal to or higher than the first charging rate and the driving load of the traveling drive source exceeds the first load, the charging rate is less than the first charging rate and the second charging rate When the driving rate of the travel drive source exceeds the second load and when the charging rate is less than the second charging rate, the engine start mode is set. The control device of a hybrid vehicle according to claim 1 or 2, characterized in that:   4. The hybrid vehicle control device according to claim 3, wherein the driving load of the traveling drive source is set based on an uphill slope of a traveling road surface of the hybrid vehicle. 5.

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