JP2021049947A - Control device for hybrid vehicle - Google Patents

Abstract

To provide a control device for a hybrid vehicle which, when the vehicle starts on an uphill road, can prevent or suppress the descending of the vehicle along the uphill road due to the limitation of the output of a motor.SOLUTION: In a control device for a hybrid vehicle, a controller for controlling the hybrid vehicle determines, in the case of starting on an uphill road with torque output by a second motor, whether uphill required torque required for starting on the uphill road exceeds an upper limit value which can be output by the second motor. When determining that the uphill required torque exceeds the upper limit value (Step S5), the controller performs launch start control in which, in addition to the second motor's output of torque corresponding to the upper limit value, a clutch is engaged, and the vehicle starts with at least one of torque output by an engine and torque output by a first motor (Step S6).SELECTED DRAWING: Figure 2

Description

The present invention relates to a control device for a hybrid vehicle, which includes an engine and a motor as a driving force source, and can switch between a mode of traveling by torque output by the motor and a mode of traveling by torque output by the engine and motor. Is.

An example of this type of device is described in Patent Document 1. The device includes an engine and two motors as a driving force source, and the first motor, the start clutch, and the transmission are arranged in this order on the output side of the engine. Further, a parallel HV running mode in which the starting clutch is engaged and the engine torque, the torque of the first motor, and the torque of the second motor are used to drive the vehicle, and the starting clutch is released to drive the first motor by the engine torque. It is possible to set a series HV driving mode in which the second motor is driven by the power generated by the first motor and travels by the torque of the second motor, and an EV driving mode in which the start clutch is released and the vehicle travels by the torque of the second motor. It is configured as follows.

Further, Patent Document 2 describes an electronic control device for a hybrid vehicle including an engine and a motor as a driving force source. The device is configured to be able to switch between a motor running mode in which the vehicle travels only by the torque of the motor and a traveling mode in which the vehicle travels by at least the engine torque. Further, when the temperature of the motor exceeds a predetermined upper limit temperature, the torque output by the motor is limited. Furthermore, when the hybrid vehicle is stopped by the torque output by the motor on an uphill road, the motor is in a so-called single-phase locked state in which the torque is output without rotating, and electricity flows to a specific phase of the motor to drive the motor. Since there is a possibility of overheating, the margin time required for the motor temperature to reach the upper limit temperature is estimated. Then, before the spare time elapses and the torque of the motor is limited, the engine is driven to switch from the motor running mode to the running mode in which the motor runs at least by the engine torque.

Further, Patent Document 3 describes an electronic control device for a hybrid vehicle including an engine and two motors as a driving force source. The first motor is a motor that cranks the engine, and the second motor is a motor that outputs torque for running. When the device is running by the torque of the first motor and the torque of the second motor, and when it is determined that the first motor is in the single-phase locked state, the engine is started by the first motor. It cranks and drives the engine, and outputs torque with the engine instead of the first motor.

Further, Patent Document 4 describes a control device for a hybrid vehicle in which a motor is connected to the output side of the engine via a clutch, and the temperature of the inverter connected to the motor is the upper limit temperature of the inverter in the control device. It is configured to increase the torque capacity target value for the clutch when a lower upper limit set temperature is reached. That is, the ratio of the engine torque to the target drive torque is increased and the ratio of the motor torque is decreased without changing the target drive torque.

JP-A-2019-123387 Japanese Unexamined Patent Publication No. 2015-006854 Japanese Unexamined Patent Publication No. 2016-20392 Japanese Unexamined Patent Publication No. 2010-11193

In the hybrid vehicle described in Patent Document 1, when starting from a state of being stopped on an uphill road in the direction of going uphill, the motor applies a driving torque that opposes the road load according to the road surface gradient, the weight of the hybrid vehicle, and the like. When the output and the torque output by the motor are substantially equal to the load and load, the motor rotates at a very low speed or outputs the torque without rotating. Therefore, the amount of heat generated by the motor may increase and the motor may overheat. When the temperature of the motor exceeds the upper limit temperature or is predicted to exceed the upper limit temperature, the output of the motor is limited from the viewpoint of protecting the motor to prevent or suppress overheating of the motor. When such control is performed, in the hybrid vehicle described in Patent Document 1, there is a possibility that the driving torque is insufficient and the hybrid vehicle descends along the uphill road. Such a situation is the same even in the hybrid vehicle described in Patent Documents 2 to 4.

The present invention has been made by paying attention to the above technical problems, and prevents or suppresses the descent of the vehicle along the uphill road due to the limitation of the output of the motor when starting on the uphill road. It is an object of the present invention to provide a control device for a hybrid vehicle capable of performing the same.

In order to achieve the above object, the present invention makes it possible to transmit torque to the engine, a transmission provided on the output side of the engine to increase or decrease the torque output by the engine, and the engine and the transmission. The first motor that is connected and drives either the front wheels or the rear wheels, the second motor that drives either the front wheels or the rear wheels, and the speed change in the transmission direction of the torque output by the engine. A hybrid vehicle having a clutch provided between the machine and the first motor and configured to set an upper limit of torque that can be output by the second motor according to the temperature of the second motor. The control device includes a controller that controls the hybrid vehicle, and the controller starts on the uphill road when the hybrid vehicle starts by the torque output by the second motor in the direction of climbing the uphill road. It is determined whether or not the required torque for climbing a slope exceeds the upper limit value of the torque output by the second motor, and if it is determined that the required torque for climbing a slope exceeds the upper limit value, the second motor In addition to outputting the torque corresponding to the upper limit value, the launch start is started by at least one torque of the torque output by the engine and the torque output by the first motor by engaging the clutch. It is characterized in that it is configured to perform control.

According to the present invention, when the hybrid vehicle starts in the direction of climbing the uphill road and the torque required for climbing uphill required for starting on the uphill road exceeds the torque of the upper limit value output by the second motor. In addition to the torque corresponding to the upper limit value being output by the second motor, the launch start control is performed by starting with at least one torque of the torque output by the engine and the torque output by the first motor. That is, in addition to the torque of the second motor, at least one torque of the engine torque and the torque of the first motor generates a drive torque larger than the required torque for climbing a slope. Therefore, when starting in the direction of climbing the uphill road, it is possible to prevent or suppress the hybrid vehicle from descending along the uphill road due to insufficient driving torque. As a result, the vehicle can start smoothly in the direction of climbing the uphill road, and the startability can be improved.

It is a schematic diagram which shows an example of the hybrid vehicle in embodiment of this invention. It is a flowchart for demonstrating an example of the control example in Embodiment of this invention. It is a time chart for demonstrating an example of the change in the operating state of a clutch, the input shaft rotation speed of an automatic transmission, the output shaft rotation speed of an automatic transmission, etc. when the control is performed according to the embodiment of the present invention.

An embodiment of the present invention will be described with reference to the drawings. It should be noted that the embodiments shown below are merely examples of cases where the present invention is embodied, and do not limit the present invention.

The vehicle to be controlled in the embodiment of the present invention is, for example, an engine and a hybrid vehicle powered by two motors. The first motor is arranged on the output side of the engine and has a function of generating electricity by being driven by receiving the engine torque output by the engine. The second motor is connected to the drive wheels so as to be able to transmit power. Then, an engagement mechanism is provided between the engine and the first motor and the other drive wheels to selectively transmit and cut off torque between them. Therefore, in the hybrid vehicle according to the embodiment of the present invention, the engine and the first motor can be separated from the drive system by releasing the engaging mechanism. In that state, the hybrid vehicle can be driven by the motor torque output by the second motor. That is, the hybrid vehicle can be driven as an electric vehicle using the second motor as a driving force source. On the other hand, by engaging the engaging mechanism, at least the hybrid vehicle can be driven by the engine torque. Alternatively, the hybrid vehicle can be driven by the engine torque and the motor torque of the second motor. Further, in addition to the engine torque and the motor torque of the second motor, the hybrid vehicle can be driven by the motor torque output by the first motor.

FIG. 1 shows an example of a hybrid vehicle according to an embodiment of the present invention. Further, the example shown in FIG. 1 is an example of a four-wheel drive vehicle based on a so-called FR (front engine / rear drive) vehicle that transmits the power of the engine 1 to the rear wheels 2. The hybrid vehicle (hereinafter, simply referred to as a vehicle) Ve shown in FIG. 1 has an engine (ENG) 1, a first motor (rear motor) 3 capable of transmitting torque to the rear wheels 2, and front wheels as power sources. A second motor (front motor) 5 capable of transmitting torque to 4 is provided. In addition, the vehicle Ve includes a battery (BATT) 6, an automatic transmission 7, a power control unit (PCU) 8, a brake system (AHBRx) 9, an ECU (electronic control device) 10, and the like as other main components. I have. The vehicle Ve to be controlled in the embodiment of the present invention is not limited to the FR vehicle shown in FIG. 1, but is an FF (front engine / front drive) vehicle, an MR (mid engine / rear drive) vehicle, or an RR (RR). It may be a rear engine / rear drive) vehicle.

The engine 1 is, for example, an internal combustion engine such as a gasoline engine or a diesel engine, and is configured to adjust the output and electrically control operating states such as start and stop. In the case of a gasoline engine, the opening degree of the throttle valve, the amount of fuel supplied or injected, the execution and stop of ignition, and the ignition timing are electrically controlled. In the case of a diesel engine, the fuel injection amount, the fuel injection timing, the opening degree of the throttle valve in the EGR [Exhaust Gas Recirculation] system, and the like are electrically controlled. Further, the engine 1 generates a deceleration force (braking force) on the rear wheels 2 by the engine brake.

The first motor 3 is arranged on the output side of the engine 1. Further, the first motor 3 has a function as a generator that generates electricity by being driven by receiving at least the engine torque output by the engine 1. Further, in the vehicle Ve according to the embodiment of the present invention, the first motor 3 also has a function as an electric motor that is driven by being supplied with electric power to output motor torque. That is, the first motor 3 is a motor (motor / generator) having a power generation function, and is composed of, for example, a permanent magnet type synchronous motor, an induction motor, or the like. A battery 6 is connected to the first motor 3 via an inverter (not shown) constituting the power control unit (Rr-PCU) 8a. Therefore, the first motor 3 can be driven as a generator, and the electricity generated at that time can be stored in the battery 6. It is also possible to supply the electric power stored in the battery 6 to the first motor 3 and drive the first motor 3 as an electric motor to output the motor torque. The first motor 3 may be connected via a transmission mechanism such as a gear mechanism instead of being directly connected to the engine 1 as shown in FIG. Further, a mechanism such as a damper mechanism or a torque converter may be arranged between the engine 1 and the first motor.

The second motor 5 has a function as an electric motor that is driven by at least being supplied with electric power and outputs motor torque. In the vehicle Ve according to the embodiment of the present invention, the second motor 5 also has a function as a generator that generates electricity by being driven by receiving torque from the outside. That is, the second motor 5 is a motor (motor generator) having a power generation function like the first motor 3, and is composed of, for example, a permanent magnet type synchronous motor, an induction motor, or the like. A battery 6 is connected to the second motor 5 via an inverter (not shown) constituting the power control unit (Fr-PCU) 8b. Therefore, the electric power stored in the battery 6 can be supplied to the second motor 5, and the second motor 5 can be driven as an electric motor to output the motor torque. Further, the second motor 5 is connected to the front wheels 4 so as to be able to transmit power. Therefore, the second motor 5 can be driven as a generator by the torque transmitted from the front wheels 4, and the regenerative power generated at that time can be stored in the battery 6. Further, the first motor 3 and the second motor 5 are connected to each other via an inverter so that electric power can be exchanged with each other. For example, it is also possible to directly supply the electricity generated by the first motor 3 to the second motor 5 and output the motor torque by the second motor 5.

The battery 6 is a power storage device that stores the electric power generated by the first motor 3 and the second motor 5, and is connected to the first motor 3 and the second motor 5 so that electric power can be exchanged. .. Therefore, the electric power generated by the first motor 3 can be stored in the battery 6 as described above. Further, the electric power stored in the battery 6 can be supplied to the first motor 3 to drive the first motor 3. Similarly, the electric power generated by the second motor 5 can be stored in the battery 6. Further, the electric power stored in the battery 6 can be supplied to the second motor 5 to drive the second motor 5. The power storage device is not limited to the battery 6 as shown in FIG. 1, and may be, for example, a capacitor.

As shown in FIG. 1, the automatic transmission 7 is arranged on the same axis as the engine 1 and is arranged on the output side of the first motor 3, and the engine 1, the first motor 3, and the rear wheel 2 are arranged. It is a transmission mechanism that transmits torque between them. The automatic transmission 7 is basically a mechanism capable of appropriately changing the ratio of the input shaft rotation speed to the output shaft rotation speed, and the automatic transmission 7 is a stepped transmission in which the gear ratio changes stepwise. Alternatively, it may be a conventionally known transmission such as a continuously variable transmission in which the gear ratio continuously changes.

Then, as shown in FIG. 1, the automatic transmission 7 is connected to the rear differential gear 11 and is configured to transmit torque to the left and right rear wheels 2 via the rear differential gear 11 and the drive shaft 12.

Further, a clutch K1 that selectively transmits and disconnects torque between the engine 1 and the first motor 3 and the automatic transmission 7 is provided in the transmission direction of the engine torque. Therefore, the vehicle Ve in the embodiment of the present invention can be driven by disengaging the clutch K1 to disconnect the engine 1 and the first motor 3 from the drive system, and vice versa. The system can be connected to the engine 1 and the first motor 3.

The power control unit (PCU) 8 includes an inverter and a converter (both not shown), and adjusts the temperature of each of the motors 3 and 5 and the output of each of the motors 3 and 5. In the vehicle Ve shown in FIG. 1, the Rr-PCU8a connected to the first motor 3 and the Fr-PCU8b connected to the second motor 5 are provided as the power control unit 8.

The brake system (AHBRx) 9 is a brake system capable of generating a braking force by coordinating a hydraulic brake and a regenerative brake, and generates a deceleration force (braking force) on the front wheels 4 and the rear wheels 2 by hydraulic pressure. At the time of regenerative braking, the hydraulic brake is configured to generate a difference from the required braking force according to the amount of regeneration.

Further, the above-mentioned second motor 5 is arranged on the front wheel 4 side of the vehicle Ve so that the motor torque output by the second motor 5 can be transmitted to the front wheel 4 to generate a driving force. It is connected to the drive system of Ve. In the example shown in FIG. 1, the output shaft of the second motor 5 is connected to the reduction gear pair 13, that is, the motor torque output by the second motor 5 is amplified by the reduction gear pair 13 and the front differential gear 14 to drive. It is transmitted to the left and right front wheels 4 via the shaft 15. Therefore, the vehicle Ve can generate a driving force by transmitting the motor torque output by the second motor 5 to the front wheels 4 while the engine 1 is stopped. Further, the engine 1 is operated with the clutch K1 released, the first motor 3 is driven by the engine torque to generate electricity, and the motor torque of the second motor 5 is transmitted to the front wheels 4 to generate a driving force. Is possible. Then, the engine 1 can be operated with the clutch K1 engaged, and the engine torque and the motor torque of the second motor 5 can be transmitted to the rear wheels 2 and the front wheels 4 to generate a driving force.

The ECU 10 corresponds to the "controller" in the embodiment of the present invention, and in the example shown in FIG. 1, the HV-ECU 10a and the AHBRx-ECU 10b are provided. The HV-ECU 10a mainly controls the first motor 3, the second motor 5, the automatic transmission 7, the clutch K1, and the battery 6, respectively, and the AHVRx-ECU 10 mainly controls the brake system 9. Although not shown, an ECU for controlling the engine 1 is provided. Each of the ECUs 10a and 10b is an electronic control device mainly composed of, for example, a microcomputer. Data detected or calculated from various sensors are input to the ECUs 10a and 10b. The input data is, for example, accelerator opening, vehicle speed, front-rear acceleration or lateral acceleration of the vehicle, brake pedal force or brake pedal depression amount, remaining charge of the battery 6, wheel speeds of the front wheels 4 and the rear wheels 2, and the like. .. Further, each of the ECUs 10a and 10b performs a calculation using various input data, data stored in advance, a calculation formula, and the like. Then, each of the ECUs 10a and 10b outputs the calculation result as a control command signal, and controls the first motor 3, the second motor 5, the clutch K1, the automatic transmission 7, the brake system 9, and the like, respectively. It is configured.

The vehicle Ve in the embodiment of the present invention can travel in a plurality of traveling modes by controlling the engine 1, the first motor 3, the second motor 5, the automatic transmission 7, the clutch K1, and the like described above. It is possible. That is, the vehicle Ve has an EV traveling mode in which the motor torque output by the second motor 5 is transmitted to the front wheels 4 to generate a drive torque while the engine 1 is stopped, and the engine 1 is released in a state where the clutch K1 is released. It operates, drives the first motor 3 with engine torque to generate power, drives the second motor 5 with the power generated by the first motor 3, and transmits the motor torque of the second motor 5 to the front wheels 4 for driving. The engine 1 is operated with the series HV running mode that generates torque and the clutch K1 engaged, and the engine torque and the motor torques of the second motor 5 and the first motor 3 are transmitted to the rear wheels 2 and the front wheels 4. The vehicle travels by setting one of the parallel HV travel modes that generate drive torque. It should be noted that such switching of each traveling mode is performed using, for example, a mode switching map in which the required driving force and the vehicle speed are parameters.

The vehicle Ve configured in this way is, for example, when the vehicle is started by depressing the accelerator pedal from a state where the vehicle is stopped using the brake on an uphill road, or when the vehicle is stopped without using the brake on an uphill road. Alternatively, when traveling at a minute speed, the accelerator opening is small because a particularly large drive torque is not required. Therefore, the traveling mode of the vehicle Ve is set to the EV traveling mode or the series HV traveling mode, and the driving torque is output by the second motor 5. In that case, there is a high possibility that the current supplied to the second motor 5 becomes larger with respect to the rotation speed and a large current flows only in a specific one phase, resulting in a so-called single-phase locked state. Since the temperature of the motor 5 and the inverter rises, control is performed to suppress the temperature rise. The single-phase locked state referred to here means that the heat load generated by the second motor 5 within a predetermined period is equal to or higher than a predetermined value due to a large current flowing only in a specific one phase of the second motor 5. Therefore, the performance and durability of the electric circuit such as the second motor 5 and the inverter which is the control device thereof are deteriorated by the heat load.

When the control for avoiding the single-phase locked state is executed, the torque output by the second motor 5 is controlled to be small in order to suppress the heat load of the second motor 5, so that it is necessary to start on an uphill road, for example. The torque output by the second motor 5 becomes smaller than the torque. Therefore, it is not possible to start with only the second motor 5, or when starting on an uphill road, the vehicle Ve may descend (backward) along the uphill road. Therefore, in the embodiment of the present invention, when the vehicle Ve starts on the uphill road due to the torque output by the second motor 5 whose output is limited, the control for avoiding the vehicle Ve descending along the uphill road is controlled. Run. An example of a control example executed by the ECU 10 will be described below. The control example described below is an example in which the series HV traveling mode is set and the vehicle Ve starts on an uphill road by the torque output by the second motor 5.

FIG. 2 is a flowchart showing an example of control according to the embodiment of the present invention. First, whether or not the second motor 5, which is a traveling motor, overheats by outputting the torque required for starting on an uphill road. (Step S1). Specifically, a predetermined torque range including the torque required for starting on an uphill road (hereinafter referred to as the required torque for climbing a slope) is set, and whether or not the torque output by the second motor 5 is within the torque range. Is judged. The torque required for climbing is the torque required to start the vehicle Ve in the direction of climbing against the load in the direction of descending the vehicle Ve along the uphill road and the running resistance of the road surface, and is the road gradient and the vehicle weight. It can be calculated based on the above. The above torque range can be obtained by experiments, simulations, or the like as a range in which the vehicle Ve can be maintained in a stopped state on an uphill road and a single-phase locked state may occur. Therefore, in step S1, if the required torque at that time is output by the second motor 5, it is determined that a single-phase locked state may occur.

If a positive judgment is made in step S1, the process proceeds to step S2, and the upper limit of the output torque according to the temperature of the second motor 5 is set. The temperature and the upper limit value are for avoiding overheating due to the second motor 5 being in the single-phase locked state, and therefore, the above temperature is the above temperature even if the second motor 5 outputs the torque of the upper limit value. , The temperature at which it is considered that the performance and durability of the second motor 5 and the electric circuit such as the inverter which is the control device thereof do not deteriorate, and the upper limit value is simple even if the second motor 5 outputs the upper limit torque. This is the torque at which it is considered that the phase lock state does not occur. The above-mentioned upper limit value is a value smaller than the maximum torque that can be output by design. Then, the process proceeds to step S4.

On the other hand, if it is negatively determined in step S1, the performance and durability of the electric circuit such as the second motor 5 and the inverter are deteriorated due to the heat load generated by the second motor 5 within a predetermined period. Since it is considered that there is no possibility, the output torque of the second motor 5 is not limited (step S3). Therefore, the second motor 5 can output the maximum torque by design. Then, the process proceeds to step S4.

In step S4, the second motor 5 outputs a torque equal to or less than the upper limit value set in step S3, or a torque equal to or less than the maximum torque that can be output by the second motor 5. The torque output by the second motor 5 is the torque required by the driver, and the required torque is obtained based on the accelerator opening degree. For example, the required torque related to the accelerator opening can be prepared in advance as a map, and the required torque can be calculated based on the map.

Then, the process proceeds to step S5, and when the vehicle Ve is on the uphill road and the second motor 5 outputs the torque of the upper limit value, it is determined whether or not the vehicle Ve descends on the uphill road. The determination that the road on which the vehicle Ve is stopped at that time is an uphill road can be performed based on the road information in the navigation system, or the acceleration obtained as a differential value between the required torque obtained from the accelerator opening and the vehicle speed. It can also be done based on the vehicle weight and so on. Whether or not the vehicle Ve descends along the uphill road can be determined by determining whether or not the required torque is larger than the required uphill torque. As described above, the torque required for climbing is the torque required to start the vehicle Ve in the direction of climbing against the load in the direction of descending the vehicle Ve along the uphill road and the running resistance of the road surface. It can be calculated based on the road slope and vehicle weight. The road gradient can be obtained at the same time as the determination of the uphill road or in the same manner.

If it is negatively determined in step S5, the torque of the upper limit value output by the second motor 5 is larger than the torque required for climbing a slope, so that the second motor 5 can start the vehicle on an uphill road. .. Therefore, in this case, this routine is once returned without any particular control.

On the other hand, when a positive judgment is made in step S5, the torque of the upper limit value output by the second motor 5 is smaller than the torque required for climbing a slope, and depending only on the torque of the upper limit value output by the second motor 5. , There is a possibility that the vehicle Ve cannot be started in the direction of climbing the uphill road. Therefore, in this case, the clutch K1 is engaged and the automatic transmission 7 sets a predetermined gear stage (step S6). In this way, the engine 1, the first motor 3, and the rear wheels 2 are connected so as to be able to transmit power, and the rear wheels 2 are driven by at least one torque of the engine torque and the torque of the first motor 3. That is, in addition to the torque output by the second motor 5, a drive torque larger than the required torque for climbing a slope is output by at least one torque of the engine torque and the torque output by the first motor 3, and the launch start control is started. Do. The launch start control is, for example, a control for starting the vehicle Ve by suppressing the idling of the rear wheels 2 and the rotation of the rear wheels 2 in the direction in which the vehicle Ve moves backward. Specifically, the engine 1 and the first motor A predetermined small torque (basic torque) such that the rear wheel 2 slightly rotates in the forward direction is output from at least one of the three, and the rotation of the rear wheel 2 is detected by a rotation speed sensor (not shown). Then, even if the above-mentioned basic torque is output, when the rear wheel 2 does not rotate in the forward direction or the vehicle Ve rotates in the backward direction, from at least one of the engine 1 and the first motor 3 The output torque is gradually increased. That is, feedback control is performed to gradually increase the torque output from at least one of the engine 1 and the first motor 3. Further, since the gear stage set by the automatic transmission 7 needs to transmit the engine torque to the rear wheels 2, it is a gear stage other than neutral, and as an example, among the gear stages that can be set by the automatic transmission 7. , The first gear with the lowest gear ratio is set. After that, this routine is returned once.

FIG. 3 is a time chart showing an example of changes in the operating state of the clutch K1, the input shaft rotation speed of the automatic transmission 7, the output shaft rotation speed of the automatic transmission 7, and the like when the control shown in FIG. 2 is performed. .. At the time of t1 which is positively determined in step S5 described above, a control command signal for switching the clutch K1 from the released state to the engaged state is output from the ECU 10 to the clutch K1. As a result, the clutch disc of the clutch K1 and the clutch plate (not shown) come close to each other. This state is described as "preparation for engagement" in FIG. After that, at t2, the clutch disc and the clutch plate start to come into contact with each other, and the clutch K1 is in a semi-engaged state. In this way, at least one torque of the engine torque and the torque of the first motor 3 is transmitted to the automatic transmission 7 and the rear wheels 2 via the clutch K1, and the input rotation speed and the output shaft rotation speed of the automatic transmission 7 increase. .. That is, the driving torque of the vehicle Ve is increased by the torque of at least one of the engine torque and the torque of the first motor 3. The rate of increase in drive torque and the transmission torque capacity of the clutch K1 until the clutch disc and the clutch plate are pressed against each other and the clutch K1 is engaged (until the time t3) without slipping. The rate of change of is set to the rate of increase or the rate of change to the extent that the drive torque and the transmission torque capacity do not suddenly change and a shock does not occur. In addition, the rate of increase or the rate of change can be determined in advance.

Therefore, in the embodiment of the present invention, the output torque of the second motor 5 is limited in order to avoid the single-phase locked state of the second motor 5, so that the drive torque is insufficient when starting on an uphill road. When there is a possibility that the clutch K1 is engaged, the launch start control is performed by engaging the clutch K1 and starting with at least one torque of the engine torque and the torque of the first motor 3 in addition to the torque of the second motor 5. Therefore, it is possible to prevent or suppress the vehicle Ve from descending along the uphill road due to insufficient drive torque with respect to the required torque for climbing the slope. That is, since the vehicle can start smoothly even on an uphill road, the startability can be improved. Further, since the brake is not operated in order to prevent the vehicle Ve from descending along the uphill road, the startability can be improved also in terms of such an operation.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned examples, and may be appropriately modified as long as the object of the present invention is achieved. For example, when the vehicle is stopped on an uphill road, the EV driving mode may be set instead of the series HV driving mode described above. When the EV traveling mode is set, the engine 1 may be started before the clutch K1 is set to the engaged state.

1 ... Engine (ENG), 2 ... Rear wheel, 3 ... 1st motor, 4 ... Front wheel, 5 ... 2nd motor, 7 ... Automatic transmission, 8, 8a, 8b ... Power control unit (PCU), 10 ... ECU (Controller), K1 ... Clutch, Ve ... Vehicle.

Claims (1)

An engine, a transmission provided on the output side of the engine to increase or decrease the torque output by the engine, and one of the front wheels and the rear wheels connected to the engine and the transmission so as to be able to transmit torque. A first motor to drive, a second motor to drive either the front wheels or the rear wheels, and the transmission between the transmission and the first motor in the direction of transmission of torque output by the engine. In a hybrid vehicle control device provided with a clutch and configured to set an upper limit of torque that can be output by the second motor according to the temperature of the second motor.
A controller for controlling the hybrid vehicle is provided.
The controller
When the hybrid vehicle starts with the torque output by the second motor in the direction of climbing the uphill road, the required torque for starting uphill on the uphill road is the torque output by the second motor. Judge whether the upper limit is exceeded and
When it is determined that the required torque for climbing a slope exceeds the upper limit value, the second motor outputs the torque corresponding to the upper limit value, and the clutch is engaged to output the engine. A control device for a hybrid vehicle, which is configured to perform launch start control that starts with at least one torque of a torque and a torque output by the first motor.

Images