JP4229104B2 - Automobile and control method thereof - Google Patents

Description

  The present invention relates to an automobile and a control method thereof.

2. Description of the Related Art Conventionally, as this type of automobile, there is proposed an automobile in which the hydraulic pressure of a wheel cylinder on the rear wheel side is pressurized and held by a brake actuator including a motor-driven hydraulic piston when parking on a slope (see, for example, Patent Document 1). . In this automobile, the hydraulic pressure of the wheel cylinder on the rear wheel side is maintained under pressure to prevent the vehicle from sliding down when parked on a slope.
JP 2001-210110 A

  In automobiles that prevent such downhills, if the driver does not output the appropriate driving force for creeping up (creep torque) when the brakes are released, the vehicle may slide down or the driving wheels may slip depending on the road surface gradient. As a result, a smooth start may not be possible. Also, in a vehicle equipped with an electric motor that outputs power to the axle, if the driving force is output from the electric motor to the axle while the hydraulic pressure of the wheel cylinder is pressurized and held, rotation does not occur. It also occurs when flowing.

  One object of the automobile and its control method of the present invention is to start smoothly on an uphill road. Another object of the automobile and the control method thereof according to the present invention is to suppress a current from flowing only in a single phase of a coil of an electric motor.

  In order to achieve at least a part of the above object, the automobile of the present invention and the control method thereof employ the following means.

The automobile of the present invention
An internal combustion engine capable of outputting power to the first axle;
An electric motor capable of inputting and outputting power to a second axle different from the first axle;
Brake operation detection means for detecting the driver's brake operation;
A braking force is applied to the first axle and the second axle based on the driver's braking operation, and the first axle and the second axle are controlled regardless of the driver's braking operation. Braking force applying means capable of applying power independently;
Road surface gradient detecting means for detecting a road surface gradient in the longitudinal direction of the vehicle;
Target operating state setting means for setting a target operating state which is an operating state of the internal combustion engine for outputting a driving force based on the road surface gradient to the first axle when the detected road surface gradient is an ascending slope; ,
An operation of releasing the brake as the driver's brake operation is detected by the brake operation detecting means in a state where the vehicle is stopped at an ascending slope due to the braking force by the braking force applying means based on the driver's braking operation. The internal combustion engine is controlled so that the operation state of the internal combustion engine gradually becomes the target operation state, and after the operation state of the internal combustion engine reaches a predetermined operation state before reaching the target operation state. Control means for controlling the electric motor so that a driving force is output to the second axle, and for controlling the braking force applying means so that the braking state in the uphill stop state is released by a predetermined release procedure;
It is a summary to provide.

  In the automobile of the present invention, when the road surface gradient in the front-rear direction of the vehicle is an uphill gradient, a target operation state that is an operation state of the internal combustion engine for outputting a driving force based on the road surface gradient to the first axle is set, The internal combustion engine so that the operation state of the internal combustion engine gradually becomes the target operation state when the driver releases the brake in the climb gradient stop state where the vehicle is stopped at the climb gradient by the braking force based on the brake operation of the driver And controlling the electric motor so that the driving force is output to the second axle after the operating state of the internal combustion engine reaches the predetermined operating state before reaching the target operating state, and the braking state in the climbing slope stop state The braking force applying means is controlled so that is released by a predetermined release procedure. Since the driving force is not output from the electric motor until the operating state of the internal combustion engine reaches a predetermined operating state, it is possible to suppress a current from flowing only in a single phase of the electric motor by preventing the second axle from rotating. As a result, it is possible to smoothly start on the uphill road.

  In such an automobile of the present invention, the control means maintains the braking state in the climb gradient stop state until the operating state of the internal combustion engine reaches the predetermined operating state, and the operating state of the internal combustion engine is the predetermined state. After reaching the driving state, it may be a means for controlling so that the braking state in the uphill stop state is gradually released. If it carries out like this, the start on an uphill road can be performed more smoothly. In this case, the control means releases the braking force of the second axle when the operating state of the internal combustion engine reaches the predetermined operating state, and then releases the braking force of the first axle. It can also be a means to control. In this way, when the driving force is output from the electric motor to the second axle, the braking force of the second axle is released, so that the second axle does not rotate so that a current is supplied only to the single phase of the electric motor. It is possible to suppress the flow more reliably. Further, in this case, the control means may be means for controlling so that the braking force of the first axle is gradually released.

  In the automobile of the present invention, the control means controls the power from the internal combustion engine not to be output to the first axle until the operating state of the internal combustion engine reaches the predetermined operating state. It can also be. By doing so, no load is applied to the internal combustion engine, so that the operating state of the internal combustion engine can be brought into a predetermined operating state more quickly.

  The automobile of the present invention further includes an accelerator operation detecting means for detecting a driver's accelerator operation, and the target driving state setting means has a driving force based on the driver's accelerator operation larger than a driving force based on the road surface gradient. In some cases, the operating state of the internal combustion engine for outputting a driving force based on the accelerator operation to the first axle may be set as a target operating state. If it carries out like this, the driving force according to accelerator operation can be output, suppressing the downhill on an uphill road. In this case, the vehicle includes a target driving force setting means for setting a target driving force to be output to the first axle and the second axle based on the detected road surface gradient and the detected accelerator operation. In the predetermined operating state, the sum of the driving force that can be output from the internal combustion engine to the first axle and the driving force that can be output from the electric motor to the second axle is set as described above. It may be in a state where the target driving force is exceeded. In this way, it is possible to output the driving force from the electric motor when the target driving force can be output.

The vehicle control method of the present invention includes:
An internal combustion engine capable of outputting power to the first axle, an electric motor capable of inputting / outputting power to / from a second axle different from the first axle, and the first axle and the second axle A braking force applying means capable of independently adjusting the braking force, and a control method when stopping at an ascending slope in an automobile,
(A) The internal combustion engine for outputting a driving force based on a road surface gradient to the first axle after the vehicle stops at an upward slope by the driver's brake operation and before the driver's brake operation is released. Set the target operating state, which is the operating state,
(B) When the driver's brake operation is released, the internal combustion engine is controlled so that the operation state of the internal combustion engine gradually becomes the target operation state, and the operation state of the internal combustion engine is changed to the target operation state. The electric motor is controlled so that driving force is output to the second axle after reaching a predetermined driving state before reaching the first axle, and the first axle and the second axle are released before releasing the driver's brake operation. Controlling the braking force applying means so that the braking force acting on the axle is released by a predetermined release procedure;
This is the gist.

  In the automobile control method according to the present invention, the driving force based on the road gradient is output to the first axle after the vehicle stops at the climbing slope by the driver's braking operation until the driver's braking operation is released. The internal combustion engine is controlled so that when the driver's brake operation is released, the internal combustion engine is gradually set to the target operational state when the target braking state is set. The motor is controlled so that the driving force is output to the second axle after the driving state reaches the predetermined driving state before reaching the target driving state, and the first operation is performed before releasing the brake operation of the driver. The braking force applying means is controlled so that the braking force acting on the axle and the second axle is released by a predetermined release procedure. Since the driving force is not output from the electric motor until the operating state of the internal combustion engine reaches a predetermined operating state, it is possible to suppress a current from flowing only in a single phase of the electric motor by preventing the second axle from rotating. As a result, it is possible to smoothly start on the uphill road.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. The hybrid vehicle 20 of the embodiment is configured as a vehicle capable of traveling by four-wheel drive, and the power from the engine 22 is transmitted to the front shaft 64 via the torque converter 25, the CVT 50 as a continuously variable transmission, and the gear mechanism 65. A front wheel drive system that outputs and drives the front wheels 63a and 63b; a rear wheel drive system that outputs power from the motor 40 to the rear shaft 67 via the gear mechanism 68 to drive the rear wheels 66a and 66b; A brake actuator 100 for controlling the hydraulic pressure of the wheels 63a, 63b, 66a, 66b to the brake wheel cylinders 98a to 98d and a hybrid electronic control unit 70 for controlling the entire apparatus are provided.

  The engine 22 is configured as an internal combustion engine capable of outputting power using a hydrocarbon-based fuel such as gasoline or light oil, and the air purified by an air cleaner 122 is passed through a throttle valve 124 as shown in FIG. Inhaled and gasoline is injected from the fuel injection valve 126 to mix the sucked air and gasoline, and this mixture is sucked into the fuel chamber through the intake valve 128 and explosively burned by an electric spark from the spark plug 130. Thus, the reciprocating motion of the piston 132 pushed down by the energy is converted into the rotational motion of the crankshaft 23. Exhaust gas from the engine 22 is discharged to the outside air through a purification device (three-way catalyst) 134 that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).

  The engine 22 is controlled by an engine electronic control unit (hereinafter referred to as engine ECU) 29. The engine ECU 29 is configured as a microprocessor centered on the CPU 29a, and includes a ROM 29b that stores a processing program, a RAM 29c that temporarily stores data, an input / output port and a communication port (not shown), in addition to the CPU 29a. . The engine ECU 29 receives signals from various sensors that detect the state of the engine 22, for example, a crank position from the crank position sensor 140 that detects the rotational position of the crankshaft 23, and a water temperature that detects the cooling water temperature of the engine 22. A cam position sensor that detects the coolant temperature from the sensor 142, the in-cylinder pressure Pin from the pressure sensor 143 installed in the combustion chamber, and the rotational position of the intake valve 128 that performs intake and exhaust to the combustion chamber and the camshaft that opens and closes the exhaust valve The cam position from 144, the throttle position from the throttle valve position sensor 146 for detecting the position of the throttle valve 124, the air flow meter signal AF from the air flow meter 148 attached to the intake pipe, and the temperature attached to the intake pipe Including an intake air temperature from sensor 149 is input via the input port. Also, the engine ECU 29 is integrated with various control signals for driving the engine 22, such as a drive signal for the fuel injection valve 126, a drive signal for the throttle motor 136 for adjusting the position of the throttle valve 124, and an igniter. The control signal to the ignition coil 138 and the control signal to the variable valve timing mechanism 150 that can change the opening / closing timing of the intake valve 128 are output via the output port. The engine ECU 29 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and outputs data related to the operation state of the engine 22 as necessary. .

  A starter motor 22 a is attached to the crankshaft 23 of the engine 22, and a mechanical oil pump 26 that generates line hydraulic pressure for driving the alternator 32 and the CVT 50 that generate electric power to supply electric power to the motor 40. Is attached by a belt 24 so that power can be generated using the power from the engine 22 or hydraulic pressure can be generated.

  The torque converter 25 is configured as a well-known fluid type torque converter with a lock-up clutch, and outputs torque corresponding to the rotational speed on the engine 22 side to the CVT 50 side when starting or running at a low vehicle speed. The torque converter 25 is connected to the crankshaft 23 of the engine 22 via a clutch 25a for realizing neutral. The lock-up clutch and the clutch 25a of the torque converter 25 are controlled by the CVT electronic control unit 59.

  The CVT 50 includes a primary pulley 53 that can be changed in groove width and connected to the input shaft 51, a secondary pulley 54 that is also changeable in groove width and connected to an output shaft 52 as a drive shaft, and a primary pulley 53 and a secondary pulley. 54, and a first actuator 56 and a second actuator 57 that change the groove widths of the primary pulley 53 and the secondary pulley 54, and the primary actuator 56 and the second actuator 57 are used as a primary. By changing the groove widths of the pulley 53 and the secondary pulley 54, the power of the input shaft 51 is changed steplessly and output to the output shaft 52. The CVT 50 is shift-controlled by a CVT electronic control unit (hereinafter referred to as CVTECU) 59. The CVTECU 59 is supplied with the rotational speed Nin of the input shaft 51 from the rotational speed sensor 61 attached to the input shaft 51 and the rotational speed Nout of the output shaft 52 from the rotational speed sensor 62 attached to the output shaft 52. The CVTECU 59 outputs drive signals to the first actuator 56 and the second actuator 57. Further, the CVTECU 59 communicates with the hybrid electronic control unit 70, controls the transmission ratio of the CVT 50 by a control signal from the hybrid electronic control unit 70, and, if necessary, the rotational speed Nin of the input shaft 51 and the output shaft. Data relating to the operating state of the CVT 50 such as the rotational speed Nout of 52 is output to the hybrid electronic control unit 70.

  The motor 40 is configured as a well-known synchronous generator motor that can be driven as a generator and can be driven as an electric motor. The motor 40 exchanges power with the high-voltage battery 31 via the inverter 41 or receives power from the alternator 32. . The motor 40 is driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 42. Applied to the motor ECU 42 is a signal necessary for driving and controlling the motor 40, for example, a signal from a rotational position detection sensor 43 that detects the rotational position of the rotor of the motor 40, or a motor 40 detected by a current sensor (not shown). Phase current to be input. The motor ECU 42 communicates with the hybrid electronic control unit 70, and controls the drive of the motor 40 by outputting a switching control signal to the inverter 41 by a control signal from the hybrid electronic control unit 70, and if necessary. Data relating to the operating state of the motor 40 is output to the hybrid electronic control unit 70.

  The high voltage battery 31 capable of supplying power to the motor 40 is configured as a secondary battery having a rated voltage Vh (for example, 42 [V]), stores the power supplied from the alternator 32, and exchanges power with the motor 40. . The high-voltage battery 31 is connected via a DC / DC converter 34 to a low-voltage battery 35 or an auxiliary device 36 configured as a secondary battery having a rated voltage Vl (for example, about 12 [V]) lower than the rated voltage Vh. The low-voltage battery 35 and the auxiliary machine 36 can be supplied with power. The high voltage battery 31, the low voltage battery 35, and the DC / DC converter 34 are managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 30. The battery ECU 30 receives signals necessary for managing the high voltage battery 31 and the low voltage battery 35, for example, the voltage between terminals of both batteries detected by a sensor (not shown), charge / discharge current, battery temperature, and the like. If necessary, data relating to the states of both batteries is output to the hybrid electronic control unit 70 by communication. Note that the battery ECU 30 also calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current in order to manage the high voltage battery 31 and the low voltage battery 35.

  As shown in FIG. 3, the brake actuator 100 includes a front wheel brake actuator 101 and a rear wheel brake actuator 111. The front-wheel brake actuator 101 is connected to the brake master cylinder 90 via a supply oil passage 102 and connected to the brake wheel cylinders 98a and 98b of the front wheels 63a and 63b via pressure-reducing oil passages 103a and 103b. The holding solenoid valves 104a and 104b are connected to the wheel cylinders 98a and 98b of the front wheels 63a and 63b through the pressure increasing / decreasing oil passages 103a and 103b, and are connected to the reservoir 107 through the pressure reducing oil passage 105. 106a and 106b, and an oil pump 108 that pressurizes oil in the reservoir 107 and supplies the oil to the supply oil passage 102. In addition, two backflow prevention valves 109a and 109b are provided upstream and downstream of the oil pump 108 to prevent backflow. The holding solenoid valves 104a and 104b are configured as normally opened solenoid valves that are closed when energized (on), and the cylinder hydraulic pressures of the brake wheel cylinders 98a and 98b are maintained even when the solenoid valves 104a and 104b are turned on and closed. A check valve is provided for returning the brake oil to the supply oil passage 102 side when the oil pressure is higher than the supply oil passage 102 side. The decompression solenoid valves 106a and 106b are configured as normally closed solenoid valves that are opened when energized (on). As with the front wheel brake actuator 101, the rear wheel brake actuator 111 is connected to the brake master cylinder 90 via a supply oil passage 112 and brakes of the rear wheels 66a and 66b via pressure increase / decrease oil passages 113a and 113b. The left and right holding solenoid valves 114a and 114b connected to the wheel cylinders 98c and 98c are connected to the wheel cylinders 98c and 98d of the rear wheels 66a and 66b through the pressure increasing / decreasing oil passages 113a and 113b and the pressure reducing oil passage 115. Pressure reducing solenoid valves 116a and 116b connected to the reservoir 117 via the oil pressure, an oil pump 118 that pressurizes oil in the reservoir 117 and supplies it to the supply oil passage 112, and two backflow prevention valves 119a and 119b. The holding solenoid valves 114 a and 114 b and the pressure reducing solenoid valves 116 a and 116 b of the rear wheel brake actuator 111 have the same configuration as the holding solenoid valves 104 a and 104 b and the pressure reducing solenoid valves 106 a and 106 b of the front wheel brake actuator 101. The following description of the operation of the front-wheel brake actuator 101 is just an explanation of the operation of the rear-wheel brake actuator 111. The operation of the front wheel brake actuator 101 will be briefly described below.

  When the driver depresses the brake pedal 85 with all of the holding solenoid valves 104a and 104b and the pressure reducing solenoid valves 106a and 106b turned off (the state shown in FIG. 3), the master pressure corresponding to the depression is applied to the brake master cylinder 90. As a result, the brake oil is supplied to the brake wheel cylinders 98a and 98b via the supply oil passage 102, the holding solenoid valves 104a and 104b, and the pressure-reducing oil passages 103a and 103b, and the cylinder oil pressure of the brake wheel cylinders 98a and 98b is increased. The braking force corresponding to the cylinder oil pressure is applied to the front wheels 63a and 63b. When the driver returns the brake pedal 85 in this state, the brake oil in the brake wheel cylinders 98a and 98b is supplied to the brake master cylinder 90 via the pressure-increasing / depressurizing oil passages 103a and 103b, the holding solenoid valves 104a and 104b, and the supply oil passage 102. And the braking force applied to the front wheels 63a and 63b is released by reducing the cylinder oil pressure accordingly. In addition to the normal operation, the front wheel brake actuator 101 can hold the cylinder hydraulic pressure of the brake wheel cylinders 98a and 98b by turning on the holding solenoid valves 104a and 104b. At this time, if the pressure reducing solenoid valves 106a and 106b are turned on (opened), the brake oil in the brake wheel cylinders 98a and 98b is supplied via the pressure increasing / decreasing oil passages 103a and 103b, the pressure reducing solenoid valves 106a and 106b, and the pressure reducing oil passage 105. The cylinder oil pressure of the brake wheel cylinders 98a and 98b can be reduced by being guided to the reservoir 107. The degree to which the cylinder hydraulic pressure is reduced can be adjusted by the time during which the pressure reducing solenoid valves 106a and 106b are turned on (opened). Further, by driving the oil pump 108, the pressurized brake oil is supplied to the brake wheel cylinders 98a and 98b via the supply oil passage 102, the holding solenoid valves 104a and 104b, and the pressure increasing / decreasing oil passages 103a and 103b. The cylinder hydraulic pressure of the brake wheel cylinders 98a and 98b can be increased. At this time, when the holding solenoid valves 104a and 104b are turned on (closed), the pressurization of the cylinder hydraulic pressure can be stopped. Therefore, the degree of pressurization of the cylinder hydraulic pressure is determined by turning the holding solenoid valves 104a and 104b on ( It can be adjusted according to the time until closing. When the holding solenoid valves 104a and 104b are turned on (closed), the state is similar to the state in which the cylinder hydraulic pressure is held, so that the pressure can be reduced by turning on (opening) the pressure reducing solenoid valves 106a and 106b. In other words, the oil pressure of the brake wheel cylinders 98a and 98b can be freely adjusted by driving the oil pump 108 and turning on and off the holding solenoid valves 104a and 104b and the pressure reducing solenoid valves 106a and 106b. Of course, since the holding solenoid valves 104a and 104b and the pressure reducing solenoid valves 106a and 106b can be turned on and off independently, the cylinder hydraulic pressures of the brake wheel cylinders 98a and 98b can be individually adjusted freely.

  The brake actuator 100 is driven and controlled by a brake electronic control unit (hereinafter referred to as a brake ECU) 120. The brake ECU 120 inputs signals such as wheel speeds Vw1 to Vw4 from the wheel speed sensors 69a to 69d and a steering angle from a steering angle sensor (not shown) through a signal line (not shown), and the driver depresses the brake pedal 85. An anti-lock brake system function (ABS) that prevents any one of the front wheels 63a, 63b and the rear wheels 66a, 66b from slipping due to locking or the front wheel 63a that is a driving wheel when the driver depresses the accelerator pedal 83. , 63b and the rear wheels 66a, 66b are subjected to traction control (TRC) for preventing slipping due to idling, posture holding control (VSC) for holding the posture while the vehicle is turning. The brake ECU 120 is in communication with the hybrid electronic control unit 70, controls the drive of the brake actuator 100 by a control signal from the hybrid electronic control unit 70, and transmits data related to the operating state of the motor 40 as necessary. Output to the control unit 70.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72. In addition to the CPU 72, a ROM 74 that stores processing programs, a RAM 76 that temporarily stores data, an input / output port and communication (not shown), and the like. And a port. The hybrid electronic control unit 70 includes an ignition signal from the ignition switch 80, a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor that detects the amount of depression of the accelerator pedal 83. 84, the accelerator opening Acc from 84, the brake pedal position BP from the brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 87, and the longitudinal acceleration from the G sensor 88 that detects acceleration. G, brake pressure Pb from the pressure sensor 91 attached to the brake master cylinder 90 for generating hydraulic pressure (master cylinder pressure) in the brake oil based on the driver's operation of the brake pedal 85, front wheels 63a, 6 b and the rear wheels 66a, such as wheel speed Vw1~Vw4 from the wheel speed sensors 69a~69d attached to 66b are input via the input port. From the hybrid electronic control unit 70, a control signal to the alternator 32, a drive signal to the auxiliary machine 36, and the like are output via an output port. The hybrid electronic control unit 70 also exchanges various control signals and data with the engine ECU 29, the battery ECU 30, the motor ECU 42, and the CVTECU 59.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly the operation when starting on an uphill road where the road surface gradient θ is greater than a predetermined gradient (for example, 5 degrees or more) will be described. FIG. 4 is a flowchart showing an example of an uphill starting control routine executed by the hybrid electronic control unit 70 when the vehicle stops on the uphill road.

  When the uphill road start control routine is executed, the CPU 72 of the hybrid electronic control unit 70 first sets the brake wheel cylinders 98a to 98d of the front wheels 63a and 63b and the rear wheels 66a and 66b when the driver depresses the brake pedal 85. While maintaining the cylinder pressure (step S100), the clutch 25a is turned off to make the engine 22 neutral (step S110), and the driver operates the brake pedal 85 based on the brake pedal position BP from the brake pedal position sensor 86. Wait until the depression is released (steps S120 and S130). Here, the holding of the brake wheel cylinders 98a to 98d can be performed by turning on (closing) the holding solenoid valves 104a, 104b, 114a, and 114b. Specifically, the control signal is transmitted from the hybrid electronic control unit 70 to the brake ECU 120, and the brake ECU 120 turns on the holding solenoid valves 104a, 104b, 114a, 114b based on the control signal.

  When the driver depresses the brake pedal 85, a road surface gradient θ in the front-rear direction of the vehicle is input (step S140), and should be output to the front wheels 63a and 63b and the rear wheels 66a and 66b based on the road surface gradient θ. A target torque Td * and a target rotational speed Ne * of the engine 22 are set (steps S150 and S160). Here, the road surface gradient θ in the front-rear direction of the vehicle is calculated from the acceleration G in the front-rear direction from the G sensor 88 and is written in a predetermined area of the RAM 76. Further, the target torque Td * is set as a driving force that allows the road surface gradient θ to travel at a constant speed at a relatively small vehicle speed (for example, 4 km / h). In the embodiment, the road surface gradient θ and the target torque Td are set. The relationship with * is determined in advance and stored in the ROM 74 as a target torque setting map, and when the road surface gradient θ is given, the corresponding target torque Td * is derived and set from the map. An example of the target torque setting map is shown in FIG. The target rotational speed Ne * of the engine 22 is a rotational speed that can output torque to be output to the front wheels 63a and 63b when the target torque Td * is output to the front wheels 63a and 63b with a predetermined front-rear distribution. In the example, the relationship between the road surface gradient θ and the target rotational speed Ne * is predetermined and stored in the ROM 74 as a target rotational speed setting map, and when the road surface gradient θ is given, the corresponding target rotational speed Ne * is obtained from the map. Derived and set. An example of the target rotation speed setting map is shown in FIG.

  Then, the throttle opening TH is set larger by a small amount ΔTH and transmitted to the engine ECU 24 (step S170), the engine speed Ne is input (step S180), and the input engine speed Ne is input. Torque Tem that can be output as the sum of the torque output from the engine 22 to the front wheels 63a and 63b (shown as f (Ne) in FIG. 4) and the torque that can be output from the motor 40 (shown as Tmset in FIG. 4). Is calculated (step S190), and the process returns to step S170 to repeat the processing of steps S170 to S190 until the calculated outputable torque Tem becomes larger than the set target torque Td * (step S190). The engine ECU 24 that has received the throttle opening TH drives the throttle motor 136 so that the set opening is obtained.

  When the output possible torque Tem becomes larger than the target torque Td *, the cylinder pressures of the brake wheel cylinders 98c and 98c of the rear wheels 66a and 66b are released, and the brakes of the rear wheels 66a and 66b are released (step S210). In order to connect the crankshaft 23 to the torque converter 25, the clutch 25a is turned on (step S220). Then, the rotational speed Ne of the engine 22 is input (step S230), it is determined whether or not the input rotational speed Ne is less than the target rotational speed Ne * (step S240), and the rotational speed Ne is the target rotational speed Ne *. If it is less, the throttle opening TH is set larger by a small amount ΔTH and transmitted to the engine ECU 24 (step S250). That is, the throttle opening TH is gradually increased until the rotational speed Ne reaches the target rotational speed Ne *. The torque command Tm * of the motor 40 is calculated as a value obtained by subtracting the torque output from the engine 22 to the front wheels 63a and 63b calculated from the target torque Td * based on the rotational speed Ne, and the calculated torque command Tm *. Is transmitted to the motor ECU 42 (step S260), the cylinder pressure of the brake wheel cylinders 98a and 98b of the front wheels 63a and 63b is decreased (step S270), and the vehicle speed V reaches the threshold value Vref or higher (steps S280 and S290). In order to repeat the processes of S230 to S290, the process returns to step S230, and when the vehicle speed V reaches the threshold value Vref or more, it is determined that the start is completed, and this routine is terminated. Here, the threshold value Vref is a vehicle speed V for determining the completion of the start, and a value such as 3 km / h or 4 km / h can be used, for example. As described above, since the processes of steps S230 to S290 are repeated until the vehicle speed V reaches the threshold value Vref or higher, the cylinder pressures of the brake wheel cylinders 98a and 98b of the front wheels 63a and 63b are gradually reduced, and the vehicle starts without slipping down. Can do.

  FIG. 7 is an explanatory diagram showing an example of changes over time in the brake pressure, the rotational speed Ne of the engine 22, the torque of the motor 40, the vehicle speed V, and the like when starting with uphill road start control. As shown in the figure, when the brake pedal 85 is returned at time T11 and the brake is turned off, the target rotational speed Ne * of the engine 22 is set according to the road surface gradient θ, and the throttle opening TH of the engine 22 is gradually increased. Increase the rotational speed Ne of the engine 22 to increase it. The brake wheel cylinder 98c of the rear wheels 66a, 66b at a time T12 when the output possible torque Tem of the torque output from the engine 22 to the front wheels 63a, 63b and the torque that can be output from the motor 40 is larger than the target torque Td *. , 98c is released, torque output from the motor 40 is started, and the cylinder pressures of the brake wheel cylinders 98a, 98b of the front wheels 63a, 63b are gradually released. For this reason, the vehicle speed V is gradually increased and the start is completed without the vehicle falling down.

  According to the hybrid vehicle 20 of the embodiment described above, when the driver returns the brake pedal 85 from a state where the vehicle is stopped on an uphill road, the engine whose rotational speed Ne is set according to the road surface gradient θ. The throttle opening TH is gradually increased so that the target rotational speed Ne * of 22 is gradually reached. The torque that can be output is the sum of the torque output from the engine 22 to the front wheels 63a and 63b and the torque that can be output from the motor 40. When Tem becomes larger than the target torque Td * set in accordance with the road surface gradient θ, the brakes of the rear wheels 66a and 66b are released and torque output from the motor 40 is started to gradually move the front wheels 63a and 63b. By releasing the cylinder pressure of the brake wheel cylinders 98a, 98b, the vehicle can start smoothly without slipping down. You can. Moreover, since the torque is not output from the motor 40 until the target torque Td * can be output, the rear wheels 66a and 66b that output the torque from the motor 40 do not rotate, so that the three-phase coils of the motor 40 are not rotated. It can suppress that an electric current flows into only a phase.

  Further, according to the hybrid vehicle 20 of the embodiment, the output possible torque Tem that is the sum of the torque output from the engine 22 to the front wheels 63a and 63b and the torque that can be output from the motor 40 is set according to the road surface gradient θ. Since the clutch 22a is turned off and the engine 22 is neutrally controlled until the target torque Td * exceeds the target torque Td *, the engine speed Ne can be quickly increased.

  In the hybrid vehicle 20 of the embodiment, a target output torque Td that is set according to the road surface gradient θ is a sum of output possible torques Tem of the torque output from the engine 22 to the front wheels 63a and 63b and the torque output from the motor 40. * When larger than the above, the brakes of the rear wheels 66a and 66b are released and the torque output from the motor 40 is started to gradually release the cylinder pressures of the brake wheel cylinders 98a and 98b of the front wheels 63a and 63b. However, when the output possible torque Tem becomes larger than the target torque Td * set according to the road surface gradient θ, the torque output from the motor 40 is started and the brake wheel cylinders 98a and 98b of the front wheels 63a and 63b are started. The cylinder pressure is also the cylinder pressure of the brake wheel cylinders 98c and 98d of the rear wheels 66a and 66b. May be released gradually. Further, when the outputtable torque Tem becomes larger than the target torque Td * set according to the road surface gradient θ, the brakes of the rear wheels 66a and 66b are released and torque output from the motor 40 is started. The cylinder pressures of the brake wheel cylinders 98a and 98b of the front wheels 63a and 63b may be released.

  In the hybrid vehicle 20 of the embodiment, a target output torque Td that is set according to the road surface gradient θ is a sum of output possible torques Tem of the torque output from the engine 22 to the front wheels 63a and 63b and the torque output from the motor 40. * Although the clutch 25a is turned off and the engine 22 is neutrally controlled until it becomes larger, the neutral control of the engine 22 may not be performed.

  In the hybrid vehicle 20 of the embodiment, when the driver returns the brake pedal 85 from a state where the vehicle is stopped on an uphill road, the target torque Td * and the target rotational speed Ne * of the engine 22 are set according to the road surface gradient θ. However, the target torque Td * and the target rotational speed Ne * of the engine 22 may be set based on the vehicle state such as the vehicle speed V in addition to the road surface gradient θ. Further, the target torque Td * and the target rotational speed Ne * of the engine 22 may be set based on the accelerator opening Acc corresponding to the subsequent depression of the accelerator pedal 83. In this case, the target torque Td * based on the accelerator opening Acc and the target rotational speed Ne * of the engine 22 are compared with the target torque Td * based on the road surface gradient θ and the target rotational speed Ne * of the engine 22, and the larger one is targeted. The torque Td * or the target rotational speed Ne * of the engine 22 may be set. In this way, even if the amount of depression of the accelerator pedal 83 is small, the vehicle can be prevented from sliding down.

  In the hybrid vehicle 20 of the embodiment, the CVT 50 of a continuously variable transmission is provided as a transmission, but is not limited to such a CVT 50, and other types of continuously variable transmissions such as a toroidal type are used. Alternatively, a stepped transmission may be used.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention can be used in the automobile manufacturing industry.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 2 is a configuration diagram showing an outline of a configuration of an engine 22. FIG. 2 is a configuration diagram showing an outline of a configuration of a brake actuator 100. FIG. 5 is a flowchart showing an example of an uphill starting control routine executed by the hybrid electronic control unit 70. It is explanatory drawing which shows an example of the map for target torque setting. It is explanatory drawing which shows an example of the map for target rotation speed setting. It is explanatory drawing which shows an example of the mode of time changes, such as the brake pressure at the time of starting by uphill road starting control, the rotation speed Ne of the engine 22, the torque of the motor 40, and the vehicle speed V.

Explanation of symbols

20 hybrid vehicle, 22 engine, 22a starter motor, 23 crankshaft, 24 belt, 25 torque converter, 25a clutch, 26 mechanical oil pump, 27 output shaft, 29 electronic control unit for engine (engine ECU), 29a CPU, 29b ROM, 29c RAM, 30 Battery electronic control unit (battery ECU), 31 High voltage battery, 32 Alternator, 34 DC / DC converter, 35 Low voltage battery, 36 Auxiliary machine, 40 Motor, 41 Inverter, 42 Motor electronic control unit ( Motor ECU), 43 rotational position detection sensor, 50 CVT, 51 input shaft, 52 output shaft, 53 primary pulley, 54 secondary pulley, 55 belt, 56 first actuator 57 Second actuator, 59 CVT electronic control unit (CVTECU), 61 Rotational speed sensor, 62 Rotational speed sensor, 63a, 63b Front wheel, 64 Front shaft, 65, 68 Gear mechanism, 66a, 66b Rear wheel, 67 Rear shaft, 69a, 69b, 69c, 69d Wheel speed sensor 70 Electronic control unit for hybrid, 72 CPU, 74 ROM, 76 RAM, 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 87 Vehicle speed sensor, 88 G sensor, 90 Brake master cylinder, 91 Pressure sensor, 98a, 98b, 98c, 98d Brake wheel cylinder, 100 Brake actuator, 1 DESCRIPTION OF SYMBOLS 1 Front wheel brake actuator, 111 Rear wheel brake actuator, 102, 112 Supply oil path, 103a, 103b, 113a, 113b Pressure-reducing oil path, 104a, 104b, 114a, 114b Holding solenoid valve, 105, 115 Pressure-reducing oil path, 106a, 106b, 116a, 116b Pressure reducing solenoid valve, 107, 117 reservoir, 108, 118 Oil pump, 109a, 109b, 119a, 119b Backflow prevention valve, 120 Brake electronic control unit (brake ECU), 122 Air cleaner, 124 Throttle valve , 126 Fuel injection valve, 128 Intake valve, 130 Spark plug, 132 Piston, 134 Purification device, 136, Throttle motor, 138 Ignition coil, 140 Crank position sensor , 142 coolant temperature sensor, 143 a pressure sensor, 144 a cam position sensor, 146 a throttle valve position sensor, 148 an air flow meter, 149 temperature sensor, 150 a variable valve timing mechanism.

Claims (7)

An internal combustion engine capable of outputting power to the first axle;
An electric motor capable of inputting and outputting power to a second axle different from the first axle;
Brake operation detection means for detecting the driver's brake operation;
A braking force is applied to the first axle and the second axle based on the driver's braking operation, and the first axle and the second axle are controlled regardless of the driver's braking operation. Braking force applying means capable of applying power independently;
Road surface gradient detecting means for detecting a road surface gradient in the longitudinal direction of the vehicle;
Target operating state setting means for setting a target operating state which is an operating state of the internal combustion engine for outputting a driving force based on the road surface gradient to the first axle when the detected road surface gradient is an ascending slope; ,
An operation of releasing the brake as the driver's brake operation is detected by the brake operation detecting means in a state where the vehicle is stopped at an ascending slope due to the braking force by the braking force applying means based on the driver's braking operation. The internal combustion engine is controlled so that the operation state of the internal combustion engine gradually becomes the target operation state, and after the operation state of the internal combustion engine reaches a predetermined operation state before reaching the target operation state. Control means for controlling the electric motor so that a driving force is output to the second axle, and for controlling the braking force applying means so that the braking state in the uphill stop state is released by a predetermined release procedure;
Automobile equipped with.   The control means maintains the braking state in the climbing slope stop state until the operating state of the internal combustion engine reaches the predetermined operating state, and after the operating state of the internal combustion engine reaches the predetermined operating state. 2. The vehicle according to claim 1, wherein the vehicle is a means for controlling the braking state in the climbing slope stop state to be gradually released.   The control means controls so that the braking force of the second axle is released when the operating state of the internal combustion engine reaches the predetermined operating state, and thereafter the braking force of the first axle is released. The automobile according to claim 2, wherein   4. The automobile according to claim 3, wherein the control means is a means for controlling the braking force of the first axle to be gradually released.   5. The control means according to claim 1, wherein the control means is a means for controlling the power from the internal combustion engine not to be output to the first axle until the operation state of the internal combustion engine reaches the predetermined operation state. Car. The automobile according to any one of claims 1 to 5, wherein
Accelerator operation detection means for detecting the driver's accelerator operation,
The target driving state setting unit is configured to output the driving force based on the accelerator operation to the first axle when the driving force based on the accelerator operation of the driver is larger than the driving force based on the road gradient. An automobile that is a means for setting a driving state as a target driving state. The automobile according to claim 6,
A target driving force setting means for setting a target driving force to be output to the first axle and the second axle based on the detected road surface gradient and the detected accelerator operation;
The predetermined operating state is set as a sum of a driving force that can be output from the internal combustion engine to the first axle and a driving force that can be output from the electric motor to the second axle according to the predetermined operating state. A car that is in a state of exceeding the target driving force

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