JP6747233B2 - Automobile - Google Patents

Description

The present invention relates to automobiles.

Conventionally, this type of vehicle includes an engine and a motor connected to a crankshaft of the engine. When the engine is cranked by the motor to start the engine, the torque of the motor is set to the first value for cranking the engine. It has been proposed to switch the torque of the motor to a second torque that is smaller than the first torque when the engine speed is equal to or higher than a predetermined speed and the crank angle of the engine is within a predetermined range after setting the torque. (For example, refer to Patent Document 1). In this vehicle, the vibration when starting the engine is reduced by setting the predetermined range to a range that includes the timing when any cylinder of the engine reaches the expansion stroke.

JP, 2005-48596, A

In the above-described automobile, after the engine cranking is started, the torque of the motor may be reduced from the first torque at the timing of approaching the expansion stroke after the halfway compression stroke. In this case, the vibration when cranking the engine by the motor may not be sufficiently suppressed.

The main object of the automobile of the present invention is to sufficiently suppress the vibration when cranking the engine by the motor.

The vehicle of the present invention employs the following means in order to achieve the above-mentioned main object.

The automobile of the present invention is
Engine,
A motor connected to the crankshaft of the engine,
When the engine is cranked and started by the motor, the motor is controlled so that a predetermined torque is output from the motor, and when the reduction start condition is satisfied, the torque from the motor is changed from the predetermined torque. A controller for controlling the motor so as to decrease,
A car comprising:
The decrease start condition is that the engine rotation speed is equal to or higher than a predetermined rotation speed, and the crank angle of the engine is within a predetermined range reaching an expansion stroke, and the rotation amount of the engine from the start of the cranking is The condition is that the amount of rotation is equal to or more than the rotation amount required to reach the predetermined range after the full compression stroke in which the compression is maximized after the start of the cranking.
Automobile.

In the vehicle of the present invention, when the engine is cranked and started by the motor, the motor is controlled so that the motor outputs a predetermined torque, and when the reduction start condition is satisfied, the torque from the motor is reduced to the predetermined torque. Control the motor to decrease from. In such control, the decrease start condition is that the engine speed is equal to or higher than a predetermined speed, the crank angle of the engine is within a predetermined range near the expansion stroke, and the engine rotation is from the start of cranking. It is assumed that the amount is equal to or more than the rotation amount required to reach a predetermined range after the full compression stroke in which the compression is maximized only after the start of cranking. Here, the “predetermined range” is a range in which the fluctuation of the engine compression is likely to be large. In addition, the inventors of the present invention have conducted experiments and analyzes and found that after starting cranking the engine, when the torque of the motor starts to decrease from the predetermined torque at the timing when it reaches the predetermined range after the first full compression stroke, it is halfway completed. It has been found that the vibration when cranking the engine by the motor can be more sufficiently suppressed as compared with the case where the torque of the motor is started to decrease from the predetermined torque at the timing when it reaches the predetermined range after the compression stroke. Therefore, by setting the reduction start condition as described above, it is possible to more sufficiently suppress the vibration when the engine is cranked by the motor.

It is a block diagram which shows the outline of a structure of the hybrid vehicle 20 as one Example of this invention. 6 is a flowchart showing an example of a startup control routine executed by the HVECU 70 of the embodiment. 6 is a flowchart showing an example of a cranking torque setting routine executed by the HVECU 70 of the embodiment.

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

FIG. 1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. As illustrated, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, and a hybrid electronic control unit (hereinafter referred to as "HVECU"). And 70.

The engine 22 is configured as a four-cylinder internal combustion engine that outputs power through four strokes of intake, compression, explosion (combustion), and exhaust using gasoline or light oil as fuel. The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24.

Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM for storing a processing program, a RAM for temporarily storing data, an input/output port, and a communication port. .. Signals from various sensors necessary for controlling the operation of the engine 22, for example, a crank angle θcr from a crank position sensor 23 that detects a rotational position of a crankshaft 26 of the engine 22 are input to the engine ECU 24 from an input port. Has been done. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 through the output port. The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 23.

The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The sun gear of the planetary gear 30 is connected to the rotor of the motor MG1. The ring gear of the planetary gear 30 is connected to a drive shaft 36 that is connected to the drive wheels 39a and 39b via a differential gear 38. The crankshaft 26 of the engine 22 is connected to the carrier of the planetary gear 30 via a damper 28.

The motor MG1 is configured as, for example, a synchronous generator motor, and the rotor is connected to the sun gear of the planetary gear 30 as described above. The motor MG2 is configured as, for example, a synchronous generator motor, and the rotor is connected to the drive shaft 36. Inverters 41 and 42 are connected to motors MG1 and MG2, and are also connected to battery 50 via power line 54. The motors MG1 and MG2 are rotationally driven by a plurality of switching elements (not shown) of the inverters 41 and 42 being switching-controlled by a motor electronic control unit (hereinafter referred to as “motor ECU”) 40.

Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM that stores a processing program, a RAM that temporarily stores data, an input/output port, and a communication port. .. The motor ECU 40 has signals from various sensors necessary for driving and controlling the motors MG1 and MG2, for example, rotational positions θm1 from rotational position detection sensors 43 and 44 that detect rotational positions of rotors of the motors MG1 and MG2. , Θm2, etc. are input through the input port. From the motor ECU 40, switching control signals to a plurality of switching elements (not shown) of the inverters 41 and 42 are output via the output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. Motor ECU 40 calculates rotational speeds Nm1 and Nm2 of motors MG1 and MG2 based on rotational positions θm1 and θm2 of rotors of motors MG1 and MG2 from rotational position detection sensors 43 and 44.

The battery 50 is configured as, for example, a lithium-ion secondary battery or a nickel-hydrogen secondary battery, and is connected to the inverters 41 and 42 via a power line 54. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as “battery ECU”) 52.

Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM that stores a processing program, a RAM that temporarily stores data, an input/output port, and a communication port. .. Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via an input port. The signal input to the battery ECU 52 may be, for example, the voltage Vb of the battery 50 from the voltage sensor 51a installed between the terminals of the battery 50 or the current of the battery 50 from the current sensor 51b attached to the output terminal of the battery 50. Ib and the temperature Tb of the battery 50 from the temperature sensor 51c attached to the battery 50 can be mentioned. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the storage ratio SOC based on the integrated value of the current Ib of the battery 50 from the current sensor 51b. The charge ratio SOC is the ratio of the capacity of the electric power that can be discharged from the battery 50 to the total capacity of the battery 50.

Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM that stores a processing program, a RAM that temporarily stores data, an input/output port, and a communication port. Signals from various sensors are input to the HVECU 70 via input ports. Examples of the signal input to the HVECU 70 include an ignition signal from the ignition switch 80 and a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81. Further, the accelerator pedal position Acc from the accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83, the brake pedal position BP from the brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85, and the vehicle speed sensor 88 from the vehicle speed sensor 88. The vehicle speed V can also be mentioned. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port.

In the hybrid vehicle 20 of the embodiment thus configured, the required driving force of the drive shaft 36 is set based on the accelerator opening Acc and the vehicle speed V, and the required power commensurate with the required driving force is output to the drive shaft 36. First, the engine 22 and the motors MG1 and MG2 are operated and controlled. The operation modes of the engine 22 and the motors MG1 and MG2 include, for example, the following modes (1) to (3).
(1) Torque conversion operation mode: The engine 22 is operated and controlled so that the power corresponding to the required power is output from the engine 22, and all the power output from the engine 22 is generated by the planetary gear 30 and the motors MG1 and MG2. A mode in which the motors MG1 and MG2 are drive-controlled so that the torque is converted by the torque converter to output the required power to the drive shaft 36. (2) Charge/discharge operation mode: Sum of the required power and the electric power required for charging/discharging the battery 50 The engine 22 is controlled so that the power corresponding to the above is output from the engine 22, and all or part of the power output from the engine 22 is generated by the planetary gear 30 and the motors MG1 and MG2 as the battery 50 is charged and discharged. A mode for driving and controlling the motors MG1 and MG2 so that the torque is converted by the torque converter and the required power is output to the drive shaft 36. (3) Motor operation mode: The operation of the engine 22 is stopped and the required power is transmitted to the drive shaft 36. Mode for controlling the drive of the motor MG2 so that it is output

Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the operation when the engine MG is cranked and started by the motor MG1 will be described. FIG. 2 is a flowchart showing an example of a start-up control routine executed by the HVECU 70 of the embodiment. This routine is executed when an instruction to start the engine 22 is issued.

When the start-up control routine is executed, the HVECU 70 first inputs data necessary for control such as the accelerator opening Acc, the vehicle speed V, and the rotation speed Ne of the engine 22 (step S100). Here, as the accelerator opening degree Acc, the value detected by the accelerator pedal position sensor 84 is input. As the vehicle speed V, the value detected by the vehicle speed sensor 88 is input. As the rotation speed Ne of the engine 22, a value calculated based on the crank angle θcr of the engine 22 from the crank position sensor 23 is input from the engine ECU 24 by communication.

When the data is thus input, the required torque Td* required for traveling (the drive shaft 36) is set based on the input accelerator opening Acc and the vehicle speed V (step S110), and the engine 22 is turned on. The cranking torque Tcr for ranking is set to the torque command Tm1* of the motor MG1 (step S120). Here, as the cranking torque Tcr, a value set by a cranking torque setting routine described later is used.

Next, the torque command Tm* of the motor MG2 is set using the required torque Td*, the torque command Tm1* of the motor MG1, and the gear ratio (the number of teeth of the sun gear/the number of teeth of the ring gear) ρ of the planetary gear 30 (step S130). ). Here, the torque command Tm2* of the motor MG2 is the torque (-Tm1*/ρ) that is output from the motor MG1 and acts on the drive shaft 36 via the planetary gear 30 when the motor MG1 is driven by the torque command Tm1*. It can be set as a value subtracted from the required torque Td*.

When the torque commands Tm1* and Tm2* for the motors MG1 and MG2 are set in this way, the set torque commands Tm1* and Tm2* for the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S140). When the motor ECU 40 receives the torque commands Tm1*, Tm2* for the motors MG1, MG2, the motor ECU 40 performs switching control of the switching elements of the inverters 41, 42 so that the motors MG1, MG2 are driven by the torque commands Tm1*, Tm2*.

Subsequently, the rotation speed Ne of the engine 22 is compared with the operation start rotation speed Nstem (step S150). Here, the operation start rotation speed Nsteg is the rotation speed at which the operation (fuel injection control or ignition control) of the engine 22 is started, and for example, 800 rpm, 900 rpm, 1000 rpm or the like can be used. When the rotation speed Ne of the engine 22 is less than the operation start rotation speed Nstem, the process returns to step S100, the processes of steps S100 to S150 are repeatedly executed, and when the rotation speed Ne of the engine 22 reaches the operation start rotation speed Nseg or more, A command to start fuel injection control and ignition control of the engine 22 is transmitted to the engine ECU 24 (step S160). Upon receiving this start command, the engine ECU 24 starts fuel injection control and ignition control of the engine 22. Then, it is determined whether or not the engine 22 has reached a complete explosion (step S170), and when it has not yet reached a complete explosion, the process returns to step S100, and the processes of steps S100 to S170 are repeatedly executed to complete the engine 22. When it arrives, this routine is finished.

Next, the process of setting the cranking torque Tcr used in the process of step S120 of the startup control routine of FIG. 2 will be described. FIG. 3 is a flowchart showing an example of a cranking torque setting routine executed by the HVECU 70 of the embodiment. This routine is executed in parallel with the startup control routine of FIG. 2 when the engine 22 is instructed to start.

When the cranking torque setting routine is executed, the HVECU 70 first inputs the crank angle θcr of the engine 22 as the initial crank angle θcrst (step S200), and sets the rotation amount threshold value Qcrref based on the input initial crank angle θcrst. (Step S210). Here, the crank angle θcr of the engine 22 is detected by the crank position sensor 23 and is input from the engine ECU 24 through communication. The rotation amount threshold value Qcrref is a predetermined range θcr1 to θcr2 (where the variation in the compression of the engine 22 varies when the compression stroke of the engine 22 goes through the full compression stroke in which the compression is maximized for the first time after the cranking of the engine 22 is started). This is the amount of rotation of the engine 22 required to reach the range (which tends to increase). Since the four-cylinder engine 22 is used in the embodiment, the rotation amount threshold value Qcrref is set such that the cylinder in the intake stroke at the start of cranking of the engine 22 (hereinafter, referred to as “start-time intake cylinder”) undergoes the compression stroke and has a predetermined range θcr1. Is the amount of rotation of the engine 22 required to reach ~cr2. The rotation amount threshold value Qcrref is set to be smaller as the initial crank angle θcrst is farther from the top dead center (closer to the bottom dead center) when viewed from the starting intake cylinder. For example, when the predetermined range θcr1 to θcr2 is defined as a range of top dead center to top dead center +10° CA for the cylinder in the compression stroke, etc., when the initial crank angle θcrst is viewed from the starting intake cylinder, When (top dead center+α)° CA, the rotation amount threshold value Qcrref is set to a value within the range of (360−α) to (370−α)° CA.

Then, a predetermined positive torque Tcrst is set to the cranking torque Tcr (step S220). Here, the predetermined torque Tcrst is a relatively large torque for rapidly increasing the rotation speed Ne of the engine 22.

Next, the rotation speed Ne, the crank angle θcr, and the rotation amount Qcr of the engine 22 are input (step S230). Here, the method of inputting the rotation speed Ne and the crank angle θcr of the engine 22 has been described above. The rotation amount Qcr of the engine 22 is calculated as a difference between the latest crank angle θcr and the initial crank angle θcr, and is input from the engine ECU 24 through communication.

When the rotation speed Ne, the crank angle θcr, and the rotation amount Qcr of the engine 22 are thus input, the rotation speed condition in which the rotation speed Ne of the engine 22 is equal to or higher than the threshold value Nstmg and the crank angle θcr of the engine 22 within the predetermined range θcr1 to θcr2. It is determined whether all of a certain crank angle condition and a rotation amount condition in which the rotation amount Qcr of the engine 22 is equal to or larger than the rotation amount threshold value Qcrref described above are satisfied (steps S240 to S260). Here, the threshold value Nstmg is defined as, for example, 300 rpm, 350 rpm, 400 rpm, or the like. The predetermined ranges θcr1 and θcr2 are defined as, for example, the range of top dead center to top dead center +10° CA as described above. The rotation speed condition, the crank angle condition, and the rotation amount condition in steps S240 to S260 are used as conditions (hereinafter, referred to as “reduction start conditions”) for starting to decrease the torque command Tm1* of the motor MG1 from the predetermined torque Tcrst.

In steps S240 to S260, when at least one of the rotation speed condition, the crank angle condition, and the rotation amount condition is not satisfied, it is determined that the decrease start condition is not satisfied, and the process returns to step S230. Then, the processes of steps S230 to S260 are repeatedly executed, and when all of the rotation speed condition, the crank angle condition, and the rotation amount condition are satisfied, it is determined that the decrease start condition is satisfied, and as shown in Expression (1). Then, the cranking torque (previously Tcr) set last time, which is obtained by subtracting the rate value ΔTcr, is limited to 0 (with lower limit guard) to set the cranking torque Tcr (step S270), and the engine 22 is completed. It is determined whether or not the explosion has occurred (step S280), and when the engine 22 has not yet reached the complete explosion, the process returns to step S270. Here, the rate value ΔTcr is a rate value when the cranking torque Tcr is reduced from the predetermined torque Tcrst. Further, whether or not the engine 22 has reached a complete explosion can be determined using the rotation speed Ne of the engine 22 and the increase rate ΔNe of the rotation speed Ne per unit time. The processing of steps S270 and S280 is processing of waiting for the complete explosion of the engine 22 while holding the cranking torque Tcr by reducing it from the predetermined torque Tcrst to a value of 0 by the rate processing using the rate value ΔTcr. .. In this way, the processing of steps S270 and S280 is repeatedly executed, and when the engine 22 reaches the complete explosion, this routine is ended.

Tcr=max (previous Tcr-ΔTcr,0) (1)

When the rotation speed condition and the crank angle condition are used as the reduction start condition (when the rotation amount condition is not used), after the cranking of the engine 22 is started, one of the cylinders of the engine undergoes a halfway compression stroke and a predetermined compression stroke is performed. There is a case where the torque command Tm1* of the motor MG1 starts to decrease at the timing of reaching the ranges θcr1 to θcr2, specifically, at the timing of the cylinder in the compression stroke at the start of the cranking of the engine 22 to reach the predetermined range θcr1 to θcr2. In this case, the vibration when cranking the engine 22 by the motor MG1 may not be sufficiently suppressed. According to experiments and analysis, the inventors of the present invention, after starting the cranking of the engine 22, start decreasing the torque command Tm1* of the motor MG1 at the timing of reaching the predetermined range θcr1 to θcr2 after the first full compression stroke, Vibration when cranking the engine 22 by the motor MG1 is more sufficiently suppressed as compared with the case where the torque command Tm1* of the motor MG1 is started to be reduced at a timing that reaches a predetermined range θcr1 to θcr2 after a halfway compression stroke. I found that I could do it. In view of this, in the embodiment, the rotation amount condition is used in addition to the rotation speed condition and the crank angle condition as the reduction start condition. This makes it possible to more sufficiently suppress vibrations when the engine MG is cranked by the motor MG1.

In the hybrid vehicle 20 of the embodiment described above, when the engine 22 is cranked by the motor MG1 and started, the torque command Tm1* of the motor MG1 is set to the predetermined torque Tcrst to control the motor MG1 and start the reduction. When the condition is satisfied, the motor MG1 is controlled so that the torque command Tm1* of the motor MG1 decreases from the predetermined torque Tcrst. In such control, as the reduction start condition, a rotation speed condition in which the rotation speed Ne of the engine 22 is equal to or more than a threshold value Nstmg and a crank angle condition in which the crank angle θcr of the engine 22 is within a predetermined range θcr1 to θcr2. In addition, the rotation amount condition in which the rotation amount Qcr of the engine 22 is equal to or more than the rotation amount threshold value Qcrref described above is also used. This makes it possible to more sufficiently suppress vibrations when the engine MG is cranked by the motor MG1.

In the hybrid vehicle 20 of the embodiment, the 4-cylinder engine 22 is used, but a 3-cylinder engine, a 6-cylinder engine, an 8-cylinder engine, or the like may be used.

Although the hybrid vehicle 20 of the embodiment includes the engine ECU 24, the motor ECU 40, and the HVECU 70, at least a part of these may be configured as a single electronic control unit.

In the embodiment, the present invention is applied to the hybrid vehicle 20 in which the engine 22 and the motor MG1 are connected to the drive shaft 36 connected to the drive wheels 39a and 39b via the planetary gear 30 and the motor MG2 is connected to the drive shaft 36. And However, the present invention may be applied to a vehicle having any configuration as long as the vehicle includes the engine and the motor connected to the crankshaft of the engine. For example, the present invention is applied to a hybrid vehicle in which a rotary shaft of a motor is connected to a drive shaft connected to drive wheels via a transmission and a crankshaft of an engine is connected to the rotary shaft of the motor via a clutch. May be Further, the present invention may be applied to a vehicle in which a crankshaft of an engine is connected to a drive shaft connected to drive wheels via a transmission and a starter motor is connected to the crankshaft.

Correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem will be described. In the embodiment, the engine 22 corresponds to the “engine”, the motor MG1 corresponds to the “motor”, and the HVECU 70, the engine ECU 24, and the motor ECU 40 correspond to the “control device”.

The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is that the embodiment implements the invention described in the section of means for solving the problem. This is an example for specifically explaining the mode for carrying out the invention, and does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problem should be made based on the description in that column, and the embodiment is the invention of the invention described in the column of means for solving the problem. This is just a specific example.

Although the embodiments for carrying out the present invention have been described above with reference to the embodiments, the present invention is not limited to these embodiments, and various embodiments are possible without departing from the scope of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention can be used in the automobile manufacturing industry and the like.

20 hybrid vehicle, 22 engine, 23 crank position sensor, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 planetary gear, 36 drive shaft, 38 differential gear, 39a, 39b drive wheel, 40 motor Electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotational position detection sensor, 46 Capacitor, 50 Battery, 51a Voltage sensor, 51b Current sensor, 51c Temperature sensor, 52 Battery electronic control unit (battery ECU), 54 electric power line, 70 hybrid electronic control unit (HVECU), 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, 88 vehicle speed sensor , MG1, MG2 motors.

Claims (1)

Engine,
A motor connected to the crankshaft of the engine,
When the engine is cranked and started by the motor, the motor is controlled so that a predetermined torque is output from the motor, and when the reduction start condition is satisfied, the torque from the motor is changed from the predetermined torque. A controller for controlling the motor so as to decrease,
A car comprising:
The decrease start condition is that the engine rotation speed is equal to or higher than a predetermined rotation speed, and the crank angle of the engine is within a predetermined range reaching an expansion stroke, and the rotation amount of the engine from the start of the cranking is The condition is that the amount of rotation is equal to or more than the rotation amount required to reach the predetermined range after the full compression stroke in which the compression is maximized after the start of the cranking.
Automobile.

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