JP2018105214A - Automobile - Google Patents

Abstract

Deterioration of drivability is suppressed when the shift position is a parking position. An internal combustion engine having an output shaft connected to an axle via a damper, and an automobile that executes dither control for controlling the internal combustion engine so that the air-fuel ratio of the internal combustion engine repeats rich and lean. When the position is a parking position, execution of dither control is prohibited. Thereby, the deterioration of drivability when the shift position is the parking position can be suppressed. [Selection] Figure 2

Description

  The present invention relates to an automobile, and more particularly to an automobile equipped with an internal combustion engine.

  Conventionally, as this type of automobile, one having a multi-cylinder internal combustion engine has been proposed (for example, see Patent Document 1). In this automobile, the internal combustion engine is controlled so as to change the air-fuel ratio for each cylinder, the air-fuel ratio of each cylinder is estimated based on the output value of the air-fuel ratio sensor, and each cylinder is estimated based on the estimation result of the air-fuel ratio. The presence or absence of abnormality is judged.

JP 2008-128080 A

  In the above-described automobile, the rotational fluctuation of the internal combustion engine becomes large during execution of the dither control. Therefore, in an automobile having a damper between the output shaft and the axle of the internal combustion engine, when the shift position is operated to the parking position and the axle is fixed, the frequency of the dither control rotation fluctuation and the natural vibration frequency of the damper are When they match, resonance occurs and drivability deteriorates.

  The main object of the automobile of the present invention is to suppress deterioration in drivability when the shift position is a parking position.

  The automobile of the present invention has taken the following means in order to achieve the main object described above.

The automobile of the present invention
An internal combustion engine whose output shaft is connected to the axle via a damper;
A control device for performing dither control for controlling the internal combustion engine such that the air-fuel ratio of the internal combustion engine repeats rich and lean;
A car equipped with
The control device prohibits execution of the dither control when the shift position is a parking position;
This is the gist.

  In the automobile according to the present invention, the dither control for controlling the internal combustion engine is executed so that the air-fuel ratio of the internal combustion engine repeats rich and lean. When the shift position is the parking position, execution of dither control is prohibited. When dither control is executed, rotational fluctuations occur in the internal combustion engine. When the frequency of the rotational fluctuation of the dither control coincides with the natural vibration frequency of the damper, resonance occurs in the vehicle, and the vibration becomes larger. When the shift position is the parking position, the axle is fixed so as not to rotate. Therefore, there are few mechanisms for attenuating this vibration, and drivability may be deteriorated. In the present invention, when the shift position is the parking position, execution of dither control is prohibited, so that such drivability deterioration can be suppressed.

  In such an automobile of the present invention, the internal combustion engine may be provided with a purification device having a purification catalyst for purifying exhaust gas in the exhaust system, or with a filter for removing particulate matter in the exhaust system. Good.

  In addition, the automobile of the present invention may include a parking lock mechanism that fixes the axle so as not to rotate when the shift position is the parking position.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 4 is a flowchart showing an example of a flag setting routine executed by an engine ECU 24. It is a table | surface which shows an example of the increase / decrease amount of the fuel injection amount in each cylinder.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the 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, a gear mechanism 60, a hybrid electronic control unit (hereinafter, referred to as a hybrid electronic control unit). 70) (referred to as “HVECU”).

  The engine 22 is configured as an in-line four-cylinder internal combustion engine that outputs power 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. An exhaust purification device 23 and a particulate matter removal filter (hereinafter referred to as “PM filter”) 25 are attached to the exhaust system of the engine 22. The exhaust purification device 23 is filled with a catalyst 23a that removes unburned fuel and nitrogen oxides in the exhaust. The PM filter 25 is formed as a porous filter from ceramics, stainless steel, or the like, and supplements particulate matter (PM) such as soot.

  Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. .

  Signals from various sensors necessary for controlling the operation of the engine 22 are input to the engine ECU 24 via an input port. The signals from the various sensors include, for example, a crank position from a crank position sensor (not shown) that detects the rotational position of the crankshaft 26, a cooling water temperature Tw from a water temperature sensor (not shown) that detects the temperature of cooling water of the engine 22 and the like. Can be mentioned. Further, a throttle opening TH from a throttle valve position sensor (not shown) for detecting the throttle valve position, an intake air amount Qa from an air flow meter (not shown) attached to the intake pipe, and a temperature sensor (not shown) attached to the intake pipe. The intake air temperature Ta can also be mentioned. Further, the air-fuel ratio AF from the air-fuel ratio sensor 23b attached on the upstream side of the exhaust purification device 23 of the exhaust system and the oxygen signal O2 from the oxygen sensor 23c attached on the downstream side of the exhaust purification device 23 The pressures P1 and P2 from the pressure sensors 25a and 25b attached to the upstream side and the downstream side can also be mentioned.

  Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 through an output port. Examples of the various control signals include a drive signal to the fuel injection valve, a drive signal to the throttle motor that adjusts the position of the throttle valve, and a control signal to the ignition coil integrated with the igniter.

  The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 controls the operation of the engine 22 by a control signal from the HVECU 70. The engine ECU 24 outputs data relating to the operating state of the engine 22 to the HVECU 70 as necessary.

  The engine ECU 24 calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on the crank angle θcr. Further, the engine ECU 24 determines the volume efficiency (the volume of air actually sucked in one cycle with respect to the stroke volume per cycle of the engine 22) based on the intake air amount Qa from the air flow meter and the rotational speed Ne of the engine 22. The ratio KL is also calculated. The engine ECU 24 determines the PM accumulation amount as an estimated accumulation amount of the particulate matter captured by the PM filter 25 based on the pressure difference ΔP (ΔP = P1−P2) between the pressures P1 and P2 from the pressure sensors 25a and 25b. Qpm is calculated, or the filter temperature Tf as the estimated temperature of the PM filter 25 is calculated based on the operating state of the engine 22. Further, the engine ECU 22 requires 30 degrees rotation, which is the time required for the crankshaft 26 to rotate by 30 degrees each time the crankshaft 26 rotates by a predetermined angle (for example, 10 degrees) based on the crank angle θcr. The time T30 (msec) is acquired, and the angular velocity ωeg (rad / sec) of the crankshaft 26 (engine 10) is calculated based on the 30-degree rotation required time T30. The angular velocity ωeg is calculated as ωeg = 2π × (30/360) / T30 × 1000.

  The planetary gear 30 includes a sun gear 31 that is an external gear, a ring gear 32 that is an internal gear disposed concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and the ring gear 32, and a plurality of pinion gears 33. Is configured as a single pinion type planetary gear mechanism having a carrier 34 that rotates and revolves. The sun gear 31 of the planetary gear 30 is connected to the rotor of the motor MG1. The ring gear 32 of the planetary gear 30 is connected to a drive shaft 36 coupled to the drive wheels 63a and 63b via the differential gear 62 and the gear mechanism 60, and to the rotor of the motor MG2 via the reduction gear 35. ing. A crankshaft 26 of the engine 22 is connected to the carrier 34 of the planetary gear 30 via a damper 28.

  The gear mechanism 60 includes a parking gear 66 coupled to a gear 60b that meshes with a gear 60a coupled to the drive shaft 36, a parking lock pole 67 that meshes with the parking gear 66 and locks in a state where its rotational drive is stopped, A parking lock mechanism 65 is attached. The parking lock pole 67 operates when an actuator (not shown) is driven and controlled by the HVECU 70 to which an operation signal from another position to the parking position (P position) or an operation signal from the parking position to another position is input. The parking lock and the release thereof are performed by the meshing with the gear 66 and the release thereof. Since the gear 60b is mechanically connected to the drive wheels 63a and 63b, the parking lock mechanism 65 indirectly locks the drive wheels 63a and 63b when the parking gear 66 and the parking lock pole 67 are engaged. Will be.

  The motor MG1 is configured as a well-known synchronous generator motor including a rotor in which permanent magnets are embedded and a stator in which a three-phase coil is wound, and the rotor is connected to the sun gear of the planetary gear 30 as described above. Has been. The motor MG2 is configured as a synchronous generator motor similar to the motor MG1, and the rotor is connected to the drive shaft 36. Motors MG1 and MG2 are driven by controlling inverters 41 and 42 by motor ECU 40. The inverters 41 and 42 are connected to a power line 54 to which the battery 50 is connected. The inverters 41 and 42 are configured as well-known inverters including six transistors and six diodes. Since the inverters 41 and 42 share the power line 54, the power generated by either the motor MG1 or MG2 can be supplied to another motor.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . Signals from various sensors necessary for driving and controlling the motors MG1, MG2 are input to the motor ECU 40 via the input port. As signals from the various sensors, for example, rotational positions θm1 and θm2 from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and currents flowing through the phases of the motors MG1 and MG2 are used. The phase current from the current sensor to detect can be mentioned. From the motor ECU 40, switching control signals to the transistors of the inverters 41 and 42 for driving and controlling the motors MG1 and MG2 are output via the output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 controls driving of the motors MG1 and MG2 by a control signal from the HVECU 70. In addition, motor ECU 40 outputs data relating to the driving state of motors MG1 and MG2 to HVECU 70 as necessary. The motor ECU 40 calculates the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2.

  The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydride secondary battery, and exchanges electric power with the motors MG1 and MG2 via the inverters 41 and 42. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52.

  Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . A signal necessary for managing the battery 50 is input to the battery ECU 52 via the input port, and data regarding the state of the battery 50 is transmitted to the HVECU 70 by communication as necessary. As a signal input via the input port, for example, the voltage Vb between terminals from a voltage sensor (not shown) installed between the terminals of the battery 50 or the power line 54 connected to the output terminal of the battery 50 is attached. Examples thereof include a charge / discharge current Ib from a current sensor (not shown), a battery temperature Tb from a temperature sensor 51 attached to the battery 50, and the like. Further, the battery ECU 52 calculates the storage ratio SOC and input / output limits Win and Wout in order to manage the battery 50. The storage ratio SOC is a ratio of the capacity of electric power that can be discharged from the battery 50 to the total capacity, and is calculated based on the integrated value of the charge / discharge current Ib detected by the current sensor. The input / output limits Win and Wout are the maximum allowable power that may charge and discharge the battery 50, and are calculated based on the calculated storage ratio SOC and the battery temperature Tb.

  Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. Signals from various sensors are input to the HVECU 70 via input ports. Examples of the signals from the various sensors include an ignition signal from the ignition switch 80 and a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81. Further, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, and the vehicle speed sensor 88 The vehicle speed V can also be mentioned. Various control signals are output from the HVECU 70 via the output port. 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. The HVECU 70 exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. The shift position SP includes a drive position (D position) for forward travel, a reverse position (R position) for reverse travel, a neutral position (N position), and a parking position (P position) used for parking. is there.

  The hybrid vehicle 20 of the embodiment configured in this way is in a hybrid travel mode (HV travel mode) that travels with the operation of the engine 22 or in an electric travel mode (EV travel mode) that travels while the operation of the engine 22 is stopped. Run.

  Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the setting of the dither control flag F for performing dither control will be described.

  Prior to the description of setting the dither control flag F, dither control will be described. The dither control is a control for operating the engine 22 by performing fuel injection so that the air-fuel ratio of the engine 22 is rich (a state in which the fuel amount is reduced compared to the stoichiometric air-fuel ratio) and lean are repeated. In this dither control, some of the plurality of cylinders of the engine 22 are made rich, the remaining cylinders are made lean, and the average value of increase / decrease in the fuel injection amount of the engine 22 as a whole becomes 0. To drive. FIG. 3 is a table showing an example of the increase / decrease amount of the fuel injection amount in each cylinder. For example, when the engine 22 is an in-line four-cylinder internal combustion engine and the cylinder numbers are # 1 to # 4 from the left when viewed from the front of the vehicle, the fuel injection amount of each cylinder is the cylinder to be ignited first (# 1 ) Is made rich by 30% with respect to the cylinder average injection amount obtained by dividing the fuel injection amount of the engine 22 by the number of cylinders, and the fuel injection amount of the cylinder (# 3) to be ignited next is the cylinder average injection amount. In contrast, the engine 22 is operated with the fuel injection amount of the remaining cylinders set as 10% lean (# 4) and 10% lean (# 2) in the order of ignition. By such control, the exhaust gas temperature is raised, and the temperature of the PM filter 25 is rapidly raised to a temperature that can be rapidly regenerated (for example, 600 ° C.) to regenerate the PM filter 25 or sulfur poisoned to the catalyst 23a. Purge for a minute. The dither control is not executed when a dither control flag F, which will be described later, is 0, and is executed by the engine ECU 24 when the dither control flag F is 1.

  Subsequently, the setting of the dither control flag F will be described. FIG. 2 is a flowchart showing an example of a flag setting routine executed by the engine ECU 24. This routine is executed when the vehicle is stopped.

  When this routine is executed, the HVECU 70 determines whether or not an execution condition for executing the dither control is satisfied (step S100). The execution conditions are the first condition in which the engine 22 is in operation, the second condition in which the regeneration of the PM filter 25 is requested, and the air-fuel ratio of the engine 22 is stable (in the air-fuel ratio control of the engine 22). The third condition in which the feedback correction amount is within a predetermined range and learning about the air-fuel ratio is completed, and the engine 22 has been warmed up (the cooling water temperature Tw of the engine 22 is a predetermined temperature (for example, 70 ° C.) , 75 [deg.] C., 80 [deg.] C., etc.). The regeneration request for the PM filter 25 is made when the PM deposition amount Qpm as the deposition amount of the particulate matter deposited on the PM filter 25 is equal to or greater than the threshold value Qpmref. Here, the PM accumulation amount Qpm is calculated (estimated) based on the differential pressure ΔP (ΔP = P1−P2) between the pressures P1 and P2 from the pressure sensors 25a and 25b. The threshold value Qpmref is a PM deposition amount Qpm that can be determined that the regeneration of the PM filter 25 is necessary. The execution condition is satisfied when all the conditions from the first condition to the fourth condition are satisfied.

  If it is determined in step S100 that the dither control execution condition is not satisfied, the dither control flag F is set to 0 (step S110), and this routine is terminated. The engine ECU 24 does not execute the above-described dither control when the dither control flag F is 0.

  If it is determined in step S100 that the dither control execution condition is satisfied, it is subsequently determined whether or not the shift position SP is the P position (step S120). When it is determined that the shift position SP is not the P position, the dither control flag F is set to 1 (step S130), and this routine is terminated. The engine ECU 24 executes the above-described dither control when the dither control flag F is a value of 1. As a result, the exhaust gas temperature is raised, the temperature of the PM filter 25 is quickly raised to a temperature above the reproducible temperature, and the PM filter 25 is regenerated, or the sulfur content poisoning the catalyst 23a is purged. .

  When it is determined in step S120 that the shift position SP is the P position, the dither control flag F is set to 0 (step S110), and this routine ends. The engine ECU 24 does not execute dither control when the dither control flag F is 0. In the dither control, the engine 22 is operated by performing fuel injection so that the air-fuel ratio of the engine 22 becomes rich or lean for each cylinder. At this time, the rotational fluctuation of the engine 22 when the lean cylinder is ignited becomes large. When the frequency of this rotational fluctuation matches the natural frequency of the damper 28, resonance occurs and the vibration of the vehicle increases. When the shift position SP is at the P position, the driving wheels 63a and 63b are locked by the parking lock mechanism 65. Therefore, when the frequency of the rotational fluctuation of the engine 22 matches the natural frequency of the damper 28, the engine 22 and the motor Vibration of the inertial body including MG1 is increased, and drivability is deteriorated. In the state where the drive wheels 63a and 63b are not locked, even if the frequency of the rotational fluctuation of the engine 22 matches the natural frequency of the damper 28, the engine 22, the motor MG1, MG2, the gear mechanism 60, the differential gear 62, the drive Since vibration energy is distributed to the grounding surfaces of the wheels 63a and 63b and the driving wheels 63a and 63b, the influence on the driver's viridy is smaller than when the driving wheels 63a and 63b are locked. In the embodiment, when the dither control execution condition is satisfied, the dither control is not executed when the shift position SP is the P position, so that such vibration can be suppressed. Therefore, the deterioration of drivability during parking can be suppressed.

  According to the hybrid vehicle 20 of the embodiment described above, when the shift position SP is the P position, the deterioration of drivability during parking can be suppressed by prohibiting execution of dither control.

  In the hybrid vehicle 20 of the embodiment, when at least one of the first to fourth conditions is not satisfied in the process of step S100, it is determined that the execution condition is not satisfied, and the first to fourth conditions are satisfied. When all the conditions are satisfied, it is determined that the execution condition is satisfied. However, since it is only necessary to determine that the execution condition is satisfied when at least one of the first to fourth conditions is satisfied, the first to third conditions are not considered. If it is determined that the execution condition is satisfied when is satisfied, or the execution condition is satisfied when only the first and fourth conditions are satisfied without considering the second and third conditions You may judge. Moreover, it is not limited to 1st-4th conditions, You may determine with execution conditions being satisfied based on other conditions.

  In the hybrid vehicle 20 of the embodiment, the engine 22 is an in-line four-cylinder internal combustion engine, but the number of cylinders is not limited, and may be, for example, a V-type eight-cylinder internal combustion engine or a single-cylinder internal combustion engine. . When the engine 22 is a single cylinder internal combustion engine, in the dither control, the engine 22 may be controlled to repeat rich and lean in one cylinder.

  In the embodiment, the case where the present invention is applied to the hybrid vehicle 20 including the PM filter 25 in the exhaust system is illustrated. However, the present invention may be applied to a hybrid vehicle that does not include a PM filter in the exhaust system.

  In the embodiment, the case where the present invention is applied to a hybrid vehicle in which the engine 22, the motor MG1, and the motor MG2 are connected to the planetary gear 30 is illustrated. However, the present invention provides various types of hybrid vehicles including an engine and a motor that outputs power for traveling, for example, a motor connected to a drive shaft coupled to drive wheels via a transmission and the motor. You may apply to the hybrid vehicle etc. of the type which connects an engine to a rotating shaft through a clutch. In addition, the present invention may be applied to a type of automobile that includes an engine but does not include a motor that outputs driving power.

  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 problems will be described. In the embodiment, the engine 22 corresponds to an “internal combustion engine”, and the engine ECU 24 corresponds to a “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 the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. In other words, the interpretation of the invention described in the column of means for solving the problem should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problem. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

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

  20 hybrid vehicle, 22 engine, 23 exhaust purification device, 23a catalyst, 23b air-fuel ratio sensor, 23c oxygen sensor, 24 engine electronic control unit (engine ECU), 25 particulate matter removal filter (PM filter), 25a, 25b pressure Sensor, 26 Crankshaft, 28 Damper, 30 Planetary gear, 31 Sun gear, 32 Ring gear, 33 Pinion gear, 34 Carrier, 35 Reduction gear, 36 Drive shaft, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 rotational position detection sensor, 50 battery, 51 temperature sensor, 52 battery electronic control unit (battery ECU), 54 power line, 60 gear mechanism, 60a, 60b gear, 62 differential gear, 65 parts -King lock mechanism, 63a, 63b drive wheel, 66 parking gear, 67 parking lock pole, 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 motor.

Claims (1)

An internal combustion engine whose output shaft is connected to the axle via a damper;
A control device for performing dither control for controlling the internal combustion engine such that the air-fuel ratio of the internal combustion engine repeats rich and lean;
A car equipped with
The control device prohibits execution of the dither control when the shift position is a parking position;
Automobile.

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