Engine controller

Abstract

To provide an engine controller capable of preventing white smoke from coming out of an exhaust pipe during resumption of an engine even when the engine is temporarily stopped after making a sharp turn continuously for a certain period of time or more.SOLUTION: When a state in which an acceleration in a vehicle width direction is equal to or larger than a predetermined acceleration continues for a first predetermined time or more, HEV-CU 80 and ECU 81 prohibits stop of an engine 10 until a second predetermined time elapses after the acceleration in the vehicle width direction decreases to less than the predetermined acceleration.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an engine control device. [Background technology]

[0002] In recent years, hybrid electric vehicles (HEVs) that can effectively improve the fuel consumption rate (fuel economy) of a vehicle by using both an engine and an electric motor (motor generator) have been widely put to practical use. In addition, hybrid electric vehicles that can run only on the electric motor with the engine stopped have been put to practical use (for example, see Patent Document 1).

[0003] In recent years, from the viewpoint of improving fuel efficiency and reducing exhaust gas, vehicles equipped with an idling stop function (idling stop system) that automatically stops the engine when, for example, waiting for a traffic light at an intersection (when stopped) have been widely put into practical use. In an idling stop system, when the engine is in an idling stop state, for example, if it is detected that the brake pedal has been released, a request to restart the engine is output, and the engine is restarted (for example, see Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-146910 A [Patent Document 2] JP 2000-329039 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, for example, if you make a sharp turn (a turn with a turning force of about 1G) continuously (continuously) for a certain period of time and then immediately thereafter stop the engine and run the vehicle in EV mode using the electric motor or perform an idling stop, white smoke may come out of the exhaust pipe the next time you restart the engine.

[0006] The present invention has been made to solve the above-mentioned problems, and has an object to provide an engine control device that can prevent white smoke from emitting from the exhaust pipe when the engine is restarted, even if the engine is temporarily stopped after making sharp turns continuously for a certain period of time or more. [Means for solving the problem]

[0007] An engine control device according to one embodiment of the present invention includes a lateral acceleration sensor that detects the acceleration in the vehicle's width direction, and a control unit that controls the operation of an engine mounted on the vehicle, and is characterized in that, when the acceleration in the vehicle width direction detected by the lateral acceleration sensor remains equal to or greater than a predetermined acceleration for a first predetermined time or more, the control unit prohibits the engine from being stopped until a second predetermined time has elapsed after the acceleration in the vehicle width direction has fallen below the predetermined acceleration.

[0008] According to an engine control device according to an aspect of the present invention, when the state in which the acceleration in the vehicle width direction is equal to or greater than a predetermined acceleration continues for a first predetermined time or more, the engine is prohibited from being stopped until the second predetermined time has elapsed after the acceleration in the vehicle width direction falls below the predetermined acceleration. Therefore, even if oil is sprayed into the intake system during a sharp turn, the oil gradually enters the combustion chamber and is burned sequentially while the engine is prohibited from being stopped, so that the oil is prevented from accumulating in the combustion chamber, etc. Therefore, even if EV driving or idling stop is performed after that (after the second predetermined time has elapsed), it is possible to prevent a large amount of oil from being burned when the engine is restarted thereafter and white smoke is generated from the exhaust pipe. Effect of the Invention

[0009] According to the present invention, even if the engine is temporarily stopped after making sharp turns continuously for a certain period of time or more, it is possible to prevent white smoke from emitting from the exhaust pipe when the engine is subsequently restarted. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing the configuration of an engine control device according to an embodiment, and a hybrid vehicle to which the engine control device is applied; [Diagram 2] 1 is a diagram showing a configuration of an engine mounted on a hybrid vehicle according to an embodiment; [Diagram 3] 5 is a flowchart showing a processing procedure of a process for preventing generation of white smoke when the engine is restarted after making successive sharp turns, performed by the engine control device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, unless otherwise necessary, the same reference numerals will be used for the same or corresponding parts in the drawings. In addition, the same reference numerals will be used for the same elements in each drawing, and duplicated explanations will be omitted.

[0012] First, the configuration of an engine control device according to an embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a diagram showing the configuration of an engine control device and a hybrid vehicle to which the engine control device is applied. Fig. 2 is a diagram showing the configuration of an engine 10 mounted on the hybrid vehicle. Note that, here, the engine control device will be described as an example in which it is applied to a series-parallel hybrid vehicle (HEV).

[0013] First, the configuration of a hybrid vehicle will be described with reference to Fig. 1. A power split mechanism 30 is connected to a crankshaft 10a of an engine 10 (details of which will be described later) via a flywheel damper 20 that absorbs rotational fluctuations of the engine 10 and a pair of gears 21. A drive train 15 that is composed of a plurality of gears, shafts, etc. and transmits torque between the drive wheels, and a first motor-generator (MG) 11 (corresponding to an electric motor in the claims) are connected to the power split mechanism 30. The power split mechanism 30 has a planetary gear mechanism composed of, for example, a sun gear 30a, a ring gear 30b, a pinion gear 30c, and a planetary carrier 30d, and splits and transmits the drive torque generated by the engine 10 to the drive train 15 and the first motor-generator 11.

[0014] More specifically, the carrier 30d is connected to the crankshaft 10a of the engine 10 via the flywheel damper 20 and a pair of gears 21. The sun gear 30a is connected to the first motor-generator 11. Meanwhile, the ring gear 30b is connected to a propeller shaft 50 constituting the drive train 15 via a pair of gears (counter gears) 31, and is further connected to a front drive shaft 60 via a driving reduction gear 43.

[0015] When the first motor-generator 11 functions as a generator, the power distribution mechanism 30 distributes the torque (driving force) from the engine 10 input from the planetary carrier 30d to the sun gear 30a and the ring gear 30b according to the gear ratios of the two. On the other hand, when the first motor-generator 11 functions as a motor, the power distribution mechanism 30 integrates the torque from the engine 10 input from the planetary carrier 30d and the torque from the first motor-generator 11 input from the sun gear 30a, and outputs the integrated torque to the ring gear 30b. The torque output to the ring gear 30b is output to a propeller shaft 50 constituting the drive train 15 via a pair of gears (counter gears) 31, and is also output to a front drive shaft 60 via a drive reduction gear 43.

[0016] On the other hand, a second motor generator (MG) 12 (corresponding to an electric motor in the claims) is also connected to the drive train 15. More specifically, the second motor generator 12 is connected to a propeller shaft 50 via a motor reduction gear 41. The second motor generator 12 is also connected to a front drive shaft 60 via a drive reduction gear mechanism 40 composed of the motor reduction gear 41 and a drive reduction gear 43. The front drive shaft 60 transmits torque to the front wheels. The propeller shaft 50 transmits torque to the rear wheels.

[0017] The first motor-generator 11 and the second motor-generator 12 are configured as synchronous generator-motors that combine a function as a motor that converts supplied electric power into mechanical power and a function as a generator that converts input mechanical power into electric power. That is, the first motor-generator 11 and the second motor-generator 12 each operate as a motor that generates driving torque when driving the vehicle, and operate as a generator during regeneration. The first motor-generator 11 mainly operates as a generator, and the second motor-generator 12 mainly operates as a motor.

[0018] The driving reduction gear mechanism 40 is configured to have a motor reduction gear 41 and a driving reduction gear 43. The motor reduction gear 41 is configured as a planetary gear, and the reduction gear 43 is configured as, for example, a spur gear (or a helical gear).

[0019] More specifically, the motor reduction gear 41 has a planetary gear mechanism including, for example, a sun gear 41a, a ring gear 41b, a pinion gear 41c, and a planetary carrier 41d. When the second motor-generator 12 functions as a motor, the motor reduction gear 41 decelerates the rotation transmitted from the second motor-generator 12 (increases the torque) and outputs it from the planetary carrier 41d. On the other hand, the motor reduction gear 41 accelerates the rotation due to the torque (driving force) input to the planetary carrier 41d (reduces the torque) and outputs it from the sun gear 41a, thereby causing the second motor-generator 12 to function as a generator.

[0020] The front drive shaft 60 transmits torque between the driving reduction gear mechanism 40 and the driving wheels (front wheels in the example of FIG. 1). More specifically, the torque transmitted to the front drive shaft 60 is transmitted to a front differential (hereinafter also referred to as "front diff") 62. The front diff 62 is, for example, a bevel gear type differential device. The torque from the front diff 62 is transmitted to a left front wheel (not shown) via a left front wheel drive shaft, and is also transmitted to a right front wheel (not shown) via a right front wheel drive shaft.

[0021] On the other hand, the propeller shaft 50 transmits torque to the rear wheels. A transfer clutch 51 is interposed in the propeller shaft 50 to adjust the torque transmitted to the rear wheels. The transfer clutch 51 controls the fastening force (i.e., the torque distribution rate to the rear wheels) according to the drive state of the four wheels (for example, the slip state of the front wheels) and the engine torque. Therefore, the torque transmitted to the propeller shaft 50 is distributed according to the fastening force of the transfer clutch 51, and is also transmitted to the rear wheels.

[0022] More specifically, the torque transmitted to the propeller shaft 50 and adjusted (distributed) by the transfer clutch 51 is transmitted to a rear differential (hereinafter also referred to as "rear diff") 52. A left rear wheel drive shaft and a right rear wheel drive shaft (not shown) are connected to the rear differential 52. The driving force from the rear differential 52 is transmitted to the left rear wheel (not shown) via the left rear wheel drive shaft, and is also transmitted to the right rear wheel (not shown) via the right rear wheel drive shaft.

[0023] As configured in this manner, in the vehicle according to this embodiment (AWD HEV vehicle), the front and rear wheels (vehicle) can be driven by the power of the engine 10 and the second motor-generator 12, etc. Also, depending on the driving conditions, it is possible to switch between driving only by the second motor-generator 12 (EV driving) and driving by the engine 10 and the second motor-generator 12, etc. Furthermore, it is also possible to generate electricity (regenerate) by the first motor-generator 11, etc.

[0024] The engine 10, which is the driving force source of the vehicle, and the second motor-generator 12 and first motor-generator 11 are comprehensively controlled by a hybrid vehicle control unit (hereinafter referred to as “HEV-CU”) 80.

[0025] HEV-CU80 is composed of a microprocessor that performs calculations, an EEPROM that stores programs and the like for causing the microprocessor to execute each process, a RAM that stores various data such as the calculation results, a backup RAM in which the stored contents are retained, and an input / output I / F, etc.

[0026] Various sensors are connected to the HEV-CU80, including, for example, an accelerator sensor 91 that detects the amount of depression of the accelerator pedal, i.e., the amount of operation of the accelerator pedal, an outside air temperature sensor 93 that detects the outside air temperature (air temperature outside the vehicle), a rotation speed sensor 95 that detects the rotation speed of the front drive shaft 60, a resolver 97 that detects the rotation speed (rotational speed) of the first motor-generator 11, and a resolver 98 that detects the rotation speed (rotational speed) of the second motor-generator 12.

[0027] The HEV-CU 80 is also connected to an engine control unit (hereinafter referred to as "ECU") 81 that controls the engine 10, a vehicle dynamics control unit (hereinafter referred to as "VDCU") 85 that improves driving stability by suppressing vehicle skids, etc., via a CAN (Controller Area Network) 70 so as to be able to communicate with each other. The HEV-CU 80 receives various information, such as engine speed, brake operation amount, and acceleration (lateral G) in the vehicle width direction (lateral direction) from the ECU 81 and the VDCU 85 via the CAN 70. Meanwhile, the HEV-CU 80 transmits various information, such as the speed (rotation speed) of the first motor-generator 11, the speed (rotation speed) of the second motor-generator 12, and accelerator operation amount, to the ECU 81, etc., via the CAN 70.

[0028] A brake switch that detects whether or not the brake pedal is depressed, and a brake fluid pressure sensor 86 that detects the master cylinder pressure (brake fluid pressure) of the brake actuator are connected to the VDCU 85. A wheel speed sensor 87 that detects the rotation speed (vehicle speed) of each wheel of the vehicle, and a steering angle sensor that detects the turning angle of the front wheels (i.e., the steering angle of the steering wheel) by detecting the rotation angle of the pinion shaft are also connected to the VDCU 85. Furthermore, a longitudinal acceleration sensor 88 that detects the acceleration in the longitudinal direction (longitudinal G) acting on the vehicle, a lateral acceleration sensor 89 that detects the acceleration in the vehicle width direction (lateral G) acting on the vehicle, and the like are also connected to the VDCU 85.

[0029] The VDCU 85 drives the brake actuator to brake the vehicle according to the amount of operation (amount of depression) of the brake pedal, detects the vehicle behavior using various sensors (e.g., wheel speed sensor 87, steering angle sensor, lateral acceleration sensor 89, yaw rate sensor, etc.), and suppresses skidding and ensures vehicle stability during cornering by controlling the brakes through automatic pressure application and torque control of the engine 10, etc. The VDCU 85 also has an anti-lock brake function (ABS function) that prevents wheel lock caused by sudden braking or braking on a slippery road surface, and ensures directional stability and steering during braking by maintaining an appropriate slip ratio for each wheel, and also has a traction control function (TCS function) that ensures vehicle stability and acceleration during starting and acceleration by suppressing spinning of the drive wheels caused by slippery road surfaces or excessive driving force.

[0030] The VDCU 85 transmits braking information (brake operation information) such as the detected brake switch and brake fluid pressure, wheel speed (vehicle speed), longitudinal acceleration, lateral acceleration, steering angle, etc. to the HEV-CU 80 and the ECU 81 via the CAN 70. On the other hand, the VDCU 85 receives the above-mentioned automatic braking (automatic brake) request information, etc. via the CAN 70. When the VDCU 85 receives the automatic braking request information, it automatically drives the brake actuator to brake the vehicle.

[0031] Based on the various types of information acquired, the HEV-CU 80 comprehensively controls the driving of the engine 10, the second motor-generator 12, and the first motor-generator 11. The HEV-CU 80 determines and outputs the required output of the engine 10, stop prohibition / permission information (details will be described later), and torque command values ​​(target motor torque) for the second motor-generator 12 and the first motor-generator 11 based on, for example, the accelerator operation amount (drive force required by the driver), the driving state of the vehicle, the charging rate (SOC: State Of Charge) of the high-voltage battery 90, lateral acceleration, etc.

[0032] A power control unit (hereinafter referred to as "PCU") 82 drives the second motor generator 12 and the first motor generator 11 via an inverter 82a based on the torque command value. The PCU 82 has an inverter 82a that converts DC power from a high-voltage battery 90 into three-phase AC power and supplies it to the second motor generator 12 and the first motor generator 11. As described above, the PCU 82 drives the second motor generator 12 and the first motor generator 11 via the inverter 82a based on the torque command value received from the HEV-CU 80. On the other hand, during regeneration, the inverter 82a converts the AC voltage generated by the first motor generator 11 and the second motor generator 12 into a DC voltage to charge the high-voltage battery 90.

[0033] Next, the configuration of the engine 10 mounted on the hybrid vehicle will be described in detail with reference to FIG.

[0034] The engine 10 may be of any type, for example a horizontally opposed four-cylinder gasoline engine. The engine 10 is an in-cylinder injection engine that directly injects fuel into the cylinders. In the engine 10, air taken in through an air cleaner 116 is throttled by an electronically controlled throttle valve (hereinafter also simply referred to as a "throttle valve") 113 provided in an intake pipe 115, passes through an intake manifold 111, and is taken into each cylinder formed in the engine 10. The intake pipe 115 and the intake manifold 111 correspond to an intake system described in the claims.

[0035] The amount of air sucked in through air cleaner 116 is detected by an air flow meter 114 disposed between air cleaner 116 and throttle valve 113. A vacuum sensor (intake pressure sensor) 130 for detecting the pressure inside intake manifold 111 (intake manifold pressure) is disposed inside a collector section (surge tank) constituting intake manifold 111. Furthermore, a throttle sensor 131 for detecting the opening degree of throttle valve 113 is disposed in throttle valve 113.

[0036] An intake port 122 and an exhaust port 123 are formed in the cylinder head for each cylinder (only one bank is shown in FIG. 2). Each intake port 122 and exhaust port 123 is provided with an intake valve 124 and an exhaust valve 125 for opening and closing the intake port 122 and exhaust port 123, respectively. A variable valve timing mechanism 126 is disposed between the intake cam shaft that drives the intake valve 124 and the intake cam pulley, which rotates the intake cam pulley and the intake cam shaft relatively to continuously change the rotational phase (displacement angle) of the intake cam shaft with respect to the crankshaft 10a, thereby advancing or retarding the valve timing (opening / closing timing) of the intake valve 124. The variable valve timing mechanism 126 variably sets the opening and closing timing of the intake valve 124 according to the engine operating state.

[0037] Similarly, a variable valve timing mechanism 127 is disposed between the exhaust camshaft and the exhaust cam pulley, which rotates the exhaust cam pulley and the exhaust camshaft relatively to continuously change the rotational phase (displacement angle) of the exhaust camshaft with respect to the crankshaft 10a, thereby advancing or retarding the valve timing (opening / closing timing) of the exhaust valve 125. The variable valve timing mechanism 127 variably sets the opening / closing timing of the exhaust valve 125 according to the engine operating state.

[0038] An injector 112 that injects fuel into the cylinder is attached to each cylinder of the engine 10. The injector 112 directly injects fuel pressurized by a high-pressure fuel pump (not shown) into the combustion chamber of each cylinder.

[0039] Further, a spark plug 117 for igniting the air-fuel mixture and an igniter-integrated coil 121 for applying high voltage to the spark plug 117 are attached to the cylinder head of each cylinder. In each cylinder of the engine 10, the air-fuel mixture of the intake air and the fuel injected by the injector 112 is ignited by the spark plug 117 and combusted. Exhaust gas after combustion is discharged through an exhaust pipe 118.

[0040] An air-fuel ratio sensor 119 is attached downstream of the collecting portion of the exhaust pipe 118 and upstream of the exhaust purification catalyst 120. As the air-fuel ratio sensor 119, a linear air-fuel ratio sensor (LAF sensor) is used which can output a signal corresponding to the oxygen concentration and unburned gas concentration in the exhaust gas (i.e., a signal corresponding to the air-fuel ratio of the mixture) and can linearly detect the air-fuel ratio.

[0041] An exhaust purification catalyst 120 is disposed downstream of the LAF sensor 119. The exhaust purification catalyst 120 is a three-way catalyst that simultaneously oxidizes hydrocarbons (HC) and carbon monoxide (CO) in the exhaust gas and reduces nitrogen oxides (NOx), purifying harmful gas components in the exhaust gas into harmless carbon dioxide (CO2), water vapor (H2O), and nitrogen (N2). A silencer (muffler) 143 that reduces exhaust noise is attached downstream of the exhaust purification catalyst 120.

[0042] An exhaust gas recirculation device (hereinafter referred to as an "EGR (Exhaust Gas Recirculation) device") 140 is provided in the exhaust pipe 118, which recirculates a portion of the exhaust gas discharged from the engine 10 to the intake manifold 111 of the engine 10. The EGR device 140 has an EGR pipe 141 that connects the exhaust pipe 118 of the engine 10 with the intake manifold 111, and an EGR valve 142 that is interposed on the EGR pipe 141 and adjusts the amount of exhaust gas recirculation (EGR flow rate). The opening degree (EGRSTP) of the EGR valve 142 is controlled by the ECU 81 according to the operating state of the engine 10.

[0043] The engine 10 also has a blow-by gas treatment device 160 that introduces blow-by gas leaking from the combustion chamber into the crankcase 10b through between the cylinder and the piston into the intake pipe 115 or the like (intake system) and combusts it. The blow-by gas treatment device 160 includes a scavenging line (PCV line) 161 that connects the inside of the crankcase 10b with the downstream side of the throttle valve 113 of the intake pipe 115 or the like and returns (introduces) the blow-by gas to the intake pipe 115 or the like, a PCV valve 162 (corresponding to a flow control valve in the claims) that is interposed in the scavenging line 161 and adjusts the flow rate of the blow-by gas flowing through the scavenging line 161 depending on the pressure of the intake pipe 115 or the like, and a fresh air line 163 that connects the upstream side of the throttle valve 113 with the inside of the crankcase 10b and introduces fresh air.

[0044] In this embodiment, the PCV valve 162 is of a type that operates according to the pressure difference between the crankcase 10b and the downstream side of the throttle valve 113 (eg, the intake manifold 111).

[0045] In addition to the above-mentioned air flow meter 114, LAF sensor 119, vacuum sensor 130, and throttle sensor 131, a cam angle sensor 132 for identifying the cylinder of engine 10 is attached near the camshaft of engine 10. Also, a crank angle sensor 133 for detecting the rotational position of crankshaft 10a is attached near the crankshaft 10a of engine 10. Here, a timing rotor 133a having, for example, 34 projections with two teeth missing formed at 10° intervals is attached to the end of crankshaft 10a, and crank angle sensor 133 detects the rotational position of crankshaft 10a by detecting the presence or absence of the projection of timing rotor 133a. As cam angle sensor 132 and crank angle sensor 133, for example, an electromagnetic pickup type sensor or the like is used.

[0046] These sensors are connected to the ECU 81. In addition, the ECU 81 is also connected to various sensors such as a water temperature sensor 134 that detects the temperature of the cooling water for the engine 10, an oil temperature sensor 135 that detects the temperature of the lubricating oil, and the like.

[0047] The ECU 81 is configured to include a microprocessor that performs calculations, an EEPROM that stores programs and the like for causing the microprocessor to execute each process, a RAM that stores various data such as calculation results, a backup RAM in which the stored contents are held by a battery or the like, and an input / output I / F, etc. The ECU 81 also includes an injector driver that drives the injector 112, an output circuit that outputs an ignition signal, and a motor driver that drives the electric motor 113a that opens and closes the electronically controlled throttle valve 113, etc. The ECU 81 also receives information such as the required output of the engine 10, stop prohibition / permission information, the number of revolutions (rotational speed) of the first motor-generator 11, the number of revolutions (rotational speed) of the second motor-generator 12, and accelerator operation amount from the HEV-CU 80 via the CAN 70.

[0048] The ECU 81 identifies the cylinder from the output of the cam angle sensor 132, and determines the rotational angular velocity and engine speed from the output of the crank angle sensor 133. The ECU 81 also acquires various information such as the intake air amount, the intake pipe negative pressure, the air-fuel ratio of the mixture, and the water temperature and oil temperature of the engine 10 based on the detection signals input from the various sensors described above. The ECU 81 then controls the engine 10 by controlling the fuel injection amount, the ignition timing, and various devices such as the throttle valve 113 and the EGR valve 142 based on the required output of the engine 10 from the HEV-CU 80, stop prohibition / permission information, and the acquired various information.

[0049] Based on the required output, the ECU 81 adjusts, for example, the opening of the electronically controlled throttle valve 113. Also, the ECU 81 prohibits or permits the stop of the engine 10 based on the stop prohibition / permission information.

[0050] The HEV-CU80 and ECU81 also have an idling stop function that automatically stops the engine 10 to put it in an idling stop state when a predetermined idling stop condition is satisfied, and automatically restarts the engine 10 when a predetermined restart condition is satisfied. The HEV-CU80 and ECU81 automatically stop the engine 10, for example, when the vehicle is waiting for a traffic light at an intersection (when the vehicle is stopped). On the other hand, when the engine 10 is in the idling stop state, the HEV-CU80 and ECU81 output a restart request for the engine 10 and restart the engine 10 when they detect, for example, the release of the brake pedal.

[0051] Incidentally, for example, if a sharp turn (a turn with a turning force of about 1 G) is continued (continuously) for a certain period of time and then immediately thereafter the engine 10 is stopped and EV driving is performed using the second motor-generator 12 or an idling stop is performed, white smoke may be emitted from the exhaust pipe 118 when the engine is next restarted. As a result of extensive research into this problem, the inventors have found that oil that is sprayed into the intake pipe 115 or the like (intake system) via the scavenging line 161 or the like during a sharp turn accumulates in the combustion chamber, the intake port 122 (near the intake valve 124), etc. while the engine 10 is stopped, and is burned when the engine is next restarted, causing white smoke to be emitted.

[0052] Therefore, the above-mentioned HEV-CU 80 and ECU 81 cooperate with each other to have a function of preventing white smoke from coming out of the exhaust pipe 118 when the engine 10 is restarted even if the engine 10 is temporarily stopped after making sharp turns continuously (continuously) for a certain period of time or more. That is, the HEV-CU 80 and ECU 81 function as a control unit described in the claims. Note that the HEV-CU 80 and ECU 81 each realize this function by executing a program stored in an EEPROM or the like by a microprocessor.

[0053] Therefore, when a state (sharp left or right turn) in which the acceleration (lateral G) in the vehicle width direction (lateral direction) is equal to or greater than a predetermined acceleration (e.g., 0.8 G) continues (continuously) for a first predetermined time period (e.g., 30 seconds) or more, the HEV-CU80 and ECU81 determine that there is a possibility of oil being sprayed from the scavenging line 161, etc. that constitutes the blow-by gas treatment device 160 into the intake pipe 115, etc. (intake system), and (thereafter) prohibits the engine 10 from being stopped until a second predetermined time period (e.g., about 3 minutes) has elapsed after the acceleration in the vehicle width direction has dropped below the predetermined acceleration.

[0054] More specifically, the HEV-CU 80 and the ECU 81 prohibit EV driving in which the engine 10 is stopped and the vehicle is driven only by the second motor-generator 12 until a second predetermined time has elapsed after the acceleration in the vehicle width direction falls below a predetermined acceleration.

[0055] Furthermore, the HEV-CU 80 and the ECU 81 prohibit an idling stop that automatically stops the engine 10 until a second predetermined time has elapsed after the acceleration in the vehicle width direction has fallen below the predetermined acceleration.

[0056] At that time (i.e., when the state in which the lateral acceleration in either the left or right direction (leftward or rightward) is equal to or greater than a predetermined acceleration continues for a first predetermined time or longer), the HEV-CU 80 transmits engine 10 stop prohibition information (request) to the ECU 81 via the CAN 70. The ECU 81 prohibits the engine 10 from stopping based on the engine 10 stop prohibition information (request).

[0057] As a result, even if oil is sprayed into the intake pipe 115 or the like (intake system) during a sharp turn, the oil gradually enters the combustion chamber and is burned sequentially while the engine 10 is prohibited from stopping, thereby preventing the oil from accumulating in the combustion chamber, etc.

[0058] On the other hand, when a second predetermined time (e.g., about three minutes) has elapsed after the acceleration in the vehicle width direction has fallen below the predetermined acceleration, the HEV-CU 80 transmits stop permission information for the engine 10 to the ECU 81 via the CAN 70. The ECU 81 permits the engine 10 to be stopped (returns to normal control) based on the stop permission information for the engine 10.

[0059] Next, the operation of the engine control device will be described with reference to Fig. 3. Fig. 3 is a flow chart showing the procedure of a process for preventing white smoke generation when the engine is restarted after making successive sharp turns by the engine control device. This process is repeatedly executed at a predetermined timing by the HEV-CU 80 and the ECU 81.

[0060] In step S100, the HEV-CU 80 determines whether the acceleration (lateral G) in the vehicle width direction (lateral direction) is equal to or greater than a predetermined acceleration (e.g., 0.8 G). If the acceleration in the vehicle width direction is equal to or greater than the predetermined acceleration, the process proceeds to step S102. On the other hand, if the acceleration in the vehicle width direction is less than the predetermined acceleration, the process temporarily exits.

[0061] In step S102, it is determined whether the state in which the acceleration in the vehicle width direction is equal to or greater than the predetermined acceleration continues (continues) for a first predetermined time period (e.g., 30 seconds) or more. If the state in which the acceleration in the vehicle width direction is equal to or greater than the predetermined acceleration continues for the first predetermined time period or more, the process proceeds to step S104. On the other hand, if the state in which the acceleration in the vehicle width direction is equal to or greater than the predetermined acceleration does not continue for the first predetermined time period or more, the process proceeds to step S100, and the process from step S100 onwards described above is repeatedly (repeatedly) executed.

[0062] In step S104, it is determined whether the acceleration in the vehicle width direction has decreased to less than a predetermined acceleration (hysteresis may be provided). If the acceleration in the vehicle width direction has decreased to less than the predetermined acceleration, the process proceeds to step S106. On the other hand, if the acceleration in the vehicle width direction has not decreased to less than the predetermined acceleration, this process is repeatedly executed until the acceleration in the vehicle width direction decreases to less than the predetermined acceleration.

[0063] In step S106, stopping of the engine 10 is prohibited. That is, engine 10 stop prohibition information (request) is transmitted from the HEV-CU 80 to the ECU 81 via the CAN 70. Then, based on the engine 10 stop prohibition information (request), stopping of the engine 10 is prohibited. More specifically, EV running in which the engine 10 is stopped and the vehicle runs only on the second motor-generator 12, and idling stop in which the engine 10 is automatically stopped are prohibited.

[0064] Next, in step S108, it is determined whether or not a second predetermined time (e.g., about three minutes) has elapsed after the acceleration in the vehicle width direction has fallen below a predetermined acceleration (i.e., after engine 10 is prohibited from being stopped). If the second predetermined time has elapsed, the process proceeds to step S110. On the other hand, if the second predetermined time has not elapsed, this process is repeatedly executed until the second predetermined time has elapsed.

[0065] In step S110, stopping of the engine 10 is permitted (prohibition is lifted). That is, engine 10 stop permission information is transmitted from the HEV-CU 80 to the ECU 81 via the CAN 70. Then, based on the engine 10 stop permission information, stopping of the engine 10 is permitted (normal control is returned to). More specifically, EV running in which the engine 10 is stopped and the vehicle runs only on the second motor-generator 12, and idling stop in which the engine 10 is automatically stopped are permitted (prohibition is lifted). That is, a switch is made to normal control. Thereafter, this process is terminated.

[0066] As described above in detail, according to this embodiment, when the state in which the acceleration (lateral G) in the vehicle width direction (lateral direction) is equal to or greater than a predetermined acceleration (e.g., 0.8 G) continues (continues) for a first predetermined time (e.g., 30 seconds) or more, the engine 10 is prohibited from being stopped until a second predetermined time (e.g., about 3 minutes) has elapsed after the acceleration in the vehicle width direction falls below the predetermined acceleration. More specifically, EV driving, in which the engine 10 is stopped and the vehicle is driven only by the second motor-generator 12, and idling stop, in which the engine 10 is automatically stopped, are prohibited. Therefore, even if oil is sprayed into the intake system during a sharp turn, the oil gradually enters the combustion chamber and is burned sequentially while the engine 10 is prohibited from being stopped, so that the oil is prevented from accumulating in the combustion chamber, etc. Therefore, even if EV driving or idling stop is performed after that (after the second predetermined time has elapsed), it is possible to prevent a large amount of oil from being burned and white smoke from the exhaust pipe 118 when the engine is restarted thereafter.

[0067] As a result, even if engine 10 is temporarily stopped after making sharp turns continuously for a certain period of time or more, it is possible to prevent white smoke from emitting from exhaust pipe 118 when the engine is subsequently restarted.

[0068] In particular, according to this embodiment, when a state (a sharp left turn or a sharp right turn) in which the acceleration in the vehicle width direction in either the left or right direction (left direction or right direction) is equal to or greater than a predetermined acceleration (e.g., 0.8 G) continues (continues) for a first predetermined time (e.g., 30 seconds) or more, it is determined that there is a possibility that oil will be sprayed from the scavenging line 161, etc. constituting the blow-by gas processing device 160 to the intake pipe 115, etc. (intake system), and the engine 10 is prohibited from being stopped until a second predetermined time (e.g., about 3 minutes) has elapsed after the acceleration in the vehicle width direction drops below the predetermined acceleration. Therefore, it is possible to accurately determine whether or not there is a possibility that oil will be sprayed into the intake pipe 115, etc. through the scavenging line 161, etc. due to a sharp left turn or a sharp right turn (i.e., whether or not there is a state in which oil can accumulate in the combustion chamber or the intake port 122 (near the intake valve 124) when the engine 10 is stopped (whether or not there is a state in which oil can burn and generate white smoke when the engine is next restarted)). Then, only when there is a possibility that oil will be sprayed into the intake pipe 115 or the like through the scavenging line 161 or the like, the engine 10 can be prohibited from stopping (that is, the deterioration of fuel efficiency can be kept to a minimum).

[0069] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and various modifications are possible. For example, in the above embodiment, the engine control device according to the present invention is applied to a series-parallel hybrid vehicle (HEV), but the engine control device can be applied to a different type of hybrid vehicle (for example, a parallel hybrid vehicle or a series hybrid vehicle) or a plug-in hybrid vehicle (PHEV) that can be charged from an external source. In addition, in the above embodiment, two electric motors (the first motor generator 11 and the second motor generator 12) are provided, but the number of electric motors is not limited to two (two motors), and may be one (one motor), or three (three motors) or more. Similarly, the configuration of a drive system or the like that is composed of a plurality of gears and shafts is not limited to the above embodiment.

[0070] In addition, in the above embodiment, the engine control device according to the present invention is applied to a hybrid vehicle (HEV) and is configured to prohibit EV driving and idling stop after a sharp turn is continued for a certain period of time or more, but the engine control device according to the present invention may also be applied to a conventional engine vehicle and configured to prohibit idling stop.

[0071] In addition, in the above embodiment, EV driving and idling stop are prohibited after a sharp turn is continued for a certain period of time or more. However, in addition to EV driving and idling stop, it is also possible to prohibit, for example, a fuel cut that stops the fuel supply to the engine 10 when the vehicle is traveling at a predetermined speed or more and the accelerator is off (during coasting).

[0072] Further, the system configuration of the controllers such as the HEV-CU 80 and the ECU 81, and the functional allocation of each controller are not limited to those in the above embodiment. For example, in the above embodiment, the lateral acceleration sensor 89 is connected to the VDCU 85, and the read lateral acceleration is transmitted to the HEV-CU 80 via the CAN 70. However, the lateral acceleration sensor 89 may be directly connected (input) to the HEV-CU 80. Also, for example, the lateral acceleration sensor 89 may be directly connected (input) to the ECU 81, and the ECU 81 may directly read the lateral acceleration, determine whether or not there is a possibility of oil being sprayed into the intake pipe 115 or the like (whether or not it is necessary to prohibit the engine 10 from stopping), and transmit the determination result to the HEV-CU 80. Furthermore, the HEV-CU 80 and the ECU 81 may be configured as an integrated piece of hardware.

[0073] In the above embodiment, the present invention is applied to a naturally aspirated (NA) engine, but the present invention can also be applied to an engine equipped with a supercharger (turbocharger, etc.). Furthermore, in the above embodiment, the present invention is applied to an AWD vehicle (all-wheel drive vehicle), but the present invention can also be applied to, for example, a 2WD vehicle (FF vehicle or FR vehicle). [Explanation of symbols]

[0074] 10 Engine 10b Crankcase 11 First motor generator 12 Second motor generator 20 Flywheel damper 30 Driving force split mechanism 40 Driving reduction gear mechanism 41 Motor reduction gear 43 Driving reduction gear 50 Propeller shaft 51 Transfer clutch 52 Rear differential 60 Front drive shaft 62 Front differential 70 CAN 80 HEV-CU 81 ECU 82 PCU 85 VDCU 86 Brake fluid pressure sensor 87 Wheel speed sensor 88 Front and rear acceleration sensor 89 Lateral acceleration sensor 90 High voltage battery (storage battery) 91 Accelerator Sensor 93 Outside Air Temperature Sensor 95 RPM Sensor 97,98 Resolver 111 Intake manifold 112 Injector 113 Electronically controlled throttle valve 114 Air flow meter 115 Intake pipe 117 Spark Plug 118 Exhaust pipe 119 Air-fuel ratio sensor 120 Exhaust purification catalyst 130 Vacuum sensor (intake pressure sensor) 131 Throttle sensor 133 Crank angle sensor 133a Timing rotor 134 Water temperature sensor 140 Exhaust Gas Recirculation System 141 EGR piping 142 EGR valve 143 Silencer 160 Blow-by gas treatment device 161 Scavenging line 162 PCV valve 163 New Air Line

Claims

1. A lateral acceleration sensor that detects acceleration in a vehicle width direction; A control unit that controls the operation of an engine mounted on the vehicle, The engine control device is characterized in that, when the acceleration in the vehicle width direction detected by the lateral acceleration sensor remains equal to or greater than a predetermined acceleration for a first predetermined time or more, the control unit prohibits the engine from being stopped until a second predetermined time has elapsed after the acceleration in the vehicle width direction falls below the predetermined acceleration.

2. the vehicle is a hybrid vehicle including an electric motor as a drive source in addition to the engine, The control unit controls the driving of the electric motor in addition to the engine.

2. The engine control device according to claim 1, wherein the control unit stops the engine and prohibits EV driving, in which the vehicle is driven only by the electric motor, until the second predetermined time has elapsed after the acceleration in the vehicle width direction falls below the predetermined acceleration.

3. 2. The engine control device according to claim 1, wherein the control unit prohibits an idling stop that automatically stops the engine until the second predetermined time has elapsed after the acceleration in the vehicle width direction falls below the predetermined acceleration.

4. 2. The engine control device according to claim 1, wherein the control unit, when a state in which the acceleration in the vehicle width direction in either the left or right direction is equal to or greater than the predetermined acceleration continues for more than the first predetermined time, prohibits the engine from being stopped until the second predetermined time has elapsed after the acceleration in the vehicle width direction falls below the predetermined acceleration.

5. The engine has a blow-by gas processing device including a scavenging line communicating a crankcase with a downstream side of a throttle valve of an intake system and returning blow-by gas to the intake system, a fresh air line communicating an upstream side of a throttle valve of the intake system with the crankcase and introducing fresh air, and a flow control valve interposed in the scavenging line and adjusting a flow rate of the blow-by gas in accordance with a pressure of the intake system, 2. The engine control device according to claim 1, wherein the control unit determines that there is a possibility that oil will be sprayed into the intake system from a scavenging line constituting the blow-by gas treatment device when a state in which the acceleration in the vehicle width direction is equal to or greater than the predetermined acceleration continues for equal to or greater than the first predetermined time, and prohibits the engine from being stopped until the second predetermined time has elapsed after the acceleration in the vehicle width direction falls below the predetermined acceleration.

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