JP4496681B2 - Start control device and start control method for in-vehicle internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a start control device and a start control method for an in-vehicle internal combustion engine.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an in-vehicle internal combustion engine, an economy running system (hereinafter referred to as “eco-run system”) that improves fuel efficiency by automatically stopping the internal combustion engine when the vehicle is stopped has been performed. This eco-run system can automatically stop the internal combustion engine when the vehicle stops running at an intersection or the like to improve fuel efficiency, and can start the vehicle by automatically starting the internal combustion engine by rotating the starter during start operation. This is an automatic stop / start system. An example of such an automatic stop / start control device for an internal combustion engine is disclosed in Japanese Patent Laid-Open No. 11-257122. In this internal combustion engine automatic stop / start control device, after the internal combustion engine is automatically stopped, when the shift position of the transmission is switched to the travel position and the vehicle is released from braking, cranking is performed to start the internal combustion engine. I am doing so.
[0003]
[Problems to be solved by the invention]
However, in the automatic stop / start control apparatus for an internal combustion engine, when the internal combustion engine is started when the automatic start condition is satisfied, the accelerator pedal may be stepped on immediately after the shift position of the transmission is switched to the travel position. is expected. In this case, it is expected that the vehicle will move forward or backward by the motor torque at the time of cranking even before the internal combustion engine is completely exploded, and for the driver, the vehicle is moved by the output of the internal combustion engine after the complete explosion. It may become difficult to recognize whether or not there is.
[0004]
The present invention has been made in view of such circumstances, and the object thereof is to eliminate the movement of the vehicle due to the motor torque during cranking of the internal combustion engine, and to move the vehicle by the engine output after the complete explosion of the internal combustion engine. It is an object of the present invention to provide a start control device and a start control method for an in-vehicle internal combustion engine that can recognize the above.
[0005]
[Means for Solving the Problems]
  In the following, means for achieving the above object and its effects are described.
  The invention described in claim 1Based on the establishment of a predetermined automatic start conditionStart the internal combustion engineRuStart of an on-vehicle internal combustion engine comprising ranking means and cranking suppression means for suppressing cranking by the cranking means when it is detected that the vehicle has started to be ready during cranking by the cranking means In the control device,Equipped with detecting means for detecting the presence or absence of obstacles,The cranking suppression means detects that the vehicle is ready to start based on the fact that cranking power can be transmitted to the wheels and that the braking is released.When it is detected that there is an obstacle in the vehicle traveling direction and it is detected that the vehicle has shifted to the vehicle startable state, the degree of control for suppressing cranking is increased, while the obstacle in the vehicle traveling direction is increased. When it is detected that the vehicle is present and the vehicle is not ready to start, the degree of cranking suppression control is reduced.It is characterized by that.
[0006]
Therefore, according to the first aspect of the present invention, since the cranking is suppressed when the vehicle is ready to start during cranking, the starting of the vehicle by only cranking is suppressed. Therefore, it can be recognized that the vehicle is moving by the engine output after the complete explosion of the internal combustion engine.
[0007]
  The invention described in claim 2Based on the establishment of a predetermined automatic start conditionStart the internal combustion engineRuStart of an on-vehicle internal combustion engine comprising ranking means and cranking suppression means for suppressing cranking by the cranking means when it is detected that the vehicle has started to be ready during cranking by the cranking means In the control device,Equipped with detecting means for detecting the presence or absence of obstacles,The cranking suppression means detects that the vehicle is ready to start based on the fact that cranking power can be transmitted to the wheels and that there is an acceleration instruction request.When it is detected that there is an obstacle in the vehicle traveling direction and it is detected that the vehicle has shifted to the vehicle startable state, the degree of control for suppressing cranking is increased, while the obstacle in the vehicle traveling direction is increased. When it is detected that the vehicle is present and the vehicle is not ready to start, the degree of cranking suppression control is reduced.It is characterized by that.
[0008]
  Therefore, according to the second aspect of the present invention, when the vehicle shifts to the vehicle startable state during the cranking, the cranking is suppressed, so that the vehicle start only by the cranking is suppressed. Therefore, it can be recognized that the vehicle is moving by the engine output after the complete explosion of the internal combustion engine.
Further, according to the first and second aspects of the present invention, when there is an obstacle in the vehicle traveling direction and the vehicle is ready to start, the degree of cranking suppression control is increased, This is practical because the vehicle start can be reliably suppressed.
[0009]
  According to a third aspect of the present invention, in the start control device for an on-vehicle internal combustion engine according to any one of the first and second aspects,The cranking means includesFirst cranking means for directly cranking based on the driver's operation, and second cranking means for performing cranking indirectly by detecting the state of each part of the vehicle. The ranking suppression means performs cranking suppression control when transition to the vehicle startable state is detected during cranking of the internal combustion engine by the second cranking means.
[0010]
When the internal combustion engine is started without using the driver's direct start operation, it is expected that the driver will concentrate more on starting because there is no direct operation. However, according to the third aspect of the present invention, when the internal cranking engine is cranked by the second cranking means, the cranking is reliably suppressed when the transition to the vehicle startable state is detected. In addition, the start of the vehicle only by cranking is suppressed.
[0011]
  As in the invention according to claim 4, the second cranking means stops the internal combustion engine when the vehicle is stopped,Auto startThe eco-run control means can start the internal combustion engine based on the establishment of the dynamic condition.
[0012]
  According to a fifth aspect of the present invention, in the start control device for an in-vehicle internal combustion engine according to the fourth aspect, the second cranking means controls the internal combustion engine based on a drive request for an on-vehicle auxiliary machine or a battery charge request. Means for starting and a means for starting the internal combustion engine when preparation for vehicle start is necessaryStepAnd at least during cranking control when preparation for vehicle start is necessary, cranking is suppressed when it is determined that the vehicle is ready to start.
[0013]
Therefore, according to the fifth aspect of the present invention, when the internal combustion engine can be started regardless of the start of the vehicle, the start of such an internal combustion engine is not linked to the driver's start consciousness. It is not preferred and practical.
[0017]
  ContractClaim6The invention described in claim 15In the start control device for an on-vehicle internal combustion engine according to any one ofWritingThe ranking means continues the cranking operation that has been started until the completion of the internal combustion engine is determined or until the cranking suppression control by the cranking suppression means is started.RukoAnd features.
[0018]
  Therefore, the claims6According to the invention described in the above, it is possible to recognize that the vehicle is driven by the output of the internal combustion engine by stopping the cranking after the complete explosion of the internal combustion engine and enabling normal start. .
[0028]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 is a system configuration diagram of an internal combustion engine to which the above-described invention is applied and its control device. Here, as the internal combustion engine, a 6-cylinder gasoline engine (hereinafter referred to as “engine”) 2 is used. The engine 2 is mounted on the vehicle for driving the vehicle.
[0029]
The rotational torque generated by the engine 2 is output from the crankshaft 2a of the engine 2 to the output shaft 6b side via a torque converter 4 and an automatic transmission (hereinafter referred to as "A / T") 6, and finally the wheel Is transmitted to.
[0030]
Further, the rotational torque generated by the engine 2 is transmitted to the belt 14 via the electromagnetic clutch 10 and the pulley 12 connected to the crankshaft 2a. The other pulleys 16, 18 and 20 are rotated by the rotational torque transmitted by the belt 14. The electromagnetic clutch 10 enables switching between transmission and non-transmission of power between the pulley 12 and the crankshaft 2a as necessary.
[0031]
Of the pulleys 16, 18, and 20, the power steering pump 22 is driven by the rotational torque transmitted to the pulley 16 to generate hydraulic pressure for power steering. Further, the compressor 24 for the air conditioner is driven by the rotational torque transmitted to the pulley 18.
[0032]
Further, a motor generator (hereinafter referred to as “M / G”) 26 is driven by the rotational torque transmitted to the pulley 20, and the M / G 26 functions as a generator. The M / G 26 is electrically connected to the inverter 28. The inverter 28 charges electric energy from the M / G 26 to the battery 30 as a power source based on a power generation command input from an electronic control unit (hereinafter referred to as “ECU”) 46. Further, when the engine 2 is stopped, the M / G 26 functions as a motor based on a control signal from the inverter 28. At this time, the inverter 28 functions to adjust the supply of electrical energy from the battery 30 to the M / G 26 based on a current command input from the ECU 46 so that the rotational speed of the M / G 26 is variable.
[0033]
The A / T 6 incorporates an oil pump that is driven by the power of the engine 2 and supplies hydraulic oil to the hydraulic pressure control unit 6a. This hydraulic oil is supplied to the clutch and brake in the A / T 6 by a control valve in the hydraulic control unit 6a. As a result, the operating states of the clutch, brake and one-way clutch inside the A / T 6 are adjusted. The rotational speed NAO of the output shaft 6b of A / T6 is detected by the output shaft rotational speed sensor 32, and the turbine rotational speed NCO that is the rotational speed of the input shaft of A / T6 is detected by the turbine rotational speed sensor 34. Yes. In addition, hydraulic oil can be supplied from the electric oil pump 36 to the hydraulic control unit 6 a of the A / T 6. For this reason, even when the engine 2 is automatically stopped, the electric oil pump 36 is driven so that the clutch, brake, and one-way clutch in the A / T 6 can be maintained in a necessary state. .
[0034]
A throttle valve 2 c that adjusts the intake air amount is provided in the intake path 2 b to the engine 2. The throttle valve 2c is adjusted in opening degree by a throttle valve motor 2d. The opening adjustment is performed by, for example, adjusting the opening of the throttle valve 2c (throttle opening) detected by the throttle opening sensor 40 to the detected value of the accelerator opening sensor 39a that detects the depression amount of the accelerator pedal 39 (accelerator opening ACCP). Degree TA) is made to correspond. Further, the accelerator pedal 39 is also provided with an idle switch 39b that outputs a state where the accelerator pedal 39 is not depressed as an idle signal IDL.
[0035]
A surge tank 2e is provided downstream of the throttle valve 2c in the intake path 2b. The negative pressure in the surge tank 2e is supplied to the brake booster 41 via the check valve 41a. The brake booster 41 increases the stepping force of the brake pedal 42, and has two pressure chambers 41c and 41d that are defined by a diaphragm 41b. Among these, a brake booster pressure sensor 41e is provided in the first pressure chamber 41c, detects the brake booster pressure in the first pressure chamber 41c, and outputs a signal corresponding to the brake booster pressure. The brake pedal 42 is provided with a brake switch 42a and outputs a signal indicating the depression state BSW of the brake pedal 42. That is, the brake switch 42a outputs an off signal when the brake pedal 42 is not depressed, and an on signal when the brake pedal 42 is depressed.
[0036]
The intake negative pressure is supplied from the surge tank 2e to the first pressure chamber 41c of the brake booster 41 via the check valve 41a. This check valve 41a allows air flow from the first pressure chamber 41c to the surge tank 2e, but prohibits reverse flow.
[0037]
The brake booster 41 functions as follows. That is, when the brake pedal 42 is not depressed, the negative pressure control valve 41f provided in the brake booster 41 introduces the negative pressure in the first pressure chamber 41c into the second pressure chamber 41d. For this reason, since the first pressure chamber 41c and the second pressure chamber 41d are in the same negative pressure state, the diaphragm 41b is pushed back toward the brake pedal 42 by the spring 41g. For this reason, the push rod 41h interlocked with the diaphragm 41b does not push the piston (not shown) in the master cylinder 41i.
[0038]
On the other hand, when the brake pedal 42 is depressed, the negative pressure control valve 41f blocks the first pressure chamber 41c and the second pressure chamber 41d in conjunction with the input side rod 42b provided on the brake pedal 42, and Air is introduced into the second pressure chamber 41d. As a result, a pressure difference is generated between the first pressure chamber 41c in the intake negative pressure state and the second pressure chamber 41d having atmospheric pressure. For this reason, the stepping force on the brake pedal 42 is doubled, and the diaphragm 41b pushes the push rod 41h toward the master cylinder 41i against the urging force of the spring 41g. As a result, the piston in the master cylinder 41i is pushed and braking is performed.
[0039]
Then, when the brake pedal 42 is stepped back, the negative pressure control valve 41f blocks the communication between the second pressure chamber 41d and the outside air in conjunction with the input side rod 42b provided on the brake pedal 42, and the first pressure The chamber 41c and the second pressure chamber 41d are brought into a communication state. As a result, intake negative pressure is introduced from the first pressure chamber 41c into the second pressure chamber 41d. For this reason, the first pressure chamber 41c and the second pressure chamber 41d have the same pressure. Therefore, the diaphragm 41b moves to the brake pedal 42 side by the urging force of the spring 41g and returns to the original non-braking state.
[0040]
The ECU 46 detects the detected values of the output shaft rotational speed sensor 32, the turbine rotational speed sensor 34, the accelerator opening degree sensor 39a, the idle switch 39b, the throttle opening degree sensor 40, the shift position sensor that detects the shift position SHFT of the A / T 6 and the like. Enter. The ECU 46 also detects detected values such as an engine speed sensor 43 that detects the engine speed NE, a brake switch 42a that detects whether or not the brake pedal 42 is depressed, and an eco-run switch that enables the driver to execute the eco-run system. Enter. The eco-run system is an operation control system that reduces fuel consumption and stops exhaust gas emission by stopping fuel supply and stopping the engine 2 when the vehicle is stopped at an intersection or the like.
[0041]
The ECU 46 also receives detection values of an air conditioner switch for enabling the operation of the air conditioner, a brake booster pressure sensor 41e, a water temperature sensor for detecting the engine cooling water temperature THW, a battery voltage, or other sensors. Further, the ECU 46 inputs detection values such as an obstacle detection sensor that detects an obstacle in front of the vehicle and an inclination angle sensor that detects an inclination state of the vehicle. As the obstacle detection sensor, a front vehicle detection sensor for laser cruise, a front image monitor, an ultrasonic sensor, a corner sensor, or the like can be used.
[0042]
The ECU 46 is configured with a microcomputer as a center, and executes a necessary calculation process according to a program written in an internal ROM, and adjusts the opening of the throttle valve 2c based on the calculation result. A valve motor 2d, a hydraulic control unit 6a, an electromagnetic clutch 10, an inverter 28, an electric oil pump 36, a starter 48, a fuel injection valve 50 or an igniter for supplying fuel into the intake port or combustion chamber of the engine 2 or other actuators. It drives and controls engine 2 and A / T6 suitably. The starter 48 is driven by the electric energy of the battery 30 and performs cranking when the engine 2 is started.
[0043]
The ECU 46 drives the starter 48 and cranks the engine 2 when a start signal STA is input based on the operation of an ignition (IG) key during normal engine start.
[0044]
Further, when the eco-run switch is turned on by the driver, the ECU 46 performs an automatic stop process and an automatic start process of the engine 2 when the vehicle enters a predetermined driving state.
[0045]
During the automatic stop process of the engine 2, the ECU 46 determines the vehicle operating state, for example, the engine cooling water temperature THW detected by the water temperature sensor, the accelerator pedal depression / non-depression detected by the idle switch, the voltage of the battery 30 and the brake switch. Whether or not the automatic stop condition is satisfied based on whether or not the brake pedal is detected and the vehicle speed SPD, brake booster negative pressure, A / T6 shift position, etc. obtained by conversion from the detected value of the output shaft rotational speed sensor Determine whether. For example,
(1) The engine 2 is warmed up and not overheated (the engine cooling water temperature THW is lower than the water temperature upper limit value THWmax and higher than the water temperature lower limit value THWmin),
(2) The accelerator pedal is not depressed (idle switch on),
(3) A state where the charge amount (SOC) of the battery 30 is a certain level or more (battery voltage is equal to or higher than a reference voltage),
(4) The brake pedal is depressed (brake switch on),
(5) A state where the vehicle is stopped (vehicle speed SPD is 0 km / h),
(6) A state where the negative pressure of the brake booster 41 is higher than a certain level (a state where the brake booster 41 can assist the pedaling force of the brake pedal 42), and (7) the shift signal SHFT of A / T6 is in the non-traveling position. When all of the conditions (1) to (7) for switching to a certain P (parking) position or N (neutral) position are satisfied, it is determined that the automatic stop condition is satisfied.
[0046]
On the other hand, when the driver stops the vehicle at an intersection or the like and the automatic stop condition is satisfied, the ECU 46 executes an engine stop process. For example, fuel injection from the fuel injection valve 50 is stopped, and ignition control for the air-fuel mixture in the combustion chamber of the engine 2 by the ignition plug is also stopped. As a result, fuel injection and ignition stop, and the operation of the engine 2 immediately stops.
[0047]
During the automatic start process of the engine 2, the ECU 46 operates the vehicle, for example, the engine coolant temperature THW, the accelerator opening ACCP, the voltage of the battery 30, the state of the brake switch, the vehicle speed SPD, the brake booster negative pressure, A / It is determined whether or not an automatic start condition is established based on a shift position at T6, a slope determination result based on a detection value of the tilt angle sensor, and the like. For example, under the condition that the engine is stopped by automatic stop processing,
(1) The engine 2 is warmed up and not overheated (the engine cooling water temperature THW is lower than the water temperature upper limit value THWmax and higher than the water temperature lower limit value THWmin),
(2) The state where the charge amount (SOC) of the battery 30 is a certain level or more (battery voltage is equal to or higher than the reference voltage),
(3) A state where the vehicle is stopped (vehicle speed SPD is 0 km / h),
(4) State where the negative pressure of the brake booster 41 is more than a certain level (state where the brake booster 41 can assist the pedaling force of the brake pedal 42), (5) The traveling road where the vehicle is stopped is a slope. ,
And (6) one of the conditions (1) to (6) that the A / T6 shift signal SHFT is switched to the non-traveling position P (parking) position or N (neutral) position is also satisfied If not, it is determined that the automatic start condition is satisfied. The above-described automatic start conditions (1) to (6) are not limited to this, and conditions other than the conditions (1) to (6) may be set. Further, it may be limited to some of the conditions (1) to (6).
[0048]
When the A / T6 shift signal SHFT is switched from the P position or N position, which is the non-traveling position, to the R (reverse) position or D (drive) position, which is the traveling position, in the automatic start condition described above, Since it indicates the will of traveling, cranking is performed by the M / G 26 to start the engine 2.
[0049]
Further, in the above automatic start condition, when the charge amount (SOC) of the battery 30 becomes less than a certain level, it becomes impossible to supply power to the M / G 26 and other electric loads. Therefore, although not related to the running of the vehicle, the M / G 26 is driven by the rotational torque of the engine 2 to generate electric power, and the battery 30 is charged. In addition, when the negative pressure of the brake booster 41 is less than a certain level, the brake booster 41 cannot assist the pedaling force of the brake pedal 42. In this case as well, the intake negative pressure is generated by rotating the engine 2, and the intake negative pressure is supplied to the brake booster 41, although it is not related to the running of the vehicle. Therefore, these conditions are automatic start conditions for the engine 2 that do not require much urgency.
[0050]
Further, in the above automatic start condition, when the vehicle starts to move and the vehicle speed SPD is not 0 km / h, it is necessary to assist the pedal force of the brake pedal 42 by the brake booster 41. Although the automatic start in this case is not related to the running of the vehicle, the negative pressure of the brake booster 41 is generated by generating the intake negative pressure by rotating the engine 2 and supplying the intake negative pressure to the brake booster 41. I try to secure it. Furthermore, in the automatic start condition described above, when it is determined that the traveling road where the vehicle is stopped is a slope and the negative pressure of the brake booster 41 is determined to be less than a certain level, the brake booster 41 causes the brake pedal 42 to There is a possibility that the vehicle will start to move because the pedaling force of the vehicle cannot be assisted. In this case as well, the intake negative pressure is generated by rotating the engine 2 and is supplied to the brake booster 41 although it is not related to the running of the vehicle. Accordingly, these conditions are conditions for automatically starting the engine 2 that require urgency.
[0051]
When any one of the above conditions (1) to (6) is not satisfied in the engine stop state by the automatic stop process, the ECU 46 performs the automatic start process of the engine 2. In this automatic starting process, the ECU 46 connects the electromagnetic clutch 10 and outputs a current command to the inverter 28 to drive the M / G 26 to forcibly rotate the crankshaft 2a of the engine 2 to perform cranking. . When the engine rotation speed reaches a predetermined rotation speed, the ECU 46 automatically starts the engine 2 by executing a fuel injection process and an ignition timing control process at the time of starting. When the start of the engine 2 is completed, the ECU 46 starts normal fuel injection amount control processing, ignition timing control processing, and other processing necessary for engine operation.
[0052]
Further, the ECU 46 is in a state in which at least the vehicle can start during the automatic start of the engine 2 that does not require much urgency and the cranking of the engine 2 based on the operation of the IG key described above. When shifting, cranking is suppressed. At the time of cranking for starting the engine 2, when the vehicle is ready to start, even if the engine 2 is not completely exhausted, the vehicle is driven by the torque of the starter 48 or the motor torque of the M / G 26 when cranking This is because the vehicle is expected to move forward or backward, and it becomes difficult for the driver to recognize whether or not the vehicle is moving by the output of the engine 2 after the complete explosion. In the present embodiment, the ECU 46 is in a state where the shift position of the A / T 6 is switched to the traveling position so that the cranking power can be transmitted to the wheels, and the brake is released by the depression operation of the brake pedal 42. Based on this, it is detected that the vehicle has shifted to a startable state. Further, the ECU 46 starts the vehicle based on the fact that the shift position of the A / T 6 is switched to the travel position so that the cranking power can be transmitted to the wheels, and the acceleration instruction is requested by depressing the accelerator pedal 39. Detect that it has entered a possible state.
[0053]
Next, the engine 2 automatic stop process and the start process including the automatic start executed by the ECU 46 will be described. The automatic stop process and automatic start process of the engine 2 are started when the driver turns on the eco-run switch.
[0054]
FIG. 2 shows a flowchart of the automatic stop process. This process is a process that is repeatedly executed periodically every preset short time. When the automatic stop process is started, first, at step 110, an operation state for determining whether to execute automatic stop is read. For example, engine coolant temperature THW detected from a water temperature sensor, accelerator pedal depression / non-depression detected from an idle switch 39b, battery 30 voltage, brake pedal 42 depression / non-depression detected from a brake switch 42a, and output shaft rotation speed The vehicle speed SPD, brake booster negative pressure, A / T6 shift position, etc. obtained by conversion from the detection value of the sensor 32 are read into the RAM work area inside the ECU 46.
[0055]
Next, in step 120, it is determined whether or not the automatic stop condition is satisfied from these operating states. For example, (1) the engine 2 is warmed up and not overheated (the engine cooling water temperature THW is lower than the water temperature upper limit value THWmax and higher than the water temperature lower limit value THWmin), and (2) the accelerator pedal is depressed. State (idle switch on), (3) state of charge (SOC) of battery 30 being over a certain level (battery voltage is above reference voltage), (4) state of brake pedal being depressed (brake switch (On), (5) State in which the vehicle is stopped (vehicle speed SPD is 0 km / h), (6) State in which the negative pressure of the brake booster 41 is more than a certain level (the brake booster 41 assists the depression force of the brake pedal 42) (7) A / T6 shift signal SHFT is a non-traveling position P (parking) It determines that the automatic stop condition is satisfied if the conditions (1) to the has been switched to Jishon or N (neutral) position (7) is satisfied all.
[0056]
If any one of the above conditions (1) to (7) is not satisfied, the automatic stop condition is not satisfied (“NO” in step 120), and the process is temporarily terminated.
On the other hand, when the driver stops the vehicle at an intersection or the like and the automatic stop condition is satisfied (“YES” in step 120), the engine stop process is executed in step 130. That is, fuel injection from the fuel injection valve 50 is stopped. As a result, the combustion in the engine combustion chamber is stopped, and the operation of the engine 2 is stopped. In this way, this process is once ended. In this way, the automatic stop process can be executed.
[0057]
FIG. 3 shows a flowchart of start processing including automatic start. This process is a process that is repeatedly executed periodically every preset short time. When the main starting process is started, first, at step 210, an operating state for determining whether to perform automatic starting is read. Here, for example, based on the engine coolant temperature THW, the state of the idle switch 39b, the voltage of the battery 30, the state of the brake switch 42a, the vehicle speed SPD, the brake booster negative pressure, the A / T6 shift position, and the detected value of the tilt angle sensor. The slope judgment result or the like is read into the RAM work area.
[0058]
Next, in step 220, it is determined whether or not the automatic start condition is satisfied from these operating states. For example, under the condition that the engine is stopped by the automatic stop process, (1) the engine 2 is warmed up and not overheated (the engine cooling water temperature THW is lower than the water temperature upper limit value THWmax and the water temperature (2) State where the charge amount (SOC) of the battery 30 is more than a certain level (battery voltage is higher than the reference voltage), (3) State where the vehicle is stopped (vehicle speed SPD is 0 km / h) ), (4) State in which the negative pressure of the brake booster 41 is above a certain level (state in which the brake booster 41 can assist the pedaling force of the brake pedal 42), (5) The traveling road where the vehicle is stopped is on a slope. And (6) P (parking) position or N (neutral) positive where the shift signal SHFT of A / T6 is a non-traveling position It determines that the automatic start condition is satisfied if it is not satisfied even one of the conditions that switched to ® switch (1) to (6).
[0059]
If the engine is not stopped by the automatic stop process, or if all of the above conditions (1) to (6) are satisfied even if the engine is stopped by the automatic stop process, the automatic start condition is not satisfied (step If “NO” in 220), the present process is temporarily terminated.
[0060]
If any one of the above conditions (1) to (6) is not satisfied in the engine stop state by the automatic stop process, the automatic start condition is assumed to be satisfied (“YES” in step 220), and the engine is started in step 230. The process is set to start, and the process is temporarily terminated.
[0061]
With the start setting of the engine starting process in step 230, the ECU 46 first connects the electromagnetic clutch 10 and drives the M / G 26 to rotate the crankshaft 2a of the engine 2 and also injects fuel at the time of starting. The processing and the ignition timing control processing are executed, and the engine 2 is automatically started. When the start is completed, normal fuel injection amount control processing, ignition timing control processing, and other processing necessary for engine operation are started.
[0062]
Next, the details of the engine start process in step 230 are shown in the flowchart of FIG. This process is a process that is repeatedly executed periodically every preset short time. When the start process is started, first, in step 232, an operation state for determining start execution is read. Here, for example, the eco-run control mode ECMOD, the brake signal STP (the state of the brake switch 42a), the idle signal IDL (the state of the idle switch 39b), the start signal STA based on the operation of the IG key, the shift signal SHFT (of A / T6) Enter the shift position status) and automatic start mode. The eco-run control mode ECMOD has modes 0, 1, 2, 3, and 4. Mode 0 is a state in which the IG key is on, and mode 1 is a state in which the engine 2 is rotating. Mode 2 is a request to stop the engine 2, mode 3 is a stop of the engine 2, and mode 4 is an automatic start state.
[0063]
Next, in step 234, it is determined whether the cranking power can be transmitted to the wheels based on whether the shift signal SHFT has been changed from the non-traveling position to the traveling position. As the shift position change determination, for example, it is determined whether the non-traveling position is changed from the P position to the R position, or whether the non-traveling position is changed from the N position to the D position or the R position. If it is determined that shift signal SHFT has been changed from the non-travel position to the travel position (“YES” in step 234), the process proceeds to step 236. If it is determined that shift signal SHFT has not been changed and remains in the non-traveling position (“NO” in step 234), the process proceeds to step 242.
[0064]
In step 236, it is determined whether the eco-run control mode ECMOD is being started. If it is determined that the engine is being started (“YES” in step 236), the process proceeds to step 238. If it is determined that the engine is not being started (“NO” in step 236), the process proceeds to step 242. To do.
[0065]
In step 238, it is determined whether the brake signal STP is OFF or the idle signal IDL is OFF. The brake signal STP being OFF indicates that braking by the brake pedal 42 has been released, and the idle signal IDL being OFF indicates that an acceleration instruction request has been made by the accelerator pedal 39. If an affirmative determination is made in step 238, it is possible to detect that the vehicle has shifted to a vehicle startable state, and it is possible to detect that the driver is willing to start the vehicle. If an affirmative determination is made in step 238, the process proceeds to step 240, and if a negative determination is made, the process returns to step 232.
[0066]
In step 240, the eco-run control mode ECMOD is switched from the engine start to the idling stop to stop the cranking by the M / G 26, and the start of the engine 2 is stopped.
[0067]
In step 242 following step 234 or step 236, it is determined whether the engine is being started based on the operation of the IG key by the driver. If it is determined that the engine is being started by operating the IG key, the process proceeds to step 238. If it is determined that the engine is not starting by operating the IG key, the process proceeds to step 244.
[0068]
In step 244, it is determined whether the automatic start is being performed based on a negative pressure drop of the brake booster 41 on a flat road, or whether the automatic start is being performed due to a battery voltage drop. That is, it is determined whether the automatic start is not urgent. If an affirmative determination is made in step 244, the process proceeds to step 238, and if a negative determination is made, the process proceeds to step 246.
[0069]
In step 246, it is determined whether or not the automatic start is being performed based on the vehicle speed signal input, or whether the automatic start is being performed based on the slope determination and the brake booster negative pressure drop. That is, it is determined whether the automatic start is urgent. If a negative determination is made in step 246, the process returns to step 232, and if a positive determination is made, the process proceeds to step 250.
[0070]
In step 250, cranking of the engine 2 by the M / G 26 is continued, and the engine 2 is reliably started.
FIG. 5 is a diagram illustrating cranking suppression control in the engine start process of FIG. 4 based on the engine start conditions.
[0071]
As can be seen from FIG. 5, the start process A is the start of the engine 2 by any one of the shift signal SHFT, the start signal STA, the brake booster negative pressure drop and the battery voltage drop, and the brake signal STP is ON. And the idle signal IDL is ON. Therefore, the M / G 26 or the starter 48 is normally driven and the cranking is not stopped, and the engine 2 is reliably started.
[0072]
The start process B is the start of the engine 2 by any one of the shift signal SHFT, the start signal STA, the brake booster negative pressure drop and the battery voltage drop. The brake signal STP is ON but the idle signal IDL is OFF. It is. Therefore, the driving of the M / G 26 or the starter 48 is stopped, the cranking is stopped, and the engine 2 is not started. The start process C is a start of the engine 2 by any one of the shift signal SHFT, the start signal STA, the brake booster negative pressure drop and the battery voltage drop, and the idle signal IDL is ON but the brake signal STP is OFF. . Therefore, the driving of the M / G 26 or the starter 48 is stopped, the cranking is stopped, and the engine 2 is not started.
[0073]
Further, since the start process D is a start of the engine 2 by inputting a vehicle speed input signal based on the movement of the vehicle, the M / G 26 is normally driven and the cranking is not stopped, and the engine 2 is started reliably. Further, since the start process E is a start of the engine 2 based on the slope determination and the brake booster negative pressure drop, the M / G 26 is normally driven and the cranking is not stopped, and the engine 2 is started reliably.
[0074]
According to the embodiment described above, the following effects can be obtained.
In the present embodiment, the ECU 46 stops cranking when the engine 2 shifts to a vehicle startable state during the cranking of the engine 2, so that the start of the vehicle by only cranking can be suppressed. Accordingly, it is possible to reliably recognize whether or not the vehicle is moving based on the engine output after the complete explosion of the engine 2. Further, the transition to the vehicle startable state is that the cranking power can be transmitted to the wheels, the braking by the brake pedal 42 has been released, or the acceleration instruction request by the accelerator pedal 39 has been made. It can be detected based on that.
[0075]
In the present embodiment, the ECU 46 automatically starts the engine 2 by driving the M / G 26 based on the state of each part of the vehicle when the engine 2 is in the automatic stop state, but the transition to the vehicle startable state is detected. In this case, the cranking is stopped, so that the start of the vehicle by only the cranking can be reliably suppressed.
[0076]
In the present embodiment, the ECU 46 continues the cranking operation that has been started until the complete explosion determination of the engine 2 is made in the starting process of the engine 2 or until the cranking stop is started. Therefore, after the complete explosion of the engine 2, cranking can be stopped to enable normal start, and it can be recognized that the vehicle is driven by the output of the engine 2.
[0077]
(Second Embodiment)
The present embodiment is different in that the engine start process shown in FIG. 6 is executed instead of the engine start process shown in FIG. Other configurations are the same as those of the first embodiment unless otherwise specified.
[0078]
Further, the ECU 46 changes the degree of cranking suppression control in the engine starting process based on the presence or absence of an obstacle in the vehicle traveling direction by the obstacle detection sensor.
[0079]
Details of the engine start process of the present embodiment are shown in the flowchart of FIG. This process is a process that is repeatedly executed periodically every preset short time. When the start process is started, first, at step 260, an operation state for determining start execution is read. Here, for example, the eco-run control mode ECMOD, the brake signal STP, the idle signal IDL, the start signal STA, the shift signal SHFT, the automatic start mode, etc., which are the same as those input at step 232 in FIG. An obstacle determination signal is input.
[0080]
Next, at step 262, it is determined whether the eco-run control mode ECMOD is being started or whether the engine is being started based on the operation of the IG key. If the determination is affirmative, the process proceeds to step 264. If the determination is negative, the process returns to step 260.
[0081]
In step 264, it is determined whether there is an obstacle ahead of the vehicle based on the obstacle determination signal. In this way, the presence / absence of an obstacle in front of the vehicle is determined, for example, when the vehicle is stopped at an intersection or the like and the engine 2 is automatically stopped. This is to change the time until the engine 2 is started by changing the degree. If it is determined that there is an obstacle ahead of the vehicle, the process proceeds to step 266, and if it is determined that there is no obstacle, the process proceeds to step 272.
[0082]
In step 266, it is determined whether the brake signal STP is OFF or the idle signal IDL is OFF. The brake signal STP being OFF indicates that braking by the brake pedal 42 has been released, and the idle signal IDL being OFF indicates that an acceleration instruction request has been made by the accelerator pedal 39. If an affirmative determination is made in step 266, it is possible to detect that the vehicle has shifted to a vehicle startable state, and it is possible to detect that the driver is willing to start the vehicle. If an affirmative determination is made in step 266, the process proceeds to step 268, and if a negative determination is made, the process proceeds to step 270.
[0083]
In step 268, engine start is permitted and the M / G 26 is driven to crank the engine 2. However, the driving force of the M / G 26 or the starter 48 is greatly reduced with respect to the normal driving force. Thereby, the time until the engine 2 is started becomes longer than usual.
[0084]
In step 270, the engine start is permitted and the M / G 26 is driven to crank the engine 2. However, the driving force of the M / G 26 or the starter 48 is reduced to a small level with respect to the normal driving force. As a result, the time until the engine 2 is started is shorter than that in the case of performing the process of step 268.
[0085]
In step 272 following step 264, it is determined whether the brake signal STP is OFF or the idle signal IDL is OFF. If an affirmative determination is made in step 272, the process proceeds to step 274, and if a negative determination is made, the process proceeds to step 276.
[0086]
In step 274, the engine start is permitted and the M / G 26 is driven to crank the engine 2. However, the driving force of the M / G 26 or the starter 48 is moderately reduced with respect to the normal driving force. As a result, the time until the engine 2 is started is shorter than that in the case of performing the process of step 268, but is longer than that in the case of performing the process of step 270.
[0087]
In step 276, the engine is continuously started and the M / G 26 is normally driven to crank the engine 2. As a result, the engine 2 is started at a normal time. Naturally, the time until the engine 2 is started is shorter than that in the case of performing the processing of step 270.
[0088]
FIG. 7 is a schematic diagram of cranking suppression control in the engine start process of FIG. 6 based on engine start conditions.
As can be seen from FIG. 7, in the starting process F, there is no obstacle determination result, the brake signal STP is ON, and the idle signal IDL is ON. Therefore, the M / G 26 or the starter 48 is driven by a normal driving force, the engine 2 is cranked, and the engine 2 is reliably started.
[0089]
In the starting process G, there is no obstacle determination result, the brake signal STP is ON, but the idle signal IDL is OFF. Therefore, the driving force of the M / G 26 or the starter 48 is moderately reduced with respect to the normal driving force. In the starting process H, there is no obstacle determination result, the idle signal IDL is ON, but the brake signal STP is OFF. Therefore, the driving force of the M / G 26 or the starter 48 is moderately reduced with respect to the normal driving force.
[0090]
In the starting process I, there is an obstacle determination result, the brake signal STP is ON, and the idle signal IDL is ON. Therefore, the driving force of the M / G 26 or the starter 48 is reduced to a small extent with respect to the normal driving force.
[0091]
Further, the start process J has an obstacle determination result, and the brake signal STP is ON but the idle signal IDL is OFF. Therefore, the driving force of the M / G 26 or the starter 48 is greatly reduced with respect to the normal driving force. In the start process K, there is an obstacle determination result, and the idle signal IDL is ON but the brake signal STP is OFF. Therefore, the driving force of the M / G 26 or the starter 48 is greatly reduced with respect to the normal driving force.
[0092]
According to the embodiment described above, the following effects can be obtained.
In this embodiment, the ECU 46 increases the degree of reduction in the driving force of the M / G 26 or the starter 48 when there is an obstacle in the vehicle traveling direction when the engine 2 is started. The vehicle start by only ranking can be suppressed and is practical.
[0093]
In addition, when the ECU 46 shifts to a vehicle startable state during the cranking of the engine 2, the degree of reduction in the driving force of the M / G 26 or the starter 48 is increased. The start can be reliably suppressed and is practical.
[0094]
The embodiment is not limited to the above, and may be modified as follows.
In the first embodiment, when the A / T6 shift position is the non-traveling position and it is determined in step 244 that the engine 2 is automatically started based on the brake booster negative pressure drop or the battery voltage drop. The engine start may be continued. That is, when the engine 2 can be started regardless of the start of the vehicle, cranking suppression is not preferable and practical.
[0095]
In the first embodiment, the determination as to whether or not the engine 2 is being automatically started based on the battery voltage drop in step 244 may be omitted.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of an internal combustion engine and a control device thereof according to a first embodiment.
FIG. 2 is a flowchart showing an automatic stop process executed by the ECU according to the first embodiment.
FIG. 3 is a flowchart showing start-up processing similarly executed by the ECU.
FIG. 4 is a flowchart of an engine start process that is also executed by the ECU.
FIG. 5 is an explanatory view showing cranking suppression control in the engine start process based on engine start conditions.
FIG. 6 is a flowchart showing a start process including an automatic start executed by an ECU according to the second embodiment.
FIG. 7 is an explanatory view showing cranking suppression control in the engine start process based on engine start conditions.
[Explanation of symbols]
2 ... Engine, 2a ... Crankshaft, 2b ... Intake path, 2c ... Throttle valve, 2d ... Throttle valve motor, 2e ... Surge tank, 4 ... Torque converter, 6 ... A / T, 6a ... Hydraulic control unit, 6b ... Output Shaft, 10 ... electromagnetic clutch, 12 ... pulley, 14 ... belt, 16, 18, 20 ... pulley, 22 ... power steering pump, 24 ... compressor for air conditioner, 26 ... M / G, 28 ... inverter, 30 ... battery, 32 ... Output shaft rotational speed sensor, 34 ... Turbine rotational speed sensor, 36 ... Electric oil pump, 39 ... Accelerator pedal, 39a ... Accelerator opening sensor, 39b ... Idle switch, 40 ... Throttle opening sensor, 41 ... Brake booster, 41e ... Brake booster pressure sensor, 42 ... Brake pedal, 42a ... Brake switch , 43: engine speed sensor, 46 ... ECU, 48 ... starter, 50 ... Fuel injection valve.

Claims (6)

A torque ranking unit to start the internal combustion engine based on satisfaction of a predetermined automatic start condition,
In a start control device for an in-vehicle internal combustion engine provided with cranking suppression means for suppressing cranking by the cranking means when it is detected that the vehicle is ready to start during cranking by the cranking means,
Equipped with detecting means for detecting the presence or absence of obstacles,
The cranking suppression means is
Detecting the transition to the vehicle startable state based on the fact that the cranking power can be transmitted to the wheels and the release of braking is performed ;
When it is detected that there is an obstacle in the vehicle traveling direction and it is detected that the vehicle has entered the vehicle startable state, the degree of cranking suppression control is increased, while there is an obstacle in the vehicle traveling direction. An on-vehicle internal combustion engine start control device characterized by reducing the degree of cranking suppression control when it is detected and it is detected that the vehicle is not in a startable state. A torque ranking unit to start the internal combustion engine based on satisfaction of a predetermined automatic start condition,
In a start control device for an in-vehicle internal combustion engine provided with cranking suppression means for suppressing cranking by the cranking means when it is detected that the vehicle is ready to start during cranking by the cranking means,
Equipped with detecting means for detecting the presence or absence of obstacles,
The cranking suppression means is
Detecting that the vehicle is ready to start based on the fact that cranking power can be transmitted to the wheels and that there is an acceleration instruction request ;
When it is detected that there is an obstacle in the vehicle traveling direction and it is detected that the vehicle has entered the vehicle startable state, the degree of cranking suppression control is increased, while there is an obstacle in the vehicle traveling direction. An on-vehicle internal combustion engine start control device characterized by reducing the degree of cranking suppression control when it is detected and it is detected that the vehicle is not in a startable state. The start control device for an onboard internal combustion engine according to any one of claims 1 and 2,
The cranking means includes a first cranking means that performs cranking directly based on a driver's operation, and a second cranking means that indirectly performs cranking by detecting the state of each part of the vehicle. The cranking suppression means performs cranking suppression control when a transition to the vehicle startable state is detected when the internal combustion engine is cranked by the second cranking means. A start control device for an in-vehicle internal combustion engine. The start control device for an on-vehicle internal combustion engine according to claim 3,
The second cranking means is an eco-run control means for stopping the internal combustion engine when the vehicle is stopped and starting the internal combustion engine based on the establishment of the automatic start condition. Control device. The start control device for an on-vehicle internal combustion engine according to claim 4,
It said second cranking means comprises means to start said internal combustion engine when preparing means and the vehicle start to start the internal combustion engine based on the charge demand of the drive request or a battery vehicle auxiliaries is required, A start control device for an on-vehicle internal combustion engine, wherein cranking is suppressed when it is determined that the vehicle is ready to start at least during cranking control when preparation for starting the vehicle is required. In the start control device for an on-vehicle internal combustion engine according to any one of claims 1 to 5,
The cranking means continues the cranking operation that has been started until the complete explosion determination of the internal combustion engine is made or until the cranking suppression control by the cranking suppression means is started. A start control device for an onboard internal combustion engine characterized by the above.

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