JP2006009716A - Vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle control device adequately controlling automatic stop/automatic start of an engine, even if a shift lever is at a neutral position. <P>SOLUTION: The vehicle control device has a control device 3 automatically starting the engine 1 by operating a brake again, when the neutral position of a shift position is detected during the automatic stop of the engine 1 in a state where the brake is in an operating state by a braking force retaining device 9. Therefore, the vehicle control device adequately controls the automatic stop/automatic start of the engine, even if the shift lever is at the neutral position. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle control apparatus for automatically stopping / starting an engine.

  For example, a vehicle control device is known that automatically stops an engine under a predetermined stop condition and then restarts the engine under a predetermined start condition when the vehicle stops at an intersection when traveling in an urban area (for example, Patent Document 1). In the conventional vehicle control apparatus that automatically stops / starts the engine, fuel can be saved and air pollution caused by exhaust gas can be reduced. In a vehicle equipped with an automatic transmission, a predetermined creep phenomenon occurs even if the accelerator pedal is not depressed when the shift lever is in the traveling position.

  In a vehicle that automatically stops / starts the engine, a predetermined creep phenomenon occurs when the engine is automatically stopped with the brake device operating when the vehicle is stopped when the shift lever is in the traveling position, and the start condition is satisfied. The engine is automatically started in the state. By the way, in the conventional vehicle control device, normally, when the shift lever is set to the neutral position, it is assumed that the vehicle is kept in a neutral state, so that the braking device is not operated. However, the present situation is that there are drivers who set the shift lever to the neutral position when the vehicle is stopped. Even in such a driver, it is a reality that there is a request to automatically stop / start the engine, and in order to meet such a driver's request, even when the shift lever is in the neutral position. It is necessary to make the braking device work during automatic stop.

  However, in order to activate the braking device when the shift lever is set to the neutral position, it is necessary to establish a restart condition. In other words, the normal restart condition is when the brake pedal is released, but if this condition is applied, if the shift lever is in the neutral position and the brake pedal is released to the driver without intention of starting, The engine will restart. For this reason, even when the shift lever is set to the neutral position, the demand for automatically stopping the engine cannot be met. Therefore, even if the case where the shift lever is set to the neutral position is used as the automatic stop condition in the conventional control device, the technology becomes infeasible.

JP 2000-8905 A

  The present invention has been made in view of the above prior art, and is capable of accurately stopping and automatically starting the engine even when the shift lever is in the neutral position (the shift position is not driven). An object is to provide an apparatus.

The vehicle control device of the present invention according to claim 1 for solving the above object is as follows.
In the vehicle control device that automatically stops the engine when the stop condition is satisfied and automatically starts the engine when the start condition is satisfied,
Vehicle stop state detecting means for detecting the stop state of the vehicle;
Braking operation detecting means for detecting operation / non-operation of the braking device by the driver;
Automatic stop control means for automatically stopping the engine when detecting the stop of the vehicle and detecting the operation of the braking device;
Shift position detecting means for detecting the drive state / non-drive state of the transmission;
Braking force holding means for operating the braking device during the automatic stop of the engine;
Automatic start control means for automatically starting the engine by re-operation of the braking device when the non-driving state of the shift position is detected during the automatic stop of the engine when the braking device is in the operating state by the braking force holding means. It is characterized by having.

  According to the present invention of claim 1, conditions for restarting the engine when the shift position is not driven can be accurately established, and even when the shift lever is set to the neutral position, the engine is automatically stopped / The vehicle control device can be automatically started.

And this invention which concerns on Claim 2 is
The vehicle control device according to claim 1,
When the engine is automatically stopped and the shift position is in the drive state, the brake device is not operated, the brake hydraulic pressure deviation is greater than or equal to a predetermined value, the vehicle speed is greater than or equal to a predetermined value, and the accumulated battery discharge current is greater than or equal to a predetermined value. A second automatic start control means for automatically starting the engine is provided.

  In the present invention of claim 2, even when the shift lever is not set to the neutral position, the engine can be automatically started without operating the brake device.

Further, the present invention according to claim 3 provides
In the vehicle control device according to claim 1 or 2,
A third automatic start control means is provided for automatically starting the engine when the shift position is in a driving state in a state where the brake device is not operated during the automatic stop of the engine.

  According to the third aspect of the present invention, the engine can be automatically started accurately when the shift position is in the drive state.

The present invention according to claim 4 provides
In the vehicle control device according to any one of claims 1 to 3,
The braking device includes a braking holding mechanism that holds the operating state of the braking even after the driver performs non-operation,
The brake holding state is released after a predetermined time has elapsed after the engine is started.

  In the fourth aspect of the present invention, after the engine is started, the holding of the brake is released after the engine has completely exploded, so that the holding of the brake can be released after obtaining an appropriate creep force.

The present invention according to claim 5
In the vehicle control device according to any one of claims 1 to 4,
The braking device includes a slope detection means for detecting the slope of the vehicle,
The braking operation detecting means detects an operation for obtaining a braking force that the vehicle does not move according to the gradient.

  According to the fifth aspect of the present invention, it is possible to eliminate the unintended behavior of the vehicle regardless of the slope state of the road surface.

  The vehicle control device of the present invention can be a vehicle control device that can automatically stop / start the engine accurately even when the shift lever is in the neutral position (non-driven state of the shift position).

  The vehicle control apparatus according to the present embodiment is an apparatus that automatically stops the engine when the stop condition is satisfied and automatically starts the engine when the start condition is satisfied.

  The stop condition for automatically stopping the engine is set when the vehicle speed is zero and a predetermined time has elapsed since the previous automatic stop, and when the water temperature reaches a predetermined temperature.

  The starting condition for automatically starting (restarting) the engine is that when the transmission is in the D range (driving state), the brake hydraulic pressure deviation is greater than or equal to the threshold, the brake switch is off, or the vehicle speed is It is set when the vehicle speed is predetermined or when the charge / discharge current of the battery exceeds a predetermined Ah and the battery is discharged (second start control means). When the transmission is in the N range (non-drive state), if the brake is stepped on again (if you keep stepping on the brake, if you release your foot once again) (Third start control means).

  Further, a mechanism for maintaining the brake operation state after the driver performs the brake release operation is provided, and the brake operation state is released after a predetermined time has elapsed after the engine is started. Furthermore, a gradient detecting means (such as an acceleration sensor) for detecting the gradient of the vehicle is provided, and the holding force is controlled so as to obtain a braking force according to the gradient.

  Embodiments of the present invention will be specifically described below with reference to the drawings.

  FIG. 1 shows a schematic configuration of a vehicle control device according to an embodiment of the present invention, FIG. 2 shows a control flowchart of the vehicle control device according to an embodiment of the present invention, and FIG. FIG. 4 is a time chart showing temporal changes in hydraulic pressure and engine rotational speed on a flat ground, and FIG. 5 is a time chart showing temporal changes in acceleration, hydraulic pressure and engine rotational speed on a slope.

  As shown in FIG. 1, the engine 1 is provided with a starter 2, and the operation of the starter 2 is controlled by a command from the control device 3. Although not shown, a fuel system device such as a fuel injection device for driving the engine 1 is connected to the engine 1, and the operation of the fuel system device is controlled by a command from the control device 3. An automatic transmission 4 is connected to an output shaft (not shown) of the engine 1, and the operation mode of the automatic transmission 4 is, for example, P (parking), R (reverse), N ( (Neutral), D (drive), 3-speed, 2-speed, and 1-speed ranges.

  The automatic transmission 4 is provided with a shift position sensor 5 as a shift position detecting means. The shift position sensor 5 is in a driving state of R (reverse), D (drive), third speed, second speed, and first speed. The non-driving state N (neutral) is detected. Detection information of the shift position sensor 5 is input to the control device 3.

  A brake device 8 is provided to generate a hydraulic pressure in the wheel cylinder 7 by operating the brake pedal 6 to operate the brake, and the brake device 8 is provided with a braking force holding means 9. The brake device 8 is provided with a brake pedal switch 10 for detecting the operation state of the brake pedal 6 and a pressure sensor 11 for detecting the oil pressure to the wheel cylinder 7. Information detected by the brake pedal switch 10 and the pressure sensor 11 is input to the control device 3.

  The braking force holding means 9 has a solenoid valve 16 provided in the hydraulic flow path 15, and the solenoid valve 16 opens and closes the hydraulic flow path 15 in a predetermined state based on a command from the control device 3. When the hydraulic flow path 15 is closed by the solenoid valve 16 in a state in which the pressure oil is supplied to the wheel cylinder 7, the supply state of the pressure oil to the wheel cylinder 7 is maintained, and even if the brake pedal 6 is loosened, depending on the gradient The braking force at which the vehicle does not move is maintained.

  On the other hand, a current sensor 18 is provided in the battery 17 of the vehicle, and the current state of the battery being discharged is input to the control device 3. Further, the vehicle is provided with an acceleration sensor 19 as a gradient detecting means, and detection information of the acceleration sensor 19 is input to the control device 3. Further, the vehicle is provided with a vehicle speed sensor 20 that detects the vehicle speed, and information detected by the vehicle speed sensor 20 is input to the control device 3.

  The control device 3 derives (calculates, maps, etc.) the road surface gradient based on the detection information of the acceleration sensor 19, and controls the holding pressure in the braking force holding means 9 according to the road surface gradient. That is, as shown in FIG. 3, the relationship between the gradient and the holding pressure is previously mapped and stored. The reference holding pressure is set in a region where the gradient is small, and the holding pressure is set to gradually increase as the gradient increases. For this reason, a predetermined holding force corresponding to the gradient is obtained.

  In FIG. 1, reference numeral 21 denotes a water temperature sensor, 22 denotes a rotation state sensor that detects the rotation speed and the like (number of steps) of the engine 1, and detection information of the water temperature sensor 21 and the rotation state sensor 22 is input to the control device 3. Is done. The control device 3 is provided with a function such as a timer, and is used for determining whether or not a condition is satisfied in the automatic stop control and restart control of the engine 1.

  In the vehicle control apparatus described above, the engine 1 is automatically stopped when the engine 1 stop condition is satisfied, and the engine 1 is automatically started when the engine 1 start condition is satisfied.

  The stop condition for automatically stopping the engine is set when the vehicle speed detected by the vehicle speed sensor 20 is zero and a predetermined time has elapsed since the previous automatic stop, and when the water temperature detected by the water temperature sensor 19 reaches a predetermined temperature. Has been.

  The starting condition for automatically starting (restarting) the engine 1 is that when the automatic transmission 4 is in the D range (driving state), the deviation of the brake hydraulic pressure detected by the pressure sensor 11 is greater than or equal to the threshold value, or the brake pedal It is set when the switch 10 is in the OFF state, when the vehicle speed detected by the vehicle speed sensor 20 is a predetermined vehicle speed, or when the integration of the discharge current of the battery 17 detected by the current sensor 18 is a predetermined Ah. (Second automatic start control means). When the automatic transmission 4 is in the N range (non-driving state), the brake pedal 6 is depressed again (when the brake pedal 6 is continuously depressed, the foot is released once and then depressed), or the D range is set. This is set when the brake pedal 6 is depressed again (third automatic start control means).

  During automatic stop, when the automatic transmission 4 is in the N range, even if the brake is not operated, the braking force is maintained by the braking force holding device 9 and the automatic start of the engine 1 is prohibited. The engine 1 is automatically started. In addition, a function of automatically starting the engine 1 when the brake is not operated while the engine 1 is automatically stopped is provided so that the engine 1 is automatically started even when the automatic transmission is in the D range when the brake is not operated. It has become. As a result, the driver's intention to start can be accurately read, and an uneasy start can be suppressed, which is advantageous in terms of fuel consumption.

  Further, a mechanism for holding the brake operating state even after the driver performs the brake releasing operation is provided, and the brake operating state is released after a predetermined time has elapsed after the engine 1 is started. Furthermore, a sensor 19 for detecting the vehicle gradient is provided, and the holding force is controlled so as to obtain a braking force according to the gradient. As a result, the automatic shifting condition is the N range, and the vehicle does not move even if the driver does not intend to start and performs a brake releasing operation.

  As shown in FIG. 2, when it is determined in step S1 whether or not the engine is in an idle stop system state in which the engine 1 is automatically stopped / automatically started (state in which the engine is stopped). In step S2, it is determined whether or not the brake is off. If it is determined in step S2 that the brake is off, it is determined in step S3 whether or not the automatic transmission 4 is in the D range. In step S3, it is determined that the automatic transmission 4 is in the D range. In this case, it is determined that there is an intention to start, and the engine 1 is automatically started in step S4.

  If it is determined in step S2 that the brake is not in an off state, that is, the brake is in an on state, it is determined that there is no intention to start, and the process proceeds to step S5 to continue holding the brake and end. When it is determined in step S3 that the automatic transmission 4 is not in the D range, the process proceeds to step S6 and it is determined whether or not the automatic transmission 4 is in the N range. If it is determined in step S6 that the engine is not in the N range, the process proceeds to step S4 and the engine 1 is automatically started.

  On the other hand, when it is determined in step S6 that the automatic transmission 4 is in the N range, the process proceeds to step S5 and the brake holding is continued to be the end. That is, the brake is held when the brake is off and the shift position is in the N range while the engine 1 is stopped. The restart condition at this time is that the brake pedal 6 is depressed again and the brake pedal switch 10 is turned on, or the automatic transmission 4 is set to the D range and the brake pedal 6 is depressed and the brake pedal switch 10 is turned on. It's time. When the shift position is in the N range, brake holding is continued when these two conditions are not satisfied.

  Therefore, the conditions for restarting the engine 1 when the shift position is in the N range are accurately established, and the engine can be automatically stopped / started accurately even when the shift lever is set to the neutral position. It becomes a vehicle control device.

  After the engine 1 is automatically started in step S4, it is determined in step S7 whether or not the number of processes when starting the engine 1 is equal to or more than a predetermined number K. The number of steps of the predetermined number of times K is set to the number of times that the engine 1 is completely exploded and a predetermined engine rotation speed is obtained to obtain a sufficient creep force. The engine 1 start process is repeated until the number of processes at the start of the engine 1 is equal to or greater than the predetermined number K. When it is determined in step S7 that the number of processes is equal to or greater than the predetermined number K, the brake holding is released in step S8 and the end is reached. .

  The predetermined number of times K in step S7 is set to, for example, a dozen IG in the case of flat ground and a number IG in the case of a slope. In the case of a slope, this is set to a low rotational speed K because the brake holding pressure is high and power is applied in the direction in which the vehicle moves backward. In addition, the release of the brake holding in step S8 is set so that the hydraulic pressure is gradually released in the case of flat ground, and the hydraulic pressure is released immediately in the case of a slope.

  The state of the brake holding pressure and the rotational speed of the engine 1 when starting the engine will be described with reference to FIGS. 4 and 5 (steps S4, S7, and S8 in FIG. 2). FIG. 4 shows the situation in the case of flat ground, and FIG. 5 shows the situation in the case of slope.

  The state of engine start on flat ground will be described.

  As shown in FIG. 4A, cranking is started and the cranking flag is changed to 1. As shown by a solid line in FIG. 4B, the holding pressure of the hydraulic passage 15 on the brake pedal 6 side is 0 MPa. To drop. As indicated by a one-dot chain line in FIG. 4B, the holding pressure on the wheel cylinder 7 side is maintained at a predetermined holding pressure until time t2 by driving the solenoid valve 16 at time t1. The predetermined number of steps is from time t1 to t2, and in the case of a flat ground, for example, it is set to a dozen IG. During this time, the engine 1 is completely detonated, and as shown in FIG. 4 (c), the rotation speed is such that a sufficient creep force is obtained. As shown by the one-dot chain line in FIG. 4B, the holding pressure on the wheel cylinder 7 side is released by driving the solenoid valve 16 at time t2, and the holding pressure is 0 MPa over time (for example, several seconds) until time t3. Is lowered.

  For this reason, after the engine 1 is started, the holding of the brake is released after the engine 1 has completely exploded, so that the holding of the brake can be released after obtaining an appropriate creep force.

  The engine starting situation on the slope will be explained.

  As shown in FIG. 5 (a), cranking is started and the flag is changed to 1. As shown by a solid line in FIG. 5 (c), the holding pressure of the hydraulic flow path 15 on the brake pedal 6 side at time t11. Decreases to 0 MPa. As indicated by the alternate long and short dash line in FIG. 5C, the holding pressure on the wheel cylinder 7 side is maintained until time t12 by driving the solenoid valve 16 at time t11. The predetermined number of steps is between time t11 and t12. As indicated by the one-dot chain line in FIG. 5C, the holding pressure on the wheel cylinder 7 side is instantaneously released by driving the solenoid valve 16 at time t12, and the holding pressure is reduced to 0 MPa until time t13. . As shown in FIG. 5 (b), in the process in which the holding pressure on the wheel cylinder 7 side is released between time t11 and t13, the acceleration is not reduced and the engine 1 is started without the vehicle moving backward. .

  For this reason, it is possible to eliminate the unintended behavior of the vehicle regardless of the inclined state of the road surface.

  The present invention can be used in the industrial field of a vehicle control device that automatically stops / starts an engine.

1 is a schematic configuration diagram of a vehicle control device according to an embodiment of the present invention. It is a control flowchart of the vehicle control apparatus which concerns on the example of 1 embodiment of this invention. It is a graph showing the relationship between a road surface gradient and holding pressure. It is a time chart showing the time-dependent change of the hydraulic pressure and engine speed in a flat ground. It is a time chart showing the time-dependent change of the acceleration in a slope, a hydraulic pressure, and an engine rotational speed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Starter 3 Control apparatus 4 Automatic transmission 5 Shift position sensor 6 Brake pedal 7 Wheel cylinder 8 Brake device 9 Braking force holding device 10 Brake pedal switch 11 Pressure sensor 15 Hydraulic flow path 16 Solenoid valve 17 Battery 18 Current sensor 19 Acceleration Sensor 20 Vehicle speed sensor 21 Water temperature sensor 22 Rotation status sensor

Claims (5)

In the vehicle control device that automatically stops the engine when the stop condition is satisfied and automatically starts the engine when the start condition is satisfied,
Vehicle stop state detecting means for detecting the stop state of the vehicle;
Braking operation detecting means for detecting operation / non-operation of the braking device by the driver;
Automatic stop control means for automatically stopping the engine when detecting the stop of the vehicle and detecting the operation of the braking device;
Shift position detecting means for detecting the drive state / non-drive state of the transmission;
Braking force holding means for operating the braking device during the automatic stop of the engine;
Automatic start control means for automatically starting the engine by re-operation of the braking device when the non-driving state of the shift position is detected during the automatic stop of the engine when the braking device is in the operating state by the braking force holding means. A vehicle control device comprising the vehicle control device. The vehicle control device according to claim 1,
When the engine is automatically stopped and the shift position is in the drive state, the brake device is not operated, the brake hydraulic pressure deviation is greater than or equal to a predetermined value, the vehicle speed is greater than or equal to a predetermined value, and the accumulated battery discharge current is greater than or equal to a predetermined value. A vehicle control apparatus comprising second automatic start control means for automatically starting an engine. In the vehicle control device according to claim 1 or 2,
A vehicle control device comprising a third automatic start control means for automatically starting the engine when the shift position is in a driving state in a non-operating state of the braking device during the automatic stop of the engine. In the vehicle control device according to any one of claims 1 to 3,
The braking device includes a braking holding mechanism that holds the operating state of the braking even after the driver performs non-operation,
A vehicle control device that releases a brake holding state after a predetermined time has elapsed after the engine is started. In the vehicle control device according to any one of claims 1 to 4,
The braking device includes a slope detection means for detecting the slope of the vehicle,
A vehicle control device characterized in that the braking operation detecting means detects an operation to obtain a braking force that does not move the vehicle in accordance with the gradient.

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