JP2016011614A - Engine automatic stop/start control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine automatic stop/start control device capable of securing safety while reducing waste engine start by starting an engine in an optimum situation in an ISS vehicle.SOLUTION: An engine 1 is automatically started (S7), in a case when a power transmission situation is in a blocked state (Yes in S2), a vehicle is not in maintenance (Yes in S3), a road surface has gradient more than prescribed gradient, and a vehicle speed is a first prescribed vehicle speed or more (Yes in S4), in a case when the vehicle speed is a second prescribed vehicle speed or more and continued for a prescribed time or more (Yes in S5), or in a case when a moving amount of the vehicle is a prescribed amount or more (Yes in S6), after automatic stop of the engine (1) (Yes in S1).

Description

  The present invention relates to an engine automatic stop / start control device.

  In recent years, from the viewpoint of environmental protection and fuel efficiency saving, the engine is automatically stopped when the vehicle is temporarily stopped due to a signal at an intersection or the like, and the engine is automatically started when the vehicle subsequently restarts. Vehicles having functions (hereinafter referred to as ISS vehicles) have been put into practical use.

  For example, in Patent Document 1, in the engine control device that starts the engine when the negative pressure of the brake booster becomes smaller than a predetermined threshold value, the predetermined threshold value is changed depending on whether the stop position of the vehicle is flat or not. Thus, a technology for improving the fuel consumption by reducing the frequency of restarting the engine during idling stop has been disclosed.

JP 2006-83830 A

  By the way, if the engine is automatically restarted due to a decrease in braking force as in Patent Document 1, there is a possibility that the driver may restart without intention depending on the situation.

  On the other hand, when the engine is automatically stopped on a slope, if the braking force is insufficient for the slope of the slope and the vehicle starts moving, the hydraulic pump and compressor that use the engine as a power source also stop. Therefore, the functions of various auxiliary machines such as power steering using hydraulic pressure and brakes using air pressure are reduced, and the driver may not be able to operate the vehicle quickly.

  For this reason, it is desirable to restart the engine when the movement of the vehicle is detected. However, for example, when the start of the vehicle is detected by the vehicle speed sensor, the vehicle speed pulse may be generated by the vibration of the vehicle. Therefore, if the engine is restarted only by detecting the vehicle speed pulse, this is also the driver's intention. There is a possibility of not restarting.

  The present invention has been made to solve such a problem, and the object of the present invention is to start safety in an appropriate situation in an ISS vehicle, thereby reducing unnecessary engine start and reducing safety. It is an object of the present invention to provide an engine automatic stop / start control device capable of ensuring the above.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

  The engine automatic stop / start control device according to this application example automatically stops the engine when a predetermined stop condition is satisfied and an engine that is a driving source for driving the vehicle, and then when the predetermined start condition is satisfied A control unit for automatically starting the engine, a first detection unit for detecting a power transmission state from the engine to drive wheels, a second detection unit for detecting whether the vehicle is under maintenance work, A third detector for detecting a road surface gradient; a fourth detector for detecting a vehicle speed of the vehicle; and a fifth detector for detecting the amount of movement of the vehicle. After the automatic stop, the power transmission status detected by the first detection unit is in a cut-off state, the second detection unit detects that the vehicle is not being maintained, and the gradient detected by the third detection unit Is above a certain gradient And when the vehicle speed detected by the fourth detector is equal to or higher than a first predetermined vehicle speed, the vehicle speed detected by the fourth detector is equal to or higher than a second predetermined vehicle speed smaller than the first predetermined vehicle speed for a predetermined time. The engine is automatically started regardless of the predetermined start condition when it has elapsed or when the amount of movement detected by the fifth detector is greater than or equal to a predetermined amount.

  According to the present invention using the above means, it is possible to ensure safety while reducing useless engine start by starting the engine in an appropriate situation in an ISS vehicle.

It is a schematic block diagram which shows the drive system of the vehicle provided with the engine automatic stop start control apparatus in one Embodiment of this invention. It is a flowchart which shows the engine starting control routine which ECU of the engine automatic stop starting control apparatus in one Embodiment of this invention performs.

  Hereinafter, an embodiment of an engine automatic stop / start control device embodying the present invention will be described.

  FIG. 1 is an overall configuration diagram showing a drive system of a vehicle provided with an engine automatic stop / start control device of the present embodiment, and the configuration of the present embodiment will be described based on the same diagram.

  The vehicle in this embodiment is a truck, and a diesel engine (hereinafter referred to as an engine) 1 is mounted as a driving power source. An input shaft 3a of an automatic transmission (hereinafter simply referred to as a transmission) 3 is connected to an output shaft 1a of the engine 1 via a clutch device 2 (clutch means), and the rotation of the engine 1 is changed when the clutch device 2 is connected. Is transmitted to the machine 3. The transmission 3 is based on, for example, a manual transmission having six forward speeds and one reverse speed. As described below, the gear shifting operation and the connection / disconnection operation of the clutch device 2 associated with the gear shifting are performed. This is an automated so-called AMT (Automated Manual Transmission).

  The clutch device 2 is configured as a friction clutch that is connected to the flywheel 4 by press-contacting the clutch plate 5 with a pressure spring 6 and is disconnected by separating the clutch plate 5 from the flywheel 4. An air cylinder 8 is connected to the clutch plate 5 via an outer lever 7, and an air tank 11 filled with compressed air is connected to the air cylinder 8 via an air passage 10 in which an electromagnetic valve 9 is interposed.

  When the electromagnetic valve 9 is opened, compressed air is supplied from the air tank 11 to the air cylinder 8 via the air passage 10, and the air cylinder 8 is activated to separate the clutch plate 5 from the flywheel 4 via the outer lever 7. Thus, the clutch device 2 is switched from the connected state to the disconnected state. On the other hand, when the solenoid valve 9 is closed, the air cylinder 8 stops operating due to the stop of the supply of compressed air, so that the clutch plate 5 is pressed against the flywheel 4 by the pressure spring 6, and thereby the clutch device 2 is released from the disconnected state. Switch to connected state. As described above, the air cylinder 8 is operated in accordance with the opening and closing of the electromagnetic valve 9 so that the clutch device 2 can be automatically connected and disconnected.

  The transmission 3 is provided with a gear shift unit 12 for switching the gear position. Although not shown, the gear shift unit 12 includes a plurality of air cylinders that operate shift forks corresponding to the respective gear speeds in the transmission 3, and It incorporates multiple solenoid valves that actuate the air cylinder. The gear shift unit 12 is connected to the above-described air tank 11 via an air passage 13, and compressed air from the air tank 11 is supplied to a corresponding air cylinder according to opening / closing of each solenoid valve, and the air cylinder is operated. When the corresponding shift fork is switched, the gear position of the transmission 3 is shifted according to the switching operation. As described above, the air cylinder is operated in accordance with the opening / closing of the electromagnetic valve of the gear shift unit 12 so that the transmission 3 can be automatically shifted.

  In the vehicle, an input / output device (not shown), a storage device (ROM, RAM, etc.) for storing control programs and control maps, an ECU (control unit) equipped with a central processing unit (CPU), a timer counter, etc. 20 is installed, and comprehensive control of the engine 1, the clutch device 2, and the transmission 3 is performed.

  On the input side of the ECU 20, a clutch stroke sensor 21 (first detection unit) that detects the clutch stroke of the clutch device 2, a gear position sensor 22 (first detection unit) that detects the gear position of the transmission 3, and a cab tilt And a maintenance sensor 23 (second detection unit) for detecting that the vehicle is being maintained from opening the front panel of the cab, and a gradient sensor 24 (third detection unit) for detecting the gradient of the road surface on which the host vehicle is traveling. ), A vehicle speed sensor 25 (fourth detector) provided on the output shaft 3b of the transmission 3 for detecting the vehicle speed from the output shaft rotation speed, an engine rotation speed sensor 26 for detecting the rotation speed of the engine 1, and the transmission 3 A clutch rotation speed sensor 27 that detects the rotation speed (clutch rotation speed) of the input shaft 3a, and an accelerator sensor 2 that detects the operation amount (accelerator opening) of the accelerator pedal 14 , The lever position sensor 29 for detecting the switching position of the change lever 15 provided near the driver's seat, the sensors of the brake switch 30, such as to detect the operation of the brake pedal 16 is connected.

  Further, the electromagnetic valve 9 of the clutch device 2 and the electromagnetic valves of the gear shift unit 12 are connected to the output side of the ECU 20, and the fuel injection valve of the engine 1 is connected (not shown). . In addition, you may make it provide ECU for exclusive use of engine control separately from ECU20, for example, without controlling comprehensively by single ECU20 in this way.

  For example, the ECU 20 calculates the fuel injection amount to each cylinder of the engine 1 from a map (not shown) based on the engine rotation speed detected by the engine rotation speed sensor 26 and the accelerator opening detected by the accelerator sensor 28. The fuel injection timing is calculated from a map (not shown) based on the engine speed and the fuel injection amount. Based on these calculated values, the engine 1 is operated while driving the fuel injection valves of the respective cylinders.

  Further, the ECU 20 executes the automatic transmission mode when the lever position sensor 29 detects that the change lever 15 is switched to the D (drive) range, and based on the accelerator opening and the vehicle speed detected by the vehicle speed sensor 25, A target shift speed is calculated from a shift map (not shown). Then, while opening / closing the electromagnetic valve 9 of the clutch device 2 and operating the clutch device 2 to be connected / disconnected by the air cylinder 8, the predetermined electromagnetic valve of the gear shift unit 12 is opened / closed and the corresponding shift fork is switched by the air cylinder. Thus, the vehicle shifts to the target shift stage, and the vehicle is always driven with an appropriate shift stage.

  The shift position that can be selected by the change lever 15 includes a P (parking) range selected during parking, a N (neutral) range in which the gear of the transmission 3 is neutral, a D (drive) range selected during forward travel, There are an R (reverse) range that is selected during reverse travel, an M (manual) range that allows manual shift-up or shift-down. Although not shown, the vehicle is also provided with a start stage selection switch for selecting a shift stage (starting stage) to be used at the start, and the ECU 20 starts the vehicle selected by the start stage selection switch when starting the vehicle. The stage is set as the target shift stage.

  On the other hand, the ECU 20 automatically stops the engine 1 when the vehicle is temporarily stopped due to a signal or the like and a predetermined engine stop condition is satisfied, and then the engine 1 is automatically started when a predetermined engine start condition is satisfied. Start control (hereinafter referred to as ISS control) is executed (control unit).

  For example, the stop of the accelerator operation (accelerator opening = 0), the brake operation (the brake switch 30 is ON), the vehicle stop (vehicle speed = 0), etc. are set in advance as the engine stop condition. If the state where all these conditions are satisfied continues for a predetermined fixed time, the ECU 20 considers that the stop condition is satisfied, stops the fuel injection of the engine 1 and automatically stops it.

  Further, for example, as a starting condition, stop of the brake operation (the brake switch 30 is OFF) or start of the accelerator operation (accelerator opening> 0) is set in advance. If any of these conditions is satisfied, the ECU 20 considers that the start condition is satisfied, and causes the engine 1 to be cranked with a starter (not shown) and automatically started. In addition, the stop condition and start condition of the above engine 1 are examples, and are not restricted to this, It can change arbitrarily.

  On the other hand, if the ECU 20 satisfies a predetermined condition different from the start condition after the automatic engine stop by the ISS control, the ECU 20 regards the vehicle as moving and immediately starts the engine 1 regardless of the start condition. Is automatically started.

  Specifically, referring to FIG. 2, there is shown a flowchart representing an engine start control routine that accompanies vehicle movement executed by the ECU 20, which will be described below along the same flowchart.

  First, in step S1, the ECU 20 determines whether or not the engine is automatically stopped by ISS control. If the determination result is false (No), the routine is returned because the engine 1 does not need to be automatically started. On the other hand, if the determination result is true (Yes), the process proceeds to step S2.

  In step S2, the ECU 20 determines whether or not the power transmission from the engine 1 to the drive wheels is in a cut-off state. Specifically, when the clutch stroke sensor 21 detects the disconnected state of the clutch device 2 or when the gear position sensor 22 detects that the transmission 3 is in the neutral state, Determine. That is, this determination determines whether the engine 1 is in a restartable state. If the determination result is true (Yes), the process proceeds to step S3.

  In step S3, the ECU 20 determines whether or not the vehicle is under maintenance work based on information from the maintenance sensor 23. If the determination result is false (No), that is, if the maintenance sensor 23 detects the tilt of the cab or the opening of the front panel, the routine returns so as not to start the engine 1. On the other hand, if the determination result is true (Yes), the process proceeds to step S4. According to the determination in step S3, starting due to erroneous detection of vehicle movement, such as an unintended vehicle speed pulse being generated in the vehicle speed sensor 25 due to vibration in the vehicle due to maintenance work, is prevented.

  In step S4, the ECU 20 determines whether or not the road surface gradient detected by the gradient sensor 24 is greater than or equal to a predetermined gradient and the vehicle speed detected by the vehicle speed sensor 25 is greater than or equal to the first vehicle speed. The first predetermined vehicle speed is set to a vehicle speed (for example, 20 km / h) at which it can be clearly determined that the vehicle is moving. If the vehicle speed is less than a predetermined gradient at which the vehicle does not move even when the brake is released, such as a flat road, and the vehicle speed is equal to or higher than the first predetermined vehicle speed, a maintenance operation state that is not detected by the maintenance sensor 23 or an abnormality in the vehicle speed sensor 25 I reckon. In such a case, when the vehicle speed road surface gradient is less than a predetermined gradient, or when the vehicle speed is less than the first vehicle speed, the determination result is false (No), and the process proceeds to the next step S5.

  In step S5, the ECU 20 determines whether or not the state where the vehicle speed detected by the vehicle speed sensor 25 is equal to or higher than the second vehicle speed continues for a predetermined time or more. The second vehicle speed is set to a vehicle speed (for example, 5 km / h) lower than the first vehicle speed in step S4. If the vehicle speed is less than the second vehicle speed, or if the vehicle speed is greater than or equal to the second vehicle speed and less than a predetermined time (for example, 5 to 10 seconds), the determination result is false (No), and the next step S6 is performed. move on.

  In step S6, the ECU 20 calculates the moving amount of the vehicle after the engine is automatically stopped from the integrated value of the vehicle speed detected by the vehicle speed sensor 25 (fifth detection unit), and the moving amount is a predetermined amount (for example, 10 to 20 m) or more. It is determined whether or not. If the determination result is false (No), that is, if the moving amount of the vehicle is a movement of an extremely short distance less than a predetermined amount, it is considered that the engine 1 does not need to be started, and the routine is returned.

  On the other hand, if any one of the determination results in steps S4 to S6 is true (Yes), the process proceeds to step S7.

  That is, when the road surface gradient is relatively steep and equal to or higher than a predetermined gradient, and the vehicle speed is also equal to or higher than the first predetermined vehicle speed, it can be estimated that the vehicle is going down a downhill road, for example. In this case, the determination result of step S4 is true (Yes), and the process proceeds to step S7.

  Further, when the vehicle speed is equal to or higher than the second predetermined vehicle speed and continued for a predetermined time or longer, it can be estimated that the vehicle is moving slowly at a low speed, for example. In this case, the determination result of step S5 is true (Yes), and the process proceeds to step S7.

  Furthermore, when the vehicle movement amount is a predetermined amount or more, for example, it can be estimated that the vehicle is moving while repeating the movement and stop of the vehicle. In this case, the determination result of step S6 is true (Yes), and the process proceeds to step S7.

  In step S7, the ECU 20 automatically starts the engine 1 and returns the routine.

  As described above, the ECU 20 satisfies the conditions of Steps S1 to S3 after the automatic engine stop, and if the conditions of any of Steps S4 to S6 are satisfied, the ECU 20 considers that the vehicle is moving and satisfies the start conditions. The engine 1 is automatically started regardless of whether or not it is present. When the engine 1 is started, a hydraulic pump or a compressor using the engine 1 as a power source is driven, and the power steering and the brake function sufficiently. As a result, the driver can safely perform the stop operation and avoidance operation of the vehicle. On the other hand, if the conditions of steps S1 to S6 are not satisfied, by not restarting the engine 1, it is possible to prevent useless engine start and sufficiently enjoy the fuel efficiency improvement effect by ISS control. it can.

  Therefore, according to the engine automatic stop / start control apparatus according to the present embodiment, the engine 1 can be started in an appropriate situation in the ISS vehicle, and safety can be ensured while reducing useless engine start. .

  Although the description of the embodiment of the engine automatic stop / start control device according to the present invention has been completed above, the embodiment is not limited to the above embodiment.

  For example, in the above embodiment, the engine 1 is a diesel engine, but the engine is not limited to this, and may be, for example, a gasoline engine.

  Moreover, in the said embodiment, although the vehicle is made into a truck, the vehicle which can apply this invention is not restricted to this, It can apply also to the passenger vehicle in which ISS control is possible.

1 Engine 2 Clutch Device 3 Transmission 20 ECU (Control Unit)
21 Clutch stroke sensor (first detector)
22 Gear position sensor (first detector)
23 Maintenance sensor (second detector)
24 Gradient sensor (third detector)
25 Vehicle speed sensor (4th detection part, 5th detection part)

Claims (1)

An engine that is a power source for driving the vehicle;
A controller that automatically stops the engine when a predetermined stop condition is satisfied, and then automatically starts the engine when a predetermined start condition is satisfied;
A first detector for detecting a power transmission state from the engine to the drive wheel;
A second detector for detecting whether or not the vehicle is undergoing maintenance work;
A third detector for detecting a road gradient;
A fourth detector for detecting a vehicle speed of the vehicle;
A fifth detector for detecting the amount of movement of the vehicle,
The control unit detects that the power transmission state detected by the first detection unit is in a cut-off state after the automatic stop of the engine, and the second detection unit detects that the vehicle is not under maintenance work, When the gradient detected by the detection unit is greater than or equal to a predetermined gradient and the vehicle speed detected by the fourth detection unit is greater than or equal to a first predetermined vehicle speed, the vehicle speed detected by the fourth detection unit is the first When a predetermined time has passed at a second predetermined vehicle speed that is lower than a predetermined vehicle speed, or when the amount of movement detected by the fifth detector is greater than a predetermined amount, the An engine automatic stop / start control device that automatically starts the engine.

Images