JP3845910B2 - Engine automatic stop start device and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine automatic stop and start apparatus and method for saving fuel and reducing exhaust gas by automatically stopping an engine at an intersection or the like and further automatically starting the engine. The present invention relates to an automatic stop and start device and method for an engine used in a vehicle equipped with a motor.
[0002]
[Prior art]
When the vehicle stops at an intersection when traveling in the city, the engine is stopped under a predetermined stop condition, and then the engine is started under a predetermined start condition to save fuel and reduce exhaust gas. Stop-start devices are known. As a prior art of this type of apparatus, for example, there is one disclosed in JP-A-57-186063.
[0003]
In the technique disclosed in Japanese Patent Laid-Open No. 57-186063, when an automatic stop / start device and an automatic transmission are used, the vehicle speed is 0, the automatic transmission is set to the neutral range, and the side brake is applied. If a stop condition such as that is established, the engine is stopped and the engine is started by releasing the side brake.
[0004]
[Problems to be solved by the invention]
In the automatic stop / start apparatus disclosed in Japanese Patent Application Laid-Open No. 57-186063, the shift lever and the side brake need to be operated for the automatic stop / start process, which may be troublesome. For this reason, the number of engine stops may be reduced and the contribution to fuel efficiency may be reduced.
[0005]
Therefore, even when the automatic transmission is set to the drive range or the reverse range, the engine may be stopped if the vehicle speed satisfies a predetermined condition such as zero. In this case, the engine may be restarted by depressing the accelerator pedal.
[0006]
However, when the engine is stopped, the oil pump (hydraulic pump) that generates hydraulic pressure by the driving force of the engine also stops, so the operating oil pressure of the automatic transmission also decreases and the clutch is released. Yes. Then, after restarting, the operating oil pressure of the automatic transmission increases as the engine speed increases, and when a sufficient operating oil pressure is obtained, the clutch is engaged and, for example, enters the first speed. At this time, since the engine is restarted by depressing the accelerator pedal, the engine is at a high speed. Therefore, when the clutch is engaged, the engine torque is abruptly transmitted to the tire as the driving force, and a shock is generated. There is a problem that it is not possible to start. In particular, a smooth start is required when the vehicle is moving backward.
[0007]
The present invention has been made in view of the above circumstances, and an object thereof is to enable a smooth start of a vehicle equipped with an automatic engine stop / start device.
Another object of the present invention is to provide an engine automatic stop and start apparatus and method excellent in driver operability.
[0008]
[Means for Solving the Problems]
According to the first aspect, there is provided means for detecting that the shift lever is located in the reverse range in a state where the engine is automatically stopped and starting the engine. Therefore, in a state where the engine is automatically stopped, the engine is started (restarted) only by setting the shift lever to the reverse range.
[0009]
According to a second aspect of the present invention, the continuation time during which the shift lever is set to the reverse range is measured, and the engine is started only when the selection of the reverse range continues for a certain time or more. After the engine stops, the shift lever may pass the reverse range and enter the parking range. According to this configuration, the operation of starting the engine in such a case can be prevented.
[0010]
According to the third aspect, the automatic stop of the engine is prohibited while the shift lever is in the reverse range. Therefore, smooth operation during reverse operation is possible.
[0011]
According to claim 4, the shift lever can be switched to the reverse range only when the brake is depressed. Accordingly, it is possible to prevent the vehicle from starting backward simultaneously with the selection of the reverse range.
[0012]
According to claim 5, at least one of the engine rotational speed and the vehicle speed after starting is continuously detected, and when the detected value is not more than a reference value, the automatic stop / start device prohibits the engine from stopping. Means. According to this configuration, after the engine is started, when the vehicle is traveling only at the reference rotational speed or the vehicle speed, the engine does not automatically stop. Therefore, it is possible to run smoothly at a very low speed using the creeping phenomenon or in a garage.
[0013]
According to the sixth aspect of the present invention, the engine is started when it is determined that the shift speed is set to reverse after the engine is stopped. Therefore, in a state where the engine is automatically stopped, the engine is started (restarted) only by setting the gear position to reverse.
[0014]
According to the seventh aspect of the present invention, the continuation time during which the gear position is set to reverse is measured, and the engine is started when the continuation time is continued for a predetermined time. Therefore, erroneous start due to temporary reverse gear selection can be prevented.
[0015]
According to claim 8, automatic stop of the engine is prohibited while the shift speed is set to reverse. Therefore, smooth operation at a low speed during reverse operation is possible.
[0016]
According to claim 9, it is possible to switch the shift speed to the reverse only when the brake is depressed. Accordingly, it is possible to prevent the vehicle from starting backward at the same time as switching to reverse.
[0017]
According to the tenth aspect, at least one of the engine rotational speed and the vehicle speed after the start is continuously detected, and the engine stop is prohibited when the detected value is only the reference value or less. According to this configuration, it is possible to run smoothly at a very low speed using the creeping phenomenon, or in a garage.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an automatic stop and start device for an engine according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration of an automatic stop / start device for an engine according to this embodiment.
As shown in the drawing, the engine 1 is provided with a fuel injector 7 for injecting fuel, a starter 2 for starting the engine 1, an igniter 15 for igniting the fuel, and the like.
The automatic transmission 3 is connected to the output shaft (rotary shaft) of the engine 1 via a fluid coupling (fluid clutch) (not shown), and the output of the automatic transmission 3 is transmitted to the tire.
[0019]
The automatic transmission 3 includes a plurality of gears and a clutch or the like for appropriately connecting the gears to each other in accordance with switching of the shift speeds. Each clutch is driven by the hydraulic pressure generated by the hydraulic pump. Therefore, when the engine 1 is stopped, even if the shift lever 8 is in a range such as a drive, the hydraulic pressure is low, so the clutch is not engaged and is substantially in a neutral state. When the engine 1 is started and a sufficient number of revolutions is obtained, the hydraulic pressure increases and the clutch is engaged.
[0020]
In the automatic transmission 3, a shift range (parking, reverse, neutral, drive, second, low) is selected by the shift lever 8, and when each range is selected, a shift range switch group 9 (outputs a signal indicating the range). A parking switch 9a, a reverse switch 9b, a neutral switch 9c, a drive switch 9d, a second switch 9e, a low switch 9f) and a vehicle speed sensor 11 for detecting the vehicle speed.
[0021]
The setting of the shift stage (gear position) of the automatic transmission 3 is determined by the range of the shift lever 8 and a control signal from a control ECU (electronic control unit) 4 described later. For example, when the shift lever 8 is set to the reverse range, the gear position of the automatic transmission 3 is set to reverse (reverse gear).
[0022]
The automatic transmission 3 includes a lock mechanism that releases the lock and allows the shift lever 8 to enter the reverse range, for example, when the brake pedal 13 is depressed. As will be described later, this lock mechanism can prevent a sudden start to the rear even when the engine 1 is automatically started by placing the shift lever 8 in the reverse range.
[0023]
In the intake manifold portion of the engine 1, a throttle valve 5 that operates in conjunction with the accelerator pedal 23, a throttle position sensor 5 a that detects the opening of the throttle valve 5, and detects that the throttle valve 5 is fully closed An idle switch 6 is disposed.
[0024]
The operation of the entire vehicle including the engine 1, in particular, the engine automatic stop / start control peculiar to this embodiment is executed by the control ECU 4. That is, the control ECU 4 controls the throttle valve 5, the fuel injector 7 and the engine stop monitor 19 for notifying that the engine 1 is stopped based on detection signals from various sensors arranged in the vehicle. To do. Further, the starter 2 is controlled to be driven / stopped via the starter relay 12. As various sensors, in addition to the throttle position sensor 5a, the idle switch 6, the shift range switch group 9, the vehicle speed sensor 11 and the like, the brake switch 14 for detecting the state of the brake pedal 13 and the driver are operated. It includes an idle stop permission switch 20 for instructing whether to perform automatic stop and start (restart), a temperature sensor 21 for measuring the temperature of engine cooling water, a rotation speed sensor 22 for detecting the rotation speed of the engine 1, and the like.
[0025]
As shown in FIG. 2, the control ECU 4 includes an MPU (microprocessor unit) 41, a memory 42, an input / output interface 43, and the like. The MPU 41 inputs various detection signals from the sensor group 44 through the input / output interface 43, stores them in the memory 42, processes the stored detection signals in accordance with the program stored in the memory 42, and passes through the input / output interface 43. Output various control signals.
[0026]
Next, the control operation of the entire vehicle executed by the control ECU 4 will be described with reference to the flowcharts of FIGS. 3 and 4.
[0027]
FIG. 3 shows a main routine of control processing executed by the control ECU 4. This main routine is started, for example, when an ignition key is turned on. In step S1, control of the engine 1 and shift control during normal running are executed.
That is, the control ECU 4 controls the rotation of the engine 1 by supplying a fuel injection signal to the fuel injector 7 from each state of the engine 1 indicated by the detection signal input from the sensor group 44 and supplying an ignition signal to the igniter 15. To do. A control signal is supplied to the automatic transmission 3 based on vehicle speed information supplied from the vehicle speed sensor 11, throttle position sensor 5a, throttle opening information supplied from the idle switch 6, and the like. Implement control.
[0028]
Next, the flow proceeds to step S11, where it is determined whether or not the rotational speed of the engine 1 has exceeded a reference value A rpm (for example, 1500 rpm) based on the detection signal from the rotational speed sensor 22. In this case, the idle stop permission flag IS is set to “1” (ON) (step S12). If the rotational speed of the engine 1 does not exceed the reference value A rpm, the process jumps to step S2.
If the rotational speed of the engine 1 exceeds the reference value A rpm even once, the idle stop permission flag IS remains “1” until the engine 1 is stopped. In the next step S2, engine automatic stop / start control is executed.
[0029]
FIG. 4 is a flowchart showing details of the engine automatic stop / start control S2. First, in step S21, it is determined from the state of the idle stop permission switch 20 whether or not the driver is permitted to stop the engine 1 when idling. When the idle stop permission switch 20 is off, that is, when the driver does not permit the automatic stop of the engine 1, the routine exits from the routine and returns to the main routine, and the automatic stop start operation of the engine 1 is not performed.
[0030]
If the idle stop permission switch 20 is on, that is, if the driver permits the engine 1 to stop when idling, the process proceeds to step S22, and it is determined whether or not the idle stop permission flag IS is “1”.
[0031]
When it is determined that the idle stop permission flag IS is “0” (off), that is, after the engine 1 is started, the engine 1 is running only at a reference value Arpm (for example, 1500 rpm) or less. Exit from this routine. As a result, during low speed operation, the engine 1 does not stop automatically, and smooth operation such as traveling at a very low speed utilizing the creeping phenomenon or entering a garage becomes possible. Similar control is possible even when the vehicle speed detected by the vehicle speed sensor 11 instead of the rotation speed of the engine 1 is used as a determination condition in step S11.
[0032]
If it is determined in step S22 that the idle stop permission flag IS is “1” (ON), that is, if the rotational speed of the engine 1 exceeds the reference value Arpm, the process proceeds to step S23, where the reverse switch 9b is It is determined whether it is off, that is, whether the shift lever 8 is not in the reverse range. When it is determined that the reverse switch 9b is on (in the reverse range), the routine is exited. Thereby, the automatic stop of the engine 1 while the vehicle is moving backward is cancelled.
[0033]
If it is determined in step S23 that the reverse switch 9b is off (not in the reverse range), an output signal from the vehicle speed sensor 11 indicates whether or not the vehicle is stopped in step S24 in order to determine the engine stop condition. In step S25, it is determined from the detection signal of the idle switch 6 whether the throttle valve 5 is fully closed.
[0034]
If it is determined in steps S24 and S25 that the vehicle speed is not zero and / or the throttle valve 5 is not fully closed (idle switch 6 is off), the routine is exited.
[0035]
If it is determined in steps S24 and S25 that the vehicle speed is 0 and the throttle valve 5 is fully closed, the flow proceeds to step S26.
In step S26, whether or not the brake signal supplied from the brake switch 14 is on (the brake pedal 13 is depressed), whether or not the temperature of the engine coolant is equal to or higher than the reference temperature is determined from the detection signal of the temperature sensor 21. Other engine stop conditions such as signal usage status are determined, and if all of them are positively determined, the process proceeds to step S27. On the other hand, if even one of the conditions is not satisfied, the routine is exited.
[0036]
In step S27, it is determined by using a software timer or the like whether or not the state determined in the affirmative in steps S23 to S26 has continued for a reference time (for example, 2 seconds). On the other hand, if it is determined that the engine has continued, the process proceeds to step S28 in order to stop the engine 1.
[0037]
In step S28, in order to stop the engine 1, a fuel cut signal is supplied to the fuel injector 7, an ignition cut signal is supplied to the igniter 15, and a signal for fully closing the idle speed control valve (ISCV) that adjusts the idle speed. Send. In addition, the engine stop monitor 19 is also displayed to notify the driver that the engine has stopped. In step S29, the idle stop permission flag IS is set to “0” (off).
[0038]
Next, in step S30, the state of the idle switch 6 is determined. If it is on, the process proceeds to step S31 described later, and if it is off, the process proceeds to step S32.
[0039]
When the driver depresses the accelerator pedal 23 to start, the throttle valve 5 is opened in conjunction with the movement of the accelerator pedal 23 and the idle switch 6 is turned off.
Whether the idle switch 6 is turned off is determined in step S30, and the flow proceeds to step S32. In order to prevent malfunction, an additional condition may be that the opening of the throttle valve 5 obtained by the throttle position sensor 5a is greater than a certain opening.
[0040]
In step S32, the control ECU 4 drives the starter 2 via the starter relay 12, supplies a fuel injection signal to the fuel injector 7, injects fuel, supplies an ignition signal to the igniter 15, and ignites the engine 1. Is started (restarted) and an ISCV signal for setting the idling speed is supplied. Further, the display of the engine stop monitor 19 is turned off.
[0041]
Since it is determined whether the reverse switch 9b is on or off in step S23, the flow proceeds from step S30 to step S32 because the reverse switch 9b is off, that is, the shift lever 8 is set to a range other than the reverse range. This is the case. Accordingly, when the shift lever 8 is set to the reverse range, the depression of the accelerator pedal 23 causes the engine 1 to start and the vehicle does not start backward.
[0042]
On the other hand, if it is determined in step S30 that the idle switch 6 remains on, whether or not the shift lever 8 is in the reverse range is determined based on whether the reverse switch 9b is on or off (step S31). When it is determined that the reverse switch 9b is off, that is, the shift lever 8 is not in the reverse range, the process proceeds to step S28, and the engine 1 is kept stopped.
[0043]
On the other hand, when it is determined that the reverse switch 9b is on, that is, the shift lever 8 is in the reverse range, the process proceeds to step S32 and the engine 1 is started.
[0044]
Since it is determined in step S23 whether the reverse switch 9b is on or off, it is determined in step S31 that the reverse switch 9b is on when the shift lever 8 is moved from the other range to the reverse range. It is. Further, in order to put the shift lever 8 in the reverse range, it is necessary to depress the brake pedal 13 by the lock mechanism. The flow proceeds from step S30 to step S31 when the idle switch 6 is off, that is, the accelerator pedal 23 is not depressed.
[0045]
Therefore, when the shift lever 8 is put in the reverse range and the engine 1 is automatically started, the brake pedal 13 is depressed and the accelerator pedal 23 is not depressed. For this reason, even if the engine 1 is automatically started, the hydraulic pressure by the hydraulic pump is increased, and the clutch of the automatic transmission 3 is engaged, the brake keeps the tire pressed, so that the vehicle is maintained in a stopped state. The output is rapidly transmitted to the tire, and the vehicle does not start to move greatly. Thereafter, when the brake pedal 13 is loosened and the accelerator 23 is depressed, the output of the engine 1 is transmitted to the tire, and the vehicle starts smoothly backward.
[0046]
After the engine 1 is started in step S32, the number of revolutions of the engine 1 is determined from the detection signal of the revolution number sensor 22, and the engine 1 is completely exploded depending on whether or not the reference number of revolutions B rpm (for example, 400 rpm) or more. Whether or not (step S33).
If the engine 1 has not completely exploded, the flow returns to step S30 and repeats the above processing.
On the other hand, when the engine 1 is completely detonated, the flow proceeds to step S34, the starter relay 12 is turned off, and the starter 2 is turned off.
[0047]
After the above processing is completed, the process exits from the automatic stop / start routine and returns to step S1 in FIG.
[0048]
With the above configuration, according to the automatic stop and start device and method for the engine 1 of this embodiment, the engine 1 can be started simply by putting the shift lever 8 in the reverse range while the engine 1 is automatically stopped. (Steps S31 and S32). Therefore, operation becomes very easy. In addition, the vehicle can be smoothly started rearward.
Further, when the shift lever 8 is in the drive range or the like, the engine 1 can be started simply by depressing the accelerator pedal 23.
[0049]
Further, the automatic stop of the engine 1 is prohibited while the automatic transmission 3 is in the reverse range according to the determination process in step S23. Can be operated smoothly without stopping.
[0050]
Further, the shift lever 8 can be switched to the reverse range only when the brake pedal 13 is depressed by the lock mechanism. Also, the engine 1 is automatically started by selecting the reverse range only when the accelerator pedal 23 is not depressed. Therefore, even if the hydraulic pressure from the hydraulic pump increases and the clutch of the automatic transmission 3 is engaged, the tire is pressed by the brake and the vehicle remains substantially stopped. Thereafter, when the brake pedal 13 is loosened and the accelerator pedal 23 is depressed, the tire is driven. Therefore, when the clutch of the automatic transmission 3 is engaged, the engine torque is suddenly transmitted to the tire as a driving force, and the occurrence of a shock at the start is prevented, and a smooth reverse is possible.
[0051]
Further, since the fluid coupling (fluid clutch) is used, the output torque of the engine 1 is transmitted to the automatic transmission 3 to some extent. For this reason, the creep phenomenon occurs as in the case of a vehicle equipped with a normal hydraulic automatic transmission, and it is possible to smoothly run at a very low speed during reverse operation, for example, to enter a garage. Further, according to the determination in step S23, even when the automobile is temporarily stopped during reverse, the engine 1 is not stopped, and the creep phenomenon can be maintained even in the case of entering the garage.
[0052]
As indicated by a broken line in FIG. 4, when the reverse range continues for a certain period of time (for example, 0.5 seconds) between the ON determination at step S31 and step S32, the engine 1 is started at step S32, When not continuing, you may insert the determination step of returning to step S31 (step S40). By doing so, it is possible to prevent the engine 1 from starting when the shift lever 8 passes through the reverse range and enters the parking range or the like.
[0053]
As the starting condition of the engine 1 in step S30, for example, “off of the brake switch 14” may be employed. Further, both “the idle switch 6 is turned off” and “the brake switch 14 is turned off” may be used as the starting conditions.
[0054]
In the above example, the condition that the shift lever 8 is placed in the reverse range is “depressing the brake pedal 13”. However, if the vehicle can start backward simultaneously with the selection of the reverse range, the lock mechanism The structure is arbitrary. For example, a button may be disposed at the upper end of the shift lever 8 and the shift lever 8 may be operated while the button is pressed. In this case, for example, the control ECU 4 performs control so that the drive wheels are automatically braked in response to the operation of the operation button. Further, “the rotational speed of the engine 1 may be a certain value or less” may be added as a condition for entering the reverse range.
[Brief description of the drawings]
FIG. 1 is a block diagram of an automatic stop / start device according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of a control ECU shown in FIG.
FIG. 3 is a main routine flowchart showing a control operation of the automatic stop / start device of FIG. 1;
4 is a flowchart showing automatic stop / start control in the main routine of FIG. 3;
[Explanation of symbols]
1 Engine 2 Starter 3 Automatic transmission 4 Control ECU
5 throttle valve 5a throttle position sensor 6 idle switch 7 fuel injector 8 shift lever 9 shift range switch group 11 vehicle speed sensor 12 starter relay 13 brake pedal 14 brake switch 15 igniter 19 engine stop monitor 20 idle stop permission switch 21 temperature sensor 22 rotation speed Sensor 23 Accelerator pedal 41 MPU (microprocessor unit)
42 Memory 43 I / O interface

Claims (10)

In an automatic stop starting device that automatically stops or starts an engine according to a predetermined condition,
A shift lever for changing a gear position of an automatic transmission , which is connected to an engine and includes a plurality of gears and a clutch driven by hydraulic pressure generated by a hydraulic pump ;
Shift lever position detecting means for detecting the position of the shift lever;
In response to detection that the shift lever is located in a reverse range by the shift lever position detection means in the engine stopped state, start means for starting the engine;
An engine automatic stop and start device comprising: The starting means measures from the output of the shift lever position detecting means a timer for measuring a duration time during which the shift lever is set to a reverse range;
2. The engine according to claim 1, further comprising means for starting the engine when the timer measures that the shift lever is set in the reverse range for a predetermined time. Automatic stop start device.   The engine automatic according to claim 1 or 2, further comprising means for prohibiting automatic stop of the engine while the shift lever is in a reverse range according to detection by the shift lever position detecting means. Stop starter.   3. A brake for restricting movement of a vehicle on which the engine is mounted, and means for enabling switching of the shift lever to a reverse range only when the brake is applied. Or the engine automatic stop start device of 3 or 3. Detection means for continuously detecting at least one of the rotational speed of the engine after startup or the speed of the vehicle on which the engine is mounted;
5. The apparatus according to claim 1, further comprising a unit that prohibits the automatic stop / start device from stopping the engine when a detection value of the detection unit is only a reference value or less. The engine automatic stop and starter described. A stopping step of stopping the engine according to a predetermined stopping condition;
A range determination step for determining whether or not a shift stage of an automatic transmission including a plurality of gears coupled to the engine and a clutch driven by hydraulic pressure generated by a hydraulic pump is set to reverse;
And a starting step of starting the engine when it is determined by the range determining step that the gear position is set to reverse. The starting step includes a measuring step of measuring a duration time during which the shift stage is set to reverse,
The engine according to claim 6, further comprising a step of starting the engine when it is determined by the measurement step that the state in which the gear position is set to reverse has continued for a predetermined time. Automatic stop start method.   The engine automatic stop start according to claim 6 or 7, further comprising a step of prohibiting the automatic stop of the engine while the shift speed is set to reverse according to the detection of the range determination step. Method. A movement restriction step for restricting movement of a vehicle equipped with the engine;
The step of enabling switching to the reverse of the shift stage only when the movement of the vehicle is restricted by the movement restriction step. How to start and stop the engine automatically. A detection step of continuously detecting at least one of a rotational speed of the engine after starting or a speed of a vehicle on which the engine is mounted;
10. The method according to claim 6, further comprising a step of prohibiting the stop of the engine by the stop step when a detection value of the detection step is equal to or less than a reference value. How to start and stop the engine automatically.

Images