JP7183572B2 - engine starting controller - Google Patents

Description

The present invention relates to an engine start control device.

In a vehicle equipped with a manual transmission as a transmission, if the switch that detects the neutral state is faulty or short-circuited, the engine will start operating even though the running gear is actually in the gear-in state. may be allowed to start. If such an engine start is permitted, the vehicle may start moving.

Japanese Patent Laid-Open No. 2004-200000 discloses a technique of stopping engine start-up when rotation of a wheel is detected after engine start-up. According to the technology described in Patent Document 1, it is possible to prevent the vehicle that has started to move due to the above reasons from moving further.

International Publication No. 2011/085145 pamphlet

However, in the device described in Patent Document 1, the engine is stopped at the timing when the rotation of the wheels is detected after the engine is started. be.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an engine start control device capable of preventing the vehicle from moving when the engine is started.

In order to achieve the above objects, the present invention provides an engine, a manual transmission, a clutch capable of switching between a transmission state for transmitting power between the engine and the manual transmission and a cutoff state for cutting off the power, An engine start control device mounted on a vehicle, comprising: an engine starting device for rotating a crankshaft of the engine to start the engine; and an engine speed detection unit for detecting the engine speed, A control unit capable of executing start control for rotating the crankshaft of the engine by the engine starter without fuel injection, wherein the control unit automatically starts the engine when a predetermined stop condition is satisfied. It is possible to execute automatic stop control for stopping, and when the start control is executed while the engine is automatically stopped by the automatic stop control, the engine speed after a predetermined time has elapsed from the start of the start control is a predetermined speed. If less than the above, it is determined whether or not to stop the starting control before the fuel injection to the engine is performed, and the starting control is stopped before the engine output that increases due to the fuel injection is transmitted to the drive wheels. It has a configuration that

According to the present invention, it is possible to provide an engine start control device capable of preventing the vehicle from moving when the engine is started.

FIG. 1 is a schematic block diagram of a vehicle equipped with an engine start control device according to an embodiment of the present invention. FIG. 2 is a flow chart showing the flow of the start stop control process executed by the engine start control device according to the embodiment of the present invention. FIG. 3 is a timing chart showing an example of an engine start request in a vehicle equipped with an engine start control device according to an embodiment of the present invention.

An engine start control device according to an embodiment of the present invention includes an engine, a manual transmission, and a clutch capable of switching between a transmission state in which power is transmitted between the engine and the manual transmission and a cutoff state in which power is cut off. , an engine starting device for starting the engine, and an engine speed detection section for detecting the engine speed, the engine starting control device mounted on a vehicle without fuel injection. The control unit is capable of executing start control for starting the engine by, and the control unit cancels the start control when the engine speed after a predetermined time has elapsed from the start of the start control is less than a predetermined speed. Characterized by As a result, the engine start control device according to the embodiment of the present invention can prevent the vehicle from moving when the engine is started.

An engine start control apparatus according to an embodiment of the present invention will be described below.

As shown in FIG. 1, a vehicle 1 equipped with an engine start control device according to this embodiment includes an engine 2, an engine start device 3, a manual transmission 4, a clutch 5, drive wheels 6, and a control device. 10.

The engine 2 is a four-cycle gasoline engine that has a plurality of cylinders and performs a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke to generate driving force for the vehicle 1 .

The engine 2 is provided with a fuel injection device 2a and an ignition device (not shown). The fuel injection device 2a is configured by a port injection type or in-cylinder injection type fuel injection device. The engine 2 may be composed of a diesel engine.

The engine starting device 3 has a starter motor, a gear and a clutch mechanism, etc., and is configured so that the starter motor can be connected to the crankshaft of the engine 2 via the gear and clutch mechanism.

The engine starting device 3 drives the starter motor based on a start signal transmitted from the control device 10 to rotate the crankshaft of the engine 2 via a gear and clutch mechanism, thereby starting the engine 2 without fuel injection. It is supposed to start.

The start signal is sent from the control device 10 to the engine on the condition that, for example, the ignition switch 7, which will be described later, is turned on, that a predetermined restart condition, which will be described later, is satisfied, or that a predetermined forced start condition, which will be described later, is satisfied. It is sent to the starting device 3 .

As the engine starting device 3, an ISG (Integrated Starter Generator) having an alternator function in addition to the starter function may be used.

A battery 31 is connected to the engine starting device 3 . The battery 31 is composed of a lead-acid battery, and supplies electric power to the engine starter 3 . The battery 31 is provided with a battery sensor 31a that detects a voltage between terminals of the battery 31 (hereinafter referred to as "Pb voltage"). The battery sensor 31a in this embodiment constitutes a voltage detector.

The manual transmission 4 is a transmission configured to establish an arbitrary gear stage among a plurality of gear stages according to the operation of the shift lever 42 by the driver. The manual transmission 4 has an input side connected to the engine 2 via a clutch 5 and an output side connected to drive wheels 6 .

When the clutch 5 is engaged, the manual transmission 4 shifts the rotation of the engine 2 input via the clutch 5 at a gear ratio corresponding to the established gear stage and transmits it to the driving wheels 6. It's like The gear stages include a plurality of forward gears for driving the vehicle 1 forward and a reverse gear for driving the vehicle 1 in reverse.

The manual transmission 4 is configured to be capable of forming a neutral state in which none of the gear stages are established, that is, a neutral state. In this neutral state, the rotation of the engine 2 input to the manual transmission 4 is not transmitted to the driving wheels 6.

Thus, the manual transmission 4 is configured to be switchable between a power transmission state in which the power of the engine 2 is transmitted to the drive wheels 6 and a power non-transmission state in which power is not transmitted between the engine 2 and the drive wheels 6. It is

The manual transmission 4 is provided with a neutral position switch 41 . The neutral position switch 41 is turned on when the shift lever 42 is in the neutral position, and detects the neutral state of the manual transmission 4 . The neutral position switch 41 is turned off when the operating position of the shift lever 42 is other than the neutral position.

The neutral position switch 41 detects whether the manual transmission 4 is in a power transmitting state or a power non-transmitting state by detecting the neutral state of the manual transmission 4 .

The clutch 5 is provided in a power transmission path between the engine 2 and the manual transmission 4, and has a power transmission state (also referred to as a clutch engaged state) in which power is transmitted between the engine 2 and the manual transmission 4, and a state in which power is transmitted between the engine 2 and the manual transmission 4. It switches between a cutoff state (also referred to as a clutch released state) in which power is cut off from the transmission 4 .

The control device 10 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory for storing backup data, an input port, and an output port. computer unit. The ROM of the computer unit stores various constants, various maps, etc., as well as programs for realizing the functions of the computer unit.

The control device 10 is connected to the ignition switch 7, the accelerator opening sensor 8, the clutch switch 9, the engine speed sensor 21, the neutral position switch 41, the vehicle speed sensor 61, the battery sensor 31a, the engine starting device 3, and the engine 2. ing.

The accelerator opening sensor 8 detects the amount of depression of the accelerator pedal 81 by the driver. A clutch switch 9 detects whether or not a clutch pedal 91 has been depressed by the driver.

An engine speed sensor 21 detects an engine speed Ne, which is the speed of the engine 2 . The engine speed sensor 21 is composed of, for example, a crank angle sensor. The engine speed sensor 21 in this embodiment constitutes an engine speed detection unit. A vehicle speed sensor 61 detects the speed of the vehicle 1, that is, the vehicle speed.

The control device 10 functions as an automatic stop control unit 11 capable of executing automatic stop control for automatically stopping the engine 2 when a predetermined stop condition is satisfied.

The predetermined stop conditions include, for example, at least that the shift lever 42 is in the neutral position, that is, the manual transmission 4 is in the neutral state, and that the clutch pedal 91 is not depressed.

However, if the neutral position switch 41 is faulty or short-circuited, the engine 2 is not automatically stopped even if the predetermined stop condition is met.

The control device 10 determines whether or not the neutral position switch 41 has failed or short-circuited. The control device 10 determines that the neutral position switch 41 is faulty or short-circuited when the neutral position switch 41 detects a neutral state for a predetermined time or longer while the vehicle 1 is running at a speed equal to or higher than a predetermined vehicle speed. . If it is determined that the neutral position switch 41 is faulty or short-circuited while the engine 2 is automatically stopped, the automatic stop of the engine 2 is canceled and the engine 2 is forcibly restarted.

The control device 10 causes the engine starting device 3 to start the engine 2 without injecting fuel while the engine 2 is automatically stopped by automatic stop control. Specifically, the starter motor applies torque to the crankshaft of the engine 2. It is configured to be able to execute the start control to be given. The control device 10 in this embodiment constitutes a control section.

This start control includes a restart control for restarting the engine 2 when a predetermined restart condition is satisfied while the engine 2 is automatically stopped, and a restart control for restarting the engine 2 when a predetermined forced start condition is satisfied while the engine 2 is automatically stopped. includes a forced start control for forcibly restarting the engine 2 (hereinafter referred to as "forced start").

Thus, the control device 10 has functions as a restart control unit 12 capable of executing restart control and a forced start control unit 13 capable of executing forced start control.

Predetermined restart conditions include, for example, at least that the manual transmission 4 is in a neutral state and that the clutch pedal 91 is depressed.

The predetermined forced start condition shall be satisfied, for example, when one of the following engine start requests is made. The engine start request includes, for example, an engine start request associated with driving auxiliary equipment such as an air conditioner, and an engine start request associated with determination that a failure or short circuit has occurred in the neutral position switch 41 during automatic stop of the engine 2. A start request or an engine start request made to cancel the automatic stop of the engine 2 due to the detection of an abnormality in the vehicle 1 can be cited.

The control device 10 functions as a start stop control unit 14 that stops the forced start control when the engine speed Ne after a predetermined time Tth has elapsed from the start of the forced start control described above is less than the predetermined speed Neth. have. As a result, when the vehicle 1 is in the gear-in state and the clutch is engaged when the forced start control is started, the forced start control is stopped before the vehicle 1 starts moving, specifically, before the fuel injection to the engine 2 is performed.

The reason for determining whether or not to stop the forced start control based on the tendency of the engine speed Ne after the start of the forced start control as described above is as follows.

When the manual transmission 4 is in the neutral state, the power of the engine 2 is not transmitted to the drive wheels 6, so the load on the engine 2 is small. Therefore, when the engine 2 is forcibly started in the neutral state, the engine speed Ne increases relatively quickly.

On the other hand, when the manual transmission 4 is not in the neutral state, i.e., in the gear-in state and the clutch-engaged state, the power of the engine 2 can be transmitted to the drive wheels 6, so the load on the engine 2 is less than in the neutral state. growing. Therefore, when the engine 2 is forcibly started in the gear-in state, it takes a longer time for the engine speed Ne to rise than in the neutral state, that is, the rate of increase becomes gradual.

In this embodiment, whether or not to stop the forced start control is determined based on the increasing tendency of the engine speed Ne at the time of forced start, which differs depending on whether the engine is in the neutral state or in the gear-in state.

For example, a failure or a short circuit occurs in the neutral position switch 41, but the controller 10 detects the occurrence of the failure or the short circuit. There are cases where it is not. In this case, the neutral position switch 41 is turned on due to a failure or a short circuit even though the shift lever 42 is in a position other than the neutral position. .

The reason why the control device 10 cannot detect the occurrence of the failure or short circuit as described above is that the following determination method is used to determine whether or not the neutral position switch 41 has a failure or short circuit. be. That is, when the neutral position switch 41 detects the neutral state for a certain period of time or more while the vehicle 1 is running at a predetermined vehicle speed or higher, it is determined that the neutral position switch 41 is faulty or short-circuited.

Another factor that causes the gear-in state and the clutch-engaged state at the start of the forced start control is, for example, when it is detected that the neutral position switch 41 has failed or short-circuited while the engine 2 is automatically stopped. mentioned. In this case, the automatic stop of the engine 2 is canceled and the engine 2 is forcibly started.

The control device 10 is configured to be able to change the predetermined time Tth and the predetermined rotation speed Neth based on the Pb voltage detected by the battery sensor 31a when the engine 2 is forcibly started by the forced start control. Therefore, the predetermined time Tth and the predetermined rotation speed Neth are set to different values depending on the Pb voltage at the forced start.

Specifically, the control device 10 calculates the predetermined time Tth and the predetermined rotation speed Neth according to the Pb voltage at the time of forced start by referring to the stop determination threshold map based on the Pb voltage at the time of forced start.

The stop determination threshold map is obtained by experimentally obtaining in advance the relationship between the Pb voltage at the time of forced start, the predetermined time Tth, and the predetermined rotation speed Neth, and is stored in the ROM of the control device 10 . The stop determination threshold map is defined such that the lower the Pb voltage at the forced start, the longer the predetermined time Tth and the lower the predetermined rotation speed Neth.

Thereby, the predetermined time Tth and the predetermined rotation speed Neth are set according to the state of deterioration of the battery 31 . That is, as the deterioration of the battery 31 progresses, the amount of Pb voltage drop due to the internal resistance of the battery 31 at the start of the engine 2 increases. This is because the internal resistance of the battery 31 increases as the deterioration of the battery 31 progresses.

At the start of the engine 2, the larger the amount of Pb voltage drop, that is, the more the deterioration of the battery 31 progresses, the more difficult it is for the engine speed Ne to increase. takes a long time.

Therefore, in the present embodiment, when the Pb voltage drop amount at the forced start is large, the control device 10 makes the predetermined time Tth longer and the predetermined rotation speed Neth smaller than when the Pb voltage drop amount is small. It's becoming

As a result, it is possible to change the criteria for whether or not to stop the forced start control according to the degree of deterioration of the battery 31, thereby preventing erroneous stop of the forced start control. In the stop determination threshold map, the Pb voltage drop amount may be used instead of the Pb voltage at the time of forced start.

Next, with reference to FIG. 2, the flow of processing for start suspension control executed by the control device 10 according to the present embodiment will be described. This start stop control is repeatedly executed at predetermined time intervals while the engine 2 is automatically stopped.

As shown in FIG. 2, the control device 10 determines whether or not there is an engine start request for forced start (step S1). That is, the control device 10 determines whether or not a predetermined forced start condition is satisfied.

When the controller 10 determines that there is no engine start request for forced start, that is, the predetermined forced start condition is not satisfied, the control device 10 ends the start stop control.

When the control device 10 determines that there is an engine start request for forced start, that is, a predetermined forced start condition is satisfied, the control device 10 starts counting the start time Ts (step S2). The start time Ts is the elapsed time from the start of the forced start control.

Next, the control device 10 transmits a start signal to the engine starting device 3 to drive the engine starting device 3 (step S3). Accordingly, the engine starting device 3 applies rotational force to the crankshaft by driving the starter motor. As a result, the engine 2 is forcibly started without fuel injection.

After that, the control device 10 acquires the Pb voltage of the battery 31 when the engine 2 is forcibly started in step S3, that is, when the engine 2 is forcibly started (step S4). Note that the counting of the starting time may be started at the timing when the Pb voltage is obtained, that is, at the timing when the process of step S4 is completed.

Next, based on the Pb voltage acquired in step S4, the control device 10 calculates and sets a predetermined time Tth and a predetermined rotation speed Neth corresponding to the Pb voltage at the time of forced start by referring to the stop determination threshold map ( step S5).

Next, the control device 10 determines whether or not the engine speed Ne detected by the engine speed sensor 21 is lower than the predetermined speed Neth set in step S5 (step S6).

When the control device 10 determines that the engine rotation speed Ne is not below the predetermined rotation speed Neth, it ends the start suspension control.

When the control device 10 determines that the engine speed Ne is lower than the predetermined speed Neth, it determines whether the starting time Ts, which started counting in step S2, exceeds the predetermined time Tth set in step S5. is determined (step S7).

When the control device 10 determines that the starting time Ts has not exceeded the predetermined time Tth, it ends the starting suspension control.

When the control device 10 determines that the starting time Ts exceeds the predetermined time Tth, the control device 10 requests the engine starting device 3 to start and stop the engine (step S8). The engine start/stop request is made by, for example, sending a start/stop signal to the engine starting device 3 from the control device 10 . As a result, the control device 10 stops the forced start control started in step S3.

When an engine start/stop request is made in step S8, the engine starter 3 stops driving the starter motor.

Next, an example of a timing chart when an engine start request for forced start is made will be described with reference to FIG.

In FIG. 3, the solid line indicating "no deterioration" indicates the Pb voltage of the battery 31 that has not deteriorated, and the broken line indicating "deteriorated" indicates the Pb voltage of the battery 31 that has deteriorated.

In FIG. 3, the solid line indicating "Normal start (no deterioration)" indicates the change in the engine speed at the time of forced start in the gear-in state and the clutch not engaged state when the battery 31 is not degraded. is shown. In FIG. 3, the dashed line indicating "Normal start (with deterioration)" indicates the change in the engine speed at the forced start in the gear-in state and the clutch not engaged state when the battery 31 is degraded. is shown. Further, in FIG. 3, the dashed-dotted line indicating "stopped starting (no deterioration)" indicates transition of the engine speed during forced starting in the gear-in state and clutch-engaged state.

(if the battery is not degraded)
As shown in FIG. 3, when an engine start request for forced starting is made at time T0, the Pb voltage of the battery 31 drops significantly because a large current is required to drive the starter motor. Also, the count of the starting time Ts is started from the time T0.

Next, at time T1, the Pb voltage drop amount becomes maximum. The Pb voltage drop amount at this time is grasped by the control device 10 based on the detection result from the battery sensor 31a, and is used to set the predetermined time Tth and the predetermined rotation speed Neth. In the example of FIG. 3, the predetermined time Tth1 and the predetermined rotation speed Neth1 are set.

After that, if the engine rotation speed Ne exceeds the predetermined rotation speed Neth1 before the start time Ts passes the predetermined time Tth1, the starter motor continues to be driven without stopping the start stop control. As a result, the engine speed Ne increases as indicated by the solid line in FIG. 3, and the engine 2 is forcibly started.

On the other hand, in the case of the gear-in and clutch-engaged state from the start of the forced start control, the , the degree of increase in the engine speed Ne from time T1 is moderate, as indicated by the one-dot chain line.

Therefore, in the case of the gear-in state and the clutch-engaged state (indicated by the solid line in FIG. 3, the start is stopped), the engine speed Ne still exceeds the predetermined speed Neth1 when the starting time Ts reaches the predetermined time Tth1. do not have.

Therefore, in such a case, the control device 10 determines that the forced start control is performed in the gear-in state and the clutch-engaged state, requests engine start/stop at a predetermined time Tth1, and stops the forced start control. As a result, the drive of the starter motor is stopped, so that the engine speed Ne decreases to 0 as indicated by the one-dot chain line in FIG.

(if the battery is degraded)
When the battery 31 has deteriorated, the amount of Pb voltage drop after the engine start request is made is larger than when the battery 31 has not deteriorated.

Here, when the battery 31 is degraded and the gear is not engaged and the clutch is not engaged (normal start indicated by the dashed line in FIG. 3), the degree of increase in the engine speed Ne is moderate.

In the present embodiment, the predetermined time period Tth and the predetermined engine speed Neth are set in consideration of such an increase characteristic of the engine speed when the battery deteriorates. In the example of FIG. 3, the predetermined time Tth2 and the predetermined rotation speed Neth2 are set.

In the example of FIG. 3, the engine rotation speed Ne exceeds the predetermined rotation speed Neth2 before the start time Ts passes the predetermined time Tth2, so the starter motor continues to be driven without stopping the start stop control. be. As a result, the engine speed Ne increases as indicated by the dashed line in FIG. 3, and the engine 2 is forcibly started.

As described above, the engine start control device according to the present embodiment stops the forced start control when the engine speed Ne after the predetermined time Tth has elapsed from the start of the forced start control is less than the predetermined speed Neth. It is designed to

Therefore, the engine start control apparatus according to the present embodiment can determine whether to stop the forced start control based on the increasing tendency of the engine speed Ne after the start of the forced start control. Since the upward tendency of the engine speed Ne differs depending on whether the forced start is in the gear-in state and the clutch-engaged state, it is easy to determine whether the engine speed Ne is in the gear-in state and the clutch-engaged state from the upward trend of the engine speed Ne. It is because it can judge.

As described above, the engine start control device according to the present embodiment can determine whether or not to stop the forced start control before fuel injection to the engine 2 is performed. 6, forced start control can be discontinued.

As a result, the engine start control device according to the present embodiment can prevent the vehicle 1 from moving even in the gear-in state and the clutch-engaged state.

Further, the engine start control device according to the present embodiment can increase the chances of detecting failure or short circuit of the neutral position switch 41 . That is, by canceling the forced start control as described above, it is possible to indirectly notify the occupant that the vehicle 1 has some trouble including a failure or a short circuit of the neutral position switch 41 .

For this reason, the engine start control device according to the present embodiment is designed so that when the neutral position switch 41 detects a neutral state for a certain period of time or more while the vehicle 1 is running at a predetermined vehicle speed or higher, the neutral position switch 41 fails or fails. In addition to determining that a short circuit has occurred, it can also be determined that there is a possibility that a failure or short circuit has occurred in the neutral position switch 41 by stopping the above-described forced start control.

In addition, the engine start control device according to the present embodiment can change the predetermined time Tth and the predetermined rotation speed Neth, which serve as criteria for whether or not to stop the forced start control, depending on the degree of deterioration of the battery 31. , it is possible to prevent erroneous termination of the forced start control.

In the engine start control device according to the present embodiment, the start control that is stopped by the start stop control (see FIG. 2) is forced start control that is performed while the engine 2 is automatically stopped. It is not the start control at the time of the first start.

Therefore, the engine start control device according to the present embodiment can prevent erroneous stoppage of the start of the engine 2 when the ignition switch 7 is turned on for the first time.

Although embodiments of the present invention have been disclosed, it will be apparent that modifications may be made by those skilled in the art without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

REFERENCE SIGNS LIST 1 vehicle 2 engine 3 engine starting device 4 manual transmission 5 clutch 6 drive wheel 10 control device (control unit)
REFERENCE SIGNS LIST 11 automatic stop control unit 12 restart control unit 13 forced start control unit 14 start stop control unit 21 engine speed sensor (engine speed detection unit)
31 battery 31a battery sensor (voltage detector)
41 Neutral position switch 42 Shift lever 61 Vehicle speed sensor Ts Starting time Tth Predetermined time Neth Predetermined rotation speed

Claims (3)

an engine, a manual transmission, a clutch capable of switching between a transmission state for transmitting power between the engine and the manual transmission and a disconnection state for blocking the power, and a crank of the engine for starting the engine. An engine start control device mounted on a vehicle, comprising: an engine starter for rotating a shaft; and an engine speed detection unit for detecting the engine speed,
A control unit capable of executing start control for rotating the crankshaft of the engine by the engine starter without fuel injection,
The control unit
It is possible to execute automatic stop control for automatically stopping the engine when a predetermined stop condition is satisfied,
When executing the start control during automatic stop of the engine by the automatic stop control, when the engine speed after a predetermined time has elapsed from the start of the start control is less than a predetermined speed, fuel injection to the engine An engine start control device characterized by determining whether or not to stop the start control before is performed, and stopping the start control before the engine output increased by fuel injection is transmitted to the drive wheels . a battery that powers the engine starter;
A voltage detection unit that detects the voltage of the battery,
The control unit changes at least one of the predetermined time period and the predetermined rotation speed based on the voltage of the battery detected by the voltage detection unit when the engine is started by the engine starting device. 2. The engine start control device according to claim 1. When the amount of voltage drop in the battery when the engine is started by the engine starting device is large, the control unit lengthens the predetermined time and reduces the predetermined number of rotations compared to when the amount of voltage drop is small. 3. The engine start control device according to claim 2, wherein:

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