JP3777910B2 - Internal combustion engine controller with automatic stop function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an erroneous fuel injection which occurs in response to an erroneous input of an engine speed signal at stopping of an engine. SOLUTION: An engine ECU 10 automatically stops the engine 1 when a stop request signal ST is inputted from an economical running ECU 12 during operation. A fuel injection control of the engine ECU 10 is set such that, upon reception of an input of a rotation signal from a rotation sensor 5 of the engine 1, the fuel injection is carried out in response to the input signal. However, after automatic stop of the engine 1, the fuel injection is inhibited as long as a starter motor 2 is not driven even when the rotation signal is input. When the rotation signal is erroneously input because of external noise or the like during automatic stop of the engine 1, the fuel injection in response to the erroneous input is prevented thereby improving startability and fuel consumption. Constitution similar to that of this device can be adopted in a hybrid system and an ordinary internal combustion engine.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an internal combustion engine control apparatus, and more particularly to an apparatus that can prevent erroneous fuel injection while the engine is stopped. The present invention is suitably applied to an internal combustion engine control device with an automatic stop function such as an eco-run. Therefore, in the present specification, the present invention will be described mainly in relation to an internal combustion engine control device with an automatic stop function. However, the present invention is not limited to an internal combustion engine control device with an automatic stop function, and can be similarly applied to other internal combustion engine control devices.
[0002]
[Prior art]
The automatic engine stop device is a device that functions during operation of the vehicle, and stops the engine when a predetermined stop condition is satisfied, and then starts the engine when a predetermined start condition is satisfied.
[0003]
One form of an internal combustion engine control device having an automatic stop function is a so-called eco-run system. When the vehicle is stopped due to traffic lights or traffic jams, the engine is idling. If the engine is stopped instead of the idling operation, fuel efficiency is improved, exhaust gas emission is reduced, and noise can be reduced. Therefore, in the eco-run system, the engine is temporarily stopped when the vehicle stops, and the engine is restarted when the vehicle starts to travel next time. This type of system is disclosed in, for example, Japanese Patent Laid-Open No. 8-74613.
[0004]
Another form of the internal combustion engine control device having an automatic stop function is a hybrid system. As is well known, a hybrid system drives a vehicle using an engine and a motor. If a predetermined engine stop condition is satisfied, the engine is stopped and the vehicle travels using only the motor output. Thereafter, if the engine start condition is satisfied, the engine is started and the engine output is used for driving the vehicle and charging the battery.
[0005]
[Problems to be solved by the invention]
By the way, paying attention to the fuel injection control, a system with an automatic stop function such as an eco-run system and a hybrid system can use a conventional typical fuel injection control function. In this typical fuel injection control, when an engine speed signal is input, the engine is instructed to inject fuel in response to the input signal.
[0006]
With respect to this rotational speed signal, the rotational speed signal may be erroneously input during the engine stop period even though the engine should not be rotating. Incorrect input occurs due to external noise or body vibration. In the conventional system, there is a possibility that fuel is erroneously injected in response to an erroneously input rotation speed signal. The erroneous fuel injection may lead to a decrease in startability due to the fogging of the plug and a decrease in fuel efficiency.
[0007]
For example, in one configuration example of the eco-run system, an upper eco-run ECU that controls the engine ECU is provided in addition to a normal engine ECU. For fuel injection control of the engine ECU, control of a normal system without an eco-run ECU can be used. In this case, the engine ECU in which the engine is automatically stopped is in an activated state with the ignition turned on as in the case of the engine rotation. The engine ECU sees a signal from an engine rotation sensor under its control and injects fuel in a reflective manner when the engine rotates. Accordingly, fuel is injected even when there is an erroneous input of the rotation speed signal.
[0008]
For example, when a large vehicle passes through the oncoming lane while stopping on an elevated road or bridge, the vehicle body shakes greatly. A rotation speed signal is instantaneously input by this vibration. In response to this rotational speed signal, fuel is injected for an instant. Each time the vehicle passes, fuel injection is repeated little by little, and fuel is wasted.
[0009]
Here, the conventional problem has been described by taking up an internal combustion engine control device with an automatic stop function. In an internal combustion engine control device with an automatic stop function, the frequency of engine stop is high and the purpose is originally to improve fuel consumption. However, the same problem can occur in a normal internal combustion engine that does not have an automatic stop function. In the state before the starter is turned on after the ignition switch is turned on and the engine is stalled due to some disturbance, etc., fuel is accidentally injected in response to an erroneous input of the engine speed. There is a possibility.
[0010]
The present invention has been made in view of the above problems, and an object of the present invention is to provide an apparatus capable of preventing erroneous fuel injection while the engine is stopped.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, an internal combustion engine control device of the present invention is a device that injects fuel into an internal combustion engine in response to an input of a rotation signal of the internal combustion engine during operation of the internal combustion engine, In the internal combustion engine control device with an automatic stop function in which the operation of the internal combustion engine is controlled by the engine ECU and the host ECU sends an engine stop signal to the engine ECU when the predetermined stop condition is satisfied, and stops the engine. Detects a rotation signal indicating the rotation of the internal combustion engine To supply to the engine ECU In response to the rotation sensor and the input of the rotation signal According to the instructions of the engine ECU Fuel injection control means for causing the internal combustion engine to perform fuel injection, and By engine ECU Internal combustion engine of While driving By the automatic stop function of the host ECU Internal combustion engine Rotation Even when the rotation signal is input in a state where the engine is stopped, an injection prohibiting means for prohibiting fuel injection is included when it is determined that an erroneous input has been performed.
[0012]
According to the present invention, fuel injection is prohibited when an erroneous rotation signal is input while the engine is stopped. Therefore, even if the rotation signal is erroneously input, erroneous fuel injection in response to the erroneous input can be prevented.
[0013]
The “state in which the internal combustion engine is stopped during the operation of the internal combustion engine” may include a state in which the engine has stalled, and may further include a state after the ignition is turned on and before the starter is driven. From the viewpoint of the control of the present invention, the latter state is also one of the engine stop during operation with the ignition turned on.
[0014]
Main departure Tomorrow An internal combustion engine control device having an automatic stop function for automatically stopping the internal combustion engine when a predetermined stop condition is satisfied during operation of the internal combustion engine, a rotation sensor for detecting a rotation signal indicating the rotation of the internal combustion engine; A fuel injection control means for injecting fuel into the internal combustion engine in response to the input of the rotation signal, and an erroneous input even when the rotation signal is input in a state where the internal combustion engine is automatically stopped during operation of the internal combustion engine. And an injection prohibiting means for prohibiting fuel injection when it is determined that the fuel injection has been performed.
[0015]
In this aspect, the present invention is applied to an internal combustion engine control device with an automatic stop function. The internal combustion engine control system includes an eco-run system and a hybrid system.
[0016]
According to the present invention, fuel injection is prohibited when an erroneous rotation signal is input after the engine has been automatically stopped. Therefore, even if the rotation signal is erroneously input, erroneous fuel injection in response to the erroneous input can be prevented.
[0017]
Preferably, the injection prohibiting means prohibits fuel injection even when the rotation signal is input while the internal combustion engine is stopped during operation of the internal combustion engine, as long as the electric motor is not driven to start the internal combustion engine. To do. An electric motor used for starting the engine is, for example, a starter motor. In the hybrid system, a motor generator for driving the vehicle is suitably used for starting the internal combustion engine.
[0018]
According to the present invention, it is possible to reliably determine whether or not the input of the rotation signal is an erroneous input based on the driving state of the electric motor, thereby preventing erroneous fuel injection. On the other hand, if the electric motor is driven for starting, the internal combustion engine can be started appropriately by performing necessary fuel injection.
[0019]
A preferred aspect of the present invention includes prohibition suppressing means for suppressing prohibition of fuel injection by the injection prohibiting means when a rotation signal of the internal combustion engine is continuously input for a predetermined time or more.
[0020]
This mode can appropriately cope with so-called pushing. When pushed, an engine rotation signal is input and the starting motor is not driven. Therefore, the fuel injection prohibition condition described above is established and cannot be pushed as it is. However, in the present invention, when the rotation signal is continuously input for a predetermined time or longer, prohibition of fuel injection is suppressed, and therefore, the rotation can be pushed.
[0021]
The “predetermined time” is set as follows. An erroneous rotation signal due to external noise or the like is generally input only for an extremely short time. In the case of pushing, a rotation signal is input for a longer period. Therefore, the “predetermined time” is set to a time longer than the input time of the erroneous rotation signal. Furthermore, it is set to be shorter than the rotation signal input time by pushing.
[0022]
The present invention may be other modes other than the internal combustion engine control device. For example, another aspect of the present invention is an internal combustion engine control method, an engine automatic stop / start device, and an automatic stop / start control method.
[0023]
One aspect of the internal combustion engine control method of the present invention is an internal combustion engine control method for automatically stopping an internal combustion engine when a predetermined stop condition is satisfied, and responding to an input of a rotation signal indicating the rotation of the internal combustion engine. The fuel injection control is performed to cause the internal combustion engine to perform fuel injection, and after the automatic stop of the internal combustion engine, the fuel is controlled as long as the electric motor is not driven to start the internal combustion engine even when the rotation signal is input. It is characterized by performing injection prohibition control for prohibiting injection.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments (hereinafter referred to as embodiments) of the invention will be described with reference to the drawings.
[0025]
Embodiment 1. FIG. (Eco-run system)
FIG. 1 is a block diagram showing the configuration of the internal combustion engine control apparatus of the present embodiment. In the present embodiment, the present invention is applied to an eco-run system as an embodiment of an internal combustion engine control device with an automatic stop function.
[0026]
In FIG. 1, an engine 1 is a conventional general internal combustion engine. The starter motor 2 is an electric motor for starting the engine 1 and is attached to a flywheel or the like of the engine 1. The ignition key device 3 is provided in a driver's seat and is a device that is operated by a driver using a key when starting driving.
[0027]
The engine 1 is provided with a rotation sensor 5 and a fuel injection device 7. The rotation sensor 5 outputs a rotation speed signal NE indicating the engine rotation speed (the rotation speed of the crankshaft) to the engine ECU 10. The rotation sensor 5 outputs a pulse signal having a frequency corresponding to, for example, the engine speed.
[0028]
The engine ECU 10 is an electronic control device that controls the engine 1 and controls the fuel injection device 7 based on the rotational speed signal NE. As is well known, detection signals are also input to the engine ECU 10 from other sensors such as a water temperature sensor, an exhaust temperature sensor, an intake air temperature sensor, an accelerator switch, a brake switch, and the engine ECU 10 ignites other than the fuel injection device 7. It also controls devices, throttle devices, etc. (not shown).
[0029]
The eco-run ECU 12 is an electronic control device that is positioned above the engine ECU 10, and has an automatic engine stop / start function that will be described later.
[0030]
In the above system, at the start of driving, the driver operates the ignition key device 3 to move the key position to “ON (ignition ON)” and further to “START”. The key operation is transmitted to the engine ECU 10 and the eco-run ECU 12, and the ECU is activated when the ignition is turned on. When the driver releases his hand, the key returns to the on position.
[0031]
When the key is in the start position, electric power is supplied to the starter motor 2, the starter motor 2 rotates the crankshaft of the engine 1, and the rotation sensor 5 outputs the rotation speed signal NE. The engine ECU 10 receiving the input of the rotational speed signal NE instructs the fuel injection device 7 to inject fuel, and further causes an ignition device (not shown) to perform ignition. As a result, the engine 1 is started.
[0032]
During operation, the engine ECU 10 calculates an appropriate fuel injection amount of the engine 1 based on the rotational speed signal NE and outputs a control signal corresponding to the injection amount to the injection device 7. The injection device 7 injects fuel according to an instruction from the engine ECU 10, thereby operating the engine 1.
[0033]
Further, during operation, the automatic stop / start function of the engine is realized as follows. The eco-run ECU 12 monitors whether or not a predetermined engine stop condition is satisfied based on the driving state of the vehicle.
[0034]
In a vehicle equipped with a manual transmission, examples of engine stop conditions are (1) the vehicle speed is 0, (2) the shift lever is in the neutral position, and (3) the clutch pedal is depressed ( The clutch is disengaged). In a vehicle equipped with an automatic transmission, an example of an engine stop condition is that (1) the vehicle speed is 0, (2) the shift lever is in the neutral position, and (3) the brake is depressed. .
[0035]
When the engine stop condition is satisfied, the eco-run ECU 12 changes the eco-run control mode from the engine rotation mode to the engine stop request mode, and further sends a stop request signal ST to the engine ECU 10. In response to the stop request signal ST, the engine ECU 10 stops the fuel injection and stops the engine 1. When the rotation speed signal NE is no longer input from the rotation sensor 5, the engine ECU 10 determines that the engine 1 has stopped.
[0036]
The engine stop (rotation speed 0) is transmitted from the engine ECU 10 to the eco-run ECU 12. In response to this, the eco-run ECU 12 sets the engine stop mode instead of the engine stop request mode.
[0037]
After setting the engine stop mode, the eco-run ECU 12 monitors whether or not a predetermined engine start condition is satisfied. In a vehicle with a manual transmission, the engine start condition is, for example, depression of a clutch pedal (connection of a clutch).
[0038]
When the engine start condition is satisfied, the engine ECU 10 sets the engine start mode as the eco-run control mode and controls the starter motor 2 to rotate the motor 2. The engine 1 is cranked by the motor 2, and the rotation sensor 5 sends a rotation speed signal NE to the engine ECU 10. The engine ECU 10 receives the rotational speed signal NE and instructs the fuel injection device 7 to inject fuel, whereby the engine 1 is started.
[0039]
In this engine restart, no direct instruction is issued from the eco-run ECU 12 to the engine ECU 10. The engine ECU 10 receives the rotational speed signal NE and causes the engine 1 to inject fuel.
[0040]
Based on the rotational speed signal NE, the engine ECU 10 determines that the engine start is completed when the engine rotational speed reaches a predetermined rotational speed (for example, about 500 rpm). Completion of the start (rotation speed increase) is transmitted from the engine ECU 10 to the eco-run ECU 12, and the eco-run ECU 12 sets the engine rotation mode as the eco-run control mode.
[0041]
With the engine automatic stop control as described above, the engine stops instead of continuing the idling state when waiting for a signal or on a congested road. Therefore, fuel efficiency is improved, exhaust gas emission is reduced, and noise can be reduced.
[0042]
However, as a problem of the prior art, as will be described below, when the engine speed signal NE is erroneously input during automatic engine stop, fuel is erroneously injected in response thereto. In the above system, the engine 1 is in an ignition-on state even when the engine 1 is stopped, and the engine ECU 10 is placed in the same starting state as the engine 1 is rotating. That is, the engine ECU 10 is ready to instruct fuel injection whenever the rotational speed signal NE is input. Therefore, even when the rotational speed signal NE is erroneously input due to external noise or vibration, the engine ECU 10 instructs the fuel injection device 7 to inject fuel, and as a result, erroneous fuel injection is performed. .
[0043]
For example, suppose a vehicle is stopped on a bridge due to traffic. When a large vehicle passes through the oncoming lane, the vehicle body shakes greatly, and a rotation speed signal NE is generated for a short period of time. Each time the vehicle passes through the oncoming lane, fuel is injected little by little. Such fuel injection may cause the fogging of the plug to deteriorate the startability of the engine, and may cause a decrease in fuel consumption.
[0044]
Such a problem occurs because the engine ECU 10 uniquely determines whether or not to perform fuel injection only by looking at the rotation speed signal NE obtained by itself. Therefore, in the present invention, erroneous injection of fuel is prevented by improving the injection-related processing and checking with reference to information from others.
[0045]
The function of preventing erroneous fuel injection according to the present invention will be described with reference to FIG. In S10, the engine ECU 10 inputs an eco-run control mode signal, a starter drive signal, and an engine speed signal.
[0046]
The eco-run control mode signal is sent from the eco-run ECU 12. The starter drive signal is a signal indicating that the starter motor 2 is being driven, and may be sent from the starter motor 2 or may be sent from the eco-run ECU 12 or the like. There may be a case where a starter drive signal is already input to the engine ECU 10 for the purpose of other control processing. In this case, the starter drive signal may be used as it is for the processing of the present invention shown in FIG. The engine speed signal is input from the rotation sensor 5 of the engine 1.
[0047]
In S12, it is determined whether or not the eco-run control mode signal is the eco-run stop mode. If S12 is NO, fuel injection is permitted in S16, and the process returns to S10.
[0048]
If YES in S12, it is determined in S14 whether the starter is being driven (whether cranking is being performed) based on the starter drive signal. For example, if the driver tries to start the engine while the engine is automatically stopped and turns the ignition key, the starter motor 2 is driven and S14 becomes YES.
[0049]
If S14 is YES, the process proceeds to S16 and fuel injection is permitted. Therefore, in response to the input of the rotational speed signal NE, the engine ECU 10 performs fuel injection, and as a result, the engine 1 is started.
[0050]
When S14 is NO, the starter motor 2 is not driven even if the rotation speed signal NE is input. Therefore, it is considered that an erroneous input of the rotation speed signal has occurred. Therefore, the process proceeds to S18, regardless of the input of the rotation speed signal, the fuel injection is prohibited (the fuel stop is continued) and the process returns.
[0051]
As described above, according to the present invention, even when a rotation speed signal is input in the engine automatic stop mode, when it is determined that the input is an erroneous input, specifically, unless the starter motor is driven. No fuel is injected (unless there is a start request). Therefore, it is possible to prevent fuel from being erroneously injected in response to an erroneous input of the rotation speed signal. On the other hand, if the starter motor is driven, it is necessary to start the engine. In this case, fuel injection is permitted and the engine can be started appropriately.
[0052]
Next, referring to FIG. 3, a further preferred aspect of the present invention will be described. In this aspect, the erroneous fuel injection prevention function of the present invention can further cope with the pushing. The system configuration corresponding to this aspect may be the same as in FIG.
[0053]
Pushing is a technique for starting the engine when the battery is up, as is well known. The vehicle is moved with the clutch disengaged, the clutch is engaged when an appropriate speed is achieved, and the engine is started by turning the kinetic energy of the vehicle body.
[0054]
When pushed, the ignition is on, the rotational speed signal NE is generated, and the starter motor is not driven. Therefore, if the control process of FIG. 2 is performed, the determination in S14 is NO, fuel injection is prohibited, and the engine does not start. This cannot be done.
[0055]
Therefore, in the present invention, S15 is inserted after S14 as shown in FIG. 3 is the same as the process of FIG. 2 except that S15 is provided.
[0056]
In S15, it is determined whether or not the input of the rotation speed signal NE has continued for a threshold time t or longer. The threshold time t is a constant for distinguishing the rotational speed input by pushing and the rotational speed input by external noise.
[0057]
Normally, the input of the rotation speed signal due to external noise is completed in a very short time. On the other hand, in the case of pushing, a rotation speed signal is input over a longer time. The threshold time t is set to be longer than the input time of the rotational speed signal due to noise and shorter than the input time of the rotational speed signal by pushing. Therefore, if the rotation speed signal is input for a time longer than the threshold time t, it can be determined that the pushing is performed.
[0058]
Therefore, if S15 is YES, the process proceeds to S16 and fuel injection is permitted. Fuel is injected by the engine 1 in accordance with an instruction from the engine ECU 10. As a result, the engine 1 can be started without driving the engine by the starter motor 2.
[0059]
On the other hand, when S15 is NO, since the input time of the rotation speed signal is short, it can be understood that the rotation speed signal is erroneously input instead of being pushed. Therefore, fuel injection is prohibited in S18 as in FIG.
[0060]
As described above, according to the present invention, when the engine speed signal is continuously input for the threshold time t or longer, the suppression means for suppressing the prohibition of fuel injection is provided. The engine can be started by injecting fuel.
[0061]
Instead of providing S15 in FIG. 3, an injection prohibition release step may be provided behind S18. That is, the injection prohibition release step is located after the fuel injection prohibition step. When the rotational speed signal is input for a threshold time or longer, the fuel injection prohibition setting once set is cancelled. Such an injection prohibition canceling means is also an aspect of the prohibition suppressing means of the present invention, and is included in the scope of the present invention. Further, the prohibition canceling means and the prohibition suppressing means can be collectively referred to as an injection permission means.
[0062]
Embodiment 2. FIG. (Hybrid system)
Next, another preferred embodiment of the present invention will be described. In the present embodiment, the present invention is applied to a hybrid system. As is well known, a hybrid system is a system that drives a vehicle using an engine and a motor. At first glance, the hybrid system and the eco-run system are very different systems. However, the two systems are common in that the engine is automatically stopped when a predetermined stop condition is satisfied, and the engine that satisfies the predetermined start condition is automatically started. Is an internal combustion engine control apparatus. The principle of the present invention is applied to the hybrid system in the same manner as the eco-run system.
[0063]
Referring to FIG. 4, the hybrid system has an engine 21 and a motor generator 22, which are connected. As is well known in vehicles in practical use, it is also preferable that the motor generator 22 is composed of two electric motors, and the motor generator 22 and the engine 21 are connected by a planetary gear. The ignition key device 23 is a key device provided in the driver's seat and operated by the driver, and the key position is transmitted to the engine ECU 30 and the hybrid ECU 32.
[0064]
The engine 21 is provided with a rotation sensor 25 and a fuel injection device 27. The rotation sensor 25 generates a pulse signal corresponding to the engine rotation speed as the rotation speed signal NE and sends the signal NE to the engine ECU 30. The engine ECU 30 is an electronic control device that controls the engine 21 and causes the fuel injection device 27 to perform fuel injection based on the rotational speed signal NE. As described in the above-described embodiment, the engine ECU 30 also uses input signals from other sensors for engine control. The engine ECU 30 also controls an ignition device and a throttle device in addition to the fuel injection device 27.
[0065]
The hybrid ECU 32 is a control device positioned above the engine ECU 30 and controls the entire hybrid system. The hybrid ECU 32 includes a motor generator ECU 34. However, motor generator ECU 34 may be provided outside hybrid ECU 32, and engine ECU 30 may be provided inside hybrid ECU 32.
[0066]
In the system of FIG. 4, when driving is started, the driver inserts a key into the ignition key device 23 and turns the key. The key is moved to the ignition-on position and further moved to the start position. When the driver releases the key, the key returns to the on position.
[0067]
A signal indicating that the key has been turned to the start position is sent from the ignition key device 23 to the engine ECU 30 and the hybrid ECU 32. The motor generator ECU 34 of the hybrid ECU 32 rotates the motor generator 22 to start the engine. That is, in this embodiment, the engine is started using the motor generator 22 instead of the conventional starter motor.
[0068]
When the motor generator 22 is driven, the engine 21 is cranked, and a rotation speed signal NE is output from the rotation sensor 25 in accordance with the crank rotation. The engine ECU 30 causes the fuel injection device 27 to inject fuel in response to the input of the rotational speed signal NE, thereby starting the engine 21.
[0069]
After the engine is started, the engine ECU 30 calculates an appropriate fuel injection amount based on the rotation speed signal NE and sends a control signal corresponding to the fuel injection amount to the injection device 27. The injection device 27 injects fuel under the control of the engine ECU 30, whereby the engine 21 is operated smoothly.
[0070]
The hybrid ECU 32 receives a signal indicating the operating state of the engine from the engine ECU 30, a signal indicating the charging state of the battery from a battery ECU (not shown), and further receives various signals of the system from other sensors and switches. A signal indicating the state is input.
[0071]
The hybrid ECU 32 controls the entire system based on these input signals. The hybrid ECU 32 determines appropriate operating states of the engine and the motor generator. It is determined whether the engine should be run or stopped. It is also determined whether the motor generator should generate power as a generator or discharge as a motor. At this time, an appropriate torque distribution between the engine and the motor generator is calculated, and a torque to be output from the engine (engine required torque) is calculated. The engine required torque is transmitted from the hybrid ECU 32 to the engine ECU 30, and the engine ECU 30 causes the engine 21 to output the engine required torque.
[0072]
The engine is automatically stopped and started as follows. For example, when a large output (vehicle driving force) is unnecessary and the charge amount of the battery is sufficiently large, the hybrid ECU 32 determines that the engine may be stopped. Therefore, the hybrid ECU 32 sets an engine stop request flag and sends a stop request signal ST to the engine ECU 30. At this time, the engine required torque is also zero. The engine ECU 30 stops the fuel injection in response to the stop request signal ST, whereby the engine 21 is stopped and the rotation speed signal NE is not generated.
[0073]
After the engine stops, the hybrid ECU 32 continues to monitor the system status. When the charge amount of the battery decreases, the hybrid ECU 32 determines that the motor generator 22 should generate power using the output of the engine 21 and charge the battery.
[0074]
At this time, the hybrid ECU 32 controls the motor generator 22 to cause the motor generator 22 to crank the engine 21. The crankshaft of the engine 21 rotates, and the rotational speed signal NE is detected by the rotational speed sensor 25. In response to this rotational speed signal NE, the engine ECU 30 causes the fuel injection device 27 to inject fuel, and as a result, the engine 21 starts.
[0075]
As described above, in the hybrid system, the engine and the motor generator are efficiently controlled to improve fuel consumption, and the engine is automatically stopped and automatically started in this control process.
[0076]
However, such a hybrid system has a problem similar to the eco-run system. The engine ECU 30 is in the same state as during rotation while the engine is stopped. That is, the ignition is on, and the engine ECU 30 is ready to inject fuel whenever the engine speed signal NE is input. Therefore, if the rotation speed signal is erroneously input due to external noise or other causes, the engine ECU 30 causes the fuel injection device 27 to inject fuel. For example, when the vehicle gets over the unevenness on the road, the rotational speed signal NE is generated due to the shaking of the vehicle body. When the unevenness continues, the fuel is injected little by little every time the unevenness is overcome. This fuel injection is incorrect, and may cause a decrease in engine startability due to plugging, and may cause a deterioration in fuel consumption.
[0077]
Such a problem occurs because, as in the case of the above-described eco-run system, the engine ECU 30 uniquely determines whether or not fuel injection is required by looking only at the rotation speed signal NE obtained by itself. . In view of the above problems, the present invention prevents erroneous fuel injection by referring to an external signal in addition to the rotational speed signal for confirmation.
[0078]
FIG. 5 is a flowchart showing a control process corresponding to the erroneous fuel injection prevention function of this embodiment. In S20, engine ECU 30 obtains the engine required torque, the motor generator drive signal, and the engine speed signal. The engine required torque is input from the hybrid ECU 32. A motor generator drive signal is also input from the hybrid ECU 32, but this signal may be input from the motor generator 22 or the like. The engine speed signal is input from the rotation sensor 25 of the engine 21.
[0079]
In S22, it is determined whether or not the engine required torque is zero. If the engine required torque is not 0, fuel injection is permitted in S26, and the process returns to S20. The engine rotates with the motor generator, and the engine is driven by the fuel supply to generate the required torque.
[0080]
When S22 is YES, it is determined based on the motor generator drive signal whether the motor generator is being driven to start the engine. In a hybrid vehicle, the motor generator is usually used for obtaining the driving force of the vehicle or charging the battery, and is not used for starting the engine. In this state, the determination in S24 is not YES. The determination in S24 is YES only when the motor generator is being driven to start the engine (including a state where the motor generator is used for both starting the engine and starting the engine).
[0081]
Moreover, S24 becomes YES, for example, when the driver turns the ignition key. It is assumed that the display of the driver's seat indicates that the engine is stopped (running state using only the motor). When the driver who sees this display tries to switch to the engine operating state and turns the ignition key, cranking using the motor generator is performed, and S24 becomes YES. As another example, S24 is YES when the driver presses the air conditioner switch. It can be considered that the engine is started when the air conditioner switch is pressed to ensure the air conditioner operation state. However, under what conditions the cranking is performed (S24 is YES) is not limited to the above, and a system employing other conditions is also included in the scope of the present invention.
[0082]
If the determination in S24 is YES, fuel injection is permitted in S26. Therefore, fuel is injected together with cranking, and the engine is started.
[0083]
On the other hand, if the determination in S24 is NO, the engine speed 21 is not cranked but the engine speed signal NE is input. Therefore, it is considered that an erroneous input of the rotational speed due to external noise or the like has occurred. Therefore, in S28, fuel injection is prohibited (stop of fuel injection is continued), and the process returns.
[0084]
As described above, the effects of the present invention can be obtained in the hybrid system as well. In the hybrid system of FIG. 4, a motor generator functions as an engine starting motor instead of the starter motor. Unless the motor generator is being driven to start the engine, fuel injection is prohibited even if the engine speed signal NE is input. As a result, erroneous fuel injection can be prevented.
[0085]
The preferred embodiment of the present invention has been described above by taking up the eco-run system of FIG. 1 and the hybrid system of FIG. However, it goes without saying that the present invention can be similarly applied to an internal combustion engine control system with an automatic stop / start function other than the present embodiment. For example, the present invention can be similarly applied to a system called MG eco-run which is one form of the eco-run system. In the MG eco-run system, a motor for eco-run that is larger than the starter motor is provided in order to improve the startability at the time of automatic engine start. The eco-run motor is preferably connected to the engine via a belt or the like for a smooth start. By applying the present invention, even if an engine speed signal is input after the engine has been automatically stopped, fuel injection is prohibited unless the eco-run motor is driven. As a result, erroneous fuel injection can be prevented.
[0086]
Embodiment 3. FIG.
Next, another embodiment of the present invention will be described.
[0087]
In the above-described embodiment, the present invention is applied to an internal combustion engine control device with an automatic stop function such as an eco-run system and a hybrid system. In the present embodiment, the present invention is applied to a general internal combustion engine control device that does not have an automatic stop function.
[0088]
FIG. 6 shows the configuration of the internal combustion engine control apparatus of the present embodiment. In the apparatus of FIG. 6, the same components as those of the apparatus of FIG. 6 and FIG. 1 is that the apparatus of FIG. 6 is not provided with an automatic stop function (eco-run function, idling stop function). Corresponding to this difference, the eco-run ECU is not provided in the system of the present embodiment.
[0089]
However, in the apparatus of FIG. 6 as well, in the same way as the apparatus of FIG.
[0090]
Here, consider a state in which the engine is stopped during engine operation. For example, an engine stall due to some disturbance is applicable. In addition, a state where only an ignition-on operation is performed as a key operation and a starter-on operation is not performed can be considered as an engine stop state during operation. For example, it is a state in which an ignition-on operation is performed to operate the device such as opening and closing a window. The ignition is already turned on, and the engine ECU 10 is in the same state as the engine stall.
[0091]
In this engine stop state, the ignition is on, and the engine is ready to inject fuel whenever the engine speed signal is input. In this state, it is assumed that the rotational speed signal NE is erroneously input. For example, an erroneous input may occur due to vibration while stopping on a bridge. In addition, erroneous input may occur due to radio noise of the road surface heater. There is a possibility that the fuel is erroneously injected in response to the erroneous input of the rotation speed signal. In the present embodiment, an injection malfunction is prevented as follows.
[0092]
Referring to FIG. 7, in S30, the engine ECU 10 inputs an ignition switch signal, a starter signal, and an engine speed signal. The ignition switch signal is sent from the ignition key device 3.
[0093]
In S32, it is determined whether or not the engine is rotating. If the engine speed NE is greater than the predetermined determination value k1 for N1 seconds, it is determined that the engine is rotating, fuel injection is permitted in S36, and the process returns to S30. The determination value k1 is set to an appropriate value that is slightly smaller than the idling rotational speed, for example. It may be the same as the value used for engine start completion determination.
[0094]
If S32 is NO, it is determined in S34 whether "ignition is on and starter is off". If S34 is NO, the starter motor is driven to start the engine, so the routine proceeds to S36 and fuel injection is permitted. Therefore, in response to the input of the rotational speed signal NE, the engine ECU 10 performs fuel injection, and as a result, the engine 1 is started.
[0095]
If S34 is YES, it is considered that an erroneous input of the rotational speed signal has occurred because the starter is off even if the rotational speed signal NE is input. Therefore, the process proceeds to S38, in which fuel injection is prohibited (fuel stop is continued) and the process returns regardless of the input of the rotation speed signal.
[0096]
As described above, also in this embodiment, as in the other embodiments described above, when it is determined that the rotation speed signal is input incorrectly, specifically, unless the starter motor is driven, Do not inject fuel. Therefore, it is possible to prevent fuel from being erroneously injected in response to an erroneous input of the rotation speed signal.
[0097]
And as demonstrated in this embodiment, this invention is applicable also to the general internal combustion engine control apparatus which is not equipped with automatic stop functions, such as an eco-run.
[0098]
Also in the present embodiment, as in the first embodiment described above, when the rotation speed signal is continuously input for a predetermined time or more, it is preferable to permit fuel injection, which can cope with so-called pushing.
[0099]
【The invention's effect】
As described above, according to the present invention, even when a signal indicating engine rotation is input in a state where the engine is stopped, when it is determined that a signal is erroneously input, specifically, for engine start. If the motor is not driven, fuel injection is prohibited. Accordingly, it is possible to prevent erroneous fuel injection in response to the rotational speed signal due to external noise or the like. As a result, it is possible to prevent the startability from being lowered due to fogging of the spark plug, and it is possible to improve fuel efficiency by eliminating unnecessary fuel consumption.
[0100]
Further, according to the present invention, the prohibition of fuel injection is suppressed when a signal indicating the rotation of the engine is continuously input for a predetermined time or more. Even in the case of pushing, it is possible to prevent the fuel injection from being prohibited by misunderstanding that the rotation speed signal is erroneously input, thereby enabling the pushing.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an eco-run system according to a preferred embodiment of the present invention.
FIG. 2 is a flowchart showing an erroneous fuel injection prevention process in the system of FIG.
FIG. 3 is a flowchart showing a process improved from the process shown in FIG.
FIG. 4 is a block diagram showing a hybrid system according to another embodiment of the present invention.
FIG. 5 is a diagram illustrating a process of preventing erroneous fuel injection in the system of FIG. 4;
FIG. 6 is a block diagram showing an internal combustion engine control system according to another embodiment of the present invention.
FIG. 7 is a diagram showing a fuel erroneous injection prevention process of the system of FIG.
[Explanation of symbols]
1,21 Engine, 2 Starter motor, 3,23 Ignition key device, 5,25 Rotation sensor, 7,27 Fuel injection device, 10,30 Engine ECU, 12 Eco-run ECU, 22 Motor generator, 32 Hybrid ECU, 34 Motor generator ECU.

Claims (3)

In the internal combustion engine control device with an automatic stop function in which the operation of the internal combustion engine is controlled by the engine ECU and the host ECU sends an engine stop signal to the engine ECU when the predetermined stop condition is satisfied, and stops the engine.
A rotation sensor that detects a rotation signal indicating rotation of the internal combustion engine and supplies the rotation signal to the engine ECU ;
Fuel injection control means for causing the internal combustion engine to perform fuel injection in response to an input of the rotation signal in response to an instruction from the engine ECU ;
Including,
Even if the rotation signal is input while the rotation of the internal combustion engine is stopped by the automatic stop function of the host ECU during the operation of the internal combustion engine by the engine ECU, if it is determined that an erroneous input has been performed, the fuel injection An internal combustion engine control device with an automatic stop function , characterized in that it includes injection prohibiting means for prohibiting injection. The internal combustion engine control device with an automatic stop function according to claim 1,
Even when the rotation signal is input while the rotation of the internal combustion engine is stopped by the automatic stop function of the host ECU during the operation of the internal combustion engine by the engine ECU , the injection prohibiting means is used to start the internal combustion engine. An internal combustion engine control device with an automatic stop function , wherein fuel injection is prohibited unless driven. In the internal combustion engine control device with an automatic stop function according to claim 1 or 2,
An internal combustion engine control system with an automatic stop function , comprising: a prohibition suppressing unit that suppresses prohibition of fuel injection by the injection prohibiting unit when a rotation signal of the internal combustion engine is continuously input for a predetermined time or more.

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