JP5772494B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine in which automatic stop and automatic start are performed.

As described in Patent Document 1, there is known an apparatus that automatically stops and automatically starts an internal combustion engine when a predetermined condition is satisfied.
In the apparatus described in Patent Document 1, when the engine is stopped based on the engine stop request and an engine start request is made while the engine speed is decreasing, the engine speed falls below a predetermined value. At that time, the engine is restarted by the starter.

JP 2008-267297 A

  In the restart, it is desirable to restart the engine operation such as fuel injection and ignition after the starter is driven. However, if there is an abnormality in the signal line, etc., through which the signal indicating that the starter is in operation, the starter drive cannot be grasped, so the engine operation cannot be resumed and the engine restarts. Becomes difficult.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a control device for an internal combustion engine that can suitably restart the engine.

In the following, means for achieving the above object and its effects are described.
The invention according to claim 1 is a control device for an internal combustion engine in which automatic stop and automatic start are performed, and the engine control unit for controlling the operation of the internal combustion engine indicates that the starter is being driven. When the engine start request is made while the engine speed is decreasing due to the execution of the engine stop based on the engine stop request, the start signal is sent to the starter signal. And at least one of the drive signals is input to the engine control unit. When at least one of the starter signal and the drive signal is input, fuel injection is started and engine operation is resumed. The gist is to do.

  According to this configuration, not only the starter signal indicating that the starter is being driven but also the engine operation is resumed when a drive signal for driving the starter is input to the engine control unit. Therefore, even when there is an abnormality in a signal line or the like through which a signal indicating that the starter is being driven, the engine can be restarted suitably.

  As an output source of the starter signal, a configuration in which the starter signal is output from a relay circuit that supplies electric power to the starter can be employed as in the invention described in claim 2.

  Further, as the output source of the drive signal, the drive signal is output from an automatic stop / start control unit that controls the automatic stop and automatic start, as in the invention described in claim 3. can do.

  According to a fourth aspect of the present invention, in the control device for an internal combustion engine according to any one of the first to third aspects, the input state of the drive signal and the starter signal to the engine control unit is inconsistent. The gist is to prohibit the automatic stop of the internal combustion engine.

  Normally, when the drive signal is input to the engine control unit, the starter is driven, so the starter signal is also input to the engine control unit. That is, if the signal line through which the starter signal flows is normal, the input state of the drive signal and the starter signal to the engine control unit coincides.

  On the other hand, when there is an abnormality in the signal line that transmits the starter signal to the engine control unit, even if a drive signal is input to the engine control unit, no starter signal is input to the engine control unit. That is, when there is an abnormality in a signal line or the like for transmitting a starter signal, the input state of the drive signal and the starter signal to the engine control unit does not match. When such a signal line or the like is abnormal, the reliability of the starter signal is lowered, so that the starter drive state cannot be accurately grasped. Therefore, in some cases, it may be difficult to restart the engine.

  Therefore, in the same configuration, when the input state of the drive signal and the starter signal to the engine control unit is inconsistent and the drive state of the starter cannot be accurately grasped, the automatic stop of the internal combustion engine is prohibited. . Therefore, it is possible to suppress the difficulty of restarting the engine.

  More specifically, according to a fourth aspect of the present invention, as in the fifth aspect of the present invention, when the drive signal is input to the engine control unit, the starter signal is A configuration in which automatic stop of the internal combustion engine is prohibited when no input is made can be employed.

  Further, as the engine control unit, as in the sixth aspect of the invention, the engine control unit controls fuel injection in the internal combustion engine, and the engine control unit performs fuel cut. Thus, it is possible to employ a configuration in which the engine is stopped and the engine operation is restarted by starting fuel injection.

  The engine control unit controls ignition in the internal combustion engine according to the invention described in claim 7, and the engine control unit executes the engine stop by performing an ignition cut. In addition, it is possible to adopt a configuration in which the engine operation is restarted by starting ignition.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of an internal combustion engine control system to which an internal combustion engine control apparatus according to an embodiment of the present invention is embodied. The flowchart which shows the procedure of the injection resumption process performed in the embodiment. The timing chart which shows a fuel cut state when the injection resumption process is performed in the same embodiment.

  Hereinafter, an embodiment of a control device for an internal combustion engine according to the present invention will be described with reference to FIGS. Since the structure of engine 100 described below is a well-known structure, detailed description thereof is omitted.

  As shown in FIG. 1, an engine 100 having a known structure is provided with an injection device 120 for injecting fuel, an ignition device 130 for igniting an air-fuel mixture of fuel and air, and the air-fuel mixture burns. The crankshaft rotates by being burned in the chamber. The crankshaft is provided with a flywheel, and a ring gear is provided on the outer periphery of the flywheel.

  The starter 110 provided on the side of the engine 100 includes a pinion gear that meshes with the ring gear, an electric motor that rotates the pinion gear, and an electromagnetic solenoid that projects the pinion gear toward the ring gear. Electric power is supplied to the electric motor and electromagnetic solenoid of the starter 110 through the relay circuit 115. The starter 110 is a so-called dive type starter that meshes with the ring gear when the engine is started, and is an electromagnetic solenoid when the engine speed is “0” and the pinion gear can be meshed with the ring gear. And energization to the electric motor is started.

  An engine control device (hereinafter referred to as an engine ECU) 200 controls various engine operations such as fuel injection control by the injection device 120, ignition control by the ignition device 130, or intake air amount control based on signal inputs from various sensors. I do. An example of the various sensors is a crank angle sensor 400 that detects the engine rotational speed NE. The engine ECU 200 constitutes the engine control unit.

  The engine ECU 200 is connected to a signal line L1 output from the relay circuit 115. A starter signal STA indicating that the starter 110 is being driven is output from the relay circuit 115 to the engine ECU 200 via the signal line L1.

  Further, the eco-run control device (hereinafter referred to as eco-run ECU) 300 performs control related to automatic stop and automatic start of the engine 100 when a predetermined condition is satisfied. Examples of the automatic stop condition include that the vehicle speed is lower than the reference speed while the vehicle is traveling and that the accelerator pedal is depressed to "0". Moreover, as conditions for automatic start, for example, an accelerator pedal is depressed during automatic stop. The eco-run ECU 300 constitutes the automatic stop / start control unit.

  The eco-run ECU 300 and the engine ECU 200 can communicate with each other via a communication line T1. The eco-run ECU 300 and the relay circuit 115 are connected by a drive signal line L2. A drive signal STD for driving the starter 110 is output from the eco-run ECU 300 to the relay circuit 115 via the drive signal line L2. When the drive signal STD is input to the relay circuit 115, power is supplied from the relay circuit 115 toward the starter 110. Various conditions are set for the output of the drive signal STD by the eco-run ECU 300, and one of them is a condition that “the engine is requested to start and the engine speed NE is“ 0 ””. Yes.

Next, the fuel injection restart process performed in the present embodiment will be described with reference to FIG. This process is repeatedly executed by engine ECU 200 at predetermined intervals.
When this process is started, it is first determined whether or not a fuel cut by a stop request is being executed (S100). The stop request here is a stop request when the driver of the vehicle on which the engine 100 is mounted turns off the ignition switch or when the above-described automatic stop condition is satisfied.

When the fuel cut due to the stop request is not being executed (S100: NO), this process is temporarily terminated.
On the other hand, when the fuel cut by the stop request is being executed (S100: YES), it is determined whether or not there is a start request (S110). Here, the start request is a start request by turning on an ignition switch by a driver of a vehicle on which the engine 100 is mounted.

When there is no start request (S110: NO), this process is temporarily terminated.
On the other hand, when there is a start request (S110: YES), it is determined whether or not the engine speed NE is “0”, that is, whether or not the output condition of the drive signal STD is satisfied (S130).

When the engine speed NE is not “0” (S120: NO), this process is temporarily terminated.
On the other hand, when the engine speed NE is “0” (S120: YES), it is determined whether at least one of the starter signal STA and the drive signal STD is input to the engine ECU 200 (S130).

  When at least one of the starter signal STA and the drive signal STD is not input, that is, when both the starter signal STA and the drive signal STD are not input (S130: NO), this process is temporarily ended.

  On the other hand, when at least one of the starter signal STA and the drive signal STD is input (S130: YES), that is, when the starter signal STA is input and the drive of the starter 110 can be grasped, or the drive signal STD is input. When it is very likely that the starter 110 is being driven, the process of step S140 is performed. In step S140, the fuel cut is stopped and fuel injection for restart is started.

  Next, it is determined whether or not the input states of the starter signal STA and the drive signal STD for the engine ECU 200 match (S150). Here, when the start signal STA is not input when the drive signal STD is input to the engine ECU 200, it is determined that the input states of the starter signal STA and the drive signal STD do not match.

When the input states of the starter signal STA and the drive signal STD match (S150: NO), this process is temporarily terminated.
On the other hand, when the input states of the starter signal STA and the drive signal STD do not match (S150: YES), the automatic stop of the engine 100 after the current execution timing of this process is prohibited (S160). Once terminated. It should be noted that the number of times that the input states of starter signal STA and drive signal STD do not match may be measured, and automatic stop of engine 100 may be prohibited when the number of times of measurement exceeds a predetermined number of determinations.

Next, the operation of the injection restart process will be described with reference to FIG.
When there is a request to stop the engine 100 at time t1 in FIG. 3, the engine speed NE is gradually decreased by executing the fuel cut.

If there is a start request from the driver at time t2, step S110 in FIG. 2 is positively determined.
When the engine rotational speed becomes “0” at time t3, a drive signal STD is output from the eco-run ECU 300, and this drive signal STD is also input to the engine ECU 200. Here, when there is no abnormality in the signal line L1, the starter 110 starts to be driven by the output of the drive signal STD, so that the starter signal STA is input to the engine ECU 200 as shown by a two-dot chain line in FIG. .

  On the other hand, when the signal line L1 has an abnormality such as disconnection, the starter signal STA is not input even if the drive signal STD is input to the engine ECU 200, as indicated by a solid line in FIG. Accordingly, when the fuel cut is stopped by the input of the starter signal STA and the fuel injection is started and the signal line L1 is abnormal, the fuel injection cannot be started, and the engine 100 It becomes difficult to restart.

  However, in this embodiment, not only the starter signal STA indicating that the starter 110 is being driven, but also when the drive signal STD for driving the starter 110 is input to the engine ECU 200, the fuel cut is stopped and the fuel is stopped. Injection is started (time t3). Therefore, even when there is an abnormality in the signal line L1 through which the starter signal STA that indicates that the starter 110 is being driven, the engine 100 can be restarted.

  Further, when the drive signal STD is input to the engine ECU 200, the starter 110 is driven, so the starter signal STA is also input to the engine ECU 200. That is, if the signal line L1 through which the starter signal STA flows is normal, the input states of the drive signal STD and the starter signal STA to the engine ECU 200 match.

  On the other hand, when there is an abnormality in the signal line L1 that transmits the starter signal STA to the engine ECU 200, the starter signal STA is not input to the engine ECU 200 even if the drive signal STD is input to the engine ECU 200. That is, when the signal line L1 that transmits the starter signal STA is abnormal, the input states of the drive signal STD and the starter signal STA to the engine ECU 200 do not match.

  When such a signal line L1 is abnormal, the reliability of the starter signal STA is lowered, so that the driving state of the starter 110 cannot be accurately grasped. Therefore, in some cases, restarting engine 100 may be difficult.

  In this regard, in this embodiment, when the input state of the drive signal STD and the starter signal STA to the engine ECU 200 is inconsistent and the drive state of the starter 110 cannot be accurately grasped, the automatic stop of the engine 100 is prohibited. (S160 in FIG. 2). More specifically, when the drive signal STD is input to the engine ECU 200 and the starter signal STA is not input, the automatic stop is prohibited. Therefore, it is possible to prevent the engine 100 from being difficult to restart.

As described above, according to the present embodiment, the following effects can be obtained.
(1) When the engine is stopped due to a fuel cut based on the engine stop request, and an engine start request is made while the engine speed is decreasing, at least one of the starter signal STA and the drive signal STD is output from the engine. The fuel injection is started after being input to the ECU 200, and the engine operation is resumed. Therefore, even when there is an abnormality in the signal line L1 indicating that the starter 110 is being driven, the engine 100 can be restarted suitably.

  (2) When the input states of the drive signal STD and the starter signal STA to the engine ECU 200 are inconsistent, more specifically, the starter signal STA is not input when the drive signal STD is input to the engine ECU 200 Sometimes, the automatic stop of the engine 100 is prohibited. Therefore, it becomes possible to prevent the engine 100 from being difficult to restart.

In addition, the said embodiment can also be changed and implemented as follows.
In the above embodiment, the injection restart process for stopping the fuel cut based on the stop request and restarting the fuel injection is executed. In addition, when the air-fuel mixture ignition cut (stop of ignition) is performed when there is a stop request, a similar restart process may be performed for such ignition control. The ignition restart process according to this modification can be implemented by changing a part of the injection restart process shown in FIG. That is, in step S100 of FIG. 2, it is determined whether or not the ignition cut is being executed due to the stop request. In step S140 in FIG. 2, the ignition cut is stopped and ignition for restart is started. Even in such a modification, it is possible to obtain the operational effects according to the above-described embodiment. The injection restart process and the ignition restart process may be performed together, or only the ignition restart process may be performed.

  In recent years, it has been considered to start the engine by injecting fuel when the engine is stopped and filling the cylinder with fuel, and by performing cranking and ignition by a starter when starting the engine. The ignition resumption process may be applied to an engine that starts the engine.

  In step S150, when the starter signal STA is input even though the drive signal STD is not input to the engine ECU 200, the input states of the starter signal STA and the drive signal STD do not match. You may make it determine.

  Although the starter signal STA indicating that the starter 110 is being driven is output from the relay circuit 115, the starter signal STA may be output in another manner. For example, a switch or a sensor that outputs a signal (starter signal STA) when the starter 110 is being driven may be provided in the starter 110.

-You may abbreviate | omit the process of step S150 and step S160 of FIG. Even in this case, the effect described in (1) above can be obtained.
The starter 110 is a jump-in starter, but may be another type of starter. For example, a so-called always-mesh starter in which a ring gear of a flywheel and a pinion gear of a starter are always meshed may be used. Further, a starter that can independently control the push-out of the pinion gear and the driving of the electric motor, that is, a so-called tandem solenoid starter may be used.

  DESCRIPTION OF SYMBOLS 100 ... Engine, 110 ... Starter, 115 ... Relay circuit, 120 ... Injection device, 130 ... Ignition device, 200 ... Engine control device (engine ECU), 300 ... Eco-run control device (Eco-run ECU), 400 ... Crank angle sensor, L1 ... signal line, L2 ... drive signal line, T1 ... communication line.

Claims (7)

A control device for an internal combustion engine that is automatically stopped and automatically started,
The engine control unit for controlling the operation of the internal combustion engine receives a starter signal indicating that the starter is being driven and a drive signal for driving the starter,
When the engine start request is made while the engine speed is decreasing due to the execution of the engine stop based on the engine stop request, at least one of the starter signal and the drive signal is sent to the engine control unit. A control apparatus for an internal combustion engine , wherein it is determined whether or not it is input, and when at least one of the starter signal and the drive signal is input, fuel injection is started and engine operation is restarted. The control device for an internal combustion engine according to claim 1, wherein the starter signal is output from a relay circuit that supplies electric power to the starter. The control device for an internal combustion engine according to claim 1, wherein the drive signal is output from an automatic stop start control unit that controls the automatic stop and the automatic start. The control device for an internal combustion engine according to any one of claims 1 to 3, wherein when the input state of the drive signal and the starter signal to the engine control unit does not match, automatic stop of the internal combustion engine is prohibited. . The control device for an internal combustion engine according to claim 4, wherein when the drive signal is input to the engine control unit and the starter signal is not input, automatic stop of the internal combustion engine is prohibited. The engine control unit controls fuel injection in the internal combustion engine, and the engine control unit performs the engine stop by performing a fuel cut and starts the engine operation by starting the fuel injection. The control apparatus for an internal combustion engine according to any one of claims 1 to 5. The engine control unit controls ignition in the internal combustion engine, and the engine control unit performs the engine stop by performing an ignition cut and restarts the engine operation by starting the ignition. The control device for an internal combustion engine according to any one of claims 1 to 6.

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