JP2010203369A - Warming-up controller for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a warming-up controller for an internal combustion engine, achieving both of reduction in fuel consumption by execution of automatic stop control and suppressing unnecessary power consumption caused by energization to a glow plug. <P>SOLUTION: The warming-up controller for an internal combustion engine is applied to a diesel engine, in which the automatic stop control for stopping operation of the internal combustion engine is performed based on satisfaction of an automatic stop condition and an automatic start control for starting the operation of the internal combustion engine is performed based on satisfaction of an automatic start condition during the stop of the engine by the automatic stop control. The warming-up controller controls energization of the glow plug disposed to the diesel engine. For example, the glow energization is started in operation of turning off to on of an ignition switch, and when operation of the diesel is stopped by the automatic stop control, glow energization is prohibited. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention provides an automatic stop control for stopping the operation of the internal combustion engine based on the establishment of the automatic stop condition, and an automatic start for starting the operation of the internal combustion engine based on the establishment of the automatic start condition during the engine stop by the automatic stop control. The present invention relates to a warm-up control device for an internal combustion engine that controls an energization mode of a glow plug provided on the internal combustion engine of a vehicle that performs control.

As the warm-up control device, for example, a device that controls the energization mode of a glow plug of a diesel engine as described in Patent Document 1 is known.
On the other hand, although a diesel engine is provided with an exhaust gas purification device that purifies exhaust gas generated by combustion of an air-fuel mixture, the catalyst of this device is not activated unless the temperature exceeds a certain level. For this reason, there has been proposed a technique for warming up the catalyst by raising the temperature of the exhaust gas by continuously energizing the glow plug even after the engine is started. In glow plug control performed for the purpose of warming up the catalyst, the required time elapses after the engine is started after the time (required time) from the start of the engine until the catalyst is sufficiently warmed up is known in advance. The glow plug is continuously energized.

JP 2006-046199 A

  The glow plug control is certainly effective from the viewpoint of ensuring engine startability and promoting warm-up of the catalyst, but the following problems arise when applied to a diesel engine that performs automatic stop control. . That is, when the engine is automatically stopped by the automatic stop control, energization to the glow plug is continued when the elapsed time from the engine start based on the operation of the ignition switch has not yet reached the required time. However, when energization of the glow plug is performed under such an engine stop state, this does not contribute to promotion of warming up of the catalyst, so that electric power is unnecessarily consumed.

  The present invention has been made in view of such circumstances, and its purpose is to reduce fuel consumption by executing automatic stop control and to suppress unnecessary power consumption due to energization of the glow plug. An object of the present invention is to provide a warm-up control device for an internal combustion engine that can achieve both.

In the following, means for achieving the above object and its effects are described.
The invention according to claim 1 is an automatic stop control for stopping the operation of the internal combustion engine based on the establishment of the automatic stop condition, and the operation of the internal combustion engine based on the establishment of the automatic start condition during the engine stop by the automatic stop control. An internal combustion engine warm-up control device for controlling an energization mode of a glow plug provided in an internal combustion engine of a vehicle that performs automatic start control for starting the engine. The main point is to ban energization.

  According to the present invention, since energization to the glow plug is prohibited while the engine is stopped by the automatic stop control, that is, even if energization to the glow plug is executed, this does not contribute to promotion of warming up of the catalyst. Therefore, it is possible to suppress unnecessary power consumption due to energization of the glow plug. That is, it is possible to achieve both the reduction of the fuel consumption by executing the automatic stop control and the suppression of unnecessary power consumption due to the energization of the glow plug.

The schematic diagram which shows typically the structure of the engine about 1st Embodiment which actualized the warm-up control apparatus of the internal combustion engine of this invention. The timing chart which shows an example of the control aspect by the glow electricity supply control of the embodiment. The flowchart which shows the process sequence about the 1st glow energization process of the embodiment. The timing chart which shows an example of the control aspect by glow energization control about 2nd Embodiment which actualized the warm-up control apparatus of the internal combustion engine of this invention. The flowchart which shows the process sequence about the 2nd glow energization process of the embodiment.

(First embodiment)
A first embodiment in which the warm-up control device for an internal combustion engine of the present invention is embodied will be described with reference to FIGS.

  The diesel engine 1 is provided with a cylinder block in which a plurality of cylinders 10 are formed, and a cylinder head 11 is provided above the cylinder block. The cylinder head 11 is provided with a fuel injection valve 12 and a glow plug 13 corresponding to each cylinder 10. The cylinder head 11 is connected to an intake manifold 21 for introducing outside air into the cylinder 10. The intake manifold 21 is connected to the intake passage 22. A throttle valve 23 for adjusting the amount of intake air is provided in the intake passage 22. The cylinder head 11 is provided with an exhaust manifold 31 for discharging combustion gas to the outside of the cylinder 10. The exhaust manifold 31 is connected to the exhaust passage 32. A catalytic converter 40 that purifies exhaust components is provided downstream of the exhaust passage 32.

  In addition, the diesel engine 1 is provided with an EGR device 50. The EGR device 50 introduces a part of the exhaust gas into the intake air to lower the combustion temperature in the cylinder 10 and reduce the amount of NOx generated. This device includes an EGR passage 51 that communicates the intake manifold 21 and the exhaust manifold 31, an EGR valve 52 provided in the EGR passage 51, an EGR cooler, and the like. Then, by adjusting the valve opening degree of the EGR valve 52, the amount of exhaust introduced into the intake manifold 21 from the exhaust manifold 31, that is, the EGR amount is adjusted. Further, the temperature of the exhaust gas flowing in the EGR passage 51 is lowered by the EGR cooler.

  The electronic control unit 90 controls the diesel engine 1 by signal input from various sensors. For example, the fuel injection amount control of the fuel injection valve 12, the opening control of the throttle valve 23, the opening control of the EGR valve 52, the energization control of the glow plug 13 and the like are performed.

Further, the electronic control device 90 starts the diesel engine 1 by rotating the starter by receiving a signal indicating that the starter start operation has been performed.
In addition to starting and stopping the diesel engine 1 based on the operation of the ignition switch IG, the electronic control device 90 starts and stops the diesel engine 1 according to the vehicle running state. Hereinafter, the start of the diesel engine 1 based on the switching operation of the ignition switch IG from OFF to ON is referred to as “normal start”. The start of the diesel engine 1 that is performed without being based on the operation of the ignition switch IG when the ignition switch IG is on, that is, the start of the diesel engine 1 that is performed based on the establishment of the automatic start condition is referred to as “automatic start”. . Further, the stop of the diesel engine 1 that is performed without being based on the operation of the ignition switch IG when the ignition switch IG is on, that is, the stop of the diesel engine 1 that is performed based on the establishment of the automatic stop condition is “automatic stop”. And

  Examples of the automatic stop condition include that the vehicle speed falls below a reference speed while the vehicle is traveling, and that the vehicle shifts to an idle state. In addition, as an automatic start condition, for example, an accelerator pedal is depressed in an idle state of the vehicle.

  The electronic control unit 90 performs glow energization control that controls the manner in which current is supplied to the glow plug 13. The glow plug 13 is heated by supplying a current through a glow relay. This heating heats the combustion chamber and ensures engine startability. In the glow energization control, heating by the glow plug 13 is continued after the engine is started in order to promote warm-up of the catalytic converter 40.

  The glow energization is started when the ignition switch IG is operated from off to on. Basically, the time during which the glow plug 13 is energized (hereinafter referred to as “glow energization time Tgr”) is set to a predetermined request time Tx. It is done until it exceeds. The required time Tx is set in advance as a sufficient time until the warm-up of the catalytic converter 40 is completed.

If the diesel engine 1 is automatically stopped before the required time Tx has elapsed, glow energization ends at that point.
With reference to FIG. 2, each relationship of the ignition switch IG, the operation state of the diesel engine 1, and the glow energized state will be described.

  If the ignition switch IG is switched from OFF to ON at time t0, energization of the glow plug 13 is started based on this switching operation. If an operation for starting the ignition switch IG is performed at a time t1 after a predetermined time has elapsed, the starter starts the engine while the energization of the glow plug 13 is continued.

  If the automatic stop condition is satisfied at time t2 after the normal start, the energization to the glow plug 13 is prohibited based on the establishment of this condition even if the glow energization time Tgr does not reach the required time Tx. On the other hand, when the automatic stop condition is not satisfied by time t3 after the normal start, the energization to the glow plug 13 is terminated based on the fact that the glow energization time Tgr has reached the required time Tx at this time t3.

  With reference to FIG. 3, the 1st glow energization process which defined the specific process sequence of the said glow energization is demonstrated. This process is repeatedly executed by the electronic control unit 90 every predetermined control period set in advance.

If it is determined in step S10 that the ignition switch IG has been switched from OFF to ON, glow energization is started in step S11.
After the start of glow energization, glow energization is continued until it is determined in step S12 that either the glow energization time Tgr has reached the required time Tx or in step S13 that the automatic stop condition has been established.

  After glow energization is completed based on the glow energization time Tgr reaching the required time Tx or the automatic stop condition being satisfied, the glow energization is continued until the ignition switch IG is switched from OFF to ON. The plug 13 is not energized.

  According to the first glow energization process described above, glow energization is started simultaneously with the switching operation of the ignition switch IG from OFF to ON, and its execution is prohibited in the first automatic stop. On the other hand, when the glow energization time Tgr exceeds the required time Tx before the first automatic stop, the glow energization is terminated at that time.

According to the warm-up control device for an internal combustion engine of the present embodiment, the following effects can be obtained.
(1) In the present embodiment, glow energization is prohibited while the operation of the diesel engine 1 is stopped by the automatic stop control. That is, even if energization to the glow plug 13 is executed, energization to the glow plug 13 is prohibited when this does not contribute to the promotion of warming up of the catalytic converter 40, and thus power is unnecessarily consumed by energization to the glow plug 13. It becomes possible to suppress this.

(Second Embodiment)
With reference to FIG. 4 and FIG. 5, a second glow energization process will be described as another example of the glow energization control. This process is repeatedly executed through the electronic control unit 90 every predetermined control period set in advance.

  The glow plug energization process of this embodiment is different from that of the first embodiment in the following points. That is, in the glow energization control of the first embodiment, the glow energization is terminated based on the establishment of the first automatic stop condition after the ignition switch IG is switched from off to on, and then the next ignition switch IG is turned off. The execution of glow energization is prohibited until the switching operation from ON to ON is performed. On the other hand, in the glow energization control of this embodiment, glow energization is executed when the automatic start condition is satisfied and the required time Tx has not elapsed even after the automatic stop condition is satisfied.

With reference to FIG. 4, the relationship among the ignition switch IG, the operation state of the diesel engine 1, the glow energization state, and the glow energization time Tgr will be described.
Assuming that the ignition switch IG is switched from OFF to ON at time t0, energization of the glow plug 13 is started based on this switching operation. If an operation for starting the ignition switch IG is performed at time t1 after a predetermined time has elapsed, the starter starts the engine while the energization of the glow plug 13 is continued.

  If the automatic stop condition is satisfied at time t2 after the normal start, the energization to the glow plug 13 is prohibited based on the establishment of this condition even if the glow energization time Tgr does not reach the required time Tx. Thereafter, if the automatic start condition is satisfied and the diesel engine 1 is restarted at time t3, the energization to the glow plug 13 is resumed. The glow energization ends at time t4 when the glow energization time Tgr reaches the required time Tx.

  That is, energization of the glow plug 13 is stopped while the diesel engine 1 is stopped, while it is continuously executed while the diesel engine 1 is operating. Such prohibition and execution of energization of the glow plug 13 are repeated until the glow energization time Tgr reaches the required time Tx.

  With reference to FIG. 5, the second glow energization process that defines a specific procedure for energizing the glow plug will be described. This process is repeatedly executed by the electronic control unit 90 every predetermined control period set in advance.

  If it is determined in step S20 that the ignition switch IG has been switched from OFF to ON, the glow energization counter GC is reset in step S21, and glow energization is executed in step S22. Here, the glow energization counter GC indicates a variable for measuring the glow energization time from the start of glow energization, and increments the count of 1 only when step S29 described later is established.

Next, when it is determined in step S23 that the glow energization time Tgr exceeds the required time Tx, the glow energization ends.
On the other hand, when it is determined that the glow energization time Tgr is equal to or shorter than the required time Tx, in step S24, after the diesel engine 1 is started for the first time based on the switching operation of the ignition switch IG from OFF to ON. It is determined whether or not there is. If the determination is negative, the glow energization state is maintained. If the determination is affirmative, it is determined in step S25 whether or not the diesel engine 1 is in operation.

  When it is determined in step S25 that the diesel engine 1 is in operation, it is further determined in step S26 whether the automatic stop condition for the diesel engine 1 is satisfied. Here, when the automatic stop condition is not satisfied, glow energization is executed in step S27. On the other hand, when the automatic stop condition of the diesel engine 1 is satisfied, glow energization is prohibited in step S28.

  After a predetermined cycle through the above series of processes, the process is executed again from step S20. At this time, if the ignition switch IG is not switched from OFF to ON, it is determined in step S29 whether or not the ignition switch IG is on and glow energization is being performed. When it is determined that the ignition switch IG is on and glow energization is being executed, the glow energization counter GC is incremented in step S30. On the other hand, when the ignition switch IG is in an off state or glow energization is prohibited, the value of the glow energization counter GC is maintained. Subsequent processing is performed in the same manner as described above.

  According to the second glow energization process described above, glow energization is executed when the diesel engine 1 is operating, and glow energization is prohibited when the diesel engine 1 is automatically stopped. When the glow energization time Tgr exceeds the required time Tx, the glow energization ends.

According to the warm-up control device for an internal combustion engine of the present embodiment, the following effects can be obtained.
(1) In this embodiment, glow energization is prohibited only during the period of stoppage of operation of the diesel engine 1 by automatic stop control. As a result, even if the diesel engine 1 is automatically stopped immediately after the ignition is turned on as described above, the required time Tx is secured as the glow energization time, so that the activity of the catalytic converter 40 that is the original purpose of the glow energization is ensured. Energy loss can be reduced while maintaining the effect of promoting the conversion.

(Other embodiments)
In addition, the embodiment of the present invention is not limited to the embodiment exemplified in each of the above-described embodiments, and can be implemented by changing it as shown below, for example.

  In the second embodiment, while the energization of the diesel engine 1 is stopped, the glow energization is prohibited, and the glow energization time Tgr is ensured until the required time Tx by executing the glow energization at the time of restart. As a result, the on / off operation of the glow plug 13 is repeated. For this reason, there is a concern that the life of the glow plug 13 may be shortened. Therefore, for the purpose of reducing the frequency of on / off operation of the glow plug 13, glow energization is prohibited for a certain period of time after the ignition switch IG is switched from off to on regardless of whether the diesel engine 1 is automatically stopped. You may perform glow energization control which prohibits itself.

  In any of the above embodiments, glow energization is always prohibited during the automatic stop of the diesel engine 1, but the glow energization control according to the present invention is not limited to such conditions. Even during automatic stop, glow energization may be executed if it can be expected that glow energization is effective. For example, when exhaust gas flows into the catalytic converter 40 due to the exhaust inertia immediately after the diesel engine 1 is automatically stopped, glow energization may be continued even when the diesel engine 1 is automatically stopped.

  In each of the above embodiments, glow energization is terminated when the glow energization time Tgr exceeds the required time Tx, but the end of glow energization is not limited to such conditions. For example, the temperature of the cooling water or the temperature of the catalytic converter 40 may be used as a reference as the glow energization end condition.

  In each of the above embodiments, the configuration in which the present invention is applied to a diesel engine has been described. However, the present invention can be applied to other engines than a diesel engine as long as the engine includes a glow plug.

  DESCRIPTION OF SYMBOLS 1 ... Diesel engine, 10 ... Cylinder, 11 ... Cylinder head, 12 ... Fuel injection valve, 13 ... Glow plug, 21 ... Intake manifold, 22 ... Intake passage, 23 ... Throttle valve, 31 ... Exhaust manifold, 32 ... Exhaust passage, 40 ... catalytic converter, 50 ... EGR device, 51 ... EGR passage, 52 ... EGR valve, 90 ... electronic control device.

Claims (1)

Vehicle for performing automatic stop control for stopping operation of the internal combustion engine based on establishment of the automatic stop condition, and automatic start control for starting operation of the internal combustion engine based on establishment of the automatic start condition during engine stop by the automatic stop control In the internal combustion engine warm-up control device for controlling the energization mode of the glow plug provided in the internal combustion engine of
A warm-up control device for an internal combustion engine, wherein energization of the glow plug is prohibited during operation stop of the internal combustion engine by the automatic stop control.

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