JP2017198146A - Device for controlling internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent deterioration in startability due to water content contained in a cover related to a control device suitable for controlling an internal combustion engine having a part covered by the cover.SOLUTION: At least part of an internal combustion engine 10 is covered by a cover (enclosure 24). A control device for an internal combustion engine includes a water detection sensor 26 for detecting water content contained in the cover. The control device for an internal combustion engine controls the internal combustion engine to continue operation till a water dissipation condition is met when the cover contains water component at the time of detection of a request for stopping the internal combustion engine 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly to a control device suitable for controlling an internal combustion engine having a portion covered with a cover.

  Patent Document 1 discloses an internal combustion engine covered with a soundproof case. According to such a structure, the operating sound volume of the internal combustion engine propagating to the outside can be suppressed, and the quietness of the vehicle can be improved.

JP 2007-146717 A

  By the way, the case for covering the internal combustion engine is generally formed of a fiber material or a foam material. These materials are hygroscopic. For this reason, the internal combustion engine may be forced to operate in a state where the case contains moisture.

  When moisture is contained in the case of the internal combustion engine, the inside of the engine compartment becomes high humidity, and the moisture ratio in the intake air tends to be high. If the moisture ratio increases, the oxygen ratio in the intake air decreases due to the influence. While the internal combustion engine continues to operate, the influence of such a decrease in the oxygen ratio on the combustibility is not so great.

  However, if the moisture ratio in the intake air is high at the time of starting, a situation may occur in which the starting is not performed smoothly. For this reason, the situation where moisture is contained in the cover of the internal combustion engine is not preferable in order to obtain smooth startability.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a control device for an internal combustion engine that can effectively prevent deterioration in startability due to moisture contained in a cover. To do.

In order to achieve the above object, the present invention provides a control device for an internal combustion engine at least partially covered by a cover,
A water detection sensor for detecting moisture contained in the cover;
A stop request detection process for detecting a stop request of the internal combustion engine;
An operation continuation process for continuing the operation of the internal combustion engine until a water loss condition is satisfied when the stop request is generated under a situation where the cover is determined to contain the water;
It is characterized by performing.

  According to the present invention, the operation of the internal combustion engine is continued until the water disappearance condition is satisfied under the condition that the cover is determined to contain moisture. While the operation of the internal combustion engine is continued, the moisture contained in the cover evaporates due to the heat generated by the internal combustion engine. And the water | moisture content contained in a cover is fully reducing in the stage in which water loss conditions are satisfied. If the moisture contained in the cover is sufficiently reduced, the moisture in the intake air will not be excessive at the time of restart, and smooth startability can be ensured.

It is a figure which shows the structure of Embodiment 1 of this invention. It is a figure for demonstrating the outline | summary of the water detection sensor shown in FIG. 3 is a flowchart of a routine executed by the ECU shown in FIG. It is a flowchart of the routine performed in Embodiment 2 of this invention. It is an example of the map which defined the relationship between 1st drying time T1 in connection with the water | moisture content contained in a cover, and external temperature. It is an example of the map which defined the relationship between 2nd drying time T2 regarding the water | moisture content contained in a cover, and the cooling water temperature of an internal combustion engine.

Embodiment 1 FIG.
[Configuration of Embodiment 1]
FIG. 1 is a diagram for explaining the configuration of the first embodiment of the present invention. The present embodiment includes an internal combustion engine 10. The internal combustion engine 10 is accommodated in the engine compartment 12 of the vehicle. Inside the engine compartment 12, a soundproof sheet 14 for absorbing sound generated by the internal combustion engine 10 is affixed.

  In FIG. 1, the left side of the drawing is the front of the vehicle. A radiator 16 and a cooling fan 18 are disposed on the vehicle front side of the internal combustion engine 10. The internal combustion engine 10 is cooled by the cooling air that has passed through the radiator 16 and the cooling fan 18.

  The internal combustion engine 10 includes an oil pan 20 at the bottom. Lubricating oil circulating inside the internal combustion engine 10 is collected in the oil pan 20. The lubricating oil is overheated in the process of circulating through the internal combustion engine 10. For this reason, the oil pan 20 tends to become high temperature.

  An exhaust pipe 22 is connected to the internal combustion engine 10. The internal combustion engine 10 discharges hot exhaust gas from the exhaust pipe 22. For this reason, the periphery of the exhaust pipe 22 is also likely to be hot as compared with other parts.

  In the present embodiment, the internal combustion engine 10 is almost entirely covered with the enclosure 24. The enclosure 24 is a cover of the internal combustion engine 10 mainly for the purpose of soundproofing. The enclosure 24 is made of a fiber material such as felt. However, the configuration of the enclosure 24 is not limited to this. For example, the enclosure 24 may be formed of a fiber material made of PET (Polyethylene terephthalate) fiber or a foamed material such as urethane. The fiber material and foam material used as the material of the enclosure 24 have a property of absorbing moisture.

  In the present embodiment, the internal combustion engine 10 is equipped with a water detection sensor 26. The water detection sensor 26 is a sensor for detecting moisture contained in the enclosure 24.

  FIG. 2 is a diagram for explaining the configuration of the water detection sensor 26. As shown in FIG. 2, the water detection sensor 26 includes a detection probe pair 28. One detection probe 30 is connected to the power supply potential (+) and to one end of the detection resistor 34. The other detection probe 32 is connected to one end of the adjustment resistor 36. The other end of the detection resistor 34 and the other end of the adjustment resistor 36 are connected to the collector terminal and the base terminal of the transistor 38, respectively. The emitter terminal of the transistor 38 is connected to the ground potential (−).

  The water detection sensor 26 is adjusted so that the detection probe pair 28 is inserted into the enclosure 24. In a situation where the enclosure 24 does not contain moisture, no current flows through the detection probe pair 28. In this case, the transistor 38 remains off. As a result, the voltage V across the detection resistor 34 becomes zero.

  When the enclosure 24 contains moisture, a current corresponding to the amount of moisture flows through the detection probe pair 28. The transistor 38 circulates a current corresponding to the voltage received by the base terminal. For this reason, a current corresponding to the current flowing through the detection probe pair 28 flows through the detection resistor 34, and the voltage V between both ends thereof has a value correlated with the amount of moisture contained in the enclosure 24. The water detection sensor 26 outputs the voltage V between both ends as a detection signal. For this reason, according to the output V of the water detection sensor 26, the state of moisture contained in the enclosure 24 can be detected.

  The description will be continued with reference to FIG. As shown in FIG. 1, the water detection sensor 26 is mounted at a position below and in front of the internal combustion engine 10, more specifically at a position directly above the oil pan 20 and immediately downstream of the cooling fan 18. . Moisture may enter the engine compartment 12 through the radiator 16 and the cooling fan 18. In addition, moisture may enter from below the floor of the vehicle. For this reason, the enclosure 24 easily receives water on the front side of the internal combustion engine 10 and in the vicinity of the bottom of the internal combustion engine 10. On the other hand, the periphery of the oil pan 20 and the periphery of the exhaust pipe 22 are likely to be hot as described above. For this reason, in those surroundings, even if the enclosure 24 absorbs moisture, the moisture absorption state is easily canceled in a short time.

  For the reasons described above, in the configuration of the present embodiment, moisture is most likely to remain in a portion of the enclosure 24 that covers the lower part and the front part of the internal combustion engine 10. And in this embodiment, since the water detection sensor 26 is arrange | positioned in the position, it can judge accurately whether the enclosure 24 is in the state containing water by the output of the water detection sensor 26. FIG. .

The output of the water detection sensor 26 is supplied to an electronic control unit (hereinafter referred to as ECU) 40. The ECU 40 is a unit for controlling the operation of the internal combustion engine 10. The ECU 40 is supplied with outputs of various sensors necessary for controlling the internal combustion engine 10, specifically, the following sensor outputs. However, these sensors are merely examples, and it is assumed that the ECU 40 is appropriately supplied with the outputs of known sensors required for controlling the internal combustion engine.
-SPD sensor 42 that emits a signal corresponding to vehicle speed SPD
-BRK sensor 44 indicating whether or not the brake pedal is depressed
-TA sensor 46 that emits a signal corresponding to the throttle opening TA
-Ne sensor 48 that emits a signal corresponding to the engine speed Ne
Ga sensor 50 that emits a signal corresponding to the intake air amount Ga
AA sensor 52 that emits a signal corresponding to the accelerator opening AA
A THW sensor 54 that emits a signal corresponding to the coolant temperature THW of the internal combustion engine 10
・ THA sensor 56 that emits a signal according to the outside temperature THA
IG switch 58 that emits a signal according to the operation status of the ignition IG

  The internal combustion engine 10 of this embodiment is mounted on a hybrid vehicle or an eco-run vehicle. In these vehicles, an automatic stop of the internal combustion engine 10 such as an idling stop is required under a situation where IG is on. The ECU 40 receives the outputs of the various sensors described above and can determine whether or not a request for automatic stop has occurred.

[Operation of Embodiment 1]
FIG. 3 is a flowchart of a routine executed by the ECU 40 in the present embodiment. The routine shown in FIG. 3 is repeatedly operated at a predetermined cycle after the IG switch 58 is turned on. When this routine is started, it is first determined whether or not the IG switch is turned off (step 100).

  If it is determined that the IG switch is not turned off, it is then determined whether or not an automatic stop condition for the internal combustion engine 10 is satisfied (step 102). Specifically, it is determined whether or not a light load condition for automatically stopping the internal combustion engine 10 is satisfied in the hybrid vehicle, or whether or not a condition for performing an idling stop is satisfied.

  If it is determined in step 102 that the condition for automatically stopping the internal combustion engine 10 is not satisfied, it is determined that the internal combustion engine 10 is to be continuously operated (step 104), and the current routine is terminated.

  On the other hand, if it is determined in step 102 that the automatic stop condition is satisfied, it is then determined whether or not the enclosure 24 is wetted (step 106). Specifically, here, it is determined whether or not the output V of the water detection sensor 26 is larger than a determination value stored in the ECU 40. This determination value is determined so that the relationship “V> determination value” is established when the amount of water in the enclosure 24 adversely affects the restart of the internal combustion engine 10. Therefore, if the condition of this step 106 is satisfied, it can be determined that if the internal combustion engine 10 is stopped at this time, smooth restart may not be obtained due to the water in the enclosure 24. In this case, regardless of the stop request to the internal combustion engine 10, the process of step 104 is subsequently executed and the operation of the internal combustion engine 10 is continued.

  When the operation of the internal combustion engine 10 is continued, evaporation of moisture in the enclosure 24 is promoted by heat generated by the internal combustion engine 10. If this state continues, the water content in the enclosure 24 will eventually be reduced to an amount that does not adversely affect the restart of the internal combustion engine 10. When this state is reached, it is determined in step 106 that the enclosure 24 is not wetted. When this determination is made, the ECU 40 next performs a process of stopping the internal combustion engine 10 (step 108). As a result, the internal combustion engine 10 is stopped.

  Thereafter, when the restart condition is satisfied, the starting process is executed without excessive moisture contained in the intake air, and the internal combustion engine 10 is restarted smoothly. For this reason, according to the configuration of the present embodiment, it is possible to realize a smooth start without shaking at the restart after the automatic stop even in a situation in which the enclosure is wetted while the vehicle is running. it can.

  If the IG switch is turned off in the process of repeatedly executing the routine shown in FIG. 3, the IG off condition is satisfied in step 100. In this case as well, the ECU 40 executes the process of step 106 before stopping the internal combustion engine 10. As a result, if the enclosure 24 is wetted when the IG switch is turned off, the operation of the internal combustion engine 10 is continued until the wettability is eliminated.

  According to the above processing, the internal combustion engine 10 is stopped in a state in which the wetness of the enclosure 24 is eliminated. If the water wetting of the enclosure 24 is eliminated at the time of stopping, generation of mold can be effectively suppressed, and durability of the enclosure 24 can be improved. Further, in a cold region, it is possible to avoid water freezing in the enclosure 24, and the durability can be greatly improved. Further, when comparing the cold start of the internal combustion engine 10 with the enclosure 24 dry and the cold start with the enclosure 24 wetted, the former is warmer than the latter. The time required for completion is shortened. Since the time required for completion of warm-up greatly affects the fuel consumption characteristics of the internal combustion engine 10, according to the configuration of the present embodiment, a significant effect can be obtained with respect to the improvement of the fuel consumption of the internal combustion engine 10.

  In the above-described first embodiment, “IG switch off” and “satisfaction of automatic stop condition” correspond to “stop request for internal combustion engine” according to claim 1. Further, denying that the enclosure is wet in step 106 described above corresponds to the establishment of the “water extinction condition” according to claim 1.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIGS. 4 and 5 together with FIG. The system of the present embodiment can be realized by causing the ECU 40 to execute the routine shown in FIG. 4 instead of the routine shown in FIG. 3 in the configuration shown in FIG.

  The routine shown in FIG. 4 is the same as the routine shown in FIG. 3 except that when it is determined in step 100 that the IG switch is OFF, the processing of steps 100 to 114 is executed instead of step 106. Hereinafter, in FIG. 4, the same steps as those shown in FIG. 3 are denoted by the same reference numerals, and redundant description is omitted.

  In the present embodiment, when the IG switch 58 is turned off during the execution of the routine shown in FIG. 4, it is first determined whether or not the enclosure 24 is wet (step 110). The processing in step 110 is substantially the same as the processing in step 106. Specifically, here, it is determined whether or not the output V of the water detection sensor 26 is larger than the water wetness determination value.

  As a result of the above determination, if it is determined that the enclosure 24 is not wetted, it can be determined that there is no problem even if the internal combustion engine 10 is stopped as it is. In this case, the ECU 40 immediately stops the internal combustion engine 10 in step 108 thereafter.

  On the other hand, if it is determined in step 110 that the enclosure 24 is wet with water, then the operation time required to eliminate the water wet is next based on the cooling water temperature THW and the outside air temperature THA of the internal combustion engine 10. T is calculated (step 112). Here, specifically, a first drying time T1 having a correlation with the outside air temperature THA and a second drying time T2 having a correlation with the cooling water temperature THW are calculated, and the total value T1 + T2 is calculated as described above. Calculated as time T.

  FIG. 5 is an example of a map that defines the relationship between the outside temperature THA and the first drying time T1. The ECU 40 stores this map, and specifies the first drying time T1 by referring to this map. The water contained in the enclosure 24 evaporates in a shorter time as the outside temperature THA is higher. For this reason, the first drying time T1 is set to be shorter as THA is higher.

  FIG. 6 is an example of a map that defines the relationship between the cooling water temperature THW and the second drying time T2. The ECU 40 specifies the second drying time T2 with reference to this map. The water contained in the enclosure 24 evaporates in a shorter time as the cooling water temperature THW is higher, that is, as the temperature of the internal combustion engine 10 is higher. For this reason, the second drying time T2 is set to be shorter as THW is higher.

  The moisture contained in the enclosure 24 continues to evaporate due to residual heat even after the internal combustion engine 10 is stopped. Even if a certain amount of moisture remains in the enclosure 24 at the time of stoppage, if the moisture disappears due to evaporation due to residual heat, the internal combustion engine 10 can be restarted satisfactorily without being affected by moisture. . For this reason, in the present embodiment, the first drying time T1 and the second drying time T2 described above are based on the use of residual heat after the internal combustion engine 10 is stopped, and the time required for the moisture in the enclosure 24 to completely disappear. It is set to a shorter time.

  When the processing in step 112 is completed, it is next determined whether or not the elapsed time from the point in time when the IG switch is turned off has reached the operation time T necessary for eliminating water wetting (step 114). As a result, when it is determined that the operation time T has not yet elapsed, the processing after step 100 is repeated again. If it is determined that the enclosure 24 is not wet before the operation time T has elapsed (see step 110), the internal combustion engine 10 is stopped at that time. In addition, if the operation time T elapses before it is determined that water has been removed, the internal combustion engine 10 is stopped at that time.

  According to the above processing, when the IG switch is turned off, it is possible to calculate the operation time T necessary to eliminate the moisture contained in the enclosure 24 on the premise of the residual heat of the internal combustion engine 10. Therefore, according to the present embodiment, the operation time after the IG switch is turned off can be shortened and the fuel consumption characteristics of the internal combustion engine 10 can be improved as compared with the case of the first embodiment.

[Modifications of Embodiments 1 and 2]
In the first and second embodiments described above, the internal combustion engine 10 is mounted on a hybrid vehicle or an eco-run vehicle, but the present invention is not limited to this. That is, the internal combustion engine 10 may be mounted on a vehicle that does not have an automatic stop function, and may be operated to eliminate water wetting only after the IG switch is turned off.

  In the first and second embodiments described above, almost the entire surface of the internal combustion engine 10 is covered by the enclosure 24, but the application of the present invention is not limited to such a configuration. That is, the present invention can be applied to an internal combustion engine that is at least partially covered with a hygroscopic cover. The purpose of the cover that covers at least a part of the internal combustion engine is not limited to soundproofing.

  In the first embodiment described above, the condition that the output V of the water detection sensor 26 is equal to or lower than the water wetness determination value is the water loss condition after the request for automatic stop and after the IG switch is turned off. In the second embodiment, the elapse of the operation time T = T1 + T2 is set as the water disappearance condition after the IG switch is turned off. However, water disappearance conditions that can be used in the present invention are not limited to these. For example, the passage of the operation time calculated based on the outside temperature THA or the cooling water temperature THW can be used as the water loss condition after the request for automatic stop. In addition, the water loss condition may be that a predetermined operation time elapses after the automatic stop request or the IG switch is turned off.

  In the second embodiment described above, the cooling water temperature THW of the internal combustion engine 10 is used as a basis for calculating the operation time T. However, this temperature may be replaced with the oil temperature of the internal combustion engine 10.

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 12 Engine compartment 24 Enclosure 26 Water detection sensor 40 Electronic control unit (ECU)

Claims (1)

A control device for an internal combustion engine at least partially covered by a cover,
A water detection sensor for detecting moisture contained in the cover;
A stop request detection process for detecting a stop request of the internal combustion engine;
An operation continuation process for continuing the operation of the internal combustion engine until a water loss condition is satisfied when the stop request is generated under a situation where the cover is determined to contain the water;
The control apparatus of the internal combustion engine characterized by performing this.

Images