JP2012112300A - Control apparatus for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably avoid an adverse effect when oil is overconsumed regarding a control apparatus of the internal combustion engine.SOLUTION: The control apparatus for the internal combustion engine includes: an oil consumption detection means (steps 102-106) that detect a rate of oil consumption of the internal combustion engine; and a load restricting means (step 114) that restricts a load that executes control for restricting the load of the internal combustion engine when the rate of oil consumption detected by the oil consumption detection means exceeds a reference.

Description

  The present invention relates to a control device for an internal combustion engine.

  If the amount of oil in the internal combustion engine is insufficient, a serious failure such as engine seizure may occur. Japanese Patent Application Laid-Open No. 2003-201905 discloses that when the engine oil amount is detected to be equal to or less than a predetermined value in order to make the driver recognize the shortage of engine oil and prevent engine burn-in, An engine control system that temporarily suppresses starting of the engine is disclosed. Further, in this engine control system, when the amount of engine oil is detected to be equal to or less than a predetermined value, the engine is stopped during operation to prevent a sudden engine stop during engine operation. It is intended to prevent or suppress the occurrence of problems for the users.

JP 2003-201905 A

  The above conventional technique provides for a problem when the amount of engine oil is insufficient. On the other hand, even if the engine oil is not deficient, there is the following problem when the consumption of the engine oil is excessive. At the time of product shipment, quality control is performed so that the oil consumption is within an appropriate range. For example, when the wear of the piston ring and cylinder bore has progressed over time, the oil consumption due to so-called oil increase increases. Sometimes. When the oil consumption is excessive, an excessive amount of oil is burned in the combustion chamber. If the amount of oil burned in the combustion chamber is excessive, abnormal combustion such as pre-ignition and excessive knocking tends to occur. If such abnormal combustion occurs, there is a risk that abnormal noise may occur or the engine may be damaged.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a control device for an internal combustion engine that can reliably avoid the occurrence of adverse effects when the oil consumption is excessive.

In order to achieve the above object, a first invention is a control device for an internal combustion engine,
Oil consumption detecting means for detecting the speed of oil consumption of the internal combustion engine;
Load limiting means for executing control for limiting the load of the internal combustion engine when the speed of oil consumption detected by the oil consumption detecting means exceeds a predetermined reference;
It is characterized by providing.

  According to the first invention, when it is predicted that the oil consumption of the internal combustion engine is fast and there is a risk of abnormal combustion due to the oil combustion in the combustion chamber, the abnormal combustion is limited by limiting the load of the internal combustion engine. Can be prevented in advance. For this reason, it is possible to reliably prevent the adverse effects of abnormal combustion, that is, abnormal noise or damage to the engine.

It is a figure for demonstrating the system configuration | structure of Embodiment 1 of this invention. It is a flowchart of the routine performed in Embodiment 1 of the present invention. It is a figure for demonstrating the method to determine the speed of oil consumption.

Embodiment 1 FIG.
FIG. 1 is a diagram for explaining a system configuration according to the first embodiment of the present invention. An engine (internal combustion engine) 10 shown in FIG. 1 is mounted as a power source in a vehicle (not shown). Each cylinder of the engine 10 is provided with a reciprocating piston 15, a combustion chamber 16, an intake valve 24, an exhaust valve 25, an injector 28 for injecting fuel into the intake port, and a spark plug 32. ing. In the present invention, the engine 10 is not limited to the port injection type as shown in the figure, and may include an in-cylinder injector that directly injects fuel into the combustion chamber 16. Moreover, you may use together port injection and in-cylinder injection.

  In the vicinity of the crankshaft 17 of the engine 10, a crank angle sensor 20 for detecting a crank angle and an engine rotational speed is disposed. The intake passage 26 is provided with an electronically controlled throttle valve (hereinafter simply referred to as “throttle valve”) 36 for adjusting the amount of intake air. The throttle valve 36 is controlled to open and close by a throttle valve motor 37. The drive of the throttle valve motor 37 is electrically controlled by a signal from an ECU (Electronic Control Unit) 50 described later. The opening degree of the throttle valve 36 (hereinafter referred to as “throttle opening degree”) is detected by a throttle sensor 37a, and the detection result is taken into the ECU 50. An accelerator opening sensor 39 for detecting the amount of depression of the accelerator pedal 38 (hereinafter referred to as “accelerator opening”) is provided in the vicinity of the accelerator pedal 38 in the driver's seat of the vehicle. The engine 10 is also provided with an oil level sensor 40 that detects the amount of engine oil (lubricating oil) (oil level) in an oil pan (not shown).

  Various sensors and actuators including those described above are electrically connected to the ECU 50. The ECU 50 controls the operation of the engine 10 by controlling the drive of each actuator based on the detection result of each sensor.

  An automatic transmission 44 is connected to the engine 10 of the present embodiment. The crankshaft 17 of the engine 10 is connected to the pump impeller 46 of the torque converter 41, and both rotate together. The turbine runner 47 of the torque converter 41 is connected to the input shaft 42 to the transmission mechanism of the automatic transmission 44, and both rotate together. The output shaft 48 of the automatic transmission 44 is connected to drive wheels (not shown) via a differential gear and a drive shaft (not shown). The transmission mechanism of the automatic transmission 44 may be either a stepped type or a stepless type.

  The automatic transmission 44 is controlled by the ECU 50. The ECU 50 stores a shift line for determining the gear stage or gear ratio of the automatic transmission 44. The ECU 50 determines the automatic transmission based on vehicle speed information detected by a vehicle speed sensor (not shown), information such as a throttle opening (or an intake pipe pressure detected by an intake pipe pressure sensor (not shown)), and the shift line. 44 is determined, and the automatic transmission 44 is caused to perform a shift.

  When the wear of the piston ring and cylinder bore of the engine 10 has progressed over time, the amount of oil consumed by so-called oil increase may increase. In addition, depending on the individual difference of the engine 10, there may be a tendency that the oil consumption is large. Alternatively, the oil consumption may increase depending on how the user operates, such as using a lot of engine brakes. When the oil consumption is excessive, an excessive amount of oil is burned in the combustion chamber 16. If the amount of oil combusted in the combustion chamber 16 is excessive, preignition, excessive knock, etc. (hereinafter collectively referred to as “abnormal combustion”) are likely to occur. If such abnormal combustion occurs, abnormal noise may occur or the engine 10 may be damaged. Abnormal combustion due to excessive oil combustion is likely to occur when the engine 10 is operated in a high load region. For this reason, even if the oil consumption is excessive, the occurrence of abnormal combustion can be prevented if the engine 10 is not operated in a high load region.

  In view of the above matters, in the present embodiment, the oil consumption rate of the engine 10 is detected, and the detected oil consumption rate is compared with a predetermined standard, so that the oil consumption is excessive. It was decided to determine whether or not. And when oil consumption is excessive, in order to prevent generation | occurrence | production of abnormal combustion, it decided to perform the control which restrict | limits the load of the engine 10. FIG.

  FIG. 2 is a flowchart of a routine executed by the ECU 50 in the present embodiment in order to realize the above function. According to the routine shown in FIG. 2, it is first determined whether or not a predetermined condition for detecting the amount of oil in the oil pan is established based on the output of the oil level sensor 40 (step 100). In order to accurately detect the oil consumption, it is necessary to detect the amount of oil in the oil pan under the same conditions every time. This step 100 is for judging the condition. For example, if the oil amount is to be detected when the engine 10 is started, it is determined in step 100 whether or not the engine 10 is starting.

  If it is determined in step 100 that the oil amount detection condition is satisfied, the oil amount in the oil pan is calculated based on the output of the oil level sensor 40 (step 102). Subsequently, the difference between the oil amount calculated last time and the oil amount calculated this time is calculated as the oil consumption amount (step 104). Then, based on the calculated oil consumption, whether or not the speed of oil consumption is faster than a predetermined reference is determined as follows (step 106).

  FIG. 3 is a diagram for explaining a method of determining the speed of oil consumption. The horizontal axis in FIG. 3 is the travel distance of the vehicle. The travel distance is detected by an odometer (not shown), and the detection result is input to the ECU 50. The vertical axis in FIG. 3 is the integrated value of the oil consumption calculated in step 104 above. As shown in FIG. 3, in this embodiment, when the slope of the increase in oil consumption with respect to the increase in travel distance exceeds the upper limit of the slope assumed to be within the normal range, the speed of oil consumption is increased. Judge that it exceeds the standard. Therefore, in step 106, the slope Qloc of the oil consumption increase with respect to the travel distance is calculated, and this Qloc is compared with a specified value Qt corresponding to the upper limit of the slope assumed to be within the normal range. It is determined whether the speed of oil consumption exceeds the standard.

  If Qloc> Qt is satisfied in step 106, it is determined that the speed of oil consumption exceeds the reference, and the large oil consumption flag Xloc indicating that is turned ON (step 108). On the other hand, when Qloc> Qt is not established, that is, when Qloc ≦ Qt, the oil consumption speed is within the normal range, so the large oil consumption flag Xloc is turned off (step 110).

  Subsequently, the value of the large oil consumption flag Xloc is determined (step 112). In step 112, when the large oil consumption flag Xloc is OFF, it is not necessary to limit the load of the engine 10, so the processing of this routine is ended as it is. On the other hand, when the large oil consumption flag Xloc is ON, load limit control is performed to limit the load of the engine 10 to a predetermined load or less (step 114).

  As the load limiting control in step 114, for example, control for limiting the throttle opening can be performed. By limiting the throttle opening, the amount of intake air is limited, so the load on the engine 10 can be limited. In the case of an engine equipped with a turbocharger having an electronically controlled wastegate valve, control for limiting the load on the engine 10 by opening the wastegate valve is performed instead of control for limiting the throttle opening. Also good. Since the increase of the supercharging pressure is suppressed by opening the waste gate valve, the load on the engine 10 can be limited.

  Further, as the load limiting control in step 114, the load on the engine 10 may be limited by performing control for changing the shift line of the automatic transmission 44, instead of the engine-side control as described above. . In this case, the use range of the engine 10 is shifted to the low load side by changing the shift line so that a lower gear stage or a larger gear ratio is selected compared to the normal shift line. The load can be limited.

  As described above, according to the present embodiment, the load on the engine 10 can be limited when the oil consumption is excessive. Thereby, it is possible to avoid occurrence of abnormal combustion due to excessive oil combustion. For this reason, it is possible to reliably prevent the adverse effects of abnormal combustion, such as the generation of abnormal noise or damage to the engine 10.

  In the first embodiment described above, the ECU 50 executes the processes of steps 102 to 106, so that the “oil consumption detecting means” in the first invention executes the process of step 114. The “load limiting means” in the first aspect of the invention is realized.

10 Engine 15 Piston 16 Combustion chamber 24 Intake valve 25 Exhaust valve 26 Intake passage 28 Injector 32 Spark plug 36 Throttle valve 44 Automatic transmission 50 ECU

Claims (1)

Oil consumption detecting means for detecting the speed of oil consumption of the internal combustion engine;
Load limiting means for executing control for limiting the load of the internal combustion engine when the speed of oil consumption detected by the oil consumption detecting means exceeds a predetermined reference;
A control device for an internal combustion engine, comprising:

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