JP2000186601A - Diesel engine controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate such a state that an engine becomes overspeeded by mixing excessive engine oil in an inlet passage, in this diesel engine wherein a fuel injection quantity from an injection nozzle is controlled according to the driving state. SOLUTION: When an engine 1 is in a state of being continuously driven at high speed more than the setting time, an oil-mix predicting means 35a predicting a mixing excessive state that engine oil to be taken out by blow-by gas becomes exceeded, and an injection quantity compensating means 35b decreasingly compensating a fuel injection quantity when the mixing excessive state is predicted by this oil-mix predicting means 35a both are installed in an inlet passage. The decreasing compensation of the fuel injection quantity is carried out till engine speed Ne is made lower than the preset return speed, and on the other hand, when this engine speed Ne is made lower than the return speed, the decreasing compensation is stopped. When a turbosuperchanger 30 has gone wrong, the fuel injection quantity may be decreasingly compensated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling a fuel supply amount to a diesel engine, and more particularly to a technical field for preventing an engine from over-rotating.

[0002]

2. Description of the Related Art Conventionally, as a control device for an engine of this type, as disclosed in, for example, Japanese Patent Application Laid-Open No. 63-94058, a reference value for determining an engine speed for determining an overspeed condition, and An overspeed allowable time corresponding to the criterion value is set, and when the engine is operated beyond the overspeed allowable time while the engine speed remains at or above the criterion value, the engine speed is forcibly set. Is known to reduce the temperature. According to this method, when the engine is over-rotated as described above, the energization of the ignition plug is stopped or the injection of fuel is stopped to forcibly reduce the engine speed. By that
The engine is prevented from being damaged by overspeed.

[0003]

Generally, blow-by gas leaking from the combustion chamber of the engine to the crank chamber through the space between the piston and the cylinder is formed by oil droplets (oil oil) of engine oil contained therein. After the mist is separated in the oil separator chamber, the mist is supplied to the intake system through a blow-by passage.

[0004] In particular, in the case of a small diesel engine mounted on a passenger car or the like, since the negative pressure of the intake system is not sufficient in the low rotation operation range, the blow-by passage from the oil separator chamber to the intake system is expanded to blow out blow-by gas. Ensuring quantity is being done.

[0005] On the other hand, in recent diesel engines, the rotation speed has been increased by reducing the weight of each part and equipping with a turbocharger. As a result, the amount of blow-by gas emission itself increases in the high rotation operation range. In addition, since the intake negative pressure is large, the amount of blow-by gas sucked out becomes too large, and there is a possibility that the carry-out of engine oil by the blow-by gas becomes excessive.

[0006] When the amount of engine oil mixed into the intake air in the high-speed operation range increases, the engine oil burns together with fuel (light oil), further increasing the engine speed. There is a difficulty that rotation is promoted. In addition, once the engine is in an overspeed state, the fuel injection is stopped as in the control device of the conventional example, and even if an attempt is made to forcibly reduce the engine speed, a large amount of gas mixed into the intake air is used. Since the engine oil burns, there arises a problem that the engine speed cannot be rapidly reduced.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to pay attention to the state of mixing of engine oil into an intake system in a diesel engine, and to cause excessive mixing of engine oil. An object of the present invention is to prevent engine overspeed.

[0008]

According to the present invention, there is provided an oil mixing predicting means for predicting in advance that an engine oil mixing amount in an intake system will be excessive, When the prediction means predicts that the engine oil is excessively mixed, the amount of fuel injection is reduced before that, thereby preventing the engine from over-rotating.

More specifically, according to the first aspect of the present invention, as shown in FIG. 1, a fuel injection valve 5 for injecting and supplying fuel is provided.
It is assumed that a diesel engine control device A controls the fuel injection amount of the fuel injection valve 5 according to the operating state of the engine 1. Then, oil mixing prediction means 35a for predicting an excessive mixing state in which excessive engine oil is mixed into the intake system 15 of the engine 1, and when the excessive mixing state is predicted by the oil mixing prediction means 35a, the fuel injection valve 5 And an injection amount correction means 35b for correcting the fuel injection amount to reduce the fuel injection amount.

According to this configuration, the amount of engine oil mixed into the intake system 15 during operation of the engine 1 increases,
When the oil mixture prediction unit 35a predicts the excessive mixture state, the fuel injection amount is reduced and corrected by the injection amount correction unit 35b, and the engine output decreases, so that the engine speed decreases. Thus, even if the engine 1 is in the high-speed operation state, it is possible to prevent the engine 1 from going into a further over-speed operation state.

Further, if the engine speed decreases, the amount of blow-by gas decreases, and the amount of engine oil taken out by the blow-by gas to the intake system 15 also decreases.
Excessive consumption of engine oil can be prevented.

In the second aspect of the present invention, the oil mixing predicting means predicts that the engine is in the excessive mixing state when the high-speed operation state of the engine continues for a set time or more. With this, when the high-speed operation state of the engine continues for the set time or longer, it is considered that the take-out of the engine oil by the blow-by gas becomes excessive, and therefore, the excessive mixing state due to this can be predicted with a high probability.

According to a third aspect of the present invention, there is provided a turbocharger for supercharging intake air by exhaust gas from the engine.
The oil mixing predicting unit predicts that the turbocharger is in a state of excessive mixing when the turbocharger breaks down. With this,
When the turbocharger breaks down, the lubricating engine oil often leaks from the bearings supporting the turbine and the blower, so that an excessive mixing state due to the leakage can be predicted with a high probability.

According to a fourth aspect of the present invention, there is provided a supercharging pressure sensor for detecting a supercharging pressure by the turbocharger according to the third aspect of the present invention, and the oil mixing predicting means includes a detection value of the supercharging pressure sensor. , A failure state of the turbocharger is detected. As a result, if the supercharging pressure by the turbocharger becomes different from that at normal time, a failure state of the turbocharger can be detected based on the fact.

[0015] In the invention according to claim 5, the injection amount correcting means includes:
If the engine speed that decreases with the fuel injection amount decrease correction becomes lower than a preset return rotation speed, the fuel injection amount decrease correction is stopped. Thus, the engine rotation speed is set to be equal to or lower than the return rotation speed by the correction of the decrease in the fuel injection amount, and the overspeed of the engine can be reliably prevented. Further, if the return rotation speed is set to a sufficiently high speed within a range that does not cause overspeed of the engine, for example, drivability is not impaired. On the other hand, if the return rotation speed is set to a sufficiently low rotation speed in response to the failure of the turbocharger,
Without causing damage to the turbocharger etc. due to the failure,
The vehicle can run safely at low speed.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows Embodiment 1 of the present invention.
1 shows an overall configuration of a diesel engine control device A according to the first embodiment.
The engine 1 has a plurality of cylinders 2, 2,... (Only one is shown), and a piston 3 is inserted into each cylinder 2 so as to be able to reciprocate. The combustion chamber 4 is partitioned. In addition, an injection nozzle (fuel injection valve) 5 is disposed at a substantially central portion of the upper surface of each combustion chamber 4 with the injection hole at the tip end facing the combustion chamber 4. The injection nozzles 5 are individually connected to a fuel injection pump (FIP) 7 by a fuel supply passage 6 and are opened by receiving high-pressure fuel pumped from the fuel injection pump 7, and open the high-pressure fuel to the combustion chamber 4. It is designed to inject directly. Further, a crankshaft (not shown) is provided with a crank angle sensor 8 for detecting the rotation angle.
The crank angle sensor 8 is composed of, for example, an electromagnetic pickup, and is disposed so as to face the outer periphery of the plate 9 to be detected provided at the end of the crankshaft. A pulse signal is output in response to the passage of the protrusion formed at an interval.

Although not shown in detail, the fuel injection pump 7 is of a distribution type in which fuel is individually supplied to the injection nozzle 5 of each cylinder by the operation of one plunger. The fuel injection pump 7 is driven by a rotation input from the crankshaft, and draws fuel (light oil) stored in a fuel tank 13 through a fuel filter 12 through a main passage 11. The plunger is operated at the fuel injection timing described above, and the fuel is individually pumped to each injection nozzle 5 through the fuel supply passage 6. Further, the fuel injection pump 7 is provided with an electromagnetic spill valve 7 a for returning a part of the fuel pressure-fed by the plunger to the return passage 14 and adjusting the fuel supply amount to each injection nozzle 5.

In FIG. 1, reference numeral 15 denotes an intake passage for supplying intake air (air) to the combustion chamber 4 of the engine 1. The downstream end of the intake passage 15 is branched into cylinders via a surge tank (not shown). Are connected to the combustion chambers 4 of the respective cylinders 2 by the intake ports 16. In the intake passage 15, an air cleaner 17 that filters intake air, a blower 18 that is driven by a turbine 27 described below to compress the intake air, and cools the intake air compressed by the blower 18, in order from the upstream side to the downstream side. Intercooler 1
9 are provided respectively.

A downstream end of a blow-by passage 20 for supplying blow-by gas to an intake system is connected to an intake passage 15 intermediate the air cleaner 17 and the blower 18. An upstream end of the blow-by passage 20 is connected to the engine 1. It is connected to the cylinder head cover 21. That is, the blow-by gas leaked from the combustion chamber 4 of the engine 1 to the crank chamber 22 is guided into the cylinder head cover 21 through a passage (not shown), and after separating oil mist therefrom,
The air flows through the blow-by passage 20 and is sucked into the intake passage 15. An intake pressure, that is, an atmospheric pressure sensor 23 for detecting an atmospheric pressure is provided in the intake passage 15 on the downstream side of the air cleaner 17, and an intake pressure is provided in the intake passage 15 on the downstream side of the intercooler 19. ,
That is, an intake pressure sensor (supercharging pressure sensor) 24 for detecting a supercharging pressure by the blower 18 is provided.

Further, in FIG.
An exhaust passage for discharging combustion gas (exhaust gas) from the combustion chamber 4 of the cylinder 2. The upstream end of the exhaust passage 25 is branched and connected to the combustion chamber 4 of each cylinder 2 by an exhaust port 26. The exhaust passage 25 includes, in order from the upstream side to the downstream side, a turbine 27 that is rotated by exhaust gas,
A catalytic converter 28 for purifying HC, CO and NOx and particulates in exhaust gas, and a silencer 29 for reducing exhaust noise are provided. The turbocharger 30 including the turbine 27 and the blower 18 is provided with a waste gate 31 for bypassing exhaust gas.

The exhaust passage 25 is a portion upstream of the turbine 27 and is branched and connected to an upstream end of an exhaust gas recirculation passage 33 for recirculating a part of exhaust gas to the intake side. The downstream end of the exhaust gas recirculation passage 33 is connected to the intake passage 15 on the downstream side of the intercooler 19.
Is arranged, and a part of the exhaust gas is recirculated to the intake passage 15 while the flow rate of a part of the exhaust gas is adjusted by the flow control valve 34.

The crank angle sensor 8 and the atmospheric pressure sensor 2
3 and an output signal from the intake pressure sensor 24 are input to a control unit (Engine Control Unit: hereinafter referred to as ECU) 35. The ECU 35 includes an accelerator opening sensor 3 for detecting an operation amount (accelerator opening) of an accelerator pedal (not shown) by a driver of the vehicle.
6 is also input, and the operating state of the engine is detected mainly based on input signals from the accelerator opening sensor 36 and the crank angle sensor 8. On the other hand, a control signal is output from the ECU 35 to the fuel injection pump 7, and the amount of fuel injected from the injection nozzle 5 is controlled according to the operating state of the engine 1 by operating the electromagnetic spill valve 7 a of the fuel injection pump 7. Is done.

Further, as a feature of the present invention, the ECU
An oil mixing prediction unit 35a for predicting an excessive mixing state in which excessive engine oil is mixed into the intake system of the engine 1 and an injection nozzle 5 when the oil mixing prediction unit 35a predicts an excessive mixing state. And an injection amount correcting means 35b for reducing the fuel injection amount of the engine 1. When the engine oil is taken out by blow-by gas and the engine 1 is likely to be over-rotated, the fuel injection amount is reduced. To reduce the engine speed. Incidentally, the oil mixing prediction means 35
The a and the injection amount correcting means 35b are realized by executing a control program electronically stored in a memory of the ECU 35.

Next, among the control procedures for preventing the engine 1 from over-rotating by the ECU 35, first, the processing procedure of oil mixing prediction for predicting an excessively mixed state of engine oil will be described in detail with reference to FIG. Description will be made based on the flowchart. The processing of this flow is executed at predetermined time intervals in synchronization with the clock of the ECU 35.

As shown in the flow chart of FIG. 2, first, at step SA1 after the start, the engine speed Ne is detected based on a signal from the crank angle sensor 8.
Subsequently, in step SA2, a timer for measuring the duration of the engine 1 in the high-speed operation state is reset (TENGO = 0), and in subsequent step SA3,
It is determined whether or not the engine speed Ne obtained in step SA1 is higher than a set speed KNENGO (for example, 4800 rpm). If the result of this determination is NO with Ne ≦ KNENGO, it is determined that the engine 1 is not in the high-speed operation state, and step S
On the other hand, if Ne> KNENGO and YES, the process proceeds to A8, and it is determined that the engine 1 is in the high rotation operation state, and the process proceeds to Step SA4.

Subsequently, in step SA4, the timer is counted up (TENGO = TENGO + α), and in step SA5, the timer value is compared with a set timer value KTENGO corresponding to a preset set time (for example, 10 seconds). Then, the timer value TENGO is set to the set timer value KTE
If the answer is NO below NGO, the process returns to step SA3, while the timer value TENGO is equal to the set timer value KTENGO.
If YES is obtained, the process proceeds to step SA6, where it is estimated that the engine oil is excessively mixed into the intake air. In the next step SA7, the excessive mixing state prediction flag FLUG (XENGO) is turned on, and the control is terminated. Yes (end).

That is, the engine speed Ne is equal to the set speed KN.
When the high-speed operation state higher than ENGO continues for more than the set time, it is predicted that the engine oil is excessively mixed into the intake air, and the mixed excessive state prediction flag FLUG (XENG
O) is turned on.

On the other hand, in step SA8, where it is determined that the engine 1 is not in the high-speed operation state in step SA3, the process proceeds to step SA8, in which an excessive mixing state prediction flag FLUG (XENGO)
Is turned off, and the control is terminated (END).

In each of the steps SA1 to SA8, an oil mixing predicting means 3 for predicting an excessive mixing state in which excessive engine oil is mixed into the intake system of the engine 1.
5a is configured.

Next, the processing procedure of the fuel injection amount reduction correction when the oil mixing prediction means 35a predicts the excessive mixing of the engine oil will be described in detail with reference to FIG.
This will be described based on the flowchart of FIG. The processing of this flow is also executed at predetermined time intervals in synchronization with the clock of the ECU 35.

As shown in the flow of FIG. 3, first, at step SB1 after the start, it is determined whether or not the mixed-in excess state prediction flag FLUG (XENGO) is in an on state.
If this determination is NO, the control is terminated without performing the fuel injection amount decrease correction. On the other hand, if the determination is YES, the process proceeds to step SB2 to perform the fuel injection amount reduction correction. That is, the correction amount KQFULE is set in advance from the basic fuel injection amount QFULEO set based on the operating state of the engine 1.
O is subtracted, and the fuel injection amount after the subtraction is set again as the fuel injection amount QFULEO.

Subsequently, in step SB3, the engine speed Ne is determined based on the signal from the crank angle sensor 8.
Is detected, and in the next step SB4, the detected engine speed Ne becomes equal to a preset return speed (for example, 46
00 rpm). If the result of this determination is NO, the engine speed Ne has not yet been sufficiently reduced by the above-described fuel injection amount reduction correction, so the flow returns to step SB2 to continue the fuel injection amount reduction correction. . On the other hand, if the engine output decreases due to the fuel injection amount reduction correction and the engine speed Ne becomes lower than the return rotation speed, the determination result becomes YES. Therefore, the reduction correction is stopped, and the process proceeds to step SB5.
In B5, the mixed state excess state prediction flag FLUG (XENGO) is turned off, and the control is ended (END).

In each of the steps SB1 to SB4, while the engine speed Ne is equal to or higher than the preset return speed, the fuel injection amount is reduced and the engine speed Ne becomes lower than the return speed. For example, an injection amount correction means 35b for stopping the reduction correction is configured.

Therefore, according to the control apparatus A for the diesel engine according to the first embodiment, during the operation of the engine 1, the engine speed Ne is higher than the set speed KNENGO and the engine is in a high speed operation state. When the state continues for a set time or longer, the oil mixing prediction unit 35a predicts that the mixing amount of the engine oil into the intake air will be in an excessive mixing state. If an excessive mixing state is predicted, the fuel injection amount is corrected to be reduced by the injection amount correcting means 35b, and the engine output is reduced. Therefore, the engine speed Ne is reduced, and the overspeed of the engine 1 is prevented. Is done.

Also, with the decrease in the engine speed Ne,
The amount of blow-by gas discharged from the combustion chamber 4 of the engine 1 itself decreases, and the flow rate of blow-by gas sucked into the intake passage 20 from inside the cylinder head cover 21 also decreases. A sufficiently large amount of oil mist can be separated, and the amount of engine oil taken out by blow-by gas can be greatly reduced. That is, excessive consumption of engine oil can be prevented.

Further, when the engine speed Ne becomes lower than the return speed, the fuel injection amount reduction correction is stopped, the required amount of fuel corresponding to the operation state of the engine 1 is injected and supplied, and the fuel is supplied in response to the accelerator operation. Also, since sufficient engine output is obtained, drivability is not impaired.

(Embodiment 2) FIG. 4 shows a processing procedure for predicting oil contamination in Embodiment 2 of the present invention. The overall configuration of the diesel engine control device A according to the second embodiment is the same as that of the first embodiment (see FIG. 1).
The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the control device A of the second embodiment, the atmospheric pressure sensor 23 and the intake pressure sensor 24
, A failure state of the turbocharger 30 is detected, and when the failure state of the turbocharger 30 is detected, it is predicted that excessive engine oil is mixed into the intake system. Like that.

Specifically, as shown in the flow chart of FIG.
First, in step SC1 after the start, the intake pressure PIM in the intake passage 10 downstream of the blower 18 is detected based on the output signal from the intake pressure sensor 24, and in subsequent step SC2, the pressure from the atmospheric pressure sensor 37 is detected. An atmospheric pressure PATM in the intake passage 10 upstream of the blower 18 is detected based on the output signal. Subsequently, in step SC3, a timer for measuring a time during which the intake pressure PIM is higher than the atmospheric pressure PATM by a predetermined value or more is reset (TTCO = 0).

Subsequently, in step SC4, it is determined whether or not the pressure difference between the atmospheric pressure PATM and the intake pressure PIM detected in steps SC1 and SC2 is larger than a set pressure difference KPATCO (for example, 100 mmhg). I do. That is, it is determined whether or not the intake negative pressure is larger than a predetermined value in the intake passage 15 downstream of the blower 18 of the turbocharger 30. If PATM-PIM ≦ KPATCO and the determination is NO, it is determined that the turbocharger 30 has not failed, because the intake negative pressure on the downstream side of the blower 18 is sufficiently small, and the process proceeds to step SC9. On the other hand, PATM-PIM> KPATCO
If the determination is YES, there is a possibility that the turbocharger 30 has failed, and the process proceeds to step SC5.

Subsequently, in step SC5, the timer is counted up (TTCO = TTCO + α) and step SC6
In step SC6, the timer value is compared with a set timer value KTTCO corresponding to a preset set time (for example, 10 seconds). If the timer value TTCO is equal to or less than the set timer value KTYCO and NO, the process returns to step SC4. If the timer value TTCO becomes YES which is larger than the set timer value KTTCO, the process proceeds to step SC7. Then, it is estimated that the amount of engine oil mixed into the intake air becomes excessive due to the failure of the turbocharger 30, and in the subsequent step SC8, the mixed state excess prediction flag FLUG (XFTCO) is turned on, and the control is ended (END) ).

That is, the blower 18 of the turbocharger 30
When the intake negative pressure on the downstream side is larger than the atmospheric pressure by a predetermined amount or more, it is considered that the blower 18 does not rotate at a high speed and becomes an intake resistance. Continuing can be presumed that the blower 18 has failed and cannot rotate normally. In this case, since it is predicted that the engine oil for lubrication leaks from the bearing portion of the blower 18 and a large amount of engine oil is mixed into the intake air, the mixed state excess state prediction flag FLUG (X
FTCO) is turned on.

On the other hand, in step SC9, where it is determined in step SC4 that the turbocharger 30 has not failed and NO has proceeded, in step SC9, the mixed-excess-state prediction flag FLUG (XFTC
O) is turned off and the control is terminated (END).

In each of the steps SC1 to SC9, the failure state of the turbocharger 30 is detected based on the value detected by the supercharging pressure sensor 24, and the turbocharger 3 is detected.
When 0 fails, oil mixing prediction means 35a for predicting an excessive mixing state of the engine oil is configured.

When the oil mixing prediction state is predicted by the oil mixing prediction section 35a, the engine speed N is increased by the injection amount correction section 35b as in the first embodiment.
Until e becomes lower than the preset return rotation speed, the fuel injection amount is reduced and corrected. The return rotation speed in this case is significantly lower than that of the first embodiment, for example, about 2500.
Set it to rpm.

That is, when the turbocharger 30 fails, the vehicle is driven at a low speed and safely while keeping the engine speed Ne sufficiently low so that damage to the turbocharger 30 and the engine 1 due to the failure is not increased. (Escape run).

Therefore, according to the diesel engine control device A of the second embodiment, the turbocharger 30
When a failure occurs in the first embodiment, it is predicted that the amount of engine oil mixed into the intake air due to the failure becomes excessive, and the fuel injection amount is reduced correspondingly.
Similarly, the engine 1 can be prevented from over-rotating. Further, by keeping the engine speed Ne extremely low, it is possible to drive the vehicle safely while preventing damage to the turbocharger 30 and the like.

(Other Embodiments) The present invention is not limited to the above embodiments, but includes various other embodiments. That is, in the second embodiment, the supercharging pressure (intake pressure PIM) by the turbocharger 30 is detected, and the failure state of the turbocharger 30 is detected based on the difference between the detected value and the atmospheric pressure PATM. However, the present invention is not limited to this. For example, a target intake pressure is determined in advance based on the engine speed Ne, and the deviation between the actual intake pressure PIM detected by the intake pressure sensor 24 and the target intake pressure is determined. When the value is equal to or more than the predetermined value, the failure state of the turbocharger 30 may be detected.

Further, in each of the above-described embodiments, an excessively mixed state of the engine oil is predicted based on the engine speed Ne and the intake pressure PIM. However, the present invention is not limited to this. An optical sensor or the like may be provided in the intake passage 15 to directly detect the amount of oil mist in the intake air.

Further, the control for preventing the engine 1 from over-rotating in the first embodiment may be performed together with the control in the second embodiment.

[0051]

As described above, according to the control apparatus for a diesel engine according to the first aspect of the present invention, the oil mixing prediction means for predicting an excessive mixing state in which excessive engine oil is mixed into the intake system of the engine is provided. When the excessive mixing state is predicted by the oil mixing predicting means, the fuel injection amount is corrected to be reduced by the injection amount correcting means. Even if the amount of mixed oil is large, it is possible to prevent the engine from rotating excessively. Further, excessive consumption of engine oil can be prevented due to a decrease in the engine speed.

According to the second aspect of the present invention, it is possible to predict with high probability that when the high-speed operation state of the engine continues, the take-out of the engine oil by the blow-by gas becomes excessive and the excessive mixing state occurs.

According to the third aspect of the present invention, when the turbocharger fails, it is possible to predict with high probability that the engine oil leaks from the bearing portion of the turbocharger and an excessive mixing state occurs. .

According to the fourth aspect of the present invention, a failure state of the turbocharger can be detected based on the value detected by the supercharging pressure sensor.

According to the fifth aspect of the present invention, the overspeed of the engine can be reliably prevented by the correction of the decrease in the fuel injection amount, but when the engine speed becomes lower than the return speed, the decrease correction is stopped. Drivability can be ensured, and the vehicle can run safely without damaging the turbocharger.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a diesel engine control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a processing procedure for predicting an excessively mixed state of engine oil.

FIG. 3 is a flowchart illustrating a processing procedure for correcting a fuel injection amount to decrease.

FIG. 4 is a diagram corresponding to FIG. 2 according to the second embodiment.

[Description of Signs] A Diesel engine control device 1 Diesel engine 5 Injection nozzle (fuel injection valve) 15 Intake passage (intake system) 24 Intake pressure sensor (supercharging pressure sensor) 30 Turbocharger 35 Control unit (ECU) 35a Oil mixing prediction means 35b Injection amount correction means

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Michio Matsushima 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda F-term (reference) 3G065 AA01 AA03 CA31 CA40 EA11 GA00 GA01 GA02 GA04 GA10 GA26 GA46 KA36 3G301 HA02 HA11 JA00 JA34 JB02 JB09 KA25 LB15 NA08 NB02 NC08 NE06 NE23 PA07Z PA09Z PA16Z PE00Z PE01Z PE03Z PF03Z

Claims (5)

[Claims] 1. A diesel engine control device comprising a fuel injection valve for injecting fuel and controlling a fuel injection amount of the fuel injection valve in accordance with an operation state of the engine. Oil mixing prediction means for predicting an excessive mixing state in which the engine oil is mixed, and an injection amount correction for correcting the fuel injection amount by the fuel injection valve when the oil mixing prediction state predicts the excessive mixing state. And a control unit for a diesel engine. 2. The control apparatus for a diesel engine according to claim 1, wherein the oil mixing prediction means predicts, when the high-speed operation state of the engine has continued for a set time or more, an excessive mixing state. . 3. The turbocharger according to claim 1, further comprising a turbocharger for supercharging intake air with exhaust gas from the engine, wherein the oil mixing predicting means detects when the turbocharger fails, and sets an excess mixing state when the turbocharger fails. A diesel engine control device, characterized in that it is predicted that 4. A turbocharger according to claim 3, further comprising a supercharging pressure sensor for detecting a supercharging pressure by the turbocharger, wherein the oil mixing prediction unit detects the supercharging pressure based on a value detected by the supercharging pressure sensor. A diesel engine control device configured to detect a failure state of a machine. 5. The fuel injection control device according to claim 1, wherein the injection amount correction unit is configured to determine whether an engine speed that decreases with the fuel injection amount reduction correction is lower than a preset return speed. A control device for a diesel engine, which is configured to stop correction of a decrease in a fuel injection amount.