JP2017137831A - Abnormality determination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine a type of an abnormality in an engine.SOLUTION: An abnormality determination device is for a diesel engine 100 including: a blow-by gas passage 15 for recirculating blow-by gas generated in a crank case 5 to an intake passage; an oil separator 21 provided in the middle of the blow-by gas passage 15 and collecting oil included in the blow-by gas; and an inner pressure detection sensor 31 for detecting inner pressure of the crank case 5. The abnormality determination device determines a type of an abnormal state of the diesel engine 100 on the basis of a difference between a detected inner pressure value input from the inner pressure detection sensor 31 and a set inner pressure value that indicates the inner pressure of the crank case 5 preset corresponding to engine speed and engine torque.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an abnormality determination device.

  Conventionally, an engine equipped with a PCV (Positive Crankcase Ventilation) system is known. The PCV system has a blow-by gas passage having one end connected to the inside of the crankcase and the other end connected to an intake passage, and an oil separator provided in the middle of the blow-by gas passage. With this configuration, blow-by gas generated inside the crankcase is returned to the intake side of the engine via the blow-by gas passage. The oil in the blow-by gas is collected by the oil separator and returned to the inside of the crankcase.

  Patent Document 1 discloses an abnormality determination device that determines whether there is an abnormality in a PCV system.

JP 2010-096032 A

  In an engine equipped with a PCV system, various types of abnormalities with different countermeasures may occur, and it is desired to determine the type of abnormality. The abnormality determination device of Patent Document 1 is not limited to determining whether or not there is an abnormality in the PCV system, and does not determine the type of abnormality in the engine.

  The objective of this invention is providing the abnormality determination apparatus which can determine the kind of abnormality in an engine.

  An abnormality determination device according to an aspect of the present invention includes a blowby gas passage for returning blowby gas generated inside a crankcase to an intake passage, and an oil contained in the blowby gas provided in the middle of the blowby gas passage. An engine abnormality determination device including an oil separator to be collected and a sensor for detecting an internal pressure of the crankcase, which corresponds to a detected internal pressure value input from the sensor, an engine speed, and an engine torque in advance. The type of the abnormal state of the engine is determined based on the difference from the set internal pressure value indicating the set internal pressure of the crankcase.

  According to the present invention, the type of abnormality in the engine can be determined.

The figure which shows an example of a structure of the diesel engine which concerns on embodiment of this invention The figure which shows an example of the setting internal pressure value table which concerns on embodiment of this invention The figure which shows an example of the flow of the abnormality determination operation | movement which concerns on embodiment of this invention

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, a diesel engine will be described as an example, but the present invention is not limited to this diesel engine, and can be applied to other engines.

  First, the structure of the diesel engine 100 which concerns on embodiment of this invention is demonstrated using FIG. FIG. 1 is a diagram illustrating an example of a configuration of a diesel engine 100 according to the present embodiment.

  As shown in FIG. 1, a diesel engine 100 includes an engine body 10, an intake passage 12, an exhaust passage 13, an EGR passage 14, an air cleaner 16, a turbocharger 17, an intercooler 18, an EGR cooler 19, an EGR valve 20, and a PCV system 24. (Blow-by gas passage 15, oil separator 21).

  The engine body 10 has a cylinder block 1. A piston ring 2 is provided in the cylinder block 1. The piston 3 slides in the cylinder block 1, the crankcase 5 that accommodates the crankshaft 4, the oil pan 6 that contains lubricating oil, and the combustion chamber 22. A fuel injection valve (injector) 23 for injecting fuel is provided.

  Further, an intake passage 12 for introducing new air A and an exhaust passage 13 for discharging exhaust gas G are connected to the combustion chamber 22 of the engine body 10. The arrows in the intake passage 12 and the arrows in the exhaust passage 13 indicate the flows of new air A and exhaust gas G, respectively.

  An air cleaner 16, a compressor 17 a of a turbocharger 17, and an intercooler 18 are disposed in the intake passage 12. A gas turbine 17 b of the turbocharger 17 is disposed in the exhaust passage 13. The compressor 17a and the gas turbine 17b are connected by a rotating shaft 17c. Although not shown, the turbocharger 17 and the inside of the crankcase 5 are connected by an oil supply passage.

  The EGR passage 14 is a passage through which the EGR gas Ge is circulated in order to perform exhaust gas recirculation (EGR), and is connected to the intake passage 12 and the exhaust passage 13. An EGR cooler 19 and an EGR valve 20 are disposed in the EGR passage 14. An arrow in the EGR passage 14 indicates the flow of the EGR gas Ge.

  The PCV system 24 includes a blow-by gas passage 15 and an oil separator 21. One end of the blowby gas passage 15 is connected to the inside of the crankcase 5, and the other end of the blowby gas passage 15 is connected to the intake passage 12 upstream of the compressor 17a. Thereby, the blow-by gas Gb generated inside the crankcase 5 is recirculated to the intake side of the diesel engine 100 through the blow-by gas passage 15. The arrow in the blowby gas passage 15 indicates the flow of the blowby gas Gb.

  The oil separator 21 is disposed in the middle of the blow-by gas passage 15. Thereby, the oil contained in the blow-by gas Gb is separated and collected from the blow-by gas Gb by the oil separator 21, returned to the inside of the crankcase 5 through an oil return passage (not shown), and stored in the oil pan 6. Is done.

  In the blow-by gas passage 15, an internal pressure detection sensor 31 that detects the pressure inside the crankcase 5 is provided upstream of the oil separator 21. A value detected by the internal pressure detection sensor 31 (hereinafter referred to as a detected internal pressure value) is output to the ECU 30. The arrangement position of the internal pressure detection sensor 31 is not limited to the position shown in FIG. 1 as long as the internal pressure of the crankcase 5 can be detected.

  In the above, the structural example of the diesel engine 100 of this Embodiment was demonstrated.

  Next, the ECU 30 shown in FIG. 1 will be described.

  The ECU (Electronic Control Unit) 30 is a control device that controls the diesel engine 100. The ECU 30 is, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory) storing a computer program, a RAM (Random Access Memory) storing various data, a backup RAM, an input / output circuit, a bus line connecting them, and the like It is configured as a logical operation circuit consisting of And each function of ECU30 mentioned below can be realized by a computer program. For example, the ECU 30 copies the computer program stored in the ROM to the RAM, and sequentially reads out and executes the instructions included in the computer program from the RAM, thereby realizing each function of the ECU 30. In addition, when the computer program is executed, data obtained by various processes is stored in the RAM and used as appropriate.

  For example, values such as engine speed, accelerator opening, fuel injection amount, cooling water temperature, exhaust temperature, turbine speed, and the like are input to the ECU 30. The ECU 30 calculates control parameters such as the EGR valve opening, the variable nozzle opening of the turbocharger 17, the fuel injection timing, and the fuel injection pressure based on these input values, preset data, and a computer program. To do. The ECU 30 then outputs a control signal corresponding to the control parameter to control the EGR valve 20, the variable nozzle (not shown) of the turbocharger 17, the fuel injection valve 23, and the fuel pump (not shown). Since these controls are publicly known, detailed description thereof is omitted.

  The detected internal pressure value is input to the ECU 30 from the internal pressure detection sensor 31. The ECU 30 performs an abnormality determination operation for determining the type of an abnormal state that occurs in the diesel engine 100 based on the detected internal pressure value and preset data (hereinafter referred to as setting data; details will be described later). Therefore, the ECU 30 corresponds to an example of an abnormality determination device. Details of the abnormality determination operation will be described later with reference to FIG.

  Here, the types of abnormal states determined by the abnormality determination operation of the present embodiment will be described.

  The types of abnormal states are, for example, seizure of the piston 3 or the piston ring 2, gas blow-out of the turbocharger 17, and dilution.

  The seizure of the piston 3 or the piston ring 2 means that the piston 3 or the piston ring 2 is worn or missing, so that a gap is formed between the piston 3 or the piston ring 2 and the inner wall of the cylinder, and the combustion chamber passes through the gap. A state in which gas flows from 22 into the crankcase 5.

  The gas blow-through of the turbocharger 17 means that, for example, a bearing (not shown) that supports the rotating shaft 17c is damaged, and the gas on the intake side passes through the oil supply passage (not shown) to the inside of the crankcase 5. The state that blows through.

  Dilution (also referred to as fuel dilution) means, for example, that fuel is mixed with oil accumulated in the oil pan 6 and the oil level rises, and the crankshaft 4 rotates to expel the oil. A state in which oil scatters inside.

  When any of the above abnormal conditions occurs, the internal pressure of the crankcase 5 increases. When dilution occurs, the internal pressure of the crankcase 5 increases with time.

  The types of abnormal states have been described above.

  Next, an example of setting data used in the abnormality determination operation of this embodiment will be described.

  The setting data is set before the start of the abnormality determination operation and is stored, for example, in the ROM of the ECU 30 or the like. Examples of the setting data include a threshold value and a set internal pressure value table.

  The threshold value is a value set based on the results of experiments and simulations performed in advance so that the seizure of the piston 3 or the piston ring 2 and the gas blow-through of the turbocharger 17 can be discriminated.

  The set internal pressure value table is a table showing a correspondence relationship between the engine speed, the engine torque, and the internal pressure value of the crankcase 5 when no abnormal state has occurred. The internal pressure value of the crankcase 5 set in this table is hereinafter referred to as “set internal pressure value”. Since the set internal pressure value is a value when no abnormal state occurs, it may be referred to as “normal value”. The set internal pressure value is set based on the results of experiments or simulations performed in advance.

  An example of the set internal pressure value table is shown in FIG. As shown in FIG. 2, in the set internal pressure value table, the set internal pressure value (kPa) is associated with the engine speed (rpm) and the engine torque (%). For example, the set internal pressure value when the engine speed is 1000 rpm and the engine torque is 50% is 0.6 kPa.

  The setting data has been described above.

  When any one of the abnormal states described above occurs, a difference (deviation) occurs between the internal pressure value of the crankcase 5 and the normal value. Therefore, if there is a difference between the internal pressure value (detected internal pressure value) of the crankcase 5 and the normal value, it can be determined that some abnormal state has occurred. Since the normal value differs depending on the engine speed and the engine torque, in this embodiment, a set internal pressure value is set in advance as a normal value for each engine speed and engine torque, and the set internal pressure value is set as the detected internal pressure value. Used for comparison.

  Further, the difference between the detected internal pressure value when the gas blow-off of the turbocharger 17 occurs and the normal value is smaller than the difference between the detected internal pressure value when the piston 3 or the piston ring 2 seizes and the normal value. It becomes. Therefore, if the magnitude of the difference is distinguished using the threshold value, it can be determined whether the piston 3 or the piston ring 2 is burned in or the turbocharger 17 is blown out. Further, when dilution occurs, the magnitude of the difference changes with time. Therefore, if a change occurs in the magnitude of the difference after a predetermined time has elapsed, it can be determined that dilution has occurred.

  The ECU 30 has been described above.

  Next, the abnormality determination operation performed by the ECU 30 will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of the flow of the abnormality determination operation according to the present embodiment.

  First, for example, when driving of the diesel engine 100 is started, the ECU 30 inputs a detected internal pressure value from the internal pressure detection sensor 31 (step S101).

  Next, the ECU 30 determines the set internal pressure value with reference to the set internal pressure value table (see FIG. 2) (step S102).

  Here, an example of the process for determining the set internal pressure value will be described.

  First, the ECU 30 inputs the engine speed and the fuel injection amount from a predetermined sensor or the like (not shown).

  Next, the ECU 30 reads a torque map stored in, for example, the ROM of the ECU 30. The torque map is data in which a correspondence relationship between the engine speed, the fuel injection amount, and the engine torque is determined in advance.

  Next, the ECU 30 refers to the torque map to determine an engine torque corresponding to the input engine speed and fuel injection amount.

  Next, the ECU 30 refers to the set internal pressure value table shown in FIG. 2 to determine the set internal pressure value corresponding to the input engine speed and the determined engine torque.

  Heretofore, an example of the process for determining the set internal pressure value has been described. Returning to the description of FIG.

  Next, the ECU 30 determines whether or not there is a difference between the detected internal pressure value and the set internal pressure value (step S103).

  If there is no difference as a result of the determination processing in step 103 (step S103: NO), the flow proceeds to step S107. Steps S107 and after will be described later.

  On the other hand, if there is a difference as a result of the determination process in step 103 (step S103: YES), the ECU 30 determines whether or not the difference is equal to or greater than a preset threshold value (step S104).

  If the difference is equal to or greater than the threshold value as a result of the determination process in step 104 (step S104: YES), the ECU 30 determines that the piston 3 or the piston ring 2 is burned in (step S105).

  On the other hand, if the difference is not greater than or equal to the threshold value as a result of the determination process in step 104 (step S104: NO), the ECU 30 determines that the gas has blown through the turbocharger 17 (step S106).

  If there is no difference as a result of the determination process in step 103 (step S103: NO), the ECU 30 determines whether or not there is a difference between the detected internal pressure value and the set internal pressure value after a predetermined time has elapsed (step S107: YES). Determination is made (step S108).

  If there is no difference as a result of the determination process in step 108 (step S108: NO), the ECU 30 determines that there is no abnormality (step S109).

  On the other hand, if there is a difference as a result of the determination process in step 108 (step S108: YES), the ECU 30 determines that the current is a dilution (step S110).

  When dilution occurs, the detected internal pressure value increases with time after the engine is started. Therefore, there may be no difference between the detected internal pressure value and the set internal pressure value when the engine is started. Therefore, as described above, even if it is determined that there is no difference in step S103, it is determined again whether or not there is a difference between the detected internal pressure value and the set internal pressure value after a predetermined time has elapsed (step S108). ) To determine the occurrence of dilution.

  Next, the ECU 30 stores the result determined in step S105, S106, S109, or S110 (determined abnormal state) in, for example, the RAM of the ECU 30 (step S111).

  The operations in steps S101 to S111 described above are repeatedly performed while the engine is being driven.

  The abnormality determination operation performed by the ECU 30 has been described above.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, the ECU 30 may output information indicating the determination result stored in step S111 to a storage device (not shown) provided outside the ECU 30.

  Further, for example, the ECU 30 may display information indicating the determination result stored in step S111 on a display device (not shown) provided outside the ECU 30. Alternatively, the ECU 30 may perform different warning operations (for example, lighting of a warning lamp, output of a warning sound or warning sound, etc.) according to the determination result stored in step S111.

  Further, for example, the ECU 30 may perform an operation of controlling the driving of the vehicle according to the determination result stored in step S111. For example, when the determination result is a gas blow-through of the turbocharger 17 or a seizure of the piston 3 or the piston ring 2, the ECU 30 may control the vehicle to shift to a limp home (emergency avoidance) mode. For example, when the determination result is dilution, the ECU 30 may perform control for reducing the fuel injection amount by a predetermined amount (for example, control called fuel throttling, reduce power, shut down, etc.).

  Further, for example, the ECU 30 may determine in step S106 in FIG. 3 that the gas has blown through the turbocharger 17 or the gas blown through an exhaust valve (not shown).

<Summary of the present invention>
An abnormality determination device according to the present invention includes a blowby gas passage that recirculates blowby gas generated inside a crankcase to an intake passage, and an oil that is provided in the middle of the blowby gas passage and collects oil contained in the blowby gas. An abnormality determination device for an engine comprising a separator and a sensor for detecting an internal pressure of the crankcase, wherein the detection internal pressure value input from the sensor, the engine speed and the engine torque are set in advance. The type of the abnormal state of the engine is determined based on the difference from the set internal pressure value indicating the internal pressure of the crankcase.

  In addition, when there is a difference between the detected internal pressure value and the set internal pressure value, the abnormality determination device determines whether the difference is equal to or greater than a preset threshold value, and the difference is equal to or greater than the threshold value. In this case, it may be determined that the abnormal state is burn-in of a piston or a piston ring, and if the difference is not greater than or equal to the threshold value, the abnormal state may be determined to be a gas blow-through of a turbocharger.

  Further, the abnormality determining device determines whether or not the difference is present again after a predetermined time when there is no difference between the detected internal pressure value and the set internal pressure value, and the difference between the detected internal pressure value and the set internal pressure value. If there is, it may be determined that the abnormal state is a dilution.

  The abnormality determination device may output information indicating the abnormal state to a predetermined storage device or display the information on a predetermined display device.

  Further, the abnormality determination device may perform different warning operations depending on the abnormal state.

  Further, the abnormality determination device may control the vehicle to shift to a limp home mode when the abnormal state is a gas blow-through of the turbocharger or a burn-in of the piston or piston ring.

  Further, the abnormality determination device may perform control to decrease the fuel injection amount by a predetermined amount when the abnormal state is the dilution.

  The abnormality determination device of the present invention is useful for all techniques for determining an abnormality that may occur in an engine.

DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Piston ring 3 Piston 4 Crankshaft 5 Crankcase 6 Oil pan 10 Engine main body 12 Intake passage 13 Exhaust passage 14 EGR passage 15 Blow-by gas passage 16 Air cleaner 17 Turbocharger 17a Compressor 17b Gas turbine 17c Rotating shaft 18 Intercooler 19 EGR cooler 20 EGR valve 21 Oil separator 22 Combustion chamber 23 Fuel injection valve 24 PCV system 30 ECU
31 Internal pressure detection sensor 100 Diesel engine

Claims (7)

A blow-by gas passage for returning blow-by gas generated inside the crank case to an intake passage; an oil separator provided in the middle of the blow-by gas passage for collecting oil contained in the blow-by gas; and an internal pressure of the crank case An engine abnormality determination device comprising a sensor for detecting
The type of abnormal state of the engine is determined based on the difference between the detected internal pressure value input from the sensor and a preset internal pressure value indicating the internal pressure of the crankcase that is set in advance corresponding to the engine speed and engine torque. To
Abnormality judgment device. If there is a difference between the detected internal pressure value and the set internal pressure value, it is determined whether the difference is greater than or equal to a preset threshold;
If the difference is greater than or equal to the threshold, it is determined that the abnormal condition is seizure of a piston or piston ring;
If the difference is not greater than or equal to the threshold, the abnormal condition is determined to be a turbocharger gas blowout;
The abnormality determination device according to claim 1. When there is no difference between the detected internal pressure value and the set internal pressure value, the presence / absence of the difference is determined again after a predetermined time has elapsed,
When there is a difference between the detected internal pressure value and the set internal pressure value, the abnormal state is determined to be dilution.
The abnormality determination device according to claim 1 or 2. Information indicating the abnormal state is output to a predetermined storage device or displayed on a predetermined display device.
The abnormality determination device according to any one of claims 1 to 3. Depending on the abnormal state, different warning actions are performed.
The abnormality determination device according to any one of claims 1 to 3. If the abnormal condition is a gas blow-out of the turbocharger or a seizure of the piston or piston ring, the vehicle is controlled to shift to a limp home mode;
The abnormality determination device according to claim 2. When the abnormal state is the dilution, control to reduce the fuel injection amount by a predetermined amount,
The abnormality determination device according to claim 3.

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