JP2009215983A - Reed valve stuck open abnormality detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reed valve stuck open abnormality detection device can prevent breakage of an EGR valve and an EGR cooler without installing a removal device for PM and the like. <P>SOLUTION: ECU 32 determines that reed valves 22, 23 are under a condition where the same are stuck to open if it is determined that supercharging pressure to an operation condition of a diesel engine 1 is lower than a prescribed range based on a first map 34 and that nozzle opening to the operation condition of the diesel engine is larger than a prescribed range based on a second map 35. Consequently, the ECU make the driver not operate the engine at heavy load by turning on an engine check lamp 33, or inhibiting the diesel engine 1 from being operated at heavy load by accelerator restriction so as to prevent high temperature exhaust gas form flowing inside of EGR route 15, 16. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a reed valve open fixing abnormality detecting device, and more particularly to a device for detecting a state in which a reed valve provided in an EGR path of an internal combustion engine is fixed open.

  In a conventional diesel engine having two banks such as a V-type or a horizontally opposed type, each having a variable capacity turbocharger in each bank, by sensing the supercharging pressure, each variable capacity turbocharger The nozzle opening is feedback controlled. The flow rate of the EGR gas taken out from each bank is controlled by an EGR valve provided in the EGR path. When the flow rate of the EGR gas flowing through each EGR path is controlled by one EGR valve, the EGR path connected to each bank merges and communicates in front of the EGR valve, so that exhaust gas energy is lost and variable. The turbine efficiency of the capacity type turbocharger is deteriorated, and as a result, the supercharging pressure is lowered. In order to avoid this deterioration in turbine efficiency, a reed valve that is a check valve may be provided in the EGR path.

  The exhaust gas contains unburned fuel and particulate matter (PM), and the EGR gas, which is a part of the exhaust gas, flows through the EGR path, adheres to the EGR valve and the EGR cooler, and carbonizes. There is a possibility of sticking to the EGR valve or clogging of the EGR cooler. Therefore, in Patent Document 1, for example, ozone is supplied to the EGR valve and the EGR cooler to oxidize and remove unburned fuel and PM adhering to the EGR valve and the EGR cooler, thereby fixing the EGR valve and clogging the EGR cooler. Has been eliminated.

JP 2007-120297 A

In an engine having a plurality of banks and one EGR valve and a reed valve installed in the EGR path, if unburned fuel or PM is fixed with the reed valve installed in the EGR path opened (hereinafter, referred to as "reed valve"). Also referred to as “open stuck state”), the two exhaust pipes through which the exhaust gas discharged from each bank circulates constantly. Therefore, particularly during high load operation, the exhaust gas that has been exhausted from one bank side and has reached the joining portion in front of the EGR valve may flow back to the other bank side.
However, although the exhaust gas purification apparatus of Patent Document 1 eliminates the sticking of the EGR valve and the clogging of the EGR cooler due to unburned fuel and PM, there is a problem that a removal apparatus such as PM has to be installed separately. It was. Further, in the exhaust gas purification device of Patent Document 1, an engine having a plurality of banks and one EGR valve and having a reed valve installed in the EGR path has not been studied. No consideration is given to detection. When the high load operation is continued while the reed valve is in the open fixed state, if the open fixed state is not detected, the state in which the high-temperature exhaust gas is discharged continues, and the EGR valve and the EGR cooler are in the high-temperature exhaust state. There has also been a problem that a secondary failure of being damaged by gas occurs.

  The present invention has been made to solve such a problem, and it is possible to determine whether the EGR valve and the EGR cooler are in an open state by using only an existing device without determining a PM or the like removal device. It is an object of the present invention to provide a reed valve open sticking abnormality detecting device capable of preventing damage in advance.

The reed valve open sticking abnormality detection device according to the present invention is a reed valve open sticking abnormality detection device provided in an internal combustion engine having two banks, one end of which is connected to the exhaust path of each bank and the other end is Two EGR paths connected to the intake path, the two EGR paths having two merged portions, a single EGR valve provided in the merge portion, and the 2 Variable displacement type having at least one reed valve provided upstream of the EGR valve in at least one of the two EGR paths, a supercharging pressure detecting means for detecting a supercharging pressure of the internal combustion engine, a turbine and a compressor A variable capacity turbocharger that is capable of controlling a flow rate of exhaust gas to the turbine by changing a nozzle opening degree. And a control device having a first map for the supercharging pressure for the operating state of the internal combustion engine and a second map for the nozzle opening, the control device is based on the first map, It is determined that the supercharging pressure with respect to the operating state of the internal combustion engine is smaller than a predetermined range, and further, based on the second map, it is determined that the nozzle opening degree with respect to the operating state of the internal combustion engine is larger than a predetermined range. In this case, it is determined that the reed valve is fixed while being opened. After it is determined that the reed valve is open and fixed, appropriate processing can be performed to prevent high-temperature exhaust gas from flowing in the EGR path.
The variable capacity turbocharger may be provided in each bank.
When it is determined that the reed valve is in an open and fixed state, an alarm means for issuing an alarm to a driver of the internal combustion engine may be provided.
When it is determined that the reed valve is in an open and fixed state, the control device may perform accelerator restriction.

  According to the present invention, the internal combustion engine is based on the first map by the control device having the first map for the supercharging pressure with respect to the operating state of the internal combustion engine and the second map for the nozzle opening of the variable displacement turbocharger. When it is determined that the supercharging pressure for the operating state of the engine is smaller than the predetermined range, and further, based on the second map, it is determined that the nozzle opening for the operating state of the internal combustion engine is larger than the predetermined range, the reed valve It is determined to be in an open fixed state. When an open-fixed state of the reed valve is detected, a warning is given to the driver and the accelerator is controlled so that the high-temperature exhaust gas discharged from one bank side It can be prevented from passing to the other bank side. Therefore, the increase in the amount of PM adhering to the reed valve is limited without configuring a separate and independent device such as a PM removal device, and further, the EGR valve and EGR are caused by high-temperature exhaust gas when the reed valve is in an open adhering state. It is possible to prevent the cooler from being damaged.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows a schematic configuration diagram of an internal combustion engine provided with a reed valve open sticking abnormality detection device according to this embodiment. A diesel engine 1 which is an internal combustion engine of an automobile is a V-type 6-cylinder diesel engine having two banks 2 and 3, and each bank 2 and 3 is provided with three cylinders. The banks 2 and 3 are connected to the intake manifolds 4 and 5, respectively, and are connected to the exhaust manifolds 6 and 7, respectively. Intake pipes 8 and 9 are connected to the intake manifolds 4 and 5, respectively, and exhaust pipes 10 and 11 are connected to the exhaust manifolds 6 and 7, respectively. Here, the intake manifolds 4 and 5 and the intake pipes 8 and 9 constitute an intake path of each bank, and the exhaust manifolds 6 and 7 and the exhaust pipes 10 and 11 constitute an exhaust path of each bank. The intake pipes 8 and 9 are provided with an intercooler 12 for commonly cooling the intake air flowing through the intake pipes 8 and 9. The intake pipes 8 and 9 are respectively provided with diesel slots 13 and 14 between the intercooler 12 and the intake manifolds 4 and 5. The intake manifold 4 is provided with a pressure sensor 21 which is a supercharging pressure detection means for measuring the pressure in the intake manifold 4, that is, the supercharging pressure.

  Each of the banks 2 and 3 is provided with EGR paths 15 and 16 having one end connected to the exhaust manifolds 6 and 7 and the other end connected to the intake manifolds 4 and 5. EGR coolers 17 and 18 are provided in the EGR paths 15 and 16, respectively. The EGR paths 15 and 16 have a merge portion 19 that partially merges on the intake manifolds 4 and 5 side with respect to the EGR coolers 17 and 18. The merge portion 19 is provided with an EGR valve 20. Reed valves 22 and 23 are provided between the EGR coolers 17 and 18 and the junction 19 in the EGR paths 15 and 16, respectively.

The banks 2 and 3 are provided with variable displacement turbochargers 28 and 29 having compressors 24 and 26 provided in the intake pipes 8 and 9 and turbines 25 and 27 provided in the exhaust pipes 10 and 11, respectively. ing. The turbines 25 and 27 are provided with a plurality of nozzle vanes 30 and 31, respectively. 2A and 2B, the plurality of nozzle vanes 30 are provided so as to surround the periphery of the turbine wheel 25a of the turbine 25, and each nozzle vane 30 is interlocked with the rotation of a support ring (not shown). Rotate as shown by arrow A. Since the size of the gap between the adjacent nozzle vanes 30 and 30 (exhaust gas passage area between the nozzle vanes 30 and 30) is changed by the rotation of the nozzle vane 30, the flow rate of the exhaust gas toward the turbine wheel 25a is controlled. . FIG. 2A shows a state where the gap is the smallest (usually referred to as “nozzle fully closed” but is expressed as “maximum nozzle opening” in this application), and FIG. 2B shows a state where the gap is the largest. (Normally referred to as “nozzle fully open”, but expressed as “nozzle opening minimum” in the present application). Here, regarding the gap between the adjacent nozzle vanes 30 and 30, the minimum value is V _min (FIG. 2A), the maximum value is V _max (FIG. 2B), and the size of an arbitrary gap is V. sometimes,
_{(V max -V) / (V} max -V min) × 100 (%)
Is defined as the nozzle opening of the variable capacity turbocharger. That is, as the nozzle opening increases, the gap (exhaust gas passage area between the nozzle vanes 30 and 30) decreases and the flow rate of exhaust gas toward the turbine wheel 25a increases. A plurality of nozzle vanes 31 (see FIG. 1) provided in the turbine 27 (see FIG. 1) also have the same configuration as the nozzle vane 30.

  As shown in FIG. 1, the diesel engine 1 is provided with an ECU 32 that is a control device. A crankshaft and fuel injection device (not shown) provided in the banks 2 and 3, the pressure sensor 21, and drive devices 36 and 37 that rotate the nozzle vanes 30 and 31 are electrically connected to the ECU 32. . As a result, the ECU 32 is configured so that the electric signal about the rotational speed of the diesel engine 1, the electric signal about the fuel injection amount injected into each combustion chamber of the diesel engine 1, and the diesel engine 1 during the operation of the diesel engine 1. An electric signal regarding the supercharging pressure and an electric signal regarding the nozzle opening of the variable capacity turbochargers 28 and 29 are received. The ECU 32 is electrically connected to an engine check lamp 33 which is an alarm means for issuing an alarm to a driver of a car equipped with the diesel engine 1.

The ECU 32 incorporates a first map 34 shown in FIG. 3 and a second map 35 shown in FIG.
As shown in FIG. 3, the first map 34 is a diesel engine for the operating state of the diesel engine 1 represented by the rotational speed (rpm) of the diesel engine 1 and the fuel injection amount (%) with respect to the maximum fuel injection amount. 1 represents the standard supercharging pressure. When there is no abnormality in the diesel engine 1, that is, when the reed valves 22 and 23 are not open and fixed, the measured value by the pressure sensor 21 is the standard boost pressure shown in the first map 34. Takes a value in the range of about ± 10%. In this embodiment, this range is defined as a predetermined range of the supercharging pressure.

  As shown in FIG. 4, the second map 35 is a variable capacity for the operating state of the diesel engine 1 represented by the rotational speed (rpm) of the diesel engine 1 and the fuel injection amount (%) with respect to the maximum fuel injection amount. The standard nozzle opening of the type | mold turbochargers 28 and 29 is represented. When there is no abnormality in the diesel engine 1, that is, when the reed valves 22 and 23 are not fixed in an open state, the nozzle vanes 30 and 31 are moved to the second map 35 when the supercharging pressure is within a predetermined range. The nozzle opening is in the range of about ± 10% with respect to the standard nozzle opening shown in FIG. In this embodiment, this range is defined as a predetermined range of the nozzle opening.

Next, the operation of the reed valve open sticking abnormality detecting device according to the embodiment of the present invention will be described based on the flowchart shown in FIG.
When the diesel engine 1 is operated, the ECU 32 receives an electrical signal regarding the rotational speed of the diesel engine 1 and an electrical signal regarding the fuel injection amount injected into each combustion chamber of the diesel engine 1, and operates the diesel engine 1. The state is authorized (step S1). Next, the ECU 32 receives an electric signal from the pressure sensor 21 and detects the supercharging pressure of the diesel engine 1 (step S2). Based on the first map 34, the ECU 32 determines whether the detected boost pressure of the diesel engine 1 is greater than a predetermined range with respect to the operating state of the diesel engine 1 (step S3). If it is determined in step S3 that the detected supercharging pressure of the diesel engine 1 is greater than the predetermined range, the ECU 32 operates the drive devices 36 and 37 to reduce the nozzle opening (step S3). S4), returning to step S3. On the other hand, when it is determined in step S3 that the supercharging pressure of the diesel engine 1 is not larger than the predetermined range, the ECU 32 determines whether or not the supercharging pressure of the diesel engine 1 is smaller than the predetermined range. (Step S5). If it is determined that the boost pressure of the diesel engine 1 is not smaller than the predetermined range, the boost pressure of the diesel engine 1 is within the predetermined range, and thus the operation of the reed valve open sticking abnormality detection device is terminated. . On the other hand, when it is determined in step S5 that the supercharging pressure of the diesel engine 1 is smaller than the predetermined range, the ECU 32 increases the nozzle opening by operating the drive devices 36 and 37 (step S6). ). Next, the ECU 32 determines whether or not the nozzle opening is larger than a predetermined range (step S7). If it is determined that the nozzle opening is not larger than the predetermined range, the ECU 32 returns to step S2. On the other hand, if it is determined in step S7 that the nozzle opening is larger than the predetermined range, the ECU 32 determines that the reed valves 22 and 23 are stuck open (step S8) and the engine check lamp 33. Is turned on (step S9), and the accelerator is limited (step S10).

  When the reed valves 22 and 23 are fixed in an open state, the exhaust pipes 10 and 11 communicate with each other. In this state, when the diesel engine 1 is operated at a high load, the high-temperature exhaust gas flows through the EGR coolers 17 and 18, whereby the cooling water in the EGR coolers 17 and 18 boils, and further, the inside of the junction 19 When the high-temperature exhaust gas flows, the high-temperature exhaust gas contacts the EGR valve 20. As a result, the EGR coolers 17 and 18 and the EGR valve 20 may be heated and damaged. However, in the diesel engine 1, when it is determined that the reed valves 22 and 23 are fixed in an open state, the engine check lamp 33 is turned on, so that the driver notices this. Be careful not to do it. Further, by restricting the accelerator, no matter how much the driver steps on the accelerator, the diesel engine 1 does not operate at a high load.

  As described above, the ECU 32 determines that the supercharging pressure for the operating state of the diesel engine 1 is smaller than the predetermined range based on the first map 34, and further, based on the second map 35, the operating state of the diesel engine 1 When it is determined that the opening degree of the nozzle is larger than the predetermined range, it is determined that the reed valves 22 and 23 are fixed in an open state, so that high-temperature exhaust gas does not flow in the EGR paths 15 and 16. In order to do so, the engine check lamp 33 can be turned on to prevent the driver from performing a high load operation, or by restricting the accelerator, the diesel engine 1 can be prevented from being in a high load operation. Therefore, damage to the EGR valve 20 and the EGR coolers 17 and 18 can be prevented in advance.

  The numbers described in the first map 34 and the second map 35 shown in this embodiment are merely examples, and the numbers differ depending on the specifications of the diesel engine 1 and the like. Further, the predetermined range for the nozzle opening and the supercharging pressure has been described as a range of about ± 10% with respect to the numerical values described in the first map 34 and the second map 35, but is limited to a numerical value of ± 10%. Not what you want. Depending on the specifications of the diesel engine 1 and the like, it can be appropriately changed in consideration of the fluctuation width from the numerical values described in the first map 34 and the second map 35.

  In this embodiment, the diesel engine 1 has been described with the configuration shown in FIG. 1, but is not limited to this configuration. For example, as shown in FIG. 6, one diesel slot 13 controls the intake air amount, only one EGR path 15 is provided with a reed valve 22, and both intake manifolds 4, 5 are provided with pressure sensors 21. The diesel engine 40 may be used.

  In this embodiment, the EGR paths 15 and 16 are connected to the intake manifolds 4 and 5 and the exhaust manifolds 6 and 7, respectively. However, the present invention is not limited to this form. Since the intake side and the exhaust side need only be communicated with each other, they may be connected to the intake pipes 8 and 9 and the exhaust pipes 10 and 11.

  In this embodiment, the engine check lamp 33 has been described as an example of alarm means, but the present invention is not limited to this. Since it is only necessary to notify the driver that the reed valves 22 and 23 are in an open state, the device may be a device that emits a buzzer or a sound.

  In this embodiment, the diesel engine 1 is a V-type 6 cylinder, but is not limited to this. If it is a diesel engine, the number of cylinders may be any number. Further, any type of diesel engine may be used as long as it has a plurality of banks. For example, a horizontally opposed diesel engine may be used.

  In this embodiment, a turbocharger is provided in each bank, but the present invention is not limited to this configuration. For example, as shown in FIG. 7, the diesel engine 50 may be configured with a plurality of banks and one variable capacity turbocharger. In this embodiment, the exhaust gas discharged from the exhaust manifolds 6 and 7 is configured to join upstream of the turbine 25. The reed valve 22 may be provided in at least one of the EGR paths 15 or 16.

1 is a schematic diagram of a configuration of an internal combustion engine including a reed valve open sticking abnormality detection device according to an embodiment of the present invention. It is a top view of the nozzle vane provided in the turbine of the variable capacity | capacitance type | mold turbocharger of the internal combustion engine provided with the reed valve open sticking abnormality detection apparatus which concerns on this embodiment. It is a conceptual diagram of the 1st map integrated in ECU of the internal combustion engine provided with the reed valve open sticking abnormality detection device concerning this embodiment. It is a conceptual diagram of the 2nd map integrated in ECU of the internal combustion engine provided with the reed valve open sticking abnormality detection device concerning this embodiment. It is a flowchart for demonstrating operation | movement of the reed valve open sticking abnormality detection apparatus which concerns on this embodiment. It is a structure schematic diagram of the modification of the internal combustion engine provided with the reed valve open sticking abnormality detection device concerning this embodiment. It is a structure schematic diagram of another modification of the internal combustion engine provided with the reed valve open sticking abnormality detection device according to this embodiment.

Explanation of symbols

  1, 40, 50 Diesel engine (internal combustion engine), 2, 3 banks, 4, 5 Intake manifold (intake path), 6, 7 Exhaust manifold (exhaust path), 8, 9 Intake pipe (intake path), 10, 11 Exhaust pipe (exhaust path), 15, 16 EGR path, 19 junction, 20 EGR valve, 21 Pressure sensor (supercharging pressure detection means), 22, 23 Reed valve, 24, 26 Compressor, 25, 27 Turbine, 28, 29 variable capacity turbocharger, 32 ECU (control device), 33 engine check lamp (alarm means), 34 first map, 35 second map.

Claims (4)

A reed valve open sticking abnormality detection device provided in an internal combustion engine having two banks,
Two EGR paths having one end connected to an exhaust path of each bank and the other end connected to an intake path, the two EGR paths having two merged portions,
One EGR valve provided in the junction,
At least one reed valve provided upstream of the EGR valve in at least one of the two EGR paths;
Supercharging pressure detecting means for detecting the supercharging pressure of the internal combustion engine;
A variable displacement turbocharger having a turbine and a compressor, the variable displacement turbocharger capable of controlling a flow rate of exhaust gas to the turbine by changing a nozzle opening;
A control device having a first map for the supercharging pressure and a second map for the nozzle opening for the operating state of the internal combustion engine;
The control device determines that the supercharging pressure with respect to the operating state of the internal combustion engine is smaller than a predetermined range based on the first map, and further, the operating state of the internal combustion engine based on the second map. A reed valve open sticking abnormality detection device that judges that the reed valve is stuck in an open state when it is determined that the nozzle opening with respect to is larger than a predetermined range.   The reed valve open sticking abnormality detection device according to claim 1, wherein the variable capacity turbocharger is provided in each bank.   The reed valve open sticking abnormality detection device according to claim 1 or 2, further comprising warning means for issuing a warning to a driver of the internal combustion engine when it is determined that the reed valve is stuck open.   The reed valve open sticking abnormality detection device according to any one of claims 1 to 3, wherein the control device performs accelerator restriction when it is determined that the reed valve is stuck in an open state.

Images