JP2017002748A - Internal combustion engine device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To propose a device which determines by a simple method whether or not misfire occurs in an internal combustion engine.SOLUTION: A differential pressure ΔP before and after (exhaust pipe 33 side, intake pipe 25 side) of an EGR valve in an EGR pipe is compared with a value (ΔPb+ΔPm) of a reference differential pressure ΔPb plus a predetermined value ΔPm (S140). When the differential pressure ΔP is larger than the value (ΔPb+ΔPm), it is determined that misfire occurs in either cylinder of an engine (S160). With this, it is possible to determined by a simple method whether or not misfire occurs in either cylinder of the engine.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an internal combustion engine device, and more particularly, to an internal combustion engine device including an internal combustion engine to which an exhaust gas recirculation device having an exhaust gas recirculation pipe for returning exhaust gas to intake air is attached.

  Conventionally, in this type of internal combustion engine device, the flow rate of the exhaust gas recirculation pipe (EGR gas flow rate) of the exhaust gas recirculation device is set such that the pressure of the exhaust pipe of the internal combustion engine (exhaust pressure) and the pressure of the intake pipe after exhaust gas recirculation (suction). What is estimated based on (atmospheric pressure) has been proposed (see, for example, Patent Document 1). In this apparatus, first, the provisional EGR gas amount is based on the exhaust pressure, the intake pressure, the effective opening area of the constricted portion interposed in the exhaust gas recirculation pipe, the density of EGR gas, and the specific heat ratio of EGR gas. Is estimated. Then, the EGR gas flow rate is estimated by multiplying the provisional EGR gas amount by a correction value corresponding to the differential pressure between the exhaust pressure and the intake pressure.

JP 2004-156458 A

  As a method for determining whether or not misfire has occurred in the internal combustion engine, a method performed using a signal from an air-fuel ratio sensor, a method performed using rotational fluctuations of the internal combustion engine, or a pressure in each cylinder of the internal combustion engine is used. The method to perform is proposed. However, when the internal combustion engine is started, in general, in order to improve the startability of the internal combustion engine, the fuel injection amount is increased and corrected, and the air-fuel ratio feedback control using the signal from the air-fuel ratio sensor is not performed. For this reason, it becomes difficult to determine whether or not misfire has occurred in the internal combustion engine using a signal from the air-fuel ratio sensor. Further, when the internal combustion engine is started, the rotational fluctuation of the internal combustion engine often becomes irregular. For this reason, it becomes difficult to determine whether or not misfire has occurred in the internal combustion engine using the rotational fluctuation of the internal combustion engine. If the pressure in each cylinder of the internal combustion engine is used, it is possible to determine whether a misfire has occurred in the internal combustion engine even when the internal combustion engine is started. In this case, it is necessary to attach a pressure sensor to each cylinder. There will be high costs. For these reasons, it is required to determine whether or not misfire has occurred in the internal combustion engine by a simple method.

  The internal combustion engine device of the present invention is mainly intended to propose a device for determining whether misfire has occurred in an internal combustion engine by a simple method.

  The internal combustion engine apparatus of the present invention employs the following means in order to achieve the main object described above.

The internal combustion engine device of the present invention is
In an internal combustion engine device comprising an internal combustion engine to which an exhaust gas recirculation device having an exhaust gas recirculation pipe for recirculating exhaust gas to intake air is attached,
A pressure loss part that causes a pressure loss in the exhaust in the exhaust gas recirculation pipe;
A differential pressure sensor for detecting a differential pressure before and after the pressure loss portion in the exhaust gas recirculation pipe;
Determination means for determining that misfire has occurred in the internal combustion engine when the differential pressure detected by the differential pressure sensor is greater than a threshold;
It is a summary to provide.

  The internal combustion engine apparatus according to the present invention includes a pressure loss part that causes a pressure loss in the exhaust gas in the exhaust gas recirculation pipe, and a differential pressure sensor that detects a differential pressure before and after the pressure loss part in the exhaust gas recirculation pipe. When the differential pressure detected by the differential pressure sensor is greater than the threshold value, it is determined that misfire has occurred in the internal combustion engine. When misfire occurs in the internal combustion engine, the exhaust gas including unburned fuel is recirculated to the intake air through the exhaust gas recirculation pipe. For this reason, compared to when no misfire occurs in the internal combustion engine, the density of the exhaust gas in the exhaust gas recirculation pipe increases, and the differential pressure before and after the pressure loss part (exhaust pressure loss at the pressure loss part) increases. . Accordingly, by determining that misfire has occurred in the internal combustion engine when this differential pressure is greater than the threshold value, it is possible to determine whether or not misfire has occurred in the internal combustion engine by a simple method. As described above, at the time of starting the internal combustion engine, it is difficult to determine whether or not misfiring has occurred in the internal combustion engine using a signal from the air-fuel ratio sensor or the rotational fluctuation of the internal combustion engine. It is considered more useful to determine whether misfire has occurred in the internal combustion engine using Of course, it is not necessary to limit the time when the internal combustion engine is started.

  In such an internal combustion engine device of the present invention, the pressure loss part may be a throttle part. In this case, it is possible to determine whether or not misfire has occurred in the internal combustion engine using the differential pressure before and after the throttle portion.

  In the internal combustion engine device of the present invention in which the pressure loss portion is a throttle portion, the exhaust gas recirculation device is attached to the exhaust gas recirculation pipe, adjusts the supply amount of exhaust gas to the intake pipe, and serves as the throttle section. It may have a functioning control valve. In this case, it is possible to determine whether or not misfire has occurred in the internal combustion engine using the differential pressure before and after the control valve.

  In the internal combustion engine device of the present invention in which the exhaust gas recirculation device has a control valve, the threshold value may be set according to the exhaust pressure and intake pressure of the internal combustion engine and the opening degree of the control valve. . In this way, the threshold value can be set more appropriately.

  In the internal combustion engine apparatus of the present invention, the exhaust gas recirculation device may include an exhaust cooler that is attached to the exhaust gas recirculation pipe and cools the exhaust gas and functions as the pressure loss unit. In this case, it is possible to determine whether or not misfire has occurred in the internal combustion engine using the differential pressure before and after the exhaust cooler.

  In the internal combustion engine device of the present invention, an air-fuel ratio sensor for detecting an air-fuel ratio of the internal combustion engine, and an air-fuel ratio detected by the air-fuel ratio sensor after the start condition of the internal combustion engine is established and after the internal combustion engine is started Control means for controlling the exhaust gas recirculation device so that the exhaust gas recirculation device starts recirculation of the exhaust gas to the intake air before starting the used air-fuel ratio feedback control may be provided.

  In the internal combustion engine apparatus according to the present invention, the internal combustion engine has a plurality of cylinders, and an air-fuel ratio sensor that detects an air-fuel ratio of the internal combustion engine, and correction of increasing the fuel injection amount of each cylinder when the internal combustion engine is started. And control means that does not perform air-fuel ratio feedback control using the air-fuel ratio detected by the air-fuel ratio sensor, and the control means causes misfire in the internal combustion engine by the determination means when the internal combustion engine is started. When it is determined that the misfire has occurred, the misfire cylinder in which the misfire has occurred is specified, the supply cylinder to which the exhaust of the misfire cylinder is supplied via the exhaust gas recirculation pipe is specified, and the fuel injection amount of the supply cylinder It is good also as a means to correct | amend weight reduction. If misfire occurs in the internal combustion engine when the internal combustion engine is started (when the fuel injection amount of each cylinder is increased and correction is not performed), the air-fuel ratio becomes relatively large and the emission becomes relatively rich. There is concern that it will get worse. On the other hand, by correcting the fuel injection amount of the supply cylinder to be reduced, it is possible to suppress the air-fuel ratio from becoming relatively large and rich, and to suppress the deterioration of emissions.

1 is a configuration diagram showing an outline of a configuration of an internal combustion engine device 10 as an embodiment of the present invention. It is a flowchart which shows an example of the misfire determination routine performed by the electronic control unit 70 of an Example. It is explanatory drawing which shows an example of the mode of the time change of the rotation speed Ne of the engine 12, the torque Te, the air fuel ratio AF, the EGR valve opening degree EV, the intake pressure Pin, the differential pressure ΔP, and the reference differential pressure ΔPb. It is a block diagram which shows the outline of a structure of the internal combustion engine apparatus 110 of the modification. It is a block diagram which shows the outline of a structure of the internal combustion engine apparatus 210 of a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of a configuration of an internal combustion engine device 10 as an embodiment of the present invention. The internal combustion engine device 10 according to the embodiment includes an engine 12 as an internal combustion engine and an electronic control unit 70 that controls the operation of the engine 12. The internal combustion engine device 10 includes an engine 12 and a motor (not shown), travels with intermittent operation of the engine 12, travels using only power from the engine 12, and performs idle stop while the vehicle is stopped. Installed in automobiles.

  The engine 12 has four cylinders and is configured as an internal combustion engine that outputs power using gasoline, light oil, or the like as fuel. As shown in the figure, the engine 12 sucks air purified by the air cleaner 22 into the intake pipe 25 and injects fuel from the fuel injection valve 26 into the intake pipe 25 to mix the air and fuel. The gas is sucked into the combustion chamber 29 through the intake valve 28. Then, the sucked air-fuel mixture is exploded and burned by an electric spark from the spark plug 30, and the reciprocating motion of the piston 32 pushed down by the energy is converted into the rotational motion of the crankshaft 14. The exhaust gas discharged from the combustion chamber 29 to the exhaust pipe 33 is a purification device having a purification catalyst (three-way catalyst) that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). It is discharged to the outside air through 34. Exhaust gas from the exhaust pipe 33 is not only discharged to the outside air but also recirculated to the intake pipe 25 via an exhaust gas recirculation device (hereinafter referred to as an “EGR (Exhaust Gas Recirculation) device”) 60. The EGR device 60 includes an EGR pipe 62, an EGR cooler 64, and an EGR valve 66. The EGR pipe 62 connects the exhaust pipe 33 downstream of the purification device 34 and the surge tank of the intake pipe 25. The EGR cooler 64 performs heat exchange between the cooling water of the engine 12 and the exhaust gas in the EGR pipe 62. The EGR valve 66 is provided closer to the intake pipe 25 than the EGR cooler 64 of the EGR pipe 62, and includes a valve seat 66a and a valve body 66b. The valve seat 66 a has a hole having a diameter smaller than the inner diameter of the EGR pipe 62. The valve body 66b is driven by a stepping motor 67 and moves in the vertical direction in the figure. The EGR valve 66 is configured such that the valve body 66b moves downward in the figure (side approaching the valve seat 66a), and the tip end (lower end in the figure) of the valve body 66b closes the hole of the valve seat 66a. Close the valve. Further, in the EGR valve 66, the valve body 66b moves to the upper side (the side away from the valve seat 66a) in the figure, and the tip of the valve body 66b is separated from the valve seat 66a to open the hole of the valve seat 66a. To open the valve. The EGR valve 66 (particularly, the tip portions of the valve seat 66a and the valve body 66b) functions as the “throttle section” of the present invention. The EGR device 60 adjusts the recirculation amount of the exhaust pipe 33 and adjusts the opening degree of the EGR valve 66 to recirculate to the intake pipe 25. In this way, the engine 12 can suck the air / exhaust gas / gasoline mixture into the combustion chamber 29. Hereinafter, the recirculation of the exhaust pipe 33 through the EGR pipe 62 to the intake pipe 25 is referred to as EGR, the exhaust gas recirculated from the exhaust pipe 33 to the intake pipe 25 is referred to as EGR gas, and the amount of EGR gas is defined as the EGR amount. That's it.

Although not shown, the electronic control unit 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, and an input / output port in addition to the CPU. Signals from various sensors necessary for controlling the operation of the engine 12 are input to the electronic control unit 70 via an input port. Examples of signals from various sensors include the following.
A crank angle θcr from a crank position sensor 40 that detects the rotational position of the crankshaft 14
-Cooling water temperature Tw from the water temperature sensor 42 which detects the temperature of the cooling water of the engine 12
Cam angles θci and θco from a cam position sensor 44 that detects the rotational position of the intake camshaft that opens and closes the intake valve 28 and the rotational position of the exhaust camshaft that opens and closes the exhaust valve
A throttle opening TH from a throttle valve position sensor 46 that detects the position of the throttle valve 24 provided in the intake pipe 25
Intake air amount Qa from the air flow meter 48 attached to the intake pipe 25
Intake air temperature Ta from the temperature sensor 49 attached to the intake pipe 25
Intake pressure Pin from an intake pressure sensor 58 that detects the pressure in the intake pipe 25
The catalyst temperature Tc from the temperature sensor that detects the temperature of the purification catalyst of the purification device 34
Air-fuel ratio AF from the air-fuel ratio sensor 35a attached to the exhaust pipe 33
The oxygen signal O2 from the oxygen sensor 35b attached to the exhaust pipe 33
Exhaust pressure Pout from the exhaust pressure sensor 35c that detects the pressure in the exhaust pipe 33
A knock signal Ks from a knock sensor 59 that is attached to the cylinder block and detects vibration caused by the occurrence of knocking.
EGR valve opening EV from the EGR valve opening sensor 68 that detects the opening of the EGR valve 66
A differential pressure ΔP from a differential pressure sensor 69 that detects a differential pressure before and after the EGR valve 66 (exhaust pipe 33 side and intake pipe 25 side from the tip of the valve seat 66a and the valve body 66b).

Various control signals for controlling the operation of the engine 12 are output from the electronic control unit 70 via the output port. Examples of the various control signals include the following.
A drive control signal to the throttle motor 36 that adjusts the position of the throttle valve 24 A drive control signal to the fuel injection valve 26 A drive control signal to the ignition coil 38 integrated with the igniter The opening of the EGR valve 66 Drive control signal to the stepping motor 67 to be adjusted

  The electronic control unit 70 calculates the rotational speed of the crankshaft 14, that is, the rotational speed Ne of the engine 12, based on the crank angle θcr from the crank position sensor 40. Further, the electronic control unit 70 determines the volume efficiency (1 cycle for the stroke volume per cycle of the engine 12) as the load of the engine 12 based on the intake air amount Qa from the air flow meter 48 and the rotational speed Ne of the engine 12. The ratio of the volume of air actually taken in) KL is calculated.

  In the internal combustion engine device 10 of the embodiment thus configured, when the engine 12 is operated, intake air amount control and fuel injection for adjusting the opening of the throttle valve 24 so that a required output is output from the engine 12. Fuel injection control for adjusting the fuel injection amount from the valve 26, ignition control for adjusting the ignition timing of the spark plug 30, and EGR control for adjusting the opening of the EGR valve 66 are performed. In the fuel injection control, when the engine 12 is started, the startability of the engine 12 is improved in consideration of the fact that the properties of the fuel differ depending on the type of fuel to be supplied and the change of fuel in the fuel tank over time. Therefore, increase correction of the fuel injection amount of each cylinder is performed and air-fuel ratio feedback control (correction of the fuel injection amount for setting the air-fuel ratio AF from the air-fuel ratio sensor 35a to the target air-fuel ratio AF *) is not performed. Then, after that, the start condition of the air-fuel ratio feedback control (for example, the condition for ending the increase correction of the fuel injection amount of each cylinder at the start (for example, the condition of performing fuel injection for each cylinder a predetermined number of times) Etc.), the air-fuel ratio feedback control is started. The intake air amount control, ignition control, and EGR control do not form the core of the present invention, and thus detailed description thereof is omitted.

  Next, the operation of the internal combustion engine apparatus 10 of the embodiment configured as described above, particularly the operation when determining whether or not misfire has occurred in the engine 12 will be described. FIG. 2 is a flowchart illustrating an example of a misfire determination routine executed by the electronic control unit 70 of the embodiment. This routine is executed while the engine 12 is stopped.

  When the misfire determination routine is executed, the electronic control unit 70 first waits for the start condition of the engine 12 to be satisfied (step S100). When the start condition of the engine 12 is satisfied, the EGR valve 66 is opened (step S110). Further, when the engine 12 start condition is satisfied, the engine 12 is cranked by a motor or starter connected to the crankshaft 14 of the engine 12, and when the engine 12 reaches a predetermined speed or higher, the operation of the engine 12 is performed. To start. In the embodiment, as the above-described start of the engine 12, the time from when the start condition of the engine 12 is satisfied to when the air-fuel ratio feedback control is started is considered.

  Subsequently, the differential pressure ΔP before and after the EGR valve 66 from the differential pressure sensor 69, the intake pressure Pin from the intake pressure sensor 58, the exhaust pressure Pout from the exhaust pressure sensor 35c, and the EGR valve opening from the EGR valve opening sensor 68 EV is input (step S120). Then, a reference differential pressure ΔPb before and after the EGR valve 66 is set based on the intake pressure Pin, the exhaust pressure Pout, and the EGR valve opening EV (step S130), and a value obtained by subtracting the reference differential pressure ΔPb from the differential pressure ΔP ( [Delta] P- [Delta] Pb) is compared with a predetermined value [Delta] Pm (step S140). When the EGR valve 66 is opened, exhaust gas (EGR gas) flows through the EGR pipe 62, thereby generating a differential pressure in the exhaust before and after the EGR valve 66 (the EGR valve 66 causes a pressure loss in the exhaust). The reference differential pressure ΔPb is a differential pressure generated before and after the EGR valve 66 when no misfire has occurred in any cylinder of the engine 12, and in the embodiment, the intake pressure Pin, the exhaust pressure Pout, the EGR valve opening EV, The relationship with the reference differential pressure ΔPb is determined in advance by experiment and analysis and stored in a ROM (not shown) as a map, and when the intake pressure Pin, the exhaust pressure Pout, and the EGR valve opening degree EV are given, this map corresponds. The reference differential pressure ΔPb was derived and set. In addition, as the predetermined value ΔPm, a value determined in advance by experiment or analysis is used as an upper limit of a range that the value (ΔP−ΔPb) can take when no misfire occurs in any cylinder of the engine 12.

  When the value (ΔP−ΔPb) is equal to or smaller than the predetermined value ΔPm in step S140, that is, when the differential pressure ΔP is equal to or smaller than the value obtained by adding the predetermined value ΔPm to the reference differential pressure ΔPb (ΔPb + ΔPm), the engine 12 is normal (engine). It is determined that no misfire has occurred in any of the 12 cylinders (step S150), and it is determined whether air-fuel ratio feedback control has been started (step S160). Then, when the air-fuel ratio feedback control is not started, the process returns to step S120. Then, the processes in steps S120 to S160 are repeatedly executed, and when it is determined in step S160 that the air-fuel ratio feedback control is started, this routine is ended.

  Before it is determined in step S160 that the air-fuel ratio feedback control is started, in step S140, when the value (ΔP−ΔPb) is larger than the predetermined value ΔPm, that is, when the differential pressure ΔP is larger than the value (ΔPb + ΔPm), It is determined that a misfire has occurred in any cylinder of the engine 12 (step S170). When a misfire occurs in any cylinder of the engine 12, the exhaust gas containing unburned fuel returns to the intake pipe 25 via the EGR pipe 62. For this reason, the exhaust gas density in the EGR pipe 62 is larger than when no misfire has occurred in any cylinder of the engine 12, and the differential pressure ΔP before and after the EGR valve 66 (the exhaust pressure at the EGR valve 66 is reduced). (Pressure loss) increases. Therefore, when this differential pressure ΔP is larger than the value (ΔPb + ΔPm), it is determined that a misfire has occurred in any cylinder of the engine 12, so that a misfire occurs in any cylinder of the engine 12 by a simple method. It can be determined whether or not. In particular, when the engine 12 is started, as described above, the fuel injection amount increase correction for each cylinder is performed and the air-fuel ratio feedback control is not performed. For this reason, it is difficult to determine whether or not misfire has occurred in any cylinder of the engine 12 using the air-fuel ratio AF from the air-fuel ratio sensor 35a. Further, when the engine 12 is started, the rotation fluctuation of the engine 12 is often irregular. For this reason, it becomes difficult to determine whether misfire has occurred in any of the cylinders of the engine 12 using the rotational fluctuation of the engine 12. If the pressure in each cylinder of the engine 12 is used, it is possible to determine whether or not a misfire has occurred in any cylinder of the engine 12 even when the engine 12 is started. It is necessary to attach a pressure sensor to each cylinder, which increases the cost. Considering these, it is considered that it is more useful at the time of starting the engine 12 to determine whether or not misfire has occurred in any cylinder of the engine 12 using the differential pressure ΔP. Note that, instead of the differential pressure ΔP before and after the EGR valve 66, it is conceivable to use a differential pressure between the exhaust pressure Pout and the intake pressure Pin. In this case, the intake pressure and the exhaust pressure are respectively set according to the operating conditions of the engine 12. Therefore, it is considered difficult to accurately determine whether or not misfire has occurred in any cylinder of the engine 12 using this differential pressure.

  When it is determined in this way that any of the cylinders of the engine 12 has misfired, the misfired cylinder in which misfire has occurred is identified, and the supply cylinder to which the exhaust of the misfired cylinder is supplied via the EGR pipe 62 is identified (step S180). Here, the misfire cylinder can be specified in consideration of the time until the exhaust from the cylinder reaches the vicinity of the EGR valve 66 in the EGR pipe 62 via the exhaust pipe 33. The supply cylinder can be specified in consideration of the time until the exhaust from the misfire cylinder reaches the cylinder via the exhaust pipe 33, the EGR pipe 62, and the intake pipe 25. Then, the reduction correction of the fuel injection amount of the supply cylinder is started (step S190), and this routine is finished. As described above, when the engine 12 is started, the fuel injection amount increase correction is performed and the air-fuel ratio feedback control is not performed. For this reason, if a misfire occurs in any cylinder of the engine 12 when the engine 12 is started, there is a concern that the air-fuel ratio becomes relatively large and becomes richer and the emission deteriorates. On the other hand, by correcting the fuel injection amount of the supply cylinder to be reduced, it is possible to suppress the air-fuel ratio from becoming relatively large and rich and to suppress the deterioration of the emission.

  FIG. 3 is an explanatory diagram showing an example of changes over time of the engine speed Ne, torque Te, air-fuel ratio AF, EGR valve opening EV, intake pressure Pin, differential pressure ΔP, and reference differential pressure ΔPb. As shown in the figure, when the start condition of the engine 12 is satisfied (time t11), the EGR valve 66 is opened and the engine 12 is started. At this time, the rotational speed Ne and the torque Te of the engine 12 increase, and the air-fuel ratio AF, the intake pressure Pin, the differential pressure ΔP, and the reference differential pressure ΔPb vary. When the differential pressure ΔP becomes larger than the value (ΔPb + ΔPm) (time t12), it is determined that a misfire has occurred in any cylinder of the engine 12. Thereby, it is possible to determine whether or not misfire has occurred in any cylinder of the engine 12 by a simple method. Thereafter, when the start condition of the air-fuel ratio feedback control is satisfied (time t13), the air-fuel ratio feedback control is started.

  In the internal combustion engine device 10 of the embodiment described above, when the differential pressure ΔP before and after the EGR valve 66 from the differential pressure sensor 69 is larger than the value obtained by adding the predetermined value ΔPm to the reference differential pressure ΔPb (ΔPb + ΔPm), It is determined that misfire has occurred in any of the 12 cylinders. Thereby, it is possible to determine whether or not misfire has occurred in any cylinder of the engine 12 by a simple method.

  In the internal combustion engine device 10 of the embodiment, when the differential pressure ΔP from the differential pressure sensor 69 is larger than the value (ΔPb + ΔPm) when the engine 12 is started (until air-fuel ratio feedback control is started), the engine 12 It was determined that misfire occurred in any of the cylinders. However, not only when the engine 12 is started (even after the air-fuel ratio feedback control is started), but when the differential pressure ΔP is larger than the value (ΔPb + ΔPm), misfire occurs in any cylinder of the engine 12. It is good also as what determines with having.

  In the internal combustion engine device 10 of the embodiment, the reference differential pressure ΔPb before and after the EGR valve 66 is set based on the intake pressure Pin, the exhaust pressure Pout, and the EGR valve opening EV. However, the reference differential pressure ΔPb may be set based on a part of the intake pressure Pin, the exhaust pressure Pout, and the EGR valve opening degree EV. A uniform value may be used as the reference differential pressure ΔPb.

  In the internal combustion engine device 10 according to the embodiment, if it is determined that a misfire has occurred in any cylinder of the engine 12 when the engine 12 is started, the misfire cylinder and the supply cylinder are specified, and the fuel injection amount reduction correction of the supply cylinder is performed. To start. However, it is possible not to perform the reduction correction of the fuel injection amount of the supply cylinder.

  In the internal combustion engine device 10 of the embodiment, a differential pressure sensor 69 that detects the differential pressure before and after the EGR valve 66 is provided, and when the differential pressure ΔP detected by the differential pressure sensor 69 is larger than a value (ΔPb + ΔPm). The engine 12 is determined to have misfired in any cylinder. However, as shown in the internal combustion engine device 110 of the modified example of FIG. 4, the EGR pipe 162 of the EGR device 160 is provided with a throttle portion (a portion having a smaller inner diameter than other portions) 163 and a differential pressure before and after the throttle portion 163. It is also possible to provide a differential pressure sensor 169 that detects the occurrence of misfire in any cylinder of the engine 12 when the differential pressure ΔP2 detected by the differential pressure sensor 169 is greater than a threshold value. . In this case, a differential pressure is generated in the exhaust (EGR gas) before and after the throttle portion 163 of the EGR pipe 162 (a pressure loss is caused in the exhaust gas by the throttle portion 163). When a misfire occurs in any cylinder of the engine 12, exhaust gas containing unburned fuel recirculates to the intake pipe 25 via the EGR pipe 162, and thus misfire occurs in any cylinder of the engine 12. Compared to the case where there is no exhaust gas, the density of the exhaust gas in the EGR pipe 162 is increased, and the differential pressure ΔP2 before and after the throttle part 163 (pressure loss of the exhaust gas at the throttle part 163) is increased. Therefore, whether or not misfire has occurred in any cylinder of the engine 12 by a simple method is determined by determining that misfire has occurred in any cylinder of the engine 12 when the differential pressure ΔP2 is greater than the threshold value. Can be determined.

  In the internal combustion engine device 10 of the embodiment, a differential pressure sensor 69 that detects the differential pressure before and after the EGR valve 66 is provided, and when the differential pressure ΔP detected by the differential pressure sensor 69 is larger than a value (ΔPb + ΔPm). The engine 12 is determined to have misfired in any cylinder. However, as shown in the internal combustion engine device 210 of the modified example of FIG. 5, a differential pressure sensor 269 that detects the differential pressure before and after the EGR cooler 64 of the EGR device 260 is provided, and the difference detected by the differential pressure sensor 269. It may be determined that a misfire has occurred in any cylinder of the engine 12 when the pressure ΔP3 is greater than the threshold value. Since the EGR cooler 64 exchanges heat between the cooling water of the engine 12 and the exhaust gas in the EGR pipe 62, a differential pressure is generated in the exhaust gas (EGR gas) before and after the EGR cooler 64 (the EGR cooler 64 has a pressure loss in the exhaust gas). ). When a misfire occurs in any cylinder of the engine 12, exhaust gas containing unburned fuel recirculates to the intake pipe 25 via the EGR pipe 62, and thus misfire occurs in any cylinder of the engine 12. Compared to the case where there is no exhaust gas, the density of the exhaust gas in the EGR pipe 62 increases, and the differential pressure ΔP3 before and after the EGR cooler 64 (the pressure loss of the exhaust gas in the EGR cooler 64) increases. Therefore, whether or not misfire has occurred in any cylinder of the engine 12 by a simple method is determined by determining that misfire has occurred in any cylinder of the engine 12 when the differential pressure ΔP3 is greater than the threshold value. Can be determined.

  In the internal combustion engine device 10 according to the embodiment, the four-cylinder engine 12 is used, but an engine such as a six-cylinder engine or an eight-cylinder engine may be used. A single-cylinder engine may be used.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 12 to which the EGR device 60 is attached corresponds to the “internal combustion engine”, the internal combustion engine device 10 corresponds to the “internal combustion engine device”, the EGR valve 66 corresponds to the “pressure loss part”, and the difference The pressure sensor 69 corresponds to a “differential pressure sensor”, and the electronic control unit 70 that executes the misfire determination routine of FIG. 2 corresponds to a “determination unit”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. In other words, the interpretation of the invention described in the column of means for solving the problem should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problem. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of internal combustion engine devices.

  10, 110, 210 Internal combustion engine device, 12 engine, 14 crankshaft, 22 air cleaner, 24 throttle valve, 25 intake pipe, 26 fuel injection valve, 28 intake valve, 29 combustion chamber, 30 spark plug, 32 piston, 33 exhaust pipe , 34 Purification device, 35a Air-fuel ratio sensor, 35b Oxygen sensor, 35c Exhaust pressure sensor, 36 Throttle motor, 38 Ignition coil, 40 Crank position sensor, 42 Water temperature sensor, 46 Throttle valve position sensor, 48 Air flow meter, 49 Temperature sensor, 58 intake pressure sensor, 59 knock sensor, 60, 160, 260 exhaust recirculation device (EGR device), 62, 162 EGR pipe, 64 EGR cooler, 66 EGR valve, 66a valve seat, 66b valve body, 67 s Tapping motor, 68 EGR valve opening sensor, 69, 169, 269 Differential pressure sensor, 70 Electronic control unit, 163 Restriction part.

Claims (5)

In an internal combustion engine device comprising an internal combustion engine to which an exhaust gas recirculation device having an exhaust gas recirculation pipe for recirculating exhaust gas to intake air is attached,
A pressure loss part that causes a pressure loss in the exhaust in the exhaust gas recirculation pipe;
A differential pressure sensor for detecting a differential pressure before and after the pressure loss portion in the exhaust gas recirculation pipe;
Determination means for determining that misfire has occurred in the internal combustion engine when the differential pressure detected by the differential pressure sensor is greater than a threshold;
An internal combustion engine device comprising: The internal combustion engine device according to claim 1,
The pressure loss part is a throttle part.
Internal combustion engine device. An internal combustion engine device according to claim 2,
The exhaust gas recirculation device includes an adjustment valve that is attached to the exhaust gas recirculation pipe and adjusts the supply amount of exhaust gas to the intake pipe and functions as the throttle unit.
Internal combustion engine device. An internal combustion engine device according to claim 3,
The threshold is set according to the exhaust pressure and intake pressure of the internal combustion engine and the opening of the control valve.
Internal combustion engine device. The internal combustion engine device according to claim 1,
The exhaust gas recirculation device includes an exhaust cooler that is attached to the exhaust gas recirculation pipe to cool the exhaust gas and functions as the pressure loss unit.
Internal combustion engine device.

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