JP2021032197A - Engine device - Google Patents

Abstract

To estimate presence/absence of blockage of a differential pressure pipe.SOLUTION: An engine device includes an engine, a differential pressure sensor having a differential pressure pipe attached to an exhaust pipe of the engine, and a control device for controlling the engine, and blockage of the differential pressure pipe is estimated when a pulsation width of the differential pressure detected by the differential pressure sensor is less than a prescribed width. Inventors have found out by experiment and analysis that the pulsation width of the detected differential pressure decreases when the differential pressure pipe is blocked. Accordingly, the presence/absence of blockage of the differential pressure pipe can be estimated by comparing the pulsation width of the detected differential pressure with the prescribed width.SELECTED DRAWING: Figure 3

Description

The present invention relates to an engine device.

Conventionally, as this type of engine device, the engine, the GPF as a filter for collecting PM (particulate matter) in the exhaust gas of the engine, and the difference between the upstream exhaust pressure and the downstream exhaust pressure of the GPF ( A differential pressure sensor that detects front-rear differential pressure) has been proposed (see, for example, Patent Document 1). In this engine device, the PM accumulation amount is calculated based on the output of the differential pressure sensor while the execution of the GPF regeneration control is stopped (before execution).

Japanese Unexamined Patent Publication No. 2016-136011

In such engine equipment, the differential pressure pipe of the differential pressure sensor is generally attached to the exhaust pipe of the engine. When this differential pressure pipe is blocked, the differential pressure detected by the differential pressure sensor has a delay in responding to the actual differential pressure, and the detection accuracy of the differential pressure sensor (particularly, the pressure in the exhaust pipe changes). There is a risk that the detection accuracy will deteriorate. Therefore, it is required to devise a method for estimating that the differential pressure pipe is blocked.

An object of the engine device of the present invention is to make it possible to estimate the presence or absence of blockage of a differential pressure pipe.

The engine device of the present invention has adopted the following means in order to achieve the above-mentioned main object.

The engine device of the present invention
With the engine
A differential pressure sensor having a differential pressure pipe attached to the exhaust pipe of the engine,
The control device that controls the engine and
It is an engine device equipped with
The control device estimates that the differential pressure pipe is blocked when the pulsation width of the detected differential pressure detected by the differential pressure sensor is less than a predetermined width.
The gist is that.

In the engine device of the present invention, it is presumed that the differential pressure pipe is blocked when the pulsation width of the detected differential pressure detected by the differential pressure sensor is less than a predetermined width. Through experiments and analysis, the inventors have found that when the differential pressure pipe is blocked, the pulsation width of the detected differential pressure becomes smaller. Therefore, by comparing the pulsating width of the detected differential pressure with the predetermined width, it is possible to estimate the presence or absence of blockage of the differential pressure pipe. Here, the "differential pressure sensor" may detect the difference pressure between the exhaust pressure of the engine and the atmospheric pressure, or the difference between the front and the back of the filter attached to the exhaust pipe of the engine and collecting particulate matter. The pressure may be detected.

In such an engine device of the present invention, when it is estimated that the differential pressure pipe is blocked, the control device sets the response delay time of the detected differential pressure so that the smaller the pulsating width of the detected differential pressure, the longer the response delay time. It may be estimated. In this way, the response delay time can be more appropriately estimated based on the degree of blockage of the differential pressure pipe.

Further, in the engine device of the present invention, when it is estimated that the differential pressure pipe is blocked, the control device may delay the determination that the engine is in a steady state by the response delay time. .. In this way, it is possible to accurately determine that the engine is in a steady state.

In the engine device of the present invention of this aspect, when the control device estimates that the differential pressure pipe is blocked, the amount of change in the intake air amount of the engine per unit time is equal to or less than a predetermined amount of change. When the quantity condition is continuously satisfied over the response delay time, it may be determined that the engine is in a steady state. In this way, it is possible to more accurately determine that the engine is in a steady state.

Further, in the engine device of the present invention of this aspect, when the control device determines that the engine is in a steady state, the post-treatment differential pressure obtained by subjecting the detected differential pressure to a slow change treatment, or the above-mentioned The amount of increase in back pressure, which is the amount of increase in the back pressure of the engine with respect to the reference value, may be estimated so that the average difference pressure obtained as the average value of the pulsation of the detected differential pressure in one cycle becomes larger. .. In this way, the amount of increase in back pressure can be estimated accurately.

Further, in the engine device of the present invention of this aspect, the engine includes an exhaust recirculation device having an exhaust recirculation pipe for circulating the exhaust of the engine to the intake air and an exhaust pipe flow valve attached to the exhaust recirculation pipe. When it is determined that the engine is in a steady state, the control device may control the exhaust / recirculation valve so that the larger the back pressure increase amount, the smaller the opening degree of the exhaust / recirculation valve. In this way, it is possible to prevent the exhaust recirculation amount from becoming excessive when the back pressure of the engine is high.

In the engine device of the present invention, when the control device determines that the engine is in a transient state, a correction value is set so that the longer the response delay time is, the larger the correction value is, and the detected differential pressure is subjected to a gradual change process. The back pressure of the engine may be estimated using the post-treatment differential pressure obtained by the application, the average differential pressure obtained as the average value of one cycle of the pulsation of the detected differential pressure, and the correction value. .. In this way, the back pressure of the engine can be estimated accurately.

In the engine device of the present invention of this aspect, when the control device determines that the engine is in a transient state, when the back pressure of the engine is larger than the predetermined back pressure, the back pressure of the engine is the predetermined. The output of the engine may be limited as compared with the case where the back pressure or less. In this way, it is possible to suppress an increase in the back pressure of the engine.

It is a block diagram which shows the outline of the structure of the hybrid vehicle 20 which mounted the engine device as one Example of this invention. It is a block diagram which shows the outline of the structure of the engine 22. It is a flowchart which shows an example of the response delay time estimation routine executed by the engine ECU 24. It is explanatory drawing which shows an example of the analysis result of the detected differential pressure DP performed by the inventors. It is explanatory drawing which shows an example of the response delay time estimation map. It is a flowchart which shows an example of the processing routine executed by the engine ECU 24. It is explanatory drawing which shows an example of the back pressure increase amount estimation map. It is explanatory drawing which shows an example of the map for setting a correction coefficient. It is explanatory drawing which shows an example of the map for setting a correction value.

Next, a mode for carrying out the present invention will be described with reference to examples.

FIG. 1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 equipped with an engine device as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, an electronic control unit for an engine (hereinafter referred to as “engine ECU”) 24, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, and the like. It includes a battery 50 as a power storage device and a hybrid electronic control unit (hereinafter, referred to as "HVECU") 70.

The engine 22 is configured as an internal combustion engine that outputs power using gasoline, light oil, or the like as fuel, and is connected to the carrier of the planetary gear 30 via a damper 28. FIG. 2 is a configuration diagram showing an outline of the configuration of the engine 22. As shown in the figure, the engine 22 sucks the air cleaned by the air cleaner 122 into the intake pipe 123 and passes it through the throttle valve 124, and injects fuel from the fuel injection valve 126 to mix the air and the fuel. The air-fuel mixture is sucked into the combustion chamber 129 via the intake valve 128. Then, the sucked air-fuel mixture is exploded and burned by an electric spark from the spark plug 130, and the reciprocating motion of the piston 132 pushed down by the energy is converted into the rotational motion of the crankshaft 26. The exhaust gas discharged from the combustion chamber 129 to the exhaust pipe 133 via the exhaust valve 131 is discharged to the outside air through the purification device 134 and the PM filter 136. The purification device 134 has a purification catalyst (three-way catalyst) 134a that purifies harmful components of carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in the exhaust gas. The PM filter 136 is formed of ceramics, stainless steel, or the like as a porous filter, and captures particulate matter (PM: Particulate Matter) such as soot in the exhaust gas. A differential pressure sensor 138 is provided between the purification device 134 and the PM filter 136 in the exhaust pipe 133. The differential pressure sensor 138 is a sensor unit 138b that detects the differential pressure between the differential pressure pipe 138a attached to the exhaust pipe 133 and the exhaust pressure and the atmospheric pressure between the purification device 134 and the PM filter 136 in the exhaust pipe 133. And.

The exhaust gas discharged from the combustion chamber 129 to the exhaust pipe 133 is not only discharged to the outside air but also returned to the intake pipe 123 via an exhaust gas recirculation device (hereinafter referred to as "EGR (Exhaust Gas Recirculation) device") 160. Will be done. The EGR device 160 includes an EGR tube 162 and an EGR valve 163. The EGR pipe 162 connects the upstream side of the purification device 134 in the exhaust pipe 133 and the downstream side of the throttle valve 124 in the intake pipe 123. The EGR valve 163 is arranged in the EGR tube 162 and is driven by the EGR motor 164. The EGR device 160 adjusts the recirculation amount of the exhaust gas of the exhaust pipe 133 by adjusting the opening degree of the EGR valve 163 by the EGR motor 164 to recirculate the exhaust gas to the intake pipe 123. In this way, the engine 22 can suck the air-fuel mixture of air, exhaust gas, and fuel into the combustion chamber 129. Hereinafter, the exhaust gas recirculation is referred to as "EGR", and the exhaust gas recirculation amount is referred to as "EGR amount". The operation of the engine 22 is controlled by the engine ECU 24.

Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and in addition to the CPU, has a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port. Be prepared. Signals from various sensors necessary for controlling the operation of the engine 22 are input to the engine ECU 24 via the input port. The signals input to the engine ECU 24 include, for example, a crank angle θcr from the crank position sensor 140 that detects the rotational position of the crankshaft 26 of the engine 22, and a water temperature sensor 142 that detects the temperature of the cooling water of the engine 22. The cooling water temperature Tw can be mentioned. Cam angles θci and θco from the cam position sensor 144 that detect the rotational position of the intake camshaft that opens and closes the intake valve 128 and the rotational position of the exhaust camshaft that opens and closes the exhaust valve 131 can also be mentioned. Throttle opening TH from the throttle position sensor 124a that detects the position of the throttle valve 124, intake air amount Qa from the air flow meter 148 attached to the intake pipe 123, and intake from the temperature sensor 149 attached to the intake pipe 123. The temperature Ta can also be mentioned. The air-fuel ratio AF from the air-fuel ratio sensor 135a attached to the exhaust pipe 133 and the oxygen signal O2 from the oxygen sensor 135b attached to the exhaust pipe 133 can also be mentioned. The differential pressure DP detected from the sensor unit 138b of the differential pressure sensor 138 that detects the differential pressure between the exhaust pressure and the atmospheric pressure between the purification device 134 and the PM filter 136 (before passing through the PM filter 136) in the exhaust pipe 133. Can also be mentioned. The EGR valve opening degree Oegr from the EGR valve opening degree sensor 165 that detects the opening degree of the EGR valve 163 can also be mentioned.

Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via the output port. Examples of the signal output from the engine ECU 24 include a control signal to the throttle motor 124b for adjusting the position of the throttle valve 124, a control signal to the fuel injection valve 126, and a control signal to the spark plug 130. The engine ECU 24 is connected to the HVECU 70 via a communication port. A target EGR valve opening degree Oegr * can be mentioned as a control signal to the EGR motor 164 for adjusting the opening degree of the EGR valve 163.

The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 140, and the temperature (catalyst) of the purification catalyst 134a of the purification device 134 based on the cooling water temperature Tw from the water temperature sensor 142 and the like. Temperature) Tc is calculated. Further, the engine ECU 24 is based on the intake air amount Qa from the air flow meter 148 and the rotation speed Ne of the engine 22, and the load factor (the air that is actually sucked in one cycle with respect to the stroke volume of the engine 22 per cycle). Volume ratio) KL is calculated. Further, the engine ECU 24 calculates the PM accumulation amount Qpm as the accumulation amount of the particulate matter deposited on the PM filter 136, and determines the temperature of the PM filter 136 based on the rotation speed Ne and the load factor KL of the engine 22. The filter temperature Tf is calculated. In addition, the engine ECU 24 has a pulsation width (maximum value and minimum value) of one cycle of the detected differential pressure DP from the differential pressure sensor 138 based on the time change of the detected differential pressure DP from the sensor unit 138b of the differential pressure sensor 138. The differential pressure pulsation width PDP is calculated as (difference from).

In the embodiment, the engine 22, the differential pressure sensor 138, and the engine ECU 24 correspond to the “engine device”.

As shown in FIG. 1, the planetary gear 30 is configured as a single pinion type planetary gear mechanism, and includes a sun gear 31, a ring gear 32, a plurality of pinion gears 33 that mesh with the sun gear 31 and the ring gear 32, respectively, and a plurality of pinion gears. It has a carrier 34 that rotates (rotates) and revolves around 33. The rotor of the motor MG1 is connected to the sun gear 31 of the planetary gear 30. A drive shaft 36 connected to the drive wheels 39a and 39b via a differential gear 38 is connected to the ring gear 32 of the planetary gear 30. As described above, the crankshaft 26 of the engine 22 is connected to the carrier 34 of the planetary gear 30 via the damper 28. Therefore, it can be said that the motor MG1, the engine 22, and the drive shaft 36 are connected to the sun gear 31, the carrier 34, and the ring gear 32 as the three rotating elements of the planetary gear 30 so as to be arranged in this order in the collinear diagram of the planetary gear 30.

The motor MG1 is configured as, for example, a synchronous motor generator, and as described above, the rotor is connected to the sun gear 31 of the planetary gear 30. The motor MG2 is configured as, for example, a synchronous motor generator, and a rotor is connected to a drive shaft 36. The inverters 41 and 42 are used to drive the motors MG1 and MG2 and are connected to the battery 50 via the power line 54. A smoothing capacitor 57 is attached to the power line 54. The motors MG1 and MG2 are rotationally driven by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42 by an electronic control unit for a motor (hereinafter referred to as “motor ECU”) 40.

Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port. Be prepared. The motor ECU 40 has signals from various sensors required to drive and control the motors MG1 and MG2, for example, rotation positions θm1 from rotation position detection sensors 43 and 44 that detect the rotation positions of the rotors of the motors MG1 and MG2. , Θm2 and the phase currents Iu1, Iv1, Iu2, Iv2 from the current sensors 45u, 45v, 46u, 46v that detect the current flowing in each phase of the motors MG1 and MG2 are input via the input port. From the motor ECU 40, switching control signals and the like to the plurality of switching elements of the inverters 41 and 42 are output via the output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 has an electric angle θe1, θe2 and an angular velocity ωm1, ωm2, a rotation number Nm1, Nm2 of the motors MG1 and MG2 based on the rotation positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from the rotation position detection sensors 43 and 44. Is calculated.

The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydrogen secondary battery, and is connected to the power line 54. The battery 50 is managed by an electronic control unit for batteries (hereinafter, referred to as "battery ECU") 52.

Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and in addition to the CPU, has a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port. Be prepared. Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input port. The signals input to the battery ECU 52 include, for example, the voltage Vb of the battery 50 from the voltage sensor 51a attached between the terminals of the battery 50 and the battery 50 from the current sensor 51b attached to the output terminal of the battery 50. Examples include the current Ib and the temperature Tb of the battery 50 from the temperature sensor 51c attached to the battery 50. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the storage ratio SOC based on the integrated value of the current Ib of the battery 50 from the current sensor 51b. The storage ratio SOC is the ratio of the amount of power that can be discharged from the battery 50 to the total capacity of the battery 50.

Although not shown, the HVECU 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, an input / output port, and a communication port in addition to the CPU. .. Signals from various sensors are input to the HVECU 70 via input ports. Examples of the signal input to the HVECU 70 include an ignition signal from the ignition switch 80 and a shift position SP from the shift position sensor 82 that detects the operating position of the shift lever 81. Further, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, the brake pedal position BR from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, and the vehicle speed sensor 88. The vehicle speed V can also be mentioned. The atmospheric pressure Pout from the atmospheric pressure sensor 89 can also be mentioned. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via a communication port.

The hybrid vehicle 20 of the embodiment configured in this way has a hybrid driving mode (HV driving mode) in which the vehicle travels with the rotation of the engine 22 and an electric driving mode (EV driving mode) in which the hybrid vehicle 20 travels with the rotation of the engine 22 stopped. It runs while switching (while operating the engine 22 intermittently).

In the HV running mode, the HVECU 70 first sets the running torque Td * required for the drive shaft 36 (required for running) based on the accelerator opening Acc and the vehicle speed V, and sets the running torque. Multiply Td * by the rotation speed Nd of the drive shaft 36 (rotation speed Nm2 of the motor MG2) to calculate the traveling power Pd * required for the drive shaft 36. Subsequently, the required charging power Pb * of the battery 50 (a positive value when discharged from the battery 50) is subtracted from the traveling power Pd * to calculate the required power Petag required for the engine 22 (required for the vehicle). Then, the calculated required power Petag is limited by the upper limit power Pelim (upper limit guard), and the target power Pe * of the engine 22 is set. Here, as the upper limit power Pelim, basically, the rated value Pe1 of the engine 22 is used. Then, the target rotation speed Ne * and the target torque Te * of the engine 22 are output so that the target power Pe * is output from the engine 22 and the running torque Td * (running power Pd *) is output to the drive shaft 36. The torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are set. Then, the target rotation speed Ne * and the target torque Te * of the engine 22 are transmitted to the engine ECU 24, and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU40.

When the engine ECU 24 receives the target rotation speed Ne * and the target torque Te * of the engine 22, the engine ECU 24 controls the operation of the engine 22 (for example, so that the engine 22 is operated based on the target rotation speed Ne * and the target torque Te *. , Intake air amount control, fuel injection control, ignition control, EGR control, etc.). In the intake air amount control, the engine ECU 24 sets the target air amount Qa * based on the target torque Te * of the engine 22, and sets the target throttle opening TH * so that the intake air amount Qa becomes the target air amount Qa *. The throttle motor 124b is controlled so that the throttle opening TH of the throttle valve 124 becomes the target throttle opening TH *. In the fuel injection control, the engine ECU 24 sets the target fuel injection amount Qf * so that the air-fuel ratio AF becomes the target air-fuel ratio AF * based on the intake air amount Qa, and the target fuel injection amount Qf * is set from the fuel injection valve 126. The fuel injection valve 126 is controlled so that the fuel of the above is injected. In ignition control, the engine ECU 24 sets the target ignition timing Tf * based on the rotation speed Ne of the engine 22 and the load factor KL, and controls the spark plug 130 so that ignition is performed at the target ignition timing Tf *. In EGR control, the engine ECU 24 sets the target EGR valve opening Oegr * based on the intake air amount Qa, and the EGR motor 164 so that the EGR valve opening Oegr of the EGR valve 163 becomes the target EGR valve opening Oegr *. To control.

When the motor ECU 40 receives the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2, the motor ECU 40 controls switching of a plurality of switching elements of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *. To do.

In the EV traveling mode, the HVECU 70 sets the traveling torque Td * of the drive shaft 36 based on the accelerator opening Acc and the vehicle speed V, sets a value 0 in the torque command Tm1 * of the motor MG1, and turns on the battery 50. The torque command Tm2 * of the motor MG2 is set so that the running torque Td * is output to the drive shaft 36 within the range of the output limits Win and Wout, and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are set by the motor ECU40. Send to. The control of the inverters 41 and 42 by the motor ECU 40 has been described above.

Next, the operation of the hybrid vehicle 20 of the embodiment configured in this manner, particularly the operation when estimating the presence or absence of blockage of the differential pressure pipe 138a of the differential pressure sensor 138 will be described. FIG. 3 is a flowchart showing an example of a response delay time estimation routine executed by the engine ECU 24. This routine is repeatedly executed in the HV driving mode (when the engine 22 is being operated).

When the response delay time estimation routine of FIG. 3 is executed, the engine ECU 24 first inputs data such as the differential pressure pulsation width PDP (step S100). Here, as the differential pressure pulsation width PDP, a value calculated as the pulsation width (difference between the maximum value and the minimum value) of one cycle of the detected differential pressure DP from the sensor unit 138b of the differential pressure sensor 138 is input.

When the data is obtained in this way, the engine ECU 24 compares the differential pressure pulsation width PDP with the threshold value PDPref (step S110). Here, the threshold value PDPref is a threshold value used for estimating (determining) whether or not the differential pressure pipe 138a is blocked, and is predetermined by experiment or analysis. When the differential pressure pulsation width PDP is equal to or greater than the threshold value PDPref, it is estimated that the differential pressure pipe 138a is not blocked (step S120), the response delay time Td is set to a value 0 (step S130), and this routine is terminated. .. Here, the response delay time Td means the response delay time with respect to the actual differential pressure of the detected differential pressure DP.

When the differential pressure pulsation width PDP is less than the threshold value PDPref in step S110, it is estimated that the differential pressure pipe 138a is blocked (step S140), and the response delay is delayed using the differential pressure pulsation width PDP and the response delay time setting map. The time Td is estimated (step S150), and this routine ends. Here, the response delay time estimation map is preset as the relationship between the differential pressure pulsation width PDP and the response delay time Td, and is stored in a ROM (not shown).

FIG. 4 is an explanatory diagram showing an example of a map for estimating the response delay time. As shown in the figure, the response delay time Td is estimated to increase as the differential pressure pulsation width PDP becomes smaller in the range where the differential pressure pulsation width PDP is less than the threshold value PDPref. The alternate long and short dash line in the figure is shown for reference by estimating the response delay time Td as a value 0 in step S120 described above when the differential pressure pulsation width PDP is equal to or greater than the threshold value PDPref.

FIG. 5 is an explanatory diagram showing an example of the analysis result of the detected differential pressure DP performed by the inventors. From FIG. 5, the detected differential pressure DP shows that when the differential pressure pipe 138a is blocked, the greater the degree of the blockage, the more the differential pressure pulsation width PDP is compared with the case where the differential pressure pipe 138a is not blocked. It can be seen that as the value decreases, the pulsation is delayed. In the embodiment, based on this, it is estimated whether or not the differential pressure pipe 138a is blocked by comparing the differential pressure pulsation width PDP and the threshold value PDPref, and when the differential pressure pulsation width PDP is less than the threshold value PDPref, the difference is obtained. The response delay time Td was estimated based on the pressure pulsation width PDP. By such a method, it is possible to estimate the presence or absence of blockage of the differential pressure pipe 138a and the response delay time Td of the detected differential pressure DP.

Next, the process of determining the operating state of the engine 22 and the like will be described. FIG. 6 is a flowchart showing an example of a processing routine executed by the engine ECU 24. This routine is repeatedly executed in parallel with the response delay time estimation routine of FIG. 3 in the HV driving mode (when the engine 22 is being operated).

When the processing routine of FIG. 6 is executed, the engine ECU 24 first inputs data such as the intake air amount Qa, the detected differential pressure DP, and the response delay time Td (step S200). Here, a value detected by the air flow meter 148 is input as the intake air amount Qa. The value detected by the sensor unit 138b of the differential pressure sensor 138 is input as the detected differential pressure DP. For the response delay time Td, a value estimated by the response delay time estimation routine of FIG. 3 is input.

When the data is input in this way, the engine ECU 24 calculates the mean differential pressure MDP as the average value of one cycle of the pulsation of the detected differential pressure DP (step S210), and the intake air amount Qa input this time and the previous time. The intake air change amount ΔQa is calculated as a difference (absolute value of a value obtained by subtracting the other from one) from the input intake air amount (previous Qa) (step S220).

Subsequently, the engine ECU 24 compares the intake air change amount ΔQa with the threshold value ΔQaref (step S230), and when the intake air change amount ΔQa is equal to or less than the threshold value ΔQaref, determines whether or not the state continues over the response delay time Td. Determine (step S240). Here, the threshold value ΔQaref is a threshold value used for determining whether or not the operating state of the engine 22 is a steady state, and is predetermined by experiments and analysis.

When the state in which the intake air change amount ΔQa is equal to or less than the threshold value ΔQaref continues over the response delay time Td in steps S230 and S240, the engine ECU 24 determines that the operating state of the engine 22 is a steady state (step 250). Even if the intake air change amount ΔQa reaches the threshold value ΔQaref or less, the average differential pressure MDP may not be stable (not substantially constant) until the state continues over the response delay time Td. is there. In consideration of this, in the embodiment, it is determined that the operating state of the engine 22 is a steady state when the state in which the intake air change amount ΔQa is equal to or less than the threshold value ΔQaref continues over the response delay time Td. .. As a result, it is possible to accurately determine that the engine 22 is in a steady state.

When it is determined in step S250 that the operating state of the engine 22 is in a steady state, the back pressure increase DBP of the engine 22 is estimated using the intake air amount Qa, the average differential pressure MDP, and the back pressure increase estimation map. Step S260). Here, the back pressure increase amount DBP is an increase amount with respect to the reference value of the back pressure (pressure of the exhaust pipe 133) of the engine 22. As the reference value, for example, the back pressure when the PM accumulation amount Qpm deposited on the PM filter 136 is 0 is assumed. The back pressure increase amount estimation map is set in advance by experiments and analyzes as the relationship between the intake air amount Qa, the average differential pressure MDP, and the back pressure increase amount DBP, and is stored in a ROM (not shown). FIG. 7 is an explanatory diagram showing an example of a map for estimating the amount of increase in back pressure. As shown in the figure, the back pressure increase amount DBP is estimated to increase as the intake air amount Qa increases, and to increase as the average differential pressure MDP increases. By estimating the back pressure increase amount DBP in this way, the back pressure increase amount DBP can be estimated accurately.

Subsequently, the engine ECU 24 sets the correction coefficient Koegr using the back pressure increase amount DBP and the correction coefficient setting map (step S270), and multiplies the target EGR valve opening degree Oegr * by the correction coefficient Koegr to obtain the target EGR. The valve opening degree Oegr * is corrected (step S280), and this routine is terminated. Here, the correction coefficient setting map is predetermined as the relationship between the back pressure increase amount DPB and the correction coefficient Koegr, and is stored in a ROM (not shown). FIG. 8 is an explanatory diagram showing an example of a correction coefficient setting map. As shown in the figure, the correction coefficient Koegr is set so as to decrease as the back pressure increase amount DBP increases in the range of less than 1 value. In this way, when the back pressure BP of the engine 22 is high, it is possible to prevent the EGR amount from becoming excessive.

When the intake air change amount ΔQa is larger than the threshold value ΔQaref in step S230, or when the state in which the intake air change amount ΔQa is equal to or less than the threshold value ΔQaref in step S240 does not continue over the response delay time Td, the engine ECU 24 uses the engine 22. It is determined that the operating state of is a transient state (step 290).

When it is determined that the operating state of the engine 22 is a transient state, the correction value CBP is set using the response delay time Td, the intake air change amount ΔQa, and the correction value setting map (step S300). Here, the correction value setting map is predetermined as the relationship between the response delay time Td, the intake air change amount ΔQa, and the correction value CBP, and is stored in a ROM (not shown). FIG. 9 is an explanatory diagram showing an example of a correction value setting map. As shown in the figure, the correction value CBP is set so that the longer the response delay time Td is, the larger the correction value CBP is, and the larger the intake air change amount ΔQa is, the larger the correction value CBP is. The reason for setting in this way is that the longer the response delay time Td, the larger the difference (deviation) between the detected value of the average differential pressure MDP and the current value, and the larger the intake air change amount ΔQ, the more the operating state of the engine 22 changes. Is large.

Subsequently, the back pressure BP of the engine 22 is estimated using the average differential pressure MDP and the correction value CBP (step S310). This estimation can be performed, for example, by calculating the sum of the average differential pressure MDP and the correction value CBP. In this way, the back pressure BP of the engine 22 can be estimated accurately.

When the back pressure BP of the engine 22 is estimated in this way, the engine ECU 24 compares the back pressure BP of the engine 22 with the threshold value BPref (step S320). Here, the threshold value BPref is a threshold value used for determining whether or not the back pressure BP of the engine 22 is relatively high, and is determined by experiment or analysis. When the back pressure BP is equal to or less than the threshold value BPref, this routine is terminated.

When the back pressure BP of the engine 22 is larger than the threshold value BPref in step S320, a predetermined value Pe2 smaller than the rated value Pe1 is set in the upper limit power Pelim of the engine 22 (step S330), and this routine is terminated. By doing so, it is possible to suppress a further increase in the back pressure BP of the engine 22, and it is possible to protect the engine 22.

In the engine device mounted on the hybrid vehicle 20 of the above-described embodiment, when the differential pressure pulsation width PDP of the detected differential pressure DP detected by the sensor unit 138b of the differential pressure sensor 138 is less than the threshold value PDPref. It is presumed that the differential pressure pipe 138a of the differential pressure sensor 138 is blocked. The inventors have found through experiments and analyzes that when the differential pressure pipe 138a of the differential pressure sensor 138 is blocked, the differential pressure pulsation width PDP of the detected differential pressure DP becomes smaller. Therefore, by comparing the differential pressure pulsation width PDP of the detected differential pressure DP with the threshold value PDPref, it is possible to estimate the presence or absence of blockage of the differential pressure pipe 138a of the differential pressure sensor 138.

In the engine device of the embodiment, a constant is used as the threshold value PDPref. However, the threshold value PDPref may be set based on the rotation speed Ne of the engine 22 and the load factor KL.

In the engine device of the embodiment, the engine ECU 24 estimates the response delay time Td of the detected differential pressure DP when it is estimated that the differential pressure pipe 138a of the differential pressure sensor 138 is blocked. The response delay time Td of the DP may not be estimated.

In the engine device of the embodiment, the engine ECU 24 estimates the back pressure increase DBP of the engine 22 by using the average differential pressure MDP as the average value of the pulsation of the detected differential pressure DP in one cycle. However, the engine ECU 24 may estimate the back pressure increase DBP of the engine 22 by using the post-process differential pressure obtained by subjecting the detected differential pressure DP to a slow change process instead of the average differential pressure MDP. Further, the back pressure increase amount DBP of the engine 22 may not be estimated.

In the engine device of the embodiment, the engine ECU 24 determines that the operating state of the engine 22 is a steady state when the state in which the intake air change amount ΔQa is equal to or less than the threshold value ΔQaref continues over the response delay time Td. did. However, the engine ECU 24 determines that the operating state of the engine 22 is a steady state when the state in which the amount of change ΔKL of the load factor KL of the engine 22 per unit time is equal to or less than the threshold value ΔKLref continues for the response delay time. It may be the one to do.

In the engine device of the embodiment, the engine ECU 24 corrects the target EGR valve opening Oegr * by multiplying the target EGR valve opening Oegr * by the correction coefficient Koegr, but corrects the target EGR valve opening Oegr *. It may not be.

In the engine device of the embodiment, the engine ECU 24 sets the correction value CBP based on the response delay time Td and the intake air change amount ΔQa. However, the engine ECU 24 may set the correction value CBP based only on the response delay time Td.

In the engine device of the embodiment, the engine ECU 24 estimates the back pressure BP of the engine 22 by using the average differential pressure MDP as the average value of one cycle of the pulsation of the detected differential pressure DP. However, the engine ECU 24 may estimate the back pressure BP of the engine 22 by using the post-process differential pressure obtained by subjecting the detected differential pressure DP to a slow change process instead of the average differential pressure MDP. Further, the back pressure BP of the engine 22 may not be estimated.

In the engine device of the embodiment, when the back pressure BP of the engine 22 is larger than the threshold value BPref, the engine ECU 24 sets the upper limit power Pelim of the engine 22 to a predetermined value Pe2 smaller than the rated value Pe1. However, regardless of the back pressure BP of the engine 22, the rated value Pe1 may be set in the upper limit power Pelim of the engine 22.

In the engine device of the embodiment, the engine ECU 24 presumes that the differential pressure pipe 138a of the differential pressure sensor 138 is blocked when the differential pressure pulsation width PDP of the detected differential pressure DP is less than the threshold value PDPref. In addition to this, the engine ECU 24 may presume that the differential pressure pipe 138a of the differential pressure sensor 138 is frozen when the outside air temperature is lower than the predetermined temperature. When it is estimated that the differential pressure pipe 138a of the differential pressure sensor 138 is frozen, the detected differential pressure DP becomes longer as the outside air temperature decreases and / or increases as the differential pressure pulsation width PDP decreases. The response delay time Td may be estimated.

In the engine device of the embodiment, the EGR device 160 is provided, but the EGR device 160 may not be provided.

In the engine device of the embodiment, it is assumed that the engine device is mounted on a hybrid vehicle including an engine 22, two motors MG1 and MG2, and a planetary gear 30, but any hybrid vehicle equipped with an engine is mounted on the hybrid vehicle. It may be mounted on a normal automobile that is not equipped with a traveling motor, or may be mounted on a non-moving facility such as a construction facility.

The correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem will be described. In the embodiment, the engine 22 corresponds to the "engine", the differential pressure sensor 138 corresponds to the "differential pressure sensor", and the engine ECU 24 corresponds to the "control device".

Regarding the correspondence between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem, the invention described in the column of the means for solving the problem in the examples is carried out. Since it is an example for specifically explaining the form for solving the problem, the elements of the invention described in the column of means for solving the problem are not limited. That is, the interpretation of the invention described in the column of means for solving the problem should be performed based on the description in the column, and the examples are the inventions described in the column of means for solving the problem. It is just a concrete example.

Although the embodiments for carrying out the present invention have been described above with reference to examples, the present invention is not limited to these examples, and various embodiments are used without departing from the gist of the present invention. Of course, it can be done.

The present invention can be used in the manufacturing industry of engine devices and the like.

20 hybrid car, 22 engine, 24 engine ECU, 26 crank shaft, 28 damper, 30 planetary gear, 31 sun gear, 32 ring gear, 33 pinion gear, 34 carrier, 36 drive shaft, 38 differential gear, 39a, 39b drive wheel, 40 motor ECU , 41,42 Inverter, 43,44 Rotation position detection sensor, 45u, 45v, 46u, 46v Current sensor, 50 battery, 52 battery ECU, 54 power line, 70 HVECU, 80 ignition switch, 81 shift lever, 82 shift position sensor , 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 122 Air cleaner, 123 Intake pipe, 124 Throttle valve, 124a Throttle position sensor, 126 Fuel injection valve, 128 Intake valve, 129 Ignition chamber, 130 Ignition plug, 131 Exhaust valve, 133 Exhaust pipe, 134 Purifier, 135a Air fuel ratio sensor, 135b Oxygen sensor, 136 PM filter, 138 Differential pressure sensor, 140 Crank position sensor, 142 Water temperature sensor, 148 Air flow meter 138a differential pressure pipe, 138b sensor unit, 149 temperature sensor, 160 EGR device, 162 EGR tube, 163 EGR valve, 164 EGR motor, 165 EGR valve opening sensor, MG1, MG2 motor.

Claims (8)

With the engine
A differential pressure sensor having a differential pressure pipe attached to the exhaust pipe of the engine,
The control device that controls the engine and
It is an engine device equipped with
The control device estimates that the differential pressure pipe is blocked when the pulsation width of the detected differential pressure detected by the differential pressure sensor is less than a predetermined width.
Engine device. The engine device according to claim 1.
When the control device estimates that the differential pressure pipe is blocked, the control device estimates the response delay time of the detected differential pressure so that the smaller the pulsating width of the detected differential pressure, the longer the response delay time.
Engine device. The engine device according to claim 1 or 2.
When the control device estimates that the differential pressure pipe is blocked, the control device delays the determination that the engine is in a steady state by the response delay time.
Engine device. The engine device according to claim 3.
When the control device estimates that the differential pressure pipe is blocked, the air amount condition in which the amount of change in the intake air amount of the engine per unit time is equal to or less than the predetermined amount of change is over the response delay time. When it is continuously established, it is determined that the engine is in a steady state.
Engine device. The engine device according to claim 3 or 4.
When the control device determines that the engine is in a steady state, the detected differential pressure is subjected to a slow change process to obtain a post-process differential pressure, or an average value of one cycle of the pulsation of the detected differential pressure. The amount of increase in back pressure, which is the amount of increase in the back pressure of the engine with respect to the reference value, is estimated so that the larger the average differential pressure obtained, the larger the amount.
Engine device. The engine device according to claim 5.
The engine includes an exhaust recirculation device having an exhaust recirculation pipe for circulating the exhaust of the engine to intake air and an exhaust pipe flow valve attached to the exhaust recirculation pipe.
When the control device determines that the engine is in a steady state, the control device controls the exhaust recirculation valve so that the larger the back pressure increase amount, the smaller the opening degree of the exhaust recirculation valve.
Engine device. The engine device according to any one of claims 1 to 6.
When the control device determines that the engine is in a transient state, it sets a correction value so that the longer the response delay time is, the larger the correction value is, and the post-processing difference obtained by subjecting the detected differential pressure to a slow change process. The back pressure of the engine is estimated using the pressure or the average differential pressure obtained as the average value of one cycle of the pulsation of the detected differential pressure and the correction value.
Engine device. The engine device according to claim 7.
When the control device determines that the engine is in a transient state, when the back pressure of the engine is larger than the predetermined back pressure, the back pressure of the engine is equal to or less than the predetermined back pressure. Limit the output of the engine,
Engine device.

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