JP7207236B2 - engine device - Google Patents

Description

The present invention relates to an engine device.

Conventionally, this type of engine device includes an engine, a GPF as a filter that collects PM (particulate matter) in the exhaust gas of the engine, and a difference between the upstream side exhaust pressure and the downstream side exhaust pressure of the GPF ( and a differential pressure sensor that detects a front-rear differential pressure (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 regeneration control of the GPF is stopped (before the execution).

JP 2016-136011 A

In such an engine device, the differential pressure pipe of the differential pressure sensor is generally attached to the exhaust pipe of the engine. If this differential pressure pipe is blocked, the differential pressure detected by the differential pressure sensor will have a response delay with respect to the actual differential pressure, and the detection accuracy of the differential pressure sensor (especially if the pressure in the exhaust pipe changes). There is a risk that the detection accuracy when Therefore, it is desired to devise a method for estimating that the differential pressure pipe is blocked.

A main object of the engine device of the present invention is to make it possible to estimate whether or not a differential pressure pipe is clogged.

The engine device of the present invention employs the following means to achieve the above-mentioned main object.

The engine device of the present invention is
engine and
a differential pressure sensor having a differential pressure pipe attached to the exhaust pipe of the engine;
a control device that controls the engine;
An engine device comprising
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.
This is the gist of it.

In the engine system of the present invention, it is estimated that the differential pressure pipe is blocked when the pulsation width of the differential pressure detected by the differential pressure sensor is less than a predetermined width. Through experiments and analyses, 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 pulsation width of the detected differential pressure with a predetermined width, it is possible to estimate whether or not the differential pressure pipe is clogged. Here, the "differential pressure sensor" may be one that detects the pressure difference between the exhaust pressure of the engine and the atmospheric pressure. It is good also as what detects a pressure.

In the engine system of the present invention, the control device, when estimating that the differential pressure pipe is clogged, sets the response delay time of the detected differential pressure so that the smaller the pulsation width of the detected differential pressure, the longer the response delay time of the detected differential pressure. It may be estimated. By doing so, it is possible to more appropriately estimate the response delay time based on the degree of blockage of the differential pressure pipe.

Further, in the engine apparatus of the present invention, when the control device estimates that the differential pressure pipe is blocked, the determination that the engine is in a steady state may be delayed by the response delay time. . This makes it possible to accurately determine that the engine is in a steady state.

In this aspect of the engine apparatus of the present invention, when the control device estimates that the differential pressure pipe is clogged, the change amount per unit time of the intake air amount of the engine is equal to or less than a predetermined change amount. It may be determined that the engine is in a steady state when the quantity condition continues to be satisfied over the response delay time. This makes it 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 control device performs a gradual change process on the detected differential pressure, or The amount of back pressure increase, which is the amount of increase in the back pressure of the engine with respect to the reference value, may be estimated such that the larger the average differential pressure obtained as the average value of one cycle of the pulsation of the detected differential pressure, the greater the increase. . By doing so, it is possible to accurately estimate the amount of back pressure increase.

Further, in the engine apparatus of this aspect of the present invention, the engine includes an exhaust gas recirculation device having an exhaust gas recirculation pipe for recirculating the exhaust gas of the engine to the intake air, and an exhaust pipe flow valve attached to the exhaust gas recirculation pipe. The control device may control the exhaust gas recirculation valve so that the opening degree of the exhaust gas recirculation valve decreases as the back pressure rise amount increases when the control device determines that the engine is in a steady state. By doing so, it is possible to prevent the exhaust gas 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, the control device sets a correction value so that the longer the response delay time is, the larger the correction value is, and gradually changes the detected differential pressure. The back pressure of the engine may be estimated using the post-processing differential pressure obtained by applying the above-described processing, 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. . By doing so, it is possible to accurately estimate the back pressure of the engine.

In this aspect of the engine apparatus of the present invention, when the control device determines that the engine is in a transient state, when the back pressure of the engine is greater than the predetermined back pressure, the back pressure of the engine is increased to the predetermined level. The output of the engine may be restricted compared to when the pressure is equal to or less than the back pressure. By doing so, it is possible to suppress an increase in the back pressure of the engine.

1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with an engine device as one embodiment of the present invention; FIG. 2 is a configuration diagram showing an outline of the configuration of an engine 22; FIG. 4 is a flowchart showing an example of a response delay time estimation routine executed by an engine ECU 24; FIG. 10 is an explanatory diagram showing an example of analysis results of the detected differential pressure DP performed by the inventors; FIG. 5 is an explanatory diagram showing an example of a response delay time estimation map; 4 is a flowchart showing an example of a processing routine executed by an engine ECU 24; FIG. 5 is an explanatory diagram showing an example of a map for estimating the amount of back pressure increase; FIG. 5 is an explanatory diagram showing an example of a correction coefficient setting map; FIG. 5 is an explanatory diagram showing an example of a correction value setting map;

Next, a mode for carrying out the present invention will be described using examples.

FIG. 1 is a configuration diagram showing the outline of the configuration of a hybrid vehicle 20 equipped with an engine device as one embodiment of the present invention. As illustrated, the hybrid vehicle 20 of the embodiment includes an engine 22, an engine electronic control unit (hereinafter referred to as "engine ECU") 24, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, 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 FIG. As shown in the figure, the engine 22 sucks air cleaned by an air cleaner 122 into an intake pipe 123, passes through a throttle valve 124, and injects fuel from a fuel injection valve 126 to mix the air and the fuel. The air-fuel mixture is drawn into the combustion chamber 129 through the intake valve 128 . The electric spark generated by the ignition plug 130 causes the inhaled air-fuel mixture to explode and burn. Exhaust gas discharged from the combustion chamber 129 to the exhaust pipe 133 via the exhaust valve 131 is discharged to the outside air via 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 such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) in the exhaust. The PM filter 136 is formed as a porous filter made of ceramics, stainless steel, or the like, and traps particulate matter (PM) such as soot in 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 includes a differential pressure pipe 138a attached to the exhaust pipe 133 and a sensor portion 138b that detects the differential pressure between the exhaust pressure and the atmospheric pressure between the purifying device 134 and the PM filter 136 in the exhaust pipe 133. and

Exhaust gas discharged from the combustion chamber 129 to the exhaust pipe 133 is not only discharged to the outside air, but also recirculated to the intake pipe 123 via an exhaust gas recirculation device (hereinafter referred to as "EGR (Exhaust Gas Recirculation) device") 160. be done. The EGR device 160 has an EGR pipe 162 and an EGR valve 163 . The EGR pipe 162 connects the exhaust pipe 133 upstream of the purification device 134 and the intake pipe 123 downstream of the throttle valve 124 . EGR valve 163 is arranged in EGR pipe 162 and driven by EGR motor 164 . The EGR device 160 adjusts the opening of the EGR valve 163 by the EGR motor 164 to adjust the recirculation amount of the exhaust gas in the exhaust pipe 133 and recirculates the exhaust gas to the intake pipe 123 . The engine 22 can draw a mixture of air, exhaust, and fuel into the combustion chamber 129 in this manner. Hereinafter, this exhaust gas recirculation will be referred to as "EGR", and the exhaust gas recirculation amount will be referred to as "EGR amount". The operation of the engine 22 is controlled by an engine ECU 24 .

Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU. In addition to the CPU, the engine ECU 24 includes a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. Prepare. Signals from various sensors necessary for controlling the operation of the engine 22 are input to the engine ECU 24 through an input port. Signals input to the engine ECU 24 include, for example, a crank angle θcr from a 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. A cooling water temperature Tw can be mentioned. Cam angles θci and θco from a cam position sensor 144 that detects the rotational position of an intake camshaft that opens and closes the intake valve 128 and the rotational position of an exhaust camshaft that opens and closes the exhaust valve 131 can also be used. A throttle opening TH from a throttle position sensor 124a that detects the position of the throttle valve 124, an intake air amount Qa from an air flow meter 148 attached to the intake pipe 123, and a temperature sensor 149 attached to the intake pipe 123. Air temperature Ta may also be mentioned. An air-fuel ratio AF from an air-fuel ratio sensor 135a attached to the exhaust pipe 133 and an oxygen signal O2 from an oxygen sensor 135b attached to the exhaust pipe 133 can also be used. Detected differential pressure DP from a sensor portion 138b of a 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 in the exhaust pipe 133 (before passing through the PM filter 136). can also be mentioned. An EGR valve opening Oegr from an EGR valve opening sensor 165 that detects the opening of the EGR valve 163 can also be used.

Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 through an output port. Signals output from the engine ECU 24 include a control signal to the throttle motor 124b that adjusts 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* as a control signal to the EGR motor 164 that adjusts the opening degree of the EGR valve 163 can be mentioned.

The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 140, and the temperature of the purification catalyst 134a of the purification device 134 (catalyst Temperature) Tc is calculated. Also, the engine ECU 24 determines the load factor (the ratio of the air actually taken in one cycle to the stroke volume of the engine 22 per cycle) based on the intake air amount Qa from the air flow meter 148 and the rotation speed Ne of the engine 22. Volume ratio) KL is calculated. Furthermore, the engine ECU 24 calculates a PM deposition amount Qpm as the deposition amount of particulate matter deposited on the PM filter 136, and calculates the temperature of the PM filter 136 based on the rotation speed Ne and the load factor KL of the engine 22. It also calculates the filter temperature Tf. In addition, the engine ECU 24 calculates the pulsation width (maximum value and minimum value ), the differential pressure pulsation width PDP is calculated.

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 meshing with the sun gear 31 and the ring gear 32, respectively, and a plurality of pinion gears. and a carrier 34 that supports 33 so that it can rotate (rotate) and revolve. The sun gear 31 of the planetary gear 30 is connected to the rotor of the motor MG1. A ring gear 32 of the planetary gear 30 is connected to a drive shaft 36 that is connected to drive wheels 39a and 39b via a differential gear 38. As shown in FIG. The carrier 34 of the planetary gear 30 is connected to the crankshaft 26 of the engine 22 via the damper 28 as described above. 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 generator-motor, and the rotor is connected to the sun gear 31 of the planetary gear 30 as described above. The motor MG2 is configured as, for example, a synchronous generator-motor, and has a rotor connected to the drive shaft 36 . Inverters 41 and 42 are used to drive motors MG1 and MG2 and are connected to battery 50 via power line 54 . A smoothing capacitor 57 is attached to the power line 54 . The motors MG1 and MG2 are rotationally driven by controlling the switching of a plurality of switching elements (not shown) of the inverters 41 and 42 by a motor electronic control unit (hereinafter referred to as "motor ECU") 40. FIG.

Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU. In addition to the CPU, the motor ECU 40 includes a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. Prepare. The motor ECU 40 receives signals from various sensors necessary to drive and control the motors MG1 and MG2, such as rotational position θm1 from rotational position detection sensors 43 and 44 for detecting the rotational positions of the rotors of the motors MG1 and MG2. , θm2 and phase currents Iu1, Iv1, Iu2, and Iv2 from current sensors 45u, 45v, 46u, and 46v for detecting currents flowing in respective phases of the motors MG1 and MG2 are inputted via input ports. The motor ECU 40 outputs switching control signals and the like to the plurality of switching elements of the inverters 41 and 42 through output ports. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 determines the electrical angles θe1, θe2, the angular velocities ωm1, ωm2, the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position detection sensors 43, 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 a power line 54 . The battery 50 is managed by a battery electronic control unit (hereinafter referred to as “battery ECU”) 52 .

Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU. In addition to the CPU, the battery ECU 52 includes a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. Prepare. Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 through an 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 voltage Vb of the battery 50 from the current sensor 51b attached to the output terminal of the battery 50. The current Ib and the temperature Tb of the battery 50 from the temperature sensor 51c attached to the battery 50 can be mentioned. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the charge ratio SOC based on the integrated value of the current Ib of the battery 50 from the current sensor 51b. The power storage ratio SOC is the ratio of the amount of electric 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 in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, an input/output port, and a communication port. . Signals from various sensors are input to the HVECU 70 through input ports. Signals input to the HVECU 70 include, for example, an ignition signal from an ignition switch 80 and a shift position SP from a shift position sensor 82 that detects the operating position of a shift lever 81 . Also, the accelerator opening Acc from an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83, the brake pedal position BR from a brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85, and the vehicle speed sensor 88 Vehicle speed V can also be mentioned. The atmospheric pressure Pout from the atmospheric pressure sensor 89 can also be mentioned. The HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via communication ports, as described above.

The hybrid vehicle 20 of the embodiment configured in this manner operates in a hybrid driving mode (HV driving mode) in which the engine 22 is rotated and an electric driving mode (EV driving mode) in which the engine 22 is stopped rotating. It travels while switching (intermittently operating the engine 22).

In the HV running mode, the HVECU 70 first sets a running torque Td* required for the drive shaft 36 (required for running) based on the accelerator opening Acc and the vehicle speed V, and applies the set running torque Td*. The running power Pd* required for the drive shaft 36 is calculated by multiplying Td* by the rotation speed Nd of the drive shaft 36 (the rotation speed Nm2 of the motor MG2). Subsequently, the required charging power Pb* of the battery 50 (positive value when the battery 50 is discharged) is subtracted from the running 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) to set the target power Pe* of the engine 22 . Here, the rated value Pe1 of the engine 22 is basically used as the upper limit power Pelim. Then, the target rotational 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. Set the torque commands Tm1* and Tm2* for the motors MG1 and MG2. Then, the target rotational 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 ECU 40.

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, , 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 adjusts 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* based on the intake air amount Qa so that the air-fuel ratio AF becomes the target air-fuel ratio AF*, and the fuel injection valve 126 outputs the target fuel injection amount Qf*. of fuel is injected. In ignition control, the engine ECU 24 sets a target ignition timing Tf* based on the rotational 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 a target EGR valve opening Oegr* based on the intake air amount Qa, and controls 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* for 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*. do

In the EV running mode, the HVECU 70 sets the running torque Td* of the drive shaft 36 based on the accelerator opening Acc and the vehicle speed V, sets the torque command Tm1* of the motor MG1 to 0, and sets the battery 50 to ON. The torque command Tm2* for 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. 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 as described above, in particular, the operation of estimating whether or not the differential pressure pipe 138a of the differential pressure sensor 138 is blocked will be described. FIG. 3 is a flow chart showing an example of a response delay time estimation routine executed by the engine ECU 24. As shown in FIG. This routine is repeatedly executed in the HV running mode (while the engine 22 is running).

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 portion 138b of the differential pressure sensor 138 is input.

After obtaining the data in this way, the engine ECU 24 compares the differential pressure pulsation width PDP with the threshold PDPref (step S110). Here, the threshold PDPref is a threshold used for estimating (determining) whether or not the differential pressure pipe 138a is blocked, and is determined in advance through experiments and analyses. When the differential pressure pulsation width PDP is equal to or greater than the threshold value PDPref, it is assumed that the differential pressure pipe 138a is not blocked (step S120), the response delay time Td is set to 0 (step S130), and this routine ends. . Here, the response delay time Td means the response delay time of the detected differential pressure DP with respect to the actual differential pressure.

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 detected using the differential pressure pulsation width PDP and the response delay time setting map. After estimating the time Td (step S150), the routine ends. Here, the response delay time estimation map is set in advance as a 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 response delay time estimation map. As shown in the figure, the response delay time Td is estimated to increase as the differential pressure pulsation width PDP decreases within the range where the differential pressure pulsation width PDP is less than the threshold value PDPref. For reference, the dashed-dotted line in the figure indicates that the response delay time Td is estimated to be 0 in the above-described step S120 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, when the differential pressure pipe 138a is blocked, the detected differential pressure DP is compared to when the differential pressure pipe 138a is not blocked. It can be seen that a delay occurs in the pulsation as . Based on this, the embodiment estimates whether or not the differential pressure pipe 138a is blocked by comparing the differential pressure pulsation width PDP and the threshold value PDPref. The response delay time Td is estimated based on the pressure pulsation width PDP. With such a method, it is possible to estimate whether or not the differential pressure pipe 138a is clogged, and to estimate the response delay time Td of the detected differential pressure DP.

Next, processing for determining the operating state of the engine 22 and the like will be described. FIG. 6 is a flow chart showing an example of a processing routine executed by the engine ECU 24. As shown in FIG. This routine is repeatedly executed in parallel with the response delay time estimation routine of FIG. 3 during the HV driving mode (while the engine 22 is running).

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 airflow meter 148 is input as the intake air amount Qa. A value detected by the sensor portion 138b of the differential pressure sensor 138 is input as the detected differential pressure DP. A value estimated by the response delay time estimation routine of FIG. 3 is input as the response delay time Td.

When the data is input in this way, the engine ECU 24 calculates the average differential pressure MDP as the average value of one cycle of the pulsation of the detected differential pressure DP (step S210), An intake air change amount ΔQa is calculated as a difference (absolute value obtained by subtracting one from the other) 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 ΔQaref (step S230), and when the intake air change amount ΔQa is equal to or less than the threshold ΔQaref, determines whether or not the state has continued over the response delay time Td. Determine (step S240). Here, the threshold ΔQaref is a threshold used to determine whether the operating state of the engine 22 is in a steady state, and is determined in advance through experiments and analyses.

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

If it is determined in step S250 that the operating state of the engine 22 is in a steady state, the amount of back pressure increase DBP of the engine 22 is estimated using the intake air amount Qa, the average differential pressure MDP, and the map for estimating the amount of back pressure increase ( step S260). Here, the back pressure increase amount DBP is the increase amount of the back pressure of the engine 22 (the pressure of the exhaust pipe 133) with respect to the reference value. As the reference value, for example, the back pressure when the PM deposition amount Qpm deposited on the PM filter 136 is 0 is assumed. The map for estimating the amount of back pressure increase is set in advance through experiments and analysis as the relationship between the intake air amount Qa, the average differential pressure MDP, and the amount of back pressure increase 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 back pressure increase. As shown in the figure, the back pressure increase amount DBP is estimated to increase as the intake air amount Qa increases and as the mean differential pressure MDP increases. By estimating the back pressure increase amount DBP in this manner, the back pressure increase amount DBP can be estimated with high accuracy.

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. After correcting the valve opening Oegr* (step S280), the routine ends. Here, the correction coefficient setting map is predetermined as a 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 to be smaller within a range of less than 1 as the back pressure increase amount DBP increases. By doing so, it is possible to prevent the EGR amount from becoming excessive when the back pressure BP of the engine 22 is high.

When the intake air change amount ΔQa is greater than the threshold ΔQaref in step S230, or when the state where the intake air change amount ΔQa is equal to or less than the threshold ΔQaref in step S240 does not continue for the response delay time Td, the engine ECU 24 controls the engine 22 is in a transient state (step 290).

When it is determined that the operating state of the engine 22 is in 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 a 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 as to increase as the response delay time Td increases and as the intake air change amount ΔQa increases. The reason for this setting is that the longer the response delay time Td, the greater the difference (deviation) between the detected value of the average differential pressure MDP and the current value, and the greater the intake air change amount ΔQ, the greater the change in the operating state of the engine 22. This is because 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. By doing so, it is possible to accurately estimate the back pressure BP of the engine 22 .

After estimating the back pressure BP of the engine 22 in this manner, the engine ECU 24 compares the back pressure BP of the engine 22 with the threshold value BPref (step S320). Here, the threshold BPref is a threshold used to determine whether or not the back pressure BP of the engine 22 is relatively high, and is determined by experiments and analyses. When the back pressure BP is equal to or less than the threshold value BPref, the routine ends.

When the back pressure BP of the engine 22 is higher than the threshold BPref in step S320, the upper limit power Pelim of the engine 22 is set to a predetermined value Pe2 smaller than the rated value Pe1 (step S330), and the routine ends. In this way, a further increase in the back pressure BP of the engine 22 can be suppressed, and the engine 22 can be protected.

In the engine device mounted on the hybrid vehicle 20 of the embodiment described above, the engine ECU 24 detects when the differential pressure pulsation width PDP of the detected differential pressure DP detected by the sensor portion 138b of the differential pressure sensor 138 is less than the threshold value PDPref. First, it is estimated that the differential pressure pipe 138a of the differential pressure sensor 138 is blocked. Through experiments and analyses, the inventors have found 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 whether or not the differential pressure pipe 138a of the differential pressure sensor 138 is blocked.

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

In the engine system 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 DP response delay time Td may not be estimated.

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

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

In the engine system 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. It is possible not to do so.

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

In the engine system of the embodiment, 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 when the back pressure BP of the engine 22 is greater than the threshold value BPref. However, regardless of the back pressure BP of the engine 22, the upper limit power Pelim of the engine 22 may be set to the rated value Pe1.

In the engine system of the embodiment, the engine ECU 24 estimates 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 estimate that the differential pressure pipe 138a of the differential pressure sensor 138 is frozen when the outside air temperature is below a 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 is increased as the outside air temperature is lower and/or as the differential pressure pulsation width PDP is decreased. may be used to estimate the response delay time Td of

Although the engine system of the embodiment is provided with the EGR device 160, the EGR device 160 may not be provided.

The engine device of the embodiment is mounted on a hybrid vehicle having an engine 22, two motors MG1 and MG2, and a planetary gear 30. However, the engine device can be mounted on any hybrid vehicle equipped with an engine. Alternatively, it may be mounted on an ordinary automobile without a motor for running, or it may be mounted on non-moving equipment such as construction equipment.

The correspondence relationship between the main elements of the embodiments 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 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".

Note that the correspondence relationship between the main elements of the examples and the main elements of the invention described in the column of Means for Solving the Problems is the Since it is an example for specifically explaining the mode for solving the problem, it does not limit the elements of the invention described in the column of the means for solving the problem. That is, the interpretation of the invention described in the column of Means to Solve the Problem should be made based on the description in that column, and the Examples are based on the description of the invention described in the column of Means to Solve the Problem. This is only a specific example.

Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to such embodiments at all, and can be modified in various forms without departing from the scope of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention is applicable to the manufacturing industry of engine devices and the like.

20 hybrid vehicle, 22 engine, 24 engine ECU, 26 crankshaft, 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 wheels, 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 combustion chamber, 130 spark plug, 131 exhaust valve, 133 exhaust pipe, 134 purification device, 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 pipe, 163 EGR valve, 164 EGR motor, 165 EGR valve opening sensor, MG1, MG2 motor.

Claims (7)

engine and
a differential pressure sensor having a differential pressure pipe attached to the exhaust pipe of the engine;
a control device that controls the engine;
An engine device comprising
The control device estimates that the differential pressure pipe is blocked when a pulsation width of the detected differential pressure detected by the differential pressure sensor is less than a predetermined width,
When estimating that the differential pressure pipe is clogged, the control device estimates the response delay time of the detected differential pressure so that the smaller the pulsation width of the detected differential pressure, the longer the response delay time.
engine device. The engine device according to claim 1 ,
When the control device estimates that the differential pressure pipe is clogged, it delays the determination that the engine is in a steady state by the response delay time.
engine device. The engine device according to claim 2 ,
When the control device estimates that the differential pressure pipe is clogged, the air amount condition in which the change amount per unit time of the intake air amount of the engine is equal to or less than a predetermined change amount is maintained over the response delay time. Determining that the engine is in a steady state when it is continuously established,
engine device. The engine device according to claim 2 or 3 ,
When the control device determines that the engine is in a steady state, the post-processing differential pressure obtained by subjecting the detected differential pressure to a slow change process, or the average value of one cycle of pulsation of the detected differential pressure Estimate the amount of back pressure increase, which is the amount of increase in the back pressure of the engine from the reference value, so that the larger the average differential pressure obtained,
engine device. The engine device according to claim 4 ,
The engine includes an exhaust gas recirculation device having an exhaust gas recirculation pipe for recirculating the exhaust gas of the engine to the intake air, and an exhaust gas recirculation valve attached to the exhaust gas recirculation pipe,
When the control device determines that the engine is in a steady state, the control device controls the exhaust gas recirculation valve such that the larger the amount of back pressure increase, the smaller the degree of opening of the exhaust gas recirculation valve.
engine device. An engine device according to any one of claims 1 to 5 ,
When the control device determines that the engine is in a transient state, the control device sets a correction value so that the longer the response delay time is, the larger the corrected value is, and the post-processing differential pressure obtained by subjecting the detected differential pressure to gradual change processing. estimating the back pressure of the engine 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 6 ,
When the control device determines that the engine is in a transient state, when the back pressure of the engine is greater than a predetermined back pressure, compared to when the back pressure of the engine is equal to or less than the predetermined back pressure, limiting the power output of said engine;
engine device.

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