JP2019060326A - Engine control device - Google Patents

Abstract

To provide an engine control device suppressed in a PM discharge amount, in incompletion of lapping of an engine.SOLUTION: An engine control device 100 including a throttle valve control portion for controlling an opening of a throttle valve 56 disposed on an intake device of an engine 1, and a lapping state determination portion for determining a lapping state of the engine, is constituted to execute negative pressure suppression control for controlling an opening of the throttle valve so that a minimum opening of the throttle valve is increased in a case when the lapping state determination portion determines incompletion of lapping, with respect to the case when completion of lapping is determined.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an engine control device that controls an intake air amount of an engine.

  For example, in a state where the lapping (lapping) of each sliding portion in the engine is not completed as in the case of a new product, friction increases after completion of the lapping. It is proposed to make it different from after completion of the alignment.

For example, Patent Document 1 reads the intake air amount, the engine speed, the cooling water temperature, and the travel distance, and determines the valve opening time (fuel injection amount) of the fuel injection valve as the prior art. It is described that the valve opening time is made equal to or less than a preset upper limit value when calculation is performed in consideration of the cooling water temperature and the engine is in the lapping operation incomplete state.
In Patent Document 2, it is determined whether or not the sliding operation period until the sliding resistance of the engine is reduced has elapsed, and when within the sliding operation period, a fuel injection amount control device that increases and corrects the fuel injection amount Have been described.
Patent Document 3 discloses an idle speed control device that reduces the amount of idle air and keeps the idle speed constant, in order to suppress the decrease in friction resistance and the increase in idle speed as engine lapping progresses. Have been described.

Japanese Patent Application Laid-Open No. 60-01940 JP, 2014-152722, A Japanese Utility Model Publication No. 56-152836

In recent years, it has been strongly demanded to suppress the number (PN) of particulate matter (PM) contained in the exhaust gas of an engine.
It is known that the mixing of lubricating oil into the combustion chamber of the engine contributes to the increase in PN, but such mixing of oil is caused by the oil from between the piston ring, the oil ring and the cylinder liner. Can occur due to so-called oil spilling into the combustion chamber side.
In particular, when the engine is new, etc., the contact between the piston ring and the oil ring provided on the outer peripheral surface of the piston and the inner surface of the cylinder liner is different from that in the completed sliding condition, and oil rise occurs. Since it is in an easy state, it is required to effectively suppress the PM emission amount at the time of the non-compliance.
SUMMARY OF THE INVENTION In view of the above-described problems, it is an object of the present invention to provide an engine control device that suppresses the amount of PM emission when the engine is not completed.

The present invention solves the above-mentioned problems by the following solutions.
The invention according to claim 1 is an engine control apparatus comprising a throttle valve control unit for controlling the opening degree of a throttle valve provided in an intake system of an engine, and a sliding condition determination unit for determining the sliding condition of the engine. The minimum opening degree of the throttle valve is larger than that in the case where the throttle valve control unit determines that the slide-in is completed when the slide-on state determination unit determines that the slide-on is not completed. An engine control apparatus is characterized in that negative pressure suppression control for controlling the opening degree of the throttle valve is executed.
According to this, when the engine has not completed the sliding and it is easy for the oil to rise due to the negative pressure in the cylinder, the minimum opening degree of the throttle valve is larger than that after the completion of the sliding. The degree of opening can be controlled to prevent the generation of an excessive negative pressure in the cylinder to suppress the oil leakage and reduce the PM discharge amount.

According to a second aspect of the present invention, there is provided a valve drive control unit for controlling a valve drive capable of switching an intake valve of an engine from a normal state to a substantially normally closed state, and an operation of a vehicle equipped with the engine. An engine control apparatus comprising: an operating condition detecting unit detecting a condition; and a sliding condition determining unit judging a sliding condition of the engine, wherein the valve drive control unit controls the sliding condition determination unit An engine control apparatus characterized by executing negative pressure suppression control for bringing the intake valve into the normally closed state when it is determined that the sliding state is not completed and the operation state detection unit detects a predetermined coasting state. It is.
According to this, in the coasting state in which the vehicle coasts while the engine does not generate the drive torque, the intake valve is substantially always closed to prevent the generation of an excessive negative pressure in the cylinder. As a result, it is possible to suppress oil spillage and reduce PM emissions.

The invention according to claim 3 is characterized in that, at the time of execution of the negative pressure suppression control, the braking coordination control is performed to cause the braking device of the vehicle on which the engine is mounted to generate a braking force. 2 is the engine control device according to 2).
Due to the reduction of the pump loss caused by the execution of the above-described negative pressure suppression control, the drag torque (drag torque) of the engine is reduced and the so-called effectiveness of the engine brake is weakened.
In this respect, according to the present invention, it is possible to compensate for the reduction of the braking force due to the reduction of the drag torque of the engine by the other braking device, to suppress the feeling of free running and to ensure the easiness of driving the vehicle.

In the invention according to claim 4, the engine includes an intake air amount sensor that detects an intake air amount, and a rotational speed sensor that detects an output shaft rotational speed, and the sliding state determination unit determines that the engine is a predetermined state. 4. The method according to any one of claims 1 to 3, wherein the completion of the matching is determined when the amount of intake air at the time of performing the idle operation at the idle rotation speed of is lower than a predetermined value. It is an engine control device.
According to this, it is possible to accurately determine the sliding state of the engine with a simple logic and device configuration.

  As described above, according to the present invention, it is possible to provide an engine control device in which the amount of PM emission at the time when the engine is not completed is reduced.

FIG. 1 is a view schematically showing a configuration of an engine having a first embodiment of an engine control device to which the present invention is applied. It is a flowchart which shows the sliding state determination in the engine control system of 1st Embodiment. It is a flowchart which shows throttle-opening control in the engine control system of 1st Embodiment. It is a flowchart which shows valve lift amount control in 2nd Embodiment of the engine control system to which this invention is applied.

First Embodiment
Hereinafter, a first embodiment of an engine control device to which the present invention is applied will be described.
The engine control apparatus according to the first embodiment is provided, for example, in a horizontally opposed four-cylinder gasoline direct injection turbocharged engine mounted as a driving power source in a car such as a passenger car, and generally controls the engine and its accessories. Control.

FIG. 1 is a view schematically showing a configuration of an engine having the engine control device of the first embodiment.
The engine 1 includes a crankshaft 10, a cylinder block 20, a cylinder head 30, a turbocharger 40, an intake system 50, an exhaust system 60, a canister 70, an EGR device 80, an engine control unit (ECU) 100, etc. There is.

The crankshaft 10 is a rotating shaft that is an output shaft of the engine 1.
A power transmission mechanism such as a transmission (not shown) is connected to one end of the crankshaft 10.
A piston is connected to the crankshaft 10 via a connecting rod (not shown).
At the end of the crankshaft 10, a crank angle sensor 11 for detecting the angular position of the crankshaft is provided.
The output of the crank angle sensor 11 is transmitted to the ECU 100.
The crank angle sensor 11 generates a pulse signal of a frequency proportional to the rotational speed of the crankshaft 10.
The ECU 100 can calculate the rotational speed (rotational speed per minute) of the crankshaft based on this pulse signal.

The cylinder block 20 is configured as a two-piece so as to sandwich the crankshaft 10 from the left and right direction in vertical mounting on a vehicle body.
At the central portion of the cylinder block 20, there is provided a crankcase portion that accommodates the crankshaft 10 and has a main bearing that rotatably supports the crankshaft 10.
Inside the left and right banks of the cylinder block 20 disposed on the left and right sides of the crankcase portion, for example, a pair of cylinders (in the case of four cylinders) in which pistons are inserted and reciprocated inside are formed.

The cylinder head 30 is provided at each end (left and right end) of the cylinder block 20 opposite to the crankshaft 10.
The cylinder head 30 includes a combustion chamber 31, an ignition plug 32, an intake port 33, an exhaust port 34, an intake valve 35, an exhaust valve 36, an intake camshaft 37, an exhaust camshaft 38, and the like.
The combustion chamber 31 is formed by, for example, indenting a portion facing the piston crown surface of the cylinder head 30 into a pent roof shape.
The spark plug 32 is provided at the center of the combustion chamber 31, generates a spark in response to an ignition signal from the ECU 100, and ignites the air-fuel mixture.

The intake port 33 is a flow path for introducing combustion air (fresh air) into the combustion chamber 31.
The exhaust port 34 is a flow path for discharging the burned gas (exhaust gas) from the combustion chamber 31.
The intake valve 35 and the exhaust valve 36 open and close the intake port 33 and the exhaust valve 34 at predetermined valve timings.
For example, two intake valves 35 and two exhaust valves 36 are provided for each cylinder.
The intake valve 35 and the exhaust valve 36 are opened and closed by an intake camshaft 37 and an exhaust camshaft 38 which rotate in synchronization at a half rotation speed of the crankshaft 10.
The cam sprockets of the intake camshaft 37 and the exhaust camshaft 38 are provided with a variable valve timing mechanism (not shown) that changes the opening timing and closing timing of each valve by advancing and retarding the phase of each camshaft. It is done.

The turbocharger 40 is a supercharger that compresses combustion air (fresh air) using the energy of the exhaust of the engine 1 and supercharges it.
The turbocharger 40 includes a turbine 41, a compressor 42, an air bypass flow path 43, an air bypass valve 44, a waste gate flow path 45, a waste gate valve 46, and the like.
The turbine 41 is rotationally driven by the exhaust gas of the engine 1.
The compressor 42 is coaxially attached to the turbine 41 and rotationally driven by the turbine 41 to compress air.

The air bypass flow path 43 extracts a part of air from the downstream side of the compressor 42 and causes the air to flow back to the upstream side of the compressor 42.
The air bypass valve 44 is provided in the air bypass flow passage 43, and is in a closed state in which the air bypass flow passage 43 is substantially closed in response to a command from the ECU 100, and an open state where air can pass through the air bypass flow passage 43 And in two steps.
The air bypass valve 44 is an electric valve having a valve body that is opened and closed by an electric actuator.
The air bypass valve 44 is opened in order to prevent surging of the turbocharger 40, protect the blades, etc., for example, when the throttle valve 56 is suddenly closed, and the air in the intake pipe downstream of the compressor 42 is opened. Are returned to the upstream side of the compressor 42 to reduce the excess pressure.
Further, the air bypass valve 44 is also used to increase the negative pressure at the inlet of the compressor 42 as an open state at the time of supercharging in order to increase the flow rate of the purge gas from the canister 70 at the time of supercharging.

The west gate channel 45 extracts a part of the exhaust gas from the upstream side of the turbine 41 and bypasses the downstream side of the turbine 41 for the purpose of supercharging pressure control, temperature rise of the catalyst, and the like.
The wastegate channel 45 is integrally formed in the housing of the turbine 41.
The waste gate valve 46 has a valve body provided in the waste gate flow path 45 for opening and closing the flow path, and controls the flow rate of the exhaust gas passing through the waste gate flow path 45.
The waste gate valve 46 is an electric waste gate valve having an electric actuator that opens and closes the valve in accordance with a command from the ECU 100.
The west gate valve 46 can switch between the fully open state and the fully closed state, and can also set an arbitrary degree of opening at these intermediate positions.

The intake system 50 introduces air to the intake port 33.
The intake system 50 includes an intake duct 51, a chamber 52, an air cleaner 53, an air flow meter 54, an intercooler 55, a throttle valve 56, an intake manifold 57, an intake pressure sensor 58, an injector 59, and the like.

The intake duct 51 is a flow path for introducing outside air and introducing it to the intake port 33.
The chamber 52 is a space provided in communication with the vicinity of the inlet of the intake duct 51.
The air cleaner 53 is provided on the downstream side of the communication point of the intake duct 51 with the chamber 52, and filters air to remove dust and the like.
The air flow meter 54 is provided in the vicinity of the outlet of the air cleaner 53 and measures the flow rate of air passing through the intake duct 51.
The air flow meter 54 functions as an air amount detection means in the present invention.
The output of the air flow meter 54 is transmitted to the ECU 100.
The compressor 42 of the turbocharger 40 is provided downstream of the air flow meter 54.

The intercooler 55 is a heat exchanger that is provided on the downstream side of the compressor 42 in the intake duct 51 and that cools the air that has been compressed to a high temperature, for example, by heat exchange with traveling air or the like.
The throttle valve 56 is a butterfly valve which is provided on the downstream side of the intercooler 55 in the intake duct 51 and adjusts the flow rate of air to control the output of the engine 1.
The throttle valve 56 is driven to open and close by an electric throttle actuator (not shown) in response to an accelerator pedal operation or the like by a driver.
Further, the throttle valve 56 is provided with a throttle sensor for detecting the opening degree, and the output thereof is transmitted to the ECU 100.
The intake manifold 57 is a branch pipe provided downstream of the throttle valve 56 and distributing the air to the intake port 33 of each cylinder.
The intake pressure sensor 58 detects the pressure of the air in the intake manifold 57 (intake pressure).
The output of the intake pressure sensor 58 is transmitted to the ECU 100.
The injector 59 is provided at an end of the intake manifold 57 on the cylinder head 30 side, and injects fuel into the combustion chamber 31 to form an air-fuel mixture according to a valve opening signal issued by the ECU 100.

The exhaust system 60 exhausts the exhaust gas discharged from the exhaust port 34 to the outside.
Exhaust system 60 includes an exhaust manifold 61, exhaust pipe 62, the front catalyst 63, the rear catalyst 64, a silencer 65, the air-fuel ratio sensor 66 is configured to have a rear _{O 2} sensor 67 or the like.
The exhaust manifold 61 is a collecting pipe for collecting the exhaust gas from the exhaust port 34 of each cylinder.
The turbine 41 of the turbocharger 40 is disposed downstream of the exhaust manifold 61.
The exhaust pipe 62 is a pipe line for discharging the exhaust gas from the turbine 41 to the outside.
The front catalyst 63 and the rear catalyst 64 are provided at an intermediate portion of the exhaust pipe 62, and each include a three-way catalyst that purifies HC, NOx, CO and the like in the exhaust gas.
The front catalyst 63 is provided adjacent to the outlet of the turbine 41, and the rear catalyst 64 is provided on the outlet side of the front catalyst.
The silencer 65 is provided in the vicinity of the outlet of the exhaust pipe 62 to reduce the acoustic energy of the exhaust gas.

The air-fuel ratio sensor 66 is provided between the outlet of the turbine 41 and the inlet of the front catalyst 63.
Rear O ₂ sensor 67 is provided between the inlet of the outlet and the rear catalyst 64 of the front catalyst 63.
Air-fuel ratio sensor 66, the rear O ₂ sensor 67 by generating an output voltage corresponding to the oxygen concentration in the exhaust gas together, and detects the amount of oxygen in the exhaust gas.
Air-fuel ratio sensor 66 is more a wide detectable linear output sensor oxygen concentration in the air-fuel ratio with respect to the rear O ₂ sensor 67.
Air-fuel ratio sensor 66, the output of the rear _{O 2} sensor 67 is transmitted together ECU 100.

The canister (charcoal canister) 70 is one in which fuel evaporative gas (evaporative) generated in a fuel tank (not shown) in which gasoline used as fuel for the engine 1 is stored is introduced and temporarily stored.
The canister 70 is configured by housing activated carbon capable of temporarily adsorbing fuel evaporation gas in a canister case which is a resin case.
The canister 70 mainly includes a non-supercharged purge line 71, a purge control valve 72, and a mainly supercharged purge line 73, a purge control valve 74, and the like.

The purge line 71 is a flow path which is connected to the canister 70 and the intake manifold 57 at both ends and which allows the insides to communicate with each other.
The purge line 71 introduces a purge gas composed of the fuel evaporation gas released from the canister 70 into the intake manifold 57 when the internal pressure of the intake manifold 57 is negative and not supercharged.
The purge control valve (PCV) 72 is a duty control solenoid valve provided in the middle of the purge line 71.
The PCV 72 can switch between an open state and a closed state, and set an opening degree in the open state, in accordance with a command from the ECU 100.

The purge line 73 is a flow path which is connected at both ends to the canister 70 and a region adjacent to the inlet of the compressor 42 in the intake duct 51 and allows the insides to communicate with each other.
The purge line 73 introduces the purge gas into the intake duct 51 on the upstream side of the compressor 42 at the time of supercharging in which the inside of the intake manifold 57 has a positive pressure and the introduction of the purge gas by the purge line 71 becomes difficult.
The purge control valve (PCV) 74 is a solenoid valve provided in the middle of the purge line 73.
The PCV 74 can switch between the open state and the closed state in response to a command from the ECU 100.

The EGR device 80 extracts exhaust gas from the exhaust manifold 61 as EGR gas and performs exhaust gas recirculation (EGR) to be introduced into the intake manifold 57.
The EGR device 80 includes an EGR passage 81, an EGR cooler 82, an EGR valve 83, and the like.

The EGR passage 81 is a pipe line for introducing the exhaust gas (EGR gas) from the exhaust manifold 61 to the intake manifold 57.
The EGR cooler 82 is provided in the middle of the EGR passage 81 and cools the EGR gas flowing through the EGR passage 81 by heat exchange with the cooling water of the engine 1.
The EGR valve 83 is provided on the downstream side of the EGR cooler 82 in the EGR flow passage 81, and is a metering valve that adjusts the flow rate of the EGR gas passing through the inside of the EGR flow passage 81.
The EGR valve 83 has a valve body driven by an electric actuator such as a solenoid, and the engine control unit 100 opens the EGR valve so that the actual EGR rate (EGR gas flow rate / new air flow rate) approaches a predetermined target EGR rate. The feedback is controlled.

An engine control unit (ECU) 100 centrally controls the engine 1 and its accessories.
The ECU 100 is configured to include an information processing unit such as a CPU, a storage unit such as a RAM or a ROM, an input / output interface, a bus connecting these, and the like.
Further, the ECU 100 is provided with an accelerator pedal sensor 101 that detects the depression amount of an accelerator pedal (not shown) by the driver.
The ECU 100 has a function of setting the driver request torque based on the output of the accelerator pedal sensor 101 or the like.
The ECU 100 controls the throttle valve opening degree, the supercharging pressure, the fuel injection amount, the fuel injection timing, the ignition timing, the valve timing, and the like so that the torque actually generated by the engine 1 approaches the set driver request torque.
The ECU 100 functions as a throttle valve control unit and a sliding state determination unit according to the present invention.

The behavior control unit 200 is connected to the ECU 100 directly or via an in-vehicle LAN device such as a CAN communication system.
The behavior control unit 200 controls the braking force of the hydraulic service brake provided on each wheel of the vehicle for each wheel.
A hydraulic control unit 210, a vehicle speed sensor 220, and the like are connected to the behavior control unit 200.

The hydraulic control unit 210 has pumps and solenoid valves that individually increase and decrease the wheel cylinder hydraulic pressure of the service brake of each wheel.
The behavior control unit 200 performs, for example, antilock control, behavior control, and the like.
Anti-lock control is to recover from the locked state by intermittently increasing or decreasing the wheel cylinder hydraulic pressure (correlated with the braking force) of the wheel when the wheel is locked.
Behavior control is to generate a yaw moment in the direction of suppressing the behavior by generating a braking force difference between the left and right wheels when understeer, oversteer behavior or a precursor thereof is detected.

The vehicle speed sensor 220 is provided on each wheel to generate a vehicle speed pulse signal having a frequency proportional to the rotation speed of the wheel.
It is possible to calculate the rotational speed (vehicle speed) of the wheel based on the vehicle speed pulse signal.
The output of the vehicle speed sensor 220 is transmitted to the ECU 100 via the behavior control unit 200.

The ECU 100 has a function of determining the lapping state of the engine 1.
FIG. 2 is a flowchart showing the sliding state determination in the engine control device of the first embodiment.
Hereinafter, each step will be described in order.

<Step S01: Idle State Determination>
The ECU 100 determines whether the current operating state of the engine 1 is a predetermined idle state.
For example, when the accelerator pedal sensor 101 does not detect depression of the accelerator pedal (driver request torque = 0) and the engine rotational speed (rotational speed of the crankshaft 10) is less than or equal to a predetermined value, it is determined to be idle. .
If it is determined that the vehicle is in the idle state, the process proceeds to step S02. If it is not determined that the vehicle is in the idle state, step S01 is repeated.

<Step S02: Idle Speed Determination>
The ECU 100 calculates the engine speed based on the output of the crank angle sensor 11, and determines whether or not the current engine speed substantially matches a predetermined idle speed (target value) set in advance. .
If the current engine speed substantially matches the predetermined idle speed, the process proceeds to step S04. If not, the process proceeds to step S03.

<Step S03: Air Content Feedback Control>
The ECU 100 performs air amount feedback control to adjust the intake air amount of the engine 1 by changing the opening degree of the throttle valve 56 so that the engine speed approaches the target value of the idle speed.
Thereafter, step S02 is repeated.

<Step S04: Intake Air Amount Detection>
The ECU 100 detects the intake air amount of the engine 1 when the engine speed coincides with the target value of the idle speed, based on the output of the air flow meter 54.
Thereafter, the process proceeds to step S05.

<Step S05: Compare Intake Air Amount with Judgment Threshold>
The ECU 100 compares the amount of intake air detected in step S04 with a predetermined determination threshold set in advance.
The determination threshold is set in consideration of the intake air amount of the engine at the idle speed when the engine 1 is completely aligned.
Since the friction decreases with the progress of the sliding of the engine 1, the amount of intake air required to maintain the same idle speed becomes lower.
If the intake air amount is equal to or less than the determination threshold, the process proceeds to step S06, and if the determination threshold is exceeded, the process proceeds to step S07.

<Step S06: Matching completion determination established>
The ECU 100 makes the determination of the completion of the matching of the engine 1 and ends the series of processing.

<Step S07: Completion of determination of completion of matching>
The ECU 100 establishes the non-compliance determination of the engine 1 and ends the series of processing.

In the first embodiment, throttle opening control and negative pressure suppression control, which will be described below, in order to suppress the PM discharge amount due to the oil rising due to the cylinder cylinder negative pressure when the engine 1 has not completed the sliding engagement. It is carried out.
FIG. 3 is a flow chart showing throttle opening control in the engine control system of the first embodiment.
Hereinafter, each step will be described in order.

<Step S11: Detection of accelerator opening>
The ECU 100 detects an accelerator opening degree (accelerator pedal depression amount) based on an output of the accelerator pedal sensor 101.
Thereafter, the process proceeds to step S12.

<Step S12: Driver request torque setting>
The ECU 100 sets a driver request torque that is a target output torque of the engine 1 based on the accelerator opening detected in step S11.
Thereafter, the process proceeds to step S13.

<Step S13: Target throttle opening setting>
The ECU 100 sets the target throttle opening degree (the target opening degree of the throttle valve 56) such that the torque actually generated by the engine 1 substantially matches the driver request torque set in step S12.
Thereafter, the process proceeds to step S14.

<Step S14: Sliding state determination>
The ECU 100 determines whether or not the matching completion determination is established by the above-described matching state determination.
If the alignment completion determination is established, the process proceeds to step S15, and if the alignment completion determination is not established (if the alignment incomplete determination is established), the process proceeds to step S16.

<Step S15: Normal throttle valve opening control>
The ECU 100 performs normal throttle valve opening control to control the throttle actuator so that the actual opening of the throttle valve 56 substantially matches the target throttle opening set in step S13.
After that, the series of processing ends (returns).

<Step S16: Lower Limit Throttle Opening Determination>
The ECU 100 compares the target throttle opening set in step S13 with a predetermined lower limit throttle opening set in advance.
The lower limit throttle opening degree is set in consideration of the throttle opening degree at which the negative pressure in the cylinder cylinder of the engine 1 becomes excessive and the PM discharge amount resulting from the oil rising may increase.
If the target throttle opening degree is less than the lower limit throttle opening degree, the process proceeds to step S17. If the target throttle opening degree is equal to or greater than the lower limit throttle opening degree, the process proceeds to step S15.

<Step S17: Throttle Opening = Lower Limit Throttle Opening>
The ECU 100 performs negative pressure suppression control that prevents the generation of excessive negative pressure in the cylinder by setting the opening degree of the throttle valve 56 to the lower limit throttle opening degree.
Thereafter, the process proceeds to step S18.

<Step S18: Brake Coordinated Control Execution>
The ECU 100 gives the behavior control unit 200 a braking force generation instruction.
The behavior control unit 200 that has received the braking force generation instruction applies hydraulic pressure to the wheel cylinders of each wheel by the hydraulic control unit 210, and generates a braking force on each wheel.
The target braking force at this time is set in consideration of the amount of reduction (the amount of reduction of the pump loss) of the drag torque of the engine 1 by opening the throttle valve 56 from the target throttle opening to the lower limit throttle opening. .
After that, the series of processing ends (returns).

According to the first embodiment described above, the following effects can be obtained.
(1) The throttle valve 56 is set so that the minimum opening degree of the throttle valve 56 becomes larger than that after completion of the sliding when the engine 1 has not completed the sliding and oil rise due to the negative pressure in the cylinder is likely to occur. By controlling the degree of opening of the cylinder, it is possible to prevent an excessive negative pressure from being generated in the cylinder cylinder, to suppress the oil rising from the crankcase side, and to reduce the PM discharge amount.
(2) When the drag torque of the engine 1 is reduced due to the reduction of the pump loss due to the execution of the negative pressure suppression control and the effectiveness of the so-called engine brake is weakened, the reduction of the braking force due to the drag torque reduction of the engine 1 A hydraulic service brake compensates for the ease of operation of the vehicle.
(3) By comparing the amount of intake air at the time of idle operation at a predetermined idle speed with a predetermined determination threshold, it is possible to accurately determine the sliding state of the engine with a simple logic.

Second Embodiment
Next, a second embodiment of the engine control device to which the present invention is applied will be described.
In the second embodiment, substantially the same parts as those in the first embodiment described above are denoted by the same reference numerals and descriptions thereof will be omitted, and differences will be mainly described.
The engine of the second embodiment is provided with a valve throttle mechanism capable of continuously changing the valve lift amount in accordance with a command from the ECU 100.
In the engine of the second embodiment, in place of the throttle valve 56 of the first embodiment, the amount of intake air is adjusted by the valve lift amount of the intake valve 35 to perform output adjustment.

In the second embodiment, the sliding condition of the engine 1 is detected by the substantially same logic as the first embodiment, and the control of the valve throttle mechanism described below is performed.
FIG. 4 is a flowchart showing valve lift amount control in the engine control device of the second embodiment.
Hereinafter, each step will be described in order.

<Step S21: Detection of accelerator opening>
The ECU 100 detects an accelerator opening degree (accelerator pedal depression amount) based on an output of the accelerator pedal sensor 101.
Thereafter, the process proceeds to step S22.

<Step S22: Driver request torque setting>
The ECU 100 sets a driver request torque that is a target output torque of the engine 1 based on the accelerator opening detected in step S21.
Thereafter, the process proceeds to step S23.

<Step S23: Target valve lift setting>
The ECU 100 sets the target valve lift (the target lift amount of the intake valve 35) such that the torque actually generated by the engine 1 substantially matches the driver request torque set in step S22.
Thereafter, the process proceeds to step S24.

<Step S24: Sliding state determination>
The ECU 100 determines whether the matching completion determination is satisfied or not by the matching state determination similar to the first embodiment.
If the alignment completion determination is established, the process proceeds to step S25, and if the alignment completion determination is not established (if the alignment incomplete determination is established), the process proceeds to step S26.

<Step S25: Intake valve lift normal control>
The ECU 100 performs normal valve lift control for controlling the valve throttle mechanism so that the actual lift amount of the intake valve 35 substantially matches the target valve lift set in step S23.
After that, the series of processing ends (returns).

<Step S26: Coasting State Determination>
The ECU 100 determines whether the current driving state of the vehicle and the engine 1 is a predetermined coasting state.
For example, the accelerator pedal sensor 101 does not detect the depression amount of the accelerator pedal and satisfies a predetermined fuel cut condition, and in a fuel cut state, the engine 1 is being taken by the coasting of the vehicle (by the back torque from the drive system) When the crankshaft 10 is rotating, the coasting state is determined.
If it is determined that it is in the coasting state, the process proceeds to step S27, and if it is not the coasting state (for example, at the time of acceleration, constant speed traveling, idle time, etc.), the process proceeds to step S25.

<Step S27: Intake valve normally closed>
The ECU 100 performs negative pressure suppression control to prevent the generation of an excessive negative pressure in the cylinder with the intake valve 35 always closed.
Here, the closed state includes a fully closed state in which the intake port is sealed, and a strictly closed state in which the intake valve is lifted but the lift amount is small to a negligible extent.
Thereafter, the process proceeds to step S28.

<Step S28: Brake Coordinated Control Execution>
The ECU 100 gives the behavior control unit 200 a braking force generation instruction.
The behavior control unit 200 applies hydraulic pressure to the wheel cylinder of each wheel by means of the hydraulic control unit 210 to generate a braking force on each wheel.
After that, the series of processing ends (returns).

  According to the second embodiment described above, even in the engine provided with the valve throttle mechanism for adjusting the intake air amount by the change of the valve lift amount, substantially the same effect as the effect of the first embodiment described above is obtained. be able to.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, which are also within the technical scope of the present invention.
(1) The configurations of the engine and its accessories are not limited to the above-described embodiments, and can be changed as appropriate.
For example, the number of cylinders, the cylinder layout, the valve drive system, the fuel used, the fuel injection system, the presence or absence of supercharging, and the type of supercharger can be changed as appropriate.
(2) In each embodiment, the completion of the sliding is determined based on the amount of intake air at the time of idle operation at a predetermined idle speed, but the method of determining the sliding state is not limited to this and is appropriately changed can do.
For example, the completion of the sliding may be determined based on the driving history of the engine (the driving time and the like as an example) and the traveling history of the vehicle on which the engine is mounted (the travel distance and the like as an example).
(3) In each embodiment, the brake coordination control is performed by supplying the hydraulic pressure from the hydraulic control unit to the wheel cylinder of the hydraulic service brake, but the invention is not limited thereto. For example, a motor generator or an integrated starter may be used. The braking force may be generated using a regenerative power generation brake using a generator or an electric parking brake. Also, multiple brakes may be coordinated and controlled.
(4) In the second embodiment, the valve throttling operation is performed to control the intake air amount of the engine by continuously varying the intake valve lift. However, the present invention is not limited thereto. A cylinder deactivation system that switches operation may be used.
(5) In the second embodiment, negative pressure suppression control is performed to close the intake valve only when sliding is not complete and is in the coasting state, but such negative pressure suppression control It may be performed after completion of the alignment.

Reference Signs List 1 engine 10 crankshaft 11 crank angle sensor 20 cylinder block 30 cylinder head 31 combustion chamber 32 ignition plug 33 intake port 34 exhaust port 35 intake valve 36 exhaust valve 37 intake camshaft 38 exhaust camshaft 40 turbocharger 41 turbine 42 compressor 43 air Bypass flow path 44 Air bypass valve 45 West gate flow path 46 West gate valve 50 Intake system 51 Intake duct 52 Chamber 53 Air cleaner 54 Air flow meter 55 Intercooler 56 Throttle valve 57 Intake manifold 58 Intake pressure sensor 59 Injector 60 Exhaust system 61 Exhaust manifold 62 exhaust pipe 63 front catalyst 4 rear catalyst 65 silencer 66 air-fuel ratio sensor 67 rear _{O 2} sensor 70 the canister 71 purge line 72 purge control valve 73 purge line 74 purge control valve 80 EGR device 81 EGR passage 82 EGR cooler 83 EGR valve 100 engine control unit (ECU)
101 accelerator pedal sensor 200 behavior control unit 210 hydraulic control unit (HCU)
220 Vehicle speed sensor

Claims (4)

A throttle valve control unit for controlling an opening degree of a throttle valve provided in an engine intake system;
An engine control device comprising: a sliding state determination unit configured to determine the sliding state of the engine;
The throttle valve control unit is configured such that the minimum opening degree of the throttle valve is larger than the case where it is determined that the sliding is completed when the sliding state determination unit determines that the sliding is not completed. An engine control apparatus characterized by performing negative pressure suppression control that controls an opening degree. A valve drive control unit for controlling a valve drive capable of switching an intake valve of an engine from a normal state to a substantially normally closed state;
A driving state detection unit that detects a driving state of a vehicle on which the engine is mounted;
An engine control device comprising: a sliding state determination unit configured to determine the sliding state of the engine;
The valve drive control unit controls the intake valve to be normally closed when the sliding state determination unit determines that the sliding state is not completed and the operating state detection unit detects a predetermined coasting state. An engine control apparatus characterized by performing negative pressure suppression control. The engine control device according to claim 1 or 2, wherein, when the negative pressure suppression control is performed, a braking coordination control is performed to cause a braking device of a vehicle on which the engine is mounted to generate a braking force. The engine includes an intake air amount sensor that detects an intake air amount, and a rotational speed sensor that detects an output shaft rotational speed.
The sliding condition determination unit determines the completion of the sliding operation when the amount of intake air when the engine performs an idle operation at a predetermined idle rotation speed is equal to or less than a predetermined value. The engine control device according to any one of claims 1 to 3.

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