JP3820848B2 - Intake air amount control device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intake air amount control device for an internal combustion engine, and more particularly to an intake air amount control device for an internal combustion engine that can control the output by controlling the opening / closing timing of an intake valve.
[0002]
[Prior art]
Conventionally, there is an internal combustion engine provided with an electromagnetically driven intake / exhaust valve. For example, as disclosed in Japanese Patent Application Laid-Open No. 10-311231, a system is known in which an intake / exhaust valve of an internal combustion engine is driven by electromagnetic force so that the opening / closing timing of the intake / exhaust valve is variable according to the operating state of the internal combustion engine. ing. In such a system, there is no intake throttle valve, or the intake throttle is made extremely small so that the pressure in the intake pipe is close to atmospheric pressure, and the amount of intake air is controlled during the valve opening period of the intake valve. Yes. As a result, it is possible to reduce the intake loss (pumping loss) and the fuel consumption rate as compared with a conventional engine that controls the intake air amount with an intake throttle valve.
[0003]
[Problems to be solved by the invention]
In an engine equipped with such an intake / exhaust valve with variable opening / closing timing, when the engine is operated with the intake pipe pressure approximately at atmospheric pressure, the engine is compared to an engine that controls the intake air amount with a conventional intake throttle valve. Since the flow rate of the intake air-fuel mixture decreases, the flow in the combustion chamber may decrease, and the combustion stability may decrease. In some cases, a predetermined negative pressure is generated in the intake pipe in order to regenerate the canister that has adsorbed the evaporated fuel in the fuel tank.
[0004]
As described above, since it is necessary to generate a predetermined negative pressure in the intake pipe, an intake throttle valve is provided in the intake pipe. For example, in a condition where the combustion state deteriorates during cold operation, the intake air is reduced by the intake throttle. By controlling the amount, the intake pipe pressure is set to a relatively small state, and the operation is performed while increasing the flow rate of the air-fuel mixture to keep the combustion state in good condition. It is conceivable to perform an operation of maintaining the state close to the atmospheric pressure and reducing the fuel consumption rate by controlling the intake air amount by controlling the opening and closing timing of the intake and exhaust valves.
[0005]
However, in an engine that performs intake air amount control of the two types of intake throttle valve control and intake valve opening / closing timing control during the above-described conventional operation, a step is generated in the engine output when the control method is switched, resulting in an operation There arises a problem that the sex is deteriorated.
[0006]
The cause of this engine output step is, first of all, when the intake air amount is controlled by the intake throttle valve, and when the intake pipe pressure is close to atmospheric pressure and the intake / exhaust valve opening / closing timing is used. When performing air volume control, the pump loss and combustion efficiency differ, so the air volume required to obtain the specified engine output differs, and the intake pipe pressure changes transiently when the intake air volume control method is switched. Therefore, the necessary amount of air changes transiently.
[0007]
Second, the response of the intake air amount control differs between when the intake air amount control is performed by the intake throttle valve and when the intake air amount control is performed at the opening and closing timing of the intake and exhaust valves. That is, in the former case, since the volume from the intake throttle valve to the intake valve acts as a delay element, the actual intake air amount changes with a delay with respect to the target intake air amount, whereas the latter case Is that there is no delay in the actual intake air amount with respect to the target intake air amount.
[0008]
SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an internal combustion engine capable of switching between two intake amount control methods, intake throttle valve control and intake valve opening / closing timing control, during operation without generating a torque step. It is to provide a control device.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 is provided: a throttle valve disposed in an intake passage of an engine, the opening of which is controlled so as to become a target opening; the intake passage, a combustion chamber of the engine; Between the intake valve and the first control method for controlling the intake air amount mainly by controlling the opening degree of the throttle valve, Control system selection means for selecting one of the second control systems for controlling the intake air amount by controlling the closing timing of the intake valve, and a steady target value of the engine torque based on the operating condition of the engine A steady target engine torque calculating means for calculating a steady target engine torque; a target engine torque calculating means for calculating a target engine torque that follows the steady target engine torque with a predetermined delay based on the steady target engine torque; The first system When the method is selected, the steady target closing timing setting means for setting the steady target closing timing indicating the steady target value of the closing timing of the intake valve as the reference closing timing, and the first control method are selected. A steady target intake passage pressure calculating means for calculating a steady target intake passage pressure indicating a steady target value of the pressure in the intake passage based on the steady target engine torque and the steady target closing timing; When the second control method is selected, the steady target intake passage pressure setting means for setting the steady target intake passage pressure to a reference pressure, and when the second control method is selected. In addition, a steady target closing timing calculation means for calculating the steady target closing timing based on the target engine torque and the steady target intake passage pressure, and an actual intake passage pressure indicating an actual pressure in the intake passage. To get Intake passage pressure acquisition means, target opening calculation means for calculating the target opening based on the steady target closing timing and the steady target intake passage pressure, the target engine torque and the actual intake passage An intake air amount control device for an internal combustion engine, comprising: target closing timing calculating means for calculating the target closing timing based on pressure.
[0010]
In order to achieve the above object, according to a second aspect of the present invention, in the intake air amount control device for an internal combustion engine according to the first aspect, the closing timing of the intake valve that maximizes the charging efficiency of the intake air is set as the reference closing timing. It is a summary.
[0011]
In order to achieve the above object, a third aspect of the invention is characterized in that, in the intake air amount control device for an internal combustion engine according to the first aspect, a pressure in the vicinity of atmospheric pressure is set as the reference pressure.
[0012]
In order to achieve the above object, according to a fourth aspect of the present invention, there is provided an intake air amount control device for an internal combustion engine according to the first aspect, wherein the intake passage with respect to a change in opening of the throttle valve based on the reference closing timing. A first response time constant calculating means for calculating a first response time constant indicating a time constant of a response delay of the pressure change in the engine, wherein the target engine torque calculating means is configured to output the first response to the steady target engine torque. The gist is to calculate the target engine torque by performing a first-order delay process of a time constant.
[0013]
In order to achieve the above object, according to a fifth aspect of the present invention, there is provided an intake air amount control device for an internal combustion engine according to the first aspect, wherein the intake passage with respect to a change in the opening of the throttle valve based on the target closing timing. And a second response time constant calculating means for calculating a second response time constant indicating a time constant of a response delay of the pressure change in the engine, wherein the actual intake passage internal pressure acquisition means is adapted to the steady target intake passage internal pressure. The gist is to perform the first-order lag processing of the second response time constant to acquire the actual intake passage pressure.
[0014]
In order to achieve the above object, according to a sixth aspect of the present invention, in the intake air amount control device for an internal combustion engine according to the first aspect, the actual intake passage pressure obtaining means obtains the actual pressure in the intake passage. The gist is to include a pressure sensor for detection.
[0015]
  In order to achieve the above object, an invention according to claim 7 is provided: a throttle valve disposed in an intake passage of an engine, the opening of which is controlled so as to become a target opening; the intake passage, a combustion chamber of the engine; Between the intake valve and the first control method for controlling the intake air amount mainly by controlling the opening degree of the throttle valve, Control method selection means for selecting one of the second control methods for controlling the intake air amount by controlling the closing timing of the intake valve, and when the first control method is selected based on the operating condition of the engine A steady target intake air amount calculating means for calculating a steady target intake air amount indicating a steady target value of the intake air amount, and based on the steady target intake air amount, the intake air amount when the second control method is selected. Calculate target intake air amount to calculate target intake air amount indicating target value And when the first control method is selected, the target opening calculation means for calculating the target opening based on the steady target intake air amount and the first control method are selected. When the target closing timing setting means for setting the target closing timing to the reference closing timing and the second control method are selected, the target opening is determined based on the pressure in the intake passage. Target opening timing calculation means for calculating the target closing timing based on the target intake air amount when the target opening setting means for setting the predetermined opening for pressure and the second control method are selected. Means,A first response time constant calculating means for calculating a first response time constant indicating a time constant of a response delay of an intake air amount change with respect to a change in the opening of the throttle valve based on the reference closing timing; and the steady target intake air An actual intake air amount calculating means for performing a first-order lag process on the first response time constant to calculate an actual intake air amount indicating an actual intake air amount when the first control method is selected, The target intake air amount calculating means calculates the target intake air amount by correcting the actual intake air amount for a decrease in pumping loss.This is an intake air amount control device for an internal combustion engine.
  In order to achieve the above object, the invention according to claim 8 provides:A throttle valve that is disposed in the intake passage of the engine and whose opening is controlled so as to achieve a target opening, and is disposed between the intake passage and the combustion chamber of the engine, and is closed so that the target closing timing is reached. The intake valve whose timing is controlled and the first control method which mainly controls the opening degree of the throttle valve to control the intake air amount, or the intake valve amount which is mainly controlled by closing timing of the intake valve A steady target intake air amount indicating a steady target value of the intake air amount when the first control method is selected, based on control method selection means for selecting any one of the second control methods to be performed and operating conditions of the engine And a target intake air amount for calculating a target intake air amount indicating a target value of the intake air amount when the second control method is selected, based on the steady target intake air amount calculating means. When the calculation means and the first control method are selected The target opening timing is set to the reference closing timing when the target opening calculation means for calculating the target opening and the first control method are selected based on the steady target intake air amount. Target closing time setting means, and when the second control method is selected, target opening setting means for setting the target opening to a predetermined opening at which the pressure in the intake passage becomes a reference pressure; When the second control method is selected, target closing timing calculating means for calculating the target closing timing based on the target intake air amount, and opening of the throttle valve based on the reference closing timing. First response time constant calculating means for calculating a first response time constant indicating a time constant of a response delay of a change in intake air amount with respect to a change in degree, and a first-order delay process for the first response time constant with respect to the steady target intake air amount To select the first control method Actual intake air amount calculating means for calculating an actual intake air amount indicating the actual intake air amount, and the target intake air amount calculating means adds a correction for deterioration of combustion efficiency to the actual intake air amount. An intake air amount control apparatus for an internal combustion engine, characterized in that the target intake air amount is calculated.
  In order to achieve the above object, the invention according to claim 9 provides:A throttle valve that is disposed in the intake passage of the engine and whose opening is controlled so as to achieve a target opening, and is disposed between the intake passage and the combustion chamber of the engine, and is closed so that the target closing timing is reached. The intake valve whose timing is controlled and the first control method which mainly controls the opening degree of the throttle valve to control the intake air amount, or the intake valve amount which is mainly controlled by closing timing of the intake valve A steady target intake air amount indicating a steady target value of the intake air amount when the first control method is selected, based on control method selection means for selecting any one of the second control methods to be performed and operating conditions of the engine A steady target intake air amount calculating means for calculating the steady target intake air amount; When a target intake air amount calculating means for calculating a target intake air amount indicating a target value of the intake air amount at the time of selecting the second control method based on the air amount and the first control method are selected. In addition, when the target opening calculation means for calculating the target opening based on the steady target intake air amount and the first control method are selected, the target closing timing is set as the reference closing timing. Target closing timing setting means for performing, when the second control method is selected, target opening setting means for setting the target opening to a predetermined opening at which the pressure in the intake passage becomes a reference pressure; When the second control method is selected, a target closing timing calculation means for calculating the target closing timing based on the target intake air amount, and a target of the intake air amount at the time of switching the control method selection Calculate target intake air amount when switching control method A control method for calculating the target closing timing at the time of switching the control method based on the target intake air amount at the time of switching the control method based on the target intake air amount at the time of switching the control method when the control method selection is switched. An intake air amount control device for an internal combustion engine characterized by comprising a target closing timing calculation means at the time of switching.
[0016]
  Claims to achieve the above object10The invention described in claim 71 to any one of 9In the intake air amount control device for an internal combustion engine described in 1), the closing timing of the intake valve that maximizes the charging efficiency of the intake air is set as the reference closing timing.
[0017]
  Claims to achieve the above object11The invention described in claim 71 to any one of 9In the intake air amount control device for an internal combustion engine described in 1), the gist is that a pressure near atmospheric pressure is set as the reference pressure.
[0021]
  Claims to achieve the above object12The invention described in claim9In the intake air amount control apparatus for an internal combustion engine according to claim 1, a first response time constant indicating a time constant of a response delay of a change in the intake air amount with respect to a change in the opening amount of the throttle valve is calculated based on the reference closing timing. 1 response time constant calculation means, and an actual intake air amount indicating an actual intake air amount when the first control method is selected by performing a first-order lag process on the steady target intake air amount. An actual intake air amount calculating means for calculating, and the control method switching target intake air amount calculating means based on the target intake air amount and the actual intake air amount based on the target intake air amount. The gist is to calculate.
[0022]
  Claims to achieve the above object13The invention described in claim12In the intake air amount control device for an internal combustion engine according to claim 2, a second response time constant indicating a time constant of a response delay of a pressure change in the intake passage with respect to a change in the opening degree of the throttle valve based on the target closing timing. A second response time constant calculating means for calculating, wherein the control method switching target intake air amount calculating means is switched when the control method is switched from the first control method to the second control method; The gist is to calculate the target intake air amount at the time of switching the control method by performing a first-order lag process for the second response time constant for the actual intake air amount just before and the target intake air amount after the switching.
[0023]
  Claims to achieve the above object14The invention described in claim12In the intake air amount control device for an internal combustion engine according to claim 2, a second response time constant indicating a time constant of a response delay of a pressure change in the intake passage with respect to a change in the opening degree of the throttle valve based on the target closing timing. A second response time constant calculating means for calculating, wherein the control method switching target intake air amount calculating means switches when the control method is switched from the second control method to the first control method; The gist is to calculate the target intake air amount at the time of switching the control method by performing first-order lag processing on the second response time constant for the immediately preceding target intake air amount and the actual intake air amount after switching.
[0024]
  Claims to achieve the above object15The invention described in claim13Or14In the intake air amount control device for an internal combustion engine according to claim 1, when the first control method is selected, a steady target value indicating a steady target value of the pressure in the intake passage is based on the steady target intake air amount. A steady target intake passage pressure calculating means for calculating a target intake passage pressure and a steady target intake passage for setting the steady target intake passage pressure to the reference pressure when the second control method is selected. Based on the internal pressure setting means, the control system switching target intake air amount and the steady target intake passage internal pressure, it is assumed that the pressure in the intake passage matches the steady target intake passage internal pressure. And a temporary closing timing calculating means for calculating a temporary closing timing indicating a closing timing of the intake valve when the intake air amount coincides with the target intake air amount at the time of switching the control method. Calculation It is summarized in that to calculate the target closing timing of applying the control method switching the first-order lag processing of the second response time constant with respect to the temporary closing timing.
[0025]
  Claims to achieve the above object16The invention described in claim9The intake air amount control device for an internal combustion engine according to claim 1, further comprising a pressure sensor for detecting an actual intake passage pressure indicating an actual pressure in the intake passage, wherein the control system switching target closing timing calculation means is the control The gist is to calculate the target closing timing at the time of switching the control method based on the target intake air amount at the time of switching the method and the pressure in the actual intake passage.
[0026]
【The invention's effect】
According to the first aspect of the present invention, the intake air amount is mainly controlled by the first control method for controlling the intake air amount mainly by controlling the opening degree of the throttle valve or mainly by controlling the closing timing of the intake valve. Regardless of which control method of the second control method to be controlled is selected, the throttle valve opening or the intake valve closing timing is controlled based on the steady target engine torque. Therefore, there is an effect that the torque response of the engine, that is, the torque response to the operation and the magnitude of the generated torque with respect to the operation amount can always be made equal.
[0027]
Furthermore, since the target closing timing of the intake valve is calculated based on the target engine torque and the actual intake passage pressure, the two control methods can be used without switching the control method without causing a torque step and deteriorating operability. There is an effect that can be switched.
[0028]
According to the second aspect of the present invention, since the intake valve closing timing at which the intake air charging efficiency is maximized is set as the reference closing timing, it is possible to increase the engine torque when the first control method is selected.
[0029]
According to the third aspect of the present invention, since the steady target value of the pressure in the intake passage is set to a pressure close to the atmospheric pressure when the second control method is selected, there is no pumping loss, and the fuel when the second control method is selected. The consumption rate can be significantly reduced from the fuel consumption rate when the first control method is selected.
[0030]
According to the fourth aspect of the invention, the target torque is calculated using the first response delay time constant indicating the response delay of the pressure change in the intake passage with respect to the change in the throttle valve opening based on the reference time. Therefore, the torque response of the engine with respect to the operation of the engine driver can always be made equal by a relatively simple calculation.
[0031]
According to the fifth aspect of the present invention, the actual intake passage pressure is determined using the second response delay time constant indicating the response delay of the pressure change in the intake passage with respect to the opening change of the throttle valve based on the target closing timing. Since it is obtained, it is possible to always make the magnitude of the generated torque of the engine with respect to the operation amount of the engine driver equal by a relatively simple calculation.
[0032]
According to the sixth aspect of the present invention, since the actual pressure in the intake passage is detected by the pressure sensor, a new sensor is required, but the calculation for always equalizing the magnitude of the generated torque of the engine. This is further simplified than the invention according to the fifth aspect.
[0033]
  Claim 7Or 8According to the described invention,ToThe first control method for controlling the intake air amount by controlling the opening of the Lottle valve or the mainSuckRegardless of which of the second control methods for controlling the intake air amount by controlling the closing timing of the air valve is selected, the throttle valve opening or intake valve closing is based on the steady target intake air amount. Control the timingSince the actual intake air amount is calculated using the first response delay time constant indicating the response delay of the intake air amount change with respect to the change in the throttle valve opening based on the reference closing timing,The torque characteristics of the engine with respect to the operation of the engine driver, that is, the torque response to the operation and the magnitude of the generated torque with respect to the operation amount.With relatively simple calculationsThere is an effect that it can always be made equal.
[0034]
  According to the ninth aspect of the present invention, the intake air amount target value at the time of switching the control method is calculated by the control method switching target intake air amount calculating means, and the intake air at the time of the control method switching is calculated based on this intake air amount target value. Since the target closing timing of the valve is calculated, it is possible to switch between the two control methods without causing a torque step when switching between the first and second control methods.
[0035]
  Claim10According to the described invention, since the closing timing of the intake valve that maximizes the charging efficiency of the intake air is set as the reference closing timing, it is possible to increase the engine torque when the first control method is selected.
[0036]
  Claim11According to the described invention, when the second control method is selected, the steady target value of the pressure in the intake passage is set to a pressure in the vicinity of the atmospheric pressure. Therefore, there is no pumping loss, and the fuel consumption rate when the second control method is selected is reduced. The fuel consumption rate when the first control method is selected can be greatly reduced.
[0039]
  Claim12According to the described invention, based on the target intake air amount and the actual intake air amount subjected to the first-order lag processing by the first response time constant indicating the response delay of the intake air amount change with respect to the steady target intake air amount. Since the target intake air amount at the time of switching the control method is calculated, it is possible to switch between the two control methods without causing a torque step when switching between the first and second control methods.
[0040]
  Claim13, 14, 15According to the described invention, using the second response time constant indicating the response delay time constant of the pressure change in the intake passage, the first order delay with respect to the actual intake air amount and the target intake air amount at the time of switching the control method. Since the processing is performed to calculate the target intake air amount at the time of switching the control method, the calculation for avoiding the occurrence of a torque step at the time of switching the control method can be made relatively simple.
[0041]
  Claim16According to the described invention, since the actual pressure in the intake passage is detected by the pressure sensor, a new sensor is required, but calculation for avoiding the occurrence of a torque step when switching the control method is performed. Claim13, 14, 15It is even simpler than the described invention.
[0042]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram of an internal combustion engine that employs an embodiment of an intake air amount control device for an internal combustion engine according to the present invention.
[0043]
In the intake passage 101 of the engine, an air cleaner 102, an air flow sensor 103, and a stall chamber 104 are disposed from the upstream side. The throttle valve 105 housed in the throttle chamber 104 can be adjusted in opening degree by a throttle actuator 106. The downstream side of the stottle chamber 104 is connected to an intake collector 107, and an intake passage 108 for each cylinder is branched from the intake collector 107.
[0044]
An injector 109 is disposed in the intake passage 108, and fuel is injected and supplied from the injector 109 into the intake passage 108. An intake valve 111 disposed between the intake passage 108 and the combustion chamber 110 is driven to open and close by an electromagnetic actuator 112. Similarly, the exhaust valve 114 disposed between the exhaust passage 113 and the combustion chamber 110 is also opened and closed by an electromagnetic actuator 115. The exhaust gas discharged to the exhaust passage 113 is purified by the catalyst 116 and then released to the atmosphere. 117 is a spark plug.
[0045]
Various controls when operating the engine are performed by an engine control module 120 (hereinafter, ECM 120). The ECM 120 includes an input port 121, a microprocessor 122, a memory 123, an output port 124, and the like. The memory 123 includes a ROM that stores a control program executed by the microprocessor 122, various control maps, control data, and the like, and a RAM that temporarily stores information during execution of the control program.
[0046]
The ECM 120 includes a signal indicating the intake air amount detected by the airflow sensor 103, a signal indicating the crank angle detected by the crank angle sensor 125, a signal indicating the accelerator opening detected by the accelerator opening sensor 126, and a water temperature sensor 127. A signal indicating the coolant temperature detected by the air-fuel ratio, a signal indicating the air-fuel ratio of the exhaust gas detected by the air-fuel ratio sensor 128, a signal indicating the pressure in the intake collector 107 detected by the pressure sensor 129, and the like are sent. It is read through the port 121 and used for arithmetic processing executed by the microprocessor 122. Various control signals obtained by this arithmetic processing are sent to the throttle actuator 106, the injector 109, the electromagnetic actuators 112 and 115, and the spark plug 117 via the output port 124.
[0047]
Further, the ECM 120 controls the opening degree through the throttle actuator 106 so that the throttle valve 105 reaches the target opening degree, and controls the closing timing of the intake valve 111 through the electromagnetic actuator 112 so as to become the target closing time. To do.
[0048]
Further, the ECM 120 mainly controls the intake air amount by controlling the opening degree of the throttle valve 105 or the second control method mainly controlling the closing timing of the intake valve 111 to control the intake air amount. A control method selecting means for selecting one of the control methods, a steady target engine torque calculating means for calculating a steady target engine torque indicating a steady target value of the engine torque based on an operating condition of the engine, and the steady target engine The target engine torque calculating means for calculating the target engine torque that follows the steady target engine torque with a predetermined delay based on the torque and the closing timing of the intake valve 111 when the first control method is selected. When the first target control method and the steady target closing timing setting means for setting the steady target closing timing indicating the steady target value as the reference closing timing and the first control method are selected, The steady target intake passage pressure calculating means for calculating the steady target intake passage pressure indicating the steady target value of the pressure in the intake passage 101 based on the closing timing and the second control method are selected. Based on the target engine torque and the steady target intake passage pressure when the second control method is selected and the steady target intake passage pressure setting means for setting the steady target intake passage pressure to the reference pressure A steady target closing timing calculating means for calculating a steady target closing timing, an actual intake passage pressure acquisition means for acquiring an actual intake passage pressure indicating an actual pressure in the intake passage 101, a steady target closing timing and a steady target. The target opening calculating means for calculating the target opening based on the intake passage pressure and the target closing timing calculating means for calculating the target closing time based on the target engine torque and the actual intake passage pressure. Is.
[0049]
The throttle actuator 106 operates in response to a target opening signal from the ECM 120, and makes the opening of the throttle valve 105 coincide with the target opening. The injector 109 operates in response to a fuel injection signal from the ECM 120, and supplies an amount of fuel such that the air-fuel ratio of the air-fuel mixture formed in the combustion chamber 110 becomes a predetermined air-fuel ratio (for example, the theoretical air-fuel ratio) at a predetermined time. To spray. The spark plug 117 operates upon receiving an ignition signal from the ECM, and performs spark ignition at a predetermined timing.
[0050]
The electromagnetic actuators 112 and 115 operate in response to a target opening / closing timing signal from the ECM 120 to open and close the intake valve 111 and the exhaust valve 114 at a predetermined timing. The structure of the electromagnetic actuators 112 and 115 will be described below with reference to FIG. The electromagnetic actuator shown in FIG. 2 can be applied to both the electromagnetic actuators 112 and 115. That is, the valve 202 in the figure may be either the intake valve 111 or the exhaust valve 114.
[0051]
In FIG. 2, 201 is an engine cylinder head, and 202 is a valve. The valve 202 is assumed to be slidable with respect to the cylinder head 201. A valve retainer 203 is fixed to the shaft portion of the valve 202. A valve spring 204 is compressed and mounted between the valve retainer 203 and the cylinder head 201. For this reason, the valve 202 is biased in the direction in which the port 201a of the cylinder head 201 is closed (the valve closing direction). .
[0052]
The cylinder head 201 is fixed with 205, 206, and 207 which are casings of the apparatus. Electromagnets 208 and 209 are provided in the housing. The electromagnets 208 and 209 are directly fixed to the housings 206 and 207.
[0053]
The electromagnets 208 and 209 are provided with electric coils 208a and 209a, respectively, and a current is passed through the electric coils 208a and 209a at a desired timing by a drive circuit (not shown). In that case, the attracting surfaces 208b and 209b of the electromagnet generate an attracting force.
[0054]
A shaft 210 is slidably installed at the center of the electromagnets 208 and 209. A movable plate 211 made of a soft magnetic material is fixed between the suction surface 208b of the electromagnet 208 and the suction surface 209b of the electromagnet 209 at an intermediate portion of the shaft 210. A spring seat 214 is fixed to the end of the shaft 210 opposite to the cylinder head 201, and the valve opening spring 215 that is compressed and installed between the spring cover 214 and the spring cover 216 fixed to the casing is used. Thus, the shaft 210 is urged in the valve opening direction (downward in the figure).
[0055]
The shaft 210 is provided coaxially with the shaft portion of the valve 202, and the end of the shaft 210 on the cylinder head side faces the top surface 202 a of the shaft of the valve 202. Therefore, when a force in the valve opening direction (downward in the figure) acts on the shaft 210, the shaft 210 pushes the valve 202 and opens the valve 202, and conversely, the shaft 210 is closed in the valve closing direction (shown in the figure). When the valve 202 moves upward, the valve 202 is displaced in the valve closing direction until the port 201a is blocked. In this way, the valve can be opened and closed by the suction operation of the electromagnets 208 and 209.
[0056]
217 is a sensor for measuring the displacement of the shaft 202. For example, the displacement of the shaft 202 is detected by using a potentiometer, and the open / close state of the valve is transmitted to a drive control circuit (not shown) by this detection signal.
[0057]
Next, intake air amount control of this embodiment will be described. In the present embodiment, the first control method for controlling the intake air amount by adjusting the opening degree of the throttle valve 105 with the closing timing of the intake valve 111 set as the reference closing timing, and the pressure in the intake passage 108 part as the reference pressure In this state, the second control method for controlling the intake air amount by adjusting the closing timing of the intake valve 111 is selectively switched and executed. It is assumed that the opening timing of intake valve 111 is always fixed at a predetermined timing (for example, intake TDC), and the opening / closing timing of exhaust valve 114 is always fixed at the predetermined timing.
[0058]
According to the first control method, since the pressure in the intake passage 108 is lower than the atmospheric pressure, the fuel injected into the intake passage 108 is easily vaporized, and the gas flow in the combustion chamber 110 is changed. It becomes relatively strong. For this reason, the first control method is an advantageous control method for ensuring the combustion stability of the engine. On the other hand, if the reference pressure is almost atmospheric pressure in the second control method, the pumping loss at the time of partial load operation can be greatly reduced, and operation with very good fuel consumption can be performed. Further, in the first control method, a delay occurs in the actual change of the intake air amount with respect to the adjustment of the opening degree of the throttle valve 105, whereas in the second control method, the actual intake air is adjusted with respect to the adjustment of the closing timing of the intake valve 111. There is also a difference that there is no delay in the change of air volume.
[0059]
FIG. 3 is a flowchart showing an intake air amount control program executed by the microprocessor 122 in the ECM 120. For example, it is assumed that it is periodically executed at a cycle of 10 msec.
[0060]
In step 1 (hereinafter referred to as S1), the steady target engine torque stTe is calculated based on the accelerator opening APS and the engine speed Ne as engine operating conditions. Specifically, the value is looked up from the control map in which stTe is stored in association with APS and Ne. The steady target engine torque stTe indicates a steady target value of the engine torque.
[0061]
That is, the engine torque in the steady state (a state where APS and Ne do not change) will eventually converge to the steady target engine torque stTe. Note that the accelerator opening APS and the engine speed Ne used in this step are set in the control program executed by the microprocessor 122 separately from the control program, and the accelerator opening Ne is set in the microprocessor 122 separately from the control program. It is assumed that the control program to be executed is calculated based on signals from the accelerator opening sensor 126 and the crank angle sensor 125 and stored in the memory 123.
[0062]
In S2, the reference closing timing IVCb of the intake valve 111 is calculated based on the engine rotational speed Ne. Specifically, the value is looked up from the control table in which IVCb is stored in correspondence with Ne. The reference closing timing IVCb is an intake valve closing timing that maximizes the intake charging efficiency and is basically a timing in the vicinity of the intake BDC. However, when the engine speed Ne increases, the intake valve 111 is closed after the BDC has passed. Therefore, IVCb is calculated from Ne to take this point into consideration.
[0063]
In S3, the response time constant Ta of the intake passage pressure is calculated based on the reference closing timing IVCb. Specifically, a value is looked up from a control table in which Ta is stored in association with IVCb. The response time constant Ta is a time constant indicating a response delay characteristic of the pressure in the intake passage 108 with respect to the opening / closing operation of the throttle valve 105, and is a value when the closing timing of the intake valve 111 is the reference closing timing IVCb. is there. This response delay characteristic changes mainly under the influence of the closing timing of the intake valve 111, but is also affected by the engine speed and the engine load (intake air amount). If Ta is calculated, the accuracy increases.
[0064]
In S4, the target engine torque tTe is calculated by subjecting the steady target engine torque stTe calculated in S1 to the first-order lag processing of the response time constant Ta. The change characteristic of the target engine torque tTe calculated by such a method is the change in torque generated by the engine when the opening degree of the throttle valve 105 is changed in a state where the closing timing of the intake valve 111 is the reference closing timing IVCb. It will match the characteristics.
[0065]
In S5, it is determined whether or not the first control method is selected. The control method is selected by a control program executed by the microprocessor 122 separately from this control program. For example, when the cooling water temperature is low and the engine has not been warmed up, or when the engine speed varies. The first control method is selected when the value is large, and the second control method is selected otherwise.
[0066]
If it is determined in S5 that the first control method is selected, the process proceeds from S6 to S7, and it is determined that the first control method is not selected (the second control method is selected). In this case, the process proceeds from S8 to S9.
[0067]
In S6, the steady target closing timing stIVC of the intake valve 111 is set as the reference closing timing IVCb. The steady target closing timing stIVC is a steady target value for the closing timing of the intake valve 111.
[0068]
In S7, the steady target intake passage pressure stP is calculated based on the steady target engine torque stTe and the steady target closing timing stIVC. The steady target intake passage pressure stP is a steady target value of the pressure in the intake passage 108, and the intake passage 108 when the generated torque of the engine becomes stTe in a state where the closing timing of the intake valve 111 coincides with stIVC. Is the pressure inside. The calculation performed here will be described below.
[0069]
The engine torque is obtained by subtracting loss torque due to pumping loss from torque generated by fuel combustion. Further, the magnitude of the torque generated by the combustion of the fuel is determined by the amount of air taken into the combustion chamber 110. Therefore, the relationship shown in the following formula (1) is established between them.
[0070]
[Expression 1]
Engine torque = f (intake air amount, pumping loss torque) (1)
The intake air amount is determined by the pressure in the intake passage 108 and the time during which the intake valve 111 is open. In the present embodiment, only the closing timing of the intake valve 111 is variable, and the valve opening time of the intake valve 111 is determined according to the intake valve closing timing. Therefore, the relationship shown in the following formula (2) is established between them.
[0071]
[Expression 2]
Intake air amount = f (intake passage pressure, intake valve closing timing) (2)
The pumping loss torque is determined by the intake passage pressure and the intake air amount. Therefore, the relationship shown in the following formula (3) is established between them.
[0072]
[Equation 3]
Heading loss torque = f (intake passage pressure, intake air amount) (3)
As described above, the three relational expressions (1) to (3) are established among the engine torque, the intake air amount, the pumping loss torque, the intake passage pressure, and the intake valve closing timing. If two of them are determined, the remaining values can be obtained.
[0073]
S7 is a calculation for obtaining the intake passage pressure from the previously determined engine torque and intake valve closing timing. As a specific calculation method, the three formulas may be solved directly, or the calculation result may be stored in the control map in advance and the stored value may be looked up.
[0074]
In S8 executed when the second control method is selected, the steady target intake passage pressure stP is set as the reference pressure Pb. In order to minimize the pumping loss torque, the reference pressure Pb may be set to atmospheric pressure. However, the vaporized fuel collected in the canister needs to be sucked into the intake passage. A slightly lower pressure (for example, −50 mmHg with respect to atmospheric pressure) is set as the reference pressure Pb.
[0075]
In S9, the steady target closing timing stIVC is calculated based on the target engine torque tTe and the steady target intake passage pressure stP. Here, the closing timing of the intake valve 111 when the generated torque of the engine becomes stTe in a state where the pressure in the intake passage 108 matches stP is calculated as the steady target closing timing stIVC. The calculation performed here is also a calculation based on the above-described three relational expressions.
[0076]
In S10, the target throttle opening tTVO is calculated based on the steady target closing timing stIVC and the steady target intake passage pressure stP. Since a certain relationship is established in the steady state among the intake passage pressure, the intake valve closing timing, and the throttle opening, the target opening of the throttle valve 105 is calculated based on this relationship. A target opening signal is generated according to the target throttle opening tTVO calculated here, and this signal is sent to the throttle actuator 106.
[0077]
In S11, the response time constant Tb of the intake passage pressure is calculated based on the previous value tIVCz of the target closing timing tIVC of the intake valve 111. Specifically, the value is looked up from the control table in which Tb is stored in association with tIBC.
[0078]
In S12, the first-order lag processing of the response time constant Tb is applied to the steady target intake passage pressure stP calculated in S7 or S8 to calculate the actual intake passage pressure rP. The actual intake passage pressure rP is a value indicating the actual pressure in the intake passage 108. If the pressure sensor 129 has sufficient accuracy and responsiveness, rP may be obtained from the sensor output. In this case, this step and S11 are unnecessary.
[0079]
In S13, the target closing timing tIVC is calculated based on the target engine torque tTe and the actual intake passage pressure rP. The calculation performed here is also a calculation based on the above-described three relational expressions. A target closing timing signal is generated according to the target closing timing tIVC calculated here, and this signal is sent to the electromagnetic actuator 112.
[0080]
FIG. 4 is a time chart when the intake air amount control method is switched from the first control method to the second control method, and FIG. 5 is a case where the intake air amount control method is switched from the second control method to the first control method. It is a time chart.
[0081]
In FIG. 4, the steady state is maintained until time t0, the steady target engine torque stTe and the target engine torque tTe, the steady target intake passage pressure stP and the actual intake passage pressure rP, the steady target closing timing stIVC and the target closing. The timings tIVC are in agreement. In particular, since the operation is being performed by the first control method, the closing timing of the intake valve 111 is the reference closing timing IVCb.
[0082]
When the accelerator opening APS increases stepwise at time t0, the steady target engine torque stTe also increases stepwise accordingly. On the other hand, the target engine torque tTe is calculated as a value asymptotic to the steady target engine torque stTe with a first-order lag. The time constant at this time is Ta.
[0083]
Between time t0 and t1, since the first control method is still selected, the steady target closing timing stIVC remains the reference closing timing IVCb. Since the steady target intake passage pressure stP is calculated from the steady target closing timing stIVC and the steady target engine torque stTe increased stepwise, the steady target intake passage pressure stP also increases stepwise at time t0. Similarly, the target throttle opening tTVO calculated from the steady target closing timing stIVC and the steady target intake passage pressure stP increased stepwise also increases stepwise at time t0.
[0084]
The actual intake passage pressure rP is calculated as a value that gradually approaches the steady target intake passage pressure stP with a first-order lag. At this time, in the actual engine, the pressure in the intake passage 108 gradually increases following the increase in the opening of the throttle valve 105, and the actual intake passage pressure rP is the actual pressure in the intake passage 108. Should almost match.
[0085]
The target closing timing tIVC is always calculated from the target engine torque tTe and the actual intake passage pressure rP, and the target closing timing tIVC is not forcibly set to the reference closing timing IVCb. Specifically, it is maintained at a time in the vicinity of the reference closing time IVCb. This is a natural result when viewed from the original method of calculating the target engine torque tTe.
[0086]
When the control method of the intake air amount is switched from the first control method to the second control method at time t1, the steady target intake passage pressure stP is set to the reference pressure Pb. Since the steady target closing timing stIVC is calculated from the steady target intake passage pressure stP and the increasing target engine torque tTe, the steady target closing timing stIVC is advanced stepwise at the time t1, and then gradually delayed. To change. In response to such a change in the steady target closing timing stIVC, the target throttle opening tTVO increases stepwise at the time t1, and then gradually increases.
[0087]
The actual intake passage pressure rP is calculated as a value that gradually approaches the steady target intake passage pressure stP, which has increased stepwise again, with a primary delay. The actual intake passage pressure rP at this time should also be substantially equal to the actual intake passage 108 pressure, but changes with a characteristic completely different from the change characteristic of the target engine torque tTe. However, since the target closing timing tIVC calculated from the target engine torque tTe and the actual intake passage pressure rP is gradually advanced, the torque generated by the engine coincides with the target engine torque tTe.
[0088]
On the other hand, in FIG. 5, the steady state is maintained until time t4, the steady target engine torque stTe, the target engine torque tTe, the steady target intake passage pressure stP, the actual intake passage pressure rP, and the steady target closing timing stIVC. And the target closing timing tIVC are in agreement. However, since the operation is being performed according to the second control method, the pressure in the intake passage 108 is in a state of matching the reference pressure Pb.
[0089]
From time t4 to t5, since the second control method is still selected, the steady target intake passage pressure stP remains at the reference pressure Pb. Since the steady target closing timing stIVC is calculated from the steady target intake passage pressure stP and the gradually increasing target engine torque tTe, the steady target closing timing stIVC also gradually changes from the time t4 to the delay side. Similarly, the target throttle opening tTVO calculated from the steady target intake passage pressure stP and the gradually increasing steady target closing timing stIVC also gradually increases from the time t4. During this time, the actual intake passage pressure rP remains unchanged at the reference pressure Pb, so that the steady target closing timing stIVC is directly calculated as the target closing timing tIVC.
[0090]
When the control method of the intake air amount is switched from the second control method to the first control method at time t5, the steady target closing timing stIVC is set to the reference closing timing IVCb. Since the steady target intake passage pressure stP is calculated from the steady target closing timing stIVC and the steady target engine torque stTe, the steady target intake passage pressure stP decreases stepwise at time t5. In response to such a change in the steady target intake passage pressure stP, the target throttle opening tTVO also decreases stepwise at the time t5.
[0091]
The actual intake passage pressure rP is calculated as a value that gradually approaches the steady target intake passage pressure stP, which decreases stepwise, with a first-order lag. The actual intake passage pressure rP at this time should also substantially match the actual intake passage 108 pressure. Here, the target closing timing tIVC calculated from the target engine torque tTe and the actual intake passage pressure rP gradually changes to the delay side, and the torque generated by the engine coincides with the target engine torque tTe.
[0092]
As described above, when the first control method is selected, the closing timing of the intake valve 111 becomes the reference closing timing IVCb except immediately after switching from the second control method, and by adjusting the opening of the throttle valve 105 The intake air amount, that is, the generated torque of the engine is controlled. On the other hand, when the second control method is selected, the pressure in the intake passage 108 becomes the reference pressure Pb except immediately after switching from the first control method, and the intake air amount is controlled by adjusting the closing timing of the intake valve 111. Is done.
[0093]
Further, the torque generated by the engine always coincides with the target engine torque tTe, and the torque does not change suddenly before and after the switching of the intake air amount control method. 4 and 5, the case where the control method is switched in the passing state immediately after the accelerator opening APS is changed has been described. However, even if the control method is switched during the steady state operation, the torque is changed. Of course, there is no sudden change.
[0094]
Next, a second embodiment of the present invention will be described in detail with reference to the drawings. The configuration of the internal combustion engine is the same as that shown in FIGS. 1 and 2, and only the control program executed by the microprocessor 122 in the ECM 120 is different from the previous embodiment.
[0095]
FIG. 6 is a flowchart showing a main control program periodically executed, for example, at a period of 10 msec. S600 for calculating the steady target intake air amount stQH01, S700 for calculating the actual intake air amount rQH01, and the steady target intake passage pressure. S800 for calculating stP, S900 for calculating the target intake air amount tQH02, S1000 for calculating the target intake air amount tQH03 at the time of switching the intake air amount control method, S1100 for calculating the target throttle opening tTVO, and calculating the target closing timing tIVC. S1200. Hereinafter, detailed processing in each step will be described.
[0096]
FIG. 7 is a flowchart showing the subprogram executed in S600 of FIG.
[0097]
In S601, an idle holding air amount Qi is calculated. The idle holding air amount Qi includes an air amount for maintaining the engine rotational speed at the idle set rotational speed and an air amount for obtaining torque corresponding to an auxiliary machine load such as an air conditioner.
[0098]
In S602, an idle hold amount throttle opening area Ai is calculated based on the idle hold air amount Qi. Specifically, a value obtained by multiplying the idle holding air amount Qi by a coefficient indicating the relationship between the throttle passing flow rate at the sonic flow rate and the throttle opening area is set as an idle holding throttle opening area Ai.
[0099]
In step S603, the throttle opening area Aa is calculated for the driver requested output based on the accelerator opening APS. Specifically, a value is looked up from a control table (FIG. 8) in which Aa is stored in association with APS.
[0100]
In S604, the throttle opening area A is calculated by adding the throttle opening area Ai for the idle holding amount and the throttle opening area Aa for the driver request output.
In S605, the parameter ANV is calculated by dividing the throttle opening area A by the engine speed Ne and the engine displacement V.
[0101]
In S606, the volume flow rate ratio QH0 is calculated based on the parameter ANV. Specifically, the value is looked up from the control table (FIG. 9) in which QH0 is stored in correspondence with ANV. The volume flow ratio QH0 is a value indicating the volume of the intake air amount in the standard state with respect to the engine stroke volume. In the control table of FIG. 9, for example, the intake valve 111 is opened by the intake TDC and the intake BDC is closed. The volume flow rate ratio is stored. In the present embodiment, this volume flow rate ratio is used as the intake air amount.
[0102]
In S607, the steady target intake air amount stQH01 is set to the volume flow rate ratio QH0. The steady target intake air amount stQH01 is a steady target value of the intake air amount when the first control method is selected. That is, the intake air amount in the steady state when the first control method is selected eventually converges to the steady target intake air amount stQH01.
[0103]
FIG. 10 is a flowchart showing the subprogram executed in S700 of FIG.
In S701, a response time constant Ta is calculated. This response time constant Ta is the same as the response time constant Ta of the previous embodiment.
[0104]
In S702, the actual target intake air amount rQH01 is calculated by subjecting the steady target intake air amount stQH01 calculated in S607 of FIG. The actual intake air amount rQH01 is a value indicating the actual intake air amount when operating in the first control method.
[0105]
FIG. 11 is a flowchart showing the subprogram executed in S800 of FIG.
[0106]
In S801, it is determined whether or not the first control method is selected.
If it is determined in S801 that the first control method is selected, the process proceeds to S802, and the steady target intake passage pressure stP is calculated based on the steady target intake air amount stQH01 and the engine speed Ne. Specifically, the value is looked up from the control map in which stP is stored in association with stQH01 and Ne. The steady target intake passage pressure stP is a value indicating a steady target value of the pressure in the intake passage 108.
[0107]
If it is determined in S801 that the first control method is not selected (the second control method is selected), the process proceeds to S803, and the steady target intake passage pressure stP is set as the reference pressure Pb. Note that Pb may be changed according to engine operating conditions such as cooling water temperature.
[0108]
FIG. 12 is a flowchart showing the subprogram executed in S900 of FIG.
[0109]
In S901, a correction coefficient PUMP1 for correcting the difference in pumping loss between the first control method and the second control method is calculated. The correction coefficient PUMP1 is a value obtained from a control map created based on the rate of change data obtained by conducting an experiment in advance to measure the amount of air that the engine outputs the same torque in the first control method and the second control method. Can be obtained by looking up.
[0110]
In S902, a correction coefficient k for correcting the difference in combustion efficiency between the first control method and the second control method is calculated. The correction coefficient k is a value obtained from a control map created based on the change rate data obtained by conducting an experiment in advance to measure the amount of air in which the first control method, the second control method, and the output engine output the same torque. Can be obtained by looking up.
[0111]
In S903, the actual intake air amount rQH01 calculated in S702 of FIG. 10 is corrected with the correction coefficients PUMP1 and k to calculate the target intake air amount tQH02. The target intake air amount tQH02 is a value indicating the target value of the intake air amount when the second control method is selected. During operation by the second control method, the same amount of torque as that during operation by the first control method can be generated by matching the intake air amount with the target intake air amount tQH02, and the torque response to the accelerator operation The gender can be equal.
[0112]
FIG. 13 is a flowchart showing the subprogram executed in S1000 of FIG.
[0113]
In S1001, a response time constant Tb is calculated. This response time constant Tb is the same as the response time constant Tb of the previous embodiment.
In S1002, it is determined whether or not the first control method is selected.
In S1003, it is determined whether or not the second control method was selected when the program was executed last time.
[0114]
  S1002NO judgment, Judgment of S1003Is YWhen ES, that is, the second control methodIs selected continuouslyWhen the process proceeds to S1004,EyeThe target intake air amount tQH03 is set to the previously calculated value tQH02 (old) of the target intake air amount tQH02. That is, the second control methodIs selected continuouslyWhenStraightThe subsequent target intake air amount tQH03 is calculated using the previous target intake air amount tQH02 as an initial value.
[0115]
  When the determination of S1002 is NO and the determination of S1003 is NO, that is, when switching from the first control method to the second control method is performed, the process proceeds to S1005,Just before switchingActual intake air volume rQH01And the target intake air amount tQH02 after switchingAgainst,Apply first-order lag processing for response time constant Tb,A target intake air amount tQH03 at the time of switching the intake air amount control method is calculated.
[0116]
In S1006, it is determined whether or not the first control method was selected when the program was executed last time.
[0117]
  S1002 is determinedYESWhen the determination in S1006 is YES, that is, the first control methodIs selected continuouslyWhen the process proceeds to S1007,EyeThe target intake air amount tQH03 is set as the previous calculated value rQH01 (old) of the actual intake air amount rQH01. That is, the first control methodIs selected continuouslyWhenStraightThe subsequent target intake air amount tQH03 is calculated with the previous actual intake air amount rQH01 as an initial value.
[0118]
  When the determination in S1002 is YES and the determination in S1006 is NO, that is, when switching from the second control method to the first control method is performed, the process proceeds to S1008, and the target intake air amount tQH02And actual intake air amount rQH01Against,Apply first-order lag processing for response time constant Tb,A target intake air amount tQH03 at the time of switching the intake air amount control method is calculated.
[0119]
FIG. 14 is a flowchart showing the subprogram executed in S1100 of FIG.
[0120]
In S1101, it is determined whether the first control method is selected. If the determination in this step is YES, S1102 and S1103 are subsequently executed, and if the determination in this step is NO, S1104 to S1106 are executed.
[0121]
In S1102, the parameter ANVm is calculated based on the steady target air amount stQH01. Specifically, the value is looked up from the control table (FIG. 15) in which ANVm is stored in correspondence with stQH01. The parameter ANVm indicates a value obtained by dividing the throttle opening area A by the engine rotational speed Ne and the engine exhaust amount V when the intake valve closing timing set in the first control method is set.
[0122]
In S1103, the throttle opening area At is calculated by multiplying the parameter ANVm by the engine rotational speed Ne and the engine displacement V.
[0123]
In S1104, the coefficient C is calculated based on the steady target intake passage pressure stP. Specifically, the value is looked up from the control table (FIG. 16) in which C is stored in correspondence with stP. When the pressure in the intake passage is constant, a proportional relationship is established between the value obtained by dividing the throttle opening area A by the engine rotational speed Ne and the engine displacement V and the volume flow rate ratio. The proportionality coefficient at this time is the coefficient C. The steady target intake passage pressure stP used here is stP (= Pb) set in S803 of FIG.
[0124]
In S1105, the parameter ANVe is calculated by multiplying the target intake air amount tQH02 by the coefficient C. The parameter ANVe indicates a value obtained by dividing the throttle opening area A in the second control method by the engine rotational speed Ne and the engine displacement V.
In S1106, the throttle opening area At is calculated by multiplying the parameter ANVe by the engine rotational speed Ne and the engine displacement V.
[0125]
In S1107, the target throttle opening tTVO is calculated based on the throttle opening area At calculated in S1103 or S1106. Specifically, a value is looked up from a control table (FIG. 17) in which tTVO is stored in association with At.
[0126]
FIG. 18 is a flowchart showing a subprogram executed in S1200 of FIG.
[0127]
In S1201, it is determined whether or not the first control method is selected.
If it is determined in S1201 that the first control method has been selected, the process proceeds to S1202, and it is determined whether or not the elapsed time since the switching of the intake air amount control has exceeded a predetermined time ε. To do.
[0128]
If it is determined in S1202 that the elapsed time exceeds ε, the process proceeds to S1203, and the target closing timing tIVC is set as the reference closing timing IVCb.
[0129]
If the elapsed time does not exceed ε, the process proceeds to S1204, and the maximum intake air amount QH0max is calculated based on the steady target intake passage pressure stP. Specifically, the value is looked up from the control table (FIG. 19) in which QH0max is stored in association with stP. The maximum intake air amount QH0max is a value indicating the maximum amount of air that can be sucked in a state where the pressure in the intake passage 108 matches the steady target intake passage pressure stP. The steady target intake passage pressure stP used here is stP calculated in S802 of FIG.
[0130]
In S1205, the intake valve opening period IVP is calculated by multiplying the crank angle from TDC to BDC by 180 ° by the ratio of the target intake air amount tQH03 and the maximum intake air amount QH0max.
[0131]
In S1206, the temporary closing timing IVC0 of the intake valve 111 is calculated based on the intake valve opening period IVP. The temporary closing timing IVC0 is a value indicating the closing timing of the intake valve 111 at which the intake air amount becomes the target intake air amount tQH03 when the pressure in the intake passage 108 is the steady target intake passage pressure stP.
[0132]
In step S1207, a first-order delay process for the response time constant Tb is performed on the temporary closing timing IVC0 to calculate the target closing timing tIVC. With this processing, the actual intake air amount becomes equal to the target intake air amount tQH03.
[0133]
If it is determined in S1201 that the first control method is not selected (the second control method is selected), the process proceeds to S1208, and the maximum intake air amount QH0max is set based on the steady target intake passage pressure stP. calculate. This calculation is the same as the processing performed in S1204, but the steady target intake passage pressure stP used here is stP (= Pb) set in S803 of FIG.
[0134]
In S1209, it is determined whether or not the elapsed time since the switching of the intake air amount control has exceeded a predetermined time ε.
If it is determined in S1209 that the elapsed time exceeds ε, the process proceeds to S1210, and the intake valve opening period IVP is calculated by multiplying 180 ° by the ratio of the target intake air amount tQH02 and the maximum intake air amount QH0max. To do.
[0135]
In S1211, the temporary closing timing IVC0 of the intake valve 111 is calculated based on the intake valve opening period IVP.
In S1212, the temporary closing timing IVC0 is set as the target closing timing tIVC as it is.
[0136]
If the elapsed time does not exceed ε, the process proceeds to S1213, and the intake valve opening period IVP is calculated by multiplying 180 ° by the ratio of the target intake air amount tQH03 and the maximum intake air amount QH0max.
[0137]
In S1214, the temporary closing timing IVC0 of the intake valve 111 is calculated based on the intake valve opening period IVP.
In step S1215, a first-order lag process for the response time constant Tb is performed on the temporary closing timing IVC0 to calculate the target closing timing tIVC.
[0138]
FIG. 20 is a time chart when the intake air amount control method is switched from the first control method to the second control method, and FIG. 21 is a case where the intake air amount control method is switched from the second control method to the first control method. It is a time chart.
[0139]
In FIG. 20, first, it is assumed that at time t0 in the first control method, the accelerator opening APS increases stepwise. As a result, the steady target intake air amount stQH01 in the first control method also increases stepwise, but the actually sucked air amount follows with a delay as indicated by the actual intake air amount rQH01. The target throttle opening tTVO increases stepwise according to the steady target intake air amount stQH01 that increases stepwise immediately after t0.
[0140]
At this time, the target intake air amount tQH02 increases as the actual intake air amount rQH01 increases, but the asymptote is at a position smaller than the steady target intake air amount stQH01. This is because the amount of air required to keep the output during switching constant is different.
[0141]
Next, at time t1, it is assumed that the switching condition for intake air amount control is satisfied and switching from the first control method to the second control method is started.
[0142]
The target intake air amount tQH03 at the time of switching the intake air amount control method is adjusted to the change characteristic of the pressure in the intake passage having the response time constant Tb with the actual intake air amount rQH01 immediately before the switching start point (t1) as an initial value. Then, it is calculated so as to approach the target intake air amount tQH02. The target closing timing tIVC is also calculated in accordance with the change characteristic of the intake passage pressure having the response time constant Tb.
[0143]
On the other hand, in FIG. 21, the target intake air amount tQH02 immediately before the switching start point (t5) is set as an initial value, and asymptotic to the actual intake air amount rQH01 in accordance with the change characteristic of the intake passage pressure having the response time constant Tb. Thus, the target intake air amount tQH03 at the time of switching is calculated.
[0144]
Further, in calculating the target throttle opening tTVO, the steady target intake air amount stQH01 and the target intake air amount tQH02 are switched in accordance with the switching of the intake air amount control, and the opening calculation is performed based on the target intake air amount. Do.
[0145]
Next, a third embodiment of the present invention will be described in detail with reference to the drawings. This embodiment differs from the second embodiment only in the processing contents of the subprogram (S1200 in FIG. 6) for calculating the target closing time tIVC. This subprogram shown in FIG. 22 can be used when the pressure sensor 129 has sufficient accuracy and responsiveness.
[0146]
In S1221, the maximum intake air amount QH0max is calculated based on the actual intake passage pressure rP obtained from the signal of the pressure sensor 129. The control table used here is the same as the table shown in FIG. 19 used in the second embodiment. However, since the maximum intake air amount QH0max is obtained from the actual pressure in the intake passage 108, the maximum intake air amount QH0max is a value indicating the maximum amount of air that the engine can actually inhale.
[0147]
In S1222, it is determined whether the first control method is selected.
In S1223, it is determined whether or not the elapsed time since the switching of the intake air amount control has exceeded a predetermined time ε.
[0148]
In S1224, the target closing timing tIVC is set as the reference closing timing IVCb.
In S1225, the intake valve opening period IVP is calculated by multiplying 180 °, which is the crank angle from TDC to BDC, by the ratio of the target intake air amount tQH03 and the maximum intake air amount QH0max.
[0149]
In S1226, the target closing timing tIVC is calculated based on the intake valve opening period IVP. In this embodiment, unlike the second embodiment, the target closing timing tIVC can be calculated directly from the intake valve opening period IVP without obtaining the temporary closing timing IVC0.
[0150]
In S1227, it is determined whether or not the elapsed time since the switching of the intake air amount control has exceeded a predetermined time ε.
In S1228, the intake valve opening period IVP is calculated by multiplying 180 ° by the ratio of the target intake air amount tQH02 and the maximum intake air amount QH0max.
[0151]
In S1229, the target closing timing tIVC is calculated based on the intake valve opening period IVP.
In S1230, the intake valve opening period IVP is calculated by multiplying 180 ° by the ratio of the target intake air amount tQH03 and the maximum intake air amount QH0max.
In S1231, the target closing timing tIVC is calculated based on the intake valve opening period IVP.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram showing a configuration of an internal combustion engine to which an intake air amount control device for an internal combustion engine according to the present invention is applied.
FIG. 2 is a cross-sectional view showing an embodiment of a configuration of an intake / exhaust valve according to the present invention.
FIG. 3 is a flowchart showing an intake air amount control program executed by a microprocessor in an engine control module (ECM) in the first embodiment.
FIGS. 4A and 4B are: (a) accelerator opening, (b) engine torque, and (c) in the intake passage when the intake air amount control method in the first embodiment is switched from the first control method to the second control method. 4 is a time chart showing pressure, (d) intake valve closing timing, and (e) throttle opening.
FIGS. 5A and 5B show (a) accelerator opening, (b) engine torque, and (c) in the intake passage when the intake air amount control method in the first embodiment is switched from the second control method to the first control method. 4 is a time chart showing pressure, (d) intake valve closing timing, and (e) throttle opening.
FIG. 6 is a schematic flowchart showing an intake air amount control program executed by a microprocessor in an engine control module (ECM) in the second embodiment.
FIG. 7 is a flowchart for explaining the operation of a steady target intake air amount tQH01 calculation subprogram in the second embodiment.
FIG. 8 is a graph showing an example of a control table storing a throttle opening area Aa for a driver requested output corresponding to an accelerator opening APS.
FIG. 9 is a graph showing an example of a control table storing a volume flow rate ratio QH0 corresponding to a parameter ANV.
FIG. 10 is a flowchart for explaining the operation of an actual intake air amount rQH01 calculation subprogram in the second embodiment.
FIG. 11 is a flowchart illustrating the operation of a steady target intake passage pressure stP calculation subprogram in the second embodiment.
FIG. 12 is a flowchart for explaining the operation of a target intake air amount tQH02 calculation subprogram in the second embodiment.
FIG. 13 is a flowchart for explaining the operation of a target intake air amount tQH03 calculation subprogram when the intake air amount control method is switched in the second embodiment.
FIG. 14 is a flowchart for explaining the operation of a target throttle opening tTVO calculation subprogram in the second embodiment.
FIG. 15 is a graph showing an example of a control table storing a parameter ANVm corresponding to the steady target air amount stQH01.
FIG. 16 is a graph showing an example of a control table in which a coefficient C is stored corresponding to the steady target intake passage pressure stP.
FIG. 17 is a graph showing an example of a control table storing a target throttle opening tTVO corresponding to the throttle opening area At.
FIG. 18 is a flowchart illustrating an operation of a target closing timing tIVC calculation subprogram in the second embodiment.
FIG. 19 is a graph showing an example of a control table storing a maximum intake air amount QH0max corresponding to a steady target intake passage pressure stP.
FIGS. 20A and 20B are (a) accelerator opening, (b) intake air amount, and (c) intake passage when switching the intake air amount control method from the first control method to the second control method in the second embodiment. It is a time chart which respectively shows internal pressure, (d) intake valve closing timing, and (e) throttle opening.
FIG. 21 shows (a) accelerator opening, (b) intake air amount, and (c) intake passage when switching the intake air amount control method from the second control method to the first control method in the second embodiment. It is a time chart which respectively shows internal pressure, (d) intake valve closing timing, and (e) throttle opening.
FIG. 22 is a flowchart for explaining the operation of a target closing time tIVC calculation subprogram in the third embodiment.
[Explanation of symbols]
101 Intake passage
102 Air cleaner
103 Air flow sensor
104 Throttle chamber
105 Throttle valve
106 Throttle actuator
107 Intake collector
108 Air intake passage
109 injector
110 Combustion chamber
111 Intake valve
112 Electromagnetic actuator
113 Exhaust passage
114 Exhaust valve
115 Electromagnetic actuator
116 Catalyst
117 spark plug
120 Engine control module (ECM)
121 Input port
122 Microprocessor
123 memory
124 output port
125 Crank angle sensor
126 Accelerator position sensor
127 Water temperature sensor
128 Air-fuel ratio sensor
129 Pressure sensor

Claims (16)

A throttle valve disposed in the intake passage of the engine, the opening degree of which is controlled so as to be the target opening degree;
An intake valve which is disposed between the intake passage and the combustion chamber of the engine and whose closing timing is controlled so as to reach a target closing timing;
Either a first control method that mainly controls the opening degree of the throttle valve to control the intake air amount or a second control method that mainly controls the intake valve closing timing to control the intake air amount. Control method selection means for selecting one;
A steady target engine torque calculating means for calculating a steady target engine torque indicating a steady target value of the engine torque based on an engine operating condition;
Target engine torque calculating means for calculating a target engine torque that follows the steady target engine torque with a predetermined delay based on the steady target engine torque;
A stationary target closing timing setting means for setting a stationary target closing timing indicating a stationary target value of the closing timing of the intake valve as a reference closing timing when the first control method is selected;
When the first control method is selected, a steady target intake passage pressure indicating a steady target value of the pressure in the intake passage is calculated based on the steady target engine torque and the steady target closing timing. A steady target intake passage pressure calculating means for
A steady target intake passage pressure setting means for setting the steady target intake passage pressure to a reference pressure when the second control method is selected;
A steady target closing timing calculating means for calculating the steady target closing timing based on the target engine torque and the steady target intake passage pressure when the second control method is selected;
An actual intake passage pressure acquisition means for acquiring an actual intake passage pressure indicating an actual pressure in the intake passage;
A target opening calculation means for calculating the target opening based on the steady target closing timing and the steady target intake passage pressure;
Target closing timing calculating means for calculating the target closing timing based on the target engine torque and the actual intake passage internal pressure;
An intake air amount control device for an internal combustion engine, comprising:   The intake air amount control device for an internal combustion engine according to claim 1, wherein the closing timing of the intake valve that maximizes the charging efficiency of the intake air is set as the reference closing timing.   2. The intake air amount control device for an internal combustion engine according to claim 1, wherein a pressure near atmospheric pressure is set as the reference pressure. A first response time constant calculating means for calculating a first response time constant indicating a time constant of a response delay of a pressure change in the intake passage with respect to a change in the opening of the throttle valve based on the reference closing timing;
2. The intake of the internal combustion engine according to claim 1, wherein the target engine torque calculation means calculates the target engine torque by performing a first-order lag processing of the first response time constant with respect to the steady target engine torque. Air quantity control device. A second response time constant calculating means for calculating a second response time constant indicating a time constant of a response delay of a pressure change in the intake passage with respect to a change in the opening degree of the throttle valve based on the target closing timing;
2. The actual intake passage pressure obtaining unit obtains the actual intake passage pressure by performing first-order lag processing of the second response time constant on the steady target intake passage pressure. An intake air amount control device for an internal combustion engine as described.   2. The intake air amount control device for an internal combustion engine according to claim 1, wherein the actual intake passage pressure acquisition means includes a pressure sensor for detecting an actual pressure in the intake passage. A throttle valve disposed in the intake passage of the engine, the opening degree of which is controlled so as to be the target opening degree;
An intake valve which is disposed between the intake passage and the combustion chamber of the engine and whose closing timing is controlled so as to reach a target closing timing;
Either the first control method that controls the intake air amount mainly by controlling the opening degree of the throttle valve or the second control method that controls the intake air amount mainly by controlling the closing timing of the intake valve. Control method selection means for selecting one;
A steady target intake air amount calculating means for calculating a steady target intake air amount indicating a steady target value of the intake air amount when the first control method is selected, based on the operating condition of the engine;
A target intake air amount calculating means for calculating a target intake air amount indicating a target value of the intake air amount when the second control method is selected based on the steady target intake air amount;
Target opening degree calculating means for calculating the target opening degree based on the steady target intake air amount when the first control method is selected;
Target closing timing setting means for setting the target closing timing to a reference closing timing when the first control method is selected;
Target opening setting means for setting the target opening to a predetermined opening at which the pressure in the intake passage becomes a reference pressure when the second control method is selected;
A target closing timing calculating means for calculating the target closing timing based on the target intake air amount when the second control method is selected;
A first response time constant calculating means for calculating a first response time constant indicating a time constant of a response delay of a change in intake air amount with respect to a change in opening of the throttle valve based on the reference closing timing;
An actual intake air amount calculation means for performing a first-order lag process on the steady target intake air amount to calculate an actual intake air amount indicating an actual intake air amount when the first control method is selected. And comprising
The intake air amount control device for an internal combustion engine, wherein the target intake air amount calculation means calculates the target intake air amount by correcting the actual intake air amount for a decrease in pumping loss . A throttle valve disposed in the intake passage of the engine, the opening degree of which is controlled so as to be the target opening degree;
  An intake valve which is disposed between the intake passage and the combustion chamber of the engine and whose closing timing is controlled so as to reach a target closing timing;
  Either the first control method that controls the intake air amount mainly by controlling the opening degree of the throttle valve or the second control method that controls the intake air amount mainly by controlling the closing timing of the intake valve. Control method selection means for selecting one;
  A steady target intake air amount calculating means for calculating a steady target intake air amount indicating a steady target value of the intake air amount when the first control method is selected, based on the operating condition of the engine;
  A target intake air amount calculating means for calculating a target intake air amount indicating a target value of the intake air amount when the second control method is selected based on the steady target intake air amount;
  Target opening degree calculating means for calculating the target opening degree based on the steady target intake air amount when the first control method is selected;
  Target closing timing setting means for setting the target closing timing to a reference closing timing when the first control method is selected;
  Target opening setting means for setting the target opening to a predetermined opening at which the pressure in the intake passage becomes a reference pressure when the second control method is selected;
  A target closing timing calculating means for calculating the target closing timing based on the target intake air amount when the second control method is selected;
  A first response time constant calculating means for calculating a first response time constant indicating a time constant of a response delay of a change in intake air amount with respect to a change in the opening of the throttle valve based on the reference closing timing;
  An actual intake air amount calculation means for performing a first-order lag process on the steady target intake air amount to calculate an actual intake air amount indicating an actual intake air amount when the first control method is selected. And comprising
  The target intake air amount calculation device is configured to calculate the target intake air amount by correcting the actual intake air amount by correcting the deterioration of combustion efficiency. Arranged in the intake passage of the engine, the opening degree is controlled so as to be the target opening degree A throttle valve,
  An intake valve which is disposed between the intake passage and the combustion chamber of the engine and whose closing timing is controlled so as to reach a target closing timing;
  Either the first control method that controls the intake air amount mainly by controlling the opening degree of the throttle valve or the second control method that controls the intake air amount mainly by controlling the closing timing of the intake valve. Control method selection means for selecting one;
  A steady target intake air amount calculating means for calculating a steady target intake air amount indicating a steady target value of the intake air amount when the first control method is selected, based on the operating condition of the engine;
  A target intake air amount calculating means for calculating a target intake air amount indicating a target value of the intake air amount when the second control method is selected based on the steady target intake air amount;
  Target opening degree calculating means for calculating the target opening degree based on the steady target intake air amount when the first control method is selected;
  Target closing timing setting means for setting the target closing timing to a reference closing timing when the first control method is selected;
  Target opening setting means for setting the target opening to a predetermined opening at which the pressure in the intake passage becomes a reference pressure when the second control method is selected;
  A target closing timing calculating means for calculating the target closing timing based on the target intake air amount when the second control method is selected;
  Control method switching target intake air amount calculating means for calculating a control method switching target intake air amount indicating a target value of intake air amount at the time of control method selection switching;
  And a control system switching target closing timing calculating means for calculating the target closing timing at the time of control system switching based on the control system switching target intake air amount when the selection of the control system is switched. An intake air amount control apparatus for an internal combustion engine. The intake air amount control device for an internal combustion engine according to any one of claims 7 to 9, wherein the closing timing of the intake valve that maximizes the charging efficiency of the intake air is set as the reference closing timing.   The intake air amount control device for an internal combustion engine according to any one of claims 7 to 9, wherein a pressure near atmospheric pressure is set as the reference pressure.   A first response time constant calculating means for calculating a first response time constant indicating a time constant of a response delay of a change in intake air amount with respect to a change in the opening of the throttle valve based on the reference closing timing;
  An actual intake air amount calculation means for performing a first-order lag process on the steady target intake air amount to calculate an actual intake air amount indicating an actual intake air amount when the first control method is selected. And further comprising
  10. The control method switching target intake air amount calculating means calculates the control method switching target intake air amount based on the target intake air amount and the actual intake air amount. Intake air amount control device for internal combustion engine.   A second response time constant calculating means for calculating a second response time constant indicating a time constant of a response delay of a pressure change in the intake passage with respect to a change in the opening degree of the throttle valve based on the target closing timing;
  When the control method is switched from the first control method to the second control method, the target intake air amount calculating means at the time of switching the control method is changed to the actual intake air amount immediately before the switching and the target after the switching. 13. The intake air amount control apparatus for an internal combustion engine according to claim 12, wherein a first-order lag process is performed on the intake air amount to calculate a target intake air amount at the time of switching the control method.   A second response time constant calculating means for calculating a second response time constant indicating a time constant of a response delay of a pressure change in the intake passage with respect to a change in the opening degree of the throttle valve based on the target closing timing;
  The target intake air amount calculating means at the time of switching the control method switches to the target intake air amount immediately before the switching when the control method is switched from the second control method to the first control method. 13. The intake of the internal combustion engine according to claim 12, wherein a first-order lag process of the second response time constant is performed on the actual intake air amount after calculation to calculate the target intake air amount at the time of switching the control method. Air quantity control device.   When the first control method is selected, a steady target intake passage pressure that calculates a steady target intake passage pressure indicating a steady target value of the pressure in the intake passage is calculated based on the steady target intake air amount. Pressure calculating means;
  Steady target intake passage pressure setting means for setting the steady target intake passage pressure to the reference pressure when the second control method is selected;
  Based on the target intake air amount when switching the control method and the steady target intake passage pressure, it is assumed that the intake air amount is the same as the steady target intake passage pressure. A temporary closing timing calculating means for calculating a temporary closing timing indicating a closing timing of the intake valve that coincides with the target intake air amount at the time of switching the control method;
  The control system switching target closing time calculating means performs a first-order lag processing of the second response time constant on the temporary closing timing to calculate the target closing timing at the time of control system switching. The intake air amount control device for an internal combustion engine according to 13 or 14.   A pressure sensor for detecting an actual intake passage pressure indicating an actual pressure in the intake passage;
  The control system switching target closing timing calculation means calculates the target closing timing at the time of control system switching based on the control system switching target intake air amount and the actual intake passage pressure. The intake air amount control device for an internal combustion engine according to claim 9.

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