JP2010106816A - Blow-by gas reduction apparatus of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blow-by gas reduction apparatus of an internal combustion engine capable of decreasing frequency of an erroneous learning on an opening degree of a ventilation control valve. <P>SOLUTION: The blow-by gas reduction apparatus 50 supplies blow-by gas from an engine body 20 to an intake passage 49 to thereby ventilate the engine body 20 and adjusts an amount of the blow-by gas supplied to the intake passage 49 using a PCV valve 54. As a learning control, the apparatus 50 drives the PCV valve 54 toward a reference position, and, if the apparatus 50 determines that the drive position of the PCV valve 54 is in the reference position, the apparatus 50 learns an opening degree of the PCV valve 54. The apparatus 50 further determines whether or not the PCV valve 54 is in a low temperature condition. If the apparatus 50 determines that the PCV valve 54 is in the low temperature condition, the apparatus 50 does not execute the learning control. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention supplies blow-by gas from an engine body to an intake passage to ventilate the engine body, and adjusts the amount of blow-by gas supplied to the intake passage by means of an electric ventilation control valve. It relates to a reduction device.

As the blow-by gas reduction device, for example, the one described in Patent Document 1 is known. In the blow-by gas reduction device of this document, the opening degree of a solenoid valve as a ventilation control valve is controlled by an electronic control device.
JP-A-9-68028

  By the way, in the blow-by gas reduction device provided with the electric ventilation control valve, the opening degree (opening control value) of the ventilation control valve and the actual opening degree (opening actual value) of the ventilation control valve grasped by the electronic control unit. There may be a gap between When such a deviation occurs, it becomes difficult to accurately control the opening degree of the ventilation control valve. Therefore, in order to appropriately adjust the amount of blow-by gas supplied to the intake passage, such a deviation of the opening degree is required. It is required to learn and reflect this in the control of the ventilation control valve.

  Here, assuming a blow-by gas reduction device in which a stepping motor is used as the actuator of the ventilation control valve, the following is given as an example of learning control of this reduction device. In the following, regarding the drive position of the ventilation control valve that is changed by the actuator, when the ventilation control valve is driven in the valve closing direction or the valve opening direction, the valve hits the wall surface of the device, etc. The drive position that cannot be driven in the direction or the valve opening direction is set as the reference position.

  When the drive position at which the opening degree of the ventilation control valve is fully closed is set as the reference position, in learning control, first the command to change the drive position of the ventilation control valve to a position closer to the valve closing side than the reference position To the actuator.

  As a result, assuming that there is no abnormality in the operation of the ventilation control valve or stepping motor, drive the valve closer to the reference position, i.e., physically drive the valve closer to the valve closing side. Even when reaching a position where it is impossible, the stepping motor tries to drive the ventilation control valve further toward the valve closing side based on a command from the electronic control unit, so that the motor steps out.

  At this time, the electronic control unit confirms that the drive position of the ventilation control valve has reached the reference position when the stepping motor has stepped out, and thereby the opening control value is set at that time. The value is updated to the control value corresponding to the fully closed position. Thereafter, by changing the opening with the updated control value as a reference, it is possible to suppress an excessive divergence between the opening control value and the actual opening value.

  However, when the temperature of the ventilation control valve itself is excessively low, for example, the viscosity of the lubricating oil adhering to the control valve increases remarkably, or moisture or lubricating oil adhering to the control valve freezes. As a result, the above-described learning control may not be performed properly. In other words, lubrication is performed even though the actual drive position has not reached the reference position in a state where a command to drive the ventilation control valve further toward the valve closing side than the fully closed position is transmitted to the actuator. The stepping motor may step out due to resistance caused by oil or the like. At this time, the electronic control unit determines that the actual drive position of the ventilation control valve has reached the reference position based on the step-out, and then sets the opening control value to a control value corresponding to the fully closed position. It will be updated.

  Thus, when there is a large gap between the command to the actuator by the electronic control device and the actual operation of the actuator based on this due to excessive resistance to the drive of the ventilation control valve, the ventilation Even if the actual value of the opening of the control valve is not fully closed, an erroneous learning is made such that the opening control value is set to fully closed.

  These problems are not limited to the case where a stepping motor is used as an actuator for a ventilation control valve. A command for maintaining the drive position of the ventilation control valve at the reference position is given to the actuator, and then the ventilation control valve is set to the reference position. As long as it is assumed that the actual drive position is at the reference position and the opening degree of the control valve is learned when it is estimated that the position has reached, it can occur in the same way regardless of the configuration of the device. It can be said that.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a blow-by gas reduction device for an internal combustion engine that can reduce the frequency with which learning of the opening degree of the ventilation control valve is mistakenly performed. There is.

In the following, means for achieving the above object and its effects are described.
According to the first aspect of the present invention, blow-by gas is supplied from the engine body to the intake passage to ventilate the engine body, and the amount of blow-by gas supplied to the intake passage is adjusted by an electric ventilation control valve. In the blow-by gas reduction device for an internal combustion engine, the ventilation control valve is driven toward a reference position, and the opening degree of the control valve is learned when it is determined that the drive position of the ventilation control valve is at the reference position. And a second process for determining whether or not the ventilation control valve is in a low temperature state and prohibiting the execution of the first process when it is determined that the ventilation control valve is in a low temperature state. Yes.

  In the present invention, when the ventilation control valve is in a low temperature state, that is, because the resistance to driving the ventilation control valve is excessively large, the control valve does not reach the reference position in the first processing. Regardless, the execution of the first process is prohibited when there is a high possibility that it is determined that the drive position of the ventilation control valve is at the reference position. Therefore, the frequency with which learning of the opening degree of the ventilation control valve is erroneously performed can be reduced.

(First embodiment)
A first embodiment in which the blow-by gas reduction device for an internal combustion engine of the present invention is embodied as a blow-by gas reduction device for a port injection internal combustion engine will be described with reference to FIGS.

  As shown in FIG. 1, the engine 10 includes an engine body 20 that obtains power through combustion of a mixture of air and fuel, an intake device 40 that supplies external air to the combustion chamber 31 of the engine body 20, and an engine body. 20 includes an electronically controlled blow-by gas reduction device 50 that supplies the blow-by gas generated at 20 to the intake device 40, and an electronic control device 60 that controls these devices in an integrated manner.

  The engine body 20 is provided with a cylinder block 21 that burns an air-fuel mixture of fuel injected through the injector 27 and air supplied through the intake device 40 in the combustion chamber 31. A crankcase 22 that supports the crankshaft 26 in cooperation with the cylinder block 21 is attached to the lower portion of the cylinder block 21. An oil pan 23 for storing lubricating oil supplied to each part of the engine 10 is attached to the lower portion of the crankcase 22. A cylinder head 24 on which valve system components are arranged is attached to the upper part of the cylinder block 21. A head cover 25 is attached to the upper portion of the cylinder head 24 to suppress the splashing of the lubricating oil to the outside due to the driving of the valve system components.

  A crank chamber 32 for accommodating the crankshaft 26 is formed inside the cylinder block 21 and the crankcase 22. Inside the cylinder head 24 and the head cover 25, a valve operating chamber 33 is formed to accommodate valve operating parts. The crank chamber 32 and the valve operating chamber 33 are connected to each other by a communication chamber 34 formed inside the cylinder block 21.

  The intake device 40 is provided with a throttle body 41 that accommodates a throttle valve 42 that adjusts the flow rate of air (hereinafter referred to as “intake”) taken into the device from the outside. An air cleaner 43 that removes foreign matter in the intake air is provided on the upstream side of the throttle body 41. An air intake 44 that takes in outside air into the apparatus is provided at the inlet of the air cleaner 43. An intake hose 45 is provided between the inlet of the throttle body 41 and the outlet of the air cleaner 43 to connect them. An intake manifold 46 is provided on the downstream side of the throttle body 41 to supply intake air that has passed through the throttle body 41 to each intake port of the cylinder head 24. The intake manifold 46 is provided with a surge tank 47 that retains intake air that has passed through the throttle body 41, and a plurality of sub-pipes 48 that supply intake air in the tank 47 to each intake port of the cylinder head 24. That is, in the intake device 40, the intake air is supplied to the engine body through the passage in the air intake 44, the passage in the air cleaner 43, the passage in the intake hose 45, the passage in the throttle body 41, and the passage in the intake manifold 46. An intake passage 49 is formed to be fed into the vehicle 20.

  The blow-by gas reduction device 50 has a function of supplying blow-by gas flowing out from the combustion chamber 31 to the crank chamber 32 to the intake device 40, and a function of supplying intake air purified by the air cleaner 43 from the intake device 40 to the valve operating chamber 33. And an apparatus having a function of adjusting the amount of blow-by gas supplied from the engine body 20 to the intake device 40. Specifically, the engine 10 is provided with the following components as components of the reduction device 50.

  That is, a first ventilation pipe 51 is provided between the cylinder block 21 and the surge tank 47 as a passage for supplying blow-by gas from the crank chamber 32 to the surge tank 47. Further, a second ventilation pipe 52 is provided between the intake hose 45 and the head cover 25 as a passage for supplying intake air from the intake passage 49 to the valve operating chamber 33. An oil separator 53 that separates oil contained in the blow-by gas from the gas is provided at the connection portion of the first ventilation pipe 51 on the cylinder block 21. Also, an opening on the oil separator 53 side of the first ventilation pipe 51 is an electronic control valve that adjusts the flow rate of the mixed gas of the blow-by gas and the intake gas (hereinafter referred to as “PCV gas”) mixed in the crank chamber 32. PCV valve 54 is provided. The PCV valve 54 is attached to the surface of the cylinder block 21. The valve body of the valve 54 is driven by an actuator 55. Here, a stepping motor is used as the actuator 55.

The flow of gas by the blow-by gas reduction device 50 is shown below.
When the engine is under low load, the negative pressure on the downstream side of the throttle valve 42 is large so that blow-by gas flows from the crank chamber 32 to the surge tank 47 via the oil separator 53, the PCV valve 54 and the first ventilation pipe 51. Become. At this time, intake air flows into the valve operating chamber 33 from the intake hose 45 through the second ventilation pipe 52. On the other hand, since the pressure in the crank chamber 32 and the valve operating chamber 33 is high at a high engine load, blow-by gas flows from the crank chamber 32 into the surge tank 47 via the oil separator 53, the PCV valve 54, and the first ventilation pipe 51. At the same time, blow-by gas flows from the valve operating chamber 33 to the intake hose 45 via the second ventilation pipe 52. Under the same engine operating conditions, the opening of the PCV valve 54 (hereinafter referred to as “ventilation opening VB”) increases, that is, the passage area of the inlet of the first ventilation pipe 51 increases. Accordingly, the flow rate of the PCV gas flowing through the first ventilation pipe 51 increases.

  The electronic control device 60 is connected with a crank position sensor 61, an air flow meter 62, a throttle position sensor 63, a cooling water temperature sensor 64, an outside air temperature sensor 65, and the like as various sensors for assisting the control. The crank position sensor 61 is provided in the vicinity of the crankshaft 26 and outputs a signal corresponding to the rotation angle of the shaft 26. The electronic control unit 60 calculates the rotational speed of the crankshaft 26 (hereinafter, “engine rotational speed NE”) based on this signal. The air flow meter 62 is provided upstream of the throttle valve 42 and the opening of the second ventilation pipe 52 in the intake passage 49, and outputs a signal corresponding to the mass flow rate of the intake air flowing through the intake passage 49. The electronic control unit 60 calculates the amount of intake air (hereinafter referred to as “intake amount GA”) supplied to the combustion chamber 31 based on this signal. The throttle position sensor 63 is provided in the vicinity of the throttle valve 42 and outputs a signal corresponding to the opening of the valve 42 (hereinafter referred to as “throttle opening VT”). The coolant temperature sensor 64 is provided in the cylinder block 21 and outputs a signal corresponding to the temperature of the engine coolant that cools the engine body 20 (hereinafter, “cooling water temperature TW”). The outside air temperature sensor 65 is provided outside the engine 10 and outputs a signal corresponding to the outside air temperature (hereinafter, “outside air temperature TA”).

  The electronic control device 60 performs various controls such as throttle control, injection control, and ventilation control after grasping the driver's request and engine operating state based on the detection results of the sensors. In the throttle control, the intake air amount GA is adjusted by changing the throttle opening VT by operating the throttle valve 42. In the injection control, the fuel injection amount (hereinafter referred to as “injection amount QI”) is adjusted by changing the valve opening time by operating the injector 27. In the ventilation control, the PCV gas flow rate (hereinafter referred to as “PCV flow rate GB”) is adjusted by changing the ventilation opening degree VB by operating the PCV valve 54.

Here, the detail of the control structure of ventilation control is demonstrated.
In this control, a required value of the PCV flow rate GB (hereinafter referred to as “PCV required value GBT”) is set based on the engine load and the engine rotational speed NE, and an actual PCV flow rate GB (hereinafter referred to as “PCV actual value GBR”). Is set as a required value (hereinafter referred to as “opening required value VBT”), and an actual ventilation opening VB (hereinafter referred to as “opening actual value VBR”) is set. ) Is controlled to the required value VBT, the actuator 55 of the PCV valve 54 is controlled. The engine load is, for example, the ratio of the actual intake amount GA to the maximum value of the intake amount GA that can be supplied to the combustion chamber 31 at that time, or the actual injection amount QI with respect to the maximum value of the injection amount QI of the injector 27. The ratio of the value (required value of the injection amount QI) can be grasped as an index.

  The ventilation control is configured to include two controls: a drive control for changing the ventilation opening VB through a command to the actuator 55, and a learning control for learning the opening reference for the control. .

  In the drive control, a command for changing the position of the valve body of the PCV valve 54, that is, the rotational position of the valve body around the rotation axis (hereinafter referred to as “drive position of the PCV valve 54”) is transmitted to the actuator 55. The ventilation opening degree VB is changed through the driving of the PCV valve 54 according to the above. The drive position of the PCV valve 54 is changed between a fully closed position where the ventilation opening VB is the minimum opening (fully closed) and a fully opened position where the ventilation opening VB is the maximum (fully open). That is, when the drive position is in the fully closed position, the valve body of the PCV valve 54 is in contact with one wall surface of the first ventilation pipe 51, so the PCV valve 54 is driven further toward the valve closing side. I can't do it. On the other hand, when the drive position is at the fully open position, the valve body of the PCV valve 54 is in contact with the other wall surface of the first ventilation pipe 51, so the PCV valve 54 is driven further to the valve opening side. It is not possible.

  In the drive control, the ventilation opening VB (hereinafter referred to as “opening control value VBC”) grasped by the electronic control unit 60 is managed based on the driving amount of the actuator 55, that is, the number of steps of the stepping motor. That is, when the electronic control unit 60 controls the ventilation opening VB in the drive control, the actual ventilation opening VB (hereinafter referred to as “opening actual value VBR”) is set to the opening control value VBC. Then, a command is given to the actuator 55 so that the opening control value VBC matches the required ventilation opening VB.

  For example, when there is a request to change the ventilation opening VB to the increase side, the number of stepping motor steps required to drive the PCV valve 54 by an amount corresponding to the increase amount of the ventilation opening VB is calculated. A command value corresponding to the number is given to the actuator 55. At this time, the opening degree control value VBC is changed to the opening degree actual value VBR by reflecting the change amount of the ventilation opening degree VB based on the opening degree control value VBC before giving the command value to the actuator 55. Follow changes in

  As described above, in the drive control of the PCV valve 54, the correspondence between the opening control value VBC and the actual opening value VBR is attempted, but the opening control value VBC is set to a value different from the actual opening value VBR. The situation as it is may occur. For example, when the actual opening degree value VBR changes after the engine is stopped, this is not reflected in the opening degree control value VBC. Therefore, there is a difference between the actual opening degree value VBR and the opening degree control value VBC after the engine starts. It comes to occur.

  When such a deviation of the initial value occurs, a command for the actuator 55 is issued based on the opening control value VBC that is different from the actual opening value VBR in the drive control, so that the opening control value VBC is opened. Therefore, an excessive divergence may occur between the required supply amount of blow-by gas and the actual supply amount.

  Therefore, in the blow-by gas reduction device 50 of the present embodiment, the PCV valve 54 is learned by learning the difference between the opening control value VBC and the actual opening value VBR through execution of learning control and reflecting this in subsequent drive control. Thus, an appropriate control mode is maintained.

  In this learning control, when the execution of the control is allowed, first, a command is given to the actuator 55 to change the drive position of the PCV valve 54 to a position closer to the valve closing side than the fully closed position which is the reference position.

  As a result, if there is no abnormality in the operation of the PCV valve 54 and the actuator 55, the time when the drive position of the PCV valve 54 reaches the reference position, that is, the valve body of the valve 54 is the wall surface of the first ventilation pipe 51. The actuator 55 further closes the PCV valve 54 on the basis of a command from the electronic control unit 60 even when reaching a driving position where the valve cannot be driven further to the valve closing side. The stepping motor will step out due to the drive toward the side.

  At this time, the electronic control unit 60 confirms that the drive position of the PCV valve 54 has reached the reference position when the stepping motor has stepped out, and thereby the opening control value VBC is set at that time. The control value is updated to the control value corresponding to the fully closed position. Thereafter, by changing the ventilation opening degree VB with the updated control value as a reference, it is possible to suppress an excessive divergence between the opening degree control value VBC and the actual opening degree value VBR. .

  However, when the temperature of the PCV valve 54 itself is excessively low, for example, the viscosity of the lubricating oil adhering to the valve 54 increases remarkably, or the moisture and lubricating oil adhering to the valve 54 are frozen. As a result, the learning control described above may not be performed properly. That is, the actual drive position has reached the fully closed position, which is the reference position, in a state where a command for driving the PCV valve 54 further toward the closed side than the fully closed position is transmitted to the actuator 55. In spite of the absence, the stepping motor may step out due to the resistance of the lubricating oil or the like. At this time, the electronic control unit 60 determines that the actual driving position of the PCV valve 54 has reached the fully closed position based on the step-out, and then the opening control value VBC corresponds to the fully closed position. It will be updated to the control value.

  As described above, due to the excessively large resistance to the driving of the PCV valve 54, there is a large gap between the command to the actuator 55 by the electronic control device 60 and the actual operation of the actuator 55 based on the command. In some cases, erroneous learning is performed such that the opening control value VBC is updated to a control value corresponding to the fully closed position even though the actual drive position is not in the fully closed position.

  Therefore, in the blow-by gas reduction device 50 of the present embodiment, the execution of learning control is prohibited when the PCV valve 54 is in a low temperature state in order to reduce the frequency with which the ventilation opening degree VB is erroneously learned as described above. I am doing so.

  With reference to FIG. 2, a processing procedure of “reference position learning processing” executed by the electronic control device 60 as processing for realizing the learning control and the determination of whether or not it has been described above will be described. This process is performed when the operation of the PCV valve 54 by the learning control has little influence on the engine operation (for example, when the engine is started), and is predetermined until the learning is completed after the process is started. This is repeated every calculation cycle.

  In the learning process, first, the outside air temperature TA detected by the outside air temperature sensor 65 in step S110 is read, and in the next step S120, it is determined whether or not the outside air temperature TA is equal to or higher than the reference temperature TAX. Here, the reference temperature TAX is a value for determining that the temperature of the PCV valve 54 itself is in an excessively low state, that is, due to an increase in the viscosity of the lubricating oil or freezing of moisture or lubricating oil. A value for determining that the resistance to driving is excessively increased (hereinafter referred to as “the low temperature state of the PCV valve 54”) is set in advance in the electronic control unit 60 after grasping through a test or the like.

  When it is determined in step S120 that the outside air temperature TA is equal to or higher than the reference temperature TAX, that is, it is estimated that the PCV valve 54 is in a higher temperature than the low temperature state (hereinafter, “the normal temperature state of the PCV valve 54”). Then, learning control is executed in the next step S140. On the other hand, when it is determined that the outside air temperature TA is lower than the reference temperature TAX, that is, when it is estimated that the PCV valve 54 is in a low temperature state, it is determined whether or not the counter value CTW is greater than or equal to the determination value CTX in the next step S130. To do.

  Here, the counter value CTW is a value updated in the “counter update process” in FIG. 3 executed in parallel with the “reference position learning process”, and the PCV valve 54 is received by heat received from the engine body 20 or PCV gas. The period in which the state where the low temperature state can be resolved is shown. The determination value CTX is set based on the outside air temperature TA detected by the outside air temperature sensor 65 as a value for determining whether or not the PCV valve 54 has shifted from the low temperature state to the room temperature state due to the continuation of such a state. The Specifically, a map that defines the relationship between the outside air temperature TA and the determination value CTX is preset in the electronic control device 60, and the determination value CTX corresponding to the outside air temperature TA at that time is read out from this map. Determination value CTX for step S130 is set.

  The period required for the low temperature state of the PCV valve 54 to be eliminated by heat received from the engine body 20 or the like is influenced by the outside air temperature TA and basically tends to become shorter as the outside air temperature TA becomes higher. Therefore, the relationship between the outside air temperature TA and the determination value CTX in the above map is set so that the determination value CTX decreases as the outside air temperature TA increases, reflecting this tendency.

  In step S130, when it is determined that the counter value CTW is equal to or greater than the determination value CTX, that is, when it is estimated that the low temperature state of the PCV valve 54 has been eliminated, learning control is executed in the next step S140. On the other hand, when it is determined that the counter value CTW is less than the determination value CTX, that is, the temperature of the engine body 20 or the like is not large enough to eliminate the low temperature state of the PCV valve 54, or such a large size. If it is estimated that the duration of the state is not sufficient, the driving of the PCV valve 54 is prohibited in the next step S150. The process of prohibiting the driving is canceled when it is determined in step S120 that the outside air temperature TA is equal to or higher than the reference temperature TAX, or when it is determined in step S130 that the counter value CTW is equal to or higher than the determination value CTX. .

  With reference to FIG. 3, the processing procedure of the “counter update process” executed by the electronic control unit 60 as part of the “reference position learning process” will be described. This update process is repeatedly performed at predetermined calculation cycles in parallel with the execution of the “reference position learning process”.

  In the update process, first, the cooling water temperature TW detected by the cooling water temperature sensor 64 in step S210 is read, and in the next step S220, it is determined whether or not the cooling water temperature TW is equal to or higher than the reference temperature TWX. Here, the reference temperature TWX is a value for determining whether or not the temperature of the engine main body 20 or the like can eliminate the low temperature state of the PCV valve 54, that is, the temperature at which the engine main body 20 decreases is a value that decreases the viscosity of the lubricant. As a value for determining whether or not the water or the freezing of the lubricating oil can be eliminated, it is set in advance in the electronic control unit 60 after being grasped through a test or the like.

  When it is determined in step S220 that the coolant temperature TW is equal to or higher than the reference temperature TWX, that is, it is estimated that the state of the PCV valve 54 is changing from the low temperature state to the normal temperature state due to heat received from the engine body 20 or the like. At this time, “1” is added to the counter value CTW in the next step S230, and this process is temporarily ended. On the other hand, when it is determined that the cooling water temperature TW is lower than the reference temperature TWX, that is, when it is estimated that the PCV valve 54 is stagnant in a low temperature state, the counter value CTW is initialized in the next step S240 and this processing is performed. Is temporarily terminated. Here, “0” is set as the initial value of the counter value CTW. When it is determined that the coolant temperature TW is lower than the reference temperature TWX after the counter value CTW has been increased, the counter value CTW is held instead of the counter value CTW, or “1”. It is also possible to perform a process of subtracting.

  When the PCV valve 54 is in a low temperature state, the engine body 20 or PCV gas gives heat to the valve 54 to change the state of the PCV valve 54 from the low temperature state to the normal temperature state. As a result, the low temperature state of the PCV valve 54 will eventually be resolved. In the “counter updating process”, in order to monitor the transition of the state of the PCV valve 54, whether or not the heat receiving mode of the PCV valve 54 prompts the transition from the low temperature state to the normal temperature state is determined in step S220. The period during which the state for prompting the transition is continued is recorded through the update of the counter value CTW in step S230.

According to the blow-by gas reduction device of the present embodiment, the following effects can be achieved.
(1) In the present embodiment, when the PCV valve 54 is in a low temperature state, that is, because the resistance to driving of the PCV valve 54 is excessively large, the valve 54 has not reached the reference position in the learning control. Nevertheless, execution of learning control is prohibited when there is a high possibility that it is determined that the drive position is at the reference position. Therefore, the frequency with which the learning of the opening degree of the PCV valve 54 is erroneously performed can be reduced.

  (2) In this embodiment, the reference position of the PCV valve 54 in the learning control is set to the fully closed position. As a result, even if a large amount of blow-by gas is present in the crank chamber 32 during the execution of the learning control, it is prevented from being supplied to the intake passage 49 at once through the operation of the PCV valve 54 for learning. can do.

  (3) In this embodiment, when it is estimated that the PCV valve 54 is in a low temperature state, the drive of the valve 54 is prohibited and the ventilation opening VB is maintained at the current size. Thereby, since the ventilation opening degree VB is not changed under a situation where there is a high possibility that the actuator 55 does not operate properly, it is possible to suppress the opening degree control value VBC from greatly deviating from the actual opening degree value VBR. it can.

(Second Embodiment)
A second embodiment in which the blow-by gas reduction device for an internal combustion engine of the present invention is embodied as a blow-by gas reduction device for a port injection internal combustion engine will be described.

  In this embodiment, instead of the drive control of the first embodiment in which the opening degree control value VBC of the PCV valve 54 is managed based on the command value for the actuator 55, the output of the opening degree sensor that detects the opening degree actual value VBR. The drive control for managing the opening control value VBC based on the above is adopted. Further, in accordance with the change in the structure of the drive control, the following structure of learning control is adopted in place of the learning control of the first embodiment in which the reference position of the PCV valve 54 is confirmed based on the stepping motor de-entering. . That is, the output of the opening sensor is driven in a state in which a command to drive the PCV valve 54 further toward the valve closing side than the fully closed position that is the reference position is continuously given to the actuator 55. It is confirmed that the PCV valve 54 has reached the reference position on the basis of a shift from one indicating a change in position to the valve closing side to one indicating a state where there is no change in drive position.

  Further, as the reference position of the PCV valve 54 is confirmed in this manner, the actuator 55 is not limited to a stepping motor, and an appropriate one can be adopted. Therefore, a DC motor is used as the actuator 55 here. ing. Except for these points, the same configuration as that of the first embodiment is adopted, and thus description of common parts is omitted.

Hereinafter, details of drive control and learning control of the PCV valve 54 will be described.
In the drive control, as described above, the opening control value VBC grasped by the electronic control unit 60 is managed based on the output of the opening sensor that monitors the opening actual value VBR that is the actual driving position of the PCV valve 54. Like to do. That is, the opening degree control value VBC is made to follow the change in the actual opening degree value VBR by setting the ventilation opening degree VB obtained based on the output of the opening degree sensor as the opening degree control value VBC at that time.

  As described above, in the drive control of the PCV valve 54, the correspondence between the opening control value VBC and the actual opening value VBR is attempted, but the opening control value VBC is set to a value different from the actual opening value VBR. The situation may arise. For example, when the opening sensor enters an output state that does not correspond to the actual drive position of the PCV valve 54 due to aging or the like, the actual opening position value VBR and the opening control value VBC are caused by this. Deviation occurs.

  When such a deviation occurs, a command for the actuator 55 is issued based on the opening control value VBC that is different from the opening actual value VBR in the drive control, whereby the opening control value VBC becomes the opening request value. Since the VBT is not maintained, an excessive divergence may occur between the required supply amount of blow-by gas and the actual supply amount.

  Therefore, in the blow-by gas reduction device 50 of the present embodiment, the PCV valve 54 is learned by learning the difference between the opening control value VBC and the actual opening value VBR through execution of learning control and reflecting this in subsequent drive control. Thus, an appropriate control mode is maintained.

  In this learning control, when the execution of the control is allowed, first, a command is given to the actuator 55 to change the drive position of the PCV valve 54 to a position closer to the valve closing side than the fully closed position which is the reference position.

  As a result, if there is no abnormality in the operation of the PCV valve 54 and the actuator 55, the time when the drive position of the PCV valve 54 reaches the reference position, that is, the valve body of the valve 54 is the wall surface of the first ventilation pipe 51. The actuator 55 further closes the PCV valve 54 on the basis of a command from the electronic control unit 60 even when reaching a driving position where the valve cannot be driven further to the valve closing side. Will drive towards the side. At this time, since the state where the actual drive position of the PCV valve 54 is maintained at the fully closed position is continued, the output of the opening sensor continuously outputs a constant value accordingly.

  At this time, the electronic control unit 60 confirms that the actual drive position of the PCV valve 54 has reached the reference position when the output of the opening sensor is constant, and the output of the opening sensor here is PCV. If it indicates the fully closed position of the valve 54, it is determined that the output of the sensor is appropriate. On the other hand, if the output of the opening sensor indicates a drive position different from the fully closed position of the PCV valve 54, it is determined that there is a deviation between the output of the sensor and the actual drive position. In this case, the difference between the output of the opening sensor at that time and the output corresponding to the fully closed position when there is no abnormality in the sensor is set as the learning value, and thereafter, this learning value is set as the opening of the moment. By updating the opening control value VBC while reflecting it in the output of the sensor, it is possible to suppress an excessive divergence between the opening control value VBC and the actual opening value VBR.

  However, when the temperature of the PCV valve 54 itself is excessively low, for example, the viscosity of the lubricating oil adhering to the valve 54 increases remarkably, or the moisture and lubricating oil adhering to the valve 54 are frozen. As a result, the above-described learning control may not be performed properly. That is, the actual drive position has reached the fully closed position, which is the reference position, in a state where a command for driving the PCV valve 54 further toward the closed side than the fully closed position is transmitted to the actuator 55. The output of the opening sensor may show a constant value due to the resistance of the lubricating oil or the like even though it is not. At this time, the electronic control unit 60 determines that the actual drive position of the PCV valve 54 has reached the fully closed position based on the tendency of the output, and then outputs the output of the opening sensor and the fully closed position at this time. The difference from the output corresponding to the position is set as a new learning value.

  As described above, due to the excessively large resistance to the driving of the PCV valve 54, there is a large gap between the command to the actuator 55 by the electronic control device 60 and the actual operation of the actuator 55 based on the command. In some cases, erroneous learning is performed such that the learning value is updated on the assumption that the actual driving position is not in the fully closed position.

  Therefore, in the blow-by gas reduction device 50 of the present embodiment, the execution of learning control is prohibited when the PCV valve 54 is in a low temperature state in order to reduce the frequency with which the ventilation opening degree VB is erroneously learned as described above. I am doing so. Specifically, in the “reference position learning process” of the first embodiment, the learning control in step S140 is replaced with the one described above, and then the “reference position learning process” is executed.

  According to the blow-by gas reduction apparatus of the present embodiment, in addition to the effects (1) and (2) that are achieved by the blow-by gas reduction apparatus of the first embodiment, the following effects can be achieved. .

  (4) In this embodiment, when it is estimated that the PCV valve 54 is in a low temperature state, the drive of the valve 54 is prohibited and the ventilation opening VB is maintained at the current size. Thereby, since the ventilation opening degree VB is not changed under a situation where there is a high possibility that the actuator 55 does not operate properly, an excessive increase in the current supplied to the actuator 55 can be suppressed.

(Other embodiments)
In addition, the embodiment of the present invention is not limited to the contents exemplified in the above embodiment, and can be modified as shown below, for example.

  In each of the above embodiments, it is determined that the PCV valve 54 is in the normal temperature state based on the fact that the outside air temperature TA is equal to or higher than the reference temperature TAX, but the parameter for determining the same state is limited to this. It is not a thing. For example, it can be determined that the PCV valve 54 is in a normal temperature state based on the cooling water temperature TW being equal to or higher than a determination value corresponding to the reference temperature TAX. Alternatively, the temperature of the PCV valve 54 can be monitored by a sensor, and it can be determined that the PCV valve 54 is in the normal temperature state based on the fact that it is equal to or higher than the determination value corresponding to the reference temperature TAX.

  In each of the above embodiments, it is determined that the PCV valve 54 is changing from the low temperature state toward the normal temperature state based on the fact that the cooling water temperature TW is equal to or higher than the reference temperature TWX. However, the parameters to do are not limited to this. For example, the temperature of the PCV valve 54 is monitored by a sensor, and it is determined that the PCV valve 54 is changing from the low temperature state to the normal temperature state based on the fact that the temperature is equal to or higher than the determination value corresponding to the reference temperature TWX. You can also.

  In each of the above embodiments, the reference position of the PCV valve 54 is set to the fully closed position in the learning control, but the reference position can be set to the fully open position instead. In addition to the fully closed position and the fully open position, in the blow-by gas reduction device in which the drive position for physically restricting the drive of the PCV valve 54 in the valve closing direction or the valve opening direction exists, the same position is used as the reference position. Can also be set.

  In the first embodiment, the drive control has a structure in which the opening control value VBC is managed based on the drive amount of the actuator 55, and in the second embodiment, the opening control value VBC is used as the output of the opening sensor. Although the drive control of the structure managed based on was employ | adopted, the management aspect of the opening degree control value VBC is not restricted to the content illustrated in these embodiment. In short, the electronic control unit 60 updates the opening degree control value VBC as an equivalent value of the opening degree actual value VBR based on information of an external device, and regards this opening degree control value VBC as the opening degree actual value VBR. If the PCV valve 54 is to be controlled, the above problem due to the low temperature state of the valve 54 may occur. Therefore, the present invention can be applied in a manner according to each of the above embodiments.

  In the first embodiment, learning control of a structure for confirming that the drive position of the PCV valve 54 is at the reference position when the actuator 55 has stepped out, and in the second embodiment, the opening degree The learning control of the structure for confirming that the drive position of the PCV valve 54 is at the reference position when the output of the sensor shows a constant value is adopted. However, the reference position confirmation method is limited to the contents exemplified in these embodiments. It is not something that can be done. In short, if the method for confirming that the PCV valve 54 is in the reference position is different from the opening control value VBC grasped by the electronic control unit 60, the specific contents of the reference position confirmation method are appropriately changed. can do.

  In each of the above embodiments, the first ventilation pipe 51 that connects the crank chamber 32 and the surge tank 47 is employed, but the configuration of the first ventilation pipe 51 is not limited to this. For example, what connects the valve operating chamber 33 and the surge tank 47 as the 1st ventilation piping 51 can also be provided. In short, if the blow-by gas of the engine body 20 is supplied to the downstream side of the throttle valve 42, the configuration of the first ventilation pipe 51 can be changed as appropriate.

  In each of the above embodiments, the second ventilation pipe 52 that connects the valve operating chamber 33 and the intake hose 45 is used, but the configuration of the second ventilation pipe 52 is not limited to this. For example, what connects the intake hose 45 and the crank chamber 32 as the 2nd ventilation piping 52 can also be provided. In short, if the intake air is supplied to the engine body 20 from the upstream side of the throttle valve 42, the configuration of the second ventilation pipe 52 can be changed as appropriate.

  In each of the above embodiments, the port injection type engine is assumed as the engine 10, but the present invention can be similarly applied to a cylinder injection type engine. Further, the configuration as the blow-by gas reduction device 50 is not limited to the configuration exemplified in each embodiment. In short, with regard to the blow-by gas reduction device having an electric PCV valve, the present invention can be applied to any engine as long as it is an internal combustion engine equipped with the same. It is possible to achieve similar effects.

The block diagram which shows typically the structure of the engine about 1st Embodiment which actualized the blow-by gas reduction apparatus of the internal combustion engine of this invention. The flowchart which shows the process sequence about the "reference | standard position learning process" performed by the electronic control apparatus of the embodiment. The flowchart which shows the process sequence about the "counter update process" performed by the electronic controller of the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Engine, 20 ... Engine main body, 21 ... Cylinder block, 22 ... Crankcase, 23 ... Oil pan, 24 ... Cylinder head, 25 ... Head cover, 26 ... Crankshaft, 27 ... Injector, 31 ... Combustion chamber, 32 ... Crank , 33 ... Valve operating chamber, 34 ... Communication chamber, 40 ... Intake device, 41 ... Throttle body, 42 ... Throttle valve, 43 ... Air cleaner, 44 ... Air intake, 45 ... Intake hose, 46 ... Intake manifold, 47 ... Surge Tank, 48 ... sub pipe, 49 ... intake passage, 50 ... blow-by gas reduction device, 51 ... first ventilation pipe, 52 ... second ventilation pipe, 53 ... oil separator, 54 ... PCV valve, 55 ... actuator, 60 ... electronic control Device, 61 ... crank position sensor, 62 ... air flow meter, 3 ... throttle position sensor, 64 ... cooling water temperature sensor, 65 ... ambient temperature sensor.

Claims (1)

In the blow-by gas reduction device for an internal combustion engine that supplies blow-by gas from the engine body to the intake passage to ventilate the engine body, and adjusts the amount of blow-by gas supplied to the intake passage by an electric ventilation control valve,
A first process for driving the ventilation control valve toward a reference position, and learning the opening of the control valve when it is determined that the drive position of the ventilation control valve is at the reference position; A blow-by gas reduction device for an internal combustion engine that performs a second process for determining whether or not the engine is in a low temperature state and prohibiting the execution of the first process when it is determined that the engine is in a low temperature state.

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