JP4998319B2 - Abnormality diagnosis device for blow-by gas reduction device - Google Patents

Description

  The present invention relates to an abnormality diagnosis device for a blow-by gas reduction device that performs abnormality diagnosis for a blow-by gas reduction device that reduces blow-by gas in an internal combustion engine.

  A blow-by gas reduction device for an internal combustion engine includes a PCV passage that introduces blow-by gas in a crankcase into an intake passage, and a PCV valve that adjusts the flow rate of the blow-by gas in the passage. As an example, a blow-by gas reduction device described in Patent Document 1 is known.

In the above blow-by gas reduction device, it is difficult to properly ventilate the crankcase due to the occurrence of sludge accumulation in the PCV passage or the PCV valve sticking. In order to do so, it is first required to diagnose whether or not the above-described abnormality has occurred.
JP 2006-250080 A

  Here, as an abnormality diagnosis of the blow-by gas reduction device, for example, a sensor for detecting the opening of the PCV valve may be provided, and it may be determined whether or not an abnormality has occurred in the PCV valve based on the output value. However, in this case, there is a problem that the sensor is necessary and an abnormality of the PCV passage itself cannot be detected.

  The present invention has been made in view of such circumstances, and its purpose is to accurately determine that an abnormality has occurred in the blow-by gas reduction device without using a sensor that detects the opening of the PCV valve. An object of the present invention is to provide an abnormality diagnosis device for a blow-by gas reduction device.

In the following, means for achieving the above object and its effects are described.
(1) The invention described in claim 1 relates to a blow-by gas reduction device comprising a PCV passage for supplying blow-by gas to an intake passage of an internal combustion engine, and a PCV valve for adjusting the flow rate of blow-by gas in the passage. in the abnormality diagnosis device of the blow-by gas recirculation system for performing abnormality diagnosis for determining whether an abnormality affecting aspects the flow of blow-by gas is occurring in at least one of the PCV passage and the PCV valve, the blow-by gas returning device Drive control for changing the control amount of the PCV valve in a direction in which the opening of the valve increases when it is determined that the abnormality of the mode has not occurred and the engine operation state is in a predetermined specific operation state. preset and executes, as the peak value of the expected engine speed to reach immediately upon execution of the drive control The reference peak value to be compared with the actual peak value of the engine rotational speed associated with the drive control, and when the actual peak value is smaller than the reference peak value, the blow-by gas reduction device has an abnormality in the above-described aspect. The gist of the invention is to provide a diagnostic means for performing the abnormality diagnosis to determine that it has occurred .

Forcibly changing the control amount in the direction of opening of the valve is increased of the PCV valve when the abnormality in the blow-by gas returning device has not occurred Then, the change in the opening degree of the PCV valve according to change of the controlled variable intake order to increase the supply amount is reflected in the supply amount of the blow-by gas to the passage, the engine speed will be increased accordingly. Hand, by predetermined as specified operating state engine operating state when the abnormality diagnosis, running driving control under the abnormality is not occurring conditions blowby gas returning apparatus, reach immediately Then, it is possible to grasp in advance the peak value of the predicted engine speed . When the abnormality occurs in the blow-by gas reduction device, the actual peak value of the engine rotation speed accompanying the drive control becomes smaller than a preset reference peak value . Abnormality can be determined. That is, it is possible to accurately determine that an abnormality has occurred in the blow-by gas reduction device without using a sensor that detects the opening of the PCV valve.

( 2 ) The invention described in claim 2 relates to a blow-by gas reduction device comprising a PCV passage for supplying blow-by gas to an intake passage of an internal combustion engine and a PCV valve for adjusting the flow rate of blow-by gas in the passage. An abnormality diagnosis device for a blow-by gas reduction device that performs abnormality diagnosis for determining whether or not an abnormality affecting the flow of blow-by gas has occurred in at least one of the PCV passage and the PCV valve. Drive control for changing the control amount of the PCV valve in a direction in which the opening of the valve decreases when it is determined that there is no abnormality in the mode and the engine operating state is in a predetermined specific operating state. And set in advance as the peak value of the engine speed that is predicted to be reached immediately after the execution of the drive control. The reference peak value is compared with the actual peak value of the engine rotational speed associated with the drive control, and if the actual peak value is larger than the reference peak value, the blow-by gas reduction device has an abnormality in the above aspect. The gist of the present invention is to provide a diagnostic means for performing the abnormality diagnosis for determining that the occurrence of the abnormality occurs .

If the control amount of the PCV valve is forcibly changed in the direction in which the opening degree of the valve decreases when the above-described abnormality does not occur in the blow-by gas reduction device, the change in the opening degree of the PCV valve due to the change in the control amount since the supply amount is reflected in the supply amount of the blow-by gas to the passage is reduced, the engine rotational speed will be lowered accordingly. On the other hand, if the engine operation state at the time of abnormality diagnosis is determined in advance as a specific operation state, when the drive control is executed under the condition that the abnormality does not occur in the blow-by gas reduction device, It is possible to grasp in advance the peak value of the predicted engine speed. When the abnormality occurs in the blow-by gas reduction device, the actual peak value of the engine rotation speed accompanying the drive control becomes larger than a preset reference peak value. Abnormality can be determined. That is, it is possible to accurately determine that an abnormality has occurred in the blow-by gas reduction device without using a sensor that detects the opening of the PCV valve.

( 3 ) The invention according to claim 3 is the abnormality diagnosis device for the blow-by gas reduction device according to claim 1 or 2 , wherein the diagnosis means is immediately before starting the engine in which the engine operating state is set as the specific operating state. The drive control is executed when it is determined that the engine is in the state of the engine, and the peak value of the engine speed immediately after the completion of the engine start set in advance as the reference peak value is detected immediately after the completion of the engine start. The gist is that the abnormality diagnosis is performed based on a comparison with the actual peak value of the engine speed.

  When performing abnormality diagnosis, the control amount of the PCV valve is forcibly changed, and thereby the engine rotational speed is changed. Therefore, the problem is that the engine vibration increases due to the change of the engine rotational speed. There is a case.

  In this regard, according to the above-described invention, the drive control is executed when it is determined that the engine operation state is in a state immediately before the engine start that is set as the specific operation state. When the engine is started, the engine rotational speed changes greatly in the first place, which causes engine vibration to increase.Therefore, the effect of the drive control on engine vibration increases compared to other engine operating conditions. And become small. Accordingly, it is possible to suppress the problem that the engine vibration increases as the engine speed changes.

( 4 ) The invention according to claim 4 is the abnormality diagnosis device for the blow-by gas reduction device according to claim 3 , wherein the diagnosis means determines that it is in a state immediately before starting the engine based on the operation position of the ignition switch. The gist of this is to execute the drive control.

( 5 ) The invention according to claim 5 is the abnormality diagnosis device for the blow-by gas reduction device according to any one of claims 1 to 4 , wherein the diagnosis means controls the amount of control of the PCV valve by the drive control. The gist is to variably set the reference peak value based on the amount of change.

  When the drive control is executed when the abnormality does not occur in the blow-by gas reduction device, the actual peak value of the engine rotational speed accompanying this or the actual peak value of the engine rotational speed detected immediately after the engine is started is PCV. It changes in accordance with the amount of change in the control amount of the valve, that is, the amount of change in the amount of blow-by gas supplied to the intake passage. For this reason, if the reference peak value is a constant value regardless of the amount by which the control amount of the PCV valve is changed, an erroneous determination may be made depending on the amount by which the control amount of the PCV valve is changed.

  In this regard, in the above invention, the reference peak value is variably set based on the amount by which the control amount of the PCV valve is changed by the drive control. Therefore, the amount by which the control amount of the PCV valve is changed, that is, the intake passage. The reference peak value can be set in accordance with the amount of change in the amount of blow-by gas supplied. Therefore, it is possible to accurately determine that an abnormality has occurred in the blow-by gas reduction device regardless of the amount by which the control amount of the PCV valve is changed.

( 6 ) The invention according to claim 6 is the abnormality diagnosis device for the blow-by gas reduction device according to any one of claims 1 to 5 , wherein the diagnosis means is an internal combustion engine immediately before executing the drive control. The gist is to variably set the reference peak value based on the state quantity.

  If the drive control is executed when the abnormality does not occur in the blow-by gas reduction device, the actual peak value of the engine rotation speed accompanying this or the actual peak value of the engine rotation speed detected immediately after the engine start is the same. It changes in accordance with the state quantity of the internal combustion engine such as the engine coolant temperature and intake air temperature immediately before the drive control is executed. For this reason, if the reference peak value is set to a constant value regardless of the state quantity of the internal combustion engine, an erroneous determination may be made depending on the state quantity of the internal combustion engine.

In this regard, according to the above-described invention, the reference peak value is variably set based on the state quantity of the internal combustion engine immediately before execution of the drive control, so that it conforms to the state quantity of the internal combustion engine at that time. A reference peak value can be set. Therefore, it is possible to accurately determine that an abnormality has occurred in the blow-by gas reduction device regardless of the state quantity of the internal combustion engine.
(7) The invention according to claim 7 is the abnormality diagnosis device for the blow-by gas reduction device according to any one of claims 1 to 6, wherein the abnormality of the aspect occurs in the blow-by gas reduction device by the diagnosis means. The gist is to increase the energization amount to the PCV valve as compared with the energization amount at that time on the basis of the determination that it is determined.
As an abnormality of the PCV valve, when the valve is fixed due to the solidification of moisture present in the valve driving unit, the solidified water that causes the valve fixation is melted by heating the valve. In view of this, in the above invention, the diagnosis means determines that the abnormality of the above aspect has occurred in the blow-by gas reduction device, that is, the PCV valve is fixed due to the solidification of the water present in the valve drive unit. When there is a possibility, the energization amount to the PCV valve is made larger than the energization amount at that time. As a result, the amount of heat generated by the PCV valve itself can be increased and the valve can be heated, whereby the solidified moisture can be melted. In addition, since the valve is heated by changing the energization amount to the PCV valve, it is not necessary to newly add a heating means for heating the valve. Therefore, the PCV valve can be fixed quickly with a simple configuration.
(8) The invention according to claim 8 relates to a blow-by gas reduction device comprising a PCV passage for supplying blow-by gas to an intake passage of an internal combustion engine and a PCV valve for adjusting the flow rate of blow-by gas in the passage. In an abnormality diagnosis device for a blow-by gas reduction device that performs abnormality diagnosis for determining whether or not an abnormality that affects the flow of blow-by gas has occurred in at least one of the PCV passage and the PCV valve, the engine operating state is predetermined. Diagnosis means for executing drive control for forcibly changing the control amount of the PCV valve when it is determined that the specified operation state is established, and performing the abnormality diagnosis based on a change mode of the engine rotational speed associated therewith And the diagnosis means determines that the abnormality of the aspect has occurred in the blow-by gas reduction device. Te, the power supply amount to the PCV valve is set to its gist be larger than the current amount at that time.
When the control amount of the PCV valve is forcibly changed when the above-described abnormality does not occur in the blow-by gas reduction device, the change in the opening of the PCV valve due to the change of the control amount causes the blow-by gas to enter the intake passage. Since it is reflected in the supply amount, the engine rotation speed changes accordingly. That is, when the supply amount of blow-by gas increases due to the forced change of the control amount, the engine speed increases accordingly, and conversely, the supply amount of blow-by gas decreases due to the forced change of the control amount. When this happens, the engine speed decreases accordingly. On the other hand, by predetermining the engine operation state when performing abnormality diagnosis as a specific operation state, the control amount is forcibly changed under the condition where the abnormality does not occur in the blow-by gas reduction device. It becomes possible to grasp in advance the change mode of the engine rotation speed. When the abnormality occurs in the blow-by gas reduction device, the grasped change mode and the actual engine rotation speed change mode are different from each other. Accordingly, the abnormality of the blow-by gas reduction device is determined. Will be able to. That is, it is possible to accurately determine that an abnormality has occurred in the blow-by gas reduction device without using a sensor that detects the opening of the PCV valve.
In addition, when the valve is fixed due to the solidification of the water present in the valve drive unit as an abnormality of the PCV valve, the solidified water that causes the valve fixation is melted by heating the valve. Become. In view of this, in the above invention, the diagnosis means determines that the abnormality of the above aspect has occurred in the blow-by gas reduction device, that is, the PCV valve is fixed due to the solidification of the water present in the valve drive unit. When there is a possibility, the energization amount to the PCV valve is made larger than the energization amount at that time. As a result, the amount of heat generated by the PCV valve itself can be increased and the valve can be heated, whereby the solidified moisture can be melted. In addition, since the valve is heated by changing the energization amount to the PCV valve, it is not necessary to newly add a heating means for heating the valve. Therefore, the PCV valve can be fixed quickly with a simple configuration.
(9) The invention according to claim 9 is the abnormality diagnosis device for the blow-by gas reduction device according to claim 8, wherein the diagnosis means does not cause any abnormality in the aspect in the blow-by gas reduction device and operates the engine. When the drive control is executed under the condition that the state is the specific operation state, a reference change mode that is a change mode of the engine rotation speed that is predicted to occur with the drive control, and the drive control. The gist is to compare the actual change mode of the engine rotation speed and to determine that the abnormality of the above-described mode has occurred in the blow-by gas reduction device when there is a difference between them.

( 10 ) The invention according to claim 10 is the abnormality diagnosis device for the blowby gas reduction device according to claim 9 , wherein the diagnosis means is based on a comparison between the change mode of the reference and the actual change mode. As an abnormality diagnosis, the control amount of the PCV valve is set as the drive control under the condition that the abnormality of the aspect does not occur in the blow-by gas reduction device and the engine operation state is in the specific operation state. When the control to change in the direction of increasing is executed, the transition of the reference that is preset as the transition of the engine rotational speed that is predicted to occur immediately after that, and the actual transition of the engine rotational speed accompanying the drive control, And determining that the abnormality of the aspect has occurred in the blow-by gas reduction device when the actual transition belongs to the region on the low rotation side with respect to the transition of the reference. It is the gist.

( 11 ) The invention according to claim 11 is the abnormality diagnosis device for the blow-by gas reduction device according to claim 9 , wherein the diagnosis means is based on a comparison between the change mode of the reference and the actual change mode. As an abnormality diagnosis, the control amount of the PCV valve is set as the drive control under the condition that the abnormality of the aspect does not occur in the blow-by gas reduction device and the engine operation state is in the specific operation state. When a control is performed to change in a direction in which the engine speed decreases, a transition of a reference preset as a transition of the engine rotational speed that is predicted to occur immediately after that, and an actual transition of the engine rotational speed accompanying the drive control, And determining that the abnormality of the aspect has occurred in the blow-by gas reduction device when the actual transition belongs to the region on the higher rotation side than the transition of the reference. It is the gist.

( 12 ) The invention according to claim 12 is the abnormality diagnosis device for the blow-by gas reduction device according to claim 9 , wherein the diagnosis means is based on a comparison between the change mode of the reference and the actual change mode. As an abnormality diagnosis, a control for increasing or decreasing the control amount of the PCV valve as the drive control under the condition that the abnormality of the aspect does not occur in the blow-by gas reduction device and the engine operation state is in the specific operation state Is compared with the amount of change in the reference that is preset as the amount of change in the engine rotation speed that is predicted to occur along with this, and the actual amount of change in the engine rotation speed that accompanies the drive control, The gist is to determine that the abnormality of the aspect has occurred in the blow-by gas reduction device when the actual change amount is smaller than the reference change amount.

  When the above abnormality does not occur in the blow-by gas reduction device, for example, if the control amount of the PCV valve is forcibly changed in the direction in which the opening of the valve increases, this increases the supply amount of blow-by gas and causes engine rotation. The speed increases with this. When this drive control is executed under the condition that the engine operation state is in the specific operation state, it is possible to grasp in advance the amount of change in the engine rotation speed that is predicted to occur along with this drive control. When the abnormality occurs in the blow-by gas reduction device, the actual change amount of the engine rotation speed accompanying the drive control is smaller than the reference change amount, and thus, the abnormality of the blow-by gas reduction device is determined. Will be able to. That is, it is possible to accurately determine that an abnormality has occurred in the blow-by gas reduction device without using a sensor that detects the opening of the PCV valve.

( 13 ) In the invention according to claim 13 , in the abnormality diagnosis device for the blow-by gas reduction device according to claim 12 , the diagnosis means is in an idle operation state in which the engine operation state is set as the specific operation state. The engine control speed immediately before executing the drive control in the idle operation state and the engine rotation speed immediately after executing the drive control in the idle operation state. The difference is calculated as an actual change amount of the engine rotation speed, and the abnormality diagnosis is performed based on a comparison between the calculated change amount and the reference change amount.

  According to the above invention, the drive control is executed when it is determined that the engine operation state is in the idle operation state set as the specific operation state, that is, when the engine rotation speed does not change significantly. . Thereby, it is possible to suppress the actual change amount of the engine rotation speed from being smaller than the reference change amount due to causes other than the drive control. Accordingly, it is possible to suppress erroneous determination that an abnormality has occurred in the blow-by gas reduction device.

( 14 ) The invention described in claim 14 is the abnormality diagnosis device for the blow-by gas reduction device according to claim 12 or 13 , wherein the diagnosis means changes the control amount of the PCV valve by the drive control. The gist is to variably set the reference change amount based on the above.

  When the drive control is executed when the abnormality is not occurring in the blow-by gas reduction device, the actual amount of change in the engine speed accompanying this is the amount to change the control amount of the PCV valve, that is, the blow-by gas to the intake passage It changes according to the amount of change in the supply amount. For this reason, if the reference change amount is set to a constant value regardless of the amount by which the control amount of the PCV valve is changed, an erroneous determination may be made depending on the amount of change of the control amount of the PCV valve.

  In this regard, in the above invention, the reference change amount is variably set based on the amount by which the control amount of the PCV valve is changed by the drive control. Therefore, the amount by which the control amount of the PCV valve is changed, that is, the intake passage. The amount of change in the standard can be set in accordance with the amount of change in the supply amount of blowby gas. Therefore, it is possible to accurately determine that an abnormality has occurred in the blow-by gas reduction device regardless of the amount by which the control amount of the PCV valve is changed.

( 15 ) The invention according to claim 15 is the abnormality diagnosis device for the blow-by gas reduction device according to any one of claims 12 to 14 , wherein the diagnosis means is an internal combustion engine immediately before executing the drive control. The gist is to variably set the reference change amount based on the state quantity.

  If the drive control is executed when the abnormality does not occur in the blow-by gas reduction device, the actual amount of change in the engine rotational speed accompanying this is the engine cooling water temperature or intake air temperature immediately before the drive control is executed. It changes according to the state quantity of the internal combustion engine. For this reason, if the reference change amount is set to a constant value regardless of the state quantity of the internal combustion engine, an erroneous determination may be made depending on the state quantity of the internal combustion engine.

  In this regard, according to the above-described invention, since the reference change amount is variably set based on the state quantity of the internal combustion engine immediately before executing the drive control, in accordance with the state quantity of the internal combustion engine at that time. A reference change amount can be set. Therefore, it is possible to accurately determine that an abnormality has occurred in the blow-by gas reduction device regardless of the state quantity of the internal combustion engine.

( 16 ) The invention described in claim 16 is the abnormality diagnosis device for the blow-by gas reduction device according to any one of claims 1 to 15 , wherein the specific operating state is abnormal in the blow-by gas reduction device. The gist of the present invention is that it is an operating state in which it is possible to grasp in advance the mode of change of the engine speed under conditions that have not occurred.

<First Embodiment>
With reference to FIGS. 1-4, 1st Embodiment of the abnormality diagnosis apparatus of the blowby gas reduction apparatus concerning this invention is described.

FIG. 1 shows a schematic configuration of a vehicular in-cylinder gasoline engine (hereinafter, “engine 10”) having a blow-by gas reduction device.
The engine 10 is provided with an injector 14 for directly injecting fuel into the combustion chamber 12 and an ignition plug 16 for igniting a mixture of fuel and air injected by the injector 14.

  The exhaust passage 18 connected to the combustion chamber 12 is provided with a catalyst device 20 that purifies HC, CO, and NOx contained in the exhaust. On the other hand, the intake passage 22 connected to the combustion chamber 12 is provided with a throttle valve 26 that is opened and closed by a throttle motor 24. A surge tank 28 is provided in the intake passage 22 at the intake downstream side of the throttle valve 26. The amount of intake air supplied to the combustion chamber 12 through the intake passage 22 is adjusted based on the opening of the throttle valve 26.

  Further, the engine 10 is provided with a blow-by gas reduction device 30 for reducing the blow-by gas in the crankcase 40 to the intake passage 22. The blow-by gas reduction device 30 includes an introduction passage 32 that introduces air into the crankcase 40 from the intake upstream side of the throttle valve 26 in the intake passage 22, and an intake downstream side of the throttle valve 26 in the intake passage 22 from inside the crankcase 40. A PCV passage 34 for introducing blowby gas into the PCV and an electronically controlled PCV valve 36 for adjusting the flow rate of the blowby gas in the PCV passage 34. The PCV valve 36 includes a step motor as an actuator for driving the valve. When the opening of the valve is changed by the actuator, the amount of blow-by gas supplied from the crankcase 40 to the intake passage 22 is changed accordingly. Become so.

  Further, the engine 10 is provided with various sensors for detecting the operating state. That is, a rotation speed sensor 51 that detects the rotation speed (hereinafter referred to as “engine rotation speed NE”) is provided in the vicinity of the crankshaft 42. Further, an accelerator sensor 52 that detects the operation amount (hereinafter referred to as “accelerator operation amount ACCP”) is provided in the vicinity of the accelerator pedal 44. A throttle sensor 53 that detects the opening (hereinafter referred to as “throttle opening TA”) is provided in the vicinity of the throttle valve 26. An air flow meter 54 for detecting the mass flow rate of the intake air passing through the intake passage 22 (hereinafter referred to as “intake amount GA”) is provided on the intake upstream side of the throttle valve 26. Further, the cylinder block 11 is provided with a water temperature sensor 55 for detecting the temperature of the engine cooling water (hereinafter referred to as “engine cooling water temperature THW”). Further, an air-fuel ratio sensor 56 for detecting the oxygen concentration of the exhaust is provided on the exhaust upstream side of the catalyst device 20. The detection signals of these sensors 51 to 56 are input to an electronic control device 60 that executes various controls of the engine 10.

  The electronic control device 60 includes a program for executing various controls, a calculation map, and a memory that stores various data calculated when the control is executed. The electronic control device 60 includes the sensors 51 to 56 described above. For example, each of the following controls is executed based on the operating state of the engine 10 that is grasped from the output values of the various sensors. That is, throttle control that adjusts the intake air amount according to the driver's request, fuel injection control that adjusts the fuel injection amount according to the intake amount, etc., idle speed that maintains the engine speed constant during idling of the engine 10 Control control (hereinafter “ISC control”) is executed. Also, the air-fuel ratio control for maintaining the air-fuel ratio of the air-fuel mixture at the target air-fuel ratio, the opening degree control of the PCV valve 36 for adjusting the amount of blow-by gas supplied from the crankcase 40 to the intake passage 22, and the blow-by gas reduction device Abnormality diagnosis control for determining the presence / absence of 30 abnormalities is executed.

  Switching between execution and stop of energization of the electronic control unit 60 and switching between operation and stop of the engine 10 are performed based on a change in the operation position of an ignition switch (hereinafter referred to as “I / G switch 61”).

  As described above, in the blow-by gas reduction device 30, it is difficult to properly ventilate the crankcase 40 due to abnormalities such as sludge accumulation in the PCV passage 34 or adhesion of the PCV valve 36. Become. For this reason, in order to eliminate such a state, first, an abnormality as described above, that is, an abnormality that affects the flow of blow-by gas (hereinafter referred to as “abnormality”) occurs in at least one of the PCV passage 34 and the PCV valve 36. It is required to diagnose whether or not.

  Therefore, as an abnormality diagnosis of the blow-by gas reduction device 30, for example, a sensor for detecting the opening degree of the PCV valve 36 may be provided, and it may be determined whether or not an abnormality has occurred in the PCV valve 36 based on the output value. However, in this case, there is a problem that the sensor is necessary and an abnormality of the PCV passage 34 itself cannot be detected.

  For this reason, in this embodiment, the abnormality diagnosis process described below is performed to accurately detect that an abnormality has occurred in the blow-by gas reduction device 30 without using a sensor that detects the opening degree of the PCV valve 36. To be able to.

That is, in the engine 10, the in-cylinder air amount GSUM, which is the amount of air sucked into the cylinder, is calculated by using the amount of air GT passing through the throttle valve 26 and the PCV valve 36 as shown in the following arithmetic expression (1). It is a combination of the passing air amount (blow-by gas amount) GP.

GSUM = GT + GP (1)

If the control amount EPA of the PCV valve 36 is forcibly changed in the direction in which the opening degree PA of the valve 36 increases when there is no abnormality in the blow-by gas reduction device 30, this increases the blow-by gas amount GP. As a result, the in-cylinder air amount GSUM increases, and the engine speed NE increases accordingly. On the contrary, when the control amount EPA of the PCV valve 36 is forcibly changed in a direction in which the opening degree PA of the valve 36 decreases when there is no abnormality in the blow-by gas reduction device 30, this reduces the blow-by gas amount GP. As a result, the in-cylinder air amount GSUM decreases, and the engine speed NE decreases accordingly. When this drive control is executed under the condition that the engine operating state is in the specific operating state, it is possible to grasp in advance the change mode of the engine rotational speed NE that is predicted to reach immediately after that.

On the other hand, when the abnormality occurs in the blow-by gas reduction device 30, the grasped change mode of the engine rotational speed NE and the actual change mode of the engine rotational speed NE are different.
As described above, when the drive control is executed under the condition that the blow-by gas reduction device 30 is not abnormal and the engine operation state is in the specific operation state, the engine that is predicted to be generated along with this is performed. The difference between the reference change mode, which is the change mode of the rotational speed NE, and the actual change mode of the engine rotational speed NE accompanying the drive control reflects the presence / absence of abnormality of the blow-by gas reduction device 30.

  In the abnormality diagnosis process of the present embodiment, the control amount EPA of the PCV valve 36 is calculated based on the degree of opening of the valve 36 under the condition that no abnormality has occurred in the blow-by gas reduction device 30 and the engine operation state is in the specific operation state. Drive control for changing in a direction in which PA increases is executed. Then, a reference peak value that is preset as a peak value of the engine speed NE that is predicted to be reached immediately after the execution of the drive control is compared with an actual peak value of the engine speed NE that accompanies the drive control. When the actual peak value is smaller than the reference peak value, it is determined that an abnormality has occurred in the blow-by gas reduction device 30.

  Specifically, from the control amount EPA1 that maintains the opening degree of the valve 36 at the first opening degree PA1 if the blow-by gas reduction device 30 is normal while the engine operation state is in a state immediately before the engine is started. The control for changing the opening degree of the valve 36 to the control amount EPA2 that maintains the second opening degree PA2 (PA2> PA1) larger than the first opening degree PA1 is executed. Then, the peak value NESX of the engine speed immediately after completion of the engine start set in advance as a reference peak value is compared with the actual peak value NESP of the engine speed detected immediately after the completion of engine start, and the actual peak value is compared. When the value NESP is smaller than the reference peak value NESX, it is determined that an abnormality has occurred in the blow-by gas reduction device 30.

  With reference to FIG. 2, a specific processing procedure of the abnormality diagnosis will be described. FIG. 3 is a flowchart showing the procedure of the abnormality diagnosis process. A series of processing shown in this flowchart is executed when energization of the electronic control device 60 is started.

  In this series of processing, first, the engine coolant temperature THW at that time is read (step S101). Then, a reference peak value NESX of the engine rotation speed immediately after the start of the engine 10 is set based on the engine coolant temperature THW (step S102). Incidentally, the lower the engine coolant temperature THW, the higher the viscosity of the engine lubricating oil. Therefore, the lower the engine coolant temperature THW, the smaller the actual peak value NESP of the engine speed immediately after the start of the engine 10 is completed. For this reason, if the reference peak value is a constant value regardless of the engine coolant temperature THW, an erroneous determination may be made depending on the engine coolant temperature THW. Therefore, in the abnormality diagnosis process, an appropriate reference peak value NESX is set in consideration of the relationship between the engine coolant temperature THW immediately before the drive control is executed and the actual peak value of the engine rotational speed NE. Yes. Specifically, when the engine coolant temperature THW is low, the reference peak value NESX is set as a smaller value than when the engine temperature THW is high.

  When the reference peak value NESX is set in this way, the control amount EPA of the PCV valve 36 is then forcibly increased from the control amount at that time (hereinafter referred to as “pre-drive control amount EPA1”) by a predetermined amount ΔEPAX. That is, the control amount EPA of the PCV valve 36 is increased from the pre-drive control amount EPA1 to a control amount obtained by adding a predetermined amount ΔEPAX (hereinafter, “post-drive control amount EPA2”) (step S103). Here, a control amount for maintaining the PCV valve 36 in a fully closed state is set as the pre-drive control amount EPA1, and a control amount for maintaining the PCV valve 36 in the fully open state is set as the post-drive control amount EPA2. The forced increase of the control amount EPA here means that the control amount EPA is changed only for the diagnosis of the abnormality, and in normal control for adjusting the blow-by gas amount. This means that the control amount EPA is changed regardless of the setting condition of the control amount EPA.

  When the control amount of the PCV valve 36 is forcibly changed in this way, it is next determined whether or not the engine 10 has been started (step S104). Here, it is determined that the start of the engine 10 has been completed when the engine rotational speed NE has reached a predetermined rotational speed NES1. Here, when it is determined that the engine 10 has not been started (step S104: NO), the determination process is repeatedly executed after a certain period until a determination result indicating that the engine 10 has been started is obtained. Is done. On the other hand, when it is determined by the determination processing in step S104 that the engine 10 has been started (step S104: YES), the engine speed NE at that time is read (step S105).

  Next, it is determined whether or not a predetermined time T1 has elapsed since the start of the engine 10 was completed (step S106). Incidentally, after it is determined that the start of the engine 10 is completed, the engine rotation speed becomes the peak value NESP. Therefore, in the abnormality diagnosis process, the determination process of step S106 is performed to extract an appropriate peak value NESP in the process of the next step S107. That is, the predetermined time T1 is a value corresponding to a time from when it is determined that the engine rotational speed NE reaches the predetermined rotational speed NES1 and the start of the engine 10 is completed until the engine rotational speed reaches the peak value NESP. Is set as a larger value. When it is determined in step S106 that the predetermined time T1 has not elapsed, the engine speed NE is newly read until a determination result indicating that the predetermined time T1 has elapsed (step S105) and the determination process. (Step S106) is repeatedly executed at regular intervals. That is, the latest engine speed NE is repeatedly read until a predetermined time T1 elapses after it is determined that the engine 10 has been started. On the other hand, when it is determined by the determination processing in step S106 that the predetermined time T1 has elapsed, the peak value NESP of the engine speed NE during the period from when the engine 10 has been started until the predetermined time T1 elapses. Is extracted (step S107).

  When the actual peak value NESP of the engine speed detected immediately after the engine start is thus extracted, it is next determined whether or not the actual peak value NESP is smaller than the reference peak value NESX (step S108). As a result, when it is determined that the actual peak value NESP is not smaller than the reference peak value NESX (step S108: NO), it is determined that no abnormality has occurred in the blow-by gas reduction device 30, that is, it is normal. (Step S109), the process is terminated. If it is determined in step S109 that the operation is normal, normal PCV valve control processing for setting the control amount EPA of the PCV valve 36 based on the engine speed NE, the intake air amount GA, and the like may be executed. Good.

  On the other hand, when it is determined that the actual peak value NESP is smaller than the reference peak value NESX (step S108: YES), it is determined that an abnormality has occurred in the blow-by gas reducing device 30 (step S110), and then energization is performed. The amount increase control is executed (step S120), and this process is terminated.

Here, the purpose of executing the energization amount increase control when it is determined that an abnormality has occurred in the blow-by gas reduction device 30 by the process of step S110 will be described.
That is, when it is determined in the blow-by gas reduction device 30 that there is an abnormality that affects the flow of blow-by gas in at least one of the PCV passage 34 and the PCV valve 36, the abnormality of the PCV valve 36 among these abnormalities is In some cases, the valve 36 may be stuck due to the solidification of moisture present in the valve drive unit. Therefore, in the abnormality diagnosis process, when there is a possibility that the valve 36 is fixed due to the coagulation of moisture present in the valve drive unit, the energization amount to the PCV valve 36 is compared with the energization amount at that time. By increasing the size, the amount of heat generated by the valve 36 itself is increased to heat the valve 36. As a result, the solidified water that causes the valve sticking is melted.

  Next, a specific processing procedure of the energization amount increase control will be described with reference to FIG. In addition, the figure is a flowchart which shows the process sequence of this energization amount increase control. The series of processes shown in this flowchart is executed when the process proceeds to step S120 in the flowchart of FIG.

  In this series of processing, first, it is determined whether or not the engine 10 is idling (step S121). Here, when it is determined that the engine 10 is not idling (step S121: NO), the determination process is repeatedly executed at regular intervals until a determination result indicating that the engine 10 is idling is obtained. The On the other hand, when it is determined by the determination process in step S121 that the engine 10 is idling (step S121: YES), the engine speed NEA at that time is read (step S122). Next, the control amount EPA of the PCV valve 36 is forcibly increased by ΔEPAY from the control amount EPA at that time (step S123). That is, the energization amount to the PCV valve 36 is increased as compared with the energization amount at that time.

  If the control amount EPA of the PCV valve 36 is forcibly increased in this way, it is next determined whether or not a predetermined time T2 has elapsed since the control amount EPA was increased (step S124). Incidentally, immediately after the control amount EPA of the PCV valve 36 is forcibly increased, the heat generation amount of the valve 36 itself is not the heat generation amount corresponding to the control amount after the increase, and the heat generation amount of the valve 36 itself. It is considered that a predetermined time is required until the heat generation amount corresponding to the increased control amount. Therefore, in the energization amount increase control, the determination process in step S124 is executed in consideration of the predetermined time to read the appropriate engine speed NEB in the subsequent step S125. That is, the predetermined time T2 is a value corresponding to the time required from when the control amount EPA of the PCV valve 36 is forcibly increased until the heat generation amount of the valve 36 itself becomes a heat generation amount corresponding to the increased control amount. Or it is set as a larger value.

  When it is determined by the determination process in step S124 that the predetermined time T2 has not elapsed, the determination process is repeatedly executed with a certain period until a determination result indicating that the predetermined time T2 has elapsed is obtained. On the other hand, when it is determined by the determination process in step S124 that the predetermined time T2 has elapsed, the engine speed NEB at that time is read (step S125).

  When the engine speed NEB is read after the predetermined time T2 has elapsed since the control amount EPA of the PCV valve 36 is forcibly increased in this way, the engine read from the engine speed NEB in step S122 is then read. It is determined whether or not the value obtained by subtracting the rotational speed NEA (hereinafter, “actual change amount ΔNE”) is equal to or greater than the reference change amount ΔNEY (step S126). As a result, when it is determined that the actual change amount ΔNE is equal to or larger than the reference change amount ΔNEY (step S126: YES), it is assumed that the solidified water is melted and the PCV valve 36 is not fixed. Next, it is determined that no abnormality has occurred in the blow-by gas reduction device 30, that is, it is normal (step S127), and this process is terminated. In addition, when it determines with it being normal by the process of step S127, what is necessary is just to perform a normal PCV valve | bulb control process.

  On the other hand, when it is determined that the actual change amount ΔNE is not equal to or greater than the reference change amount NEY by the determination process in step S126 (step S126: NO), it is assumed that the melting of the solidified water has not sufficiently progressed. In order to further increase the heat generation amount of the PCV valve 36 itself, the process proceeds to the process of the previous step S123, and the processes of steps S123 to S126 are repeatedly executed. Even when the energization amount of the PCV valve 36 is increased to the maximum energization amount that is the maximum value, it is determined that the actual change amount ΔNE is not equal to or greater than the reference change amount NEY by the determination process in step S126 (step S126). : NO), the energization amount increase control may be terminated on the assumption that the cause of the abnormality of the blow-by gas reduction device 30 is not due to the adhesion of the PCV valve 36 due to the coagulation of moisture present in the valve drive unit.

  Next, referring to the timing chart of FIG. 4, (a) transition of the energization state to the electronic control device 60 with execution of the abnormality diagnosis process and the energization amount increase control, and (b) the operating state of the engine 10. Transition, (c) transition of control amount EPA of PCV valve 36, (c) transition of opening degree PA of PCV valve 36, (d) transition of engine speed NE, (e) start completion determination result, (f) abnormality An example of the diagnosis result will be described. Here, it is assumed that the PCV valve 36 is fixed due to the solidification of moisture present in the valve driving unit.

  When energization of the electronic control unit 60 is started at time t1 (FIG. 4A), the control amount EPA of the PCV valve 36 is forcibly changed from the pre-drive control amount EPA1 to the post-drive control amount EPA2. It is changed (FIG. 4C). The actuator of the PCV valve 36 receives the change in the control amount EPA, and changes the actual opening degree from the pre-drive opening degree PA1 corresponding to the pre-drive control quantity EPA1 to the post-drive opening degree PA2 corresponding to the post-drive control quantity EPA2. Although it is going to be changed, since the PCV valve 36 is stuck as described above, the actual opening degree PA does not change (FIG. 4D).

  When the operation of the engine 10 is started at time t2 (FIG. 4 (b)), the engine speed NE increases accordingly (FIG. 4 (e)). At time t3, when the engine rotational speed NE reaches a predetermined rotational speed NES1 (FIG. 4 (e)), it is determined that the engine 10 has been started (FIG. 4 (f)). Here, since the actual opening PA of the PCV valve 36 is fully closed as described above, the blow-by gas is not supplied to the intake passage 22 and the predetermined time has elapsed from the time t3 when it is determined that the engine 10 has been started. The actual peak value NESP of the engine rotational speed NE in the period up to time t4 when T1 elapses is smaller than the reference peak value NESX indicated by the one-dot chain line. For this reason, at time t4, it is determined that an abnormality has occurred in the blow-by gas reduction device 30 (FIG. 4 (g)).

  When the engine 10 enters an idle operation state at time t5, the control amount EPA of the PCV valve 36 is forcibly changed from the control amount EPA2 at that time to the control amount EPA3 (FIG. 4C). In response to the change in the control amount EPA, the amount of heat generated by the PCV valve 36 itself gradually increases, and the solidified water gradually melts accordingly. As a result, the actual opening PA of the PCV valve 36 gradually increases from the opening PA1 toward the opening PA2 (FIG. 4D). As a result, the amount of blow-by gas supplied to the intake passage 22 increases, so that the engine speed NE gradually increases (FIG. 4 (e)).

  At a time t6 when the predetermined time T2 has elapsed from the time t5, a value ΔNE1 obtained by subtracting the engine rotational speed NEB at the time t6 from the engine rotational speed NEA at the time t5 becomes equal to or greater than the reference change amount ΔNEY. Then, at time t6, it is determined that the blow-by gas reduction device 30 is normal (FIG. 4 (g)). After time t6, the control amount EPA of the PCV valve 36 is set based on normal PCV valve control processing.

According to the abnormality diagnosis device for the blow-by gas reduction device according to the present embodiment, the following operational effects can be obtained.
(1) The control amount EPA of the PCV valve 36 is increased in the direction in which the opening degree PA of the valve 36 increases under the condition that no abnormality has occurred in the blow-by gas reduction device 30 and the engine operation state is in the specific operation state. The drive control to be changed was executed. Then, a reference peak value NESX preset as a peak value of the engine speed NE predicted to be reached immediately after the drive control is compared with an actual peak value NESP of the engine speed NE accompanying the drive control. Then, when the actual peak value NESP is smaller than the reference peak value NESX, it is determined that an abnormality has occurred in the blow-by gas reduction device 30. This makes it possible to accurately determine that an abnormality has occurred in the blow-by gas reduction device 30 without using a sensor that detects the opening of the PCV valve 36.

  (2) When the abnormality diagnosis is performed, the control amount EPA of the PCV valve 36 is forcibly changed to change the engine rotational speed NE, so that the engine vibration is caused by the change of the engine rotational speed. Increasing may be a problem. In this regard, in the above-described embodiment, the drive control is executed when it is determined that the engine operation state is in a state immediately before the engine start that is set as the specific operation state. When the engine is started, the engine rotational speed NE changes greatly in the first place, resulting in an increase in engine vibration. Therefore, the effect of the drive control on the increase in engine vibration is compared with other engine operating conditions. And become small. Accordingly, it is possible to suppress the problem that the engine vibration increases as the engine speed NE changes.

  (3) The reference peak value NESX is variably set based on the engine coolant temperature THW immediately before the drive control is executed. As a result, it is possible to accurately determine that an abnormality has occurred in the blow-by gas reduction device regardless of the engine coolant temperature THW.

  (4) Based on the determination that an abnormality has occurred in the blow-by gas reduction device 30, the energization amount to the PCV valve 36 is made larger than the energization amount at that time. Thereby, the calorific value of the PCV valve 36 itself can be increased and the valve 36 can be heated, whereby the solidified water can be melted. In addition, since the valve is heated by changing the energization amount to the PCV valve 36, it is not necessary to add a heating means for heating the valve 36. Accordingly, the PCV valve 36 can be fixed quickly with a simple configuration.

Second Embodiment
With reference to FIG. 5, 2nd Embodiment of the abnormality diagnosis apparatus of the blowby gas reduction apparatus concerning this invention is described.

  In the abnormality diagnosis process of this embodiment, when it is determined that the engine operating state is in a predetermined specific operating state, the control amount EPA of the PCV valve 36 is changed in a direction in which the opening degree PA of the valve 36 increases. At the same time, the drive control is executed, and at the same time, the drive control for changing the control amount ETA of the throttle valve 26 in the direction in which the opening degree TA of the valve 26 decreases is executed. Then, it is determined that an abnormality has occurred in the blow-by gas reduction device 30 when the change amount of the engine rotation speed NE accompanying the drive control is equal to or greater than the reference change amount.

  Specifically, if the blow-by gas reduction device 30 is normal under the condition that the engine operation state is in the idle operation state, the control amount EPA4 that maintains the opening degree PA of the valve 36 at the fourth opening degree PA4. To the control amount EPA5 that is maintained at the fifth opening degree PA5 (PA5> PA4) in which the blow-by gas amount GP supplied to the intake passage 22 is increased by a predetermined amount ΔG. ing. At the same time, the opening amount TA5 (the amount of air GT passing through the valve 26 is decreased by the predetermined amount ΔG from the control amount ETA4 which maintains the control amount ETA of the throttle valve 26 at the opening degree TA4 at that time. The control for changing to the control amount ETA5 maintained at TA5 <TA4) is executed. Then, it is determined that an abnormality has occurred in the blow-by gas reduction device 30 when the change amount ΔNE of the engine rotational speed NE accompanying the drive control is equal to or greater than the reference change amount ΔNEZ.

FIG. 5 is a flowchart showing the procedure of the abnormality diagnosis process of the present embodiment. It should be noted that a series of processing shown in this flowchart is repeatedly executed while the engine 10 is in operation.
In this series of processing, it is first determined whether or not the engine 10 is idling based on the accelerator operation amount ACCP (step S201). Here, when it is determined that the engine 10 is not idling (step S201: NO), this series of processes is temporarily terminated. On the other hand, when it is determined that the engine 10 is idling (step S201: YES), the engine speed at that time (hereinafter referred to as “drive speed NEC”) is read (step S202). Then, the control amount EPA of the PCV valve 36 is forcibly increased by a predetermined amount ΔEPAZ from the control amount at that time (hereinafter referred to as “pre-drive control amount EPA4”). That is, the control amount EPA of the PCV valve 36 is increased from the pre-drive control amount EPA4 to a control amount obtained by adding a predetermined amount ΔEPAZ (hereinafter, “post-drive control amount EPA5”) (step S203).

  Next, the control amount of the throttle valve 26 is forcibly decreased by a predetermined amount ΔETAZ from the control amount at that time (hereinafter referred to as “pre-drive control amount ETA4”). That is, the control amount ETA of the throttle valve 26 is decreased from the pre-drive control amount ETA4 to a control amount obtained by subtracting the predetermined amount ΔETAZ (hereinafter “post-drive control amount ETA5”) (step S204).

  When the drive control of the PCV valve 36 and the throttle valve 26 is executed in this way, the engine speed at that time (hereinafter referred to as “post-drive speed NED”) is read (step S205). Next, it is determined whether or not the value obtained by subtracting the post-drive rotational speed NED from the pre-drive rotational speed NEC, that is, the change amount ΔNE of the engine rotational speed NE is greater than or equal to the reference change amount NEZ (step S206). Here, the reference change amount NEZ is set as a constant value, but instead, the reference change amount NEZ is variably set based on the engine coolant temperature THW in the same manner as in the first embodiment. You can also. As a result, when it is determined that the change amount ΔNE of the engine rotational speed NE is not equal to or greater than the reference change amount ΔNEZ (step S206: NO), it is determined that no abnormality has occurred in the blow-by gas reduction device 30, that is, it is normal. (Step S208), and this process is temporarily terminated.

  On the other hand, when it is determined that the change amount ΔNE of the engine rotational speed NE is greater than or equal to the reference change amount ΔNEZ (step S206: YES), it is determined that an abnormality has occurred in the blow-by gas reduction device 30 (step S207). This process is temporarily terminated.

According to the abnormality diagnosis device for the blow-by gas reduction device according to the present embodiment, the following operational effects can be obtained.
(1) The control amount EPA of the PCV valve 36 is increased by the opening degree PA of the valve 36 as drive control under the condition that no abnormality has occurred in the blow-by gas reduction device 30 and the engine operation state is in the specific operation state. At the same time, the control amount ETA of the throttle valve 26 is changed to the direction in which the opening degree TA of the valve 26 decreases. Then, it is determined that an abnormality has occurred in the blow-by gas reduction device 30 when the change amount ΔNE of the engine rotational speed NE accompanying the drive control is equal to or greater than the reference change amount ΔNEZ. This makes it possible to accurately determine that an abnormality has occurred in the blow-by gas reduction device 30 without using a sensor that detects the opening of the PCV valve 36.

  (2) In the configuration in which the control amount EPA of the PCV valve 36 is forcibly changed in accordance with the execution of the abnormality diagnosis, the engine speed NE changes in accordance with the forcible change of the control amount EPA of the PCV valve 36. This may cause a problem that the engine vibration increases.

  In this regard, in the above embodiment, the control amount of the PCV valve 36 is set so that the blow-by gas amount GP supplied to the intake passage 22 is increased by a predetermined amount ΔG under the condition that the engine operation state is the idle operation state. At the same time, the control is performed to change the control amount of the throttle valve 26 so that the air amount GT passing through the throttle valve 26 is decreased by the predetermined amount ΔG. As a result, as long as no abnormality occurs in the blow-by gas reduction device 30, the engine speed NE does not change with the execution of the abnormality diagnosis. Accordingly, it is possible to suppress the problem that the engine vibration increases as the engine speed changes.

<Other embodiments>
The embodiment of the abnormality diagnosis device for the blow-by gas reduction device according to the present invention is not limited to the configuration exemplified in the above-described embodiment. You can also.

  In the first embodiment, when it is determined that an abnormality has occurred in the blow-by gas reduction device 30 through the abnormality diagnosis process, the energization amount is increased so that the energization amount to the PCV valve 36 is larger than the energization amount at that time. Control is executed. However, the means for heating the PCV valve 36 is not limited to this, and the PCV valve 36 may be heated by a heating means such as a heater different from the PCV valve 36, for example.

  In the first embodiment, when it is determined that an abnormality has occurred in the blow-by gas reduction device 30 through the abnormality diagnosis process, the energization amount increase control is always executed. However, for example, when the engine coolant temperature THW is high As described above, when the possibility of coagulation of moisture present in the valve drive unit is low as a cause of sticking of the PCV valve 36, such energization amount increase control can be omitted.

  In the first embodiment, in the abnormality diagnosis process, the reference peak value NESX of the engine speed NE immediately after the start of the engine 10 is set based on the engine coolant temperature THW. However, the reference peak value The parameter used when variably setting NESX is not limited to this. In addition, for example, the reference peak value may be variably set based on the state quantity of another internal combustion engine such as the temperature of the lubricating oil. Also, the reference peak value can be a constant value regardless of the state quantity of the internal combustion engine.

  In the first embodiment, the control amount for maintaining the PCV valve 36 in the fully closed state is set as the pre-drive control amount EPA1, and the control amount for maintaining the PCV valve 36 in the fully open state is set as the post-drive control amount EPA2. However, the pre-drive control amount EPA1 and the post-drive control amount EPA2 are not limited to the control amounts for maintaining the PCV valve 36 in the fully closed state and the fully open state, respectively. That is, the pre-drive control amount EPA1 and the post-drive control amount EPA2 can be appropriately set to control amounts that maintain an arbitrary opening degree from fully closed to fully open of the PCV valve 36.

  In the first embodiment, control for changing the control amount EPA of the PCV valve 36 in the direction in which the opening degree PA of the valve 36 is increased is executed as the drive control. It is not limited to this. In addition, for example, control for changing the control amount EPA of the PCV valve 36 in the direction in which the opening degree PA of the valve 36 decreases may be executed as drive control. In this case, a reference peak value set in advance as a peak value of the engine speed predicted to be reached immediately after the drive control is compared with an actual peak value of the engine speed associated with the drive control, and the actual peak value is compared. It may be determined that an abnormality has occurred in the blow-by gas reduction device 30 when the value is larger than the reference peak value.

  If the reference peak value is variably set based on the amount by which the control amount EPA of the PCV valve 36 is changed by the drive control, the blow-by gas reduction device regardless of the amount by which the control amount EPA of the PCV valve 36 is changed It is possible to accurately determine that an abnormality has occurred in 30.

  In the first embodiment, the reference peak value NESX preset as the peak value of the engine speed predicted to be reached immediately after the drive control, and the actual peak value of the engine speed associated with the drive control An abnormality diagnosis is performed based on a comparison with NESP. However, the object to be compared at the time of abnormality diagnosis is not limited to these peak values. For example, a reference transition preset as a transition of an engine speed that is predicted to occur immediately after the drive control is used. Then, an abnormality diagnosis may be performed based on a comparison with the actual transition of the engine speed accompanying the drive control. Specifically, when the control amount EPA of the PCV valve 36 is changed to the direction in which the opening degree PA of the valve 36 increases as the drive control, the actual transition is lower than the reference transition. What is necessary is just to determine that abnormality has arisen in the blowby gas reduction apparatus 30 by belonging to the area | region of the side. On the contrary, when the control for changing the control amount EPA of the PCV valve 36 in the direction in which the opening degree PA of the valve 36 is decreased as the drive control, the actual transition is higher than the reference transition. It may be determined that an abnormality has occurred in the blow-by gas reduction device 30 by belonging to the region.

  Further, a control amount for increasing or decreasing the control amount of the PCV valve 36 is executed, and a reference change amount that is preset as a change amount of the engine rotational speed that is predicted to be caused by the drive control, and the drive control is accompanied. The actual change amount of the engine speed may be compared, and it may be determined that an abnormality has occurred in the blow-by gas reduction device 30 when the actual change amount is smaller than the reference change amount. In short, a reference change mode, which is a change mode of the engine rotation speed predicted to occur with the drive control, is compared with an actual change mode of the engine rotation speed with the drive control, and there is a difference between them. What is necessary is just to determine that an abnormality has occurred in the blow-by gas reduction device 30 by the presence of stagnation.

  In the second embodiment, the control amount of the PCV valve 36 is changed so that the blow-by gas amount GP supplied to the intake passage 22 increases by a predetermined amount ΔG, and at the same time, the air amount GT passing through the throttle valve 26 Is controlled so as to change the control amount of the throttle valve 26 so as to decrease by the predetermined amount ΔG. However, the drive control mode of the PCV valve 36 and the throttle valve 26 is not limited to this. In addition, for example, the control amount of the PCV valve 36 is changed so that the blow-by gas amount GP supplied to the intake passage 22 is reduced by a predetermined amount ΔG, and at the same time, the air amount GT passing through the throttle valve 26 is the predetermined amount. You may make it control to change the control amount of the throttle valve 26 so that it may increase only (DELTA) G.

  In the above-described embodiment, the drive control is executed and the abnormality diagnosis is performed immediately before starting the engine 10 or during the idle operation of the engine 10, but the execution timing of the drive control and the abnormality diagnosis is limited to this. Instead, it is determined that the engine operating state is in an operating state in which the change mode of the engine rotation speed can be grasped in advance under the condition that no abnormality has occurred in the blow-by gas reduction device 30, that is, in a specific operating state. If so, the execution time can be changed as appropriate.

  After all, as a diagnostic means, when it is determined that the engine operating state is in a predetermined specific operating state, drive control for forcibly changing the control amount of the PCV valve is executed, and the engine rotation accompanying this is executed. What is necessary is just to perform abnormality diagnosis based on the speed change mode.

The block diagram which shows schematic structure of the cylinder injection type gasoline engine for vehicles with which the abnormality diagnosis apparatus is applied about 1st Embodiment of the abnormality diagnosis apparatus of the blowby gas reduction apparatus concerning this invention. The flowchart which shows the process sequence of the abnormality diagnosis of the embodiment. The flowchart which shows the process sequence of the energization amount increase control of the embodiment. The timing chart based on the abnormality diagnosis process and energization amount increase control of the embodiment. The flowchart which shows the process sequence of the abnormality diagnosis by the abnormality diagnostic apparatus about 2nd Embodiment of the abnormality diagnostic apparatus of the blowby gas reduction apparatus concerning this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Engine, 11 ... Cylinder block, 12 ... Combustion chamber, 14 ... Injector, 16 ... Spark plug, 18 ... Exhaust passage, 20 ... Catalytic device, 22 ... Intake passage, 24 ... Throttle motor, 26 ... Throttle valve, 28 ... Surge tank, 30 ... Blow-by gas reduction device, 32 ... Introduction passage, 34 ... PCV passage, 36 ... PCV valve, 40 ... Crankcase, 42 ... Crankshaft, 51 ... Rotation speed sensor, 52 ... Accelerator sensor, 53 ... Throttle sensor 54 ... Air flow meter, 55 ... Water temperature sensor, 56 ... Air-fuel ratio sensor, 60 ... Electronic control device (diagnostic means), 61 ... I / G switch.

Claims (16)

A blow-by gas reduction device comprising a PCV passage for supplying blow-by gas to an intake passage of an internal combustion engine and a PCV valve for adjusting the flow rate of the blow-by gas in the passage is provided in at least one of the PCV passage and the PCV valve. In the abnormality diagnosis device of the blow-by gas reduction device that performs abnormality diagnosis for determining whether or not an abnormality of the aspect affecting the flow of the fuel has occurred,
A direction in which the opening of the valve increases the control amount of the PCV valve when it is determined that the abnormality of the aspect does not occur in the blow-by gas reduction device and the engine operating state is in a predetermined specific operating state. executes driving control to change along with the peak value preset as a reference as a peak value of the expected engine speed to reach immediately after execution of the driving control, the actual engine rotational speed caused by the drive control A diagnostic unit that compares the peak value and determines that the abnormality of the aspect is occurring in the blow-by gas reduction device when the actual peak value is smaller than the reference peak value. An abnormality diagnosis device for a blowby gas reduction device.   A blow-by gas reduction device comprising a PCV passage for supplying blow-by gas to an intake passage of an internal combustion engine and a PCV valve for adjusting the flow rate of the blow-by gas in the passage is provided in at least one of the PCV passage and the PCV valve. In the abnormality diagnosis device of the blow-by gas reduction device that performs abnormality diagnosis for determining whether or not an abnormality of the aspect affecting the flow of the fuel has occurred,
  A direction in which the opening of the valve is decreased when it is determined that the abnormality of the aspect does not occur in the blow-by gas reduction device and the engine operating state is in a predetermined specific operating state. And a reference peak value preset as a peak value of the engine speed that is predicted to be reached immediately after the execution of the drive control, and an actual engine speed associated with the drive control. Comparing with a peak value, the diagnostic means for performing the abnormality diagnosis for determining that the abnormality of the aspect has occurred in the blow-by gas reduction device when the actual peak value is larger than the reference peak value
  An abnormality diagnosis device for a blow-by gas reduction device. In the abnormality diagnosis device for a blow-by gas reduction device according to claim 1 or 2 ,
The diagnosis means executes the drive control when it is determined that the engine operating state is in a state immediately before the engine start that is set as the specific operating state, and is set in advance as the reference peak value. The abnormality diagnosis is performed based on a comparison between a peak value of the engine speed immediately after the completion of the engine start and an actual peak value of the engine speed detected immediately after the completion of the engine start. Abnormality diagnosis device. In the abnormality diagnosis device for a blowby gas reduction device according to claim 3 ,
The diagnosis means determines that the engine is in a state immediately before starting the engine based on the operation position of the ignition switch, and executes the drive control accordingly. In the abnormality diagnosis device for a blow-by gas reduction device according to any one of claims 1 to 4 ,
The abnormality diagnosis device for a blow-by gas reduction device, wherein the diagnosis unit variably sets the reference peak value based on an amount by which the control amount of the PCV valve is changed by the drive control. In the abnormality diagnosis device for a blow-by gas reduction device according to any one of claims 1 to 5 ,
The abnormality diagnosis device for a blow-by gas reduction device, wherein the diagnosis means variably sets the reference peak value based on a state quantity of the internal combustion engine immediately before executing the drive control. In the abnormality diagnosis apparatus for the blowby gas reduction apparatus according to any one of claims 1 to 6 ,
On the basis of the fact that it is determined by the diagnostic means that an abnormality of the aspect has occurred in the blow-by gas reduction device, the energization amount to the PCV valve is made larger than the energization amount at that time. Abnormality diagnosis device for blow-by gas reduction device.   A blow-by gas reduction device comprising a PCV passage for supplying blow-by gas to an intake passage of an internal combustion engine and a PCV valve for adjusting the flow rate of the blow-by gas in the passage is provided in at least one of the PCV passage and the PCV valve. In the abnormality diagnosis device of the blow-by gas reduction device that performs abnormality diagnosis for determining whether or not an abnormality of the aspect affecting the flow of the fuel has occurred,
  When it is determined that the engine operation state is in a predetermined specific operation state, drive control for forcibly changing the control amount of the PCV valve is executed, and the abnormality is determined based on the change mode of the engine rotation speed associated therewith. A diagnostic means for performing diagnosis,
  Based on the determination that the abnormality of the aspect has occurred in the blow-by gas reduction device by the diagnostic means, the energization amount to the PCV valve is made larger than the energization amount at that time.
  An abnormality diagnosis device for a blow-by gas reduction device. In the abnormality diagnosis device for a blowby gas reduction device according to claim 8 ,
The diagnostic means is caused when the drive control is executed under the condition that the abnormality of the aspect does not occur in the blow-by gas reduction device and the engine operation state is in the specific operation state. A reference change mode, which is a predicted change mode of the engine rotation speed, is compared with an actual change mode of the engine rotation speed accompanying the drive control, and if there is a difference between them, the blow-by gas reduction device An abnormality diagnosis device for a blow-by gas reduction device, characterized in that it is determined that an abnormality of the above-described aspect has occurred. In the abnormality diagnosis device for a blowby gas reduction device according to claim 9 ,
As the abnormality diagnosis based on the comparison between the reference change mode and the actual change mode, the diagnosis means has no abnormality of the mode in the blow-by gas reduction device and the engine operating state is in the specific operating state. As the drive control under certain conditions, when the control amount of the PCV valve is changed in the direction in which the opening of the valve increases, Compare the transition of the standard set in advance with the actual transition of the engine speed accompanying the drive control, and if the actual transition belongs to the region on the lower rotation side than the transition of the reference, the blow-by gas reduction device An abnormality diagnosis device for a blow-by gas reduction device, characterized in that it is determined that an abnormality of the above-described aspect has occurred. In the abnormality diagnosis device for a blowby gas reduction device according to claim 9 ,
As the abnormality diagnosis based on the comparison between the reference change mode and the actual change mode, the diagnosis means has no abnormality of the mode in the blow-by gas reduction device and the engine operating state is in the specific operating state. As the drive control under certain conditions, when the control amount of the PCV valve is changed in the direction in which the opening degree of the valve is decreased, Compare the transition of the reference set in advance with the actual transition of the engine speed accompanying the drive control, and if the actual transition belongs to the region on the higher rotation side than the transition of the reference, the blow-by gas reduction device An abnormality diagnosis device for a blow-by gas reduction device, characterized in that it is determined that an abnormality of the above-described aspect has occurred. In the abnormality diagnosis device for a blowby gas reduction device according to claim 9 ,
As the abnormality diagnosis based on the comparison between the reference change mode and the actual change mode, the diagnosis means has no abnormality of the mode in the blow-by gas reduction device and the engine operating state is in the specific operating state. When a control for increasing or decreasing the control amount of the PCV valve is executed as the drive control under a certain condition, a reference value set in advance as a change amount of the engine rotational speed that is predicted to be caused by the control is executed. The amount of change is compared with the actual amount of change in engine rotation speed associated with the drive control, and when the actual amount of change is smaller than the reference amount of change, the blow-by gas reduction device has an abnormality in the aspect. An abnormality diagnosis device for a blow-by gas reduction device, characterized by: In the abnormality diagnosis device for a blowby gas reduction device according to claim 12 ,
The diagnosis means executes the drive control when it is determined that the engine operation state is in an idle operation state set as the specific operation state, and immediately before executing the drive control in the idle operation state. The difference between the engine rotation speed of the engine and the engine rotation speed immediately after executing the drive control in the idle operation state is calculated as an actual change amount of the engine rotation speed, and the calculated change amount and the reference change amount An abnormality diagnosis device for a blow-by gas reduction device, characterized in that the abnormality diagnosis is performed based on the comparison. In the abnormality diagnosis device for a blow-by gas reduction device according to claim 12 or 13 ,
The abnormality diagnosis device for a blow-by gas reduction device, wherein the diagnosis means variably sets the reference change amount based on an amount by which the control amount of the PCV valve is changed by the drive control. In the abnormality diagnosis device of the blow-by gas returning device according to any one of claims 12-14,
The abnormality diagnosis device for a blow-by gas reduction device, wherein the diagnosis unit variably sets the reference change amount based on a state quantity of the internal combustion engine immediately before the drive control is executed. In the abnormality diagnosis device for a blowby gas reduction device according to any one of claims 1 to 15 ,
The specific operation state is an operation state in which a change mode of the engine rotation speed under a condition in which no abnormality has occurred in the blow-by gas reduction device can be grasped in advance. Diagnostic device.

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