JP2010173548A - Blow-by gas reducing device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blow-by gas reducing device for a hybrid vehicle ensuring smooth travel regardless of freezing of a PCV valve. <P>SOLUTION: An engine ECU 70 and a hybrid control computer (HVCC) 70a, upon determining that the PCV valve 63 is "frozen", EV mode is set to stop the operation of an engine 10 and run the vehicle only by a motor 80, and unfreeze the PCV valve 63 by a heater 63. In the EV mode, when the valve is unfreezed and the PCV valve 63 is determined to be "unfrozen", the EV mode is released to set a normal travel mode to run the hybrid vehicle by the engine 10 and the motor 80. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a blow-by gas reduction device provided in a hybrid vehicle.

  2. Description of the Related Art An internal combustion engine of a vehicle such as an automobile has a passage area that can be changed by a throttle valve, an intake passage that introduces outside air into a combustion chamber, a fuel supply device that supplies fuel to the combustion chamber, and a blow-by that includes fuel. There is provided a blow-by gas reduction device that reduces the gas from the combustion chamber to the intake passage and burns it again in the combustion chamber.

  The blow-by gas reduction device generally includes a first ventilation passage that connects the intake downstream side of the throttle valve in the intake passage to the crank chamber and the valve operating chamber to reduce the blow-by gas in the crank chamber to the intake passage. A second ventilation passage for connecting intake upstream of the throttle valve to the crank chamber and the valve chamber in the intake passage to supply intake air to the crank chamber, and a first ventilation for adjusting the flow rate of blow-by gas The PCV valve is provided in the passage and changes the passage area.

  Among these blow-by gas reduction devices, those that employ a mechanical (negative pressure) PCV valve in which the PCV opening is adjusted using the pressure difference between the crank chamber or valve chamber and the intake passage are used for the internal combustion engine. Since the pressure difference disappears when the operation is stopped, the PCV valve is fully closed, and in cold districts, a large amount of cryogenic outside air containing moisture is introduced into the intake air, so the PCV valve is fully closed. It may freeze in a state.

  As a result, when the internal combustion engine is started, blow-by gas flows back to the intake passage through the crank chamber, the combustion chamber, and the second ventilation passage, and the throttle valve freezes due to the back-flowed cryogenic gas. The internal combustion engine of the vehicle stops.

  For example, Patent Document 1 discloses a technique for solving such a problem by heating a PCV valve with a heater disposed in a first ventilation passage to eliminate the freeze. Thereby, it is supposed that freezing of water in the frozen first ventilation passage is eliminated, and freezing of the PCV valve can be prevented.

  However, even with this technique, the blow-by gas flows back into the intake passage until the PCV valve freeze is eliminated, so the possibility that the throttle valve freezes and the internal combustion engine stops still remains. Become.

By the way, in recent years, hybrid vehicles that obtain power for traveling by combining an internal combustion engine and a motor have been developed and are becoming popular.
In such a hybrid vehicle, an electronically controlled blow-by gas reduction device having an electronically controlled PCV valve (variable PCV valve) whose PCV opening degree is controlled by an electronic control device (ECU) that comprehensively controls the internal combustion engine and the motor. The required value of the blowby gas flow rate is set based on the engine operating state of the internal combustion engine via the electronic control unit, and the PCV opening degree is set so that the actual blowby gas flow rate becomes this required value. It is controlled (see, for example, Patent Document 2).

Japanese Utility Model Publication No. 5-73216 (FIG. 4, paragraph [0012], etc.) JP 2005-207367 A

  In this way, power for vehicle travel can be obtained by a motor other than the internal combustion engine, and the above-mentioned problem can be obtained by taking advantage of the characteristics of the hybrid vehicle in which an electronically controlled PCV valve is often used in the blow-by gas reduction device. If the point can be effectively eliminated, it is considered that there is a great merit not only for automobile manufacturers but also for automobile users.

  The present invention has been made in the background of such a situation, and an object of the present invention is to provide a blow-by gas reduction device for a hybrid vehicle that can ensure smooth running regardless of the freeze of the PCV valve in the hybrid vehicle. There is.

  In order to solve the above problems, the invention according to claim 1 is provided in a hybrid vehicle including an electronic control unit that controls the internal combustion engine and the motor in an integrated manner, and introduces outside air into the combustion chamber of the internal combustion engine. Freezing detection means for detecting whether or not the PCV valve is frozen in a blowby gas reduction apparatus having a PCV passage for reducing blowby gas to an intake passage and a PCV valve for adjusting a flow rate of blowby gas passing through the PCV passage And an anti-freezing means for eliminating freezing of the PCV valve, and when the electronic control unit determines that freezing has occurred via the freezing detecting means, the operation of the internal combustion engine is stopped and only the motor is Is set to EV driving mode in which the hybrid vehicle is driven, and freezing of the PCV valve is canceled by the freezing eliminating means. On the other hand, when the freezing is resolved and it is determined that the PCV valve is not frozen, the EV traveling mode is canceled and the normal traveling mode in which the hybrid vehicle is driven by the internal combustion engine and the motor is set. The gist.

  According to this configuration, when the electronic control unit determines that the PCV valve is frozen, the electronic control unit is set to the EV traveling mode in which the operation of the internal combustion engine is stopped and the hybrid vehicle is driven only by the motor, When the freeze of the PCV valve is canceled and the freeze is resolved and it is determined that the PCV valve is not frozen, the EV travel mode is canceled and the normal travel mode in which the hybrid vehicle is driven by the internal combustion engine and the motor is set. It was to so. For this reason, if the PCV valve freezing is completed while the electronic control unit is set in the EV driving mode, the normal driving mode is set, and the hybrid vehicle can be driven by the internal combustion engine and the motor. Regardless of the freeze of the PCV valve, the backflow of blow-by gas to the intake passage is prevented, and smooth running of the hybrid vehicle is ensured.

  ADVANTAGE OF THE INVENTION According to this invention, the hybrid vehicle blow-by gas reduction apparatus which can ensure smooth driving | running | working in a hybrid vehicle irrespective of freezing of a PCV valve can be provided.

1 is a structural diagram schematically showing the configuration of a direct injection internal combustion engine including a blow-by gas reduction device for a hybrid vehicle according to an embodiment of the present invention. 1 is a block diagram schematically showing an electrical configuration of a control system of an electronically controlled PCV valve according to an embodiment of the present invention. The flowchart figure which shows operation | movement of the control system of the electronically controlled PCV valve which concerns on embodiment of this invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.
As shown in FIG. 1, an in-cylinder injection type engine 10 is provided in a hybrid vehicle that obtains driving power by cooperation between the engine 10 and a motor 80, and is powered through combustion of a mixture of air and fuel. , An intake device 40 for taking external air into the engine body 20, an injector 52 for supplying fuel to the combustion chamber 31 in the engine body 20, It is provided to supply blow-by gas (BBG) to the intake device 40, and is configured to include an engine ECU 70 as an electronic control device and an electronically controlled blow-by gas reduction device 60 having a hybrid control computer (HVCC) 70a. . Here, the engine ECU 70 and the hybrid control computer 70a are connected via a CAN communication bus 70b so as to communicate with each other so as to control the engine 10 and the motor 80 in an integrated manner. The hybrid control computer 70a can be set to an EV travel mode in which the operation of the engine 10 is stopped and the hybrid vehicle is traveled only by the motor 80, and a normal travel mode in which the hybrid vehicle is traveled by the engine 10 and the motor 80. ing. Note that the normal travel mode includes a state in which the hybrid vehicle travels using only the engine 10.

  The engine body 20 stores a cylinder block 21 for burning the air-fuel mixture in the combustion chamber 31, a crankcase 22 for supporting the crankshaft 26 in cooperation with the cylinder block 21, and engine oil. The oil pan 23, a cylinder head 24 for arranging valve-operated parts, and a head cover 25 for suppressing scattering of engine oil to the outside. A crank chamber 32 formed by the cylinder block 21 and the crankcase 22 and a valve operating chamber 33 formed by the cylinder head 24 and the head cover 25 are connected by a communication chamber 34 formed in the cylinder block 21. .

  The intake device 40 has an air intake 41 for taking outside air into the device, and an air cleaner 42 for catching foreign matter in the air taken in via the air intake 41 (hereinafter referred to as “intake”). A throttle body 44 for adjusting the flow rate of intake air through the opening and closing of the throttle valve 45, an intake hose 43 connecting the intake downstream side of the air cleaner 42 and the intake upstream side of the throttle body 44, and the intake downstream of the throttle body 44 And an intake manifold 46 that connects the intake side of the cylinder head 24 to the intake upstream side. The intake manifold 46 is provided with a surge tank 47 for retaining the intake air that has passed through the throttle body 44 and a plurality of sub-pipes 48 for sending the intake air in the surge tank 47 to the intake ports of the cylinder head 24. ing. That is, in the intake device 40, the intake air is supplied to the engine by the passage in the air intake 41, the passage in the air cleaner 42, the passage in the intake hose 43, the passage in the throttle body 44, and the passage in the intake manifold 46. An intake passage 49 for feeding into the main body 20 is formed.

  The injector 52 directly injects high-pressure fuel from the pressure accumulation pipe into the combustion chamber 31, and the injector 52 pressurizes and discharges the fuel tank that stores the fuel and the fuel in the tank. A supply device main body (none of which is shown) including a high pressure pump and a pressure accumulating pipe for storing fuel pressurized by the pump in a high pressure state is provided.

  In the present embodiment, the blow-by gas reduction device 60 has a function of supplying the blow-by gas that has flowed from the combustion chamber 31 into the crank chamber 32 to the intake downstream side of the throttle valve 45 in the intake device 40, and the air cleaner 42. A function of supplying the purified intake air into the crank chamber 32 from the intake upstream side of the throttle valve 45 in the intake device 40 and a function of adjusting the flow rate of blow-by gas supplied from the engine body 20 into the intake device 40. It is comprised as an apparatus provided.

  Specifically, the blow-by gas reduction device 60 includes a PCV passage for sending blow-by gas in the crank chamber 32 from the valve chamber 33 into the surge tank 47 in addition to the engine ECU 70 and the hybrid control computer (HVCC) 70a. As described above, the first ventilation passage 61 formed so as to connect the head cover 25 and the surge tank 47, the passage for sending the intake air in the intake hose 43 into the valve operating chamber 33, or the intake from the valve operating chamber 33 is used. As a passage for sending blow-by gas into the hose 43, a second ventilation passage 62 formed in a manner of connecting the head cover 25 and the intake hose 43 is provided.

  The blow-by gas reduction device 60 is provided in the head cover 25 as a valve for adjusting the flow rate of the blow-by gas flowing from the valve operating chamber 33 toward the surge tank 47, and reduces the passage area of the first ventilation passage 61. An electronically controlled PCV valve 63 (hereinafter referred to as “PCV valve 63”) that is changed by electronic control of the hybrid control computer 70a is provided. Under the same engine operating conditions, the valve opening degree of the PCV valve 63 (hereinafter referred to as “PCV opening degree TB”) is increased to move from the valve operating chamber 33 into the surge tank 47. The flow rate of the blow-by gas supplied increases.

  When the engine 10 is at a low engine load such as when the engine 10 is idling, the negative pressure on the intake downstream side of the throttle valve 45 is large, so that the communication chamber 34, the valve chamber 33, and the first ventilation passage 61 are opened from the crank chamber 32. As a result, blow-by gas flows into the surge tank 47. At this time, intake air flows into the valve operating chamber 33 from the intake hose 43 through the second ventilation passage 62.

  On the other hand, when the engine 10 is at a high engine load, such as when traveling at high speed, the pressure in the crank chamber 32 and the valve operating chamber 33 is large. The blow-by gas flows into the surge tank 47 through 61, and the blow-by gas also flows into the intake hose 43 from the valve operating chamber 33 through the second ventilation passage 62.

  Further, in the configuration shown in FIG. 1, an accelerator operation amount AC, which is a depression amount of an accelerator pedal of a hybrid vehicle, is detected as various sensors for assisting engine control by the engine ECU 70 and the hybrid control computer 70 a, and according to the detected amount. Accelerator position sensor 71 that outputs the detected signal, crank position sensor 72 that detects the rotational speed of the crankshaft 26 (hereinafter referred to as “engine rotational speed NE”), and outputs a signal corresponding to the detected amount, and intake passage 49 The air flow meter 73 that detects the mass flow rate of the intake air flowing through the air and outputs a signal corresponding to the detected amount, the throttle opening degree TA that is the opening degree of the throttle valve 45, and the signal corresponding to the detected amount Position sensor 74 that outputs engine and engine body 20 is cooled A coolant temperature sensor 75 that detects the temperature of Seki cooling water and outputs a signal corresponding to the detected amount, a fuel pressure PI that is the pressure of fuel supplied to the injector 52, and outputs a signal corresponding to the detected amount A fuel pressure sensor 76 that detects the air-fuel ratio of the air-fuel mixture (hereinafter referred to as “air-fuel ratio A / F”) based on the oxygen concentration in the exhaust gas, and outputs a signal corresponding to the detected amount; By detecting the rotational speed (vehicle speed) of the wheel of the hybrid vehicle and outputting a signal corresponding to the detected amount and the position of the valve body 11 of the PCV valve 63, the PCV opening as the valve opening degree is detected. A PCV opening sensor 63b (see FIG. 2) for detecting the degree TB is provided.

  In the configuration shown in FIG. 1, the crank position sensor 72, the air flow meter 73, the throttle position sensor 74, the coolant temperature sensor 75, the fuel pressure sensor 76, and the air-fuel ratio sensor 77 are connected to the engine ECU 70 and the accelerator position. The sensor 71, the wheel speed sensor 79, and the PCV opening sensor 63b are electrically connected to the hybrid control computer 70a.

  As shown in FIG. 1, the hybrid control computer 70 a generates electric power using the motor 80 used for running the hybrid vehicle and the power of the engine 10 and is driven by the motor 80 when the EV running mode is set. A generator 81 that stores electricity in a battery (not shown) that supplies utility power is electrically connected. Further, a battery computer 78 is electrically connected to the hybrid control computer 70a, and a signal including information on a state of charge (SOC) of the battery is transmitted from the battery computer 78, and the SOC is transmitted. The charge / discharge state of the battery is controlled so as to be held within a predetermined range. Specifically, when the hybrid control computer 70a detects that the SOC of the battery falls below a preset SOC lower limit SOCL, the hybrid control computer 70a sets the required load of the engine 10 high via the engine ECU 70, and the engine 10 Increase the driving force. Further, the hybrid control computer 70a charges the battery by operating the generator 81 in consideration of the traveling state of the hybrid vehicle, while the battery charging by the generator 81 is executed as prescribed, and the SOC is set in advance. When it is detected that the SOC upper limit value SOCH has been reached, charging is stopped.

  In the configuration shown in FIG. 1, a PCV valve 63 is electrically connected to the hybrid control computer 70a, and the target value set according to the engine operating state determined by the detection result of each sensor is set to the current value. The PCV opening degree TB can be recognized based on the position of the valve body 11 of the PCV valve 63 via the PCV opening degree sensor 63b so that the PCV opening degree TB approaches, and the valve body 11 is controlled by electronic control. Can be displaced (see FIG. 2).

  In the present embodiment, the engine ECU 70 and the hybrid control computer 70a are based on the throttle control that adjusts the intake flow rate GA and the injector 52 after grasping the driver's request and the engine operating state based on the detection results of the respective sensors. Injection control for adjusting the injection amount QI that is the fuel injection amount, fuel pressure control for adjusting the fuel pressure PI supplied to the injector 52, air-fuel ratio control for bringing the air-fuel ratio A / F of the air-fuel mixture closer to the target value, and the engine Various controls such as ventilation control for bringing the flow rate of blow-by gas supplied from the main body 20 into the intake device 40 (hereinafter referred to as “PCV flow rate GB”) close to the target value are performed.

  In the throttle control, the required value of the engine load factor is grasped based on the accelerator operation amount AC and the engine rotational speed NE, the intake flow rate GA corresponding to the required value is set as a target value, and the intake flow by the air flow meter 73 is set. The opening degree of the throttle valve 45 is controlled so that the flow rate GA approaches this target value.

  Further, in the injection control, an injection amount QI at which the air-fuel ratio A / F of the air-fuel mixture becomes a target value with respect to the intake flow rate GA by the air flow meter 73 is set as a basic injection amount. A value that reflects the corrected injection amount set through the control is set as a required value QIT of the injection amount that is the final value of the injection amount QI, and the actual value QIR of the injection amount that is the actual injection amount QI is set to the required value QIT. Therefore, the valve opening mode of the injector 52 is controlled.

  In the fuel pressure control, a target value PIT of the fuel pressure that is the target fuel pressure PI is set based on the engine load factor, and the actual value PIR of the fuel pressure that is the fuel pressure PI by the fuel pressure sensor 76 is set as the target value PIT. The discharge amount of the high-pressure pump is controlled so as to be maintained at the same level. When the actual fuel pressure value PIR is changed to a lower value through this fuel pressure control, the minimum injection amount QImin, which is the minimum value of the injection amount QI of the injector 52, and the maximum injection amount QImax, which is the maximum value. Is changed to a smaller value accordingly. On the contrary, when the actual value PIR of the fuel pressure is changed to a higher value through the fuel pressure control, the minimum injection amount QImin and the maximum injection amount QImax of the injector 52 are changed to larger values accordingly.

  In the air-fuel ratio control, the deviation amount and the deviation tendency between the target value AFT of the air-fuel ratio which is the target air-fuel ratio A / F and the actual value AFR of the air-fuel ratio which is the air-fuel ratio A / F by the air-fuel ratio sensor 77 are increased. Based on this, the correction injection amount of the injector 52 for setting the actual value AFR of the air-fuel ratio close to the target value AFT is set.

  Further, in the ventilation control, a PCV flow rate GB (hereinafter referred to as “PCV flow rate required value GBT”) required based on the engine load factor and the engine speed NE is set. Further, the PCV opening TB that is expected to maintain the actual PCV flow rate GB (hereinafter referred to as “actual value GBR of the PCV flow rate”) at the required value GBT is set as the required value TBT of the PCV opening. Then, the valve opening degree of the PCV valve 63 is controlled so that the actual PCV opening degree TB (hereinafter referred to as “actual value TBR of the PCV opening degree”) coincides with the required value TBT.

  The engine load factor is, for example, the ratio of the actual intake amount to the maximum value of the intake amount that can be supplied into 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 52. The ratio of the value (required value QIT of the injection amount) can be grasped as an index.

  As shown in FIG. 2, as described above, the accelerator position sensor 71, the battery computer 78, the wheel speed sensor 79, and the PCV opening sensor 63b are electrically connected to the hybrid control computer 70a, and each sensor detects it. The various types of information are input as signals, and the step motor 63s is electrically connected via the driver 63d.

In the configuration shown in FIG. 2, the PCV valve 63 is configured by the step motor 63s, the PCV opening sensor 63b, and the PCV valve main body 63e.
The PCV valve 63 functions to adjust the PCV flow rate GB and reduce the blow-by gas into the combustion chamber 31 through the first ventilation passage 61 and the intake manifold 46 for combustion.

  The PCV valve main body 63e includes the sub housing 14 and the main housing 15 assembled to each other, and the valve body 11 that is displaceable within the sub housing 14 and the main housing 15 and has a shape in which the tip portion is gradually reduced in diameter. It is comprised including.

  The PCV valve main body 63 e further includes a heater 63 a as a freeze eliminating means embedded in the main housing 15 and a seal ring 13 fitted on the outer periphery of the main housing 15. The main housing 15 is assembled to the sub housing 14 by fastening a female screw at one end thereof to a male screw at the other end of the sub housing 14. Further, one end portion (tip portion) of the sub-housing 14 forms a pipe joint for connecting to the first ventilation passage 61. The PCV valve 63 is attached to the engine body 20 by a male screw on the outer periphery of the other end of the main housing 15 being screwed into the head cover 25 (see FIG. 1).

  In the PCV valve main body 63e shown in FIG. 2, the valve body 11 is accommodated in the main housing 15 and communicated with the valve operating chamber 33 side through an opening 15a opened on the other end side of the main housing 15. A valve chamber 15b is formed. A hollow portion 14a is formed through the sub housing 14 so as to communicate with the valve chamber 15b. In addition, a compression spring 12 is disposed in the hollow portion 14a so as to be able to contact the tip of the valve body 11. The valve chamber 15b and the hollow portion 14a constitute a blow-by gas passage. An annular valve seat 11 a is interposed between the sub-housing 14 and the main housing 15. The valve body 11 can be moved back and forth (displaced) with respect to the valve seat 11a while passing through the valve chamber 15b and the hollow portion 14a along the axial direction of the PCV valve 63. The size of the gap between 11a and the valve body 11, that is, the PCV opening degree TB is changed.

  The step motor 63s is disposed in the PCV valve main body 63e so that the valve body 11 can be displaced in the valve chamber 15b and the hollow portion 14a in an airtight state via a rack and pinion mechanism (not shown).

  Then, when the PCV opening degree sensor 63b detects the current position of the valve body 11 in order to execute the above-described ventilation control, the hybrid control computer 70a sets the position based on the PCV flow rate required value GBT. The position command signal is sent to the step motor 63s via the driver 63d so that the current position (actual value TBR) of the valve body 11 matches the target position. Then, positioning control of the valve body 11 is executed. That is, the PCV opening degree TB is changed by the positioning control of the valve body 11 in this manner, and the PCV opening degree TB is required for the engine operating state (engine load factor and engine speed NE) of the engine 10. The required value TBT of the PCV opening as the opening is set. As shown in FIG. 2, in this state, the blow-by gas passes from the valve operating chamber 33 through the valve chamber 15 b and the hollow portion 14 a of the PCV valve main body 63 e, the first ventilation passage 61, and the intake passage 49, and the combustion chamber 31. It is reduced inside and burned again.

  In the present embodiment, the hybrid control computer 70a detects whether or not the valve body 11 of the PCV valve 63 is displaced according to the position command signal to the step motor 63s via the PCV opening sensor 63b. Thus, it is determined whether or not the PCV valve 63 is frozen. That is, in this embodiment, the PCV opening sensor 63b and the hybrid control computer 70a function as freezing detection means.

  The heater 63a includes a coil, and is electrically connected to the hybrid control computer 70a via a connection terminal and external wiring provided in the coil so as to be turned on and off. The valve body 11 of the PCV valve 63 is heated via the main housing 15 by supplying a required current to the heater 63a. The required energization current value is set to a value that can eliminate the freezing when the PCV valve main body 63e is frozen (fixed) at the portion of the valve body 11 in the cold state.

The blow-by gas reduction device 60 for a hybrid vehicle according to the present embodiment is configured as described above, and hereinafter, the freeze elimination logic as the operation will be described.
This freezing elimination logic is based on the cooperation of the engine ECU 70 as an electronic control unit and the hybrid control computer 70a in order to eliminate the following freezing phenomenon of the PCV valve 63 and the accompanying freezing phenomenon of the throttle valve 45 that occur in a cold region. Is to be executed.

  In other words, when the engine 10 is in a low engine load state, the negative pressure on the intake downstream side of the throttle valve 45 is large, so the surge tank 47 passes from the crank chamber 32 through the communication chamber 34, the valve operating chamber 33, and the first ventilation passage 61. Blow-by gas flows inside. Accordingly, the outside cold air containing moisture flows into the valve operating chamber 33 from the intake hose 43 through the second ventilation passage 62, so that the PCV valve 63 is frozen and the valve body 11 is fixed.

  When the engine 10 is in a high engine load state in this state, the pressure in the crank chamber 32 and the valve operating chamber 33 increases this time, so that the water generated by the combustion of the fuel in the combustion chamber 31 is included. The blow-by gas flows back to the upstream side of the intake of the throttle valve 45 through the second ventilation passage 62 and is cooled by the external cold air. The throttle valve 45 is frozen by the moisture contained therein, and the engine is stopped (engine stopped). cause.

  This freeze-freeing logic is executed according to the flowchart shown in FIG. That is, first, in step S1, it is determined whether or not the PCV valve 63 is frozen. Specifically, whether or not the PCV valve 63 has been displaced in response to a position command signal to the step motor 63s (whether or not the actual value TBR of the PCV opening is controlled so as to match the required value TBT). Is detected and determined at a predetermined sampling cycle via the PCV opening degree sensor 63b (step S1). If it is determined that there is no displacement according to the position command signal, “freezing” is set (in the case of YES), and the process proceeds to step S2. On the other hand, if it is determined that the position is displaced according to the position command signal, “no freezing” is set (in the case of NO), the process proceeds to step S10, and the hybrid control computer 70a receives the engine 10 and the motor. The normal driving mode in which the hybrid vehicle is driven by 80 is set, and the processing here is temporarily terminated.

  In step S2, it is determined whether or not the SOC indicating the state of charge of the battery is greater than or equal to the SOC lower limit SOCL. If it is determined that the SOC is greater than or equal to SOCL, the process proceeds to step S3 and the flag (FLG) is set to 1. (Step S3), and the hybrid control computer 70a is set to an EV traveling mode in which the hybrid vehicle is driven by only the motor 80 (step S4). On the other hand, if it is determined that it is less than SOCL, the process proceeds to step S3a, and the flag (FLG) is set to 0 (step S3a). In step S4a, the internal combustion engine and the motor are stopped, and the process proceeds to step S5.

  When the EV traveling mode is set in step S4 or the internal combustion engine and the motor are stopped in step S4a, energization to the heater 63a is turned on in the subsequent step S5. Then, whether or not the PCV valve 63 is frozen at a predetermined sampling period is determined in the same manner as in step S1 (step S6). Here, when “no freezing” is set (NO), the process proceeds to step S6, and the energization to the heater 63a is turned off (step S7). On the other hand, if “freezing” is set (in the case of YES), step S5 is continued and energization to the heater 63a is maintained.

  When energization to the heater 63a is turned off in step S7, it is determined in the subsequent step S8 whether or not the flag is 1, and if it is 1 (in the case of YES), the EV travel mode is determined in step S9. Is released. On the other hand, when it is not 1 (when 0) (when NO), the stop of the engine 10 and the motor 80 is released at step S9a. Then, in the subsequent step S10, the hybrid control computer 70a is set to the normal travel mode in which the hybrid vehicle is traveled by the engine 10 and the motor 80, and the process here is temporarily terminated.

According to the blow-by gas reduction device 60 for a hybrid vehicle of the present embodiment, the following operations and effects can be obtained.
(1) When it is determined that the PCV valve 63 is frozen, the hybrid control computer 70a is set to an EV traveling mode in which the operation of the engine 10 is stopped and the hybrid vehicle is driven only by the motor 80, and the heater 63a When the freezing of the PCV valve 63 is canceled and the freezing is canceled and it is determined that the PCV valve 63 is not frozen, the EV driving mode is canceled, and the engine 10 and the motor 80 drive the hybrid vehicle. The mode is set. Therefore, if the freezing of the PCV valve 63 is completed while the hybrid vehicle is set in the EV travel mode, the normal travel mode is set and the hybrid vehicle can be driven by the engine 10 and the motor 80. Regardless of the freeze of the PCV valve 63, the backflow of blow-by gas to the intake passage 49 is prevented, and smooth running of the hybrid vehicle is ensured.

  (2) It is possible to accurately determine whether or not the PCV valve 63 is frozen based on the determination criterion that the PCV opening degree TB of the PCV valve 63 is uncontrollable (is not maintained at the required value TBT). It becomes possible.

  (3) When the hybrid control computer 70a recognizes that the PCV valve 63 is frozen, the PCV valve 63 can be defrosted by turning on the heater 63a and energizing the heater 63a. When the computer 70a recognizes that the PCV valve 63 is not frozen, the heater 63a can be turned off to stop energization of the heater 63a. For this reason, the freeze-release logic of the PCV valve 63 can be performed efficiently and rationally.

  (4) When the battery power required to drive the motor 80 is insufficient and the SOC of the battery is below the SOC lower limit SOCL, the PCV valve 63 is frozen while the engine 10 and the motor 80 are stopped. Therefore, the smooth running of the hybrid vehicle is ensured without causing the engine 10 to stop (engine stall) due to the freezing of the throttle valve 45.

The above embodiment may be modified as follows.
In the above embodiment, the PCV valve 63 is of an electronic control type in which the PCV opening degree TB is automatically changed based on the engine operating state. However, the present invention is not limited to this, and a negative pressure type PCV valve may be used in which the valve is opened when the intake passage 49 has a negative pressure with respect to the crank chamber 32 or the valve operating chamber 33.

  In the above embodiment, the PCV opening sensor 63b and the hybrid control computer 70a function as freezing detection means, and the hybrid is determined based on whether or not the PCV valve 63 is displaced according to the position command signal to the step motor 63s. Whether or not the PCV valve 63 is frozen is determined by the control computer 70a. However, the present invention is not limited to this. For example, the PCV opening sensor 63b and the hybrid control computer 70a function as freezing detection means, and the air / fuel ratio A / F based on the oxygen concentration in the exhaust gas is predicted according to the engine operating state. Whether or not it is true can be used as a criterion. That is, when the PCV valve 63 is frozen, the blow-by gas is not reduced to the combustion chamber 31, so that the freezing of the PCV valve 63 can be detected by increasing the air-fuel ratio A / F above the predicted value. It becomes.

  In the above embodiment, the heater 63a is used as the freeze-releasing means, and the PCV valve 63 is defrosted by turning on the heater 63a and energizing the heater 63a. However, the present invention is not limited to this. For example, the stepping motor 63s may be used as the freezing unit, and the freezing operation of the PCV valve 63 may be performed using the self-heating of the stepping motor 63s.

Further, technical ideas that can be grasped from the above-described embodiments and modifications will be described below.
The blow-by gas reduction device for a hybrid vehicle according to claim 1, wherein the PCV valve is an electronically controlled PCV valve whose PCV opening degree is controlled by the electronic control device.

According to this configuration, it is possible to accurately determine whether or not the PCV valve is frozen based on the determination criterion that the PCV opening degree of the PCV valve is uncontrollable.
The blow-by gas reducing device for a hybrid vehicle according to claim 1, wherein the freeze eliminating means is a heater provided on the PCV valve and controlled to be turned on and off by the electronic control device.

  According to this configuration, when the electronic control unit recognizes that the PCV valve is frozen, the PCV valve can be defrosted by turning on the heater and energizing the heater. When recognizing that the PCV valve is not frozen, the heater can be turned off to stop energization of the heater. As a result, the PCV valve freezing logic can be performed efficiently and rationally.

  The electronic control device drives the motor to the hybrid vehicle and determines the magnitude relationship between the SOC of a battery provided in the hybrid vehicle to store the regenerative energy and a preset SOC lower limit value. At the same time, if it is determined that the SOC does not reach the SOC lower limit value, the internal combustion engine and the motor are stopped without being set to the EV travel mode, and the PCV valve is frozen by the freeze release means. The blow-by gas reduction device for a hybrid vehicle according to claim 1, wherein only the cancellation is executed.

  According to this configuration, when the battery power required to drive the motor is insufficient and the SOC of the battery is below the SOC lower limit value, the PCV valve is frozen while the internal combustion engine and the motor are stopped. Since only the canceling operation is performed, even when the battery power necessary to drive the motor is insufficient, the hybrid vehicle can smoothly travel without causing the internal combustion engine to stop due to the freezing of the throttle valve. Will be secured.

  2. The PCV valve according to claim 1, wherein the PCV valve is a negative pressure PCV valve that is opened when the intake passage has a negative pressure with respect to a crank chamber or a valve chamber of an internal combustion engine. Blow-by gas reduction device for hybrid vehicles.

  According to this configuration, it is possible to configure the PCV valve with an inexpensive and reliable negative pressure type PCV valve.

  DESCRIPTION OF SYMBOLS 10 ... Engine (internal combustion engine), 49 ... Intake passage, 60 ... Blow-by gas reduction device, 61 ... 1st ventilation passage (PCV passage), 62 ... 2nd ventilation passage, 63 ... (electronic control type) PCV valve, 63a ... Heater heater (freezing elimination means), 63b ... PCV opening sensor (freezing detection means), 70 ... engine ECU (electronic control device), 70a ... hybrid control computer (electronic control device, freezing detection means), 80 ... motor.

Claims (1)

A PCV passage for reducing blowby gas to an intake passage for introducing outside air into a combustion chamber of the internal combustion engine, and a PCV passage that passes through the PCV passage. A blow-by gas reduction device having a PCV valve for adjusting the flow rate of blow-by gas
Freezing detecting means for detecting the presence or absence of freezing of the PCV valve, and freezing eliminating means for canceling freezing of the PCV valve,
When the electronic control unit determines that there is freezing through the freezing detection means, the electronic control unit is set to an EV traveling mode in which the operation of the internal combustion engine is stopped and the hybrid vehicle is traveled only by the motor, and the freezing is eliminated. When the PCV valve is freezing by the means, the freezing is canceled and it is determined that the PCV valve is not frozen. The EV traveling mode is canceled and the hybrid vehicle is driven by the internal combustion engine and the motor. A blow-by gas reduction device for a hybrid vehicle characterized by being made.

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