JP4718522B2 - PCV valve control device - Google Patents

Description

  The present invention relates to a blow-by gas reduction device that returns blow-by gas that has leaked from a combustion chamber of an engine to a crankcase and returns the blow-by gas to the combustion system of the engine. Specifically, the present invention relates to a control device for a PCV valve (positive crankcase ventilation valve) provided in the reduction device and provided with a heater.

  Conventionally, as this type of technology, those described in Patent Documents 1 to 5 below are known. In particular, Patent Document 1 describes a PCV valve (blow-by gas flow control valve) including a heater. The heater is provided in the PCV valve in order to release the freezing of the valve body and the like inside the PCV valve by causing the heater to generate heat when cold. In Patent Document 1, a PTC heater is attached to the outside of the valve housing. An engine ignition switch and a power source are connected in series to the PTC heater. When the engine is started, the ignition switch is turned on, and energization is performed when the engine is below a predetermined temperature, so that the PTC heater generates heat.

Japanese Utility Model Publication No. 5-87212 Japanese Utility Model Publication No. 4-117129 Japanese Utility Model Publication No. 47-15536 Japanese Utility Model Publication No. 60-98709 Japanese Utility Model Publication No. 61-122313

  However, in the technique described in Patent Document 1, the PTC heater is only energized uniformly when the engine is at a predetermined temperature or lower during startup. Here, when the PCV valve is lightly frozen, it may be possible to release the PCV valve from being frozen by relatively short heating. In this case, according to the technique described in Patent Document 1, it is possible to energize the PTC heater more than necessary. For this reason, there is a concern that the PTC heater may be overheated, and there is a concern that the burden on the battery is increased and the fuel consumption of the engine is deteriorated.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a control device for a PCV valve that does not energize an electric heater more than necessary for releasing the freeze of the PCV valve. .

In order to achieve the above object, a first aspect of the present invention is a PCV valve control device for controlling energization of an electric heater provided in a PCV valve, wherein the PCV valve is controlled based on a temperature state around the PCV valve. A target heat amount calculating means for calculating a target heat amount necessary for releasing the freezing, a heat generation amount integrating means for integrating the heat generation amount by the electric heater after energization of the electric heater is started, and a predetermined amount Based on the energization control means for energizing the electric heater from the start of energization to the electric heater based on the target power until the heat generation amount integration result reaches the target heat amount, and the temperature state around the PCV valve Target power calculation means for calculating the target power, and the heat generation amount integration means is intended to integrate the heat generation amount based on the calculated target power .

According to the configuration of the above invention, when the electric heater is energized, the target heat amount calculating means calculates the target heat amount necessary for releasing the freeze of the PCV valve based on the temperature state around the PCV valve. Further, the amount of heat generated by the electric heater since the energization of the electric heater is started is integrated by the heat generation amount integrating means. Then, after the energization to the electric heater is started based on the predetermined target power, the energization control means performs the energization to the electric heater until the heat generation amount integration result reaches the target heat amount. Therefore, the electric heater is energized only while the PCV valve is released from freezing. Further, the target power is calculated by the target power calculation means as an appropriate value reflecting the temperature state around the PCV valve. Since the heat generation amount is integrated based on the target power, the time until the integrated heat generation amount reaches the target heat amount is not prolonged regardless of the temperature state around the PCV valve.

In order to achieve the above object, according to a second aspect of the present invention, in the first aspect of the present invention, the PCV valve is provided attached to an engine mounted on an automobile, and the target power calculation means is an engine The purpose is to calculate the target power based on the temperature state at the start of the vehicle and the traveling speed of the automobile.

According to the configuration of the invention described above, in addition to the operation of the invention according to claim 1 , the temperature state at the time of starting the engine is related to the degree of freezing of the PCV valve. The traveling speed of the automobile is related to the traveling wind strength that inhibits the heat generation of the electric heater. In the present invention, since the target power is calculated based on the temperature state at the start of the engine and the travel speed of the automobile, the difference between the degree of freezing of the PCV valve and the travel wind strength is reflected in the target power.

In order to achieve the above object, according to a third aspect of the present invention, in the first or second aspect of the present invention, the electric heater is supplied with electric power from a battery, and the energization control means includes a calculated target electric power and The purpose is to determine the current required for energizing the electric heater from the voltage of the battery.

According to the configuration of the invention described above, in addition to the operation of the invention according to claim 1 or 2 , even if the voltage of the battery fluctuates, the current that can secure the target power is determined for energizing the electric heater. Is done.

In order to achieve the above object, the invention according to claim 4 is the invention according to any one of claims 1 to 3 , wherein the electric heater includes a coil that generates heat when energized.

According to the configuration of the above invention, in addition to the operation of the invention according to any one of claims 1 to 3 , the upper limit is set by the target heat amount for the heat generation amount by the electric heater, or the target energization is performed for the energization time to the electric heater. Since the upper limit is set according to time, overheating of the coil can be suppressed.

In order to achieve the above object, according to a fifth aspect of the present invention, there is provided an electric heater according to any one of the first to fourth aspects, wherein the temperature state of the engine provided with the PCV valve is one of the determination conditions. The purpose is to provide execution determination means for determining in advance whether or not to energize the battery.

According to the configuration of the above invention, in addition to the operation of the invention according to any one of claims 1 to 4 , it is determined whether or not to energize the electric heater using the engine temperature state as one of the determination conditions. Since it is determined by the means, the electric heater is not energized under a temperature condition in which the PCV valve is not frozen.

According to the first aspect of the present invention, it is possible to prevent the electric heater from being energized more than necessary for releasing the freeze of the PCV valve. In addition, the minimum necessary amount of heat can be supplied to the PCV valve for releasing the freeze according to the temperature state around the PCV valve.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the invention, in particular, the necessary minimum amount of heat for releasing the freeze according to the difference between the degree of freezing of the PCV valve and the traveling wind strength. Can be supplied to the PCV valve.

According to the invention described in claim 3 , in addition to the effect of the invention described in claim 1 or 2 , even if the voltage of the battery fluctuates, it is possible to supply the PCV valve with the amount of heat necessary for releasing the freeze.

According to the invention described in claim 4 , in addition to the effect of the invention described in any one of claims 1 to 3 , it is possible to prevent the coil of the electric heater from being melted.

According to the invention described in claim 5 , in addition to the effect of the invention described in any one of claims 1 to 4 , it is possible to energize the electric heater only when it is necessary to release the freeze, and wasteful power consumption. Can be suppressed.

  Hereinafter, an embodiment of a PCV valve control device of the present invention embodied in an engine system including a blow-by gas reduction device will be described in detail with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an engine system including a blow-by gas reduction device of this embodiment. In the engine system of this embodiment, a direct injection type multi-cylinder spark ignition engine 1 that directly injects fuel into the combustion chamber 2 is employed. A plurality of cylinder bores 4 are formed in the engine block 3 constituting the engine 1, and a piston 5 is provided in each cylinder bore 4 so as to be movable up and down. A crankcase 3a is provided below the engine block 3, and an oil pan 6 is assembled to the crankcase 3a. A crank chamber 7 is formed by the crankcase 3 a and the oil pan 6. A crankshaft 8 is rotatably supported in the crank chamber 7, and each piston 5 is connected to the crankshaft 8 via a connecting rod 9.

  The combustion chamber 2 formed on the upper side of the piston 5 in each cylinder bore 4 has an inclined pent roof shape whose upper center is raised. Corresponding to each combustion chamber 2, an intake port 10 and an exhaust port 11 are formed in the upper part of the engine block 3. The intake port 10 is provided with an intake valve 12, and the exhaust port 11 is provided with an exhaust valve 13. Each intake valve 12 and each exhaust valve 13 are opened and closed in conjunction with the rotation of the crankshaft 8 by a known valve mechanism 14. When the intake valve 12 and the exhaust valve 13 are opened and closed, outside air is introduced from the intake port 10 to the combustion chamber 2, and exhaust gas after combustion is discharged from the combustion chamber 2 to the exhaust port 11. An engine cover 15 that covers the valve operating mechanism 14 and the like is provided on the upper portion of the engine block 3.

  An intake passage 21 including an intake manifold is connected to the intake port 10. An air cleaner 22 is provided at the inlet of the intake passage 21. An electronic throttle 25 including a throttle valve 23 and a motor 24 is provided in the middle of the intake passage 21. The electronic throttle 25 is configured to open and close the throttle valve 23 by a motor 24. The electronic throttle 25 is operated based on an operation of an accelerator pedal 20 provided at the driver's seat. The air purified by the air cleaner 22 is sucked into the combustion chamber 2 through the intake passage 21, the electronic throttle 25 and the intake port 10. The intake air amount is adjusted according to the opening of the throttle valve 23. An injector 26 for directly injecting fuel into each combustion chamber 2 is attached to the engine block 3. The fuel injected from the injector 26 into the combustion chamber 2 forms an air-fuel mixture with the air sucked into the combustion chamber 2 from the intake port 10. A spark plug 27 for igniting the air-fuel mixture in each combustion chamber 2 is provided at the top of the engine block 3.

  An exhaust passage 28 including an exhaust manifold is connected to the exhaust port 11. Exhaust gas after combustion generated in each combustion chamber 2 is discharged to the outside through the exhaust port 11 and the exhaust passage 28.

  The engine 1 described above is provided with a blow-by gas reduction device for flowing the blow-by gas leaked from each combustion chamber 2 into the intake passage 21 and reducing it to each combustion chamber 2. In other words, the oil separator 31 communicating with the crank chamber 7 is provided in the crankcase 3a. The oil separator 31 has a function of separating and capturing oil components such as lubricating oil mixed in the blow-by gas in the crank chamber 7 from the blow-by gas. Between the oil separator 31 and the intake passage 21 downstream of the throttle valve 23, a reduction passage 32 for flowing blow-by gas from the crank chamber 7 to the intake passage 21 is provided. A PCV valve 33 for adjusting the blow-by gas flow rate is provided in the middle of the reduction passage 32. The detailed configuration of the PCV valve 33 will be described later. Between the intake passage 21 in the vicinity of the air cleaner 22 and the engine cover 15, a scavenging passage 34 for introducing outside air into the crank chamber 7 is provided to scavenge blow-by gas accumulated in the crank chamber 7 of the engine 1. The engine block 3 is formed with a vent hole 35 that allows the crank chamber 7 to communicate with the engine cover 15. The outside air introduced into the engine cover 15 is guided to the crank chamber 7 through the vent hole 35. The vent hole 35 constitutes a part of the scavenging passage 34.

  Here, the configuration of the PCV valve 33 will be described in detail. 2 and 3 are sectional views of the PCV valve 33. FIG. FIG. 2 shows an initial state of the PCV valve 33, and FIG. 3 shows an operating state of the PCV valve 33. As shown in FIGS. 2 and 3, the PCV valve 33 includes a resin housing 41 having a hollow shape. The housing 41 includes a main housing 42 and a sub-housing 43 that are assembled together.

  The main housing 42 includes a connector portion 42a formed at an upper portion thereof, an electric heater 44 integrally provided therein, and a seal ring 45 attached to the outer periphery. The sub housing 43 is assembled to the main housing 42 by tightening a male screw 43 a on the outer periphery of one end thereof to a female screw 42 b on the other end of the main housing 42. The sub housing 43 can also be assembled to the main housing 42 by press-fitting one end portion of the sub housing 43 into the other end portion of the main housing 42 and performing ultrasonic welding. The other end portion of the sub housing 43 is a pipe joint 43b. A pipe constituting the reduction passage 32 is connected to the pipe joint 43d. The housing 3 is attached by tightening a male screw 42c on the outer periphery of one end of the main housing 42 to a female screw in a mounting hole (not shown) formed in the oil separator 31.

  The hollow portion of the main housing 42 constitutes a valve chamber 42d. The valve chamber 42d includes an inlet 42e at one end in the central axis direction. The inlet 42 e is formed in one end wall of the main housing 42 and communicates with the crank chamber 7 of the engine block 3 through the oil separator 31. The sub housing 43 includes a hollow portion 43 c communicating with the valve chamber 42 d of the main housing 42. The valve chamber 42d and the hollow portion 43c constitute a passage for blow-by gas. An annular valve seat 46 is sandwiched between the main housing 42 and the sub-housing 43. Corresponding to the valve seat 46, a valve body 47 is provided in the valve chamber 42d so as to be movable in the central axis direction. The valve body 47 has a substantially cylindrical shape and is provided so as to be able to penetrate the valve seat 46. As shown in FIGS. 2 and 3, the valve body 47 has a shape whose diameter is gradually reduced from the base end portion (right side of the drawing) to the distal end portion. Accordingly, when the valve element 47 moves in the central axis direction in the valve chamber 42d, the size of the gap between the valve seat 46 and the valve element 47, that is, the opening degree as the blow-by gas flow path area, changes. . A gap between the valve seat 46 and the valve body 47 constitutes an outlet 48 located at the other end in the central axis direction of the valve chamber 42d.

  The valve body 47 has a flange 47a at its base end, that is, an inlet side end located in the vicinity of the inlet 42e. A part of the outer peripheral surface of the flange 47a is slidably provided on the inner peripheral surface of the valve chamber 42d. The flange 47a is provided with a notch that allows passage of blow-by gas in a part thereof. A compression spring 49 is provided between the valve seat 46 and the flange 47a. The spring 49 urges the valve body 47 in the direction of the inlet 42e of the valve chamber 42d, that is, in the valve opening direction. Further, the distal end portion of the valve body 47 is provided so as to penetrate the valve seat 46 and enter the hollow portion 43 c of the sub housing 43. Another compression spring 50 is provided in the hollow portion 43 c of the sub-housing 43 so as to be able to contact the tip of the valve body 47.

  When the engine 1 enters the operating state from the initial state shown in FIG. 2, negative intake pressure acts on the hollow portion 43 c of the sub housing 43 from the intake passage 21 through the reduction passage 32. The blow-by gas filled in the crank chamber 7 of the engine 1 enters the valve chamber 42d of the main housing 42 from the inlet 42e, and the gas pressure acts on the valve body 47. At this time, the negative intake pressure acts on the valve body 47 against the urging force of the spring 49, and the gas pressure acts on the valve body 47, so that the valve body 47 moves to the valve seat 46 as shown in FIG. It moves in the direction of its central axis and the size (opening) of the outlet 48 between the valve seat 46 and the valve body 47 changes. Thereby, the blow-by gas flow rate that is measured from the valve chamber 42d of the main housing 42 to the hollow portion 43c of the sub-housing 43, that is, measured by the PCV valve 33, is adjusted. The movement of the valve body 47 is restricted by the tip of the valve body 47 coming into contact with the spring 50 in the hollow portion 43 c of the sub-housing 43. Thus, in the PCV valve 33, the valve body 47 changes the position of the blow-by gas passage between the valve seat 46 and the valve seat 46 by changing the position in the central axis direction by the action of the intake negative pressure.

  As shown in FIGS. 2 and 3, the electric heater 44 is provided inside the main housing 42. The electric heater 44 includes a cylindrical bobbin 51 having large and small flanges 51a and 51b at both ends in the central axis direction, a coil 52 provided by winding a nichrome wire around the outer periphery of the bobbin 51, and a large flange 51a. Connected terminal 53. The coil 52 generates heat when energized. The connection terminal 53 has a proximal end portion electrically connected to the coil 52, and a distal end portion that protrudes into the connector portion 42a.

  The electric heater 44 is insert-molded with respect to the main housing 42. That is, when the main housing 42 is molded with resin, the electric heater 44 is loaded into the mold as an insert, and then molten resin is injected into the mold. As a result, the electric heater 44 is wrapped with the molten resin and solidified to produce the main housing 42 as an integrated composite part. Here, as shown in FIGS. 2 and 3, the electric heater 44 is disposed at the center of the main housing 42, and the hollow of the bobbin 52 of the electric heater 44 constitutes most of the valve chamber 42 d of the main housing 42. The valve seat 46 is included in the large flange 51a of the bobbin 51, and is provided integrally with the main housing 42 in contact with the inner peripheral surface of the large flange 51a.

  Here, the operation of the valve body 47 will be described. As shown in FIGS. 2 and 3, the valve body 47 is provided in the hollow of the bobbin 51 of the electric heater 44 so as to be able to penetrate along the central axis of the bobbin 51 and the coil 52. As shown in FIG. 2, in the initial state of the PCV valve 33, that is, in the state where no negative intake pressure is acting on the valve chamber 42d, the valve body 47 is brought close to the inlet 42e by the biasing force of the spring 49. Is placed at the initial position. Further, in the operating state of the PCV valve 33, that is, in the state where intake negative pressure is applied to the valve chamber 42d, as shown in FIG. 3, the valve body 47 is disposed at a specific position determined by the action of the intake negative pressure. The

  An external connector (not shown) is connected to the connector portion 42a of the main housing 42 shown in FIGS. The external connector is configured to be electrically connectable to the connection terminal 53. In order to control the electric heater 44, the external connector is connected to an electronic control unit (ECU) 60 (see FIG. 1), which will be described later, through an external wiring (not shown).

  In this embodiment, an ECU 60 is provided to control the engine system described above. An air flow meter 61 for measuring the intake air amount QA is provided on the upstream side of the intake passage 21. The electronic throttle 25 is provided with a throttle sensor 62 for detecting the opening degree (throttle opening degree) TA of the throttle valve 23. The engine block 3 is provided with a crank angle sensor 63 for detecting the rotation angle (crank angle) of the crankshaft 8 as the engine rotation speed NE. The engine block 3 is provided with a water temperature sensor 64 for detecting the coolant temperature THW. The oil pan 6 is provided with an oil temperature sensor 65 for detecting the temperature (oil temperature) THO of the lubricating oil. The exhaust passage 27 is provided with an oxygen sensor 66 for detecting the oxygen concentration Ox in the exhaust gas. The accelerator pedal 20 is provided with an accelerator sensor 67 for detecting the operation amount (accelerator opening) ACCP. Further, a vehicle equipped with the engine 1 is provided with a vehicle speed sensor 68 for detecting the traveling speed (vehicle speed) SPD. In addition, an intake air temperature sensor 69 for detecting the temperature (intake air temperature) THA of the air taken into the intake passage 21 is provided in the vicinity of the air cleaner 22. These various sensors 61 to 69 correspond to an operation state detection means for detecting the operation state of the engine 1 and the like. The ECU 60 discriminates each stroke of intake, compression, expansion (explosion), and exhaust in each cylinder based on the crank angle detected by the crank angle sensor 63, and calculates the engine rotational speed NE. The ECU 60 also detects the intake air amount QA, throttle opening TA, engine speed NE, cooling water temperature THW, oil temperature THO, oxygen concentration Ox, accelerator opening ACCP, and vehicle speed SPD detected by various sensors 61-69. Based on the above, fuel injection control, ignition timing control, electronic throttle control, PCV valve control, and the like are executed. The ECU 60 controls the injector 25 by executing fuel injection control. The ECU 60 controls the spark plug 26 by executing ignition timing control. The ECU 60 controls the electronic throttle 25 by executing electronic throttle control. That is, the ECU 60 drives the motor 24 based on the accelerator opening ACCP detected by the accelerator sensor 67 to drive the throttle valve 23 to open and close. In addition, the ECU 60 controls the energization of the electric heater 44 by executing PCV valve control in order to heat the PCV valve 33. In this embodiment, the ECU 60 corresponds to a target heat amount calculation unit, a heat generation amount integration unit, an energization control unit, a target power calculation unit, and an execution determination unit of the present invention. A battery 70 is connected to the ECU 60 to supply power.

  FIG. 4 is a flowchart showing the processing contents of PCV valve control. The ECU 60 executes this routine after the engine 1 is started.

  That is, in step 100, the ECU 60 determines whether or not a precondition for energizing the electric heater 44 is satisfied. The ECU 60 determines that this precondition is satisfied based on detection signals from the various sensors 61 to 69 and the voltage of the battery 70 (battery voltage). As preconditions, the following conditions must be satisfied. That is, first, it is necessary that the battery voltage is equal to or higher than a predetermined value (for example, “10.5 V”). Second, it is necessary that the various sensors 61 to 69 have no abnormality. Third, the history of the previous trip is a predetermined state (the coolant temperature THW at the end of the trip is a predetermined value (for example, “80 ° C.”) or more, and the intake air temperature THA at the end of the trip is a predetermined value (for example, “20 ° C.” or less). If all of these conditions are not satisfied, the ECU 60 stops energizing the electric heater 44 of the PCV valve 33 in step 200, assuming that the preconditions are not satisfied. If all the above conditions are satisfied, the ECU 60 proceeds to step 110 assuming that the precondition is satisfied.

  In step 110, the ECU 60 determines whether an execution condition for energizing the electric heater 44 is satisfied. The ECU 60 determines whether this execution condition is satisfied based on detection signals from the various sensors 61-69. The following conditions must be satisfied as execution conditions. That is, first, it is necessary that the cooling water temperature THW (starting water temperature) at the time of starting the engine is not more than a predetermined value (for example, “−10 ° C.”). This is to confirm the freezing conditions. Second, it is necessary that the intake air temperature THA (start-up intake air temperature) at the time of starting the engine is not more than a predetermined value (for example, “−10 ° C.”). It is also for confirming freezing conditions. Thirdly, it is necessary that the elapsed time after starting the engine is not less than a predetermined value (for example, “10 seconds”) and not more than a predetermined value (for example, “600 seconds”). This is to prevent the cranking of the engine 1 and the energization of the electric heater 44 from overlapping. Fourth, the vehicle speed SPD needs to be a predetermined value (for example, “50 km / h”) or more. This is to confirm the freezing conditions. Fifth, it is necessary that the integrated intake air amount is not more than a predetermined value (for example, “5500 g”). This is for confirming natural freezing release as the engine 1 warms up. Sixth, it is necessary that a certain amount of blow-by gas flows through the PCV valve 33, that is, the intake pressure in the intake passage 21 is not more than a predetermined value (for example, “50 kPa”). This is to prevent the electric heater 44 from overheating when blow-by gas does not flow. Seventh, the operation elapsed time of the electric heater 44 needs to be a predetermined value (for example, “600 seconds”) or less. This is for fail safe of the electric heater 44. Eighth, the elapsed time after the power supply to the electric heater 44 is stopped needs to be a predetermined value (for example, “2 seconds”) or more. This is for preventing chattering of energization. If all of these conditions are not satisfied, the ECU 60 stops energization of the PCV valve 33 to the electric heater 44 in step 200, assuming that the execution conditions are not satisfied. On the other hand, if all the above conditions are satisfied, the ECU 60 proceeds to step 120 assuming that the execution condition is satisfied.

In step 120, the ECU 60 calculates a target power necessary for energizing the electric heater 44. The ECU 60 calculates the target electric power according to the following (Equation 1) based on the basic electric power and the vehicle speed coefficient in order to give the target electric power as a conforming value depending on the driving environment and the driving situation of the engine 1.
Target power = Basic power * Vehicle speed coefficient (Equation 1)

  Here, the ECU 60 calculates the basic power based on the starting water temperature by referring to the function data (map) shown in FIG. In this function data, when the starting water temperature is in the range of “−40 to −20 ° C.”, the basic power is the maximum value “about 9 W”, and in the range where the starting water temperature is “−20 to 20 ° C.”, the basic power is “ It decreases almost linearly in the range of “about 9 to 0 W”, and the basic power becomes a constant value of “0 W” in the range of the water temperature at start-up “20 to 80 ° C.”.

  Further, the ECU 60 calculates the vehicle speed coefficient based on the vehicle speed SPD by referring to the function data (map) shown in FIG. In this function data, the vehicle speed coefficient is “0” when the vehicle speed SPD is “0 to 25 km / h”, and the vehicle speed coefficient is “0 to 1” when the vehicle speed SPD is “25 to 100 km / h”. The vehicle speed coefficient increases substantially in a curve, and the vehicle speed coefficient becomes a constant value of “1” in the range of the vehicle speed SPD of “100 to 200 km / h”.

In step 130, the ECU 60 integrates the amount of heat (heat generation amount) generated by energization of the electric heater 44. The ECU 60 integrates this heat generation amount according to the following (Equation 2) based on the target power.
Calorific value = ∫ (target power) dt (Expression 2)

  In step 140, the ECU 60 calculates a target heat amount to be generated by the electric heater 44. Here, the ECU 60 calculates the target heat quantity based on the starting water temperature by referring to the function data (map) shown in FIG. In this function data, when the starting water temperature is in the range of “−40 to 0 ° C.”, the target heat amount decreases in a substantially curved manner in the range of “about 550 to 0 cal”, and the starting water temperature is in the range of “0 to 80 ° C.”. Then, the target heat amount is a constant value of “0 cal”. In this map, the target heat quantity is set assuming a minimum heat quantity necessary for releasing the freezing according to the degree of freezing of the PCV valve 33 that varies depending on the water temperature at the start.

  Thereafter, in step 150, the ECU 60 determines whether or not the integrated heat generation amount is equal to or less than the calculated target heat amount. If the determination result is affirmative, the ECU 60 proceeds to step 160.

  That is, in step 160, the ECU 60 calculates an output duty ratio for energizing the electric heater 44. Here, the ECU 60 calculates the output duty ratio from the target power and the battery voltage by referring to the function data (map) shown in FIG. That is, a current is calculated from the target power and the battery voltage, and an output duty ratio corresponding to the current is calculated. For example, when the battery voltage is “10 V”, the output duty ratio corresponding to the battery voltage and the current value is determined by referring to the data indicated by the thick line in FIG. Alternatively, when the battery voltage is “14V”, the output duty ratio corresponding to the battery voltage and the current value is determined by referring to the data indicated by the broken line in FIG.

  In step 170, the ECU 60 causes the electric heater 44 to generate heat by energizing the electric heater 44 based on the calculated output duty ratio.

  On the other hand, if the determination result in step 150 is negative, the ECU 60 proceeds to step 200 and stops energization of the electric heater 44.

  By executing the above-described routine, as shown in FIG. 9, energization to the electric heater 44 is started, and the accumulated amount of heat generated by the electric heater 44 increases in a substantially curved manner. And when the integration result of the calorific value reaches the target calorific value, energization to the electric heater 44 is stopped.

  According to the blow-by gas reduction device in this embodiment described above, the blow-by gas leaked from the combustion chamber 2 to the crank chamber 7 during operation of the engine 1 is transmitted from the crank chamber 7 to the oil separator 31, the PCV valve 33, and the reduction passage 32. To the intake passage 21 and is reduced to the combustion chamber 2 for combustion. The blow-by gas flow rate in the reduction passage 32 is adjusted by the PCV valve 33.

  Here, in a cold region in winter, when the engine 1 is started, freezing of the valve body 47 and the like with respect to the PCV valve 33 becomes a problem. Therefore, according to the control device for the PCV valve in this embodiment configured to control the energization to the electric heater 44, when the electric heater 44 is energized, the PCV valve 33 is controlled based on the temperature state around the PCV valve 33. The ECU 60 estimates the target heat amount necessary for releasing the freezing. Then, after the energization of the electric heater 44 is started based on the predetermined target power, the ECU 60 energizes the electric heater 44 until the accumulated amount of heat generated by the electric heater 44 reaches the target heat amount.

  Specifically, the ECU 60 calculates a target heat amount necessary for releasing the freeze of the PCV valve 33 based on the temperature state around the PCV valve 33. In addition, the ECU 60 integrates the amount of heat generated by the electric heater 44 after the energization of the electric heater 44 is started. Then, after the energization of the electric heater 44 is started based on the predetermined target power, the energization of the electric heater 44 is performed by the ECU 60 until the heat generation amount integration result reaches the target heat amount. Accordingly, the electric heater 44 is energized only while the PCV valve 33 is released from freezing. For this reason, it is possible to prevent the electric heater 44 from being energized more than necessary for the freeze release of the PCV valve 33. Thereby, overheating of the electric heater 44 can be prevented, and the PCV valve 33 can be protected from the overheating. In addition, by not energizing more than necessary, it is possible to reduce the burden on the battery 70 and prevent the fuel consumption of the engine 1 from deteriorating.

  In this embodiment, the target power is not a uniform value but is calculated by the ECU 60 as a suitable value reflecting the temperature state around the PCV valve 33. Since the heat generation amount is integrated based on the target power, the time until the integrated heat generation amount reaches the target heat amount is not prolonged regardless of the temperature state around the PCV valve 33. For example, by setting the target power to increase as the ambient temperature of the PCV valve 33 decreases, it is possible to prolong the time until the accumulated heat generation amount reaches the target heat amount even at low temperatures. Absent. For this reason, the minimum necessary amount of heat can be supplied to the PCV valve 33 for releasing the freeze according to the difference in the temperature state around the PCV valve 33.

  In particular, in this embodiment, the target electric power is calculated by the ECU 60 based on the starting water temperature reflecting the temperature state of the engine 1 at the time of starting and the vehicle speed SPD. Here, the starting water temperature is related to the degree of freezing of the PCV valve 33. The vehicle speed SPD is related to the traveling wind strength that inhibits the heat generation of the electric heater 44. In this embodiment, since the target power is calculated based on the starting water temperature and the vehicle speed SPD, the difference between the degree of freezing of the PCV valve 33 and the traveling wind strength is reflected in the target power. Therefore, in particular, the minimum necessary amount of heat can be supplied to the PCV valve 33 for releasing the freeze according to the difference between the degree of freezing of the PCV valve 33 and the traveling wind strength.

  In this embodiment, the current required for energizing the electric heater 44 is determined as the output duty ratio from the calculated target power and battery voltage. That is, even when the battery voltage fluctuates, a current (output duty ratio) that can ensure the target power is determined for energizing the electric heater 44. For this reason, even if the battery voltage fluctuates, it is possible to supply the PCV valve 33 with the amount of heat necessary for releasing the freeze. Thereby, regardless of the fluctuation of the battery voltage, the characteristic fluctuation related to the operation of the electric heater 44 can be within the allowable range, and the robustness related to the control of the electric heater 44 can be improved.

  In this embodiment, since the electric heater 44 includes the coil 52 that generates heat when energized, the electric heater 44 can be made relatively inexpensive. On the other hand, since the coil-type electric heater 44 has a flat temperature-resistance characteristic, it is difficult to limit the current at high temperatures and tends to overheat. On the other hand, in this embodiment, since the upper limit is set by the target heat amount with respect to the heat generation amount by the electric heater 44, overheating of the coil 52 is suppressed. For this reason, it is possible to prevent the coil 52 of the electric heater 44 from being melted by overheating.

  Further, in this embodiment, the ECU 60 determines whether or not the PCV valve 33 is frozen by using the temperature state of the engine 1, that is, the coolant temperature THW as one of the determination conditions. Thereby, it is determined in advance whether or not to energize the electric heater 44. Accordingly, the electric heater 44 is not energized under a temperature condition in which the PCV valve 33 is not frozen. For this reason, the electric heater 44 can be energized only when the PCV valve 33 needs to be released from freezing, and wasteful power consumption can be suppressed.

  In addition, this invention is not limited to the said embodiment, A part of structure can also be changed suitably and implemented in the range which does not deviate from the meaning of invention.

  For example, in the above-described embodiment, the “target heat amount” necessary for releasing the freeze of the PCV valve 33 is estimated based on the ambient temperature state of the PCV valve 33, and the electric heater 44 is supplied based on a predetermined target power. After the energization was started, the electric heater 44 was energized until the total amount of heat generated by the electric heater 44 reached the “target heat amount”. On the other hand, the “target energization time” necessary for releasing the freeze of the PCV valve 33 is estimated based on the temperature state around the PCV valve 33, and the electric heater 44 is energized based on the predetermined target power. You may comprise so that it may energize to the electric heater 44 from the start until the energization time to the electric heater 44 reaches the “target energization time”. In this case, when the electric heater 44 is energized, a “target energization time” necessary for releasing the freeze of the PCV valve 33 is calculated based on the temperature state around the PCV valve 33. Then, after the energization of the electric heater 44 is started based on the predetermined target power, the electric heater 44 is energized until the energization time of the electric heater 44 reaches the target energization time. Accordingly, in this case as well, the electric heater 44 is energized only while the PCV valve 33 is released from freezing. As a result, it is possible to prevent the electric heater 44 from being energized more than necessary for the freeze release of the PCV valve 33.

  Moreover, in the said embodiment, although the control apparatus of the PCV valve of this invention was actualized to the blow-by gas reduction apparatus provided in the direct injection type multi-cylinder spark ignition engine 1, the normal multi-cylinder which is not a direct injection type The control device for the PCV valve of the present invention can be embodied in the blow-by gas reduction device for a spark ignition engine.

The schematic block diagram which shows the engine system containing a blow-by gas reduction apparatus. Sectional drawing which shows the initial state of a PCV valve | bulb. Sectional drawing which shows the operating state of a PCV valve. The flowchart which shows the processing content of PCV valve | bulb control. A map showing the relationship between starting water temperature and basic power. A map showing the relationship between the vehicle speed and the vehicle speed coefficient. The map which shows the relationship between the water temperature at the time of starting, and target heat quantity. The map which shows the relationship between an electric current, a battery voltage, and an output duty ratio. The time chart which shows the change of the calorie | heat amount from an energization start to an energization stop.

1 Engine 33 PCV valve 44 Electric heater 52 Coil 60 ECU (target heat amount calculation means, heat generation amount integration means, energization control means, target power calculation means and execution determination means)
70 battery

Claims (5)

In a control device for a PCV valve that controls energization to an electric heater provided in the PCV valve,
A target heat amount calculating means for calculating a target heat amount necessary for releasing the freeze of the PCV valve based on a temperature state around the PCV valve;
A calorific value integrating means for integrating the calorific value of the electric heater after energization of the electric heater is started;
Energization control means for energizing the electric heater until starting the energization result of the heat generation amount reaches the target heat amount after starting energization to the electric heater based on a predetermined target power ;
Target power calculation means for calculating the target power based on a temperature state around the PCV valve;
And the calorific value integrating means integrates the calorific value based on the calculated target power . The PCV valve is provided attached to an engine mounted on a vehicle, and the target power calculation means calculates the target power based on a temperature state at the start of the engine and a traveling speed of the vehicle. The control device for a PCV valve according to claim 1 . The electric heater is supplied with electric power from a battery, and the energization control means determines a current required for energizing the electric heater from the calculated target electric power and the voltage of the battery. 3. A control device for a PCV valve according to 1 or 2 . The electric heater, the control device of the PCV valve according to any one of claims 1 to 3, characterized in that it comprises a coil for generating heat by energization. An execution determination means for determining in advance whether or not to energize the electric heater using the temperature state of the engine provided with the PCV valve as one of the determination conditions is provided. The control device for a PCV valve according to any one of 1 to 4 .

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