JP2013194629A - Blow-by gas treating device for internal combustion engine with supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a deposit from being stuck to a compressor caused by an oil contained in a blow-by gas in a blow-by gas treating device for an internal combustion engine with a supercharger.SOLUTION: In addition to a blow-by gas passage connecting a cylinder head and an upstream side of a compressor in an intake passage, a blow-by gas treating device includes a second blow-by gas passage making the inside of a crank case communicate with the upstream side of the compressor in the intake passage. In the second blow-by gas passage, a control valve (PCV valve) is provided and opening/closing of the control valve is controlled by a control device. The control device acquires a soot concentration α1 in an oil and a mileage L1 after oil exchange, respectively, and is programmed to open the control valve in the case where a value β1 obtained by dividing the soot concentration α1 by the mileage L1 (or a value proportional thereto) becomes a reference value βs or more.

Description

  The present invention relates to a blow-by gas processing device for an internal combustion engine with a supercharger.

  BACKGROUND ART An internal combustion engine for a vehicle is provided with a blow-by gas processing device that processes blow-by gas leaking from a combustion chamber into a crankcase by returning it to an intake passage. Patent Documents 1-4 listed below disclose inventions related to such blow-by gas processing apparatuses.

  Patent Literature 1 and Patent Literature 2 disclose blow-by gas processing apparatuses for an internal combustion engine with a supercharger. In the apparatus disclosed in Patent Document 1, the upstream of the compressor in the intake passage and the crankcase are communicated with each other by a blow-by gas passage, and an oil separator is provided in the blow-by gas passage. An inlet guide vane is provided upstream of the outlet of the blow-by gas passage in the intake passage. According to this device, by controlling the inlet guide vane and increasing the negative pressure acting on the outlet of the blow-by gas passage, the amount of blow-by gas drawn into the blow-by gas passage increases and the inside of the crankcase is ventilated. .

  In the apparatus disclosed in Patent Document 2, the downstream of the throttle valve in the intake passage and the crankcase are communicated with each other by a blow-by gas passage (first communication passage), and the upstream of the compressor in the intake passage and the cylinder head are different from each other. The blow-by gas passage (second communication passage) communicates. A PCV valve is provided in the first communication passage. According to this device, during supercharging by the supercharger, when the PCV valve is opened, high-pressure air is introduced into the crankcase through the first communication passage, and the blowby gas in the crankcase is the second It is returned to the intake passage through the communication passage. On the other hand, when there is no supercharging, when the PCV valve is opened, air is introduced into the crankcase through the second communication passage, and blow-by gas in the crankcase is introduced into the intake passage through the first communication passage. Returned.

  Patent Document 3 and Patent Document 4 disclose a blow-by gas processing apparatus for a naturally aspirated internal combustion engine that does not include a supercharger. In these blow-by gas processing apparatuses, the downstream of the throttle valve in the intake passage and the cylinder head are communicated by the first PCV passage, and the upstream of the throttle valve in the intake passage and the cylinder head are communicated by the second PCV passage. It has been. A PCV valve is provided in the first PCV passage. The configuration of these devices can be applied to an internal combustion engine with a supercharger as it is. The configuration in that case is the same as the configuration disclosed in Patent Document 2.

JP 2011-185168 A JP 2006-274931 A JP 2006-183639 A JP 2009-293464 A

  One of the problems in the blow-by gas processing apparatus of an internal combustion engine with a supercharger is deposit accumulation caused by oil mist in the blow-by gas. The oil mist generated in the crankcase includes a carbon suit generated by fuel combustion. The oil mist including the suit is taken out of the crankcase by blow-by gas and is carried along with the blow-by gas to the intake passage. In an internal combustion engine with a supercharger, oil mist including a suit is brought into a compressor together with air. Since the inside of the compressor becomes hot as the air is compressed, the oil adhering to the inner wall surface of the compressor, particularly the diffuser surface, evaporates, and the stickiness increases due to oxidative degradation. The high-viscosity oil with high suit concentration gradually becomes sludge and eventually deposits and accumulates on the wall. Deposits accumulated in the compressor reduce the efficiency of the compressor, and consequently reduce the fuel consumption of the internal combustion engine.

  Such a problem also applies to each device disclosed in Patent Documents 1 and 2 described above. In the case of the apparatus disclosed in Patent Document 1, since an oil separator is provided in the blow-by gas passage, oil mist in the blow-by gas can be separated and recovered by the oil separator. However, a general oil separator used in an internal combustion engine can collect oil mist having a large particle size, but does not have a structure capable of collecting even oil mist having a small particle size. This is because if the oil separator has a structure capable of collecting even oil mist having a small particle size, the pressure loss before and after the oil separator increases and the crankcase pressure increases. For this reason, blow-by gas containing a large amount of oil mist having a small particle diameter is returned from the blow-by gas passage to the intake passage. FIG. 4 shows the particle size distribution of the oil mist in the blow-by gas returned from the blow-by gas passage to the intake passage. Oil mist with a small particle size evaporates quickly when exposed to high temperatures in the compressor, and tends to deposit in the compressor. For this reason, in the apparatus disclosed in Patent Document 1, deposits may accumulate in the compressor due to the oil mist having a small particle diameter that has not been collected by the oil separator.

  In the case of the apparatus disclosed in Patent Document 2, high-temperature air compressed by the compressor is introduced into the crankcase through the first communication passage when supercharging is performed by the supercharger, The blow-by gas is returned to the intake passage through the second communication passage. For this reason, the temperature of the air flowing into the compressor rises, and a temperature environment in which deposits are likely to occur is created in the compressor. For this reason, deposits may accumulate in the compressor even in the apparatus disclosed in Patent Document 2. Moreover, in the apparatus disclosed in Patent Document 2, air once compressed is returned again to the inlet of the compressor, which causes another problem that the efficiency of the compressor is lowered.

  The present invention has been made in view of the above-described problems, and is a blow-by of an internal combustion engine with a supercharger capable of suppressing deposit accumulation on a compressor caused by oil contained in blow-by gas. An object is to provide a gas processing apparatus.

  The present invention is an invention applied to a blow-by gas processing apparatus that is provided in an internal combustion engine with a supercharger having a compressor in an intake passage and connects a cylinder head of the internal combustion engine and an upstream of the compressor in the intake passage by a blow-by gas passage. is there. The blow-by gas processing apparatus according to the present invention includes, in addition to the blow-by gas passage, a second blow-by gas passage that communicates the inside of the crankcase of the internal combustion engine and the upstream of the compressor in the intake passage. Generally, an oil separator is provided in the blow-by gas passage connecting the cylinder head and the upstream side of the compressor in the intake passage, but no oil separator is provided in the second blow-by gas passage. The inlet of the second blow-by gas passage is preferably connected to an oil pan. The blow-by gas processing apparatus according to the present invention further includes a control valve provided in the second blow-by gas passage and a control device that controls opening and closing of the control valve.

  According to such a configuration, when the control valve is opened by the control device, blow-by gas in the crankcase is supplied to the upstream of the compressor through the second blow-by gas passage. Of the oil mist contained in blow-by gas, the cause of deposits is oil mist with a small particle size, but the blow-by gas filled in the crankcase contains a high percentage of oil mist with a large particle size. ing. The oil mist having a large particle size increases the fluidity of oil adhering to the wall surface of the compressor, and is easily blown away by high-speed air passing through the compressor. Therefore, deposits on the compressor can be suppressed by opening the control valve and supplying blow-by gas in the crankcase upstream of the compressor.

  However, when to open the control valve is an important issue. If the control valve is always open, a large amount of oil is always taken away by blow-by gas from the oil pan, and the oil consumption of the internal combustion engine increases. What is needed in the present invention is to suppress deposit build-up on the compressor without causing other problems such as increased oil consumption.

  For this reason, the blow-by gas processing apparatus according to the present invention controls the opening and closing of the control valve as follows by the control device.

  The control device of the blow-by gas processing apparatus according to the present invention first acquires the suit concentration in the oil and the travel distance after the oil change. The suit concentration can be measured by a sensor using an optical or electrochemical method. The mileage can be obtained from an odometer mounted on the vehicle. Next, the control device calculates a value obtained by dividing the suit density by the travel distance or a value proportional thereto. Since the suit concentration is an index value indicating the degree of deterioration of the oil, it can be seen that the higher the suit concentration with respect to the travel distance, the faster the oil deteriorates. Therefore, a value obtained by dividing the suit concentration by the travel distance or a value proportional thereto can be treated as an index value indicating the oil deterioration rate. The control device performs the above calculation at an arbitrary timing, compares the calculated index value of the oil deterioration rate with the reference value, and opens the control valve when the index value becomes larger than the reference value. Although the setting of the reference value used here is arbitrary, it is preferably set based on the limit value of the suit density and the travel distance to be secured at a minimum.

  By controlling the opening and closing of the control valve in this way, the inside of the crankcase can be ventilated before the degree of oil deterioration reaches the limit, and the further deterioration of oil due to contamination by blow-by gas is suppressed. Can do. In addition, when the index value of the oil deterioration rate is less than the reference value, the control valve is closed, so that a large amount of oil in the oil pan is prevented from being taken away by blow-by gas. That is, the blow-by gas processing apparatus according to the present invention opens the control valve only in a situation where the effect of suppressing oil deterioration due to ventilation in the crankcase is high, so that a large amount of oil is not consumed and the deposit to the compressor is reduced. Both suppression of accumulation and suppression of deterioration of oil in the oil pan are achieved.

  In the opening / closing control of the control valve by the control device, it is preferable that the condition that the outlet temperature of the compressor is equal to or higher than the reference temperature is included in the condition for opening the control valve. In other words, the control valve may be opened only when the outlet temperature of the compressor is equal to or higher than the reference temperature and the index value of the oil deterioration rate is larger than the reference value. As the reference temperature, a temperature near a temperature at which deposits start to be generated, specifically, a temperature around 160 ° C. is preferable. The deposit accumulation suppression effect obtained by supplying blow-by gas containing large oil mist to the compressor is an effect obtained regardless of the compressor outlet temperature. However, when the compressor outlet temperature is equal to or higher than the generation temperature of the deposit, it is possible to obtain both a preventive effect by giving fluidity to the oil on the wall surface and an effect of washing away the deposit that has started to be generated. The utilization efficiency of oil mist contained in blow-by gas is particularly high. Therefore, by adding the above-mentioned conditions relating to the outlet temperature of the compressor to the conditions for opening the control valve, it is possible to obtain a high effect in terms of suppressing deposit accumulation on the compressor while minimizing oil consumption.

  According to the present invention, it is possible to suppress deposit accumulation on the compressor caused by the oil contained in the blow-by gas while suppressing the progress of the deterioration of the oil in the oil pan.

It is a figure which shows the structure of the internal combustion engine with a supercharger which concerns on embodiment of this invention. It is a figure for demonstrating the content of the deposit accumulation suppression control which concerns on embodiment of this invention. It is a flowchart which shows the routine of the deposit accumulation suppression control performed by ECU in embodiment of this invention. It is a figure which shows distribution of the particle size of the oil mist in blow-by gas returned to a suction passage from a blow-by gas passage.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of an internal combustion engine with a supercharger to which a blow-by gas processing apparatus according to the present invention is applied. An internal combustion engine 100 shown in FIG. 1 includes an engine body 10 configured as a diesel engine. An intake passage 32 is connected to the engine body 10 via an intake manifold 12. An exhaust passage 34 is connected to the engine body 10 via an exhaust manifold 13.

  The intake passage 32 includes an air cleaner 31 at the entrance thereof. The air that has passed through the air cleaner 31 is taken into the intake passage 32 and supplied to the engine body 10. A compressor 21 of the turbocharger 20 is attached in the middle of the intake passage 32. A throttle valve 11 is provided downstream of the compressor 21 in the intake passage 32. An intercooler 33 is provided between the compressor 21 and the throttle valve 11 in the intake passage 32. An oil return passage 35 for returning the oil accumulated in the intercooler 33 to the oil pan 14 is connected to the lower portion of the intercooler 33. The oil return passage 35 is provided with an opening / closing valve 36 for opening and closing the oil return passage 35.

  The exhaust passage 34 is provided with a catalyst device 95 for purifying the exhaust gas. The turbine 22 of the turbocharger 20 is attached between the engine body 10 and the catalyst device 95 in the exhaust passage 34. The turbine 22 and the compressor 21 are connected by a rotating shaft.

  The internal combustion engine 100 includes two blow-by gas passages 41 and 43. The first blow-by gas passage 41 connects the cylinder head of the engine body 10 and the upstream side of the compressor 21 in the intake passage 32. An oil separator 42 is provided in the first blow-by gas passage 41. The second blow-by gas passage 43 communicates the crankcase of the engine body 10 with the upstream side of the compressor 21 in the intake passage 32. More specifically, the inlet of the second blow-by gas passage 43 is connected to the upper portion of the oil pan 14, specifically, the portion above the oil level. The second blow-by gas passage 43 is provided with a PCV valve 44 as a control valve. The first blow-by gas passage 41 is not provided with a PCV valve, and the second blow-by gas passage 43 is not provided with an oil separator.

  The operation of the internal combustion engine 100 configured as described above is controlled by the ECU 90. The ECU 90 is a computer that operates according to a program, to which a control device for a blow-by gas processing apparatus according to the present invention is applied. The ECU 90 captures and processes signals from various sensors included in the internal combustion engine 100 and the vehicle. Sensors are attached to the internal combustion engine 100 and various parts of the vehicle. For example, a temperature sensor 51 for measuring the compressor outlet temperature is attached downstream of the compressor 21 in the intake passage 32. The oil pan 14 is provided with an oil sensor 52 for measuring the suit concentration in the oil. Further, a sensor for detecting on / off of the ignition (IG) is also provided. The ECU 90 processes the signals of the acquired sensors and operates the actuators according to a predetermined control program. The actuator operated by the ECU 90 includes the throttle valve 11, the on-off valve 36, the PCV valve 44, and the like. There are many actuators and sensors connected to the ECU 90 other than those shown in the figure, but the description thereof is omitted in this specification.

  Since the internal combustion engine 100 is configured to recirculate the blow-by gas upstream of the compressor 21, oil mist contained in the blow-by gas adheres to the inside of the compressor 21, particularly the diffuser surface, and accumulates in the deposit. There is a risk. As the deposit builds up, the compression efficiency of the compressor 21 decreases, and the fuel consumption of the internal combustion engine 100 deteriorates. Therefore, the engine control executed by the ECU 90 in the present embodiment includes engine control for suppressing deposit accumulation on the compressor 21 (hereinafter, deposit accumulation suppression control). Hereinafter, the outline of the deposit accumulation suppression control according to the present embodiment will be described.

  In the internal combustion engine 100, it is the blow-by gas returned from the first blow-by gas passage 41 to the intake passage 32 that causes deposits to be generated inside the compressor 21. Since no PCV valve is provided in the first blow-by gas passage 41, the blow-by gas is always returned from the first blow-by gas passage 41 to the intake passage 32. The blow-by gas flowing through the first blow-by gas passage 41 is blow-by gas that has passed through the oil separator 42. For this reason, although large oil mist is removed, many oil mists with small particle diameters that cannot be collected by the oil separator 42 are contained. This blow-by gas containing a large amount of small oil mist flows into the compressor 21 together with air, which causes deposits to accumulate on the compressor 21.

  One feature of the deposit accumulation suppression control according to the present embodiment is that the inner wall surface of the compressor 21 is cleaned using the blow-by gas returned from the second blow-by gas passage 43 to the intake passage 32. Since the second blow-by gas passage 43 is not provided with an oil separator, the blow-by gas in the crankcase containing a large proportion of oil mist having a large particle diameter can be supplied to the intake passage 32 as it is. The oil mist having a large particle size increases the fluidity of oil adhering to the wall surface of the compressor 21, and is easily blown away by high-speed air passing through the compressor 21. Therefore, by recirculating the blow-by gas from the second blow-by gas passage 43 to the intake passage 32, the inner wall surface of the compressor 21 is washed with the oil mist having a large particle size, thereby suppressing deposit accumulation. Can do.

  However, since the second blow-by gas passage 43 is connected to the oil pan 14 and its inlet is very close to the oil level, the blow-by gas taken into the second blow-by gas passage 43 contains a large amount of oil. It is included. As the amount of oil taken away by blow-by gas increases, the amount of oil stored in the oil pan 14 naturally decreases. For this reason, recirculation of blow-by gas from the second blow-by gas passage 43 to the intake passage 32 cannot be simply allowed in order not to cause another problem such as an increase in oil consumption. In this regard, since the PCV valve 44 is provided in the second blow-by gas passage 43, the supply of blow-by gas from the second blow-by gas passage 43 to the intake passage 32 is arbitrarily controlled by opening and closing the PCV valve 44. can do. In the deposit accumulation suppression control according to the present embodiment, the opening and closing of the PCV valve 44 is controlled as follows.

  In the deposit accumulation suppression control according to the present embodiment, the outlet temperature of the compressor 21 measured by the temperature sensor 51 is acquired. One of the main conditions for depositing in the compressor 21 is the temperature in the compressor 21, more specifically, the outlet temperature in the diffuser section. Deposits begin to occur when the outlet temperature of the compressor 21 rises to approximately 160 ° C. The deposit accumulation suppressing effect obtained by supplying blow-by gas containing large oil mist is an effect obtained regardless of the outlet temperature of the compressor 21. However, when the outlet temperature of the compressor 21 is equal to or higher than the deposit generation temperature, it is possible to obtain both a preventive effect by imparting fluidity to the oil on the wall surface and an effect of washing away the deposit that has started to be generated. That is, waste of oil consumption can be reduced by using oil mist contained in blow-by gas more efficiently. For this reason, in the deposit accumulation suppression control according to the present embodiment, one of the valve opening conditions of the PCV valve 44 is that the outlet temperature of the compressor 21 is equal to or higher than the reference temperature set near the deposit generation temperature. I will.

  In the deposit accumulation suppression control according to the present embodiment, the suit concentration in the oil measured by the oil sensor 52 is further acquired. The suit concentration is an index value indicating the degree of deterioration of the oil at the present time. For this reason, there is a limit value that requires oil change in the suit concentration. The cause of the increase in the suit concentration is contamination of oil by blow-by gas, which progresses according to the travel distance of the vehicle. The graph shown in FIG. 2 represents the relationship between the suit concentration and the travel distance after the oil change. As described in this graph, a standard oil change distance Ls is set for each vehicle corresponding to the limit value α0 of the suit concentration. However, since the standard oil change distance Ls is only when the vehicle is driven in the standard mode, the oil deterioration speed is high when the vehicle is operated in the high load mode, and the travel distance is the standard oil change distance. There is a risk that the suit concentration will reach the limit before reaching.

  In order to make the travelable distance after the oil change closer to the standard oil change distance, the suit concentration may be delayed as much as possible. As a means for that, the deposit accumulation suppression control according to the present embodiment uses the PCV valve 44. By opening the PCV valve 44, the crankcase can be ventilated through the second blow-by gas passage 43. According to the configuration of the internal combustion engine 100 according to the present embodiment, since the first blow-by gas passage 41 is always open, ventilation by the two blow-by gas passages 41 and 43 is performed simultaneously when the PCV valve 44 is opened. It becomes like this. As a result, ventilation in the crankcase is promoted, and further deterioration of oil due to contamination by blow-by gas is suppressed.

  What is important here is the timing at which the PCV valve 44 is opened. In the deposit accumulation suppression control according to the present embodiment, the fact that the oil deterioration rate exceeds the reference value indicates that the other PCV valve 44 is opened. Condition. That is, the condition for opening the PCV valve 44 is that the compressor outlet temperature is equal to or higher than the reference temperature and the oil deterioration rate exceeds the reference value. In the present specification, a value obtained by dividing the suit concentration by the travel distance after the oil change is defined as the oil deterioration rate. This is because it can be determined that the higher the suit concentration with respect to the same travel distance, or the shorter the travel distance with respect to the same suit concentration, the faster the oil deteriorates. The mileage after the oil change can be acquired from an odometer mounted on the vehicle. In the deposit accumulation suppression control according to the present embodiment, the suit concentration and the travel distance after the oil change are respectively acquired at a constant period, and the oil deterioration rate is calculated from the information. Then, the PCV valve 44 is opened when the oil deterioration rate becomes larger than a predetermined reference value. The reference value of the oil deterioration rate is set based on the limit value of the suit concentration and the minimum travel distance to be secured.

  If the PCV valve 44 is opened when the oil deterioration speed exceeds the reference value, it is possible to extend the travelable distance while suppressing the deterioration of the oil. Referring to FIG. 2, it is assumed that the suit concentration is α1 and the travel distance is L1 at a certain point in time, and the oil deterioration rate calculated from them exceeds the reference value. In this case, if the PCV valve 44 is kept closed, the deterioration of the oil proceeds at the same speed, and eventually the suit concentration reaches the limit value α0 when the travel distance is L2. However, if the PCV valve 44 is opened when the oil deterioration speed exceeds the reference value, the oil deterioration speed after that can be slowed, and the travelable distance L3 until the suit concentration reaches the limit value α0 is set as the standard oil. The replacement distance Ls can be approached.

  Further, one of the main conditions for depositing in the compressor 21 is the suit concentration in the oil. The higher the suit concentration, the higher the viscosity of the oil, and the easier it is to deposit under high temperature conditions. For this reason, when the suit density reaches the limit value, there is a possibility that a lot of deposits have already accumulated in the compressor 21. In this regard, if the opening / closing of the PCV valve 44 is controlled based on the oil deterioration rate as described above, supply of blow-by gas from the second blow-by gas passage 43 is started before the suit concentration reaches the limit value. can do. According to this, since the oil that has adhered to the wall surface and has increased in viscosity is removed by the large oil mist contained in the blow-by gas, it is possible to effectively prevent deposits from being deposited on the compressor 21.

  FIG. 3 is a flowchart showing a routine for executing the deposit accumulation suppression control described above. The ECU 90 executes this routine at a constant cycle. In the first step S102, the ECU 90 reads various conditions used for deposit accumulation suppression control from the memory. The conditions include a standard recommended oil change distance Ls, an oil limit suit concentration α 0, and a deposit generation temperature Tc of the compressor 21.

  In the next step S104, the ECU 90 compares the compressor outlet temperature T3 measured using the temperature sensor 51 with the deposit generation temperature Tc, and determines whether the compressor outlet temperature T3 is equal to or higher than the deposit generation temperature Tc. If the determination result of step S104 is negative, the process by the ECU 90 proceeds to step S116. In step S116, the ECU 90 keeps the PCV valve 44 closed as usual. If the PCV valve 44 has already been opened, it is returned to the closed state.

  When the compressor outlet temperature T3 is equal to or higher than the deposit generation temperature Tc, the processing by the ECU 90 proceeds to step S106. In step S106, the ECU 90 calculates a reference oil deterioration rate βs (= α0 / Ls) using the standard oil replacement recommended distance Ls and the limit suit concentration α0 read in step S102.

  In the next step S108, the ECU 90 acquires the current driving state value. The operating state value includes the suit concentration α1 measured using the oil sensor 52 and the travel distance L1 after oil change obtained from the travel distance meter.

  In the next step S110, the ECU 90 calculates the oil deterioration rate β1 (= α1 / L1) using the current suit concentration α1 acquired in step S108 and the travel distance L1 after oil change.

  In the next step S112, the ECU 90 compares the current oil deterioration rate β1 calculated in step S110 with the reference oil deterioration rate βs calculated in step S106, and the current oil deterioration rate β1 is the reference oil deterioration rate. It is determined whether or not βs is exceeded. If the determination result of step S112 is negative, the process by the ECU 90 proceeds to step S116, and the ECU 90 keeps the PCV valve 44 closed as usual. If the PCV valve 44 has already been opened, it is returned to the closed state.

  If the current oil deterioration rate β1 exceeds the reference oil deterioration rate βs, the processing by the ECU 90 proceeds to step S114. In step S114, the ECU 90 opens the PCV valve 44. Thus, blow-by gas containing large oil mist is supplied from the second blow-by gas passage 43 to the upstream of the compressor 21.

  When the ECU 90 executes the routine including the steps described above, the compressor 21 is cleaned using the oil contained in the blow-by gas while minimizing oil consumption. Thereby, the accumulation of deposits on the compressor 21 is suppressed, and the efficiency of the compressor 21 can be maintained and the deterioration of the fuel consumption of the internal combustion engine 100 can be suppressed.

  Note that, according to the configuration of the internal combustion engine 100 according to the present embodiment, the oil used for cleaning the compressor 21 is accumulated in the lower portion of the intercooler 33. Since an oil return passage 35 leading to the oil pan 14 is connected to the lower portion of the intercooler 33, the oil in the intercooler 33 is transferred to the oil pan 14 by opening the on-off valve 36 provided in the oil return passage 35. Can be returned. The ECU 90 closes the on-off valve 36 when the ignition is on, and opens the on-off valve 36 when the ignition is off.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the supercharger provided in the internal combustion engine according to the above-described embodiment is a turbocharger. However, in the present invention, the supercharger may be a mechanical type. In the present invention, the internal combustion engine may be a gasoline engine.

  In the above-described embodiment, the compressor outlet temperature is measured using a temperature sensor. However, since there is a correlation between the outlet temperature of the compressor and the outlet pressure, the outlet temperature of the compressor may be measured by a pressure sensor, and the outlet temperature may be estimated from the outlet pressure.

DESCRIPTION OF SYMBOLS 10 Engine body 11 Throttle valve 14 Oil pan 20 Turbo supercharger 21 Compressor 32 Intake passage 33 Intercooler 35 Oil return passage 36 On-off valve 41 First blow-by gas passage 42 Oil separator 43 Second blow-by gas passage 44 PCV valve 51 Temperature sensor 52 Oil sensor 90 ECU
100 Internal combustion engine

Claims (2)

In a blow-by gas processing apparatus that is provided in an internal combustion engine with a supercharger that includes a compressor in an intake passage and connects a cylinder head of the internal combustion engine and an upstream of the compressor in the intake passage by a blow-by gas passage,
A second blow-by gas passage communicating the crankcase of the internal combustion engine with the upstream of the compressor in the intake passage;
A control valve provided in the second blow-by gas passage;
A control device for controlling opening and closing of the control valve,
The controller is
Acquire the suit concentration in oil and the travel distance after oil change, and open the control valve when the value obtained by dividing the suit concentration by the travel distance or a value proportional to it is greater than the reference value A blow-by gas processing apparatus for an internal combustion engine with a supercharger, which is programmed as follows.   2. The supercharged internal combustion engine according to claim 1, wherein the control device is programmed to open the control valve on condition that an outlet temperature of the compressor is equal to or higher than a reference temperature. Blow-by gas processing equipment.

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