JP5533220B2 - Blow-by gas processing device for internal combustion engine - Google Patents

Description

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

  Conventionally, for example, as disclosed in Japanese Patent Application Laid-Open No. 2009-275632 and Japanese Patent Application Laid-Open No. 2008-111422, an internal combustion engine including a blow-by gas processing device is known. A blow-by gas processing apparatus according to Japanese Patent Application Laid-Open No. 2009-275632 includes a mechanism for returning blow-by (blow-by gas) to an intake system. In the configuration according to the publication, the gas in the crankcase is sucked with a pump to depressurize the crankcase, and the oil component contained in the gas sucked with the pump is separated with a separator.

JP 2009-275632 A JP 2008-111422 A

  In the conventional blow-by gas processing apparatus, it is common to flow blow-by gas through the same oil separator regardless of the engine speed and load. However, in such a configuration, adverse effects occur when the operating conditions change.

  Specifically, for example, when a separator specification is to be determined from the viewpoint of reducing oil removal in a high rotation and high load region, a separator with a high pressure loss is selected. Since the pressure difference between the crankcase and the upstream side of the compressor is large in the high rotation and high load region, even if a high pressure loss separator is used, a PCV flow rate sufficient to obtain sufficient scavenging performance can be secured. On the other hand, however, the pressure difference between the crankcase and the upstream side of the compressor is small in the low rotation and high load region. If a separator with a high pressure loss is used in a low rotation and high load region, the PCV flow rate is small and good scavenging performance cannot be obtained. As a result, sludge is generated inside the internal combustion engine, leading to accelerated deterioration of engine oil.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a blow-by gas processing apparatus for an internal combustion engine that can perform blow-by gas processing without any problem even if the operating region changes. And

In order to achieve the above object, a first invention is a blow-by gas processing apparatus for an internal combustion engine,
The crankcase of the internal combustion engine and the intake passage of the internal combustion engine communicate with each other, the passage includes at least one oil separator, and the total pressure loss due to the blow-by gas oil separator in the passage is the first pressure loss. A first gas path,
The crankcase communicates with the intake passage of the internal combustion engine, includes at least one oil separator in the path, and the total pressure loss due to the blow-by gas oil separator in the path is lower than the first pressure loss A second gas path that is a second pressure loss;
A switching mechanism capable of switching between the first gas path and the second gas path;
When the internal combustion engine is in a predetermined high rotation / high load region, the crankcase is scavenged through the first gas path, and when the internal combustion engine is in a predetermined low rotation / high load region, the second Control means for controlling the switching mechanism so as to scavenge the crankcase via a gas path;
It is characterized by providing.

The second invention is the first invention, wherein
The first gas path includes a first gas passage connecting the crankcase and the intake passage, and a total value of pressure loss caused by an oil separator of blow-by gas in the passage provided in the first gas passage. A first oil separator having a pressure loss of 1,
The second gas path includes a second gas path connected in parallel with the first gas path between the crankcase and the intake path, and an oil separator for blow-by gas provided in the second gas path. A total value of pressure loss due to the second oil separator is the second pressure loss,
The switching mechanism may be one or a plurality of valves that bring the crankcase and the intake passage into communication with each other through one of the first gas passage and the second gas passage .

In order to achieve the above object , a third invention is a blow-by gas processing apparatus for an internal combustion engine,
The crankcase of the internal combustion engine and the intake passage of the internal combustion engine communicate with each other, the passage includes at least one oil separator, and the total pressure loss due to the blow-by gas oil separator in the passage is the first pressure loss. A first gas path,
The crankcase communicates with the intake passage of the internal combustion engine, includes at least one oil separator in the path, and the total pressure loss due to the blow-by gas oil separator in the path is lower than the first pressure loss A second gas path that is a second pressure loss;
A switching mechanism capable of switching between the first gas path and the second gas path;
With
The first gas path includes a first end connected to the crankcase, a second end connected to the intake passage, and a first end connecting the first end and the second end. 1 gas passage, and a first oil separator in which the total pressure loss due to the oil separator of blow-by gas in the passage is the first pressure loss,
The second gas path includes one or more second gases provided in parallel between the crankcase and the first end or / and between the intake passage and the second end. A passage, and a second oil separator in which the total pressure loss due to the blow-by gas oil separator in the passage is the second pressure loss,
The switching mechanism includes a state in which the first gas passage and the second gas passage are interposed in series between the crankcase and the intake passage, and only the first gas passage is provided between the crankcase and the intake passage. It is a valve which can switch the state interposed in series between the two .

Moreover, 4th invention is set in 3rd invention,
The pressure loss of the first oil separator and the second oil separator is the same.

According to the first invention, a plurality of gas paths each including an oil separator and having different pressure losses can be switched as necessary. When the operating region changes, a plurality of gas paths having different pressure losses can be selectively used from the viewpoint of obtaining good scavenging performance in the crankcase. In the low rotation and high load region, the crankcase can be scavenged via a gas path with a relatively low pressure loss.

According to the second invention, a plurality of gas paths each including an oil separator can be provided in parallel, and the plurality of gas paths can be used alternatively.

According to the third aspect of the present invention, the pressure loss of the gas path including the oil separator can be switched by connecting another gas path in series to one gas path as necessary.

According to the fourth invention , two different pressure losses can be generated by two separators having the same pressure loss.

It is a figure which shows the structure of the blowby gas processing apparatus of the internal combustion engine concerning Embodiment 1 of this invention. It is a figure for demonstrating operation | movement of the blow-by gas processing apparatus of the internal combustion engine concerning Embodiment 1 of this invention. It is a figure which shows the structure of the blowby gas processing apparatus of the internal combustion engine concerning Embodiment 2 of this invention.

Embodiment 1 FIG.
1 is a diagram showing a configuration of a blow-by gas processing apparatus for an internal combustion engine according to a first embodiment of the present invention. The blow-by gas processing apparatus according to the first embodiment is suitably used for a vehicle internal combustion engine. The blow-by gas processing apparatus according to the first embodiment is applied to the internal combustion engine 10. The internal combustion engine 10 includes a head cover 12, a cylinder head, a cylinder block, a crankcase, and an oil pan. Inside, a piston and a crankshaft are provided. The internal combustion engine 10 is a supercharged internal combustion engine having a turbocharger 26. The internal combustion engine 10 is not particularly limited in the number of cylinders and the system thereof, and may be a multi-cylinder internal combustion engine that is common in an internal combustion engine for automobiles.

  An intake manifold 20 communicates with an intake port of a cylinder head in the internal combustion engine 10. The intake manifold 20 communicates with the intercooler 24. A throttle valve 22 is provided between them. The upstream of the intercooler 24 communicates with the intake passage upstream portion 28 via the compressor of the turbocharger 26. The intake passage upstream portion 28 is connected to the air cleaner 30.

  A gas passage 40 is connected to the crankcase of the internal combustion engine 10. The gas passage 40 is connected to the intake passage upstream portion 28 via the oil separator 44. A gas passage 42 is connected to the gas passage 40 so as to bypass the oil separator 44. An oil separator 46 and a switching valve 48 are provided in the gas passage 42.

  In the blow-by gas processing apparatus according to the first embodiment, the oil separator 46 is an oil separator having a lower pressure loss than the oil separator 44. According to such a configuration, when the switching valve 48 is opened, blow-by gas can be introduced into the gas path via the low pressure loss oil separator 46.

  The intake manifold 20 and the positions downstream of the oil separators 44 and 46 in the gas passage 40 are connected via a PCV valve 50.

  The blow-by gas processing apparatus according to the first embodiment is controlled by an ECU (Electronic Control Unit) 60. The ECU 60 can be connected to the switching valve 48 and issue a control signal for controlling opening and closing of the switching valve 48.

  Although not shown, in the first embodiment, the internal combustion engine 10 is provided with a configuration for detecting the intake air amount such as an air flow meter, and various sensors such as a crank angle sensor and an engine water temperature sensor. The ECU 60 is connected to various sensors (not shown) to detect the operating state of the engine (engine speed, load, etc.), or is connected to an actuator of various devices for operating the internal combustion engine 10 to operate them. Or The ECU 60 processes signals from each sensor provided in the internal combustion engine 10 and reflects the processing result in the operation of each actuator.

  In the blow-by gas processing apparatus according to the first embodiment, in a supercharged internal combustion engine provided with a turbocharger 26, when the PCV flow rate is low in a low rotation and high load region and the scavenging performance in the crankcase deteriorates, a low pressure loss The blow-by gas is introduced into the oil separator 46. Otherwise, blow-by gas is introduced into the high pressure loss oil separator 44.

  In the first embodiment, the ECU 60 switches the use of these oil separators 44 and 46 by controlling the switching valve 48 according to the operation region. By such an operation, sufficient scavenging performance can be ensured.

  By flowing blow-by gas into the low pressure loss oil separator, the PCV flow rate can be secured and sufficient scavenging performance can be obtained even if the pressure difference between the crankcase and the compressor upstream of the turbocharger 26 is small. . In addition, since the amount of oil mist flowing into the oil separator is reduced in the low rotation region, even if the oil separator has a low pressure loss, the oil removal amount can be satisfied.

  FIG. 2 is a diagram for explaining the operation of the blow-by gas processing apparatus for the internal combustion engine according to the first embodiment of the present invention. FIG. 2 shows a map in which the use regions of the oil separators 44 and 46 are divided according to the torque and the engine speed in the first embodiment. In the first embodiment, the ECU 60 specifies the operating region of the internal combustion engine 10 and then controls the switching valve 48 according to the map of FIG.

  FIG. 2 shows a torque curve and a boundary line 70 for dividing the operation region into region A and region B. A region A in FIG. 2 shows a use region of the oil separator 46 having a low pressure loss.

  On the other hand, a region B in FIG. 2 indicates a use region of the oil separator 44 having a high pressure loss. As shown in FIG. 2, in the first embodiment, a region A is defined in a region where the rotation is lower than the predetermined rotation speed Ne1 and on the higher torque side than the predetermined torque Tr1. .

  According to the blow-by gas processing apparatus according to the first embodiment, by providing two blow-by introduction paths each including an oil separator and having different pressure losses, the plurality of gas paths can be switched as necessary. . When the operating region changes, a plurality of gas paths with different pressure losses can be selectively used from the viewpoint of obtaining scavenging performance in the crankcase.

  According to the blow-by gas processing apparatus according to the first embodiment, the ECU 60 controls the switching valve 48 according to the map of FIG. 2, so that in the low rotation and high load region, the gas path has a relatively low pressure loss. The crankcase can be scavenged.

  Further, according to the blow-by gas processing apparatus according to the first embodiment, the gas passage 40 on the oil separator 44 side and the gas passage 42 on the oil separator 46 side provided in parallel can be used alternatively.

Embodiment 2. FIG.
FIG. 3 is a diagram showing the configuration of the blow-by gas processing apparatus for an internal combustion engine according to the second embodiment of the present invention. The configuration of the second embodiment is that the gas passage 140 is provided instead of the gas passage 40, the oil separators 144 and 146 are provided instead of the oil separators 44 and 46, and the oil separators 144 and 146 are provided. The configuration is the same as that of the first embodiment except that the connecting gas passage 142 is provided. Hereinafter, in order to avoid duplication, the same reference numerals are given to the same or corresponding components as those described in the first embodiment, and the description will be omitted or simplified as appropriate.

  The oil separator 144 and the oil separator 146 are oil separators having the same pressure loss. The blow-by gas processing apparatus according to the second embodiment introduces blow-by gas to the oil separator 146 side by opening the switching valve 48 and closes the switching valve 48 to blow-by to both the oil separator 146 and the oil separator 144. Gas can be introduced.

  According to the blow-by gas processing apparatus according to the second embodiment, the path through which one oil separator passes and the path through which two oil separators pass can be switched by opening and closing the switching valve 48. Thereby, the function similar to that performed by switching the oil separators 44 and 46 in the first embodiment, that is, switching between introduction of blow-by gas into the path of high pressure loss and introduction of blow-by gas into the path of low pressure loss. Function can be realized.

  In the second embodiment, the oil separators 144 and 146 have the same pressure loss, but the present invention is not limited to this. Oil separators having different pressure losses may be used in the second embodiment depending on the magnitude of the difference in pressure loss between the low pressure loss and the high pressure loss.

  In the first and second embodiments described above, two oil separators are used. However, the present invention is not limited only to the form using two oil separators. Three or more oil separators having the same or different pressure loss may be used in series or in parallel as appropriate. Thereby, for example, the pressure loss may be more finely differentiated.

  Further, the division of the operation region is not limited to the specific example of the map of the first embodiment shown in FIG. 2, and the regions A and B are determined by drawing a boundary line different from the boundary line 70 to make the pressure loss different. Also good. After specifying the operation region where the PCV flow rate is low and the scavenging performance in the crankcase deteriorates in the low-rotation and high-load region, it is determined which of the multiple blow-by introduction routes having different pressure losses to use. It may be determined according to the area.

  Note that the blow-by gas processing apparatus according to Japanese Patent Application Laid-Open No. 2008-111422 includes two introduction paths (a first introduction path and a second introduction path) for introducing outside air from the intake passage into the engine. . Furthermore, the said Unexamined-Japanese-Patent No. 2008-111422 is disclosing the structure which provides two oil separators, and interposes one oil separator in one introduction path, and the other oil separator in the other introduction path, respectively. . However, the configuration disclosed in this publication has an oil separator interposed in each of the introduction passages. This publication does not describe a configuration in which a plurality of blow-by introduction paths each including an oil separator and having different pressure losses are provided between the crankcase and the intake passage as in the present invention.

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 12 Head cover 20 Intake manifold 22 Throttle valve 24 Intercooler 26 Turbocharger 28 Intake passage upstream part 30 Air cleaner 48 Switching valve 50 PCV valve 70 Boundary lines 40, 42, 140, 142 Gas passages 44, 46, 144, 146 Oil Separator

Claims (4)

The crankcase of the internal combustion engine and the intake passage of the internal combustion engine communicate with each other, the passage includes at least one oil separator, and the total pressure loss due to the blow-by gas oil separator in the passage is the first pressure loss. A first gas path,
The crankcase communicates with the intake passage of the internal combustion engine, includes at least one oil separator in the path, and the total pressure loss due to the blow-by gas oil separator in the path is lower than the first pressure loss A second gas path that is a second pressure loss;
A switching mechanism capable of switching between the first gas path and the second gas path;
When the internal combustion engine is in a predetermined high rotation / high load region, the crankcase is scavenged through the first gas path, and when the internal combustion engine is in a predetermined low rotation / high load region, the second Control means for controlling the switching mechanism so as to scavenge the crankcase via a gas path;
Blow-by gas processing apparatus for an internal combustion engine, characterized in that it comprises a. Before Symbol first gas path, the a first gas passage connecting between the crankcase and the intake passage, the sum of the pressure loss due to the oil separator of the blow-by gas in the first provided in the gas passage passage the A first oil separator that is a first pressure loss,
The second gas path includes a second gas path connected in parallel with the first gas path between the crankcase and the intake path, and an oil separator for blow-by gas provided in the second gas path. A total value of pressure loss due to the second oil separator is the second pressure loss,
The switching mechanism is one or a plurality of valves that bring the crankcase and the intake passage into communication with each other via one of the first gas passage and the second gas passage. blow-by gas processing device for an internal combustion engine mounting serial to claim 1. The crankcase of the internal combustion engine and the intake passage of the internal combustion engine communicate with each other, the passage includes at least one oil separator, and the total pressure loss due to the blow-by gas oil separator in the passage is the first pressure loss. A first gas path,
The crankcase communicates with the intake passage of the internal combustion engine, includes at least one oil separator in the path, and the total pressure loss due to the blow-by gas oil separator in the path is lower than the first pressure loss A second gas path that is a second pressure loss;
A switching mechanism capable of switching between the first gas path and the second gas path;
With
The first gas path includes a first end connected to the crankcase, a second end connected to the intake passage, and a first end connecting the first end and the second end. 1 gas passage, and a first oil separator in which the total pressure loss due to the oil separator of blow-by gas in the passage is the first pressure loss,
The second gas path includes one or more second gases provided in parallel between the crankcase and the first end or / and between the intake passage and the second end. A passage, and a second oil separator in which the total pressure loss due to the blow-by gas oil separator in the passage is the second pressure loss,
The switching mechanism includes a state in which the first gas passage and the second gas passage are interposed in series between the crankcase and the intake passage, and only the first gas passage is provided between the crankcase and the intake passage. blow-by gas processing apparatus of the internal combustion engine you characterized by a condition mediated in series is switchable valve between. The blow-by gas processing apparatus for an internal combustion engine according to claim 3, wherein the first oil separator and the second oil separator have the same pressure loss.

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