JP5846059B2 - Engine oil separator - Google Patents

Description

  The present invention relates to an engine oil separation device, and more particularly to an engine oil separation device arranged on a return path of blow-by gas to an intake system.

  In a vehicular engine (internal combustion engine), blow-by gas including unburned gas and exhaust gas leaks into the crankcase from the combustion chamber through the gap between the cylinder and the piston, preventing air pollution and engine oil. In order to prevent deterioration, etc., a blow-by gas reduction device is provided to ventilate the crankcase.

  This blow-by gas reduction device includes an oil separator (oil separator) that collects, separates and recovers mist-like oil from high-temperature blow-by gas that is recirculated from the crankcase of the engine into the intake passage. It is used.

  As such an oil separation device, a device equipped with a cyclone separator that generates a swirl flow in blow-by gas and separates the oil by centrifugal separation exhibits maximum oil separation performance at a certain gas flow rate. Some have a plurality of switchable cyclone separators that are connected or disconnected depending on the gas flow rate in order to achieve optimal oil separation for the gas flow rate.

  Conventional oil separators for this type of engine include a plurality of cyclone separators and switching means for switching the path of blow-by gas so that the number of oil separators through which blow-by gas passes is increased according to the flow rate of blow-by gas. Are known (for example, see Patent Document 1).

  The device described in Patent Document 1 is configured to control the number of oil separators through which blow-by gas passes by a control piston or the like.

JP 2006-526731 A

  However, in the engine oil separation apparatus described in Patent Document 1, the length of the blow-by gas discharge path is not uniform among the plurality of cyclone separators used when the gas flow rate of the blow-by gas is large. Therefore, a difference in gas flow rate occurs between the cyclone separators, resulting in a cyclone separator that cannot exhibit the maximum oil separation performance. For this reason, the maximum oil separation performance could not be exhibited as a whole oil separation device.

  The present invention has been made to solve the above-described conventional problems, and in a cyclone separator that allows blow-by gas to pass through, exhibits maximum oil separation performance, so that it can be used in both low and high flow rates. An object of the present invention is to provide an engine oil separation device that can exhibit good oil separation performance.

  In order to achieve the above object, an engine oil separation device according to the present invention provides: (1) a flow for introducing the blow-by gas in the engine oil separation device for separating oil contained in the blow-by gas generated inside the engine; An inlet and an outlet for flowing out the blow-by gas that has flowed in are formed, and a plurality of cyclone separators having a cylindrical member that separates oil by swirling the blow-by gas in an internal space, and the plurality of cyclone separators are accommodated A gas-liquid separation chamber in which an inlet for introducing the blow-by gas and a first blow-by gas outlet and a second blow-by gas outlet for discharging the blow-by gas from which oil has been separated by the cyclone separator are formed. And the first blow-by gas outlet is the plurality of The second blow-by gas discharge port is disposed at an equal distance from each outlet of the cyclone separator, and the second blow-by gas discharge port is disposed near the outlet of any one of the plurality of cyclone separators. It is composed of

  With this configuration, the engine oil separation device causes the blow-by gas to be discharged from the second blow-by gas discharge port disposed in the vicinity of the outlet of any one cyclone separator in the low flow rate region of the blow-by gas. By allowing high-speed blow-by gas to pass through only the separator, the maximum oil separation performance can be exhibited.

  The oil separation device of the engine discharges blow-by gas from a first blow-by gas discharge port arranged at an equal distance from each outlet of the plurality of cyclone separators in a high flow rate region of the blow-by gas, and the plurality of cyclone separators The maximum oil separation performance can be exhibited by allowing the blowby gas to pass through at a high speed without any bias. Therefore, good oil separation performance can be exhibited in both the low flow rate region and the high flow rate region.

  In the engine oil separation device having the configuration described in (1) above, it is preferable that (2) the introduction port be arranged at an equal distance from each inlet of the plurality of cyclone separators.

  With this configuration, it is possible to further prevent the deviation of the flow rate and flow rate of the blow-by gas between the plurality of cyclone separators, so that the maximum oil separation performance can be exhibited.

  In the engine oil separator having the configuration described in (1) and (2) above, (3) the first blow-by gas discharge port is located upstream of the compressor of the turbocharger that compresses the intake air by the exhaust gas. Preferably, the blow-by gas is discharged to an intake passage, and the second blow-by gas discharge port discharges the blow-by gas to an intake passage downstream of the throttle valve via a PCV valve.

  With this configuration, the blow-by gas is blown by the pressure difference between the first blow-by gas discharge port and the intake passage upstream of the turbocharger compressor and the pressure difference between the second blow-by gas discharge port and the intake passage downstream from the throttle valve. Since the gas discharge path can be switched between the first blow-by gas discharge port and the second blow-by gas discharge port, there is no need for a switching mechanism and a switching control device for switching the blow-by gas discharge path, thereby reducing manufacturing costs. In addition, reliability can be improved.

  In the engine oil separation device having the configuration according to any of the above (3), (4) the first blow-by gas discharge port takes air from the downstream intake passage to the upstream intake passage of the compressor. It is preferable that the blow-by gas is discharged to an intake passage upstream of the compressor by a negative pressure generated in the ejector.

  With this configuration, the blow-by gas discharged from the first blow-by gas discharge port can be increased by discharging the blow-by gas from the first blow-by gas discharge port due to the negative pressure generated in the ejector.

  According to the present invention, the first blow-by gas discharge port is disposed at an equal distance from each outlet of the plurality of cyclone separators, and the second blow-by gas discharge port is any of the plurality of cyclone separators. Since it is disposed in the vicinity of the outlet of the single cyclone separator, it is possible to provide an engine oil separation device that can exhibit good oil separation performance in both the low flow rate region and the high flow rate region.

1 is a cross-sectional view of an engine equipped with an engine oil separation device according to an embodiment of the present invention. It is principal part sectional drawing of the oil separation apparatus of the engine which concerns on embodiment of this invention. It is a figure which shows the oil separation performance with respect to the gas flow rate of the oil separation apparatus of the engine which concerns on embodiment of this invention. It is a perspective view showing composition in which an oil separation device of an engine concerning an embodiment of the invention is provided with four cyclone separators.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  1 to 3 are views showing an embodiment of an engine oil separation device according to the present invention.

  First, the configuration will be described. 2 is installed in the in-line multi-cylinder internal combustion engine, for example, a four-cycle gasoline engine (hereinafter simply referred to as the engine) 10 shown in FIG.

  As shown in FIG. 1, the engine 10 includes a head cover 11, a cylinder head 12, a cylinder block 13, and a crankcase 14 in order from the top in the figure, and a plurality of cylinders 13 a of the cylinder head 12 and the cylinder block 13. A plurality of cylinders 15 are formed (only one is shown in the figure).

  Here, the head cover 11, the cylinder head 12, the cylinder block 13, and the crankcase 14 constitute a block (engine block) that forms the outer wall of the engine 10.

  Each cylinder 15 accommodates a piston 16, and although not shown in detail, a crankshaft 17 in the crankcase 14 is connected to each piston 16 via a connecting rod 18.

  An oil pan 19 is provided at the lower part of the crankcase 14, and contains engine oil for lubrication and cooling (hereinafter simply referred to as oil) (not shown).

  A known valve operating mechanism 20 and ignition device 23 are accommodated inside the head cover 11 and the cylinder head 12, and the valve operating mechanism 20 is driven based on power from the crankshaft 17. .

  The engine 10 is provided with an oil pump (not shown) that is driven based on the power of the crankshaft 17. The oil pump pumps oil from the oil pan 19 and camshafts 21 and 22 of the valve mechanism 20. Etc., or each rotating / sliding portion such as a bearing portion of the crankshaft 17 is lubricated and cooled.

  Air is sucked into the combustion chamber 10a formed in the upper part of the piston 16 in each cylinder 15 through the intake passage 31 and the intake port 10b according to the stroke of the piston 16, and after combustion in the combustion chamber 10a. The exhaust gas is exhausted to the outside of the engine 10 through the exhaust port 10c and an exhaust passage (not shown).

  The intake passage 31 of the engine 10 includes a throttle body 33 that accommodates the throttle valve 32 so that the throttle valve 32 can be opened and closed, and an upstream intake pipe 34 and a downstream intake pipe provided on the upstream and downstream sides of the throttle body 33 in the intake direction. 35.

  An air cleaner 36 having a filter element 36 f is provided on the upstream side of the upstream side intake pipe 34, and air from which dust or the like has been removed by the air cleaner 36 is taken into the upstream side intake pipe 34. Yes.

  The downstream side intake pipe 35 is formed integrally with the surge tank 37, and is fastened and fixed to the cylinder head 12 that forms the intake port 10 b of the engine 10. A fuel injection valve 24 is mounted near the intake port 10b of the cylinder head 12 to which the downstream intake pipe 35 is fixed.

  Further, the engine 10 includes a turbocharger 86 as a supercharger on the downstream side of the air cleaner 36. The turbocharger 86 includes a turbine 86a that is driven by exhaust gas discharged from the exhaust port 10c, and a compressor 86b that is connected to the turbine 86a and compresses intake air that has passed through the air cleaner 36.

  The engine 10 includes an intercooler 84 on the downstream side of the turbocharger 86, and the intake air is cooled by the intercooler 84. The intercooler 84 communicates with the upstream side intake pipe 34. The upstream of the intercooler 84 communicates with the intake passage upstream portion 88 via the compressor 86 b of the turbocharger 86. The intake passage upstream portion 88 is connected to the air cleaner 36.

  An ejector 82 is provided between the upstream side and the downstream side of the compressor 86b of the turbocharger 86 in the intake passage 31 to return intake air from the downstream intake passage to the upstream intake passage. The ejector 82 is connected to an oil separation device 50 described later by a gas passage 80.

  The ejector 82 uses the pressure difference between the upstream side and the downstream side of the compressor 86b of the turbocharger 86 to flow blow-by gas from the engine 10 to the upstream portion 88 of the intake passage.

  Further, in the engine 10, since blow-by gas including unburned gas and exhaust gas leaks from the combustion chamber 10 a through the gap between the cylinder 13 a and the piston 16 into the internal space of the crankcase 14 during operation, air pollution occurs. For prevention, prevention of oil deterioration inside the engine 10 and prevention of corrosion, etc., a PCV (Positive Crankcase Ventilation) type blow-by gas reduction device for forcibly ventilating the inside of the crankcase 14 is equipped.

  The oil separation device 50 of the present embodiment is provided in the blow-by gas recirculation path of this blow-by gas reduction device.

  Specifically, the engine 10 is formed with at least one ventilation passage 10v that communicates the inner space of the head cover 11 and the cylinder head 12 that accommodates the valve mechanism 20 and the inner space of the crankcase 14.

  Further, between the engine 10 and the upstream side intake pipe 34, an air introduction pipe for introducing fresh air from the intake passage upstream portion 88 upstream of the turbocharger 86, that is, new air directly into the engine 10. 41 is interposed.

  Between the engine 10 and the downstream side intake pipe 35, a blowby gas recirculation pipe 42 that recirculates blowby gas generated inside the cylinder block 13 and the crankcase 14 to the intake passage 31 b on the downstream side of the throttle valve 32. A PCV valve 43 serving as a PCV mechanism capable of opening and closing a reflux passage in the blow-by gas reflux pipe 42, and an oil separating device 50 positioned in the middle of the blow-by gas reflux path 44 via the blow-by gas reflux pipe 42. It is intervened.

  The oil separation device 50 forms a gas-liquid separation chamber 51 in a part of the blow-by gas recirculation path 44 via the blow-by gas recirculation pipe 42, and the mist-like oil contained in the blow-by gas in the gas-liquid separation chamber 51. The oil component is separated from the blow-by gas by capturing the gas in a recoverable manner.

  The oil separation device 50 forms a substantially bottomed cylindrical drain passage forming member 62 that hangs downward from the gas-liquid separation chamber 51 at the lower portion of the gas-liquid separation chamber 51. Oil separated from blow-by gas in the gas-liquid separation chamber 51 is discharged through a drain passage 65 (see FIG. 2), which will be described later, which is an internal space.

  Next, a detailed configuration of the oil separation device 50 will be described. As shown in FIG. 2, inside the gas-liquid separation chamber 51, substantially cylindrical cyclone separators 71 and 72 formed in a tapered shape having an open lower end are provided.

  A bottom wall member 61 that forms the bottom wall of the gas-liquid separation chamber 51 is formed with an inlet 53 having a circular cross section for introducing blow-by gas into the gas-liquid separation chamber 51. The cyclone separators 71 and 72 are formed with inlets 71a and 72a through which blow-by gas flows, respectively. The blow-by gas introduced from the inlet 53 is connected to each cyclone separator via the inlets 71a and 72a. 71 and 72 are supplied along the tangential direction to the internal space of the upper part.

  The blow-by gas introduced into the cyclone separators 71 and 72 changes from a linear flow to a vortex flow inside the cyclone separators 71 and 72, and rotates in a spiral manner while increasing the rotation speed along the inner walls of the cyclone separators 71 and 72. Descend.

  At this time, the relatively fine mist-like oil contained in the blow-by gas is separated from the blow-by gas by obtaining centrifugal force by the swirling motion and colliding with the inner walls of the cyclone separators 71 and 72, and the cyclone separators 71 and 72. The liquid is collected while flowing down the inner wall of the gas, and drops from the lower end to the upper surface of the bottom wall member 61 of the gas-liquid separation chamber 51.

  The cyclone separators 71 and 72 are formed with gas outflow pipes 71c and 72c arranged coaxially with the central axis thereof, and the openings of the gas outflow pipes 71c and 72c are outlets 71b and 72b through which blow-by gas flows out. Is configured.

  A first discharge port 91 and a second discharge port 92 for discharging blow-by gas from the gas-liquid separation chamber 51 are formed in the upper part of the gas-liquid separation chamber 51. The first discharge port 91 opens on the upper surface of the gas-liquid separation chamber 51 and is connected to the ejector 82. That is, the first discharge port 91 discharges blow-by gas to the intake passage on the upstream side of the compressor 86 b of the turbocharger 86 due to the negative pressure generated in the ejector 82. The cyclone separators 71 and 72, the introduction port 53, the first discharge port 91, the second discharge port 92, and the like constituting the gas-liquid separation chamber 51 are made of the same resin having excellent heat resistance and molding accuracy, for example. Or by partial welding after molding.

  On the other hand, the second discharge port 92 opens to the side surface of the gas-liquid separation chamber 51 and is connected via the PCV valve 43 to a downstream side intake pipe 35 that is an intake passage downstream of the throttle valve 32.

  That is, the second discharge port 92 discharges blow-by gas to the downstream side intake pipe 35 due to the negative pressure generated in the downstream side intake pipe 35.

  The PCV valve 43 opens according to the pressure in the internal space of the oil separation device 50 and the intake negative pressure of the intake system (pressure in the internal space of the downstream intake pipe 35).

  Specifically, the PCV valve 43 operates when the engine 10 is operated at a relatively low speed, the supercharging pressure by the turbocharger 86 is low, and the blow-by gas is also in a low flow rate. Is higher than the pressure in the internal space of the downstream side intake pipe 35, the valve is opened.

  When the engine 10 is operated at a relatively high speed and the turbocharger 86 has a high supercharging pressure and a high flow rate of blow-by gas, the pressure in the internal space of the oil separation device 50 is high. The valve is closed because it is lower than the pressure in the internal space of the downstream side intake pipe 35.

  Therefore, when the engine 10 is operated at a relatively low speed and the amount of blow-by gas generated is small, the blow-by gas is opened by the PCV valve 43 and the negative pressure of the ejector 82 is not generated (the ejector 82 is not operated). ) Is discharged from the second discharge port 92.

  On the other hand, when the engine 10 is operated at a relatively high speed and a large amount of blow-by gas is generated, the blow-by gas closes the PCV valve 43 and increases the negative pressure generated in the ejector 82 (operation of the ejector 82). Is discharged from the first discharge port 91.

  The blow-by gas from which the oil has been separated and removed flows into the gas outflow pipes 71c and 72c, flows out from the outflow ports 71b and 72b, and is then discharged from the oil separation device 50. The discharged blowby gas is returned to the intake system of the engine 10 through at least one of the PCV valve 43 and the ejector 82.

  In this way, the oil separator 50 functions as a tangential inflow tandem cyclone separator.

  The oil separation device 50 includes a bottom wall member 61 that forms an inner bottom wall surface 51a of the gas-liquid separation chamber 51 so as to collect the oil separated in the gas-liquid separation chamber 51, and a vertically downward direction from the bottom wall member 61. And a drain passage forming member 62 having a substantially bottomed cylindrical shape that forms a drain passage 65 having a circular cross section that protrudes to the side (or may be inclined) and communicates with the gas-liquid separation chamber 51.

  The bottom wall member 61 is supported by the head cover 11 of the engine 10. For example, the bottom wall member 61 is attached to the head cover 11 as a part of the head cover 11, thereby partitioning the space on the valve mechanism 20 side and the gas-liquid separation chamber 51. ing.

  Alternatively, the bottom wall member 61 is supported by the head cover 11 so as to be positioned on the inner side of the head cover 11, thereby serving as a baffle plate that restricts scattering of oil from the valve operating mechanism 20 side. Alternatively, it may be supported by the head cover 11 so as to be located on the outer side of the head cover 11, and the drain passage forming member 62 may penetrate a part of the head cover 11.

  The bottom wall member 61 is at least internally disposed so as to guide oil that has flowed down on the inner bottom wall surface 51a of the gas-liquid separation chamber 51 by gas-liquid separation of the blow-by gas in the gas-liquid separation chamber 51 into a drain passage 65 described later. The upper surface side forming the bottom wall surface 51a is inclined with respect to the horizontal plane.

  The bottom wall member 61 and the drain passage forming member 62 are made of, for example, the same resin excellent in heat resistance and molding accuracy, and are integrated by molding or by partial welding after molding.

  Further, the drain passage forming member 62 and the internal drain passage 65 have a gentle taper shape such as a die cutting gradient for injection molding of the drain passage forming member 62, for example.

  The drain passage forming member 62 includes a substantially cylindrical tubular portion 62a that constitutes a side surface thereof, and a disk-like bottom wall portion 62b that constitutes a bottom surface thereof and closes a lower end side of the tubular portion 62a. Yes.

  The cylindrical part 62a has a relatively large diameter on the upper end side connected to the bottom wall member 61 in order to give a die-cutting gradient at the time of injection molding, and a bottom wall part 62b is formed. The taper is tapered so that the diameter is relatively small on the lower end side.

  The drain wall forming member 62 has a bottom wall portion 62b formed with a discharge hole 62h that communicates with the internal drain passage 65 and discharges oil.

  The discharge hole 62 h communicates with the lower end portion of the drain passage 65 inside the drain passage forming member 62. The discharge hole 62h is formed in a circular shape, and its diameter is set to about 4 mm, for example.

  The camshaft 22 is provided with a plurality of valve drive cams for driving valves corresponding to any of the plurality of cylinders 15 (only one valve drive cam 22b is shown in FIG. 2).

  Here, the positional relationship between the first outlet 91 and the second outlet 92 with respect to the outlets 71b and 72b of the cyclone separators 71 and 72, and the positional relationship of the inlet 53 with respect to the inlets 71a and 72a of the cyclone separators 71 and 72, The operation of these positional relationships will be described.

  In the present embodiment, the second discharge port 92 is disposed in the vicinity of the outlet 71 b of the cyclone separator 71 among the two cyclone separators 71 and 72. In other words, the path length from the outlet 71 b of the cyclone separator 71 to the second outlet 92 is longer than the path length from the outlet 72 b of the cyclone separator 72 to the second outlet 92.

  Thus, when the engine 10 is operated at a relatively low speed and the amount of blow-by gas generated is small, the blow-by gas is discharged from the second discharge port 92 by opening the PCV valve 43 and inactivating the ejector 82. However, since the second discharge port 92 is disposed in the vicinity of the outlet 71b of the cyclone separator 71, the blow-by gas having a small flow rate passes through the cyclone separator 71 at a high speed and is broken by a broken line in FIG. It flows out along the path indicated by the arrow and is discharged from the second discharge port 92, but the cyclone separator 72 passes only a little.

  As described above, the oil separation device 50 discharges the blow-by gas from the second discharge port 92 disposed in the vicinity of the cyclone separator 71 by opening the PCV valve 43 and inactivating the ejector 82 in the low flow rate region of the blow-by gas. In addition, since a high-speed blow-by gas is allowed to pass from one cyclone separator 71, the maximum oil separation performance can be exhibited as shown in FIG.

  On the other hand, the 1st discharge port 91 is arrange | positioned so that it may become equal distance from each outflow port 71b, 72b of the cyclone separators 71,72. In other words, the path length from the outlet 71 b of the cyclone separator 71 to the second outlet 92 is equal to the path length from the outlet 72 b of the cyclone separator 72 to the second outlet 92.

  Thus, when the engine 10 is operated at a relatively high rotation and the amount of blow-by gas generated is large, the blow-by gas is discharged from the second discharge port 92 by closing the PCV valve 43 and operating the ejector 82. However, since the first outlet 91 is arranged at an equal distance from each of the outlets 71b and 72b, the blow-by gas having a large flow rate passes through the cyclone separator 71 and the cyclone separator 72 evenly and at high speed. In addition to flowing out along the path indicated by the solid line arrow in FIG.

  As described above, the oil separation device 50 is configured so that, in the high flow rate region of the blow-by gas, the PCV valve 43 is opened and the ejector 82 is not operated, so Since the blow-by gas is discharged from the first discharge port 91 disposed at a distance and the blow-by gas without any bias is allowed to pass from the two cyclone separators 71 and 72, as shown in FIG. The oil separation performance superior to the conventional one can be exhibited.

  Further, regarding the positional relationship of the inlet 53 with respect to the inlets 71a and 72a of the cyclone separators 71 and 72, as shown in FIG. 2, the inlet 53 also has an equal distance from the inlets 71a and 72a of the cyclone separators 71 and 72. It is preferable to arrange so that.

  As a result, when the engine 10 is operated at a relatively high speed and the amount of blow-by gas generated is large, the introduction port 53 is arranged at an equal distance from each of the inflow ports 71a and 72a. A large amount of blow-by gas can pass through the cyclone separator 71 and the cyclone separator 72 evenly and at high speed.

  Accordingly, the occurrence of a bias in the flow rate and flow velocity of the blowby gas between the cyclone separator 71 and the cyclone separator 72 is further prevented, and the maximum oil separation performance can be exhibited as the oil separation device 50.

  In the present embodiment, the configuration including the two cyclone separators 71 and 72 is illustrated, but the oil separation device 50 may include more cyclone separators. For example, as shown in FIG. 4, the oil separation device 50 may include four cyclone separators 101, 102, 103, and 104 configured in the same manner as the cyclone separators 71 and 72.

  Also in this case, the first discharge port 91 is arranged above the centers of the cyclone separators 101, 102, 103, 104 so as to be an equal distance from the outlets of the four cyclone separators 101, 102, 103, 104. The second discharge port 92 is disposed in the vicinity of the outlet of any one of the four cyclone separators 101, 102, 103, 104.

  Further, in the present embodiment, an ejector 82 for returning intake air from the intake passage on the downstream side of the compressor 86b to the intake passage on the upstream side is provided, and the negative pressure generated in the ejector 82 blows into the intake passage on the upstream side of the compressor 86b. Although the configuration configured to discharge the gas is illustrated, the blow-by gas may be discharged from the first discharge port 91 to the intake passage on the upstream side of the compressor 86b.

  In this case, the blow-by gas discharge path becomes the first due to the pressure difference between the first exhaust port 91 and the intake passage upstream of the compressor 86b and the pressure difference between the second exhaust port 92 and the intake passage downstream of the throttle valve 32. Switching between the first outlet 91 and the second outlet 92 will be performed.

  As described above, in the present embodiment, the oil separation device 50 is arranged such that the first discharge port 91 is at an equal distance from the outlets 71b and 72b of the plurality of cyclone separators 71 and 72. The discharge port 92 is composed of one disposed in the vicinity of the outlet 71 b of any one of the plurality of cyclone separators 71, 72.

  With this configuration, the oil separation device 50 discharges blow-by gas from the second discharge port 92 disposed in the vicinity of the outlet 71b of the cyclone separator 71 in a low flow rate region of the blow-by gas, and allows high speed from only one cyclone separator 71. The maximum oil separation performance can be exhibited by passing the blowby gas.

  Further, the oil separation device 50 discharges the blow-by gas from the first outlet 91 arranged at an equal distance from the outlet 71b of the cyclone separator 71 and the outlet 72b of the cyclone separator 72 in a high flow rate region of the blow-by gas, The maximum oil separation performance can be exerted by passing the blow-by gas without any bias from the two cyclone separators 71 and 72. Therefore, good oil separation performance can be exhibited in both the low flow rate region and the high flow rate region.

  In the present embodiment, the oil separation device 50 is configured such that the introduction port 53 is disposed at an equal distance from the inflow ports 71a and 72a of the plurality of cyclone separators 71 and 72.

  With this configuration, the occurrence of an uneven flow rate and flow velocity of the blowby gas between the cyclone separator 71 and the cyclone separator 72 is further prevented, and the maximum oil separation performance can be exhibited.

  In the present embodiment, the first discharge port 91 discharges blow-by gas into the intake passage on the upstream side of the compressor 86b of the turbocharger 86 that compresses the intake air with the exhaust gas, and the second discharge port 92 includes the PCV valve. The blow-by gas is discharged to the intake passage downstream of the throttle valve 32 through 43.

  With this configuration, the blow-by gas is caused by the pressure difference between the first exhaust port 91 and the intake passage upstream of the compressor 86 b of the turbocharger 86 and the pressure difference between the second exhaust port 92 and the intake passage downstream of the throttle valve 32. Since the discharge path can be switched between the first discharge port 91 and the second discharge port 92, a switching mechanism and a switching control device for switching the blow-by gas discharge path become unnecessary, reducing the manufacturing cost and improving the reliability. Can be improved.

  Further, in the present embodiment, the first discharge port 91 is connected to an ejector 82 that returns intake air from the downstream intake passage to the upstream intake passage of the compressor 86b, and the compressor 86b is caused by the negative pressure generated in the ejector 82. The blow-by gas is discharged into the intake passage on the upstream side.

  With this configuration, the blow-by gas discharged from the first discharge port 91 can be increased by discharging the blow-by gas from the first discharge port 91 due to the negative pressure generated in the ejector 82.

  As described above, the oil separation device for an engine according to the present invention has an effect of being able to exhibit good oil separation performance in both the low flow rate region and the high flow rate region, and is effective for the intake system. This is useful for all engine oil separation devices arranged on the reflux path of blow-by gas.

DESCRIPTION OF SYMBOLS 10 Engine 11 Head cover 12 Cylinder head 31 Intake passage 32 Throttle valve 34 Upstream side intake pipe 35 Downstream side intake pipe 36 Air cleaner 41 Air inlet pipe 42 Blow-by gas recirculation pipe 43 PCV valve 44 Blow-by gas recirculation path 50 Oil separator 51 Gas-liquid separation Chamber 53 Inlet 65 Drain passage 71, 72, 101, 102, 103, 104 Cyclone separators 71a, 72a Inlet 71b, 72b Outlet 71c, 72c Gas outlet pipe 80 Gas passage 82 Ejector 84 Intercooler 86 Turbocharger 86b Compressor 88 Inlet passage upstream portion 91 First exhaust port (first blow-by gas exhaust port)
92 Second outlet (second blow-by gas outlet)

Claims (4)

In an engine oil separation device that separates oil contained in blow-by gas generated inside the engine,
A plurality of cyclone separators having a cylindrical member that forms an inflow port through which the blow-by gas flows in and an outflow port through which the blow-by gas flows out, and separates oil by swirling the blow-by gas in an internal space;
An inlet for accommodating the plurality of cyclone separators and introducing the blow-by gas, and a first blow-by gas outlet and a second blow-by gas outlet for discharging the blow-by gas from which oil has been separated by the cyclone separator And a gas-liquid separation chamber formed with
The first blow-by gas discharge port is disposed at an equal distance from each outlet of the plurality of cyclone separators,
The engine oil separation device, wherein the second blow-by gas discharge port is disposed in the vicinity of an outlet of any one of the plurality of cyclone separators.   The engine oil separator according to claim 1, wherein the introduction port is disposed at an equal distance from each inlet of the plurality of cyclone separators. The first blow-by gas discharge port discharges the blow-by gas into an intake passage on the upstream side of a compressor of a turbocharger that compresses intake air with exhaust gas,
3. The engine oil separator according to claim 1, wherein the second blow-by gas discharge port discharges the blow-by gas to an intake passage downstream of the throttle valve via a PCV valve. .   The first blow-by gas discharge port is connected to an ejector for returning intake air from an intake passage on the downstream side of the compressor to an intake passage on the upstream side. The negative pressure generated in the ejector causes an intake passage on the upstream side of the compressor to be connected to the ejector. The engine oil separator according to claim 3, wherein the blow-by gas is discharged.

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