JP2019214956A - Oil separator - Google Patents

Abstract

To provide an oil separator capable of controlling fuel consumption of an internal combustion engine and cost of a mechanism.SOLUTION: An oil separator 100 is an oil separator for centrifuging oil O from blow-by gas B of an internal combustion engine 1, and comprises: a rotor 20 provided in a casing 10; a gas flow passage 30 formed inside the rotor 20; an inlet 31 and an outlet 32 formed in the rotor 20; and a turbine 40 connected to the rotating body 20 and rotationally driven by compressed air A generated by a compressor 3a of a turbocharger 3.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to an oil separator, and more particularly to an oil separator for centrifuging oil from blow-by gas of an internal combustion engine.

  2. Description of the Related Art In an internal combustion engine mounted on a vehicle or the like, a system called PCV (Positive Crankcase Ventilation) for recirculating blow-by gas to an intake passage is known. In the PCV, an oil separator for centrifuging oil from blow-by gas may be provided.

  As the above oil separator, a method of rotating a rotating body in a casing, discharging blow-by gas into the casing from a gas flow path in the rotating body, and separating oil by centrifugal force at that time is known.

JP 2009-008082 A

  In the above oil separator, a hydraulic or electric motor or the like can be considered as a drive source for rotating the rotating body. However, with these drive sources, the fuel efficiency of the internal combustion engine may deteriorate, and the cost of the mechanism may increase.

  Then, this indication is made in view of such a situation, and an object is to provide an oil separator which can control fuel consumption of an internal-combustion engine, and cost of a mechanism.

  An oil separator according to the present disclosure is an oil separator for centrifuging oil from blow-by gas of an internal combustion engine, wherein the internal combustion engine includes an intake passage, and a turbocharger compressor provided in the intake passage. The oil separator is provided with a casing, a rotating body provided in the casing, a gas flow path formed inside the rotating body, and a blow-by gas formed in the rotating body. An introduction port for introducing, an outlet formed in the rotating body, and an outlet for leading blow-by gas out of the gas flow path, connected to the rotating body, and rotationally driven by compressed air generated by the compressor. And a turbine.

  Further, it is preferable that the internal combustion engine further includes an intercooler provided in the intake passage downstream of the compressor, and the turbine is driven to rotate by the compressed air cooled by the intercooler.

  Further, the casing has an introduction chamber in which a gas inlet for introducing blow-by gas before oil separation is formed, a gas outlet for discharging blow-by gas after oil separation, and a case for discharging separated oil. A discharge chamber in which an oil outlet is formed, and a turbine chamber in which an air inlet and an air outlet for introducing and discharging the compressed air are formed. The rotating body includes the introduction chamber and the discharge chamber. Preferably, the inlet extends through the turbine chamber, the inlet is located in the inlet chamber, the outlet is located in the discharge chamber, and the turbine is located in the turbine chamber.

  Further, the rotating body is connected to the turbine, a hollow rotating shaft in which the gas flow path is defined, and a disk provided coaxially on an outer peripheral portion of the rotating shaft and arranged in the discharge chamber. It is preferable that the rotating shaft is disposed vertically so that the center of rotation is along the vertical direction, and the outlet is disposed at a position near and above the disk.

  Further, it is preferable that a plurality of the outlets and the disks are provided in an axial direction of the rotation shaft.

  Further, it is preferable that the disk is inclined such that its radially outer side is located above the radially inner side.

  ADVANTAGE OF THE INVENTION According to the oil separator which concerns on this indication, the fuel consumption of an internal combustion engine and the cost of a mechanism can be suppressed.

FIG. 1 is a schematic configuration diagram of an entire internal combustion engine including an oil separator. It is a schematic sectional drawing of the oil separator shown in FIG.

  Hereinafter, an embodiment of the present disclosure will be described with reference to the accompanying drawings. In the following embodiments, it is assumed that the upper, lower, left, and right directions shown in the drawings are merely defined for convenience of description. Further, the present disclosure is not limited to the embodiments described below, and can be appropriately modified and implemented without departing from the gist of the present disclosure.

  FIG. 1 is a schematic configuration diagram of the entire internal combustion engine 1 including an oil separator 100. FIG. 2 is a schematic sectional view of the oil separator 100 shown in FIG. Note that, in the drawing, the outline arrow A indicates the flow of the compressed air, and the hatched arrow B indicates the flow of the blow-by gas. The dashed line C indicates the central axis of the casing 10 and the rotation centers of the rotating body 20 and the turbine 40. The black arrow O indicates the flow of the oil separated from the blow-by gas B.

  As shown in FIGS. 1 and 2, the oil separator 100 is an oil separator for centrifuging oil O from blow-by gas B of the internal combustion engine 1.

  The internal combustion engine 1 is a multi-cylinder compression ignition type internal combustion engine for a vehicle, that is, a diesel engine. However, the use and type of the internal combustion engine 1 may be arbitrary, and may be, for example, a gasoline engine.

  The internal combustion engine 1 includes an engine body 1a. Further, the internal combustion engine 1 includes an intake pipe 2 as an intake passage, and a compressor 3a of a turbocharger 3 provided in the intake pipe 2. Further, the internal combustion engine 1 further includes an intercooler 4 provided in the intake pipe 2 downstream of the compressor 3a. The internal combustion engine 1 also includes exhaust system components such as an exhaust pipe (not shown), but a description thereof is omitted here.

  The engine body 1a includes a cylinder block 1b and a crankcase 1c integrally formed below the cylinder block 1b. The engine body 1a includes a cylinder head 1d connected to an upper part of the cylinder block 1b, and a head cover 1e attached to an upper part of the cylinder head 1d.

  In the internal combustion engine 1 of the present embodiment, a PCV (Positive Crankcase Ventilation) for returning the blow-by gas B to the intake pipe 2 is used. As is well known, the blow-by gas B is gas leaked into the crankcase 1c from a gap between a cylinder and a piston (not shown).

  The engine body 1a includes a gas passage (not shown) extending from inside the crankcase 1c to inside the head cover 1e through the inside or outside of the cylinder block 1b and the cylinder head 1d. A gas pipe 5 for recirculating blow-by gas B to the intake pipe 2 is connected to the head cover 1e. The gas pipe 5 communicates with the crankcase 1c through a gas passage of the engine body 1a. For the gas pipe 5, for example, a resin hose member is used.

  An intake manifold 6 that distributes intake air to each cylinder (not shown) is connected to the cylinder head 1d.

  The intake pipe 2 is connected to a cylinder head 1d via an intake manifold 6. The turbocharger 3 includes a turbine (not shown) that is rotationally driven by exhaust gas flowing through an exhaust pipe, and a compressor 3a that is rotationally driven by the rotational force of the turbine. The compressor 3 a is configured to compress the intake air flowing through the intake pipe 2 to generate the compressed air A. The intercooler 4 is configured to cool the compressed air A generated by the compressor 3a.

  A compressed air pipe 7 for extracting compressed air A is connected to the intake pipe 2 downstream of the intercooler 4. For the compressed air pipe 7, for example, a resin hose member is used.

  The downstream end of the gas pipe 5 is connected to the intake pipe 2 upstream of the compressor 3a.

  The oil separator 100 is provided in the middle of the gas pipe 5. In the present embodiment, the gas pipe 5 located upstream of the oil separator 100 is referred to as an upstream gas pipe 5a, and the gas pipe 5 located downstream is referred to as a downstream gas pipe 5b.

  The oil separator 100 includes a casing 10, a rotator 20 provided in the casing 10, a gas flow path 30 formed inside the rotator 20, and a blower gas B formed in the rotator 20. And an introduction port 31 for introduction into the apparatus 30. The oil separator 100 is formed in the rotating body 20 and is connected to the outlet 32 for leading the blow-by gas B out of the gas flow path 30 and the compressed air A generated by the compressor 3a. And a driven turbine 40.

  The casing 10 has an introduction chamber 11 in which a gas inlet 11a for introducing the blow-by gas B before oil separation is formed. The casing 10 has a gas outlet 12a for discharging the blow-by gas B after oil separation, and a discharge chamber 12 in which an oil outlet 12b for discharging the separated oil O is formed. The casing 10 has a turbine chamber 13 in which an air inlet 13a and an air outlet 13b for introducing and discharging the compressed air A are formed.

  The downstream end of the upstream gas pipe 5a is connected to the gas inlet 11a. The upstream end of the downstream gas pipe 5b is connected to the gas outlet 12a. An oil return pipe (not shown) for returning oil O into the crankcase 1c is connected to the oil outlet 12b. The downstream end of the compressed air pipe 7 is connected to the air inlet 13a. On the other hand, the air outlet 13b is open to the atmosphere.

  Specifically, the casing 10 of the present embodiment has a side wall 10a, a ceiling 10b, and a bottom wall 10c. The side wall 10a is formed in a cylindrical shape extending in the vertical direction. The ceiling part 10b and the bottom wall part 10c are each formed in a disk shape. The ceiling 10b is inclined such that the inner side in the radial direction is located higher than the outer side. In the illustrated example, the bottom wall portion 10c has a central portion in the radial direction that is curved downward so as to be recessed along a lower portion of the turbine 40 described later.

  In the casing 10, a discharge chamber 12, an introduction chamber 11, and a turbine chamber 13 are provided in this order from above. More specifically, the casing 10 includes a first partition 14 that partitions the discharge chamber 12 and the introduction chamber 11 into upper and lower stages, and a second partition 15 that partitions the introduction chamber 11 and the turbine chamber 13 into upper and lower stages. Provided.

  The gas inlet 11 a is provided in the side wall 10 a located in the introduction chamber 11. The gas outlet 12a is provided on the ceiling 10b. The air inlet 13a and the air outlet 13b are provided on the side wall 10a located in the turbine chamber 13. The oil outlet 12b is provided on the side wall 10a located at the lower end of the discharge chamber 12.

  The gas inlet 11a, the oil outlet 12b, the air inlet 13a, and the air outlet 13b are formed in a tubular shape protruding radially outward from the side wall 10a. The gas outlet 12a is formed in a tubular shape that protrudes upward from a central portion of the ceiling 10b. The air inlet 13a and the air outlet 13b are formed at positions opposite to each other with respect to the center axis C of the casing 10. However, these gas inlet 11a, gas outlet 12a, oil outlet 12b, air inlet 13a, and air outlet 13b may have any orientation. For example, any one of the air inlet 13a and the air outlet 13b may be formed in a tubular shape that protrudes downward from the central portion of the bottom wall 10c like a radial flow turbine.

  The first partition 14 and the second partition 15 are formed in a disk shape with a central portion opened. The first partition 14 is provided in a lower part in the casing 10 in a horizontal direction. The second partition 15 is provided in a horizontal direction at a position between the first partition 14 and the bottom wall 10c. Note that the first partition wall 14 has a part on the outside in the radial direction inclined downward toward the oil outlet 12b so that the oil O can easily flow into the oil outlet 12b.

  Further, bearings 16 and 17 provided coaxially with the central axis C of the casing 10 are provided at the center portions of the first partition 14 and the second partition 15. The bearings 16 and 17 are configured to rotatably support a rotating shaft 21 described later. As the bearings 16 and 17, ball bearings are desirable.

  The rotating body 20 extends through the introduction chamber 11, the discharge chamber 12, and the turbine chamber 13. The rotating body 20 is connected to the turbine 40 and has a hollow rotating shaft 21 in which the gas flow path 30 is defined, and is provided coaxially on the outer peripheral portion of the rotating shaft 21, and is disposed in the discharge chamber 12. And a disk 22.

  The rotation shaft 21 is arranged coaxially with the casing 10. Further, the rotation shaft 21 is arranged vertically so that the rotation center C is along the vertical direction. Further, the rotating shaft 21 extends downward from an upper position in the discharge chamber 12, passes through the introduction chamber 11, and extends into the turbine chamber 13. The rotating shaft 21 is inserted through bearings 16 and 17 of the partition walls 14 and 15 and is rotatably supported. Further, a disk member 23 provided coaxially with the rotation center C is connected to the upper end of the rotating shaft 21.

  More specifically, the rotating shaft 21 of the present embodiment is formed in a cylindrical shape. The opening on the upper end side of the rotating shaft 21 is sealed by fitting a projection 23 a formed on the lower surface of the disk member 23. The opening on the lower end side of the rotating shaft 21 is sealed by a turbine 40 described later. As a result, a gas flow path 30 extending in the axial direction and having both ends sealed is defined inside the rotary shaft 21.

  The disk 22 is formed in a disk shape with an opening at the center, and the opening and the rotating shaft 21 are fixed. The disk 22 is inclined such that its radially outer side is located above the radially inner side.

  The disk 22 and the disk member 23 have outer diameters smaller than the inner diameter of the side wall 10 a of the casing 10. Thus, a flow path for the blow-by gas B and the oil O is defined in the gap S between the outer peripheral surface of the disk 22 and the outer peripheral surface of the disk member 23 and the inner peripheral surface of the side wall 10a.

  The introduction port 31 is provided to penetrate the rotation shaft 21 and is disposed in the introduction chamber 11. The outlet 32 is provided through the rotating shaft 21 and is disposed in the discharge chamber 12. The outlet 32 is located near and above the disk 22. In addition, a plurality of pairs of the outlet 32 and the disk 22 are provided in the axial direction of the rotating shaft 21 (four at equal intervals in the present embodiment).

  The introduction port 31 of the present embodiment extends in the radial direction of the rotating shaft 21 and communicates the gas flow path 30 and the introduction chamber 11. The outlet 32 extends in the radial direction of the rotation shaft 21 and communicates the gas flow path 30 and the discharge chamber 12. A plurality of inlets 31 and outlets 32 are provided in the circumferential direction of the rotating shaft 21 (four at regular intervals in the present embodiment).

  The turbine 40 is arranged in the turbine chamber 13. The turbine 40 is configured to receive the compressed air A introduced from the air inlet 13a, rotate around the axis, and to flow the compressed air A in the rotational direction to be discharged from the air outlet 13b.

  As the turbine 40 of the present embodiment, a turbine wheel fixed coaxially to the lower end of the rotating shaft 21 and disposed downward is used. The type of the turbine 40 may be arbitrary, and for example, an impeller such as a runner of a Pelton turbine may be used.

  Further, the shape, size, and the like of the turbine 40, the turbine chamber 13, and the compressed air pipe 7 are, for example, relative to the entire flow rate of the compressed air A generated by the compressor 3a. The flow rate is set so as to be within 5%.

  Next, the operation and effect of the oil separator 100 according to the present embodiment will be described.

  First, during operation of the internal combustion engine 1, blow-by gas B in the crankcase 1c is introduced into the introduction chamber 11 from the gas inlet 11a through the gas passage (not shown) of the engine body 1a and the upstream gas pipe 5a. The blow-by gas B introduced into the introduction chamber 11 is introduced into the gas flow path 30 from the introduction port 31, and is discharged from the discharge port 32 to the discharge chamber 12 while flowing upward in the axial direction in the gas flow path 30.

  The blow-by gas B led out from the gas passage 30 to the discharge chamber 12 is discharged radially outward along the direction of the outlet 32. At this time, the blow-by gas B passes between the upper and lower disks 11 of the disk 22 and the oil O contained in the blow-by gas B adheres to the upper surface of the disk 22 and rotates together with the disk 22. At this time, the oil O scatters radially outward from the disk 22 and is finally centrifuged from the blow-by gas B.

  The blow-by gas B after oil separation flows upward in the discharge chamber 12 along the gap S between the disk 22 and the disk member 23 and the side wall 10a, and is discharged from the gas outlet 12a. Then, the blow-by gas B discharged from the gas outlet 12a is returned to the intake pipe 2 through the downstream gas pipe 5b.

  On the other hand, the oil O centrifugally separated from the blow-by gas B adheres to the side wall 10a, flows along the inner peripheral surface of the side wall 10a and the upper surface of the bottom wall 10c, and is discharged from the oil outlet 12b.

  On the other hand, the compressed air A generated by the compressor 3a of the turbocharger 3 is taken out of the intake pipe 2 through the compressed air pipe 7, and introduced into the turbine chamber 13 through the air inlet 13a. The compressed air A introduced into the turbine chamber 13 drives the turbine 40 to rotate, and then is discharged to the atmosphere from the air outlet 13b.

  That is, the oil separator 100 of the present embodiment can rotate the rotating shaft 21 by extracting the compressed air A generated by the compressor 3a and applying it to the turbine 40.

  Here, as a comparative example, a case where the rotary shaft 21 is rotated by a hydraulic or electric drive source (motor or the like) will be considered.

  The hydraulic motor is driven to rotate by engine oil supplied from an oil pump provided in the internal combustion engine. Further, the electric motor is driven to rotate by electric power supplied from a battery mounted on the vehicle.

  However, in a hydraulic motor, the work of an oil pump increases, and in an electric motor, the power consumption of a battery increases. Therefore, fuel efficiency of the internal combustion engine may be deteriorated.

  Further, in a hydraulic motor, it is necessary to use a hydraulic pipe having a high pressure resistance. In addition, an electric motor requires electric drive components such as a rotor and a stator. Therefore, the cost of the mechanism may be extremely high.

  On the other hand, in the case of the turbine 40 of the present embodiment, since the rotation is driven by the compressed air A generated by the compressor 3a, the work of an oil pump such as a hydraulic motor is increased, or the electric motor is increased. This can suppress an increase in power consumption. Therefore, it is possible to suppress deterioration of fuel efficiency of the internal combustion engine.

  In particular, in the present embodiment, the ratio of the flow rate of the compressed air A introduced into the turbine chamber 13 to the entire flow rate of the generated compressed air A is suppressed to a relatively small value, for example, within 5%. For this reason, the influence on the engine performance and fuel efficiency due to the extraction of the compressed air A can be ignored.

  In addition, since the pressure of the compressed air A is lower than the hydraulic pressure, a resin hose having a low pressure resistance can be used for the compressed air pipe 7 instead of a pipe having a high pressure resistance such as a hydraulic pipe. Further, since the mechanism of the turbine 40 is not a complicated mechanism as compared with the electric motor, it can be manufactured relatively inexpensively. Therefore, the cost of the oil separator 100 can be reduced.

  As described above, according to the present embodiment, it is possible to suppress the fuel consumption of the internal combustion engine 1 and the cost of the mechanism.

  On the other hand, in the present embodiment, the following operational effects also exist in addition to the above.

  First, in the hydraulic or electric motor of the comparative example, for example, the flow rate of the blow-by gas is changed in order to make the centrifugal separation performance variable according to the amount of oil contained in the blow-by gas (that is, the flow rate of the blow-by gas). It is necessary to detect with a sensor and control the rotation speed of the motor based on the detected value.

  On the other hand, in the present embodiment, the rotation speed of the turbine 40 is proportional to the flow rate of the compressed air A flowing through the intake pipe 2, and the flow rate of the blow-by gas B is also the flow rate of the compressed air A flowing through the intake pipe 2. Is proportional to That is, since the rotation speed of the turbine 40 is proportional to the flow rate of the blow-by gas B, the centrifugal separation performance can be made variable according to the flow rate of the blow-by gas B without using a sensor or control.

  Next, the turbine 40 of the present embodiment is driven to rotate by the compressed air A cooled by the intercooler 4. Therefore, compared to the case where the compressed air A generated by the compressor 3a is taken out on the upstream side of the intercooler 4, the thermal deterioration of the compressed air pipe 7, the turbine 40, and the turbine chamber 13 due to the compressed air A can be suppressed.

  Further, if the turbine 40 is driven to rotate by high-temperature exhaust gas taken out from the exhaust pipe, the exhaust pipe, the turbine 40 and the turbine chamber 13 are formed of a heat-resistant material in order to prevent deterioration or damage due to exhaust heat. There is a need to.

  On the other hand, according to the present embodiment, the turbine 40 is rotationally driven by the low-temperature compressed air A cooled by the intercooler 4, so that the compressed air pipe 7, the turbine 40, and the turbine chamber 13 are made of a heat-resistant material. It is not necessary to form with. Therefore, costs can be reduced in selecting these materials.

  Although not shown, the above-described embodiment can be modified as follows or a combination of those modified examples.

(First modification)
In the casing 10, the order of arrangement of the introduction chamber 11, the discharge chamber 12, and the turbine chamber 13 may be arbitrary. For example, an introduction chamber 11, a discharge chamber 12, and a turbine chamber 13 may be provided in this order from the top. In this case, the gas outlet 12a is provided on the side wall 10a located in the discharge chamber 12.

  In this modification, the disk member 23 may not be connected to the upper end of the rotating shaft 21, and an inlet 31 may be formed instead.

  The disk 22 may have a disk shape extending in the horizontal direction, or may be inclined so that its radially outer side is located below the radially inner side. In addition, the outlet 32 may be arranged at a position near and below the disk 22.

(Second modification)
The direction of the rotating shaft 21 may be arbitrary. For example, the rotation shaft 21 may be arranged laterally so that the center of rotation is along the horizontal direction. In this case, the direction of the casing 10 is not horizontal but is arranged in the horizontal direction according to the direction of the rotating shaft 21.

(Third Modification)
The compressed air pipe 7 may be connected to the intake pipe 2 located between the compressor 3a and the intercooler 4.

(Fourth modification)
The outlet 32 and the disk 22 may be provided only in one set instead of a plurality of sets. If necessary centrifugation is possible, the disk 22 may be omitted.

  As described above, the basic embodiment of the present disclosure has been described in detail. However, the embodiment of the present disclosure is not limited to the above-described embodiment, and may include any modifications and modifications included in the concept of the present disclosure defined by the claims. Applications and equivalents are included in the present disclosure. Accordingly, the present disclosure should not be construed as being limited, but can be applied to any other technique belonging to the scope of the idea of the present disclosure.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 1a Engine main body 1b Cylinder block 1c Crank case 1d Cylinder head 1e Head cover 2 Intake pipe 3 Turbocharger 3a Compressor 4 Intercooler 5 Gas pipe 6 Intake manifold 7 Compressed air pipe 10 Casing 10a Side wall 10b Ceiling 10c Bottom wall Reference Signs List 11 Introducing chamber 11a Gas inlet 12 Discharging chamber 12a Gas outlet 12b Oil outlet 13 Turbine chamber 13a Air inlet 13b Air outlet 14 First partition 15 Second partition 16, 17 Bearing 20 Rotating body 21 Rotating shaft 22 Disk 23 Disk member 30 Gas flow Road 31 Inlet 32 Outlet 40 Turbine 100 Oil separator A Compressed air B Blow-by gas C Rotating center O Oil

Claims (6)

An oil separator for centrifuging oil from blow-by gas of an internal combustion engine,
The internal combustion engine,
An intake passage, a turbocharger compressor provided in the intake passage,
The oil separator,
A casing,
A rotating body provided in the casing,
A gas flow path formed inside the rotating body,
An inlet formed in the rotating body, for introducing blow-by gas into the gas flow path,
An outlet formed in the rotating body, for extracting blow-by gas from the gas flow path,
And a turbine connected to the rotating body and driven to rotate by compressed air generated by the compressor. The internal combustion engine further includes an intercooler provided in the intake passage downstream of the compressor.
The oil separator according to claim 1, wherein the turbine is driven to rotate by compressed air cooled by the intercooler. The casing is
An introduction chamber formed with a gas inlet for introducing blow-by gas before oil separation,
A gas outlet for discharging blow-by gas after oil separation, and a discharge chamber formed with an oil outlet for discharging separated oil,
A turbine chamber formed with an air inlet and an air outlet for introducing and discharging the compressed air,
The rotating body extends through the introduction chamber, the discharge chamber, and the turbine chamber,
The introduction port is arranged in the introduction chamber,
The outlet is disposed in the discharge chamber,
The oil separator according to claim 1, wherein the turbine is disposed in the turbine chamber. The rotating body is
A hollow rotary shaft connected to the turbine and defining the gas flow path therein;
A disk provided coaxially on the outer peripheral portion of the rotating shaft and disposed in the discharge chamber,
The rotation axis is arranged vertically so that the rotation center is along the vertical direction,
The oil separator according to claim 3, wherein the outlet is located near and above the disk. The oil separator according to claim 4, wherein a plurality of the outlets and the disks are provided in an axial direction of the rotation shaft. The oil separator according to claim 4, wherein the disk is inclined such that a radially outer side is located higher than a radially inner side.

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