BLOW-BY-GAS PROCESSING DEVICE, INTERNAL COMBUSTION ENGINE AND TURBOCHARGER

Abstract

A blow-by gas processing device comprises an intake duct, a blow-by gas duct, and a storage chamber for storing the emulsion contained in the blow-by gas. The blow-by gas duct includes a separation chamber, an upstream channel through which the blow-by gas flows, and a downstream channel connecting the separation chamber to the intake duct. An upstream opening, to which the upstream channel is connected, is located opposite the wall of the separation chamber. The storage chamber is located downstream of the opposite wall in a vertical direction. The opposite wall is continuous with a boundary wall that serves to delimit the storage chamber.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention

[0001] The present invention relates to a blow-by gas processing device, an internal combustion engine, and a turbocharger. 2. Description of the related prior art

[0002] JP 2021 - 8 859 A discloses a blow-by gas processing device for an internal combustion engine. The blow-by gas processing device mixes blow-by gas in a crankcase with intake air and then combusts the mixture in a combustion chamber of the internal combustion engine.

[0003] Furthermore, DE 199 29 876 A1 discloses an oil separator that can be understood as a device for treating blow-by gas. An intake manifold assembly of an internal combustion engine has a first pipe section to supply atmospheric fresh air to a compressor of a turbocharger. The internal combustion engine also has a crankcase ventilation system for blow-by gases. In addition, an oil tank and an oil separator are provided. The crankcase ventilation system for blow-by gas is an upstream passage that (indirectly) connects a crankcase to a distributor of the oil separator. Furthermore, a downstream passage ("first pipe") is provided that leads from the oil tank to the first pipe section of the intake manifold assembly above an oil level. An upstream opening is provided through which the upstream passage opens into the oil separator.Furthermore, a wall of the oil tank opposite the upstream opening is provided.

[0004] JP 2021 - 8 859 A further discloses an oil separator, a blow-by gas discharge line, a blow-by gas return line, and an oil return line. The oil separator functions as a separator that separates the blow-by gas from the oil, for example, by causing the blow-by gas to collide with a collision plate or the like, and allowing the oil contained in the blow-by gas to adhere to the collision surface of the collision plate. SUMMARY OF THE INVENTION

[0005] In a turbocharged internal combustion engine, intake air containing blow-by gas is compressed by the turbocharger's compressor wheel and then fed into a combustion chamber. The blow-by gas contains oil and water produced during fuel combustion. When this oil and water mix, an emulsion is formed. This emulsion has a higher density than the blow-by gas itself, which does not contain emulsion. Therefore, there is a risk of damaging the compressor wheel if the emulsion collides with it.

[0006] A blow-by gas processing device for an internal combustion engine for solving the above problem comprises an intake duct in which a compressor wheel of a turbocharger is arranged, a blow-by gas duct, and a storage chamber for storing emulsion contained in blow-by gas, wherein the blow-by gas duct has a separation chamber for separating the emulsion from the blow-by gas, an upstream duct connecting the interior of a crankcase of the internal combustion engine to the separation chamber, and a downstream duct connecting the separation chamber to the intake duct, wherein the separation chamber has an upstream opening to which the upstream duct is connected and a wall opposite the upstream opening, the storage chamber is arranged downstream of the opposite wall in a vertical direction, and the opposite wall is connected to a boundary wall that delimits the storage chamber.The compressor housing, which accommodates the compressor wheel, includes the separation chamber and the storage chamber.

[0007] A turbocharger for an internal combustion engine for solving the above problem comprises an intake duct, a blow-by gas duct with a separation chamber designed to separate emulsion from blow-by gas, an upstream duct and a downstream duct, a compressor wheel arranged in the intake duct, and a storage chamber for storing the emulsion contained in the blow-by gas, wherein the separation chamber is connected via the upstream duct to the interior of a crankcase of the internal combustion engine and via the downstream duct to the intake duct, and has an upstream opening to which the upstream duct is connected and a wall opposite the upstream opening, the storage chamber is arranged downstream of the opposite wall in a vertical direction, and the opposite wall is connected to a boundary wall delimiting the storage chamber.The compressor housing, which accommodates the compressor wheel, includes the separation chamber and the storage chamber.

[0008] In the blow-by gas processing device, the internal combustion engine and the turbocharger disclosed in the present disclosure, it is unlikely that the compressor wheel will be damaged by the impact of emulsion. BRIEF DESCRIPTION OF THE FIGURES

[0009] Features, advantages and technical and industrial significance of exemplary embodiments of the invention are described below with reference to the accompanying figures, in which the same symbols denote the same elements: Fig. Figure 1 is a schematic representation of an internal combustion engine equipped with a blow-by gas processing device; Fig. Figure 2 is a sectional view showing a compressor housing of the internal combustion engine; Fig. Figure 3 is a sectional view of the compressor housing along line 3-3 in Fig. 2; and Fig. Figure 4 is a sectional view showing a modification example of the blow-by gas processing device. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0010] An embodiment of a blow-by gas processing device 1 is described below with reference to Fig. 1, Fig. 2 to Fig. 3. It should be noted that the figures may depict components that have been enlarged for clarity. The relative sizes of the components may differ from the actual dimensions or from those shown in other figures. Furthermore, in the following description, upstream and downstream in a vertical direction may simply be referred to as top and bottom, respectively. When describing the relative positions of components in the vertical direction (up and down), reference may be made to the upper and lower sections of the components. internal combustion engine

[0011] The internal combustion engine 2 equipped with this blow-by gas processing device 1 is an internal combustion engine that burns hydrogen as fuel.

[0012] As in Fig. As shown in Figure 1, the internal combustion engine 2 comprises a cylinder block 3, a crankcase 8 attached to a lower section of the cylinder block 3, and a cylinder head 9 attached to an upper section of the cylinder block 3. The internal combustion engine 2 also includes an oil pan 7 attached to a lower section of the crankcase 8 and a cylinder head cover 12 attached to an upper section of the cylinder head 9.

[0013] The cylinder block 3 has one cylinder 4. A reciprocating piston 5 is located in cylinder 4. The cylinder block 3 and the cylinder head 9 have a combustion chamber 6 in which hydrogen is burned. The combustion chamber 6 is located above a piston 5 in cylinder 4. Oil is stored in the oil pan 7. The cylinder head 9 has an intake port 10 and an exhaust port 11.

[0014] The internal combustion engine 2 comprises an inlet valve 14 that opens and closes the inlet opening 10, an exhaust valve 15 that opens and closes the exhaust opening 11, a fuel injector 16 and an ignition device 17.

[0015] The internal combustion engine 2 has an intake port 22 connected to the inlet port 10 and an outlet port 23 connected to the exhaust port 11.

[0016] The internal combustion engine 2 includes a turbocharger 13. The turbocharger 13 comprises a compressor wheel 26 and a compressor housing 27, which accommodates the compressor wheel 26. The intake duct 22 comprises a section inside the compressor housing 27 (hereinafter referred to as the inner housing intake duct 22A), a section upstream of the inner housing intake duct 22A, and a section downstream of the inner housing intake duct 22A. A throttle valve 29 is provided in a section of the intake duct 22 downstream of the compressor housing 27. Blow-by gas processing device

[0017] As in Fig. As shown in Figure 1, the blow-by gas processing device 1 comprises a ventilation duct 32, a blow-by gas duct 33, and a PCV valve 36. The ventilation duct 32 connects a downstream section of the throttle valve 29 in the intake port 22 to the interior of the crankcase 8. The blow-by gas duct 33 connects the inner intake port 22A of the intake port 22 to the interior of the crankcase 8. The PCV valve 36 is located in the ventilation duct 32. The PCV valve 36 opens during blow-by gas processing.

[0018] As in Fig. 1, Fig. 2 to Fig. As shown in Figure 3, the blow-by gas processing device 1 comprises the intake duct 22 and a storage chamber 37, which stores the emulsion 46 contained in the blow-by gas. The compressor wheel 26 of the turbocharger 13 is arranged in a section upstream of the throttle valve 29 in the intake duct 22. turbocharger

[0019] The turbocharger 13 functions as part of the blow-by gas processing device 1. The blow-by gas channel 33 comprises a separation chamber 39 configured to separate the emulsion 46 from the blow-by gas, an upstream channel 33A, and a downstream channel 33B. The upstream channel 33A includes a section extending from the crankcase 8 to the compressor housing 27 and a section provided within the compressor housing 27 (hereinafter referred to as the housing gas passage 331A). The housing gas passage 331A is a passage defined by the inner wall of a section inserted into a through-hole 20 in the PCV fitting 40. The compressor housing 27 has the housing gas passage 331A, the downstream channel 33B, and the separation chamber 39.The separation chamber 39 further comprises an upstream opening 39A to which the upstream channel 33A is connected, a downstream opening 39B to which the downstream channel 33B is connected, and a wall 41 opposite the upstream opening 39A. The opposite wall 41 is part of the inner wall of the compressor housing 27.

[0020] The compressor housing 27 has a through-hole 20 that connects the outside of the compressor housing 27 to the separation chamber 39. The upstream opening 39A is an opening of the through-hole 20 on the side of the separation chamber 39. A PCV nozzle 40 is inserted into the through-hole 20, into which blow-by gas flows from the upstream channel 33A. The separation chamber 39 is connected via the upstream channel 33A to the interior of the crankcase 8 of the internal combustion engine 2 and via the downstream channel 33B to the inner housing intake duct 22A.

[0021] The compressor housing 27 has the storage chamber 37. The storage chamber 37 is located in a lower section of the compressor housing 27. The storage chamber 37 is located downstream of the opposite wall 41. Furthermore, the opposite wall 41 is connected to a boundary wall 42, which delimits the storage chamber 37. The continuity between the opposite wall 41 and the boundary wall 42 includes both the case where the opposite wall 41 and the boundary wall 42 are directly connected to each other, and the case where the opposite wall 41 and the boundary wall 42 are connected to each other via another wall.

[0022] A case in which two walls of the opposite wall 41, the boundary wall 42, and one or more other walls connecting the two walls 41, 42 are directly connected includes a case in which a ridge line or a valley line exists on the boundary segment between the two walls, and a case in which a ridge line or a valley line does not exist. In the case in which a ridge line or a valley line is not present on the boundary segment between the two walls, the boundary segment between the two walls is formed by the same planar surface or the same curved surface.

[0023] If the opposite wall 41 and the boundary wall 42 are directly connected, the emulsion 46 flows down along the opposite wall 41 towards the boundary wall 42. If the opposite wall 41 and the boundary wall 42 are connected via another wall, the emulsion 46 first flows down along the opposite wall 41 towards the other wall and then down along the other wall towards the boundary wall 42.

[0024] The compressor housing 27 has a connecting hole 43 that connects the separation chamber 39 and the storage chamber 37. The connecting hole 43 extends in an arc along the circumferential direction of the compressor wheel 26. The storage chamber 37 has an opening 18 to which the connecting hole 43 is connected.

[0025] In the present embodiment, the boundary wall 42 is connected to the opposite wall 41 by the inner wall of the connecting hole 43.

[0026] The inner wall of the connecting hole 43 is an example of another wall that connects the opposite wall 41 and the boundary wall 42.

[0027] The compressor housing 27 has an outlet hole 47 for discharging the emulsion 46 stored in the storage chamber 37 to the outside of the compressor housing 27. The outlet hole 47 is preferably located on a lower section of the compressor housing 27. The outlet hole 47 connects the storage chamber 37 and the outside of the compressor housing 27. The compressor housing 27 has a cover 48 that closes the outlet hole 47. The cover 48 is designed to be removable from the outlet hole 47. In the present embodiment, the outlet hole 47 extends downstream of the storage chamber 37. The cover 48 seals off the outlet hole 47 from the outside of the compressor housing 27. Separation of blow-by gas and emulsion

[0028] The oil and water in the crankcase 8 are mixed together. The mixed oil and water, along with the blow-by gas, flows through the upstream channel 33A. As the oil and water pass through the upstream channel 33A, they gradually cool and liquefy. As a result, the emulsion 46 is formed in the upstream channel 33A.

[0029] The blow-by gas flowing from the upstream opening 39A into the separation chamber 39 collides with the opposite wall 41. Since the emulsion 46 has a higher density than the blow-by gas, it has a greater inertial force than the blow-by gas, which does not contain the emulsion 46. Therefore, when the blow-by gas strikes the opposite wall 41, the emulsion 46 contained in the blow-by gas adheres to the opposite wall 41. This separates the emulsion 46 from the blow-by gas.

[0030] As in Fig. As shown in Figure 2, the emulsion 46 attached to the opposite wall 41 gradually falls due to the force of gravity acting on the emulsion 46 and flows into the connecting hole 43. The emulsion 46 that has flowed into the connecting hole 43 flows downwards along the inner wall of the connecting hole 43 and then flows through the opening 18 into the storage chamber 37.

[0031] On the other hand, as if through an imaginary line B, flows into Fig. 2 indicated, the blow-by gas, from which the emulsion 46 was separated, from the downstream opening 39B into the downstream channel 33B and mixes with the intake air flowing through the inner housing intake channel 22A.

[0032] The greater the difference between the flow direction of the blow-by gas from the downstream opening 39A to the opposite wall 41 and the flow direction of the blow-by gas when it strikes the opposite wall 41, exits the separation chamber 39 through the downstream opening 39B, and then flows into the downstream channel 33B, the greater the amount of emulsion 46 that adheres to the opposite wall 41. Conversely, with a large difference in the flow direction of the blow-by gas described above, the pressure drop during the flow of the blow-by gas increases, so the amount of blow-by gas flowing into the inner housing intake channel 22A tends to decrease. For this reason, the following configuration is desirable.

[0033] First, a section connected to the upstream opening 39A in the upstream channel 33A is designated as upstream section 44, and a section connected to the downstream opening 39B in the downstream channel 33B is designated as downstream section 45. An imaginary line extending parallel to a direction of extension of the upstream section 44 is designated as the first imaginary line 44A. Furthermore, among the imaginary lines extending parallel to the direction of extension of the downstream section 45, an imaginary line that intersects the first imaginary line 44A is designated as the second imaginary line 45A.

[0034] In this case, it is preferred that an angle of intersection θ1, which is the angle of intersection between the first imaginary line 44A and the second imaginary line 45A in Fig. 2 is 70 degrees or more and 110 degrees or less. Furthermore, it is preferred that the intersection angle θ1 is 80 degrees or more and 100 degrees or less. In the present embodiment, the intersection point angle θ1 is 90 degrees.

[0035] In the present embodiment, the opposite wall 41 is a flat surface. Since the blow-by gas strikes the opposite wall 41 at a near-perpendicular angle, the amount of emulsion 46 adhering to the opposite wall 41 is relatively large. Therefore, it is preferable to have an angle of impact θ2, which is the angle of intersection between the Fig. The angle of impact between the first imaginary line 44A shown in Figure 2 and the opposite wall 41 is 70 degrees or more and 110 degrees or less. Furthermore, it is even more preferred that the angle of impact θ2 be 80 degrees or more and 100 degrees or less. In the present embodiment, the angle of impact θ2 is 90 degrees. Effects and impacts of the current embodiment

[0036] (1) The blow-by gas flowing into the separation chamber 39 impacts the opposite wall 41. The emulsion 46 contained in the blow-by gas adheres to the opposite wall 41, thus reducing the amount of emulsion 46 flowing from the separation chamber 39 through the downstream channel 33B into the inner casing intake channel 22A. This makes damage to the compressor wheel 26 caused by the impact of the emulsion 46 less likely.

[0037] (2) The emulsion 46 adhering to the opposite wall 41 flows downwards along the opposite wall 41 to the boundary wall 42. The flowing emulsion 46 is stored in the storage chamber 37. Since the storage chamber 37 is located downstream of the opposite wall 41 and the connecting hole 43, the emulsion 46 is stored in the lower section of the storage chamber 37. Therefore, it is unlikely that the emulsion 46 will revert to blow-by gas.

[0038] (3) Since the angle of impact θ2 is 90 degrees, i.e., the blow-by gas strikes the opposite wall 41 perpendicularly, the emulsion 46 is likely to adhere to the opposite wall 41. Therefore, the amount of emulsion 46 separated from the blow-by gas is likely to increase.

[0039] (4) The temperature of the compressor housing 27 increases due to the heat generated when air is compressed by the compressor wheel 26. Consequently, the temperature of the opposite wall 41 also increases. As a result, the viscosity of the emulsion 46 adhering to the opposite wall 41 decreases. Therefore, the emulsion 46 tends to flow rapidly from the opposite wall 41 into the storage chamber 37.

[0040] (5) As the temperature of the compressor housing 27 increases, the temperature of the boundary wall 42 of the storage chamber 37 also increases in the same way as that of the opposite wall 41. This reduces the viscosity of the emulsion 46 to be stored in the storage chamber 37. Accordingly, it is easier to empty the emulsion 46 located in the storage chamber 37 to the outside through the outlet hole 47.

[0041] (6) The emulsion 46 stored in the storage chamber 37 is discharged to the outside through the outlet hole 47 by loosening the lid 48. In particular, if the outlet hole 47 extends downstream of the storage chamber 37, the lid 48 blocks the outlet hole 47 from below in the vertical direction. Therefore, the emulsion 46 in the storage chamber 37 can be efficiently discharged to the outside by loosening the lid 48.

[0042] (7) The emulsion 46 adhering to the opposite wall 41 flows into the connecting hole 43. As the emulsion 46 flows downwards from the opposite wall 41 towards the storage chamber 37, the emulsion 46 is surrounded by the inner wall of the connecting hole 43, so that it is unlikely that the emulsion will scatter into the surroundings.

[0043] (8) In an internal combustion engine that burns hydrogen as fuel, the amount of emulsion contained in the blow-by gas tends to increase, for example, compared to an internal combustion engine that burns gasoline as fuel. This makes it easier for the compressor wheel to be damaged by the impact of the emulsion. Therefore, according to the present embodiment, a damage limitation effect on the compressor wheel 26 is important. the change

[0044] The above embodiment can be achieved by the following configuration change. The above embodiment and the following change can be combined, provided they are not technically contradictory. It should be noted that the same components as in the above embodiment are provided with the same reference numerals, and duplicate descriptions are omitted.

[0045] In the Fig.In the modification shown in Figure 4, the compressor housing 27 is provided with a space 25 below a rotational axis 26A of the compressor wheel 26 in the vertical direction. The rotational axis 26A is an imaginary straight line that passes through the center of rotation of the compressor wheel 26 and extends along the axis of the compressor wheel 26.

[0046] The separation chamber 39 is located in an upper section of the space 25. The storage chamber 37 is located in a lower section of the space 25. The opposite wall 41 is continuously connected to the boundary wall 42. In the present embodiment, the opposite wall 41 is directly connected to the boundary wall 42.

[0047] The opposite wall 41 is directly connected to the boundary wall 42. Therefore, it is less likely that the emulsion 46 will scatter into the surroundings when it flows from the opposite wall 41 into the storage chamber 37.

[0048] Since the storage chamber 37 is also arranged downstream of the rotation axis 26A in the vertical direction, the emulsion 46 stored in the storage chamber 37 can be easily and quickly discharged to the outside through the outlet hole 47.

[0049] At least one of the separation chamber 39, the storage chamber 37, the upstream channel 33A, the downstream channel 33B and the connecting hole 43 may be provided in a section other than the compressor housing 27 of the turbocharger 13, for example in a turbine housing that accommodates a turbine wheel.

[0050] The separation chamber 39 and the storage chamber 37 can both be located outside the compressor housing 27. In the present modification, the storage chamber 37 is also arranged below the opposite wall 41. Furthermore, the opposite wall 41 is continuously connected to the boundary wall 42.

[0051] The storage chamber 37 can be located outside the compressor housing 27, in relation to the separation chamber 39 and the storage chamber 37. In the present embodiment, the storage chamber 37 is located below the opposite wall 41. The storage chamber 37 is connected to the separation chamber 39 via an external line installed outside the compressor housing 27. The external line is designed such that the emulsion 46 separated in the separation chamber 39 flows into the storage chamber 37. The opposite wall 41 is connected to the boundary wall 42 via the inner wall of the outer tube. The inner wall of the outer tube is an example of a further wall for connecting the opposite wall 41 and the boundary wall 42.

[0052] The opposite wall 41 may have a curved surface. If the opposite wall 41 has a curved surface, the angle of impact θ2 described above is an angle of intersection between the first imaginary line 44A and a tangent to the curved surface at the intersection between the first imaginary line 44A and the opposite wall 41. If the opposite wall 41 has a curved surface, to increase the amount of emulsion 46 that adheres to the opposite wall 41, it is preferable that the curved surface has a shape that is indented towards the opposite side of the upstream opening 39A, rather than a shape that bulges towards the upstream opening 39A.

[0053] In the upstream channel 33A, the upstream section 44, which is a connecting section with the upstream opening 39A, can be provided with a convex section, such as a partition plate or projection, in a state where it has an opening through which the blow-by gas flows. By providing the convex section in the upstream section 44, some of the blow-by gas flowing through the upstream channel 33A collides with the convex section, causing some of the emulsion 46 to accumulate near the convex section. This makes it possible to reduce the amount of emulsion 46 flowing into the separation chamber 39 and to reduce the size of the storage chamber 37.

[0054] In the above modification, it is desirable that the convex section be located at the lower end of the upstream section 44 in the vertical direction. The lower end of the upstream section 44 tends to allow a greater amount of emulsion 46 to pass through in the vertical direction than the upper end of the upstream section 44. Therefore, the amount of emulsion 46 that accumulates near the convex section is increased. Consequently, the present modification can further contribute to the miniaturization of the storage chamber 37.

[0055] The internal combustion engine 2 can be an internal combustion engine that burns gasoline as fuel.

Claims

Blow-by gas processing device (1) for an internal combustion engine (2) equipped with a turbocharger (13), comprising: an intake duct (22) in which a compressor wheel (26) of the turbocharger (13) is arranged; a blow-by gas duct (33); and a storage chamber (37) for storing emulsion contained in blow-by gas, wherein: the blow-by gas channel (33) has a separation chamber (39) for separating the emulsion from the blow-by gas, an upstream channel (33A) connecting an interior of a crankcase (8) of the internal combustion engine (2) to the separation chamber (39), and a downstream channel (33B) connecting the separation chamber (39) to the intake channel (22), the separation chamber (39) has an upstream opening (39A) to which the upstream channel (33A) is connected, and an opposite wall (41) facing the upstream opening (39A), the storage chamber (37) is arranged downstream of the opposite wall (41) in a vertical direction,and the opposite wall (41) transitions into a boundary wall (42) that defines the storage chamber (37), characterized in that a compressor housing (27) which accommodates the compressor wheel (26) has the separation chamber (39) and the storage chamber (37). Blow-by gas processing device (1) according to claim 1, wherein the compressor housing (27) has a connecting hole (43) that connects the separation chamber (39) and the storage chamber (37). Internal combustion engine (2) which burns hydrogen as fuel and which has the blow-by gas processing device (1) according to one of claims 1 or 2. Turbocharger (13) for an internal combustion engine (2), comprising: an intake duct (22); a blow-by gas duct (33) comprising a separation chamber (39) configured to separate an emulsion from a blow-by gas, an upstream duct (33A) and a downstream duct (33B); a compressor wheel (26) arranged in the intake duct (22);and a storage chamber (37) for storing emulsion contained in the blow-by gas, wherein: the separation chamber (39) is connected to an interior of a crankcase (8) of the internal combustion engine (2) via the upstream channel (33A) and is connected to the intake channel (22) via the downstream channel (33B) and has an upstream opening (39A) to which the upstream channel (33A) is connected, and an opposite wall (41) facing the upstream opening (39A), the storage chamber (37) is arranged downstream of the opposite wall (41) in a vertical direction, and the opposite wall (41) transitions into a boundary wall (42) that defines the storage chamber (37), characterized in that a compressor housing (27) accompanies the compressor wheel (26), the separation chamber (39) and the storage chamber (37) exhibits; Turbocharger according to claim 4, wherein: the compressor housing (27) has a space (25) located downstream of a rotational axis (26A) of the compressor wheel (26) in a vertical direction; the separation chamber (39) is located at an upper section of the space (25); the storage chamber (37) is located at a lower section of the space (25); and the opposite wall (41) is directly connected to the boundary wall (42).

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