Blow-by gas processing device, combustion engine and turbocharger

Abstract

A blow-by gas processing device includes an intake channel, a blow-by gas channel, and a storage chamber that stores the emulsion contained in the blow-by gas. The blow-by gas channel 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 channel. An opposite wall of the separation chamber faces an upstream opening to which the upstream channel is connected. The storage chamber is located downstream of the opposite wall in a vertical direction. The opposite wall is continuously provided with a boundary wall, which serves as a wall for delimiting 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 art

[0002] JP 2021 - 008 859 A discloses a blow-by gas processing device for an internal combustion engine. The blow-by gas processing device mixes blow-by gas with intake air in a crankcase and then combusts the mixture in a combustion chamber of the internal combustion engine. SUMMARY OF THE INVENTION

[0003] In a turbocharged internal combustion engine, intake air containing blow-by gas is compressed by a 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 together, an emulsion forms. The emulsion has a higher density than blow-by gas, which does not contain an emulsion. Therefore, there is a risk of damage to the compressor wheel if the emulsion collides with the compressor wheel.

[0004] A blow-by gas processing device for an internal combustion engine for solving the above problem comprises an intake passage in which a compressor wheel of a turbocharger is arranged, a blow-by gas passage, and a storage chamber for storing emulsion contained in blow-by gas, wherein the blow-by gas passage has a separation chamber for separating the emulsion from the blow-by gas, an upstream passage connecting an interior of a crankcase of the internal combustion engine with the separation chamber, and a downstream passage connecting the separation chamber with the intake passage, wherein the separation chamber has an upstream opening to which the upstream passage 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 continuous with a boundary wall defining the storage chamber.

[0005] A turbocharger for an internal combustion engine to solve 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 to an interior of a crankcase of the internal combustion engine via the upstream duct and to the intake duct via the downstream 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 continuous with a boundary wall delimiting the storage chamber.

[0006] In the blow-by gas processing device, the internal combustion engine, and the turbocharger disclosed in the present disclosure, the compressor wheel is unlikely to be damaged by emulsion impingement. BRIEF DESCRIPTION OF THE CHARACTERS

[0007] Features, advantages and technical and industrial significance of exemplary embodiments of the invention are described below with reference to the accompanying figures, in which like symbols denote like elements: Fig. 1 is a schematic diagram of an internal combustion engine equipped with a blow-by gas processing device; Fig. 2 is a sectional view showing a compressor housing of the internal combustion engine; Fig. 3 is a sectional view of the compressor housing taken along line 3-3 in Fig. 2; and Fig. 4 is a sectional view showing a modification example of the blow-by gas processing apparatus. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0008] An embodiment of a blow-by gas processing device 1 will be described below with reference to Fig. 1 to Fig. 3. Please note that the figures may depict components that have been enlarged for clarity. The proportions of the components may differ from the actual ones or from those in other figures. Furthermore, in the following description, upstream and downstream in a vertical direction may be simply referred to as top and bottom, respectively. When describing the relative positions of components in the up and down vertical directions, reference may be made to upper and lower portions of the components. combustion engine

[0009] The internal combustion engine 2 equipped with this blow-by gas processing device 1 is an internal combustion engine that burns hydrogen as fuel.

[0010] As in Fig. As shown in Figure 1, the internal combustion engine 2 includes a cylinder block 3, a crankcase 8 attached to a lower portion of the cylinder block 3, and a cylinder head 9 attached to an upper portion of the cylinder block 3. The internal combustion engine 2 includes an oil pan 7 attached to a lower portion of the crankcase 8 and a head cover 12 attached to an upper portion of the cylinder head 9.

[0011] The cylinder block 3 has a cylinder 4. A reciprocating piston 5 is housed in the 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 the cylinder 4. Oil is stored in the oil pan 7. The cylinder head 9 has an intake port 10 and an exhaust port 11.

[0012] The internal combustion engine 2 comprises an intake valve 14 that opens and closes the intake port 10, an exhaust valve 15 that opens and closes the exhaust port 11, a fuel injection valve 16 and an ignition device 17.

[0013] The internal combustion engine 2 has an intake duct 22 connected to the inlet opening 10 and an exhaust duct 23 connected to the exhaust opening 11.

[0014] The internal combustion engine 2 includes a turbocharger 13. The turbocharger 13 includes a compressor wheel 26 and a compressor housing 27 that houses the compressor wheel 26. The intake passage 22 includes a portion inside the compressor housing 27 (hereinafter referred to as the inner-case intake passage 22A), a portion upstream of the inner-case intake passage 22A, and a portion downstream of the inner-case intake passage 22A. A throttle valve 29 is provided in a portion of the intake passage 22 downstream of the compressor housing 27. Blow-by gas processing device

[0015] As in Fig. 1, the blow-by gas processing device 1 includes a ventilation passage 32, a blow-by gas passage 33, and a PCV valve 36. The ventilation passage 32 connects a downstream portion of the throttle valve 29 in the intake passage 22 to the interior of the crankcase 8. The blow-by gas passage 33 connects the inner-case intake passage 22A of the intake passage 22 to the interior of the crankcase 8. The PCV valve 36 is provided in the ventilation passage 32. The PCV valve 36 opens during blow-by gas processing.

[0016] As in Fig. 1 to Fig. As shown in Figure 3, the blow-by gas processing device 1 comprises the intake passage 22 and a storage chamber 37 that 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 passage 22. Turbocharger

[0017] The turbocharger 13 functions as a part of the blow-by gas processing device 1. The blow-by gas passage 33 includes a separation chamber 39 configured to separate the emulsion 46 from the blow-by gas, an upstream passage 33A, and a downstream passage 33B. The upstream passage 33A includes a portion extending from the crankcase 8 to the compressor housing 27 and a portion provided in the compressor housing 27 (hereinafter, it may be referred to as the in-housing gas passage 331A). The in-housing gas passage 331A is a passage defined by the inner wall of a portion inserted into a through hole 20 in the PCV fitting 40. The compressor housing 27 has the in-housing gas passage 331A, the downstream passage 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.

[0018] The compressor housing 27 has a through-hole 20 connecting 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 port 40 is inserted into the through-hole 20, into which blow-by gas flows from the upstream passage 33A. The separation chamber 39 is connected to the interior of the crankcase 8 of the internal combustion engine 2 via the upstream passage 33A and to the inner-case intake passage 22A via the downstream passage 33B.

[0019] The compressor housing 27 has the storage chamber 37. The storage chamber 37 is located at a lower portion 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 that defines the storage chamber 37. The continuity of 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.

[0020] A case where 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 to each other includes a case where a ridge line or a valley line exists at the boundary portion between the two walls, and a case where a ridge line or a valley line does not exist. In the case where a ridge line or a valley line does not exist at the boundary portion between the two walls, the boundary portion between the two walls is formed by the same flat surface or the same curved surface.

[0021] When the opposite wall 41 and the boundary wall 42 are directly connected to each other, the emulsion 46 flows downward along the opposite wall 41 toward the boundary wall 42. When the opposite wall 41 and the boundary wall 42 are connected to each other via another wall, the emulsion 46 first flows downward along the opposite wall 41 toward the other wall and then along the other wall toward the boundary wall 42.

[0022] 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 arcuately 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.

[0023] In the present embodiment, the boundary wall 42 is connected to the opposite wall 41 through the inner wall of the connecting hole 43. The inner wall of the connecting hole 43 is an example of another wall connecting the opposite wall 41 and the boundary wall 42.

[0024] 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 at a lower portion 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 blocks the outlet hole 47 from the outside of the compressor housing 27. Separation of blow-by gas and emulsion

[0025] The oil and water in the crankcase 8 are mixed together in the crankcase 8. The mixed oil and water flow through the upstream passage 33A along with the blow-by gas. As the oil and water pass through the upstream passage 33A, they are gradually cooled and liquefied. As a result, the emulsion 46 is formed in the upstream passage 33A.

[0026] 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, the emulsion 46 has a greater inertial force than the blow-by gas that does not contain the emulsion 46. Therefore, when the blow-by gas collides with 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.

[0027] As in Fig. 2, the emulsion 46 attached to the opposite wall 41 gradually falls due to the gravity acting on the emulsion 46 and flows into the communication hole 43. The emulsion 46, which has flowed into the communication hole 43, flows downward along the inner wall of the communication hole 43 and then flows through the opening 18 into the storage chamber 37.

[0028] On the other hand, as shown by an imaginary line B in Fig. 2, the blow-by gas from which the emulsion 46 has been separated flows from the downstream opening 39B into the downstream channel 33B and mixes with the intake air flowing through the inner casing intake channel 22A.

[0029] 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 the blow-by gas impacts the opposite wall 41, exits the separation chamber 39 through the downstream opening 39B, and then flows into the downstream passage 33B, the greater the amount of emulsion 46 adhering to the opposite wall 41. On the other hand, with a large difference in the flow direction of the blow-by gas described above, the pressure loss during the flow of the blow-by gas increases, so that the amount of blow-by gas flowing into the inner casing intake passage 22A tends to decrease. For this reason, it is desirable to adopt the following configuration.

[0030] First, a portion connected to the upstream opening 39A in the upstream passage 33A is referred to as an upstream portion 44, and a portion connected to the downstream opening 39B in the downstream passage 33B is referred to as a downstream portion 45. An imaginary line extending parallel to an extending direction of the upstream portion 44 is referred to as a first imaginary line 44A. Further, among the imaginary lines extending parallel to the extending direction of the downstream portion 45, an imaginary line intersecting with the first imaginary line 44A is referred to as a second imaginary line 45A.

[0031] In this case, it is preferable that an intersection angle θ1 which is the intersection angle 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 preferable that the intersection angle θ1 is 80 degrees or more and 100 degrees or less. In the present embodiment, the intersection angle θ1 is 90 degrees.

[0032] In the present embodiment, the opposite wall 41 is a flat surface. Since the blow-by gas impinges on the opposite wall 41 rather perpendicularly, the amount of the emulsion 46 adhering to the opposite wall 41 is rather large. Therefore, it is preferable that an impingement angle θ2, which is the intersection angle between the Fig. 2 and the opposite wall 41 is 70 degrees or more and 110 degrees or less. Furthermore, it is more preferable that the incident angle θ2 is 80 degrees or more and 100 degrees or less. In the present embodiment, the incident angle θ2 is 90 degrees. Effects and consequences of the current embodiment (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, so that the amount of the emulsion 46 flowing from the separation chamber 39 through the downstream passage 33B into the inner casing intake passage 22A is reduced. Therefore, damage to the compressor wheel 26 caused by the impact of the emulsion 46 on the compressor wheel 26 is less likely. (2) The emulsion 46 adhering to the opposite wall 41 flows down along the opposite wall 41 to the boundary wall 42. The flowed-down 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 at the lower portion of the storage chamber 37. Therefore, the emulsion 46 is unlikely to become blow-by gas again. (3) Since the impact angle θ2 is 90 degrees, that is, the blow-by gas impacts perpendicularly to the opposite wall 41, the emulsion 46 is likely to adhere to the opposite wall 41. Therefore, the amount of the emulsion 46 separated from the blow-by gas is likely to increase. (4) The temperature of the compressor housing 27 increases due to the heat generated when air is compressed by the compressor wheel 26. Therefore, 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 quickly flow from the opposite wall 41 into the storage chamber 37. (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 in the storage chamber 37 to the outside through the outlet hole 47. (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. Particularly, when 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. (7) The emulsion 46 adhering to the opposite wall 41 flows into the communication hole 43. When the emulsion 46 flows downward from the opposite wall 41 toward the storage chamber 37, the emulsion 46 is surrounded by the inner wall of the communication hole 43, so that the emulsion is unlikely to scatter into the surroundings. (8) In an internal combustion engine that burns hydrogen as fuel, the emulsion contained in the blow-by gas tends to increase, for example, compared to an internal combustion engine that burns gasoline as fuel. As a result, the compressor wheel is more likely to be damaged by the impact of the emulsion. Therefore, according to the present embodiment, a damage control effect on the compressor wheel 26 is important. the change

[0033] The above embodiment can be realized by the following configuration change. The above embodiment and the following modification can be combined with each other as long as they are not technically contradictory. Note that the same components as in the above embodiment are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0034] 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 passing through the center of rotation of the compressor wheel 26 and extending along the axis of the compressor wheel 26.

[0035] The separation chamber 39 is located at an upper portion of the space 25. The storage chamber 37 is located at a lower portion 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.

[0036] The opposite wall 41 is directly connected to the boundary wall 42. Therefore, the emulsion 46 is less likely to scatter into the environment when flowing from the opposite wall 41 into the storage chamber 37.

[0037] In addition, since the storage chamber 37 is 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.

[0038] At least one of the separation chamber 39, the storage chamber 37, the upstream passage 33A, the downstream passage 33B, and the communication hole 43 may be provided in a portion other than the compressor housing 27 of the turbocharger 13, for example, in a turbine housing that accommodates a turbine wheel.

[0039] The separation chamber 39 and the storage chamber 37 can both be provided 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.

[0040] Of the separation chamber 39 and the storage chamber 37, the storage chamber 37 can be arranged outside the compressor housing 27. 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 so 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.

[0041] The opposing wall 41 may have a curved surface. When the opposing wall 41 has a curved surface, the above-described incident angle θ2 is an intersection angle between the first imaginary line 44A and a tangent to the curved surface at the intersection point between the first imaginary line 44A and the opposing wall 41. When the opposing wall 41 has a curved surface, in order to increase the amount of emulsion 46 adhering to the opposing wall 41, it is preferable that the curved surface has a shape that is depressed toward the opposite side of the upstream opening 39A, rather than a shape that bulges toward the upstream opening 39A.

[0042] In the upstream passage 33A, the upstream portion 44, which is a connecting portion with the upstream opening 39A, may be provided with a convex portion such as a partition plate or a protrusion in a state where it has an opening portion through which the blow-by gas flows. By providing the convex portion in the upstream portion 44, a portion of the blow-by gas flowing through the upstream passage 33A collides with the convex portion, so that a portion of the emulsion 46 accumulates near the convex portion. This makes it possible to reduce the amount of the emulsion 46 flowing into the separation chamber 39 and to downsize the storage chamber 37.

[0043] In the above modification, it is desirable that the convex portion be provided at the lower portion of the upstream portion 44 in the vertical direction. The lower portion of the upstream portion 44 tends to pass a larger amount of emulsion 46 in the vertical direction than the upper portion of the upstream portion 44. Therefore, the amount of emulsion 46 that accumulates near the convex portion increases. As a result, the present modification can further contribute to the miniaturization of the storage chamber 37.

[0044] The internal combustion engine 2 may be an internal combustion engine that burns gasoline as fuel. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2021 - 008 859 A

[0002]

Claims

[1] Blow-by gas processing device for an internal combustion engine equipped with a turbocharger, comprising: an intake duct in which a compressor wheel of the 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 channel has a separation chamber for separating the emulsion from the blow-by gas, an upstream channel connecting an interior of a crankcase of the internal combustion engine to the separation chamber, and a downstream channel connecting the separation chamber to the intake channel, the separation chamber has an upstream opening to which the upstream channel is connected and an opposite wall facing the upstream opening, the storage chamber is arranged downstream of the opposite wall in a vertical direction, and the opposite wall merges into a boundary wall that defines the storage chamber. [2] The blow-by gas processing apparatus according to claim 1, wherein a compressor housing accommodating the compressor wheel includes the separation chamber and the storage chamber. [3] The blow-by gas processing apparatus according to claim 2, wherein the compressor housing has a communication hole connecting the separation chamber and the storage chamber. [4] An internal combustion engine burning hydrogen as fuel, comprising the blow-by gas processing device according to any one of claims 1 to 3. [5] Turbocharger for an internal combustion engine, comprising: an intake duct; a blow-by gas channel having a separation chamber configured to separate an emulsion from a blow-by gas, an upstream channel, and a downstream channel; a compressor wheel arranged in the intake duct; and a storage chamber for storing emulsion contained in the blow-by gas, wherein: the separation chamber is connected to an interior of a crankcase of the internal combustion engine via the upstream channel and is connected to the intake channel via the downstream channel and has an upstream opening to which the upstream channel is connected and an opposite wall facing the upstream opening, the storage chamber is arranged downstream of the opposite wall in a vertical direction, and the opposite wall merges into a boundary wall that defines the storage chamber. [6] Turbocharger according to claim 5, wherein: a compressor housing accommodating the compressor wheel, having a space located downstream of a rotation axis of the compressor wheel in a vertical direction; the separation chamber is located at an upper part of the room; the storage chamber is located at a lower part of the room; and the opposite wall is directly connected to the boundary wall.

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