Blow-by gas treatment device, internal combustion engine and supercharger

Abstract

To solve a problem in which when emulsion hits a compressor wheel, it may cause damage to the compressor wheel.SOLUTION: A blow-by gas treatment device 1 comprises an intake passage 22, a blow-by gas passage 33, and a storage chamber 37 that stores emulsion 46 contained in blow-by gas. The blow-by gas passage 33 includes a separation chamber 39, an upstream passage 33A through which blow-by gas passes, and a downstream passage 33B communicating between the separation chamber 39 and the intake passage 22. An opposing wall 41 of the separation chamber 39 faces an upstream opening 39A to which the upstream passage 33A is connected. The storage chamber 37 is located vertically below the opposing wall 41. The opposing wall 41 is continuous with a partition wall 42 that is a wall defining the storage chamber 37.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a blow-by gas treatment device, an internal combustion engine, and a turbocharger. [Background technology]

[0002] Patent Document 1 discloses a blow-by gas treatment device for an internal combustion engine. The blow-by gas treatment device mixes blow-by gas inside a crankcase with intake air and then combusts the gas in a combustion chamber of the internal combustion engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-008859 Summary of the Invention [Problem to be solved by the invention]

[0004] In an internal combustion engine equipped with a turbocharger, intake air containing blow-by gas is compressed by the turbocharger's compressor wheel and then supplied to the combustion chamber. The blow-by gas contains oil and water produced by fuel combustion. When this oil and water mix, an emulsion is formed. The emulsion has a higher density than emulsion-free blow-by gas. Therefore, if the emulsion collides with the compressor wheel, the compressor wheel may be damaged. [Means for solving the problem]

[0005] A blow-by gas treatment device for an internal combustion engine for solving the above problems 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 the blow-by gas, wherein the blow-by gas passage includes a separation chamber for separating the emulsion from the blow-by gas, an upstream passage connecting the interior of the crankcase of the internal combustion engine with the separation chamber, and a downstream passage connecting the separation chamber with the intake passage, and the separation chamber includes an upstream opening to which the upstream passage is connected and an opposing wall opposite the upstream opening, and the storage chamber is located lower than the opposing wall in the vertical direction, and the opposing wall is continuous with a defining wall that defines the storage chamber.

[0006] A turbocharger for an internal combustion engine that solves the above problem comprises an intake passage, a blow-by gas passage including a separation chamber configured to separate emulsion from blow-by gas, an upstream passage, and a downstream passage, a compressor wheel arranged in the intake passage, and a storage chamber that stores the emulsion contained in the blow-by gas, wherein the separation chamber is connected to the inside of a crankcase of the internal combustion engine via the upstream passage and is connected to the intake passage via the downstream passage, and includes an upstream opening to which the upstream passage is connected and an opposing wall that faces the upstream opening, and the storage chamber is located lower than the opposing wall in the vertical direction, and the opposing wall is continuous with a defining wall that defines the storage chamber. [Effects of the Invention]

[0007] In the blow-by gas treatment device, internal combustion engine, and turbocharger of the present disclosure, damage to the compressor wheel caused by the collision of emulsion is unlikely to occur. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of an internal combustion engine equipped with a blow-by gas treatment device. [Figure 2] FIG. 2 is a cross-sectional view showing a compressor housing of the internal combustion engine. [Figure 3]3 is a cross-sectional view of the compressor housing taken along line 3-3 in FIG. 2. FIG. [Figure 4] FIG. 4 is a cross-sectional view showing a modified example of the blow-by gas treatment device. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the blow-by gas treatment device 1 will be described below with reference to FIGS. 1 to 3. The drawings may show components enlarged to facilitate understanding. The dimensional ratios of the components may differ from the actual ones or from those in other drawings. In the following description, the upper and lower parts in the vertical direction may be simply referred to as the upper and lower parts, respectively. When describing the relative positions of components in the vertical direction, the upper and lower parts of the components may be referred to as the upper and lower parts of the components.

[0010] <Internal combustion engine> The internal combustion engine 2 equipped with this blow-by gas treatment device 1 is an internal combustion engine that burns hydrogen as fuel.

[0011] 1, the internal combustion engine 2 includes a cylinder block 3, a crankcase 8 attached to the bottom of the cylinder block 3, and a cylinder head 9 attached to the top of the cylinder block 3. The internal combustion engine 2 also includes an oil pan 7 attached to the bottom of the crankcase 8, and a head cover 12 attached to the top of the cylinder head 9.

[0012] The cylinder block 3 has a cylinder 4. The cylinder 4 houses a reciprocating piston 5. The cylinder block 3 and a cylinder head 9 have a combustion chamber 6 in which hydrogen is burned. The combustion chamber 6 is located above the piston 5 in the cylinder 4. Oil is stored in an oil pan 7. The cylinder head 9 has an intake port 10 and an exhaust port 11.

[0013] The internal combustion engine 2 includes 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 . The internal combustion engine 2 includes an intake passage 22 connected to the intake port 10 and an exhaust passage 23 connected to the exhaust port 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 is made up of a portion provided within the compressor housing 27 (hereinafter sometimes referred to as an intra-housing intake passage 22A), a portion upstream of the intra-housing intake passage 22A, and a portion downstream of the intra-housing intake passage 22A. A throttle valve 29 is provided in the intake passage 22 in a portion downstream of the compressor housing 27.

[0015] <Blow-by gas treatment device> 1, the blow-by gas treatment 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 with the inside of the crankcase 8. The blow-by gas passage 33 connects an intra-housing intake passage 22A of the intake passage 22 with the inside of the crankcase 8. The PCV valve 36 is provided in the ventilation passage 32. The PCV valve 36 opens when treating blow-by gas.

[0016] 1 to 3, the blow-by gas treatment device 1 includes an intake passage 22 and a storage chamber 37 that stores emulsion 46 contained in blow-by gas. A compressor wheel 26 of a turbocharger 13 is disposed in the intake passage 22 upstream of the throttle valve 29.

[0017] <Turbocharger> 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 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 within the compressor housing 27 (hereinafter, sometimes referred to as an intra-housing gas passage 331A). The intra-housing gas passage 331A is a passage defined by the inner wall of the portion of the PCV union 40 inserted into the through-hole 20. The compressor housing 27 has the intra-housing gas passage 331A, the downstream passage 33B, and the separation chamber 39. The separation chamber 39 also includes an upstream opening 39A to which the upstream passage 33A is connected, a downstream opening 39B to which the downstream passage 33B is connected, and an opposing wall 41 facing the upstream opening 39A. The opposing wall 41 is a part of the inner wall of the compressor housing 27 .

[0018] The compressor housing 27 has a through hole 20 that connects the outside of the compressor housing 27 with a separation chamber 39. An upstream opening 39A is the opening of the through hole 20 on the separation chamber 39 side. A PCV union 40 into which blow-by gas flows from an upstream passage 33A is inserted into the through hole 20. The separation chamber 39 is connected to the inside of the crankcase 8 of the internal combustion engine 2 via the upstream passage 33A and is connected to the intra-housing intake passage 22A via the downstream passage 33B.

[0019] The compressor housing 27 has a storage chamber 37. The storage chamber 37 is located in the lower part of the compressor housing 27. The storage chamber 37 is located below an opposing wall 41. The opposing wall 41 is continuous with a defining wall 42 that defines the storage chamber 37. The opposing wall 41 and the defining wall 42 being continuous includes a case where the opposing wall 41 and the defining wall 42 are directly connected, as well as a case where the opposing wall 41 and the defining wall 42 are connected via another wall.

[0020] When two walls directly connect among the opposing wall 41, the defining wall 42, and one or more other walls connecting both walls 41, 42, there may or may not be a ridge or valley line at the boundary between the two walls. When there is no ridge or valley line at the boundary between the two walls, the boundary between the two walls is formed by the same flat surface or the same curved surface.

[0021] When the opposing wall 41 and the defining wall 42 are directly connected, the emulsion 46 flows down the opposing wall 41 toward the defining wall 42. When the opposing wall 41 and the defining wall 42 are connected via another wall, the emulsion 46 flows down the opposing wall 41 toward the other wall, and then flows down the other wall toward the defining wall 42.

[0022] The compressor housing 27 has a communication hole 43 that connects the separation chamber 39 and the storage chamber 37. The communication hole 43 extends in an arc shape along the circumferential direction of the compressor wheel 26. The storage chamber 37 has an opening 18 to which the communication hole 43 is connected.

[0023] In this embodiment, the defining wall 42 is continuous with the opposing wall 41 via the inner wall of the communication hole 43. The inner wall of the communication hole 43 is an example of another wall that connects the opposing wall 41 and the defining wall 42. The compressor housing 27 has a discharge hole 47 for discharging the emulsion 46 stored in the storage chamber 37 to the outside of the compressor housing 27. The discharge hole 47 is preferably located in the lower part of the compressor housing 27. The discharge hole 47 connects the storage chamber 37 to the outside of the compressor housing 27. The compressor housing 27 has a lid 48 that closes the discharge hole 47. The lid 48 is configured to be removable from the discharge hole 47. In this embodiment, the discharge hole 47 extends downward from the storage chamber 37. The lid 48 closes the discharge hole 47 from the outside of the compressor housing 27.

[0024] <Blow-by gas and emulsion separation> The oil and water inside the crankcase 8 are mixed inside the crankcase 8. The mixed oil and water flow through the upstream passage 33A together with the blow-by gas. As the oil and water pass through the upstream passage 33A, their temperatures gradually decrease and they liquefy. As a result, an emulsion 46 is generated inside the upstream passage 33A.

[0025] The blow-by gas that flows into the separation chamber 39 from the upstream opening 39A collides with the opposing wall 41. The emulsion 46 has a higher density than the blow-by gas, and therefore has a larger inertial force than the blow-by gas that does not contain the emulsion 46. Therefore, when the blow-by gas collides with the opposing wall 41, the emulsion 46 contained in the blow-by gas adheres to the opposing wall 41. As a result, the emulsion 46 is separated from the blow-by gas.

[0026] As shown by the imaginary line A in Figure 2, the emulsion 46 adhering to the opposing wall 41 gradually falls due to gravity acting on the emulsion 46 and flows into the communication hole 43. The emulsion 46 that has flowed into the communication hole 43 flows down along the inner wall of the communication hole 43, and then flows into the storage chamber 37 through the opening 18.

[0027] On the other hand, as shown by the 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 passage 33B and merges with the intake air flowing through the housing internal intake passage 22A.

[0028] The greater the difference between the flow direction of the blow-by gas from the upstream opening 39A to the opposing wall 41 and the flow direction of the blow-by gas when it collides with the opposing wall 41 and then flows from the separation chamber 39 through the downstream opening 39B into the downstream passage 33B, the greater the amount of emulsion 46 that adheres to the opposing wall 41. On the other hand, if the difference in the flow direction of the blow-by gas described above becomes large, the pressure loss when the blow-by gas flows increases, and the amount of blow-by gas that flows into the intra-housing intake passage 22A is likely to decrease. For this reason, it is desirable to adopt the following configuration.

[0029] First, in the upstream passage 33A, a portion connected to the upstream opening 39A is referred to as an upstream portion 44. In the downstream passage 33B, a portion connected to the downstream opening 39B is referred to as a downstream portion 45. An imaginary line extending parallel to the direction in which the upstream portion 44 extends is referred to as a first imaginary line 44A. Furthermore, of the imaginary lines extending parallel to the direction in which the downstream portion 45 extends, an imaginary line that intersects with the first imaginary line 44A is referred to as a second imaginary line 45A.

[0030] In this case, the intersection angle θ1, which is the angle between the first virtual line 44A and the second virtual line 45A shown in Fig. 2, is preferably 70 degrees or more and 110 degrees or less. Furthermore, the intersection angle θ1 is more preferably 80 degrees or more and 100 degrees or less. In this embodiment, the intersection angle θ1 is 90 degrees.

[0031] In this embodiment, the opposing wall 41 is flat. The more perpendicularly the blow-by gas collides with the opposing wall 41, the more likely it is that a larger amount of emulsion 46 will adhere to the opposing wall 41. For this reason, the collision angle θ2, which is the angle between the first virtual line 44A shown in FIG. 2 and the opposing wall 41, is preferably 70 degrees or more and 110 degrees or less. Furthermore, the collision angle θ2 is more preferably 80 degrees or more and 100 degrees or less. In this embodiment, the collision angle θ2 is 90 degrees.

[0032] <Actions and Effects of This Embodiment> (1) The blow-by gas that flows into the separation chamber 39 collides with the opposing wall 41. At this time, the emulsion 46 contained in the blow-by gas adheres to the opposing wall 41, and therefore the amount of emulsion 46 that flows from the separation chamber 39 through the downstream passage 33B into the intra-housing intake passage 22A is reduced. As a result, damage to the compressor wheel 26 caused by the emulsion 46 colliding with the compressor wheel 26 is less likely to occur.

[0033] (2) The emulsion 46 adhering to the opposing wall 41 flows down along the opposing wall 41 toward the partition wall 42. The emulsion 46 that flows down is stored in the storage chamber 37. Since the storage chamber 37 is located below the opposing wall 41 and the communication hole 43, the emulsion 46 is stored in the lower part of the storage chamber 37. Therefore, the emulsion 46 is unlikely to return to the blow-by gas again.

[0034] (3) Because the collision angle θ2 is 90 degrees, that is, because the blow-by gas collides perpendicularly with the opposing wall 41, the emulsion 46 is likely to adhere to the opposing wall 41. Therefore, the amount of emulsion 46 separated from the blow-by gas is likely to be large.

[0035] (4) The temperature of the compressor housing 27 rises due to heat generated when the compressor wheel 26 compresses air. Therefore, the temperature of the opposing wall 41 also rises. As a result, the viscosity of the emulsion 46 adhering to the opposing wall 41 decreases. Therefore, the emulsion 46 tends to quickly flow down from the opposing wall 41 into the storage chamber 37.

[0036] (5) As the temperature of the compressor housing 27 rises, the temperature of the defining wall 42 of the storage chamber 37 also rises, similar to that of the opposing wall 41. This reduces the viscosity of the emulsion 46 stored in the storage chamber 37. This makes it easier to discharge the emulsion 46 from the storage chamber 37 to the outside through the discharge hole 47.

[0037] (6) By removing the lid 48, the emulsion 46 stored in the storage chamber 37 is discharged to the outside through the discharge hole 47. In particular, when the discharge hole 47 extends downward from the storage chamber 37, the lid 48 blocks the discharge hole 47 from below in the vertical direction. Therefore, by removing the lid 48, the emulsion 46 in the storage chamber 37 can be efficiently discharged to the outside.

[0038] (7) The emulsion 46 adhering to the opposing wall 41 flows into the communication hole 43. When the emulsion 46 flows down from the opposing wall 41 toward the storage chamber 37, it is surrounded by the inner wall of the communication hole 43, and therefore is less likely to scatter to the surroundings.

[0039] (8) In an internal combustion engine that burns hydrogen as fuel, blow-by gas tends to contain a larger amount of emulsion than, for example, an internal combustion engine that burns gasoline as fuel. This makes the compressor wheel more susceptible to damage caused by the collision of emulsion. Therefore, this embodiment is highly effective in suppressing damage to the compressor wheel 26.

[0040] <Example of change> The above embodiment can be implemented with the following configuration changes. The above embodiment and the following modifications can be implemented in combination with each other to the extent that no technical contradiction occurs. Note that the same components as those in the above embodiment are designated by the same reference numerals, and redundant explanations will be omitted.

[0041] 4, a space 25 is provided in the compressor housing 27 vertically below the rotation axis 26A of the compressor wheel 26. The rotation axis 26A is an imaginary line that passes through the rotation center of the compressor wheel 26 and extends along the axis of the compressor wheel 26.

[0042] A separation chamber 39 is located in the upper part of the space 25. A storage chamber 37 is located in the lower part of the space 25. The opposing wall 41 is continuous with the defining wall 42. In this modification, the opposing wall 41 is directly connected to the defining wall 42.

[0043] The opposing wall 41 is directly connected to the partition wall 42. Therefore, when the emulsion 46 flows down from the opposing wall 41 into the storage chamber 37, it is less likely to scatter around. Furthermore, since the storage chamber 37 is positioned vertically below the rotation axis 26A, the emulsion 46 stored in the storage chamber 37 can be easily discharged quickly through the discharge hole 47 to the outside.

[0044] 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.

[0045] The separation chamber 39 and the storage chamber 37 may both be provided outside the compressor housing 27. In this modification, the storage chamber 37 is also located below the opposing wall 41. The opposing wall 41 is also continuous with the partition wall 42.

[0046] Of the separation chamber 39 and the storage chamber 37, the storage chamber 37 may be disposed outside the compressor housing 27. In this modified example, the storage chamber 37 is located below the opposing wall 41. The storage chamber 37 is connected to the separation chamber 39 via an external pipe installed outside the compressor housing 27. The external pipe is configured to cause the emulsion 46 separated in the separation chamber 39 to flow into the storage chamber 37. The opposing wall 41 is continuous with the defining wall 42 via the inner wall of the external pipe. The inner wall of the external pipe is an example of another wall connecting the opposing wall 41 and the defining wall 42.

[0047] The opposing wall 41 may have a curved surface. When the opposing wall 41 has a curved surface, the collision angle θ2 described above is the angle between the first imaginary line 44A and a tangent to the curved surface at the intersection of 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 that adheres to the opposing wall 41, it is preferable that the curved surface have a shape that is concave on the side opposite to the upstream opening 39A rather than a shape that bulges toward the upstream opening 39A.

[0048] In the upstream passage 33A, an upstream section 44, which is a connection section with the upstream opening 39A, may be provided with a convex portion such as a partition plate or a projection, while having an opening through which blow-by gas flows. By providing a convex portion in the upstream section 44, part of the blow-by gas flowing through the upstream passage 33A hits the convex portion, and part of the emulsion 46 accumulates near the convex portion. This reduces the amount of emulsion 46 flowing into the separation chamber 39, allowing the storage chamber 37 to be smaller.

[0049] In the above modification, the convex portion is preferably provided at the lower portion of the upstream portion 44 in the vertical direction. A larger amount of emulsion 46 tends to pass through the lower portion of the upstream portion 44 in the vertical direction than through the upper portion. Therefore, a larger amount of emulsion 46 accumulates near the convex portion. As a result, this modification can further contribute to the miniaturization of the storage chamber 37.

[0050] The internal combustion engine 2 may be an internal combustion engine that burns gasoline as fuel. [Explanation of symbols]

[0051] 1... Blow-by gas treatment device 2... Internal combustion engine 13... Supercharger 22... Intake passage 26... Compressor wheel 27... Compressor housing 33... Blow-by gas passage 33A... Upstream passage 33B... Downstream passage 37... Storage chamber 39... Separation chamber 39A... Upstream opening 41... Opposing wall 42... Partition wall 43... Communication hole 46... Emulsion

Claims

1. A blow-by gas treatment device for an internal combustion engine equipped with a turbocharger, an intake passage in which a compressor wheel of the turbocharger is disposed; A blow-by gas passage, a storage chamber for storing emulsion contained in blow-by gas, the blow-by gas passage includes a separation chamber for separating emulsion from the blow-by gas, an upstream passage communicating the separation chamber with the inside of a crankcase of the internal combustion engine, and a downstream passage communicating the separation chamber with the intake passage, the separation chamber includes an upstream opening to which the upstream passage is connected and an opposing wall opposing the upstream opening, The storage chamber is located below the opposing wall in the vertical direction, The opposing wall is continuous with a defining wall that defines the storage chamber. Blow-by gas treatment device.

2. A compressor housing that houses the compressor wheel has the separation chamber and the storage chamber. The blow-by gas treatment device according to claim 1 .

3. The compressor housing has a communication hole that communicates the separation chamber with the storage chamber. The blow-by gas treatment device according to claim 2 .

4. An internal combustion engine that burns hydrogen as fuel, An internal combustion engine equipped with the blow-by gas treatment device according to any one of claims 1 to 3.

5. A supercharger for an internal combustion engine, An intake passage; a blow-by gas passage including a separation chamber configured to separate emulsion from the blow-by gas, an upstream passage, and a downstream passage; a compressor wheel disposed in the intake passage; a storage chamber for storing emulsion contained in blow-by gas, the separation chamber is in communication with the interior of a crankcase of the internal combustion engine via the upstream passage and in communication with the intake passage via the downstream passage, and includes an upstream opening to which the upstream passage is connected, and an opposing wall opposing the upstream opening, The storage chamber is located below the opposing wall in the vertical direction, The opposing wall is continuous with a defining wall that defines the storage chamber. Supercharger.

6. a compressor housing that accommodates the compressor wheel has a space vertically below a rotation axis of the compressor wheel, The separation chamber is located in an upper portion of the space, The storage chamber is located in a lower portion of the space, The opposing wall is directly connected to the defining wall. The turbocharger according to claim 5.

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