Internal combustion engine

Abstract

Provided is an internal combustion engine. The internal combustion engine is provided with a second separator, a connection pipe, and a pressure sensor. A main chamber inside the second separator is formed in a cylinder head cover, and a first sub chamber and a second sub chamber inside the second separator are formed in a joint portion that is located outside the cylinder head cover. The first sub chamber and the second sub chamber are divided by a partition wall. A communication hole is formed in the partition wall, and the communication hole connects the first sub chamber and the second sub chamber. The first sub chamber is connected to the main chamber via a throttle portion. The joint portion is provided with a first connection port and a second connection port. The first connection port is connected to the first sub chamber, and the second connection port is connected to the second sub chamber. The first connection port is connected to an intake passage via the connection pipe. The second connection port is connected to the pressure sensor.

Description

Technical Field

[0001] This invention relates to internal combustion engines. Background Technology

[0002] Japanese Patent Application Publication No. 2019-132233 discloses an internal combustion engine equipped with a blow-by treatment device. The blow-by treatment device is used to treat blow-by gases leaking from the combustion chamber of the internal combustion engine into the crankcase by returning them from the cylinder head cover to the intake passage. The blow-by treatment device includes piping fittings and connecting pipes.

[0003] The aforementioned piping connector is located on the cylinder head cover of the internal combustion engine. The piping connector is connected to the intake passage of the internal combustion engine via the aforementioned connecting pipe. A throttling section is provided inside the piping connector. Thus, the connecting pipe communicates with the interior of the cylinder head cover via the throttling section of the piping connector. The interior of the cylinder head cover is connected to the intake passage through the piping connector and the connecting pipe. A connecting portion is provided on the piping connector. The connecting portion is located between the portion of the piping connector that connects to the connecting pipe and the throttling section. A pressure sensor is connected to the connecting portion.

[0004] When the connecting pipe detaches from the pipe fitting or from the air intake passage, the pressure value detected by the pressure sensor changes drastically. Therefore, by monitoring the pressure value detected by the pressure sensor, it is possible to detect when the connecting pipe is detached. Similarly, when the connecting pipe is damaged, the pressure value detected by the pressure sensor also changes drastically. Therefore, by monitoring the pressure value detected by the pressure sensor, it is also possible to detect damage to the connecting pipe. Summary of the Invention

[0005] However, during the operation of an internal combustion engine, intake pulsations are generated in the intake passage, and gas pulsations accompany the reciprocating motion of the piston within the crankcase. When these pulsations propagate into the internal piping, the pressure values ​​detected by pressure sensors also fluctuate due to these pulsations. As a result, it becomes impossible to properly detect anomalies such as disconnection or damage to the piping.

[0006] The following describes the methods used to solve the above problems and their effects.

[0007] The internal combustion engine that solves the above problem has a blow-by treatment device that returns blow-by gas leaking from the combustion chamber to the crankcase to the intake passage for treatment.

[0008] The blow-by device includes an oil separator, connecting pipes, and a pressure sensor. The oil separator is located in the cylinder head cover and has a main chamber and a secondary chamber inside. The oil separator has a connector and a throttling section; the connector forms the secondary chamber, and the throttling section connects the secondary chamber to the main chamber.

[0009] The secondary chambers are divided into a first secondary chamber and a second secondary chamber by a partition wall.

[0010] A connecting hole is formed in the partition wall, which connects the first sub-chamber and the second sub-chamber.

[0011] The first auxiliary chamber is connected to the main chamber via the aforementioned throttling section.

[0012] A first connection port and a second connection port are formed at the joint. The first connection port is connected to the first auxiliary chamber, and the second connection port is connected to the second auxiliary chamber.

[0013] The first connection port is connected to the air intake passage via a connecting pipe. The second connection port is connected to the pressure sensor.

[0014] According to the above structure, the pressure sensor is connected to the first sub-chamber via the second sub-chamber and the connecting hole. Therefore, even if a pulsation propagates to the first sub-chamber, the pulsation is mitigated as it passes through the connecting hole and the second sub-chamber. Thus, fluctuations in the pressure value detected by the pressure sensor caused by the aforementioned pulsation can be suppressed. As a result, by monitoring the pressure value detected by the pressure sensor, abnormalities in the connecting piping can be appropriately detected. Furthermore, the first and second sub-chambers are formed by dividing the joint portion with a partition wall. Therefore, the second sub-chamber for mitigating the aforementioned pulsation is provided without occupying a large space. Therefore, a structure for mitigating the aforementioned pulsation can be implemented with a smaller space.

[0015] In the aforementioned internal combustion engine, the main chamber of the oil separator is located inside the cylinder head cover.

[0016] The connector of the oil separator is located on the outside of the cylinder head cover.

[0017] The first and second auxiliary chambers within the connector are arranged along the cylinder head cover.

[0018] According to the above structure, since the first auxiliary chamber and the second auxiliary chamber are arranged along the cylinder head cover, the amount of protrusion of the joint portion forming the first auxiliary chamber and the second auxiliary chamber from the cylinder head cover can be minimized.

[0019] In the aforementioned internal combustion engine, it is possible to consider forming the connecting hole and the first connection port in such a way that the axis of the connecting hole and the axis of the first connection port are not aligned.

[0020] According to this structure, even if intake pulsations in the internal combustion engine propagate to the first auxiliary chamber via the connecting pipe and the first connection port, these pulsations are unlikely to propagate to the second auxiliary chamber via the connecting hole. Therefore, it is possible to more effectively suppress fluctuations in the pressure value detected by the pressure sensor caused by the aforementioned pulsations.

[0021] In the aforementioned internal combustion engine, it is possible to consider forming the connecting hole and the throttling section in such a way that the axis of the connecting hole is not aligned with the axis of the throttling section.

[0022] According to this structure, even if gas pulsations in the crankcase of the internal combustion engine propagate to the first auxiliary chamber via the main chamber and the throttling section, these pulsations are unlikely to propagate to the second auxiliary chamber via the connecting hole. Therefore, it is possible to more effectively suppress fluctuations in the pressure value detected by the pressure sensor caused by the aforementioned pulsations.

[0023] In the aforementioned internal combustion engine, the connection between the partition wall and the inner wall of the joint can be considered.

[0024] According to this structure, since the joint head can be reinforced by the partition wall, the vibration of the joint and the sound generated by the vibration can be suppressed.

[0025] In the aforementioned internal combustion engine, it is possible to consider forming the throttling section and the first connection port in such a way that the axis of the throttling section is aligned with the axis of the first connection port.

[0026] This structure ensures smooth gas flow between the throttling section and the first connection port in the first sub-chamber. Consequently, the aforementioned pulsations are less likely to propagate to the second sub-chamber via the connecting hole. Therefore, fluctuations in the pressure value detected by the pressure sensor due to these pulsations can be more effectively suppressed.

[0027] In the aforementioned internal combustion engine, it can be considered that the distance from the throttling section to the connecting hole is longer than the distance from the throttling section to the first connection port.

[0028] This structure allows the second chamber to be further away from the flow of gas between the throttling section and the first connection port. Consequently, the aforementioned pulsations are less likely to propagate to the second chamber via the connecting hole. Therefore, fluctuations in the pressure value detected by the pressure sensor due to the aforementioned pulsations can be more effectively suppressed. Attached Figure Description

[0029] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and wherein:

[0030] Figure 1 It is a schematic diagram representing an internal combustion engine.

[0031] Figure 2 This is a cross-sectional view showing the second separator.

[0032] Figure 3 This is a cross-sectional view showing the second separator.

[0033] Figure 4 This is a cross-sectional view showing another example of a second separator.

[0034] Figure 5 This is a cross-sectional view showing another example of a second separator. Detailed Implementation

[0035] [First Implementation Method]

[0036] The following is for reference Figure 1 and Figure 2 The first embodiment of the internal combustion engine will be described.

[0037] like Figure 1 As shown, the internal combustion engine 90 includes a cylinder block 91, a cylinder head 97, a cylinder head cover 98, a crankcase 95, and an oil pan 96.

[0038] Multiple cylinders 92 are formed on the cylinder block 91. Each cylinder 92 houses a piston 94, which reciprocates in conjunction with the rotation of the crankshaft housed in the crankcase 95.

[0039] The intake valve and exhaust valve of the internal combustion engine 90 are assembled on the cylinder head 97. Additionally, a cylinder head cover 98, mounted on the cylinder head 97, covers the camshaft that drives the intake and exhaust valves. The cylinder head cover 98 is molded from resin material. A baffle is installed on the cylinder head 97 side of the cylinder head cover 98.

[0040] Oil pan 96 stores oil used for lubrication of various parts of internal combustion engine 90 and hydraulic drive mechanism.

[0041] The internal combustion engine 90 has a combustion chamber 93 divided by a cylinder 92, a piston 94, and a cylinder head 97. The internal combustion engine 90 has an intake passage 71 for introducing intake air into the combustion chamber 93. Furthermore, the internal combustion engine 90 has an exhaust passage 78 for discharging the air-fuel mixture after combustion in the combustion chamber 93 as exhaust gas.

[0042] The internal combustion engine 90 includes a turbocharger 80. The turbocharger 80's turbine 82 is located in the exhaust passage 78. Furthermore, the compressor 81, which is connected to the turbine 82, is located in the intake passage 71.

[0043] An air filter 72 is provided upstream of the compressor 81 in the intake passage 71 of the internal combustion engine 90. An intercooler 73 is provided downstream of the compressor 81 in the intake passage 71. A throttle valve 74 is provided downstream of the intercooler 73 in the intake passage 71. An intake manifold 75 is provided downstream of the throttle valve 74 in the intake passage 71. The intake manifold 75 is connected to the cylinder head 97.

[0044] Intake air through intake manifold 75 is introduced into combustion chamber 93 via intake port 76 formed in cylinder head 97. Additionally, exhaust port 77 is formed in cylinder head 97 to discharge exhaust gases from combustion chamber 93. Exhaust gases discharged from combustion chamber 93 are discharged into exhaust passage 78 via exhaust port 77. Internal combustion engine 90 includes blow-by treatment device 30.

[0045] <Regarding the gas leakage treatment device 30>

[0046] The blow-by gas treatment device 30 has a blow-by gas passage 49 that connects the crankcase 95 and the intake passage 71, so that blow-by gas leaking from the combustion chamber 93 into the crankcase 95 flows back to the intake passage 71.

[0047] A first separator 43 is provided in the blow-by passage 49 of the blow-by treatment device 30. The first separator 43 is used to separate oil contained in the blow-by gas from the blow-by gas. The first separator 43 is located in the cylinder head cover 98. The first separator 43 is connected to the intake manifold 75 of the intake passage 71 via a blow-by vent pipe 47. The blow-by vent pipe 47 can be a rubber hose or a resin tube, etc. A PCV valve 48 is provided in the blow-by vent pipe 47 to open and close the connection between the first separator 43 and the intake manifold 75. The PCV valve 48 opens when the pressure in the intake manifold 75 is lower than the pressure in the first separator 43, thereby connecting the first separator 43 to the intake manifold 75.

[0048] The blow-by gas treatment device 30 includes a suction passage 41 for guiding blow-by gas in the crankcase 95 into a first separator 43. The suction passage 41 is formed in the cylinder block 91 and the cylinder head 97. A pre-separator 42 is provided in the suction passage 41 to separate oil from the blow-by gas passing through the suction passage 41.

[0049] The blow-by gas treatment device 30 includes a connecting pipe 31 that introduces fresh air into the crankcase 95 from the intake passage 71. The connecting pipe 31 can be a rubber hose or a resin tube, etc. One end of the connecting pipe 31 is connected between the air filter 72 and the compressor 81 in the intake passage 71. The other end of the connecting pipe 31 is connected to a second separator 32, which serves as an oil separator. The second separator 32 is located on the cylinder head cover 98. The second separator 32 is divided by the cylinder head cover 98 and a baffle.

[0050] The second separator 32 includes a connector 10 for connecting to the connecting pipe 31. A pressure sensor 54 for detecting pressure within the connecting pipe 31 is connected to the connector 10 via a connection passage 60. The detection signal from the pressure sensor 54 is input to the control unit of the internal combustion engine 90. The control unit detects the pressure within the pipe 31 based on the detection signal from the pressure sensor 54, and detects an abnormality in the connecting pipe 31 if the pressure fluctuation exceeds a predetermined range.

[0051] A connecting passage 99 is formed in the cylinder block 91, which communicates with the crankcase 95. The intake passage 71 and the crankcase 95 are connected via a connecting pipe 31, a second separator 32, and the connecting passage 99. Hereinafter, the passage including the connecting pipe 31 and connecting the intake passage 71 and the crankcase 95 will sometimes be referred to as the "fresh air introduction passage".

[0052] The blow-by gas treatment device 30 includes an injector 50 that generates negative pressure when driven by the supercharger 80. The injector 50 includes an injector body 51 connected to a first separator 43. A first intake circulation passage 52 and a second intake circulation passage 53 are connected to the injector body 51. The first intake circulation passage 52 connects the compressor 81 and the intercooler 73 in the intake passage 71, and the second intake circulation passage 53 connects the air filter 72 and the compressor 81 in the intake passage 71. The connection between the second intake circulation passage 53 and the intake passage 71 is located downstream of the connection between the connecting pipe 31 and the intake passage 71. The injector body 51 includes a nozzle portion 51A that injects intake air supplied via the first intake circulation passage 52 into the second intake circulation passage 53. A diffuser portion 51B, whose gas flow path gradually widens, is provided on the injector body 51 on the side of the second intake circulation passage 53, compared to the nozzle portion 51A. The injector 50 consists of an injector body 51, a first intake circulation passage 52, and a second intake circulation passage 53.

[0053] When the internal combustion engine 90 is not operating in the turbocharged region and the pressure in the intake manifold 75 is lower than the pressure in the first separator 43, the PCV valve 48 opens, thereby introducing blow-by gas from the first separator 43 into the intake passage 71. At this time, blow-by gas from the crankcase 95 is introduced into the first separator 43 via the suction passage 41. Then, intake air is introduced into the crankcase 95 from the intake passage 71 via the fresh air introduction passage.

[0054] On the other hand, when the internal combustion engine 90 operates in the turbocharged region, the intake air flowing from the downstream side of the compressor 81 in the intake passage 71 into the first intake recirculation passage 52 returns to the upstream side of the compressor 81 via the injector body 51 and the second intake recirculation passage 53. When the intake air passes through the nozzle portion 51A of the injector body 51, a negative pressure is generated inside the injector body 51. At this time, the injector 50 draws in blow-by air from the crankcase 95 via the first separator 43. Furthermore, the injector 50 releases the blow-by air that has passed through the diffuser portion 51B into the intake passage 71 via the second intake recirculation passage 53.

[0055] Furthermore, when the internal combustion engine 90 is operating in the turbocharged region, the pressure of the blow-by gas leaking from the combustion chamber 93 to the crankcase 95 is relatively high. When the pressure inside the crankcase 95 is higher than the pressure inside the portion of the intake passage 71 connected to the connecting pipe 31, the blow-by gas from the crankcase 95 flows into the intake passage 71 via the fresh air intake passage. Additionally, even when the internal combustion engine 90 is not operating in the turbocharged region, for example, when the throttle valve 74 is fully open, the blow-by gas leaking from the combustion chamber 93 to the crankcase 95 sometimes flows into the intake passage 71 via the fresh air intake passage.

[0056] <Regarding the second separator 32>

[0057] like Figure 2 As shown, a main chamber 12 is formed inside the portion of the second separator 32 located within the cylinder head cover 98. A connector 10 of the second separator 32 is located outside the cylinder head cover 98. The connector 10 is fused to the cylinder head cover 98. A first auxiliary chamber 13 and a second auxiliary chamber 14 are formed inside the connector 10. The first auxiliary chamber 13 and the second auxiliary chamber 14 are separated by a partition wall 11. A connecting hole 15 is formed in the partition wall 11, connecting the first auxiliary chamber 13 and the second auxiliary chamber 14. The first auxiliary chamber 13 is connected to the main chamber 12 via a throttling portion 16 penetrating the cylinder head cover 98.

[0058] A first connection port 66 and a second connection port 67 are formed at the connector 10. The first connection port 66 is connected to the first auxiliary chamber 13, and the second connection port 67 is connected to the second auxiliary chamber 14. The aforementioned connecting pipe 31 is connected to the first connection port 66. Figure 1 Therefore, the first auxiliary chamber 13 is connected to the air intake passage 71 via the first connection port 66 and the connecting pipe 31. The aforementioned connecting passage 60 is connected to the second connection port 67. Therefore, the second auxiliary chamber 14 is connected to the pressure sensor 54 via the second connection port 67 and the connecting passage 60.

[0059] <Regarding the First Assistant Room 13 and the Second Assistant Room 14>

[0060] like Figure 2 As shown, the partition wall 11 protrudes downward from the inner wall 10a of the upper end of the connector portion 10, i.e., toward the cylinder head cover 98. The partition wall 11 is connected to the inner wall 10a of the connector portion 10. A gap is formed between the front end of the partition wall 11 in the protruding direction and the cylinder head cover 98. This gap becomes the aforementioned connecting hole 15. By forming the partition wall 11 in this way, the first auxiliary chamber 13 and the second auxiliary chamber 14 in the connector portion 10 are arranged in a manner that runs along the cylinder head cover 98.

[0061] The connecting hole 15 and the first connection port 66 are formed such that their axes L1 and L2 are not aligned. Furthermore, the connecting hole 15 and the throttling section 16 are formed such that their axes L1 and L3 are not aligned. The distance from the throttling section 16 to the connecting hole 15 is longer than the distance from the throttling section 16 to the first connection port 66. The throttling section 16 and the first connection port 66 are formed such that their axes L3 and L2 are aligned.

[0062] The surface of the cylinder head cover 98 located in the second auxiliary chamber 14 is inclined in a manner that slopes downwards as it approaches the connecting hole 15. As a result, fluids such as water and oil entering the second auxiliary chamber 14 flow toward the connecting hole 15. Subsequently, this fluid is discharged from the connecting hole 15 to the outside of the second auxiliary chamber 14. The flow cross-sectional area of ​​the fluid in the connecting hole 15 is determined based on the pressure range to be detected by the pressure sensor 54, and is determined to be a value that allows the fluid to be discharged from the second auxiliary chamber 14. The flow cross-sectional area of ​​the fluid in the connecting hole 15 is smaller than the flow cross-sectional area of ​​the fluid in the first auxiliary chamber 13, and smaller than the flow cross-sectional area of ​​the fluid in the second auxiliary chamber 14.

[0063] Next, the function of the internal combustion engine 90 in this embodiment will be explained.

[0064] The cylinder head cover 98 of the internal combustion engine 90 equipped with a blow-by treatment device 30 has a connector 10 for a second separator 32 that functions as an oil separator. A connecting pipe 31 is connected to a first connection port 66 of the connector 10. The connecting pipe 31 is connected to a first auxiliary chamber 13 within the connector 10 via the first connection port 66. The first auxiliary chamber 13 is connected to a pressure sensor 54 via a connecting hole 15 within the connector 10, a second auxiliary chamber 14, and a connecting passage 60. The position in the first auxiliary chamber 13 where the pressure sensor 54 is connected is closer to the first connection port 66 than the throttling section 16 of the second separator 32. Therefore, in the event of an abnormality such as detachment or damage to the connecting pipe 31, the pressure sensor 54's reading tends to fluctuate near atmospheric pressure as the first connection port 66 of the connector 10 opens to the atmosphere. This fluctuation in the pressure sensor 54's reading allows for the detection of the aforementioned abnormality.

[0065] During the operation of the internal combustion engine 90, intake pulsations are generated in the intake passage 71, and gas pulsations associated with the reciprocating motion of the piston 94 are generated in the crankcase 95. These pulsations propagate to the first auxiliary chamber 13 of the connector 10. The pressure sensor 54 is connected to the first auxiliary chamber 13 via the connection passage 60, the second connection port 67, the second auxiliary chamber 14, and the connecting hole 15. Therefore, when the aforementioned pulsations propagate from the first auxiliary chamber 13 toward the pressure sensor 54, the pulsations are mitigated in the second auxiliary chamber 14. Thus, it is possible to suppress fluctuations in the pressure value detected by the pressure sensor 54 due to the influence of the aforementioned pulsations. As a result, it is possible to suppress situations where abnormalities such as disconnection or damage to the connecting pipe 31 cannot be properly detected by monitoring the pressure value detected by the pressure sensor 54.

[0066] The first sub-chamber 13 and the second sub-chamber 14 are formed by dividing the joint portion 10 by a partition wall 11. Therefore, the second sub-chamber 14 for mitigating the aforementioned pulsations is provided without occupying a large space. Thus, a structure for mitigating the aforementioned pulsations can be implemented in a smaller space.

[0067] Based on the embodiment described in detail above, the following effects can be obtained.

[0068] (1-1) It can suppress the fluctuations in the pressure value detected by the pressure sensor 54 caused by the above-mentioned pulsation, and can implement a structure for mitigating the above-mentioned pulsation in a small space.

[0069] (1-2) The connector 10 is fused to the cylinder head cover 98. The first sub-chamber 13 and the second sub-chamber 14 formed inside the connector 10 are arranged in a manner that runs along the cylinder head cover 98. Therefore, the amount of protrusion of the connector 10 from the cylinder head cover 98 can be minimized.

[0070] (1-3) The connecting hole 15 and the first connection port 66 of the connector portion 10 are formed in a manner where their axes L1 and L2 are not aligned. Therefore, even if pulsations in the intake air of the internal combustion engine 90 propagate to the first auxiliary chamber 13 via the connecting pipe 31 and the first connection port 66, these pulsations are unlikely to propagate to the second auxiliary chamber 14 via the connecting hole 15. Thus, fluctuations in the pressure value detected by the pressure sensor 54 caused by the aforementioned pulsations can be more effectively suppressed.

[0071] (1-4) The connecting hole 15 and the throttling section 16 are formed with their axes L1 and L3 not aligned. Therefore, even if pulsations of gas in the crankcase 95 of the internal combustion engine 90 propagate to the first auxiliary chamber 13 via the main chamber 12 and the throttling section 16, these pulsations are unlikely to propagate to the second auxiliary chamber 14 via the connecting hole 15. Thus, fluctuations in the pressure value detected by the pressure sensor 54 caused by the aforementioned pulsations can be more effectively suppressed.

[0072] (1-5) Since the partition wall 11 is connected to the inner wall 10a of the connector 10, the connector head 10 can be strengthened by the partition wall 11. Therefore, the vibration of the connector 10 and the sound generated by the vibration can be suppressed.

[0073] (1-6) The throttling section 16 and the first connection port 66 are formed with their axes L3 and L2 aligned. Therefore, the flow of gas between the throttling section 16 and the first connection port 66 within the first sub-chamber 13 is smooth. Consequently, the aforementioned pulsations are less likely to propagate to the second sub-chamber 14 via the connecting hole 15. Therefore, fluctuations in the pressure value detected by the pressure sensor 54 caused by the aforementioned pulsations can be more effectively suppressed.

[0074] (1-7) The distance from the throttling section 16 to the connecting hole 15 is longer than the distance from the throttling section 16 to the first connection port 66. Therefore, the second sub-chamber 14 can be further away from the flow of gas between the throttling section 16 and the first connection port 66. As a result, the aforementioned pulsations are less likely to propagate to the second sub-chamber 14 via the connecting hole 15. Therefore, fluctuations in the pressure value detected by the pressure sensor 54 caused by the aforementioned pulsations can be suppressed more effectively.

[0075] (1-8) The surface of the cylinder head cover 98 located in the second auxiliary chamber 14 is inclined in a manner that descends as it approaches the connecting hole 15. As a result, fluids such as water and oil that enter the second auxiliary chamber 14 can flow toward the connecting hole 15 and be discharged from the connecting hole 15 to the outside of the second auxiliary chamber 14.

[0076] (1-9) A connecting hole 15 is formed between the end of the partition wall 11 and the cylinder head cover 98. Inside the cylinder head cover 98, hot oil splashes out when the internal combustion engine 90 is running. Therefore, it is possible to prevent the connecting hole 15 from being blocked by freezing moisture at low temperatures.

[0077] [Second Implementation]

[0078] Next, refer to Figure 3 The second embodiment of the internal combustion engine will be described.

[0079] Figure 3 This refers to the second separator 32 in the internal combustion engine 90 of this embodiment. (The text abruptly ends here.) Figure 3 It can be seen that the interior of the connector 10 in the second separator 32 is composed of... Figure 3 The partition wall 11, extending in the left-right direction, divides the cylinder head cover 98 into a first sub-chamber 13 and a second sub-chamber 14. The partition wall 11 is connected to the inner wall 10a of the connector portion 10. The first sub-chamber 13 is located closer to the cylinder head cover 98 than the partition wall 11. The first sub-chamber 13 is connected to the throttle portion 16. The second sub-chamber 14 is located further away from the cylinder head cover 98 than the partition wall 11.

[0080] A connecting hole 15 is formed in the partition wall 11 through the partition wall 11. The partition wall 11 is inclined in a manner that decreases as it approaches the connecting hole 15. In other words, the connecting hole 15 is located at the lowest point of the partition wall 11.

[0081] A first connection port 66 and a second connection port 67 are formed in the connector portion 10. The first connection port 66 is connected to the first auxiliary chamber 13, and the second connection port 67 is connected to the second auxiliary chamber 14. The connecting hole 15 and the first connection port 66 are formed in a manner where their axes L1 and L2 are not aligned. In addition, the connecting hole 15 and the throttling portion 16 are formed in a manner where their axes L1 and L3 are not aligned. The distance from the throttling portion 16 to the connecting hole 15 is set to be longer than the distance from the throttling portion 16 to the first connection port 66.

[0082] According to this embodiment, in addition to the same effects as those of (1-1), (1-3) to (1-5) and (1-7) of the first embodiment, the following effects can also be obtained.

[0083] (2-1) The partition wall 11 is inclined in such a way that it descends as it approaches the connecting hole 15. As a result, fluids such as water and oil that have entered the second sub-chamber 14 can flow toward the connecting hole 15 and be discharged from the connecting hole 15 to the outside of the second sub-chamber 14.

[0084] [Other Implementation Methods]

[0085] Furthermore, the above-described embodiments can also be modified in the following ways. The above-described embodiments and the following modifications can be combined and implemented with each other within the scope of technical non-contradiction.

[0086] In the first embodiment, the connecting hole 15 may not be formed by the gap between the protruding front end of the partition wall 11 and the cylinder head cover 98. For example, the partition wall 11 contacts the cylinder head cover 98, and the connecting hole 15 penetrates the partition wall 11. In this case, multiple connecting holes 15 may also be formed. Moreover, at least one of the multiple connecting holes 15 is capable of discharging liquids such as water or oil from the second auxiliary chamber 14 to the first auxiliary chamber 13.

[0087] In the first embodiment, the partition wall 11 may also extend from the cylinder head cover 98 toward... Figure 2 The upper part protrudes and contacts the inner wall 10a of the connector portion 10. In this case, the connecting hole 15 penetrates the partition wall 11 as described above.

[0088] • In the first embodiment, the surface of the cylinder head cover 98 located in the second auxiliary chamber 14 does not necessarily have to be tilted in a manner that descends as it approaches the connecting hole 15.

[0089] • In the second embodiment, the partition wall 11 does not necessarily have to be inclined in a way that descends as it approaches the connecting hole 15.

[0090] • In the second embodiment, the axes L1 and L2 of the connecting hole 15 of the connector 10 and the first connecting port 66 can also be the same.

[0091] In the first and second embodiments, the distance from the throttling section 16 to the connecting hole 15 does not necessarily have to be longer than the distance from the throttling section 16 to the first connection port 66. For example, as Figure 4 As shown, the distance from the throttling section 16 to the connecting hole 15 can also be shorter than the distance from the throttling section 16 to the first connection port 66. In this case, it is preferable to form the throttling section 16 and the first connection port 66 such that their axes L3 and L2 are aligned.

[0092] In the first embodiment, as Figure 5 As shown, the axes L3 and L2 of the throttling section 16 and the first connection port 66 may not be the same. In this case, it is preferable that the distance from the throttling section 16 to the connecting hole 15 is longer than the distance from the throttling section 16 to the first connection port 66.

[0093] In the second embodiment, the opening on the first sub-chamber 13 side of the connecting hole 15 may extend into the first sub-chamber 13, or the opening on the second sub-chamber 14 side may extend into the second sub-chamber 14. In these cases, since the resistance to gas passing through the connecting hole 15 increases, gas pulsation is less likely to be transmitted from the first sub-chamber 13 to the second sub-chamber 14. Furthermore, when only the opening on the first sub-chamber 13 side of the connecting hole 15 extends into the first sub-chamber 13, the resulting decrease in the discharge capacity of fluids such as water and oil from the second sub-chamber 14 to the first sub-chamber 13 can be suppressed.

[0094] The internal combustion engine 90 in the first and second embodiments includes a turbocharger 80, but the turbocharger 80 is not a necessary component. Even an internal combustion engine 90 without a turbocharger 80 can detect abnormalities in the connecting pipe 31 via the pressure sensor 54, just as in the embodiments described above. Even in an internal combustion engine 90 without a turbocharger 80, when the throttle valve 74 is fully open, blow-by gas leaking from the combustion chamber 93 to the crankcase 95 may sometimes flow into the intake passage 71 via the fresh air intake passage.

[0095] In the internal combustion engine 90 of the first and second embodiments, it is configured such that when the internal combustion engine 90 is operating in the turbocharged region, negative pressure is generated by the injector 50 to release blow-by gas into the intake passage 71, but the injector 50 may be omitted. In this case, when the internal combustion engine 90 is operating in the turbocharged region, the blow-by gas can be released into the intake passage 71 via the fresh air inlet passage.

[0096] Alternatively, the first separator 43 in the first and second embodiments can be configured with the same structure as the second separator 32, and the pressure sensor 54 can be connected to the second auxiliary chamber of the connector, which connects the gas venting pipe 47 to the first separator 43. In this case, the pressure sensor 54 detects any abnormalities in the gas venting pipe 47.

Claims

1. An internal combustion engine comprising a blow-by treatment device that treats blow-by gases leaking from the combustion chamber into the crankcase by returning them to the intake passage, wherein... The gas leakage treatment device includes an oil separator, connecting pipes, and a pressure sensor. The oil separator is disposed on the cylinder head cover and has a main chamber and a secondary chamber formed inside it. It also has a connector and a throttling section. The connector forms the secondary chamber, and the throttling section connects the secondary chamber to the main chamber. The secondary chambers are a first secondary chamber and a second secondary chamber, which are divided by a partition wall. A connecting hole is formed in the partition wall, which connects the first sub-chamber and the second sub-chamber. The first auxiliary chamber is connected to the main chamber via the throttling device. A first connection port and a second connection port are formed at the connector portion. The first connection port is connected to the first sub-chamber, and the second connection port is connected to the second sub-chamber. The first connection port is connected to the air intake passage via the connecting pipe. The second connection port is connected to the pressure sensor. The main chamber of the oil separator is located inside the cylinder head cover. The connector of the oil separator is located on the outside of the cylinder head cover. The first and second auxiliary chambers within the connector are arranged along the cylinder head cover.

2. The internal combustion engine according to claim 1, wherein, The connecting hole and the first connection port are formed in such a way that the axis of the connecting hole is not aligned with the axis of the first connection port.

3. The internal combustion engine according to claim 1 or 2, wherein, The connecting hole and the throttling section are formed in such a way that the axis of the connecting hole and the axis of the throttling section are not aligned.

4. The internal combustion engine according to claim 1 or 2, wherein, The partition wall is connected to the inner wall of the joint.

5. The internal combustion engine according to claim 1 or 2, wherein, The throttling section and the first connection port are formed such that the axis of the throttling section is aligned with the axis of the first connection port.

6. The internal combustion engine according to claim 1 or 2, wherein, The distance from the throttling section to the connecting hole is longer than the distance from the throttling section to the first connection port.

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