JP7276169B2 - Blow-by gas recirculation device for internal combustion engine - Google Patents

Description

The present invention relates to a blow-by gas recirculation device for an internal combustion engine.

Blow-by gas that has leaked into the crankcase from the combustion chamber of the internal combustion engine flows into the space defined by the cylinder head and the head cover via a communication passage formed across the cylinder block and the cylinder head. In a blow-by gas processing device for an internal combustion engine, the blow-by gas flowing into the head cover is recirculated into the intake pipe through a blow-by gas passage connected to both the head cover and the intake pipe.

In the blow-by gas treatment device, a blow-by gas valve is provided in the blow-by gas passage. A pressure sensor for detecting the pressure in the blow-by gas passage is connected to a portion of the blow-by gas passage between the connecting portion with the intake pipe and the blow-by gas valve. Then, by utilizing the pressure fluctuation in the blow-by gas passage detected by the pressure sensor, it is determined whether or not an abnormality such as breakage of the blow-by gas passage has occurred (for example, Patent Documents 1 and 2). reference).

JP-A-10-184336 JP 2019-132232 A

By the way, when the pressure sensor is connected to a portion of the blow-by gas passage between the connecting portion with the intake pipe and the blow-by gas valve, the pressure sensor detects the pressure of the blow-by gas flowing from the blow-by gas valve into the blow-by gas passage. , the pressure may not be detected accurately.

For example, if the pressure sensor is connected to a portion near the blow-by gas valve, the pressure detected by the pressure sensor may not be stable because it is strongly affected by the blow-by gas flow. As described above, depending on the portion to which the pressure sensor is connected, the pressure sensor may not be able to accurately detect the pressure of the blow-by gas, and an abnormality such as breakage of the blow-by gas passage may not be accurately determined.

Accordingly, an object of the present invention is to improve the accuracy of detecting the pressure of blow-by gas.

A blow-by gas recirculation device for an internal combustion engine according to the present invention includes an outflow member including an outflow port for outflowing blow-by gas after oil components have been separated, and a recirculation member for recirculating the blow-by gas flowing in from the outflow port to an intake pipe. and the return member comprises a first wall standing on a predetermined surface including the outlet and spaced apart from the outlet and having a passage connected to a pressure sensor; a second wall that intersects the outflow direction from the outlet and is provided at a height equal to or higher than the height of the first wall; The second wall extends obliquely toward the passage from a second position spaced apart in a direction to a height above the height of the passage, and the larger of two angles formed with the predetermined plane and the second position and a third wall that is within a predetermined angle and a predetermined position that can reduce the effect of the blow-by gas flow , wherein the region for reducing the effect is a region near the location of the passage .

ADVANTAGE OF THE INVENTION According to this invention, the precision which detects the pressure of blow-by gas can be improved.

FIG. 1 is a diagram for explaining an example of a blow-by gas recirculation device. FIG. 2(a) is a diagram schematically showing a cross section of an air-side separator and a pre-chamber according to the first embodiment. FIG. 2B is a diagram for explaining the flow of blow-by gas according to the first embodiment. FIG. 3A is a diagram schematically showing cross sections of an atmosphere-side separator and a pre-chamber according to the second embodiment. FIG. 3B is a diagram for explaining the flow of blow-by gas according to the second embodiment. FIG. 4 is a diagram schematically showing cross sections of an atmosphere-side separator and a pre-chamber according to the third embodiment. FIG. 5 is a diagram for explaining another example of the blow-by gas recirculation device. FIG. 6 is a diagram schematically showing the cross section of the ejector and the pre-chamber.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the present invention, an oil separator is used as an example of the outflow member, but the outflow member is not limited to the oil separator, and may be an ejector of an internal combustion engine, for example.

(First embodiment)
FIG. 1 is a diagram for explaining an example of a blow-by gas recirculation device 100. As shown in FIG. A blow-by gas recirculation device 100 is provided in the internal combustion engine EG. FIG. 1 shows a series engine in which a plurality of cylinders 16 are arranged in series as an example of the internal combustion engine EG. The internal combustion engine EG is a V-type engine in which a plurality of cylinders 16 are arranged in a V shape. There may be. In this case, the blow-by gas recirculation device 100 is provided in one or both of the left and right banks of the V-type engine.

First, the internal combustion engine EG will be explained. As shown in FIG. 1, the internal combustion engine EG includes a cylinder block 11, a cylinder head 11a, a head cover 13, and an oil pan . A piston 15 is reciprocally provided in the cylinder 16 of the cylinder block 11 . A combustion chamber 17 is formed by a space surrounded by the inner wall surface of the cylinder 16, the crown surface of the piston 15, and the cylinder head 11a. Although not shown, the cylinder head 11a is rotatably provided with an intake camshaft that drives the intake valves to open and close, and an exhaust camshaft that drives the exhaust valves to open and close. A fuel injection valve is also provided in the cylinder head 11a.

A crankcase 19 that rotatably supports a crankshaft 18 is provided below the cylinder block 11 . Below the crankcase 19, the oil pan 14 for storing lubricating oil is assembled. An intake manifold 29 having a surge tank 60 is connected to the cylinder head 11a. The intake pipe 12, the surge tank 60, and the intake manifold 29 form an intake passage of the internal combustion engine EG.

The intake pipe 12 is provided with an air cleaner 21, a compressor TBc of a supercharger TB driven by exhaust gas emitted from the combustion chamber 17, an intercooler 27, and an electric throttle valve 28 in this order from the upstream side. It is The air cleaner 21 filters the intake air taken into the intake pipe 12 , and the supercharger 24 pumps (supercharges) the air taken into the intake pipe 12 . The intercooler 27 cools the air after passing through the compressor TBc, and the opening of the throttle valve 28 is adjusted to adjust the amount of intake air.

The internal combustion engine EG is provided with a suction passage 32 for guiding combustion gas leaking into the crankcase 19 from the combustion chamber 17 , so-called blow-by gas, to the main separator 31 . The main separator 31 is provided separately from the cylinder block 11 on the outer wall of the cylinder block 11 as an oil separator. The suction path 32 extends through the interior of the cylinder block 11 and is connected to the main separator 31 .

The main separator 31 is connected to an intake manifold 29 via a discharge passage 33 , a PCV (Positive Crankcase Ventilation) valve 34 which is a differential pressure valve, and a PCV passage 35 . The discharge passage 33 extends through the interior of the cylinder block 11 and the cylinder head 11a and is connected to the PCV valve 34 . The PCV valve 34 opens when the pressure in the intake manifold 29 becomes lower than the pressure in the main separator 31 to allow blow-by gas to flow from the main separator 31 to the intake manifold 29 .

When the internal combustion engine EG is operated in a non-supercharged state (naturally aspirated state), the pressure in the intake manifold 29 is lower than the pressure in the main separator 31, so that the blow-by gas in the crankcase 19 flows into the suction path. 32 , main separator 31 , discharge passage 33 , PCV valve 34 , and PCV passage 35 , into intake manifold 29 . The sucked blow-by gas is sent to the combustion chamber 17 together with the intake air and burned. That is, the main separator 31 takes in the blow-by gas through the suction passage 32 and separates the oil component from the taken-in blow-by gas. The main separator 31 discharges the blow-by gas from which the oil component has been separated to the intake manifold 29 via the discharge passage 33 , the PCV valve 34 and the PCV passage 35 .

Furthermore, the internal combustion engine EG has a PCV hose 20 and a communication passage 37 for introducing air into the crankcase 19 . A blow-by gas recirculation device 100 is provided between the PCV hose 20 and the communication passage 37 . A blow-by gas recirculation device 100 is installed on the head cover 13 . The blow-by gas recirculation device 100 includes an atmosphere-side separator 110 as an oil separator and a sub-chamber 120 as a recirculation member. One end of the PCV hose 20 is connected to a portion of the intake pipe 12 between the air cleaner 21 and the compressor TBc, and the other end of the PCV hose 20 is connected to the pre-chamber 120 . The communication passage 37 extends from the head cover 13 through the cylinder head 11 a and the cylinder block 11 to the crankcase 19 .

A negative pressure is generated in the internal space of the auxiliary chamber 120 when the internal combustion engine EG is operated in a supercharged state. By utilizing the negative pressure generated in the internal space of the pre-chamber 120 , the blow-by gas inside the crankcase 19 is sucked into the pre-chamber 120 via the communication passage 37 and the atmosphere side separator 110 . The blow-by gas sucked into the pre-chamber 120 is introduced together with air into the intake pipe 12 on the upstream side of the compressor TBc via the PCV hose 20 . That is, the atmosphere-side separator 110 takes in the blow-by gas introduced into the head cover 13 and separates the oil component from the taken-in blow-by gas. The air-side separator 110 allows the blow-by gas from which the oil component has been separated to flow out to the intake pipe 12 via the auxiliary chamber 120 . The blow-by gas introduced into the intake pipe 12 is sent to the combustion chamber 17 together with the intake air and burned.

The auxiliary chamber 120 recirculates the blow-by gas that has flowed out of the atmosphere side separator 110 to the intake pipe 12 . The sub-chamber 120 is installed above the atmosphere-side separator 110, as shown in FIG. One end of the pressure sensor hose 10 is connected to the auxiliary chamber 120 . The other end of pressure sensor hose 10 is connected to pressure sensor 30 . The pressure sensor 30 detects the pressure of blow-by gas (specifically, static pressure). That is, the pressure sensor 30 takes in the blow-by gas that has flowed into the sub-chamber 120 through the pressure sensor hose 10, and detects the pressure inside the sub-chamber 120 using the taken-in blow-by gas.

If the PCV hose 20 is not damaged or disconnected while the internal combustion engine EG is being supercharged, the pressure sensor 30 detects a significant negative pressure. However, if the PCV hose 20 is damaged while the internal combustion engine EG is being supercharged, the interior of the pre-chamber 120 will fluctuate from negative pressure to atmospheric pressure, and if the PCV hose 20 is disconnected, atmospheric pressure will increase. get close. Therefore, when the pressure sensor 30 detects, for example, the atmospheric pressure, it can be diagnosed that the PCV hose 20 has come off.

FIG. 2A is a diagram schematically showing cross sections of the atmosphere-side separator 110 and the pre-chamber 120 according to the first embodiment. The atmosphere-side separator 110 includes a constricted portion 111 as an outlet for blow-by gas.

The auxiliary chamber 120 includes a first union 121 which is a passage connecting with the pressure sensor hose 10 and a second union 122 which is a passage connecting with the PCV hose 20 . Therefore, the pressure sensor hose 10 is connected to the first union 121 to communicate with the sub chamber 120 , and the PCV hose 20 is connected to the second union 122 to communicate to the sub chamber 120 .

Here, in the first embodiment, the sub-chamber 120 includes a plurality of outer walls that separate the inside of the sub-chamber 120 from the outside of the sub-chamber 120 . The sub-chamber 120 constitutes an internal space of the sub-chamber 120 with a plurality of outer walls. Specifically, as shown in FIG. 2A, the auxiliary chamber 120 has a plurality of outer walls, a side wall 123 corresponding to a first wall, a ceiling wall 124 corresponding to a second wall, and a third wall. angled wall 125 or the like. Since the pre-chamber 120 according to the first embodiment is bowl-shaped, it does not have a bottom wall, and a predetermined surface, which will be described later, also serves as the bottom wall of the pre-chamber 120 .

The side wall 123 is an outer wall standing upright on a predetermined plane including the drawn portion 111 at a position away from the vicinity of the drawn portion 111 . The predetermined surface is specifically the top surface of the atmosphere-side separator 110 . The side wall 123 may stand perpendicular to a predetermined plane, or may stand at an angle of several degrees. Side wall 123 also has a first union 121 connected to pressure sensor 30 . In particular, the first union 121 is provided at any position from the base of the side wall 123 to the tip facing the base.

The ceiling wall 124 is an outer wall that intersects with the arrow X indicating the outflow direction of the blow-by gas from the throttle portion 111 . The ceiling wall 124 is provided at a height higher than the height of the side walls 123 . In addition, in the first embodiment, the ceiling wall 124 is provided at a height higher than the height of the side wall 123 . Also, the ceiling wall 124 is provided at an angle. More specifically, the tip of the ceiling wall 124 on the side of the first union 121 is located at a position lower than the tip of the top wall 124 on the side of the constricted portion 111 . In this way, the top wall 124 is not parallel to the predetermined plane, but may be provided so as to be parallel to the predetermined plane without tilting the top wall 124 .

The slant wall 125 extends from a second position on the ceiling wall 124 which is separated in the direction of the side wall 123 from a first position where the constricted portion 111 is projected onto the ceiling wall 124 to a height higher than the height of the first union 121 . It is an outer wall that extends slanted to the side. In the first embodiment, the second position corresponds to the position of one tip of the ceiling wall 124 . The specific position of the second position is not particularly limited as long as it is within the range of positions that can reduce the influence of the blow-by gas flow. Of the two angles formed by the inclined wall 125 and the predetermined plane, the larger angle θ is within the range of angles that can reduce the influence of the blow-by gas flow. For example, if the angle θ is greater than 90° and less than 120°, the effect of blow-by gas flow can be reduced. The angle θ is preferably larger than 95° and smaller than 115°, and more preferably larger than 100° and smaller than 110°.

As shown in FIG. 2A, in the first embodiment, of the two tip portions of the inclined wall 125, the tip portion that is not joined to the tip portion of the top wall 124 does not contact the side wall 123. separated by For this reason, a flat wall 126 is provided as a fourth wall between this tip and the tip facing the base of the side wall 123, thereby connecting the two tips. In this case, the length of the flat wall 126 can be determined to be, for example, about one-seventh to one-fifth of the distance from the narrowed portion 111 to the side wall 123 .

Here, since the pre-chamber 120 is connected to the intake pipe 12 via the PCV hose 20, if the PCV hose 20 is partially damaged, the internal pressure of the pre-chamber 120 shifts to the atmospheric pressure side. In particular, when the PCV hose 20 is removed from the auxiliary chamber 120, the internal pressure of the auxiliary chamber 120 approaches atmospheric pressure. As described above, since the pressure sensor 30 detects the pressure inside the pre-chamber 120, when the pressure inside the pre-chamber 120 shifts toward the atmospheric pressure or detects a pressure approaching the atmospheric pressure, PCV Abnormality of the PCV hose 20 such as disconnection or breakage of the hose 20 can be detected.

FIG. 2B is a diagram for explaining the flow of blow-by gas according to the first embodiment. In particular, in FIG. 2B, the size of the white arrow indicates the flow speed of the blow-by gas. Thus, the blow-by gas swirls inside the pre-chamber 120 and flows to the PCV hose 20 through the second union 122 (see FIG. 2). Specifically, first, the blow-by gas immediately after flowing into the pre-chamber 120 from the narrowed portion 111 flows while maintaining the outflow direction from the narrowed portion 111 , and the flow direction is changed to the side wall 123 side by the ceiling wall 124 . Since the blow-by gas vigorously flows into the pre-chamber 120 from the throttle portion 111, the blow-by gas flows rapidly inside the pre-chamber 120 for a while.

As the blow-by gas flows along the top wall 124 , the flow speed of the blow-by gas gradually slows down, and the slanted wall 125 further changes the flow direction of the blow-by gas. The blow-by gas whose flow direction is changed by the slanted wall 125 weakens and flows in the direction of the atmosphere-side separator 110 . Then, when the blow-by gas reaches the vicinity of the atmosphere-side separator 110 , the blow-by gas flows along the top surface of the atmosphere-side separator 110 . The blow-by gas then flows into the PCV hose 20 via the second union 122 .

Here, part of the blow-by gas crawls along the top surface of the atmosphere-side separator 110 and also flows in the direction of the side wall 123 , but since the force of the flow of the blow-by gas is weak, the blow-by gas flows slightly along the side wall 123 . Although it rises, it cannot maintain sufficient momentum to the position of the first union 121 . That is, the blow-by gas flow weakens in the region near the position of the first union 121 . Therefore, this region is not strongly affected by the blow-by gas flow, and as a result, the pressure sensor 30 can accurately detect the pressure of the blow-by gas flowing inside the auxiliary chamber 120 .

In addition, since the angle of the slanted wall 125 is limited within a specific angle range, the blow-by gas flow along the slanted wall 125 is separated by the slanted wall 125 and does not reach the area near the position of the first union 121. . As a result, the pressure sensor 30 can accurately detect the pressure of the blow-by gas flowing inside the auxiliary chamber 120 without being strongly affected by the blow-by gas flow in that region.

As described above, according to the first embodiment, the blow-by gas recirculation device 100 for the internal combustion engine EG includes the atmosphere side separator 110 including the throttle portion 111 through which the blow-by gas after the oil component is separated flows out, and the blow-by gas flowing in from the throttle portion 111 . a pre-chamber 120 for recirculating gas to the intake pipe 12 . In particular, the subchamber 120 includes a side wall 123 having a first union 121 that rises above a predetermined plane containing the constriction 111 and away from the constriction 111 and that is connected to the pressure sensor 30 . The auxiliary chamber 120 also includes a ceiling wall 124 that intersects with the outflow direction of the blow-by gas from the throttle portion 111 and is provided at a height equal to or higher than the height of the side wall 123 . Further, the auxiliary chamber 120 extends from a second position on the top wall 124 away from the first position in the direction of the side wall 123 to a height above the height of the first union 121 with respect to the first position where the throttle portion 111 is projected onto the top wall 124 . 1 sloping wall extending obliquely to the union 121 side, wherein the larger of the two angles formed with the predetermined surface and the second position are within the range of the predetermined angle and the predetermined position that can reduce the influence of the blow-by gas flow. 125 included. Thereby, the accuracy of detecting the pressure of the blow-by gas can be improved.

(Second embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. 3(a) and 3(b). FIG. 3A is a diagram schematically showing cross sections of the atmosphere-side separator 110 and the sub-chamber 120 according to the second embodiment. FIG. 3B is a diagram for explaining the flow of blow-by gas according to the second embodiment. The same reference numerals are assigned to the same components as those of the atmosphere-side separator 110 and the auxiliary chamber 120 according to the first embodiment, and the description thereof will be omitted. The same applies to a third embodiment, which will be described later.

First, as shown in FIG. 3A, the auxiliary chamber 120 according to the second embodiment is different in that it has a slanted wall 127 instead of the slanted wall 125 described in the first embodiment. The slant wall 127 extends from a second position on the top wall 124 away in the direction of the side wall 123 with respect to a first position where the constricted portion 111 is projected onto the top wall 124 to a height above the height of the first union 121 . It is an inner wall that extends obliquely to the 121 side. That is, the slanted wall 127 is an inner wall protruding into the auxiliary chamber 120 . The second position in the second embodiment corresponds to a position other than the tip of the top wall 124, unlike the second position in the first embodiment. That is, since one tip of the top wall 124 is joined to the tip facing the base of the side wall 123, the inclined wall 127 is provided between one tip and the other tip of the top wall 124. ing.

Of the two angles formed by the inclined wall 127 and the predetermined plane described in the first embodiment, the larger angle θ is an angle that can reduce the influence of the blow-by gas flow, as in the first embodiment. For example, an angle greater than 90° and less than 120° can be employed. Also, since one tip of the top wall 124 and the tip facing the base of the side wall 123 are joined, the one tip of the top wall 124 and the tip facing the base of the side wall 123 have the same height. become.

In FIG. 3(b), similarly to FIG. 2(b), the size of the white arrow indicates the flow speed of the blow-by gas. Thus, the blow-by gas swirls inside the pre-chamber 120 and flows to the PCV hose 20 through the second union 122 (see FIG. 2(a)). Specifically, first, the blow-by gas immediately after flowing into the pre-chamber 120 from the narrowed portion 111 flows while maintaining the outflow direction from the narrowed portion 111 , and the flow direction is changed to the side wall 123 side by the ceiling wall 124 . Since the blow-by gas vigorously flows into the pre-chamber 120 from the throttle portion 111, the blow-by gas flows rapidly inside the pre-chamber 120 for a while.

As the blow-by gas flows along the ceiling wall 124 , the flow speed of the blow-by gas gradually slows down, and the slanted wall 127 further changes the flow direction of the blow-by gas. The blow-by gas whose flow direction is changed by the slanted wall 127 weakens and flows in the direction of the atmosphere-side separator 110 . Then, when the blow-by gas reaches the vicinity of the atmosphere-side separator 110 , the blow-by gas flows along the top surface of the atmosphere-side separator 110 . The blow-by gas then flows into the PCV hose 20 via the second union 122 .

As in the first embodiment, part of the blow-by gas crawls along the top surface of the atmosphere-side separator 110 and also flows in the direction of the side wall 123 . , but cannot maintain sufficient momentum until the position of the first union 121 . That is, the blow-by gas flow weakens in the region near the position of the first union 121 . Therefore, this region is not strongly affected by the blow-by gas flow, and as a result, the pressure sensor 30 can accurately detect the pressure of the blow-by gas flowing inside the auxiliary chamber 120 .

In addition, since the angle of the slanted wall 127 is limited within a specific angle range, the blow-by gas flow along the slanted wall 127 is separated by the slanted wall 127 and does not reach the area near the position of the first union 121. . As a result, the pressure sensor 30 can accurately detect the pressure of the blow-by gas flowing inside the auxiliary chamber 120 without being strongly affected by the blow-by gas flow in that region. Thus, even in the second embodiment, it is possible to improve the accuracy of detecting the pressure of the blow-by gas.

(Third Embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a diagram schematically showing cross sections of the atmosphere-side separator 110 and the auxiliary chamber 120 according to the third embodiment. As shown in FIG. 4, the auxiliary chamber 120 according to the third embodiment is different from the first and second embodiments in that it further has a bottom wall 128 . Bottom wall 128 is a horizontal outer wall that continues from the bottom surface of side wall 123 . Therefore, the bottom wall 128 faces the top wall 124 instead of being parallel.

A portion of the bottom wall 128 is formed with an inlet 128a through which blow-by gas flows. The inflow port 128a is provided in the vicinity of the outer wall facing the side wall 123, and the tip of the throttle portion 111 is connected to the inflow port 128a. The tip of the narrowed portion 111 may be parallel to the top surface of the atmosphere-side separator 110 without connecting the tip of the narrowed portion 111 to the inlet 128a. In this case, the blow-by gas flowing out of the throttle portion 111 flows into the auxiliary chamber 120 through the inlet 128a. As a result, the blow-by gas swirls inside the auxiliary chamber 120 and flows to the PCV hose 20 through the second union 122 (see FIG. 2(a)). Even in such an embodiment, it is possible to improve the accuracy of detecting the pressure of the blow-by gas.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIGS. 5 and 6. FIG. FIG. 5 is a diagram for explaining another example of the blow-by gas recirculation device 100. As shown in FIG. FIG. 6 is a diagram schematically showing a cross section of the ejector 40 and the auxiliary chamber 120a. 5 and 6, the same reference numerals are assigned to the same configurations as those according to the above-described embodiments, and detailed description thereof will be omitted. As shown in FIG. 5, the discharge passage 33 according to the fourth embodiment is bifurcated inside the cylinder head 11a, and one of the bifurcated discharge passages 33 is connected to the ejector 40 via the head cover 13. be done. Therefore, the main separator 31 is connected to the ejector 40 via one of the bifurcated discharge passages 33 . The other end of the bifurcated discharge passage 33 is connected to the PCV valve 34 .

The ejector 40 is provided in the middle of a bypass passage 42 connected to the intake pipe 12 on the downstream side of the compressor TBc. That is, the ejector 40 is provided in the middle of the bypass passage 42 one end of which is connected to the intake pipe 12 . The ejector 40 is of a single-stage type, and is provided therein with a flow rate control valve (not shown) that closes when the flow rate of the air flowing through the bypass passage 42 exceeds a predetermined amount.

The other end of the bypass passage 42 is connected to the auxiliary chamber 120a. Therefore, the ejector 40 and the auxiliary chamber 120a are connected by the bypass passage 42. As shown in FIG. The auxiliary chamber 120a is also connected to the PCV hose 20a connected to the intake pipe 12 on the upstream side of the compressor TBc. One end of the pressure sensor hose 10a is connected to the auxiliary chamber 120a. The other end of the pressure sensor hose 10a is connected to the pressure sensor 30a. Like the pressure sensor 30, the pressure sensor 30a also detects the pressure of the blow-by gas. That is, the pressure sensor 30a takes in the blow-by gas that has flowed into the auxiliary chamber 120a through the pressure sensor hose 10a, and uses the taken-in blow-by gas to detect the pressure inside the auxiliary chamber 120a.

When the internal combustion engine EG is operated in a supercharged state, negative pressure is generated in the internal space of the ejector 40 by air flowing through the bypass passage 42 from the downstream side to the upstream side of the compressor TBc. By utilizing the negative pressure generated in the internal space of the ejector 40, the blow-by gas in the crankcase 19 is sucked into the ejector 40 through the suction passage 32, the main separator 31, and the discharge passage 33. .

The blow-by gas sucked into the ejector 40 is introduced from the outflow port of the ejector 40 into the intake pipe 12 on the upstream side of the compressor TBc through the bypass passage 42 together with air. That is, the main separator 31 takes in the blow-by gas through the suction passage 32 and separates the oil component from the taken-in blow-by gas. The main separator 31 allows the blow-by gas from which the oil component has been separated to flow out to the intake pipe 12 via the ejector 40 . The blow-by gas introduced into the intake pipe 12 is sent to the combustion chamber 17 together with the intake air and burned.

As described above, in the first embodiment, the blow-by gas recirculation device 100 including the atmosphere-side separator 110 and the sub-chamber 120 has been described. A passageway 42 may be employed.

As shown in FIG. 6, the outflow port 42b of the bypass passage 42 is connected to a blow-by gas inflow port 128b formed in a portion of the bottom wall 128. As shown in FIG. In FIG. 6, the inflow port 128b is provided near the substantially central portion of the bottom wall 128, but the inflow port 128b may be provided near the outer wall facing the side wall 123. FIG. On the other hand, the inflow port 42 a of the bypass passage 42 is connected to the ejector 40 .

When the internal combustion engine EG is operated in a supercharged state, as shown in FIG. As shown in FIG. 6, the blow-by gas that has flowed into the ejector 40 flows through the bypass passage 42 into the auxiliary chamber 120a. As a result, the blow-by gas swirls inside the auxiliary chamber 120a and flows through the second union 122 (see FIG. 2(a)) to the PCV hose 20a. Even in such an embodiment, it is possible to improve the accuracy of detecting the pressure of the blow-by gas.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations can be made within the scope of the gist of the present invention described in the scope of claims. Change is possible.

EG internal combustion engine 10, 10a pressure sensor hose 11 cylinder block 11a cylinder head 12 intake pipe 13 head cover 20, 20a PCV hose 30, 30a pressure sensor 31 main separator 40 ejector (outflow member)
42 bypass passage (outflow member)
100 blow-by gas recirculation device 110 atmosphere side separator (outflow member)
111 throttling part (outflow port)
120, 120a auxiliary chamber (reflux member)
121 1st union (passage)
122 second union 123 side wall (first wall)
124 ceiling wall (second wall)
125, 127 Slanted wall (third wall)
126 flat wall 128 bottom wall

Claims (1)

an outflow member including an outflow port for outflowing the blow-by gas after separating the oil component;
a recirculation member for recirculating the blow-by gas flowing from the outflow port to the intake pipe;
The reflux member is
a first wall standing on a predetermined plane containing the outlet and spaced from the outlet and having a passageway connected to a pressure sensor;
a second wall intersecting the outflow direction of the blow-by gas from the outflow port and provided at a height equal to or higher than the height of the first wall;
From a second position of the second wall separated in the direction of the first wall based on a first position where the outlet is projected onto the second wall, the second wall is tilted toward the passage to a height higher than the height of the passage. a third wall extending and having the larger of two angles with the predetermined surface and the second position within the range of the predetermined angle and the predetermined position that can reduce the effect of the flow of the blow-by gas. ,
The area to reduce the impact is an area near the position of the passage,
A blow-by gas recirculation device for an internal combustion engine , characterized by:

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