JP2017002737A - Blow-by gas recycling structure and internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of keeping an inside part of a crank case in a negative pressure state in a wide operation range of an internal combustion engine while keeping a simple configuration and restricting an increased number of components.SOLUTION: A blow-by bas recycling structure is configured in such a way that blow-by gas in a crank chamber CR is recycled to a collector part 6a of an intake manifold 6 or a clean side air duct 16 through a gas-liquid separation chamber 42 arranged in a rocker cover 4. A pipe 82 for connecting a first chamber 42a of the gas-liquid separation chamber 42 with the clean side air duct 16 is fixed to the rocker cover 4 through a metering member 72. The metering member 72 protrudes toward a flow of air [new gas] flowing in the pipe 82 from the clean side air duct 16 toward the first chamber 42a and has a tapered pipe part 76 with its passage sectional area being gradually increased toward a flowing direction of the air [new gas]. With this arrangement as above, a pressure loss [head loss] is made large as compared with the case in which the air flows from the first chamber 42a toward the clean side air duct 16.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a blow-by gas recirculation structure that recirculates blow-by gas generated inside an internal combustion engine body to an intake passage and an internal combustion engine.

  In Japanese Patent No. 3222246 (Patent Document 1), a portion upstream of the position where the throttle valve is disposed in the intake passage of the internal combustion engine communicates with the inside of the head cover through a fresh air introduction passage. A portion of the intake passage downstream from the position where the throttle valve is disposed and the inside of the head cover are connected via a PCV valve through a blow-by gas recirculation passage. When the load is relatively low, this occurs in the downstream portion of the intake passage. The blow-by gas generated in the crankcase due to the negative pressure is recirculated from the blow-by gas recirculation passage to the intake passage, and when the load is relatively high, the blow-by gas is recirculated from the fresh air introduction passage to the intake passage. A structured blowby gas reflux structure is described.

  In the blowby gas recirculation structure, a portion of the intake passage downstream of the connection portion between the fresh air introduction passage and the intake passage and immediately upstream of the throttle valve in an idle state, and a fresh air introduction passage are provided. By providing a bypass passage to be connected, it is possible to achieve both improvement in blow-by gas recirculation performance at high loads and suppression of increase in idle rotation when the internal combustion engine is in an idle state, and negative pressure is generated in the crankcase in a wide operating range of the internal combustion engine. Can be kept in a state.

Japanese Patent No. 3222246

  However, in the above-described blowby gas recirculation structure, not only the structure is complicated, but also a passage member for configuring the bypass passage is separately required. Therefore, the improvement in terms of simplification of the structure and reduction in the number of parts is still required. There is room.

  The present invention has been made in view of the above, and provides a technique capable of maintaining the inside of a crankcase in a negative pressure state in a wide operation region of an internal combustion engine while suppressing an increase in the number of components with a simple configuration. For the purpose.

  The blow-by gas recirculation structure of the present invention employs the following means in order to achieve the above object.

  According to the preferred embodiment of the blow-by gas recirculation structure according to the present invention, the blow-by gas recirculation structure that recirculates the blow-by gas generated inside the internal combustion engine body to the downstream intake passage disposed downstream of the throttle valve device is configured. Is done. The blowby gas recirculation structure includes a blowby gas recirculation passage, an air introduction passage, and a resistance imparting member. The blow-by gas recirculation passage is configured to recirculate an amount of blow-by gas corresponding to the magnitude of the negative pressure generated in the downstream intake passage from the inside of the internal combustion engine body to the downstream intake passage. When the negative pressure generated in the downstream intake passage is greater than or equal to the first magnitude, a part of the air flowing through the upstream intake passage disposed upstream of the throttle valve device is passed through the air introduction passage. When the negative pressure generated in the downstream intake passage is smaller than the first magnitude, part of the blow-by gas generated inside the internal combustion engine body is recirculated to the upstream intake passage. . The resistance imparting member is disposed in the air introduction passage, and the flow of air flowing from the upstream intake passage toward the inside of the internal combustion engine body rather than the flow resistance of the blowby gas from the inside of the internal combustion engine body toward the upstream intake passage. The resistor is configured to be larger.

  According to the present invention, when the negative pressure generated in the downstream intake passage is greater than or equal to the first magnitude, part of the air flowing through the upstream intake passage is introduced into the internal combustion engine body through the air introduction passage. At the same time, when the blow-by gas generated inside the internal combustion engine body is returned to the downstream intake passage through the blow-by gas return passage, and the negative pressure generated in the downstream intake passage is smaller than the first magnitude, Since the blow-by gas generated inside is recirculated from both the blow-by gas recirculation passage and the air introduction passage to the upstream intake passage, the inside of the crankcase can be maintained in a negative pressure state in a wide operation region of the internal combustion engine. Note that the flow resistance of the air flowing from the upstream intake passage toward the inside of the internal combustion engine body is larger than the flow resistance of the blow-by gas flowing from the inside of the internal combustion engine body toward the upstream intake passage. Therefore, when the negative pressure generated in the downstream side intake passage is greater than or equal to the first magnitude, the amount of air introduced into the internal combustion engine body through the air introduction passage can be suppressed, and the internal combustion engine is in an idle state. It is possible to suppress an increase in idle rotation at. Moreover, since it is a structure which only arrange | positions a resistance provision member in an air introduction channel | path, it can implement | achieve with a simple structure and can also suppress the increase in a number of parts.

  According to the further form of the blowby gas recirculation structure according to the present invention, the resistance applying member has a tapered shape configured such that the cross-sectional area of the resistance is gradually reduced from the internal side of the internal combustion engine body toward the upstream side intake passage side. It has a diaphragm.

  According to the present embodiment, since only the tapered throttle portion is provided, the flow resistance of the blowby gas from the inside of the internal combustion engine body toward the upstream intake passage is directed toward the inside of the internal combustion engine body from the upstream intake passage. A configuration for increasing the flow resistance of the flowing air can be easily ensured.

  According to the further form of the blowby gas recirculation | reflux structure which concerns on this invention, the resistance provision member has a holding | maintenance part which can hold | maintain the condensed water produced with the condensation of the water | moisture content contained in blowby gas. And the resistance provision member is comprised so that at least one part of a holding | maintenance part may be attached in the state which contacted the internal combustion engine main body.

  According to this form, since it is not necessary to provide a separate holding member in order to hold | maintain condensed water, it can prevent favorably that a number of parts increases. And since the heat | fever of an internal combustion engine main body can be effectively conducted to a holding | maintenance part, it can suppress that the held condensed water freezes.

  According to the further form of the blowby gas recirculation structure according to the present invention, the resistance applying member is configured such that, in a state where the internal combustion engine body is mounted on the vehicle, the flow direction of the blowby gas and air flowing through the resistance applying member is the vertical direction. It is attached to the internal combustion engine body. And the holding | maintenance part is provided in the downward part of the perpendicular direction of the resistance provision member.

  According to this embodiment, when the moisture contained in the blow-by gas is condensed and condensed water is generated, the condensed water falls vertically downward due to its own weight, so that the condensed water is well collected in the holding unit. Can be held.

  According to the further form of the blowby gas recirculation structure according to the present invention, the internal combustion engine body includes a cylinder head having an intake port, a rocker cover having a gas-liquid separation chamber and mounted above the cylinder head, It has a cylinder block attached below and an oil pan member attached below the cylinder block. The intake passage includes a throttle valve device configured to be capable of adjusting an air amount, an air piping member for supplying air to the throttle valve device, and an intake air for supplying air from the throttle valve device to an intake port. And a manifold. The gas-liquid separation chamber has first and second chambers. A crank chamber is constituted by the cylinder block and the oil pan member. The blow-by gas recirculation passage is configured to communicate the crank chamber and the intake manifold via the first chamber, and the air introduction passage communicates the crank chamber and the air piping via the second chamber. It is configured as follows.

  According to this embodiment, the blow-by gas after the oil component contained in the blow-by gas is removed in the gas-liquid separation chamber can be returned to the intake passage. Thereby, reduction of oil consumption can be aimed at.

  According to the further form of the blowby gas recirculation | reflux structure which concerns on this invention, the connection piping member which connects a 2nd chamber and air piping is further provided. And the resistance provision member is comprised as an attachment member for attaching a connection piping member to a rocker cover.

  According to this embodiment, since the resistance applying member also functions as an attachment member for the connection piping member, an increase in the number of parts can be satisfactorily suppressed as compared with a configuration in which the resistance giving member is a separate part.

  According to a preferred embodiment of the internal combustion engine of the present invention, an internal combustion engine that outputs power by converting the linear motion of a piston that reciprocates in a cylinder bore into the rotational motion of a crankshaft is configured. The internal combustion engine is configured so that the blowby gas leaked into the crank chamber from the gap between the cylinder bore and the piston is recirculated to the intake passage by the blowby gas recirculation structure according to the present invention of any of the above-described aspects.

  According to the present invention, since the blowby gas is recirculated to the intake passage using the blowby gas recirculation structure according to the present invention in any of the above-described aspects, the same effect as the blowby gas recirculation structure of the present invention is exhibited. An effect, for example, an effect that the inside of the crankcase can be maintained in a negative pressure state in a wide operating region of the internal combustion engine while suppressing an increase in the number of parts with a simple configuration can be achieved.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which can hold | maintain the inside of a crankcase to a negative pressure state in the wide driving | running area | region of an internal combustion engine can be provided, suppressing an increase in a number of parts with a simple structure.

1 is a configuration diagram showing an outline of a configuration of an internal combustion engine 1 according to an embodiment of the present invention. It is explanatory drawing which shows the outline of a blowby gas recirculation | reflux structure. It is explanatory drawing which shows a blow-by gas recirculation | reflux structure typically. FIG. 6 is an exploded perspective view showing a state when pipes 82 and 84 are connected to the rocker cover 4. 4 is a perspective view showing an appearance of a diaphragm member 72. FIG. 4 is a cross-sectional view showing a cross section of the throttle member 72 cut along a plane including the central axis of the throttle member 72. FIG. It is explanatory drawing which shows a mode that the piping 82 was attached to the rocker cover 4 via the throttle member 72. FIG. It is sectional drawing which shows the outline of a structure of the aperture member 172 of a modification. It is sectional drawing which shows the outline of a structure of the aperture member 272 of a modification.

  Next, the best mode for carrying out the present invention will be described using examples.

  As shown in FIG. 1, the internal combustion engine 1 according to the present embodiment includes a cylinder head 2, a rocker cover 4 attached to the upper part of the cylinder head 2, and an intake manifold 6 attached to the side wall of the cylinder head 2. The exhaust manifold 7 (see FIG. 2) attached to the side wall of the cylinder head 2, the cylinder block 8 attached to the lower part of the cylinder head 2, the upper oil pan 10 attached to the lower part of the cylinder block 8, and the upper A lower oil pan 12 attached to the lower part of the oil pan 10, a throttle valve device 14 attached to the intake manifold 6, and a clean side air duct 16 connected to the throttle valve device 14 are provided.

  The cylinder head 2, the rocker cover 4, the cylinder block 8, the upper oil pan 10, and the lower oil pan 12 correspond to the “internal combustion engine body” in the present invention, and the upper oil pan 10 and the lower oil pan 12 in the present invention “ It is an example of the implementation structure corresponding to an "oil pan member." Moreover, the clean side air duct 16 is an example of the implementation structure corresponding to the "air piping member" in this invention.

  As shown in FIG. 2, the cylinder head 2 includes a combustion chamber constituting recess 22, an intake port 24 and an exhaust port 26 communicating with the combustion chamber constituting recess 22, and the cylinder head 2 in the vertical direction (the vertical direction in FIG. 2). Through holes 28a, 28b are formed. The through hole 28a is provided near the side wall on the intake port 24 side, and the through hole 28b is provided on the side wall on the exhaust port 26 side.

  Note that the valve mechanism chamber VMC is configured by fastening the rocker cover 4 to the cylinder head 2. The valve mechanism mechanism VMC accommodates a valve mechanism including a camshaft (not shown) that drives the intake valve 92 and the exhaust valve 94 to open and close.

  As shown in FIG. 2, the rocker cover 4 is provided with a gas-liquid separation chamber 42. The gas-liquid separation chamber 42 is partitioned into a first chamber 42a and a second chamber 42b by a baffle plate or the like. The first chamber 42a and the second chamber 42b communicate with the valve mechanism chamber VMC through the opening 43a and the opening 43b.

  The opening 43a is preferably provided at a position corresponding to the through hole 28a of the cylinder head 2 when the rocker cover 4 is fastened to the cylinder head 2. The opening 43b is preferably provided at a position corresponding to the through hole 28b of the cylinder head 2 when the rocker cover 4 is fastened to the cylinder head 2.

  As shown in FIGS. 2 and 3, the first chamber 42 a of the gas-liquid separation chamber 42 is connected to the clean side air duct 16 through a pipe 82. As shown in FIGS. 3 and 4, the pipe 82 is connected to the rocker cover 4 via a throttle member 72. The pipe 82 is an example of an implementation configuration corresponding to the “connection pipe member” in the present invention.

  As shown in FIGS. 5 and 6, the throttle member 72 includes a cylindrical tubular portion 74, a tapered tubular portion 76 provided coaxially with the cylindrical tubular portion 74 inside the cylindrical tubular portion 74, and the cylindrical tubular portion 74. And a connecting portion 78 for connecting the tapered tubular portion 76. The throttle member 72 corresponds to the “resistance imparting member” in the present invention, and the tapered tubular portion 76 is an example of an implementation configuration corresponding to the “tapered throttle portion” in the present invention.

  As shown in FIG. 6, the drawing member 72 is bent inward with one longitudinal end portion (lower side in FIG. 6) of the long pipe member facing the other longitudinal end portion (upper side in FIG. 6). Thus, the cylindrical tubular portion 74, the tapered tubular portion 76, and the connecting portion 78 are integrally formed. On the outer peripheral surface side (inside the cylindrical tubular portion 74) of the tapered tubular portion 76, an annular bag path space 79 is formed by a portion below the longitudinal central portion of the cylindrical tubular portion 74, the tapered tubular portion 76 and the connecting portion 78. The The portion below the central portion in the longitudinal direction of the cylindrical tubular portion 74, the tapered tubular portion 76, and the connecting portion 78 are an example of an implementation configuration corresponding to the “holding portion” in the present invention.

  As shown in FIGS. 5 and 6, the tapered tubular portion 76 has a tapered shape in which both the outer diameter and the inner diameter are reduced as the distance from the connecting portion 78 side increases.

  As shown in FIG. 7, the throttle member 72 thus configured has a rocker cover covering a portion of the cylindrical tubular portion 74 opposite to the connection portion 78 side (a portion above the longitudinal central portion of the cylindrical tubular portion 74). 4, the portion on the connection portion 78 side of the cylindrical tubular portion 74 is attached by press-fitting into the attachment hole 4 a of the rocker cover 4.

  That is, as shown in FIG. 7, the throttle member 72 is press-fitted into the mounting hole 4 a of the rocker cover 4 at a lower portion than the central portion in the longitudinal direction of the cylindrical tubular portion 74. The throttle member 72 is attached to the rocker cover 4 so that the axial direction of the throttle member 72 faces the vertical direction when the internal combustion engine 1 is mounted on the vehicle. The aspect in which the lower part of the cylindrical tubular part 74 is press-fitted to the rocker cover 4 from the longitudinal center part corresponds to the "attached state in which at least a part of the holding part is in contact with the internal combustion engine body" in the present invention. It is an example of the implementation structure to do.

  In addition, a pipe 82 is externally fitted to a portion of the cylindrical tubular portion 74 of the throttle member 72 opposite to the connection portion 78 side (a portion above the central portion in the longitudinal direction of the cylindrical tubular portion 74). Thus, by using the throttle member 72 as a connecting member between the pipe 82 and the rocker cover 4, it is possible to favorably suppress an increase in the number of parts.

  In addition, the second chamber 42 b of the gas-liquid separation chamber 42 is connected to the collector portion 6 a of the intake manifold 6 through a pipe 84 as shown in FIGS. 2 and 3. As shown in FIGS. 3 and 4, the pipe 84 is connected to the rocker cover 4 via the PCV valve 46.

  The PCV valve 46 is configured to open when the pressure in the collector portion 6a of the intake manifold 6 becomes negative, and closes when the pressure in the collector portion 6a becomes positive. It is configured as a flow control valve capable of flowing an amount of blow-by gas corresponding to the magnitude of the negative pressure.

  As shown in FIG. 2, the cylinder block 8 is formed with a cylinder bore 52 and through holes 54 a and 54 b that penetrate the cylinder block 8 in the vertical direction (vertical direction in FIG. 2). The cylinder block 8 is configured to be able to rotatably support the crankshaft 62. A piston P is attached to the crankshaft 62 via a connecting rod 64. A crank chamber CR is formed by fastening the upper oil pan 10 to the cylinder block 8, and the top of the piston P slidably accommodated in the cylinder bore 52, and the combustion chamber constituting recess 22 of the cylinder bore 52 and the cylinder head 2. The combustion chamber CC is configured by the above. The crank chamber CR is an example of an implementation configuration corresponding to “inside of the internal combustion engine body” in the present invention.

  As shown in FIG. 2, the through hole 54 a is provided near the side wall on the side where the intake manifold 6 is disposed. When the cylinder head 2 is fastened to the cylinder block 8, the through hole 54 a is formed in the through hole 28 a of the cylinder head 2. Communicate. The valve mechanism chamber VMC and the crank chamber CR are communicated with each other through the through holes 28a and 54a.

  Further, as shown in FIG. 2, the through hole 54 b is provided near the side wall on the side where the exhaust manifold 7 is arranged, and when the cylinder head 2 is fastened to the cylinder block 8, the through hole of the cylinder head 2 is provided. It communicates with 28b. The valve mechanism chamber VMC and the crank chamber CR communicate with each other through the through holes 28b and 54b.

  Next, a state in which blow-by gas leaking from the gap between the cylinder bore 52 and the piston P accompanying the operation of the internal combustion engine 1 thus configured is returned to the collector portion 6a of the intake manifold 6 and the clean side air duct 16 is shown. 2, description will be made with reference to FIGS.

  When the operation of the internal combustion engine 1 is started, the piston P reciprocates in the cylinder bore 52 in the axial direction of the cylinder bore 52 (vertical direction in FIG. 2). At this time, part of the air-fuel mixture (for example, air-gasoline air-fuel mixture) supplied to the combustion chamber CC (mainly unburned air-fuel mixture) leaks into the crank chamber CR from the gap between the piston P and the cylinder bore 52. As a result, blow-by gas is generated.

  When the internal combustion engine 1 is operated in a relatively low load state, that is, when the opening of the throttle valve (not shown) of the throttle valve device 14 is relatively small, the negative pressure in the collector portion 6a is large. The opening degree of the PCV valve 46 is increased by the action of the negative pressure. As a result, the blow-by gas in the crank chamber CR flows toward the collector portion 6a due to the negative pressure. That is, the blow-by gas in the crank chamber CR flows into the second chamber 42b of the gas-liquid separation chamber 42 from the opening 43b through the through hole 54b and the through hole 28b, and gas-liquid separation is performed in the second chamber 42b. Then, it flows in the pipe 84 from the PCV valve 46 and is returned to the collector 6a.

  The passage constituted by the through hole 54b and the through hole 28b, the opening 43b, the second chamber 42b of the gas-liquid separation chamber 42, the PCV valve 46 and the pipe 84 has an implementation configuration corresponding to the “blow-by gas recirculation passage” in the present invention. It is an example.

  As described above, the blow-by gas in the crank chamber CR flows toward the collector portion 6a, so that the crank chamber CR also has a negative pressure. Thereby, a part of the air (fresh air) flowing through the clean side air duct 16 flows toward the crank chamber CR by the negative pressure. That is, a part of the air (fresh air) flowing in the clean side air duct 16 is introduced from the pipe 82 through the throttle member 72 into the first chamber 42a of the gas-liquid separation chamber 42, and through the opening 43a through the through hole 28a and It is introduced into the crank chamber CR through the through hole 54a. Thus, ventilation in the crank chamber CR is performed.

  The passage constituted by the pipe 82, the throttle member 72, the first chamber 42a of the gas-liquid separation chamber 42, the opening 43a, the through hole 28a, and the through hole 54a is an example of an implementation configuration corresponding to the “air introduction passage” in the present invention. is there.

  Here, as shown in FIG. 7, the throttle member 72 is attached to the rocker cover 4 so that the tapered tubular portion 76 protrudes toward the flow of air (fresh air) flowing from the clean side air duct 16 toward the crank chamber CR. In addition, since the passage cross-sectional area of the tapered tubular portion 76 gradually increases in the flow direction of the air (fresh air), it flows from the first chamber 42a side through the throttle member 72 to the pipe 82 side. Compared with the case, the pressure loss (head loss) becomes larger when flowing from the pipe 82 side to the first chamber 42a side through the throttle member 72.

  Thereby, it can suppress favorably that the flow rate of the air (fresh air) introduced from the clean side air duct 16 to the crank chamber CR side with a simple configuration becomes excessive. As a result, the inside of the crank chamber CR can be favorably maintained in a negative pressure state. Further, when the internal combustion engine 1 is operated in an idling state, the amount of air that substantially bypasses the throttle valve device 14 (the air introduced from the clean side air duct 16 (fresh air) passes through the PCV valve 46 to the collector section). It is possible to satisfactorily suppress an excessive increase in the amount of air to be introduced into 6a, so that an increase in idling rotation can be suppressed.

  On the other hand, when the internal combustion engine 1 is operated in a relatively high load state, that is, when the opening degree of the throttle valve (not shown) of the throttle valve device 14 is relatively large, the negative pressure in the collector portion 6a is small. Therefore, the opening degree of the PCV valve 46 is reduced. As a result, the amount of blow-by gas flowing from the crank chamber CR toward the collector portion 6a is reduced.

  However, since the opening of the throttle valve (not shown) of the throttle valve device 14 is large, the amount of intake air is large, so that the blow-by gas in the crank chamber CR is sucked up by the flow of the intake air and clean. It will also flow to the side air duct 16 side. That is, the blow-by gas in the crank chamber CR flows into the first chamber 42a of the gas-liquid separation chamber 42 from the opening 43a through the through hole 54a and the through hole 28a, and gas-liquid separation is performed in the first chamber 42a. After that, it is returned to the clean side air duct 16 from the pipe 82 through the throttle member 72.

  Here, as described above, the throttle member 72 is attached to the rocker cover 4 so that the tapered tubular portion 76 protrudes toward the flow of air (fresh air) flowing from the clean side air duct 16 toward the crank chamber CR side. In addition, since the passage cross-sectional area of the tapered tubular portion 76 gradually increases in the flow direction of the air (fresh air), it flows from the first chamber 42a side through the throttle member 72 to the pipe 82 side. Compared with the case, since the pressure loss (head loss) is larger when flowing from the piping 82 side to the first chamber 42a side through the restricting member 72, the crank chamber CR is sufficient to the clean side air duct 16 side. An amount of blow-by gas can be refluxed.

  Thereby, since the blow-by gas is suppressed from being filled in the crank chamber CR, it is possible to favorably suppress the positive pressure in the crank chamber CR. In other words, the inside of the crank chamber CR can be favorably maintained in a negative pressure state. As a result, even if the inside of the crank chamber CR communicates with the outside due to damage or deterioration of the cylinder block 8 or the upper oil pan 10 or a seal member that seals the gap between them, it is possible that the blow-by gas leaks to the outside. It is possible to suppress the deterioration of the environmental performance of the internal combustion engine 1.

  In addition, since the pipe 82 is exposed to the atmosphere, and the temperature inside the pipe 82 is lower than that in the first chamber 42 a of the gas-liquid separation chamber 42, the pipe 82 is passed through the throttle member 72. The blow-by gas discharged to the pipe 82 is cooled while flowing in the pipe 82, and the moisture in the blow-by gas is condensed to generate condensed water. In this embodiment, the condensed water is As shown in FIG. 7, the throttle member 72 is held by a bag path space 79.

  Here, when the internal combustion engine 1 is mounted on the vehicle, the throttle member 72 is attached to the rocker cover 4 so that the axial direction of the throttle member 72 faces the vertical direction, so that the condensed water falls in the vertical direction by its own weight. Can be satisfactorily collected and held in the bag path space 79.

  Therefore, when the blow-by gas is recirculated into the clean side air duct 16 through which air having a relatively low temperature flows, the water in the blow-by gas is well removed. It is possible to satisfactorily prevent adhesion and freezing.

  Since the lower portion of the cylindrical tubular portion 74 is attached in a state where the lower portion is in contact with the rocker cover 4, the heat of the rocker cover 4, which is at a high temperature, passes through the cylindrical tubular portion 74 to the bag path space. 79 is effectively conducted into. Thereby, the freezing of the condensed water hold | maintained in the dead end space 79 can also be suppressed favorably.

  In the present embodiment, the throttle member 72 is press-fitted into the mounting hole 4a of the rocker cover 4, but this is not restrictive. For example, a male screw is formed in a lower portion (a portion of the cylindrical tubular portion 74 on the connection portion 78 side) than a central portion in the longitudinal direction of the cylindrical tubular portion 74, and a female screw is formed in the mounting hole 4a of the rocker cover 4. Thus, the diaphragm member 72 may be screw-engaged with the mounting hole 4a.

  Alternatively, as shown in a drawing member 172 of a modification of FIG. 8, a flange portion 180 is integrally formed so as to project radially outward on the connection portion 78 side of the cylindrical tubular portion 174 of the drawing member 172, and the flange. The portion 180 may be attached to the rocker cover 4 by welding, vibration welding, adhesion, or the like.

  In the present embodiment, the throttle member 72 is configured such that the cylindrical tubular portion 74, the tapered tubular portion 76, and the connecting portion 78 are integrally formed, but the present invention is not limited thereto. For example, as shown in the drawing member 272 of the modified example in FIG. 9, after the cylindrical tubular portion 274, the tapered tubular portion 276 and the connecting portion 278 are formed separately, these are welded, vibration welded, bonded, or the like. It is good also as a structure shape | molded integrally.

  This embodiment shows an example for carrying out the present invention. Therefore, the present invention is not limited to the configuration of the present embodiment.

1 Internal combustion engine (internal combustion engine)
2 Cylinder head (internal combustion engine body, cylinder head)
4 Rocker cover (internal combustion engine body, rocker cover)
4a Mounting hole 6 Intake manifold (Intake manifold)
6a Collector 7 Exhaust manifold 8 Cylinder block (Internal combustion engine body, cylinder block)
10 Upper oil pan (internal combustion engine body, oil pan member)
12 Lower oil pan (internal combustion engine body, oil pan member)
14 Throttle valve device (throttle valve device)
16 Clean side air duct (air piping member)
22 Combustion chamber configuration recess 24 Intake port (intake port)
26 Exhaust port 28a Through hole (air introduction passage)
28b Through hole (Blowby gas recirculation passage)
42 Gas-liquid separation chamber (gas-liquid separation chamber)
42a First chamber (first chamber, air introduction passage)
42b Second chamber (second chamber, blow-by gas recirculation passage)
43a Opening (air introduction passage)
43b Opening (Blowby gas recirculation passage)
46 PCV valve 52 Cylinder bore (Cylinder bore)
54a Through hole (air introduction passage)
54b Through hole (Blow-by gas recirculation passage)
62 Crankshaft (Crankshaft)
64 Connecting rod 72 Diaphragm member (resistance imparting member)
74 Cylindrical tubular part 76 Tapered tubular part (tapered throttle part)
78 Connection section 79 Bag alley space (holding section)
82 Piping (air introduction passage, connecting piping member)
84 Piping (Blowby gas recirculation passage)
92 Intake valve 94 Exhaust valve 172 Restriction member (resistance imparting member)
174 Cylindrical tubular portion 180 Flange portion 272 Drawing member (resistance imparting member)
274 Cylindrical tubular portion 276 Tapered tubular portion (tapered throttle portion)
278 Connection VMC Valve mechanism chamber CC Combustion chamber CR Crank chamber (internal combustion engine body, crank chamber)
P Piston (Piston)

Claims (8)

A blowby gas recirculation structure that recirculates blowby gas generated inside the internal combustion engine body to a downstream intake passage disposed downstream of the throttle valve device,
A blowby gas recirculation passage configured to recirculate the blowby gas in an amount corresponding to the magnitude of the negative pressure generated in the downstream intake passage from the inside of the internal combustion engine body to the downstream intake passage;
When the negative pressure generated in the downstream intake passage is greater than or equal to a first magnitude, a part of the air flowing through the upstream intake passage disposed upstream of the throttle valve device is introduced into the internal combustion engine body. When the negative pressure generated in the downstream intake passage is smaller than the first magnitude, a part of the blow-by gas generated inside the internal combustion engine body is recirculated to the upstream intake passage. An air introduction passage;
The flow resistance of the air that flows from the upstream intake passage toward the inside of the internal combustion engine body rather than the flow resistance of the blowby gas that is disposed in the air introduction passage and travels from the inside of the internal combustion engine body toward the upstream intake passage. A resistance imparting member configured to be larger,
Blowby gas recirculation structure. 2. The blow-by according to claim 1, wherein the resistance applying member has a tapered throttle portion configured such that a passage cross-sectional area gradually decreases from the internal side of the internal combustion engine body toward the upstream intake passage side. Gas reflux structure. The resistance imparting member has a holding part capable of holding condensed water generated due to condensation of moisture contained in the blow-by gas, and at least a part of the holding part is in contact with the internal combustion engine body The blowby gas recirculation structure according to claim 1 or 2, wherein the blowby gas recirculation structure is attached.   The blow-by gas recirculation structure according to claim 3, wherein the holding portion is configured on an outer peripheral surface of the throttle portion. The resistance applying member is attached to the internal combustion engine main body so that the flow direction of the blowby gas and the air flowing through the resistance applying member is a vertical direction when the internal combustion engine main body is mounted on a vehicle. ,
The blowby gas recirculation structure according to claim 3 or 4, wherein the holding portion is provided at a lower portion of the resistance applying member in the vertical direction. The internal combustion engine main body includes a cylinder head having an intake port, a rocker cover attached above the cylinder head, a cylinder block attached below the cylinder head, and an oil pan member attached below the cylinder block. , And
The rocker cover has a gas-liquid separation chamber,
The upstream side intake passage has an air piping member for supplying air to the throttle valve device,
The downstream side intake passage has an intake manifold for supplying air from the throttle valve device to the intake port,
The gas-liquid separation chamber has first and second chambers,
A crank chamber is constituted by the cylinder block and the oil pan member,
The blow-by gas recirculation passage is configured to communicate the crank chamber and the intake manifold via the first chamber,
The blowby gas recirculation structure according to any one of claims 1 to 5, wherein the air introduction passage is configured to communicate the crank chamber and the air piping member via the second chamber. A connection piping member that connects the second chamber and the air piping member;
The blow-by gas recirculation structure according to claim 6, wherein the resistance applying member is configured as an attachment member for attaching the connection piping member to the rocker cover. An internal combustion engine that outputs power by converting linear motion of a piston that reciprocates in a cylinder bore into rotational motion of a crankshaft,
The blow-by gas leaked into the crank chamber from the gap between the cylinder bore and the piston is configured to return to the intake passage by the blow-by gas return structure according to any one of claims 1 to 6. .

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