JP2014152759A - Intake pipe of internal combustion engine and intake system structure of the internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intake pipe of an internal combustion engine, capable of suitably suppressing the deterioration of a gasket resulting from the residence of oil, and to provide an intake system structure of the internal combustion engine.SOLUTION: A protrusion 15 is formed on the inner wall at the lower part in the vertical direction of a connection end 12 of an intake manifold of the internal combustion engine. A gasket 20 is stored in a storage groove 13 formed in an end face 12a of the connection end 12 opposed to a cylinder head 51. In the inner wall of the connection end 12 at a position on the downstream side of the protrusion 15, a hole 16 communicated with the storage groove 13 is provided along an axial direction L of the connection end 12. In the inner peripheral face at the lower part in the vertical direction of the gasket 20, a communication passage 32 is formed to communicate a clearance formed by the end face 12a of the connection end 12, an end face 51a of the cylinder head 51 opposed thereto and the inner peripheral face of the gasket 20, with the hole 16.

Description

  The present invention relates to an intake pipe of an internal combustion engine and an intake system structure of the internal combustion engine provided with the intake pipe.

  Conventionally, as shown in FIG. 9, an intake port 52 is formed in the cylinder head 51 of the internal combustion engine, and a branch pipe 311 of the intake manifold 310 is connected to the intake port 52. An annular storage groove 313 is formed on an end surface 312a of the end 312 of the branch pipe 311 facing the cylinder head 51, and a gasket 320 is stored in the storage groove 313 (see, for example, Patent Document 1). . As a result, the gap between the end 312 of the branch pipe 311 and the end surface 51 a of the cylinder head 51 is sealed.

International Publication No. 2004-007937

  By the way, the fuel injected from the injector 55 to the intake port 52 is pushed back together with the combustion gas to the upstream side in the flow direction of the intake air, and the oil containing the fuel (hereinafter referred to as oil F) is the inner wall of the intake port 52 and the branch pipe 311 of the intake manifold 310. Adhere to. Further, such oil F enters a gap 331 formed by the end surface 312 a of the intake manifold 310, the end surface 51 a of the cylinder head 51 facing this, and the inner peripheral surface of the gasket 320. Then, as shown in FIG. 10, the oil F flows down the vertical direction along the gap 331 due to its own weight and stays in the lower part of the gap 331 in the vertical direction. As a result, the problem that the gasket 320 deteriorates arises.

  An object of the present invention is to provide an intake pipe of an internal combustion engine and an intake system structure of the internal combustion engine that can suitably suppress deterioration of a gasket due to oil retention.

  In order to achieve the above object, an intake pipe of an internal combustion engine includes a connection end connected to an intake port of a cylinder head and a storage groove formed in an end face of the connection end facing the cylinder head and storing a gasket. And a protrusion formed on the inner wall of the connection end.

  According to this configuration, since the protrusion is formed on the inner wall of the connection end, the flow cross-sectional area of the airflow is locally reduced at the position of the protrusion in the intake pipe. For this reason, when the airflow passes through the protrusion, the flow velocity increases and the pressure decreases. As a result, negative pressure is generated on the downstream side of the protrusion, and a gap formed by the end surface of the connecting end where the storage groove is formed, the end surface of the cylinder head facing the end surface, and the inner peripheral surface of the gasket is formed. The oil that has entered is sucked out by the negative pressure. Therefore, it is possible to suitably suppress deterioration of the gasket due to oil retention. The oil sucked out by the negative pressure is sucked into the combustion chamber together with the intake air and burned.

In this case, it is preferable that the protrusion is provided with an inclined surface having a larger protrusion amount toward the central axis of the intake pipe toward the downstream side.
According to this aspect, since the inclined surface of the above aspect is provided on the protrusion, it is possible to suitably suppress disturbance of the flow of intake air by adding the protrusion, and to the downstream side of the protrusion. Negative pressure can be suitably generated.

Moreover, the aspect that the said protrusion is provided in the perpendicular direction lower part of the said connection edge part is preferable.
The oil that has entered the gap formed by the end face of the connecting end where the storage groove is formed, the end face of the cylinder head opposite to the end face, and the inner peripheral face of the gasket flows down the vertical direction through the gap due to its own weight. .

  In this regard, according to the above configuration, since negative pressure is generated on the downstream side of the protrusion provided on the inner wall of the connecting portion at the lower portion in the vertical direction, the oil that has flowed down in the vertical direction through the gap is reduced. Sucked out by. Therefore, it is possible to suitably suppress oil from staying in the lower part in the vertical direction of the gap, and it is possible to suitably suppress deterioration of the lower part in the vertical direction of the gasket.

  The intake system structure of the internal combustion engine for achieving the object includes an intake pipe in which the protrusion is provided at a lower portion in the vertical direction of the connection end, and a gasket that is fitted in the storage groove, A hole communicating with the storage groove is provided at a position downstream of the protrusion on the inner wall of the connection end portion, and the gap between the inner peripheral surface of the lower part in the vertical direction of the gasket and the opposing surface of the storage groove facing this is provided. Is formed with a communication path that connects the hole and the gap formed by the end face of the connection end, the end face of the cylinder head facing the end face, and the inner peripheral face of the gasket.

  According to this configuration, the oil that has flowed downward in the vertical direction through the gap formed by the end surface of the connection end, the end surface of the cylinder head opposite to the end surface of the connecting end, and the inner peripheral surface of the gasket, It sucks out through the hole of the inner wall of a communicating path and a connection end part. For this reason, an oil flow is generated in the order of the gap, the communication path, and the hole, and it is possible to more suitably suppress the oil from staying in the lower part in the vertical direction of the gap.

  In this case, a seal portion protruding toward the facing surface is provided along the circumferential direction of the gasket at a position downstream of the hole on the inner circumferential surface of the gasket, and the communication path on the inner circumferential surface of the gasket is provided. A mode in which a cutout portion in which the seal portion is not provided is provided at a corresponding position is preferable.

  According to this aspect, the gap with the opposing surface of the storage groove is suitably sealed by the seal portion provided along the circumferential direction of the gasket. Moreover, a communicating path can be easily embodied by providing the notch part in which the seal part is not provided.

  In this case, a mode in which a pair of seal portions extending in the axial direction of the gasket and sandwiching the hole is provided at a position upstream of the notch portion on the inner peripheral surface of the gasket.

  According to the same aspect, since the width in the circumferential direction of the communication path is defined by the pair of seal portions, oil flows out along the circumferential direction from between the inner peripheral surface of the gasket and the facing surface of the storage groove. It is possible to suppress the stagnation of oil.

Sectional drawing which shows the cross-section of the connection part of the intake manifold of one Embodiment, and the intake port of a cylinder head. The expanded sectional view which expands and shows the X section of FIG. The perspective view which shows partially the perspective structure seen from the internal peripheral surface side of the perpendicular direction lower part of the gasket of the embodiment. The top view which shows the planar structure seen from the A direction of FIG. It is a figure corresponding to FIG. 2, Comprising: The figure for demonstrating the effect | action of the embodiment. The figure for demonstrating the effect | action of the embodiment. The perspective view which shows partially the perspective structure seen from the inner peripheral surface side of the perpendicular direction lower part about the gasket of a modification. The expanded sectional view which expands and shows the cross-section of the intake manifold of another modification, the intake port of a cylinder head, and a connection part. Sectional drawing which shows the cross-section of the connection part of the conventional intake manifold and the intake port of a cylinder head. FIG. 10 is a cross-sectional view showing a cross-sectional structure taken along line 10-10 in FIG. 9;

  Hereinafter, an embodiment embodying an intake pipe of an internal combustion engine and an intake system structure of the internal combustion engine will be described with reference to FIGS. The structure of the cylinder head 51 and the structure of the injector 55 and the like provided in the cylinder head 51 are the same as the structure shown in FIG.

  As shown in FIG. 1, the branch pipe 11 of the intake manifold 10 is provided with a connection end portion 12 connected to an intake port 52. Only the outer diameter of the connection end portion 12 is larger than the portion upstream of the connection end portion 12 of the branch pipe 11, and the connection end portion 12 is thicker than that portion. An annular storage groove 13 is formed on the end surface 12 a of the connection end 12 facing the cylinder head 51, and an annular gasket 20 is stored in the storage groove 13. The length of the storage groove 13 in the axial direction L of the central axis C of the branch pipe 11 is shorter than the length of the connection end 12. In either case, the intake manifold 10 is fixed to the cylinder head 51 by inserting a bolt through a hole of a flange extending from the connection end 12 (not shown) and a hole of the cylinder head 51.

  As shown in FIGS. 2 and 3, a gap 31 is formed over the entire circumference by the end surface 12 a of the connection end portion 12, the end surface 51 a of the cylinder head 51 facing the end surface 12 a, and the inner peripheral surface of the gasket 20.

  Here, a protrusion 15 is formed on the inner wall of the connection end portion 12 in the vertical direction. The protrusion 15 has an inclined surface 15a in which the protrusion amount toward the central axis C of the connection end 12 is larger toward the downstream side, and has a triangular shape in cross section.

Further, a hole 16 communicating with the storage groove 13 is provided at a position downstream of the protrusion 15 on the inner wall of the connection end portion 12 in the vertical direction.
As shown in FIG. 3, the protrusion 15 and the hole 16 are both located at the lowermost center in the circumferential direction, and the circumferential width d1 of the hole 16 is smaller than the circumferential width d2 of the protrusion 15. Yes.

  As shown in FIGS. 2 and 4, the gasket 20 has a substantially hexagonal cross section that is long in the axial direction L, and a first seal portion 21 protrudes from the inner circumferential surface of the gasket 20 over the entire circumference. Further, a second seal portion 22 projects from the inner peripheral surface of the gasket 20 on the downstream side of the first seal portion 21 along the circumferential direction of the gasket 20. As shown in FIG. 2, the seal portions 21 and 22 are both in pressure contact with the facing surface 14 of the storage groove 13 that faces the inner peripheral surface of the gasket 20.

  As shown in FIGS. 2 and 4, seal portions 25 and 26 are respectively provided on the outer peripheral surface of the gasket 20 at positions corresponding to the first seal portion 21 and the second seal portion 22 over the entire circumference. As shown in FIG. 2, the seal portions 25 and 26 are both in pressure contact with the surface of the storage groove 13 facing the outer peripheral surface of the gasket 20.

As shown in FIG. 4, a notch portion 22 a where the second seal portion 22 is not provided is provided on the inner peripheral surface of the gasket 20 in the lower vertical direction.
As shown in FIGS. 2 and 4, a pair of third seals extending along the axial direction L of the gasket 20 and sandwiching the hole 16 at a position upstream of the notch 22 a on the inner peripheral surface of the gasket 20. A portion 23 is provided. All of these third seal portions 23 are in pressure contact with the facing surface 14 of the storage groove 13.

  As shown in FIGS. 2 to 4, the cutout portion 22 a and the third seal portion 23 form a communication path 32 that connects the gap 31 and the hole 16 on the inner peripheral surface of the gasket 20 in the vertical direction. Yes.

Next, the operation of this embodiment will be described.
The oil F that has entered the gap 31 formed by the end face 12a of the connecting end portion 12 and the end face 51a of the cylinder head 51 facing the end face 12a and the inner peripheral face of the gasket 20 travels along the gap 31 by its own weight and moves vertically downward. Flow down.

  As shown in FIG. 5, since the flow cross-sectional area of the airflow is locally reduced at the position of the protrusion 15 provided on the inner wall of the connection end 12, the flow velocity increases when the airflow passes through the protrusion 15. At the same time, the pressure decreases, and a negative pressure is generated on the downstream side of the protrusion 15. As a result, the oil F that has flowed downward in the vertical direction through the gap 31 is sucked out by the negative pressure through the communication passage 32 of the gasket 20 and the hole 16 in the inner wall of the connection end portion 12. The sucked out oil F is sucked into the combustion chamber together with the intake air and burned.

  Further, the oil F flows in the order of the gap 31, the communication path 32, and the hole 16, and the oil F is preferably suppressed from staying in the lower part in the vertical direction of the gap 31. Therefore, it is possible to suitably suppress deterioration of the lower portion in the vertical direction of the gasket 20 due to the retention of the oil F.

  Moreover, since the protrusion 15 has the inclined surface 15a in which the protrusion amount toward the central axis C of the connection end portion 12 is larger toward the downstream side, it is preferable that adding the protrusion 15 disturbs the flow of intake air. And negative pressure is suitably generated on the downstream side of the protrusion 15.

  Further, as shown in FIG. 6, the first seal portion 21 and the second seal portion 22 are provided along the circumferential direction of the gasket 20 on the inner peripheral surface of the gasket 20. Is preferably sealed. Further, since the seal portions 25 and 26 are provided on the outer peripheral surface of the gasket 20 along the circumferential direction of the gasket 20, the gap with the surface of the storage groove 13 facing the outer peripheral surface of the gasket 20 is suitably sealed. The

  Further, as shown in FIG. 4, since the pair of third seal portions 23 are provided on the inner peripheral surface of the gasket 20, the width in the circumferential direction of the communication path 32 is defined by the pair of third seal portions 23. The For this reason, it is suppressed suitably that the oil F flows out along the circumferential direction from between the inner peripheral surface of the gasket 20 and the facing surface 14 of the storage groove 13.

According to the intake pipe of the internal combustion engine and the intake system structure of the internal combustion engine according to the present embodiment described above, the following effects can be obtained.
(1) A protrusion 15 is formed on the inner wall of the lower end in the vertical direction of the connection end 12 of the intake manifold 10 of the internal combustion engine. A gasket 20 is housed in the housing groove 13 formed in the end surface 12 a of the connection end 12 facing the cylinder head 51. Further, a hole 16 communicating with the storage groove 13 is provided at a position downstream of the protrusion 15 on the inner wall of the connection end portion 12 in the vertical direction. Further, a gap 31 and a hole 16 formed by the end surface 12 a of the connection end 12, the end surface 51 a of the cylinder head 51 facing the end surface 51 a and the inner peripheral surface of the gasket 20 are formed on the inner peripheral surface of the gasket 20 in the vertical direction. A communication path 32 that communicates with each other is formed. According to such a configuration, the oil F that has flowed down in the vertical direction through the gap 31 formed by the end surface 12a of the connection end portion 12, the end surface 51a of the cylinder head 51 facing the end surface 12a, and the inner peripheral surface of the gasket 20 is provided. The negative pressure generated by the airflow passing through the protrusion 15 is sucked out through the communication passage 32 of the gasket 20 and the hole 16 in the inner wall of the connection end portion 12. Further, the oil F flows in the order of the gap 31, the communication path 32, and the hole 16, and the oil F is preferably suppressed from staying in the lower part in the vertical direction of the gap 31. Therefore, it is possible to suitably suppress deterioration of the lower portion in the vertical direction of the gasket 20 due to the retention of the oil F.

  (2) Since the protrusion 15 has the inclined surface 15a in which the protrusion amount toward the central axis C of the connecting end portion 12 is larger toward the downstream side, the addition of the protrusion 15 disturbs the flow of intake air. While being able to suppress suitably, a negative pressure can be suitably generated in the downstream of the protrusion 15. FIG.

  (3) A second seal portion 22 that protrudes toward the facing surface 14 of the storage groove 13 is provided along the circumferential direction of the gasket 20 at a position downstream of the hole 16 on the inner peripheral surface of the gasket 20. Therefore, the gap between the housing groove 13 and the facing surface 14 is suitably sealed. Moreover, since the notch part 22a in which the 2nd seal | sticker part 22 is not provided is provided in the position corresponding to the communication path 32 in the internal peripheral surface of the gasket 20, the communication path 32 can be embodied easily. .

  (4) A pair of third seal portions 23 extending in the axial direction L of the gasket 20 and sandwiching the holes 16 are provided at positions upstream of the notches 22 a on the inner peripheral surface of the gasket 20. According to such a configuration, since the width in the circumferential direction of the communication path 32 is defined by the pair of third seal portions 23, the gap between the inner circumferential surface of the gasket 20 and the facing surface 14 of the storage groove 13 extends in the circumferential direction. The oil F can be suitably prevented from flowing along, and the retention of the oil F can be suitably suppressed.

  In addition, the intake pipe of the internal combustion engine and the intake system structure of the internal combustion engine according to the present invention are not limited to the configuration exemplified in the above-described embodiment, and are implemented as, for example, the following forms appropriately modified. You can also.

-A hole can also be made into a long shape with respect to the axial direction L. FIG.
-For example, when the length of the connecting end portion in the axial direction L cannot be secured, it is preferable that the hole has a long shape with respect to the circumferential direction.

  -As shown in FIG. 7, a pair of 3rd seal | sticker part 123 can also be provided so that it may mutually adjoin with upstream. In FIG. 7, the same or corresponding components as those in FIG. 4 are denoted by reference numerals with “100” added.

It is also possible to provide only the first seal portion 21 on the inner peripheral surface of the gasket 20 and omit the second seal portion 22 and the third seal portion 23.
-A groove can be formed in the opposing surface which opposes the inner peripheral surface of the vertical direction lower part of the gasket in a storage groove, and a communicating path can also be comprised by the groove.

  As shown in FIG. 8, the communication path is omitted, and the lower end in the vertical direction of the connection end 212, the end surface 212 a of the connection end 212, the end surface 51 a of the cylinder head 51 facing this, and the inner periphery of the gasket 220 The protrusion 215 may be formed on the upstream side of the gap 231 formed by the surface. Even in this case, since the oil F that has entered the gap 231 is sucked out by the negative pressure generated by the airflow passing through the protrusions 215, it is preferable that the gasket 220 is deteriorated due to the retention of the oil F. Can be suppressed.

-You may make it provide several protrusion in the perpendicular direction lower part of a connection end part. Further, in addition to the lower portion in the vertical direction of the connection end, a protrusion may be provided in a portion other than the lower portion in the vertical direction.
-Adopting the projection 15 having the inclined surface 15a as in the above embodiment can favorably suppress the disturbance of the flow of intake air by adding the projection 15, and the downstream side of the projection 15 It is desirable to generate a negative pressure suitably. However, even a protrusion that does not have such an inclined surface can generate a negative pressure downstream thereof.

  DESCRIPTION OF SYMBOLS 10 ... Intake manifold (intake pipe), 11 ... Branch pipe, 12 ... Connection end part, 12a ... End surface, 13 ... Storage groove, 14 ... Opposing surface, 15 ... Projection, 15a ... Inclined surface, 16 ... Hole, 20 ... Gasket, 21 ... 1st seal part, 22 ... 2nd seal part, 22a ... Notch part, 23 ... 3rd seal part, 25, 26 ... Seal part, 31 ... Clearance, 32 ... Communication path, 51 ... Cylinder head, 51a ... End surface 52 ... Intake port, 53 ... Combustion chamber, 54 ... Intake valve, 55 ... Injector.

Claims (6)

A connecting end connected to the intake port of the cylinder head;
A storage groove formed on an end surface of the connection end facing the cylinder head, in which a gasket is stored;
A protrusion formed on the inner wall of the connection end.
An intake pipe for an internal combustion engine. The protrusion has an inclined surface whose protrusion toward the central axis of the intake pipe is larger toward the downstream side,
The intake pipe of the internal combustion engine according to claim 1. The protrusion is provided at a lower part in the vertical direction of the connection end.
An intake pipe for an internal combustion engine according to claim 1 or 2. An intake pipe according to claim 3;
A gasket to be fitted in the storage groove,
A hole communicating with the storage groove is provided at a position downstream of the protrusion on the inner wall of the connection end,
Between the inner peripheral surface of the lower part in the vertical direction of the gasket and the opposing surface of the storage groove facing this, an end surface of the connection end, an end surface of the cylinder head facing the end surface, and an inner peripheral surface of the gasket are formed. A communication path is formed to communicate the gap and the hole.
Intake system structure of an internal combustion engine. A seal portion protruding toward the facing surface is provided along the circumferential direction of the gasket at a position downstream of the hole on the inner peripheral surface of the gasket,
A notch portion where the seal portion is not provided is provided at a position corresponding to the communication path on the inner peripheral surface of the gasket,
An intake system structure for an internal combustion engine according to claim 4. A pair of seal portions extending in the axial direction of the gasket and sandwiching the holes are provided at positions upstream of the notches on the inner peripheral surface of the gasket.
6. An intake system structure for an internal combustion engine according to claim 5.