JP2008002384A - Intake air straightening body and intake air port structure for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake air straightening body and an intake air port structure capable of forming a stronger tumble flow of intake air in a combustion chamber. <P>SOLUTION: The intake air straightening body 50 is equipped with: an insertion hole 51 for having a valve stem 31 of an intake valve 30 inserted therein when disposed inside the intake air port 20; and a straightening part 52 for covering a valve guide 12 protruding inside the intake air port 20 and covering part of an upper side wall face 21 of the intake air port 20, having a smoother surface roughness than an inner wall face of the intake air port 20, and having a straightening face 52b along which surface the intake air flows, for straightening the intake air flowing inside the intake air port 20 of an internal combustion engine. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an intake air rectifier and an intake port structure of an internal combustion engine.

  2. Description of the Related Art In an internal combustion engine of a vehicle, a technique for generating a gas flow such as a tumble flow in a combustion chamber by intake air flowing into the combustion chamber is widely known in order to improve fuel combustion performance.

In the internal combustion engine described in Patent Literature 1, a protruding portion is formed so that the intake port upper wall surface in the vicinity of the intake valve protrudes into the intake port, and the intake air flow velocity in the intake port upper side is rectified while the intake flow in the vicinity of the intake valve is rectified. To form a tumble flow in the combustion chamber.
JP 2004-143594 A

  However, the cylinder head in which the intake port is formed is cast. Therefore, a mold (sand mold) mark remains on the inner wall surface of the intake port, and the surface becomes rough. Therefore, even if the protrusion is formed in the vicinity of the intake valve of the intake port as in the invention described in Patent Document 1, the intake flow is hindered by the surface roughness, and the effect of improving the tumble flow is reduced. There is.

  Accordingly, an object of the present invention is to provide an intake air rectifier and an intake port structure capable of forming a stronger intake air tumble flow in a combustion chamber.

  The intake rectifier (50) according to the present invention includes an insertion hole (51) through which the valve stem (31) of the intake valve (30) is inserted and the intake port (20). The valve guide (12) and the intake port upper wall surface (21) projecting to the surface of the intake port are covered, and the surface roughness is smoother than that of the intake port inner wall surface. A first rectification unit (52) is provided to rectify the intake air flowing through the intake port (20) of the internal combustion engine.

  The intake rectification body of the present invention includes a first rectification unit having a rectification surface whose surface roughness is smoother than the inner wall surface of the intake port. Therefore, it is possible to prevent a decrease in the intake air flow velocity of the intake air flowing along the rectifying surface among the intake air flowing through the intake port. As a result, the intake air flow rate on the upper side of the intake port increases more than the intake air flow rate on the lower side of the intake port, and a stronger tumble flow can be formed in the combustion chamber.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view showing an intake port structure of the internal combustion engine of the present embodiment.

  As shown in FIG. 1, the intake system 100 of the internal combustion engine includes an intake port 20 formed in the cylinder head 10.

  The cylinder head 10 forms a combustion chamber 11 by a cylinder block and a piston (not shown). The cylinder head 10 forms an intake port 20 through which intake air from the intake manifold flows to the combustion chamber 11. A valve guide 12 that slidably supports the intake valve 30 is installed on the cylinder head 10 above the intake port 20 so as to protrude into the intake port 20.

  The intake port 20 communicates an intake manifold (not shown) and the combustion chamber 11. The intake port 20 allows intake air from the intake manifold side (upstream side) to flow to the opening 13 side (downstream side) of the intake port. A valve seat 40 that seals the combustion chamber 11 and the intake port 20 by the intake valve 30 is installed in the intake port 20 in the vicinity of the opening 13.

  The intake valve 30 includes a valve stem 31 and a valve head 32. The intake valve 30 opens and closes the intake port 20 in response to the vertical movement of a piston (not shown). The valve stem 31 of the intake valve 30 slides with respect to the valve guide 12. The valve head 32 of the intake valve 30 opens and closes the intake port 20 by being seated on the valve seat 40 from the lower surface side.

  The intake rectifier 50 is inserted through the valve stem 31 of the intake valve 30 described above. The intake rectifier 50 rectifies the intake flow in the intake port 20 and forms a tumble flow in the combustion chamber 11.

  FIG. 2 is a view showing an intake rectifier 50 that rectifies the intake flow inside the intake port 20. 2A is a side view of the intake rectifier 50, and FIG. 2B is a plan view of the intake rectifier 50. As shown in FIG. FIG. 2C is a bottom view of the intake rectifier 50.

  As shown in FIGS. 2A to 2C, the intake rectifier 50 includes an insertion hole 51 through which the valve stem 31 is inserted, a first rectifier 52 and a second rectifier 53 that rectify the intake flow, And a deflecting blade 54 for deflecting the intake flow.

  The insertion hole 51 is formed with a diameter slightly larger than the shaft diameter of the valve stem 31 and allows the valve stem 31 to slide freely.

  The first rectifying unit 52 has an upper surface 52a and a lower surface 52b. The upper surface 52a of the first rectifying unit 52 is formed so as to be in close contact with the upper wall surface 21 of the intake port 20 where the valve guide 12 is disposed (see FIG. 1). Further, the lower surface 52b of the first rectification unit 52 is a rectification surface, and is formed in a shape that increases the radius of curvature of the upper wall surface 21 of the intake port 20.

  The second rectification unit 53 is formed below the first rectification unit 52 along the axial direction of the valve stem 31. The second rectification unit 53 has a streamline that gradually increases in thickness from the upstream side of the intake port 20 toward the stem axis and gradually decreases in thickness from the stem axis toward the downstream side of the intake port 20. It has a shape.

  The deflecting blades 54 are connected to the lower side of the second rectifying unit 53 and are formed so as to protrude from the stem axis to both sides in the width direction of the intake port 20. The deflection blades 54 are inclined with respect to the upper wall surface 21 so that the distance from the upper wall surface 21 is larger on the upstream side and smaller on the downstream side, and the intake air flow is guided to the upper side of the intake port 20.

  The intake rectifier 50 described above is formed of synthetic resin or the like. Therefore, it is lighter than metals. Further, the intake air rectifier 50 can have a smoother surface roughness than the case of casting like a cylinder head or the like. Note that the intake rectifier 50 may be formed not only by integrally forming the first rectifier 52, the second rectifier 53, and the deflecting blade 54, but may be separately formed and coupled.

  In the present embodiment, by providing the intake rectifier 50 in the intake port 20, the intake flow in the intake port 20 is rectified and a tumble flow is formed in the combustion chamber 11.

  The effect | action of this embodiment is demonstrated based on FIGS. 3-5.

  FIG. 3 is a view showing an intake flow that flows inside the intake port 20. FIG. 3A shows the operation of the first rectification unit 52 of the intake rectifier 50. FIG. 3B shows a secondary flow generated in the intake port 20, and FIG. 3C shows a CC cross section in FIG.

  As shown in FIG. 3A, the intake rectifier 50 is inserted through the valve stem 31 of the intake valve 30. And the 1st rectification | straightening part 52 is installed so that the recessed part 22 of the upper side wall surface 21 of the intake port 20 in which the valve guide 23 is arrange | positioned may be covered. As for the 1st rectification | straightening part 52, the upper surface 52a and the upper side wall surface 21 of the intake port 20 are adhere | attached.

  In order to stably fix the intake rectifier 50 in the intake port 20, it is desirable that the upper surface 52a of the first rectifier 52 be as large as possible.

  When the first rectification unit is arranged in the intake port 20 in this manner, the radius of curvature of the upper wall surface 21 of the intake port 20 becomes larger than before the first rectification unit is installed.

  As shown in FIG. 3B, when the intake port 20 is considered as a bent pipe having a large radius of curvature, the intake air flowing through the bent portion 23 of the intake port 20 flows from the lower wall surface 24 of the intake port 20 to the upper wall surface 21. Centrifugal force acts toward. Then, due to the centrifugal force, as shown in FIG. 3C, the intake air flows into the intake port 20 from the lower wall surface 24 to the upper wall surface 21 along the inner peripheral wall of the intake port 20, and from the upper wall surface 21. A circulating flow (hereinafter referred to as “secondary flow”) flows into the center of the intake port 20. This secondary flow becomes an intake resistance in the intake port 20 and inhibits the intake flow.

  However, in the present embodiment, as shown in FIG. 3A, the radius of curvature of the intake port 20 can be increased by the first rectification unit 52 of the intake rectifier 50, so that the secondary flow of intake air is suppressed. Thus, it is possible to suppress a decrease in the intake flow rate caused by the secondary flow.

  Moreover, since the cross section of the intake port 20 becomes small by providing the 1st rectification | straightening part 52, the flow velocity of the intake air which passes through this part increases. The first rectifying unit 52 is made of synthetic resin or the like, and the surface roughness of the lower surface 52b is smoother than the inner wall surface of the intake port, so that the intake flow velocity flowing along the lower surface 52b is not particularly reduced. Therefore, the intake air flow rate on the upper side of the intake port 20 is increased more than the intake air flow rate on the lower side of the intake port 20.

  FIG. 4 is a view showing a cross section IV-IV of FIG. 1 of the second rectification unit 53 of the intake rectifier 50.

  The second rectification unit 53 of the intake rectifier 50 is connected to the lower side of the first rectification unit 52 and is arranged to be located on the upper side of the intake port 20. As shown in FIG. 4, the second rectifying unit 53 gradually increases in thickness from the upstream side of the intake port 20 toward the axial center of the valve stem 31, and from the axial center toward the downstream side of the intake port 20. The streamline shape gradually decreases in thickness. Therefore, the intake air flowing from the upstream side of the intake port 20 flows along the streamline shape of the intake second rectification unit 53 and is prevented from colliding with the valve stem 31 of the intake valve 30 to become a vortex. Therefore, a decrease in the intake flow rate that flows above the intake port 20 caused by the generation of vortex is suppressed, and the intake flow rate above the intake port 20 increases more than the intake flow rate below the intake port 20.

  FIG. 5 is a diagram illustrating the operation of the deflecting blade 54 of the intake rectifier 50.

  The deflection wing 54 of the intake rectifier 50 is connected to the lower side of the second rectifier 53 and is formed to protrude in the width direction of the intake port 20. The deflecting blade 54 is formed to have a predetermined inclination θ with respect to the axis A of the valve stem 31 and deflects the intake air flowing inside the intake port 20 toward the upper wall surface 21. Therefore, a part of the intake air flowing from the upstream side of the intake port 20 is deflected to the upper wall surface 21 of the intake port 20 by the deflecting blades 54, and the intake flow rate on the upper side of the intake port 20 is higher than the intake flow rate on the lower side of the intake port 20. To increase.

  Thus, in this embodiment, since the intake rectifier 50 is provided on the upper side of the intake port 20, the intake flow rate on the upper side of the intake port 20 increases more than the intake flow rate on the lower side of the intake port 20. A tumble flow can be formed in the combustion chamber 11 by the intake flow rate difference.

  Note that even if only the first rectification unit 52 of the intake rectifier 50 is installed in the intake port 20, it is possible to suppress a decrease in the intake flow velocity flowing along the lower surface 52b, so that the intake flow rate on the upper side of the intake port 20 is increased. And a tumble flow can be formed in the combustion chamber 11.

  As described above, the present embodiment can obtain the following effects.

  In the present invention, the intake rectifier 50 is provided in the intake port 20 in the vicinity of the valve guide 12 so as to insert the valve stem 31. Since the first rectification unit 52 of the intake rectification means 50 increases the radius of curvature of the intake port 20, it is possible to suppress the secondary flow of intake air. Moreover, the 1st rectification | straightening part 52 is manufactured with the synthetic resin, and can form surface roughness smoothly. For this reason, it is possible to prevent a decrease in the intake air flow velocity flowing along the lower surface 52b of the first rectifying unit 52, and the intake air flow rate on the upper side of the intake port 20 is higher than the intake air flow rate on the lower side of the intake port 20.

  Since the second rectification unit 53 of the intake rectifier 50 has a streamline shape in the direction of the intake flow, the intake air flowing from the upstream of the intake port 20 flows along the second rectification unit 53. Therefore, it is possible to suppress the intake air from striking the valve stem 31 of the intake valve 30 and forming a vortex flow, thereby preventing a decrease in the intake flow rate caused by the generation of the vortex flow. Therefore, it is possible to suppress the intake air flow rate on the upper side of the intake port 20 from being lower than the intake flow rate on the lower side of the intake port 20.

  Since the deflection wing 54 of the intake rectifier 50 has a predetermined inclination θ with respect to the axial center of the valve stem 31, a part of the intake air flowing from the upstream to the downstream of the intake port 20 is placed above the intake port 20. Can be deflected. Therefore, the intake air flow rate on the upper side of the intake port 20 is increased more than the intake air flow rate on the lower side of the intake port 20.

  As described above, in the present embodiment, by increasing the intake flow rate on the upper side of the intake port 20 to be higher than the intake flow rate on the lower side of the intake port 20, a stronger tumble flow can be formed in the combustion chamber.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  For example, the intake air rectifier 50 is manufactured from a synthetic resin, but may be formed by molding with metal or the like and polishing it so that the surface roughness is smooth. Moreover, although the intake rectifier 50 has been described as a separate member from the intake port 20, it may be formed integrally with the intake port.

It is a figure which shows the intake port structure of the internal combustion engine of this embodiment. It is a figure which shows an intake air rectifier. It is a figure which shows the effect | action of a 1st rectification | straightening part. It is a figure which shows the effect | action of a 2nd rectification | straightening part. It is a figure which shows the effect | action of a deflection | deviation blade.

Explanation of symbols

100 Intake System 10 Cylinder Head 11 Combustion Chamber 12 Valve Guide 13 Opening 20 Intake Port 21 Upper Wall 30 Intake Valve 31 Valve Stem 32 Valve Head 40 Valve Seat 50 Intake Rectifier 51 Insertion Hole 52 First Rectifier (First Rectifier) Part)
52a Upper surface 52b Lower surface (rectifying surface)
53 Second rectifier (second rectifier)
54 Deflection wing (deflection part)

Claims (15)

An intake rectifier for rectifying intake air flowing in an intake port of an internal combustion engine,
Covers the insertion hole through which the valve stem of the intake valve is inserted when placed in the intake port, the valve guide protruding into the intake port, and part of the upper wall surface of the intake port, and is more surface than the inner wall surface of the intake port The first rectification unit having a rectification surface having smoothness and a rectification surface along which intake air flows is provided.
An intake rectifier characterized by that. The rectifying surface has a larger radius of curvature than the intake port upper wall surface,
The intake rectifier according to claim 1. A second rectifying unit that protrudes from the rectifying surface and passes through the valve stem and rectifies the intake air flowing around the valve stem;
The intake rectifier according to claim 1 or 2. The second rectification unit gradually increases in thickness from the upstream side of the intake port toward the axial center of the valve stem, and gradually decreases in thickness from the valve stem axis toward the downstream side of the intake port. The streamline shape is
The intake rectifier according to claim 3. A deflection unit that is connected to the second rectification unit and deflects the flow direction of the intake air so that the intake air easily flows from the ceiling side of the combustion chamber;
The intake rectifier according to claim 3 or 4, characterized by the above. The deflecting portion extends in the width direction of the intake port.
The intake rectifier according to claim 5. The intake rectifier is made of resin.
The intake rectifier according to any one of claims 1 to 6, wherein The intake rectifier is made of metal and polished to have a smooth surface roughness.
The intake rectifier according to any one of claims 1 to 6, wherein An intake port structure for rectifying intake air flowing in an intake port of an internal combustion engine,
A valve guide protruding into the intake port;
An intake valve having a valve stem slidably supported by the valve guide;
A rectifying surface that passes through the valve stem and covers part of the upper wall surface of the valve guide and the intake port that protrudes into the intake port, has a smoother surface roughness than the inner wall surface of the intake port, and the intake air flows along the surface. An intake air rectifier including a first rectifier including:
An intake port structure characterized by comprising: The rectifying surface has a larger radius of curvature than the intake port upper wall surface,
The intake port structure according to claim 9. A second rectification unit that protrudes from the rectification surface side of the first rectification unit, passes through the valve stem, and rectifies the intake air flowing around the valve stem;
The intake port structure according to claim 9 or 10, wherein: The second rectification unit gradually increases in thickness from the upstream side of the intake port toward the axial center of the valve stem, and gradually decreases in thickness from the valve stem axis toward the downstream side of the intake port. The streamline shape is
The intake port structure according to claim 11. A deflection unit that is connected to the second rectification unit and deflects the flow direction of the intake air so that the intake air easily flows from the ceiling side of the combustion chamber;
The intake port structure according to claim 11 or 12, characterized in that: The deflecting portion extends in the width direction of the intake port.
The intake port structure according to claim 13. The intake rectifier is polished to have a smooth surface roughness.
The intake port structure according to any one of claims 9 to 14, wherein the intake port structure is provided.